| Project/Area Number |
16591121
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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 |
Dermatology
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| Research Institution | St.Marianna University School of Medicine |
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Principal Investigator |
KAWAKAMI Tamihiro St.Marianna University School of Medicine, Department of Dermatology, associate professor, 医学部, 助教授 (20297659)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | BMP / neural crest cells / melanocyte / mouse NCC / malignant melanoma / differentiation / KIT / proliferation / 悪性黒色腫 / メラノブラスト |
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| Research Abstract |
Genes encoding Kit and Kit ligand (Kit1) play essential roles in the differentiating melanoblasts. We previously established three immortal but distinct cell populations of mouse neural crest (NC) cells. NCCmelb4M5 cells do not express Kit and grow independently of Kit1 ; they have the potential to differentiate into NCCmelb4 cells, which are Kit-positive melanocyte precursors. NCCmelan5 cells show the characteristics of differentiated melanocytes. We investigated the effects of BMP-4 on the differentiation of immature melanocyte precursors. Three cell lines showed BMP-receptor expression. BMP-4 up-regulated Kit protein and mRNA expression in most immature NCCmelb4M5 cells. Noggin, a BMP-4 antagonist, dramatically decreased the Kit expression induced by BMP-4. Western blot analysis revealed that extrinsic BMP-4 leads to the phosphorylation of Smads and activates signaling in NCCmelb4M5 cells. We conclude that in NCCmelb4M5 cells, BMP-4 promotes melanocyte precursor differentiation via Kit expression. We further investigated the influence of BMP-4 in vitro using primary NC cells cultured from wild-type mice. Addition of BMP-4 to the medium increased the number of Kit-positive cells compared to untreated controls. An excess of BMP-4 added to wild-type NC explants abolished the growth of NC cells. Thus, we have identified BMP-4 as a differentiation factor for prepubertal Kit-negative melanoblasts just before they enter the Kit-dependent cycle of melanogenesis.
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