Amyotrophic lateral sclerosis is a fatal multisystemic neurodegenerative disease with motor neurons being a primary target.Although progressive weakness is a hallmark feature of amyotrophic lateral sclerosis,there is ...Amyotrophic lateral sclerosis is a fatal multisystemic neurodegenerative disease with motor neurons being a primary target.Although progressive weakness is a hallmark feature of amyotrophic lateral sclerosis,there is considerable heterogeneity,including clinical presentation,progression,and the underlying triggers for disease initiation.Based on longitudinal studies with families harboring amyotrophic lateral sclerosis-associated gene mutations,it has become apparent that overt disease is preceded by a prodromal phase,possibly in years,where compensatory mechanisms delay symptom onset.Since 85-90%of amyotrophic lateral sclerosis is sporadic,there is a strong need for identifying biomarkers that can detect this prodromal phase as motor neurons have limited capacity for regeneration.Current Food and Drug Administration-approved therapies work by slowing the degenerative process and are most effective early in the disease.Skeletal muscle,including the neuromuscular junction,manifests abnormalities at the earliest stages of the disease,before motor neuron loss,making it a promising source for identifying biomarkers of the prodromal phase.The accessibility of muscle through biopsy provides a lens into the distal motor system at earlier stages and in real time.The advent of“omics”technology has led to the identification of numerous dysregulated molecules in amyotrophic lateral sclerosis muscle,ranging from coding and non-coding RNAs to proteins and metabolites.This technology has opened the door for identifying biomarkers of disease activity and providing insight into disease mechanisms.A major challenge is correlating the myriad of dysregulated molecules with clinical or histological progression and understanding their relevance to presymptomatic phases of disease.There are two major goals of this review.The first is to summarize some of the biomarkers identified in human amyotrophic lateral sclerosis muscle that have a clinicopathological correlation with disease activity,evidence of a similar dysregulation in the SOD1G93A mouse during presymptomatic stages,and evidence of progressive change during disease progression.The second goal is to review the molecular pathways these biomarkers reflect and their potential role in mitigating or promoting disease progression,and as such,their potential as therapeutic targets in amyotrophic lateral sclerosis.展开更多
Background:Recurrent acute cholecystitis(RAC)can occur after non-surgical treatment for acute cholecystitis(AC),and can be more severe in comparison to the first episode of AC.Low skeletal muscle mass or adiposity hav...Background:Recurrent acute cholecystitis(RAC)can occur after non-surgical treatment for acute cholecystitis(AC),and can be more severe in comparison to the first episode of AC.Low skeletal muscle mass or adiposity have various effects in several diseases.We aimed to clarify the relationship between RAC and body parameters.Methods:Patients with AC who were treated at our hospital between January 2011 and March 2022 were enrolled.The psoas muscle mass and adipose tissue area at the third lumbar level were measured using computed tomography at the first episode of AC.The areas were divided by height to obtain the psoas muscle mass index(PMI)and subcutaneous/visceral adipose tissue index(SATI/VATI).According to median VATI,SATI and PMI values by sex,patients were divided into the high and low PMI groups.We performed propensity score matching to eliminate the baseline differences between the high PMI and low PMI groups and analyzed the cumulative incidence and predictors of RAC.Results:The entire cohort was divided into the high PMI(n=81)and low PMI(n=80)groups.In the propensity score-matched cohort there were 57 patients in each group.In Kaplan-Meier analysis,the low PMI group and the high VATI group had a significantly higher cumulative incidence of RAC than their counterparts(log-rank P=0.001 and 0.015,respectively).In a multivariate Cox regression analysis,the hazard ratios of low PMI and low VATI for RAC were 5.250(95%confidence interval 1.083-25.450,P=0.039)and 0.158(95%confidence interval:0.026-0.937,P=0.042),respectively.Conclusions:Low skeletal muscle mass and high visceral adiposity were independent risk factors for RAC.展开更多
Objective:To evaluate the effects of Catalpa bignonioides fruit extract on the promotion of muscle growth and muscular capacity in vitro and in vivo.Methods:Cell viability was measured using the 3-(4,5-dimethylthiazol...Objective:To evaluate the effects of Catalpa bignonioides fruit extract on the promotion of muscle growth and muscular capacity in vitro and in vivo.Methods:Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Cell proliferation was assessed using a 5-bromo-2’-deoxyuridine(BrdU)assay kit.Western blot analysis was performed to determine the protein expressions of related factors.The effects of Catalpa bignonioides extract were investigated in mice using the treadmill exhaustion test and whole-limb grip strength assay.Chemical composition analysis was performed using high-performance liquid chromatography(HPLC).Results:Catalpa bignonioides extract increased the proliferation of C2C12 mouse myoblasts by activating the Akt/mTOR signaling pathway.It also induced metabolic changes,increasing the number of mitochondria and glucose metabolism by phosphorylating adenosine monophosphate-activated protein kinase.In an in vivo study,the extract-treated mice showed improved motor abilities,such as muscular endurance and grip strength.Additionally,HPLC analysis showed that vanillic acid may be the main component of the Catalpa bignonioides extract that enhanced muscle strength.Conclusions:Catalpa bignonioides improves exercise performance through regulation of growth and metabolism in skeletal muscles,suggesting its potential as an effective natural agent for improving muscular strength.展开更多
Over the course of several decades,robust research has firmly established the significance of mitochondrial pathology as a central contributor to the onset of skeletal muscle atrophy in individuals with diabetes.Howev...Over the course of several decades,robust research has firmly established the significance of mitochondrial pathology as a central contributor to the onset of skeletal muscle atrophy in individuals with diabetes.However,the specific intricacies governing this process remain elusive.Extensive evidence highlights that individuals with diabetes regularly confront the severe consequences of skeletal muscle degradation.Deciphering the sophisticated mechanisms at the core of this pathology requires a thorough and meticulous exploration into the nuanced factors intricately associated with mitochondrial dysfunction.展开更多
Spinal cord injuries affect nearly five to ten individuals per million every year. Spinal cord injury causes damage to the nerves, muscles, and the tissue surrounding the spinal cord. Depending on the severity, spinal...Spinal cord injuries affect nearly five to ten individuals per million every year. Spinal cord injury causes damage to the nerves, muscles, and the tissue surrounding the spinal cord. Depending on the severity, spinal injuries are linked to degeneration of axons and myelin, resulting in neuronal impairment and skeletal muscle weakness and atrophy. The protection of neurons and promotion of myelin regeneration during spinal cord injury is important for recovery of function following spinal cord injury. Current treatments have little to no effect on spinal cord injury and neurogenic muscle loss. Clemastine, an Food and Drug Administration-approved antihistamine drug, reduces inflammation, protects cells, promotes remyelination, and preserves myelin integrity. Recent clinical evidence suggests that clemastine can decrease the loss of axons after spinal cord injury, stimulating the differentiation of oligodendrocyte progenitor cells into mature oligodendrocytes that are capable of myelination. While clemastine can aid not only in the remyelination and preservation of myelin sheath integrity, it also protects neurons. However, its role in neurogenic muscle loss remains unclear. This review discusses the pathophysiology of spinal cord injury, and the role of clemastine in the protection of neurons, myelin, and axons as well as attenuation of skeletal muscle loss following spinal cord injury.展开更多
