Hiroko Ogawa

Increased activity and expression of histone deacetylase 1 in relation to tumor necrosis factor-alpha in synovial tissue of rheumatoid arthritis

IntroductionThe purpose of this study was to investigate the profile of histone deacetylase (HDAC) expression in the synovial tissue of rheumatoid arthritis (RA) compared with that of normal control and osteoarthritis (OA), and to examine whether there is a link between HDAC activity and synovial inflammation.MethodsHDAC activity and histone acetyltransferase (HAT) activity were determined in nuclear extracts of total synovial tissue surgically obtained from normal, OA and RA joints. The level of cytoplasmic tumor necrosis factor a (TNFα) fraction was measured by ELISA. Total RNA of synovial tissue was used for RT-PCR of HDAC1-8. In synovial fibroblasts from RA (RASFs), the effects of TNFα on nuclear HDAC activity and class I HDACs (1, 2, 3, 8) mRNA expressions were examined by quantitative real-time PCR. The protein expression and distribution of class I HDACs were examined by Western blotting.ResultsNuclear HDAC activity was significantly higher in RA than in OA and normal controls and correlated with the amount of cytoplasmic TNFα. The mRNA expression of HDAC1 in RA synovial tissue was higher than in OA and normal controls, and showed positive correlation with TNFα mRNA expression. The protein level of nuclear HDAC1 was higher in RA synovial tissue compared with OA synovial tissue. Stimulation with TNFα significantly increased the nuclear HDAC activity and HDAC1 mRNA expression at 24 hours and HDAC1 protein expression at 48 hours in RASFs.ConclusionsOur results showed nuclear HDAC activity and expression of HDAC1 were significantly higher in RA than in OA synovial tissues, and they were upregulated by TNFα stimulation in RASFs. These data might provide important clues for the development of specific small molecule HDAC inhibitors.

Hyaluronan receptors involved in cytokine induction in monocytes

During inflammation, lower molecular weight fragments of hyaluronan accumulate, and this is known to be inflammatory and immune-stimulatory. In diseases such as inflammatory bowel disease, inflammatory cells bind to hyaluronan; however, the cellular response and molecular mechanism of hyaluronan-hyaluronan receptor interactions in mononuclear cells are not well understood. The expression of hyaluronan receptors in peripheral blood mononuclear cells (PBMC) was examined. PBMC were stimulated with lower and higher molecular weight hyaluronan (molecular weight 100-150 kDa and 2700 kDa) and the induction of proinflammatory cytokines (interleukin-6 (IL-6) and monocyte chemoattractant protein (MCP-1)) was compared by enzyme-linked immunoabsorbant assay (ELISA). Cells were coincubated with various signaling pathway inhibitors. In addition, neutralizing antibodies against CD44 and TLR4 were added and the effects on PBMC were investigated. Finally, mononuclear cells from CD44-null and toll-like receptor 4 (TLR4) mutant mice were both stimulated with lower molecular weight hyaluronan. Among the hyaluronan receptors, TLR4 and CD44 were markedly expressed on PBMC. Hyaluronan-stimulated PBMC enhanced the attachment to the extracellular matrix. Lower molecular weight hyaluronan induced IL-6 and MCP-1 production in PBMC, but high-molecular-weight hyaluronan did not induce IL-6 and MCP-1 production. An anti-CD44 antibody attenuated the induction of both IL-6 and MCP-1 in lower molecular weight hyaluronan-stimulated PBMC. In both TLR4 mutant and CD44-null mice, the induction of IL-6 by lower molecular weight hyaluronan stimulation was decreased. SB203580 completely abolished IL-6 production in both TLR4 mutant and CD44-null mononuclear cells, while PD98059 abolished IL-6 production in CD44-null mononuclear cells. Hyaluronan receptors, CD44 and TLR4, play distinct roles in cytokine induction in hyaluronan-stimulated mononuclear cells.

