ROLE OF ALPHA-SNAP IN THE MAINTENANCE OF N-CADHERIN-BASED ADHERENS JUNCTIONS IN MOUSE OVARIAN FOLLICLE

ARCOS, ALEXIS; TORO, G.; GIANETTI, D.; DE PAOLA, M. MATILDE; MICHAUT, MARCELA A.; BÁTIZ, LUIS FEDERICO

Mendoza

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012

Several studies suggest that N-cadherin-based adherens junctions between granulosa cells (GC) play a key role in the ovarian follicle development. Alpha-SNAP, a protein involved in membrane fusion, has also been associated to the maintenance of cadherin-based junctions. We hypothesized that alpha-SNAP is a regulator of N-cadherin-based cell-cell junctions between granulosa cells and follicle development.  To test this we used a spontaneous mutant mouse model for alpha-SNAP known as hyh (hydrocephalus with hop gait). We analyzed the expression of alpha-SNAP in wild type (wt) and hyh ovaries from pre-pubertal to post-pubertal stages. Western blots showed that in wt, alpha-SNAP increased at post-pubertal ages and after gonadotrophic stimulation; this increase correlates with the number of maturing follicles. On the other hand, hyh mice responded to hormonal stimulation, however, they showed lower levels of alpha-SNAP at all stages, did not display the post-pubertal increase, and the number of maturing follicles was diminished. Immunofluorescence revealed that wt GC were joined together by well-developed N-cadherin-based adherens junctions; in contrast, hyh GC showed scarce adherens junctions and a punctate cytoplasmic pattern. Several GC with piknotic nuclei were observed in the follicular antrum. Our results suggest that alpha-SNAP is important for the physiology of GC during follicle development in mouse.