Hiroshi Iwao

Osaka City University, Ōsaka, Ōsaka, Japan

Are you Hiroshi Iwao?

Claim your profile

Publications (247)914.85 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Remote ischemic conditioning (RIC) by repeated treatment of transient limb ischemia is a clinically applicable method for protecting the heart against injury at the time of reperfusion. In this study, we investigated the effects of repeated RIC on cardiac dysfunction after myocardial infarction (MI). At 4weeks after MI, rats were separated into the untreated (UT) group or the RIC-treated group. RIC treatment was performed by 5cycles of 5min of bilateral hindlimb ischemia and 5min of reperfusion once a day for 4weeks. Despite comparable MI size, left ventricular (LV) ejection fraction (LVEF) was significantly improved in the RIC group compared with the UT group. Furthermore, the LVEF in the RIC group was improved, although not significantly, after treatment. RIC treatment also prevented the deterioration of LV diastolic function. MI-induced LV interstitial fibrosis in the boundary region and oxidant stress were significantly attenuated by RIC treatment. MicroRNA-29a (miR-29a), a key regulator of tissue fibrosis, was highly expressed in the exosomes and the marginal area of the RIC group. Even in the differentiated C2C12-derived exosomes, miR-29a expression was significantly increased under hypoxic condition. As well as miR-29a, insulin-like growth factor 1 receptor (IGF-1R) was highly expressed both in the exosomes and remote non-infarcted myocardium of the RIC group. IGF-1R expression was also increased in the C2C12-derived exosomes under hypoxic conditions. Repeated RIC reduces adverse LV remodeling and oxidative stress by MI. Exosome-mediated intercellular communication may contribute to the beneficial effect of RIC treatment. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
    International Journal of Cardiology 10/2014; 178C:239-246. · 6.18 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Metabolic syndrome (MetS) induces serious complications; therefore, we developed a noninvasive MetS model using an extremely small minipig, the Microminipig. For 8 weeks, Microminipigs were administrated a high-fat and high-cholesterol diet (HFCD) for atherosclerosis and N(G)-nitro-l-arginine methyl ester (l-NAME) for inhibiting nitric oxide synthase. HFCD significantly increased serum low-density lipoprotein levels, l-NAME increased blood pressure and cardiac hypertrophy, and HFCD-induced aortal arteriosclerosis was accelerated by l-NAME administration. Endothelium-dependent relaxation of the coronary artery was remarkably decreased by l-NAME administration. This model may be useful for elucidating the mechanisms of MetS and developing new therapeutic medicines for its treatment.
    Journal of Pharmacological Sciences 09/2014; · 2.11 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Aim: Highly concentrated carbon dioxide (CO2) is thought to be useful for ischemic diseases. We investigated whether treatment with a few micrometers of CO2 molecules atomized via two fluidnozzles (CO2 mist) exerts an angiogenic effect in a mouse ischemic hindlimb model. Methods: Mice with unilateral hindlimb ischemia were divided into untreated (UT), 100% CO2 gas alone-treated (CG), mixed air (O2; 20%, N2; 80%) mist-treated (AM) and 100% CO2 mist-treated (CM) groups. The lower body of the mice was encased in a polyethylene bag filled with each gaseous agent using a gas mist generator for 10 minutes daily. Results: According to a laser Doppler analysis, the ischemic hindlimb blood flow was persistently higher after the seventh day of induction of ischemia in the CM group than in the UT group. The capillary density was also greater in the CM group on day 28 compared with that observed in the UT group. In addition, the parameters in the AM and CG groups were similar to those obtained in the UT group. The observed effects were abolished by the administration of an inhibitor of nitric oxide synthase (NOS). The vascular endothelial growth factor mRNA expression and protein levels and the phosphorylated endothelial NOS level were increased in the CM group compared with that observed in the UT group. A proteomic analysis using liquid chromatography-tandem mass spectrometry identified novel protein candidates regulated by CO2 mist. Conclusion: Percutaneous CO2 mist therapy may be useful for treating ischemia-induced angiogenesis.
