Takako Nishikawa

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OBJECTIVES Recent accumulating evidence indicates that lysophosphatidic acid (LPA) is a lipid mediator, abundantly present in blood, with a wide range of biologic actions including the regulation of proliferation and contraction in liver cells. Although it is speculated that LPA might play a role in pathophysiologic processes in vivo, not only its role but(More)
Lysophosphatidic acid (LPA) is a lipid mediator with multiple biological actions. We have reported that LPA stimulates hepatic stellate cell proliferation and inhibits DNA synthesis in hepatocytes, suggesting that LPA might play some role in the liver. We have found that plasma LPA level and serum autotaxin (ATX) activity were increased in patients with(More)
Hepatic stellate cells (HSCs) play a central role in the development of hepatic fibrosis. Recent evidence has revealed that HSCs also play a role in its resolution, where HSC apoptosis was determined. Moreover, induction of HSC apoptosis caused a reduction of experimental hepatic fibrosis in rats. Thus knowing the mechanism of HSC apoptosis might be(More)
Sphingosine 1-phosphate (S1P), a bioactive lipid mediator, stimulates proliferation and contractility in hepatic stellate cells, the principal matrix-producing cells in the liver, and inhibits proliferation via S1P receptor 2 (S1P(2)) in hepatocytes in rats in vitro. A potential role of S1P and S1P(2) in liver regeneration and fibrosis was examined in(More)
A protective effect of Rho-kinase inhibitor on various organ injuries is gaining attention. Regarding liver injury, Rho-kinase inhibitor is reported to prevent carbon tetrachloride (CCl4)- or dimethylnitrosamine-induced liver fibrosis and hepatic ischemia-reperfusion injury in rats. Because Rho-kinase inhibitor not only improved liver fibrosis but also(More)
BACKGROUND AND AIMS Hepatic ischemic preconditioning decreases sinusoidal endothelial cell injury and Kupffer cell activation after cold ischemia/reperfusion, leading to improved survival of liver transplant recipients in rats. Ischemic preconditioning also protects livers against warm ischemia/reperfusion injury, in which hepatocyte injury is remarkable.(More)
BACKGROUND Bioactive lipid mediator S1P has been suggested to play pathophysiological roles in various fields of clinical science as a circulating paracrine mediator. We previously established a reliable method of measuring plasma S1P concentration, and reported that the one in healthy subjects has a gender difference and a correlation with red blood cell(More)
Branched-chain amino acids (BCAAs) modulate various cellular functions, in addition to providing substrates for the production of proteins. In this study, we examined the effect of BCAAs on the secretion of hepatocyte growth factor (HGF) by hepatic stellate cells. A hepatic stellate cell clone was cultured in medium supplemented with various concentrations(More)
Although structural changes are most important to determine vascular resistance in portal hypertension, vasoactive mediators also contribute to its regulation. Hepatic stellate cells (HSCs) are assumed to play a role in modulating intrahepatic vascular resistance based on their residence in the space of Disse and capacity to contract. Because sphingosine(More)
Branched chain amino acids modulate various cellular functions in addition to providing substrates for the production of proteins. We examined the mechanism underlying the stimulation by leucine of hepatocyte growth factor (HGF) production by hepatic stellate cells. Both p70 S6 kinase activity and phosphorylation of eukaryotic initiation factor 4E-binding(More)