Insulin treatment was confirmed to reduce insulin resistance, but the underlying mechanism remains unknown. Caveolin-1 (Cav-1) is a functional protein of the membrane lipid rafts, known as caveolae, and is widely expressed in mammalian adipose tissue. There is increasing evidence that show the involvement of Cav-1 in the AKT activation, which is responsible for insulin sensitivity. Our aim was to investigate the effect of Cav-1 depletion on insulin sensitivity and AKT activation in glargine-treated type 2 diabetic mice. Mice were exposed to a high-fat diet and subject to intraperitoneal injection of streptozotocin to induce diabetes. Next, glargine was administered to treat T2DM mice for 3 weeks (insulin group). The expression of Cav-1 was then silenced by injecting lentiviral-vectored short hairpin RNA (shRNA) through the tail vein of glargine-treated T2DM mice (CAV1-shRNA group), while scramble virus injection was used as a negative control (Ctrl-shRNA group). The results showed that glargine was able to upregulate the expression of PI3K and activate serine phosphorylation of AKT through the upregulation of Cav-1 expression in paraepididymal adipose tissue of the insulin group. However, glargine treatment could not activate AKT pathway in Cav-1 silenced diabetic mice. These results suggest that Cav-1 is essential for the activation of AKT and improving insulin sensitivity in type 2 diabetic mice during glargine treatment.

汇总中国知网全文数据库及万方数据库创库至2019年12月31日发表的关于全程导师制在住院医师规范化培训中实施情况的文献,总结该制度在住院医师规范化培训中的开展情况及效果评价.

Objective:To investigate the role of caveolin-1 (Cav1) in palmitic acid-induced survival of pancreatic islet β-cell.Methods:Cav1-deficient NIT-1 cells and mouse primary islets were constructed through lentiviral vector transfection. Control-shRNA was transfected as a control. After fatty-acid-free bovine serum albumin (BSA) and palmitic acid (0.5 mmol/L) incubation for 24 and 48 hours, cell viability and apoptosis werecalculated by methylcyclopentadienyl manganese tricarbonylassay and Hoechst33342/propidium iodide (PI) double staining.Real time PCR and Western blot were used to detect the expression of apoptosis-associated mRNA and protein. The t test and one-way ANOVA were used for statistical analysis. Results:Compared with the control group, the cell survival rate of the palmitic acid treatment group was significantly decreased (0.89±0.10 vs 0.24±0.04, t=13.49, P<0.01), and mRNA and protein expressions of P18 and P19 were up-regulated (1.00±0.09 vs 1.30±0.04, 1.00±0.04 vs 1.37±0.13, t=5.28, 4.71, both P<0.05; 0.87±0.04, 1.48±0.05, 1.02±0.06 vs 1.41±0.07, t=16.50, 7.33, both P<0.01); mRNA expression levels of cysteine-containing aspartic proteolytic enzymes (Caspase-6, Caspase-9, and Caspase-12) were significantly up-regulated (1.00±0.04 vs 1.57±0.08, 1.01±0.15 vs 1.57±0.20, 1.02±0.19 vs 1.57±0.09, t=11.04,3.88, 4.53, all P<0.05), and protein expression of them were also significantly increased (0.86±0.10 vs 1.28±0.11, 0.69±0.01 vs 0.86±0.06, 0.70±0.02 vs 1.18±0.01, t=4.89,4.84, 37.18, all P<0.01). The cell survival rate of Cav1-shRNA+palmitic acid group was significantly higher than that of Ctrl-shRNA+palmitic acid group (0.53±0.10 vs 0.26±0.08, t=4.71, P<0.01). The mRNA and protein expression of P19 were all down-regulated (1.53±0.18 vs 0.66±0.04, 1.48±0.05 vs 0.70±0.02, t=8.17, 25.09, both P<0.01); mRNA expression levels of Caspase-6, Caspase-7, Caspase-9 and Caspase-12 were down-regulated (1.82±0.11 vs 1.03±0.07, 1.43±0.24 vs 0.42±0.15, 1.41±0.22 vs 0.51±0.18, 1.45±0.18 vs 0.42±0.13, t=5.48-10.49, all P<0.01), and protein expression of them were also down-regulated (0.99±0.14 vs 0.63±0.11, 0.90±0.14 vs 0.62±0.04, 0.90±0.02 vs 0.60±0.04, 1.30±0.01 vs 0.65±0.04, t=3.50-27.31, all P<0.01). Conclusion:Cav1 deficiency inhibites palmitic acid-induced pancreatic β-cell apoptosis via regulating Caspase family, and ultimately protects β cell viability.

