Toll样受体2在阻塞性睡眠呼吸暂停综合征患者血清中的表达及对肺部损伤的影响

Toll-like receptor 2 expression in serum of patients with obstructive sleep apnea syndrome and its effect on lung injury

摘要:

目的： 探讨Toll样受体2（Toll-like receptor 2，TLR2）在阻塞性睡眠呼吸暂停综合征（obstructive sleep apnea syndrome，OSAS）患者血清中的表达及对肺部损伤的影响。方法： 酶联免疫吸附法（enzyme-linked immunosorbent assay，ELISA）检测患者血清中TLR2的表达水平；Wistar大鼠分为对照组（Control组），慢性间歇性缺氧组（CIH组）和TLR2拮抗剂T2.5组（T2.5组），利用低氧舱建立CIH模型，并对CIH模型进行鉴定；动物肺功能分析系统测定各组大鼠的肺功能指标[深吸气量（inspiratory capacity，IC）、第0.3秒用力呼气后的容积（volume after forced exhalation in 0.3 s，FEV0.3）、每分钟呼气量（breath volume per minute，MV）及呼气峰流速（peak expiratory flow，PEF）]变化；HE染色检测各组大鼠肺组织病理损伤变化；qRT-PCR和Western blot检测各组大鼠肺组织中TLR2的表达水平；ELISA检测各组大鼠肺组织中超氧化物歧化酶（superoxide dismutase，SOD）活性、丙二醛（malondialdehyde，MDA）、肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）和白细胞介素-6（interleukin-6，IL-6）含量的表达变化；ELISA检测各组大鼠血清中TLR2、TNF-α和IL-6含量的表达变化。结果： 随着OSAS程度的加重，OSAS患者血清中TLR2的含量越高（P<0.05）；造模组大鼠的生理特征接近OSAHS病理生理特点，因此CIH大鼠模型建立成功；与CIH组（IC：4.71±0.28，FEV0.3：4.48±0.31，MV：156.78±6.11，PEF：20.89±1.37）比较，T2.5使大鼠IC（6.01±0.32）、FEV0.3（5.51±0.38）、MV（187.56±5.53）和PEF（29.75±1.43）均升高（均P<0.05）；T2.5使大鼠的肺部组织损伤得到抑制，中性粒细胞浸润较少，毛细血管仅轻微扩张；与CIH组比较，T2.5组大鼠肺组织中TLR2蛋白表达水平下调（P<0.05）；与CIH组比较，T2.5组大鼠肺组织中SOD活性增加（P<0.05）、MDA含量降低（P<0.05）、TNF-α和IL-6含量减少（均P<0.05）；与CIH组比较，T2.5组大鼠血清中TLR2、TNF-α和IL-6含量减少（均P<0.05）。结论： OSAS会引起肺部损伤、氧化应激和炎症反应，而TLR2拮抗剂能改善大鼠肺部功能、减轻氧化应激反应和炎症因子的表达。

Abstract:

Objective: To investigate the expression of Toll-like receptor 2 (TLR2) in the serum of patients with obstructive sleep apnea syndrome (OSAS) and its effect on lung injury. Methods: Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression level of TLR2 in the patients’serum. Wistar rats were divided into Control group, chronic intermittent hypoxia group (CIH group) and TLR2 antagonist T2.5 group (T2.5 group), the hypoxic chamber was used to establish the CIH model and it was identified. The animal lung function analysis system was used to measure the lung function indexes changes of each group of rats[inspiratory capacity (IC), volume after forced exhalation in 0.3 s (FEV0.3), breath volume per minute (MV) and peak expiratory flow (PEF) ]. HE staining was used to detect the pathological changes of lung tissue in each group of rats; qRT-PCR and Western blot were used to detect the expression level of TLR2 in the lung tissue of each group of rats; ELISA was used to detect the expression changes of superoxidedismutase (SOD) activity, malondialdehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the lung tissue of each group and ELISA was used to de tect changes in the expression of TLR2, TNF-α and IL-6 in serum of rats in each group. Results: With the aggravation of OSAS, the TLR2 content in the serum of OSAS patients increased (P<0.05). The physiological characteristics of the model rats were close to the pathophysiological characteristics of OSAHS, so the CIH rat model was successfully established. Compared with CIH group (IC: 4.71±0.28, FEV0.3:4.48±0.31, MV:156.78±6.11, PEF:20.89±1.37), T2.5 increased the IC (6.01±0.32), FEV0.3 (5.51±0.38), MV (187.56±5.53) and PEF (29.75±1.43) of rats (all P<0.05); T2.5 inhibited lung tissue damage in rats, neutrophil infiltration was less, and capillaries only expanded slightly; the expression level of TLR2 protein in lung tissue of T2.5 group was down-regulated (P<0.05), the SOD activity increased (P<0.05), the MDA content decreased (P<0.05), and the TNF-α and IL-6 levels decreased (all P<0.05) in the lung tissue; the serum levels of TLR2, TNF-α and IL-6 in the T2.5 group decreased (all P<0.05). Conclusion: OSAS can cause lung damage, oxidative stress and inflammatory response, while TLR2 antagonists can improve lung function in rats and reduce the expression of oxidative stress and inflammatory factors.