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Scientific Reports Jun 2024Cardiac ischemic preconditioning (Pre) reduces cardiac ischemia-reperfusion injury (IRI) by stimulating opioid receptors. Chronic use of opioids can alter the signaling...
Cardiac ischemic preconditioning (Pre) reduces cardiac ischemia-reperfusion injury (IRI) by stimulating opioid receptors. Chronic use of opioids can alter the signaling pathways. We investigated the effects of chronic methadone use on IRI and Pre. The experiments were performed on isolated hearts of male Wistar rats in four groups: IRI, Methadone + IRI (M-IRI), Pre + IRI (Pre-IRI), Methadone + Pre + IRI (M-Pre-IRI). The infarct size (IS) in the Pre-IRI group was smaller than the IRI group (26.8% vs. 47.8%, P < 0.05). In the M-IRI and M-Pre-IRI groups, the infarct size was similar to the IRI group. Akt (Ak strain transforming) phosphorylation in the Pre-IRI, M-IRI, and M-Pre-IRI groups was significantly higher than in the IRI group (0.56 ± 0.15, 0.63 ± 0.20, and 0.93 ± 0.18 vs 0.28 ± 0.17 respectively). STAT3 (signal transducer and activator of transcription 3) phosphorylation in the Pre-IRI and M-Pre-IRI groups (1.38 ± 0.14 and 1.46 ± 0.33) was significantly higher than the IRI and M-IRI groups (0.99 ± 0.1 and 0.98 ± 0.2). Thus, chronic use of methadone not only has no protective effect against IRI but also destroys the protective effects of ischemic preconditioning. This may be due to the hyperactivation of Akt and changes in signaling pathways.
Topics: Animals; Methadone; STAT3 Transcription Factor; Male; Proto-Oncogene Proteins c-akt; Phosphorylation; Rats; Rats, Wistar; Myocardial Reperfusion Injury; Ischemic Preconditioning, Myocardial; Signal Transduction; Reperfusion Injury
PubMed: 38906975
DOI: 10.1038/s41598-024-65349-x -
PCN Reports : Psychiatry and Clinical... Jun 2024Restless legs syndrome (RLS) is a neurological sensorimotor disorder characterized by an uncontrollable urge to move the legs. In the perioperative period, patients with...
BACKGROUND
Restless legs syndrome (RLS) is a neurological sensorimotor disorder characterized by an uncontrollable urge to move the legs. In the perioperative period, patients with RLS may experience an acute exacerbation of symptoms. Although studies on the exacerbation of RLS after brain surgery are limited, we present a case wherein symptoms worsened following left amygdalohippocampectomy.
CASE PRESENTATION
A 58-year-old woman diagnosed with mesiotemporal lobe epilepsy accompanied by left hippocampal sclerosis underwent a left amygdalohippocampectomy. The patient reported uncomfortable sensations in the lower limbs preoperatively. However, the urge to move her legs was manageable and not distinctly diagnosed with RLS. The symptoms began to deteriorate on the fifth postoperative day primarily affecting the legs and back, with a notable emphasis on the right side. Pramipexole treatment effectively ameliorated these symptoms.
CONCLUSION
No reports are available highlighting the exacerbation of RLS after amygdalohippocampectomy. Perioperative factors, such as anesthesia and iron deficiency due to hemorrhage, have been proposed as aggravating factors for RLS; however, the asymmetry of RLS, particularly the atypical right-sided exacerbation in this case, makes it unlikely that this was the primary cause. A negative correlation between opioid receptor availability in the amygdala and RLS severity has been reported, suggesting that amygdalohippocampectomy contributes to the exacerbation of RLS symptoms. This case provides valuable insights into the possible involvement of the amygdala in the pathophysiology of RLS and practical considerations for the clinical management of the condition.
PubMed: 38904065
DOI: 10.1002/pcn5.213 -
Redox Biology Jun 2024Morphine, a typical opiate, is widely used for controlling pain but can lead to various side effects with long-term use, including addiction, analgesic tolerance, and...
