Fusiogenic endogenous-retroviral syncytin-1 exerts anti-apoptotic functions in staurosporine-challenged CHO cells.
Fusiogenic glycoprotein syncytin-1, expressed in human placenta, is a promising candidate for acquiring a basic knowledge of placental syncytialization. However, its cellular mode of action is unidentified. We investigated whether syncytin-1 may exert influence on apoptotic processes. Therefore, we incubated CHO cells after stable transfection with syncytin-1 (CHO-52) in the presence or absence of staurosporine (STS), a kinase inhibitor well characterized to induce apoptosis. When testing the phenotype of CHO-52 cells, we could demonstrate that the induction of apoptosis by STS was delayed over a period of up to 24 h. Furthermore, the cell death rate was decreased by approx 75% following transfection of syncytin-1 in CHO-52 compared to mock-treated cells. In detail, after 18h of incubation with 500 nM STS, 64 +/- 2% of CHO-52 cells were viable compared to 16 +/- 1% of CHO-mocks, after 24 h 43 +/- 3% vs 5 +/- 2%, respectively. CHO-52 cells exhibited a lower expression of active caspase 3 and anti-apoptotic Bcl-2 was found to be increased in CHO-52 cells at baseline and following STS treatment. Our study provides first evidence that syncytin-1 serves anti-apoptotic function under certain conditions. A lessened activation of caspase 3 and an increased expression of Bcl-2 are possible mechanisms.
Knerr
Ina
I
Children and Youth Hospital, University of Erlangen-Nuremberg, Loschgestr. 15, D-91054, Erlangen, Germany. ina.knerr@kinder.imed.uni-erlangen.de
Schnare
Markus
M
Hermann
Kathrin
K
Kausler
Susanne
S
Lehner
Manfred
M
Vogler
Tina
T
Rascher
Wolfgang
W
Meissner
Udo
U
D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology*; D016466:CHO Cells; D002459:Cell Fusion; D006224:Cricetinae; D003412:Cricetulus; D020077:Endogenous Retroviruses / Q000235:genetics / Q000502:physiology; D005260:Female; D015686:Gene Products, env / Q000235:genetics / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D008856:Microscopy, Fluorescence; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D019311:Staurosporine / Q000494:pharmacology*; D014162:Transfection
D015686:Gene Products, env; D011257:Pregnancy Proteins; D011994:Recombinant Proteins; C405335:syncytin; D019311:Staurosporine