Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and immunomodulation.The aim of this study was to evaluate the protective effects ...Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and immunomodulation.The aim of this study was to evaluate the protective effects and possible underlying mechanisms of MFGM on cow’s milk allergy(CMA)in aβ-lactoglobulin(BLG)-induced allergic mice model.MFGM was supplemented to allergic mice induced by BLG at a dose of 400 mg/kg body weight.Results demonstrated that MFGM alleviated food allergy symptoms,decreased serum levels of lipopolysaccharide,pro-inflammatory cytokines,immunoglobulin(Ig)E,Ig G1,and Th2 cytokines including interleukin(IL)-4,while increased serum levels of Th1 cytokines including interferon-γand regulatory T cells(Tregs)cytokines including IL-10 and transforming growth factor-β.MFGM modulated gut microbiota and enhanced intestinal barrier of BLG-allergic mice,as evidenced by decreased relative abundance of Desulfobacterota,Rikenellaceae,Lachnospiraceae,and Desulfovibrionaceae,while increased relative abundance of Bacteroidetes,Lactobacillaceae and Muribaculaceae,and enhanced expressions of tight junction proteins including Occludin,Claudin-1 and zonula occludens-1.Furthermore,MFGM increased fecal short-chain fatty acids(SCFAs)levels,which elevated G protein-coupled receptor(GPR)43 and GPR109A expressions.The increased expressions of GPR43 and GPR109A induced CD103+dendritic cells accumulation and promoted Tregs differentiation in mesenteric lymph node to a certain extent.In summary,MFGM alleviated CMA in a BLG-induced allergic mice model through enhancing intestinal barrier and promoting Tregs differentiation,which may be correlated with SCFAs-mediated activation of GPRs.These findings suggest that MFGM may be useful as a promising functional ingredient against CMA.展开更多
The milk fat globule membrane(MFGM)is a complex structure with numerous functions,and its composition is affected by many factors.There have been few systematic investigations on goat MFGM proteome profiling during la...The milk fat globule membrane(MFGM)is a complex structure with numerous functions,and its composition is affected by many factors.There have been few systematic investigations on goat MFGM proteome profiling during lactation.Individual milk samples from 15 healthy dairy goats were obtained at six lactation time points for investigation of the MFGM proteome using both data-independent acquisition(DIA)and data-dependent acquisition(DDA)proteomics techniques combined with multivariate statistical analysis.Using the DIA method,890 variably abundant MFGM proteins were discovered throughout the lactation cycle.From 1 to 240 d,butyrophilin subfamily 1 member A1,lipoprotein lipase,perilipin-2,and adipose triglyceride lipase were upregulated,while APOE,complement C3,clusterin,and IgG were downregulated.Furthermore,from 1 to 90 d,annexin A1,annexin A2,and antithrombin-ll were downregulated,then upregulated by d 240.Albumin had a high degree of connectedness,indicating that it was a key protein,according to protein-protein interaction research.Overall,our findings gave new insights into the biological features of MFGM protein in goat milk throughout lactation,which may aid in the creation of specialized MFGM products and infant formula.展开更多
BACKGROUND Liver injury is common in severe acute pancreatitis(SAP).Excessive autophagy often leads to an imbalance of homeostasis in hepatocytes,which induces lipid peroxidation and mitochondrial iron deposition and ...BACKGROUND Liver injury is common in severe acute pancreatitis(SAP).Excessive autophagy often leads to an imbalance of homeostasis in hepatocytes,which induces lipid peroxidation and mitochondrial iron deposition and ultimately leads to ferroptosis.Our previous study found that milk fat globule epidermal growth factor 8(MFG-E8)alleviates acinar cell damage during SAP via binding toαvβ3/5 integrins.MFG-E8 also seems to mitigate pancreatic fibrosis via inhibiting chaperone-mediated autophagy.AIM To speculate whether MFG-E8 could also alleviate SAP induced liver injury by restoring the abnormal autophagy flux.METHODS SAP was induced in mice by 2 hly intraperitoneal injections of 4.0 g/kg L-arginine or 7 hly injections of 50μg/kg cerulein plus lipopolysaccharide.mfge8-knockout mice were used to study the effect of MFG-E8 deficiency on SAPinduced liver injury.Cilengitide,a specificαvβ3/5 integrin inhibitor,was used to investigate the possible mechanism of MFG-E8.RESULTS The results showed that MFG-E8 deficiency aggravated SAP-induced liver injury in mice,enhanced autophagy flux in hepatocyte,and worsened the degree of ferroptosis.Exogenous MFG-E8 reduced SAP-induced liver injury in a dose-dependent manner.Mechanistically,MFG-E8 mitigated excessive autophagy and inhibited ferroptosis in liver cells.Cilengitide abolished MFG-E8’s beneficial effects in SAP-induced liver injury.CONCLUSION MFG-E8 acts as an endogenous protective mediator in SAP-induced liver injury.MFG-E8 alleviates the excessive autophagy and inhibits ferroptosis in hepatocytes by binding to integrinαVβ3/5.展开更多
Background Dietary fat is important for energy provision and immune function of lactating sows and their progeny.However,knowledge on the impact of fat on mammary transcription of lipogenic genes,de novo fat synthesis...Background Dietary fat is important for energy provision and immune function of lactating sows and their progeny.However,knowledge on the impact of fat on mammary transcription of lipogenic genes,de novo fat synthesis,and milk fatty acid(FA)output is sparse in sows.This study aimed to evaluate impacts of dietary fat levels and FA composition on these traits in sows.Forty second-parity sows(Danish Landrace×Yorkshire)were assigned to 1 of 5 dietary treatments from d 108 of gestation until weaning(d 28 of lactation):low-fat control diet(3%added animal fat);or 1 of 4 high-fat diets with 8%added fat:coconut oil(CO),fish oil(FO),sunflower oil(SO),or 4%octanoic acid plus 4%FO(OFO).Three approaches were taken to estimate de novo milk fat synthesis from glucose and body fat.Results Daily intake of FA was lowest in low-fat sows within fat levels(P<0.01)and in OFO and FO sows within highfat diets(P<0.01).Daily milk outputs of fat,FA,energy,and FA-derived carbon reflected to a large extent the intake of those.On average,estimates for de novo fat synthesis were 82 or 194 g/d from glucose according to method 1 or 2 and 255 g de novo+mobilized FA/d according to method 3.The low-fat diet increased mammary FAS expression(P<0.05)and de novo fat synthesis(method 1;P=0.13)within fat levels.The OFO diet increased de novo fat synthesis(method 1;P<0.05)and numerically upregulated mammary FAS expression compared to the other high-fat diets.Across diets,a daily intake of 440 g digestible FA minimized milk fat originating from glucose and mobilized body fat.Conclusions Sows fed diets with low-fat or octanoic acid,through upregulating FAS expression,increased mammary de novo fat synthesis whereas the milk FA output remained low in sows fed the low-fat diet or high-fat OFO or FO diets,indicating that dietary FA intake,dietary fat level,and body fat mobilization in concert determine de novo fat synthesis,amount and profiles of FA in milk.展开更多
Milk fat contains a variety of nutritive and health-promoting compounds that guard against some disease. In the current system of global competition, when the quality of milk and milk products is not an option but rat...Milk fat contains a variety of nutritive and health-promoting compounds that guard against some disease. In the current system of global competition, when the quality of milk and milk products is not an option but rather a requirement, therefore, determining the purity of milk fat is critical. This study aims to validate analytical methods for detecting palm oil in a mixture of milk fat and palm oil. Methods of this study was involved detection of non-milk fat in fat blinders by determining the saponification value, iodine number, refractive index, butyro refractometer reading, Gas chromatography, Reverse Phase High-performance liquid chromatography, and Fourier transforms Infrared. The results of this study revealed that the saponification value, Iodine number, refractive index, and Butyro Reading could be used to detect the addition of palm oil by a level of 10% - 20% or more to the milk. The level of some fatty acids in the milk as determined by GC, such as myristic acid (C14:0), palmitic acid (C16:0), and stearic acid (C18:0), is correlated well with the level of adding palm oil to milk fat. The determination of cholesterol and β-sito-sterol content by RP-HPLC could be used for the detection of the addition of palm oil to milk fat. The spectrum behavior produced by FTIR spectroscopy in this adulterated sample is almost the same, so this technique could not be used to detect the palm oil in milk fat.展开更多
