Diao Xiaogao, Yao Lingyun, Duan Tao, Qin Jiaxin, He Liwen, Zhang Wei
Department of Animal Nutrition and Feed Science, State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China.
J Anim Sci Biotechnol. 2023 Apr 7;14(1):51. doi: 10.1186/s40104-023-00849-w.
The quality and yield of cashmere fibre are closely related to the differentiation and development of secondary hair follicles in the skin of cashmere goats. The higher the density of secondary hair follicles, the higher the quality and yield of cashmere from the fleece. Development of secondary hair follicles commences in the embryonic stage of life and is completed 6 months after birth. Preliminary experimental results from our laboratory showed that melatonin (MT) treatment of goat kids after their birth could increase the density of secondary hair follicles and, thus, improve the subsequent yield and quality of cashmere. These changes in the secondary hair follicles resulted from increases in levels of antioxidant and expression of anti-apoptotic protein, and from a reduction in apoptosis. The present study was conducted to explore the molecular mechanism of MT-induced secondary hair follicle differentiation and development by using whole-genome analysis.
MT had no adverse effect on the growth performance of cashmere kids but significantly improved the character of the secondary hair follicles and the quality of cashmere, and this dominant effect continued to the second year. Melatonin promotes the proliferation of secondary hair follicle cells at an early age. The formation of secondary hair follicles in the MT group was earlier than that in the control group in the second year. The genome-wide data results involved KEGG analysis of 1044 DEmRNAs, 91 DElncRNAs, 1054 DEcircRNAs, and 61 DEmiRNAs which revealed that the mitogen-activated protein kinase (MAPK) signaling pathway is involved in the development of secondary hair follicles, with key genes (FGF2, FGF21, FGFR3, MAPK3 (ERK1)) being up-regulated and expressed. We also found that the circMPP5 could sponged miR-211 and regulate the expression of MAPK3.
We conclude that MT achieves its effects by regulating the MAPK pathway through the circMPP5 sponged the miR-211, regulating the expression of MAPK3, to induce the differentiation and proliferation of secondary hair follicle cells. In addition there is up-regulation of expression of the anti-apoptotic protein causing reduced apoptosis of hair follicle cells. Collectively, these events increase the numbers of secondary hair follicles, thus improving the production of cashmere from these goats.
羊绒纤维的品质和产量与绒山羊皮肤中次级毛囊的分化和发育密切相关。次级毛囊密度越高，羊毛中羊绒的品质和产量就越高。次级毛囊的发育始于胚胎期，并在出生后6个月完成。我们实验室的初步实验结果表明，在山羊幼崽出生后用褪黑素（MT）处理可以增加次级毛囊的密度，从而提高随后羊绒的产量和品质。次级毛囊的这些变化是由于抗氧化剂水平的增加和抗凋亡蛋白表达的增加以及细胞凋亡的减少所致。本研究旨在通过全基因组分析探索MT诱导次级毛囊分化和发育的分子机制。
MT对绒山羊幼崽的生长性能没有不良影响，但显著改善了次级毛囊的特征和羊绒的品质，并且这种显著效果持续到第二年。褪黑素在幼年时促进次级毛囊细胞的增殖。第二年，MT组次级毛囊的形成早于对照组。全基因组数据结果涉及对1044个差异表达信使核糖核酸（DEmRNAs）、91个差异表达长链非编码核糖核酸（DElncRNAs）、1054个差异表达环状核糖核酸（DEcircRNAs）和61个差异表达微小核糖核酸（DEmiRNAs）的京都基因与基因组百科全书（KEGG）分析，结果显示丝裂原活化蛋白激酶（MAPK）信号通路参与次级毛囊的发育，关键基因（FGF2、FGF21、FGFR3、MAPK3（细胞外信号调节激酶1（ERK1）））上调并表达。我们还发现环状MPP5（circMPP5）可以吸附微小核糖核酸-211（miR-211）并调节MAPK3的表达。
我们得出结论，MT通过circMPP5吸附miR-211来调节MAPK通路，调节MAPK3的表达，从而诱导次级毛囊细胞的分化和增殖。此外，抗凋亡蛋白的表达上调，导致毛囊细胞凋亡减少。总的来说，这些事件增加了次级毛囊的数量，从而提高了这些山羊的羊绒产量。
