RNA Binding Protein Ybx2 Regulates RNA Stability During Cold-Induced Brown Fat Activation

Abstract

Recent years have seen an upsurge of interest in brown adipose tissue (BAT) to combat the epidemic of obesity and diabetes. How its development and activation are regulated at the posttranscriptional level, however, has yet to be fully understood. RNA binding proteins (RBPs) lie in the center of posttranscriptional regulation. To systemically study the role of RBPs in BAT, we profiled >400 RBPs in different adipose depots and identified Y-box binding protein 2 (Ybx2) as a novel regulator in BAT activation. Knockdown of Ybx2 blocks brown adipogenesis, whereas its overexpression promotes BAT marker expression in brown and white adipocytes. Ybx2-knockout mice could form BAT but failed to express a full thermogenic program. Integrative analysis of RNA sequencing and RNA-immunoprecipitation study revealed a set of Ybx2's mRNA targets, including Pgc1α, that were destabilized by Ybx2 depletion during cold-induced activation. Thus, Ybx2 is a novel regulator that controls BAT activation by regulating mRNA stability.

The RNA-binding protein HuR is a negative regulator in adipogenesis

“…Primary mouse brown and white preadipocytes were isolated from 3-to 4-week-old C57BL6 mice. Preadipocytes isolation, culture and differentiation were conducted as previous studies with minor modifications 13,36,38 . Briefly, interscapular BATs or iWATs from~3-week-old mice were minced, and digested in 0.2% collagenase, which were subsequently filtered by 40 μm cell strainer and centrifuged to collect stromal vascular fraction (SVF) cells in the pellets.…”

“…293T cells (ATCC) for retroviral packing were cultured in DMEM containing 10% FBS (HyClone). The retroviral vector pSUPER (Oligoengine) was used to generate short hairpin (sh)RNAs to infect preadipocytes; XZ201 vector 13 was used to overexpress HuR for gain-of-function studies. All of the retroviruses were packaged in 293T cells with the pCL-eco (IMGENEX/Ret-roMax) packaging vector for mouse preadipocyte infection and with pCL-10A (IMGENEX/RetroMax) packaging vector for human preadipocyte infection.…”

“…RNA pull-down. RNA pull-down was performed according to our published protocol with minor modifications 13,39 . The mouse eWAT lysate was prepared as described in RNA Immunoprecipitation above.…”

“…PSPC1 (paraspeckle component 1) promotes adipogenesis by facilitating the export of many adipocyte RNAs, including the RNA encoding the transcriptional regulator EBF1, from the nucleus to the cytosol 12 . Our recent work indicates that Ybx2 is an important regulator that controls brown adipose tissue activation by regulating mRNA stability 13 . However, the functions of most RBPs in adipocytes remain unexplored.…”

WITHDRAWN: hnRNPM Deficiency Deteriorates Cognitive Function by Decreasing Synaptic Proteins

“…Furthermore, we found results consistent with the observed changes in vivo in hippocampus, and in vitro, in primary cultured neuron. RNA binding proteins (RBPs) comprise a large and diverse group [36] that lie at the center of posttranscriptional regulation by governing the fate of mRNA transcripts from biogenesis, stabilization, and translation to RNA decay [37]. The regulation of mRNA decay is a major control point in gene expression by RBPs [28].…”