Microphthalmia-associated transcription factor/T-box factor-2 axis acts through Cyclin D1 to regulate melanocyte proliferation
Microphthalmia-associated transcription factor/T-box factor-2 axis acts through Cyclin D1 to regulate melanocyte proliferation
复制标题
小眼症相关转录因子/T-box 因子 2 轴通过 Cyclin D1 发挥作用，调节黑素细胞增殖。
DOI：
10.1111/cpr.12227
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发表时间：
2015-12-01
影响因子：
8.5
通讯作者：
Hou, L.
中科院分区：
文献类型：
--
作者：
Pan, L.;Ma, X.;Hou, L.
目的：在发育和再生过程中，控制细胞增殖对于准确的细胞分化和组织形成至关重要。在此，我们分析了小眼球相关转录因子MITF及其直接靶点T-box因子TBX2在调节哺乳动物神经脊源性黑素细胞增殖中的作用。材料和方法：采用免疫组织化学方法检测在体黑素细胞中TBX2的时空表达。用RNAi和细胞增殖分析研究了TBX2的功能作用。结果：在小鼠毛囊黑素细胞中，TBX2与MITF共表达。在原代神经脊细胞中，特异性的Tbx2基因敲除导致抑制MITF阳性的黑素母细胞的增殖。在Melan-a细胞中，Tbx2基因被敲除后，细胞周期蛋白Cyclin D1表达下降，细胞周期停滞于G1期。Tbx2通过与Ccnd1启动子中的特定序列结合直接激活Ccnd1转录，而Tbx2基因敲除黑素细胞中Cyclin D1的过表达可部分挽救细胞增殖缺陷。结论：MITF-Tbx2-Cyclin D1通路在黑素细胞增殖调控中起重要作用，为深入研究黑素细胞的复杂生理机制提供了新的思路。
Objectives: Control of cell proliferation is critical for accurate cell differentiation and tissue formation, during development and regeneration. Here, we have analysed the role of microphthalmia-associated transcription factor MITF and its direct target, T-box factor TBX2, in regulating proliferation of mammalian neural crest-derived melanocytes.Materials and methods: Immunohistochemistry was used to examine spatial and temporal expression of TBX2 in melanocytes in vivo. RNAi and cell proliferation analysis were used to investigate functional roles of TBX2. Furthermore, quantitative RT-PCR, western blot analysis and flow cytometry were used to further scrutinize molecular mechanisms underlying TBX2-dependent cell proliferation.Results: TBX2 was found to be co-expressed with MITF in melanocytes of mouse hair follicles. Specific Tbx2 knockdown in primary neural crest cells led to inhibition MITF-positive melanoblast proliferation. Tbx2 knockdown in melan-a cells led to reduction in Cyclin D1 expression and G1-phase cell cycle arrest. TBX2 directly activated Ccnd1 transcription by binding to a specific sequence in the Ccnd1 promoter, and the defect in cell proliferation could be rescued partially by overexpression of Cyclin D1 in Tbx2 knockdown melanocytes.Conclusions: Results suggest that the Mitf-Tbx2-Cyclin D1 pathway played an important role in regulation of melanocyte proliferation, and pro-vided novel insights into the complex physiology of melanocytes.