RESUMO
Multiple morphological abnormalities of the sperm flagella (MMAF) are a major cause of asthenoteratozoospermia. We have identified protease serine 50 (PRSS50) as having a crucial role in sperm development, because Prss50-null mice presented with impaired fertility and sperm tail abnormalities. PRSS50 could also be involved in centrosome function because these mice showed a threefold increase in acephalic sperm (head-tail junction defect), sperm with multiple heads (spermatid division defect) and sperm with multiple tails, including novel two conjoined sperm (complete or partial parts of several flagellum on the same plasma membrane). Our data support that, in the testis, as in tumorigenesis, PRSS50 activates NFκB target genes, such as the centromere protein leucine-rich repeats and WD repeat domain-containing protein 1 (LRWD1), which is required for heterochromatin maintenance. Prss50-null testes have increased IκκB, and reduced LRWD1 and histone expression. Low levels of de-repressed histone markers, such as H3K9me3, in the Prss50-null mouse testis may cause increases in post-meiosis proteins, such as AKAP4, affecting sperm formation. We provide important insights into the complex mechanisms of sperm development, the importance of testis proteases in fertility and a novel mechanism for MMAF.
Assuntos
Fertilidade , Serina Proteases/metabolismo , Cauda do Espermatozoide/enzimologia , Testículo/enzimologia , Animais , Astenozoospermia/enzimologia , Astenozoospermia/genética , Heterocromatina/enzimologia , Heterocromatina/genética , Histonas/biossíntese , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Masculino , Camundongos , Camundongos Mutantes , Proteínas dos Microtúbulos/genética , Proteínas dos Microtúbulos/metabolismo , Serina Proteases/deficiência , Cabeça do Espermatozoide/enzimologiaRESUMO
Cryptorchidism is the most common urologic birth defect in men and is a predisposing factor of male infertility and testicular cancer, yet the etiology remains largely unknown. E2F1 microdeletions and microduplications contribute to cryptorchidism, infertility and testicular tumors. Although E2f1 deletion or overexpression in mice causes spermatogenic failure, the mechanism by which E2f1 influences testicular function is unknown. This investigation revealed that E2f1-null mice develop cryptorchidism with severe gubernacular defects and progressive loss of germ cells resulting in infertility and, in rare cases, testicular tumors. It was hypothesized that germ cell depletion resulted from an increase in WNT4 levels. To test this hypothesis, the phenotype of a double-null mouse model lacking both Wnt4 and E2f1 in germ cells was analyzed. Double-null mice are fertile. This finding indicates that germ cell maintenance is dependent on E2f1 repression of Wnt4, supporting a role for Wnt4 in germ cell survival. In the future, modulation of WNT4 expression in men with cryptorchidism and spermatogenic failure due to E2F1 copy number variations may provide a novel approach to improve their spermatogenesis and perhaps their fertility potential after orchidopexy.
Assuntos
Fator de Transcrição E2F1/metabolismo , Espermatogênese , Testículo/metabolismo , Proteína Wnt4/metabolismo , Envelhecimento/patologia , Animais , Animais Recém-Nascidos , Barreira Hematotesticular/patologia , Ciclo Celular/genética , Criptorquidismo/genética , Criptorquidismo/patologia , Fator de Transcrição E2F1/deficiência , Fertilidade , Regulação da Expressão Gênica , Masculino , Camundongos Endogâmicos C57BL , Modelos Biológicos , Transdução de Sinais , Espermatozoides/metabolismo , Testículo/patologiaRESUMO
BACKGROUND: Genitourinary anomalies occur in approximately 1% of humans, but in most cases, the cause is unknown. Aristaless-like homeobox 4 (ALX4) is an important homeodomain transcription factor. ALX4 mutations in humans and mouse have been associated with craniofacial defects and genitourinary anomalies such as cryptorchidism and epispadias. OBJECTIVES: To investigate the presence and the functional impact of ALX4 variants in patients with genitourinary defects. MATERIALS AND METHODS: Two separate patient cohorts were analyzed. One includes clinical exome-sequencing (ES) data from 7500 individuals. The other includes 52 ALX4 Sanger-sequenced individuals with bladder exstrophy-epispadias complex (BEEC). Dual luciferase assays were conducted to investigate the functional transcriptional impact of ALX4 variants in HeLa cells and HEK293 cells. RESULTS: A total of 41 distinct ALX4 heterozygous missense variants were identified in the ES cohort with 15 variants present as recurrent in multiple patients. p.G369E and p.L373F were the only two present in individuals with genitourinary defects. A p.L373F heterozygous variant was also identified in one of the 52 individuals in the BEEC cohort. p.L373F and p.G369E were tested in vitro as both are considered damaging by MutationTaster, although only p.G369E was considered damaging by PolyPhen-2. p.L373F did not alter transcriptional activity in HeLa and HEK293 cells. p.G369E caused a significant 3.4- and 1.8-fold decrease in transcriptional activities relative to wild-type ALX4 in HEK293 and HeLa cells, respectively. DISCUSSION AND CONCLUSIONS: Our study supports the idea that transcription factors like ALX4 could influence the normal development of the GU tract in humans as demonstrated in mouse models as ALX4 variant p.G369E (predicted pathogenic by multiple databases) affects ALX4 function in vitro. Variant p.L373F (predicted pathogenic by only MutationTaster) did not affect ALX4 function in vitro. Exon-sequence information and mouse genetics provide important insights into the complex mechanisms driving genitourinary defects allowing the association of transcriptional defects with congenital disorders.
