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ObjectiveTesticular germ cell tumours (TGCT) are the most common cancer in men of working age and its incidence has increased notably over the past 40 years. Several occupations have been identified as potentially associated with TGCT risk. The aim of this study was to further explore the relationship between occupations, industries and TGCT risk in men aged 18–45 years.MethodsThe TESTIS study is a multicenter case–control study conducted between January 2015 and April 2018 in 20 of 23 university hospital centers in metropolitan France. A total of 454 TGCT cases and 670 controls were included. Full job histories were collected. Occupations were coded according to the International Standard Classification of Occupation 1968 version (ISCO-1968) and industry according to the 1999 version of Nomenclature d’Activités Française (NAF-1999). For each job held, ORs and 95% CIs were estimated using conditional logistic regression.ResultsA positive association was observed between TGCT and occupation as agricultural, animal husbandry worker (ISCO: 6–2; OR 1.71; 95% CI (1.02 to 2.82)), as well as salesman (ISCO: 4–51; OR 1.84; 95% CI (1.20 to 2.82)). An increased risk was further observed among electrical fitters and related, electrical and electronics workers employed for 2 years or more (ISCO: 8–5; OR≥2 years1.83; 95% CI (1.01 to 3.32)). Analyses by industry supported these findings.ConclusionsOur findings suggest that agricultural, electrical and electronics workers, and salesmen workers experience an increased risk of TGCT. Further research is needed to identify the agents or chemicals in these high-risk occupations which are relevant in the TGCT development.Trial registration numberNCT02109926.

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PURPOSE: The purpose of this study was to identify mutations that cause non-syndromic male infertility using whole exome sequencing of family cases. METHODS: We recruited a consanguineous Turkish family comprising nine siblings with male triplets; two of the triplets were infertile as well as one younger infertile brother. Whole exome sequencing (WES) performed on two azoospermic brothers identified a mutation in the melanoma antigen family B4 (MAGEB4) gene which was confirmed via Sanger sequencing and then screened for on control groups and unrelated infertile subjects. The effect of the mutation on messenger RNA (mRNA) and protein levels was tested after in vitro cell transfection. Structural features of MAGEB4 were predicted throughout the conserved MAGE domain. RESULTS: The novel single-base substitution (c.1041A>T) in the X-linked MAGEB4 gene was identified as a no-stop mutation. The mutation is predicted to add 24 amino acids to the C-terminus of MAGEB4. Our functional studies were unable to detect any effect either on mRNA stability, intracellular localization of the protein, or the ability to homodimerize/heterodimerize with other MAGE proteins. We thus hypothesize that these additional amino acids may affect the proper protein interactions with MAGEB4 partners. CONCLUSION: The whole exome analysis of a consanguineous Turkish family revealed MAGEB4 as a possible new X-linked cause of inherited male infertility. This study provides the first clue to the physiological function of a MAGE protein. journal article 2017 May 2017 04 11 imported

Gametes are generated through a specialized cell differentiation process, meiosis which, in most mammals, is initiated in ovaries during fetal life. It is widely admitted that all-transretinoic acid (ATRA) is the molecular signal triggering meiosis initiation in mouse female germ cells, but a genetic approach in which ATRA synthesis is impaired disputes this proposal. In the present study, we investigated the contribution of endogenous ATRA to meiosis by analyzing fetuses lacking all RARs ubiquitously, obtained through a tamoxifen-inducible cre recombinase-mediated gene targeting approach. Efficient ablation of RAR-coding genes was assessed by the multiple congenital abnormalities displayed by the mutant fetuses. Unexpectedly, their germ cells robustly expressed STRA8, REC8, SYCP1 and SYCP3, showing that RAR are actually dispensable up to the zygotene stage of meiotic prophase I. Thus our study goes against the current model according to which meiosis is triggered by endogenous ATRA in the developing ovary and revives the identification of the meiosis-preventing substance synthesized by CYP26B1 in the fetal testis.