Background:Starch is an important substance that supplies energy to ruminants.To provide sufficient energy for high-yielding dairy ruminants,they are typically fed starch-enriched diets.However,starch-enriched diets h...Background:Starch is an important substance that supplies energy to ruminants.To provide sufficient energy for high-yielding dairy ruminants,they are typically fed starch-enriched diets.However,starch-enriched diets have been proven to increase the risk of milk fat depression(MFD)in dairy cows.The starch present in ruminant diets could be divided into rumen-degradable starch(RDS)and rumen escaped starch(RES)according to their different degradation sites(rumen or intestine).Goats and cows have different sensitivities to MFD.Data regarding the potential roles of RDS in milk fat synthesis in the mammary tissue of dairy goats and in regulating the occurrence of MFD are limited.Results:Eighteen Guanzhong dairy goats(day in milk=185±12 d)with similar parity,weight,and milk yield were selected and randomly assigned to one of three groups(n=6),which were fed an LRDS diet(Low RDS=20.52%),MRDS diet(Medium RDS=22.15%),or HRDS diet(High RDS=24.88%)for 5 weeks.Compared with that of the LRDS group,the milk fat contents in the MRDS and HRDS groups significantly decreased.The yields of short-,mediumand long-chain fatty acids decreased in the HRDS group.Furthermore,increased RDS significantly decreased ruminal B.fibrisolvens and Pseudobutyrivibrio abundances and increased the trans-10,cis-12 conjugated linoleic acid(CLA)and trans-10 C18:1 contents in the rumen fluid.A multiomics study revealed that the HRDS diet affected mammary lipid metabolism down-regulation of ACSS2,MVD,AGPS,SCD5,FADS2,CERCAM,SC5D,HSD17B7,HSD17B12,ATM,TP53RK,GDF1 and LOC102177400.Remarkably,the significant decrease of INSIG1,whose expression was depressed by trans-10,cis-12 CLA,could reduce the activity of SREBP and,consequently,downregulate the downstream gene expression of SREBF1.Conclusions:HRDS-induced goat MFD resulted from the downregulation of genes involved in lipogenesis,particularly,INSIG1.Specifically,even though the total starch content and the concentrate-to-fiber ratio were the same as those of the high-RDS diet,the low and medium RDS diets did not cause MFD in lactating goats.展开更多
Milk fatty acid composition is determined by several factors including diet. The milk fatty acid profile of dairy cows is low in polyunsaturated fatty acids, especially those of the n-3 series. Efforts to change and i...Milk fatty acid composition is determined by several factors including diet. The milk fatty acid profile of dairy cows is low in polyunsaturated fatty acids, especially those of the n-3 series. Efforts to change and influence fatty acid profile with longer chain polyunsaturated fatty acids have proven challenging. Several barriers prevent easy transfer of dietary polyunsaturated fatty acids to milk fat including rumen biohydrogenation and fatty acid esterification. The potential for cellular uptake and differences in fatty acid incorporation into milk fat might also have an effect, though this has received less research effort. Given physiological impediments to enriching milk fat with polyunsaturated fatty acids, manipulating the genome of the cow might provide a greater increase than diet alone, but this too may be challenged by the physiology of the cow.展开更多
Background:The biosynthesis of milk fat affects both the technological properties and organoleptic quality of milk and dairy products.MicroRNAs(miRNAs)are endogenous small non-coding RNAs that inhibit the expression o...Background:The biosynthesis of milk fat affects both the technological properties and organoleptic quality of milk and dairy products.MicroRNAs(miRNAs)are endogenous small non-coding RNAs that inhibit the expression of their mRNA targets and are involved in downstream signaling pathways that control several biological processes,including milk fat synthesis.miR-34b is a member of the miR-34 miRNA cluster,which is differentially expressed in the mammary gland tissue of dairy cows during lactation and dry periods.Previous studies have indicated miR-34b is a potential candidate gene that plays a decisive role in regulating milk fat synthesis;therefore,it is important to focus on miR-34b and investigate its regulatory effect on the biosynthesis of milk fat in bovine mammary epithelial cells(BMECs).Results:In this study,elevated miR-34b levels reduced milk fat synthesis,upregulated 1,999 genes,and downregulated 2,009 genes in BMECs.Moreover,Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis of differentially expressed genes suggested that miR-34b may play an inhibitory role in milk fat synthesis via the protein kinase B(Akt)/mammalian target of rapamycin(mTOR)signaling pathway by reducing phosphorylation levels.Notably,the mTOR activator MHY1485 rescued the inhibitory effect of miR-34b.Furthermore,we demonstrated that retinoic acid-induced protein 14(RAI14)is a target of miR-34b via TargetScan and immunofluorescence assays.RAI14 mRNA and protein levels were significantly decreased by the miR-34b mimic and increased by the miR-34b inhibitor.Moreover,the reduction in RAI14 levels led to the inhibition of the Akt/mTOR signaling pathway.Conclusions:Overall,our results identified a miR-34b-RAI14-Akt/mTOR regulatory network,while also providing a theoretical basis for the molecular breeding of dairy cows.展开更多
Background: Characterising the regulation of milk component synthesis in response to macronutrient supply is critical for understanding the implications of nutritional interventions on milk production. Gene expression...Background: Characterising the regulation of milk component synthesis in response to macronutrient supply is critical for understanding the implications of nutritional interventions on milk production. Gene expression in mammary gland secretory cells was measured using RNA isolated from milk fat globules from 6 Holstein-Friesian cows receiving 5-d abomasal infusions of saline, essential amino acids(AA), or glucose(GG) or palm olein(LG)without(LAA) or with(HAA) essential AA, according to a 6 × 6 Latin square design. RNA was isolated from milk fat samples collected on d 5 of infusion and subjected to real-time quantitative PCR. We hypothesised that m RNA expression of genes involved in de novo milk fatty acid(FA) synthesis would be differently affected by GG and LG,and that expression of genes regulating transfer of tricarboxylic acid cycle intermediates would increase at the HAA level. We also hypothesised that the HAA level would affect genes regulating endoplasmic reticulum(ER)homeostasis but would not affect genes related to the mechanistic target of rapamycin complex 1(m TORC1) or the integrated stress response(ISR) network.Results: Infusion of GG did not affect de novo milk FA yield but decreased expression of FA synthase(FASN).Infusion of LG decreased de novo FA yield and tended to decrease expression of acetyl-Co A carboxylase 1(ACC1).The HAA level increased both de novo FA yield and expression of ACC1, and tended to decrease expression of mitochondrial phosphoenolpyruvate carboxykinase(PCK2). m RNA expression of m TORC1 signaling participants was not affected by GG, LG, or AA level. Expression of the ε subunit of the ISR constituent eukaryotic translation initiation factor 2 B(EIF2 B5) tended to increase at the HAA level, but only in the presence of LG. X-box binding protein 1(XBP1) m RNA was activated in response to LG and the HAA level.Conclusions: Results show that expression of genes involved in de novo FA synthesis responded to glucogenic,lipogenic, and aminogenic substrates, whereas genes regulating intermediate flux through the tricarboxylic acid cycle were not majorly affected. Results also suggest that after 5 d of AA supplementation, milk protein synthesis is supported by enhanced ER biogenesis instead of signaling through the mTORC1 or ISR networks.展开更多
To correct the light scattering property parameters of milk fat for improving the detection accuracy,the Mie-theory was used to establish a predictive model for light scattering properties of milk fat globule with mul...To correct the light scattering property parameters of milk fat for improving the detection accuracy,the Mie-theory was used to establish a predictive model for light scattering properties of milk fat globule with multi-diameter distributions, by means of Monte Carlo approach to simulate actual multi-diameter size distribution of milk fat globule in milk fat solution. Scattering coefficient and absorption coefficient of multidiameter distribution milk fat particles were calculated by simulating the particles size distribution in milk fat solution. And the light scattering properties of multi-diameter distribution was compared with that of volume mean diameter,Sauter mean diameter and numerical mean diameter in milk fat solution. Theoretical simulation results indicate that the scattering coefficient and absorption coefficient of milk fat particles are determined by the particle size distribution in milk fat solution. There is a distinct difference in scattering characteristics between the milk fat particles with multi-diameter distribution and that with mean diameters. Compared to that with multi-diameter distribution,the scattering coefficient of the milk fat particles with mean diameter has a maximum mean deviation of 9042 m-1. The particle size distribution is not completely determined by the mean diameters. The dependence of the light scattering properties on the particle size distribution should be considered into the model and simulation. Therefore,it is found that the particle size distribution in milk fat solution is an essential and critical factor to significantly improve the detection accuracy of milk fat content.展开更多
To determine whether insulin exerts an effect on milk fat yield through the direct regulation of milk fat synthesis in the mammary gland, the hyperinsulinemic-euglycemic clamp procedure was performed in lactating goat...To determine whether insulin exerts an effect on milk fat yield through the direct regulation of milk fat synthesis in the mammary gland, the hyperinsulinemic-euglycemic clamp procedure was performed in lactating goats in the present study. The effects of the hyperinsulinemic-euglycemic clamp on milk yield, milk composition, milk fatty acid yield and the expression levels of mRNAs of milk fat synthesis-related genes were examined. The results revealed that the hyperinsulinemiceuglycemic clamp had no significant effect on the milk yield, the milk protein yield, the yield and content of lactose or the yield and content of solids-not-fat (SNF) (P > 0.05). In contrast, the milk fat percentage and milk fat yield were decreased by 35.3% and 33.6%, respectively (P < 0.01). Among the 19 fatty acids examined, the yields of 9 fatty acids were significantly reduced (P < 0.05) following the clamp procedure, including C16:0 (hexadecanoic acid), 3 fatty acids derived from blood (>C16) and 5 fatty acids synthesized de novo in the mammary gland ( 0.05), including acetyl-coenzyme A carboxylase (ACC), fatty acid synthase (FAS), fatty acidbinding protein (FABP), lipoprotein lipase (LPL), stearoyl-CoA desaturase (SCD) and glycerol-3-phosphate acyltransferase (GPAT). However, the expression level of the SCD gene was significantly reduced during the post-procedure period (P < 0.05) but returned to a normal level at 48 h after termination of the clamp procedure. It was concluded that the hyperinsulinemic-euglycemic clamp exerted a direct effect on milk fatty acid desaturation.展开更多
