RESUMO
OBJECTIVES: The congenital diaphragmatic hernia (CDH), characterized by malformation of the diaphragm and lung hypoplasia, is a common and severe birth defect that affects around 1 in 4000 live births. However, the etiology of most cases of CDH remains unclear. The aim of this study was to perform a retrospective analysis of copy number variations (CNVs) using a high-resolution array comparative genomic hybridization (array-CGH) in a cohort of fetuses and newborns with CDH. METHODS: Forty seven fetuses and newborns with either isolated or syndromic CDH were analyzed by oligonucleotide-based array-CGH Agilent 180K technique. RESULTS: A mean of 10.2 CNVs was detected by proband with a total number of 480 CNVs identified based on five categories: benign, likely benign, of uncertain signification, likely pathogenic, and pathogenic. Diagnostic performance was estimated at 19.15% (i.e., likely pathogenic and pathogenic CNVs) for both CDH types. We identified 11 potential candidate genes: COL25A1, DSEL, EYA1, FLNA, MECOM, NRXN1, RARB, SPATA13, TJP2, XIRP2, and ZFPM2. CONCLUSION: We suggest that COL25A1, DSEL, EYA1, FLNA, MECOM, NRXN1, RARB, SPATA13, TJP2, XIRP2, and ZFPM2 genes may be related to CDH occurrence. Thus, this study provides a possibility for new methods of a positive diagnosis.
Assuntos
Hérnias Diafragmáticas Congênitas , Recém-Nascido , Humanos , Hérnias Diafragmáticas Congênitas/genética , Variações do Número de Cópias de DNA , Hibridização Genômica Comparativa/métodos , Estudos Retrospectivos , Feto , Fatores de Transcrição/genéticaRESUMO
Filamin A (FLNa) links the cell membrane with the cytoskeleton and is central in several cellular processes. Heterozygous mutations in the X-linked FLNA gene are associated with a large spectrum of conditions, including macrothrombocytopenia, called filaminopathies. Using an isogenic pluripotent stem cell model derived from patients, we show that the absence of the FLNa protein in megakaryocytes (MKs) leads to their incomplete maturation, particularly the inability to produce proplatelets. Reduction in proplatelet formation potential is associated with a defect in actomyosin contractility, which results from inappropriate RhoA activation. This dysregulated RhoA activation was observed when MKs were plated on fibrinogen but not on other matrices (fibronectin, vitronectin, collagen 1, and von Willebrand factor), strongly suggesting a role for FLNa/αIIbß3 interaction in the downregulation of RhoA activity. This was confirmed by experiments based on the overexpression of FLNa mutants deleted in the αIIbß3-binding domain and the RhoA-interacting domain, respectively. Finally, pharmacological inhibition of the RhoA-associated kinase ROCK1/2 restored a normal phenotype and proplatelet formation. Overall, this work suggests a new etiology for macrothrombocytopenia, in which increased RhoA activity is associated with disrupted FLNa/αIIbß3 interaction.
Assuntos
Filaminas/metabolismo , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Trombocitopenia/etiologia , Feminino , Fibrinogênio/metabolismo , Filaminas/genética , Humanos , Megacariócitos/química , Megacariócitos/patologia , Mutação , Ligação Proteica/fisiologia , Quinases Associadas a rho/antagonistas & inibidores , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
RESEARCH QUESTION: Chromosomal translocations are known genetic causes of male infertility. Are certain translocations or chromosomal regions more directly associated with sperm defects? Is there a threshold of sperm impairment that can be relevant for detection of translocations? DESIGN: This is a monocentric retrospective observational study covering a 10-year period. Eighty-one patients carrying a reciprocal translocation (RCT) and 63 carrying a Robertsonian translocation (ROBT) were compared with 105 fertile patients. Semen quality before and after sperm migration was compared. The aims were to define whether a threshold based on sperm analysis could be proposed for detection of translocations and to identify whether some redundant chromosomal regions might be associated with sperm quality defects. RESULTS: The number of progressive spermatozoa retrieved after sperm preparation (NPS-ASP) was altered in both RCT and ROBT carriers compared with controls, with a stronger alteration in ROBT. Based on the NPS-ASP results in this large group of translocation carriers, a relatively robust threshold, fixed at less than 5 million, may be proposed for detection of translocations. The alteration of NPS-ASP was independent of the chromosome involved in ROBT, while in RCT, four redundant chromosomal regions (1q21, 6p21, 16q21, 17q11.2) were associated with poor or very poor NPS-ASP. CONCLUSIONS: The NPS-ASP appears to be a good parameter to assess sperm function and would be a useful tool to detect chromosomal translocations. Four redundant regions have been identified on four chromosomes, suggesting that they may contain genes of interest to study sperm functions.
