El Hader Carlos, Tremblay Sandra, Solban Nicolas, Gingras Denis, Béliveau Richard, Orlov Sergei N, Hamet Pavel, Tremblay Johanne
Laboratory of Cellular Biology of Hypertension, Centre Hospitalier de l'Université de Montréal, Quebec, Canada.
Am J Physiol Renal Physiol. 2005 Dec;289(6):F1273-80. doi: 10.1152/ajprenal.00103.2005. Epub 2005 Jul 20.
We have shown previously that the hypertension-related, calcium-regulated gene (HCaRG) is involved in the control of renal cell proliferation and differentiation (Devlin AM, Solban N, Tremblay S, Gutkowska J, Schurch W, Orlov SN, Lewanczuk R, Hamet P, and Tremblay J. Am J Physiol Renal Physiol 284: F753-F762, 2003). To determine whether HCaRG plays a role in kidney repair after injury, we extended our studies on the cellular function of HCaRG by comparing cell migration of two kidney cell lines [HEK293 and Madin-Darby canine kidney (MDCK)-C7] stably transfected with the plasmid alone or with a plasmid containing HCaRG cDNA. HCaRG-expressing HEK293 cells, which undergo lower proliferation, migrated faster than control cells and presented greater adhesiveness to the extracellular matrix. Faster migration was also observed for the MDCK-C7 cells, after they were stably transfected with HCaRG cDNA. HCaRG overexpression induced major morphological changes in HEK293 cells, including the formation of lamellipodia. Expression microarrays of HCaRG-expressing HEK293 cells revealed the elevated expression of several genes known to be involved in cell migration and lamellipodia formation, including transforming growth factor-alpha (TGF-alpha), galectins, autotaxins and fibronectin. These cells exhibited augmented synthesis and release of activated TGF-alpha. Conditioned medium from HCaRG-expressing cells stimulated the migration and induced significant morphological changes in control cells, in part, through activation of the TFG-alpha/EGF receptor. Together, these data support a role for HCaRG in kidney repair after injury through its effect on renal cell migration and TGF-alpha secretion.
我们之前已经表明，高血压相关的钙调节基因（HCaRG）参与肾细胞增殖和分化的调控（Devlin AM，Solban N，Tremblay S，Gutkowska J，Schurch W，Orlov SN，Lewanczuk R，Hamet P，以及Tremblay J。《美国生理学杂志：肾脏生理学》284：F753 - F762，2003年）。为了确定HCaRG在损伤后肾脏修复中是否发挥作用，我们通过比较单独用质粒或用含HCaRG cDNA的质粒稳定转染的两种肾细胞系[人胚肾293细胞（HEK293）和麦氏犬肾细胞（MDCK）-C7]的细胞迁移，扩展了对HCaRG细胞功能的研究。表达HCaRG的HEK293细胞增殖较低，其迁移速度比对照细胞快，并且对细胞外基质的黏附性更强。在用HCaRG cDNA稳定转染后，MDCK-C7细胞也观察到更快的迁移。HCaRG的过表达诱导了HEK293细胞的主要形态变化，包括片状伪足的形成。表达HCaRG的HEK293细胞的表达微阵列显示，几个已知参与细胞迁移和片状伪足形成的基因表达升高，包括转化生长因子-α（TGF-α）、半乳糖凝集素、自分泌运动因子和纤连蛋白。这些细胞表现出活化的TGF-α合成和释放增加。来自表达HCaRG细胞的条件培养基刺激对照细胞的迁移并诱导显著的形态变化，部分是通过激活TFG-α/表皮生长因子受体。总之，这些数据支持HCaRG通过其对肾细胞迁移和TGF-α分泌的影响在损伤后肾脏修复中发挥作用。
