Objective The ventromedial hypothalamic nucleus (VMH) regulates energy balance and glucose homeostasis. Leptin and insulin exert metabolic effects via their cognate receptors expressed by the steroidogenic factor 1 (SF1) neurons within the VMH. However, detailed cellular mechanisms involved in the regulation of these neurons by leptin and insulin remain to be identified. Methods We utilized genetically-modified mouse models and performed patch-clamp electrophysiology experiments to resolve this issue. Results We identified distinct populations of leptin-activated and leptin-inhibited SF1 neurons. In contrast, insulin uniformly inhibited SF1 neurons. Notably, we found that leptin-activated, leptin-inhibited, and insulin-inhibited SF1 neurons are distinct subpopulations within the VMH. Leptin depolarization of SF1 neuron also required the PI3K p110β catalytic subunit. This effect was mediated by the putative transient receptor potential C (TRPC) channel. On the other hand, hyperpolarizing responses of SF1 neurons by leptin and insulin required either of the p110α or p110β catalytic subunits, and were mediated by the putative ATP-sensitive K+ (KATP) channel. Conclusions Our results demonstrate that specific PI3K catalytic subunits are responsible for the acute effects of leptin and insulin on VMH SF1 neurons, and provide insights into the cellular mechanisms of leptin and insulin action on VMH SF1 neurons that regulate energy balance and glucose homeostasis.
Bibliographical noteFunding Information:
This work was supported by the Korean Ministry of Health and Welfare ( HI14C1946 to J.-W.S. ), the Korean Ministry of Science, ICT & Future Planning ( NRF-2015M3A9E7029177 to J.-W.S.; NRF-2014K1A3A1A19066980, NRF-2016R1C1B3012748 to K.W.K. ), KAIST Future Systems Health Care Project (to J.-W.S.); NIH R01 DK100699 (to K.W.W.); NIH R01 DK100659 , R37 DK053301 , P01 DK088761 (to J.K.E.).
© 2016 The Authors
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology