Hattori Kazunori, Mabuchi Reiko, Fujiwara Hironobu, Sanzen Noriko, Sekiguchi Kiyotoshi, Kawai Koji, Akaza Hideyuki
Department of Urology, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
J Urol. 2003 Nov;170(5):2040-3. doi: 10.1097/01.ju.0000091971.10816.d2.
Laminins are extracellular matrix proteins that are involved in various cellular functions, including adhesion, proliferation and differentiation. In this study we examined the expression patterns of the laminin chains in human ureteral tissue in vitro and in vivo.
We screened the expression of laminin chains at the mRNA level and determined the major laminins expressed in epithelial and stromal cells of human ureteral tissue by reverse transcriptase-polymerase chain reaction and Western blot analysis. We also examined their expression in vivo by immunofluorescence study.
Reverse transcriptase-polymerase chain reaction analysis revealed that urothelial cells in vitro expressed laminins alpha1, alpha3, alpha5, beta1, beta2, beta3, gamma1 and gamma2, while stromal cells expressed alpha1, alpha2, alpha4, alpha5, beta1, beta2 and gamma1. Western blot analysis under reduced conditions confirmed that urothelial cells expressed laminin alpha3 and alpha5, while stromal cells strongly expressed alpha4 and alpha2. Immunofluorescence labeling with antilaminin alpha chain antibodies in human ureteral tissues confirmed that laminin alpha2, alpha3 and alpha5 chains were strongly expressed in the basement membrane of the urothelium, while alpha4 was expressed predominantly in smooth muscle cells.
The most prominent laminin of urothelial cells was laminin 5 (alpha3beta3gamma2), whereas in stromal cells we noted laminins 8/9 (alpha4beta1/2gamma1). Laminin alpha5 showed the widest distribution pattern in vivo. Our data may be useful for understanding the mechanism involved not only in cell growth and differentiation, but also in cancer invasion in the urinary tract.
层粘连蛋白是细胞外基质蛋白,参与多种细胞功能,包括黏附、增殖和分化。在本研究中,我们检测了层粘连蛋白链在人输尿管组织体内外的表达模式。
我们通过逆转录聚合酶链反应和蛋白质印迹分析,在mRNA水平筛选层粘连蛋白链的表达,并确定人输尿管组织上皮和基质细胞中表达的主要层粘连蛋白。我们还通过免疫荧光研究检测了它们在体内的表达。
逆转录聚合酶链反应分析显示,体外培养的尿路上皮细胞表达层粘连蛋白α1、α3、α5、β1、β2、β3、γ1和γ2,而基质细胞表达α1、α2、α4、α5、β1、β2和γ1。还原条件下的蛋白质印迹分析证实,尿路上皮细胞表达层粘连蛋白α3和α5,而基质细胞强烈表达α4和α2。用人输尿管组织中的抗层粘连蛋白α链抗体进行免疫荧光标记证实,层粘连蛋白α2、α3和α5链在尿路上皮基底膜中强烈表达,而α4主要在平滑肌细胞中表达。
尿路上皮细胞中最突出的层粘连蛋白是层粘连蛋白5(α3β3γ2),而在基质细胞中我们发现了层粘连蛋白8/9(α4β1/2γ1)。层粘连蛋白α5在体内显示出最广泛的分布模式。我们的数据可能有助于理解不仅涉及细胞生长和分化,还涉及尿路癌症侵袭的机制。