RESUMO
Bisphenols and Perfluoroalkyls are chemical compounds widely used in industry known to be endocrine disruptors (EDs). Once ingested through contaminated aliments, they mimic the activity of endogenous hormones leading to a broad spectrum of diseases. Due to the extensive use of plastic in human life, particular attention should be paid to antenatal exposure to Bisphenols and Perfluoroalkyls since they cross the placental barrier and accumulates in developing embryo. Here we investigated the effects of Bisphenol-A (BPA), Bisphenol-S (BPS), perfluorooctane-sulfonate (PFOS) and perfluorooctanoic-acid (PFOA), alone or combined, on human-induced pluripotent stem cells (hiPSCs) that share several biological features with the stem cells of blastocysts. Our data show that these EDs affect hiPSC inducing a great mitotoxicity and dramatic changes in genes involved in the maintenance of pluripotency, germline specification, and epigenetic regulation. We also evidenced that these chemicals, when combined, may have additive, synergistic but also negative effects. All these data suggest that antenatal exposure to these EDs may affect the integrity of stem cells in the developing embryos, interfering with critical stages of early human development that might be determinant for fertility. The observation that the effects of exposure to a combination of these chemicals are not easily foreseeable further highlights the need for wider awareness of the complexity of the EDs effects on human health and of the social and economic burden attributable to these compounds.
Assuntos
Disruptores Endócrinos , Fluorocarbonos , Infertilidade , Humanos , Feminino , Gravidez , Epigênese Genética , Placenta , Fertilidade , Compostos Benzidrílicos/toxicidade , Compostos Benzidrílicos/química , Fluorocarbonos/toxicidade , Disruptores Endócrinos/toxicidadeRESUMO
Phosphodiesterases are key regulators that fine tune the intracellular levels of cyclic nucleotides, given their ability to hydrolyze cAMP and cGMP. They are critical regulators of cAMP/cGMP-mediated signaling pathways, modulating their downstream biological effects such as gene expression, cell proliferation, cell-cycle regulation but also inflammation and metabolic function. Recently, mutations in PDE genes have been identified and linked to human genetic diseases and PDEs have been demonstrated to play a potential role in predisposition to several tumors, especially in cAMP-sensitive tissues. This review summarizes the current knowledge and most relevant findings regarding the expression and regulation of PDE families in the testis focusing on PDEs role in testicular cancer development.
Assuntos
Neoplasias Testiculares , Masculino , Humanos , Neoplasias Testiculares/genética , AMP Cíclico/metabolismo , Diester Fosfórico Hidrolases/metabolismo , GMP Cíclico/metabolismoRESUMO
This systematic review and meta-analysis summarize the difference in the methylation of the H19 gene in patients with abnormal versus normal conventional sperm parameters. It also evaluates the effects of age and sperm concentration on H19 methylation in spermatozoa using meta-regression analysis. It was performed according to the MOOSE guidelines for meta-analyses and Systematic Reviews of Observational Studies and the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). The quality of the evidence reported in the studies included was assessed using the Cambridge Quality Checklists. A total of 11 articles met our inclusion criteria. Quantitative analysis showed that H19 methylation levels were significantly lower in the group of infertile patients than in fertile controls. The reduction in methylation was much more pronounced in patients with oligozoospermia (alone or associated with other sperm parameter abnormalities) and in those with recurrent pregnancy loss. Meta-regression analysis showed the results to be independent of both patient age and sperm concentration. Therefore, the H19 methylation pattern should be evaluated among couples accessing assisted reproductive techniques (ART), in order to gain prognostic information on ART outcome and offspring health.
