补肾益气方对哮喘大鼠下丘脑-垂体-肾上腺轴及CD4^+CD25^+调节性T细胞功能的影响

目的通过观察哮喘大鼠下丘脑-垂体-肾上腺轴与CD4^+CD25^+调节性T细胞(Regulatory T cells,Tregs)功能的改变,探讨补肾益气方对哮喘的干预机制。方法将SD大鼠随机分为正常对照组、哮喘模型组、布地奈德组、低剂量中药组、中剂量中药组、高剂量中药组,每组10只。采用卵蛋白致敏并激发制备哮喘模型,中药组采用相应剂量药物灌胃给药,西医治疗组采用布地奈德雾化吸入。最后1次激发24 h后,采用Buxco有创肺功能仪检测气道阻力;HE染色观察肺组织病理形态学改变;Bio-Plex悬液芯片技术检测血清、BALF中细胞因子水平;流式细胞术检测BALF中Tregs比例;ELISA法测定血浆促肾上腺皮质激素(ACTH)、皮质酮(CORT)水平;采用Real time-PCR法检测下丘脑促肾上腺激素释放激素(CRH)mRNA的表达。结果与正常组比较,哮喘组气道阻力及气道炎症显著增加(P<0.05);BALF中Tregs比例明显下降(P<0.05);血清及BALF中IL-10水平显著下降(P<0.05);血浆中CORT、ACTH水平明显下降(P<0.05);下丘脑CRH mRNA表达水平无明显变化(P>0.05)。与哮喘组比较,低、中、高剂量中药组气道阻力和气道炎症明显减轻(P<0.05);BALF中Tregs比例显著增加(P<0.05),并增加血清中IL-10水平(P<0.05);血浆中CORT、ACTH水平明显升高(P<0.05);下丘脑CRH mRNA表达水平明显增加(P<0.05)。结论哮喘大鼠存在下丘脑-垂体-肾上腺轴与Tregs功能紊乱,补肾益气方可显著改善哮喘大鼠气道炎症和气道高反应性,可能与其改善HPA轴与调节Treg细胞功能,增加内源性皮质酮,增加血清IL-10分泌有关。

Changes of Hypothalamic-pituitary-adrenal Axis and CD~+_4CD~+_(25) Treg Cells in Ratswith Asthma and Effects of Replenishing Kidney and Strengthening Qi Chinese Medicine

Objective To investigate the changes of hypothalamic-pituitary-adrenal axis and CD4^+CD25^+regulatory T cells(Tregs)in a rat asthma model,and explore the anti-asthma effects ofreplenishing kidney and strengthening Qi(RSSQ)Chinese medicine:Herba Epimedii and Radix Astragali.Methods Sixty SD rats were randomly divided into 6 groups:the normal control group,the model group,the budesonide group and the low-dose RSSQ formula group,the median-dose RSSQ formula group and the high-dose RSSQ formula group with 10 rats in each group.Asthma model was established by ovalbumin sensitization and aerosol challenge in all groups except the control group.The treatment groups were administrated with budesonide inhalation and RSSQ formula respectively by gavage,while the normal group was administrated with physiological saline.Within 24 hours after the last ovalbumin challenge,airway reactivity was measured by the Buxco measurement system.Changes in airway histopathology were examined by HE staining.Cytokines in serum and BALF were detected by Bio-Plex Suspension Chip technology.Polychromatic flow cytometry was applied to delineate the Tregs in BALF.IL-10 levels in BALF and serum were measured by ELISA.Results Compared with the control group,rats in model group exhibited increased airway hyperresponsiveness and airway inflammation(P<0.05).The percentage of Treg cells in BALF,the levels of IL-10 in serum and BALF were significantly decreased(P<0.05).The diminished levels of corticosterone(CORT)and ACTH were observed in plasma(P<0.05),but there was no significant difference in the expression of CRH in hypothalamus(P>0.05).The RSSQ formula significantly attenuated airway hyperresponsiveness and inflammation(P<0.05),and further markedly increased the percentage of Tregs in BALF and IL-10 levels in serum(P<0.05)as compared to those of OVA-exposed mice.The levels of CORT and ACTH in plasma were increased and the expressions of CRH in hypothalamus were also increased in the group of RSSQ formula groups(P<0.05).Conclusion The dysfunction of HPA axis and Tregs were observed in the asthma rat model and the RSSQ formula could alleviate the airway inflammation and airway hyperresponsiveness.The potential mechanism may be related to the improvement of HPA axis function and the regulation of Tregs function,thereby increased the levels of endogenous CORT in plasma and IL-10 in serum.