Expression of miR-140-5p and prediction of its target gene in human mesenchymal stem cells during adipogenic differentiation / 南方医科大学学报

<p><b>OBJECTIVE</b>To screen the differentially expressed miRNAs and their target genes in adipogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs) to better understand the mechanism for regulating the balance between osteoblast and adipocyte differentiation.</p><p><b>METHODS</b>Cultured hMSCs were induced for adipogenic differentiation, and at 0, 7, 14, and 21 days of induction, the cells were examined for miRNA and mRNA expression profiles using miRNA chip and transcriptome sequencing (RNA-seq) techniques. Correlation analysis was carried out for the miRNAs and mRNAs of potential interest. The databases including TargetScan, PicTar and miRanda were used to predict the target genes of the differentially expressed miRNA.</p><p><b>RESULTS</b>The expression of miR-140-5p was down-regulated and leukemia inhibitory factor receptor (LIFR) expression increased progressively during adipogenic differentiation of hMSCs, showing a negative correlation between them. Target gene prediction using the 3 databases identified LIFR as the target gene of miR-140-5p.</p><p><b>CONCLUSION</b>miRNA-140-5p may play an important role by regulating its target gene LIFR during adipogenic differentiation of hMSCs.</p>

Protective effect and mechanism of astragaloside IV on oxidative stress injury of mesangial cells / 中国中药杂志

<p><b>OBJECTIVE</b>To study the protective effect of astragaloside IV (AS IV) on H2O2 induced human mesangial cells (HMC), and further explore its molecular mechanism.</p><p><b>METHOD</b>The cultured mesangial cells were divided into 5 groups: the normal control group, the H2O2 model group, the AS IV (12.5, 100 nmol x L(-1)) group and the Tempol (1 x 10(5) nmol x L(-1)) group. The MTT method was used to observe cell viability. Hoechst 33258 staining was used to observe the HMC apoptosis and DHE staining was used to detect the generation of reactive oxygen species (ROS). The flow cytometry was used to detect the changes in cell cycle. Western blot was used to detect the expression of Cyclin D1, CyclinA, p38, and T-p38.</p><p><b>RESULT</b>H2O2 (1 x 10(5), 2 x 10(5), 3 x 10(5), and 4 x 10(5) nmol x L(-1)) could induce HMC oxidative stress injury, with significant decrease in the cell survival rate. AS IV (100 nmol x L(-1)) could significantly inhibit HMC oxidative stress injury induced by H2O2 (3 x 10(5) nmol x L(-1)), increase the survival rate of HMC cells, inhibit cell apoptosis, and decrease intracellular ROS production. AS IV could also increase the expression of Cyclin D1, recover normal cell proliferation, and decrease the expression of p38.</p><p><b>CONCLUSION</b>AS IV can protect H2O2 induced oxidative stress injury in mesangial cells. Its mechanisms may be related to inhibiting the p38/MAPK signaling pathway, increasing the expression of Cyclin D1 and decreasing the intracellular ROS oxidative stress injury.</p>

Relationship between the morphological and functional alterations of pancreatic islets and peripheral insulin resistance in rats with long-term high-fat diet / 中华内分泌代谢杂志

Objective To investigate the effect of long-term high-fat diet on insulin resistance and the morphology and function of islets in rats and the relationship between them.Methods Thirty normal male Wistar rats (8 weeks old) were divided into two groups and fed either with normal chow (NC,n=15),or high-caloric and high-fat diet (HF,n=15).Insulin resistance was assessed by euglycemic hyperinsulinemic clamp technique. The insulin secretory function of islets was evaluated by intravenous insulin releasing test.Morphological and quantitative analysis of pancreatic tissues was performed by double-label insulin and glucagon immunohistochemistry.Proinsulin mRNA was detected by RT-PCR.Results The glucose infusion rate (GIR) in HF rats was significandy lower than that in NC rats [(5.83?0.79)mg?kg~(-1)?min~(-1) vs (7.60?1.29)mg?kg~(-1)?min~(-1),P＜0.05].Immunohistochemistry showed that HF rats had larger islet size [(15168?1327)?m~2 vs (6264?1840)?m~2,P＜0.01] and significantly reduced insulin relative concentration of?cells[(-5.15?0.03) vs (-4.81?0.17),P＜0.01],as compared with NC rats.The islet relative?cell volume was decreased signifieandy (P＜0.01),whereas the relative?cell volume was increased (P＜0.01).So the ratio of?to?were lower in HF [(4.68?1.01) vs (11.84?3.82),P＜0.05].The peak of insulin secretion in intravenous insulin releasing test in HF was at 10 min,whereas that in NC rats was at 5 min.AUC (area under curve) 10-60 rain of insulin in HF was higher than that in NC rats [(152.51?34.53)mIU?L~(-1)?min~(-1) vs (86.40?21.21) mIU?L~(-1)?min~(-1),P＜0.01].There was no difference in proinsulin mRNA levels between two groups. Conclusion Long-term high-caloric and high-fat diet results in early impairment of islet morphology and function, as well as significant insulin resistance,suggesting that the compensation ability of islets has already been impaired in the early course of type 2 diabetes mellitus.