OB-RGRP regulates the phosphorylation of JAK2 and STAT3 in primary rat adipocytes

Abstract

This study aimed to explore the role of obestatin R gene-related protein (OB-RGRP) in autocrine signal transduction of adipocytes. Primary rat adipocytes were isolated and verified by microscopic observation and oil red O staining. OB-RGRP expression vector and OB-RGRP siRNA (si-OB-RGRP) were constructed and transfected into adipocytes. Adipocytes were then divided into five groups: (1) Control; (2) Vector (empty expression vector); (3) OB-RGRP (OB-RGRP expression vector); (4) si-OB-RGRP NC (si-OB-RGRP negative control); (5) si-OB-RGRP. mRNA and protein levels of OB-RGRP, JAK2, phosphorylated JAK2 (p-JAK2), STAT3 and phosphorylated STAT3 (p-STAT3) were examined using RT-PCR and western blot, respectively. Results showed that mRNA and protein levels of OB-RGRP in the Vector and si-OB-RGRP NC groups were similar to those in the Control group. Their levels in the si-OB-RGRP and OB-RGRP groups were significantly down-regulated and up-regulated (p < .05), respectively, in comparison with the control cells. There was no significant difference in the mRNA and protein levels of JAK2 and STAT3 among various groups. Moreover, the si-OB-RGRP NC and Vector groups induced similar ratios of p-JAK2 to JAK2 (p-JAK2/JAK2) and p-STAT3 to STAT3 (p-STAT3/STAT3) to the Control group. However, these two ratios in the si-OB-RGRP and OB-RGRP groups were significantly reduced and elevated (p < .05), respectively, in comparison with the Control group. These results suggested that OB-RGRP overexpression enhanced the levels of p-JAK2 and p-STAT3 while OB-RGRP silencing lowered their levels. In conclusion, OB-RGRP regulated the phosphorylation of JAK2 and STAT3 in primary rat adipocytes.

Keywords:

• Obesity
• leptin
• OB-RGRP
• leptin receptor
• JAK2
• STAT3

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability

The analyzed data sets generated during the study are available from the corresponding author on reasonable request.

Additional information

Funding

This work was supported by the Jiangxi Provincial Science and Technology Pillar Program [20092DS15900 and 2010BSA12400] and Jiangxi Provincial Natural Science Foundation [20122BAB205010].