title: Supplementation of tauroursodeoxycholic acid during IVC did not enhance in vitro development and quality of buffalo IVF embryos but combated endoplasmic reticulum stress.
abstract: Endoplasmic reticulum (ER) stress, a dysfunction in protein-folding capacity of ER, is involved in many pathologic and physiological responses including embryonic development. This study investigated the effect of supplementation of IVC medium with an ER stress inducer, tunicamycin (TM), and an inhibitor, tauroursodeoxycholic acid (TUDCA), on the developmental competence, apoptosis, and gene expression in buffalo embryos produced by IVF. Treatment of presumed zygotes with TM resulted in a significant (P < 0.01) decrease in the blastocyst rate, whereas TUDCA supplementation did not improve the blastocyst development rate. Further, presence of TUDCA could not ameliorate the adverse effects of TM in terms of the blastocyst rate in combined (TM + TUDCA) treatment. Tunicamycin treatment increased (P < 0.01) the apoptotic index and reduced the total cell number, whereas TUDCA did not affect them significantly. However, TUDCA reduced the extent of TM-mediated apoptosis during combined (TM + TUDCA) treatment. Tunicamycin treatment increased (P < 0.01) and TUDCA treatment decreased (P < 0.01) the expression level of ER chaperones, GRP78 and GRP94. In the combined TM + TUDCA treatment, TUDCA decreased their expression level compared to that in the controls. A similar pattern was observed in the case of proapoptotic gene BAX. We did not find any significant difference in the expression level of BCl-XL, BID, P53, and CASPASE 3 after TM and TUDCA supplementation. In conclusion, our study reported that TM induces ER stress in buffalo embryos produced in vitro resulting in a decrease in the blastocyst rate and an increase in the level of apoptosis and that these actions are mediated by modulating the expression of apoptosis-related genes and ER chaperones. Tauroursodeoxycholic acid did not improve the developmental potential of buffalo embryos; however, it attenuated the TM-induced apoptosis by downregulating BAX and ER chaperones.
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India.
authors.forename: Arpna
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India.
authors.forename: Himanshu
authors.initials: H
authors.lastname: Agrawal
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India.
authors.forename: Nowsheen
authors.initials: N
authors.lastname: Mullani
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India.
authors.forename: Anjit
authors.initials: A
authors.lastname: Sandhu
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India.
authors.forename: Manoj Kumar
authors.initials: MK
authors.lastname: Singh
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India.
authors.forename: Manmohan Singh
authors.initials: MS
authors.lastname: Chauhan
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India.
authors.forename: Suresh Kumar
authors.initials: SK
authors.lastname: Singla
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India.
authors.forename: Prabhat
authors.initials: P
authors.lastname: Palta
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India. Electronic address: manik_rs@rediffmail.com.
authors.forename: Radhay Sham
authors.initials: RS
authors.lastname: Manik
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D001755:Blastocyst / Q000187:drug effects / Q000502:physiology; D002020:Buffaloes / Q000196:embryology*; D003470:Culture Media; D046149:Embryo Culture Techniques / Q000379:methods / Q000662:veterinary*; D047108:Embryonic Development / Q000187:drug effects*; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D005307:Fertilization in Vitro / Q000662:veterinary*; D015870:Gene Expression / Q000187:drug effects; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones / Q000235:genetics; D013657:Taurodeoxycholic Acid / Q000008:administration & dosage*; D014415:Tunicamycin / Q000494:pharmacology; D051028:bcl-2-Associated X Protein / Q000235:genetics
chemical_list: D003470:Culture Media; D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D051028:bcl-2-Associated X Protein; D014415:Tunicamycin; D013657:Taurodeoxycholic Acid
keywords: Apoptosis; Blastocyst; Endoplasmic reticulum stress; Gene expression; IVF