摘要
目的通过观察低氧时大鼠肺动脉赖氨酰氧化酶(LOX)以及细胞外基质胶原蛋白交联变化,探讨LOX抑制剂β-APN对低氧性肺动脉高压的逆转作用。方法清洁级SD大鼠24只随机均分为常氧对照组、低氧组及低氧+β-APN干预组。测定平均肺动脉压右心室肥大指标RV/(LV+S)及肺动脉结构重建指标管腔面积/管总面积(WA/TA)及相对血管中膜厚度(MT/ED)。采用羟脯氨酸比色法测定可溶性及不可溶性胶原蛋白的含量评价胶原的交联,荧光光谱法检测LOX酶活性,Western blot法和荧光定量PCR分别检测肺动脉LOX蛋白、m RNA表达。结果与常氧组比较,低氧组大鼠m PAP、RV/(LV+S)、WA/TA及MT/ED均明显升高,但均能被β-APN所抑制,差异有统计学意义(P均<0.05)。低氧组大鼠肺组织胶原交联、LOX酶活性以及肺动脉LOX m RNA、蛋白表达均显著高于常氧组,差异均有统计学意义(P<0.05)。β-APN干预组尽管不影响低氧大鼠肺动脉LOX m RNA、蛋白表达,差异无统计学意义(P>0.05),但β-APN干预组大鼠肺组织LOX酶活性及胶原交联明显低于低氧组,差异有统计学意义(P<0.01)。结论低氧能诱导肺动脉LOX高表达,通过促进胶原合成及其交联,参与肺动脉高压的形成和结构重建。抑制LOX信号通路可能有助于延缓低氧性肺动脉高压的进展。
Objective To explore whether hypoxia affects the expression of lysyl oxidase （LOX） and cross-linking of collagen, and LOX inhibitor β-aminopropionitrile （β-APN） ameliorates hypoxia-induced pulmonary arterial hypertensive （PAH） remodeling in rat lung.Methods Twenty four male Sprague-Dawley （SD） rats were randomly divided into 3 groups：normoxic group, hypoxic group and hypoxic＋β-APN group. Mean pulmonary arterial pressure （mPAP） and the ratio of RV to LV plus septum weight （RV/LV ＋ S） were measured. The indicators of wall areas/total areas （WT/TA） and media thickness/external diameter （MT/ED） of pulmonary arterial vessel were observed under image analysis system. LOX activity was detected by fluorescence spectrophotometry. LOX protein was detected by Western blot. LOX mRNA in pulmonary artery was detected by Real time quantitative PCR.Results The levels of mPAP, WA/TA and MT/ED in hypoxic group were significantly higher than those in normoxic group, but were ameliorated in hypoxic＋β-APN group （P〈0.05）. Compared with normoxic group, the collagen cross-linking in the lung tissue in the hypoxic rats was significantly increased （P〈0.01）. The increased collagen cross-linking in the hypoxic rats was reversed by administration of β-APN （P〈0.01）. Moreover, the expression of LOX mRNA, protein in pulmonary arteries and its activity in rat lung tissue of hypoxic group were significantly upregulated when compared with that of normoxic group （P〈0.05）. Although there was no significant difference in the expressions of LOX mRNA and protein between hypoxic and hypoxic＋β-APN group（P〉0.05）, LOX activity was lower in hypoxic＋β-APN group compared with that in hypoxic group （P〈0.05）.Conclusion Up-expression of LOX and cross-linking of collagen mediate hypoxia-induced PAH in rat. Targeting at suppression of LOX signaling pathway could be an approach to ameliorate the development of PAH.
出处
《医学研究杂志》
2017年第12期36-40,24,共6页
Journal of Medical Research
基金
浙江省自然科学基金资助项目(LY12H01002)
温州市科技计划项目(Y20170285)
关键词
低氧
肺动脉高压
赖氨酰氧化酶
胶原
Hypoxia
Pulmonary hypertension
Lysyl oxidase
Collagen
