Critical Role of p38 in Spinal Cord Injury by Regulating Inflammation and Apoptosis in a Rat Model.

STUDY DESIGN: To evaluate the effect of p38 pathway on spinal cord injury (SCI), a rat model of SCI was performed. OBJECTIVE: We determined the effect of p38 on SCI and SCI related inflammation, apoptosis, and autophagy. SUMMARY OF BACKGROUND DATA: SCI is a severe clinical problem worldwide. It is difficult to prevent cell necroptosis and promote the survival of residual neurons after SCI. p38, a class of mitogen-activated protein kinases, its effect on SCI and SCI related inflammation, apoptosis, and autophagy have not been studied very well. METHODS: The rats were randomly divided into the following four groups: the sham-operated (sham) group, the SCI group, the SCI + vehicle group, and the SCI + SB203580 (10 mg/kg) group. The p38 inhibitor SB203580 was administered by oral (10 mg/kg/d) gavage once per day for 14 days. Neurological recovery was assessed using the Basso, Beattie, and Bresnahan locomotion rating scale. Apoptosis, autophagy, and inflammation related proteins were measured by enzyme-linked immunosorbent assay kits or western blotting. RESULTS: Our results showed that p38 was upregulated after SCI from day 3, which was paralleled with the levels of its proteins ATF-2, suggesting an increase in p38 activity. Our results showed administration of SB203580 attenuated histopathology and promoted locomotion recovery in rats after SCI. SB203580 administration significantly inhibited inflammatory cytokines levels as well as the inflammation signaling pathway. SB203580 administration also modulated the apoptosis and autophagy signaling pathway. CONCLUSION: Our findings suggest that p38 inhibitor SB203580 treatment alleviates secondary SCI by inhibiting inflammation and apoptosis, thereby promoting neurological and locomoter functional recovery, thus suggest the important role of p38 in neuronal protection after SCI. LEVEL OF EVIDENCE: N/A.

[Effect of simvastatin on atherosclerosis and central aortic pressure in ApoE gene knockout mice].

OBJECTIVE: To investigate the effects of simvastatin on atherosclerosis and central aortic pressure in ApoE-knockout (ApoE-/-) mice. METHODS: Ten 5-week-old male ApoE-/- mice and 5 C57 mice were fed with high-lipid diet for 3 weeks, and then C57 mice (WT group) and 5 ApoE-/- mice (ApoE-/- group) were given 1% carboxymethyl cellulose solution (8 ml·kg-1·d-1), and another 5 ApoE-/- mice (ApoE-/-/S group) were given simvastatin solution (50 mg·kg-1·d-1) by gavege for 3 weeks. The areas of atherosclerotic lesion in aortic root, central aortic pressure and serum lipid levels were examined. RESULTS: No atherosclerotic plaques were observed in WT group. Compared with ApoE-/- group, simvastatin significantly decreased atherosclerotic lesion area in aortic root (89 818.05±16 980.93 µm2 vs 34 937.01±13 280.65 µm2, P<0.05). The systolic pressure (SP), mean arterial pressure (MAP), pulse pressure (PP) and diastolic pressure (DP) of central aortic pressure were significantly increased in ApoE-/- group compared with those in WT group (P<0.05). Compared to ApoE-/- group, the SP, MAP and PP of central aortic pressure were significantly reduced in ApoE-/-/S group (P<0.05). SP and MAP of central aortic pressure were positively correlated with atherosclerotic lesion area (SP: r=0.7152, P=0.0461; PP: r=0.7594， P=0.0288). Compared with WT group, serum triglyceride, total cholesterol and low-density lipoprotein levels were markedly increased in ApoE-/- group (P<0.05). Serum high-density lipoprotein level was decreased in ApoE-/- group compared with WT group. No differences in serum triglyceride, total cholesterol, low-density lipoprotein and high-density lipoprotein levels were found between ApoE-/- group and ApoE-/-/S group. CONCLUSION: Simvastatin can attenuate atherosclerosis of aorta in ApoE-/- mice, which is associated with the reduced central aortic systolic pressure but not with the serum lipids levels.