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ABSTRACT: This study was performed in order to evaluate the angiogenic effect of implantation of either peripheral blood mononuclear cells (PBMNCs) or bone marrow mononuclear cells (BMMNCs) on diabetic peripheral neuropathy. Streptozotocin (50 mg/kg) was injected intravenously into 6-week-old male Lewis rats. Four weeks after the induction of diabetes, 6 x 10(7) of PBMNCs or 1 x 10(8) of BMMNCs were implanted into the left hindlimb muscle. Motor nerve conduction velocity (MNCV) was monitored before and after implantation. At the end of the experiment, bilateral nerve blood flow (NBF) was measured by laser Doppler and the number of vessels in the sciatic nerves quantified by Factor VIII staining of the sections. Diabetes resulted in an approximately 20% reduction (P < 0.01) in sciatic MNCV. Four weeks after implantation, MNCV was improved by 54% with PBMNCs and by 67% with BMMNCs (both P < 0.01). Moreover, the effects of implantation were almost abolished by administration of VEGF-neutralizing antibody. Sciatic NBF was reduced by approximately 50% by diabetes (P < 0.05). This reduction in perfusion was improved by 74% by implantation of PBMNCs and by 62% by implantation of BMMNCs (P < 0.05 and P < 0.01, respectively). These effects were observed only in the implanted limb. Immunohistochemical staining of sciatic nerve sections for Factor VIII showed no significant increase in the number of vessels in the sciatic nerve following implantation of either PBMNCs or BMMNCs. These data suggest that implantation of hematopoietic mononuclear cell fractions is associated with an improvement in MNCV as a result of arteriogenic effects in the sciatic nerve, and that VEGF may contribute to this effect. This improvement occurred in the absence of angiogenesis. Implantation of these cell fractions may therefore be a potential new therapeutic method for treating diabetic peripheral neuropathy.
Experimental Neurology 07/2006; 199(2):274-80. · 4.70 Impact Factor
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Yoko Uchiyama-Tanaka,
Yasukiyo Mori,
Noriko Kishimoto,
Masayoshi Fukui,
Atsuko Nose,
Yasuaki Kijima,
Hideki Yamahara, Takamasa Hasegawa,
Atsushi Kosaki,
Hiroaki Matsubara,
Toshiji Iwasaka
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ABSTRACT: Ultrasonographic evidence of increased carotid intima-media thickness (IMT) is known to be associated with generalized atherosclerosis. Therapeutic blockade of the renin-angiotensin system (RAS) with angiotensin-converting enzyme (ACE) inhibitors reportedly reduces carotid IMT in humans. However, there has been no head-to-head comparison of the effects of ACE inhibitor and angiotensin receptor blocker (ARB), a newer type of RAS inhibitor, on carotid IMT.
57 hypertensive patients were randomly assigned to treatment with one of two antihypertensive drugs: ACE inhibitor (quinapril; n = 25, group Q) or ARB (losartan; n = 18, group L).
After 1 year of treatment, a similar decrease in mean blood pressure was observed in all groups. Carotid IMT was decreased significantly in group Q (10% decrease, p < 0.05) but did not change in group L. There were no significant changes in other atherosclerotic factors between these two groups. Conclusion: Our findings suggest that the antiatherosclerotic effect of quinapril is more potent than that of losartan in hypertensive patients. This effect appears unrelated to the drug's antihypertensive action or to traditional atherosclerotic factors.
Kidney and Blood Pressure Research 02/2005; 28(2):111-6. · 1.46 Impact Factor
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Atsushi Kosaki, Takamasa Hasegawa,
Tatsuji Kimura,
Kumiko Iida,
Jiro Hitomi,
Hiroaki Matsubara,
Yasukiyo Mori,
Mitsuhiko Okigaki,
Nagaoki Toyoda,
Hiroya Masaki,
Megumi Inoue-Shibata,
Mitsushige Nishikawa,
Toshiji Iwasaka
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ABSTRACT: S100A12, also called EN-RAGE (extracellular newly identified receptor for advanced glycation end products binding protein) or calcium-binding protein in amniotic fluid-1, is a ligand for RAGE. It has been shown that S100A12 induces adhesion molecules such as vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 in the vascular endothelial cell and mediates migration and activation of monocytes/macrophages through RAGE binding and that infusion of lipopolysaccharide into mice causes time-dependent increase of S100A12 in the plasma. Therefore, circulating S100A12 protein may be involved in chronic inflammation in the atherosclerotic lesion. In this study, we developed an ELISA system that uses specific monoclonal antibodies against recombinant human S100A12 to measure plasma S100A12 levels in patients with diabetes. On using our S100A12 ELISA system, the coefficients of variation of intra- and interassay were less than 4 and 9%, respectively. The analytical lower detection limit was 0.2 ng/ml. When plasma S100A12 levels were measured by this system, the concentrations were more than twice as high in the patients with diabetes, compared with those without. Using univariate analysis in all subjects, plasma S100A12 concentrations correlated with hemoglobin A1c, fasting glucose, high-sensitivity C-reactive protein and white blood cell count. Stepwise multiple regression analyses, however, revealed that only white blood cell count and hemoglobin A1c remained significant independent determinants of plasma S100A12 concentration. These results suggest that plasma S100A12 protein levels are regulated by factors related to subclinical inflammation and glucose control in patients with type 2 diabetes.