Versican is induced in infiltrating monocytes in myocardial infarction

Versican, a large chondroitin sulfate proteoglycan, plays a role in conditions such as wound healing and tissue remodelling. To test the hypothesis that versican expression is transiently upregulated and plays a role in the infarcted heart, we examined its expression in a rat model of myocardial infarction. Northern blot analysis demonstrated increased expression of versican mRNA. Quantitative real-time RT-PCR analysis revealed that versican mRNA began to increase as early as 6 h and reached its maximal level 2 days after coronary artery ligation. Versican mRNA then gradually decreased, while the mRNA of decorin, another small proteoglycan, increased thereafter. Versican mRNA was localized in monocytes, as indicated by CD68-positive staining, around the infarct tissue. The induction of versican mRNA was accelerated by ischemia/reperfusion (I/R), which was characterized by massive cell infiltration and enhanced inflammatory response. To examine the alteration of versican expression in monocytes/macrophages, we isolated human peripheral blood mononuclear cells and stimulated them with granulocyte/macrophage colony-stimulating factor (GM-CSF). Stimulation of mononuclear cells with GM-CSF increased the expression of versican mRNA as well as cytokine induction. The production of versican by monocytes in the infarct area represents a novel finding of the expression of an extracellular matrix gene by monocytes in the infarcted heart. We suggest that upregulation of versican in the infarcted myocardium may have a role in the inflammatory reaction, which mediates subsequent chemotaxis in the infarcted heart. (Mol Cell Biochem xxx: 47–56, 2005)

ADAMTS1 Is a Unique Hypoxic Early Response Gene Expressed by Endothelial Cells

ADAMTS1 (a disintegrin and metalloproteinase with thrombospondin motifs 1) is a member of the matrix metalloproteinase family. We have previously reported that ADAMTS1 was strongly expressed in myocardial infarction. In this study, we investigated whether hypoxia induced ADAMTS1 and investigated its regulatory mechanism. In hypoxia, the expression level of ADAMTS1 mRNA and protein rapidly increased in endothelial cells, but not in other cell types. Interestingly, the induction of ADAMTS1 by hypoxia was transient, whereas vascular endothelial growth factor induction by hypoxia in human umbilical vein endothelial cells (HUVEC) increased in a time-dependent manner. CoCl2, a transition metal that mimics hypoxia, induced ADAMTS1 in HUVEC. The phosphatidylinositol 3-kinase inhibitor LY294002 dose-dependently inhibited the increase of ADAMTS1 mRNA expression in hypoxia. We characterized the promoter region of ADAMTS1, and the secreted luciferase assay system demonstrated that hypoxia induced luciferase secretion in the culture medium 4.6-fold in HUVEC. In the promoter region of ADAMTS1, we found at least three putative hypoxia-inducible factor (HIF) binding sites, and the chromatin immunoprecipitation assay revealed HIF-1 binding to HIF binding sites in the promoter region of ADAMTS1 under hypoxia. Recombinant ADAMTS1 protein promoted the migration of HUVEC under hypoxic conditions. In summary, we found that ADAMTS1 is transiently induced by hypoxia in endothelial cells, and its transcription is mediated by HIF-1 binding. Our data indicate that ADAMTS1 is a novel acute hypoxia-inducible gene.

Cachectin/tumor necrosis factor and interleukin-1 show different modes of combined effect on lipoprotein lipase activity and intracellular lipolysis in 3T3-L1 cells

Cachectin/tumor necrosis factor (cachectin/TNF) and interleukin-1 (IL-1) share many effects in various tissues and cells, including suppression of lipoprotein lipase (LPL) activity and enhancement of intracellular lipolysis. A possible interaction between cachectin/TNF and IL-1 in these lipase systems was studied in 3T3-L1 adipocytes. The two cytokines showed marked synergy in their suppression of LPL activity in these adipocytes. The least effective dose of cachectin/TNF or IL-1 was at around 5 x 10(-11) or 2.5 x 10(-12) M, respectively. However, when present in combination in amounts as small as 1/20 or 1/100 of the minimum effective dose for either cytokine alone (2.5 x 10(-12) M cachectin/TNF and 2.5 x 10(-14) M IL-1), the cytokines showed marked suppression of LPL activity. In marked contrast, such synergism was not seen for enhancement of intracellular lipolysis. This discrepancy in the combined effects of the two monokines on the two different enzyme systems in the same cells suggests that synergism between cachectin/TNF and IL-1 is unlikely at the level of their receptors on the surface of 3T3-L1 cells. Because the two monokines are considered to be secreted from macrophages under similar conditions, their effect on LPL suppression in many pathophysiological situations would be much greater than that of either monokine alone.