To determine the effect of dietary supplementation with vegetable oilseeds on the composition of bovine milk fatty acids (FAs), 40 Holstein dairy cows were used with a complete randomized design. At the beginning of t...To determine the effect of dietary supplementation with vegetable oilseeds on the composition of bovine milk fatty acids (FAs), 40 Holstein dairy cows were used with a complete randomized design. At the beginning of the experiment, the cows were 150 ± 25 day in milk (DIM). Total duration of the experiment was six weeks. Measurements were made during the last three weeks. Cows in four treatments were fed with a basal diet (CT) or basal diet supplemented with either whole full fat soybean (WFS), full fat expanded soybean (FPS) or whole full fat soybean with whole cottonseed and full fat expanded soybean (MIX). The composition of the milk fat was analyzed by gas chromatography. Relative to control, the conjugated linoleic acid (CLA) concentration in milk fat from cows on FPS was significantly increased by 83.88% (P < 0.05). The proportions of C12:0 were decreased by 35.7, 35.51, and 38.65% in milk fat from cows on WFS, MIX, and FPS compared with cows on CT. Similar decreases in C14:0 were 23.83, 24.85, and 31.48% in WFS, MIX, and FPS treatments, respectively. Feeding vegetable oilseeds increased the proportion of healthy FAs (mainly CLA), whereas decreased the concentration of C12:0 and C14:0. Therefore, milk and dairy products would have higher nutritive and therapeutic value.展开更多
Background: It is well known that feeding a high concentrate(HC) diet to lactating ruminants likely induces subacute ruminal acidosis(SARA) and leads to a decrease in milk fat production. However, the effects of feedi...Background: It is well known that feeding a high concentrate(HC) diet to lactating ruminants likely induces subacute ruminal acidosis(SARA) and leads to a decrease in milk fat production. However, the effects of feeding a HC diet for long periods on milk fatty acids composition and the mechanism behind the decline of milk fat still remains poorly understood. The aim of this study was to investigate the impact of feeding a HC diet to lactating dairy goats on milk fat yield and fatty acids composition with an emphasis on the mechanisms underlying the milk fat depression. Seventeen mid-lactating dairy goats were randomly allocated to three groups. The control treatment was fed a low-concentrate diet(35% concentrate, n = 5, LC) and there were two high-concentrate treatments(65% concentrate, HC), one fed a high concentrate diet for a long period(19 wks, n = 7, HL); one fed a high concentrate diet for a short period of time(4 wk, n = 5, HS). Milk fat production and fatty acids profiles were measured. In order to investigate the mechanisms underlying the changes in milk fat production and composition,the gene expression involved in lipid metabolism and DNA methylation in the mammary gland were also analyzed.Results: Milk production was increased by feeding the HC diet in the HS and HL groups compared with the LC diet(P < 0.01), while the percentage of milk fat was lower in the HL(P < 0.05) but not in the HS group. The total amount of saturated fatty acids(SFA) in the milk was not changed by feeding the HC diet, whereas the levels of unsaturated fatty acids(UFA) and monounsaturated fatty acids(MUFA) were markedly decreased in the HL group compared with the LC group(P < 0.05). Among these fatty acids, the concentrations of C15:0(P < 0.01), C17:0(P < 0.01), C17:1(P < 0.01), C18:1 n-9 c(P < 0.05), C18:3 n-3 r(P < 0.01) and C20:0(P < 0.01) were markedly lower in the HL group, and the concentrations of C20:0(P < 0.05) and C18:3 n-3 r(P < 0.01) were lower in the HS group compared with the LC group. However, the concentrations of C18:2 n-6 c(P < 0.05) and C20:4 n-6(P < 0.05) in the milk fat were higher in the HS group. Real-time PCR results showed that the m RNA expression of the genes involved in milk fat production in the mammary gland was generally decreased in the HL and HS groups compared with the LC group. Among these genes, ACSL1, ACSS1 & 2, ACACA, FAS, SCD, FADS2, and SREBP1 were downregulated in the mammary gland of the HL group(P < 0.05), and the expressions of ACSS2, ACACA, and FADS2 m RNA were markedly decreased in the HS goats compared with the LC group(P < 0.05). In contrast to the gene expression, the level of DNA methylation in the promoter regions of the ACACA and SCD genes was increased in the HL group compared with the LC group(P < 0.05). The levels of ACSL1 protein expression and FAS enzyme activity were also decreased in the mammary gland of the HL compared with the LC group(P < 0.05).Conclusions: Long-term feeding of a HC diet to lactating goats induced milk fat depression and FAs profile shift with lower MUFAs but higher SFAs. A general down-regulation of the gene expression involved in the milk fat production and a higher DNA methylation in the mammary gland may contribute to the decrease in milk fat production in goats fed a HC diet for long time periods.展开更多
Milk fat globule epithelial growth factor VIII(MFG-E8) is a novel adhesion protein mainly produced by macrophages and dendritic cells; it is expressed in most of the human tissues and functions to prompt cancer progre...Milk fat globule epithelial growth factor VIII(MFG-E8) is a novel adhesion protein mainly produced by macrophages and dendritic cells; it is expressed in most of the human tissues and functions to prompt cancer progression and survival. MFG-E8 contains a signal sequence for secretion, two epidermal growth factor(EGF)-like domains at the NH2 terminus and two discoidin domains with blood-clotting factor V/factor Ⅷ(C1 and C2) at the COOH terminus. The second EGF domain contains an arginine-glycine-aspartic(RGD) integrin-binding motif that engages α_vβ_5 integrins to facilitate cell adhesion and induce integrinmediated signal transduction. Integrin α_vβ_3 associates with VEGF receptor 2, engagement of integrins can promote angiogenesis, which plays key roles in growth, proliferation, and survival of cancer cells. VEGF stimulates the expression of α_vβ_3 and α_vβ_5 integrins on angiogenic vasculature, thereby potentiating effects of VEGF receptor engagement. Mice expressing a mutant form of α_vβ_3 integrin are unable to undergo tyrosine phosphorylation, confirming the important role that this integrin plays in pathological angiogenesis and providing important mechanistic insights. The C-terminus discoidin-like domains promote binding to membrane phospholipids, functioning close to VEGF like angiogenesis. MFG-E8 is an opsonin for apoptotic cells, and it acts as a bridging protein between apoptotic cells and phagocytes. It also influences cell immunities by altering CD4^+ and/or CD8^+ cells. Antibody or small peptide works with MFG-E8 at different functional sites or interacts with EGF-like domains and/or discoidin-like domains may play an important role in anti-angiogenesis or immune restoration. Altering the structures and/or functions of MFG-E8 and/or its domains is promising for development of novel anti-cancer strategies.展开更多
Milk fat globule membrane(MFGM)possesses various nutritional and biological benefits for mammals,whereas its effects on neonatal gut microbiota and barrier integrity remained unclear.This study investigated the effect...Milk fat globule membrane(MFGM)possesses various nutritional and biological benefits for mammals,whereas its effects on neonatal gut microbiota and barrier integrity remained unclear.This study investigated the effects of MFGM administration on microbial compositions and intestinal barrier functions of neonatal piglets.Sixteen newborn piglets were randomly allocated into a CON group or MFGM group,orally administered with saline or MFGM solution(1 g/kg body weight)respectively during the first postnatal week,and all piglets were breastfed during the whole neonatal period.The present study found that the MFGM oral administration during the first postnatal week increased the plasma immunoglobulin(lg)G level,body weight and average daily gain of piglets(P<0.05)on 21 d.Addi-tionally,MFGM administration enriched fecal SCFA-producing bacteria(Ruminococaceae_UCG-002,Ruminococaceae_UCG-010,Ruminococaceae_UCG-004,Ruminococaceae_UCG-014 and[Ruminococcus]_gauvrearuii_group),SCFA concentrations(acetate,propionate and butyrate;P<0.05)and their receptor(G-protein coupled receptor 41,GPR41).Furthermore,MFGM administration promoted intestinal villus morphology(P<0.05)and barrier functions by upregulating genes of tight junctions(E-cadherin,claudin-1,occludin and zonula occludin 1[ZO-1]),mucins(mucin-13 and mucin-20)and interleukin(IL)-22(P<0.05).Positive correlation was found between the beneficial microbes and SCFA levels pairwise with the intestinal barrier genes(P<0.05).In conclusion,orally administrating MFGM during the first postnatal week stimulated SCFA-producing bacteria colonization and SCFA generation,enhanced intes-tinal barrier functions and consequently improved growth performance of neonatal piglets on 21 d.Our findings will provide new insights about MFGM intervention for microbial colonization and intestinal development of neonates during their early life.展开更多
