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Keiichi Hishikawa

Publications and source records attributed to Keiichi Hishikawa.

13 recordsLinked to original sources
PubMed2006

Inhibition of histone deacetylase activity suppresses epithelial-to-mesenchymal transition induced by TGF-beta1 in human renal epithelial cells.

Histone acetylation plays an important role in regulating gene expressions by modulating chromatin structure. Histone deacetylase (HDAC) inhibitors have been reported to have an antifibrogenic effect in some organs, such as the liver, skin, and lung, but the underlying mechanisms remain to be clarified. In the kidney, bone morphologic protein 7 (BMP-7) and hepatocyte growth factor are reported to antagonize TGF-beta1-induced tubular epithelial-to-mesenchymal transition (EMT), but nothing is known concerning the effect of HDAC inhibitors on EMT. It was shown that trichostatin A (TSA), an HDAC inhibitor, prevented TGF-beta1-induced EMT in cultured human renal proximal tubular epithelial cells. Treatment with TGF-beta1 induced morphologic changes such as EMT in human renal proximal tubular epithelial cells. However, co-treatment with TSA completely prevented TGF-beta1-induced morphologic changes and significantly prevented TGF-beta1-induced downregulation of E-cadherin and upregulation of collagen type I. Treatment with TSA did not alter TGF-beta1-induced phosphorylation of Smad2 and Smad3 but induced several inhibitory factors of TGF-beta1 signals, such as inhibitors of DNA binding/differentiation 2 (Id2) and BMP-7. Chromatin immunoprecipitation assay confirmed that histone acetylation was involved in the downregulation of E-cadherin and upregulation of Id2 and BMP-7. These results suggest that TSA and other HDAC inhibitors could be new therapeutic agents for tubular EMT.

Base Sequence↗
PubMed2006

Aldosterone impairs bone marrow-derived progenitor cell formation.

Aldosterone has been suggested recently to cause vascular injury by directly acting on the vasculature, in addition to causing injury by raising the blood pressure. Bone marrow-derived endothelial progenitor cells (EPCs) have been shown to exert an important role in the repair of the endothelium. In addition, cell-based therapy using EPCs is emerging as a novel therapeutic strategy for myocardial and peripheral vascular diseases. However, impaired formation and function of EPCs has been observed in patients with risk factors for cardiovascular diseases. We evaluated the possible effects of aldosterone on EPCs by examining the progenitor cell formation from bone marrow mononuclear cells ex vivo. Aldosterone (10 to 1000 nmol/L) reduced the formation of progenitor cells in a concentration-dependent manner. This effect of aldosterone was attenuated by cotreatment with spironolactone. Aldosterone reduced the mRNA levels of vascular endothelial growth factor (VEGF) receptor (VEGFR) 2 without having any effect on the production of VEGF or mRNA levels of VEGF and hepatocyte growth factor in the progenitor cells. However, the expression of stromal-derived growth factor 1 mRNA was paradoxically increased. Consistent with the downregulation of VEGFR-2, VEGF-induced phosphorylation of Akt was abolished in the progenitor cells after aldosterone treatment. N-acetylcysteine, an antioxidant, attenuated the inhibitory effects of aldosterone. These data indicate that aldosterone inhibits the formation of bone marrow-derived progenitor cells, at least partly, by attenuating VEGFR-2 expression and the subsequent Akt signaling. Reduction of aldosterone levels, blockade of mineralocorticoid receptor, and/or cotreatment with antioxidants may, therefore, enhance vascular regeneration by EPCs.

Acetylcysteine↗
PubMed2005

Musculin/MyoR is expressed in kidney side population cells and can regulate their function.

Musculin/MyoR is a new member of basic helix-loop-helix transcription factors, and its expression is limited to skeletal muscle precursors. Here, we report that musculin/MyoR is expressed in adult kidney side population (SP) cells and can regulate their function. SP phenotype can be used to purify stem cell-rich fractions. Microarray analysis clarified that musculin/MyoR was exclusively expressed in kidney SP cells, and the cells resided in the renal interstitial space. Musculin/MyoR-positive cells were decreased in acute renal failure, but infusion of kidney SP cells increased musculin/MyoR-positive cells and improved renal function. Kidney SP cells in reversible acute renal failure expressed a high level of renoprotective factors and leukemia inhibitory factor (LIF), but not in irreversible chronic renal failure. In cultured kidney SP cells, LIF stimulated gene expression of renoprotective factors, and down-regulation of musculin/MyoR augmented LIF-induced gene expression. Our results suggest that musculin/MyoR may play important roles not only in developmental processes but also in regenerative processes in adult tissue.

Animals↗
PubMed2005

Leukemia inhibitory factor induces multi-lineage differentiation of adult stem-like cells in kidney via kidney-specific cadherin 16.

