INVESTIGADORES
SOSA ESCUDERO Miguel Angel
congresos y reuniones científicas
Título:
Mannose-6-phosphate receptors mediate the interaction of lysosomal enzymes with bovine epididymal spermatozoa.
Autor/es:
BOSCHIN V; AGUILERA AC; CARVELLI L; SOSA MA
Lugar:
Mendoza
Reunión:
Congreso; XXXI Reunión Anual de la Sociedad de Biología de Cuyo.; 2013
Institución organizadora:
Sociedad de Biología de Cuyo
Resumen:
Mammalian epididymis
is crucial for the sperm maturation, since it provides the conditions for the
acquisition of their progressive motility and fertilizing ability. The presence
of acid hydrolases in the epididymal fluid is striking. These enzymes may
participate in sperm maturation, although they could also extert activity in
the female genital tract. In most cell types, lysosomal enzymes are normally
transported to lysosomes via two mannose-6-phosphate
receptors (MPRs); the cation dependent- and the cation independent-MPR (CD-MPR
and CI-MPR, respectively). The MPRs have also been detected in spermatozoa of
several species of mammals. This study was addressed to know whether these
receptors are also expressed in bovine spermatozoa (BS), and if they mediate
interaction with epididymal enzymes. Epididymis from adult bulls (Aberdeen
Angus) were carefully dissected into caput, corpus and cauda and processed
separatelly. Epididymal spermatozoa and fluid were separated from each region
and stored for MRP detection and to characterize the interaction enzyme-gamete. By immunoblot and IFI, using specific
antibodies, we observed that both MPRs are detected in BS and the CD-MPR is
redistributed along sperm surface during epididymal transit. Some acid
hydrolases, such as b-galactosidase, b-N-acetyl-glucosaminidase, and b-glucosidase can be
partially removed from the sperm surface with high ionic strenght or
mannose-6-phosphate, indicating that they interact with MPRs. This interaction
was corroborated by binding assays, showing a preference of the enzymes to
CI-MPR. Other enzymes, such as a-mannosidase and a-fucosidase may be transported by an alternative
mechanisms. We conclude that MPRs can be
detected also in bovine spermatozoa and they could be transported to the female
tract and participate in events as capacitation, acrosomal reaction and/or
oocyte penetration