Polymorphonuclear leukocyte (neutrophil) apoptosis is an important mechanism regulating the life span and some functions of neutrophils at inflamed sites. Opioid peptides are present in the peripheral circulation and their concentrations rapidly increase as a result of stress and inflammation. The effect of opioid peptides such as met-enkephalin (M-ENK) and beta-endorphin (beta-END) on tumor necrosis factor (TNF)-alpha-induced apoptosis in human neutrophils in vitro was investigated. Neutrophils isolated from peripheral blood were cultured in the absence or presence of 10(-6)-10(-10) M of opioid peptides for 8, 12 and 18 h. Features of apoptotic neutrophils were measured by a flow cytometric method based on analysis of the apoptotic nuclei (DNA content). We found that M-ENK and beta-END enhanced both uninduced and TNF-alpha-induced neutrophil apoptosis in vitro in a dose-dependent manner. The effect of opioid peptides on the modulation of neutrophil apoptosis was not reversed by the opioid-receptor antagonist naloxone. The results suggest that M-ENK and beta-END can regulate neutrophil life span via apoptosis and in this way may participate in the resolution of inflammation.
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Neuropsychopharmacol Rep
March 2025
Department of Neurology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
Aim: We aimed to create a rat model of drug-induced parkinsonism and tardive dyskinesia by chronic administration of haloperidol and examine the expression of direct and indirect pathway markers in the striatum of the model rats.
Methods: We treated 21 rats, 14 with haloperidol decanoate and 7 with placebo. The number of vacuous chewing movements per 2 min was counted, and haloperidol-treated rats were classified into two groups: mild and severe tardive dyskinesia.
Zhong Nan Da Xue Xue Bao Yi Xue Ban
July 2024
Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha 410008.
Pain is a signal of inflammation that can have both protective and pathogenic effects. Macrophages, significant components of the immune system, play crucial roles in the occurrence and development of pain, particularly in neuroimmune communication. Macrophages exhibit plasticity and heterogeneity, adopting either pro-inflammatory M1 or anti-inflammatory M2 phenotypes depending on their functional orientation.
View Article and Find Full Text PDFCells
December 2024
Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, Switzerland.
The nociceptin receptor (NOP) and nociceptin are involved in the pathways of pain and inflammation. The potent role of nuclear factor-κB (NFκB) in the modulation of tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β on the nociceptin system in human THP-1 cells under inflammatory conditions were investigated. Cells were stimulated without/with phorbol-myristate-acetate (PMA), TNF-α, IL-1β, or PMA combined with individual cytokines.
View Article and Find Full Text PDFFront Mol Biosci
December 2024
Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates.
Hemorphins are short atypical opioid peptide fragments embedded in the β-chain of hemoglobin. They have received considerable attention recently due to their interaction with opioid receptors. The affinity of hemorphins to opioid receptors μ-opioid receptor (MOR), δ-opioid receptor (DOR), and κ-opioid receptor (KOR) has been well established.
View Article and Find Full Text PDFNeuropharmacology
March 2025
Tufts University Cummings School of Veterinary Medicine, North Grafton, MA, USA. Electronic address:
Background: The opioid epidemic is leading to increased opioid use in adolescent populations. A growing body of evidence suggests that taking opioids during adolescence can disrupt normal development and impact future offspring. This study investigates the impact of paternal morphine exposure during adolescence on the hypothalamic-pituitary-adrenal (HPA) axis and release of endorphins in the offspring.
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