Background Sterility is a major late effect of radiotherapy and chemotherapy treatments. Iatrogenic sterility is often permanent and greatly impacts long-term quality of life. Ovarian tissue cryopreservation (OTC) performed before gonadotoxic treatments with subsequent autograft is a method of fertility preservation available for girls and women. Its application in prepubertal girls is of particular value as it is the only possible approach in this patient group. In addition, it does not require a delay in cancer therapy and no ovarian stimulation is needed. Objective The primary aim of this protocol is to help increase the implementation of ovarian tissue autografting in France. Knowledge is still lacking regarding the efficacy of ovarian transplantation in restoring ovarian function and regarding the safety of this procedure, especially the risk of cancer cell reseeding in certain types of cancer. A secondary aim of this study is to generate data to improve our understanding of these two essential aspects. Methods The DATOR (Development of Ovarian Tissue Autograft in Order to Restore Ovarian Function) study is ongoing in 17 university hospitals. The DATOR protocol includes the autograft of ovarian cortex fragments. Candidates are identified from an observational prospective cohort (called the Prospective Cohort of Patients Candidates for Ovarian Tissue Autograft [PERIDATOR]) of patients who have undergone OTC. Enrollment in the study is initiated at the patient’s request and must be validated by the center’s multidisciplinary team and by the study steering committee. The DATOR study begins with a total medical checkup. Ovarian tissue qualification and residual disease detection, if required, are performed. Results The study is ongoing. Currently, 38 patients have provided informed consent and have been entered into the DATOR study. Graft has been performed for 34 of these patients. An interim analysis was conducted on the first 25 patients for whom the period of at least 1 year posttransplantation was achieved. Out of these 25 patients, 11 women succeeded in becoming pregnant (pregnancy rate=44% [11/25]; delivery rate=40% [10/25]). Among these, 6 women conceived twice, and 1 pregnancy led to a miscarriage. Conclusions Our preliminary analysis appears to be coherent with the accumulating body of evidence indicating the potential utility of ovarian tissue autograft for patients with premature ovarian failure. All these elements justify the pursuit of our study. Trial Registration ClinicalTrials.gov NCT02846064; https://clinicaltrials.gov/ct2/show/NCT02846064 International Registered Report Identifier (IRRID) DERR1-10.2196/12944

Study Objective To describe a laparoscopic technique for the transplantation of a cryopreserved ovarian cortex. Design Educational video. Setting University Hospital of Strasbourg, France. Interventions A 28-year-old nulliparous woman presented with anaplastic T lymphoma and was then treated with chemotherapy. Before the treatment, the ovarian cortex was collected by laparoscopy to preserve fertility. Remission was achieved, but the patient suffered from premature ovarian failure. At the age of 32 years, she wished to become pregnant. The patient was thus included in the research protocol Development of Ovarian Tissue Autograft in Order to Restore Ovarian Function, and the transplantation site was chosen accordingly. The cortex was stored in liquid nitrogen at ˗196°C after slow congelation. To restore ovarian function and because of pregnancy desire, we transplanted the cryopreserved ovarian cortex in the right ovary and inside a pocket of the peritoneum of the left ovarian fossa. The first step included adhesiolysis to treat small adhesions developed after the first surgery. On the right, the ovarian cortex was opened by an antimesial incision with cold scissors. The cryopreserved ovarian cortex was placed through the cortex of the right ovary and fixed with stitches. On the left side, the peritoneum of the ovarian fossa was opened, and a subperitoneal pocket was dissected. The cortex was inserted. It was then closed with absorbable sutures or with a hemostatic pad. Six months after her surgery, the patient had natural cycles. We monitored an ovulation of both the sides. She underwent 3 in vitro fertilizations but with failures of embryo transfer. She conceived spontaneously a year after the surgery. She gave birth to a healthy child weighing 3300 g. Conclusion For patients who have suffered from premature ovarian failure owing to chemotherapy, ovarian cortex transplantation can restore the ovulatory function, allow in vitro fertilization, and permit, as in our case, a spontaneous pregnancy.

Research question: Is luteal phase stimulation capable of improving fertility preservation? Materials and methods: We performed a retrospective cohort study of consecutive ovarian stimulations, during July 2012 and September 2018 at Strasbourg University Teaching Hospital in France. Enrollment criteria were patients aged below 40 who had been referred to our center following a diagnosis of cancer or requiring gonadotoxic treatment. All patients enrolled had regular menstrual cycles and normal ovulation. Non-enrollment criteria were an expected low ovarian response (defined by an anti-Müllerian hormone (AMH) level