Morphine, a typical opiate, is widely used for controlling pain but can lead to various side effects with long-term use, including addiction, analgesic tolerance, and hyperalgesia. At present, however, the mechanisms underlying the development of morphine analgesic tolerance are not fully understood. This tolerance is influenced by various opioid receptor and kinase protein modifications, such as phosphorylation and ubiquitination. Here, we established a murine morphine tolerance model to investigate whether and how S-nitrosoglutathione reductase (GSNOR) is involved in morphine tolerance. Repeated administration of morphine resulted in the down-regulation of GSNOR, which increased excessive total protein S-nitrosation in the prefrontal cortex. Knockout or chemical inhibition of GSNOR promoted the development of morphine analgesic tolerance and neuron-specific overexpression of GSNOR alleviated morphine analgesic tolerance. Mechanistically, GSNOR deficiency enhanced S-nitrosation of cellular protein kinase alpha (PKCα) at the Cys78 and Cys132 sites, leading to inhibition of PKCα kinase activity, which ultimately promoted the development of morphine analgesic tolerance. Our study highlighted the significant role of GSNOR as a key regulator of PKCα S-nitrosation and its involvement in morphine analgesic tolerance, thus providing a potential therapeutic target for morphine tolerance.
PubMed: 38901102
DOI: 10.1016/j.redox.2024.103239 -
BioRxiv : the Preprint Server For... Jun 2024The ventral tegmental area (VTA) contains projection neurons that release the neurotransmitters dopamine, GABA, and/or glutamate from distal synapses. VTA also contains...
The ventral tegmental area (VTA) contains projection neurons that release the neurotransmitters dopamine, GABA, and/or glutamate from distal synapses. VTA also contains GABA neurons that synapse locally on to VTA dopamine neurons, synapses widely credited to a population of so-called VTA interneurons. Interneurons in cortex, striatum, and elsewhere have well-defined morphological features, physiological properties, and molecular markers, but such features have not been clearly described in VTA. Indeed, there is scant evidence that local and distal synapses originate from separate populations of VTA GABA neurons. In this study we tested whether several markers expressed in non-dopamine VTA neurons are selective markers of interneurons, defined as neurons that synapse locally but not distally. Challenging previous assumptions, we found that VTA neurons genetically defined by expression of parvalbumin, somatostatin, neurotensin, or mu-opioid receptor project to known VTA targets including nucleus accumbens, ventral pallidum, lateral habenula, and prefrontal cortex. Moreover, we provide evidence that VTA GABA and glutamate projection neurons make functional inhibitory or excitatory synapses locally within VTA. These findings suggest that local collaterals of VTA projection neurons could mediate functions prior attributed to VTA interneurons. This study underscores the need for a refined understanding of VTA connectivity to explain how heterogeneous VTA circuits mediate diverse functions related to reward, motivation, or addiction.
PubMed: 38895464
DOI: 10.1101/2024.06.07.597996 -
Cureus May 2024Perforated peptic ulcers, though relatively rare, represent critical surgical emergencies with potentially life-threatening consequences. Their significance lies not...
