Research Paper Volume 13, Issue 14 pp 18606—18619

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

ERK phosphorylation, NOX4 expression, oxidative stress and inflammation are elevated in the L4, L5 spinal cord and DRG of obese CCD rats, which are abolished by an ERK inhibitor. (A–C) The protein levels of p-ERK, ERK, and NOX4 in nervous tissue of rats were determined by western blot and immunohistochemistry. (D–F) SOD, MDA, NADPH oxidase activity in nervous tissue were detected by kit. (G–I) IL-1β, IL-6, and TNF-α mRNA levels in nervous tissue were detected by PCR. N = 10-15 per group, *P P #P ##P

Figure 3. ERK phosphorylation, NOX4 expression, oxidative stress and inflammation are elevated in the L4, L5 spinal cord and DRG of obese CCD rats, which are abolished by an ERK inhibitor. (AC) The protein levels of p-ERK, ERK, and NOX4 in nervous tissue of rats were determined by western blot and immunohistochemistry. (DF) SOD, MDA, NADPH oxidase activity in nervous tissue were detected by kit. (GI) IL-1β, IL-6, and TNF-α mRNA levels in nervous tissue were detected by PCR. N = 10-15 per group, *P < 0.05 vs. NCCD group, **P < 0.01 vs. NCCD group, #P < 0.05 vs. saline group, ##P < 0.01 vs. saline group. U0126, ERK inhibitor; ERK, extracellular-regulated kinase; NOX4, NAD(P)H oxidase 4; DRG, dorsal root ganglia; CCD, chronic compression of the dorsal root ganglia; MDA, malondialdehyde; SOD, superoxide dismutase; IL-1β, interleukin-1 beta; IL-6, interleukin-6; TNF-α, tumor necrosis factor alpha; qRT-PCR, quantitative real-time polymerase chain reaction; NCCD, normal CCD; OCCD, obese CCD.