BACKGROUND:Sarcopenia is an age-related condition characterized by the loss of skeletal muscle mass,strength,and/or physical function.Currently,effective treatments for sarcopenia remain limited.A new therapeutic approach to improve symptoms and prognosis of sarcopenia patients clinically was important.OBJECTIVE:To explore the effects of canine adipose-derived mesenchymal stem cells and their exosomes on a dexamethasone-induced sarcopenia in mice.METHODS:Mesenchymal stem cells were isolated and cultured from canine adipose tissue,and identified and functionally evaluated through flow cytometry and differentiation assays for osteogenesis,adipogenesis,and chondrogenesis.Subsequently,exosomes from adipose-derived mesenchymal stem cells were extracted and characterized using transmission electron microscopy,western blot assay,and nanocoulter tracking analysis.In vitro,the effects of canine adipose-derived mesenchymal stem cells and their exosomes on myotube growth and the expression of muscle atrophy-related genes were investigated using dexamethasone-induced C2C12 myotube atrophy and aging C2C12 models.In vivo,a dexamethasone-induced mouse sarcopenia model was established and received intraperitoneal or intravenous injection of canine adipose-derived mesenchymal stem cells.Therapeutic efficacy was assessed through mouse rotarod performance,histopathological analysis,and muscle atrophy-related genes testing.RESULTS AND CONCLUSION:(1)The isolated canine adipose-derived mesenchymal stem cells highly expressed CD73,CD90,and CD105,and lowly expressed MHC-Ⅱ,CD14,CD19,CD34,and CD45,and successfully differentiated into osteoblasts,adipocytes,and chondrocytes in vitro.(2)The adipose-derived mesenchymal stem cells-derived exosomes met the identification criteria in terms of particle size,electron microscopy morphology,and positive expression of specific markers.(3)Compared to the dexamethasone-induced C2C12 atrophy group,treatment with adipose-derived mesenchymal stem cells and their exosomes promoted the recovery and growth of myotubes,inhibited the expression of muscle atrophy-related genes MuRF1 and Atrogin-1.(4)Compared to the aging C2C12 group,adipose-derived mesenchymal stem cells and their exosomes significantly enhanced the recovery and growth of aged muscle tubes in aging cells.(5)Compared to the control group,the rotarod time in dexamethasone-induced sarcopenia model mice was significantly decreased(P＜0.01).After 7 days(P＜0.01,P＜0.01)and 10 days(P＜0.01,P＜0.05)of adipose-derived mesenchymal stem cells treatment via intraperitoneal and intravenous injection,rotarod time was significantly increased,respectively.After 14 days,all treatment groups showed longer rotarod times than the model group,although with no significant differences between them.(6)Compared to the control group,the cross-sectional area of anterior tibial muscle in the model group was significantly reduced(P＜0.01),and it was significantly increased after intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells(P＜0.05,P＜0.01).(7)Compared to the model group,intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells significantly inhibited the mRNA expression of MuRF1 and Atrogin-1 genes(P＜0.01,P＜0.01,P＜0.01,P＜0.01).The results indicated that adipose-derived mesenchymal stem cells and their exosomes promoted recovery and growth of atrophic myotube cells by inhibiting the expression of muscle atrophy-related genes,and both intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells provided good therapeutic effects on sarcopenia in mice.

BACKGROUND:Sarcopenia is an age-related condition characterized by the loss of skeletal muscle mass,strength,and/or physical function.Currently,effective treatments for sarcopenia remain limited.A new therapeutic approach to improve symptoms and prognosis of sarcopenia patients clinically was important.OBJECTIVE:To explore the effects of canine adipose-derived mesenchymal stem cells and their exosomes on a dexamethasone-induced sarcopenia in mice.METHODS:Mesenchymal stem cells were isolated and cultured from canine adipose tissue,and identified and functionally evaluated through flow cytometry and differentiation assays for osteogenesis,adipogenesis,and chondrogenesis.Subsequently,exosomes from adipose-derived mesenchymal stem cells were extracted and characterized using transmission electron microscopy,western blot assay,and nanocoulter tracking analysis.In vitro,the effects of canine adipose-derived mesenchymal stem cells and their exosomes on myotube growth and the expression of muscle atrophy-related genes were investigated using dexamethasone-induced C2C12 myotube atrophy and aging C2C12 models.In vivo,a dexamethasone-induced mouse sarcopenia model was established and received intraperitoneal or intravenous injection of canine adipose-derived mesenchymal stem cells.Therapeutic efficacy was assessed through mouse rotarod performance,histopathological analysis,and muscle atrophy-related genes testing.RESULTS AND CONCLUSION:(1)The isolated canine adipose-derived mesenchymal stem cells highly expressed CD73,CD90,and CD105,and lowly expressed MHC-Ⅱ,CD14,CD19,CD34,and CD45,and successfully differentiated into osteoblasts,adipocytes,and chondrocytes in vitro.(2)The adipose-derived mesenchymal stem cells-derived exosomes met the identification criteria in terms of particle size,electron microscopy morphology,and positive expression of specific markers.(3)Compared to the dexamethasone-induced C2C12 atrophy group,treatment with adipose-derived mesenchymal stem cells and their exosomes promoted the recovery and growth of myotubes,inhibited the expression of muscle atrophy-related genes MuRF1 and Atrogin-1.(4)Compared to the aging C2C12 group,adipose-derived mesenchymal stem cells and their exosomes significantly enhanced the recovery and growth of aged muscle tubes in aging cells.(5)Compared to the control group,the rotarod time in dexamethasone-induced sarcopenia model mice was significantly decreased(P＜0.01).After 7 days(P＜0.01,P＜0.01)and 10 days(P＜0.01,P＜0.05)of adipose-derived mesenchymal stem cells treatment via intraperitoneal and intravenous injection,rotarod time was significantly increased,respectively.After 14 days,all treatment groups showed longer rotarod times than the model group,although with no significant differences between them.(6)Compared to the control group,the cross-sectional area of anterior tibial muscle in the model group was significantly reduced(P＜0.01),and it was significantly increased after intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells(P＜0.05,P＜0.01).(7)Compared to the model group,intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells significantly inhibited the mRNA expression of MuRF1 and Atrogin-1 genes(P＜0.01,P＜0.01,P＜0.01,P＜0.01).The results indicated that adipose-derived mesenchymal stem cells and their exosomes promoted recovery and growth of atrophic myotube cells by inhibiting the expression of muscle atrophy-related genes,and both intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells provided good therapeutic effects on sarcopenia in mice.

