Thyroid Hormone Regulation of Adipose Tissue Thermogenesis

Thyroid hormones are central regulators of energy homeostasis, acting both centrally and peripherally to modulate heat production in adipose tissue. The active hormone triiodothyronine (T3) binds to nuclear thyroid hormone receptors in brown adipose tissue (BAT) and white adipose tissue (WAT), inducing transcriptional programmes that enhance mitochondrial biogenesis, fuel oxidation and uncoupled respiration. In BAT, T3 amplifies adrenergic signalling to increase expression of uncoupling protein 1 (UCP1), the key mediator of non-shivering thermogenesis. Under thermoneutral conditions, thyroid hormone can also trigger UCP1-independent pathways, accelerating metabolic fluxes that dissipate energy as heat. In WAT, thyroid hormone promotes browning by driving the emergence of thermogenic adipocytes within white depots. These processes are fine-tuned by local conversion of thyroxine (T4) to T3 via type II iodothyronine deiodinase (D2), ensuring precise control of adipose thermogenesis in response to environmental cues such as cold exposure and nutritional state. Dysregulation of this axis contributes to metabolic disorders, whereas targeted modulation holds promise for combating obesity and related pathologies.

Research from Nature Portfolio

Recent studies in murine models have revealed that maternal activation of thyroid hormone receptor β during gestation leads to persistent programming of brown adipose thermogenesis in offspring. Exposure to elevated T3 levels in utero enhances postnatal BAT recruitment, improves cold tolerance and ameliorates glucose homeostasis in adult progeny. This effect depends on intact TRβ signalling in the mother and involves changes in maternal serum metabolites that influence fetal developmental pathways.

Seminal work has also identified the adipokine A-FABP as a physiological amplifier of BAT thermogenesis. A-FABP increases the expression of D2 in brown adipocytes, promoting local conversion of T4 into active T3. Loss of A-FABP markedly reduces adaptive thermogenic responses to cold and high-fat feeding, whereas reconstitution restores energy expenditure. These findings establish a feed-forward mechanism linking lipid chaperones to thyroid-dependent heat generation.

Thyroid Hormone Regulation of Adipose Tissue Thermogenesis publication trend

The graph below shows the total number of articles in thyroid hormone regulation of adipose tissue thermogenesis across all publications each year (not limited to Nature Index journals).

Technical terms

Brown adipose tissue (BAT): A specialised fat depot rich in mitochondria and UCP1, dedicated to heat production through non-shivering thermogenesis.

White adipose tissue (WAT): The primary energy storage tissue, capable of undergoing browning to acquire thermogenic properties under the influence of thyroid hormones and adrenergic signals.

Uncoupling protein 1 (UCP1): A mitochondrial membrane protein that dissipates the proton gradient to generate heat instead of ATP, central to thermogenic function in adipocytes.

Type II iodothyronine deiodinase (D2): An enzyme that locally converts inactive thyroxine (T4) into active triiodothyronine (T3), regulating tissue-specific thyroid hormone action.

Triiodothyronine (T3): The biologically active thyroid hormone that binds nuclear receptors to regulate genes controlling metabolism and thermogenesis.

Browning: The process by which white adipocytes acquire mitochondrial density and UCP1 expression, adopting a thermogenic phenotype similar to brown adipocytes.

References

1. Thermogenesis in Adipose Tissue Activated by Thyroid Hormone. International Journal of Molecular Sciences (2020).
2. Triiodothyronine amplifies norepinephrine stimulation of uncoupling protein gene transcription by a mechanism not requiring protein synthesis.. Journal of Biological Chemistry (1988).
3. At thermoneutrality, acute thyroxine-induced thermogenesis and pyrexia are independent of UCP1. Molecular Metabolism (2019).
4. Thyroid hormone status defines brown adipose tissue activity and browning of white adipose tissues in mice. Scientific Reports (2016).
5. Maternal thyroid hormone receptor β activation in mice sparks brown fat thermogenesis in the offspring. Nature Communications (2023).
6. A-FABP mediates adaptive thermogenesis by promoting intracellular activation of thyroid hormones in brown adipocytes. Nature Communications (2017).
7. A Systematic Review and Meta-Analysis of Free Triiodothyronine (FT3) Levels in Humans Depending on Seasonal Air Temperature Changes: Is the Variation in FT3 Levels Related to Nonshivering Thermogenesis?. International Journal of Molecular Sciences (2023).
8. Adipose Tissue Remodeling in Obesity: An Overview of the Actions of Thyroid Hormones and Their Derivatives. Pharmaceuticals (2023).
9. Trk-fused gene plays a critical role in diet-induced adipose tissue expansion and is also involved in thyroid hormone action. PNAS Nexus (2024).