Assuntos
Aberrações Cromossômicas , Motilidade dos Espermatozoides/genética , Espermatozoides , Translocação Genética , Adulto , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Masculino , Estudos Retrospectivos , Análise do Sêmen , Contagem de EspermatozoidesRESUMO
OBJECTIVES: Congenital heart defects (CHDs) may be isolated or associated with other malformations. The use of chromosome microarray (CMA) can increase the genetic diagnostic yield for CHDs by between 4% and 10%. The objective of this study was to evaluate the value of CMA after the prenatal diagnosis of an isolated CHD. METHODS: In a retrospective, nationwide study performed in France, we collected data on all cases of isolated CHD that had been explored using CMAs in 2015. RESULTS: A total of 239 fetuses were included and 33 copy number variations (CNVs) were reported; 19 were considered to be pathogenic, six were variants of unknown significance, and eight were benign variants. The anomaly detection rate was 10.4% overall but ranged from 0% to 16.7% as a function of the isolated CHD in question. The known CNVs were 22q11.21 deletions (n = 10), 22q11.21 duplications (n = 2), 8p23 deletions (n = 2), an Alagille syndrome (n = 1), and a Kleefstra syndrome (n = 1). CONCLUSION: The additional diagnostic yield was clinically significant (3.1%), even when anomalies in the 22q11.21 region were not taken into account. Hence, patients with a suspected isolated CHD and a normal karyotype must be screened for chromosome anomalies other than 22q11.21 duplications and deletions.
Assuntos
Testes Genéticos/métodos , Cardiopatias Congênitas/genética , Análise em Microsséries/métodos , Diagnóstico Pré-Natal/métodos , Adulto , Aberrações Cromossômicas , Cromossomos/química , Cromossomos/genética , Hibridização Genômica Comparativa/métodos , Variações do Número de Cópias de DNA , Feminino , Feto/química , Feto/metabolismo , França , Cardiopatias Congênitas/diagnóstico , Humanos , Cariotipagem , Gravidez , Estudos Retrospectivos , SíndromeRESUMO
Manganese Superoxide dismutase 2 (SOD2) plays a crucial role in antioxidant defense but there are no data suggesting its role in genetic instability in CML. We evaluated the effects of SOD2 silencing in human UT7 cell line expressing either non-mutated or T315I-mutated BCR-ABL. Array-CGH experiments detected in BCR-ABL-expressing cells silenced for SOD2 a major genetic instability within several chromosomal loci, especially in regions carrying the glypican family (duplicated) and ß-defensin genes (deleted). In a large cohort of patients with chronic myeloid leukemia (CML), a significant decrease of SOD2 mRNA was observed. This reduction appeared inversely correlated with leukocytosis and Sokal score, high-risk patients showing lower SOD2 levels. The analysis of anti-oxidant gene expression analysis revealed a specific down-regulation of the expression of PRDX2 in UT7-BCR-ABL and UT7-T315I cells silenced for SOD2 expression. Gene set enrichment analysis performed between the two SOD2-dependent classes of CML patients revealed a significant enrichment of Reactive Oxygen Species (ROS) Pathway. Our data provide the first evidence for a link between SOD2 expression and genetic instability in CML. Consequently, SOD2 mRNA levels should be analyzed in prospective studies as patients with low SOD2 expression could be more prone to develop a mutator phenotype under TKI therapies.
