FAM153A Is a Novel Biomarker of Human Thermogenic Adipocytes

Childhood obesity may be associated with an accelerated loss of thermogenic adipocytes, increasing the risk of progressive lipid accumulation and metabolic deterioration. Early detection of the loss of thermogenic adipocytes would allow improved intervention to abrogate childhood obesity, yet reliable markers of human thermogenic adipocytes remain limited. We previously identified expression of FAM153A (family with sequence similarity 153 member A) in the developing human adipose tissue. Here, we investigated the expression pattern and potential association of FAM153A with the thermogenic transcriptional program in the adipose tissue of infants, children, and adolescents. We found that adipocyte FAM153A expression was triggered by beta adrenergic receptor stimulation, a key signal of adipocyte thermogenesis. FAM153A protein was confined to preadipocyte and adipocyte nuclei, and FAM153A mRNA expression positively correlated with the mRNA levels of canonical thermogenic adipocyte markers including uncoupling protein 1 (UCP1), myogenic differentiation 1 (MYOD1), type II iodothyronine deiodinase (DIO2), transmembrane protein 26 (TMEM26), Lim Homeobox 8 (LHX8), beta adrenergic receptor 2 (ADRB2), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A). Importantly, FAM153A expression was positively associated not only with the expression of individual thermogenic genes but also with their coordinated co-expression. Collectively, our findings identify FAM153A as a novel mRNA biomarker of human thermogenic adipocytes that serves as a robust indicator of the thermogenic transcriptional network.