Perforated peptic ulcers, though relatively rare, represent critical surgical emergencies with potentially life-threatening consequences. Their significance lies not only in their acute presentation but also in the diagnostic challenges they pose, particularly in patients with complex medical histories. Here we present a case of a 71-year-old female with a complex medical history, including insulin-dependent type 2 diabetes mellitus, hypertension, hyperlipidemia, hypothyroidism, dementia, diverticulitis, and chronic back pain, who initially were unresponsive and cyanotic. Despite challenges in diagnosis due to her medical complexity and opioid use, she was ultimately diagnosed with a perforated duodenal ulcer. Tragically, despite immediate surgical intervention, she succumbed to her illness, highlighting the complexities involved in managing perforated peptic ulcers, especially in patients with multiple chronic medical conditions. Peptic ulcer disease (PUD) can often remain asymptomatic, leading to delayed diagnosis and potentially life-threatening complications like perforation. Mortality rates associated with perforated peptic ulcers vary widely, ranging from 1.3% to 20%, with risk factors including nonsteroidal anti-inflammatory drug (NSAID) use, infection, smoking, and corticosteroid use. Diagnosis necessitates a high index of suspicion, thorough clinical examination, and imaging modalities such as computed tomography (CT) scans with oral contrast. Treatment strategies range from nonoperative management with intravenous (IV) histamine H2-receptor blockers or proton pump inhibitors (PPIs) to surgical intervention, depending on the patient's hemodynamic stability. However, the case presented underscores the challenges in timely diagnosis and intervention, particularly in patients with complex medical histories, where symptoms may be masked or attributed to other comorbidities. Recent studies indicate a demographic shift toward older age and a higher prevalence among females, emphasizing the importance of increased awareness and vigilance among healthcare providers. Early recognition of symptoms, prompt investigation, and interdisciplinary collaboration are crucial in optimizing outcomes for patients presenting with perforated peptic ulcers, especially in the context of their underlying medical conditions.
PubMed: 38894771
DOI: 10.7759/cureus.60620 -
Molecules (Basel, Switzerland) Jun 2024Sigma receptors (SRs), including SR1 and SR2 subtypes, have attracted increasing interest in recent years due to their involvement in a wide range of activities,...
Sigma receptors (SRs), including SR1 and SR2 subtypes, have attracted increasing interest in recent years due to their involvement in a wide range of activities, including the modulation of opioid analgesia, neuroprotection, and potential anticancer activity. In this context, haloperidol (HAL), a commonly used antipsychotic drug, also possesses SR activity and cytotoxic effects. Herein, we describe the identification of novel SR ligands, obtained by a chemical hybridization approach. There wereendowed with pan-affinity for both SR subtypes and evaluated their potential anticancer activity against SH-SY5Y and HUH-7 cancer cell lines. Through a chemical hybridization approach, we identified novel compounds (, , , and ) with dual affinity for SR1 and SR2 receptors. These compounds were subjected to cytotoxicity testing using a resazurin assay. The results revealed potent cytotoxic effects against both cancer cell lines, with IC values comparable to HAL. Interestingly, the cytotoxic potency of the novel compounds resembled that of the SR1 antagonist HAL rather than the SR2 agonist siramesine (SRM), indicating the potential role of SR1 antagonism in their mechanism of action. The further exploration of their structure-activity relationships and their evaluation in additional cancer cell lines will elucidate their therapeutic potential and may pave the way for the development of novel anticancer agents that target SRs.
Topics: Receptors, sigma; Haloperidol; Humans; Antineoplastic Agents; Cell Line, Tumor; Drug Design; Structure-Activity Relationship; Molecular Structure; Cell Survival; Ligands; Cell Proliferation; Drug Screening Assays, Antitumor
PubMed: 38893570
DOI: 10.3390/molecules29112697 -
Molecules (Basel, Switzerland) Jun 2024The opioid crisis in the United States is a significant public health issue, with a nearly threefold increase in opioid-related fatalities between 1999 and 2014. In... (Review)
Review
The opioid crisis in the United States is a significant public health issue, with a nearly threefold increase in opioid-related fatalities between 1999 and 2014. In response to this crisis, society has made numerous efforts to mitigate its impact. Recent advancements in understanding the structural intricacies of the κ opioid receptor (KOR) have improved our knowledge of how opioids interact with their receptors, triggering downstream signaling pathways that lead to pain relief. This review concentrates on the KOR, offering crucial structural insights into the binding mechanisms of both agonists and antagonists to the receptor. Through comparative analysis of the atomic details of the binding site, distinct interactions specific to agonists and antagonists have been identified. These insights not only enhance our understanding of ligand binding mechanisms but also shed light on potential pathways for developing new opioid analgesics with an improved risk-benefit profile.
