μ-opioid receptor-mediated alterations of allergen-induced immune responses of bronchial lymph node cells in a murine model of stress asthma

The A118G single-nucleotide polymorphism in OPRM1 is a risk factor for asthma severity

BACKGROUND

Although population studies have implicated emotional burden in asthma severity, the underlying genetic risk factors are not completely understood. We aimed to evaluate the genetic influence of a functional single-nucleotide polymorphism (SNP) in the stress-related μ-opioid receptor gene (OPRM1; A118G SNP, rs1799971) on asthma severity.

METHODS

We initially assessed disease severity in asthmatic outpatients carrying A118G. Using an ovalbumin-induced experimental asthma rodent model harboring the functionally equivalent SNP, we investigated the mechanism by which this SNP influences the allergic immune response.

RESULTS

Among 292 outpatients, 168 underwent airway hyperresponsiveness (AHR) to methacholine testing. Compared with patients carrying the AA and AG genotypes, those carrying the GG genotype exhibited enhanced AHR. The stress levels were presumed to be moderate among patients and were comparable among genotypes. Compared with Oprm1 AA mice, GG mice demonstrated aggravated asthma-related features and increased pulmonary interleukin-4⁺CD4⁺ effector and effector memory T cells under everyday life stress conditions. Intraperitoneal naloxone methiodide injection reduced effector CD4⁺ T cell elevation associated with increased eosinophil numbers in bronchoalveolar lavage fluid of GG mice to the levels in AA mice, suggesting that elevated Th2 cell generation in the bronchial lymph node (BLN) of GG mice induces enhanced eosinophilic inflammation.

CONCLUSIONS

Without forced stress exposure, patients with asthma carrying the OPRM1 GG genotype exhibit enhanced AHR, attributable to enhanced Th2 cell differentiation in the regional lymph node. Further research is necessary to elucidate the role of the OPRM1 A118G genotype in the Th2 cell differentiation pathway in the BLN.

Factors Associated with Thyroid-Related Adverse Events in Patients Receiving PD-1 or PD-L1 Inhibitors Using Machine Learning Models

Simple Summary

Although immune checkpoint inhibitors have a potential role in thyroid-related complications, no study has investigated factors associated with such adverse events. This study aims to explore the factors associated with thyroid-related adverse events in patients with anti-PD-1/PD-L1 agents by training predictive models utilizing various machine learning approaches. The results of this study could be used to develop individually tailored intervention strategies to prevent immune checkpoint inhibitor-induced thyroid-related outcomes.

Abstract

Targets of immune checkpoint inhibitors (ICIs) regulate immune homeostasis and prevent autoimmunity by downregulating immune responses and by inhibiting T cell activation. Although ICIs are widely used in immunotherapy because of their good clinical efficacy, they can also induce autoimmune-related adverse events. Thyroid-related adverse events are frequently associated with anti-programmed cell death 1 (PD-1) or anti-programmed cell death-ligand 1 (PD-L1) agents. The present study aims to investigate the factors associated with thyroid dysfunction in patients receiving PD-1 or PD-L1 inhibitors and to develop various machine learning approaches to predict complications. A total of 187 patients were enrolled in this study. Logistic regression analysis was conducted to investigate the association between such factors and adverse events. Various machine learning methods were used to predict thyroid-related complications. After adjusting for covariates, we found that smoking history and hypertension increase the risk of thyroid dysfunction by approximately 3.7 and 4.1 times, respectively (95% confidence intervals (CIs) 1.338–10.496 and 1.478–11.332, p = 0.012 and 0.007). In contrast, patients taking opioids showed an approximately 4.0-fold lower risk of thyroid-related complications than those not taking them (95% CI 1.464–11.111, p = 0.007). Among the machine learning models, random forest showed the best prediction, with an area under the receiver operating characteristic of 0.770 (95% CI 0.648–0.883) and an area under the precision-recall of 0.510 (95%CI 0.357–0.666). Hence, this study utilized various machine learning models for prediction and showed that factors such as smoking history, hypertension, and opioids are associated with thyroid-related adverse events in cancer patients receiving PD-1/PD-L1 inhibitors.

