Effect of melatonin and nitric oxide on capacitation and apoptotic changes induced by epidermal growth factor in ram sperm
Sara Miguel-Jiménez
A , Melissa Carvajal-Serna A , Victoria Peña-Delgado A , Adriana Casao A and Rosaura Pérez-Pe A *
+ Author Affiliations
- Author Affiliations
A Department of Biochemistry and Molecular and Cell Biology, Faculty of Veterinary Sciences, Institute of Environmental Sciences of Aragón (IUCA), University of Zaragoza, Miguel Servet 177, Zaragoza 50013, Spain.
Reproduction, Fertility and Development 35(3) 282-293 https://doi.org/10.1071/RD22146
Published online: 21 November 2022
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing
Abstract
Context: Apart from the canonical cAMP-PKA pathway, ram sperm capacitation can be achieved by the MAPK ERK1/2 signalling cascade, activated by epidermal growth factor (EGF).
Aims: This study aims to investigate the effect of melatonin and nitric oxide (NO·) on capacitation and apoptotic-like changes in EGF-capacitated ram spermatozoa.
Methods: In vitro capacitation was induced by EGF in the absence or presence of melatonin (100 pM or 1 μM). Also, a NO· precursor, L-arginine, or a NOS inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), were added to capacitation media to study the interaction of NO· and melatonin during EGF-capacitation. Sperm functionality parameters (motility, viability, capacitation state), apoptotic markers (caspase activation and DNA damage), NO· levels, and phosphorylated c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (assessed by Western blot), were evaluated in swim-up and capacitated samples with EGF.
Key results: NO· levels and the apoptotic-related markers were raised after EGF incubation. Melatonin had a bimodal role on sperm EGF-capacitation, preventing it at high concentration and promoting acrosome reaction at low concentration, but neither of the two concentrations prevented the increase in apoptotic-like markers or NO· levels. However, melatonin at 1 μM prevented the activation of JNK.
Conclusions: NO· metabolism does not seem to modulate the apoptosis-like events in ram spermatozoa. Melatonin at 1 μM prevents ram sperm capacitation induced by EGF independently from nitric oxide metabolism, and it could be exerted by limiting the JNK mitogen-activated protein kinase (MAPK) activation.
Implications: This study improves our understanding of the biochemical mechanisms involved in sperm capacitation, and ultimately, fertility.
Keywords: apoptosis, epidermal growth factor, MAP kinases, melatonin, nitric oxide, oxidative stress, ram spermatozoa, sperm capacitation.
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