木犀草素调控JAK1/STAT3通路对抑郁症大鼠海马小胶质细胞极化的影响

Effect of luteolin on polarization of hippocampal microglia in depression rats by regulating JAK1/STAT3 pathway

目的基于小胶质细胞的极化探讨木犀草素发挥抗抑郁活性的相关机制。方法将72只雄性大鼠随机分为对照组,模型组,ABT-494组(10 mg/kg,JAK1抑制剂),木犀草素低、高剂量(30、60 mg/kg)组和木犀草素(60 mg/kg)+ABT-494(10 mg/kg)组,每组12只。除对照组外,其余组大鼠采用慢性不可预知性温和应激(CUMS)联合孤养复制抑郁大鼠模型。建模成功后ig相应剂量的药物进行干预,1次/d,连续28 d。分别于造模前1 d、造模结束后和给药结束后,采用糖水偏好实验和强迫游泳实验对大鼠抑郁样行为进行评估;免疫荧光双染法检测大鼠海马齿状回(DG)小胶质细胞中离子钙结合衔接分子-1(Iba-1)和诱导型一氧化氮合酶(iNOS)的表达;ELISA检测海马组织炎性因子白细胞介素(IL)-6、肿瘤坏死因子-α(TNF-α)、IL-4、IL-10的水平;Western blotting检测海马组织Janus激酶1(JAK1)/信号转导与转录激活因子3(STAT3)通路相关蛋白表达。结果与对照组比较,模型组大鼠体质量、糖水偏好度、海马组织IL-4、IL-10水平显著降低,强迫游泳时不动时间、海马DG区Iba-1/iNOS共表达的阳性细胞数、海马组织TNF-α、IL-6水平和p-JAK1/JAK1、p-STAT3/STAT3值显著增加(P<0.05);与模型组比较,ABT-494组、木犀草素+ABT-494组和木犀草素低、高剂量组大鼠体质量、糖水偏好度、海马组织IL-4、IL-10水平显著增加,强迫游泳时不动时间、海马DG区Iba-1/iNOS共表达的阳性细胞数、海马组织TNF-α、IL-6水平和p-JAK1/JAK1、p-STAT3/STAT3比值显著降低(P<0.05);且木犀草素和ABT-494联合使用后作用优于两者单独应用。结论木犀草素的抗抑郁作用可能与抑制JAK1/STAT3信号通路的激活,进而抑制小胶质细胞向M1型活化有关。

Objective Based on the polarization of microglia, to explore the relevant mechanism of luteolin exerting antidepressant activity. Methods Seventy-two male rats were randomly divided into control group, model group, ABT-494 group(10 mg/kg),luteolin low(30 mg/kg), high(60 mg/kg) dose groups, luteolin(60 mg/kg) + ABT-494(10 mg/kg) group, 12 rats in each group.Except for control group, rats in the other groups were treated with chronic unpredictable mild stress(CUMS) combined with orphan rearing to replicate depression rat models. After the modeling was successful, the corresponding dose of drugs was given to the stomach for intervention, once a day, for 28 consecutive days. On one day before modeling, after modeling, and after drug administration respectively, sugar water preference experiment and forced swimming experiment were used to evaluate the depressive behavior of rats;immunofluorescence double staining method was used to detect the expression of Iba-1 and iNOS in rat hippocampal dentate gyrus(DG) microglia;ELISA was used to detect the levels of inflammatory factors interleukin(IL)-6, tumor necrosis factor-α(TNF-α), IL-4 and IL-10 in hippocampus;Western blotting was used to detect the expression of Janus kinase 1(JAK1)/signal transducer and activator of transcription 3(STAT3) pathway related proteins in hippocampus. Results Compared with control group, the body weight, sugar water preference, and the levels of hippocampal IL-4 and IL-10 reduced significantly in the model group, the immobility time during forced swimming, the number of positive cells co-expressed with ionized calcium-binding adapter molecule-1(Iba-1)/inducible nitric oxide synthase(iNOS) in the hippocampal DG area, and the levels of TNF-α and IL-6 in hippocampus and the ratios of p-JAK1/JAK1 and p-STAT3/STAT3 increased significantly(P < 0.05). Compared with the model group, the body weight, sugar water preference, and the levels of hippocampal IL-4 and IL-10 increased significantly in the luteolin low and high dose groups, the immobility time during forced swimming, the number of positive cells co-expressed with Iba-1/iNOS in the hippocampal DG area, the levels of TNF-α and IL-6 in hippocampus and the ratios of p-JAK1/JAK1 and p-STAT3/STAT3 reduced significantly(P < 0.05). In addition, the combined use of luteolin and JAK1 inhibitor ABT-494 could inhibit the JAK1/STAT3 signaling pathway and improve depression-like behavior in model rats better than the two alone. Conclusion The antidepressant effect of luteolin may be related to the inhibition of the activation of JAK1/STAT3 signaling pathway and the inhibition of the activation of microglia to M1 type.