1992 Fiscal Year Final Research Report Summary
Role of vitamin D_3 on differentiation of bone marrow-derived stromal cells.
| Project/Area Number |
03670873
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Functional basic dentistry
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| Research Institution | Showa University |
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Principal Investigator |
SHINKI Toshimasa Showa Univ., School of Dentistry Lecturer, 歯学部, 講師 (90138420)
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| Co-Investigator(Kenkyū-buntansha) |
TAKITO Jiro Showa Univ., School of Dentistry Assistant, 歯学部, 助手 (00197237)
SUDA Tatsuo Showa Univ., School of Dentistry Professor, 歯学部, 教授 (90014034)
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| Project Period (FY) |
1991 – 1992
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| Keywords | adipocyte / adipogenesis / osteoporosis / phospholipids / preadipocyte / triacylglycerol / vitamin D derivatives / デキサメタゾン |
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| Research Abstract |
MC3T3-G2/PA6 cells established from newborn mouse calvaria are preadipocytic stromal cells, which differentiate into adipocytes in response to glucocorticoids. We examined the effects of lalpha, 25-dihydroxyvitamin D_3 [lalpha, 25(OH) _2D_3] on adipgenesis in PA6 cells. When PA6 cells were cultured with 10^<-8> M dexamethasone, adipocytes contatining oil red O-positive droplets first appeared on day 7 (3 days after confluence was attained) and the maximal synthesis of neutral lipids occurred on day 12.
Simultanieous addition of lalpha, 25(OH) _2D_3 at 10^<-9> M completely blocked this dexamethasone-induced neutral lipid synthesis throughout the 14-day culture period. Dose-response studies of vitamin D_3 derivatives showed that lalpha, 25(OH) _2D_3 was the most potent in inhibiting neutral lipid synthesis in PA6 and 24, 25-dihydroxyvitamin D_3, in that order. Dexamethasone greatly enhanced incorporation of [^<14>C]-acetic acid into triglycerol in PA6 cells. The incorporation was markedly inhibited by the addition of 10^<-9> M lalpha, 25(OH)_2D_3. Instead, lalpha, 25(OH) _2D_3 greatly increased incorporation of [^<14>C]-acetic acid into phospholipids, such as phosphatidylcholine and phosphatidylthanolamine, irrespective of the presence or absence of dexamethasone. These results suggest that 1alpha, 25(OH) _2D_3 modulation of lipid metabolism in bone marrow stromal cells is receptor mediated.
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