期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1993
卷号：90
期号：2
页码：725-729
DOI：10.1073/pnas.90.2.725
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Apolipoprotein J (apoJ) is a sulfated secreted glycoprotein that exhibits ubiquitous expression, evolutionary conservation, and diverse tissue inducibility. It has been proposed to have roles in programmed cell death, sperm maturation, complement regulation, and lipid transport. To identify cell types that synthesize apoJ and to aid evaluation of its function, we screened mouse and human tissues by in situ hybridization. ApoJ was expressed at high levels in an array of specialized cell types of adult and fetal mouse tissues and in similar cell types of human tissues. Most of these cell types are highly secretory and form the cellular interfaces of many fluid compartments. This group includes epithelial boundary cells of the esophagus, biliary ducts, gallbladder, urinary bladder, ureter, kidney distal convoluted tubules, gastric glands, Brunner's glands, choroid plexus, ependyma, ocular ciliary body, endometrium, cervix, vagina, testis, epididymus, and visceral yolk sac. Several nonepithelial secretory cell types that express high levels of apoJ also line fluid compartments, such as synovial lining cells and ovarian granulosa cells. In the context of its known biochemical properties, this expression pattern suggests that localized synthesis of apoJ serves to protect a variety of secretory, mucosal, and other barrier cells from surface-active components of the extracellular environment.
