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Nuclear transfer with apoptotic bovine fibroblasts: can programmed cell death be reprogrammed?
Moyses dos Santos Miranda1, Fabiana Fernandes Bressan, Tiago Henrique Camara De Bem
1Faculdade de Biotecnologia, Universidade Federal do Pará (UFPA), Belém, Pará, Brazil. moyses_m@hotmail.com
Cellular Reprogramming
|June 13, 2012
Summary
Apoptosis, or programmed cell death, may be reversible in early stages. Somatic cell nuclear transfer using early apoptotic cells showed potential for reversing cell death before caspase-9 activation.
Area of Science:
- Reproductive biology
- Cell biology
- Developmental biology
Background:
- Apoptosis is generally considered irreversible.
- Previous research suggests reversibility is possible before a critical
- point of no return.
Purpose of the Study:
- To investigate the reversibility of apoptosis using somatic cell nuclear transfer (SCNT).
- To identify the stage of apoptosis at which it becomes irreversible.
Main Methods:
- Adult bovine fibroblasts were induced into apoptosis using staurosporine (STP).
- Cells were analyzed for phosphatidylserine externalization (Annexin assay) and active caspase-9.
- Annexin-positive and Caspase-9-positive cells were used as nuclear donors in SCNT.
Main Results:
- STP treatment induced significant phosphatidylserine externalization (89.9% Annexin-positive) and caspase-9 activation (24.9% Caspase-9-positive).
- SCNT using Annexin-positive cells did not affect fusion, cleavage, or blastocyst production rates.
- However, SCNT using Caspase-9-positive cells significantly reduced blastocyst formation.
Conclusions:
- Apoptosis is reversible only in its early stages, prior to caspase-9 activation.
- The "point of no return" for apoptosis may coincide with the activation of caspase-9.
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