火针通过调控PI3K/Akt/mTOR信号通路改善椎动脉型颈椎病模型大鼠自噬和氧化应激OA

Objective:To investigate the mechanism of fire needling in improving autophagy and oxidative stress in rats with cervical spondylosis of vertebral artery type(CSA)by regulating protein kinase B(PKB/Akt)/mammalian target of rapamycin(mTOR)signaling pathway. Methods:The rats were randomly divided into a sham-operation group(Sham group)and a model group.After successful modeling,the rats were randomly divided into a CSA group,a fire needling group,and a fire needling+insulin-like growth factor 1(IGF-1)group.No intervention was performed in the Sham and CSA groups;the fire needling group received fire needling intervention;the fire needling+IGF-1 group received both fire needling and intraperitoneal injection of IGF-1 solution intervention.The inclined plate test was used to detect the exercise ability of rats.Laser Doppler was used to detect the blood flow in the pia mater microcirculation.Multi-mode high-frequency acoustic was used to detect the blood flow velocity of both sides of the vertebral artery.The serum levels of endothelin-1(ET-1),nitric oxide(NO),superoxide dismutase(SOD),and malondialdehyde(MDA)were measured.A transmission electron microscope was used to observe vertebral artery autophagosomes.Western blotting was used to detect the ratios of phosphorylated(phospho)-phosphoinositide 3-kinase(PI3K)/PI3K,phospho-Akt/Akt,phospho-mTOR/mTOR,autophagy-related proteins(Beclin-1 and p62),and the ratios of microtubule-associated protein 1A/1B light chain 3(LC3Ⅱ/LC3Ⅰ)in vertebral artery tissues. Results:Compared to the Sham group,the inclination angle of the inclined plate,pia mater microcirculation blood flow,blood flow velocity of the left vertebral artery(LVA),right vertebral artery(RVA),NO level,and SOD activity were significantly decreased(P<0.05),and the serum ET-1 and MDA levels were significantly increased(P<0.05)in the CSA group.Compared to the CSA group,the inclination angle of the inclined plate,blood flow of pia mater microcirculation,blood flow velocity of the LVA and RVA,NO level,and SOD activity were significantly increased(P<0.05),and the serum ET-1 and MDA levels were significantly decreased(P<0.05)in the fire needling group.The inclination angle of the inclined plate,blood flow of pia mater microcirculation,blood flow velocity of the LVA and RVA,NO level,and SOD activity in the fire needling+IGF-1 group were significantly lower than those in the fire needling group(P<0.05),and the serum ET-1 and MDA levels were higher than those in the fire needling group(P<0.05).Compared to the Sham group,a large number of autophagosomes and autophagy degradation vesicles were found in the vertebral artery tissues of the CSA group.Compared to the CSA group,autophagosomes and autophagy degradation vesicles in rat vertebral artery tissues of the fire needling group were significantly reduced.Compared to the fire needling group,the autophagosomes and autophagy degradation vesicles in the vertebral artery tissues of the fire needling+IGF-1 group were increased significantly.The expression ratios of phospho-PI3K/PI3K,phospho-Akt/Akt,phospho-mTOR/mTOR,LC3Ⅱ/LC3Ⅰ,and Beclin protein expression in rat vertebral artery tissues of the CSA group were higher than those in the Sham group(P<0.05),and p62 protein expression was lower than that in the Sham group(P<0.05).The above expression ratios in rat vertebral artery tissues of the fire needling group were lower than those of the CSA group(P<0.05),and p62 protein expression was higher than that of the CSA group(P<0.05).The above protein expression ratios in rat vertebral artery tissues of the fire needling+IGF-1 group were higher than those of the fire needling group(P<0.05),and p62 protein expression was lower than that of the fire needling group(P<0.05). Conclusion:Fire needling can reduce oxidative stress levels by promoting autophagy in CSA rats.The mechanism may be related to the inhibition of PI3K/Akt/mTOR signaling pathway activation.