PM2.5-induced cellular senescence drives brown adipose tissue impairment in middle-aged mice

Autor: Renjie Hu, Wenjun Fan, Sanduo Li, Guoqing Zhang, Lu Zang, Li Qin, Ran Li, Rucheng Chen, Lu Zhang, Weijia Gu, Yunhui Zhang, Sanjay Rajagopalan, Qinghua Sun, Cuiqing Liu
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Ecotoxicology and Environmental Safety, Vol 278, Iss , Pp 116423- (2024)
Druh dokumentu: article
ISSN: 0147-6513
DOI: 10.1016/j.ecoenv.2024.116423
Popis: Airborne fine particulate matter (PM2.5) exposure is closely associated with metabolic disturbance, in which brown adipose tissue (BAT) is one of the main contributing organs. However, knowledge of the phenotype and mechanism of PM2.5 exposure-impaired BAT is quite limited. In the study, male C57BL/6 mice at three different life phases (young, adult, and middle-aged) were simultaneously exposed to concentrated ambient PM2.5 or filtered air for 8 weeks using a whole-body inhalational exposure system. H&E staining and high-resolution respirometry were used to assess the size of adipocytes and mitochondrial function. Transcriptomics was performed to determine the differentially expressed genes in BAT. Quantitative RT-PCR, immunohistochemistry staining, and immunoblots were performed to verify the transcriptomics and explore the mechanism for BAT mitochondrial dysfunction. Firstly, PM2.5 exposure caused altered BAT morphology and mitochondrial dysfunction in middle-aged but not young or adult mice. Furthermore, PM2.5 exposure increased cellular senescence in BAT of middle-aged mice, accompanied by cell cycle arrest, impaired DNA replication, and inhibited AKT signaling pathway. Moreover, PM2.5 exposure disrupted apoptosis and autophagy homeostasis in BAT of middle-aged mice. Therefore, BAT in middle-aged mice was more vulnerable to PM2.5 exposure, and the cellular senescence-initiated apoptosis, autophagy, and mitochondrial dysfunction may be the mechanism of PM2.5 exposure-induced BAT impairment.
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