A Transcriptomic Analysis Of ERK Functional Inhibition And Its Role In Lipogenesis In Cashmere Goat Fetal Fibroblasts

Inner Mongolian White Cashmere Goat is a local breed formed through long-term natural selection featuring high quality cashmere and meat-type.Apart from producing the world’s finest chorionic fibers,it also has the characteristics of good performance of meat production,tender meat.The key factors of meat quality is its intramuscular fat content,but the mechanism of synthesis and deposition is not yet clear.Extracellular signal-regulated kinase 1/2(ERK 1/2)belongs to the mitogen-activated protein kinase(MAPK)superfamily.ERK 1/2 is an important component of the Ras/Raf/MEK/ERK pathway and can mediate a Cell growth and metabolic processes.The role of ERK in human and multi-pattern animal cells has been well-understood,but we still don’t know much about the function in the cashmere goat cells,especially the role on the adipogenesis.Cashmere goat fetal fibroblasts(GFb)is the most commonly used cell model for the study of the growth and metabolism of Inner Mongolian white cashmere goats.To explore the function of ERK in GFb cells and study its regulation and mechanism in cell lipid synthesis,we compared the transcriptome of GFb cells after treated with ERK1/2 specific inhibitor SCH772984 or not.The results showed that GFb cells is sensitive to SCH772984,and SCH772984 inhibited cell proliferation when concentration of the inhibitor over 0.5 μM(p<0.05).0.1 μM SCH772984 treated GFb cells for 24 h,the synthesis of intracellular TAG,PA and DHA was inhibited(p<0.05),companied with inhibition of ERK/mTORC1 signaling activation and expression of lipogenesis related transcript factors—PPARγ and SREBP1,and key ezymes—Lipin1,DGAT1,FAS and ACC.The possible mechanism is that ERK 1/2 regulates the expression of lipid synthesis-related transcription factors and key enzymes through mTOR signaling,thereby regulating lipid synthesis.Transcriptome analysis showed that ERK 1/2 activity was inhibited by treatment with 0.1 μM SCH772984 for 24 h,and 66 new genes(transcripts)and 76 differentially expressed genes were found in GFb cells,of which 47 were up-regulated and 29 were down-regulated.Among these,they can be annotated in various databases.There were 69 genes including 53 GOs,19 COGs,40 KEGGs,62 Swiss-Prots,65 TrEMBLs,65 nr,and 69 nts.Differentially expressed genes are mainly concentrated in biological processes and are in line with the general features of ERK functions.In this study,the function of ERK in fetal fibroblasts of Inner Mongolian white cashmere goat was analyzed at the transcriptome level,and the role and mechanism of ERK in intracellular fat synthesis were explored.The results will provide basic datas for further studying growth and metabolism of cashmere goat cells,and the formation mechanism of intramuscular fat and deposition in particular is of great significance for improving the flesh quality of cashmere goats.