Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.174
Filtrar
1.
Gene ; 764: 145080, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-32858178

RESUMO

Spermatocyte (spc) formation from spermatogonia (spg) differentiation is the first step of spermatogenesis which produces prodigious spermatozoa for a lifetime. After decades of studies, several factors involved in the functioning of a mouse were discovered both inside and outside spg. Considering the peculiar expression and working pattern of each factor, this review divides the whole conversion of spg to spc into four consecutive development processes with a focus on extracellular cues and downstream transcription network in each one. Potential coordination among Dmrt1, Sohlh1/2 and BMP families mediates Ngn3 upregulation, which marks progenitor spg, with other changes. After that, retinoic acid (RA), as a master regulator, promotes A1 spg formation with its helpers and Sall4. A1-to-B spg transition is under the control of Kitl and impulsive RA signaling together with early and late transcription factors Stra8 and Dmrt6. Finally, RA and its responsive effectors conduct the entry into meiosis. The systematic transcription network from outside to inside still needs research to supplement or settle the controversials in each process. As a step further ahead, this review provides possible drug targets for infertility therapy by cross-linking humans and mouse model.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Espermatócitos/fisiologia , Espermatogênese/genética , Espermatogônias/fisiologia , Animais , Proteínas Morfogenéticas Ósseas/metabolismo , Autorrenovação Celular/genética , Humanos , Masculino , Camundongos , Túbulos Seminíferos/citologia , Túbulos Seminíferos/crescimento & desenvolvimento , Fatores de Transcrição/metabolismo , Transcrição Genética , Tretinoína/metabolismo , Regulação para Cima
2.
Nat Commun ; 11(1): 5656, 2020 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-33168808

RESUMO

Establishment of spermatogonia throughout the fetal and postnatal period is essential for production of spermatozoa and male fertility. Here, we establish a protocol for in vitro reconstitution of human prospermatogonial specification whereby human primordial germ cell (PGC)-like cells differentiated from human induced pluripotent stem cells are further induced into M-prospermatogonia-like cells and T1 prospermatogonia-like cells (T1LCs) using long-term cultured xenogeneic reconstituted testes. Single cell RNA-sequencing is used to delineate the lineage trajectory leading to T1LCs, which closely resemble human T1-prospermatogonia in vivo and exhibit gene expression related to spermatogenesis and diminished proliferation, a hallmark of quiescent T1 prospermatogonia. Notably, this system enables us to visualize the dynamic and stage-specific regulation of transposable elements during human prospermatogonial specification. Together, our findings pave the way for understanding and reconstructing human male germline development in vitro.


Assuntos
Células Germinativas Embrionárias/fisiologia , Células-Tronco Pluripotentes Induzidas/fisiologia , Espermatogênese/genética , Espermatogênese/fisiologia , Animais , Diferenciação Celular , Epigenômica , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Elementos Reguladores de Transcrição , Análise de Sequência de RNA , Espermatogônias/citologia , Espermatozoides , Testículo/citologia , Transcriptoma
3.
PLoS Biol ; 18(8): e3000838, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32804933

RESUMO

In humans, most germline mutations are inherited from the father. This observation has been widely interpreted as reflecting the replication errors that accrue during spermatogenesis. If so, the male bias in mutation should be substantially lower in a closely related species with similar rates of spermatogonial stem cell divisions but a shorter mean age of reproduction. To test this hypothesis, we resequenced two 3-4 generation nuclear families (totaling 29 individuals) of olive baboons (Papio anubis), who reproduce at approximately 10 years of age on average, and analyzed the data in parallel with three 3-generation human pedigrees (26 individuals). We estimated a mutation rate per generation in baboons of 0.57×10-8 per base pair, approximately half that of humans. Strikingly, however, the degree of male bias in germline mutations is approximately 4:1, similar to that of humans-indeed, a similar male bias is seen across mammals that reproduce months, years, or decades after birth. These results mirror the finding in humans that the male mutation bias is stable with parental ages and cast further doubt on the assumption that germline mutations track cell divisions. Our mutation rate estimates for baboons raise a further puzzle, suggesting a divergence time between apes and Old World monkeys of 65 million years, too old to be consistent with the fossil record; reconciling them now requires not only a slowdown of the mutation rate per generation in humans but also in baboons.