Journal of Clinical Endocrinology & Metabolism 12/2004; 89(11):5423-8. · 6.50 Impact Factor
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Takamasa Hasegawa,
Atsushi Kosaki,
Tatsuji Kimura,
Hiroaki Matsubara,
Yasukiyo Mori,
Mitsuhiko Okigaki,
Hiroya Masaki,
Nagaoki Toyoda,
Megumi Inoue-Shibata,
Yutaka Kimura,
Mitsushige Nishikawa,
Toshiji Iwasaka
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ABSTRACT: EN-RAGE is a ligand for the receptor for advanced glycation end products (RAGE) and may be involved in the development of diabetic macro- and micro-angiopathy. This study is designed to investigate the regulation of EN-RAGE gene expression in human macrophages. The amounts of EN-RAGE mRNA were measured in cultured human THP-1 macrophages after treatment with various stimuli known to modulate atherosclerosis. First, interleukin-6 (IL-6), a proinflammatory cytokine, increased the level of EN-RAGE mRNA by approximately 2-fold in a time- and a dose-dependent fashion. EN-RAGE protein was detected in the cultured medium and increased significantly by the addition of IL-6. The induction was abolished by pretreatment with the JAK kinase inhibitor and cycloheximide, but not with the MEK kinase inhibitor. Second, pioglitazone (PIO), a thiazolidinedione, decreased the level of EN-RAGE mRNA by approximately 25% of the basal in a time- and a dose-dependent fashion. Pioglitazone also inhibited the induction of EN-RAGE mRNA by IL-6. These results indicate the production of EN-RAGE is induced by IL-6 through de novo protein synthesis via the JAK-STAT kinase pathway and inhibited by the activation of peroxisome proliferator-activated receptor-gamma (PPARgamma) in human macrophages.
Atherosclerosis 01/2004; 171(2):211-8. · 3.79 Impact Factor
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Hiroaki Matsubara,
Yasunobu Shibasaki,
Mitsuhiko Okigaki,
Yasukiyo Mori,
Hiroya Masaki,
Atsushi Kosaki,
Yoshiaki Tsutsumi,
Yoko Uchiyama,
Soichiro Fujiyama,
Atsuko Nose,
Osamu Iba,
Eriko Tateishi, Takamasa Hasegawa,
Masatsugu Horiuchi,
Clara Nahmias,
Toshiji Iwasaka
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ABSTRACT: Angiotensin II (Ang II) has two major receptor isoforms, AT1 and AT2. AT1 transphosphorylates Ca2+-sensitive tyrosine kinase Pyk2 to activate c-Jun NH2-terminal kinase (JNK). Although AT2 inactivates extracellular signal-regulated kinase (ERK) via tyrosine phosphatases (PTP), the action of AT2 on Pyk2 and JNK remains undefined. Using AT2-overexpressing vascular smooth muscle cells (AT2-VSMC) from AT2-transgenic mice, we studied these undefined actions of AT2. AT1-mediated JNK activity was increased 2.2-fold by AT2 inhibition, which was abolished by orthovanadate. AT2 did not affect AT1-mediated Pyk2 phosphorylation, but attenuated c-Jun mRNA accumulation by 32%. The activity of src-homology 2 domain-containing PTP (SHP-1) was significantly upregulated 1 min after AT2 stimulation. Stable overexpression of SHP-1 dominant negative mutant in AT2-VSMC completely abolished AT2-mediated inhibition of JNK activation and c-Jun expression. These findings suggest that AT2 inhibits JNK activity by affecting the downstream signal of Pyk2 in a SHP-1-dependent manner, leading to a decrease in c-Jun expression.
Biochemical and Biophysical Research Communications.
