从脊髓背角脂氧素及其受体介导的Nrf2抗氧化应激途径探讨电针治疗糖尿病神经痛的作用机制OA

Objective To investigate the mechanism of electroacupuncture in treating diabetic neuropathic pain(DNP)through the lipoxin A4(LXA4)and its receptor-mediated Nrf2 antioxidative stress pathway in the spinal dorsal horn.Methods A total of 36 SPF-grade male SD rats were randomly divided into a normal control group(n=6)and a model induction group(n=30).The DNP model was established by single intraperitoneal injection of streptozotocin(65 mg/kg)in the model induction group.After successful modeling,the rats were further randomized into five groups(n=6 for each group):model group,aspirin-triggered lipoxin A4(ATL)group,ATL+BOC-2 group,electroacupuncture(EA)group,and EA+BOC-2 group.The ATL group received intrathecal injection of ATL solution(25 μL)once weekly for 4 consecutive weeks.The ATL+BOC-2 group received intrathecal injection of a mixed solution of ATL(25 μL)and BOC-2(50 μg)with the same treatment course.The EA group received electroacupuncture at bilateral"Shenshu"(BL23)and"Zusanli"(ST36)acupoints,30 min per session,once every other day,three times per week,for 4 consecutive weeks.The EA+BOC-2 group received the same electroacupuncture intervention combined with intrathecal injection of BOC-2 solution.Paw withdrawal latency(PWL)to thermal stimulation was measured before modeling,2 weeks after modeling,and 6 weeks after modeling.At 6 weeks after modeling,spinal dorsal horn and sciatic nerve tissue samples were collected.Sciatic nerve ultrastructure was observed by transmission electron microscopy;LXA4 content in the spinal dorsal horn was detected by ELISA;protein relative expression levels of nuclear factor erythroid 2-related factor 2(Nrf2),heme oxygenase-1(HO-1),NAD(P)H:quinone oxidoreductase 1(NQO1),protein kinase B(Akt)and phosphorylated Akt(p-Akt)were detected by Western blot.Results Com‐pared with the normal control group,LXA4 content in the spinal dorsal horn was lower in the model group after intervention(P<0.05);ompared with the model group,LXA4 content was higher in the EA group(P<0.05).No significant difference in PWL was found among all groups before modeling(P>0.05).At 2 weeks after modeling,PWL in all modeled subgroups was lower than that in the normal control group(P<0.05),indicating successful DNP modeling.At 6 weeks after modeling(at completion of intervention),compared with the normal control group,PWL was lower in the model group(P<0.05);compared with the model group,PWL was higher in the ATL and EA groups(P<0.05);compared with the ATL group,PWL was lower in the ATL+BOC-2 group(P<0.05);compared with the EA group,PWL was lower in the EA+BOC-2 group(P<0.05).Transmission electron microscopy revealed moder‐ate to severe pathological structural damage in the sciatic nerve of the model group;all treatment groups showed markedly attenuated lesions compared with the model group,with the EA group exhibiting the most prominent improvement.Compared with the normal control group,the model group showed lower protein realtive expression levels of Nrf2,HO-1 and NQO1,and higher p-Akt protein realtive expression levels in the spinal dorsal horn(P<0.05);compared with the model group,the ATL and EA groups showed higher Nrf2,HO-1 and NQO1 protein realtive expression levels,and lower p-Akt protein realtive expression levels(P<0.05);compared with the ATL group,the ATL+BOC-2 group showed lower Nrf2,HO-1 and NQO1 protein realtive expression levels,and higher p-Akt protein realtive expression levels(P<0.05);compared with the EA group,the EA+BOC-2 group showed lower Nrf2,HO-1 and NQO1 protein realtive expression levels,and higher p-Akt protein realtive expression levels(P<0.05).Conclusion Electroacu‐puncture may exert its analgesic effect by promoting LXA4 expression and upregulating its receptor,thereby inhibiting Akt phos‐phorylation in the spinal dorsal horn,upregulating the Nrf2-mediated antioxidative stress pathway,and attenuating peripheral nerve injury in DNP rats.