Secretory phospholipase A 2 group IIA enhances the metabolic rate and increases glucose utilization in response to thyroid hormone

FASEB J. 2019 Jan;33(1):738-749. doi: 10.1096/fj.201800711R. Epub 2018 Jul 18.

Abstract

Secretory phospholipase A2 group IIA (PLA2G2A) is a phospholipase which has a role in inflammation, atherogenesis, and host defense. Previously, we found that PLA2G2A protects mice on high-fat diets from weight gain and insulin resistance. Here, we examined the regulation of PLA2G2A and the metabolic changes that occur in response to variations in thyroid status. In particular, the impact of PLA2G2A on the brown adipose tissue (BAT) thermogenic gene expression was explored. We induced hypothyroidism in C57BL/6 and PLA2G2A-overexpressing (IIA+) mice over a 10 wk period or treated them with thyroid hormone (T3) for 5 wk. There were no significant changes in PLA2G2A abundance in response to thyroid status. The energy expenditure of hypothyroid IIA+ mice did not increase; however, the energy expenditure, substrate utilization, insulin sensitivity, and glucose tolerance were all elevated in the IIA+ mice given T3. Moreover, white adipocytes from IIA+ mice were much more prone to "beiging," including increased expression of brown adipose thermogenic markers such as uncoupling protein 1 (UCP1), PR domain containing 16, and early B cell factor 2. Finally, the BAT of IIA+ mice had increased UCP1 and other proteins indicative of mitochondrial uncoupling and nonshivering adaptive thermogenesis. These data reveal a novel role for PLA2G2A on adipose tissue thermogenesis depending on thyroid status.-Kuefner, M. S., Deng, X., Stephenson, E. J., Pham, K., Park, E. A. Secretory phospholipase A2 group IIA enhances the metabolic rate and increases glucose utilization in response to thyroid hormone.

Keywords: PLA2G2A; UCP1; brown adipose tissue.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adipose Tissue, Brown / drug effects
  • Adipose Tissue, Brown / metabolism*
  • Adipose Tissue, White / drug effects
  • Adipose Tissue, White / metabolism*
  • Animals
  • Body Weight / drug effects
  • Energy Metabolism / drug effects*
  • Female
  • Glucose / metabolism*
  • Group II Phospholipases A2 / genetics
  • Group II Phospholipases A2 / metabolism*
  • Hypothyroidism / drug therapy*
  • Hypothyroidism / metabolism
  • Hypothyroidism / pathology
  • Insulin / metabolism
  • Insulin Resistance
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Thermogenesis
  • Triiodothyronine / pharmacology*

Substances

  • Insulin
  • Triiodothyronine
  • Group II Phospholipases A2
  • Pla2g2a protein, mouse
  • Glucose