The effect of two different Ginkgo biloba extracts (GB1 and GB4) was studied in-vitro on cultured neurons exposed to oxidative stress caused by H2O2(50 micromol L(-1)) and FeSO4(100 micromol L(-1)). Only about 50% of the neurons were still viable at the end of the experiment (8 h) in control conditions, while the two extracts dose dependently increased the number of viable cells, in the concentration range 10-200 microg mL(-1). The two Ginkgo biloba extracts differed in their effect on hydroxyl-radical-scavenging capacity: GB1 and GB4 had an IC50 (50% inhibiting concentration) value of 78 microg mL(-1) and 186 microg mL(-1), respectively. However, both extracts inhibited apoptosis in cortical neurons after oxidative stress in-vitro. These observations make one suppose that different preparations of Ginkgo biloba have quantitatively different actions and outline the importance of the contribution of apoptosis prevention toward their neuroprotective action.

Macrophage-stimulating protein (MSP) is a scatter factor that causes cell proliferation and migration, and receptor origin nantaise (RON) is its receptor. RON is expressed in macrophages and mesangial cells, and MSP is produced by renal tubular cells. This study investigated whether MSP/RON participate in the pathogenesis of anti-Thy 1 nephritis, a glomerular disease that is characterized by invasion of circulating monocytes into glomeruli and migration and proliferation of mesangial cells. In vivo, renal function and histopathology were studied in rats that had anti-Thy 1 disease and were untreated and treated with a neutralizing anti-MSP antibody. In vitro, whether monocytes express RON and whether MSP has a chemotactic effect on monocytes were studied. In vivo, in anti-Thy 1 disease, MSP was expressed de novo in glomeruli, and neutralization of MSP attenuated the rise in serum creatinine and proteinuria, stopped glomerular neutrophil and monocyte influx, protected from glomerular injury, and lessened mesangial cell overgrowth. M acrophage-stimulating protein (MSP) is a "scatter factor" that is homologous to hepatocyte growth factor (HGF) (1-3). The receptor of MSP is receptor origin nantaise (RON), a proto-oncogene product (4). Information on the cell source of MSP and the biologic meaning of the MSP/RON system is very limited. Originally, MSP was described as a serum factor produced by hepatocytes that enhanced the chemotactic response of macrophages to the C5a fraction of complement (5-8). It was then demonstrated that MSP induces proliferation, migration, and invasive growth of keratinocytes and epithelial tumor cell lines. These findings have suggested a role of MSP in skin-wound healing and in oncogenesis (8 -15).We have shown that MSP is diffusely expressed in tubular epithelium of human kidney and that proximal tubular cells release MSP. In addition, we have shown that human mesangial cells express RON and that MSP induces in human mesangial cell growth, migration, invasion into an artificial collagen matrix, and synthesis of IL-6 (16). These findings suggest that MSP, either circulating or as paracrine product, may participate in the pathogenesis of mesangial proliferative glomerulonephritis (e.g., by inducing mesangial cell proliferation, movement, and invasion into the subendothelial space). An additional mechanism of glomerular endocapillary proliferation that may be induced by MSP is the recruitment of circulating monocytes into the glomerulus. In fact, MSP has a chemoattractant action on macrophages that are derived from monocytes. As yet, however, we ignore whether circulating monocytes express RON, and indeed the role of MSP in the pathogenesis of glomerulonephritis or any else inflammatory disease has never been investigated.This study was performed to understand whether the MSP/ RON system plays a pathogenic role in mesangial proliferative glomerulonephritis. We investigated MSP/RON in anti-Thy 1 glomerulonephritis because in this experimental disease, both proliferation of resident mesangial...

Hepatocyte growth factor (HGF) is a glycoprotein that induces in vitro epithelial tubular cell growth, motility, scattering and branching morphogenesis. The cell machineries that account for HGF biological effects are still unclear. In previous study, we found that HGF upregulated in epithelial tubular cell line (HK2) 3 genes: potassium channel KCNA1, calcium channel (transient receptor potential channel, subfamily C, member 6, TRPC6) and Na(+)/H(+) exchanger-1 (NHE1). In this study, we validated these results with reverse transcription PCR and WB analysis. To investigate whether KCNA1, TRPC6, NHE1 mediate the changes induced by HGF in HK2, we studied the effects of their inhibitors: 4-aminopyridine, charybdotoxin, dendrotoxin K inhibitors of KCNA1, lanthanum, N-(p-amylcinnamoyl) anthranilic acid inhibitors of TRPC6, 5-(N-ethyl-N-isopropyl)amiloride, cariporide inhibitors of NHE1. The inhibitors prevented HGF-induced growth, migration, cytoskeletal reorganization and tubulogenesis in HK2. These results indicate that KCNA1, TRPC6 and NHE1 are cell machineries that are exploited by HGF to effect its biological outcome in renal tubular cells.

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