Side population (SP) is reported to be a stem cell-rich population. In the presence of leukemia inhibitory factor (LIF), cultured kidney SP cells differentiated into multi-lineage in collagen gel but not in synthesized polymer that has no cell adhesion factor. In cultured kidney SP cells, gene expression of kidney-specific cadherin 16 was specifically upregulated in collagen gel but not in synthesized polymer. Moreover, decreasing cadherin 16 expression using siRNA abolished LIF-induced multi-lineage differentiation of kidney SP in collagen gel. These results indicated that LIF induced multi-lineage differentiation of adult stem-like cells in kidney via cadherin 16.

Animals↗
PubMed2005

Intrarenal injection of bone marrow-derived angiogenic cells reduces endothelial injury and mesangial cell activation in experimental glomerulonephritis.

Loss of glomerular endothelial cells has been suggested to contribute to the progression of glomerular injury. Although therapeutic angiogenesis induced by administration of bone marrow-derived endothelial progenitor cells has been observed in disease models of endothelial injury, the effects on renal disease have not been clarified. Whether administration of culture-modified bone marrow mononuclear cells would mitigate the glomerular endothelial injury in anti-Thy1.1 nephritis was investigated. After cultivation under conditions that promote endothelial progenitor cell growth, bone marrow mononuclear cells were labeled with CM-DiI, a fluorescence marker, and injected into the left renal artery of Lewis rats with anti-Thy1.1 glomerulonephritis. The decrease in glomerular endothelial cells was significantly attenuated in the left kidney, as compared with the right, in nephritic rats that received the cell infusion. Glomerular injury score, the area positive for mesangial alpha-smooth muscle actin, and infiltration of macrophages were significantly decreased in the left kidney. CM-DiI-positive cells were distributed in glomeruli of the left kidney but not in those of the right kidney. Among CM-DiI-labeled cells incorporated into glomeruli, 16.5 +/- 1.2% of cells were stained with an endothelial marker, rat endothelial cell antigen-1. Culture-modified mononuclear cells secreted 281.2 +/- 85.0 pg of vascular endothelial growth factor per 10(5) cells per day. In conclusion, intra-arterial administration of culture-modified bone marrow mononuclear cells reduced endothelial injury and mesangial activation in anti-Thy1.1 glomerulonephritis. Incorporation into the glomerular endothelial lining and production of angiogenic factor(s) are likely to contribute to the protective effects of culture-modified mononuclear cells against glomerular injury.

Animals↗
PubMed2005

NF-kappaB-dependent increase in intrarenal angiotensin II induced by proteinuria.

BACKGROUND: Intrarenal activation of the renin-angiotensin system has been suggested to play a pivotal role in the progression of various renal diseases, but the regulation of each component has not been fully clarified. We investigated the roles of nuclear factor kappaB (NF-kappaB) activation in the intrarenal renin-angiotensin system changes induced by proteinuria. METHODS: We used unilaterally nephrectomized rats loaded with bovine serum albumin as a model of proteinuric renal injury. Renal NF-kappaB activation was inhibited by gene transfer of the truncated form of IkappaBalpha via injection of a recombinant adenovirus vector into the renal artery, as we reported previously. RESULTS: Inhibition of renal NF-kappaB activation attenuated the increases in intrarenal angiotensinogen protein (2.0-fold in rats with protein overloading and saline injection to 1.3-fold in rats with protein overloading and injection of a truncated form of IkappaBalpha) and angiotensin II (1.8-fold to 1.2-fold), and angiotensinogen mRNA. The increases in angiotensin-converting enzyme (ACE) and angiotensin II receptor type 2 were unaffected by NF-kappaB inhibition. The expression of ACE2, an enzyme that metabolizes angiotensins I and II, was decreased by 37%, and NF-kappaB inhibition abolished the decrease. Immunohistochemical analysis revealed that the angiotensinogen and ACE2 expression changes occurred mainly in proximal tubule cells (i.e., the target of adenoviral gene transfer). CONCLUSION: These results indicate that proteinuria induces an increase in renal angiotensin II in an NF-kappaB-dependent manner. Induction of angiotensinogen and decrease in ACE2 levels may be involved in this NF-kappaB-dependent increase in angiotensin II.

Adenoviridae↗
PubMed2004

Oral flavonoid supplementation attenuates atherosclerosis development in apolipoprotein E-deficient mice.

