Tomohiro Katsuya

Publications (205) View all

• Article: Inhibition of Neointima Formation through DNA Vaccination for Apolipoprotein(a): A New Therapeutic Strategy for Lipoprotein(a).

  Mariko Kyutoku, Hironori Nakagami, Hiroshi Koriyama, Futoshi Nakagami, Munehisa Shimamura, Hitomi Kurinami, Hideki Tomioka, Takashi Miyake, Tomohiro Katsuya, Ryuichi Morishita
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  ABSTRACT: Lipoprotein(a) [Lp(a)] is an unique lipoprotein consisting of the glycoprotein apolipoprotein(a) [apo(a)] in low-density lipoprotein. Although Lp(a) is a well-known independent risk factor for cardiovascular disease; however, there is no drugs to decrease plasma Lp(a) level. Thus, to inhibit the biological activity of Lp(a), we developed DNA vaccine for apo(a) by the targeting to the selected 12 hydrophilic amino acids in the kringle-4 type 2 domain of apo(a). Hepatitis B virus core protein was used as an epitope carrier to enhance the immunogenicity. Intramuscular immunization with apo(a) vaccine resulted in the significant inhibition of neointima formation in carotid artery ligation model using Lp(a) transgenic mice, associated with anti-apo(a) antibody and decrease in vascular Lp(a) deposition. Overall, this study provided the first evidence that the pro-atherosclerotic actions of Lp(a) could be prevented by DNA vaccine directed against apo(a), suggesting a novel therapeutic strategy to treat cardiovascular diseases related to high Lp(a).
  Scientific Reports 04/2013; 3:1600.
• Article: Apolipoprotein E genotype, cardiovascular biomarkers and risk of stroke: Systematic review and meta-analysis of 14 015 stroke cases and pooled analysis of primary biomarker data from up to 60 883 individuals.

  Tauseef A Khan, Tina Shah, David Prieto, Weili Zhang, Jackie Price, Gerald R Fowkes, Jackie Cooper, Philippa J Talmud, Steve E Humphries, Johan Sundstrom, [......], Meena Kumari, Liam Smeeth, Kay-Tee Khaw, Michael Nalls, James Meschia, Kai Sun, Rutai Hui, Ian Day, Aroon D Hingorani, Juan P Casas
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  ABSTRACT: BACKGROUND: At the APOE gene, encoding apolipoprotein E, genotypes of the ε2/ε3/ε4 alleles associated with higher LDL-cholesterol (LDL-C) levels are also associated with higher coronary risk. However, the association of APOE genotype with other cardiovascular biomarkers and risk of ischaemic stroke is less clear. We evaluated the association of APOE genotype with risk of ischaemic stroke and assessed whether the observed effect was consistent with the effects of APOE genotype on LDL-C or other lipids and biomarkers of cardiovascular risk. METHODS: We conducted a systematic review of published and unpublished studies reporting on APOE genotype and ischaemic stroke. We pooled 41 studies (with a total of 9027 cases and 61 730 controls) using a Bayesian meta-analysis to calculate the odds ratios (ORs) for ischaemic stroke with APOE genotype. To better evaluate potential mechanisms for any observed effect, we also conducted a pooled analysis of primary data using 16 studies (up to 60 883 individuals) of European ancestry. We evaluated the association of APOE genotype with lipids, other circulating biomarkers of cardiovascular risk and carotid intima-media thickness (C-IMT). RESULTS: The ORs for association of APOE genotypes with ischaemic stroke were: 1.09 (95% credible intervals (CrI): 0.84-1.43) for ε2/ε2; 0.85 (95% CrI: 0.78-0.92) for ε2/ε3; 1.05 (95% CrI: 0.89-1.24) for ε2/ε4; 1.05 (95% CrI: 0.99-1.12) for ε3/ε4; and 1.12 (95% CrI: 0.94-1.33) for ε4/ε4 using the ε3/ε3 genotype as the reference group. A regression analysis that investigated the effect of LDL-C (using APOE as the instrument) on ischaemic stroke showed a positive dose-response association with an OR of 1.33 (95% CrI: 1.17, 1.52) per 1 mmol/l increase in LDL-C. In the separate pooled analysis, APOE genotype was linearly and positively associated with levels of LDL-C (P-trend: 2 × 10(-152)), apolipoprotein B (P-trend: 8.7 × 10(-06)) and C-IMT (P-trend: 0.001), and negatively and linearly associated with apolipoprotein E (P-trend: 6 × 10(-26)) and HDL-C (P-trend: 1.6 × 10(-12)). Associations with lipoprotein(a), C-reactive protein and triglycerides were non-linear. CONCLUSIONS: In people of European ancestry, APOE genotype showed a positive dose-response association with LDL-C, C-IMT and ischaemic stroke. However, the association of APOE ε2/ε2 genotype with ischaemic stroke requires further investigation. This cross-domain concordance supports a causal role of LDL-C on ischaemic stroke.
  International Journal of Epidemiology 04/2013; 42(2):475-492. · 6.41 Impact Factor
• Article: Effect of tablets with a combination of telmisartan and amlodipine on patients with hypertension: the Cotalo study.