In mammals, all-trans retinoic acid (ATRA) is instrumental to spermatogenesis. It is synthesized by two retinaldehyde dehydrogenases (RALDH) present in both Sertoli cells (SCs) and germ cells (GCs). In order to determine the relative contributions of each source of ATRA, we have generated mice lacking all RALDH activities in the seminiferous epithelium (SE). We show that both the SC- and GC-derived sources of ATRA cooperate to initiate and propagate spermatogenetic waves at puberty. In adults, they exert redundant functions and, against all expectations, the GC-derived source does not perform any specific roles despite contributing to two-thirds of the total amount of ATRA present in the testis. The production from SCs is sufficient to maintain the periodic expression of genes in SCs, as well and the cycle and wave of the SE, which account for the steady production of spermatozoa. The production from SCs is also specifically required for spermiation. Importantly, our study shows that spermatogonia differentiation depends upon the ATRA synthesized by RALDH inside the SE, whereas initiation of meiosis and expression of STRA8 by spermatocytes can occur without ATRA., Summary: All-trans retinoic acid made by Sertoli cells is instrumental to spermatogenesis and is specifically required for spermatid release.

All-trans retinoic acid (atRA), the active metabolite of vitamin A, plays critical functions in spermatogenesis, a complex, highly organized and regulated process comprising three phases. During the proliferative phase, undifferentiated spermatogonia divide to maintain a stem cell population and expand a progenitor cell population, of which a fraction enters the differentiation pathway yielding primary spermatocytes. During the meiotic phase, primary spermatocytes undergo recombination, segregation and reduction by half of chromosomes to produce haploid round spermatids. During the morphogenetic, post-meiotic phase, spermatids differentiate and elongate to ultimately form spermatozoa. Studies performed during the past 20 years have significantly improved our knowledge on the location of the proteins transducing the atRA signal, on the target genes of atRA and on its mechanism of action. This article is part of a Special Issue entitled: Nuclear receptors in animal development.

The modalities of gametogenesis differ markedly between sexes. Female are born with a definitive reserve of oocytes whose size is crucial to ensure fertility. Male fertility, in contrast, relies on a tightly regulated balance between germ cell self-renewal and differentiation, which operates throughout life, according to recurring spatial and temporal patterns. Genetic and pharmacological studies conducted in the mouse and discussed in this review have revealed that all-trans retinoic acid and its nuclear receptors are major players of gametogenesis and are instrumental to fertility in both sexes.

The modalities of gametogenesis differ markedly between sexes. Female are born with a definitive reserve of oocytes whose size is crucial to ensure fertility. Male fertility, in contrast, relies on a tightly regulated balance between germ cell self-renewal and differentiation, which operates throughout life, according to recurring spatial and temporal patterns. Genetic and pharmacological studies conducted in the mouse and discussed in this review have revealed that all-trans retinoic acid and its nuclear receptors are major players of gametogenesis and are instrumental to fertility in both sexes.

Tex19 genes are mammalian specific and duplicated to give Tex19.1 and Tex19.2 in some species, such as the mouse and rat. It has been demonstrated that mutant Tex19.1 males display a variable degree of infertility whereas they all upregulate MMERVK10C transposons in their germ line. In order to study the function of both paralogs in the mouse, we generated and studied Tex19 double knockout (Tex19DKO) mutant mice. Adult Tex19DKO males exhibited a fully penetrant phenotype, similar to the most severe phenotype observed in the single Tex19.1KO mice, with small testes and impaired spermatogenesis, defects in meiotic chromosome synapsis, persistence of DNA double-strand breaks during meiosis, lack of post-meiotic germ cells and upregulation of MMERVK10C expression. The phenotypic similarities to mice with knockouts in the Piwi family genes prompted us to check and then demonstrate, by immunoprecipitation and GST pulldown followed by mass spectrometry analyses, that TEX19 paralogs interact with PIWI proteins and the TEX19 VPTEL domain directly binds Piwi-interacting RNAs (piRNAs) in adult testes. We therefore identified two new members of the postnatal piRNA pathway.