Assuntos
Metilação de DNA , Infertilidade Masculina , Feminino , Humanos , Masculino , Gravidez , Impressão Genômica , Histonas/metabolismo , Infertilidade Masculina/genética , Infertilidade Masculina/metabolismo , Metanálise como Assunto , Sêmen , Espermatozoides/metabolismoRESUMO
RATIONALE: Cardiotoxic ß1 adrenergic receptor (ß1AR)-CaMKII (calmodulin-dependent kinase II) signaling is a major and critical feature associated with development of heart failure. SAP97 (synapse-associated protein 97) is a multifunctional scaffold protein that binds directly to the C-terminus of ß1AR and organizes a receptor signalosome. OBJECTIVE: We aim to elucidate the dynamics of ß1AR-SAP97 signalosome and its potential role in chronic cardiotoxic ß1AR-CaMKII signaling that contributes to development of heart failure. METHODS AND RESULTS: The integrity of cardiac ß1AR-SAP97 complex was examined in heart failure. Cardiac-specific deletion of SAP97 was developed to examine ß1AR signaling in aging mice, after chronic adrenergic stimulation, and in pressure overload hypertrophic heart failure. We show that the ß1AR-SAP97 signaling complex is reduced in heart failure. Cardiac-specific deletion of SAP97 yields an aging-dependent cardiomyopathy and exacerbates cardiac dysfunction induced by chronic adrenergic stimulation and pressure overload, which are associated with elevated CaMKII activity. Loss of SAP97 promotes PKA (protein kinase A)-dependent association of ß1AR with arrestin2 and CaMKII and turns on an Epac (exchange protein directly activated by cAMP)-dependent activation of CaMKII, which drives detrimental functional and structural remodeling in myocardium. Moreover, we have identified that GRK5 (G-protein receptor kinase-5) is necessary to promote agonist-induced dissociation of SAP97 from ß1AR. Cardiac deletion of GRK5 prevents adrenergic-induced dissociation of ß1AR-SAP97 complex and increases in CaMKII activity in hearts. CONCLUSIONS: These data reveal a critical role of SAP97 in maintaining the integrity of cardiac ß1AR signaling and a detrimental cardiac GRK5-CaMKII axis that can be potentially targeted in heart failure therapy. Graphical Abstract: A graphical abstract is available for this article.
Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proteína 1 Homóloga a Discs-Large/metabolismo , Quinase 5 de Receptor Acoplado a Proteína G/metabolismo , Insuficiência Cardíaca/enzimologia , Miócitos Cardíacos/enzimologia , Receptores Adrenérgicos beta 1/metabolismo , Animais , Apoptose , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteína 1 Homóloga a Discs-Large/genética , Modelos Animais de Doenças , Acoplamento Excitação-Contração , Quinase 5 de Receptor Acoplado a Proteína G/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Contração Miocárdica , Miócitos Cardíacos/patologia , beta-Arrestina 1/metabolismoRESUMO
Obesity is a major current public health problem of global significance. A progressive sperm quality decline, and a decline in male fertility, have been reported in recent decades. Several studies have reported a strict relationship between obesity and male reproductive dysfunction. Among the many mechanisms by which obesity impairs male gonadal function, sirtuins (SIRTs) have an emerging role. SIRTs are highly conserved nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases that play a role in gene regulation, metabolism, aging, and cancer. SIRTs regulate the energy balance, the lipid balance, glucose metabolism, and adipogenesis, but current evidence also indicates a role for SIRTs in male reproduction. However, the majority of the studies have been conducted in animal models and very few have been conducted with humans. This review shows that SIRTs play an important role among the molecular mechanisms by which obesity interferes with male fertility. This highlights the need to deepen this relationship. It will be of particular interest to evaluate whether synthetic and/or natural compounds capable of modifying the activity of SIRTs may also be useful for the treatment of obesity and its effects on gonadal function. Although few studies have explored the role of SIRT activators in obesity-induced male infertility, some molecules, such as resveratrol, appear to be effective in modulating SIRT activity, as well as counteracting the negative effects of obesity on male fertility. The search for strategies to improve male reproductive function in overweight/obese patients is a challenge and understanding the role of SIRTs and their activators may open new interesting scenarios in the coming years.
Assuntos
Infertilidade Masculina/metabolismo , Obesidade/metabolismo , Sirtuínas/metabolismo , Humanos , Infertilidade Masculina/etiologia , Masculino , Obesidade/complicações , Análise do Sêmen , Transdução de SinaisRESUMO
Phosphodiesterase 5A (PDE5A) is involved in cGMP hydrolysis, regulating many physiological processes. Increased activity of PDE5A has been found in several pathological conditions, and the pharmacological inhibition of PDE5 has been demonstrated to have several therapeutic applications. We have identified the presence of three different Pde5a isoforms in cardiomyocytes, and we have found that the expression of specific Pde5a isoforms may have a causal role in the onset of pathological responses in these cells. In our previous study, we demonstrated that PDE5A inhibition could ameliorate muscular dystrophy by acting at different levels, as assessed by the altered genomic response of muscular cells following treatment with the PDE5A inhibitor tadalafil. Thus, considering the importance of PDE5A in various pathophysiological conditions, we further investigated the regulation of this enzyme. Here, we analysed the expression of Pde5a isoforms in the pathophysiology of skeletal muscle. We found that skeletal muscle tissues and myogenic cells express Pde5a1 and Pde5a2 isoforms, and we observed an increased expression of Pde5a1 in damaged skeletal muscles, while Pde5a2 levels remained unchanged. We also cloned and characterized the promoters that control the transcription of Pde5a isoforms, investigating which of the transcription factors predicted by bioinformatics analysis could be involved in their modulation. In conclusion, we found an overexpression of Pde5a1 in compromised muscle and identified an involvement of MyoD and Runx1 in Pde5a1 transcriptional activity.
