Ultrastructural and proteomic profiling of mitochondria-associated endoplasmic reticulum membranes reveal aging signatures in striated muscle

Autor: Xue Lu, Yingchao Gong, Wanyu Hu, Yankai Mao, Ting Wang, Zeyu Sun, Xiaoling Su, Guosheng Fu, Yanpeng Wang, Dongwu Lai
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Cell Death and Disease, Vol 13, Iss 4, Pp 1-15 (2022)
Druh dokumentu: article
ISSN: 2041-4889
DOI: 10.1038/s41419-022-04746-4
Popis: Abstract Aging is a major risk for developing cardiac and skeletal muscle dysfunction, yet the underlying mechanism remains elusive. Here we demonstrated that the mitochondria-associated endoplasmic reticulum membranes (MAMs) in the rat heart and skeletal muscle were disrupted during aging. Using quantitative morphological analysis, we showed that the mitochondria-endoplasmic reticulum contacts (MERCs) were reduced by half over the lifespan with an early onset of accelerated thickening in the clefts. The ultrastructural changes were further validated by proteomic profiling of the MAM fractions. A combination of subcellular fractionation and quantitative mass spectrometry identified 1306 MAM-enriched proteins in both heart and skeletal muscle, with a catalog of proteins dysregulated with aging. Functional mapping of the MAM proteome suggested several aging signatures to be closely associated with the ER-mitochondria crosstalk, including local metabolic rewiring, calcium homeostasis imbalance, and impaired organelle dynamics and autophagy. Moreover, we identified a subset of highly interconnected proteins in an ER-mitochondria organization network, which were consistently down-regulated with aging. These decreased proteins, including VDAC1, SAMM50, MTX1 and MIC60, were considered as potential contributors to the age-related MAM dysfunction. This study highlights the perturbation in MAM integrity during the striated muscle aging process, and provides a framework for understanding aging biology from the perspective of organelle interactions.
Databáze: Directory of Open Access Journals