Background Genetically induced hepatocellular carcinoma (HCC) models are generally used to investigate carcinogenesis pathways, but very few attempts were made to valorize them for pharmacological testing. This study describes a micro-computed tomography (micro-CT) - based methodology for the diagnostic and lifelong follow-up of HCC in the hepatocyte-specific Trim24-null mouse line. Myo-inositol trispyrophosphate (ITPP) was tested as anti-cancer drug. Methods Partial hepatectomy was performed in 2 months-old Trim24-null mice, in order to accelerate the carcinogenesis process. HCC diagnosis was obtained by micro-CT scan with double contrast agent: 10 μl/g Fenestra™ LC was injected intraperitoneally 6 h prior to imaging and 10 μl/g Fenestra™ VC was injected intravenously 15 min prior to imaging. Twenty three hepatocyte-specific Trim24-null mice were considered for ITPP testing (3 mg/g/week intraperitoneally during 10 months in 12 mice, versus 11 controls). Lifelong follow-up was performed using micro-CT. Comparative analysis was performed using unpaired t test with Welch correction and survival curves were compared by log-rank test. Gene expression analysis was performed using the RT q-PCR technique. Results Double contrast micro-CT scan allowed HCC diagnosis as hypodense, isodense or hyperdense nodules. Positive predictive value was 81.3 %. Negative predictive value was 83.3 %. Tumor growth could be objectified by micro-CT scan before the ITPP treatment was started, and at 3 and 9 months follow-up. Significant progression of tumor volume was demonstrated in the both groups, with no difference between groups (p > 0.05). In the ITPP group, a mild decrease in tumor doubling time was first observed (31.9 +/− 12 days, p > 0.05) followed by a significant increase (59.8 +/− 18.3 days, p = 0.008). However, tumor doubling time was not different between groups (p > 0.05). Median survival after treatment initiation was 223 days (controls) versus 296 days (ITPP group, p = 0.0027). HIF1α, VEGF, glutamine synthase, osteopontin expression levels were not significantly modified at the end of follow-up. In the ITPP group, the p53 expression profile was inversed as compared to the control group, higher in non-tumor livers than in tumors. Conclusion ITPP treatment allowed for a two-month survival improvement, with better tolerance of tumor burden and apoptosis increase in non-tumor, pathological livers. Electronic supplementary material The online version of this article (doi:10.1186/s13046-016-0434-8) contains supplementary material, which is available to authorized users.

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BACKGROUND/AIM: Recognition of the limitations of liver biopsies has led to the need for non-invasive tests to assess liver fibrosis from intensity and kinetic point of views. The aim of the present study was to evaluate non-invasive ultrasonic tissue characterization for the continuous monitoring of this process in mice. METHODS: Twelve-week-old male and female C57Bl6/J mice were submitted to repetitive carbon-tetrachloride (CCl4) intraperitoneal injections during 8 weeks or analysed 28 days after common bile duct ligation (BDL). The extent and kinetic of the disease progression were followed by the measurement of ultrasound backscatter intensity. This was compared with histological and blood parameter analysis. RESULTS: CCl4 induced a progressive increase in in vivo liver tissue backscatter intensity in both males and females. This increase was mainly correlated with interstitial fibrosis and, to a lower extent, with nuclear surface of the hepatocytes. A similar result was found after BDL. CONCLUSIONS: These data demonstrate for the first time in a systematic study that ultrasound tissue characterization can be used as a reliable tool to follow liver remodelling in mice continuously.

Infertility is a global healthcare problem, and despite long years of assisted reproductive activities, a significant number of cases remain idiopathic. Our currently restricted understanding of basic mechanisms driving human gametogenesis severely limits the improvement of clinical care for infertile patients. Using exome sequencing, we identified a nonsense mutation leading to a premature stop in the TEX15 locus (c.2130T>G, p.Y710*) in a consanguineous Turkish family comprising eight siblings in which three brothers were identified as infertile. TEX15 displays testis-specific expression, maps to chromosome 8, contains four exons and encodes a 2789-amino acid protein with uncertain function. The mutation, which should lead to early translational termination at the first exon of TEX15, co-segregated with the infertility phenotype, and our data strongly suggest that it is the cause of spermatogenic defects in the family. All three affected brothers presented a phenotype reminiscent of the one observed in KO mice. Indeed, previously reported results demonstrated that disruption of the orthologous gene in mice caused a drastic reduction in testis size and meiotic arrest in the first wave of spermatogenesis in males while female KO mice were fertile. The data from our study of one Turkish family suggested that the identified mutation correlates with a decrease in sperm count over time. A diagnostic test identifying the mutation in man could provide an indication of spermatogenic failure and prompt patients to undertake sperm cryopreservation at an early age.