    Journal of atherosclerosis and thrombosis 08/2014; · 2.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Fibroblast growth factor-2 (FGF-2) plays a critical role in endothelial survival, proliferation, and angiogenesis and is localized on the cell membrane by binding to heparan sulfate proteoglycans. Here we established a neutralizing monoclonal antibody, 1B9B9, against FGF-2 using the rat medial iliac lymph node method. 1B9B9 blocked the binding of FGF-2 to its receptor, inhibiting FGF-2-induced proliferation and corresponding downstream signaling in endothelial cells. Treatment of human umbilical vein endothelial cells with 1B9B9 reduced the basal phosphorylation levels of Akt and MAPK. Furthermore, continued treatment with 1B9B9 induced cell death by apoptosis. Compared with FGF-2 knockdown, 1B9B9 significantly reduced cell survival. In addition, the combination of FGF-2 siRNA and 1B9B9 showed a synergistic effect. The data indicate that 1B9B9 established by the rat iliac lymph node method is a fully compatible neutralizing antibody.
    Monoclonal antibodies in immunodiagnosis and immunotherapy. 08/2014; 33(4):261-9.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Heat shock cognate protein 70 (Hsc70) acts as a molecular chaperone for the maintenance of intracellular proteins, which allows cancer cells to survive under proteotoxic stress. We attempted to use Hsc70 to identify key molecules in cancer cell survival. Here, we performed mass-spectrometry-based proteomics analysis utilizing affinity purification with anti-Hsc70 antibodies; as a result, 83 differentially expressed proteins were identified under stress conditions. This result implies that there was a change in the proteins with which Hsc70 interacted in response to stress. Among the proteins identified under both serum-depleted and 5-fluorouracil-treated conditions, Rab1A was identified as an essential molecule for cancer cell survival. Hsc70 interacted with Rab1A in a chaperone-dependent manner. In addition, Hsc70 knockdown decreased the level of Rab1A and increased the level of its ubiquitination under stress conditions, suggesting that Hsc70 prevented the degradation of Rab1A denatured by stress exposure. We also found that Rab1A knockdown induced cell death by inhibition of autophagosome formation. Rab1A may therefore contribute to overcoming proteotoxic insults, which allows cancer cells to survive under stress conditions. Analysis of Hsc70 interactors provided insight into changes of intracellular status. We expect further study of the Hsc70 interactome to provide a more comprehensive understanding of cancer cell physiology.
    PLoS ONE 05/2014; 9(5):e96785. · 3.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hypoxia occurs within adipose tissues as a result of adipocyte hypertrophy and is associated with adipocyte dysfunction in obesity. Here, we examined whether hypoxia affects the characteristics of adipocyte-derived exosomes. Exosomes are nanovesicles secreted from most cell types as an information carrier between donor and recipient cells, containing a variety of proteins as well as genetic materials. Cultured differentiated 3T3-L1 adipocytes were exposed to hypoxic conditions and the protein content of the exosomes produced from these cells was compared by quantitative proteomic analysis. A total of 231 proteins were identified in the adipocyte-derived exosomes. Some of these proteins showed altered expression levels under hypoxic conditions. These results were confirmed by immunoblot analysis. Especially, hypoxic adipocyte-released exosomes were enriched in enzymes related to de novo lipogenesis such as acetyl-CoA carboxylase, glucose-6-phosphate dehydrogenase, and fatty acid synthase (FASN). The total amount of proteins secreted from exosomes increased by 3-4 fold under hypoxic conditions. Moreover, hypoxia-derived exosomes promoted lipid accumulation in recipient 3T3-L1 adipocytes, compared with those produced under normoxic conditions. FASN levels were increased in undifferentiated 3T3-L1 cells treated with FASN-containing hypoxic adipocytes-derived exosomes. This is a study to characterize the proteomic profiles of adipocyte-derived exosomes. Exosomal proteins derived from hypoxic adipocytes may affect lipogenic activity in neighboring preadipocytes and adipocytes.
