RESUMEN
Nitric oxide (NO) enhances human sperm motility and capacitation associated with increased protein phosphorylation. NO activates soluble guanylyl cyclase, but can also modify protein function covalently via S-nitrosylation of cysteine. Remarkably, this mechanism remains unexplored in sperm although they depend on post-translational protein modification to achieve changes in function required for fertilisation. Our objective was to identify targets for S-nitrosylation in human sperm. Spermatozoa were incubated with NO donors and S-nitrosylated proteins were identified using the biotin switch assay and a proteomic approach using MS/MS. 240 S-nitrosylated proteins were detected in sperm incubated with S-nitroso-glutathione. Minimal levels were observed in glutathione or untreated samples. Proteins identified consistently based on multiple peptides included established targets for S-nitrosylation in other cells e.g. tubulin, GST and HSPs but also novel targets including A-kinase anchoring protein (AKAP) types 3 and 4, voltage-dependent anion-selective channel protein 3 and semenogelin 1 and 2. In situ localisation revealed S-nitrosylated targets on the postacrosomal region of the head and throughout the flagellum. Potential targets for S-nitrosylation in human sperm include physiologically significant proteins not previously reported in other cells. Their identification will provide novel insight into the mechanism of action of NO in spermatozoa.
Asunto(s)
Óxido Nítrico/metabolismo , Compuestos Nitrosos/metabolismo , Proteoma/metabolismo , Proteómica/métodos , Espermatozoides/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Cisteína/metabolismo , Humanos , Masculino , Proteínas de Transporte de Membrana Mitocondrial , Donantes de Óxido Nítrico/metabolismo , Donantes de Óxido Nítrico/farmacología , Óxido Nítrico Sintasa de Tipo III/metabolismo , Proteoma/química , S-Nitrosoglutatión/metabolismo , S-Nitrosoglutatión/farmacología , Proteínas de Secreción de la Vesícula Seminal/metabolismo , Espectrometría de Masas en Tándem , Canales Aniónicos Dependientes del Voltaje/metabolismoRESUMEN
Although sperm dysfunction is the single most common cause of infertility, we have poor methods of diagnosis and surprisingly no effective treatment (excluding assisted reproductive technology). In this review, we challenge the usefulness of a basic semen analysis and argue that a new paradigm is required immediately. We discuss the use of at-home screening to potentially improve the diagnosis of the male and to streamline the management of the sub-fertile couple. Additionally, we outline the recent progress in the field, for example, in proteomics, which will allow the development of new biomarkers of sperm function. This new knowledge will transform our understanding of the spermatozoon as a machine and is likely to lead to non-ART treatments for men with sperm dysfunction.
Asunto(s)
Infertilidad Masculina/diagnóstico , Espermatozoides/fisiología , Calcio/metabolismo , Humanos , Masculino , Proteómica , Capacitación Espermática/fisiología , Recuento de Espermatozoides , Espermatozoides/citologíaAsunto(s)
Fertilización/fisiología , Capacitación Espermática/fisiología , Espermatozoides/fisiología , Reacción Acrosómica , Adenosina , Animales , Calcitonina , Membrana Celular/fisiología , Trompas Uterinas , Femenino , Humanos , Masculino , Ácido Pirrolidona Carboxílico/análogos & derivados , Transducción de Señal , Espermatozoides/ultraestructura , Hormona Liberadora de Tirotropina/análogos & derivadosRESUMEN
BACKGROUND: The study explores the relationship between serum chlamydia antibody titres (CATs) and detection of tubal damage in infertile women. METHODS: The tubal status and pelvic findings in 1006 women undergoing laparoscopy for infertility were related to CAT, which was measured using the whole-cell inclusion immunofluorescence test. RESULTS: A negative correlation between CAT and age was noted. A linear trend between serum CAT and the likelihood of tubal damage, including severe damage, was observed (P < 0.001). Titres in women with tubal damage (median 1:1024; range <1:64-1:4096) were significantly (P < 0.001) higher than in women with endometriosis alone (median <1:64; range <1:64-1:512) or those with a normal pelvis (median <1:64; range <1:64-1:1024). Women with positive titres were more likely to have pelvic adhesions than tubal occlusion unless titres were very high, when tubal damage was likely to be more severe. CONCLUSIONS: CATs are of predictive value in the detection of tubal damage and are quantitatively related to the severity of damage. For practical clinical purposes, Chlamydia serology is useful mainly as a screening test for the likelihood of tubal damage in infertile women and may facilitate decisions on which women should proceed with further investigations without delay.