All-trans retinoic acid (ATRA) is instrumental to male germ cell differentiation, but its mechanism of action remains elusive. To address this question, we have analyzed the phenotypes of mice lacking, in spermatogonia, all rexinoid receptors (RXRA, RXRB and RXRG) or all ATRA receptors (RARA, RARB and RARG). We demonstrate that the combined ablation of RXRA and RXRB in spermatogonia recapitulates the set of defects observed both upon ablation of RAR in spermatogonia. We also show that ATRA activates RAR and RXR bound to a conserved regulatory region to increase expression of the SALL4A transcription factor in spermatogonia. Our results reveal that this major pluripotency gene is a target of ATRA signaling and that RAR/RXR heterodimers are the functional units driving its expression in spermatogonia. They add to the mechanisms through which ATRA promote expression of the KIT tyrosine kinase receptor to trigger a critical step in spermatogonia differentiation. Importantly, they indicate also that meiosis eventually occurs in the absence of a RAR/RXR pathway within germ cells and suggest that instructing this process is either ATRA-independent or requires an ATRA signal originating from Sertoli cells., Author Summary Differentiation of spermatozoa from immature germ cells, called spermatogonia, critically depends on retinoic acid (ATRA), the active metabolite of vitamin A that acts though binding to nuclear receptors called RXR and RAR. To understand the mechanism by which ATRA control germ cell differentiation, we generated mice simultaneously lacking all RXR or all RAR specifically in spermatogonia. From their phenotypic analysis, we demonstrate that meiosis does not require a RAR/RXR-dependent pathway in germ cells and propose that this process is either ATRA-independent or requires an ATRA signal originating from somatic cells. We also show that RXR, in the form of dimers with RAR, can drive spermatogonia differentiation through binding to a regulatory region located in the Sall4 gene. This finding is significant, as the transcription factor encoded by Sall4 is known to regulate the expression of KIT, a key tyrosine kinase receptor which is frequently deregulated in testicular cancer.

To investigate the role of retinoid X receptors (RXRs) in epidermal homeostasis, we generated RXRαβ ep-/- somatic mutants in which both RXRα and RXRβ are selectively ablated in epidermal keratinocytes of adult mice. These mice develop a chronic dermatitis mimicking that observed in atopic dermatitis (AD) patients. In addition, they exhibit immunological abnormalities including elevated serum levels of IgE and IgG, associated with blood and tissue eosinophilia, indicating that keratinocyte-selective ablation of RXRs also generates a systemic syndrome similar to that found in AD patients. Furthermore, the profile of increased expression of cytokines and chemokines in skin of keratinocyte-selective RXRαβ-ablated mutants was typical of a T helper 2-type inflammation, known to be crucially involved in human AD pathogenesis. Finally, we demonstrate that thymic stromal lymphopoietin, whose expression is rapidly and strongly induced in RXRαβ-ablated keratinocytes, plays a key role in initiating the skin and systemic AD-like pathologies.

The advent of human induced pluripotent stem cells (hiPSC) is revolutionizing many research fields including cell-replacement therapy, drug screening, physiopathology of specific diseases and more basic research such as embryonic development or diseases modeling. Despite the large number of reports on reprogramming methods, techniques in use remain globally inefficient. We present here a new optimized approach to improve this efficiency. After having tested different monocistronic vectors with poor results, we adopted a polycistronic cassette encoding Thomson's cocktail OCT4, NANOG, SOX2 and LIN28 (ONSL) separated by 2A peptides. This cassette was tested in various vector backbones, based on lentivirus or retrovirus under a LTR or EF1 alpha promoter. This allowed us to show that ONSL-carrier retrovectors re- programmed adult fibroblast cells with a much higher efficiency (up to 0.6%) than any other tested. We then compared the reprogramming ef- ficiencies of two different polycistronic genes, ONSL and OCT4, SOX2, KLF4 and cMYC (OSKM) placed in the same retrovector backbone. Interestingly, in this context ONSL gene reprograms more efficiently than OSKM but OSKM reprograms faster suggesting that the two cocktails may reprogram through distinct pathways. By equally mixing RV-LTR-ONSL and RV-LTR-OSKM, we indeed observed a remarkable synergy, yielding a reprogramming efficiency of .2%. We present here a drastic improvement of the reprogramming efficiency, which opens doors to the development of automated and high throughput strategies of hiPSC production. Furthermore, non-integrative reprogramming protocols (i.e. mRNA) may take advantage of this synergy to boost their efficiency.

