Ameliorative effect of melatonin against increased intestinal permeability in diabetic rats: possible involvement of MLCK-dependent MLC phosphorylation

• Published in: Molecular and cellular biochemistry Vol. 416; no. 1-2; pp. 23 - 32
• Main Authors: Yang, Xiaoping, Zou, Duobing, Tang, Songtao, Fan, Tingting, Su, Huan, Hu, Ruolei, Zhou, Qing, Gui, Shuyu, Zuo, Li, Wang, Yuan
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2016; Springer; Springer Nature B.V
• Subjects: Animals; Biochemistry; Biomedical and Life Sciences; Blood sugar; Cardiology; Diabetes; Diabetes Mellitus, Experimental - metabolism; Diabetes Mellitus, Experimental - pathology; Diabetes Mellitus, Type 2 - metabolism; Diabetes therapy; Extracellular Signal-Regulated MAP Kinases - metabolism; Intestinal Absorption - drug effects; Kinases; Life Sciences; Male; Medical Biochemistry; Melatonin; Melatonin - pharmacokinetics; Melatonin - pharmacology; Muscle proteins; Myosin; Myosin Light Chains - metabolism; Myosin-Light-Chain Kinase - metabolism; Oncology; Permeability; Phosphorylation; Rats; Rats, Sprague-Dawley; Receptor, Melatonin, MT1 - metabolism; Receptor, Melatonin, MT2 - metabolism; rho-Associated Kinases - metabolism; Rocks; Streptozocin; Type 2 diabetes; Melatonin; Diabetes; Myosin light chain kinase; Intestinal epithelial permeability
• ISSN: 0300-8177; 1573-4919
• DOI: 10.1007/s11010-016-2691-4

The increased intestinal permeability and functional impairment play an important role in type 2 diabetes (T2D), and melatonin may possess enteroprotection properties. Therefore, we used streptozotocin-induced diabetic rat model to investigate the regulation of intestinal permeability by melatonin. Rats were randomly divided into three groups, including control, diabetes mellitus (DM), and DM rats treated with melatonin. Melatonin was administered (10 mg/kg/day) by gavage for 24 weeks. The DM rats significantly increased the serum fasting blood glucose and lipid levels, which were alleviated by melatonin treatment. Importantly, the intestinal epithelial permeability was significantly increased in DM rats but was ameliorated following treatment with melatonin. These findings also indicated the expression of myosin light chain kinase (MLCK) and phosphorylation of MLC targeting subunit (MYPT) induced myosin light chain (MLC) phosphorylation level was markedly elevated in hyperglycemic and hyperlipidemic status. They were partly associated with down-regulated membrane type 1 and 2 (MT1 and MT2) expression, and up-regulated Rho-associated protein kinase (ROCK) expression and increased extracellular signal-regulated kinase (ERK) phosphorylation. However, the changes in target protein expression were reversed by melatonin. In conclusion, our results show melatonin beneficial effects on impaired intestinal epithelial permeability in T2D by suppressing ERK/MLCK- and ROCK/MCLP-dependent MLC phosphorylation.