title: Bovine spermatozoa react to in vitro heat stress by activating the mitogen-activated protein kinase 14 signalling pathway.
abstract: Heat stress has long been recognised as a cause of subfertility in farm animals. The objectives of the present study were to elucidate the effect of heat stress on sperm function and involvement of the mitogen-activated protein kinase (MAPK) 14 signalling pathway. Spermatozoa incubated for 4 h at a physiological temperature (38.5°C) exhibited significantly (P<0.05) reduced motility, plasma membrane integrity and mitochondrial potential compared with non-incubated spermatozoa; the reductions in these parameters were more severe following incubation at a hyperthermic (41°C) temperature (P<0.01). Percentages of fertilisation and embryo development were highly affected in spermatozoa incubated at 41°C compared with non-incubated spermatozoa (P<0.01). Similarly, embryo quality was adversely affected by sperm incubation at 41°C, as indicated by a higher apoptotic cell ratio in Day 7 blastocysts compared with that in the non-incubated control group (14.6% vs 6.7%, respectively; P<0.01). Using SB203580 (10 µgmL(-1)), a specific inhibitor of the p38 MAPK pathway, during sperm hyperthermia reduced MAPK14 activation (24.9% vs 35.6%), increased sperm motility (45.8% vs 26.5%) and reduced DNA fragmentation (16.9% vs 23.4%) compared with the untreated control group, but did not improve subsequent fertilisation and embryo development. In conclusion, heat stress significantly affects the potential of spermatozoa to penetrate oocytes, as well as subsequent embryo development and quality. Notably, the data show that the MAPK14 signalling pathway is largely involved in heat-induced sperm damage. However, further research is needed to elucidate other signalling pathways possibly involved in heat-induced sperm damage.
authors: Department of Reproduction, Obstetrics and Herd Health, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors: Mohammad Bozlur
authors: MB
authors: Rahman
authors: Department of Animal Science, Institute for Agricultural and Fisheries Research, Scheldeweg 68, 9090 Melle, Belgium.
authors: Leen
authors: L
authors: Vandaele
authors: Department of Reproduction, Obstetrics and Herd Health, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors: Tom
authors: T
authors: Rijsselaere
authors: Department of Animal Production, Suez Canal University, Ismailia 41522, Egypt.
authors: Mohamed Shehab
authors: MS
authors: El-Deen
authors: Department of Reproduction, Obstetrics and Herd Health, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors: Dominiek
authors: D
authors: Maes
authors: Department of Surgery and Obstetrics, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
authors: Mohammed
authors: M
authors: Shamsuddin
authors: Department of Reproduction, Obstetrics and Herd Health, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors: Ann
authors: A
authors: Van Soom
mesh_terms: D000818:Animals; D017209:Apoptosis; D001755:Blastocyst / Q000473:pathology; D002417:Cattle; D002462:Cell Membrane / Q000473:pathology; D046149:Embryo Culture Techniques; D004789:Enzyme Activation; D005307:Fertilization in Vitro; D018869:Heat-Shock Response; D006358:Hot Temperature; D008297:Male; D053078:Membrane Potential, Mitochondrial; D048308:Mitogen-Activated Protein Kinase 14 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D015398:Signal Transduction; D013081:Sperm Motility; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D013997:Time Factors
chemical_list: D047428:Protein Kinase Inhibitors; D048308:Mitogen-Activated Protein Kinase 14