Down-regulation of osteoglycin expression and its influence on the metabolism of collagen in the lung tissues after acute pulmonary embolism / 解放军医学杂志

ABSTRACT

Objective To study the changes in expression of osteoglycin (OGN) in the lung tissue in a rat acute pulmonary embolism (PE) model and its effects on the metabolism of collagen. Methods A rat acute PE model was reproduced by injecting 3-4 emboli into the left jugular vein. The lung tissue samples were collected at different time points as following 1h, 8h, 24h and 48h, then the total RNA and total proteins of the lung tissue were extracted. Normal rats were used as control. The changes in mRNA level in OGN were assayed by semi-quantitative RT-PCR, and the changes in protein level were determined by Western blot method. The immunohistochemical method was employed to study the distribution and expression changes in OGN in the lung tissue after PE. Masson staining was employed to observe the deposition of collagen in the lung tissue 4 weeks after acute PE. Results t different time points, the mRNA levels and the protein levels of OGN were lowered gradually in the lung tissue in rat acute PE models. The immunohistochemical study indicated that OGN was distributed beneath the bronchial epithelium, and in the periphery of cartilaginous tissue and the lung alveoli. It also could be observed beneath the arterial endothelium and in the adventitia of pulmonary arteries. In pulmonary veins, OGN accumulated in the adventitia, media, and intima. The deposition of collagen in the lung tissue increased obviously 4 weeks after acute PE. Conclusion The expression of OGN is down-regulated after acute PE. It facilitates the deposition of collagen in the lung tissue.