    Biochemical and Biophysical Research Communications 03/2014; · 2.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Arginine vasopressin (AVP) is a 9-amino acid peptide that is secreted from the posterior pituitary in response to high plasma osmolality and hypotension. AVP has important roles in circulatory and water homoeostasis, which are mediated by oxytocin receptors and by AVP receptor subtypes: V1a (mainly vascular), V1b (pituitary), and V2 (renal). Vaptans are orally and intravenously active nonpeptide vasopressin-receptor antagonists. Recently, subtype-selective nonpeptide vasopressin-receptor agonists have been developed. A selective V1a-receptor antagonist, relcovaptan, has shown initial positive results in the treatment of Raynaud's disease, dysmenorrhea, and tocolysis. A selective V1b-receptor antagonist, nelivaptan, has beneficial effects in the treatment of psychiatric disorders. Selective V2-receptor antagonists including mozavaptan, lixivaptan, satavaptan, and tolvaptan induce highly hypotonic diuresis without substantially affecting the excretion of electrolytes. A nonselective V1a/V2-receptor antagonist, conivaptan, is used in the treatment for euvolaemic or hypervolemic hyponatremia. Recent basic and clinical studies have shown that AVP-receptor antagonists, especially V2-receptor antagonists, may have therapeutic potential for heart failure. This review presents current information about AVP and its antagonists.
    Journal of Pharmacological Sciences 01/2014; · 2.11 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Triple-negative breast cancers (TNBCs) are defined as tumors that lack expression of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2. Clinically, TNBC patients are treated with cytotoxic drugs including 5-fluorouracil (5-FU). However, TNBCs develop resistance to such drugs after a series of treatments. To elucidate the mechanisms of drug resistance, establishment of drug-resistant cancer cell lines should be one of the most useful model systems. However, 5-FU-resistant TNBC cell lines have not been previously reported. In this study, we established a 5-FU-resistant cell line, MDA-MB-231/5-FU, from the human TNBC cell line MDA-MB-231, by repeated exposure to stepwise increases in the concentration of 5-FU. The IC50 value of 5-FU for MDA-MB-231/5-FU was 5.5-fold that for the parental cells. The MDA-MB-231/5-FU cell line acquired resistance to not only 5-FU, but also vinorelbine, paclitaxel and gemcitabine. Additionally, we performed iTRAQ-based quantitative proteomics in MDA-MB-231/5-FU cells and the parental cells in order to characterize MDA-MB-231/5-FU. The proteins upregulated in the newly established cells were mainly classified into the categories of 'DNA recombination', 'cell cycle', 'complex assembly', 'cytoskeleton organization', 'transport' and 'negative regulation of cell death'. These proteins may be related to mechanisms of drug resistance in TNBCs. Our established MDA-MB-231/5-FU cell line should be a useful tool for identifying new mechanisms of drug resistance and new drug targets in TNBCs.
    International Journal of Oncology 10/2013; · 2.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Tolvaptan, a non-peptide V2-receptor antagonist, is a newly developed diuretic agent. Recently, we reported that tolvaptan has diuretic as well as anti-inflammatory and anti-fibrotic actions in chronic heart failure. In this study, we investigated whether tolvaptan has a cardioprotective effect in acute heart failure after myocardial infarction (MI). After MI induction, rats were randomized into 6 groups as follows: vehicle group, group treated with 15 mg∙kg(-1)∙day(-1) furosemide, 2 groups treated with 3 or 10 mg∙kg(-1)∙day(-1) tolvaptan, and 2 groups treated with 15 mg∙kg(-1)∙day(-1) furosemide combined with 3 or 10 mg∙kg(-1)∙day(-1) tolvaptan. Each agent was administered for 2 weeks, and blood pressure levels and infarct sizes were similar in all MI groups. Lower left ventricular end-systolic volumes and greater improvement of left ventricular ejection fraction were observed in the tolvaptan-treated groups compared with the vehicle group. In contrast, furosemide alone did not improve them. Sirius red staining revealed that tolvaptan significantly repressed MI-induced interstitial fibrosis in the left ventricle. MI-induced mRNA expressions related to cardiac load, inflammation, and fibrosis were significantly attenuated in the combination group. The combination treatment also repressed MI-induced mineralocorticoid receptor expression. Tolvaptan, or combination of furosemide and tolvaptan, may improve cardiac function in acute MI.
