The Function And Mechanism Of UHRF1 In Sertoli Cells On The Development Of Sertoli Cells And Spermatogenic Cells In Mice

[Purpose] To investigate the role and mechanism of UHRF1 of SCs in spermatogenesis.[Methods] By immunofluorescence and conditional knockout of Uhrf1 in SCs with CreLoxp system,we detected the expression of UHRF1 in human and mouse testis and investigated UHRF1 function of SCs in spermatogenesis.[Results] UHRF1 was expressed in some immature SCs of human and mouse testes,but not in mature SCs.In proliferative environment,UHRF1 was induced to re-expression in mature primary SCs.Uhrf1 mutant in SCs resulted in atrophy of testis,germ cells apoptosis and reduced number in male mice,immature germ cells sheding and male sterility.However,the deficient of UHRF1 in SCs had no effect on germ cell proliferation and differentiation at early stage.[Conclusions] UHRF1 is expressed in the nuclei of some immature SCs in human and mouse testes,and may be involved in proliferation of SCs;UHRF1 in SCs has an important role in spermatogenesis,and its mutant in SCs lead to immature germ cells at the epithelium of seminiferous epithelium slough to the epididymis,accompanied by the apoptosis of germ cells,abnormal spermatogenesis and male infertility.[Purpose] To investigate the function of Uhrf1 in SCs on the structure development of SCs and the mechanism of spermatogenesis.[Methods] Combined with the model of conditional knockout animal,immunofluorescence,RNA-seq and whole-genome bisulfite sequencing analysis,we investigated the function and mechanism of SCs UHRF1 in SCs development.[Results] UHRF1 mutant in SCs induced SCs proliferation capacity reduced from P3 to P5 without change of the proliferation capacity at later stages,and the differentiation and maturation of SCs delayed;UHRF1 deficiency led to the loss of SCs polarity,disturbed Factin distribution,and massive abnormal aggregation around round spermatozoa,especially at stage I-VIII;UHRF1 deficiency in SCs also leads to abnormal accumulation of lipid droplets in SCs,abnormal lipid metabolism,BTB destruction,and disruption of adhesion and communication between SCs and GCs;UHRF1 mutant in SCs led to the genes related to extracellular matrix and cell adhesion were significantly up-regulated in Uhrf1 c KO SCs,accompanied by a large number of abnormal activations of some transposons elements,especially the IAPs;Overexpression of extracellular matrix and cell adhesion-related genes disrupted SCs cytoskeleton structure and SCs-GCs connections and resulted in many immature SCs sloughing from the seminiferous epithelium.[Conclusions] Uhrf1,as an epigenetic regulator,regulates DNA methylation of SCs,controls the methylation level of extracellular matrix and intercellular adhesion-related genes in SCs,and regulates the connection and communication between SCs and GCs,which is necessary for spermatogenesis.Once the UHRF1 mutant in SCs,the SCs microstructure,cell polarity and lipid metabolism are impaired,which in turn induces the disfunction of SCsGCs connection and communication and leads to massive GCs slough,abnormal spermatogenesis and male sterility.