Friedreich's ataxia (FRDA) is a recessive neurodegenerative disorder commonly associated with hypertrophic cardiomyopathy. FRDA is due to expanded GAA repeats within the first intron of the gene encoding frataxin, a conserved mitochondrial protein involved in iron-sulphur cluster biosynthesis. This mutation leads to partial gene silencing and substantial reduction of the frataxin level. To overcome limitations of current cellular models of FRDA, we derived induced pluripotent stem cells (iPSCs) from two FRDA patients and successfully differentiated them into neurons and cardiomyocytes, two affected cell types in FRDA. All FRDA iPSC lines displayed expanded GAA alleles prone to high instability and decreased levels of frataxin, but no biochemical phenotype was observed. Interestingly, both FRDA iPSC-derived neurons and cardiomyocytes exhibited signs of impaired mitochondrial function, with decreased mitochondrial membrane potential and progressive mitochondrial degeneration, respectively. Our data show for the first time that FRDA iPSCs and their neuronal and cardiac derivatives represent promising models for the study of mitochondrial damage and GAA expansion instability in FRDA., Journal Article, SCOPUS: ar.j, info:eu-repo/semantics/published

STUDY QUESTION What is the consequence of Tex19.1 gene deletion in mice? SUMMARY ANSWER The Tex19.1 gene is important in spermatogenesis and placenta-supported development. WHAT IS KNOWN ALREADY Tex19.1 is expressed in embryonic stem (ES) cells, primordial germ cells (PGCs), placenta and adult gonads. Its invalidation in mice leads to a variable impairment in spermatogenesis and reduction of perinatal survival. STUDY DESIGN, SIZE, DURATION We generated knock-out mice and ES cells and compared them with wild-type counterparts. The phenotype of the Tex19.1 knock-out mouse line was investigated during embryogenesis, fetal development and placentation as well as during adulthood. PARTICIPANTS/MATERIALS, SETTING, METHODS We used a mouse model system to generate a mutant mouse line in which the Tex19.1 gene was deleted in the germline. We performed an extensive analysis of Tex19.1-deficient ES cells and assessed their in vivo differentiation potential by generating chimeric mice after injection of the ES cells into wild-type blastocysts. For mutant animals, a morphological characterization was performed for testes and ovaries and placenta. Finally, we characterized semen parameters of mutant animals and performed real-time RT-PCR for expression levels of retrotransposons in mutant testes and ES cells. MAIN RESULTS AND THE ROLE OF CHANCE While Tex19.1 is not essential in ES cells, our study points out that it is important for spermatogenesis and for placenta-supported development. Furthermore, we observed an overexpression of the class II LTR-retrotransposon MMERVK10C in Tex19.1-deficient ES cells and testes. LIMITATIONS, REASONS FOR CAUTION The Tex19.1 knock-out phenotype is variable with testis morphology ranging from severely altered (in sterile males) to almost indistinguishable compared with the control counterparts (in fertile males). This variability in the testis phenotype subsequently hampered the molecular analysis of mutant testes. Furthermore, these results were obtained in the mouse, which has a second isoform (i.e. Tex19.2), while other mammals possess only one Tex19 (e.g. in humans). WIDER IMPLICATIONS OF THE FINDINGS The fact that one gene has a role in both placentation and spermatogenesis might open new ways of studying human pathologies that might link male fertility impairment and placenta-related pregnancy disorders. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Centre National de la Recherche Scientifique (CNRS), the Institut National de la Sante et de la Recherche Medicale (INSERM) (Grant Avenir), the Ministere de l'Education Nationale, de l'Enseignement Superieur et de la Recherche, the Universite de Strasbourg, the Association Francaise contre les Myopathies (AFM) and the Fondation pour la Recherche Medicale (FRM) and Hopitaux Universitaires de Strasbourg.The authors have nothing to disclose.

TRIM24 (TIF1α), TRIM28 (TIF1β), and TRIM33 (TIF1γ) are three related cofactors belonging to the tripartite motif superfamily that interact with distinct transcription factors. TRIM24 interacts with the liganded retinoic acid (RA) receptor to repress its transcriptional activity. Germ line inactivation of TRIM24 in mice deregulates RA-signaling in hepatocytes leading to the development of hepatocellular carcinoma (HCC). Here we show that TRIM24 can be purified as at least two macromolecular complexes comprising either TRIM33 or TRIM33 and TRIM28. Somatic hepatocyte-specific inactivation of TRIM24, TRIM28, or TRIM33 all promote HCC in a cell-autonomous manner in mice. Moreover, HCC formation upon TRIM24 inactivation is strongly potentiated by further loss of TRIM33. These results demonstrate that the TIF1-related subfamily of TRIM proteins interact both physically and functionally to modulate HCC formation in mice.

