Eun-Ju Chang1, Seul Ki Lee, Young Sook Song, Yeon Jin Jang, Hye Soon Park, Joon Pio Hong, A Ra Ko, Dae Yeon Kim, Jong-Hyeok Kim, Yeon Ji Lee, Yoon-Suk Heo. 1. Departments of Biomedical Sciences (E.-J.C.) and Physiology (S.K.L., Y.S.S., Y.J.J.), Cell Dysfunction Research Center, and Departments of Family Medicine (H.S.P.), Plastic Surgery (J.P.H.), and Obstetrics and Gynecology (A.R.K., D.Y.K., J.-H.K.), University of Ulsan College of Medicine, Seoul 138-736, Korea; and Departments of Family Medicine (Y.J.L.) and General Surgery (Y.-S.H.), Inha University, College of Medicine, Incheon 402-751, Korea.
Abstract
OBJECTIVES: IL-34 is a recently identified alternative ligand for colony-stimulating factor-1 (CSF-1) receptor. IL-34 and CSF-1 are regulators of differentiation, proliferation, and survival in mononuclear phagocytes. Here, we investigated the IL-34 serum concentration and expression in human adipose tissues and any associations with insulin resistance. METHODS: We recruited 19 nondiabetic obese women, 9 type 2 diabetic women, and 27 normal-weight women. Metabolic parameters, abdominal fat distribution, serum IL-34 concentration, and IL-34 mRNA expression were measured in abdominal sc adipose tissue (SAT) and visceral adipose tissue (VAT). In addition, the expression/secretion and putative effects of IL-34 were assessed in human differentiated adipocytes. Serum IL-34 concentration was measured before and 5 to 9 months after laparoscopic Roux-en-Y gastric bypass surgery was performed on the 20 obese patients. RESULTS: Regardless of diabetes status, obese patients demonstrated significantly higher serum IL-34 concentrations than controls. Serum IL-34 was significantly and positively correlated with insulin resistance-related metabolic parameters. IL-34 mRNA was significantly higher in VAT than SAT. IL-34 was expressed in adipocytes as well as nonadipocytes, and expression was significantly higher during adipogenesis. In differentiated adipocytes, the expression/secretion of IL-34 was enhanced by TNFα and IL-1β. In addition, IL-34 augmented fat accumulation and inhibited the stimulatory effects of insulin on glucose transport. Moreover, serum IL-34 was significantly decreased after Roux-en-Y gastric bypass-induced weight loss. CONCLUSION: The present study demonstrates, for the first time, that IL-34 is expressed in human adipose tissues and the circulating concentration is significantly elevated in obese patients. This suggests that IL-34 is associated with insulin resistance.
OBJECTIVES:IL-34 is a recently identified alternative ligand for colony-stimulating factor-1 (CSF-1) receptor. IL-34 and CSF-1 are regulators of differentiation, proliferation, and survival in mononuclear phagocytes. Here, we investigated the IL-34 serum concentration and expression in human adipose tissues and any associations with insulin resistance. METHODS: We recruited 19 nondiabetic obesewomen, 9 type 2 diabeticwomen, and 27 normal-weight women. Metabolic parameters, abdominal fat distribution, serum IL-34 concentration, and IL-34 mRNA expression were measured in abdominal sc adipose tissue (SAT) and visceral adipose tissue (VAT). In addition, the expression/secretion and putative effects of IL-34 were assessed in human differentiated adipocytes. Serum IL-34 concentration was measured before and 5 to 9 months after laparoscopic Roux-en-Y gastric bypass surgery was performed on the 20 obesepatients. RESULTS:Regardless of diabetes status, obesepatients demonstrated significantly higher serum IL-34 concentrations than controls. Serum IL-34 was significantly and positively correlated with insulin resistance-related metabolic parameters. IL-34 mRNA was significantly higher in VAT than SAT. IL-34 was expressed in adipocytes as well as nonadipocytes, and expression was significantly higher during adipogenesis. In differentiated adipocytes, the expression/secretion of IL-34 was enhanced by TNFα and IL-1β. In addition, IL-34 augmented fat accumulation and inhibited the stimulatory effects of insulin on glucose transport. Moreover, serum IL-34 was significantly decreased after Roux-en-Y gastric bypass-induced weight loss. CONCLUSION: The present study demonstrates, for the first time, that IL-34 is expressed in human adipose tissues and the circulating concentration is significantly elevated in obesepatients. This suggests that IL-34 is associated with insulin resistance.
Authors: Paula F Rosenbaum; Ruth S Weinstock; Allen E Silverstone; Andreas Sjödin; Marian Pavuk Journal: Environ Int Date: 2017-08-02 Impact factor: 9.621
Authors: Anja Meyer; Ryan Sienes; Brian Zanotti; Katrien van Raemdonck; Karol Palasiewicz; Daniel P Mass; Michael V Volin; Shiva Shahrara Journal: Cell Mol Immunol Date: 2022-06-08 Impact factor: 22.096