    Journal of Pharmacological Sciences 09/2013; · 2.11 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: -Arginine vasopressin (AVP), which promotes the reabsorption of renal water is increased in chronic heart failure. Here, we compared the effects of tolvaptan, a newly developed non-peptide V(2) receptor antagonist, with those of furosemide, a loop diuretic, and a combination of these 2 agents in rats with left ventricular (LV) dysfunction after myocardial infarction (MI). METHODS AND RESULTS: -After 10 week of MI induction, rats were separated them into the following 6 groups adjusted to the infarct size: a vehicle group, a group treated with 15 mg·kg(-1)·day(-1) of furosemide; 2 groups treated with 3 or 10 mg·kg(-1)·day(-1) of tolvaptan, and 2 groups treated with 15 mg·kg(-1)·day(-1) of furosemide plus 3 or 10 mg(-)·kg(-1)·day(-1) tolvaptan. Each treatment agent was administered for 4 weeks, and all groups had similar blood pressure levels and infarct size. The tolvaptan-treated groups were found to have lower levels of LV end-diastolic and systolic cardiac volumes than the vehicle group. Furthermore, the improvement in the ejection fraction in the tolvaptan-treated groups was significantly greater than those in the vehicle group. ED-1 immunostaining and Sirius red staining revealed that tolvaptan significantly repressed MI-induced macrophage infiltration and interstitial fibrosis in the left ventricle, respectively. Tolvaptan attenuated the MI-induced mRNA expressions of atrial and brain natriuretic peptides, monocyte chemotactic protein-1, transforming growth factor-β1, AVP V(1a) receptor, and endothelin-1 in the marginal infarct region. CONCLUSIONS: -Tolvaptan may improve cardiac dysfunction after MI, which is partially mediated by the suppression of V(1a) receptor, neurohumoral activation and inflammation.
    Circulation Heart Failure 09/2012; · 6.68 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although angiotensin II potently affects blood pressure and fluid balance, it is also involved in deterioration in atherosclerotic cardiovascular disease. Recently, angiotensin AT(1) receptor blockers have been demonstrated to be effective in patients with atherosclerotic disease, but the exact mechanisms of these blockers are still controversial. Atherosclerotic plaques are characterized by cholesterol ester accumulation and acyl-CoA:cholesterol acyltransferase-1 (ACAT-1) expression, which are both parameters of degeneration of macrophage-derived foam cells. We examined the effects of angiotensin AT(1) receptor blockers on the formation of foam cells from macrophages. When macrophages from a human cell line were stimulated with oxidized low-density lipoprotein (oxLDL), the angiotensin AT(1) receptor blockers candesartan and losartan attenuated the intracellular accumulation of cholesterol ester and the increases in mRNA and protein levels of ACAT-1. Moreover, the increase in oxLDL-induced ACAT-1 was reduced by AG1478, an inhibitor of the epidermal growth factor (EGF) receptor. Additionally, oxLDL up-regulated the protein level of heparin-binding EGF-like growth factor (HB-EGF), a ligand of the EGF receptor. Inhibitors of angiotensin-converting enzyme affected neither cholesterol ester accumulation nor the expression of ACAT-1. Although oxLDL itself increased the secretion of angiotensin II, the amount of secreted angiotensin II was insufficient to induce expression of ACAT-1 protein. Thus, we first demonstrated that angiotensin AT(1) receptor blockers suppress ACAT-1 expression and cholesterol ester accumulation through an oxLDL-activated EGF receptor, but it is unclear how oxLDL activates angiotensin AT1 receptor in an angiotensin II-independent manner. The therapeutic mechanism of angiotensin AT(1) receptor blockers for atherosclerosis may be at least partially explained by our present results.
