Research Paper Volume 13, Issue 14 pp 18606—18619

Obesity increases neuropathic pain via the AMPK-ERK-NOX4 pathway in rats

AMPK activation reduces ERK phosphorylation, NOX4 expression and improves oxidative stress and inflammation of DRG neurons cultured in PA-added medium in vitro. DRG neurons isolated from rats were cultured. PA was applied to simulate a high-fat environment and AICAR to activate AMPK. (A) The expression of p-AMPK, AMPK, p-ERK, ERK, and NOX4 in DRG neurons were detected by western blot. (B–D) The supernatant of cultured cells was collected and SOD, MDA, NADPH oxidase activity in the supernatant were detected by kit. (E–G) The supernatant of cultured cells was collected and the secretion of IL-1β, IL-6, and TNF-α was measured by ELISA. N = 5 per group, **P #P ##P

Figure 7. AMPK activation reduces ERK phosphorylation, NOX4 expression and improves oxidative stress and inflammation of DRG neurons cultured in PA-added medium in vitro. DRG neurons isolated from rats were cultured. PA was applied to simulate a high-fat environment and AICAR to activate AMPK. (A) The expression of p-AMPK, AMPK, p-ERK, ERK, and NOX4 in DRG neurons were detected by western blot. (BD) The supernatant of cultured cells was collected and SOD, MDA, NADPH oxidase activity in the supernatant were detected by kit. (EG) The supernatant of cultured cells was collected and the secretion of IL-1β, IL-6, and TNF-α was measured by ELISA. N = 5 per group, **P < 0.01 vs. con group, #P < 0.05 vs. saline group, ##P < 0.01 vs. saline group. AMPK, AMP-activated protein kinase; ERK, extracellular-regulated kinase; NOX4, NAD(P)H oxidase 4; DRG, dorsal root ganglia; PA, palmitic acid; AICAR, AMPK agonists; MDA, malondialdehyde; SOD, superoxide dismutase; IL-1β, interleukin-1 beta; IL-6, interleukin-6; TNF-α, tumor necrosis factor alpha; ELISA, enzyme-linked immunosorbent assay.