OBJECTIVE: Caffeic acid phenethyl ester (CAPE), a natural flavonoid, specifically blocks activation of nuclear factor-kappaB (NF-kappaB). We examined the effects of oral CAPE supplementation on atherogenesis in apolipoprotein E-deficient (apoE-/-) mice. METHODS AND RESULTS: Ten-week-old male apoE-/- mice were supplemented orally with CAPE (30 mg/kg body weight) for 12 weeks. At the end of administration, atherosclerosis progression, NF-kappaB activity, gene expression profiling by microarray analysis, and oxidative stress were studied. Treatment of apoE-/- mice with CAPE significantly reduced aortic atherosclerosis, NF-kappaB activity, and expression of NF-kappaB-related genes in the aorta. Moreover, expression of other gene clusters such as basic transcription factors, growth factors, cytokines, cell adhesion proteins, and extracellular matrix were also significantly reduced by treatment with CAPE. Plasma isoprostane level in apoE-/- mice was also significantly reduced by CAPE. CONCLUSIONS: In apoE-/- mice, oral CAPE supplementation attenuates the atherosclerotic process. This may be attributable to direct inhibition of NF-kappaB in the lesion and reduction of systemic oxidative stress. In apoE-/- mice, oral caffeic acid phenethyl ester (CAPE) supplementation attenuates the atherosclerotic process and reduces NF-kappaB activity and expression of NF-kappaB-related genes in the aorta. This may be attributable to direct inhibition of NF-kappaB in the lesion and reduction of systemic oxidative stress.

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PubMed2004

Gene expression profile of human mesenchymal stem cells during osteogenesis in three-dimensional thermoreversible gelation polymer.

This study attempted to characterize the ability of thermoreversible gelation polymer (TGP) to induce differentiation of human mesenchymal stem cells (hMSC) into osteoblasts. Using a long oligo microarray system consisting of 3760 genes, we compared the expression profiles of the cells in 2-dimensional (2D) culture, 3D culture in collagen gel, and 3D culture in TGP with or without osteogenic induction. Compared to 2D culture, the gene expression profile of hMSC showed almost the same pattern in TGP without osteogenic induction, but 72% of genes (2701/3760) were up-regulated in collagen gel. With osteogenic induction, hMSC showed higher ALP activity and osteocalcin production in TGP as compared to 2D culture. Moreover, up-regulation and down-regulation of osteogenic genes were augmented in 3D culture in TGP as compared to 2D culture. As TGP is chemically synthesized and completely free from pathogen such as prion in bovine spongiform encephalopathy, these results suggest that TGP could be applied clinically to induce osteogenic differentiation of hMSC.

Alkaline Phosphatase↗
PubMed2003

Caffeic acid phenethyl ester induces apoptosis by inhibition of NFkappaB and activation of Fas in human breast cancer MCF-7 cells.

The transcription factor NFkappaB plays a role in cell survival. Apoptosis, programmed cell death, via numerous triggers including death receptor ligand binding is antagonized by NFkappaB activation and potentiated by its inhibition. In the present study, we found that caffeic acid phenethyl ester (CAPE), known to inhibit NFkappaB, induced apoptosis via Fas signal activation in human breast cancer MCF-7 cells. CAPE activated Fas by a Fas ligand (Fas-L)-independent mechanism, induced p53-regulated Bax protein, and activated caspases. CAPE also activated MAPK family proteins p38 and JNK. SB203580, a specific inhibitor of p38 MAPK, partially suppressed CAPE-induced p53 activation, Bax expression, and apoptosis, consistent with a mechanism by which CAPE leads to Bax activation, known to be regulated by p38 and p53. The expression of dominant negative c-Jun, which inhibits the JNK signal, also suppresses CAPE-induced apoptosis, suggesting MAPKs are involved in CAPE-induced apoptosis. The expression of Fas antisense oligomers significantly suppressed the CAPE-induced activations of JNK and p38 and apoptosis as compared with Fas sense oligomers. To ascertain whether these phenomena are attributable to the inhibition of NFkappaB by CAPE, we examined the effect of a truncated form of IkappaBalpha (IkappaBDeltaN) lacking the phosphorylation sites essential for NFkappaB activation. IkappaBDeltaN expression not only inhibited NFkappaB activity but also induced Fas activation, Bax expression, and apoptosis. Our findings demonstrate that NFkappaB inhibition is sufficient to induce apoptosis and that Fas activation plays a role in NFkappaB inhibition-induced apoptosis in MCF-7 cells.

Adenoviridae↗
PubMed2002

[The arginine paradox].

L-Arginine has attracted major interest because it has been identified as the natural substrate of nitric oxide synthase and is now recognized as a major player in the regulation of biological function. The arginine paradox refers to the phenomenon that exogenous L-arginine causes NO-mediated biological effects despite the fact that nitric oxide synthases (NOS) are theoretically saturated with the substrate L-arginine. There have been several explanations for this phenomenon, although none of them can explain the arginine paradox fully: (1) L-arginine-induced insulin, which has vasodilatory actions. (2) Neither extracellular nor intracellular concentration determines the NOS activity but rather the L-arginine amount transported across the plasma membrane may do so. (3) Endogenous NOS inhibitors reduce the enzyme sensitivity to L-arginine. These inhibitors include, NG, NG-dimethyl-L-arginine, L-citrulline, argininosuccinic acid and agmatine. (4) Intracellular L-citrulline, an NOS product, is a potent inhibitor of NOS so that the cells may need extra L-arginine to compete with L-citrulline inhibition.

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