Assuntos
Proteínas de Fusão bcr-abl/genética , Regulação Leucêmica da Expressão Gênica , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Superóxido Dismutase/genética , Linhagem Celular Tumoral , Estudos de Coortes , Inativação Gênica , Humanos , Mutação , Peroxirredoxinas/genética , Mutação PuntualRESUMO
To explore how RUNX1 mutations predispose to leukemia, we generated induced pluripotent stem cells (iPSCs) from 2 pedigrees with germline RUNX1 mutations. The first, carrying a missense R174Q mutation, which acts as a dominant-negative mutant, is associated with thrombocytopenia and leukemia, and the second, carrying a monoallelic gene deletion inducing a haploinsufficiency, presents only as thrombocytopenia. Hematopoietic differentiation of these iPSC clones demonstrated profound defects in erythropoiesis and megakaryopoiesis and deregulated expression of RUNX1 targets. iPSC clones from patients with the R174Q mutation specifically generated an increased amount of granulomonocytes, a phenotype reproduced by an 80% RUNX1 knockdown in the H9 human embryonic stem cell line, and a genomic instability. This phenotype, found only with a lower dosage of RUNX1, may account for development of leukemia in patients. Altogether, RUNX1 dosage could explain the differential phenotype according to RUNX1 mutations, with a haploinsufficiency leading to thrombocytopenia alone in a majority of cases whereas a more complete gene deletion predisposes to leukemia.
Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Hematopoese , Leucemia/genética , Mutação , Trombocitopenia/genética , Linhagem Celular , Células Cultivadas , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Deleção de Genes , Predisposição Genética para Doença , Instabilidade Genômica , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Leucemia/metabolismo , Leucemia/patologia , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Trombocitopenia/metabolismo , Trombocitopenia/patologiaRESUMO
BACKGROUND: Monochorionic twins are generally considered as a monozygotic twin pregnancy. However, several cases of monochorial dizygotic twin pregnancies have been reported. CASE REPORT: We report on a rare case of monochorionic dizygotic twin pregnancy conceived after induced ovulation in a 32-year-old woman. The diagnosis was made on morphological ultrasound examination at 18+4 weeks of gestation, showing two fetuses with discordant sex. The amniocentesis was declined by the patient. RESULTS: The monochorionic status was confirmed after a histopathalogical study of the placenta. At delivery, both a phenotypically normal boy and a phenotypically normal girl without sexual abnormality were observed. This analysis also revealed the presence of vascular anastomoses between both fetal circulations. Postnatal cytogenetic analyses indicated the presence of a chimerism in peripheral blood lymphocytes. This chimerism was not observed in cells obtained from a buccal swab. Molecular determination of zygosity confirmed the existence of the confined peripheral blood chimerism with the presence of four parental alleles. CONCLUSION: We report on a case of monochorionic dizygotic twin pregnancy. This observation underlies the need to carefully assess twin pregnancies, especially when obtained after assisted reproductive technology.
Assuntos
Quimerismo , Gêmeos Dizigóticos , Adulto , Feminino , Humanos , Masculino , Indução da Ovulação , GravidezRESUMO
AIMS: Comparative studies suggest that stem cells committed to a cardiac lineage are more effective for improving heart function than those featuring an extra-cardiac phenotype. We have therefore developed a population of human embryonic stem cell (ESC)-derived cardiac progenitor cells. METHODS AND RESULTS: Undifferentiated human ESCs (I6 line) were amplified and cardiac-committed by exposure to bone morphogenetic protein-2 and a fibroblast growth factor receptor inhibitor. Cells responding to these cardio-instructive cues express the cardiac transcription factor Isl-1 and the stage-specific embryonic antigen SSEA-1 which was then used to purify them by immunomagnetic sorting. The Isl-1(+) SSEA-1(+) cells were then embedded into a fibrin scaffold which was surgically delivered onto the infarct area in a 68-year-old patient suffering from severe heart failure [New York Heart Association [NYHA] functional Class III; left ventricular ejection fraction (LVEF): 26%]. A coronary artery bypass was performed concomitantly in a non-infarcted area. The implanted cells featured a high degree of purity (99% were SSEA-1(+)), had lost the expression of Sox-2 and Nanog, taken as markers for pluripotency, and strongly expressed Isl-1. The intraoperative delivery of the patch was expeditious. The post-operative course was uncomplicated either. After 3 months, the patient is symptomatically improved (NYHA functional Class I; LVEF: 36%) and a new-onset contractility is echocardiographically evident in the previously akinetic cell/patch-treated, non-revascularized area. There have been no complications such as arrhythmias, tumour formation, or immunosuppression-related adverse events. CONCLUSION: This observation demonstrates the feasibility of generating a clinical-grade population of human ESC-derived cardiac progenitors and combining it within a tissue-engineered construct. While any conclusion pertaining to efficacy would be meaningless, the patient's functional outcome yet provides an encouraging hint. Beyond this case, the platform that has been set could be useful for generating different ESC-derived lineage-specific progenies.
