TY - JOUR
T1 - Sphingosine 1-phosphate protects bovine oocytes from heat shock during maturation
AU - Roth, Z.
AU - Hansen, P. J.
PY - 2004/12
Y1 - 2004/12
N2 - Sphingosine 1-phosphate (S1P) is a sphingolipid metabolite that can block apoptosis by counteracting the proapoptotic effects of ceramide. Experiments were performed to evaluate whether S1P blocks the disruption in oocyte developmental competence caused by heat shock. Cumulus-oocyte complexes (COCs) were placed in maturation medium and cultured at 38.5 or 41°C for the first 12 h of maturation. Incubation during the last 10 h of maturation, fertilization, and embryonic development were performed at 38.5°C. Heat shock during the first 12 h of maturation reduced cleavage rate, the number of oocytes developing to the blastocyst stage, and the percentage of cleaved embryo that subsequently developed to blastocysts. Addition of 50 nM S1P to maturation medium had no effect on oocytes matured at 38.5°C but blocked effects of thermal stress on cleavage and subsequent development. The blastocysts formed at Day 8 did not differ between S1P and control groups in caspase activity, total cell number, or percentage of cells that were apoptotic. Blocking endogenous generation of S1P by addition of 50 nM N1N-dimethylsphingosine, a sphingosine kinase inhibitor, reduced or tended to reduce cleavage rate and blastocyst development regardless of whether maturation of COCs was at 38.5 or 41°C. Results demonstrate that S1P protects oocytes from a physiologically relevant heat shock and affects oocyte maturation even in the absence of heat shock. The S1P-treated oocytes that survived heat shock and became blastocysts had a normal developmental potential as determined by caspase activity, total cell number, and percentage of apoptotic cells. Thus, modulation of developmental competence of oocytes using S1P may be a useful approach for enhancing fertility in situations where developmental competence of oocytes is compromised.
AB - Sphingosine 1-phosphate (S1P) is a sphingolipid metabolite that can block apoptosis by counteracting the proapoptotic effects of ceramide. Experiments were performed to evaluate whether S1P blocks the disruption in oocyte developmental competence caused by heat shock. Cumulus-oocyte complexes (COCs) were placed in maturation medium and cultured at 38.5 or 41°C for the first 12 h of maturation. Incubation during the last 10 h of maturation, fertilization, and embryonic development were performed at 38.5°C. Heat shock during the first 12 h of maturation reduced cleavage rate, the number of oocytes developing to the blastocyst stage, and the percentage of cleaved embryo that subsequently developed to blastocysts. Addition of 50 nM S1P to maturation medium had no effect on oocytes matured at 38.5°C but blocked effects of thermal stress on cleavage and subsequent development. The blastocysts formed at Day 8 did not differ between S1P and control groups in caspase activity, total cell number, or percentage of cells that were apoptotic. Blocking endogenous generation of S1P by addition of 50 nM N1N-dimethylsphingosine, a sphingosine kinase inhibitor, reduced or tended to reduce cleavage rate and blastocyst development regardless of whether maturation of COCs was at 38.5 or 41°C. Results demonstrate that S1P protects oocytes from a physiologically relevant heat shock and affects oocyte maturation even in the absence of heat shock. The S1P-treated oocytes that survived heat shock and became blastocysts had a normal developmental potential as determined by caspase activity, total cell number, and percentage of apoptotic cells. Thus, modulation of developmental competence of oocytes using S1P may be a useful approach for enhancing fertility in situations where developmental competence of oocytes is compromised.
KW - Early development
KW - Embryo
KW - Environment
KW - Gamete biology
KW - Heat shock
KW - Oocyte
KW - Oocyte development
KW - Sphingosine T-phosphate
UR - http://www.scopus.com/inward/record.url?scp=9744226427&partnerID=8YFLogxK
U2 - 10.1095/biolreprod.104.031989
DO - 10.1095/biolreprod.104.031989
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C2 - 15317688
AN - SCOPUS:9744226427
SN - 0006-3363
VL - 71
SP - 2072
EP - 2078
JO - Biology of Reproduction
JF - Biology of Reproduction
IS - 6
ER -