Document Detail


The predominance of one of the SR-BI isoforms is associated with increased esterified cholesterol levels not apoptosis in mink testis.
MedLine Citation:
PMID:  16861621     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Scavenger receptor class B type I (SR-BI) contributes to HDL-mediated cellular cholesterol efflux and is a phagocytosis-inducing phospholipid phosphatidylserine receptor in rat Sertoli cells, whereas the spliced variant of the SR-B gene, SR-BII, is implicated in the efflux of free cholesterol in macrophages. This study aimed to assess whether spontaneous autoimmune orchitis (AIO), which causes impaired clearance of apoptotic germ cells and spermatogenic arrest, involves SR-BI, SR-BII, and/or cholesterol. The levels measured during development and the annual reproductive cycle in normal mink were compared with those in mink with spontaneous AIO. Time periods with lowest tubular esterified cholesterol (EC) levels showed maximal SR-BI and SR-BII levels, and the periods when one or the other SR-BI isoform predominated showed increased EC levels and spermatogenic arrest in normal mink seminiferous tubules. In tubules with AIO, the predominance of only one or the other SR-BI isoform was the reverse of that measured in normal tubules, and it was associated with an increase in EC levels but not with apoptosis levels. SR-BI and SR-BII levels were not correlated with serum testosterone levels. SR-BI mainly localized to the Leydig cell, germ cell, and Sertoli cell surface, where its distribution was stage-specific. SR-BII was principally intracellular. Tubules from testes with AIO showed a deregulation of cholesterol homeostasis and SR-BI expression but relatively unchanged apoptosis levels. These results suggest that the expression of both SR-BI isoforms is required for the maintenance of low EC levels and that the predominance of only one isoform is associated with the accumulation of EC but not with apoptosis in the tubules.
Authors:
Casimir D Akpovi; Suk Ran Yoon; María Leiza Vitale; R-Marc Pelletier
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2006-07-21
Journal Detail:
Title:  Journal of lipid research     Volume:  47     ISSN:  0022-2275     ISO Abbreviation:  J. Lipid Res.     Publication Date:  2006 Oct 
Date Detail:
Created Date:  2006-09-29     Completed Date:  2007-03-29     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0376606     Medline TA:  J Lipid Res     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2233-47     Citation Subset:  IM    
Affiliation:
Département de Pathologie et Biologie Cellulaire, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada.
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MeSH Terms
Descriptor/Qualifier:
Animals
Apoptosis
Cholesterol / blood
Cholesterol Esters / blood,  metabolism*
Immunohistochemistry
Infertility, Male
Male
Mink
Protein Isoforms / chemistry,  metabolism
Scavenger Receptors, Class B / chemistry*,  metabolism*
Testis / anatomy & histology,  cytology,  metabolism*
Testosterone / blood
Chemical
Reg. No./Substance:
0/Cholesterol Esters; 0/Protein Isoforms; 0/Scavenger Receptors, Class B; 57-88-5/Cholesterol; 58-22-0/Testosterone

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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