circNrxn2 Promoted WAT Browning via Sponging miR-103 to Relieve Its Inhibition of FGF10 in HFD Mice
MOLECULAR THERAPY-NUCLEIC ACIDS
Authors: Zhang, Tiantian; Zhang, Zhenzhen; Xia, Tianyu; Liu, Chenlong; Sun, Chao
Abstract
The accumulation of excess white adipose tissue (WAT) has harmful consequences on metabolic health. WAT browning confers beneficial effects on adiposity, insulin resistance, and hyperlipidemia. In this study, it was found out that circNrxn2 sponged miR-103 and enhanced FGF10 levels in HFD mice WAT. We discovered that circNrxn2 promoted WAT browning and mitochondria functions. Furthermore, circNrxn2 also increased M2 macrophage polarization in HFD mouse adipose tissue, and the PPAR gamma signaling pathway participated in these biological processes. Moreover, eliminating adipose tissue macrophages (ATMs) by clodronate-crippled circNrxn2 promoted WAT browning, and the simulation co-culture of macrophages and adipocytes results suggested that circNrxn2 promoted WAT browning through increasing M2 macrophage polarization. Our finding revealed that circNrxn2 acted as an endogenous miR-103 sponge, blocked miR-103 effects, and relieved its inhibition of FGF10 expression to promote WAT browning through increasing M2 macrophage polarization. This study provides a good therapeutic strategy for treating obesity and improving obesity-related metabolic disorders.
Regulation of FGF10 Signaling in Development and Disease
FRONTIERS IN GENETICS
Authors: Watson, Joanne; Francavilla, Chiara
Abstract
Fibroblast Growth Factor 10 (FGF10) is a multifunctional mesenchymal-epithelial signaling growth factor, which is essential for multi-organ development and tissue homeostasis in adults. Furthermore, FGF10 deregulation has been associated with human genetic disorders and certain forms of cancer. Upon binding to FGF receptors with heparan sulfate as co-factor, FGF10 activates several intracellular signaling cascades, resulting in cell proliferation, differentiation, and invasion. FGF10 activity is modulated not only by heparan sulfate proteoglycans in the extracellular matrix, but also by hormones and other soluble factors. Despite more than 20 years of research on FGF10 functions, context-dependent regulation of FGF10 signaling specificity remains poorly understood. Emerging modes of FGF10 signaling regulation will be described, focusing on the role of FGF10 trafficking and sub-cellular localization, heparan sulfate proteoglycans, and miRNAs. Systems biology approaches based on quantitative proteomics will be considered for globally investigating FGF10 signaling specificity. Finally, current gaps in our understanding of FGF10 functions, such as the relative contribution of receptor isoforms to signaling activation, will be discussed in the context of genetic disorders and tumorigenesis.