2007 Fiscal Year Final Research Report Summary
Inhibition of injury and promotion of regeneration in pancreatic islets of diabetes mellitus the by molecular intervention
| Project/Area Number |
17590948
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Metabolomics
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| Research Institution | Jikei University School of Medicine |
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Principal Investigator |
SASAKI Takashi Jikei University School of Medicine, Department of medicine, Professor (90205849)
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| Co-Investigator(Kenkyū-buntansha) |
NEMOTO Masami The Jikei University, Department of medicine, Associate Professor (10281396)
FUJIMOTO Kei The Jikei University, Department of medicine, Clinical Associate (40372974)
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| Project Period (FY) |
2005 – 2007
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| Keywords | reaenerative medicine / cell cycle / aene therapy / insulin / cvclin / cyclin-deuendent kinase / endocrine pancreas / adenoassociated virus |
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| Research Abstract |
Increased expression of pl6^<INK4a>, an inhibitor of Cyclin-Dependent Kinase (CDK) , could lead to inactivation of CDK. Therefore molecular intervention to cell cycle regulation of residual islet cells has therapeutic potential. In the present study,we aimed to reactivate the inactive CDK4, recover islet 13 cell mass in adult diabetic mice. CDK4^<R24C> gene, a variant that can promote G 1/S transition with least suppression by p16^<INK4a>, was transferred to islets of adult mice in vivo. The 8.0x10^<12>vg/body of rAAV8 was directly injected to murine pancreas by an open surgery. For evaluation of the 13 cell mass, total 13 cell area of whole pancreas (total (3 cell) of 210 slices and for each treatment were measured as well as [3 cell area within each islet (islet mass) of 360 islets. CDK4 was localized exclusively at cytoplasm of (3 cells in mock-treated mice, while it localized at nucleus in addition to cytoplasm in most 13 cells of the R24C-treated islets, suggesting reactivation and translocation to nucleus of Cyclin D/CDK4 complex. Both total 13 cell area and islet mass of R24C-treated mice turned out to be 2.5 fold than those of mock treated mice. Histogram analysis also revealed that distribution of islet mass of the R24C-treated mice almost recovered to that of normal mice. PCNA and TUNEL staining of the R24C treated mice showed that proliferating 13 cells were significantly increased while apoptotic cells did not. All of the Insulin-expressing cells including PCNA (+) cells in islets of the R24C treated mice were shown to be MafB (+) , indicating the proliferated islet cells should be terminally differentiatedβcell. Plasma glucose level of the R24C treated mice after glucose load were significantly lower than that of mock treated mice.
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