What markers track brown adipose tissue?
Brown adipose tissue (BAT) activity is tracked with markers spanning circulating TGF-β superfamily ligands, adipokines, NAD+ availability, and imaging readouts. This page summarises the research models and the markers ea
Brown adipose tissue (BAT) is a thermogenic adipose depot that oxidises fatty acids to produce heat. In the research literature it is also referred to as brown fat, and its thermogenic adipocytes are called brown adipocytes. BAT is distinct from white adipose tissue (WAT), which stores energy, and from beige adipocytes, which arise in WAT depots through a process called browning. The identifiers used to track BAT in the studies below include circulating proteins such as follistatin-like 1 (FSTL1), follistatin (FST), growth differentiation factor 11 (GDF-11), erythropoietin (EPO), the coenzyme nicotinamide adenine dinucleotide (NAD+), and imaging or physiological readouts such as FDG-PET/CT and indirect calorimetry. The evidence block does not provide sequence, formula, or molecular weight values for these markers.
The work centres on the transforming growth factor-beta (TGF-β) superfamily and its signalling through SMAD proteins, together with adrenergic and metabolic pathways that regulate adipose thermogenesis.
Research Studies
FSTL1 and WAT browning in male mice
Follistatin-like 1 (FSTL1) is an adipokine that has been studied for its roles in WAT adipogenesis, brown adipose tissue involution, and thermogenesis. In male mice at ambient room temperature, FSTL1 overexpression induced WAT browning, enhanced energy metabolism, and promoted glucose uptake. Overexpression of FSTL1 specifically in WAT prevented metabolic dysfunction in mice with diet-induced obesity. Mice with FSTL1 deficiency exhibited cold intolerance and were prone to obesity. The same study reported that FSTL1 cannot directly induce browning, indicating an indirect mechanism [1].
Follistatin and atherosclerosis in mice
Follistatin (FST) binds to and neutralises members of the TGF-β superfamily, regulating skeletal muscle, adipose, and bone homeostasis. FST promotes adipose browning and enhances energy metabolism, leading to improved plasma lipid profiles and metabolic health in mice. Because BAT activation has been associated with reduced atherosclerosis, one study investigated the anti-atherogenic potential of FST. Transcriptomic and metabolomic analyses of the Hybrid Mouse Diversity Panel (HMDP) revealed that Fst expression was negatively correlated with aortic lesion area [2].
GDF-11 and cold-induced browning in mice and 3T3-L1 cells
Growth differentiation factor 11 (GDF-11) is a circulating member of the TGF-β superfamily. In a study of adipose tissue plasticity, mice were exposed to cold to induce browning, and GDF-11 expression and SMAD2/3 activation were assessed in brown adipose tissue (BAT), visceral and subcutaneous WAT, and skeletal muscle. The study combined in vivo results with in vitro approaches using 3T3-L1 cells [3].
Capsinoid supplementation and BAT in obese adolescents
A clinical study is examining the effect of capsinoid supplementation on BAT in obese adolescents. The rationale notes that BAT is specialised for energy expenditure through heat production via oxidation of fatty acids in brown adipocytes, and that BAT has an anti-obesogenic role rather than a storage role. Cold exposure is described as the major physiological stimulus for BAT activation [4].
Erythropoietin and metabolic regulation in adipose tissue
Erythropoietin (EPO) is a key regulator of erythrocyte production. Beyond haematopoiesis, EPO influences non-haematopoietic tissues including glucose and fat metabolism in adipose tissue, skeletal muscle, and the liver. EPO enhances lipolysis while inhibiting lipogenic gene expression in white adipose tissue, brown adipose tissue, skeletal muscle, and other tissues. EPO is used clinically to treat anaemia associated with chronic kidney disease and plays a role in maintaining metabolic homeostasis and regulating fat mass [5].
