Project description:To elucidate the role(s) of WNT/CTNNB1 signaling in the testis, transgenic Ctnnb1 tm1Mmt/+;Amhr2 tm3(cre)Bhr/+ mice were generated to obtain sustained activation of the WNT/CTNNB1 pathway in Sertoli cells. Male Ctnnb1 tm1Mmt/+;Amhr2 tm3(cre)Bhr/+ mice were sterile because of testicular atrophy starting at 5 wk of age, associated with degeneration of seminiferous tubules and the progressive loss of germ cells. Sustained WNT/CTNNB1 pathway activation was obtained in Ctnnb1 tm1Mmt/+;Amhr2 tm3(cre)Bhr/+ Sertoli cells. Sertoli cells often exhibited morphological characteristics suggestive of incomplete differentiation that appeared in a manner coincident with germ cell loss, accompanied by an increase in the expression of the immature Sertoli cell marker AMH. Microarray analyses performed on cultured Sertoli cells showed that CTNNB1 induces the expression of genes associated with the female sex determination pathway as well as cell-cycle associated genes . Together, these data suggest that the WNT/CTNNB1 pathway regulates Sertoli cell functions critical to their capacity to support spermatogenesis and to proliferate in the postnatal testis.
Project description:To elucidate the role(s) of WNT/CTNNB1 signaling in the testis, transgenic Ctnnb1 tm1Mmt/+;Amhr2 tm3(cre)Bhr/+ mice were generated to obtain sustained activation of the WNT/CTNNB1 pathway in Sertoli cells. Male Ctnnb1 tm1Mmt/+;Amhr2 tm3(cre)Bhr/+ mice were sterile because of testicular atrophy starting at 5 wk of age, associated with degeneration of seminiferous tubules and the progressive loss of germ cells. Sustained WNT/CTNNB1 pathway activation was obtained in Ctnnb1 tm1Mmt/+;Amhr2 tm3(cre)Bhr/+ Sertoli cells. Sertoli cells often exhibited morphological characteristics suggestive of incomplete differentiation that appeared in a manner coincident with germ cell loss, accompanied by an increase in the expression of the immature Sertoli cell marker AMH. Microarray analyses performed on cultured Sertoli cells showed that CTNNB1 induces the expression of genes associated with the female sex determination pathway as well as cell-cycle associated genes . Together, these data suggest that the WNT/CTNNB1 pathway regulates Sertoli cell functions critical to their capacity to support spermatogenesis and to proliferate in the postnatal testis. Sertoli cells were obtained from 3wks-old Ctnnb1(tm1Mmt/tm1Mmt) mice. Cells were infected with adenoviruses to express eGFP or Cre in serum-free medium, and subsequently harvested for RNA extraction. Preliminary experiments demonstrated that an infection efficiency of nearly 100% could be obtained at an MOI of 50 (as determined by analysis of fluorescent signal in Ad-eGFP-infected cells) and that the Ad-Cre virus produced complete recombination of the floxed Ctnnb1 allele after 12 hours. Microaaray analyses were done using triplicate RNA samples from each adenoviral treatment using MouseRef-6 v.2.0 expression BeadChips technology (Illumina, San Diego, CA).
Project description:<p>Sertoli cell-only syndrome is severe form of human male infertility in which most seminiferous tubules appear to lack all spermatogenic cells, including spermatogonial stem cells (SSCs). However, a few small tubule segments of some patients have active spermatogenesis and, thus, functional stem cell niches and SSCs. Normally SSCs replicate, migrate and refill adjacent empty niches, but this does not appear to occur in SCO syndrome. We hypothesized that this failure occurs because most niches are dysfunctional. As Sertoli cells are essential to formation of these niches, we used RNAseq to compare the transcriptomes of human testes with qualitatively normal (complete) spermatogenesis (n=4) with the transcriptomes of human testes with SCO syndrome (n=7). We then focused our analysis on the expression of transcripts that bioinformatic analyses identified as Sertoli cell signature transcripts. Results show that Sertoli cells in SCO testes express abnormally low levels of GDNF, FGF8 and BMP4, all of which are important regulators of mouse SSCs and/or progenitor spermatogonia. Sertoli cells in SCO testes express significantly reduced levels of transcripts for proteins that polarize the Sertoli cell plasma membrane and regulate the trafficking of cell adhesion and gap junction proteins in and out of that plasma membrane.</p>
Project description:A core evolutionary function of the p53 family is to protect the genomic integrity of gametes. However, the role of p73 in the male germline is unknown. Here we uncover that TAp73 unexpectedly functions as adhesion and maturation factor of the seminiferous epithelium orchestrating spermiogenesis. TAp73KO and p73KO mice, but not ΔNp73KO mice, display a ‘near-empty seminiferous tubule’ phenotype due to massive premature loss of immature germ cells. Its cellular basis are defective cell-cell adhesions of developing germ cells to Sertoli nurse cells, with secondary degeneration of Sertoli cells including the blood-testis-barrier, thereby disrupting the adhesive integrity and maturation of the germ epithelium. At the molecular level, TAp73, produced in germ cells, controls a coordinated transcriptional program of adhesion- and migration-related proteins including peptidase inhibitors, proteases, receptors and integrins required for germ-Sertoli cell adhesion and dynamic junctional restructuring. Thus, the testis emerges as unique organ with strict division of labor among all family members: p63 and p53 safeguard germline fidelity, while TAp73 ensures fertility by enabling sperm maturation.