Background The skeletal muscle of pigs is vulnerable to oxidative damage,resulting in growth retardation.Selenoproteins are important components of antioxidant systems for animals,which are generally regulated by diet...Background The skeletal muscle of pigs is vulnerable to oxidative damage,resulting in growth retardation.Selenoproteins are important components of antioxidant systems for animals,which are generally regulated by dietary selenium(Se)level.Here,we developed the dietary oxidative stress(DOS)-inducing pig model to investigate the protective effects of selenoproteins on DOS-induced skeletal muscle growth retardation.Results Dietary oxidative stress caused porcine skeletal muscle oxidative damage and growth retardation,which is accompanied by mitochondrial dysfunction,endoplasmic reticulum(ER)stress,and protein and lipid metabolism disorders.Supplementation with Se(0.3,0.6 or 0.9 mg Se/kg)in form of hydroxy selenomethionine(OH-SeMet)linearly increased muscular Se deposition and exhibited protective effects via regulating the expression of selenotranscriptome and key selenoproteins,which was mainly reflected in lower ROS levels and higher antioxidant capacity in skeletal muscle,and the mitigation of mitochondrial dysfunction and ER stress.What’s more,selenoproteins inhibited DOS induced protein and lipid degradation and improved protein and lipid biosynthesis via regulating AKT/mTOR/S6K1 and AMPK/SREBP-1 signalling pathways in skeletal muscle.However,several parameters such as the activity of GSH-Px and T-SOD,the protein abundance of JNK2,CLPP,SELENOS and SELENOF did not show dose-dependent changes.Notably,several key selenoproteins such as MSRB1,SELENOW,SELENOM,SELENON and SELENOS play the unique roles during this protection.Conclusions Increased expression of selenoproteins by dietary OH-SeMet could synergistically alleviate mitochondrial dysfunction and ER stress,recover protein and lipid biosynthesis,thus alleviate skeletal muscle growth retardation.Our study provides preventive measure for OS-dependent skeletal muscle retardation in livestock husbandry.展开更多
Skeletal muscle regeneration is a complex process where various cell types and cytokines are involved.Single-cell RNA-sequencing (scRNA-seq) provides the opportunity to deconvolute heterogeneous tissue into individual...Skeletal muscle regeneration is a complex process where various cell types and cytokines are involved.Single-cell RNA-sequencing (scRNA-seq) provides the opportunity to deconvolute heterogeneous tissue into individual cells based on their transcriptomic profiles.Recent scRNA-seq studies on mouse muscle regeneration have provided insights to understand the transcriptional dynamics that underpin muscle regeneration.However,a database to investigate gene expression profiling during skeletal muscle regeneration at the single-cell level is lacking.Here,we collected over 105 000 cells at 7 key regenerative time-points and non-injured muscles and developed a database,the Singlecell Skeletal Muscle Regeneration Database (SCSMRD).SCSMRD allows users to search the dynamic expression profiles of genes of interest across different cell types during the skeletal muscle regeneration process.It also provides a network to show the activity of regulons in different cell types at different time points.Pesudotime analysis showed the state changes trajectory of muscle stem cells (MuSCs) during skeletal muscle regeneration.This database is freely available at https://scsmrd.fengs-lab.com.展开更多
This review highlights some established and some more contemporary mechanisms responsible for heart failure(HF)-induced skeletal muscle wasting and weakness.We first describe the effects of HF on the relationship betw...This review highlights some established and some more contemporary mechanisms responsible for heart failure(HF)-induced skeletal muscle wasting and weakness.We first describe the effects of HF on the relationship between protein synthesis and degradation rates,which determine muscle mass,the involvement of the satellite cells for continual muscle regeneration,and changes in myofiber calcium homeostasis linked to contractile dysfunction.We then highlight key mechanistic effects of both aerobic and resistance exercise training on skeletal muscle in HF and outline its application as a beneficial treatment.Overall,HF causes multiple impairments related to autophagy,anabolic-catabolic signaling,satellite cell proliferation,and calcium homeostasis,which together promote fiber atrophy,contractile dysfunction,and impaired regeneration.Although both wasting and weakness are partly rescued by aerobic and resistance exercise training in HF,the effects of satellite cell dynamics remain poorly explored.展开更多
Insulin resistance is a hallmark of type-2 diabetes(T2D)pathogenesis.Because skeletal muscle(SkM)is the major tissue for insulin-mediated glucose disposal,insulin resistance in SkM is considered a major risk factor fo...Insulin resistance is a hallmark of type-2 diabetes(T2D)pathogenesis.Because skeletal muscle(SkM)is the major tissue for insulin-mediated glucose disposal,insulin resistance in SkM is considered a major risk factor for developing T2D.Thus,the identifi cation of compounds that enhance the ability of SkM to take up glucose is a promising strategy for preventing T2D.Our previous work showed that kaempferol,a fl avonol present in many foods,improves insulin sensitivity in obese mice,however,the mechanism underlying this beneficial action remains unclear.Here,we show that kaempferol directly stimulates glucose uptake and prevents lipotoxicity-impaired glucose uptake in primary human SkM.Kaempferol stimulates Akt phosphorylation in a time-dependent manner in human SkM cells.The effect of kaempferol on glucose uptake was blunted by inhibition of glucose transporter 4,phosphoinositide 3-kinase(PI3K),or AMPK.In addition,kaempferol induced AMPK phosphorylation,and inhibition of AMPK prevented kaempferol-stimulated Akt phosphorylation.In vivo,kaempferol administration induced rapid glucose disposal accompanied with increased Akt and AMPK phosphorylation in SkM tissue of the mice.Taken together,these fi ndings suggest that kaempferol stimulates glucose uptake in SkM via an AMPK/Akt dependent mechanism,and it may be a viable therapeutic agent for insulin resistance.展开更多
Objective:The present study was conducted to demonstrate the age-dependent changes in skeletal muscle mass and visceral fat area in a population of Chinese adults aged 30-92 years old.Methods:A total of 6669 healthy C...Objective:The present study was conducted to demonstrate the age-dependent changes in skeletal muscle mass and visceral fat area in a population of Chinese adults aged 30-92 years old.Methods:A total of 6669 healthy Chinese men and 4494 healthy Chinese women aged 30-92 years old were assessed for their skeletal muscle mass and visceral fat area.Results:The results showed age-dependent decreases in the total skeletal muscle mass indexes in both men and women aged 40-92 years old as well as age-dependent increases in the visceral fat area in men aged 30-92 years old and in women aged 30-80 years old.Multivariate regression models showed that the total skeletal muscle mass index was positively associated with the body mass index and negatively associated with the age and visceral fat area in both sexes.Conclusion:The loss of skeletal muscle mass becomes obvious at approximately 50 years of age,and the visceral fat area commences to increase at approximately 40 years of age in this Chinese population.展开更多
As a key coordinator of metabolism,AMP-activated protein kinase(AMPK)is vitally involved in skeletal muscle maintenance.AMPK exerts its cellular effects through its function as a serine/threonine protein kinase by reg...As a key coordinator of metabolism,AMP-activated protein kinase(AMPK)is vitally involved in skeletal muscle maintenance.AMPK exerts its cellular effects through its function as a serine/threonine protein kinase by regulating many downstream targets and plays important roles in the development and growth of skeletal muscle.AMPK is activated by phosphorylation and exerts its function as a kinase in many processes,including synthesis and degradation of proteins,mitochondrial biogenesis,glucose uptake,and fatty acid and cholesterol metabolism.Skeletal muscle atrophy is a result of various diseases or disorders and is characterized by a decrease in muscle mass.The pathogenesis and therapeutic strategies of skeletal muscle atrophy are still under investigation.In this review,we discuss the role of AMPK in skeletal muscle metabolism and atrophy.We also discuss targeting AMPK for skeletal muscle treatment,including exercise,AMPK activators including 5-amino-4-imidazolecarboxamide ribonucleoside and metformin,and low-level lasers.These studies show the important roles of AMPK in regulating muscle metabolism and function;thus,the treatment of skeletal muscle atrophy needs to take into account the roles of AMPK.展开更多