NAD+ metabolism in human brown adipose tissue
A clinical study is investigating whether NAD+ availability contributes to the age-related decline in brown fat functionality in human adults. The rationale states that fully functional brown fat helps maintain a healthy weight and decreases the risk of metabolic diseases such as type II diabetes, and that brown fat functionality declines with age, contributing to central obesity. The project aims to clarify whether NAD+-based molecules play a role in the decline in brown fat metabolism [6].
Beta3-adrenergic receptor agonists and BAT adaptation
A clinical study is examining the physiological responses and adaptation of BAT to chronic treatment with beta3-adrenergic receptor agonists. The background states that BAT may prevent weight gain, improve insulin sensitivity, and reduce fatty liver. The study enrols people ages 18–40 with a body mass index between 18 and 40, and includes baseline visits with exercise tests, scans involving a radioactive substance, and a FSIVGIT procedure [7].
Hyperthyroidism and BAT amount and activity
An observational study is evaluating the effect of thyroid hormones on BAT in humans with thyrotoxicosis. The investigators use FDG-PET/CT, indirect calorimetry, and fat biopsies in the acute phase of the disease and in the euthyroid phase after treatment. The hypothesis is that high levels of circulating T3 might affect the amount and function of BAT [8].
EGCG and BAT-independent thermogenesis in subcutaneous adipose tissue
A study of epigallocatechin gallate (EGCG) reported that EGCG triggers a BAT-independent thermogenic switch and remodels the immune microenvironment in subcutaneous adipose tissue in the context of obesity. The work notes that adaptive thermogenesis is a promising therapy but its efficacy is limited by low BAT activity [9].
Markers compared across models
| Marker | Model or population | Reported observation |
|---|---|---|
| FSTL1 | Male mice, ambient room temperature | Overexpression induced WAT browning, enhanced energy metabolism, promoted glucose uptake; deficiency caused cold intolerance and obesity proneness [1] |
| FST | Mice; HMDP transcriptomic and metabolomic analyses | Fst expression negatively correlated with aortic lesion area; promotes adipose browning and improves plasma lipid profiles [2] |
| GDF-11 | Mice exposed to cold; 3T3-L1 cells | GDF-11 expression and SMAD2/3 activation assessed in BAT, visceral and subcutaneous WAT, and skeletal muscle [3] |
| EPO | Adipose tissue, skeletal muscle, liver | Enhances lipolysis and inhibits lipogenic gene expression in WAT, BAT, and skeletal muscle [5] |
| NAD+ | Human adults | Under investigation for role in age-related decline in brown fat functionality [6] |
| FDG-PET/CT and indirect calorimetry | Humans with thyrotoxicosis | Used to assess BAT amount and activity in acute and euthyroid phases [8] |
If you are reading this for personal health reasons
The compounds and markers described here are sold for laboratory research use only. We do not provide dosing, medical guidance, or recommendations for personal use. Anyone considering a compound for themselves should speak to a licensed clinician.
Sources
- [1] The Adipose-Sympathetic Nerve Crosstalk: FSTL1 as an Adipocyte-Derived Neurotrophic Factor for WAT Browning
- [2] Follistatin Mitigates Atherosclerosis Through Activation of Arginine Metabolism and Adipose Browning
- [3] GDF-11 triggers cold-induced browning and metabolic activation of adipose tissue
- [4] Study of the Effect of Capsinoid Supplementation on Brown Adipose Tissue in Obese Adolescents
- [5] The Role of Erythropoietin in Metabolic Regulation
- [6] Nicotinamide Adenine Dinucleotide (NAD+) Metabolism in Human Brown Adipose Tissue
- [7] The Physiological Responses and Adaptation of Brown Adipose Tissue to Chronic Treatment With Beta3-Adrenergic Receptor Agonists
- [8] Effects of Hyperthyroidism on Amount and Activity of Brown Adipose Tissue
- [9] EGCG combats obesity by triggering a BAT-independent thermogenic switch and remodeling the immune microenvironment in subcutaneous adipose tissue