Interpretation of clinical guidelines for comprehensive interventional diagnosis and treatment of diabetic foot (fifth edition) / 医学研究生学报

According to the latest research progress at home and abroad, and the domestic situation, China Diabetic Cellular and Interventional Therapy Technology Alliance forDiabetic Foot developed and issued the fifth edition of clinical guidelines for comprehensive interventional diagnosis and treatment of diabetic foot, which covers domestic evidence,references foreign evidence, and reflects the progress in China. The interpretation focuses on the updated key points.

Interpretation of clinical guidelines for comprehensive interventional diagnosis and treatment of diabetic foot (fifth edition) / 医学研究生学报

According to the latest research progress at home and abroad, and the domestic situation, China Diabetic Cellular and Interventional Therapy Technology Alliance forDiabetic Foot developed and issued the fifth edition of clinical guidelines for comprehensive interventional diagnosis and treatment of diabetic foot, which covers domestic evidence,references foreign evidence, and reflects the progress in China. The interpretation focuses on the updated key points.

Glucagon-like peptide-1 improves proliferation and differentiation of endothelial progenitor cells via upregulating VEGF generation.

BACKGROUND: Glucagon-like peptide-1(GLP-1), released from enteroendocrine cells of the intestine, exerted cardiovascular protective effect. Circulating endothelial progenitor cells (EPCs) play an important role in maintaining endothelial integrity regulating neovascularization and reendothelialization after endothelial injury. Vascular endothelial growth factor (VEGF) is an important cytokine in the process of EPCs vascular differentiation and proliferation. MATERIAL/METHODS: This study was designed to investigate the association between VEGF changes and the proliferation/differentiation function of EPCs in the presence of GLP-1. RESULTS: We demonstrated that GLP-1 markedly enhanced the EPCs proliferation and expression of EC-specific markers, and simultaneously upregulated VEGF secretion in EPCs. Exogenous VEGF augmented EPCs proliferation/differentiation abilities in a dose-dependent manner. However, all of the beneficial effects of GLP-1were suppressed by anti-VEGFmAb or the KDR-specific tyrosine kinase inhibitor SU1498. CONCLUSIONS: These findings suggest that GLP-1 improves VEGF generation, which contributed to improvement of EPCs biological function, partly by tyrosine kinase KDR. VEGF is a necessary intermediate, mediating the effects of GLP-1 on EPCs. These changes offer a novel explanation that upregulation EPCs bioactivities may be one of the mechanisms of GLP-1 cardiovascular protective effect.

Ceramide mediates inhibition of the AKT/eNOS signaling pathway by palmitate in human vascular endothelial cells.

BACKGROUND: In metabolic syndrome, down-regulation of the insulin signaling leads to insulin-regulated metabolism and cardiovascular dyfunctions. Free fatty acids (FFAs) in the circulation are increased in this disorder and inhibit insulin signaling. Lipid oversupply contributes to the development of insulin resistance, likely by promoting the accumulation of lipid metabolites capable of inhibiting signal transduction. MATERIAL/METHODS: This study was designed to examine the effects of FFAs and their metabolites on the insulin signaling pathway that leads to the activation of endothelial nitric oxide synthase (eNOS) and increase in nitric oxide (NO) production in endothelial cells. RESULTS: Here we demonstrate that exposing human umbilical vein endothelial cells (HUVECs) to palmitate inhibits activation of Akt/eNOS signal pathway by insulin, and subsequently insulin-stimulated NO generation. Palmitate concomitantly induced the accumulation of ceramide, a product of acyl-CoA that has been shown to accumulate in insulin-resistant tissues and to inhibit insulin signaling. Preventing de novo ceramide synthesis abolished the antagonistic effect of palmitate toward the Akt/ eNOS pathway. Moreover, inducing ceramide buildup augmented the inhibitory effect of palmitate. CONCLUSIONS: Taken together, we have demonstrated that palmitic acid induces accumulation of ceramide, which appears to mediate palmitic acid's inhibitory effects on the Akt/eNOS pathway, leading to a significant decrease in NO generation. Therefore, ceramide is a necessary and sufficient intermediate mediating the inhibition of the AKT/eNOS signaling pathway by palmitate in endothelial cells.

PI3K p85alpha expression and its role in the progression of colorectal cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of PI3K p85alpha in normal colorectal tissue, colorectal adenoma and primary colorectal carcinoma and explore its significance in the progression of colorectal cancer.</p><p><b>METHODS</b>The expression of PI3K p85alpha was detected in 116 normal colorectal tissue, colorectal adenoma and primary colorectal carcinoma specimens using immunohistochemical staining, and the relationship between the expression of PI3K p85alpha protein and the clinicopathological factors was analyzed.</p><p><b>RESULTS</b>The positivity rates of the expression of PI3K p85alpha protein increased gradually in the progression of colorectal cancer and showed significant differences between the tissues (P<0.05). A significant difference was also noted in the positivity rates of the PI3K p85alpha expression in colorectal carcinoma tissues at different Dukes' stages (P<0.05). No obvious correlation was found between PI3K p85alpha expression and the degree of the tumor differentiation.</p><p><b>CONCLUSIONS</b>Abnormal PI3K p85alpha expression occurs in the progression of colorectal cancer in close relation to the clinical stage, and the PI3K/AKT pathway plays an important role in the progression of colorectal cancer.</p>

Hyperlipidemia induced by high fat diet ingestion activates TGF-beta/Smad signaling pathway in the kidney of diabetic rats / 中南大学学报(医学版)