Assuntos
Insuficiência Cardíaca/terapia , Células-Tronco Embrionárias Humanas/transplante , Feminino , Humanos , Pessoa de Meia-Idade , Isquemia Miocárdica/terapia , Alicerces Teciduais , Resultado do Tratamento , Disfunção Ventricular Esquerda/terapiaRESUMO
AIM: There is now compelling evidence that cells committed to a cardiac lineage are most effective for improving the function of infarcted hearts. This has been confirmed by our pre-clinical studies entailing transplantation of human embryonic stem cell (hESC)-derived cardiac progenitors in rat and non-human primate models of myocardial infarction. These data have paved the way for a translational programme aimed at a phase I clinical trial. METHODS AND RESULTS: The main steps of this programme have included (i) the expansion of a clone of pluripotent hESC to generate a master cell bank under good manufacturing practice conditions (GMP); (ii) a growth factor-induced cardiac specification; (iii) the purification of committed cells by immunomagnetic sorting to yield a stage-specific embryonic antigen (SSEA)-1-positive cell population strongly expressing the early cardiac transcription factor Isl-1; (iv) the incorporation of these cells into a fibrin scaffold; (v) a safety assessment focused on the loss of teratoma-forming cells by in vitro (transcriptomics) and in vivo (cell injections in immunodeficient mice) measurements; (vi) an extensive cytogenetic and viral testing; and (vii) the characterization of the final cell product and its release criteria. The data collected throughout this process have led to approval by the French regulatory authorities for a first-in-man clinical trial of transplantation of these SSEA-1(+) progenitors in patients with severely impaired cardiac function. CONCLUSION: Although several facets of this manufacturing process still need to be improved, these data may yet provide a useful platform for the production of hESC-derived cardiac progenitor cells under safe and cost-effective GMP conditions.
Assuntos
Células-Tronco Embrionárias Humanas/transplante , Separação Imunomagnética/métodos , Bancos de Tecidos/organização & administração , Animais , Terapia Baseada em Transplante de Células e Tecidos/métodos , Ensaios Clínicos Fase I como Assunto , Análise Citogenética , Estudos de Avaliação como Assunto , Humanos , Camundongos SCID , Miócitos Cardíacos/citologia , Miócitos Cardíacos/transplante , Preservação de Tecido/métodos , Alicerces TeciduaisRESUMO
Small supernumerary marker chromosomes (sSMC) are structurally abnormal chromosomes that cannot be unambiguously identified by banding cytogenetics. The objective of this study was to provide an overview of sSMC frequency and characterization in a context of infertility and to review the literature describing sSMC in relation with male and female infertility. Therefore, a systematic literature review on sSMC associated with infertility was conducted by means of a PubMed literature and a sSMC database (http://ssmc-tl.com/sSMC.html) search. A total of 234 patients with infertility were identified as carriers of sSMC. All chromosomes, except chromosomes 10, 19 and the X, were involved in sSMC, and in 72% the sSMC originated from acrocentric chromosomes. Euchromatic imbalances were caused by the presence of sSMC in 30% of the cases. Putative genes have been identified in only 1.2% of sSMC associated with infertility. The implication of sSMC in infertility could be due to a partial trisomy of some genes but also to mechanical effects perturbing meiosis. Further precise molecular and interphase-architecture studies on sSMC are needed in the future to characterize the relationship between this chromosomal anomaly and human infertility.