Assuntos
Mutação em Linhagem Germinativa , Hominidae/genética , Taxa de Mutação , Papio/genética , Reprodução/genética , Espermatozoides/metabolismo , Fatores Etários , Animais , Evolução Biológica , Divisão Celular , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Modelos Genéticos , Linhagem , Fatores Sexuais , Especificidade da Espécie , Espermatogênese/genética , Espermatozoides/citologia
4.
Proc Natl Acad Sci U S A ; 117(36): 22237-22248, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32839316

RESUMO

NOD-like receptors (NLRs) are traditionally recognized as major inflammasome components. The role of NLRs in germ cell differentiation and reproduction is not known. Here, we identified the gonad-specific Nlrp14 as a pivotal regulator in primordial germ cell-like cell (PGCLC) differentiation in vitro. Physiologically, knock out of Nlrp14 resulted in reproductive failure in both female and male mice. In adult male mice, Nlrp14 knockout (KO) inhibited differentiation of spermatogonial stem cells (SSCs) and meiosis, resulting in trapped SSCs in early stages, severe oligozoospermia, and sperm abnormality. Mechanistically, NLRP14 promoted spermatogenesis by recruiting a chaperone cofactor, BAG2, to bind with HSPA2 and form the NLRP14-HSPA2-BAG2 complex, which strongly inhibited ChIP-mediated HSPA2 polyubiquitination and promoted its nuclear translocation. Finally, loss of HSPA2 protection and BAG2 recruitment by NLRP14 was confirmed in a human nonsense germline variant associated with male sterility. Together, our data highlight a unique proteasome-mediated, noncanonical function of NLRP14 in PGCLC differentiation and spermatogenesis, providing mechanistic insights of gonad-specific NLRs in mammalian germline development.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Diferenciação Celular/fisiologia , Proteínas de Choque Térmico HSP70/metabolismo , Chaperonas Moleculares/metabolismo , Espermatogênese/genética , Transporte Ativo do Núcleo Celular/genética , Transporte Ativo do Núcleo Celular/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Células-Tronco Germinativas Adultas/fisiologia , Animais , Proteínas Reguladoras de Apoptose/genética , Feminino , Deleção de Genes , Regulação da Expressão Gênica/fisiologia , Variação Genética , Células Germinativas , Proteínas de Choque Térmico HSP70/genética , Humanos , Infertilidade Masculina/genética , Masculino , Camundongos , Chaperonas Moleculares/genética , Nucleosídeo-Trifosfatase/genética , Nucleosídeo-Trifosfatase/metabolismo , Espermatogênese/fisiologia
5.
Am J Hum Genet ; 107(2): 342-351, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32673564

RESUMO

Male infertility affects ∼7% of men, but its causes remain poorly understood. The most severe form is non-obstructive azoospermia (NOA), which is, in part, caused by an arrest at meiosis. So far, only a few validated disease-associated genes have been reported. To address this gap, we performed whole-exome sequencing in 58 men with unexplained meiotic arrest and identified the same homozygous frameshift variant c.676dup (p.Trp226LeufsTer4) in M1AP, encoding meiosis 1 associated protein, in three unrelated men. This variant most likely results in a truncated protein as shown in vitro by heterologous expression of mutant M1AP. Next, we screened four large cohorts of infertile men and identified three additional individuals carrying homozygous c.676dup and three carrying combinations of this and other likely causal variants in M1AP. Moreover, a homozygous missense variant, c.1166C>T (p.Pro389Leu), segregated with infertility in five men from a consanguineous Turkish family. The common phenotype between all affected men was NOA, but occasionally spermatids and rarely a few spermatozoa in the semen were observed. A similar phenotype has been described for mice with disruption of M1ap. Collectively, these findings demonstrate that mutations in M1AP are a relatively frequent cause of autosomal recessive severe spermatogenic failure and male infertility with strong clinical validity.


