title: Melatonin is able to delay endoplasmic reticulum stress-induced apoptosis in leukocytes from elderly humans.
abstract: The mechanisms regulating neutrophil apoptosis are basically unaffected by the aging process. However, a significant impairment of cell survival occurs in elderly individuals following neutrophil challenge with pro-inflammatory stimuli, such as granulocyte-macrophage colony-stimulating factor (GM-CSF). The goal of the present study was to prove the effects of melatonin supplementation on apoptosis induced by calcium signaling in human leukocytes from elderly volunteers. Treatments with the specific inhibitor of cytosolic calcium re-uptake, thapsigargin, and/or the calcium mobilizing agonist, N-formyl-methionyl-leucyl-phenylalanine (fMLP), induced mitochondrial membrane depolarization, caspase activation, phosphatidylserine (PS) externalization, and DNA fragmentation in leukocytes from both young and elderly volunteers, although such effects were much more evident in aged leukocytes. Importantly, melatonin treatment substantially preserved mitochondrial membrane potential, reversed caspase activation, reduced PS exposure and forestalled DNA fragmentation in leukocytes from both age groups. In conclusion, melatonin is able to delay endoplasmic reticulum stress-induced apoptosis in aged leukocytes and may counteract, at the cellular level, age-related degenerative phenomena linked to oxidative stress.
authors.affiliation: Department of Physiology, Neuroimmunophysiology and Chrononutrition Research Group, Faculty of Science, University of Extremadura, Badajoz, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Espino
authors.forename: Ignacio
authors.initials: I
authors.lastname: Bejarano
authors.forename: Sergio D
authors.initials: SD
authors.lastname: Paredes
authors.forename: Carmen
authors.initials: C
authors.lastname: Barriga
authors.forename: Russel J
authors.initials: RJ
authors.lastname: Reiter
authors.forename: José A
authors.initials: JA
authors.lastname: Pariente
authors.forename: Ana B
authors.initials: AB
authors.lastname: Rodríguez
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002478:Cells, Cultured; D053938:DNA Fragmentation / Q000187:drug effects; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D006801:Humans; D007962:Leukocytes / Q000502:physiology*; D008550:Melatonin / Q000494:pharmacology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000502:physiology; D010718:Phosphatidylserines / Q000378:metabolism; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: D010718:Phosphatidylserines; D009240:N-Formylmethionine Leucyl-Phenylalanine; D019284:Thapsigargin; D053148:Caspase 3; D053453:Caspase 9; D008550:Melatonin; D002118:Calcium