Assuntos
Aberrações Cromossômicas , Transtornos Cromossômicos/genética , Infertilidade Feminina/genética , Infertilidade Masculina/genética , Adulto , Feminino , Predisposição Genética para Doença , Humanos , Padrões de Herança , MasculinoRESUMO
Results obtained in various species, from mammals to invertebrates, show that arrest in the cell cycle of mature oocytes is due to a high ERK activity. Apoptosis is stimulated in these oocytes if fertilization does not occur. Our previous data suggest that apoptosis of unfertilized sea urchin eggs is the consequence of an aberrant short attempt of development that occurs if ERK is inactivated. They contradict those obtained in starfish, another echinoderm, where inactivation of ERK delays apoptosis of aging mature oocytes that are nevertheless arrested at G1 of the cell cycle as in the sea urchin. This suggests that the cell death pathway that can be activated in unfertilized eggs is not the same in sea urchin and in starfish. In the present study, we find that protein synthesis is necessary for the survival of unfertilized sea urchin eggs, contrary to starfish. We also compare the effects induced by Emetine, an inhibitor of protein synthesis, with those triggered by Staurosporine, a non specific inhibitor of protein kinase that is widely used to induce apoptosis in many types of cells. Our results indicate that the unfertilized sea urchin egg contain different mechanisms capable of leading to apoptosis and that rely or not on changes in ERK activity, acidity of intracellular organelles or intracellular Ca and pH. We discuss the validity of some methods to investigate cell death such as measurements of caspase activation with the fluorescent caspase indicator FITC-VAD-fmk or acidification of intracellular organelles, methods that may lead to erroneous conclusions at least in the sea urchin model.
Assuntos
Apoptose/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Óvulo/citologia , Ouriços-do-Mar/citologia , Animais , Cálcio/metabolismo , Caspase 3/metabolismo , Emetina/farmacologia , Mitocôndrias/metabolismo , Óvulo/efeitos dos fármacos , Biossíntese de Proteínas , Inibidores de Proteínas Quinases/farmacologia , Inibidores da Síntese de Proteínas/farmacologia , Ouriços-do-Mar/fisiologia , Transdução de Sinais , Estaurosporina/farmacologiaRESUMO
IMPORTANCE: A paradoxical increase of growth hormone (GH) following oral glucose load has been described in â¼30% of patients with acromegaly and has been related to the ectopic expression of the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) in somatotropinomas. Recently, we identified germline pathogenic variants and somatic loss of heterozygosity of lysine demethylase 1A (KDM1A) in patients with GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome. The ectopic expression of GIPR in both adrenal and pituitary lesions suggests a common molecular mechanism. OBJECTIVE: We aimed to analyze KDM1A gene sequence and KDM1A and GIPR expressions in somatotroph pituitary adenomas. SETTINGS: We conducted a cohort study at university hospitals in France and in Italy. We collected pituitary adenoma specimens from acromegalic patients who had undergone pituitary surgery. We performed targeted exome sequencing (gene panel analysis) and array-comparative genomic hybridization on somatic DNA derived from adenomas and performed droplet digital PCR on adenoma samples to quantify KDM1A and GIPR expressions. RESULTS: One hundred and forty-six patients with sporadic acromegaly were studied; 72.6% presented unsuppressed classical GH response, whereas 27.4% displayed a paradoxical rise in GH after oral glucose load. We did not identify any pathogenic variant in the KDM1A gene in the adenomas of these patients. However, we identified a recurrent 1p deletion encompassing the KDM1A locus in 29 adenomas and observed a higher prevalence of paradoxical GH rise (P = .0166), lower KDM1A expression (4.47 ± 2.49 vs 8.56 ± 5.62, P < .0001), and higher GIPR expression (1.09 ± 0.92 vs 0.43 ± 0.51, P = .0012) in adenomas from patients with KDM1A haploinsufficiency compared with those with 2 KDM1A copies. CONCLUSIONS AND RELEVANCE: Unlike in GIP-dependent primary bilateral macronodular adrenal hyperplasia, KDM1A genetic variations are not the cause of GIPR expression in somatotroph pituitary adenomas. Recurrent KDM1A haploinsufficiency, more frequently observed in GIPR-expressing adenomas, could be responsible for decreased KDM1A function resulting in transcriptional derepression on the GIPR locus.
