Abstract
Vitrified MII porcine oocytes are characterized by reduced developmental competence, associated with the activation of the apoptotic pathway. Resveratrol (R), a polyphenolic compound present in several vegetal sources, has been reported to exert, among all its other biological effects, an antiapoptotic one. The aim of this study was to determine the effects of R (2 µM) on the apoptotic status of porcine oocytes vitrified by Cryotop method, evaluating phosphatidylserine (PS) exteriorization and caspases activation. R was added during IVM (A); 2 h postwarming incubation (B); vitrification/warming and 2 h postwarming incubation (C); all previous phases (D). Data on PS exteriorization showed, in each treated group, a significantly higher (P < 0.05) percentage of live nonapoptotic oocytes as compared with CTR; moreover, the percentage of live apoptotic oocytes was significantly (P < 0.05) lower in all R-treated groups relative to CTR. The results on caspase activation showed a tendency to an increase of viable oocytes with inactive caspases in B, C, and D, while a significant (P < 0.05) increase in A compared to CTR was recorded. These data demonstrate that R supplementation in various phases of IVM and vitrification/warming procedure can modulate the apoptotic process, improving the resistance of porcine oocytes to cryopreservation-induced damage.
Highlights
IntroductionVitrification of oocytes is the most recent cryopreservation methodology, used in different species such as human [1], bovine [2], goat, and swine [3].Currently, several studies have been carried out to improve the efficacy of cryopreservation protocols, validating different cryoprotectant solutions, incubation times, oocytes containers, and other many conditions [4].Recent progresses in the vitrification technique are attested by the high number of born after cryopreservation of human [5], mouse [6], cat [7], and bovine [8] oocytes, but no piglets have been obtained from cryopreserved swine oocytes so far.Compared with other domestic species, the high intracellular lipid content [9] and the wide cell volume make porcine oocytes more susceptible to storage at low temperature, with a consequent decrease of oocytes survival rate and apoptotic progression after thawing [10, 11].the survival and development of unfertilized vitrified porcine oocytes are significantly lower than those of fertilized vitrified ones [12, 13]
In all groups supplemented with R the percentage of live apoptotic oocytes (A+propidium iodide (PI)−) was significantly (P < 0.05) lower than in CTR group
Our results demonstrate that 2 μM R in In Vitro Maturation (IVM) and vitrification-warming phases increases oocytes viability, modulating the apoptotic process
Summary
Vitrification of oocytes is the most recent cryopreservation methodology, used in different species such as human [1], bovine [2], goat, and swine [3].Currently, several studies have been carried out to improve the efficacy of cryopreservation protocols, validating different cryoprotectant solutions, incubation times, oocytes containers, and other many conditions [4].Recent progresses in the vitrification technique are attested by the high number of born after cryopreservation of human [5], mouse [6], cat [7], and bovine [8] oocytes, but no piglets have been obtained from cryopreserved swine oocytes so far.Compared with other domestic species, the high intracellular lipid content [9] and the wide cell volume make porcine oocytes more susceptible to storage at low temperature, with a consequent decrease of oocytes survival rate and apoptotic progression after thawing [10, 11].the survival and development of unfertilized vitrified porcine oocytes are significantly lower than those of fertilized vitrified ones [12, 13]. Vitrification of oocytes is the most recent cryopreservation methodology, used in different species such as human [1], bovine [2], goat, and swine [3]. Recent progresses in the vitrification technique are attested by the high number of born after cryopreservation of human [5], mouse [6], cat [7], and bovine [8] oocytes, but no piglets have been obtained from cryopreserved swine oocytes so far. Compared with other domestic species, the high intracellular lipid content [9] and the wide cell volume make porcine oocytes more susceptible to storage at low temperature, with a consequent decrease of oocytes survival rate and apoptotic progression after thawing [10, 11]. During the vitrification/warming process many oocyte ultrastructures, such as mitochondria, smooth endoplasmatic reticulum, meiotic spindle, and plasma membrane, show considerable damages that contribute to reduce the developmental potential of oocytes after fertilization [14, 15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