To investigate the role of glucose in regulating milk fatty acid synthesis,6 lactating Guanzhong dairy goats were infused with 0,60,or 100 g/d glucose via the external pubic artery in a 33 repeated Latin square experi...To investigate the role of glucose in regulating milk fatty acid synthesis,6 lactating Guanzhong dairy goats were infused with 0,60,or 100 g/d glucose via the external pubic artery in a 33 repeated Latin square experiment.A concomitant in vitro experiment was conducted to investigate possible mechanisms whereby glucose regulates milk fatty acid synthesis.RNA sequencing was used for cellular transcriptome analysis.Drugs,MK-2206,rapamycin,and dorsomorphin were used to block cellular mammalian AMP-activated protein kinase(AMPK),AKT serine/threonine kinase 1,and mechanistic target of rapamycin kinase signaling pathways,respectively.Carbohydrate response element binding protein(ChREBP)was knockdown and overexpressed to investigate its role in regulating milk fatty acid synthesis in mammary epithelial cells.Glucose infusion linearly elevated the concentration of C8:0(P=0.039)and C10:0(P=0.041)in milk fat while it linearly decreased(P=0.049)that of C16:0.This result was in agreement with the upregulation of genes related to de novo synthesis of fatty acids and lipid droplet formation,including adipose differentiation-related protein,butyrophilin subfamily 1 member A1,fatty acid synthase(FASN)and ChREBP.Their expression increased(P<0.05)linearly in the lactating goat mammary gland.In vitro,glucose linearly stimulated the expression of genes related to de novo synthesis of fatty acids and cellular triacylglycerol in cultured mammary epithelial cells.RNA sequencing and inhibition studies revealed that glucose induced transcriptomic changes increasing lipogenic pathways,with AMPK responding to glucose by controlling ChREBP and FASN.Knockdown and overexpression of ChREBP highlighted its essential role in lipogenesis.The knockdown and overexpression of ChREBP protein also revealed an essential role in regulating the de novo synthesis of fatty acids.Collectively,our data highlight that glucose supplementation promotes de novo fatty acid synthesis via the AMPK-ChREBP axis,hence increasing milk fat yield in the goat mammary gland.Results from the current study provide possible strategies to manipulate the fatty acid composition as well as improve ruminant milk quality.展开更多
Objectives:Thermal processes,such as refining and frying,result in the formation of trans fatty acids(TFAs)in edible oils or fats.Concerning the detrimental effect of TFAs on human health,milk fat samples of cow,buffa...Objectives:Thermal processes,such as refining and frying,result in the formation of trans fatty acids(TFAs)in edible oils or fats.Concerning the detrimental effect of TFAs on human health,milk fat samples of cow,buffalo,and goat are collected in order to elucidate TFAs accumulation during thermal processing.Methods:The increased amount of TFAs due to heating is analyzed by attenuated total reflection-Fourier transform infrared(ATR-FTIR)spectroscopy in conjunction with second-derivative treatment and gas chromatographic(GC)analysis.Results:The total amount of TFAs has been increased from 7.71 to 8.25 per cent for cow milk fat,7.12 to 7.82 per cent for buffalo milk fat,and from 6.82 to 7.61 per cent for goat milk fat on heating the samples to 125°C-175°C as predicted by GC.Conclusions:Local food products fried in these milk fats are hence very harmful to human health.These results demonstrate that thermally induced TFAs in milk fats are closely related to the process temperature and time,which should be considered to reduce the formation of TFAs during thermal treatment.展开更多
To compare mid-infrared(MIR)and near-infrared(NIR)spectroscopies for the determination of the fat and protein contents in milk,the same sample sets with varying concentrations of fat and protein were measured in the M...To compare mid-infrared(MIR)and near-infrared(NIR)spectroscopies for the determination of the fat and protein contents in milk,the same sample sets with varying concentrations of fat and protein were measured in the MIR range of 3 200-700 cm-1 and NIR range of 9 000-4 000 cm-1.The spectral features in the two regions were analyzed.The MIR spectra of milk were characteristic due to the MIR inherent molecular specificity,whereas the NIR spectra were relatively characterless due to the NIR low selectivity.Partial least squares(PLS)regression models for fat and protein were developed by using both MIR and NIR spectra.MIR data with no pretreatment gave better results than NIR data.The square correlation coefficient(R2)and the root mean square error of prediction(RMSEP)were 0.98 and 0.10 g/dL for fat and 0.97 and 0.11 g/dL for protein.With NIR techniques,satisfactory results were not obtained with raw data.However,NIR data after pretreatment gave similarly good results to the ones using MIR method.This paper indicates that either of the MIR and NIR spectral methods is reliable for the determination of the fat and protein contents.展开更多
This study demonstrated that homogenization did not increase the activity of lipoprotein lipase (LPL) in spite of a fast accumulation of free fatty acids (FFA). Two homogenization pressures (100 and 170 bar) and two t...This study demonstrated that homogenization did not increase the activity of lipoprotein lipase (LPL) in spite of a fast accumulation of free fatty acids (FFA). Two homogenization pressures (100 and 170 bar) and two temperatures (40℃and 50℃) were examined. The activity of LPL was analyzed and the formation of FFA was measured with two different methods, the B.D.I.-method and a nonesterified fatty acids (NEFA) method. A homogenization temperature of 50℃ resulted in a decreased LPL activity compared to 40℃. No effect of homogenization pressure was found. Analyzing FFA concentration with the B.D.I.-method resulted in significant effect of homogenization temperature and no effect of pressure. The largest formation of FFA was found in milk homogenized at 40℃. Using the NEFA method, another result was obtained, indicating no effect of homogenization temperature and a larger FFA accumulation at 100 bar than at 170 bar. Both analytic methods demonstrated significant production of FFA during 60 min incubation at homogenization temperature after treatment. The level of FFA in the milk samples immediately after homogenization was very high, demonstrating that LPL cleaves the triglycerides very rapidly when the native membrane was damaged. The regression between the B.D.I.-method and the NEFA was fair in the interval between 4 and 14 mmol/100 g fat, whereas at higher concentrations, the correlation was poor.展开更多
Genetic parameters for milk,fat yield and age at first calving of Chinese Holsteins in Heilongjiang were evaluated using multiple trait restricted maximum likelihood procedures with an animal model.Data consisted of r...Genetic parameters for milk,fat yield and age at first calving of Chinese Holsteins in Heilongjiang were evaluated using multiple trait restricted maximum likelihood procedures with an animal model.Data consisted of records of 2496 Chinese Holsteins first lactation cows collected from 1989 to 2000.The model included 21 herd effects,four calving season effects,nine age at first calving effects,6697 animal effects.(Co)variance components of milk yield,fat yield and age at first calving were estimated with the software package for variance component estimation(VCE) by an animal model. The heritabilities were 0.14,0.21,0.38 for milk yield,fat yield and age at first calving,respectively.The estimates of genetic correlation between milk yield and fat yield,age at first calving were 0.96,-0.29,respectively.The estimate of genetic correlation between fat yield and age at first calving was -0.28.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2019YFC1605000)National Natural Science Foundation of China(Grant No.31871806)the Beijing Livestock Industry Innovation Team(BAIC05-2023)。
文摘Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and immunomodulation.The aim of this study was to evaluate the protective effects and possible underlying mechanisms of MFGM on cow’s milk allergy(CMA)in aβ-lactoglobulin(BLG)-induced allergic mice model.MFGM was supplemented to allergic mice induced by BLG at a dose of 400 mg/kg body weight.Results demonstrated that MFGM alleviated food allergy symptoms,decreased serum levels of lipopolysaccharide,pro-inflammatory cytokines,immunoglobulin(Ig)E,Ig G1,and Th2 cytokines including interleukin(IL)-4,while increased serum levels of Th1 cytokines including interferon-γand regulatory T cells(Tregs)cytokines including IL-10 and transforming growth factor-β.MFGM modulated gut microbiota and enhanced intestinal barrier of BLG-allergic mice,as evidenced by decreased relative abundance of Desulfobacterota,Rikenellaceae,Lachnospiraceae,and Desulfovibrionaceae,while increased relative abundance of Bacteroidetes,Lactobacillaceae and Muribaculaceae,and enhanced expressions of tight junction proteins including Occludin,Claudin-1 and zonula occludens-1.Furthermore,MFGM increased fecal short-chain fatty acids(SCFAs)levels,which elevated G protein-coupled receptor(GPR)43 and GPR109A expressions.The increased expressions of GPR43 and GPR109A induced CD103+dendritic cells accumulation and promoted Tregs differentiation in mesenteric lymph node to a certain extent.In summary,MFGM alleviated CMA in a BLG-induced allergic mice model through enhancing intestinal barrier and promoting Tregs differentiation,which may be correlated with SCFAs-mediated activation of GPRs.These findings suggest that MFGM may be useful as a promising functional ingredient against CMA.