  Mitsuru Ohishi, Tatsuo Kawai, Norihiro Hayashi, Shoichi Kitano, Tomohiro Katsuya, Masahiro Nagano, Atsushi Hirotani, Koichi Yamamoto, Kei Kamide, Hiromi Rakugi
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  ABSTRACT: Fixed-dose combination (FDC) therapy with telmisartan 40 mg+amlodipine 5 mg (T40/A5) is expected to achieve tight blood pressure (BP) control because of the strong efficacy and long half-life of each drug. The aims of this study were to evaluate the 24-h antihypertensive efficacy of T40/A5 FDC therapy and to explore differences that may arise owing to different administration times in Japanese patients whose hypertension was not controlled by 5 mg of amlodipine per day. In this randomized clinical trial, 44 patients who had been taking amlodipine 5 mg per day and did not achieve their optimal BP target were enrolled (mean age: 67.8±10.2 years). The subjects were then randomly assigned to a T40/A5 morning or evening administration group (22 patients per group). At baseline and 8 weeks after randomization, we evaluated clinical BP and various laboratory values and performed ambulatory BP monitoring (ABPM). Clinical and mean BP evaluated with ABPM at 8 weeks (24 h, daytime, nighttime and early morning) were significantly decreased compared with BP at baseline. There were no significant differences in the diurnal BP profile change from baseline to 8 weeks between subjects in the morning and evening administration groups. There were also no significant differences in the diurnal BP profile change from baseline to 8 weeks between subjects with or without metabolic syndrome. We conclude that T40/A5 FDC therapy significantly decreased the 24-h mean and clinical BP, independent of administration time, in patients whose hypertension was not controlled by 5 mg of amlodipine.Hypertension Research advance online publication, 21 February 2013; doi:10.1038/hr.2013.10.
  Hypertension Research 02/2013; · 2.58 Impact Factor
• Article: Decrease in Blood Pressure and Regression of Cardiovascular Complications by Angiotensin II Vaccine in Mice.

  Futoshi Nakagami, Hiroshi Koriyama, Hironori Nakagami, Mariana Kiomy Osako, Munehisa Shimamura, Mariko Kyutoku, Takashi Miyake, Tomohiro Katsuya, Hiromi Rakugi, Ryuichi Morishita
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  ABSTRACT: Vaccines have been recently developed to treat various diseases such as cancer, rheumatoid arthritis and Alzheimer's disease in addition to infectious diseases. However, before use in the clinical setting, vaccines targeting self-antigens must be demonstrated to be effective and safe, evoking an adequate humoral immune response from B cells while avoiding T cell activation in response to self. Although the vaccine targeting angiotensin II (Ang II) is efficient in rodents and humans, little is known regarding the immunological activation and safety of the vaccine. In this study, we evaluated the efficiency and safety of an Ang II peptide vaccine in mice. Immunization with Ang II conjugated to keyhole limpet hemocyanin (KLH) successfully induced the production of anti-Ang II antibody, which blocked Ang II signaling in human aortic smooth muscle cells. However, Ang II itself did not activate T cells, as assessed by the proliferation and lymphokine production of T cells in immunized mice, whereas KLH activated T cells. In an Ang II-infused model, the non-immunized mice showed high blood pressure (BP), whereas the immunized mice (Ang II-KLH) showed a significant decrease in systolic BP, accompanied by significant reductions in cardiac hypertrophy and fibrosis. Importantly, anti-Ang II antibody titer was not elevated even after the administration of large amounts of Ang II, indicating that Ang II itself boosted antibody production, most likely due to less activation of T cells. In addition, no accumulation of inflammatory cells was observed in immunized mice, because endogenous Ang II would not activate T cells after immunization with Ang II-KLH. Taken together, these data indicate that vaccines targeting Ang II might be effective to decrease high BP and prevent cardiovascular complications without severe side effects.
  PLoS ONE 01/2013; 8(3):e60493. · 4.09 Impact Factor
• Article: Genetic Impact on Uric Acid Concentration and Hyperuricemia in the Japanese Population.

  Fumihiko Takeuchi, Ken Yamamoto, Masato Isono, Tomohiro Katsuya, Koichi Akiyama, Keizo Ohnaka, Hiromi Rakugi, Yukio Yamori, Toshio Ogihara, Ryoichi Takayanagi, Norihiro Kato
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  ABSTRACT: Aim: Using general Japanese populations, we performed a replication study of genetic loci previously identified in European-descent populations as being associated with uric acid and gout. The relative contribution of non-genetic and genetic factors to the variances in serum uric acid concentration was then evaluated.Methods: Seven single nucleotide polymorphisms (SNPs) were genotyped from 7 candidate loci robustly confirmed in Europeans. Genotyping was performed in up to 17,226 individuals, from which 237 hyperuricemia cases and 3,218 controls were chosen for a case-control study. For 6 SNPs showing a replication of uric acid association in 17,076 general population samples, we further tested the associations with other metabolic traits (n≤5,745) and with type 2 diabetes (931 cases and 1404 controls) and coronary artery disease (806 cases and 1337 controls).Results: Significant uric acid associations (one-tailed p<0.05) were replicated for 6 loci in Japanese. The strongest association was detected at SLC22A12 rs505802 for uric acid (p=2.4×10(-50)) and ABCG2 rs2231142 for hyperuricemia (p3.6×10(-10)). The combined genetic effect could explain some proportion of inter-individual variation in uric acid (R(2)=0.03) and was more or less comparable to the effect of well-recognized risk factors -BMI (R(2)=0.04) and alcohol intake (R(2)=0.01). The tested SNPs were not significantly associated with cardiovascular risk traits except for GCKR rs780094.Conclusion: Our results confirm that 6 common uric acid variant loci are reproducible in Japanese. Further investigation is warranted to efficiently use the knowledge about genetic factors in combination with modifiable risk factors when we decide an individual's treatment strategy for hyperuricemia.
  Journal of atherosclerosis and thrombosis 12/2012; · 2.69 Impact Factor