Assuntos
Pontos de Checagem do Ciclo Celular/genética , Infertilidade Masculina/genética , Meiose/genética , Mutação/genética , Proteínas/genética , Espermatogênese/genética , Adulto , Alelos , Animais , Azoospermia/genética , Homozigoto , Humanos , Masculino , Camundongos , Fenótipo , Espermatozoides/anormalidades , Testículo/anormalidades , Turquia , Sequenciamento Completo do Exoma/métodos
6.
Nature ; 584(7822): 635-639, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32674113

RESUMO

In mammals, the acquisition of the germline from the soma provides the germline with an essential challenge: the need to erase and reset genomic methylation1. In the male germline, RNA-directed DNA methylation silences young, active transposable elements2-4. The PIWI protein MIWI2 (PIWIL4) and its associated PIWI-interacting RNAs (piRNAs) instruct DNA methylation of transposable elements3,5. piRNAs are proposed to tether MIWI2 to nascent transposable element transcripts; however, the mechanism by which MIWI2 directs the de novo methylation of transposable elements is poorly understood, although central to the immortality of the germline. Here we define the interactome of MIWI2 in mouse fetal gonocytes undergoing de novo genome methylation and identify a previously unknown MIWI2-associated factor, SPOCD1, that is essential for the methylation and silencing of young transposable elements. The loss of Spocd1 in mice results in male-specific infertility but does not affect either piRNA biogenesis or the localization of MIWI2 to the nucleus. SPOCD1 is a nuclear protein whose expression is restricted to the period of de novo genome methylation. It co-purifies in vivo with DNMT3L and DNMT3A, components of the de novo methylation machinery, as well as with constituents of the NURD and BAF chromatin remodelling complexes. We propose a model whereby tethering of MIWI2 to a nascent transposable element transcript recruits repressive chromatin remodelling activities and the de novo methylation apparatus through SPOCD1. In summary, we have identified a previously unrecognized and essential executor of mammalian piRNA-directed DNA methylation.


Assuntos
Metilação de DNA/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Animais , Proteínas Argonauta/metabolismo , Montagem e Desmontagem da Cromatina , DNA (Citosina-5-)-Metiltransferases/metabolismo , Elementos de DNA Transponíveis/genética , Feminino , Fertilidade/genética , Inativação Gênica , Genes de Partícula A Intracisternal/genética , Elementos Nucleotídeos Longos e Dispersos/genética , Masculino , Camundongos , RNA Interferente Pequeno/biossíntese , Espermatogênese/genética
7.
Nat Commun ; 11(1): 3491, 2020 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-32661239

RESUMO

Sperm contributes genetic and epigenetic information to the embryo to efficiently support development. However, the mechanism underlying such developmental competence remains elusive. Here, we investigated whether all sperm cells have a common epigenetic configuration that primes transcriptional program for embryonic development. Using calibrated ChIP-seq, we show that remodelling of histones during spermiogenesis results in the retention of methylated histone H3 at the same genomic location in most sperm cell. This homogeneously methylated fraction of histone H3 in the sperm genome is maintained during early embryonic replication. Such methylated histone fraction resisting post-fertilisation reprogramming marks developmental genes whose expression is perturbed upon experimental reduction of histone methylation. A similar homogeneously methylated histone H3 fraction is detected in human sperm. Altogether, we uncover a conserved mechanism of paternal epigenetic information transmission to the embryo through the homogeneous retention of methylated histone in a sperm cells population.


Assuntos
Metilação de DNA/genética , Epigênese Genética/genética , Animais , Cromatina/genética , Cromatina/metabolismo , Desenvolvimento Embrionário/genética , Desenvolvimento Embrionário/fisiologia , Histonas/genética , Histonas/metabolismo , Masculino , Espermatogênese/genética , Espermatogênese/fisiologia , Xenopus
8.
Nat Genet ; 52(7): 728-739, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32601478

RESUMO

Pachytene PIWI-interacting RNAs (piRNAs), which comprise >80% of small RNAs in the adult mouse testis, have been proposed to bind and regulate target RNAs like microRNAs, cleave targets like short interfering RNAs or lack biological function altogether. Although piRNA pathway protein mutants are male sterile, no biological function has been identified for any mammalian piRNA-producing locus. Here, we report that males lacking piRNAs from a conserved mouse pachytene piRNA locus on chromosome 6 (pi6) produce sperm with defects in capacitation and egg fertilization. Moreover, heterozygous embryos sired by pi6-/- fathers show reduced viability in utero. Molecular analyses suggest that pi6 piRNAs repress gene expression by cleaving messenger RNAs encoding proteins required for sperm function. pi6 also participates in a network of piRNA-piRNA precursor interactions that initiate piRNA production from a second piRNA locus on chromosome 10, as well as pi6 itself. Our data establish a direct role for pachytene piRNAs in spermiogenesis and embryo viability.


