Macrophages: a source of luteotropic cybernins.
ABSTRACT A macrophage homogenate contained substances which stimulated primary cultures of mouse granulosa cells to secrete more progesterone. The response to the luteotropic substances was similar to that observed when intact macrophages were co-cultured with granulosa cells. The bioactive polypeptides present in cytosolic and particulate fractions of cell homogenates were non-dialyzable, heat labile and trypsin sensitive. When the surface of intact macrophages was treated with trypsin there was a loss of activity from the particulate fraction suggesting that some luteotropic proteins reside on the plasma membrane of mononuclear phagocytes. Treatment of macrophages with Con A but not the succinyl derivative of the lectin caused a release of luteotropic proteins with apparent molecular weights of 26,000 and 41,000. These findings in conjunction with our prior observation that macrophages must contact granulosa cells to stimulate progesterone secretion suggest that aggregation of mononuclear cell surface proteins may occur when the two cells interact thus resulting in the expression of luteotropic activity. Hence, it appears that macrophages which are found within corpus luteum may be a source of ovarian cybernins. This is the first description that a cell of the immune system can communicate at the molecular level with a steroid secreting cell of the ovary.
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ABSTRACT: It has been shown previously that the intact adult rat testis produces large amounts of an interleukin-1 (IL-1)-like growth factor. The present study has investigated whether this testicular IL-1-like factor (tIL-1) is produced and secreted differentially by the fourteen stages of the seminiferous epithelial cycle in the rat testis. Seminiferous tubule segments representing defined stages were identified by tran-sillumination-assisted microscopy and isolated by microdissection. Pooled segments were either homogenized and extracted with aqueous buffer or incubated for 24 h to produce conditioned media (CM). The recovered material was then analysed for IL-1 bioactivity in a sensitive murine thymocyte proliferation assay. When divided into four stage groups, extracts of stages II-VI, IX-XII and XIII-I showed equally high IL-1 activity whereas stage group VII-VIII showed much lower activity. More detailed analysis with 10 different stage groups showed that tIL-1 activity was undetectable in extracts of substages VIIab and VIIcd. The same pattern was seen when CM from cultured tubular segments were analysed. Labelling of seminiferous tubules with tritiated thymidine in vitro and analysis by auto-radiography revealed that DNA-synthesizing spermatogonia were absent in sub-stages VIIb and VIIc and sparse in substages VIIa and VIId. The results show that tIL-1 activity is produced in a stage-dependent manner and suggest that tIL-1 might be involved in the regulation of spermatogonial proliferation in vivo.International Journal of Andrology 06/1991; 14(3):223-231. · 3.21 Impact Factor
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ABSTRACT: Tumor necrosis factor- (TNF-), a cytokine which is produced by activated macrophages, has been shown to participate in the regulation of ovarian functions. In the course of our investigation on the mechanism of maturation, fertilization and degeneration of mouse oocytes, immunoreactivity to TNF- was found in the cytoplasm of the cells surrounding the maturing oocytes and of granulosa cells facing the antral cavity. Immunoblot analysis with the specific antibody to TNF- identified the 17 kDa Mr band in the extract of cumulusoocyte complexes. Various concentrations of TNF- (mouse, recombinant) and anti TNF- antiserum (polyclonal rabbit anti-mouse recombinant TNF-) were then used to determine their effect on the germinal vesicle breakdown (GVBD), polar body extrusion, fertilization and fragmentation of mouse oocytes/eggs. TNF- at concentrations of 10 ng/mL or less and anti-TNF- antiserum at concentrations of 10% or less, had no effect on the spontaneous GVBD and polar body extrusion of mouse oocytes in culture. Mouse follicular oocytes cultured for more than 72 h in modified Krebs-Ringer solution in vitro undergo spontaneous fragmentation, which is a degenerative change to form ‘blastomeres’ with or without nuclear fragments or chromatin. Ghost-like blastomeres were also identified in the space among fragmented ‘blastomeres’. The spontaneous fragmentation of mouse follicular oocytes was suppressed in the presence of TNF- at concentrations of 1 ng/mL or greater. Anti-TNF- antiserum (1%) accelerated the induction of fragmentation of oocytes cultured in vitro. The addition of anti TNF- antiserum (10%) to the culture medium did not influence the fertilization rates of the eggs surrounded by the expanded cumulus. These results appear to indicate that the process of degeneration of mouse oocytes/eggs is modulated by TNF- accumulated in the expanded cumulus during oocyte maturation.Embryologia 10/2003; 37(4):413 - 420. · 2.18 Impact Factor
Article: Immunology of the ovaryImmunology and Allergy Clinics of North America 08/2002; 22(3):435-454. · 2.22 Impact Factor