Molecular anatomy of functional structural expression of gap junctions.

采用免疫组织化学、生化和分子生物学等方法分析间隙连接的功能结构，探讨连接蛋白家族在不同组织和细胞类型以及不同功能状态下的分子多样性和分布规律。1)大鼠上切牙成釉细胞发育过程中，未分化细胞中的连接蛋白43在牙釉质形成前消失一次，分泌活性成熟后重新出现。2)在发育中的大鼠卵巢颗粒细胞中，间隙连接由不同磷酸化状态的Cx43和Cx45组成。虽然Cx45保持不变，但Cx43在成熟过程中增加，但在排卵后很快消失。此外，卵巢中RNA印迹检测到的Cx40仅局限于血管壁。3)在大鼠乳腺中，Cx26和Cx32定位于分泌性腺泡细胞之间，Cx43定位于肌上皮细胞之间。它们在怀孕期间逐渐增加。Cx32和Cx43在分娩后较易诱导，在哺乳期早期达到高峰。在大鼠心内膜和血管中，内皮细胞根据其连接蛋白的表达模式可分为Cx40显性型和Cx37显性型。5)在大鼠气管中，Cx37在出生3周后在平滑肌细胞中表达，此后表达量增加，并与Cx43共定位，而不与Cx43共定位。6)在豚鼠中，Cx43定位于小肠圆形平滑肌外层成纤维细胞样细胞和深肌丛之间以及大肠肌下丛之间。这些含有Cx43的细胞也呈c-Kit阳性，并与具有肠起搏器活性的间质细胞相互连接。本课题从具有特定生理特性的复合蛋白连接蛋白家族出发，成功地阐明了缝隙连接功能的各个方面；间隙连接蛋白的表达在发育阶段、不同功能状态和不同组织之间具有特征性的调控。它们受多种机制控制，如表达水平或磷酸化状态。最后，在心脏和肠道运动的起搏器细胞等特殊功能细胞中发现了特定的连接蛋白分子。少

Functional structures of gap junctions were analyzed by immunohistochemical, biochemical and molecular biological methods to examine the molecular diversity and distribution patterns of connexin protein family in various tissue and cell types as well as in different functional states.1) During ameloblast development of the rat upper incisor, connexin 43 in undifferentiated cells once disappears just before enamel formation and reappears after maturation of secretion activity.2) In granulosa cells of developing rat ovary, gap junctions are composed of Cx43 and Cx45 in various phosphorylation states. While Cx45 remains constant, Cx43 increases during maturations but disappears soon after ovulation. In addition, Cx40 detected in RNA blot in ovary is localized only in blood vessel wall.3) In rat mammary glands, Cx26 and Cx32 are colocalized between secretory acinar cells and Cx43 is localized between myoepithels. They gradually increase during pregnancy. Cx32 and Cx43 are induced dramatica … More lly just after delivery, and reach a maximum at the early lactation period. There seems to bea gap between mRNA and protein expression levels as well as the additional shift from P1 to P2 phosphorylation state of Cx43.4) In rat endocardium and blood vessels, endothelial cells can be classified as Cx40 dominant or Cx37 dominant type according to their connexin expression patterns.5) In rat trachea Cx37 is expressed in smooth muscle cells after 3weeks after birth and increases thereafter and colocalized with Cx43, but not with Cx40.6) In guinea pig, Cx43 is localized between fibroblast like cells in the outer layr of circular smooth muscles and deep muscular plexus of the small intestine and between submuscular plexus in the large intestine. These Cx43 containing cells are also c-Kit positive and interconnect the interstitial cells with intestinal pacemaker activity.This research project has successfully elucidated the diverse aspects of gap junction functions in the light of composite protein connexin family with specific physiological properties ; Gap junction protein expressions are characteristically regulated during developmental stages, in different functional states and between different tissues. They are controlled by various mechanisms such as expression levels or phosphorylation states. Finally, specific connexin molecules are identified in specialized functional cells such as pacemaker cells in heart and intestinal movement. Less