[Objectives]This study was conducted to investigate the effects of Astragalus membranaceus in different groups on energy metabolism and CNTF protein expression in skeletal muscle of exercise-induced fatigue rats.[Meth...[Objectives]This study was conducted to investigate the effects of Astragalus membranaceus in different groups on energy metabolism and CNTF protein expression in skeletal muscle of exercise-induced fatigue rats.[Methods]Thirty-five clean male SD rats were randomly divided into a normal group,and low-,meddle-and high-dose groups of A.membranaceus aqueous solution,with 7 rats in each group.The low-dose,medium-dose and high-dose groups were given by gavage at 0.65,1.3 and 2.6 g/kg,respectively,while the normal group and the model group were given normal food and water.The weight of rats was observed.The contents of serum urea,lactate,muscle glycogen,liver glycogen and CNTF expression were detected.[Results]After modeling,compared with the normal group,the serum lactate and urea contents of rats in the model group significantly increased(P<0.01),while the muscle glycogen content(P<0.01)and liver glycogen content(P<0.05)of the skeletal muscle significantly decreased.Compared with the model group,the low-,meddle-and high-dose groups of A.membranaceus significantly reduced the levels of lactate and urea in serum(P<0.01),while the levels of muscle glycogen and liver glycogen in the skeletal muscle significantly increased(P<0.01,P<0.05).[Conclusions]This study provides a good research foundation for the treatment of exercise-induced fatigue using traditional Chinese herb A.membranaceus in modern clinical practice.展开更多
The growth and development of skeletal muscle also determine the meat production of yak, ultimately affecting the economic benefits. Hence, improving growth performance is a top priority in the yak industry. Skeletal ...The growth and development of skeletal muscle also determine the meat production of yak, ultimately affecting the economic benefits. Hence, improving growth performance is a top priority in the yak industry. Skeletal muscle development is a complex process involving the regulation of several genes, including microRNAs(miRNAs). However,the transcription of miRNAs in yak skeletal muscle during prenatal to postnatal stages is unknown. We used small RNA sequencing(small RNA-Seq) to determine the global miRNAs of longissimus dorsi muscle from yak(the samples were collected from three fetuses and three adults). Totally 264 differently expressed miRNAs(|log2(fold change)|>1and P-value≤0.05) were detected between the two groups. Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) analysis showed that differently expressed miRNAs-targeted genes participated in pathways associated with muscle development, such as MAPK, PI3K-Akt, and Hippo signaling pathways, etc. MiR-652, which was up-regulated in the fetal group, was transfected into C2C12 myoblasts to examine its role. miR-652 promoted(P≤0.05)proliferation and differentiation, but inhibited(P≤0.001) apoptosis at early period. Furthermore, miR-652 reduced(P≤0.001) the proportion of C2C12 myoblasts in the G1 phase while increasing(P≤0.01) the proportion of cells in the S and G2 phases. Dual-luciferase reporter assays indicated that ISL1 served as a target of miR-652. In general, these findings expand our understanding of yak skeletal muscle miRNAs, and suggested that miR-652 probably regulated myogenesis by regulating ISL1.展开更多
The Boer goat is one of the top meat breeds in modern animal husbandry and has attracted widespread attention for its unique growth performance.However,the genetic basis of muscle development in the Boer goat remains ...The Boer goat is one of the top meat breeds in modern animal husbandry and has attracted widespread attention for its unique growth performance.However,the genetic basis of muscle development in the Boer goat remains obscure.In this study,we identified specific structural variants in the Boer goat based on genome-wide selection signals and analyzed the basis of the molecular heredity of related candidate genes in muscle development.A total of9 959 autosomal copy number variations(CNVs) were identified through selection signal analysis in 127 goat genomes.Specifically,we confirmed that the highest signal CNV(HSV) was a chromosomal arrangement containing an approximately 1.11 Mb(CHIR17:60062304-61171840 bp) duplicated fragment inserted in reverse orientation and a 5 362 bp deleted region(CHIR17:60145940-60151302 bp) with overlapping genes(e.g.,ARHGAP10,NR3C2,EDNRA,PRMT9,and TMEM184C).The homozygous duplicated HSV genotype(+/+) was found in 96% of Boer goats but was not detected in Eurasian goats and was only detected in 4% of indigenous African goats.The expression network of three candidate genes(ARHGAP10,NR3C2,and EDNRA)regulating dose transcription was constructed by RNA sequencing.Results indicated that these genes were involved in the proliferation and differentiation of skeletal muscle satellite cells(SMSCs) and their overexpression significantly increased the expression of SAA3.The HSV of the Boer goat contributed to superior skeletal muscle growth via the dose effects of overlapping genes.展开更多
BACKGROUND Previous reports have focused on muscle mass as a prognostic factor in esophageal cancer.AIM To investigate how preoperative body type influences the prognosis of patients with esophageal squamous cell carc...BACKGROUND Previous reports have focused on muscle mass as a prognostic factor in esophageal cancer.AIM To investigate how preoperative body type influences the prognosis of patients with esophageal squamous cell carcinoma who underwent neoadjuvant chemotherapy(NAC)and surgery.METHODS The subjects were 131 patients with clinical stage Ⅱ/Ⅲ esophageal squamous cell carcinoma who underwent subtotal esophagectomy after NAC.Skeletal muscle mass and quality were calculated based on computed tomography images prior to NAC,and their statistical association with long-term outcomes was examined retrospectively in this case-control study.RESULTS The disease-free survival rates in the low psoas muscle mass index(PMI)group vs the high PMI group were 41.3%vs 58.8%(P=0.036),respectively.In the high intramuscular adipose tissue content(IMAC)group vs the low IMAC group,the disease-free survival rates were 28.5%vs 57.6%(P=0.021),respectively.The overall survival(OS)rates for the low PMI group vs the high PMI group were 41.3%vs 64.5%(P=0.008),respectively,and for the high IMAC group vs the low IMAC group,they were 29.9%vs 61.9%(P=0.024),respectively.Analysis of the OS rate revealed significant differences in patients aged 60 years or older(P=0.018),those with pT3 or above disease(P=0.021),or those with lymph node metastasis(P=0.006),aside from PMI and IMAC.Multivariate analysis demonstrated that pT3 or above hazard ratio(HR):1.966,95%confidence interval(CI):1.089-3.550,(P=0.025),lymph node metastasis(HR:2.154,95%CI:1.118-4.148,P=0.022),low PMI(HR:2.266,95%CI:1.282-4.006,P=0.005),and high IMAC(HR:2.089,95%CI:1.036-4.214,P=0.022)were significant prognostic factors for esophageal squamous cell carcinoma.CONCLUSIONSkeletal muscle mass and quality before NAC in patients with esophageal squamous cellcarcinoma are significant prognostic factors for postoperative OS.展开更多
[Objectives]miRNAs play an important role in the proliferation and differentiation of different myoblasts.This study was conducted to elucidate the complex genetic mechanisms that affect the meat production performanc...[Objectives]miRNAs play an important role in the proliferation and differentiation of different myoblasts.This study was conducted to elucidate the complex genetic mechanisms that affect the meat production performance of Sichuan white rabbits and reveal the regulatory role of miRNAs in their muscle growth and meat quality formation.[Methods]Three constructed skeletal muscle libraries of Sichuan white rabbits aged six months were sequenced by the solexa technology to identify known miRNAs,predict new miRNAs and construct an expression profile of muscle miRNAs.[Results]A total of 511 known miRNAs and 42 miRNAs were detected in 34089472 pure sequences,and the proportion of miRNAs with a length of 22 nt was the highest.The number of known miRNA sequences accounted for 71.38%of pure sequences,which was much higher than the proportion of other types of RNAs.The proportion of sequences from exons was 0.38%,indicating a low degree of mRNA degradation in the samples.Base U had the highest proportion at the first position,and the bases with the highest proportions at positions 8 and 10 were U and A,respectively.Muscle-specific miRNAs(miR-1,miR-133,and miR-206)ranked in the top 10 in terms of expression level.The number and expression levels of new miRNAs were lower than those of known miRNAs.The length distribution,base bias at different positions and expression profile characteristics of miRNAs might be related to the biological function of miRNAs in regulating muscle proliferation and differentiation and the action mechanisms with target genes.[Conclusions]The identification and expression of miRNAs in muscle tissues of Sichuan white rabbits will help to understand the complex molecular mechanisms of meat production performance and provide a theoretical basis for the functional research of miRNAs in meat rabbits.展开更多