【Objective】 To evaluate the differential miRNA expression of breast milk exosome in premature and full-term groups, and to analyze the regulatory pathways by bioinformatics, so as to provide guidance and scientific basis for the growth and development of premature infants and the prevention and treatment of related diseases. 【Methods】 From August 2020 to June 2021, breast milk samples from 13 premature (premate group) and 9 full-term infants(full-term group) in the Department of Child Health Care of the Second Affiliated Hospital of Nanjing Medical University were collected to extract exosomes. The miRNAs of two groups of breast milk exosomes were sequenced by high-throughput sequencing. According to the sequencing results, miRNA expression profiles of milk exosome were analyzed. Biological function software was used to carry out GO and KEGG pathway analysis of differential miRNA. 【Results】 The expression of miRNA in human milk exosomes was rich, especially hsa-miR-148a-3p,hsa-let-7b-5p, hsa-let-7g-5p, hsa-miR-22-3p, hsa-miR-99a-5p, hsa-miR-200, hsa-miR-146b-5p and hsa-miR-26a-5p were relatively high expressed in preterm group and full-term group. Differential expression analysis showed that compared with full-term infant breast milk, 7 miRNAs were up-regulated(log2|fold change|=2.803, 2.714, 1.632, 2.360, 1.350, 3.387, 2.137, respectively), and 5 miRNAs were down-regulated(log2|fold change|=-2.553, -2.197, -2.771, -1.395, -1.136, respectively)(|fold change>2|, P<0.05) in breast milk for preterm infants. In these differential expressed miRNAs, down-regulated miR-29b(P=0.001) and up-regulated miR-133a-3p(P=0.004) were associated with inflammation, and up-regulated miR-126-5p(P=0.021) and miR-126-3p(P=0.041) were associated with lipid metabolism. The fatty acid biosynthesis pathway was obviously enriched in preterm group. MiR-7-5p, miR-29b-3p and miR-100-5p played a role in the fatty acid synthesis pathway. 【Conclusions】 Exosomal miRNAs are rich in breast milk, and have significant differences between preterm and full-term infants′ mothers. The differentially expressed miRNA in preterm infants treast milk may be related to inflammation and promote the growth and development of preterm infants through the fatty acid biosynthesis pathway.

Objective:To investigate the absorption characteristics of matrine and glycyrrhizic acid in different intestinal segment and at various mass concentration,and explore the absorption changes of the combination of the two drugs.Methods:In situ single pass intestinal perfusion (SPIP) model was used,and the concentration changes of matrine and glycyrrhizic acid were determined by HPLC, and Kaand Peffwere calculated. Results:Matrine was absorbed in the whole of small intestine, and best in jejunum, and compared with the duodenum and ileum,the absorption had significant difference (P<0.05).The absorption at different mass concentrations had significant difference(P<0.05). The absorption of glycyrrhizic acid in small intestine was poor without significant differences in different intestinal segments and at various doses (P>0.05). After the combination of the two drugs, the absorption of matrine and glycyrrhizic acid had significant difference when compared with that of separated use(P<0.05). Conclusion:The absorption of ma-trine is dose-dependent,and with the dose increase,the absorption increases. Glycyrrhizic acid absorption does not change with mass concentration,and the absorption may be passive transport. The combination of the two drugs can improve the in vivo absorption of ma-trine and increase the concentration of glycyrrhizic acid in intestine.

Objective To evaluate the efficacy of liraglutide in the treatment of Nonalcoholic Fatty Liver Disease(NAFLD).Methods Randomized controlled trials(RCTs)that evaluated the efficacy of liraglutide for NAFLD treatment were searched in multiple databases,including Pubmed,EMBASE,the Cochrane library,CNKI,Wanfang database and VIP.Literature identification and data extraction were based on the inclusion and exclusion criteria.RevMan 5.3 software was used for Meta-analysis.Results A total of 7 RCTs with 500 patients of NAFLD were included.Improved liver histology,or improved the level of alanine aminotransferase[WMD=-25.32,95％CI(-37.22,-13.41),P<0.01] and aspartate aminotransferase[WMD=-24.56,95％CI(-35.10,-14.03),P<0.01] were seen in 12-48 weeks liraglutide treatment.However,liraglutide could not decreased the level of serum cholesterol[WMD=-14.38,95％CI(-48.95,-20.20),P=0.42] and triglyceride[WMD=-15.55,95％CI(-36.20,-5.10),P=0.14].Conclusion liraglutide has the therapeutic effect of NAFLD.