Assuntos
RNA Interferente Pequeno/genética , RNA Interferente Pequeno/fisiologia , Espermatogênese/genética , Animais , Evolução Biológica , Núcleo Celular , Desenvolvimento Embrionário , Feminino , Fertilidade , Deleção de Genes , Regulação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Estágio Paquíteno/genética , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Capacitação Espermática/genética , Capacitação Espermática/fisiologia , Interações Espermatozoide-Óvulo/fisiologia
9.
Chemosphere ; 258: 127238, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32563064

RESUMO

Dibutyl phthalate (DBP) and diisobutyl phthalate (DiBP) are phthalate compounds frequently detected in the environment. Despite increasing awareness of their toxicity in human and animals, the male reproductive toxicity of their combined exposure remains elusive. The purposes of this study were to investigate whether combined exposure to DBP and DiBP could induce male reproductive toxicity, and to explore the potential toxicological mechanisms. Adult male zebrafish were exposed to DBP (11, 113 and 1133 µg L-1), DiBP (10, 103 and 1038 µg L-1) and their mixtures (Mix) (11 + 10, 113 + 103, 1133 + 1038 µg L-1) for 30 days, and their effects on plasma hormone secretion, testis histology and transcriptomics were examined. Highest concentrations of Mix exposure caused greater imbalance ratio of T/E2 and more severe structural damage to testis than single exposure. These effects were consistent with the testis transcriptome analysis for which 4570 genes were differentially expressed in Mix exposure, while 2795 and 1613 genes were differentially expressed in DBP and DiBP, respectively. KEGG pathway analysis showed that both single and combined exposure of DBP and DiBP could affect cytokine-cytokine receptor interaction. The difference was that combined exposure could also affect steroid hormone synthesis, extracellular matrix receptor interaction, retinol metabolism, and PPAR signaling pathways. These results demonstrated that combined exposure to DBP and DiBP could disrupt spermatogenesis and elicit male reproductive toxicity in zebrafish.


Assuntos
Dibutilftalato/análogos & derivados , Dibutilftalato/toxicidade , Reprodução/efeitos dos fármacos , Testículo/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Animais , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Humanos , Masculino , Modelos Teóricos , Espermatogênese/efeitos dos fármacos , Espermatogênese/genética , Testículo/metabolismo
10.
Gene ; 753: 144812, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32470507

RESUMO

Spermatogenesis is a complex and elaborate differentiation process and is critical for male fertility. The hypothalamic-pituitary-gonadal axis serves as a significant neuroendocrine system to regulate spermatogenesis. As a constitute of the hypothalamic-pituitary-gonadal axis, Sertoli cells promote spermatogenesis via protecting, nourishing, and supporting germ cells upon hormone determination. Here we clarified how the hormones in the hypothalamic-pituitary-gonadal axis, including FSH, testosterone and LH, regulate spermatogenesis via the androgen receptor, cAMP/PKA, PI3k/Akt signaling pathways in Sertoli cells. Other endogenous hormones in higher vertebrates, including ouabain, estradiol, leptin, MIS, PGD2, and thyroid hormone, also regulate spermatogenesis via the AR or cAMP/PKA signaling pathway. Among them, the dynamics of adherens junctions, gap junctions, and blood-testis barrier, glucose uptake, lactate supply and differentiation of Sertoli cells are regulated by more comprehensive hormones and signaling pathways in Sertoli cells. In infertile patients or patients with blocked spermatogenesis, the AR, cAMP/PKA and PI3k/Akt signaling pathways and related components exhibit abnormal activity or disordered content. The clinical specimens from patients with testicular cancer show similar mutated AR genes. According to the existing clinical evidence, it is valuable to study the deep mechanism of male infertility and testicular tumors from the perspective of hormones and signaling pathways in Sertoli cells.


Assuntos
Infertilidade Masculina/metabolismo , Células de Sertoli/metabolismo , Células de Sertoli/fisiologia , Animais , Hormônio Foliculoestimulante/metabolismo , Humanos , Hormônio Luteinizante/metabolismo , Masculino , Neoplasias Embrionárias de Células Germinativas/metabolismo , Receptores Androgênicos/genética , Transdução de Sinais/fisiologia , Espermatogênese/genética , Neoplasias Testiculares/metabolismo , Neoplasias Testiculares/fisiopatologia , Testículo/metabolismo , Testosterona/metabolismo
11.
Cytogenet Genome Res ; 160(4): 167-176, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32396893

