The Role Of ADAMTS18 In The Development Of Male Reproductive System In Mice

ADAMTS（A Disintegrin and Metalloproteinase with Thrombospondin type I motifs）are secreted metalloproteinases.They play crucial roles in diverse morphogenesis processes by modifying extracellular matrix.ADAMTS18 an orphan ADAMTS,is less understood with regard to its functions and substrate profiles.We have previously developed an Adamts18 knockout(Adamts18^-/-)mouse model.It was shown that the fertility of Adamts18^-/-mice（both male and female）was reduced compared to wild-type mice(Adamts18^+/+)during breeding.Another study in our group shows that some female Adamts18^-/-mice exhibit vaginal atresia and are infertile.In this study,the role of ADAMTS18 in the development of the reproductive system in male mice was investigated.Methods:Adamts18 m RNA levels in cells of different developmental stages of male reproductive system were determined by q RT-PCR.RNA in situ hybridization was used to reveal the origin cells of Adamts18 m RNA in preputial gland（PG）of1-week-old male mice.The genital tubercles of both Adamts18^+/+and Adamts18^-/-male embryos at E14.5 were in vitro cultured and examined every 48 h for 96 h.To investigate the underlying mechanisms by which ADAMTS18 affects the morphogenesis of preputial gland,the expression of major ECMs in preputial glands of 2 weeks old male mice was examined.Masson’s trichrome staining was used to show the fibrosis and keratinized squamous cell layer of 7 and 10 months old Adamts18^-/-and Adamts18^+/+mice preputial glands.The effect of ADAMTS18 on mouse preputial glands,prostate and testes morphogenesis was examined by anatomy and histology.Tail lengths of sperms which were collected from the epididymis of Adamts18^-/-and Adamts18^+/+mice were measured.The percentage of abnormal sperms,including those with folded head,duplicated tail,hairpin loop,amorphous,folded tail,broken tail,hammerhead,and headless were calculated.Results:Adamts18 m RNA was found to be highly expressed in basal cells of developing preputial gland.Male mice lacking Adamts18(Adamts18^-/-)exhibit abnormal PG morphogenesis,including reduced size and sharp outline.This PG malformation is associated with reduced expression of Lama1,Lama3,and Lama5.Abnormal PG morphogenesis in Adamts18^-/-mice results in increased incidence of PG cystic dilatation,cellular keratinization,and stroma fibrosis.There was no difference in branching morphogenesis and in the number of branches in prostate.The testes and sperm of adult Adamts18^-/-mice exhibited similar morphologic features to those of Adamts18^+/+mice.These results indicate that ADAMTS18 is required for normal morphogenesis of the preputial gland in male mice.This study demonstrated for the first time that ADAMTS18 regulates the morphogenesis of preputial gland during the development of male reproductive system in mice.In summary,we investigated the role of ADAMTS18 in the development of the male reproductive system and found that mice lacking ADAMTS18 exhibit abnormal preputial gland morphogenesis and increased incidence of preputial gland cystic dilatation and fibrosis.