SRC1 deficiency in hypothalamic arcuate nucleus increases appetite and body weight

Area of Science:

• Neuroendocrinology
• Metabolic regulation
• Molecular endocrinology

Background:

• Appetite is regulated by complex neural and hormonal signals.
• Steroid receptor coactivator 1 (SRC1) is known to enhance steroid hormone signaling in energy balance.
• The specific roles of SRC1 in energy balance and appetite control are not fully understood.

Purpose of the Study:

• To investigate the role of SRC1 in the hypothalamic arcuate nucleus (ARC) in regulating appetite and body weight.
• To determine the effect of SRC1 deficiency on feeding behavior and energy balance.
• To explore the involvement of AMP-activated protein kinase (AMPK) signaling in SRC1-mediated appetite regulation.

Main Methods:

• Confirmation of SRC1 expression in the ARC and its co-localization with key neuronal markers.
• Manipulation of SRC1 expression in the ARC using lentivirus-mediated shRNA.
• Assessment of food intake, body weight changes, and AMPK pathway activation in response to SRC1 repression, particularly under high-fat diet conditions.

Main Results:

• SRC1 is abundantly expressed in the ARC and its expression fluctuates with nutritional status.
• Repression of SRC1 in the ARC significantly increased food intake and body weight gain, especially in mice on a high-fat diet.
• SRC1 deficiency led to the activation of the AMPK signaling pathway.

Conclusions:

• SRC1 in the ARC plays a crucial role in regulating appetite and body weight.
• AMPK signaling is implicated in the mechanism by which SRC1 influences energy balance.
• These findings highlight the integrated roles of steroid hormone receptors in appetite regulation.