The role of the septin family in spermiogenesis

Lin, Ying-Hung; Kuo, Yung Che; Chiang, Han-Sun; Kuo, Pao‐Lin

doi:10.4161/spmg.1.4.18326

Cited by 48 publications

(24 citation statements)

References 46 publications

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“…Using whole-testis explants, we confirmed that Lh preferentially upregulates the transcription of spermatid-specific genes (rsph1 and sept7a) possibly involved in the formation of the spermatozoan flagellum and the acquisition of motility (Schlecht et al 2004, Lin et al 2011 during stage I-II. The effect of Lh on testicular sept7a expression was steroid-independent, which is consistent with our previous findings showing that sept7a upregulation is mediated by direct activation of Lhcgrba in spermatids (Chauvigné et al 2014).…”

Section: Lh Directly Modulates the Expression Of Spermatozoan Differesupporting

confidence: 49%

Fsh and Lh direct conserved and specific pathways during flatfish semicystic spermatogenesis

Chauvigné

Zapater

Crespo

et al. 2014

Journal of Molecular Endocrinology

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The current view of the control of spermatogenesis by Fsh and Lh in non-mammalian vertebrates is largely based on studies carried out in teleosts with cystic and cyclic spermatogenesis. Much less is known concerning the specific actions of gonadotropins during semicystic germ cell development, a type of spermatogenesis in which germ cells are released into the tubular lumen where they transform into spermatozoa. In this study, using homologous gonadotropins and a candidate gene approach, for which the genes' testicular cell-type-specific expression was established, we investigated the regulatory effects of Fsh and Lh on gene expression during spermatogenesis in Senegalese sole (Solea senegalensis), a flatfish with asynchronous and semicystic germ cell development. During early spermatogenesis, Fsh and Lh upregulated steroidogenesis-related genes and nuclear steroid receptors, expressed in both somatic and germ cells, through steroid-dependent pathways, although Lh preferentially stimulated the expression of downstream genes involved in androgen and progestin syntheses. In addition, Lh specifically promoted the expression of spermatid-specific genes encoding spermatozoan flagellar proteins through direct interaction with the Lh receptor in these cells. Interestingly, at this spermatogenic stage, Fsh primarily regulated genes encoding Sertoli cell growth factors with potentially antagonistic effects on germ cell proliferation and differentiation through steroid mediation. During late spermatogenesis, fewer genes were regulated by Fsh or Lh, which was associated with a translational and posttranslational downregulation of the Fsh receptor in different testicular compartments. These results reveal that conserved and specialized gonadotropic pathways regulate semicystic spermatogenesis in flatfish, which may spatially adjust cell germ development to maintain a continuous reservoir of spermatids in the testis.

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Section: Lh Directly Modulates the Expression Of Spermatozoan Differesupporting

confidence: 49%

Fsh and Lh direct conserved and specific pathways during flatfish semicystic spermatogenesis

Chauvigné

Zapater

Crespo

et al. 2014

Journal of Molecular Endocrinology

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“…The rLh-stimulated spermatid differentiation was also repressed by both ACT and cycloheximide, suggesting that rLh-promoted de novo protein synthesis is required during the spermatid-to-spermatozoa transition. This hypothesis was further tested by real-time quantitative RT-PCR (qRT-PCR) of rsph1, as well as of septin 7a (sept7a) and outer dense fiber of sperm tails 2-like (odf2l), which are potentially involved in spermatozoa flagellum formation and motility (25,26), and cullin 3 (cull3), a component of the ubiquitin ligase complex necessary for caspase activation in spermatids (27). The rLh induced an approximately three-to fourfold increase in the expression of the four genes in the SLL cells, which was prevented in the presence of MDL or H-89 (Fig.…”

Section: Lh Promotes Spermatid Differentiation To Spermatozoa In Vitromentioning

confidence: 99%

Germ-line activation of the luteinizing hormone receptor directly drives spermiogenesis in a nonmammalian vertebrate