Assuntos
3',5'-GMP Cíclico Fosfodiesterases , Transdução de Sinais , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/genética , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/metabolismo , GMP Cíclico/metabolismo , Músculo Esquelético/metabolismoRESUMO
Resveratrol (RSV) (3,4',5 trihydroxystilbene) is a natural non-flavonoid polyphenol widely present in the Mediterranean diet. In particular, RSV is found in grapes, peanuts, berries, and red wine. Many beneficial effects of this molecule on human health have been reported. In fact, it improves some clinical aspects of various diseases, such as obesity, tumors, hypertension, Alzheimer's disease, stroke, cardiovascular diseases, and diabetes mellitus. However, little is known about the relationship between this compound and male fertility and the few available results are often controversial. Therefore, this review evaluated the effects of RSV on human male fertility and the mechanisms through which this polyphenol could act on human spermatozoa.
Assuntos
Fármacos para a Fertilidade Masculina/química , Fertilidade/efeitos dos fármacos , Polifenóis/química , Resveratrol/química , Arachis/química , Dieta Mediterrânea , Fertilidade/fisiologia , Fármacos para a Fertilidade Masculina/uso terapêutico , Frutas/química , Humanos , Masculino , Polifenóis/uso terapêutico , Resveratrol/uso terapêutico , Espermatozoides/efeitos dos fármacos , Vitis/química , VinhoRESUMO
Introduction: Androgen insensitivity syndrome (AIS), an X-linked recessive disorder of sex development (DSD), is caused by variants of the androgen receptor (AR) gene, mapping in the long arm of the X chromosome, which cause a complete loss of function of the receptor. Case presentation: We report a patient diagnosed with complete AIS (CAIS) at birth due to swelling in the bilateral inguinal region. Transabdominal ultrasound revealed the absence of the uterus and ovaries and the presence of bilateral testes in the inguinal region. The karyotype was 46,XY. She underwent bilateral orchiectomy at 9 months and was given estrogen substitutive therapy at the age of 11 years. Genetic analysis of the AR gene variants was requested when, at the age of 20, the patient came to our observation. Methods: The genetic testing was performed by next-generation sequence (NGS) analysis. Results: The genetic analysis showed the presence of the c.2242T>A, p.(Phe748Ile) variant in the AR gene. To the best of our knowledge, this variant has not been published so far. Furthermore, the patient has a heterozygous c.317A>G, p.(Gln106Arg) variation of the gonadotropin-releasing hormone receptor (GNRHR) gene, a heterozygous c.2273G>A, p.Arg758His variation of the chromodomain helicase DNA binding protein 7 (CHD7) gene, and compound heterozygous c.875A>G, p.Tyr292Cys, and c.8023A>G, p.Ile2675Val variations of the Dynein Axonemal Heavy Chain 11 (DNAH11) gene. Conclusions: The case herein reported underlines the importance of an accurate genetic analysis that has to include karyotype and AR gene variant analysis. This is useful to confirm a clinical diagnosis and establish the proper management of patients with CAIS. Numerous variants of the AR gene have not yet been identified. Moreover, several pitfalls are still present in the management of these patients. More studies are needed to answer unresolved questions, and common protocols are required for the clinical follow-up of patients with CAIS.
