Figure 2.Comprehensive proteomic profiling of the senescence-associated secretome in hiPSC-derived myocytes. Proteomic analyses were performed using conditioned media from irradiated hiPSC-derived myocytes. A total of 65 proteins were found to be upregulated on day 7 post X-ray irradiation. (A) Distribution of the 65 upregulated proteins. (B) Gene Ontology (GO) analysis of the secreted proteins in the myocyte-conditioned media, focused on molecular function. The top five GO terms are listed. (C) Total RNA was isolated at the indicated time points following X-ray irradiation. mRNA levels were quantified by real-time PCR and normalized to 18S rRNA. Relative mRNA expression levels in nonirradiated controls (Ctrl) were set to 1. (D) Culture media from hiPSC-derived myocytes were collected at the indicated time points after X-ray irradiation and subjected to immunoblotting to assess the expression of the indicated proteins. Data are presented as mean ± SD (n = 3). Statistical significance was assessed using Student’s t-test. *p < 0.05, **p < 0.01. Abbreviations: INHBA: inhibin subunit beta A; GDF15: growth differentiation factor 15; PAI-1: serpin family E member 1; FN1: fibronectin 1; CYR61: cellular communication network factor 1; IGFBP7: insulin like growth factor binding protein 7.