基金This work was supportedby theNational KeyR&D Program of China(2022YFD1301005)the Shandong Provincial Natural Science Foundation,China(ZR2022MC184)the High-level Talents Foundation of Qingdao Agricultural University,China(665/1120053,665/1120080).
文摘The milk fat globule membrane(MFGM)is a complex structure with numerous functions,and its composition is affected by many factors.There have been few systematic investigations on goat MFGM proteome profiling during lactation.Individual milk samples from 15 healthy dairy goats were obtained at six lactation time points for investigation of the MFGM proteome using both data-independent acquisition(DIA)and data-dependent acquisition(DDA)proteomics techniques combined with multivariate statistical analysis.Using the DIA method,890 variably abundant MFGM proteins were discovered throughout the lactation cycle.From 1 to 240 d,butyrophilin subfamily 1 member A1,lipoprotein lipase,perilipin-2,and adipose triglyceride lipase were upregulated,while APOE,complement C3,clusterin,and IgG were downregulated.Furthermore,from 1 to 90 d,annexin A1,annexin A2,and antithrombin-ll were downregulated,then upregulated by d 240.Albumin had a high degree of connectedness,indicating that it was a key protein,according to protein-protein interaction research.Overall,our findings gave new insights into the biological features of MFGM protein in goat milk throughout lactation,which may aid in the creation of specialized MFGM products and infant formula.
基金Supported by the National Natural Science Foundation of China,No.82100685the Scientific Research Fund of Xi’an Health Commission,No.2021yb08+1 种基金Scientific Research Fund of Xi’an Central Hospital,No.2022QN07Innovation Capability Support Plan of Xi’an Science and Technology Bureau,No.23YXYJ0097.
文摘BACKGROUND Liver injury is common in severe acute pancreatitis(SAP).Excessive autophagy often leads to an imbalance of homeostasis in hepatocytes,which induces lipid peroxidation and mitochondrial iron deposition and ultimately leads to ferroptosis.Our previous study found that milk fat globule epidermal growth factor 8(MFG-E8)alleviates acinar cell damage during SAP via binding toαvβ3/5 integrins.MFG-E8 also seems to mitigate pancreatic fibrosis via inhibiting chaperone-mediated autophagy.AIM To speculate whether MFG-E8 could also alleviate SAP induced liver injury by restoring the abnormal autophagy flux.METHODS SAP was induced in mice by 2 hly intraperitoneal injections of 4.0 g/kg L-arginine or 7 hly injections of 50μg/kg cerulein plus lipopolysaccharide.mfge8-knockout mice were used to study the effect of MFG-E8 deficiency on SAPinduced liver injury.Cilengitide,a specificαvβ3/5 integrin inhibitor,was used to investigate the possible mechanism of MFG-E8.RESULTS The results showed that MFG-E8 deficiency aggravated SAP-induced liver injury in mice,enhanced autophagy flux in hepatocyte,and worsened the degree of ferroptosis.Exogenous MFG-E8 reduced SAP-induced liver injury in a dose-dependent manner.Mechanistically,MFG-E8 mitigated excessive autophagy and inhibited ferroptosis in liver cells.Cilengitide abolished MFG-E8’s beneficial effects in SAP-induced liver injury.CONCLUSION MFG-E8 acts as an endogenous protective mediator in SAP-induced liver injury.MFG-E8 alleviates the excessive autophagy and inhibits ferroptosis in hepatocytes by binding to integrinαVβ3/5.
基金Financially supported by the Danish Council for Independent Research,Technology and Production Sciences (Copenhagen K,Denmark)。
文摘Background Dietary fat is important for energy provision and immune function of lactating sows and their progeny.However,knowledge on the impact of fat on mammary transcription of lipogenic genes,de novo fat synthesis,and milk fatty acid(FA)output is sparse in sows.This study aimed to evaluate impacts of dietary fat levels and FA composition on these traits in sows.Forty second-parity sows(Danish Landrace×Yorkshire)were assigned to 1 of 5 dietary treatments from d 108 of gestation until weaning(d 28 of lactation):low-fat control diet(3%added animal fat);or 1 of 4 high-fat diets with 8%added fat:coconut oil(CO),fish oil(FO),sunflower oil(SO),or 4%octanoic acid plus 4%FO(OFO).Three approaches were taken to estimate de novo milk fat synthesis from glucose and body fat.Results Daily intake of FA was lowest in low-fat sows within fat levels(P<0.01)and in OFO and FO sows within highfat diets(P<0.01).Daily milk outputs of fat,FA,energy,and FA-derived carbon reflected to a large extent the intake of those.On average,estimates for de novo fat synthesis were 82 or 194 g/d from glucose according to method 1 or 2 and 255 g de novo+mobilized FA/d according to method 3.The low-fat diet increased mammary FAS expression(P<0.05)and de novo fat synthesis(method 1;P=0.13)within fat levels.The OFO diet increased de novo fat synthesis(method 1;P<0.05)and numerically upregulated mammary FAS expression compared to the other high-fat diets.Across diets,a daily intake of 440 g digestible FA minimized milk fat originating from glucose and mobilized body fat.Conclusions Sows fed diets with low-fat or octanoic acid,through upregulating FAS expression,increased mammary de novo fat synthesis whereas the milk FA output remained low in sows fed the low-fat diet or high-fat OFO or FO diets,indicating that dietary FA intake,dietary fat level,and body fat mobilization in concert determine de novo fat synthesis,amount and profiles of FA in milk.
文摘Milk fat contains a variety of nutritive and health-promoting compounds that guard against some disease. In the current system of global competition, when the quality of milk and milk products is not an option but rather a requirement, therefore, determining the purity of milk fat is critical. This study aims to validate analytical methods for detecting palm oil in a mixture of milk fat and palm oil. Methods of this study was involved detection of non-milk fat in fat blinders by determining the saponification value, iodine number, refractive index, butyro refractometer reading, Gas chromatography, Reverse Phase High-performance liquid chromatography, and Fourier transforms Infrared. The results of this study revealed that the saponification value, Iodine number, refractive index, and Butyro Reading could be used to detect the addition of palm oil by a level of 10% - 20% or more to the milk. The level of some fatty acids in the milk as determined by GC, such as myristic acid (C14:0), palmitic acid (C16:0), and stearic acid (C18:0), is correlated well with the level of adding palm oil to milk fat. The determination of cholesterol and β-sito-sterol content by RP-HPLC could be used for the detection of the addition of palm oil to milk fat. The spectrum behavior produced by FTIR spectroscopy in this adulterated sample is almost the same, so this technique could not be used to detect the palm oil in milk fat.
