Wang Yongji, Sheibani Nader
Department of Ophthalmology and Visual Sciences Madison, University of Wisconsin Medical School, Madison, Wisconsin 53792-4673, USA.
J Cell Biochem. 2002;87(4):424-38. doi: 10.1002/jcb.10321.
PECAM-1 (CD31) is a cell adhesion molecule that is highly expressed in the endothelium. Hematopoietic cells including platelets, monocytes, neutrophils, and some T cells also express moderate levels of PECAM-1. PECAM-1 undergoes alternative splicing generating a number of isoforms in the endothelium. However, the expression of PECAM-1 isoforms in hematopoietic cells and platelets has not been determined. Here, we examined the expression pattern of PECAM-1 isoforms in human and rodent hematopoietic cells and platelets by RT-PCR and DNA sequencing analysis. Our results showed that multiple PECAM-1 isoforms are expressed in a cell-type and species-specific pattern. We identified seven human PECAM-1 isoforms, six murine PECAM-1 isoforms, and four rat PECAM-1 isoforms. The full-length PECAM-1 was the predominant isoform detected in human cells. The PECAM-1 isoforms that lack exon 14 and 15 (delta14&15) or delta12,14&15 were the predominant isoform in rodent cells. In addition, we identified a novel PECAM-1 isoform, delta13&14, in human hematopoietic cells. Thus, hematopoietic cells express multiple isoforms of PECAM-1 in a pattern similar to that observed in the endothelium of the same species. The regulated expression of these isoforms may be important during hematopoiesis and transendothelial migration.
血小板内皮细胞黏附分子-1（PECAM-1，CD31）是一种在内皮细胞中高表达的细胞黏附分子。包括血小板、单核细胞、中性粒细胞和一些T细胞在内的造血细胞也中度表达PECAM-1。PECAM-1可发生可变剪接，在内皮细胞中产生多种异构体。然而，PECAM-1异构体在造血细胞和血小板中的表达尚未确定。在此，我们通过逆转录聚合酶链反应（RT-PCR）和DNA测序分析，检测了人和啮齿动物造血细胞及血小板中PECAM-1异构体的表达模式。我们的结果表明，多种PECAM-1异构体以细胞类型和物种特异性模式表达。我们鉴定出7种人类PECAM-1异构体、6种小鼠PECAM-1异构体和4种大鼠PECAM-1异构体。全长PECAM-1是在人类细胞中检测到的主要异构体。缺少外显子14和15（δ14&15）或δ12、14&15的PECAM-1异构体是啮齿动物细胞中的主要异构体。此外，我们在人类造血细胞中鉴定出一种新的PECAM-1异构体δ13&14。因此，造血细胞以与同物种内皮细胞中观察到的模式相似的方式表达多种PECAM-1异构体。这些异构体的调控表达在造血和跨内皮迁移过程中可能很重要。
