Salidroside ameliorates insulin resistance through activation of a mitochondria-associated AMPK/PI3K/Akt/GSK3β pathway

Background and Purpose

Recent reports have suggested that salidroside could protect cardiomyocytes from oxidative injury and stimulate glucose uptake in skeletal muscle cells by activating AMP-activated protein kinase (AMPK). The aim of this study was to evaluate the therapeutic effects of salidroside on diabetic mice and to explore the underlying mechanisms.

Experimental Approach

The therapeutic effects of salidroside on type 2 diabetes were investigated. Increasing doses of salidroside (25, 50 and 100 mg·kg⁻¹·day⁻¹) were administered p.o. to db/db mice for 8 weeks. Biochemical analysis and histopathological examinations were conducted to evaluate the therapeutic effects of salidroside. Primary cultured mouse hepatocytes were used to further explore the underlying mechanisms in vitro.

Key Results

Salidroside dramatically reduced blood glucose and serum insulin levels and alleviated insulin resistance. Hypolipidaemic effects and amelioration of liver steatosis were observed after salidroside administration. In vitro, salidroside dose-dependently induced an increase in the phosphorylations of AMPK and PI3K/Akt, as well as glycogen synthase kinase 3β (GSK3β) in hepatocytes. Furthermore, salidroside-stimulated AMPK activation was found to suppress the expression of PEPCK and glucose-6-phosphatase. Salidroside-induced AMPK activation also resulted in phosphorylation of acetyl CoA carboxylase, which can reduce lipid accumulation in peripheral tissues. In isolated mitochondria, salidroside inhibited respiratory chain complex I and disturbed oxidation/phosphorylation coupling and moderately depolarized the mitochondrial membrane potential, resulting in a transient increase in the AMP/ATP ratio.

Conclusions and Implications

Salidroside exerts an antidiabetic effect by improving the cellular metabolic flux through the activation of a mitochondria-related AMPK/PI3K/Akt/GSK3β pathway     

Preparation of MoS2-based polydopamine-modified core–shell nanocomposites with elevated adsorption performances

New molybdenum disulfide (MoS₂)-based core–shell nanocomposite materials were successfully prepared through the self-assembly of mussel-inspired chemistry. Characterization by Fourier transform infrared, thermogravimetric analysis, scanning electron microscope and transmission electron microscopy revealed that the surface of the flaked MoS₂ was homogeneously coated with a thin layer of polydopamine (PDA). Dye adsorption performances of the synthesized MoS₂–PDA nanocomposites were investigated at different pH values and reaction times. Compared with pure MoS₂ nanosheets, the obtained core–shell nanocomposites showed elevated adsorption performances and high stability, indicating their potential applications in wastewater treatment and composite materials.

New core–shell MoS₂–PDA nanocomposites are prepared via mussel-inspired chemistry and a simple interfacial self-assembly process, demonstrating potential applications in wastewater treatment and self-assembled core–shell composite materials.     

Polydopamine-coated graphene nanosheets as efficient electrocatalysts for oxygen reduction reaction

Polydopamine-modified graphene (G-PDA) materials were synthesized by in situ polymerization of a dopamine monomer on the surface of graphene oxide. X-ray photoelectron spectroscopy (XPS) has confirmed that new N-containing functional groups are formed during the synthesis process, which result in the excellent electrocatalytic activity of the composite towards ORR in terms of onset potential, number of electron transferred and limiting current density. The electrocatalytic activity of the optimized G-PDA sample is better than N-doped graphene and comparable to the commercial 20 wt% Pt/C catalyst. Furthermore, compared with the Pt-based catalysts, the G-PDA showed superior stability and methanol resistance, which favored its practical applications in fuel cells.

Polydopamine-coated graphene nanosheets show excellent electrocatalytic activity towards oxygen reduction reaction.     

