Antibody Preparation and Expression Analysis of a New Protein Mimecan in Pituitary Tumors / 中国生物化学与分子生物学报

Mimecan belongs to a family of leucine-rich proteoglycans that are secreted into the extracellular matrix. In order to investigate the function of mimecan, the coding region of mimecan was amplifed from a human pituitary cDNA by PCR and the recombinant prokaryotic expression vector pGEX-M was constructed. The vactor was transformed into E.coli BL21(DE3)and the GST-M fusion protein of 38 Kd was ecpressed in the bacteria under induction of IPTG. After purification, the fusion protein was infucted into New Zealand rabbits to prepare polyclonal antibody. The antibody was tested by Western blotting for their specificity and sensitivity. Using the antibody it was found the mimecan was expressed highly in certain types of human pituitary tumor tissues. These results make it possible for studying the biological function of mimecan.

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

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.