Assuntos
Síndrome de Resistência a Andrógenos , Caderinas/genética , Dineínas/genética , Receptores Androgênicos/genética , Receptores LHRH/genética , Síndrome de Resistência a Andrógenos/diagnóstico , Síndrome de Resistência a Andrógenos/genética , Criança , Feminino , Terapia de Reposição Hormonal , Humanos , Recém-Nascido , Masculino , Mutação , UltrassonografiaRESUMO
As the "-omic" technology has largely developed, its application in the field of medical science seems a highly promising tool to clarify the etiology, at least in part, of the so-called idiopathic male infertility. The seminal plasma (SP) is made-up of secretions coming from the male accessory glands, namely epididymis, seminal vesicles, and prostate. It is not only a medium for sperm transport since it is able to modulate the female reproductive environment and immunity, to allow the acquisition of sperm competence, to influence the sperm RNA content, and even embryo development. The aim of this systematic review was to provide an updated and comprehensive description of the main transcripts and proteins reported by transcriptome and proteome studies performed in the human SP of patients with idiopathic infertility, in the attempt of identifying possible candidate molecular targets. We recurrently found that micro RNA (miR)-34, miR-122, and miR-509 are down-regulated in patients with non-obstructive azoospermia (NOA) and oligozoospermia compared with fertile controls. These molecules may represent interesting targets whose predictive role in testicular sperm extraction (TESE) or assisted reproductive techniques (ART) outcome deserves further investigation. Furthermore, according to the available proteomic studies, ECM1, TEX101, lectingalactoside-binding andsoluble 3 binding protein (LGALS3BP) have been reported as accurate predictors of TESE outcome. Interestingly, ECM1 is differently expressed in patients with different ART outcomes. Further prospective, ample-sized studies are needed to validate these molecular targets that will help in the counseling of patients with NOA or undergoing ART.
Assuntos
Infertilidade Masculina/genética , Proteoma/genética , Sêmen/metabolismo , Transcriptoma/genética , Humanos , Infertilidade Masculina/diagnóstico , Infertilidade Masculina/patologia , Masculino , Proteômica , Espermatozoides/metabolismoRESUMO
The prevalence of idiopathic male infertility is high, up to 75% of patients with abnormal sperm parameters. Hence, the research of its causes is mandatory. Oxidative stress (OS) can be responsible for male infertility in 30-80% of cases. In recent years, seminal plasma (SP) proteomics has developed as a useful tool to provide biomarkers of specific diseases. This systematic review aims to collect the available evidence on the changes of SP proteome in patients exposed to OS to provide possible SP biomarkers of sperm OS. To accomplish this, the following keyterms "seminal fluid proteome", "seminal plasma proteome", "oxidative stress", and "sperm oxidative stress" were used and 137 records were found. Among these, 17 were finally included. Nine proteins involved with OS were found overexpressed in patients with OS. Twenty-three proteins were found differentially expressed in patients with clinical conditions associated with OS, such as varicocele, male accessory gland infection/inflammation, cigarette smoke, and obesity. These proteins do not seem to overlap among the clinical conditions taken into account. We speculate that specific SP proteins may mediate OS in different clinical conditions. Altogether, these results suggest that proteomics could help to better understand some of the molecular mechanisms involved in the pathogenesis of infertility. However, further studies are needed to identify potential biomarkers of male infertility with valuable clinical significance.
Assuntos
Biomarcadores/metabolismo , Estresse Oxidativo , Proteômica , Sêmen/metabolismo , Animais , Humanos , Obesidade/patologia , Proteoma/metabolismoRESUMO
Altered ß-adrenergic receptor (ß-AR) density has been reported in cells, animals, and humans receiving ß-blocker treatment. In some cases, ß-AR density is upregulated, but in others, it is unaffected or even reduced. Collectively, these results would imply that changes in ß-AR density and ß-blockade are not related. However, it has still not been clarified whether the effects of ß-blockers on receptor density are related to their ability to activate different ß-AR signaling pathways. To this aim, five clinically relevant ß-blockers endowed with inverse, partial or biased agonism at the ß2-AR were evaluated for their effects on ß2-AR density in both human embryonic kidney 293 (HEK293) cells expressing exogenous FLAG-tagged human ß2-ARs and human lymphocytes expressing endogenous ß2-ARs. Cell surface ß2-AR density was measured by enzyme-linked immunosorbent assay (ELISA) and flow cytometry. Treatment with propranolol, carvedilol, pindolol, sotalol, or timolol did not induce any significant change in surface ß2-AR density in both HEK293 cells and human lymphocytes. On the contrary, treatment with the ß-AR agonist isoproterenol reduced the number of cell surface ß2-ARs in the tested cell types without affecting ß2-AR-mRNA levels. Isoproterenol-induced effects on receptor density were completely antagonized by ß-blocker treatment. In conclusion, the agonistic activity of ß-blockers does not exert an important effect on short-term regulation of ß2-AR density.