The depressed protein synthetic response,a phenomenon termed anabolic resistance,has been shown to be involved in muscle wasting induced by cancer cachexia.Moreover,a positive relationship between the protein syntheti...The depressed protein synthetic response,a phenomenon termed anabolic resistance,has been shown to be involved in muscle wasting induced by cancer cachexia.Moreover,a positive relationship between the protein synthetic rate and intracellular glutamine(GLN)concentration has been found in skeletal muscles.This study investigated the effects of neuromuscular electrical stimulation(ES)and GLN administration on muscle wasting and GLN metabolism in colon-26(C-26)tumor-bearing mice.CD2F1 mice were divided into 8 groups:control(CNT),CNT+ES,CNT+GLN,CNT+ES+GLN,C-26,C-26+ES,C-26+GLN,C-26+ES+GLN.Cancer cachexia was induced by subcutaneous injection of C-26 cells and developed for four weeks.ES was performed on the left plantar flexor muscles every other day,and GLN(1 g/kg)was administered daily intraperitoneally starting one day after the C-26 injection.Tumor-free body mass and fast-twitch gastrocnemius(Gas)muscle weight were lower in the C-26 group than in the CNT group(-19%and-17%,respectively).Neither ES training nor GLN administration,alone or in combination,ameliorated the loss of Gas muscle weight in the C-26 mice.However,ES training in combination with GLN administration inhibited the increased expression of GLN synthetase(GS)in the C-26 muscles.Thus,it is likely that GLN plays a critical role in muscle protein metabolism and,therefore,can be targeted as a tentative treatment of cancer cachexia.展开更多
BACKGROUND:In the repair of nerve defects,collapse of the venous wall,as a result of vein grafting alone,could impede nerve regeneration.Therefore,vein lumens filled with muscle and nerve segments have been used to br...BACKGROUND:In the repair of nerve defects,collapse of the venous wall,as a result of vein grafting alone,could impede nerve regeneration.Therefore,vein lumens filled with muscle and nerve segments have been used to bridge nerve defects.OBJECTIVE:To compare the effects of autogenous,inside-out,vein-skeletal,muscle-combined grafting versus standard,vein-skeletal,muscle-combined grafting for the repair of facial nerve defects.DESIGN,TIME AND SETTING:A randomized,controlled,neuroanatomical,animal study was performed at the Animal Experimental Center and Laboratories of the Capital Medical University Xuanwu Hospital and the Peking Union Medical College Hospital from September 2007 to October 2008.MATERIALS:A total of 10 healthy,male,New Zealand rabbits,aged 6 months,were randomly assigned to inside-out,vein-skeletal,muscle-combined grafting and standard,vein-skeletal,muscle-combined grafting groups,with 5 rabbits in each group.METHODS:A 20-mm gap in the buccal branch of the right facial nerve was made in each animal,which was respectively repaired with inside-out,vein-skeletal,muscle-combined grafts or standard vein-skeletal muscle-combined grafts.MAIN OUTCOME MEASURES:At 6 months after implantation,evoked maximal compound muscle action potentials were recorded on bilateral facial nerves using electromyogram.Myelinated nerve fibers of the regenerating nerves were quantified using myelin sheath osmic acid staining.RESULTS:There was no significant difference between the groups in terms of ratios of bilateral amplitude and latency of compound muscle action potential(P>0.05).Moreover,morphology of regenerating nerves and quantity of myelinated nerve fibers were similar between the groups(P> 0.05).CONCLUTION:Compared with standard vein grafting,the inside-out vein grafting did not significantly improve nerve regeneration.Therefore,it is not necessary to utilize inside-out vein grafting for the repair of nerve defects,in particular with the combined use of autogenous vein and skeletal muscle grafts.展开更多
Pig is an important economic animal in China. Improving meat quality and meat productivity is a long time issue in animal genetic breeding. Micro RNAs(mi RNAs) are short non-coding RNAs that participate in various bio...Pig is an important economic animal in China. Improving meat quality and meat productivity is a long time issue in animal genetic breeding. Micro RNAs(mi RNAs) are short non-coding RNAs that participate in various biological processes, such as muscle development and embryogenesis. mi R-22 differentially expresses in embryonic and adult skeletal muscle. However, the underlying mechanism is unclear. In this study, we investigated mi R-22 function in proliferation and differentiation of porcine satellite cells(PSCs) in skeletal muscle. Our data show that mi R-22 expressed in both proliferation and differentiated PSCs and is significantly upregulated(P<0.05) during differentiation. After treated with the mi R-22 inhibitor, PSCs proliferation was significantly increased(P<0.05), as indicated by the up-regulation(P<0.01) of cyclin D1(CCND1), cyclin B1(CCNB1) and down-regulation(P<0.05) of P21. Conversely, over-expression of mi R-22 resulted in opposite results. Differentiation of PSCs was significantly suppressed(P<0.05), evidenced by two major myogenic markers: myogenin(Myo G) and myosin heavy chain(My HC), after transfecting the PSCs with mi R-22 inhibitor. Opposite results were demonstrated in the other way around by transfection with mi R-22 mimics. In conclusion, the data from this study indicated that mi R-22 inhibited the PSCs proliferation but promoted their differentiation.展开更多
基金supported by NIH Grants R01NS092651 and R21NS111275-01the Department of Veterans Affairs,BX001148 and BX005899(to PHK)。
文摘Amyotrophic lateral sclerosis is a fatal multisystemic neurodegenerative disease with motor neurons being a primary target.Although progressive weakness is a hallmark feature of amyotrophic lateral sclerosis,there is considerable heterogeneity,including clinical presentation,progression,and the underlying triggers for disease initiation.Based on longitudinal studies with families harboring amyotrophic lateral sclerosis-associated gene mutations,it has become apparent that overt disease is preceded by a prodromal phase,possibly in years,where compensatory mechanisms delay symptom onset.Since 85-90%of amyotrophic lateral sclerosis is sporadic,there is a strong need for identifying biomarkers that can detect this prodromal phase as motor neurons have limited capacity for regeneration.Current Food and Drug Administration-approved therapies work by slowing the degenerative process and are most effective early in the disease.Skeletal muscle,including the neuromuscular junction,manifests abnormalities at the earliest stages of the disease,before motor neuron loss,making it a promising source for identifying biomarkers of the prodromal phase.The accessibility of muscle through biopsy provides a lens into the distal motor system at earlier stages and in real time.The advent of“omics”technology has led to the identification of numerous dysregulated molecules in amyotrophic lateral sclerosis muscle,ranging from coding and non-coding RNAs to proteins and metabolites.This technology has opened the door for identifying biomarkers of disease activity and providing insight into disease mechanisms.A major challenge is correlating the myriad of dysregulated molecules with clinical or histological progression and understanding their relevance to presymptomatic phases of disease.There are two major goals of this review.The first is to summarize some of the biomarkers identified in human amyotrophic lateral sclerosis muscle that have a clinicopathological correlation with disease activity,evidence of a similar dysregulation in the SOD1G93A mouse during presymptomatic stages,and evidence of progressive change during disease progression.The second goal is to review the molecular pathways these biomarkers reflect and their potential role in mitigating or promoting disease progression,and as such,their potential as therapeutic targets in amyotrophic lateral sclerosis.