    European journal of pharmacology 03/2012; 679(1-3):9-15. · 2.59 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Pruritus is a severe symptom that is difficult to treat in atopic dermatitis patients. Red ginseng (RG), a natural medicine, has various biological activities such as anti-inflammatory effects. In this study, we examined the efficacy of RG extract (RGE) and its mechanism on experimental atopic dermatitis in mice. The effects of RGE on vascular permeability and itching were first evaluated. Histamine-induced permeability and itching were significantly inhibited by embrocation with RGE as well as diphenhydramine, an antihistamine drug. Next, we assessed the therapeutic effect of topical RGE in a mouse model of atopic dermatitis. Dermatitis was induced by repeated application of 2,4-dinitrofluorobenzene (DNFB) acetone solution to the mouse ear. The effects of tacrolimus (a calcineurin blocker), dexamethasone (a corticosteroid), and RGE on dermatitis and associated scratching behavior were compared. Repeated DNFB application caused frequent scratching behaviors and ear swelling. Topical treatment with tacrolimus, dexamethasone, and RGE for 8 days before the final challenge with DNFB significantly inhibited ear swelling. Tacrolimus and RGE significantly inhibited scratching behavior, whereas dexamethasone failed to do so. DNFB-induced nerve growth factor expression and nerve fiber extension were significantly attenuated by tacrolimus and RGE, but not by dexamethasone. RGE may have the potential for treatment of atopic dermatitis.
    Journal of Pharmacological Sciences 03/2012; 118(3):391-400. · 2.11 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Carbon dioxide (CO(2)) baths have been used to treat a variety of diseases, but developing an artificial bath of highly concentrated CO(2) is difficult. Here, we tried the efficacy of a novel device instead of a CO(2) bath. Using a device equipped with double fluid nozzles, CO(2) gas and H(2)O were compounded and compressed at 4 barometric pressures. As a result, CO(2) gas was dissolved in H(2)O, which contained a few micrometers of CO(2) particles, namely, a CO(2) mist. Wistar rats with myocardial infarction (MI) by ligation of the left coronary artery were percutaneously administered CO(2) mist or CO(2) gas alone or no treatment for 30 min daily. With regard to tissue blood flow during treatment, the group treated with CO(2) mist had significantly increased tissue oxygenated hemoglobin levels and tissue saturation levels, and significantly decreased deoxygenated hemoglobin levels compared with the group treated with CO(2) gas. After 4 weeks treatment, the group treated with CO(2) mist had a significantly improved ejection fraction by echocardiography compared with the untreated group. Interestingly, the group treated with CO(2) mist had significantly increased nitrate concentrations in serum and vascular endothelial growth factor mRNA expression levels in the myocardium compared with the untreated group. Our new mist production device may be potentially useful for the treatment of heart failure caused by MI.
    Circulation Journal 02/2012; 76(5):1203-12. · 3.69 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The HMG-CoA reductase inhibitors (statins) have been shown to exert several protective effects on the vasculature that are unrelated to changes in the cholesterol profile, and to induce angiogenesis. The proangiogenic effect exerted by statins has been attributed to the activation of the PI3K/Akt pathway in endothelial cells; however, it is unclear how statins activate this pathway. Pravastatin-mediated activation of Akt and MAPK occurs rapidly (within 10 min.) and at low doses (10 nM). Here, we hypothesized that FGF-2 contributes to the proangiogenic effect of statins. We found that pravastatin, a hydrophilic statin, induced phosphorylation of the FGF receptor (FGFR) in human umbilical vein endothelial cells. SU5402, an inhibitor of FGFR, abolished pravastatin-induced PI3K/Akt and MAPK activity. Likewise, anti-FGF-2 function-blocking antibodies inhibited Akt and MAPK activity. Moreover, depletion of extracellular FGF-2 by heparin prevented pravastatin-induced phosphorylation of Akt and MAPK. Treatment with FGF-2 antibody inhibited pravastatin-enhanced endothelial cell proliferation, migration and tube formation. These observations indicate that pravastatin exerts proangiogenic effects in endothelial cells depending upon the extracellular FGF-2.