基金This research was financially supported by the National Key Research and Development Program of China(award number:2017YFD0500500)the Science&Technological Project of Shaanxi Province,China(award number:2017 TSCXL-NY-04-01).
文摘Background:Starch is an important substance that supplies energy to ruminants.To provide sufficient energy for high-yielding dairy ruminants,they are typically fed starch-enriched diets.However,starch-enriched diets have been proven to increase the risk of milk fat depression(MFD)in dairy cows.The starch present in ruminant diets could be divided into rumen-degradable starch(RDS)and rumen escaped starch(RES)according to their different degradation sites(rumen or intestine).Goats and cows have different sensitivities to MFD.Data regarding the potential roles of RDS in milk fat synthesis in the mammary tissue of dairy goats and in regulating the occurrence of MFD are limited.Results:Eighteen Guanzhong dairy goats(day in milk=185±12 d)with similar parity,weight,and milk yield were selected and randomly assigned to one of three groups(n=6),which were fed an LRDS diet(Low RDS=20.52%),MRDS diet(Medium RDS=22.15%),or HRDS diet(High RDS=24.88%)for 5 weeks.Compared with that of the LRDS group,the milk fat contents in the MRDS and HRDS groups significantly decreased.The yields of short-,mediumand long-chain fatty acids decreased in the HRDS group.Furthermore,increased RDS significantly decreased ruminal B.fibrisolvens and Pseudobutyrivibrio abundances and increased the trans-10,cis-12 conjugated linoleic acid(CLA)and trans-10 C18:1 contents in the rumen fluid.A multiomics study revealed that the HRDS diet affected mammary lipid metabolism down-regulation of ACSS2,MVD,AGPS,SCD5,FADS2,CERCAM,SC5D,HSD17B7,HSD17B12,ATM,TP53RK,GDF1 and LOC102177400.Remarkably,the significant decrease of INSIG1,whose expression was depressed by trans-10,cis-12 CLA,could reduce the activity of SREBP and,consequently,downregulate the downstream gene expression of SREBF1.Conclusions:HRDS-induced goat MFD resulted from the downregulation of genes involved in lipogenesis,particularly,INSIG1.Specifically,even though the total starch content and the concentrate-to-fiber ratio were the same as those of the high-RDS diet,the low and medium RDS diets did not cause MFD in lactating goats.
基金Funding for this work was provided in part,by the Virginia Agricultural Experiment Station and the Hatch Program of the National Institute of Food and Agriculture,U.S.Department of Agriculture
文摘Milk fatty acid composition is determined by several factors including diet. The milk fatty acid profile of dairy cows is low in polyunsaturated fatty acids, especially those of the n-3 series. Efforts to change and influence fatty acid profile with longer chain polyunsaturated fatty acids have proven challenging. Several barriers prevent easy transfer of dietary polyunsaturated fatty acids to milk fat including rumen biohydrogenation and fatty acid esterification. The potential for cellular uptake and differences in fatty acid incorporation into milk fat might also have an effect, though this has received less research effort. Given physiological impediments to enriching milk fat with polyunsaturated fatty acids, manipulating the genome of the cow might provide a greater increase than diet alone, but this too may be challenged by the physiology of the cow.
基金supported by the Natural Science Foundation of Shaanxi Province(2021JM-100)the Shaanxi Key Research and Development Program(2018ZDXM-NY-046).
文摘Background:The biosynthesis of milk fat affects both the technological properties and organoleptic quality of milk and dairy products.MicroRNAs(miRNAs)are endogenous small non-coding RNAs that inhibit the expression of their mRNA targets and are involved in downstream signaling pathways that control several biological processes,including milk fat synthesis.miR-34b is a member of the miR-34 miRNA cluster,which is differentially expressed in the mammary gland tissue of dairy cows during lactation and dry periods.Previous studies have indicated miR-34b is a potential candidate gene that plays a decisive role in regulating milk fat synthesis;therefore,it is important to focus on miR-34b and investigate its regulatory effect on the biosynthesis of milk fat in bovine mammary epithelial cells(BMECs).Results:In this study,elevated miR-34b levels reduced milk fat synthesis,upregulated 1,999 genes,and downregulated 2,009 genes in BMECs.Moreover,Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis of differentially expressed genes suggested that miR-34b may play an inhibitory role in milk fat synthesis via the protein kinase B(Akt)/mammalian target of rapamycin(mTOR)signaling pathway by reducing phosphorylation levels.Notably,the mTOR activator MHY1485 rescued the inhibitory effect of miR-34b.Furthermore,we demonstrated that retinoic acid-induced protein 14(RAI14)is a target of miR-34b via TargetScan and immunofluorescence assays.RAI14 mRNA and protein levels were significantly decreased by the miR-34b mimic and increased by the miR-34b inhibitor.Moreover,the reduction in RAI14 levels led to the inhibition of the Akt/mTOR signaling pathway.Conclusions:Overall,our results identified a miR-34b-RAI14-Akt/mTOR regulatory network,while also providing a theoretical basis for the molecular breeding of dairy cows.
基金conducted by Wageningen University and Research(Wageningen Livestock Research, Wageningen, the Netherlands)commissioned and funded by the Ministry of Agriculture+2 种基金Nature and Food Quality (The Hague, the Netherlands) within the framework of Policy Support Research theme ‘Feed4 Foodure’(BO-31.03-005-001TKI-AF12039)by the Vereniging Diervoederonderzoek Nederland (Rijswijk, the Netherlands)。
文摘Background: Characterising the regulation of milk component synthesis in response to macronutrient supply is critical for understanding the implications of nutritional interventions on milk production. Gene expression in mammary gland secretory cells was measured using RNA isolated from milk fat globules from 6 Holstein-Friesian cows receiving 5-d abomasal infusions of saline, essential amino acids(AA), or glucose(GG) or palm olein(LG)without(LAA) or with(HAA) essential AA, according to a 6 × 6 Latin square design. RNA was isolated from milk fat samples collected on d 5 of infusion and subjected to real-time quantitative PCR. We hypothesised that m RNA expression of genes involved in de novo milk fatty acid(FA) synthesis would be differently affected by GG and LG,and that expression of genes regulating transfer of tricarboxylic acid cycle intermediates would increase at the HAA level. We also hypothesised that the HAA level would affect genes regulating endoplasmic reticulum(ER)homeostasis but would not affect genes related to the mechanistic target of rapamycin complex 1(m TORC1) or the integrated stress response(ISR) network.Results: Infusion of GG did not affect de novo milk FA yield but decreased expression of FA synthase(FASN).Infusion of LG decreased de novo FA yield and tended to decrease expression of acetyl-Co A carboxylase 1(ACC1).The HAA level increased both de novo FA yield and expression of ACC1, and tended to decrease expression of mitochondrial phosphoenolpyruvate carboxykinase(PCK2). m RNA expression of m TORC1 signaling participants was not affected by GG, LG, or AA level. Expression of the ε subunit of the ISR constituent eukaryotic translation initiation factor 2 B(EIF2 B5) tended to increase at the HAA level, but only in the presence of LG. X-box binding protein 1(XBP1) m RNA was activated in response to LG and the HAA level.Conclusions: Results show that expression of genes involved in de novo FA synthesis responded to glucogenic,lipogenic, and aminogenic substrates, whereas genes regulating intermediate flux through the tricarboxylic acid cycle were not majorly affected. Results also suggest that after 5 d of AA supplementation, milk protein synthesis is supported by enhanced ER biogenesis instead of signaling through the mTORC1 or ISR networks.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51206038)the Scientific Research Fund of Heilongjiang Provincial Education Department(Grant No.12521122)
文摘To correct the light scattering property parameters of milk fat for improving the detection accuracy,the Mie-theory was used to establish a predictive model for light scattering properties of milk fat globule with multi-diameter distributions, by means of Monte Carlo approach to simulate actual multi-diameter size distribution of milk fat globule in milk fat solution. Scattering coefficient and absorption coefficient of multidiameter distribution milk fat particles were calculated by simulating the particles size distribution in milk fat solution. And the light scattering properties of multi-diameter distribution was compared with that of volume mean diameter,Sauter mean diameter and numerical mean diameter in milk fat solution. Theoretical simulation results indicate that the scattering coefficient and absorption coefficient of milk fat particles are determined by the particle size distribution in milk fat solution. There is a distinct difference in scattering characteristics between the milk fat particles with multi-diameter distribution and that with mean diameters. Compared to that with multi-diameter distribution,the scattering coefficient of the milk fat particles with mean diameter has a maximum mean deviation of 9042 m-1. The particle size distribution is not completely determined by the mean diameters. The dependence of the light scattering properties on the particle size distribution should be considered into the model and simulation. Therefore,it is found that the particle size distribution in milk fat solution is an essential and critical factor to significantly improve the detection accuracy of milk fat content.