基金This study was approved by the Ethics Committee of Kyushu Rosai Hospital Moji Medical Center(No:04-01,date of approval:June 2,2022).This study was conducted in compliance with the principles of the Declaration of Helsinki.
文摘Background:Recurrent acute cholecystitis(RAC)can occur after non-surgical treatment for acute cholecystitis(AC),and can be more severe in comparison to the first episode of AC.Low skeletal muscle mass or adiposity have various effects in several diseases.We aimed to clarify the relationship between RAC and body parameters.Methods:Patients with AC who were treated at our hospital between January 2011 and March 2022 were enrolled.The psoas muscle mass and adipose tissue area at the third lumbar level were measured using computed tomography at the first episode of AC.The areas were divided by height to obtain the psoas muscle mass index(PMI)and subcutaneous/visceral adipose tissue index(SATI/VATI).According to median VATI,SATI and PMI values by sex,patients were divided into the high and low PMI groups.We performed propensity score matching to eliminate the baseline differences between the high PMI and low PMI groups and analyzed the cumulative incidence and predictors of RAC.Results:The entire cohort was divided into the high PMI(n=81)and low PMI(n=80)groups.In the propensity score-matched cohort there were 57 patients in each group.In Kaplan-Meier analysis,the low PMI group and the high VATI group had a significantly higher cumulative incidence of RAC than their counterparts(log-rank P=0.001 and 0.015,respectively).In a multivariate Cox regression analysis,the hazard ratios of low PMI and low VATI for RAC were 5.250(95%confidence interval 1.083-25.450,P=0.039)and 0.158(95%confidence interval:0.026-0.937,P=0.042),respectively.Conclusions:Low skeletal muscle mass and high visceral adiposity were independent risk factors for RAC.
基金supported by Korea Environment Industry&Technology Institute through Project to make multi-ministerial national biological research resources more advanced Project,funded by Korea Ministry of Environment(grant number RS-2023-00230403).
文摘Objective:To evaluate the effects of Catalpa bignonioides fruit extract on the promotion of muscle growth and muscular capacity in vitro and in vivo.Methods:Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Cell proliferation was assessed using a 5-bromo-2’-deoxyuridine(BrdU)assay kit.Western blot analysis was performed to determine the protein expressions of related factors.The effects of Catalpa bignonioides extract were investigated in mice using the treadmill exhaustion test and whole-limb grip strength assay.Chemical composition analysis was performed using high-performance liquid chromatography(HPLC).Results:Catalpa bignonioides extract increased the proliferation of C2C12 mouse myoblasts by activating the Akt/mTOR signaling pathway.It also induced metabolic changes,increasing the number of mitochondria and glucose metabolism by phosphorylating adenosine monophosphate-activated protein kinase.In an in vivo study,the extract-treated mice showed improved motor abilities,such as muscular endurance and grip strength.Additionally,HPLC analysis showed that vanillic acid may be the main component of the Catalpa bignonioides extract that enhanced muscle strength.Conclusions:Catalpa bignonioides improves exercise performance through regulation of growth and metabolism in skeletal muscles,suggesting its potential as an effective natural agent for improving muscular strength.
基金the Foundation of State Key Laboratory of Component-based Chinese Medicine,No.CBCM2023107National Natural Science Foundation of China,No.81901853Specially Funded Scientific Research Project of the Fourth Affiliated Hospital of Harbin Medical University,No.HYDSYTB202126.
文摘Over the course of several decades,robust research has firmly established the significance of mitochondrial pathology as a central contributor to the onset of skeletal muscle atrophy in individuals with diabetes.However,the specific intricacies governing this process remain elusive.Extensive evidence highlights that individuals with diabetes regularly confront the severe consequences of skeletal muscle degradation.Deciphering the sophisticated mechanisms at the core of this pathology requires a thorough and meticulous exploration into the nuanced factors intricately associated with mitochondrial dysfunction.
基金supported in part by funding from the Veterans Administration (1IOBX001262, 1I01 BX004269)South Carolina State Spinal Cord Injury Research Fund (SCIRF-2015P-01, SCIRF-2015P-04, SCIRF-2015-I-01, SCIRF#2016 I-03, and SCIRF#2018 I-01)(to AH)+1 种基金supported in part by funding from the National Institutes of Health (1R21NS118393-01)(to AH)a Research Career Scientist award (#IK6BX005964) from the Department of veterans Affairs。
文摘Spinal cord injuries affect nearly five to ten individuals per million every year. Spinal cord injury causes damage to the nerves, muscles, and the tissue surrounding the spinal cord. Depending on the severity, spinal injuries are linked to degeneration of axons and myelin, resulting in neuronal impairment and skeletal muscle weakness and atrophy. The protection of neurons and promotion of myelin regeneration during spinal cord injury is important for recovery of function following spinal cord injury. Current treatments have little to no effect on spinal cord injury and neurogenic muscle loss. Clemastine, an Food and Drug Administration-approved antihistamine drug, reduces inflammation, protects cells, promotes remyelination, and preserves myelin integrity. Recent clinical evidence suggests that clemastine can decrease the loss of axons after spinal cord injury, stimulating the differentiation of oligodendrocyte progenitor cells into mature oligodendrocytes that are capable of myelination. While clemastine can aid not only in the remyelination and preservation of myelin sheath integrity, it also protects neurons. However, its role in neurogenic muscle loss remains unclear. This review discusses the pathophysiology of spinal cord injury, and the role of clemastine in the protection of neurons, myelin, and axons as well as attenuation of skeletal muscle loss following spinal cord injury.