The role of opioids in cancer response to immunotherapy

Background

The response to immunotherapy can be impaired by several factors including external intervention such as drug interactions with immune system. We aimed to examine the immunomodulatory action of opioids, since immune cells express opioid receptors able to negatively influence their activities.

Methods

This observational, multicenter, retrospective study, recruited patients with different metastatic solid tumors, who have received immunotherapy between September 2014 and September 2019. Immunotherapy was administered according to the standard schedule approved for each primary tumor and line of treatment. The concomitant intake of antibiotics, antifungals, corticosteroids and opioids were evaluated in all included patients. The relationship between tumor response to immunotherapy and the oncological outcomes were evaluated. A multivariate Cox-proportional hazard model was used to identify independent prognostic factors for survival.

Results

One hundred ninety-three patients were recruited. Overall, progression-free survival (PFS) and overall survival (OS) were significantly shorter in those patients taking opioids than in those who didn’t (median PFS, 3 months vs. 19 months, HR 1.70, 95% CI 1.37–2.09, p < 0.0001; median OS, 4 months vs. 35 months, HR 1.60, 95% CI 1.26–2.02, p < 0.0001). In addition, PFS and OS were significantly impaired in those patients taking corticosteroids, antibiotics or antifungals, in those patients with an ECOG PS ≥ 1 and in patients with a high tumor burden. Using the multivariate analyses, opioids and ECOG PS were independent prognostic factors for PFS, whereas only ECOG PS resulted to be an independent prognostic factor for OS, with trend toward significance for opioids as well as tumor burden.

Discussion

Our study suggests that the concomitant administration of drugs as well as some clinical features could negatively predict the outcomes of cancer patients receiving immunotherapy. In particular, opioids use during immunotherapy is associated with early progression, potentially representing a predictive factor for PFS and negatively influencing OS as well.

Conclusions

A possible negative drug interaction able to impair the immune response to anti-PD-1/PD-L1 agents has been highlighted. Our findings suggest the need to further explore the impact of opioids on immune system modulation and their role in restoring the response to immunotherapy treatment, thereby improving patients' outcomes.

Evaluation of the efficacy of isopathic immunotherapy in the treatment of allergic asthma in BALB/C mice

Introduction: Homeopathy is a therapeutic method based on the fundamental principle of "like cures like." Homeopathic remedies are extremely dilute but involve vigorous shaking at each dilution. Isopathy is one approach of homeopathy, in which the causative agents or products of a disease are used to treat the same disease. Allergen immunotherapy is the only potential disease-modifying treatment for allergic patients. Subcutaneous immunotherapy is more effective than sublingual immunotherapy. However, subcutaneous immunotherapy is ineffective at a low dose, whereas at high doses it can result in an unacceptably high frequency of systemic reactions. In the current study, we evaluated the efficacy of isopathic immunotherapy with highly diluted ovalbumin (HD OVA) in the treatment of OVA-induced allergic asthma in BALB/c mice.Methods: BALB/c mice were sensitized with OVA and alum. Two weeks later, the mice received HD OVA on days 21, 22, 32 and 41 (8 h after the last challenge) of the treatment. The mice were challenged with OVA (5%) aerosols on days 35, 38 and 41 for 20 minutes using an ultrasonic nebulizer and sacrificed the next day.Results: Isopathic immunotherapy significantly reduced lung tissue inflammation, the number of eosinophils in bronchoalveolar fluid, allergen-specific IgE and interleukin-4 production. It also insignificantly increased the production of transforming growth factor-beta and proliferation of regulatory T cells against the allergen.Conclusion: Isopathic immunotherapy may be a good candidate treatment for allergic asthma.