RESUMO

During gametogenesis, the human genome can acquire various de novo rearrangements. Most constitutional genomic rearrangements are created through 1 of the 4 well-known mechanisms, i.e., nonallelic homologous recombination, erroneous repair after double-strand DNA breaks, replication errors, and retrotransposition. However, recent studies have identified 2 types of extremely complex rearrangements that cannot be simply explained by these mechanisms. The first type consists of chaotic structural changes in 1 or a few chromosomes that result from "chromoanagenesis (an umbrella term that covers chromothripsis, chromoanasynthesis, and chromoplexy)." The other type is large independent rearrangements in multiple chromosomes indicative of "transient multifocal genomic crisis." Germline chromoanagenesis (chromothripsis) likely occurs predominantly during spermatogenesis or postzygotic embryogenesis, while multifocal genomic crisis appears to be limited to a specific time window during oogenesis and early embryogenesis or during spermatogenesis. This review article introduces the current understanding of the molecular basis of de novo rearrangements in the germline.


Assuntos
Cromotripsia , Mutação em Linhagem Germinativa/genética , Recombinação Genética , Desenvolvimento Embrionário/genética , Humanos , Oogênese/genética , Espermatogênese/genética
12.
Nucleic Acids Res ; 48(12): 6624-6639, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32463460

RESUMO

Repair of DNA double-strand breaks (DSBs) with homologous chromosomes is a hallmark of meiosis that is mediated by recombination 'bridges' between homolog axes. This process requires cooperation of DMC1 and RAD51 to promote homology search and strand exchange. The mechanism(s) regulating DMC1/RAD51-ssDNA nucleoprotein filament and the components of 'bridges' remain to be investigated. Here we show that MEIOK21 is a newly identified component of meiotic recombination bridges and is required for efficient formation of DMC1/RAD51 foci. MEIOK21 dynamically localizes on chromosomes from on-axis foci to 'hanging foci', then to 'bridges', and finally to 'fused foci' between homolog axes. Its chromosome localization depends on DSBs. Knockout of Meiok21 decreases the numbers of HSF2BP and DMC1/RAD51 foci, disrupting DSB repair, synapsis and crossover recombination and finally causing male infertility. Therefore, MEIOK21 is a novel recombination factor and probably mediates DMC1/RAD51 recruitment to ssDNA or their stability on chromosomes through physical interaction with HSF2BP.


Assuntos
Proteínas de Ligação a DNA/genética , Recombinação Homóloga/genética , Infertilidade Masculina/genética , Espermatogênese/genética , Animais , Proteínas de Transporte/genética , Proteínas de Ciclo Celular/genética , Pareamento Cromossômico/genética , Cromossomos/genética , Quebras de DNA de Cadeia Dupla , Reparo do DNA/genética , DNA de Cadeia Simples/genética , Técnicas de Inativação de Genes , Proteínas de Choque Térmico/genética , Masculino , Meiose/genética , Camundongos , Camundongos Knockout , Proteínas de Ligação a Fosfato/genética , Rad51 Recombinase/genética
13.
Sci China Life Sci ; 63(7): 1006-1015, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32361911

RESUMO

Being infected by SARS-CoV-2 may cause damage to multiple organs in patients, such as the lung, liver and heart. Angiotensin-converting enzyme 2 (ACE2), reported as a SARS-CoV-2 receptor, is also expressed in human male testes. This suggests a potential risk in human male reproductive system. However, the characteristics of ACE2-positive cells and the expression of other SARS-CoV-2 process-related genes are still worthy of further investigation. Here, we performed singlecell RNA seq (scRNA-seq) analysis on 853 male embryo primordial germ cells (PGCs) and 2,854 normal testis cells to assess the effects of the SARS-CoV-2 virus on the male reproductive system from embryonic stage to adulthood. We also collected and constructed the scRNA-seq library on 228 Sertoli cells from three non-obstructive azoospermia (NOA) patients to assess the effects at disease state. We found that ACE2 expressing cells existed in almost all testis cell types and Sertoli cells had highest expression level and positive cells ratio. Moreover, ACE2 was also expressed in human male PGCs. In adulthood, the level of ACE2 expression decreased with the increase of age. We also found that ACE2 positive cells had high expressions of stress response and immune activation-related genes. Interestingly, some potential SARS-CoV-2 process-related genes such as TMPRSS2, BSG, CTSL and CTSB had different expression patterns in the same cell type. Furthermore, ACE2 expression level in NOA donors' Sertoli cells was significantly decreased. Our work would help to assess the risk of SARS-CoV-2 infection in the male reproductive system.