Assuntos
Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Antagonistas de Receptores Adrenérgicos beta 2/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Receptores Adrenérgicos beta 2/genética , Receptores Adrenérgicos beta 2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Imunofluorescência , Humanos , Especificidade de ÓrgãosRESUMO
Phosphodiesterase 2A (PDE2A) is a cAMP-cGMP hydrolyzing enzyme essential for mouse development and the PDE2A knockout model (PDE2A-/-) is embryonic lethal. Notably, livers of PDE2A-/- embryos at embryonic day 14.5 (E14.5) have extremely reduced size. Morphological, cellular and molecular analyses revealed loss of integrity in the PDE2A-/- liver niche that compromises the hematopoietic function and maturation. Hematopoietic cells isolated from PDE2A-/- livers are instead able to differentiate in in vitro assays, suggesting the absence of blood cell-autonomous defects. Apoptosis was revealed in hepatoblasts and at the endothelial and stromal compartments in livers of PDE2A-/- embryos. The increase of the intracellular cAMP level and of the inducible cAMP early repressor (ICER) in liver of PDE2A-/- embryos might explain the impairment of liver development by downregulating the expression of the anti-apoptotic gene Bcl2. In summary, we propose PDE2A as an essential gene for integrity maintenance of liver niche and the accomplishment of hematopoiesis.
Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/genética , Hematopoese/genética , Fígado/embriologia , Fígado/metabolismo , Organogênese/genética , Animais , Apoptose/genética , Biomarcadores , Diferenciação Celular , Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/metabolismo , Células Endoteliais/metabolismo , Endotélio/metabolismo , Genótipo , Imuno-Histoquímica , Camundongos , Camundongos Transgênicos , Mutação , Células-Tronco/citologia , Células-Tronco/metabolismo , Células Estromais/metabolismoRESUMO
Forster resonance energy transfer (FRET)-based biosensors have been recently applied to the study of biological pathways. In this study, a new biosensor was validated for the first time in live HEK293 and steroidogenic MLTC-1 cell lines for studying the effect of the PDE5 inhibitor on the hCG/LH-induced steroidogenic pathway. The sensor improves FRET between a donor (D), the fluorescein-like diarsenical probe that can covalently bind a tetracysteine motif fused to the PDE5 catalytic domain, and an acceptor (A), the rhodamine probe conjugated to the pseudosubstrate cGMPS. Affinity constant ( Kd) values of 5.6 ± 3.2 and 13.7 ± 0.8 µM were obtained with HEK293 and MLTC-1 cells, respectively. The detection was based on the competitive displacement of the cGMPS-rhodamine conjugate by sildenafil; the Ki values were 3.6 ± 0.3 nM (IC50 = 2.3 nM) in HEK293 cells and 10 ± 1.0 nM (IC50 = 3.9 nM) in MLTC-1 cells. The monitoring of both cAMP and cGMP by bioluminescence resonance energy transfer allowed the exploitation of the effects of PDE5i on steroidogenesis, indicating that sildenafil enhanced the gonadotropin-induced progesterone-to-testosterone conversion in a cAMP-independent manner.
Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/metabolismo , Inibidores da Fosfodiesterase 5/metabolismo , Progesterona/biossíntese , Citrato de Sildenafila/metabolismo , Testosterona/biossíntese , Animais , Arsenicais/química , Técnicas Biossensoriais/métodos , Domínio Catalítico , Linhagem Celular Tumoral , Gonadotropina Coriônica/farmacologia , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/química , Cisteína/química , Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/química , Células HEK293 , Humanos , Hormônio Luteinizante/farmacologia , Camundongos , Inibidores da Fosfodiesterase 5/farmacologia , Progesterona/metabolismo , Ligação Proteica , Rodaminas/química , Citrato de Sildenafila/farmacologia , Testosterona/metabolismoRESUMO
Phosphodiesterase 5A (PDE5A) specifically degrades the ubiquitous second messenger cGMP and experimental and clinical data highlight its important role in cardiac diseases. To address PDE5A role in cardiac physiology, three splice variants of the PDE5A were cloned for the first time from mouse cDNA library (mPde5a1, mPde5a2, and mPde5a3). The predicted amino acidic sequences of the three murine isoforms are different in the N-terminal regulatory domain. mPDE5A isoforms were transfected in HEK293T cells and they showed high affinity for cGMP and similar sensitivity to sildenafil inhibition. RT-PCR analysis showed that mPde5a1, mPde5a2, and mPde5a3 had differential tissue distribution. In the adult heart, mPde5a1 and mPde5a2 were expressed at different levels whereas mPde5a3 was undetectable. Overexpression of mPDE5As induced an increase of HL-1 number cells which progress into cell cycle. mPDE5A1 and mPDE5A3 overexpression increased the number of polyploid and binucleated cells, mPDE5A3 widened HL-1 areas, and modulated hypertrophic markers more efficiently respect to the other mPDE5A isoforms. Moreover, mPDE5A isoforms had differential subcellular localization: mPDE5A1 was mainly localized in the cytoplasm, mPDE5A2 and mPDE5A3 were also nuclear localized. These results demonstrate for the first time the existence of three PDE5A isoforms in mouse and highlight their potential role in the induction of hypertrophy.
