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Poultry Science Jun 2024The effects of the administration of the opioid agonist, morphine, on plasma and tissue concentrations of Met-enkephalin were determined in 14 wk old female chickens. In...
Research Note: Morphine influences circulating and tissue concentrations of met-enkephalin and proenkephalin (PENK) expression and plasma concentrations of corticosterone in chickens.
The effects of the administration of the opioid agonist, morphine, on plasma and tissue concentrations of Met-enkephalin were determined in 14 wk old female chickens. In addition, effects of morphine on proenkephalin (PENK) expression were examined. Plasma concentrations of Met-enkephalin were reduced 10 minutes after morphine administration. Plasma concentrations of peptides that contain Met-enkephalin motifs were decreased 30 minutes after morphine administration. Tissue concentrations of Met-enkephalin tended to be depressed following morphine administration. Adrenal concentrations of PENK peptides containing Met-enkephalin motifs were decreased in chickens challenged with morphine. Expression of PENK in the anterior pituitary gland and adrenal glands were decreased in morphine treated compared to control pullets. In contrast, plasma concentrations of corticosterone were elevated 10 min after morphine treatment. Morphine also induced changes in mu (µ) opioid receptors and delta (δ) opioid receptors in both anterior pituitary tissue and adrenal tissues.
Topics: Animals; Morphine; Chickens; Enkephalin, Methionine; Female; Corticosterone; Protein Precursors; Enkephalins; Analgesics, Opioid; Adrenal Glands; Avian Proteins
PubMed: 38603935
DOI: 10.1016/j.psj.2024.103712 -
Cells Jan 2024The recent emphasis on circadian rhythmicity in critical skin cell functions related to homeostasis, regeneration and aging has shed light on the importance of the...
The recent emphasis on circadian rhythmicity in critical skin cell functions related to homeostasis, regeneration and aging has shed light on the importance of the circadian clock gene as a vital antitumor gene. Furthermore, delta-opioid receptors (DOPrs) have been identified as playing a crucial role in skin differentiation, proliferation and migration, which are not only essential for wound healing but also contribute to cancer development. In this study, we propose a significant association between cutaneous opioid receptor (OPr) activity and circadian rhythmicity. To investigate this link, we conducted a 48 h circadian rhythm experiment, during which RNA samples were collected every 5 h. We discovered that the activation of DOPr by its endogenous agonist Met-Enkephalin in N/TERT-1 keratinocytes, synchronized by dexamethasone, resulted in a statistically significant 5.6 h delay in the expression of the core clock gene . Confocal microscopy further confirmed the simultaneous nuclear localization of the DOPr-β-arrestin-1 complex. Additionally, DOPr activation not only enhanced but also induced a phase shift in the rhythmic binding of β-arrestin-1 to the promoter. Furthermore, we observed that β-arrestin-1 regulates the transcription of its target genes, including , by facilitating histone-4 acetylation. Through the ChIP assay, we determined that Met-Enkephalin enhances β-arrestin-1 binding to acetylated H4 in the promoter. In summary, our findings suggest that DOPr activation leads to a phase shift in expression via β-arrestin-1-facilitated chromatin remodeling. Consequently, these results indicate that DOPr, much like its role in wound healing, may also play a part in cancer development by influencing .
Topics: Humans; beta-Arrestins; Receptors, Opioid; Keratinocytes; Circadian Rhythm; beta-Arrestin 1; Enkephalin, Methionine; Neoplasms
PubMed: 38334624
DOI: 10.3390/cells13030232 -
Proteome Science Jan 2024The aim of this work was to investigate the immunological effect of MENK by analyzing the protein spectrum and bioinformatics of macrophage RAW264.7, and to explore the...
OBJECTIVE
The aim of this work was to investigate the immunological effect of MENK by analyzing the protein spectrum and bioinformatics of macrophage RAW264.7, and to explore the relationship between macrophage and ferroptosis.
RESULT
We employed proteomic analysis to identify differentially expressed proteins (DEPs) between macrophages and macrophages intervened by MENK. A total of 208 DEPs were identified. Among these, 96 proteins had upregulated expression and 112 proteins had downregulated expression. Proteomic analysis revealed a significant enrichment of DEPs associated with iron metabolism. The identification of hub genes was conducted using KEGG pathway diagrams and protein-protein interaction (PPI) analysis. The hub genes identified in this study include HMOX1 and Ferritin (FTH and FTL). A correlation was established between HMOX1, FTH, and FTL in the GO and KEGG databases. The results of PCR, WB and immunofluorescence showed that MENK downregulated the level of HMOX1 and FTH.
