Effect of High Glucose on the Gene Expression Profiling in Cardiac Fibroblasts from Rats at Different Ages

Methods: CFs were isolated from neonatal (S1, 0–3 days), juvenile (S2, 3–4 weeks), adult (S3, 10–13 weeks), and aged (S4, 20 months) rats. CFs were exposed to normal (5.5 mM, NG) or high glucose (33 mM, HG). The cellular RNA was extracted for sequencing and analysis. Differentially expressed genes (DEGs) were validated by quantitative real-time PCR. Results: After NG treatment, fibrosis and inflammation-related gene expression in CFs (e.g., Col8a1, Col8a2, IL-6, Ccl2, Ccl20, Mmp2 and Mmp9) increased with age, while proliferation-related genes (MCM family, Sox10, Sox11) decreased. HG treatment most affected S3-CFs, showing 228 DEGs; it suppressed growth-related genes (Adra1d, Htr2b) and enhanced inflammatory genes (IL-6, Olr1). In S1-CFs, 197 inflammation-rich genes were upregulated under HG. S4-CFs displayed 166 DEGs, mostly metabolic downregulation (G6pc). S2-CFs had the fewest DEGs (112), focusing on cell metabolism. Conclusions: Fibrosis- and inflammation-associated gene expression in CFs showed an age-dependent stepwise elevation. CFs from distinct developmental stages responded differently to HG stimulation, with S3-CFs exhibiting the most pronounced response. These findings highlight the developmental characteristics of CFs and provide implications for the selection of appropriate CFs to investigate diabetes-associated cardiac fibrosis.