Assuntos
Proteínas de Ligação a DNA/genética , Fatores de Transcrição/genética , Anormalidades Urogenitais/genética , Variação Genética , Células HEK293 , Células HeLa , HumanosRESUMO
STUDY OBJECTIVE: Paratubal cysts (PTCs) occur in 7%-10% of women, regardless of age. Although common, PTCs often are found incidentally because of the potential for these cysts to be asymptomatic. The specific aims of the study were to determine if PTC number and size correlated with signs of hyperandrogenism and obesity, as well as to investigate the molecular profiles of these PTCs in samples derived from female adolescents. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: A prospective cohort study was performed in a single children's hospital. Girls 18 years of age or younger who underwent surgery for PTC suspected on the basis of the presence of a persistent adnexal cyst on imaging or a concern for adnexal torsion involving a cyst were consented to participate in the study. RESULTS: Nineteen patients met enrollment criteria with a mean age at menarche of 11.2 ± 1.3 years. Most of the patients (84%; n = 16/19) had adnexal torsion at the time of diagnosis of PTC. Irregular menses and hirsutism was found in 52.6% (n = 10/19) of the patients, among whom 36.8% (n = 7/19) were obese. The mean PTC size was 10.4 ± 4.3 cm with 57.9% (n = 11/19) of the cohort having more than 1 PTC. When patients were compared on the basis of their body mass index, the size of PTCs was significantly larger in the overweight/obese group. The wingless-type (WNT) signaling members catenin beta 1 (CTNBB1) and wingless-type MMTV integration site family, member 7A (WNT7A) were upregulated in 86% (n = 12/14) and 79% (n = 11/14) of the patients, respectively. WNT7A was significantly upregulated in girls with 1 cyst and low body mass index. CONCLUSION: A correlation exists between obesity, cyst size, and hyperandrogenism. Activation of the WNT/CTNBB1 pathway via WNT7A might play a role in PTC development.
Assuntos
Hiperandrogenismo/complicações , Obesidade/complicações , Cisto Parovariano/complicações , Proteínas Wnt/metabolismo , Adolescente , Adulto , Criança , Estudos de Coortes , Feminino , Hirsutismo , Hospitais Pediátricos , Humanos , Menarca , Cisto Parovariano/metabolismo , Cisto Parovariano/cirurgia , Estudos Prospectivos , Via de Sinalização WntRESUMO
In this paper, we have shown that Cu/TiO(2) catalysts are highly active in CO oxidation. For instance, a 3.4% Cu/TiO(2) catalyst exhibits a higher turnover rate for the effective removal of CO in air than 3-5% Pt/TiO(2) and 20% Cu/ZnO/Al(2)O(3) catalysts. A small amount of Cu(+) species is formed during the calcination treatment at 225 °C, which is the main active phase for the CO oxidation. However, it is proposed that some highly dispersed CuO can also form in the TiO(2) lattice during the calcination treatment. Furthermore, a strong electron interaction between Cu(2+) in highly dispersed CuO and Ti(3+) on rutile TiO(2) (Cu(2+)+Ti(3+)âCu(+)+Ti(4+)) has been shown to occur. Overall, the reduction of Cu(+) is a major factor that contributes to the reaction rate of the CO oxidation.