Background Studying the composition and developmental mechanisms in mammary gland is crucial for healthy growth of newborns. The mammary gland is inherently heterogeneous, and its physiological function dependents on ...Background Studying the composition and developmental mechanisms in mammary gland is crucial for healthy growth of newborns. The mammary gland is inherently heterogeneous, and its physiological function dependents on the gene expression of multiple cell types. Most studies focused on epithelial cells, disregarding the role of neighboring adipocytes.Results Here, we constructed the largest transcriptomic dataset of porcine mammary gland cells thus far. The dataset captured 126,829 high-quality nuclei from physiological mammary glands across five developmental stages(d 90 of gestation, G90;d 0 after lactation, L0;d 20 after lactation, L20;2 d post natural involution, PI2;7 d post natural involution, PI7). Seven cell types were identified, including epithelial cells, adipocytes, endothelial cells, fibroblasts cells, immune cells, myoepithelial cells and precursor cells. Our data indicate that mammary glands at different developmental stages have distinct phenotypic and transcriptional signatures. During late gestation(G90), the differentiation and proliferation of adipocytes were inhibited. Meanwhile, partly epithelial cells were completely differentiated. Pseudo-time analysis showed that epithelial cells undergo three stages to achieve lactation, including cellular differentiation, hormone sensing, and metabolic activation. During lactation(L0 and L20), adipocytes area accounts for less than 0.5% of mammary glands. To maintain their own survival, the adipocyte exhibited a poorly differentiated state and a proliferative capacity. Epithelial cells initiate lactation upon hormonal stimulation. After fulfilling lactation mission, their undergo physiological death under high intensity lactation. Interestingly, the physiological dead cells seem to be actively cleared by immune cells via CCL21-ACKR4 pathway. This biological process may be an important mechanism for maintaining homeostasis of the mammary gland. During natural involution(PI2 and PI7), epithelial cell populations dedifferentiate into mesenchymal stem cells to maintain the lactation potential of mammary glands for the next lactation cycle.Conclusion The molecular mechanisms of dedifferentiation, proliferation and redifferentiation of adipocytes and epithelial cells were revealed from late pregnancy to natural involution. This cell transcriptomic profile constitutes an essential reference for future studies in the development and remodeling of the mammary gland at different stages.展开更多
Aptamers as a kind of biological recognition element have shown great potential in monitoring and the rapid quantification of organophosphorus pesticides(OPPs). However, molecules of OPPs are structurally similar and ...Aptamers as a kind of biological recognition element have shown great potential in monitoring and the rapid quantification of organophosphorus pesticides(OPPs). However, molecules of OPPs are structurally similar and original aptamers selected by systematic evolution of ligands by exponential enrichment are usually long-chain bases, which hamper the further application under OPPs-aptamer recognition. The aim of the research was to develop a new strategy to design oligonucleotide sequences for binding OPPs by combination of experimental and molecular modeling methods. 3D models of aptamers binding OPPs were constructed, and binding energy and the most probable binding site for the OPPs were then determined by molecular docking, and the binding sites were further confirmed by the results of 2-AP replaced experiments. Based on the docking results, a new aptamer for detection 4 representative OPPs with only 29 bases was designed by reasonable truncation and mutation of the reported aptamer(named S4-29). The interaction between this new aptamer and OPPs were analyzed by molecular docking, microscale thermophoresis, circular dichroism and fluorometric analysis. The results revealed that the new aptamer exhibit more superior recognition performance to OPPs, which can be promote the monitoring ability of OPPs contaminations in food.展开更多
Summary:Recent studies suggested that serum secretory phospholipase A2 group IB(sPLA2-IB)was increased in idiopathic membranous nephropathy(IMN).However,the interference of high lipemia on the sPL.A2-IB levels was not...Summary:Recent studies suggested that serum secretory phospholipase A2 group IB(sPLA2-IB)was increased in idiopathic membranous nephropathy(IMN).However,the interference of high lipemia on the sPL.A2-IB levels was not taken into account in these studies.The present study aimed to investigate the correlation between sPLA2-IB and lipemia,and the clinical merit of sPLA2-IB in the prediction of prognosis of IMN patients.A total of 64 IMN patients,39 immunoglobulin A nephropathy(IgAN)patients and 64 healthy controls were included in the study.The levels of serum sPLA2-IB,lipemia and proteinuria were measured.Fifty IMN patients were followed up for 6 months.Pathologic stages were made for all IgAN and IMN patients.The results showed that the levels of serum sPLA2-IB,cholesterol and