Assuntos
Cardiomegalia/enzimologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/metabolismo , Miócitos Cardíacos/enzimologia , Animais , Cardiomegalia/genética , Cardiomegalia/patologia , Ciclo Celular , Núcleo Celular/enzimologia , Núcleo Celular/patologia , Proliferação de Células , Clonagem Molecular , GMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/genética , Citosol/enzimologia , Feminino , Citometria de Fluxo , Regulação Enzimológica da Expressão Gênica , Células HEK293 , Humanos , Masculino , Camundongos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Células NIH 3T3 , Inibidores da Fosfodiesterase 5/farmacologia , Poliploidia , Isoformas de Proteínas , Transdução de Sinais , Citrato de Sildenafila/farmacologia , TransfecçãoRESUMO
BACKGROUND: Type 2 diabetes mellitus (DM) and obesity independently increase the risk of heart failure by incompletely understood mechanisms. We propose that hyperinsulinemia might promote adverse consequences in the hearts of subjects with type-2 DM and obesity. METHODS: High-fat diet feeding was used to induce obesity and DM in wild-type mice or mice lacking ß2-adrenergic receptor (ß2AR) or ß-arrestin2. Wild-type mice fed with high-fat diet were treated with a ß-blocker carvedilol or a GRK2 (G-protein-coupled receptor kinase 2) inhibitor. We examined signaling and cardiac contractile function. RESULTS: High-fat diet feeding selectively increases the expression of phosphodiesterase 4D (PDE4D) in mouse hearts, in concert with reduced protein kinase A phosphorylation of phospholamban, which contributes to systolic and diastolic dysfunction. The expression of PDE4D is also elevated in human hearts with DM. The induction of PDE4D expression is mediated by an insulin receptor, insulin receptor substrate, and GRK2 and ß-arrestin2-dependent transactivation of a ß2AR-extracellular regulated protein kinase signaling cascade. Thus, pharmacological inhibition of ß2AR or GRK2, or genetic deletion of ß2AR or ß-arrestin2, all significantly attenuate insulin-induced phosphorylation of extracellular regulated protein kinase and PDE4D induction to prevent DM-related contractile dysfunction. CONCLUSIONS: These studies elucidate a novel mechanism by which hyperinsulinemia contributes to heart failure by increasing PDE4D expression and identify ß2AR or GRK2 as plausible therapeutic targets for preventing or treating heart failure in subjects with type 2 DM.
Assuntos
Diabetes Mellitus Tipo 2/complicações , Insuficiência Cardíaca/etiologia , Obesidade/complicações , Receptores Adrenérgicos beta 2/genética , Animais , Carbazóis/farmacologia , Carvedilol , Células Cultivadas , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/genética , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Dieta Hiperlipídica , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Quinase 2 de Receptor Acoplado a Proteína G/antagonistas & inibidores , Quinase 2 de Receptor Acoplado a Proteína G/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Contração Miocárdica/efeitos dos fármacos , Miocárdio/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Propanolaminas/farmacologia , Receptores Adrenérgicos beta 2/deficiência , Transdução de Sinais , Vasodilatadores/farmacologia , beta-Arrestina 2/deficiência , beta-Arrestina 2/genéticaRESUMO
RATIONALE: In heart failure, myofilament proteins display abnormal phosphorylation, which contributes to contractile dysfunction. The mechanisms underlying the dysregulation of protein phosphorylation on myofilaments is not clear. OBJECTIVE: This study aims to understand the mechanisms underlying altered phosphorylation of myofilament proteins in heart failure. METHODS AND RESULTS: We generate a novel genetically encoded protein kinase A (PKA) biosensor anchored onto the myofilaments in rabbit cardiac myocytes to examine PKA activity at the myofilaments in responses to adrenergic stimulation. We show that PKA activity is shifted from the sarcolemma to the myofilaments in hypertrophic failing rabbit myocytes. In particular, the increased PKA activity on the myofilaments is because of an enhanced ß2 adrenergic receptor signal selectively directed to the myofilaments together with a reduced phosphodiesterase activity associated with the myofibrils. Mechanistically, the enhanced PKA activity on the myofilaments is associated with downregulation of caveolin-3 in the hypertrophic failing rabbit myocytes. Reintroduction of caveolin-3 in the failing myocytes is able to normalize the distribution of ß2 adrenergic receptor signal by preventing PKA signal access to the myofilaments and to restore contractile response to adrenergic stimulation. CONCLUSIONS: In hypertrophic rabbit myocytes, selectively enhanced ß2 adrenergic receptor signaling toward the myofilaments contributes to elevated PKA activity and PKA phosphorylation of myofilament proteins. Reintroduction of caveolin-3 is able to confine ß2 adrenergic receptor signaling and restore myocyte contractility in response to ß adrenergic stimulation.
