Localization of epidermal-type fatty acid binding protein in macrophages in advanced atretic follicles of adult mice.
The localization of epidermal-type fatty acid binding protein (E-FABP) in the mature mouse ovary was examined by immuno-light and electron microscopy. Numerous macrophages immunopositive for both anti-E-FABP and F4/80 antibodies, together with immunonegative cells, were found in advanced atretic follicles that had eccentric lumens containing deformed ova. While some E-FABP-immunopositive macrophages were spider in shape and appeared singly, others, especially close to the lumen, were round and voluminous and tended to be aggregated. The voluminous macrophages contained phagosomes of various sizes and they were regarded as those actively involved in the phagocytosis of apoptotic granulosa cells. E-FABP-immunopositive macrophages and their processes were often apposed to adjacent immunonegative cells, and some of them lined the lumen containing deformed ova. On the other hand, E-FABP-immunonegative cells in the atretic follicles were classified into two types: the one, a minority, was characterized by small mitochondria containing non-tubular cristae and presumably represented residual granulosa cells, while the other dominant type was characterized by large mitochondria containing tubular cristae and presumably represented theca cells originally surrounding the follicles to be atretic. The present detection of E-FABP-immunopositivity selectively in macrophages of the atretic follicles suggests possible involvement of E-FABP and/or its ligand fatty acids in the process of follicular atresia, and it makes more reliable the identification of the advanced atretic follicles with the antral spaces obliterated, which could provide further details on the histology of the follicular atresia than before.
Nourani
Mohammad Reza
MR
Division of Histology, Department of Cell Biology, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Japan.
Owada
Yuji
Y
Kitanaka
Noriko
N
Abdelwahab
Soha Abdelkawi
SA
Iwasa
Hiroo
H
Sakagami
Hiroyuki
H
Spener
Friedrich
F
Kondo
Hisatake
H
D000818:Animals; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins / Q000378:metabolism*; D005260:Female; D008264:Macrophages / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D051379:Mice; D008810:Mice, Inbred C57BL; D009363:Neoplasm Proteins / Q000378:metabolism*; D006080:Ovarian Follicle / Q000166:cytology* / Q000378:metabolism* / Q000648:ultrastructure; D021381:Protein Transport
C493409:Fabp3 protein, mouse; C082667:Fabp5 protein, mouse; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins; D009363:Neoplasm Proteins