目的 探讨小鼠胰岛提取方法 的改良及效果.方法根据胰岛提取方法不同,将小鼠随机分为胆总管穿刺组和胆总管穿刺联合胰腺原位注射组(联合注射组),每组各100只.胰岛提取的改良方法采用胆总管穿刺联合胰腺原位注射法灌注胰腺,体视显微镜下挑选并纯化胰岛.鉴定胰岛的形态和纯化情况,统计两组的胰岛产量及胰岛提取成功率.分析胰岛在体外培养1周内的存活情况,并评估体外培养24 h和4 d后胰岛的胰岛素分泌功能.结果 与胆总管穿刺组比较,联合注射组提取胰岛的产量显著增高(P<0.001).两组胰岛提取成功率均为83％,差异无统计学意义(P>0.05).胆总管穿刺联合胰腺原位注射法所提取的胰岛形态完好、纯度高、活性好.新鲜分离的胰岛体外培养24 h后胰岛存活率接近100％;体外培养1～5 d,胰岛细胞存活情况良好;体外培养6 d开始,胰岛出现中心性死亡.体外培养24 h和4 d后,给予高葡萄糖刺激胰岛后,小鼠胰岛功能均正常.结论 胆总管穿刺联合胰腺原位注射法可以提高胰岛的产量,且获取的胰岛细胞活性和功能良好.

目的 探讨妊娠期低FT4合并低TSH的实质及其与碘水平的关系.方法 将278例因甲状腺指标异常而就诊的孕妇分为低FT4合并低TSH组(43例)、亚临床甲减组(87例)、单纯低FT4血症组(46例)、单纯抗过氧化物酶抗体(TPOAb)阳性组(102例).比较各组的FT4、TSH、反三碘甲状腺原氨酸(rT3)和尿碘.对尿碘低于150μg/L者给予补碘治疗,比较治疗前后甲状腺功能与尿碘变化.结果 低FT4合并低TSH组的rT3高于亚临床甲减组、单纯低FT4血症组和单纯TPOAb阳性组[(54.8±9.3)ng/dl vs.(37.7±10.0)ng/dl、(35.4±10.1)ng/dl、(41.3±10.8)ng/dl,P均<0.05];而尿碘则低于其他3组[(125.8±22.9)μg/L vs.(144.0±15.8)μg/L、(138.5±28.5)μg/L、(147.9±32.2)μg/L,P均<0.05].低FT4合并低TSH组中尿碘低于150μg/L的33例孕妇经过补碘治疗后,FT4、TSH和尿碘均上升(P均<0.05).结论 妊娠期的低FT4合并低TSH可能是非甲状腺性病态综合征,或与缺碘有一定关系.

Our study aims to access the influence of caveolin1 (CAV1) on β cell expression profiles. We knocked down the expression of CAV1 in both NIT-1 cells and islets isolated from C57BL/6J mice using an RNA interference technique, which was realized by the transfer of an shRNA vector targeting CAV1 mRNA into NIT-1 cells or islets through latent virus infection. First, we identified the change in gene expression profiles in islets, in which the CAV1 expression level was down-regulated, as ascertained by mouse gene expression microarray, and the results showed that pathways related to β cell proliferation and pancreatic secretion functions were significantly influenced. The results of MTT demonstrated that the knockdown of CAV1 expression in NIT-1 cells promoted proliferation. The protein array results showed that pro-apoptotic cytokines were down-regulated in the NIT-1 cell line with CAV1 knockdown. These findings suggest that CAV1 might be involved in apoptosis and proliferation regulation in β cells, and therefore could be a potential target for the development of novel therapies for diabetes mellitus.

Lipotoxicity leads to insulin secretion deficiency, which is among the important causes for the onset of type 2 diabetes mellitus. Thus, the restoration of β-cell mass and preservation of its endocrine function are long-sought goals in diabetes research. Previous studies have suggested that the membrane protein caveolin-1 (Cav-1) is implicated in β-cell apoptosis and insulin secretion, however, the underlying mechanisms still remains unclear. Our objective is to explore whether Cav-1 depletion protects pancreatic β cells from lipotoxicity and what are the underlying mechanisms. In this study, we found that Cav-1 silencing significantly promoted β-cell proliferation, inhibited palmitate (PA)-induced pancreatic β-cell apoptosis and enhanced insulin production and secretion. These effects were associated with enhanced activities of Akt and ERK1/2, which in turn downregulated the expression of cell cycle inhibitors (FOXO1, GSK3β, P21, P27 and P53) and upregulated the expression of Cyclin D2 and Cyclin D3. Subsequent inhibition of PI3K/Akt and ERK/MAPK pathways abolished Cav-1 depletion induced β-cell mass protection. Furthermore, under PA induced endoplasmic reticulum (ER) stress, Cav-1 silencing significantly reduced eIF2α phosphorylation and the expression of ER stress-responsive markers BiP and CHOP, which are among the known sensitizers of lipotoxicity. Our findings suggest Cav-1 as potential target molecule in T2DM treatment via the preservation of lipotoxicity-induced β-cell mass reduction and the attenuation of insulin secretion dysfunction.