CONCLUSION
MENK had the potential to become an adjuvant chemotherapy drug by regulating iron metabolism in macrophages, reducing levels of HMOX1 and ferritin. We proposed an innovative research direction on the therapeutic potential of MENK, focusing on the relationship between ferroptosis and macrophage activity.
PubMed: 38245706
DOI: 10.1186/s12953-024-00228-x -
BMC Immunology Oct 2023Novel prophylactic drugs and vaccination strategies for protection against influenza virus should induce specific effector T-cell immune responses in pulmonary airways...
Novel prophylactic drugs and vaccination strategies for protection against influenza virus should induce specific effector T-cell immune responses in pulmonary airways and peripheral lymphoid organs. Designing approaches that promote T-cell-mediated responses and memory T-cell differentiation would strengthen host resistance to respiratory infectious diseases. The results of this study showed that pulmonary delivery of MENK via intranasal administration reduced viral titres, upregulated opioid receptor MOR and DOR, increased the proportions of T-cell subsets including CD8 T cells, CD8 T cells, NP/PA-effector CD8 T cells in bronchoalveolar lavage fluid and lungs, and CD4/CD8 T cells in lymph nodes to protect mice against influenza viral challenge. Furthermore, we demonstrated that, on the 10th day of infection, the proportions of CD4 T and CD8 T cells were significantly increased, which meant that a stable T and T lineage was established in the early stage of influenza infection. Collectively, our data suggested that MENK administered intranasally, similar to the route of natural infection by influenza A virus, could exert antiviral activity through upregulating T-cell-mediated adaptive immune responses against influenza virus.
Topics: Mice; Animals; Humans; Influenza, Human; CD8-Positive T-Lymphocytes; Enkephalin, Methionine; Memory T Cells; Influenza A virus; Immunologic Memory; Mice, Inbred C57BL
PubMed: 37828468
DOI: 10.1186/s12865-023-00573-0 -
Acta Neurobiologiae Experimentalis 2023In the central nervous system, long‑term effects of a vagotomy include disturbance of monoaminergic activity of the limbic system. Since low vagal activity is observed...
In the central nervous system, long‑term effects of a vagotomy include disturbance of monoaminergic activity of the limbic system. Since low vagal activity is observed in major depression and autism spectrum disorder, the study aimed to determine whether animals fully recovered after subdiaphragmatic vagotomy demonstrates neurochemical indicators of altered well‑being and social component of sickness behavior. Bilateral vagotomy or sham surgery was performed in adult rats. After one month of recovery, rats were challenged with lipopolysaccharide or vehicle to determine the role of central signaling upon sickness. Striatal monoamines and met‑enkephalin concentrations were evaluated using HPLC and RIA methods. We also defined a concentration of immune‑derived plasma met‑enkephalin to establish a long‑term effect of vagotomy on peripheral analgesic mechanisms. The data indicate that 30 days after vagotomy procedure, striatal dopaminergic, serotoninergic, and enkephalinergic neurochemistry was altered, both under physiological and inflammatory conditions. Vagotomy prevented inflammation‑induced increases of plasma met‑enkephalin - an opioid analgesic. Our data suggest that in a long perspective, vagotomized rats may be more sensitive to pain and social stimuli during peripheral inflammation.
Topics: Rats; Animals; Enkephalin, Methionine; Autism Spectrum Disorder; Vagotomy; Vagus Nerve; Inflammation; Amines
PubMed: 37078817
DOI: 10.55782/ane-2023-009 -
Proteome Science Apr 2023Macrophages have a vital role in phagocytosis and antiviral effect against invading influenza viruses. Previously, we found that methionine enkephalin (MENK) inhibited...
