南蛇藤素调节TRAF6/Akt/NF-κB通路对脑卒中后抑郁大鼠的保护作用及机制探究OA

Objective To explore the protective effect and mechanism of celastrol(Cel)on post-stroke depression(PSD)rats by adjusting the tumor necrosis factor receptor associated factor 6(TRAF6)/protein kinase B(Akt)/nuclear factor kappa-B(NF-κB)pathway.Methods The PSD model was established by combining middle cerebral artery occlusion(MCAO)with chronic unpredictable mild stress.Then the rats were randomly separated into the PSD group,the Cel-low group(1.5 mg·kg-1 Cel),the Cel-high group(3.0 mg·kg-1 Cel),the fluoxetine group(1.8 mg·kg-1 fluoxetine),and the Cel-high+lipopolysaccharide(LPS)group(3.0 mg·kg-1 Cel+0.4 mg·kg-1 LPS).Ten normal rats were assigned to the sham operation group,in which only the neck muscles were isolated and the left common carotid artery,internal carotid artery,and external carotid artery were fully exposed but not ligated.After intervention,the neurological function behavior scores of the rats were evaluated.The sucrose preference test was used to assess the depressive behaviors of the rats.Enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of inflammatory factors in the serum.Nissl staining and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling(TUNEL)assay were used to detect the pathological changes and cell apoptosis of hippocampal neurons.Golgi staining was conducted to observe the morphology of dendritic spines in hippocampal neurons.In addition,Western blot was conducted to detect the expression changes of toll-like receptor 4(TLR4),TRAF6,p-Akt/Akt,and p-NF-κB/NF-κB in the hippocampal tissue.Results The sucrose preference rates in the Sham operation,PSD,Cel-low,Cel-high,Fluoxetine,and Cel-high+LPS groups were(82.36±8.41)％,(42.05±4.35)％,(59.37±6.18)％,(79.69±8.06)％,(79.91±8.11)％,and(59.04±6.13)％,respectively;Longa scores were(0±0),(3.20±0.35),(2.30±0.25),(1.10±0.14),(1.00±0.12),and(2.30±0.24)scores,respectively;TNF-α levels were(42.63±4.47),(103.08±11.14),(80.08±8.19),(51.14±5.24),(50.37±5.21),and(81.05±8.22)pg·mL-1,respectively;IL-6 levels were(61.35±6.34),(125.67±13.58),(92.34±9.46),(67.34±7.14),(67.29±7.05),and(93.05±9.51)pg·mL-1,respectively;neuronal apoptosis rates were(7.15±0.85)％,(26.07±2.77)％,(14.65±1.58)％,(9.05±1.02)％,(8.92±0.97)％,and(14.25±1.51)％,respectively;dendritic spine length was(1.31±0.15),(0.58±0.07),(0.81±0.09),(1.22±0.14),(1.24±0.15),and(0.88±0.10)μm,respectively;TLR4 protein relative expression levels were 0.38±0.05,0.97±0.11,0.69±0.08,0.48±0.06,0.43±0.05,and 0.72±0.08,respectively;TRAF6 protein relative expression levels were 0.44±0.05,1.26±0.14,0.82±0.10,0.59±0.07,0.52±0.06,and 0.81±0.09,respectively;p-Akt/Akt relative expression levels were 0.85±0.09,0.15±0.02,0.31±0.04,0.65±0.07,0.69±0.07,and 0.35±0.04,respectively;p-NF-κB/NF-κB relative expression levels were 0.24±0.03,0.88±0.09,0.61±0.07,0.40±0.05,0.37±0.04,and 0.60±0.07,respectively.Comparisons of these parameters between the Sham group and the PSD group,between the PSD group and the Fluoxetine,Cel-low,and Cel-high groups,and between the Cel-high group and the Cel-high+LPS group all showed statistically significant differences(all P＜0.05).Conclusion Cel improved neuronal damage in PSD rats by inhibiting TRAF6 and upregulating the phosphorylation level of Akt,thereby downregulating the activation of the NF-κB pathway,and exerting neuroprotective effects..