title: Effects of ghrelin on the apoptosis of human neutrophils in vitro.
abstract: Acute respiratory distress syndrome (ARDS) is characterized by lung inflammation and the diffuse infiltration of neutrophils into the alveolar space. Neutrophils are abundant, short-lived leukocytes that play a key role in immune defense against microbial infections. These cells die via apoptosis following the activation and uptake of microbes, and will also enter apoptosis spontaneously at the end of their lifespan if they do not encounter pathogens. Apoptosis is essential for the removal of neutrophils from inflamed tissues and for the timely resolution of neutrophilic inflammation. Ghrelin is an endogenous ligand for the growth hormone (GH) secretagogue receptor, produced and secreted mainly from the stomach. Previous studies have reported that ghrelin exerts anti-inflammatory effects in lung injury through the regulation of the apoptosis of different cell types; however, the ability of ghrelin to regulate alveolar neutrophil apoptosis remains largely undefined. We hypothesized that ghrelin may have the ability to modulate neutrophil apoptosis. In this study, to examine this hypothesis, we investigated the effects of ghrelin on freshly isolated neutrophils in vitro. Our findings demonstrated a decrease in the apoptotic ratio (as shown by flow cytometry), as well as in the percentage of cells with decreased mitochondrial membrane potential (ΔΨm) and in the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick‑end labeling-positive rate, accompanied by an increased B-cell lymphoma 2/Bax ratio and the downregulation of cleaved caspase-3 in neutrophils following exposure to lipopolysaccharide (100 ng/ml). However, pre-treatment with ghrelin at a physiological level (100 nM) did not have a notable influence on the neutrophils in all the aforementioned tests. Our findings suggest that ghrelin may not possess the ability to modulate the neutrophil lifespan in vitro.
authors.affiliation: Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Mian
authors.initials: M
authors.lastname: Zeng
authors.affiliation: Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Haichong
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Chunrong
authors.initials: C
authors.lastname: Huang
authors.affiliation: Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Wanmei
authors.initials: W
authors.lastname: He
authors.affiliation: Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Guifang
authors.initials: G
authors.lastname: Lu
authors.affiliation: Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Yanzhu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Ruijie
authors.initials: R
authors.lastname: Xie
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects; D005434:Flow Cytometry; D054439:Ghrelin / Q000494:pharmacology*; D006801:Humans; D020287:In Situ Nick-End Labeling; D008070:Lipopolysaccharides / Q000494:pharmacology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D008856:Microscopy, Fluorescence; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494826:BAX protein, human; D054439:Ghrelin; D008070:Lipopolysaccharides; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D053148:Caspase 3