Topics: Receptors, Opioid, kappa; Humans; Analgesics, Opioid; Animals; Binding Sites; Ligands; Signal Transduction; Protein Binding; Structure-Activity Relationship; Narcotic Antagonists; Pain
PubMed: 38893511
DOI: 10.3390/molecules29112635 -
Journal of Clinical Medicine May 2024: The anxiolytic effect of transcutaneous electrical nerve stimulation (TENS) is associated with the activation of endogenous inhibitory mechanisms in the central...
Comparative Analysis of High-Frequency and Low-Frequency Transcutaneous Electrical Stimulation of the Right Median Nerve in the Regression of Clinical and Neurophysiological Manifestations of Generalized Anxiety Disorder.
: The anxiolytic effect of transcutaneous electrical nerve stimulation (TENS) is associated with the activation of endogenous inhibitory mechanisms in the central nervous system. Both low-frequency, high-amplitude TENS (LF-TENS) and high-frequency, low-amplitude TENS (HF-TENS) are capable of activating opioid, GABA, serotonin, muscarinic, and cannabinoid receptors. However, there has been no comparative analysis of the effectiveness of HF-TENS and LF-TENS in the treatment of GAD. The purpose of our research was to study the effectiveness of direct HF-TENS and LF-TENS of the right median nerve in the treatment of patients with GAD compared with sham TENS. The effectiveness of direct HF-TENS and LF-TENS of the right median nerve in the treatment of GAD was studied using Generalized Anxiety Disorder 7-item scale (GAD-7) and the Hamilton Anxiety Rating Scale (HAM-A). 40 patients underwent sham TENS, 40 patients passed HF-TENS (50 Hz-50 μs-sensory response) and 41 patients completed LF -TENS (1 Hz-200 μs-motor response) for 30 days daily. After completion of treatment, half of the patients received weekly maintenance therapy for 6 months. Electroencephalography was performed before and after treatment. Our study showed that a significant reduction in the clinical symptoms of GAD as assessed by GAD-7 and HAM-A was observed after HF-TENS and LF-TENS by an average of 42.4%, and after sham stimulation only by 13.5% for at least 2 months after the end of treatment. However, LF-TENS turned out to be superior in effectiveness to HF-TENS by 51% and only on electroencephalography leads to an increase in PSD for the alpha rhythm in the occipital regions by 24% and a decrease in PSD for the beta I rhythm in the temporal and frontal regions by 28%. The prolonged effect of HF-TENS and LF-TENS was maintained without negative dynamics when TENS treatment was continued weekly throughout the entire six-month observation period. A prolonged anxiolytic effect of direct TENS of the right median nerve has been proven with greater regression of clinical and neurophysiological manifestations of GAD after LF-TENS compared to HF-TENS. Minimal side effects, low cost, safety, and simplicity of TENS procedures are appropriate as a home treatment modality.
PubMed: 38892737
DOI: 10.3390/jcm13113026 -
Cell Communication and Signaling : CCS Jun 2024Kappa opioid receptor (KOR) signaling is involved in joint development and inflammation in Osteoarthritis (OA), while the biochemical mechanism remains unclarified. This...
OBJECTIVE
Kappa opioid receptor (KOR) signaling is involved in joint development and inflammation in Osteoarthritis (OA), while the biochemical mechanism remains unclarified. This study aims to investigate downstream molecular events of KOR activation, to provide novel perspectives in OA pathology.
METHODS
U50,488H, a selective KOR agonist, was intra-articularly injected in mice upon destabilization of the medial meniscus (DMM) as OA models, with PBS injection as control. The behavioral and histological evaluation was assessed by hot plate test and red solid green staining, respectively. Alterations in mRNA and protein expression were assessed by RNA-seq, RT-qPCR, immunohistochemistry and western blotting (WB) in chondrocytes treated with TNF-α or TNF-α + U50,488H. Proteins interacted with KOR were explored using proximity labeling followed by mass spectrometry and then testified by co-immunoprecipitation (Co-IP) assay and immunofluorescence (IF).
