miR-487a-3p upregulated in type 1 diabetes targets CTLA4 and FOXO3
DIABETES RESEARCH AND CLINICAL PRACTICE
Authors: Zurawek, Magdalena; Dzikiewicz-Krawczyk, Agnieszka; Izykowska, Katarzyna; Ziolkowska-Suchanek, Iwona; Skowronska, Bogda; Czainska, Maria; Podralska, Marta; Fichna, Piotr; Przybylski, Grzegorz; Fichna, Marta; Nowak, Jerzy
Abstract
Aims: Type 1 diabetes (T1D) is an autoimmune disorder caused by the T-cell mediated destruction of the insulin-producing pancreatic beta cells. T1D is a consequence of complex processes, influenced by genetic, epigenetic and environmental factors. MicroRNAs (miRNAs) are small non-coding RNAs that target multiple mRNAs and regulate gene expression. The implication of miRNAs in T1D pathogenesis, as potential modulators of immune response genes, remains poorly defined. The aim of this study was to investigate the expression profile of miRNAs in new onset T1D and the impact of deregulated miRNAs on target genes. Methods: Total RNA from peripheral blood mononuclear cells of newly diagnosed T1D pediatric patients and age-matched controls was screened for disease-associated miRNAs by a microarray analysis, with subsequent validation by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). miRNA targets were identified by luciferase reporter assays. Results: The microarray analysis revealed 91 deregulated miRNAs (P < 0.05) in T1D group compared to non-diabetic controls. Within this group we observed one upregulated and seven downregulated miRNAs with fold change >2.0. qRT-PCR validation revealed overexpression of miR-487a-3p which has not been previously reported in the context of T1D. Luciferase reporter assays indicated CTLA4 and FOXO3 genes as miR-487a-3p targets. Conclusion: Our study suggests that miR-487a-3p might repress CTLA4 and FOXO3 by binding to their 3'UTRs and contribute to the development of T1D. (C) 2018 Elsevier B.V. All rights reserved.
Matrine improves skeletal muscle atrophy by inhibiting E3 ubiquitin ligases and activating the Akt/mTOR/FoxO3 alpha signaling pathway in C2C12 myotubes and mice
ONCOLOGY REPORTS
Authors: Chen, Li; Chen, Linlin; Wan, Lili; Huo, Yan; Huang, Jinlu; Li, Jie; Lu, Jin; Xin, Bo; Yang, Quanjun; Guo, Cheng
Abstract
Skeletal muscle wasting is a feature of cancer cachexia that increases patient morbidity and mortality. Matrine, the main bioactive component of Sophora flavescens, has been approved for the prevention and therapy of cancer cachexia in China. However, to the best of our knowledge, its mechanism in improving muscle wasting remains unknown. The present study demonstrated that matrine increases muscle fiber size and muscle mass in an in vivo CT26 colon adenocarcinoma cachexia mouse model. Concurrently, other cachexia symptoms, including body and organ weight loss, were alleviated. In in vitro experiments, matrine substantially improved C2C12 myoblast differentiation with or without dexamethasone treatment. In addition, matrine reduced C2C12 myotube atrophy and apoptosis induced by dexamethasone, tumor necrosis factor alpha and conditioned medium. Two E3 ubiquitin ligases, muscle RING-finger containing protein-1 and muscle atrophy Fbox protein, which are specifically expressed in wasting skeletal muscle, were also significantly downregulated (P<0.05) by matrine both in C2C12 myotubes and skeletal muscle. Furthermore, matrine increased the phosphorylation of Akt, mTOR and FoxO3 alpha in the atrophying C2C12 myotube induced by dexamethasone. In conclusion, matrine can alleviate muscle atrophy and improve myoblast differentiation possibly by inhibiting E3 ubiquitin ligases and activating the Akt/mTOR/FoxO3 alpha signaling pathway.