1997 Fiscal Year Final Research Report Summary
Studies on functional xonation of adrenocortical cells
| Project/Area Number |
09044333
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Field |
Functional biochemistry
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| Research Institution | Keio University |
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Principal Investigator |
ISIMURA Yuzuru Keio University, Professor, 医学部, 教授 (40025599)
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| Co-Investigator(Kenkyū-buntansha) |
MUKAI Kuniaki Keio University, Instructor, 医学部, 助手 (80229913)
MITANI Fumiko Keio University, Assistant Professor, 医学部, 講師 (60041852)
PARKER Keith Texas University, Professor, 医学部, 教授
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| Project Period (FY) |
1997
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| Keywords | adrenal cortex / mineralocorticoid / glucocorticoid / thymidine kinase / transgenic mice / SV40 large T antigen / Y-1 cells / AP-1 transcription factor |
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| Research Abstract |
Mechanisms for the functional zonation of adrenocortical cells were studied using mice that were genetically manipulated. Findings obtained from research results are described below.
1. Production of mice whose mineralocorticoid synthesizing cell-zone in the adrenal cortex are conditionally ablated. Thymidine kinase gene of herpes simplex virus was inserted into the locus at mineralocorticoid synthase gene of embryonic stem cells by transfection with a targeting vector. Recombinant embryonic stem cell clones were successfully obtained, and introduction of them into mouse blastocysts for chimeric animals are undergoing.
2. Establishment of adrenocortical precursor cell-lines. Adrenocortical cells from transgenic mice which harbor an immortalizing gene encoding temperature sensitive SV40 large T antigen, were cultured and cloned with a conventional methods. The cell lines were characterized for expression of various steroidogenic genes by analyzing their mRNAs. The results indicated that a cell-line was undifferentiated at the permissive temperature and express glucocorticoid synthase gene at the nonpermissive temperature. Thus, and adrenocortical precursor cell-line which was able to differentiate upon a temperature shift was established.
3. Molecular mechanisms by which adrenocorticotropic hormone (ACTH) stimulates glucocorticoid synthase gene expression. Using mouse adrenocortical Y-1 cells, ACTH was found to regulate transcription of the gene by causing compositional changes in AP-1 transcripotion factors in the cells via a cAMP-dependent pathway.
4. Histochemical analyzes of mouse adrenal cortex. Immunohistochemical and in situ hybridization analyzes of mouse adrenal cortex showed the presence of an undifferentiated cell layr which express neither mineralonor glucocorticoid synthase.
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