Assuntos
Acromegalia , Adenoma , Adenoma Hipofisário Secretor de Hormônio do Crescimento , Hormônio do Crescimento Humano , Neoplasias Hipofisárias , Somatotrofos , Humanos , Neoplasias Hipofisárias/patologia , Acromegalia/metabolismo , Somatotrofos/metabolismo , Somatotrofos/patologia , Hibridização Genômica Comparativa , Hiperplasia/patologia , Estudos de Coortes , Genótipo , Adenoma Hipofisário Secretor de Hormônio do Crescimento/metabolismo , Adenoma/patologia , Hormônio do Crescimento Humano/metabolismo , Hormônio do Crescimento/metabolismo , Glucose , Histona Desmetilases/genética , Histona Desmetilases/metabolismoRESUMO
In the past decade, the therapeutic value of mesenchymal stromal cells (MSCs) has been studied in various indications, thereby taking advantage of their immunosuppressive properties. Easy procurement from bone marrow, adipose tissue or other sources and conventional in vitro expansion culture have made their clinical use attractive. Bridging the gap between current scientific knowledge and regulatory prospects on the transformation potential and possible tumorigenicity of MSCs, the Cell Products Working Party and the Committee for Advanced Therapies organized a meeting with leading European experts in the field of MSCs. This meeting elucidated the risk of potential tumorigenicity related to MSC-based therapies from two angles: the scientific perspective and the regulatory point of view. The conclusions of this meeting, including the current regulatory thinking on quality, nonclinical and clinical aspects for MSCs, are presented in this review, leading to a clearer way forward for the development of such products.
Assuntos
Carcinogênese , Proliferação de Células , Transplante de Células-Tronco Mesenquimais/efeitos adversos , Células-Tronco Mesenquimais/citologia , Tecido Adiposo/citologia , Células da Medula Óssea/citologia , Técnicas de Cultura de Células , Diferenciação Celular/genética , Humanos , Células-Tronco Mesenquimais/metabolismoRESUMO
Early onset myopathies are a clinically and histologically heterogeneous monogenic diseases linked to approximately 90 genes. Molecular diagnosis is challenging, especially in patients with a mild phenotype. We describe a 26-year-old man with neonatal hypotonia, motor delay and seizures during infancy, and non-progressive, mild muscular weakness in adulthood. Serum Creatine kinase level was normal. Whole-body muscle MRI showed thin muscles, and brain MRI was unremarkable. A deltoid muscle biopsy showed glycogen storage. WGS revealed a de novo 1.4 Mb-deletion of chromosome 14, confirmed by Array-CGH. This microdeletion causes the loss of ten genes including RALGAPA1, encoding for RalA, a regulator of glucose transporter 4 (GLUT4) expression at the membrane of myofibers. GLUT4 was overexpressed in patient's muscle. Here we highlight the importance to search for chromosomal alterations in the diagnostic workup of early onset myopathies.
Assuntos
Glicogênio , Doenças Musculares , Masculino , Recém-Nascido , Humanos , Adulto , Cromossomos Humanos Par 14 , Doenças Musculares/genética , Hipotonia Muscular/genética , Fenótipo , Proteínas do Tecido Nervoso/genética , Proteínas Ativadoras de GTPase/genéticaRESUMO
BACKGROUND: Kallmann syndrome (KS) is a genetic disorder associating pubertal failure with congenitally absent or impaired sense of smell. KS is related to defective neuronal development affecting both the migration of olfactory nerve endings and GnRH neurons. The discovery of several genetic mutations responsible for KS led to the identification of signaling pathways involved in these processes, but the mutations so far identified account for only 30% of cases of KS. Here, we attempted to identify new genes responsible for KS by using a pan-genomic approach. METHODS: From a cohort of 120 KS patients, we selected 48 propositi with no mutations in known KS genes. They were analyzed by comparative genomic hybridization array, using Agilent 105K oligonucleotide chips with a mean resolution of 50 kb. RESULTS: One propositus was found to have a heterozygous deletion of 213 kb at locus 7q21.11, confirmed by real-time qPCR, deleting 11 of the 17 SEMA3A exons. This deletion cosegregated in the propositus' family with the KS phenotype, that was transmitted in autosomal dominant fashion and was not associated with other neurological or non-neurological clinical disorders. SEMA3A codes for semaphorin 3A, a protein that interacts with neuropilins. Mice lacking semaphorin 3A expression have been showed to have a Kallmann-like phenotype. CONCLUSIONS: SEMA3A is therefore a new gene whose loss-of-function is involved in KS. These findings validate the specific role of semaphorin 3A in the development of the olfactory system and in neuronal control of puberty in humans.