Project description:A core evolutionary function of the p53 family is to protect the genomic integrity of gametes. However, the role of p73 in the male germline is unknown. Here we uncover that TAp73 unexpectedly functions as adhesion and maturation factor of the seminiferous epithelium orchestrating spermiogenesis. TAp73KO and p73KO mice, but not ΔNp73KO mice, display a ‘near-empty seminiferous tubule’ phenotype due to massive premature loss of immature germ cells. Its cellular basis are defective cell-cell adhesions of developing germ cells to Sertoli nurse cells, with secondary degeneration of Sertoli cells including the blood-testis-barrier, thereby disrupting the adhesive integrity and maturation of the germ epithelium. At the molecular level, TAp73, produced in germ cells, controls a coordinated transcriptional program of adhesion- and migration-related proteins including peptidase inhibitors, proteases, receptors and integrins required for germ-Sertoli cell adhesion and dynamic junctional restructuring. Thus, the testis emerges as unique organ with strict division of labor among all family members: p63 and p53 safeguard germline fidelity, while TAp73 ensures fertility by enabling sperm maturation.
Project description:To identifiy stage-dependent genes in Sertoli cells, we performed expression microarray analysis of the adult whole testes, cultured primary Sertoli cells, Sertoli cells directly isolated from wild-type and Nanos3 (germ-less) testes,seminiferous tubules at stages I-III, IV-VI, VII-VIII and IX-XII. Next to examine the relationship between stage-dependent gene expression change and retinoic acid signaling, we performed expression microarray analysis of the cultured primary Sertoli cells treated with retinoic acid and stage-specific seminiferous tubules injected with lentivirus containing Venus or dominat negative form of RARa, a dominant receptor for retinoic acid in Sertoli cells. Biological duplicates were examined at each sample
Project description:Stable activation of the WNT signaling effector beta-catenin (CTNNB1(ex3) in ovarian granulosa cells results in the formation of premalignant lesions that develop into granulosa cell tumors (GCTs) spontaneously later in life. Loss of the tumor suppressor gene Pten accelerates GCT formation in the CTNNB1 strain. Conversely, expression of oncogenic KRASG12D causes the dramatic arrest of proliferation, differentiation and apoptosis in granulosa cells, and consequently, small abnormal follicle-like structures devoid of oocytes accumulate in the ovary. Because of the potent anti-proliferative effects of KRASG12D in granulosa cells, we sought to determine if KRASG12D would block precancerous lesion and tumor formation in follicles of the CTNNB1 mutant mice. Unexpectedly, transgenic Ctnnb1;Kras mutant mice developed early-onset GCTs leading to premature death in a manner similar to theCtnnb1;Pten mutant mice. Moreover, the GCTs in the Ctnnb1;Kras mutant mice exhibited increased GC proliferation, decreased apoptosis and impaired differentiation. Microarray and RT-PCR analyses revealed that ovaries from mice expressing dominant-stable CTNNB1 with either Pten loss or KRAS activation were unpredictably similar. Specifically, gene regulatory processes induced by CTNNB1 were mostly enhanced by either KRAS activation or Pten loss in remarkably similar patterns and degree. Furthermore, the concomitant activation of CTNNB1 and KRAS in Sertoli cells resulted in the development of granulosa cell tumors of the testis. RT-PCR studies showed a partial overlap in gene regulatory processes associated with tumor development in the ovary and testis. Together, these results suggest that KRAS activation and Pten loss induce GCT development from premalignant lesions via highly similar molecular mechanisms. four samples: average of two wild type samples (previously submitted as GSM403220 and GSM403221), beta-Catenin constitutively active mutant, beta-Catenin;Pten double mutant, and beta-Catenin;Kras(G12D) double mutant
Project description:To identifiy stage-dependent genes in Sertoli cells, we performed expression microarray analysis of the adult whole testes, cultured primary Sertoli cells, Sertoli cells directly isolated from wild-type and Nanos3 (germ-less) testes,seminiferous tubules at stages I-III, IV-VI, VII-VIII and IX-XII. Next to examine the relationship between stage-dependent gene expression change and retinoic acid signaling, we performed expression microarray analysis of the cultured primary Sertoli cells treated with retinoic acid and stage-specific seminiferous tubules injected with lentivirus containing Venus or dominat negative form of RARa, a dominant receptor for retinoic acid in Sertoli cells.