Assuntos
Azoospermia/genética , Betacoronavirus/patogenicidade , Infecções por Coronavirus , Pandemias , Peptidil Dipeptidase A/genética , Pneumonia Viral , Testículo/metabolismo , Testículo/virologia , Adulto , Azoospermia/complicações , Azoospermia/metabolismo , Betacoronavirus/metabolismo , Infecções por Coronavirus/complicações , Infecções por Coronavirus/fisiopatologia , Infecções por Coronavirus/virologia , Células Germinativas Embrionárias/metabolismo , Células Germinativas Embrionárias/virologia , Expressão Gênica , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Masculino , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/complicações , Pneumonia Viral/fisiopatologia , Pneumonia Viral/virologia , Receptores Virais/genética , Receptores Virais/metabolismo , Células de Sertoli/metabolismo , Células de Sertoli/virologia , Análise de Célula Única , Espermatogênese/genética , Espermatogênese/fisiologia , Testículo/citologia
14.
PLoS One ; 15(5): e0233163, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32413098

RESUMO

Inositol polyphosphate-4-phosphatase type II (INPP4B) is a dual-specificity phosphatase that acts as a tumor suppressor in multiple cancers. INPP4B dephosphorylates phospholipids at the 4th position of the inositol ring and inhibits AKT and PKC signaling by hydrolyzing of PI(3,4)P2 and PI(4,5)P2, respectively. INPP4B protein phosphatase targets include phospho-tyrosines on Akt and phospho-serine and phospho-threonine on PTEN. INPP4B is highly expressed in testes, suggesting its role in testes development and physiology. The objective of this study was to determine whether Inpp4b deletion impacts testicular function in mice. In testis, Inpp4b expression was the highest in postmeiotic germ cells in both mice and men. The testes of Inpp4b knockout male mice were significantly smaller compared to the testes of wild-type (WT) males. Inpp4b-/- males produced fewer mature sperm cells compared to WT, and this difference increased with age and high fat diet (HFD). Reduction in early steroidogenic enzymes and luteinizing hormone (LH) receptor gene expression was detected, although androgen receptor (AR) protein level was similar in WT and Inpp4b-/- testes. Germ cell apoptosis was significantly increased in the knockout mice, while expression of meiotic marker γH2A.X was decreased. Our data demonstrate that INPP4B plays a role in maintenance of male germ cell differentiation and protects testis functions against deleterious effects of aging and high fat diet.


Assuntos
Monoéster Fosfórico Hidrolases/metabolismo , Espermatogênese/genética , Espermatozoides/metabolismo , Testículo/metabolismo , Animais , Apoptose/genética , Citocinas/metabolismo , Dieta Hiperlipídica/efeitos adversos , Regulação da Expressão Gênica no Desenvolvimento/genética , Histonas/metabolismo , Humanos , Masculino , Meiose/genética , Camundongos , Camundongos Knockout , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Monoéster Fosfórico Hidrolases/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA-Seq , Receptores Androgênicos/metabolismo , Receptores do LH/genética , Receptores do LH/metabolismo , Análise de Célula Única , Contagem de Espermatozoides , Testículo/crescimento & desenvolvimento
15.
Genes Dev ; 34(9-10): 619-620, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32358039

RESUMO

In this issue of Genes & Development, Lu and colleagues (pp. 663-677) have discovered a key new mechanism of alternative promoter choice that is involved in differentiation of spermatocytes. Promoter choice has strong potential as mechanism for differentiation of many different cell types.


Assuntos
Proteínas de Drosophila/genética , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/genética , Regiões Promotoras Genéticas/genética , Espermatócitos/citologia , Espermatogênese/genética , Motivos de Aminoácidos/genética , Animais , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Masculino , Transcriptoma/genética
16.
Proc Natl Acad Sci U S A ; 117(14): 7837-7844, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32229564