low-density lipoprotein cholesterol(LDL-C)were significantly higher,and the levels of albumin and high-density lipoprotein cholesterol(HDL-C)were significantly lower in IMN patients than in healthy controls and IgAN patients.Serum sPLA2-IB levels were also found to be higher in IgAN patients than in heathy controls,but the association of serum sPLA2-IB levels with proteinuria,cholesterol and albumin was only shown in IMN patients.Antibody against M-type receptor for secretory phospholipase A2(PLA2R1)was positive in 813%IMN patients.Glomerular sPLA2-IB deposition,podocyte fused processes,and density deposition on thickened basement membrane were seen in IMN patients,but not in IgAN patients.IMN patients with lower sPLA2-IB and proteinuria levels were found to have better outcome after the 6-month follow-up.In IMN patients,sPLA2-IB levels were significantly increased in both serum and renal tissue.In conclusion,serum sPLA2-IB was closely correlated with proteinuria,albumin and cholesterol,and IMN patients with lower sPLA2-IB levels were more likely to achieve a better outcome.展开更多
Staphylococcus aureus produces staphyloxanthin,a C30 carotenoid with golden color,as an antioxidant to promote bacterial resistance to reactive oxygen species.The biosynthesis pathway of staphyloxanthin involves a ser...Staphylococcus aureus produces staphyloxanthin,a C30 carotenoid with golden color,as an antioxidant to promote bacterial resistance to reactive oxygen species.The biosynthesis pathway of staphyloxanthin involves a series of catalytic enzymes.Aldehyde dehydrogenase(AldH)is a dehydrogenase recently identified to convert 4,4’-diaponeurosporenaldehyde into 4,4’-diaponeurosporenoic acid during staphyloxanthin biosynthesis.Here,we present the crystallographic structures of apo-and holo-forms of S.aureus AldH.The dimeric enzyme contains a unique C-terminal helix,which resembles a“gatekeeper”helix found in human membrane-bound fatty aldehyde dehydrogenase(FALDH).Particularly,the helix adopts“open”and“closed”conformations in apo-and holo-AldH,respectively,to control the access of the substrate tunnel.Mutagenesis in combination with in vitro and in vivo activity assays identifies several residues essential for S.aureus AldH substrate recognition and enzyme catalytic turnover.Our results provide insights into substrate recognition of S.aureus AldH toward polyunsaturated long-chain aldehydes at atomic resolution.展开更多
基金supported by the National Key R&D Program of China (2020YFA0509500,2021YFD1301101 and 2021YFA0805903)the Sichuan Science and Technology Program+3 种基金(2023YFN0088 and 2021YFYZ0030)the National Center of Technology Innovation for Pigs (SCCXTD-2023-08)the National Natural Science Foundation of China (32272837 and 32225046)Tianfu Agricultural Master Project。
文摘Background Studying the composition and developmental mechanisms in mammary gland is crucial for healthy growth of newborns. The mammary gland is inherently heterogeneous, and its physiological function dependents on the gene expression of multiple cell types. Most studies focused on epithelial cells, disregarding the role of neighboring adipocytes.Results Here, we constructed the largest transcriptomic dataset of porcine mammary gland cells thus far. The dataset captured 126,829 high-quality nuclei from physiological mammary glands across five developmental stages(d 90 of gestation, G90;d 0 after lactation, L0;d 20 after lactation, L20;2 d post natural involution, PI2;7 d post natural involution, PI7). Seven cell types were identified, including epithelial cells, adipocytes, endothelial cells, fibroblasts cells, immune cells, myoepithelial cells and precursor cells. Our data indicate that mammary glands at different developmental stages have distinct phenotypic and transcriptional signatures. During late gestation(G90), the differentiation and proliferation of adipocytes were inhibited. Meanwhile, partly epithelial cells were completely differentiated. Pseudo-time analysis showed that epithelial cells undergo three stages to achieve lactation, including cellular differentiation, hormone sensing, and metabolic activation. During lactation(L0 and L20), adipocytes area accounts for less than 0.5% of mammary glands. To maintain their own survival, the adipocyte exhibited a poorly differentiated state and a proliferative capacity. Epithelial cells initiate lactation upon hormonal stimulation. After fulfilling lactation mission, their undergo physiological death under high intensity lactation. Interestingly, the physiological dead cells seem to be actively cleared by immune cells via CCL21-ACKR4 pathway. This biological process may be an important mechanism for maintaining homeostasis of the mammary gland. During natural involution(PI2 and PI7), epithelial cell populations dedifferentiate into mesenchymal stem cells to maintain the lactation potential of mammary glands for the next lactation cycle.Conclusion The molecular mechanisms of dedifferentiation, proliferation and redifferentiation of adipocytes and epithelial cells were revealed from late pregnancy to natural involution. This cell transcriptomic profile constitutes an essential reference for future studies in the development and remodeling of the mammary gland at different stages.