Assuntos
Deleção de Genes , Síndrome de Kallmann/genética , Semaforina-3A/genética , Feminino , Humanos , Masculino , Linhagem , Fenótipo , Puberdade/genética , Puberdade/fisiologia , Semaforina-3A/fisiologia , Olfato/genética , Olfato/fisiologiaRESUMO
Small supernumerary marker chromosome (sSMC) lacking alpha satellite DNA or endogenous centromere regions are rare and contain fully functional centromeres, called neocentromeres. We report on a woman with a 14-week gestation pregnancy with a cystic hygroma and cerebellar hypoplasia at ultrasound examination. Cytogenetic studies showed a karyotype 47,XY,+mar dn. This sSMC was observed in chorionic villi, lung, and muscle tissue. Array Comparative Genomic Hybridization showed a gain from 13q31.1 to 13qter region. Fluorescent in situ hybridization with pan alpha satellite probe and probes specific for chromosome 13 showed a marker corresponding to an inversion duplication of the 13q distal chromosomal region without alpha satellite DNA sequence, suggesting the presence of a neocentromere. Examination of the fetus showed dysmorphic features, cystic cervical hygroma, postaxial polydactyly of the right hand and left foot with short fingers, malrotation of the gut, and a micropenis with hypospadias. Genotype-phenotype correlation in tetrasomy 13q is discussed according to the four 13q chromosomal breakpoints reported (13q32, 13q31, 13q21, 13q14) for chromosome 13 supernumerary markers.
Assuntos
Anormalidades Múltiplas/genética , Inversão Cromossômica , Cromossomos Humanos Par 13/genética , Feto/anormalidades , Tetrassomia , Cerebelo/anormalidades , Bandeamento Cromossômico , Hibridização Genômica Comparativa , Feminino , Estudos de Associação Genética , Humanos , Hibridização in Situ Fluorescente , Cariótipo , Linfangioma Cístico , Masculino , Gravidez , Complicações na Gravidez/genética , Ultrassonografia Pré-NatalRESUMO
Despite increasing insight into the genetics of infertility, the developmental disease processes remain unclear due to the lack of adequate experimental models. The advent of induced pluripotent stem cell (iPSC) technology has provided a unique tool for in vitro disease modeling enabling major advances in our understanding of developmental disease processes. We report the full characterization of complex genetic abnormalities in two infertile patients with either azoospermia or XX male syndrome and we identify genes of potential interest implicated in their infertility. Using the erythroblasts of both patients, we generated primed iPSCs and converted them into a naive-like pluripotent state. Naive-iPSCs were then differentiated into primordial germ-like cells (PGC-LCs). The expression of early PGC marker genes SOX17, CD-38, NANOS3, c-KIT, TFAP2C, and D2-40, confirmed progression towards the early germline stage. Our results demonstrate that iPSCs from two infertile patients with significant genetic abnormalities are capable of efficient production of PGCs. Such in vitro model of infertility will certainly help identifying causative factors leading to early germ cells development failure and provide a valuable tool to explore novel therapeutic strategies.