Chauvigné

Zapater

Gasol

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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In both mammals and teleosts, the differentiation of postmeiotic spermatids to spermatozoa (spermiogenesis) is thought to be indirectly controlled by the luteinizing hormone (LH) acting through the LH/choriogonadotropin receptor (LHCGR) to stimulate androgen secretion in the interstitial Leydig cells. However, a more direct, nonsteroidal role of LH mediating the spermiogenic pathway remains unclear. Using a flatfish with semicystic spermatogenesis, in which spermatids are released into the seminiferous lobule lumen (SLL), where they develop into spermatozoa without direct contact with the supporting Sertoli cells, we show that haploid spermatids express the homolog of the tetrapod LHCGR (Lhcgrba). Both native Lh and intramuscularly injected His-tagged recombinant Lh (rLh) are immunodetected bound to the Lhcgrba of free spermatids in the SLL, showing that circulating gonadotropin can reach the intratubular compartment. In vitro incubation of flatfish spermatids isolated from the SLL with rLh specifically promotes their differentiation into spermatozoa, whereas recombinant follicle-stimulating hormone and steroid hormones are ineffective. Using a repertoire of molecular markers and inhibitors, we find that the Lh-Lhcgrba induction of spermiogenesis is mediated through a cAMP/PKA signaling pathway that initiates the transcription of genes potentially involved in the function of spermatozoa. We further show that Lhcgrba expression in germ cells also occurs in distantly related fishes, suggesting this feature is likely conserved in teleosts regardless of the type of germ cell development. These data reveal a role of LH in vertebrate germ cells, whereby a Lhcgrbaactivated signaling cascade in haploid spermatids directs gene expression and the progression of spermiogenesis.reproduction | testis | fertility C urrent models of vertebrate spermatogenesis highlight the role of gonadotropins on the somatic Sertoli and Leydig cells as the major mediators of germ cell development through the secretion of steroid hormones and growth factors (1). The gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) exert their actions on spermatogenesis by binding to the FSH receptor (FSHR) in Sertoli cells and the LH/choriogonadotropin receptor (LHCGR) in Leydig cells, respectively (1). In mammals, FSH regulates Sertoli cell functions in the seminiferous tubules, whereas the LHCGR mediates the actions of LH on Leydig cell steroidogenesis and the production of the androgen testosterone (T) to sustain germ cell development and the final differentiation of haploid spermatids to spermatozoa (spermiogenesis) (1). In contrast, in teleost fish, both Fsh and Lh are potent steroidogenic hormones acting through the expression of the Fshr and Lhcgr in Leydig cells (2-4), which results in the production of estrogens, androgens, and progestins that control the different stages of spermatogenesis (5-8).Studies in mammals indicate that LH is crucial for fertility; in LHCGR and ligand knockout mice, serum T levels are reduced and ...

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“…Septin4 (Sept4) is a member of Septin family and may be involved in apoptosis, vesicle trafficking and other cell processes [6,7]. It has been reported that the expression of Sept4 alters in the disease courses of Parkinson's disease, acute lymphoblastic leukemia (ALL), spermatogenesis and hepatic fibrosis [8][9][10][11]. Using the Sept4 −/− mice, Iwaisako et al found that loss of Sept4 could aggravate the collagen deposition [11].…”

Section: Introductionmentioning

confidence: 97%

Adenovirus-mediated over-expression of Septin4 ameliorates hepatic fibrosis in mouse livers infected with Schistosoma japonicum

Bao

Chen

et al. 2015

Parasitology International

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The role of the septin family in spermiogenesis

Cited by 48 publications

References 46 publications

Fsh and Lh direct conserved and specific pathways during flatfish semicystic spermatogenesis

Fsh and Lh direct conserved and specific pathways during flatfish semicystic spermatogenesis

Germ-line activation of the luteinizing hormone receptor directly drives spermiogenesis in a nonmammalian vertebrate

Adenovirus-mediated over-expression of Septin4 ameliorates hepatic fibrosis in mouse livers infected with Schistosoma japonicum

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