Tmprss12 is required for sperm motility and uterotubal junction migration in mice†

Abstract

Spermatozoa are produced in the testis but gain their fertilizing ability during epididymal migration. This necessary step in sperm maturation includes posttranslational modification of sperm membrane proteins that includes protein processing by proteases. However, the molecular mechanism underpinning this epididymal sperm maturation remains unknown. In this study, we focused on transmembrane serine protease 12 (Tmprss12). Based on multi-tissue expression analysis by PCR, Tmprss12 was specifically expressed in the testis, and its expression started on day 10 postpartum, corresponding to the stage of zygotene spermatocytes. TMPRSS12 was detected in the acrosomal region of spermatozoa by immunostaining. To reveal the physiological function of TMPRSS12, we generated two knockout (KO) mouse lines using the CRISPR/Cas9 system. Both indel and large deletion lines were male sterile showing that TMPRSS12 is essential for male fertility. Although KO males exhibited normal spermatogenesis and sperm morphology, ejaculated spermatozoa failed to migrate from the uterus to the oviduct. Further analysis revealed that a disintegrin and metalloprotease 3 (ADAM3), an essential protein on the sperm membrane surface that is required for sperm migration, was disrupted in KO spermatozoa. Moreover, we found that KO spermatozoa showed reduced sperm motility via computer-assisted sperm analysis, resulting in a low fertilization rate in vitro. Taken together, these data indicate that TMPRSS12 has dual functions in regulating sperm motility and ADAM3-related sperm migration to the oviduct. Because Tmprss12 is conserved among mammals, including humans, our results may explain some genetic cases of idiopathic male infertility, and TMPRSS12 and its downstream cascade may be novel targets for contraception.

ZDHHC19 Is Dispensable for Spermatogenesis, but Is Essential for Sperm Functions in Mice

“…Indeed, our sperm morphology analysis showed that Zdhhc19 KO sperm had coiled and bent tails (Figure 4E). Under natural fertilization conditions, sperm must migrate through the UTJ, penetrate into the zona pellucida, and fuse to the oocyte [35]. Although spermatozoa with low motility may not reach UTJ, it is possible that they are capable of penetrating eggs in vitro.…”

“…Given that Zdhhc19 KO mice were sterile yet with normal spermatogenesis, reduced sperm motility, and abnormal acrosome reaction, male infertility can be caused by failure of spermatozoa to migrate through the female uterotubal junction (UTJ) due to low sperm motility [35]. Alternatively, the sterility of Zdhhc19 KO mice may be attributed to defects in induced acrosome reaction and oocyte interaction/activation.…”

Understanding the cross-talk between mediators of infertility and COVID-19

“…Endosomal cysteine proteases such as CTSB and CTSL are abundant in Leydig cells, Sertoli cells, seminal vesicles, the epididymis, and germ cells, and participate in the priming of S protein [ 23 , 24 ]. Expression of TMPRSS2, an important serine protease needed for viral entry into the host, is also evident in primordial germ cells and the acrosomal region of developing spermatogonia [ 6 , 7 ]. Finally as per the human protein atlas, neuropilin-1 (NRP-1) is expressed in Leydig cells and seminal vesicles.…”

“…Hence, organs expressing these entry factors are at greater risk of COVID-19 mediated pathology and organ dysfunction. Studies have claimed the expression of these entry-factors in gonads and other accessory reproductive organs [ 6 , 7 ]. Therefore, it is possible that this virus might be able to invade reproductive organs and disrupt the reproductive health of infected individuals.…”

Discovery of potent thrombin inhibitors from a protease-focused DNA-encoded chemical library

“…Proteases also play important roles in reproduction, and several serine proteases and serine protease-like proteins are essential for normal fertility and therefore could be unique targets for nonhormonal male contraception (i.e., a male pill). For example, among the proteins essential for male fertility are the following: TMPRSS12, a testis-specific transmembrane serine protease required for sperm motility and uterotubal junction migration ( 21 ) and structurally similar to TMPRSS2; serine protease 55 (PRSS55), a glycosylphosphatidylinositol-anchored testis-specific serine protease that is necessary for sperm uterotubal junction migration and sperm–oocyte binding ( 22 , 23 ); serine protease 37 (PRSS37), a testis-specific inactive serine protease-like protein required for sperm uterotubal junction migration and fertilization ( 24 ); and ovochymase 2 (OVCH2), an epididymis-specific secreted serine protease required for maturation of sperm ( 25 ). Thus, there are multiple healthcare areas that could benefit from advances in the production of unique protease-biased chemical matter for inhibiting this important target class.…”