Nicotine, as a novel tolerogenic adjuvant, enhances the efficacy of immunotherapy in a mouse model of allergic asthma

An increasing trend in the incidence of allergic diseases including asthma and related morbidity and mortality is observed worldwide during the last decades. Allergen-specific immunotherapy is suggested for the treatment of some allergic diseases; nevertheless, there is always a menace of uncommon, but life-treating reactions due to increasing the administration of allergen extract doses. Hence, improving its efficacy may reduce the required doses as well as the risk of such reactions. The current study aimed at examining the effects of nicotine (NIC), as a tolerogenic adjuvant, on the improvement of immunotherapy efficacy in a mouse model of allergic asthma. BALB/c mice were sensitized using alum and ovalbumin (OVA) on the days 0 and 7. Mice received OVA either alone or together with NIC (1 or 10 mg/kg) on the days 21, 23, and 25. Then, the mice were challenged with OVA 5% using a nebulizer on the days 35, 38, and 41 and sacrificed the next day. Co-administration of OVA and NIC decreased the inflammation of the lung tissue, eosinophils count in the bronchoalveolar lavage (BAL) fluid, the serum level of OVA-specific immunoglobulin E, as well as interleukin (IL)-4 production, while increasing the population of antigen-specific regulatory T-cells (Treg cells) and transforming growth factor-β/IL-4 (TGF-β/IL-4) ratio compared to the OVA and control groups in a dose-dependent manner. Collectively, the findings suggest that administration of NIC plus the allergen increased immunotherapy efficacy through decreasing allergic inflammation and allergic responses intensity, and increasing Treg cells population.

Evaluation of the efficacy of nicotine in treatment of allergic asthma in BALB/c mice

Nicotine, an nAChR agonist, shows prominent anti-inflammatory properties, and some studies have illustrated its suppressive effects on inflammation. Here, we have examined whether nicotine as a medicine may have beneficial effects on the treatment of asthma in a mouse model of allergic asthma. BALB/c mice were sensitized with OVA and alum. Two weeks later, the mice received nicotine with concentrations of 1 and 10 mg/kg three times every other day. After 10 days, the mice were challenged with OVA (5%) using an ultrasonic nebulizer and died the next day. Our results showed that the administration of nicotine reduced lung-tissue inflammation, the number of eosinophils in bronchoalveolar fluid, allergen-specific IgE and IL-4 production, while it increased the TGF-β/IL-4 ratio and the number of Treg cells. Our results showed that nicotine applies its suppressive effects in a dose-dependent manner: administration of 10 mg/kg of nicotine showed more suppressive effects than 1 mg/kg. Such data suggested that nicotine might be a good candidate to be used as a medicine in the treatment of allergic asthma by decreasing allergic inflammation severity and potentiating Treg cells proliferation against the allergen.

The interplay between neuroendocrine activity and psychological stress-induced exacerbation of allergic asthma

Psychological stress is recognized as a key factor in the exacerbation of allergic asthma, whereby brain responses to stress act as immunomodulators for asthma. In particular, stress-induced enhanced type 2 T-helper (Th2)-type lung inflammation is strongly associated with asthma pathogenesis. Psychological stress leads to eosinophilic airway inflammation through activation of the hypothalamic-pituitary-adrenal pathway and autonomic nervous system. This is followed by the secretion of stress hormones into the blood, including glucocorticoids, epinephrine, and norepinephrine, which enhance Th2 and type 17 T-helper (Th17)-type asthma profiles in humans and rodents. Recent evidence has shown that a defect of the μ-opioid receptor in the brain along with a defect of the peripheral glucocorticoid receptor signaling completely disrupted stress-induced airway inflammation in mice. This suggests that the stress response facilitates events in the central nervous and endocrine systems, thus exacerbating asthma. In this review, we outline the recent findings on the interplay between stress and neuroendocrine activities followed by stress-induced enhanced Th2 and Th17 immune responses and attenuated regulatory T (Treg) cell responses that are closely linked with asthma exacerbation. We will place a special focus on our own data that has emphasized the continuity from central sensing of psychological stress to enhanced eosinophilic airway inflammation. The mechanism that modulates psychological stress-induced exacerbation of allergic asthma through neuroendocrine activities is thought to involve a series of consecutive pathological events from the brain to the lung, which implies there to be a "neuropsychiatry phenotype" in asthma.