A new promising nucleating agent for polymer foaming: effects of hollow molecular-sieve particles on polypropylene supercritical CO2 microcellular foaming

Because polypropylene (PP) foam normally exhibits nonuniform cell size and cracked cellular structure, a narrow cell-size distribution and a well-defined morphology are always the focus of PP foaming technology. In this work, hollow molecular-sieve (MS) particles were applied as a potential nucleating agent in supercritical carbon dioxide (scCO₂) foaming of PP. It was observed that the addition of MS particles largely narrowed the cell-size distribution. The resultant PP/MS foams exhibited significant concurrent enhancement in their cell density and mechanical properties: the cell density increased remarkably, by approximately 10 times, and the tensile strength increased from 6.1 MPa to 12.6 MPa. The hollow-structure MS particles resulted in a higher heterogeneous nucleation efficiency in the PP foaming process. We believe that the trapping of CO₂ in the hollow holes of MS particles largely increased the solubility CO₂ in PP and a number of gas cavities were formed. The existence of gas cavities reduced the energy barrier of heterogeneous nucleation, favoring the formation of a well-defined cellular structure. Additionally, the regular-hexagon shape of the cells might endow the PP foam with better mechanical properties compared with a circular cell shape.

Hollow molecular-sieve particles were applied as a new nucleating agent in preparing PP foam with outstanding mechanical properties by using scCO₂.     

临床采供血信息管理系统的建立与应用

目的通过建立临床采供血信息管理系统,规范医院采供血流程,确保临床用血安全。方法系统采用C/S(客户端/服务器)架构,基于可视化编程语言PowerBuilder10.5开发,操作界面友好。系统与医院信息系统(HIS)和实验室信息管理系统(LIS)建立数据接口,实现了医疗数据共享。结果各系统间互联互通、血液信息资源共享,并可对每袋血液从采集到临床使用进行全程实时监控和追踪。结论输血科实时对HIS输血子系统进行维护,可进一步保证血液质量和临床用血安全。     

腹腔感染病原菌及其耐药性

目的了解腹腔感染病原菌构成及其耐药性,为临床腹腔感染的治疗提供参考依据。方法对某院2011年1月—2013年12月住院患者送检的腹腔感染标本进行菌种鉴定及药物敏感性检测,并将数据输入WHONET5.6软件进行统计分析。结果 15 946份腹腔感染标本分离非重复病原菌810株,培养阳性率5.08%;革兰阴性杆菌485株(59.88%),革兰阳性菌275株(33.95%),真菌50株(6.17%);居前5位的病原菌分别为大肠埃希菌(24.20%)、屎肠球菌(15.06%)、鲍曼不动杆菌(8.89%)、肺炎克雷伯菌(7.66%)和凝固酶阴性葡萄球菌(6.91%)。产超广谱β-内酰胺酶(ESBLs)大肠埃希菌和肺炎克雷伯菌检出率分别为59.18%和32.79%,各种肠杆菌科细菌对亚胺培南仍高度敏感,但对碳青霉烯类耐药的菌株占4.08%~6.67%;多重耐药鲍曼不动杆菌占52.11%(37/71),耐甲氧西林金黄色葡萄球菌(MRSA)占53.57%(15/28),耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)占71.43%(40/56),耐万古霉素屎肠球菌(VRE)占8.26%。结论该院腹腔感染病原菌主要是以大肠埃希菌为代表的革兰阴性菌,屎肠球菌是最常见革兰阳性致病菌,细菌耐药形势严峻。     

Folate Deficiency Decreases Apoptosis of Endometrium Decidual Cells in Pregnant Mice via the Mitochondrial Pathway

It is well known that maternal folate deficiency results in adverse pregnancy outcomes. In addition to aspects in embryonic development, maternal uterine receptivity and the decidualization of stromal cells is also very important for a successful pregnancy. In this study, we focused on endometrium decidualization and investigated whether apoptosis, which is essential for decidualization, was impaired. Flow cytometry and TUNEL detection revealed that apoptosis of mouse endometrium decidual cells was suppressed in the dietary folate-deficient group on Days 7 and 8 of pregnancy (Day 1 = vaginal plug) when decidua regression is initiated. The endometrium decidual tissue of the folate deficiency group expressed less Bax compared to the normal diet group while they had nearly equal expression of Bcl2 protein. Further examination revealed that the mitochondrial transmembrane potential (ΔΨm) decreased, and the fluorescence of diffuse cytoplasmic cytochrome c protein was detected using laser confocal microscopy in normal decidual cells. However, no corresponding changes were observed in the folate-deficient group. Western blotting analyses confirmed that more cytochrome c was released from mitochondria in normal decidual cells. Taken together, these results demonstrated that folate deficiency could inhibit apoptosis of decidual cells via the mitochondrial apoptosis pathway, thereby restraining decidualization of the endometrium and further impairing pregnancy.