Assuntos
Técnicas Biossensoriais/métodos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Insuficiência Cardíaca/enzimologia , Insuficiência Cardíaca/genética , Miofibrilas/enzimologia , Miofibrilas/genética , Animais , Células Cultivadas , Miócitos Cardíacos/enzimologia , Fosforilação/fisiologia , CoelhosRESUMO
NEK2 is a serine/threonine kinase that promotes centrosome splitting and ensures correct chromosome segregation during the G2/M phase of the cell cycle, through phosphorylation of specific substrates. Aberrant expression and activity of NEK2 in cancer cells lead to dysregulation of the centrosome cycle and aneuploidy. Thus, a tight regulation of NEK2 function is needed during cell cycle progression. In this study, we found that NEK2 localizes in the nucleus of cancer cells derived from several tissues. In particular, NEK2 co-localizes in splicing speckles with SRSF1 and SRSF2. Moreover, NEK2 interacts with several splicing factors and phosphorylates some of them, including the oncogenic SRSF1 protein. Overexpression of NEK2 induces phosphorylation of endogenous SR proteins and affects the splicing activity of SRSF1 toward reporter minigenes and endogenous targets, independently of SRPK1. Conversely, knockdown of NEK2, like that of SRSF1, induces expression of pro-apoptotic variants from SRSF1-target genes and sensitizes cells to apoptosis. Our results identify NEK2 as a novel splicing factor kinase and suggest that part of its oncogenic activity may be ascribed to its ability to modulate alternative splicing, a key step in gene expression regulation that is frequently altered in cancer cells.
Assuntos
Processamento Alternativo , Apoptose , Neoplasias/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/enzimologia , Sobrevivência Celular , Humanos , Quinases Relacionadas a NIMA , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinases/análise , Proteínas de Ligação a RNA/metabolismo , Fatores de Processamento de Serina-Arginina , Proteína bcl-X/genéticaRESUMO
PURPOSE: To evaluate the diagnostic accuracy of unenhanced and quantitative contrast-enhanced ultrasonography (US) in the differential diagnosis of small nonpalpable testicular lesions. MATERIALS AND METHODS: The local review board approved the protocol, and all patients provided written informed consent. One hundred fifteen patients (median age, 34 years; age range, 14-61 years) with nonpalpable testicular lesions were consecutively enrolled between 2006 and 2012 and underwent unenhanced scrotal US, contrast-enhanced US, surgical enucleation, and at least 18 months of follow-up. Clinical and histologic features were recorded, and qualitative and quantitative analysis of contrast-enhanced US time-intensity curves were performed. Logistic regression analysis was performed to explore features of malignancy. Receiver operating characteristic ( ROC receiver operating characteristic ) curves were developed for cumulative unenhanced and contrast-enhanced US scores. RESULTS: All lesions were 1.5 cm or smaller. Forty-four of the 115 patients (38%) had malignant tumors, 42 had benign tumors (37%), and 29 (25%) had nonneoplastic lesions. The features at unenhanced US that enabled the best differentiation of tumors versus nonneoplastic lesions and benign versus malignant tumors were parenchymal microlithiasis (26 of 86 patients with tumors vs five of 29 patients with nonneoplastic lesions [P = .178]; four of 42 patients with benign lesions vs 22 of 44 patients with malignant tumors [P < .001]), irregular margins (26 of 86 patients with tumors vs three of 29 patients with nonneoplastic lesions [P < .001]; eight of 42 patients with benign lesions vs 18 of 44 patients with malignant tumors [P < .001]), and internal vascularization (70 of 86 patients with tumors vs seven of 29 patients with nonneoplastic lesions [P < .001]; 28 of 42 patients with benign lesions vs 42 of 44 patients with malignant tumors [P < .001]). For contrast-enhanced US, the rapidity of wash-in (34 of 44 patients vs 15 of 42 patients, P < .001) and washout (33 of 44 patients vs five of 42 patients, P < .001) were the parameters that best differentiated malignant from benign tumors, with a typical prolonged washout observed in Leydig cell tumors (12 of 21 patients, P < .001 when compared with seminomas). Overall, the combination of unenhanced and contrast-enhanced US achieved a high accuracy in the diagnosis of small testicular malignancies (area under the ROC receiver operating characteristic curve performance: 0.927; 95% confidence interval: 0.872, 0.981). CONCLUSION: Benign testicular tumors are frequent incidental findings. Quantitative scrotal contrast-enhanced US is a noninvasive diagnostic tool that could improve the differential diagnosis and individualized management of small testicular lesions.