文摘To determine whether insulin exerts an effect on milk fat yield through the direct regulation of milk fat synthesis in the mammary gland, the hyperinsulinemic-euglycemic clamp procedure was performed in lactating goats in the present study. The effects of the hyperinsulinemic-euglycemic clamp on milk yield, milk composition, milk fatty acid yield and the expression levels of mRNAs of milk fat synthesis-related genes were examined. The results revealed that the hyperinsulinemiceuglycemic clamp had no significant effect on the milk yield, the milk protein yield, the yield and content of lactose or the yield and content of solids-not-fat (SNF) (P > 0.05). In contrast, the milk fat percentage and milk fat yield were decreased by 35.3% and 33.6%, respectively (P < 0.01). Among the 19 fatty acids examined, the yields of 9 fatty acids were significantly reduced (P < 0.05) following the clamp procedure, including C16:0 (hexadecanoic acid), 3 fatty acids derived from blood (>C16) and 5 fatty acids synthesized de novo in the mammary gland ( 0.05), including acetyl-coenzyme A carboxylase (ACC), fatty acid synthase (FAS), fatty acidbinding protein (FABP), lipoprotein lipase (LPL), stearoyl-CoA desaturase (SCD) and glycerol-3-phosphate acyltransferase (GPAT). However, the expression level of the SCD gene was significantly reduced during the post-procedure period (P < 0.05) but returned to a normal level at 48 h after termination of the clamp procedure. It was concluded that the hyperinsulinemic-euglycemic clamp exerted a direct effect on milk fatty acid desaturation.
文摘To determine the effect of dietary supplementation with vegetable oilseeds on the composition of bovine milk fatty acids (FAs), 40 Holstein dairy cows were used with a complete randomized design. At the beginning of the experiment, the cows were 150 ± 25 day in milk (DIM). Total duration of the experiment was six weeks. Measurements were made during the last three weeks. Cows in four treatments were fed with a basal diet (CT) or basal diet supplemented with either whole full fat soybean (WFS), full fat expanded soybean (FPS) or whole full fat soybean with whole cottonseed and full fat expanded soybean (MIX). The composition of the milk fat was analyzed by gas chromatography. Relative to control, the conjugated linoleic acid (CLA) concentration in milk fat from cows on FPS was significantly increased by 83.88% (P < 0.05). The proportions of C12:0 were decreased by 35.7, 35.51, and 38.65% in milk fat from cows on WFS, MIX, and FPS compared with cows on CT. Similar decreases in C14:0 were 23.83, 24.85, and 31.48% in WFS, MIX, and FPS treatments, respectively. Feeding vegetable oilseeds increased the proportion of healthy FAs (mainly CLA), whereas decreased the concentration of C12:0 and C14:0. Therefore, milk and dairy products would have higher nutritive and therapeutic value.
基金supported by the National Nature Science Foundation of China(project no.31572433)the National Key R&D Program(2016YFD0501203)+1 种基金the Program for New Century Excellent Talents in University(NCET-13-0862)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Background: It is well known that feeding a high concentrate(HC) diet to lactating ruminants likely induces subacute ruminal acidosis(SARA) and leads to a decrease in milk fat production. However, the effects of feeding a HC diet for long periods on milk fatty acids composition and the mechanism behind the decline of milk fat still remains poorly understood. The aim of this study was to investigate the impact of feeding a HC diet to lactating dairy goats on milk fat yield and fatty acids composition with an emphasis on the mechanisms underlying the milk fat depression. Seventeen mid-lactating dairy goats were randomly allocated to three groups. The control treatment was fed a low-concentrate diet(35% concentrate, n = 5, LC) and there were two high-concentrate treatments(65% concentrate, HC), one fed a high concentrate diet for a long period(19 wks, n = 7, HL); one fed a high concentrate diet for a short period of time(4 wk, n = 5, HS). Milk fat production and fatty acids profiles were measured. In order to investigate the mechanisms underlying the changes in milk fat production and composition,the gene expression involved in lipid metabolism and DNA methylation in the mammary gland were also analyzed.Results: Milk production was increased by feeding the HC diet in the HS and HL groups compared with the LC diet(P < 0.01), while the percentage of milk fat was lower in the HL(P < 0.05) but not in the HS group. The total amount of saturated fatty acids(SFA) in the milk was not changed by feeding the HC diet, whereas the levels of unsaturated fatty acids(UFA) and monounsaturated fatty acids(MUFA) were markedly decreased in the HL group compared with the LC group(P < 0.05). Among these fatty acids, the concentrations of C15:0(P < 0.01), C17:0(P < 0.01), C17:1(P < 0.01), C18:1 n-9 c(P < 0.05), C18:3 n-3 r(P < 0.01) and C20:0(P < 0.01) were markedly lower in the HL group, and the concentrations of C20:0(P < 0.05) and C18:3 n-3 r(P < 0.01) were lower in the HS group compared with the LC group. However, the concentrations of C18:2 n-6 c(P < 0.05) and C20:4 n-6(P < 0.05) in the milk fat were higher in the HS group. Real-time PCR results showed that the m RNA expression of the genes involved in milk fat production in the mammary gland was generally decreased in the HL and HS groups compared with the LC group. Among these genes, ACSL1, ACSS1 & 2, ACACA, FAS, SCD, FADS2, and SREBP1 were downregulated in the mammary gland of the HL group(P < 0.05), and the expressions of ACSS2, ACACA, and FADS2 m RNA were markedly decreased in the HS goats compared with the LC group(P < 0.05). In contrast to the gene expression, the level of DNA methylation in the promoter regions of the ACACA and SCD genes was increased in the HL group compared with the LC group(P < 0.05). The levels of ACSL1 protein expression and FAS enzyme activity were also decreased in the mammary gland of the HL compared with the LC group(P < 0.05).Conclusions: Long-term feeding of a HC diet to lactating goats induced milk fat depression and FAs profile shift with lower MUFAs but higher SFAs. A general down-regulation of the gene expression involved in the milk fat production and a higher DNA methylation in the mammary gland may contribute to the decrease in milk fat production in goats fed a HC diet for long time periods.
基金Supported by a grant from Medical Technology Research Center for Health Development of China National Health and Family Planning Commission(No.W2012FZ007)
文摘Milk fat globule epithelial growth factor VIII(MFG-E8) is a novel adhesion protein mainly produced by macrophages and dendritic cells; it is expressed in most of the human tissues and functions to prompt cancer progression and survival. MFG-E8 contains a signal sequence for secretion, two epidermal growth factor(EGF)-like domains at the NH2 terminus and two discoidin domains with blood-clotting factor V/factor Ⅷ(C1 and C2) at the COOH terminus. The second EGF domain contains an arginine-glycine-aspartic(RGD) integrin-binding motif that engages α_vβ_5 integrins to facilitate cell adhesion and induce integrinmediated signal transduction. Integrin α_vβ_3 associates with VEGF receptor 2, engagement of integrins can promote angiogenesis, which plays key roles in growth, proliferation, and survival of cancer cells. VEGF stimulates the expression of α_vβ_3 and α_vβ_5 integrins on angiogenic vasculature, thereby potentiating effects of VEGF receptor engagement. Mice expressing a mutant form of α_vβ_3 integrin are unable to undergo tyrosine phosphorylation, confirming the important role that this integrin plays in pathological angiogenesis and providing important mechanistic insights. The C-terminus discoidin-like domains promote binding to membrane phospholipids, functioning close to VEGF like angiogenesis. MFG-E8 is an opsonin for apoptotic cells, and it acts as a bridging protein between apoptotic cells and phagocytes. It also influences cell immunities by altering CD4^+ and/or CD8^+ cells. Antibody or small peptide works with MFG-E8 at different functional sites or interacts with EGF-like domains and/or discoidin-like domains may play an important role in anti-angiogenesis or immune restoration. Altering the structures and/or functions of MFG-E8 and/or its domains is promising for development of novel anti-cancer strategies.
