Yasushi Kasahara

Publications (2)4.73 Total impact

• Article: Two novel sandwich ELISAs identify PAD4 levels and PAD4 autoantibodies in patients with rheumatoid arthritis.

  Akihito Ishigami, Yoshiaki Uchida, Tsuyoshi Miyazaki, Setsuko Handa, Eun-Kyoung Choi, Yong-Sun Kim, Yasushi Kasahara, Naoki Maruyama
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  ABSTRACT: OBJECTIVE: The peptidylarginine deiminase 4 (PAD4) gene and PAD4 autoantibodies have been associated with rheumatoid arthritis (RA) and its pathogenesis. Therefore, methods for accurately determining their levels in the peripheral blood of these patients would be a diagnostic asset. The objective of our study was to adapt the enzyme-linked immunosorbent assay (ELISA) method for evaluating PAD4 levels in human blood. METHODS: We prepared recombinant human (h)PAD1, -2, -3, and -4 proteins to develop mouse monoclonal antibodies specific to hPAD4. We then generated six monoclonal antibodies against hPAD4 and developed two new sandwich ELISA methods for evaluating hPAD4 and PAD4 autoantibodies in the peripheral blood from 32 patients with RA, ten patients with osteoarthrosis, and 20 healthy individuals. RESULTS: The distribution of hPAD4 in the patients' plasma was determined. Two populations were identified: one group with high hPAD4 levels (>0.57 ng/mL) and a second group with near-zero levels (<0.1 ng/mL). Most patients approximating zero hPAD4 levels had PAD4 autoantibodies. In contrast, most of those with higher plasma hPAD4 levels did not have detectable PAD4 autoantibodies. CONCLUSION: The combination of these sandwich ELISA methods may be a potentially beneficial clinical tool for diagnosing RA.
  Modern Rheumatology 09/2012; · 1.58 Impact Factor
• Article: Senescence marker protein-30 knockout mouse as an aging model.

  Naoki Maruyama, Akihito Ishigami, Masashi Kuramoto, Setsuko Handa, Sachiho Kubo, Toshiyuki Imasawa, Kuniaki Seyama, Tatsuo Shimosawa, Yasushi Kasahara
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  ABSTRACT: A mouse strain lacking SMP30 can be regarded as a strain showing ultimate decrease of the SMP30 molecule. After three months of age, SMP30-KO mice had an increased mortality rate, compared with the SMP30-WT mice, all of which remained alive. Electron microscopic observation of the hepatocytes from 12-month-old SMP30-KO mice revealed many empty vacuoles, presumably lipid droplets, abnormally enlarged mitochondria with indistinct cristae, and exceptionally large lysosomes filled with electron-dense bodies. The total hepatic triglyceride concentration of SMP30-KO mice was approximately 3.6-fold higher than that of the age-matched wild type. Similarly, the total hepatic cholesterol of SMP30-KO mice reached an approximate 3.3-fold greater value than that of the comparative group. Total hepatic phospholipids of SMP30-KO mice achieved an approximately 3.7-fold higher level compared with that of the wild-type mice. The cells from SMP30-KO mice were sensitive to apoptotic reagents. Those results supported the idea that SMP30 has an antiapoptotic function with wide spectrum. These findings indicate that SMP30-KO mice are highly susceptible to various harmful reagents. This strain might be a useful tool for aging and biological monitoring.
  Annals of the New York Academy of Sciences 07/2004; 1019:383-7. · 3.15 Impact Factor