基金supported by the National Natural Science Foundation of China (31801647)Sichuan Science and Technology Program (2018JY0194,2020YFN0153,2020YFN0151)。
文摘Aptamers as a kind of biological recognition element have shown great potential in monitoring and the rapid quantification of organophosphorus pesticides(OPPs). However, molecules of OPPs are structurally similar and original aptamers selected by systematic evolution of ligands by exponential enrichment are usually long-chain bases, which hamper the further application under OPPs-aptamer recognition. The aim of the research was to develop a new strategy to design oligonucleotide sequences for binding OPPs by combination of experimental and molecular modeling methods. 3D models of aptamers binding OPPs were constructed, and binding energy and the most probable binding site for the OPPs were then determined by molecular docking, and the binding sites were further confirmed by the results of 2-AP replaced experiments. Based on the docking results, a new aptamer for detection 4 representative OPPs with only 29 bases was designed by reasonable truncation and mutation of the reported aptamer(named S4-29). The interaction between this new aptamer and OPPs were analyzed by molecular docking, microscale thermophoresis, circular dichroism and fluorometric analysis. The results revealed that the new aptamer exhibit more superior recognition performance to OPPs, which can be promote the monitoring ability of OPPs contaminations in food.
基金This study was funded by the National Natural Science Foundation of China(No.81670635)Talents Training Program of Pudong Hospital Affiliated to Fudan University(No.PY202002)Natxiral Science Foundation of Fujian Province of China(No.2019J01441).
文摘Summary:Recent studies suggested that serum secretory phospholipase A2 group IB(sPLA2-IB)was increased in idiopathic membranous nephropathy(IMN).However,the interference of high lipemia on the sPL.A2-IB levels was not taken into account in these studies.The present study aimed to investigate the correlation between sPLA2-IB and lipemia,and the clinical merit of sPLA2-IB in the prediction of prognosis of IMN patients.A total of 64 IMN patients,39 immunoglobulin A nephropathy(IgAN)patients and 64 healthy controls were included in the study.The levels of serum sPLA2-IB,lipemia and proteinuria were measured.Fifty IMN patients were followed up for 6 months.Pathologic stages were made for all IgAN and IMN patients.The results showed that the levels of serum sPLA2-IB,cholesterol and low-density lipoprotein cholesterol(LDL-C)were significantly higher,and the levels of albumin and high-density lipoprotein cholesterol(HDL-C)were significantly lower in IMN patients than in healthy controls and IgAN patients.Serum sPLA2-IB levels were also found to be higher in IgAN patients than in heathy controls,but the association of serum sPLA2-IB levels with proteinuria,cholesterol and albumin was only shown in IMN patients.Antibody against M-type receptor for secretory phospholipase A2(PLA2R1)was positive in 813%IMN patients.Glomerular sPLA2-IB deposition,podocyte fused processes,and density deposition on thickened basement membrane were seen in IMN patients,but not in IgAN patients.IMN patients with lower sPLA2-IB and proteinuria levels were found to have better outcome after the 6-month follow-up.In IMN patients,sPLA2-IB levels were significantly increased in both serum and renal tissue.In conclusion,serum sPLA2-IB was closely correlated with proteinuria,albumin and cholesterol,and IMN patients with lower sPLA2-IB levels were more likely to achieve a better outcome.
基金supported by the National Natural Science Foundation of China(21671203 and 21877131)RGC of Hong Kong(17305415 and 17333616)+1 种基金the Ministry of Education of China(IRT-17R111)the Fundamental Research Funds for the Central Universities.
文摘Staphylococcus aureus produces staphyloxanthin,a C30 carotenoid with golden color,as an antioxidant to promote bacterial resistance to reactive oxygen species.The biosynthesis pathway of staphyloxanthin involves a series of catalytic enzymes.Aldehyde dehydrogenase(AldH)is a dehydrogenase recently identified to convert 4,4’-diaponeurosporenaldehyde into 4,4’-diaponeurosporenoic acid during staphyloxanthin biosynthesis.Here,we present the crystallographic structures of apo-and holo-forms of S.aureus AldH.The dimeric enzyme contains a unique C-terminal helix,which resembles a“gatekeeper”helix found in human membrane-bound fatty aldehyde dehydrogenase(FALDH).Particularly,the helix adopts“open”and“closed”conformations in apo-and holo-AldH,respectively,to control the access of the substrate tunnel.Mutagenesis in combination with in vitro and in vivo activity assays identifies several residues essential for S.aureus AldH substrate recognition and enzyme catalytic turnover.Our results provide insights into substrate recognition of S.aureus AldH toward polyunsaturated long-chain aldehydes at atomic resolution.