Assuntos
Azoospermia , Células-Tronco Pluripotentes Induzidas , Azoospermia/genética , Azoospermia/metabolismo , Diferenciação Celular/genética , Eritroblastos , Células Germinativas/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , MasculinoRESUMO
Metformin is an insulin sensitizer molecule used for the treatment of infertility in women with polycystic ovary syndrome and insulin resistance. It modulates the reproductive axis, affecting the release of gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH). However, metformin's mechanism of action in pituitary gonadotropin-secreting cells remains unclear. Adenosine 5' monophosphate-activated protein kinase (PRKA) is involved in metformin action in various cell types. Here, we investigated the effects of metformin on gonadotropin secretion in response to activin and GnRH in primary rat pituitary cells (PRP), and studied PRKA in rat pituitary. In PRP, metformin (10 mM) reduced LH and follicle-stimulating hormone (FSH) secretion induced by GnRH (10(-8) M, 3 h), FSH secretion, and mRNA FSHbeta subunit expression induced by activin (10(-8) M, 12 or 24 h). The different subunits of PRKA are expressed in pituitary. In particular, PRKAA1 is detected mainly in gonadotrophs and thyrotrophs, is less abundant in lactotrophs and somatotrophs, and is undetectable in corticotrophs. In PRP, metformin increased phosphorylation of both PRKA and acetyl-CoA carboxylase. Metformin decreased activin-induced SMAD2 phosphorylation and GnRH-induced mitogen-activated protein kinase (MAPK) 3/1 (ERK1/2) phosphorylation. The PRKA inhibitor compound C abolished the effects of metformin on gonadotropin release induced by GnRH and on FSH secretion and Fshb mRNA induced by activin. The adenovirus-mediated production of dominant negative PRKA abolished the effects of metformin on the FSHbeta subunit mRNA and SMAD2 phosphorylation induced by activin and on the MAPK3/1 phosphorylation induced by GnRH. Thus, in rat pituitary cells, metformin decreases gonadotropin secretion and MAPK3/1 phosphorylation induced by GnRH and FSH release, FSHbeta subunit expression, and SMAD2 phosphorylation induced by activin through PRKA activation.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Ativinas/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Hormônio Liberador de Gonadotropina/farmacologia , Gonadotropinas/metabolismo , Metformina/farmacologia , Hipófise/metabolismo , Acetil-CoA Carboxilase/metabolismo , Animais , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Regulação para Baixo , Ativação Enzimática , Feminino , Hormônio Foliculoestimulante/metabolismo , Isoenzimas/metabolismo , Hormônio Luteinizante/metabolismo , Fosforilação/efeitos dos fármacos , Hipófise/citologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Ratos , Ratos Wistar , Transdução de SinaisRESUMO
Embryonic stem cells (ESC) are self-renewal and pluripotent cells that are able to differentiate in vitro into several cell types in favourable conditions. Technical protocols for in vitro gametes production have been developed in mice and human species. The functionality of such differentiated cells is not always analysed and an early meiotic arrest is a current observation. These kinds of experimentations have also been tested from human induced pluripotent stem cells (IPSC). However, differentiation ends shortly at the primordial germ cell stage.
Assuntos
Células-Tronco Embrionárias/citologia , Oócitos/citologia , Oogênese/efeitos dos fármacos , Células-Tronco Pluripotentes/citologia , Espermatócitos/citologia , Espermatogênese/efeitos dos fármacos , Animais , Linhagem da Célula , Células Cultivadas/citologia , Células Cultivadas/efeitos dos fármacos , Microambiente Celular , Células-Tronco Embrionárias/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Transferência de Genes , Hormônios/farmacologia , Humanos , Técnicas In Vitro , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Masculino , Camundongos , Células-Tronco Pluripotentes/efeitos dos fármacos , Injeções de Esperma IntracitoplásmicasRESUMO
BACKGROUND: Terminal deletions of the long arm of chromosome 7 are well known and frequently associated with syndromic holoprosencephaly due to the involvement of the SHH (aliases HHG1, SMMCI, TPT, TPTPS, and MCOPCB5) gene region. However, interstitial deletions including CNTNAP2 (aliases Caspr2, KIAA0868, and NRXN4) and excluding the SHH region are less common. METHODS: We report the clinical and molecular characterization associated with pure 7q35 and 7q35q36.1 deletion in two unrelated patients as detected by oligonucleotide-based array-CGH analysis. RESULTS: The common clinical features were abnormal maternal serum screening during first-trimester pregnancy, low occipitofrontal circumference at birth, hypotonia, abnormal feet, developmental delay, impaired language development, generalized seizures, hyperactive behavior, friendly personality, and cranio-facial dysmorphism. Both deletions occurred de novo and sequencing of CNTNAP2, a candidate gene for epilepsy and autism showed absence of mutation on the contralateral allele. CONCLUSION: Combined haploinsufficiency of GALNTL5 (alias GalNAc-T5L), CUL1, SSPO (aliases SCO-spondin, KIAA0543, and FLJ36112), AOC1 (alias DAO), RHEB, and especially KMT2C (alias KIAA1506 and HALR) with monoallelic disruption of CNTNAP2 may explain neurologic abnormalities, hypotonia, and exostoses. Haploinsufficiency of PRKAG2 (aliases AAKG, AAKG2, H91620p, WPWS, and CMH6) and KCNH2 (aliases Kv11.1, HERG, and erg1) genes may be responsible of long QT syndrome observed for one patient.