基金supported by the National Natural Science Foundation of China(No.31772643 and 31272468)the Special Research Funding for Discipline Construction in Sichuan Agricultural University(No.03570126)Adisseo France(18SES533).
文摘Background The skeletal muscle of pigs is vulnerable to oxidative damage,resulting in growth retardation.Selenoproteins are important components of antioxidant systems for animals,which are generally regulated by dietary selenium(Se)level.Here,we developed the dietary oxidative stress(DOS)-inducing pig model to investigate the protective effects of selenoproteins on DOS-induced skeletal muscle growth retardation.Results Dietary oxidative stress caused porcine skeletal muscle oxidative damage and growth retardation,which is accompanied by mitochondrial dysfunction,endoplasmic reticulum(ER)stress,and protein and lipid metabolism disorders.Supplementation with Se(0.3,0.6 or 0.9 mg Se/kg)in form of hydroxy selenomethionine(OH-SeMet)linearly increased muscular Se deposition and exhibited protective effects via regulating the expression of selenotranscriptome and key selenoproteins,which was mainly reflected in lower ROS levels and higher antioxidant capacity in skeletal muscle,and the mitigation of mitochondrial dysfunction and ER stress.What’s more,selenoproteins inhibited DOS induced protein and lipid degradation and improved protein and lipid biosynthesis via regulating AKT/mTOR/S6K1 and AMPK/SREBP-1 signalling pathways in skeletal muscle.However,several parameters such as the activity of GSH-Px and T-SOD,the protein abundance of JNK2,CLPP,SELENOS and SELENOF did not show dose-dependent changes.Notably,several key selenoproteins such as MSRB1,SELENOW,SELENOM,SELENON and SELENOS play the unique roles during this protection.Conclusions Increased expression of selenoproteins by dietary OH-SeMet could synergistically alleviate mitochondrial dysfunction and ER stress,recover protein and lipid biosynthesis,thus alleviate skeletal muscle growth retardation.Our study provides preventive measure for OS-dependent skeletal muscle retardation in livestock husbandry.
基金supported by the National Natural Science Foundation of China(31972539 and 32102513)the Science,Technology,and Innovation Commission of Shenzhen Municipality,China(JCYJ20180306173644635)+2 种基金the Fundamental Research Funds for the Central Universities,China(G2020KY05109)the Natural Science Basic Research Program of Shaanxi Province,China(2022JQ-644)the Basic Research Programs of Taicang,China(TC2021JC14)。
文摘Skeletal muscle regeneration is a complex process where various cell types and cytokines are involved.Single-cell RNA-sequencing (scRNA-seq) provides the opportunity to deconvolute heterogeneous tissue into individual cells based on their transcriptomic profiles.Recent scRNA-seq studies on mouse muscle regeneration have provided insights to understand the transcriptional dynamics that underpin muscle regeneration.However,a database to investigate gene expression profiling during skeletal muscle regeneration at the single-cell level is lacking.Here,we collected over 105 000 cells at 7 key regenerative time-points and non-injured muscles and developed a database,the Singlecell Skeletal Muscle Regeneration Database (SCSMRD).SCSMRD allows users to search the dynamic expression profiles of genes of interest across different cell types during the skeletal muscle regeneration process.It also provides a network to show the activity of regulons in different cell types at different time points.Pesudotime analysis showed the state changes trajectory of muscle stem cells (MuSCs) during skeletal muscle regeneration.This database is freely available at https://scsmrd.fengs-lab.com.
基金supported by Heart Research UK(Grant number 119191)British Heart Foundation(Grant number 124055)。
文摘This review highlights some established and some more contemporary mechanisms responsible for heart failure(HF)-induced skeletal muscle wasting and weakness.We first describe the effects of HF on the relationship between protein synthesis and degradation rates,which determine muscle mass,the involvement of the satellite cells for continual muscle regeneration,and changes in myofiber calcium homeostasis linked to contractile dysfunction.We then highlight key mechanistic effects of both aerobic and resistance exercise training on skeletal muscle in HF and outline its application as a beneficial treatment.Overall,HF causes multiple impairments related to autophagy,anabolic-catabolic signaling,satellite cell proliferation,and calcium homeostasis,which together promote fiber atrophy,contractile dysfunction,and impaired regeneration.Although both wasting and weakness are partly rescued by aerobic and resistance exercise training in HF,the effects of satellite cell dynamics remain poorly explored.
基金partially supported by grants from Diabetes Action Research and Education Foundation。
文摘Insulin resistance is a hallmark of type-2 diabetes(T2D)pathogenesis.Because skeletal muscle(SkM)is the major tissue for insulin-mediated glucose disposal,insulin resistance in SkM is considered a major risk factor for developing T2D.Thus,the identifi cation of compounds that enhance the ability of SkM to take up glucose is a promising strategy for preventing T2D.Our previous work showed that kaempferol,a fl avonol present in many foods,improves insulin sensitivity in obese mice,however,the mechanism underlying this beneficial action remains unclear.Here,we show that kaempferol directly stimulates glucose uptake and prevents lipotoxicity-impaired glucose uptake in primary human SkM.Kaempferol stimulates Akt phosphorylation in a time-dependent manner in human SkM cells.The effect of kaempferol on glucose uptake was blunted by inhibition of glucose transporter 4,phosphoinositide 3-kinase(PI3K),or AMPK.In addition,kaempferol induced AMPK phosphorylation,and inhibition of AMPK prevented kaempferol-stimulated Akt phosphorylation.In vivo,kaempferol administration induced rapid glucose disposal accompanied with increased Akt and AMPK phosphorylation in SkM tissue of the mice.Taken together,these fi ndings suggest that kaempferol stimulates glucose uptake in SkM via an AMPK/Akt dependent mechanism,and it may be a viable therapeutic agent for insulin resistance.
基金supported by the Basic Public Welfare Research Program of Zhejiang Province(No.LGF20H020009)a Taizhou Science and Technology Plan Project(No.22ywb105)。
文摘Objective:The present study was conducted to demonstrate the age-dependent changes in skeletal muscle mass and visceral fat area in a population of Chinese adults aged 30-92 years old.Methods:A total of 6669 healthy Chinese men and 4494 healthy Chinese women aged 30-92 years old were assessed for their skeletal muscle mass and visceral fat area.Results:The results showed age-dependent decreases in the total skeletal muscle mass indexes in both men and women aged 40-92 years old as well as age-dependent increases in the visceral fat area in men aged 30-92 years old and in women aged 30-80 years old.Multivariate regression models showed that the total skeletal muscle mass index was positively associated with the body mass index and negatively associated with the age and visceral fat area in both sexes.Conclusion:The loss of skeletal muscle mass becomes obvious at approximately 50 years of age,and the visceral fat area commences to increase at approximately 40 years of age in this Chinese population.
基金supported by the Natural Science Foundation of China(Grant No.32071517,82072106)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2020JM-100).
