Subfatin is a Novel Adipokine and Unlike Meteorin in Adipose and Brain Expression
CNS NEUROSCIENCE & THERAPEUTICS
Authors: Li, Zhi-Yong; Zheng, Si-Li; Wang, Pei; Xu, Tian-Ying; Guan, Yun-Feng; Zhang, Yi-Jie; Miao, Chao-Yu
Abstract
Aims Adipose tissue releases adipokines that play important roles in metabolic and cardio-cerebro-vascular homeostasis. This study was to discover novel adipokines using caloric restriction model. Methods Adipokine candidates were captured by gene array and bioinformatics analysis and verified by preparation of recombinant protein and antibody. Results We established a potential secreted protein database containing 208 genes and identified a novel adipokine, Subfatin, that was the highest expressed in subcutaneous fat of both rodents and humans among 15 detected tissues. The secreted mammalian Subfatin was a glycosylated protein. Subfatin was located diffusely throughout the adipose tissue except lipid droplets, with comparable expression between adipocytes and stromal cells, but much lower expression in macrophages than adipocytes. Subfatin was downregulated in white adipose tissue of caloric restriction rats, whereas dramatically upregulated during white adipocyte differentiation as well as in white adipose tissue of diet-induced obese mice. Subfatin was annotated as Meteorin-like (Metrnl) in public databases, a similar transcript of Meteorin (Metrn, also known as glial cell differentiation regulator). Meteorin displayed a brain-specific expression and was scarce in various adipose tissues, in contrast to the tissue expression patterns of Subfatin. Conclusions Subfatin is a novel adipokine regulated by adipogenesis and obesity, with tissue distribution different from its homologue Meteorin.
Circular RNA-ZNF609 regulates retinal neurodegeneration by acting as miR-615 sponge
THERANOSTICS
Authors: Wang, Jia-Jian; Liu, Chang; Shan, Kun; Liu, Bai-Hui; Li, Xiu-Miao; Zhang, Shu-Jie; Zhou, Rong-Mei; Dong, Rui; Yan, Biao; Sun, Xing-Huai
Abstract
Glaucoma is a major cause of visual impairment characterized by progressive retinal neurodegeneration. Circular RNAs are a class of endogenous noncoding RNAs that regulate gene expression in eukaryotes. In this study, we investigated the role of cZNF609 in retinal neurodegeneration induced by glaucoma. Methods: qRT-PCR and Sanger sequencing were conducted to detect cZNF609 expression pattern during retinal neurodegeneration. Immunofluorescence staining was conducted to detect the effect of cZNF609 silencing on retinal neurodegeneration in vivo. MTT assay, Ki67 staining, and PI staining were conducted to detect the effect of cZNF609 silencing on retinal glial cells and RGC function in vitro. Bioinformatics analysis, RNA pull-down assays, and in vitro studies were conducted to reveal the mechanism of cZNF609-mediated retinal neurodegeneration. Results: cZNF609 expression was significantly up-regulated during retinal neurodegeneration. cZNF609 silencing reduced retinal reactive gliosis and glial cell activation, and facilitated RGC survival in vivo. cZNF609 silencing directly regulated Muller cell function but indirectly regulated RGC function in vitro. cZNF609 acted as an endogenous miR-615 sponge to sequester and inhibit miR-615 activity, which led to increased METRN. METRN overexpression could partially rescue cZNF609 silencing-mediated inhibitory effects on retinal glial cell proliferation. Conclusion: Intervention of cZNF609 expression is a promising therapeutic strategy for retinal neurodegeneration.