基金the Beijing Municipal Natural Science Foundation(S170001)the National Natural Science Foundation of China(31630074,31902170,31972596 and 31902189)+2 种基金the National Key Research and Development Program of China(2016YFD0500506 and 2018YDF0501002)the Agriculture Research System of China(CARS-35)the Higher Education Discipline Innovation Project(B16044).
文摘Milk fat globule membrane(MFGM)possesses various nutritional and biological benefits for mammals,whereas its effects on neonatal gut microbiota and barrier integrity remained unclear.This study investigated the effects of MFGM administration on microbial compositions and intestinal barrier functions of neonatal piglets.Sixteen newborn piglets were randomly allocated into a CON group or MFGM group,orally administered with saline or MFGM solution(1 g/kg body weight)respectively during the first postnatal week,and all piglets were breastfed during the whole neonatal period.The present study found that the MFGM oral administration during the first postnatal week increased the plasma immunoglobulin(lg)G level,body weight and average daily gain of piglets(P<0.05)on 21 d.Addi-tionally,MFGM administration enriched fecal SCFA-producing bacteria(Ruminococaceae_UCG-002,Ruminococaceae_UCG-010,Ruminococaceae_UCG-004,Ruminococaceae_UCG-014 and[Ruminococcus]_gauvrearuii_group),SCFA concentrations(acetate,propionate and butyrate;P<0.05)and their receptor(G-protein coupled receptor 41,GPR41).Furthermore,MFGM administration promoted intestinal villus morphology(P<0.05)and barrier functions by upregulating genes of tight junctions(E-cadherin,claudin-1,occludin and zonula occludin 1[ZO-1]),mucins(mucin-13 and mucin-20)and interleukin(IL)-22(P<0.05).Positive correlation was found between the beneficial microbes and SCFA levels pairwise with the intestinal barrier genes(P<0.05).In conclusion,orally administrating MFGM during the first postnatal week stimulated SCFA-producing bacteria colonization and SCFA generation,enhanced intes-tinal barrier functions and consequently improved growth performance of neonatal piglets on 21 d.Our findings will provide new insights about MFGM intervention for microbial colonization and intestinal development of neonates during their early life.
基金the National Natural Science Foundation of China(31702090)the Fundamental Research Funds for the Central Universities(2020QNA6029 and 2021FZZX003-02-06).
文摘To investigate the role of glucose in regulating milk fatty acid synthesis,6 lactating Guanzhong dairy goats were infused with 0,60,or 100 g/d glucose via the external pubic artery in a 33 repeated Latin square experiment.A concomitant in vitro experiment was conducted to investigate possible mechanisms whereby glucose regulates milk fatty acid synthesis.RNA sequencing was used for cellular transcriptome analysis.Drugs,MK-2206,rapamycin,and dorsomorphin were used to block cellular mammalian AMP-activated protein kinase(AMPK),AKT serine/threonine kinase 1,and mechanistic target of rapamycin kinase signaling pathways,respectively.Carbohydrate response element binding protein(ChREBP)was knockdown and overexpressed to investigate its role in regulating milk fatty acid synthesis in mammary epithelial cells.Glucose infusion linearly elevated the concentration of C8:0(P=0.039)and C10:0(P=0.041)in milk fat while it linearly decreased(P=0.049)that of C16:0.This result was in agreement with the upregulation of genes related to de novo synthesis of fatty acids and lipid droplet formation,including adipose differentiation-related protein,butyrophilin subfamily 1 member A1,fatty acid synthase(FASN)and ChREBP.Their expression increased(P<0.05)linearly in the lactating goat mammary gland.In vitro,glucose linearly stimulated the expression of genes related to de novo synthesis of fatty acids and cellular triacylglycerol in cultured mammary epithelial cells.RNA sequencing and inhibition studies revealed that glucose induced transcriptomic changes increasing lipogenic pathways,with AMPK responding to glucose by controlling ChREBP and FASN.Knockdown and overexpression of ChREBP highlighted its essential role in lipogenesis.The knockdown and overexpression of ChREBP protein also revealed an essential role in regulating the de novo synthesis of fatty acids.Collectively,our data highlight that glucose supplementation promotes de novo fatty acid synthesis via the AMPK-ChREBP axis,hence increasing milk fat yield in the goat mammary gland.Results from the current study provide possible strategies to manipulate the fatty acid composition as well as improve ruminant milk quality.
文摘Objectives:Thermal processes,such as refining and frying,result in the formation of trans fatty acids(TFAs)in edible oils or fats.Concerning the detrimental effect of TFAs on human health,milk fat samples of cow,buffalo,and goat are collected in order to elucidate TFAs accumulation during thermal processing.Methods:The increased amount of TFAs due to heating is analyzed by attenuated total reflection-Fourier transform infrared(ATR-FTIR)spectroscopy in conjunction with second-derivative treatment and gas chromatographic(GC)analysis.Results:The total amount of TFAs has been increased from 7.71 to 8.25 per cent for cow milk fat,7.12 to 7.82 per cent for buffalo milk fat,and from 6.82 to 7.61 per cent for goat milk fat on heating the samples to 125°C-175°C as predicted by GC.Conclusions:Local food products fried in these milk fats are hence very harmful to human health.These results demonstrate that thermally induced TFAs in milk fats are closely related to the process temperature and time,which should be considered to reduce the formation of TFAs during thermal treatment.
基金Supported by National Natural Science Foundation of China(No.30170261)the 10th Five-Year Plan of China(No.2004BA706B12).
文摘To compare mid-infrared(MIR)and near-infrared(NIR)spectroscopies for the determination of the fat and protein contents in milk,the same sample sets with varying concentrations of fat and protein were measured in the MIR range of 3 200-700 cm-1 and NIR range of 9 000-4 000 cm-1.The spectral features in the two regions were analyzed.The MIR spectra of milk were characteristic due to the MIR inherent molecular specificity,whereas the NIR spectra were relatively characterless due to the NIR low selectivity.Partial least squares(PLS)regression models for fat and protein were developed by using both MIR and NIR spectra.MIR data with no pretreatment gave better results than NIR data.The square correlation coefficient(R2)and the root mean square error of prediction(RMSEP)were 0.98 and 0.10 g/dL for fat and 0.97 and 0.11 g/dL for protein.With NIR techniques,satisfactory results were not obtained with raw data.However,NIR data after pretreatment gave similarly good results to the ones using MIR method.This paper indicates that either of the MIR and NIR spectral methods is reliable for the determination of the fat and protein contents.
文摘This study demonstrated that homogenization did not increase the activity of lipoprotein lipase (LPL) in spite of a fast accumulation of free fatty acids (FFA). Two homogenization pressures (100 and 170 bar) and two temperatures (40℃and 50℃) were examined. The activity of LPL was analyzed and the formation of FFA was measured with two different methods, the B.D.I.-method and a nonesterified fatty acids (NEFA) method. A homogenization temperature of 50℃ resulted in a decreased LPL activity compared to 40℃. No effect of homogenization pressure was found. Analyzing FFA concentration with the B.D.I.-method resulted in significant effect of homogenization temperature and no effect of pressure. The largest formation of FFA was found in milk homogenized at 40℃. Using the NEFA method, another result was obtained, indicating no effect of homogenization temperature and a larger FFA accumulation at 100 bar than at 170 bar. Both analytic methods demonstrated significant production of FFA during 60 min incubation at homogenization temperature after treatment. The level of FFA in the milk samples immediately after homogenization was very high, demonstrating that LPL cleaves the triglycerides very rapidly when the native membrane was damaged. The regression between the B.D.I.-method and the NEFA was fair in the interval between 4 and 14 mmol/100 g fat, whereas at higher concentrations, the correlation was poor.
文摘Genetic parameters for milk,fat yield and age at first calving of Chinese Holsteins in Heilongjiang were evaluated using multiple trait restricted maximum likelihood procedures with an animal model.Data consisted of records of 2496 Chinese Holsteins first lactation cows collected from 1989 to 2000.The model included 21 herd effects,four calving season effects,nine age at first calving effects,6697 animal effects.(Co)variance components of milk yield,fat yield and age at first calving were estimated with the software package for variance component estimation(VCE) by an animal model. The heritabilities were 0.14,0.21,0.38 for milk yield,fat yield and age at first calving,respectively.The estimates of genetic correlation between milk yield and fat yield,age at first calving were 0.96,-0.29,respectively.The estimate of genetic correlation between fat yield and age at first calving was -0.28.