Studies of prostate cancer pathogenesis and development of new therapies have been hampered by a lack of appropriate mouse models. We have generated PSA-Cre-ER T2 mice that express the tamoxifen-dependent Cre-ER T2 recombinase selectively in prostatic epithelium, thus allowing us to target floxed genes selectively in epithelial cells of fully differentiated prostate of adult mice and to modulate the number of genetically altered cells. Our present mouse model, in which prostate carcinogenesis is initiated through Cre-ER T2 -mediated somatic biallelic ablation of the tumor suppressor gene PTEN after puberty, closely mimics the course of human cancer formation. Indeed, mutant mice developed prostate epithelium hyperplasia within 4 weeks after PTEN ablation and prostatic intraepithelial neoplasia (PIN) in all lobes within 2–3 months, with the highest incidence in the dorsolateral lobe, which is considered to be the most similar to the peripheral zone of the human prostate, in which adenocarcinoma is preferentially localized. Eight to 10 months after PTEN ablation some PINs of the dorsolateral lobe had progressed to adenocarcinoma, but no distant metastases were found up to 20 months after PTEN ablation, indicating that progression to metastasis requires an additional mutation or mutations. Interestingly, monoallelic Cre-ER T2 -mediated PTEN ablation in epithelial cells of adult prostate also generated focal hyperplasia and PINs, but exclusively in the dorsolateral lobe, and in much lower number and after a longer latency. However, no progression to adenocarcinoma was observed. Because PTEN expression was undetectable in epithelial cells from these PINs, loss of PTEN function appears to act as a permissive event for uncontrolled cell proliferation.

Calcification of arteries is a major risk factor for cardiovascular mortality in humans. Using genetic approaches, we demonstrate here that the transcriptional intermediary factor 1α (TIF1α), recently shown to function as a tumor suppressor in murine hepatocytes, also participates in a molecular cascade that prevents calcifications in arterioles and medium-sized arteries. We further provide genetic evidence that this function of TIF1α is not exerted in hepatocytes. The sites of ectopic calcifications in mutant mice lacking TIF1α resemble those seen in mice carrying an activating mutation of the calcium sensor receptor ( Casr ) gene and, in TIF1 α-deficient kidneys, Casr expression is increased together with that of many other vitamin D receptor (VDR) direct target genes, namely Car2 , Cyp24a1 , Trpv5 , Trpv6 , Calb1 , S100g , Pthlh , and Spp1 . Thus, our data indicate that TIF1α represses the VDR pathway in kidney and suggest that an up-regulation of Casr expression in this organ could account for ectopic calcifications generated upon TIF1 α deficiency. Interestingly, the calcifying arteriopathy of TIF1 α-null mutant mice shares features with the human age-related Mönckeberg's disease and, overall, the TIF1 α-null mutant pathological phenotype supports the hypothesis that aging is promoted by increased activity of the vitamin D signaling pathway.

Hepatocellular carcinoma (HCC) is a major cause of death worldwide. Here, we provide evidence that the ligand-dependent nuclear receptor co-regulator Trim24 (also known as Tif1alpha) functions in mice as a liver-specific tumor suppressor. In Trim24-null mice, hepatocytes fail to execute proper cell cycle withdrawal during the neonatal-to-adult transition and continue to cycle in adult livers, becoming prone to a continuum of cellular alterations that progress toward metastatic HCC. Using pharmacological approaches, we show that inhibition of retinoic acid signaling markedly reduces hepatocyte proliferation in Trim24-/- mice. We further show that deletion of a single retinoic acid receptor alpha (Rara) allele in a Trim24-null background suppresses HCC development and restores wild-type expression of retinoic acid-responsive genes in the liver, thus demonstrating that in this genetic background Rara expresses an oncogenic activity correlating with a dysregulation of the retinoic acid signaling pathway. Our results not only provide genetic evidence that Trim24 and Rara co-regulate hepatocarcinogenesis in an antagonistic manner but also suggest that aberrant activation of Rara is deleterious to liver homeostasis.

TIF1 (transcriptional intermediary factor 1) proteins are encoded by an expanding family of developmental and physiological control genes that are conserved from flies to man. These proteins are characterized by an N-terminal RING-B box-coiled-coil (RBCC) motif and a C-terminal PHD finger/bromodomain unit, and have been implicated in epigenetic mechanisms of transcriptional repression involving histone modifiers and heterochromatin-binding proteins. We describe here the isolation and functional characterization of a fourth murine TIF1 gene, TIF1delta. The predicted TIF1delta protein displays all the structural hallmarks of a bona fide TIF1 family member and resembles the other TIF1s in that it can exert a deacetylase-dependent silencing effect when tethered to a promoter region. Moreover, like TIF1alpha and TIF1beta, TIF1delta can homodimerize and contains a PXVXL motif necessary and sufficient for HP1 (heterochromatin protein 1) binding. Although TIF1alpha and TIF1beta also bind nuclear receptors and Kruppel-associated boxes specifically and respectively, TIF1delta appears to lack nuclear receptor- and Kruppel-associated box binding activity. Furthermore, TIF1delta is unique among the TIF1 family proteins in that its expression is largely restricted to the testis and confined to haploid elongating spermatids, where it associates preferentially with HP1 isotype gamma (HP1gamma) and forms discrete foci dispersed within the centromeric chromocenter and the surrounding nucleoplasm. Collectively, these data are consistent with specific, nonredundant functions for the TIF1 family members in vivo and suggest a role for TIF1delta in heterochromatin-mediated gene silencing during postmeiotic phases of spermatogenesis.

