Expression and localization of hypoxia-inducible factor-1 subunits in the adult rat epididymis.
Biol Reprod
; 70(4): 1121-30, 2004 Apr.
Article
en En
| MEDLINE
| ID: mdl-14668208
ABSTRACT
The epididymal epithelium contributes to formation of a luminal fluid that is essential for the protection of spermatozoa from a variety of insults including changes in oxygen tension. A key regulator of the response to oxygen debt in many cells is hypoxia-inducible factor-1 (HIF-1). A transcription factor composed of alpha and beta subunits, HIF-1 activates genes that mediate oxygen homeostasis and cell survival pathways or trigger cell death responses. Previously we have shown that HIF-1alpha mRNA is expressed in the adult rat epididymis. Goals of this study were to determine whether HIF-1alpha protein is activated by ischemia in the rat epididymis, to determine whether epididymal HIF-1alpha mRNA expression is androgen dependent, and to identify epididymal cell types expressing HIF-1alpha and beta. Immunoblot analysis revealed that HIF-1alpha protein is primarily present in corpus and cauda of the normoxic epididymis and unaffected by ischemia, whereas HIF-1beta was detected equally in all regions and also unaffected by ischemia. HIF-1alpha mRNA expression in all regions was not affected by 15 days bilateral orchiectomy. Principal cells stained positive for HIF-1alpha by immunocytochemistry, with the epithelium of initial segment and caput epididymidis staining less intensely than corpus and cauda. HIF-1beta immunoreactivity was equally present in principal cells in all regions. Clear, narrow, and basal cells were unreactive for HIF-1alpha and beta. The presence of HIF-1 in normoxic epididymis and the regional distribution of HIF-1alpha suggests fundamental differences in how proximal and distal regions of the epididymis maintain oxygen homeostasis to protect the epithelium and spermatozoa from hypoxia.
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Base de datos:
MEDLINE
Asunto principal:
Factores de Transcripción
/
Receptores de Hidrocarburo de Aril
/
Proteínas de Unión al ADN
/
Epidídimo
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Biol Reprod
Año:
2004
Tipo del documento:
Article