Low-Dose Acrolein,an Endogenous and Exogenous Toxic Molecule,Inhibits Glucose Transport via an Inhibition of Akt-Regulated GLUT4 Signaling in Skeletal Muscle Cells

Urinary acrolein adduct levels have been reported to be increased in both habitual smokers and type-2 diabetic patients. The impairment of glucose transport in skeletal muscles is a major factor responsible for glucose uptake reduction in type-2 diabetic patients. The effect of acrolein on glucose metabolism in skeletal muscle remains unclear. Here, we investigated whether acrolein affects muscular glucose metabolism in vitro and glucose tolerance in vivo. Exposure of mice to acrolein (2.5 and 5 mg/kg/day) for 4 weeks substantially increased fasting blood glucose and impaired glucose tolerance. The glucose transporter-4 (GLUT4) protein expression was significantly decreased in soleus muscles of acrolein-treated mice. The glucose uptake was significantly decreased in differentiated C2C12 myotubes treated with a non-cytotoxic dose of acrolein (1 μM) for 24 and 72 h. Acrolein (0.5–2 μM) also significantly decreased the GLUT4 expression in myotubes. Acrolein suppressed the phosphorylation of glucose metabolic signals IRS1, Akt, mTOR, p70S6K, and GSK3α/β. Over-expression of constitutive activation of Akt reversed the inhibitory effects of acrolein on GLUT4 protein expression and glucose uptake in myotubes. These results suggest that acrolein at doses relevant to human exposure dysregulates glucose metabolism in skeletal muscle cells and impairs glucose tolerance in mice.     

合成丙烯酸用催化剂的研究进展

对近期丙烯选择氧化和丙烷选择氧化制丙烯酸的催化剂研究进行了综述,前者主要是钼-铋系列催化剂和钼-钒系列催化剂,后者涉及到钒-磷-氧（VPO）催化剂、杂多酸（HPA）及其盐催化剂以及以钼为主要成分的复合金属氧化物（CMO）催化剂。     

茶碱及其复配多酚协同清除丙烯醛作用研究

目的 考察茶碱及结构相似的生物碱在模拟加工体系中对丙烯醛（acrolein, ACR）的清除活性并探究12种常见多酚与茶碱复配对其活性的影响。方法 通过高效液相色谱法分析模拟加工体系中茶碱及结构相似的生物碱对ACR的清除活性以及模拟生理条件下12种多酚与茶碱复配后反应体系中茶碱和ACR一加合产物（TP-ACR）含量的变化，并以表没食子儿茶素没食子酸酯（Epigallocatechin gallate, EGCG）为代表，根据Chou-Talalay法则将茶碱与EGCG以1:50的比例进行复配, 计算联合作用指数，分析复配组分之间作用效果。结果 茶碱、副黄嘌呤、可可碱在模拟加工体系均有良好的ACR清除活性，茶碱的活性最佳，30min时可清除体系中79%的ACR。12种多酚中杨梅素、槲皮素、山奈酚、高良姜素和姜黄素可促进茶碱对ACR的清除作用，促进效果分别可达10.7%、26.8%、20.1%、19.4%、43.1%，而根皮素、表儿茶素、EGCG、阿魏酸、绿原酸、咖啡酸和白藜芦醇则抑制了茶碱的清除活性。茶碱与EGCG的添加浓度范围分别为0.05-0.5 μg/mL与2.5-25 μg/mL时联用在低温和高温条件下均可表现出较好的协同效应。结论 茶碱自身可在模拟加工条件下发挥良好的ACR清除作用，且可与多酚联用协同增效，从而提高其清除活性。