Energy balance regulation by thyroid hormones at central level

Area of Science:

• Endocrinology
• Neuroscience
• Metabolism

Background:

• Traditional view: Thyroid hormones (THs) primarily act on peripheral tissues for energy homeostasis.
• Emerging evidence: THs exert significant effects at the central level, influencing food intake, energy expenditure, and metabolism.
• Interactions: THs interact with central energy sensors like uncoupling protein 2 (UCP2), AMP-activated protein kinase (AMPK), and mechanistic target of rapamycin (mTOR).

Purpose of the Study:

• To review the current understanding of thyroid hormones' role in regulating energy balance.
• To highlight the shift from a peripheral to a central perspective on TH action.
• To discuss the interplay between THs and key CNS energy sensors.

Main Methods:

• Literature review of studies on thyroid hormones and energy metabolism.
• Analysis of research on central nervous system regulation of energy balance.
• Synthesis of findings on TH interactions with UCP2, AMPK, and mTOR.

Main Results:

• Thyroid hormones significantly influence central mechanisms regulating appetite and energy expenditure.
• The central nervous system plays a crucial role in mediating TH effects on metabolism.
• Specific energy sensors in the CNS are modulated by thyroid hormones.

Conclusions:

• The understanding of thyroid hormone action in energy homeostasis has evolved towards a central paradigm.
• Thyroid hormones act centrally, interacting with key metabolic regulators to control energy balance.
• Further research is warranted to fully elucidate the central mechanisms of TH action.