Screening Of Key Proteins In The Initiation Of Secondary Hair Follicle Growth Phase In Liaoning Cashmere Goats And Their Functional Regulatory Network And Verificatio

Liaoning cashmere goat is a precious germplasm resource in China,and its cashmere fiber is soft in texture and is an extremely valuable natural fiber.The periodic activity of hair follicles is closely related to the growth and development of cashmere.Proteins,as executors of biological functions,play an important regulatory role in the periodic activity of hair follicles,but there are relatively few screening and functional studies on key proteins in the periodic activity of hair follicles in Liaoning cashmere goat skin.In this study,the Liaoning cashmere goat skin hair follicles were used as the research object,and the key proteins in the growth phase initiation process of the cashmere goat hair follicles were screened and verified by proteomics,which provided a basis for further exploration of the laws and regulatory mechanisms of cashmere goat skin hair follicle development.The research contents are as follows:1.Make cross-section and longitudinal-section paraffin sections of Liaoning cashmere goat skin tissue,and stain with H.E.The structure of the hair follicles of the goat was observed under the microscope,and it was found that the hair follicles of the goat hair follicles in Liaoning were distributed in groups and were mainly composed of binary and ternary hair follicles.Significantly.2.Based on tandem mass spectrometry technology and DIA data collection and identification,623 differential proteins in telogen phase and anagen phase(including338 up-regulated proteins and 285 down-regulated proteins)were identified.In GO analysis,the differential proteins were mainly enriched in cellular processes,etc.24,There are 10 molecular functions such as a biological process,10 molecular functions such as structure moleculer activity,and 17 cellular components such as cell part.Differential proteins in the KEGG analysis were mainly enriched in signaling pathways such as extracellular matrix receptor(ECM-receptor)and PPAR signaling pathway.The PPI interaction network was constructed by the up-regulated and down-regulated differential proteins,and COL1A2,TP63,ALB,KRT5,KRTAP11-1,SCD,VIM,and EGFR were screened out as key proteins by GO and KEGG analysis.The PPI interaction network revealed the direct or indirect regulatory relationship between key proteins.The bioinformatics platform and software are used to construct 3D models,protein docking and interaction surface prediction of key proteins with interactions,and display the hydrogen bonds and amino acid residues involved in the interaction of protein interaction surfaces.3.The key proteins(TP63,KRT5,SCD,COL1A2)were randomly selected for Western-blot verification.The results showed that the expression levels of TP63,KRT5,and SCD in the growing phase were higher than those in the resting phase,which was consistent with the sequencing results.It indicated that TP63,KRT5 and SCD play a positive regulatory role in the initiation of hair follicle anagen phase,and COL1A2 acts as a positive regulator during telogen.Immunohistochemical results showed that KRT5 protein mainly expressed in the outer root sheath and inner root sheath of the SHF,COL1A2 protein was positively expressed in the inner root sheath and connective tissue sheath,and TP63 was mainly expressed in the outer root sheath.In conclusion,this study identified the differential proteins of cashmere goat skin hair follicles based on proteomics,and selected the key proteins located at the central node by constructing a PPI interaction network,and found that the key proteins have interactions.The prediction of key protein interaction networks and interaction regions revealed that there were direct or indirect interactions between key proteins,which then affected the entire protein interaction network to regulate the initiation of the growth phase of the hair follicle.Finally,the quantitative and localization research of key proteins was carried out.It was speculated that TP63,KRT5 and SCD were involved in the process of hair follicle initiation and played a role in promoting the initiation of hair follicles,laying a foundation for further research on the molecular mechanism of hair follicle development of cashmere goat,and for the quality of cashmere goat hair.Improvement is also very important.