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Biomedical subjects

Jia-Xuan Chen

Publications and source records attributed to Jia-Xuan Chen.

2 recordsLinked to original sources

Quantitative proteomics reveals coordinated changes in the proteome during replicative senescence.

Cellular senescence is a state of irreversible cell cycle arrest triggered by telomere erosion, persistent DNA damage or chronic stress. The accumulation of senescent cells disrupts tissue function and contributes to aging and disease. Here, we employ mass spectrometry-based proteomics to systematically interrogate dynamic proteome changes at multiple levels during the progression of replicative cellular senescence. We demonstrate that proteome changes during senescence occur in a coordinated manner, characterized by widespread protein depletion on chromatin. Moreover, components of the cytoplasmic translation machinery are depleted, while mitochondrial proteins display increased insolubility. Autophagic and proteasome activity is compromised in senescent cells along with remodeling of ubiquitin linkages and depletion of ubiquitin E3 ligases. Comparison of the senescent proteome with different pathophysiological cellular states reveals a distinctive senescent signature shaped by changes in the proteostasis network. Collectively, we provide a resource for the exploration of temporally resolved changes in the senescent proteome.

Cellular Senescence↗

Correlations between bone mineral density of the hand and other skeletal sites as measured by DXA in Chinese women and men.

This study was aimed at assessing the correlations between the bone mineral density (BMD) of the hand and other skeletal sites in Chinese women and men. We measured the BMD of the total body, the anteroposterior lumbar spine (L2-L4), bilateral proximal femurs (i.e., total hip, femoral neck, and trochanter), and bilateral total hands in 363 Chinese adults (96 males, 267 females) using dual-energy X-ray absorptiometry (DXA). Data were analyzed by descriptive statistics, Student's t tests, and Pearson's correlation coefficients (r). We found that bilateral hand measurements reduced precision error by 36% as compared with a single hand measurement. Dominant hand BMD was significantly higher than nondominant hand BMD. For both the dominant and nondominant sides, hand BMD was significantly higher in males than in females. Hand BMD correlated significantly (p<0.001) with the BMD of all skeletal sites for all subjects (r=0.681-0.848), the male group (r=0.568-0.857), and the female group (r=0.687-0.859). After normal references for the Chinese population have been established, further investigations may determine the clinical usefulness of hand BMD measurement in the diagnosis of osteoporosis and the prediction of fracture risk.

Absorptiometry, Photon↗