    Journal of Cellular and Molecular Medicine 11/2011; 16(9):2001-9. · 3.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Pirfenidone (5-methyl-1-phenyl-2-[(1)H]-pyridone) is an effective drug for idiopathic interstitial pneumonia that can prevent and reverse tissue fibrosis in several organs. Therefore, we investigated whether pirfenidone has a potential role in preventing angiotensin II (Ang II)-induced cardiac hypertrophy. A cardiac hypertrophic mouse model was created using an Ang II infusion (200 ng kg(-1) min(-1)) in wild-type mice for 2 weeks. Mice were divided into the following three groups: a saline-infused (control) group, an Ang II infusion (vehicle) group and an Ang II infusion+pirfenidone-treated (PFD) group, which received pirfenidone (300 mg kg(-1) per day) by gastric gavage during the Ang II infusion. At 2 weeks, we assessed hemodynamics and cardiac function and investigated tissue fibrosis of the myocardium histologically and genetically. Blood pressure in the vehicle group was significantly increased compared to the control group. Although blood pressure was not different between the vehicle and PFD groups, heart weight was significantly decreased in the PFD group. Echocardiography revealed that left ventricular hypertrophy was significantly increased in the vehicle group vs. the control group. Interestingly, pirfenidone significantly inhibited this effect. Continuous infusion of Ang II increased the perivascular and interstitial tissue fibrosis, and pirfenidone inhibited these fibrotic changes. Pirfenidone also inhibited Ang II-induced hypertrophy. In the vehicle group, the mRNA expressions of atrial natriuretic peptide, brain natriuretic peptide and transforming growth factor-β1 were increased, which was significantly inhibited by pirfenidone. Furthermore, the expression of mineralocorticoid receptors was attenuated by pirfenidone. These results indicate that pirfenidone might be effective as an antifibrotic drug in the treatment of cardiac hypertrophy induced by hypertension.
    Hypertension Research 08/2011; 35(1):34-40. · 2.94 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The heat shock protein 70 (Hsp70) family members function as ATP-dependent molecular chaperones that assist in the folding of newly synthesized polypeptides and in the refolding of misfolded/aggregated proteins. These heat shock proteins comprise at least eight sets of molecular groups that share high homology, but differ from each other in their expression level and subcellular localization. Hsp72, which is also known as Hsp70 and Hsp70-1, is localized mainly in the cytoplasm but is also found in the nucleus. Stress-induced Hsp72 functions as a chaperone enabling the cells to cope with harmful aggregations of denatured proteins during and following stress. The difference in the function of Hsp72 from that of other Hsp70 members, however, remains unclear. We report the establishment of a monoclonal antibody specific for Hsp72 using the rat medial iliac lymph node method. Immunoblot analysis revealed that our monoclonal antibody against Hsp72 specifically identified the 65 kDa protein. Immunocytochemical staining also revealed that Hsp72 localized in the cytoplasm and nucleus, and aggregated in the nucleus in response to heat stress. This MAb against Hsp72 will allow for further studies to elucidate the mechanism by which Hsp72 is localized in the cell in response to stress stimuli, and aid in the identification of specific interacting molecules.
    Hybridoma (2005) 08/2011; 30(4):397-400. · 0.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Prekallikrein deficiency is a rare autosomal recessive disease not considered to be associated with a tendency for bleeding, despite marked prolongation of activated partial thromboplastin time. Currently, six kinds of mutations in the prekallikrein gene are known to be associated with prekallikrein deficiency. In this report, we describe a patient with idiopathic thrombocytopenic purpura who was recognized to have severe prekallikrein deficiency. Molecular analysis of the patient's prekallikrein gene showed a homozygous Trp499Stop nonsense mutation that has not been reported previously. The mutant allele is predicted to encode a truncated protein lacking half of the catalytic domain of prekallikrein, suggesting that the truncated protein causes prekallikrein deficiency in the patient.