RESULTS
OA-induced pain was reduced and cartilage degeneration was alleviated upon KOR activation in DMM mice. In chondrocytes, activation of KOR reversed the upregulation of MMPs, IL-6, IL-1β and phosphorylated(p-) STAT3, stimulated by TNF-α, while the expression of NF-κB, MAPKs and AKT signaling weren't reversed. RNA-seq and IF results presented that KOR activation evidently reduced STAT3 nuclear translocation in chondrocytes upon TNF-α stimuli. The reduction may be resulted from the binding of KOR and STAT3 in the plasma membrane, revealed by proximity labeling and Co-IP results.
CONCLUSIONS
KOR activation protects cartilage from OA, and this protective effect is mainly exerted via sequestering STAT3 on the plasma membrane, resulting in inactivation of STAT3-dependent immune responses which otherwise contributes to OA.
Topics: Animals; Male; Mice; 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; Cell Membrane; Chondrocytes; Mice, Inbred C57BL; Osteoarthritis; Receptors, Opioid, kappa; Signal Transduction; STAT3 Transcription Factor
PubMed: 38890746
DOI: 10.1186/s12964-024-01709-4 -
Harm Reduction Journal Jun 2024During the initial wave of the COVID-19 pandemic, there was a surprisingly low incidence of SARS-CoV-2 among People Who Use Drugs (PWUD) in Oslo, Norway, despite their...
BACKGROUND
During the initial wave of the COVID-19 pandemic, there was a surprisingly low incidence of SARS-CoV-2 among People Who Use Drugs (PWUD) in Oslo, Norway, despite their heightened vulnerability regarding risk of infection and severe courses of the disease.This study aims to investigate the seroprevalence of SARS-CoV-2 antibodies among PWUD, their antibody responses to relevant virus infections and COVID-19 mRNA vaccines, and their vaccination coverage compared to the general population.
METHODS
Conducted as a prospective cohort study, data was collected from residents in six institutions for homeless PWUD and users of a low-threshold clinic for opioid agonist treatment. Ninety-seven participants were recruited for SARS-CoV-2 seroprevalence analysis. Additional two participants with known positive SARS-CoV-2 test results were recruited for further analyses. Twenty-five participants completed follow-up. Data included questionnaires, nasal swabs and blood samples. Data on vaccination coverage was obtained from the National Vaccine Register. Serologic methods included detection of antibodies to relevant virus proteins, neutralizing antibodies to SARS-CoV-2, antibodies to the full-length spike protein, and receptor-binding domain from SARS-CoV-2.
RESULTS
Among PWUD, antibodies to SARS-CoV-2 were detected in 2 out of 97 samples before vaccines against SARS-CoV-2 were available, comparable to a 2.8% frequency in population-based screening. Levels of serum antibodies to seasonal coronaviruses and Epstein-Barr-Virus (EBV) in PWUD were similar to population-based levels. After the second vaccine dose, binding and neutralizing antibody levels to SARS-CoV-2 in PWUD were comparable to controls. Eighty-four of PWUD received at least one dose of COVID-19 mRNA vaccine, compared to 89% in the general population.
CONCLUSION
Results indicate that PWUD did not exhibit increased SARS-CoV-2 seroprevalence or elevated serum antibodies to seasonal coronaviruses and EBV. Moreover, vaccine responses in PWUD were comparable to controls, suggesting that vaccination is effective in conferring protection against SARS-CoV-2 also in this population.
Topics: Humans; Seroepidemiologic Studies; COVID-19; Male; Female; COVID-19 Vaccines; Adult; SARS-CoV-2; Antibodies, Viral; Middle Aged; Prospective Studies; Norway; Immunity, Humoral; mRNA Vaccines; Drug Users; Antibodies, Neutralizing; Vaccines, Synthetic; Vaccination Coverage; Cohort Studies
PubMed: 38890611
DOI: 10.1186/s12954-024-01023-9