RESUMO

The blood-testis barrier (BTB) is thought to be indispensable for spermatogenesis because it creates a special environment for meiosis and protects haploid cells from the immune system. The BTB divides the seminiferous tubules into the adluminal and basal compartments. Spermatogonial stem cells (SSCs) have a unique ability to transmigrate from the adluminal compartment to the basal compartment through the BTB upon transplantation into the seminiferous tubule. Here, we analyzed the role of Cldn11, a major component of the BTB, in spermatogenesis using spermatogonial transplantation. Cldn11-deficient mice are infertile due to the cessation of spermatogenesis at the spermatocyte stage. Cldn11-deficient SSCs failed to colonize wild-type testes efficiently, and Cldn11-deficient SSCs that underwent double depletion of Cldn3 and Cldn5 showed minimal colonization, suggesting that claudins on SSCs are necessary for transmigration. However, Cldn11-deficient Sertoli cells increased SSC homing efficiency by >3-fold, suggesting that CLDN11 in Sertoli cells inhibits transmigration of SSCs through the BTB. In contrast to endogenous SSCs in intact Cldn11-deficient testes, those from WT or Cldn11-deficient testes regenerated sperm in Cldn11-deficient testes. The success of this autologous transplantation appears to depend on removal of endogenous germ cells for recipient preparation, which reprogrammed claudin expression patterns in Sertoli cells. Consistent with this idea, in vivo depletion of Cldn3/5 regenerated endogenous spermatogenesis in Cldn11-deficient mice. Thus, coordinated claudin expression in both SSCs and Sertoli cells expression is necessary for SSC homing and regeneration of spermatogenesis, and autologous stem cell transplantation can rescue congenital defects of a self-renewing tissue.


Assuntos
Fertilidade/genética , Infertilidade/terapia , Espermatogônias/transplante , Transplante de Células-Tronco , Animais , Modelos Animais de Doenças , Fertilidade/fisiologia , Humanos , Infertilidade/genética , Infertilidade/patologia , Masculino , Camundongos , Espermatogênese/genética , Espermatogônias/crescimento & desenvolvimento , Espermatozoides/crescimento & desenvolvimento , Espermatozoides/transplante , Células-Tronco/citologia , Transplante Autólogo/métodos
17.
Nucleic Acids Res ; 48(9): 4780-4796, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32232334

RESUMO

Previously, we have shown that human sperm Prohibitin (PHB) expression is significantly negatively correlated with mitochondrial ROS levels but positively correlated with mitochondrial membrane potential and motility. However, the possible role of PHB in mammalian spermatogenesis has not been investigated. Here we document the presence of PHB in spermatocytes and its functional roles in meiosis by generating the first male germ cell-specific Phb-cKO mouse. Loss of PHB in spermatocytes resulted in complete male infertility, associated with not only meiotic pachytene arrest with accompanying apoptosis, but also apoptosis resulting from mitochondrial morphology and function impairment. Our mechanistic studies show that PHB in spermatocytes regulates the expression of STAG3, a key component of the meiotic cohesin complex, via a non-canonical JAK/STAT pathway, and consequently promotes meiotic DSB repair and homologous recombination. Furthermore, the PHB/JAK2 axis was found as a novel mechanism in the maintenance of stabilization of meiotic STAG3 cohesin complex and the modulation of heterochromatin formation in spermatocytes during meiosis. The observed JAK2-mediated epigenetic changes in histone modifications, reflected in a reduction of histone 3 tyrosine 41 phosphorylation (H3Y41ph) and a retention of H3K9me3 at the Stag3 locus, could be responsible for Stag3 dysregulation in spermatocytes with the loss of PHB.


Assuntos
Código das Histonas , Meiose/genética , Proteínas Repressoras/fisiologia , Espermatócitos/metabolismo , Espermatogênese/genética , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular , Pareamento Cromossômico , Epigenoma , Histonas/metabolismo , Recombinação Homóloga , Infertilidade/genética , Janus Quinase 2/metabolismo , Janus Quinases/metabolismo , Masculino , Camundongos , Camundongos Knockout , Mitocôndrias/fisiologia , Mitocôndrias/ultraestrutura , Estágio Paquíteno , Fosforilação , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Espermatócitos/enzimologia , Espermatócitos/ultraestrutura , Testículo/metabolismo
18.
PLoS One ; 15(4): e0230930, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32267870