    Blood coagulation & fibrinolysis: an international journal in haemostasis and thrombosis 03/2011; 22(4):337-9. · 1.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Human heat shock cognate protein 70 (Hsc70), also known as Hsp73 and Hsp70-8, is a molecular chaperone. The human Hsp70 family comprises at least eight different molecular groups with strong homology. Among them, Hsc70 and Hsp72 share 86% homology. Both Hsp72 and Hsc70 localize in the cell cytoplasm and the nucleus. While Hsp72 expression is enhanced by stress, Hsc70 is constitutively expressed, suggesting that Hsc70 is critically involved in cell functions other than the stress response. Hsc70 has cell-specific and tissue-specific functions, such as cellular signaling, but its functions are not well understood. To further study the functions of Hsc70, we established a monoclonal antibody specific for Hsc70 using a rat medial iliac lymph node method. Immunoblot analysis with this antibody revealed that it specifically recognizes Hsc70. Immunocytochemical staining using this newly established antibody revealed that Hsc70 localizes predominantly in the cytoplasm in unstressed cells, whereas oxidative stress produced by H2O2 induces Hsc70 to translocate into the nucleus. This monoclonal antibody will be useful for further studies of Hsc70, including changes in its intracellular location, binding molecules, and functions.
    Hybridoma (2005) 10/2010; 29(5):453-6. · 0.33 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Heat shock protein 70s (Hsp70s) are molecular chaperones that protect cells from damage in response to various stress stimuli. However, the functions and mechanisms in endothelial cells (ECs) have not been examined. Herein, we investigate the role of Hsp70s, including heat shock cognate protein 70 (Hsc70), which is constitutively expressed in nonstressed cells (ie, ECs). The Hsp70 inhibitor, KNK437, significantly decreased vascular endothelial growth factor (VEGF)-induced cell migration and tube formation in vitro. KNK437 inhibited the phosphorylation of VEGF-induced Akt and endothelial nitric oxide synthase (eNOS) in human umbilical vein endothelial cells. In a mouse hind limb model of vascular insufficiency, intramuscular inhibition of Hsp70s attenuated collateral and capillary vessel formation. Silencing the Hsc70 gene by short interfering RNA abolished VEGF-induced Akt phosphorylation and VEGF-stimulated human umbilical vein endothelial cell migration and tube formation. As the molecular mechanisms, Hsc70 knockdown reduced the expression of phosphatidylinositol 3-kinase. Collectively, Hsc70 plays a significant role in ECs via the phosphatidylinositol 3-kinase/Akt pathway. Hsc70 may provide the basis for the development of new therapeutic strategies for angiogenesis.
    Arteriosclerosis Thrombosis and Vascular Biology 12/2009; 30(3):491-7. · 6.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although liposome-encapsulated clodronate has been used as a means to deplete macrophages from certain tissues, target leukocyte subtypes within the kidney are not clearly known under normal and pathologic conditions. The present study was therefore conducted to examine the effects of liposome clodronate on renal infiltrating cell type following unilateral ureteral obstruction (UUO) and tried to correlate these changes to the mechanisms of early development of renal fibrosis. Renal infiltrating leukocyte subtypes and counts were determined by using multicolor flow cytometric analysis of cell suspensions from obstructed kidneys. UUO for 5 days elicited renal tubular apoptosis and renal fibrosis and showed 4-fold increase in renal leukocytes including monocytes/macrophages, dendritic cells, and T-cells. Repeated administration of liposome clodronate selectively depleted F4/80+ monocytes/macrophages and F4/80+ dendritic cells but not F4/80(-) dendritic cells or other cell types in both obstructed and non-obstructed kidneys. Tubular apoptosis and renal fibrosis were also significantly attenuated by liposome clodronate. Increased gene expression of TNF-alpha and TGF-beta observed in obstructed kidneys were markedly attenuated by depletion of renal mononuclear phagocytes. These findings suggest that F4/80+ monocytes/macrophages and/or F4/80+ dendritic cells play a pivotal role in the development of obstruction-induced tubular apoptosis and renal fibrosis, possibly through TNF-alpha and TGF-beta dependent mechanisms.
    Journal of Pharmacological Sciences 11/2009; 111(3):285-92. · 2.11 Impact Factor

Publication Stats

5k Citations
914.85 Total Impact Points


  • 1997–2014
    • Osaka City University
      • • Department of Pharmacology
      • • Graduate School of Medicine
      • • First Department of Internal Medicine
      • • Third Department of Internal Medicine
      Ōsaka, Ōsaka, Japan
  • 2003
    • Kobe Pharmaceutical University
      Kōbe, Hyōgo, Japan