In vitro analysis of signaling pathway involved in pathgenesis of renal or cardiac disease using animal models.

1-磷酸鞘氨醇(S1P)可以调节细胞的增殖、凋亡和运动。最近，我们报道了S1P及其类似物二氢S1P(DHS1P)促进大鼠肾小球系膜细胞增殖。为了研究S1P和DHS1P诱导系膜细胞增殖的信号机制，我们对系膜细胞增殖过程中的基因表达进行了基因芯片分析。就总体模式而言，S1P和DHS1P诱导的基因表达波与强大的系膜有丝分裂原血小板衍生生长因子(PDGF)诱导的基因表达波相似，但我们发现有几个基因，如结缔组织生长因子(CTGF)和肝素结合EGF样生长因子(HB-EGF)，可由鞘磷脂诱导，而不是由PDGF诱导。聚类分析还发现，与S1P刺激的细胞相比，DHS1P刺激的细胞高表达钙依赖分子。钙动员分析显示，DHS1P具有比S1P更高的细胞内钙动员幅度，提示SIP1和DHS1P对细胞内钙动员的调控不同，可能导致系膜细胞基因表达的差异。在此进行的大规模基因表达监测使我们能够确定S1P在系膜细胞增殖过程中诱导的转录特性。

Sphingosine 1-phosphate(S1P) is known to regulate cell proliferation, apoptosis, and motility. Recently, we have reported that S1P and its analogue dihydro-S1P(DHS1P) promote proliferation of rat cultured mesangial cells. To investigate the signaling mechanisms underlying S1P- and DHS1P-induced mesangial cell proliferation, we performed cDNA microarray analysis of gene expression during mesangial cell proliferation. In terms of the overall pattern, gene expression waves induced by S1P and DHS1P were similar to those induced by a potent mesangial mitogen platelet-derived growth factor(PDGF), whereas we found several genes, such as two growth factors, connective tissue growth factor(CTGF) and heparin-binding EGF-like growth factor(HB-EGF), which were induced by the sphingolipids, but not by PDGF. Cluster analysis also identified calcium-dependent molecules highly expressed in DHS1P-stimulated cells compared to S1P-stimulated cells. Calcium mobilization analysis showed that DHS1P had higher magnitudes of intracellular calcium mobilization than S1P, suggesting that SIP and DHS1P differentially regulate intracellular calcium mobilization, possibly leading to different gene expression in mesangial cells. The large-scale monitoring of gene expression performed here allows us to identify S1P-induced transcriptional properties during mesangial cell proliferation.