Tumor-specific expression of the RGD-α3(IV)NC1 domain suppresses endothelial tube formation and tumor growth in mice

Angiogenesis plays an essential role in tumor growth. This study investigated expression of the noncollagenous domain of α3(IV) collagen (α3(IV)NC1) transduced into tumors and its inhibition of tumor growth. We hypothesized that if a human telomerase reverse transcriptase (hTERT) promoter‐driven RGD motif containing α3(IV)NC1 (hTERT/ RGD‐α3(IV)NC1) were expressed in telomerase‐expressing tumor cells, it would inhibit tumor growth by its anti‐angiogenic property. Adenoviral transduction of hTERT/RGD‐α3(IV)NC1 expressed RGD‐α3(IV)NC1 in hTERT‐positive tumor cell lines. However, hTERT/RGD‐α3(IV)NC1 did not express RGD‐α3(IV)NC1 in hTERT‐negative cells such as keratinocytes and fibroblasts. The secreted RGD‐α3(IV)NC1 in the conditioned medium from tumor cells inhibited cell proliferation as well as tube formation in cultured endothelial cells, but had no effect on other types of cells. In an in vivo model, adenoviral hTERT/RGD‐α3(IV)NC1 gene therapy showed limited expression of RGD‐α3(IV)NC1 in tumors and resulted in a significant decrease of vessel density in tumors. The growth of subcutaneous (s.c.) tumors in nude mice was significantly suppressed by treatment with hTERT/ RGD‐α3(IV)NC1. In addition, long‐term inhibition of tumor growth was achieved by intermittent administration of hTERT/RGD‐α3(IV)NC1. In conclusion, our findings demonstrate that tumor‐specific anti‐angiogenic gene therapy utilizing RGD‐α3(IV)NC1 under the hTERT promoter inhibited angiogenesis in tumors, resulting in an antitumor effect.—Miyoshi, T., Hirohata, S., Ogawa, H., Doi, M., Obika, M., Yonezawa, T., Sado, Y., Kusachi, S., Kyo, S., Kondo, S., Shiratori, Y., Hudson, B. G., Ninomiya, Y. Tumor‐specific expression of the RGD‐α3(IV)NC1 domain suppresses endothelial tube formation and tumor growth in mice. FASEB J. 20, 1264–1275 (2006)

Connective tissue growth factor induction in a pressure-overloaded heart ameliorated by the angiotensin II type 1 receptor blocker olmesartan.

Connective tissue growth factor (CTGF) is a secreted protein that regulates fibrosis. We hypothesized that CTGF is induced in a pressure-overloaded (PO) heart and that blocking the angiotensin II type 1 receptor would reduce CTGF expression. Accordingly, we administered olmesartan and compared its effects with other antihypertensive drugs in a PO heart. CTGF induction was determined in a rat PO model, and olmesartan, hydralazine or saline was continuously administered. The effects of olmesartan on CTGF induction, myocyte hypertrophy and fibrosis were evaluated. The effect of olmesartan on cardiac function was also examined in CTGF- and transforming growth factor-beta 1 (TGF-β1)-infused rats. CTGF was increased in the PO heart 3 days after aortic banding and was markedly distributed around the perivascular fibrotic area. After 28 days, blood pressure was not significantly different in the olmesartan and hydralazine groups, but olmesartan treatment reduced CTGF distribution in PO hearts. Olmesartan was associated with a significantly reduced myocyte hypertrophy index (4.77±0.48 for olmesartan and 6.05±1.45 for saline, P<0.01), fibrosis area (32.0±15.5% compared with the saline group, P<0.05) and serum TGF-β1 level (62.6±10.6 ng ml−1 for olmesartan and 84.4±7.2 ng ml−1 for hydralazine, P<0.05). In addition, cardiac function was significantly preserved in the olmesartan group compared with the saline group. Finally, olmesartan ameliorated the cardiac dysfunction in CTGF- and TGF-β1-infused rats. Olmesartan attenuated CTGF induction, reduced perivascular fibrosis and ameliorated cardiac dysfunction in a PO heart. Our results provide insight into the beneficial effects of olmesartan on PO hearts, independent of blood-pressure lowering.

Tumor growth inhibitory effect of ADAMTS1 is accompanied by the inhibition of tumor angiogenesis.