文摘As a key coordinator of metabolism,AMP-activated protein kinase(AMPK)is vitally involved in skeletal muscle maintenance.AMPK exerts its cellular effects through its function as a serine/threonine protein kinase by regulating many downstream targets and plays important roles in the development and growth of skeletal muscle.AMPK is activated by phosphorylation and exerts its function as a kinase in many processes,including synthesis and degradation of proteins,mitochondrial biogenesis,glucose uptake,and fatty acid and cholesterol metabolism.Skeletal muscle atrophy is a result of various diseases or disorders and is characterized by a decrease in muscle mass.The pathogenesis and therapeutic strategies of skeletal muscle atrophy are still under investigation.In this review,we discuss the role of AMPK in skeletal muscle metabolism and atrophy.We also discuss targeting AMPK for skeletal muscle treatment,including exercise,AMPK activators including 5-amino-4-imidazolecarboxamide ribonucleoside and metformin,and low-level lasers.These studies show the important roles of AMPK in regulating muscle metabolism and function;thus,the treatment of skeletal muscle atrophy needs to take into account the roles of AMPK.
基金Supported by Undergraduate Innovation and Entrepreneurship Training Program of Guizhou University of Traditional Chinese Medicine(GZYDCHZ[2019]42)National Key R&D Plan(2019YFC1712500)Guizhou Provincial Science and Technology Planning Project(QKHHBZ[2020]3003).
文摘[Objectives]This study was conducted to investigate the effects of Astragalus membranaceus in different groups on energy metabolism and CNTF protein expression in skeletal muscle of exercise-induced fatigue rats.[Methods]Thirty-five clean male SD rats were randomly divided into a normal group,and low-,meddle-and high-dose groups of A.membranaceus aqueous solution,with 7 rats in each group.The low-dose,medium-dose and high-dose groups were given by gavage at 0.65,1.3 and 2.6 g/kg,respectively,while the normal group and the model group were given normal food and water.The weight of rats was observed.The contents of serum urea,lactate,muscle glycogen,liver glycogen and CNTF expression were detected.[Results]After modeling,compared with the normal group,the serum lactate and urea contents of rats in the model group significantly increased(P<0.01),while the muscle glycogen content(P<0.01)and liver glycogen content(P<0.05)of the skeletal muscle significantly decreased.Compared with the model group,the low-,meddle-and high-dose groups of A.membranaceus significantly reduced the levels of lactate and urea in serum(P<0.01),while the levels of muscle glycogen and liver glycogen in the skeletal muscle significantly increased(P<0.01,P<0.05).[Conclusions]This study provides a good research foundation for the treatment of exercise-induced fatigue using traditional Chinese herb A.membranaceus in modern clinical practice.
基金supported by the Agricultural Science and Technology Innovation Program, CAAS (25-LZIHPS-01)the China Agriculture Research System of MOF and MARA (CARS-37)the National Natural Science Foundation of China (32102500)。
文摘The growth and development of skeletal muscle also determine the meat production of yak, ultimately affecting the economic benefits. Hence, improving growth performance is a top priority in the yak industry. Skeletal muscle development is a complex process involving the regulation of several genes, including microRNAs(miRNAs). However,the transcription of miRNAs in yak skeletal muscle during prenatal to postnatal stages is unknown. We used small RNA sequencing(small RNA-Seq) to determine the global miRNAs of longissimus dorsi muscle from yak(the samples were collected from three fetuses and three adults). Totally 264 differently expressed miRNAs(|log2(fold change)|>1and P-value≤0.05) were detected between the two groups. Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) analysis showed that differently expressed miRNAs-targeted genes participated in pathways associated with muscle development, such as MAPK, PI3K-Akt, and Hippo signaling pathways, etc. MiR-652, which was up-regulated in the fetal group, was transfected into C2C12 myoblasts to examine its role. miR-652 promoted(P≤0.05)proliferation and differentiation, but inhibited(P≤0.001) apoptosis at early period. Furthermore, miR-652 reduced(P≤0.001) the proportion of C2C12 myoblasts in the G1 phase while increasing(P≤0.01) the proportion of cells in the S and G2 phases. Dual-luciferase reporter assays indicated that ISL1 served as a target of miR-652. In general, these findings expand our understanding of yak skeletal muscle miRNAs, and suggested that miR-652 probably regulated myogenesis by regulating ISL1.
基金supported by the National Natural Science Foundation of China (32272834)。
文摘The Boer goat is one of the top meat breeds in modern animal husbandry and has attracted widespread attention for its unique growth performance.However,the genetic basis of muscle development in the Boer goat remains obscure.In this study,we identified specific structural variants in the Boer goat based on genome-wide selection signals and analyzed the basis of the molecular heredity of related candidate genes in muscle development.A total of9 959 autosomal copy number variations(CNVs) were identified through selection signal analysis in 127 goat genomes.Specifically,we confirmed that the highest signal CNV(HSV) was a chromosomal arrangement containing an approximately 1.11 Mb(CHIR17:60062304-61171840 bp) duplicated fragment inserted in reverse orientation and a 5 362 bp deleted region(CHIR17:60145940-60151302 bp) with overlapping genes(e.g.,ARHGAP10,NR3C2,EDNRA,PRMT9,and TMEM184C).The homozygous duplicated HSV genotype(+/+) was found in 96% of Boer goats but was not detected in Eurasian goats and was only detected in 4% of indigenous African goats.The expression network of three candidate genes(ARHGAP10,NR3C2,and EDNRA)regulating dose transcription was constructed by RNA sequencing.Results indicated that these genes were involved in the proliferation and differentiation of skeletal muscle satellite cells(SMSCs) and their overexpression significantly increased the expression of SAA3.The HSV of the Boer goat contributed to superior skeletal muscle growth via the dose effects of overlapping genes.
文摘BACKGROUND Previous reports have focused on muscle mass as a prognostic factor in esophageal cancer.AIM To investigate how preoperative body type influences the prognosis of patients with esophageal squamous cell carcinoma who underwent neoadjuvant chemotherapy(NAC)and surgery.METHODS The subjects were 131 patients with clinical stage Ⅱ/Ⅲ esophageal squamous cell carcinoma who underwent subtotal esophagectomy after NAC.Skeletal muscle mass and quality were calculated based on computed tomography images prior to NAC,and their statistical association with long-term outcomes was examined retrospectively in this case-control study.RESULTS The disease-free survival rates in the low psoas muscle mass index(PMI)group vs the high PMI group were 41.3%vs 58.8%(P=0.036),respectively.In the high intramuscular adipose tissue content(IMAC)group vs the low IMAC group,the disease-free survival rates were 28.5%vs 57.6%(P=0.021),respectively.The overall survival(OS)rates for the low PMI group vs the high PMI group were 41.3%vs 64.5%(P=0.008),respectively,and for the high IMAC group vs the low IMAC group,they were 29.9%vs 61.9%(P=0.024),respectively.Analysis of the OS rate revealed significant differences in patients aged 60 years or older(P=0.018),those with pT3 or above disease(P=0.021),or those with lymph node metastasis(P=0.006),aside from PMI and IMAC.Multivariate analysis demonstrated that pT3 or above hazard ratio(HR):1.966,95%confidence interval(CI):1.089-3.550,(P=0.025),lymph node metastasis(HR:2.154,95%CI:1.118-4.148,P=0.022),low PMI(HR:2.266,95%CI:1.282-4.006,P=0.005),and high IMAC(HR:2.089,95%CI:1.036-4.214,P=0.022)were significant prognostic factors for esophageal squamous cell carcinoma.CONCLUSIONSkeletal muscle mass and quality before NAC in patients with esophageal squamous cellcarcinoma are significant prognostic factors for postoperative OS.
