Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA.
Department of Dermatology, University of Maryland School of Medicine, Baltimore, MD, USA.
Pigment Cell Melanoma Res. 2021 Sep;34(5):905-917. doi: 10.1111/pcmr.12959. Epub 2021 May 18.
Melanocyte stem cells (McSCs) are key components of the hair follicle (HF) stem cell system that regenerate differentiated melanocytes during successive HF cycles. To facilitate continued research on melanocyte development and differentiation and McSCs, we backcrossed inducible Dct-H2BGFP mice into the C57BL/6J background (B6-Dct-H2BGFP). We compared the expression pattern of B6-Dct-H2BGFP to that of Dct-H2BGFP mice on a mixed genetic background reported previously. To characterize B6-Dct-H2BGFP mice, we confirmed not only the expression of GFP in all melanocyte lineage cells, but also doxycycline regulation of GFP expression. Furthermore, ex vivo culture of the McSC subsets isolated by fluorescence-activated cell sorting (FACS) showed the propensity of bulge/CD34+ McSCs to differentiate with expression of non-melanocytic, neural crest lineage markers including glia (Gfap and CNPase, 73 ± 1% and 77 ± 2%, respectively), neurons (Tuj1 26 ± 5%), and smooth muscle (α-Sma, 31 ± 9%). In contrast, CD34-/secondary hair germ (SHG) McSCs differentiated into pigmented melanocytes, with higher expression of melanogenic markers Tyr (71 ± 1%), Tyrp1 (68 ± 4%), and Mitf (75 ± 7%). These results establish the utility of B6-Dct-H2BGFP bitransgenic mice for future in vivo studies of melanocytes requiring a defined genetic background.
黑素细胞干细胞（McSCs）是毛囊（HF）干细胞系统的关键组成部分，可在连续的 HF 周期中再生分化的黑素细胞。为了促进黑素细胞发育和分化以及 McSCs 的持续研究，我们将诱导型 Dct-H2BGFP 小鼠与 C57BL/6J 背景（B6-Dct-H2BGFP）进行回交。我们比较了 B6-Dct-H2BGFP 与先前报道的混合遗传背景下的 Dct-H2BGFP 小鼠的表达模式。为了表征 B6-Dct-H2BGFP 小鼠，我们不仅证实了 GFP 在所有黑素细胞谱系细胞中的表达，还证实了强力霉素对 GFP 表达的调控。此外，通过荧光激活细胞分选（FACS）分离的 McSC 亚群的离体培养显示，毛囊隆突/CD34+McSCs 具有分化的倾向，表达非黑素细胞、神经嵴谱系标记物，包括神经胶质（Gfap 和 CNPase，分别为 73±1%和 77±2%）、神经元（Tuj1 为 26±5%）和平滑肌（α-Sma，31±9%）。相比之下，CD34-/次级毛囊生发中心（SHG）McSCs 分化为有色素的黑素细胞，其黑素生成标记物 Tyr（71±1%）、Tyrp1（68±4%）和 Mitf（75±7%）的表达更高。这些结果确立了 B6-Dct-H2BGFP 双转基因小鼠在未来需要明确遗传背景的体内黑素细胞研究中的应用价值。