Lipotoxicity induced intracellular lipid accumulation in pancreatic β cells, one of the strongest predictors for T2DM. The objective of this study is to explore the role of Cav-1 in intracellular lipid accumulation of β cells under lipotoxicity condition. Our data showed that Cav-1 silencing significantly reduced PA-induced intracellular triglyceride (TG) accumulation, enhanced autophagy and insulin secretion in NIT-1 cells and murine pancreatic islets. Further investigation found that Cav-1 depletion facilitated AMPK phosphorylation, decreased the expression of downstream lipogenic makers (SREBP-1c, FAS and ACC) and increased the expression of fatty acid oxidation maker (CPT-1), leading to the ultimate enhancement of lipid metabolism. Meanwhile, Cav-1 depletion also suppressed mTOR phosphorylation, decreased the expression of p62 protein and increased the expression of LC3-II proteins, resulting in the ultimate increase of autophagy. Subsequent inhibition of AMPK and mTOR pathways abolished Cav-1 depletion mediated autophagy enhancement and TG content reduction, leading to the reduction of insulin secretion. Our findings suggest the potential application of the Cav-1 molecule as a target for effective T2DM treatment through preservation of lipotoxicity-induced β-cell intracellular lipid accumulation and dysfunction. Disclosure W. Zeng: None. K. Liu: None. J. Tang: None. H. Peng: None. C. Lin: None. S. Lin: None. K. Lin: None. Y. Jiang: None. L. Zeng: None.

Insulin treatment improves insulin sensitivity, but the underlying mechanism remains unknown. Caveolin-1(Cav-1) konckout mice present insulin resistance.Our aim is to investigate the effect of Cav-1 depletion on insulin sensitivity and PI3K/AKT activation in glargine treatment of type 2 diabetic mice. C57BL/6J mice were divided into five groups(n=5 for each group).We firstly used high-fat high-carbonhydrate diet with intraperitoneal injection of streptozotocin(40mg/kg for 3 days) to induce type 2 diabetic(T2DM group) mice. Next, glargine was started at a dose of 0.4u/day to T2DM mice for 3 weeks(Insulin group).Lastly, Cav-1 expression was silenced by lentiviral-vectored short hairpin RNA (shRNA) through tail vein injection in glargine treated T2DM mice(CAV1-shRNA group) with scramble virus injection as a negative control(Ctrl-shRNA group). As a result, improvement of insulin sensitivity and PI3K/AKT activation with upregulation of Cav-1 were observed in visceral adipose tissue of Insulin group compared with T2DM group (P<0.05). In CAV1-shRNA group,impairment of insulin tolerance and PI3K/AKT activation couldn’t be improved by glargine compared with Ctrl-shRNA group (P<0.05). Our findings suggest that Cav-1 is required for insulin to improve insulin sensitivity and PI3K/AKT activation. More studies are needed to elucidate the mechanism. Disclosure H. Peng: None. H. Li: None. S. Lin: None. W. Zeng: None. C. Lin: None. K. Lin: None. L. Zeng: None.

Objective To investigate the role of glargine in glucose metabolism improvement and antiinflammation of skeletal muscle in Caveolin-1 silenced type 2 diabetic mice.Methods Multiple low doses of streptozotocin (STZ) intraperitoneal injection and high-fat high-glucose (HFHG) were used to induce type 2 diabetic mice model.The mice were divided into normal control group (NC group) and type 2 diabetic model group (T group).Then according to virus injection and glargine treatment,T group were further divided into type 2 diabetes group (T2DM group),type 2 diabetes with insulin treatment group (insulin group),Caveolin-1 silenced with insulin treatment group (LV-CAV1 group),and scramble virus with insulin treatment group (LV-GFP group).Glucose metabolism was accessed by the fluctuation of blood glucose.TNF-α protein expression in skeletal muscle was detected by Western blot.Results The glycemic control of LV-CAV1 group needed more dosages of glargine (P ＜ 0.05).The expression of TNFαin skeletal muscle was elevated in LV-CAV 1 group than that in LV-GFP and insulin group (P ＜ 0.05).Conclusion The anti-inflammation function and glycemic metabolism improvement of glargine may be associated with the expression of Caveoin-1 in skeletal muscle.

Syndrome of inappropriate antidiuretic hormone secretion (SIADH)is characterized by hy-po-osmolar hyponatremia and impaired urine dilution capacity.The etiology of SIADH is complicated.Water restriction is the main therapy.Here we reported a 65-year female patient suffered from transient SIADH.She was admitted due to mental tension for over 10 years,bilateral lower limb fatigue for 6 months,vomiting for 3 days and anxiety symptoms.The examination findings revealed hypo-osmolar hyponatremia,which was consist-ent with the diagnostic criterion of SIADH.After anti-anxiety therapy and physiological saline supplement,the level of serum sodium gradually returned to normal range.During the advanced stage,she could maintain elec-trolyte balance by normal diet.After 17 d-hospitalization,she was discharged with no recurrent symptoms. Therefore,the possibility of transient SIADH should be considered for the elderly patients with anxiety symp-toms,especially those complicated with gastrointestinal disorders.