生长/分化因子MK家族的生物学作用的研究进展

RESEARCH PROGRESS IN THE BIOLOGICAL ROLES OF THE MIDKINE FAMILY OF GROWTH/DIFFERENTIATION FACTORS

孕中期肾蛋白（Ｍｉｄｋｉｎｅ，ＭＫ）和多效生长因子（Ｐｌｅｉｏｔｒｏｐｈｉｎ，ＰＴＮ）组成一种新的肝素结合生长／分化因子家族。它们都是分泌性单肽链蛋白，蛋白质结构都类似。ＭＫ和ＰＴＮ基因均可在胚胎发育期在多种组织大量表达，而仅ＰＴＮ在出生后，有一种神经系统的短暂表达高峰，两者不同地见于数种成年期组织。这些发现结合体外实验结果，提示它们在发育上有重要的促生长／分化作用，并具有神经营养活性，在成年期也有某些未知的生理功能。其中，尤以对神经系统的发育和维持最为重要。它们还可促进血管内皮细胞的纤溶活性。

Midkine (MK) and pleiotrophin(PTN) constitute a new family of heparin binding growth/defferentiation factors.They are secreted proteins of a single polypeptide and are similar in protein and gene structures.Both MK and PTN gene are strongly expressed in a wide variaty of animal tissues during embryogenesis,but only PTN gene shows a transient postnatal peak of expression in the nervous system.They are differently found in several specific tissues in adult period.These findings suggest,together with the resu...