Assuntos
Neoplasias Testiculares/diagnóstico por imagem , Adulto , Meios de Contraste , Diagnóstico Diferencial , Humanos , Achados Incidentais , Masculino , Fosfolipídeos , Estudos Prospectivos , Hexafluoreto de Enxofre , Neoplasias Testiculares/patologia , Neoplasias Testiculares/cirurgia , UltrassonografiaRESUMO
BACKGROUND: The myocardial effects of phosphodiesterase type 5 inhibitors (PDE5i) have recently received consideration in several preclinical studies. The risk/benefit ratio in humans remains unclear. METHODS: We performed a meta-analysis of randomized, placebo-controlled trials (RCTs) to evaluate the efficacy and safety of PDE5i on cardiac morphology and function. From March 2012 to December 2013 (update: May 2014), we searched English-language studies from MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and SCOPUS-selecting RCTs of continuous PDE5i administration that reported cardiovascular outcomes: cardiac geometry and performance, afterload, endothelial function and safety. The pooled estimate of a weighted mean difference between treatment and placebo was obtained for all outcomes using a random effects model. A test for heterogeneity was performed and the I2 statistic calculated. RESULTS: Overall, 1,622 subjects were treated, with 954 randomized to PDE5i and 772 to placebo in 24 RCTs. According to our analysis, sustained PDE5 inhibition produced: (1) an anti-remodeling effect by reducing cardiac mass (-12.21 g/m2, 95% confidence interval (CI): -18.85; -5.57) in subjects with left ventricular hypertrophy (LVH) and by increasing end-diastolic volume (5.00 mL/m2; 95% CI: 3.29; 6.71) in non-LVH patients; (2) an improvement in cardiac performance by increasing cardiac index (0.30 L/min/m2, 95% CI: 0.202; 0.406) and ejection fraction (3.56%, 95% CI: 1.79; 5.33). These effects are parallel to a decline of N-terminal-pro brain natriuretic peptide (NT-proBNP) in subjects with severe LVH (-486.7 pg/ml, 95% CI: -712; -261). PDE5i administration also produced: (3) no changes in afterload parameters and (4) an improvement in flow-mediated vasodilation (3.31%, 95% CI: 0.53; 6.08). Flushing, headache, epistaxis and gastric symptoms were the commonest side effects. CONCLUSIONS: This meta-analysis suggests for the first time that PDE5i have anti-remodeling properties and improve cardiac inotropism, independently of afterload changes, with a good safety profile. Given the reproducibility of the findings and tolerability across different populations, PDE5i could be reasonably offered to men with cardiac hypertrophy and early stage heart failure. Given the limited gender data, a larger trial on the sex-specific response to long-term PDE5i treatment is required.
Assuntos
Disfunção Erétil/tratamento farmacológico , Insuficiência Cardíaca/patologia , Inibidores da Fosfodiesterase 5/uso terapêutico , Endotélio Vascular/efeitos dos fármacos , Humanos , Masculino , Inibidores da Fosfodiesterase 5/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Reprodutibilidade dos TestesRESUMO
Smoking habits (from classic cigarettes to e-cigarettes and heated tobacco) are a relatively common finding in the medical histories of couples referred to fertility centers. Tobacco smoke and e-cigarettes may deliver many substances with known harmful effects on both general and reproductive health, including nicotine. Nicotinic Acetylcholine receptors (nAChRs) form a heterogeneous family of ion channels that are differently expressed in different tissues. According to the homomeric or heteromeric combination of at least five different subunits (named from α to ε), they have peculiar pharmacological and biophysical properties. nAChRs respond to the neurotransmitter acetylcholine, which influences a number of physiological functions not restricted to neurons and plays an important role in the structure and function of non-neuronal tissues such as the testis. nAChRs are also the target of Nicotine, the active element responsible for tobacco addiction. This review summarizes recent findings on the involvement of nAChRs in testicular physiology, highlighting the effects of nicotine exposure observed in animal studies and clinical settings. We will discuss the latest data on fertility outcomes and the implications for understanding nAChR functions in reproductive health.