温燥伤肺的分子机制实验研究

Molecular Mechanisms of Warm Dryness Damaging the Lung

目的观察温燥对小鼠肺组织超微结构及功能与肺黏液素基因表达的影响。方法 78只昆明种小鼠随机分为常温常湿组、常温燥组、温燥组,每组26只,采用"温度-相对湿度-风"综合条件刺激造模。造模后第6天、第12天观察各组肺呼吸膜与Ⅱ型肺泡细胞(ATⅡ)超微结构,检测肺组织肺黏液素基因5ac(Muc 5ac)表达、核因子NF-κB、肿瘤坏死因子(TNF-α)、二棕榈酰卵磷酯(DPPC)水平。结果与常温常湿组比较,常温燥组第12天ATⅡ内嗜锇板层小体(OMB)数量减少、线粒体(M)多呈肿胀。温燥组第6天Ⅰ型肺泡细胞(ATⅠ)与ATⅡ连接处肿胀,ATⅡ微绒毛排列紊乱且胞内OMB数量减少;第12天呼吸膜增厚,ATⅡ内OMB明显减少,M数量减少且明显肿胀;常温燥组、温燥组第6天、第12天OMB平均面积减少,NF-κB活性下降(P<0.05或P<0.01),DPPC水平下降(P<0.01),Muc 5ac mRNA表达上调而TNF-α下降(P<0.05)。与常温燥组同时间比较,温燥组第6天、第12天OMB平均面积、DPPC、TNF-α水平明显降低(P<0.05)。结论温燥犯肺引起ATⅡ能量代谢障碍与分泌肺表面活性物质功能受损,肺呼吸膜病理状态刺激Muc 5ac基因表达上调、抑制NF-κB活性与降低TNF-α的调节作用,进而导致肺呼吸膜增厚而影响肺通气功能。NF-κB活性水平、TNF-α和DPPC可作为温燥伤肺分子机制的特征性指标。

Objective To observe the effect of warm dryness on the ultra-structure, function and mucin gene expression of the lung tissue. Methods Seventy eight Kunming mice were randomized into the normal temperature and humidity group, normal warm dryness group and warm dryness group, with 26 in each. The models were established with the stimulation of tem- perature, relative humidity and wind. On the 6th and 12th day of modeling, the ultra-structure of respiratory membrane and type II alveolar cell （ATII）, the expression of lung mucin gene 5ac （Muc 5ac）, and the level of nuclear factor kappa-light- chain-enhancer of activated B cells （NF-κB）, tumor necrosis factor-α （TNF-α） and dipalmitoyl phosphatidyl choline （DPPC） were observed. Results Comparing with the normal temperature and humidity group, the number of osmiophilic muhilamellar body （OMB） was reduced and mitochondria （M） showed swelling in the normal warm dryness group on the 12th day of modeling. In the warm dryness group, the junction of type I alveolar cell （AT I ） and ATII showed swelling and resulted in disor- ganized microvilli and declining OMB in AT II on the 6th＇day of modeling. On the 12th day of modeling, membrane thickening, significantly declining of OMB in AT II and declining and swelling of M were observed in the warm dryness group. The average area of OMB in ATII and the activity of NF-κB reduced （P〈0.05 or P〈0.01）, the level of DPPC decreased （P〈0.01）, the expression of Muc Sac gene increased and the expression of TNF-α decreased （P〈0.05） on the 6th and 12th day of modeling in the normal warm dryness group and warm dryness group. Comparing with the normal warm dryness group at the same time point, the average area of OMB and the level of DPPC and TNF-α decreased significantly in the warm dryness group on the 6th and 12th day of modeling （P〈0.05）. Conclusion Warm dryness damaging the lung could result in the disorders of energy metabolism and impaired secretion of pulmonary surfactant in AT II , the increasing expression of Muc 5ac gene, the decreasing activity of NF-κB and TNF-α, thickening respiratory membrane and pulmonary dysfunction. The activity of NF-κB, TNF-α and DPPC could be used as the characteristic indicators for molecular pathogenesis of warm dryness damaging the lung.