OBJECTIVE@#To investigate the effect of diet-induced hyperlipidemia on TGF-beta/Smad signaling pathway in the kidney of diabetic rats, and to explore the mechanism by which hyperlipidemia leads to renal injury in diabetes.@*METHODS@#Diabetic rats and non-diabetic rats were fed with normal fat diet and high fat diet for 16 weeks, respectively. The expressions of TGF-beta1, TbetaRII, and Col-IV mRNA in the renal cortex were examined by reverse transcriptase-PCR,TbetaRII and p-Smad staining in glomerular cells were detected by immunohistochemical staining, and the expression of TGF-beta1 and Col-IV protein was determined by Western blot.@*RESULTS@#Diet-induced hyperlipidemia up-regulated the levels of TGF-beta1, TbetaRII, p-Smad, and Col-IV protein and mRNA in the renal cortex of diabetic rats compared with those of non-diabetic rats. However, feeding high fat diet to non-diabetic rats had no influence on the expression of TGF-beta1, TbetaRII, p-Smad2, and Col-IV in the renal cortex.@*CONCLUSION@#Hyperlipidemia induced by high fat diet ingestion leads to renal injury in diabetic rats through activating TGF-beta1 /Smad signaling pathway.

Aortic endothelium-dependent vasodilation function and PI3K-, PKB-, eNOS mRNA expressions in insulin-resistant and type 2 diabetic rats / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the changes of aortic endothelium-dependent vasodilation function (EDVR) and expressions of endothelial nitric oxide synthase (eNOS), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (PKB) in insulin-resistance (IR) and type 2 diabetic rats.</p><p><b>METHODS</b>IR rat model was established by feeding 4-6 week-old male SD rats with high glucose and cholesterol diet for 6 weeks and type 2 diabetes (DM) were induced by intraperitoneal injection with low dose streptozotocin (STZ) to IR rats. Glucose infusion rate (GIR) was determined by euglycemic hyperinsulinemic clamp technique, EDVR by acetylcholine (Ach)-induced vasodilation response in isolated aortic rings, aortic NO concentration by Griess Reaction, activation of eNOS detected by immunohistochemical SP method, mRNA expressions of eNOS-, PI3K- and PKB of aorta were assayed by RT-PCR, aorta ultrastructure observed by electron microscopy. Body weight, fast plasma glucose (FPG), insulin (FINS), triglyceride (TG), cholesterol (TC) were determined and the insulin sensitivity index (ISI) was calculated.</p><p><b>RESULTS</b>(1) Body weight, FINS, TG and TC levels were significantly higher while ISI and GIR significantly lower in IR and DM rats than that in normal control rats (P < 0.05). (2) Aorta EDVR decreased significantly in IR and DM group compared with that in control group (P < 0.05) and EDVR was also significantly reduced in DM rats than that in IR rats (P < 0.05). The maximum Ach-induced vasodilation response (EDVR(max), P < 0.01) was positively correlated with ISI and negatively correlated with FPG, TG, TC and FINS (P < 0.01). (3) Aortic NO concentration, the mRNA expressions of eNOS-, PI3K-, and PKB and eNOS immunohistochemical expression in aorta were significantly lower in IR and DM rats compared with normal control rats and the decrease was more pronounced in DM rats (P < 0.05 vs. IR). (4) Pathologic aortic ultrastructure changes were also visualized in IR and DM rats.</p><p><b>CONCLUSION</b>Our results suggest that reduced NO concentration and expression as well as reduced PI3K-, PKB-, and eNOS mRNA expressions might contributed to the reduced EDVR function and related pathological ultrastructure changes in IR and DM rats.</p>

Effect of rosiglitazone on NO and eNOS via PI3K/PKB signal pathways in cultured human umbilical vein endothelial cells / 中南大学学报(医学版)

OBJECTIVE@#To observe the effect of rosiglitazone on the production of nitric oxide (NO) and the expression of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB) /the endothelial nitric oxide synthase (eNOS) in cultured human umbilical vein endothelial cells(HUVECs), and to investigate the mechanism of signal transduction of rosiglitazone in improving the endothelial function.@*METHODS@#HUVECs were treated with various concentrations of rosiglitazone. The NO level was measured using Griess Reaction in cell culture supernatants; the expressions of PI3K-, PKB- and eNOS mRNA were measured using RT-PCR; and the expressions of PKB, eNOS, and phosphorylation of PKB-Ser473, eNOS-Ser1177 were measured using Western Blot.@*RESULTS@#Rosiglitazone increased the endothelial NO production in a dose- and time-dependent manner in cultured HUVECs, and also increased the expression of PI3K mRNA and the phosphorylation of PKB-Ser473 and eNOS-Ser1177 in a concentration-dependent manner, with no alteration in the expression of PKB and eNOS in cultured HUVECs. N(w)-nitro-L- arginine methyl ester (L-NAME, eNOS synthase inhibitor) blocked the rosiglitazone-induced NO formation; LY294002 (a PI3K inhibitor) prevented the NO production; and the phosphorylation of eNOS and PKB was induced by rosiglitazone.@*CONCLUSION@#Treatment with rosiglitazone can increase the NO production and improve the endothelial function through up-regulating the PI3K/PKB/eNOS signal pathways in cultured HUVECs.

Exercise-induced Weight Reduce and Leptin (review) / 中国康复理论与实践

@#With the standard of living improved, people had less and less interests in exercise, adiposity has being a problem that people have to be up against all over the world. Exercise can step up energy expenditure, decrease fat accumulation, minish the volume of fat cell, and is one of widely used, effective, safe, economical measures of anti-adiposity. The adaptable change of neuroendocrine system in exercise quicken up fat to burn more. Leptine is an important signal of measuring fat content of body. The relationship between adiposity and leptin, and the effect of exercise on leptin was reviewed in this paper.