AUTHOR=Pan Xiao-Xi , Yao Kang-Li , Yang Yong-Feng , Ge Qian , Zhang Run , Gao Ping-Jin , Ruan Cheng-Chao , Wu Fang TITLE=Senescent T Cell Induces Brown Adipose Tissue “Whitening” Via Secreting IFN-γ JOURNAL=Frontiers in Cell and Developmental Biology VOLUME=9 YEAR=2021 URL=https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2021.637424 DOI=10.3389/fcell.2021.637424 ISSN=2296-634X ABSTRACT=

Aging-associated chronic inflammation is a key contributing factor to a cluster of chronic metabolic disorders, such as cardiovascular disease, obesity, and type 2 diabetes. Immune cells particularly T cells accumulate in adipose tissue with advancing age, and there exists a cross talk between T cell and preadipocyte, contributing to age-related adipose tissue remodeling. Here, we compared the difference in morphology and function of adipose tissue between young (3-month-old) and old (18-month-old) mice and showed the phenomenon of brown adipose tissue (BAT) “whitening” in old mice. Flow cytometry analysis suggested an increased proportion of T cells in BAT of old mice comparing with the young and exhibited senescent characteristics. We take advantage of coculture system to demonstrate directly that senescent T cells inhibited brown adipocyte differentiation of preadipocytes in adipose tissue. Mechanistically, both in vitro and in vivo studies suggested that senescent T cells produced and released a higher level of IFN-γ, which plays a critical role in inhibition of preadipocyte-to-brown adipocyte differentiation. Taken together, the data indicate that senescent T cell-derived IFN-γ is a key regulator in brown adipocyte differentiation.