Leptin Receptors in RIP-Cre25Mgn Neurons Mediate Anti-dyslipidemia Effects of Leptin in Insulin-Deficient Mice

Ashish Singha, Juan Pablo Palavicini, Meixia Pan, Scotlynn Farmer, Darleen Sandoval, Xianlin Han, Teppei Fujikawa

Research output: Contribution to journalArticlepeer-review

Abstract

Leptin is a potent endocrine hormone produced by adipose tissue and regulates a broad range of whole-body metabolism such as glucose and lipid metabolism, even without insulin. Central leptin signaling can lower hyperglycemia in insulin-deficient rodents via multiple mechanisms, including improvements of dyslipidemia. However, the specific neurons that regulate anti-dyslipidemia effects of leptin remain unidentified. Here we report that leptin receptors (LEPRs) in neurons expressing Cre recombinase driven by a short fragment of a promoter region of Ins2 gene (RIP-Cre25Mgn neurons) are required for central leptin signaling to reverse dyslipidemia, thereby hyperglycemia in insulin-deficient mice. Ablation of LEPRs in RIP-Cre25Mgn neurons completely blocks glucose-lowering effects of leptin in insulin-deficient mice. Further investigations reveal that insulin-deficient mice lacking LEPRs in RIP-Cre25Mgn neurons (RIP-CreΔLEPR mice) exhibit greater lipid levels in blood and liver compared to wild-type controls, and that leptin injection into the brain does not suppress dyslipidemia in insulin-deficient RIP-CreΔLEPR mice. Leptin administration into the brain combined with acipimox, which lowers blood lipids by suppressing triglyceride lipase activity, can restore normal glycemia in insulin-deficient RIP-CreΔLEPR mice, suggesting that excess circulating lipids are a driving-force of hyperglycemia in these mice. Collectively, our data demonstrate that LEPRs in RIP-Cre25Mgn neurons significantly contribute to glucose-lowering effects of leptin in an insulin-independent manner by improving dyslipidemia.

Original languageEnglish (US)
Article number588447
JournalFrontiers in Endocrinology
Volume11
DOIs
StatePublished - Sep 23 2020

Keywords

  • glucose metabolism
  • insulin deficiency
  • leptin
  • lipid metabolism
  • the hypothalamus

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism

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