Role of tumor necrosis factor in preovulatory follicles of swine.
The effects of tumor necrosis factor (TNF) on cultured porcine granulosa cells that were obtained from preovulatory follicles were studied with regard to following parameters: 1) TNF receptor type I expression, 2) progesterone receptor and transforming growth factor beta receptor type II (TbetaR II) as markers of luteinization, 3) proliferation, and 4) apoptosis. For comparative purposes the effects of TNF were also studied on insulin/forskolin-treated cells, as this treatment is well established to induce luteinization. Cytochemical methods followed by semiquantitative analysis were used. Our data show that TNF treatment upregulates TNF receptor type I expression in granulosa cells. TNF downregulates the expression of TbetaR II of insulin/forskolin-stimulated and of unstimulated cells. The progesterone receptor is also downregulated by the cytokine after insulin/forskolin-induced luteinization. Supplementation of the medium with TNF leads to increased proliferation and at the same time it induces apoptosis. Our results indicate that TNF exerts an inhibitory influence on luteinization and that TNF influences the balance between follicular growth (proliferation) and atresia (apoptosis).
Prange-Kiel
J
J
Institute of Anatomy, Ernst Moritz Arndt University, Friedrich-Loeffler-Strasse 23c, 17487 Greifswald, Germany. prange@mail.uni-greifswald.de
Kreutzkamm
C
C
Wehrenberg
U
U
Rune
G M
GM
D000818:Animals; D017304:Annexin A5 / Q000032:analysis; D015703:Antigens, CD / Q000032:analysis; D017209:Apoptosis; D002455:Cell Division / Q000187:drug effects; D002467:Cell Nucleus / Q000737:chemistry; D005576:Colforsin / Q000494:pharmacology; D005260:Female; D006107:Granulosa Cells / Q000737:chemistry / Q000166:cytology / Q000187:drug effects; D020287:In Situ Nick-End Labeling; D007328:Insulin / Q000494:pharmacology; D006080:Ovarian Follicle / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D011980:Receptors, Progesterone / Q000032:analysis; D018125:Receptors, Transforming Growth Factor beta / Q000032:analysis; D018124:Receptors, Tumor Necrosis Factor / Q000032:analysis; D047888:Receptors, Tumor Necrosis Factor, Type I; D013552:Swine; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology / Q000502:physiology*
D017304:Annexin A5; D015703:Antigens, CD; D007328:Insulin; D011980:Receptors, Progesterone; D018125:Receptors, Transforming Growth Factor beta; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D014409:Tumor Necrosis Factor-alpha; D005576:Colforsin