Fu Li, Ping Chen, Lina Ma, Yu Wang, Shaojing Xi
Background: Norepinephrine may induce inflammatory changes and cellular injury in epicardial adipose-derived cells. This study investigated the effects of norepinephrine on these cells and examined calcium-related responses and cellular injury in H9c2 cells following exposure to media collected from differently treated epicardial adipose-derived cell cultures.Methods: Adipogenically differentiated epicardial adipose-derived cells were treated with norepinephrine, atropine, or their combination. Inflammatory responses, apoptosis, autophagy-related protein expression, and activation of the p38 MAPK and NF-κB signaling pathways were evaluated using ELISA, flow cytometry, immunofluorescence, and Western blotting. H9c2 rat cardiomyoblasts were exposed to the corresponding culture media, designated as epicardial adipose tissue (EAT)-CM, norepinephrine (NE)-CM, atropine-CM, and NE + atropine-CM. Fluo-4 fluorescence intensity, calcium-handling protein expression, Cx43 expression, and apoptosis were assessed. Pathway inhibitors were used to investigate the roles of p38 MAPK and NF-κB signaling pathways in NE-induced inflammatory responses and cellular injury in epicardial adipose-derived cells.Results: Compared with the control group, norepinephrine significantly increased Tumor necrosis factor-alpha (TNF-α), Interleukin-6 (IL-6), and leptin levels, decreased adiponectin levels, and promoted apoptosis and altered autophagy-related protein expression in epicardial adipose-derived cells (all p < 0.05). Norepinephrine also activated the p38 MAPK and NF-κB signaling pathways (all p < 0.05). Compared with the EAT-CM group, the NE-CM group showed increased Fluo-4 fluorescence intensity, reduced SERCA2a expression and PLB phosphorylation, enhanced RyR2 phosphorylation, decreased Cx43 expression, and increased apoptosis. These alterations were most pronounced in the NE + atropine-CM group. Treatment with SB203580 or Bay 11-7082 attenuated norepinephrine-induced inflammatory responses and cellular injury (all p < 0.05).Conclusions: Norepinephrine activated the p38 MAPK and NF-κB signaling pathways and induced inflammatory changes and cellular injury in epicardial adipose-derived cells. H9c2 cells in the NE-CM and NE + atropine-CM groups showed coordinated changes in Fluo-4 fluorescence intensity, calcium-handling protein and Cx43 expression, and apoptosis. H9c2 cells exposed to media collected from norepinephrine-treated epicardial adipose-derived cell cultures showed calcium-related alterations and cellular injury.