RESUMEN
During development of ovarian follicles in mammals, cumulus cells and the oocyte form a mucoelastic mass that detaches itself from peripheral granulosa cell layers upon an ovulatory surge. The integrity of this cumulus-oocyte complex (COC) relies on the cohesiveness of a hyaluronan (HA)-enriched extracellular matrix (ECM). We previously identified a serum glycoprotein, inter-alpha-inhibitor (IalphaI), that is critical in organizing and stabilizing this matrix. Following an ovulatory stimulus, IalphaI diffuses into the follicular fluid and becomes integrated in the ECM through its association with HA. TSG-6 (the secreted product of the tumor necrosis factor-stimulated gene 6), another HA binding protein, forms a complex with IalphaI in synovial fluid. The purpose of this study was to investigate whether TSG-6 is involved in the ECM organization of COCs. Immunolocalization of TSG-6 and IalphaI in mouse COCs at different ovulatory stages was analyzed by immunofluorescence and laser confocal microscopy. IalphaI, TSG-6, and HA colocolized in the cumulus ECM. Western blot analyses were consistent with the presence of both TSG-6 and TSG-6/IalphaI complexes in ovulated COCs. These results suggest that TSG-6 has a structural role in COC matrix formation possibly mediating cross-linking of separate HA molecules through its binding to IalphaI.
Asunto(s)
alfa-Globulinas/metabolismo , Moléculas de Adhesión Celular/metabolismo , Matriz Extracelular/metabolismo , Ácido Hialurónico/metabolismo , Oocitos/metabolismo , Secuencia de Aminoácidos , Animales , Western Blotting , Femenino , Inmunohistoquímica , Ratones , Ratones Endogámicos , Datos de Secuencia Molecular , Ovulación/fisiología , Pruebas de Precipitina , Unión Proteica , Regulación hacia Arriba/fisiologíaRESUMEN
Nitric oxide (NO) and the dura mater are implicated in the pathogenesis of vascular headache. Many studies have demonstrated the participation of NO in headache; however, few studies have identified NO in the dura mater. In this study, nine Sprague-Dawley rats were examined with immunohistochemistry using two different endothelial nitric oxide synthase (eNOS) monoclonal antibodies, H32 and ECNOS. eNOS was successfully localized to the endothelium of the middle meningeal artery. To the best of our knowledge, this is the first study to report NOS immunopositive endothelial cells in the blood vessels of the rat dura mater. The authors propose that NO plays an active role in dural vasodilation, contributing to the pathogenesis of vascular headache; in the future, NO inhibitors could serve as pharmacological agents to treat vascular headache.