In this unit, a procedure for post-mortem examination of mice and tissue collection is provided. This procedure is performed for post-mortem analysis of anatomical defects (necropsy) and histological analysis and/or tissue collection destined for molecular biology applications. In both cases, tissue preservation is the major issue, but the way to achieve it depends on the objective. When histological analysis is the aim, tissue preservation is achieved by rapid transfer into fixative solutions. In contrast, molecular biology applications require rapid freezing of tissue samples to preserve mRNA integrity. Consequently, performing both procedures simultaneously may be at the expense of the final product quality.

Functional oocytes are produced in the complete absence of retinoic acid receptors., Gametes are generated through a specialized cell differentiation process, meiosis, which, in ovaries of most mammals, is initiated during fetal life. All-trans retinoic acid (ATRA) is considered as the molecular signal triggering meiosis initiation. In the present study, we analyzed female fetuses ubiquitously lacking all ATRA nuclear receptors (RAR), obtained through a tamoxifen-inducible cre recombinase-mediated gene targeting approach. Unexpectedly, mutant oocytes robustly expressed meiotic genes, including the meiotic gatekeeper STRA8. In addition, ovaries from mutant fetuses grafted into adult recipient females yielded offspring bearing null alleles for all Rar genes. Thus, our results show that RAR are fully dispensable for meiotic initiation, as well as for the production of functional oocytes. Assuming that the effects of ATRA all rely on RAR, our study goes against the current model according to which meiosis is triggered by endogenous ATRA in the developing ovary. It therefore revives the search for the meiosis-inducing substance.

L’obésité est un fléau qui touche de plus en plus de personnes à travers le monde. Parallèlement, on constate, depuis plusieurs décennies, une baisse de la qualité du sperme chez l’homme. Nous avons donc tenté ici de mettre en relation ces deux phénomènes. Pour cela, nous avons réalisé une étude rétrospective, en deux temps, sur une cohorte de patients du Centre Médico-Chirurgical Obstétrique des Hôpitaux Universitaires de Strasbourg. Nous avons tout d’abord observé les résultats des spermogrammes des patients en fonction de leur IMC puis dans un second temps, nous avons analysé les issues des tentatives, en insémination intra utérine et en fécondation in vitro, en fonction de l’IMC de l’homme. Nous obtenons des modifications significatives du spermogramme pour certains paramètres, comme le volume de l’éjaculat et la numération en spermatozoïdes, alors que d’autres ne sont pas touchés par l’obésité. Pour les issues des tentatives en AMP, l’IMC de l’homme ne modifie pas les taux de réussite. Ces résultats suggèrent que l’obésité a un impact sur la fonction de reproduction masculine, mais que des études supplémentaires, avec des examens complémentaires, comme un bilan hormonal ou la mesure du taux de fragmentation de l’ADN spermatique, mériteraient d’être réalisées afin de mieux comprendre les mécanismes qui interviennent.

L’infertilité est un problème de santé public ayant un impact mondial. La prévalence de l’infertilité est estimée à environ 10%. Les origines sont autant féminines que masculines. On estime la fréquence de l’azoospermie, parmi les hommes infertiles, à 5%. La seule technique d’assistance médicale à la procréation permettant à ces hommes de mener à bien leur projet parental est l’injection intracytoplasmique de spermatozoïde d’origine testiculaire (ICSI (BT)). L’objectif de cette thèse est de calculer quel pourcentage de chance ont ces hommes d’obtenir une naissance s’ils sont pris en charge au CMCO, et le constat est très rassurant à partir du moment ou un spermatozoïde mobile est retrouvé les chances de paternité sont aussi élevées que pour les patients ayant recours aux autres techniques d’AMP comme la FIV classique ou l’ICSI utilisant un spermatozoïde éjaculé.