Fas-mediated apoptosis is suppressed by calf serum in cultured bovine luteal cells.
Calf serum (CS) is a common supplement used in cell culture. It has been suggested that CS contains substances protecting cells against apoptosis. To examine whether a culture system including CS is appropriate for studying apoptosis in bovine luteal cells, we examined the influence of CS on the expression of Fas, bcl-2 and bax gene. Since progesterone (P(4)) is known to be an anti-apoptotic factor in bovine luteal cells, the present study was carried out to examine the P(4) effect on apoptosis. Bovine mid-luteal cells were exposed to Fas ligand (Fas L) in the presence or in the absence of P(4) antagonist (onapristone, OP) in a basal medium (BM) containing 5% CS (BM-CS) or BM containing 0.1% BSA (BM-BSA). Although Fas L alone, OP alone or Fas L plus OP did not show any cytotoxic effect on the cells cultured in BM-CS, administration of OP or OP in combination with Fas L resulted in the killing of 30% and 55% of the cells cultured in BM-BSA medium, respectively (p<0.05). Concomitantly, CS inhibited bax mRNA expression and stimulated bcl-2 expression in the cells (p<0.05). Moreover, in the cells cultured with BM-CS, Fas mRNA expression was smaller than that of cells incubated in BM-BSA medium (p<0.05). The overall results suggest that CS suppressed Fas-mediated cell death in cultured bovine luteal cells by promoting the ratio of bcl-2 to bax expression and by inhibiting Fas expression. Therefore, it may be suggested that CS contains such anti-apoptotic substances (growth factors) amplifying the cell survival pathways in the bovine corpus luteum (CL) in vitro.
Skarzynski
Dariusz J
DJ
Department of Reproductive Immunology, Institute of Animal Reproduction and Food Research, PAS, Tuwima St 10, Olsztyn 10-747, Poland. skadar@pan.olsztyn.pl
Shibaya
Masami
M
Tasaki
Yukari
Y
Korzekwa
Anna
A
Murakami
Shuko
S
Woclawek-Potocka
Izabela
I
Majewska
Magdalena
M
Okuda
Kiyoshi
K
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002417:Cattle; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D003470:Culture Media; D053222:Fas Ligand Protein / Q000494:pharmacology*; D005260:Female; D008184:Luteal Cells / Q000187:drug effects*; D011374:Progesterone / Q000494:pharmacology*; D044967:Serum / Q000378:metabolism*
D003470:Culture Media; D053222:Fas Ligand Protein; D011374:Progesterone