Macrophages have a vital role in phagocytosis and antiviral effect against invading influenza viruses. Previously, we found that methionine enkephalin (MENK) inhibited influenza virus infection by upregulating the "antiviral state" of macrophages. To investigate the immunoregulatory mechanism of action of MENK on macrophages, we employed proteomic analysis to identify differentially expressed proteins (DEPs) between macrophages infected with the influenza-A virus and cells infected with the influenza-A virus after pretreatment with MENK. A total of 215 DEPs were identified: 164 proteins had upregulated expression and 51 proteins had downregulated expression. Proteomics analysis showed that DEPs were highly enriched in "cytokine-cytokine receptor interaction", "phagosome", and "complement and coagulation cascades pathway". Proteomics analysis revealed that MENK could be an immune modulator or prophylactic for the prevention and treatment of influenza. MENK promoted the polarization of M1 macrophages, activated inflammatory responses, and enhanced phagocytosis and killing function by upregulating opsonizing receptors.
PubMed: 37041527
DOI: 10.1186/s12953-023-00205-w -
BioRxiv : the Preprint Server For... Aug 2023Enkephalins are opioid peptides that modulate analgesia, reward, and stress. detection of enkephalins remains difficult due to transient and low endogenous...
Enkephalins are opioid peptides that modulate analgesia, reward, and stress. detection of enkephalins remains difficult due to transient and low endogenous concentrations and inherent sequence similarity. To begin to address this we previously developed a system combining in vivo optogenetics with microdialysis and a highly sensitive mass spectrometry-based assay to measure opioid peptide release in freely moving rodents (Al-Hasani, 2018, eLife). Here not only do we show improved detection resolution but also a critical discovery in the stabilization of enkephalin detection, which together allowed us to investigate enkephalin release during acute stress. We present an analytical method for Met- and Leu-Enkephalin (Met-Enk & Leu-Enk) detection in the mouse Nucleus Accumbens shell (NAcSh) after acute stress. We confirm that acute stress activates enkephalinergic neurons in the NAcSh using fiber photometry and that this leads to the release of Met- and Leu-Enk. We also demonstrate the dynamics of Met- and Leu-Enk release as well as how they correlate to one another in the ventral NAc shell, which was previously difficult due to the use of approaches that relied on mRNA transcript levels rather than post-translational products. This approach increases spatiotemporal resolution, optimizes the detection of Met-Enkephalin through methionine oxidation, and provides novel insight into the relationship between Met- and Leu-Enkephalin following stress.
PubMed: 36824728
DOI: 10.1101/2023.02.15.528745 -
The Journal of Pain May 2023Venom-derived Na1.7 channel blockers have promising prospects in pain management. The 34-residue tarantula peptide GpTx-1 is a potent Na1.7 channel blocker. Its powerful...
Venom-derived Na1.7 channel blockers have promising prospects in pain management. The 34-residue tarantula peptide GpTx-1 is a potent Na1.7 channel blocker. Its powerful analog [Ala, Phe, Leu, Arg]GpTx-1 (GpTx-1-71) displayed excellent Na1.7 selectivity and analgesic properties in mice. The current study aimed to elucidate the anti-hyperalgesic activities of GpTx-1-71 in inflammatory pain and reveal the underlying mechanisms. Our results demonstrated that intrathecal and intraplantar injections of GpTx-1-71 dose-dependently attenuated CFA-induced inflammatory hypersensitivity in rats. Moreover, GpTx-1-71-induced anti-hyperalgesia was significantly reduced by opioid receptor antagonists and the enkephalin antibody and diminished in proenkephalin (Penk) gene knockout animals. Consistently, GpTx-1-71 treatment increased the enkephalin level in the spinal dorsal horn and promoted the Penk transcription and enkephalin release in primary dorsal root ganglion (DRG) neurons, wherein sodium played a crucial role in these processes. Mass spectrometry analysis revealed that GpTx-1-71 mainly promoted the secretion of Met-enkephalin but not Leu-enkephalin from DRG neurons. In addition, the combination of subtherapeutic Met-enkephalin and GpTx-1-71 produced synergistic anti-hyperalgesia in CFA-induced inflammatory hypersensitivity. These findings suggest that the endogenous enkephalin pathway is essential for GpTx-1-71-induced spinal and peripheral analgesia in inflammatory pain. PERSPECTIVE: This article presents a possible pharmacological mechanism underlying Na1.7 blocker-induced analgesia in inflammatory pain, which helps us to better understand and develop venom-based painkillers for incurable pain.
Topics: Rats; Mice; Animals; Pain; Hyperalgesia; Analgesics; Enkephalins; Enkephalin, Methionine; Ganglia, Spinal; NAV1.7 Voltage-Gated Sodium Channel
PubMed: 36586660
DOI: 10.1016/j.jpain.2022.12.012