Hypothalamic leptin action is mediated by histone deacetylase 5

Area of Science:

• Neuroendocrinology
• Metabolic Regulation
• Molecular Biology

Background:

• Hypothalamic leptin signaling is crucial for controlling food intake and energy balance.
• Impaired leptin signaling is a common feature in obesity.
• The precise molecular mechanisms regulating leptin sensitivity require further elucidation.

Purpose of the Study:

• To identify novel regulators of hypothalamic leptin signaling.
• To investigate the role of histone deacetylase 5 (HDAC5) in energy balance and leptin action.
• To explore HDAC5's mechanism of action in modulating leptin signaling pathways.

Main Methods:

• Utilized global HDAC5 knockout (KO) mice and mice with targeted hypothalamic HDAC5 inhibition.
• Administered high-fat diet (HFD) to assess diet-induced obesity.
• Employed pharmacological and genetic approaches to manipulate HDAC5 activity.
• Investigated STAT3 protein localization, deacetylation, and phosphorylation.
• Assessed leptin sensitivity and body weight regulation in vivo.

Main Results:

• Global HDAC5 KO mice exhibited increased food intake and exacerbated diet-induced obesity.
• Inhibition of hypothalamic HDAC5 activity led to increased food intake and altered leptin signaling pathways.
• HDAC5 directly regulates STAT3 by deacetylation at Lys685 and phosphorylation at Tyr705, impacting its transcriptional activity.
• HDAC5 loss-of-function mice displayed significantly impaired leptin sensitivity.
• Overexpression of hypothalamic HDAC5 enhanced leptin action and offered partial protection against HFD-induced obesity and leptin resistance.

Conclusions:

• Hypothalamic HDAC5 acts as a critical regulator of leptin signaling.
• HDAC5 activity modulates food intake and body weight in response to dietary conditions.
• Targeting hypothalamic HDAC5 may represent a therapeutic strategy for obesity and leptin resistance.