RESUMEN
This study was to investigate the bidirectional estrogen-like effects of genistein on murine experimental autoimmune ovarian disease (AOD). Female BALB/c mice were induced by immunization with a peptide from murine zona pellucida. The changes of estrous cycle, ovarian histomorphology were measured, and the levels of serum sex hormone were analyzed using radioimmunoassay. Proliferative responses of the ovary were also determined by immunohistochemistry. Administration of 25 or 45 mg/kg body weight genistein enhanced ovary development with changes in serum sex hormone levels and proliferative responses. Meanwhile, the proportions of growing and mature follicles increased and the incidence of autoimmune oophoritis decreased, which exhibited normal ovarian morphology in administration of 25 or 45 mg/kg body weight genistein, while a lower dose (5 mg/kg body weight genistein) produced the opposite effect. These findings suggest that genistein exerts bidirectional estrogen-like effects on murine experimental AOD, while a high dose (45 mg/kg body weight) of genistein may suppress AOD.
Asunto(s)
Estradiol/sangre , Genisteína/farmacología , Ooforitis/tratamiento farmacológico , Folículo Ovárico/efectos de los fármacos , Fitoestrógenos/farmacología , Poliendocrinopatías Autoinmunes/tratamiento farmacológico , Administración Oral , Animales , Estradiol/farmacología , Ciclo Estral/efectos de los fármacos , Ciclo Estral/fisiología , Femenino , Hormona Folículo Estimulante/sangre , Hormesis , Humanos , Hormona Luteinizante/sangre , Ratones , Ratones Endogámicos BALB C , Ooforitis/inducido químicamente , Ooforitis/inmunología , Ooforitis/patología , Folículo Ovárico/inmunología , Folículo Ovárico/patología , Péptidos/administración & dosificación , Péptidos/aislamiento & purificación , Poliendocrinopatías Autoinmunes/inducido químicamente , Poliendocrinopatías Autoinmunes/inmunología , Poliendocrinopatías Autoinmunes/patología , Zona Pelúcida/químicaRESUMEN
The egg envelope of most animal eggs is modified following fertilization, resulting in the prevention of polyspermy and hardening of the egg envelope. In frogs and mammals a prominent feature of envelope modification is N-terminal proteolysis of the envelope glycoprotein ZPA. We have purified the ZPA protease from Xenopus laevis eggs and characterized it as a zinc metalloprotease. Proteolysis of isolated egg envelopes by the isolated protease resulted in envelope hardening. The N-terminal peptide fragment of ZPA remained disulfide bond linked to the ZPA glycoprotein moiety following proteolysis. We propose a mechanism for egg envelope hardening involving ZPA proteolysis by an egg metalloprotease as a triggering event followed by induction of global conformational changes in egg envelope glycoproteins.
Asunto(s)
Proteínas del Huevo/química , Glicoproteínas de Membrana/química , Receptores de Superficie Celular/química , Zona Pelúcida/química , Animales , Anticuerpos/química , Western Blotting , Clonación Molecular , ADN Complementario/metabolismo , Electroforesis en Gel de Poliacrilamida , Inhibidores Enzimáticos/farmacología , Femenino , Fertilización , Masculino , Metaloproteasas/metabolismo , Óvulo/metabolismo , Péptido Hidrolasas/química , Inhibidores de Proteasas/farmacología , Estructura Terciaria de Proteína , Proteínas/química , Espermatozoides/metabolismo , Temperatura , Xenopus laevis , Zona Pelúcida/metabolismo , Glicoproteínas de la Zona PelúcidaRESUMEN
The mouse zona pellucida glycoprotein, mZP2, is thought to be the secondary receptor on eggs for retention of acrosome-reacted sperm during fertilization. Here, we present evidence that one of its complementary binding proteins on sperm is proacrosin/acrosin. mZP2 binds to proacrosin null sperm considerably less effectively than to wild-type sperm. Binding is mediated by a strong ionic interaction between polysulphate groups on mZP2 and basic residues on an internal proacrosin peptide. The stereochemistry of both sulphate groups and basic amino acids determines the specificity of binding. Structurally relevant sulphated polymers and suramin, a polysulphonated anticancer drug, compete with mZP2 for complementary binding sites on proacrosin/acrosin in solid-phase binding assays. The same competitors also displace attached sperm from the zona pellucida of eggs in an in vitro fertilization system. This combination of genetic, biochemical and functional data supports the hypothesis that mZP2-proacrosin interactions are important for retention of acrosome-reacted sperm on the egg surface during fertilization. Safe mimetics of suramin have potential as non-steroidal antifertility agents.