RESUMO

Human epidemiological studies have shown that paternal aging as one of the risk factors for neurodevelopmental disorders, such as autism, in offspring. A recent study has suggested that factors other than de novo mutations due to aging can influence the biology of offspring. Here, we focused on epigenetic alterations in sperm that can influence developmental programs in offspring. In this study, we qualitatively and semiquantitatively evaluated histone modification patterns in male germline cells throughout spermatogenesis based on immunostaining of testes taken from young (3 months old) and aged (12 months old) mice. Although localization patterns were not obviously changed between young and aged testes, some histone modification showed differences in their intensity. Among histone modifications that repress gene expression, histone H3 lysine 9 trimethylation (H3K9me3) was decreased in the male germline cells of the aged testis, while H3K27me2/3 was increased. The intensity of H3K27 acetylation (ac), an active mark, was lower/higher depending on the stages in the aged testis. Interestingly, H3K27ac was detected on the putative sex chromosomes of round spermatids, while other chromosomes were occupied by a repressive mark, H3K27me3. Among other histone modifications that activate gene expression, H3K4me2 was drastically decreased in the male germline cells of the aged testis. In contrast, H3K79me3 was increased in M-phase spermatocytes, where it accumulates on the sex chromosomes. Therefore, aging induced alterations in the amount of histone modifications and in the differences of patterns for each modification. Moreover, histone modifications on the sex chromosomes and on other chromosomes seems to be differentially regulated by aging. These findings will help elucidate the epigenetic mechanisms underlying the influence of paternal aging on offspring development.


Assuntos
Histonas/genética , Meiose/genética , Espermatócitos/fisiologia , Espermatogênese/genética , Testículo/fisiologia , Acetilação , Animais , Epigênese Genética/genética , Epigenômica/métodos , Expressão Gênica/genética , Código das Histonas/genética , Humanos , Lisina/genética , Masculino , Metilação , Camundongos , Processamento de Proteína Pós-Traducional/genética , Cromossomos Sexuais/genética , Espermátides/fisiologia
19.
Urol Clin North Am ; 47(2): 219-225, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32272994

RESUMO

Transgenerational epigenetic inheritance provides a mechanism by which environmental exposures and lifestyle decisions can affect the offspring directly through the gamete. It is this pattern of inheritance that has shed light on the fact that preconception lifestyle decisions that a father makes are significant because they can significantly impact the offspring. Understanding the epigenetic alterations in gametes and the potential implications of these changes is key to the health of future generations.


Assuntos
Epigênese Genética/genética , Infertilidade Masculina/genética , Exposição Paterna , Herança Paterna/genética , Espermatogênese/genética , Efeito de Coortes , Metilação de DNA/genética , Humanos , Infertilidade Masculina/etiologia , Masculino , Exposição Paterna/efeitos adversos
20.
Nucleic Acids Res ; 48(8): 4115-4138, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32182340

RESUMO

Epigenetic regulation of gene expression is tightly controlled by the dynamic modification of histones by chemical groups, the diversity of which has largely expanded over the past decade with the discovery of lysine acylations, catalyzed from acyl-coenzymes A. We investigated the dynamics of lysine acetylation and crotonylation on histones H3 and H4 during mouse spermatogenesis. Lysine crotonylation appeared to be of significant abundance compared to acetylation, particularly on Lys27 of histone H3 (H3K27cr) that accumulates in sperm in a cleaved form of H3. We identified the genomic localization of H3K27cr and studied its effects on transcription compared to the classical active mark H3K27ac at promoters and distal enhancers. The presence of both marks was strongly associated with highest gene expression. Assessment of their co-localization with transcription regulators (SLY, SOX30) and chromatin-binding proteins (BRD4, BRDT, BORIS and CTCF) indicated systematic highest binding when both active marks were present and different selective binding when present alone at chromatin. H3K27cr and H3K27ac finally mark the building of some sperm super-enhancers. This integrated analysis of omics data provides an unprecedented level of understanding of gene expression regulation by H3K27cr in comparison to H3K27ac, and reveals both synergistic and specific actions of each histone modification.


Assuntos
Elementos Facilitadores Genéticos , Epigênese Genética , Código das Histonas , Regiões Promotoras Genéticas , Espermatogênese/genética , Acetilcoenzima A/metabolismo , Acetilação , Acil Coenzima A/metabolismo , Animais , Evolução Biológica , Crotonatos/metabolismo , Genômica , Histonas/química , Histonas/metabolismo , Lisina/metabolismo , Masculino , Metabolômica , Camundongos Endogâmicos C57BL , Proteômica , Transcrição Genética , Leveduras/metabolismo , Leveduras/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA