Ricono Jill M, Wagner Brent, Gorin Yves, Arar Mazen, Kazlauskas Andrius, Choudhury Goutam Ghosh, Abboud Hanna E
Department of Molecular Medicine, Institute of Biotechnology, Univ. of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA.
Am J Physiol Renal Physiol. 2009 Feb;296(2):F406-17. doi: 10.1152/ajprenal.90368.2008. Epub 2008 Nov 19.
PDGF B chain or PDGF receptor (PDGFR)-beta-deficient (-/-) mice lack mesangial cells. To study responses of alpha- and beta-receptor activation to PDGF ligands, metanephric mesenchymal cells (MMCs) were established from embryonic day E11.5 wild-type (+/+) and -/- mouse embryos. PDGF BB stimulated cell migration in +/+ cells, whereas PDGF AA did not. Conversely, PDGF AA was chemotactic for -/- MMCs. The mechanism by which PDGFR-beta inhibited AA-induced migration was investigated. PDGF BB, but not PDGF AA, increased intracellular Ca(2+) and the production of reactive oxygen species (ROS) in +/+ cells. Transfection of -/- MMCs with the wild-type beta-receptor restored cell migration and ROS generation in response to PDGF BB and inhibited AA-induced migration. Inhibition of Ca(2+) signaling facilitated PDGF AA-induced chemotaxis in the wild-type cells. The antioxidant N-acetyl-l-cysteine (NAC) or the NADPH oxidase inhibitor diphenyleneiodonium (DPI) abolished the BB-induced increase in intracellular Ca(2+) concentration, suggesting that ROS act as upstream mediators of Ca(2+) in suppressing PDGF AA-induced migration. These data indicate that ROS and Ca(2+) generated by active PDGFR-beta play an essential role in suppressing PDGF AA-induced migration in +/+ MMCs. During kidney development, PDGFR beta-mediated ROS generation and Ca(2+) influx suppress PDGF AA-induced chemotaxis in metanephric mesenchyme.
血小板源性生长因子B链或血小板源性生长因子受体（PDGFR）-β缺陷（-/-）小鼠缺乏系膜细胞。为了研究α受体和β受体激活对血小板源性生长因子（PDGF）配体的反应，从胚胎第11.5天的野生型（+/+）和-/-小鼠胚胎中分离出后肾间充质细胞（MMC）。PDGF BB刺激+/+细胞的迁移，而PDGF AA则无此作用。相反，PDGF AA对-/- MMC具有趋化作用。研究了PDGFR-β抑制AA诱导迁移的机制。PDGF BB而非PDGF AA可增加+/+细胞内的Ca(2+)及活性氧（ROS）的产生。用野生型β受体转染-/- MMC可恢复细胞对PDGF BB的迁移和ROS生成反应，并抑制AA诱导的迁移。抑制Ca(2+)信号传导可促进野生型细胞中PDGF AA诱导的趋化作用。抗氧化剂N-乙酰-L-半胱氨酸（NAC）或NADPH氧化酶抑制剂二苯基碘鎓（DPI）可消除BB诱导的细胞内Ca(2+)浓度升高，提示ROS作为Ca(2+)的上游介质抑制PDGF AA诱导的迁移。这些数据表明，活性PDGFR-β产生的ROS和Ca(2+)在抑制+/+ MMC中PDGF AA诱导的迁移中起重要作用。在肾脏发育过程中，PDGFR β介导的ROS生成和Ca(2+)内流抑制后肾间充质中PDGF AA诱导的趋化作用。