基金Supported by Science and Technology Achievement Transformation Project of Scientific Research Institutions(2021JDZH0019)National Modern Agricultural Industry Technology System of the Ministry of Agriculture(CARS-43-D-1)+4 种基金Sichuan Provincial Breeding Research(2021YFYZ0033)Special Fund for Basic Scientific Research Business of Sichuan Animal Science Academy(SASA202105SASA202305)Natural Science Foundation of Sichuan Province(2023NSFSC0171)Basic Research for Application of Sichuan Provincial Science and Technology Planning Project(2021YJ0267)。
文摘[Objectives]miRNAs play an important role in the proliferation and differentiation of different myoblasts.This study was conducted to elucidate the complex genetic mechanisms that affect the meat production performance of Sichuan white rabbits and reveal the regulatory role of miRNAs in their muscle growth and meat quality formation.[Methods]Three constructed skeletal muscle libraries of Sichuan white rabbits aged six months were sequenced by the solexa technology to identify known miRNAs,predict new miRNAs and construct an expression profile of muscle miRNAs.[Results]A total of 511 known miRNAs and 42 miRNAs were detected in 34089472 pure sequences,and the proportion of miRNAs with a length of 22 nt was the highest.The number of known miRNA sequences accounted for 71.38%of pure sequences,which was much higher than the proportion of other types of RNAs.The proportion of sequences from exons was 0.38%,indicating a low degree of mRNA degradation in the samples.Base U had the highest proportion at the first position,and the bases with the highest proportions at positions 8 and 10 were U and A,respectively.Muscle-specific miRNAs(miR-1,miR-133,and miR-206)ranked in the top 10 in terms of expression level.The number and expression levels of new miRNAs were lower than those of known miRNAs.The length distribution,base bias at different positions and expression profile characteristics of miRNAs might be related to the biological function of miRNAs in regulating muscle proliferation and differentiation and the action mechanisms with target genes.[Conclusions]The identification and expression of miRNAs in muscle tissues of Sichuan white rabbits will help to understand the complex molecular mechanisms of meat production performance and provide a theoretical basis for the functional research of miRNAs in meat rabbits.
文摘The depressed protein synthetic response,a phenomenon termed anabolic resistance,has been shown to be involved in muscle wasting induced by cancer cachexia.Moreover,a positive relationship between the protein synthetic rate and intracellular glutamine(GLN)concentration has been found in skeletal muscles.This study investigated the effects of neuromuscular electrical stimulation(ES)and GLN administration on muscle wasting and GLN metabolism in colon-26(C-26)tumor-bearing mice.CD2F1 mice were divided into 8 groups:control(CNT),CNT+ES,CNT+GLN,CNT+ES+GLN,C-26,C-26+ES,C-26+GLN,C-26+ES+GLN.Cancer cachexia was induced by subcutaneous injection of C-26 cells and developed for four weeks.ES was performed on the left plantar flexor muscles every other day,and GLN(1 g/kg)was administered daily intraperitoneally starting one day after the C-26 injection.Tumor-free body mass and fast-twitch gastrocnemius(Gas)muscle weight were lower in the C-26 group than in the CNT group(-19%and-17%,respectively).Neither ES training nor GLN administration,alone or in combination,ameliorated the loss of Gas muscle weight in the C-26 mice.However,ES training in combination with GLN administration inhibited the increased expression of GLN synthetase(GS)in the C-26 muscles.Thus,it is likely that GLN plays a critical role in muscle protein metabolism and,therefore,can be targeted as a tentative treatment of cancer cachexia.
基金the Postdoctoral Science Foundation of China,No.20070420402
文摘BACKGROUND:In the repair of nerve defects,collapse of the venous wall,as a result of vein grafting alone,could impede nerve regeneration.Therefore,vein lumens filled with muscle and nerve segments have been used to bridge nerve defects.OBJECTIVE:To compare the effects of autogenous,inside-out,vein-skeletal,muscle-combined grafting versus standard,vein-skeletal,muscle-combined grafting for the repair of facial nerve defects.DESIGN,TIME AND SETTING:A randomized,controlled,neuroanatomical,animal study was performed at the Animal Experimental Center and Laboratories of the Capital Medical University Xuanwu Hospital and the Peking Union Medical College Hospital from September 2007 to October 2008.MATERIALS:A total of 10 healthy,male,New Zealand rabbits,aged 6 months,were randomly assigned to inside-out,vein-skeletal,muscle-combined grafting and standard,vein-skeletal,muscle-combined grafting groups,with 5 rabbits in each group.METHODS:A 20-mm gap in the buccal branch of the right facial nerve was made in each animal,which was respectively repaired with inside-out,vein-skeletal,muscle-combined grafts or standard vein-skeletal muscle-combined grafts.MAIN OUTCOME MEASURES:At 6 months after implantation,evoked maximal compound muscle action potentials were recorded on bilateral facial nerves using electromyogram.Myelinated nerve fibers of the regenerating nerves were quantified using myelin sheath osmic acid staining.RESULTS:There was no significant difference between the groups in terms of ratios of bilateral amplitude and latency of compound muscle action potential(P>0.05).Moreover,morphology of regenerating nerves and quantity of myelinated nerve fibers were similar between the groups(P> 0.05).CONCLUTION:Compared with standard vein grafting,the inside-out vein grafting did not significantly improve nerve regeneration.Therefore,it is not necessary to utilize inside-out vein grafting for the repair of nerve defects,in particular with the combined use of autogenous vein and skeletal muscle grafts.
基金supported by the Key Foundation for Basic and Application Research in Higher Education of guangdong, China (2017KZDXM009)the China Postdoctoral Science Foundation (2018M640789)the Provincial Agricultural Science Innovation and Promotion Project, China. (2018LM2150)
文摘Pig is an important economic animal in China. Improving meat quality and meat productivity is a long time issue in animal genetic breeding. Micro RNAs(mi RNAs) are short non-coding RNAs that participate in various biological processes, such as muscle development and embryogenesis. mi R-22 differentially expresses in embryonic and adult skeletal muscle. However, the underlying mechanism is unclear. In this study, we investigated mi R-22 function in proliferation and differentiation of porcine satellite cells(PSCs) in skeletal muscle. Our data show that mi R-22 expressed in both proliferation and differentiated PSCs and is significantly upregulated(P<0.05) during differentiation. After treated with the mi R-22 inhibitor, PSCs proliferation was significantly increased(P<0.05), as indicated by the up-regulation(P<0.01) of cyclin D1(CCND1), cyclin B1(CCNB1) and down-regulation(P<0.05) of P21. Conversely, over-expression of mi R-22 resulted in opposite results. Differentiation of PSCs was significantly suppressed(P<0.05), evidenced by two major myogenic markers: myogenin(Myo G) and myosin heavy chain(My HC), after transfecting the PSCs with mi R-22 inhibitor. Opposite results were demonstrated in the other way around by transfection with mi R-22 mimics. In conclusion, the data from this study indicated that mi R-22 inhibited the PSCs proliferation but promoted their differentiation.