Neuropsychiatry phenotype in asthma: Psychological stress-induced alterations of the neuroendocrine-immune system in allergic airway inflammation

Since the recognition of asthma as a syndrome with complex pathophysiological signs and symptoms, recent research has sought to classify asthma phenotypes based on its clinical and molecular pathological features. Psychological stress was first recognized as a potential immune system modulator of asthma at the end of the 19th century. The activation of the central nervous system (CNS) upon exposure to psychological stress is integral for the initiation of signal transduction processes. The stress hormones, including glucocorticoids, epinephrine, and norepinephrine, which are secreted following CNS activation, are involved in the immunological alterations involved in psychological stress-induced asthma exacerbation. The mechanisms underlying this process may involve a pathological series of events from the brain to the lungs, which is attracting attention as a conceptually advanced phenotype in asthma pathogenesis. This review presents insights into the critical role of psychological stress in the development and exacerbation of allergic asthma, with a special focus on our own data that emphasizes on the continuity from the central sensing of psychological stress to enhanced eosinophilic airway inflammation.

The involvement of central nervous system histamine receptors in psychological stress-induced exacerbation of allergic airway inflammation in mice

BACKGROUND

Psychological stress is one of the major risk factors for asthma exacerbation. Although histamine in the brain acts as an excitatory and inhibitory neurotransmitter associated with psychological stress, the contribution of brain histamine to psychological stress-induced exacerbation of asthma remains unclear. The objective of this study was to investigate the role of histamine receptors in the CNS on stress induced asthma aggravation.

METHODS

We monitored the numbers of inflammatory cells and interleukin (IL)-13 levels in bronchoalveolar lavage fluid, airway responsiveness to inhaled methacholine, mucus secretion in airway epithelial cells, and antigen-specific IgE contents in sera in a murine model of stress-induced asthma treated with epinastine (an H1R antagonist), thioperamide (an H3/4R antagonist), or solvent.

RESULTS

All indicators of stress-induced asthma exacerbation were significantly reduced in stressed mice treated with epinastine compared with those treated with solvent, whereas treatment with thioperamide did not reduce the numbers of inflammatory cells in the stressed mice.

CONCLUSIONS

These results suggest that H1R, but not H3/4R, may be involved in stress-induced asthma exacerbations in the central nervous system.

Differential pharmacokinetics and the brain distribution of morphine and ephedrine constitutional isomers in rats after oral administration with Keke capsule using rapid-resolution LC-MS/MS

Opioid and ephedra alkaloids known as the active ingredients for Keke capsule, which is used to treat coughs and bronchial asthma, could have potential adverse effects on the central nervous system. Therefore, an efficient, sensitive rapid-resolution LC-MS/MS method for the simultaneous determination of morphine, ephedrine, and pseudoephedrine in rat plasma and brain tissue homogenate has been developed. The method was validated in the plasma and brain tissue samples, showed good linearity over a wide concentration range (r(2) > 0.99). The intra- and interday assay variability was less than 15% for all analytes, and the accuracy was between -8.8 and 5.7%. The study provided the pharmacokinetics profiles and the brain regional distribution of the three active alkaloids after oral administration of Keke capsule. The results also indicated that significant difference in pharmacokinetics parameters of the epimers was observed between ephedrine and pseudoephedrine.

Endogenous opiates and behavior: 2012

This paper is the thirty-fifth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2012 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).