Angiogenesis plays an important role in tumor progression. Several reports have demonstrated that a disintegrin and metalloproteinase with thrombospondin motifs1 (ADAMTS1) inhibited angiogenesis via multiple mechanisms. The aim of this study was to investigate the effect of ADAMTS1 on endothelial cells in vitro and on tumor growth with regard to angiogenesis in vivo. We examined the effects of the transfection of ADAMTS1 using two constructs, full‐length ADAMTS1 (full ADAMTS1) and catalytic domain‐deleted ADAMTS1 (delta ADAMTS1). Transfection of both the full ADAMTS1 and delta ADAMTS1 gene constructs demonstrated the secretion of tagged‐ADAMTS1 protein into the conditioned medium, so we examined the effects of ADAMTS1‐containing conditioned medium on endothelial cells. Both types of conditioned media inhibited endothelial tube formation, and this effect was completely abolished after immunoprecipitation of the secreted protein from the medium. Both types of conditioned media also inhibited endothelial cell migration and proliferation. We then examined the impact of ADAMTS1 on endothelial cell apoptosis. Both conditioned media increased the number of Annexin V‐positive endothelial cells and caspase‐3 activity and this effect was attenuated when z‐vad was added. These results indicated that ADAMTS1 induced endothelial cell apoptosis. We next examined the effects of ADAMTS1 gene transfer into tumor‐bearing mice. Both full ADAMTS1 and delta ADAMTS1 significantly inhibited the subcutaneous tumor growth. Collectively, our results demonstrated that ADAMTS1 gene transfer inhibited angiogenesis in vitro and in vivo, likely as a result of the induction of endothelial cell apoptosis by ADAMTS1 that occurs independent of the protease activity.

Combination therapy of calcium channel blocker and angiotensin II receptor blocker reduces augmentation index in hypertensive patients.

Introduction:The optimal combination treatment for hypertension has not been established. We investigated the effect of a calcium channel blocker or a diuretic added to angiotensin II receptor blockers (ARBs) on the augmentation index (AI), as a marker of arterial stiffness and wave reflection, in hypertensive patients. Methods:Thirty-seven patients treated with ARBs were randomly allocated to either of the 2 groups receiving an ARB plus azelnidipine (AZ group) or trichlormethiazide (TCM group). Changes in brachial blood pressure (BP), AI, high-sensitive C-reactive protein (hsCRP), and serum asymmetric dimethylarginine, as an endogenous nitric oxide synthase inhibitor, were determined. Results:Systolic and diastolic blood pressure after 6 months were significantly reduced in both the groups similarly; however, after adjustment for baseline covariates, the extent of the reduction in AI (%) in the AZ group was significantly greater than in the TCM group (between-group difference was 3.2; 95%CI: 0.2–6.3; P = 0.03). The reduction of high-sensitive C-reactive protein (mg/L) and serum asymmetric dimethylarginine (&mgr;mol/L) was significantly greater in the AZ group than in the TCM group (between-group difference was 0.18 and 0.05; 95%CI: −0.01 to 0.36 and −0.01 to 0.11; P = 0.04 and 0.02, respectively). Further, when patients were analyzed according to age younger than 60 years or older than 60 years, the reduction in AI in the AZ group aged older than 60 years was significantly greater than in the TCM group. Conclusion:The results suggest that azelnidipine has a more beneficial effect on vascular properties in combination therapy with ARB than trichlormethiazide.

Cholesteatoma Debris as an Activator of Human Monocytes: Potentiation of the Production of Tumor Necrosis Factor

Tumor necrosis factor (TNF) is a cytokine which stimulates osteoclastic bone resorption and inhibits collagen synthesis in vitro. In this study the effect of human cholesteatoma debris and its constituents on the production of TNF-alpha by human monocytes in vitro was studied. Cultured human peripheral monocytes secreted TNF into the culture medium when exposed to cholesteatoma debris in a dose-dependent manner. The TNF production, however, was partially inhibited by the treatment of the debris with polymyxin B which inhibits biological activities of lipopolysaccharide (LPS). When individual constituents of cholesteatoma debris, i.e. keratin, cholesterol, lauric acid and LPS, were added to the cultured monocytes at concentrations equivalent to those in the debris, significant production of TNF was observed only with the keratin and LPS. These data suggest that cholesteatoma debris is a potent activator of the TNF production of human monocytes in vitro, and that LPS and keratin are responsible for the production.