Project description:Sry is sufficient to induce testis formation and subsequent male development of internal and external genitalia in chromosomally female mice and humans. In XX sex-reversed males such as XX/Sry-transgenic (XX/Sry) mice, however, testicular germ cells always disappear soon after birth due to germ cell autonomous defects. Therefore, it remains unclear whether or not Sry alone is sufficient to induce a fully functional testicular soma capable of supporting complete spermatogenesis in the XX body. Here we demonstrated that the testicular somatic environment of XX/Sry males is defective in the later phases of spermatogenesis. Spermatogonial transplantation analyses using XX/Sry male mice revealed that donor XY spermatogonia are capable of proliferating, entering meiosis and differentiating into the round spermatid stage. XY donor-derived round spermatids, however, were frequently detached from the XX/Sry seminiferous epithelia and underwent cell death, thereby preventing further progress beyond the elongated spermatid stage. In contrast, immature XY seminiferous tubule segments transplanted under XX/Sry testis capsules clearly displayed proper differentiation into elongated spermatids in the transplanted XY donor tubules. Microarray analysis of seminiferous tubules isolated from XX/Sry testes confirmed missing expression of several Y-linked genes and alterations in the expression profile of genes associated with spermatogenesis. Therefore, our findings indicate dysfunction of the somatic tubule components, probably Sertoli cells, of XX/Sry testes, supporting our hypothesis that Sry alone is insufficient to induce a fully functional Sertoli cell in XX mice. Experiment Overall Design: Whole testes and seminiferous tubules of XX/Sry and W/Wv males were used for microarray expression analysis using the Affymetrix GeneChip system (Affymetrix, CA). In order to isolate the seminiferous tubules, the tunica was carefully removed from the testes which were then incubated in the medium with 5 mg/ml collagnease at 37oC for 40 min. The remaining seminiferous tubules were washed several times with PBS using a 70-ºm cell strainer to remove interstitial cells. After total RNA was extracted using a RNeasy Mini Kit (Qiagen, Germantown, MD), double-stranded cDNA and biotin-labeled cRNA were synthesized using One-Cycle cDNA Synthesis and IVT Labeling kits (Affymetrix, CA), respectively. Twenty micrograms of fragmented biotin-labeled cRNA was hybridized to the Affymetrix Mouse Expression Array MOE 430A for 16 hr at 45oC. The chips were washed, stained, and then scanned with the GeneArray Scanner (Hewlett Packard, CA) in accordance with the manufacturer's standard protocols. Finally, the microarray data were analyzed using Microarray Suite ver. 5.0 (Affymetrix). Differential expression was defined as a difference of 2-fold or more in both whole testis and seminiferous tubule samples between two recipient males. Mouse 430A Affymetrix Genome Array IDs were used to query the NetAffx data mining tool for gene annotations.
Project description:Stable activation of the WNT signaling effector beta-catenin (CTNNB1(ex3) in ovarian granulosa cells results in the formation of premalignant lesions that develop into granulosa cell tumors (GCTs) spontaneously later in life. Loss of the tumor suppressor gene Pten accelerates GCT formation in the CTNNB1 strain. Conversely, expression of oncogenic KRASG12D causes the dramatic arrest of proliferation, differentiation and apoptosis in granulosa cells, and consequently, small abnormal follicle-like structures devoid of oocytes accumulate in the ovary. Because of the potent anti-proliferative effects of KRASG12D in granulosa cells, we sought to determine if KRASG12D would block precancerous lesion and tumor formation in follicles of the CTNNB1 mutant mice. Unexpectedly, transgenic Ctnnb1;Kras mutant mice developed early-onset GCTs leading to premature death in a manner similar to theCtnnb1;Pten mutant mice. Moreover, the GCTs in the Ctnnb1;Kras mutant mice exhibited increased GC proliferation, decreased apoptosis and impaired differentiation. Microarray and RT-PCR analyses revealed that ovaries from mice expressing dominant-stable CTNNB1 with either Pten loss or KRAS activation were unpredictably similar. Specifically, gene regulatory processes induced by CTNNB1 were mostly enhanced by either KRAS activation or Pten loss in remarkably similar patterns and degree. Furthermore, the concomitant activation of CTNNB1 and KRAS in Sertoli cells resulted in the development of granulosa cell tumors of the testis. RT-PCR studies showed a partial overlap in gene regulatory processes associated with tumor development in the ovary and testis. Together, these results suggest that KRAS activation and Pten loss induce GCT development from premalignant lesions via highly similar molecular mechanisms.