Leukotriene Research Articles

Preservation of β-Cells as a Therapeutic Strategy for Diabetes.

The preservation of pancreatic islet β-cells is crucial in diabetes mellitus, encompassing both type 1 and type 2 diabetes. β-cell dysfunction, reduced mass, and apoptosis are central to insufficient insulin secretion in both types. Research is focused on understanding β-cell characteristics and the factors regulating their function to develop novel therapeutic approaches. In type 1 diabetes (T1D), β-cell destruction by the immune system calls for exploring immunosuppressive therapies, non-steroidal anti-inflammatory drugs, and leukotriene antagonists. Islet transplantation, stem cell therapy, and xenogeneic transplantation offer promising strategies for type 1 diabetes treatment. For type 2 diabetes (T2D), lifestyle changes like weight loss and exercise enhance insulin sensitivity and maintain β-cell function. Additionally, various pharmacological approaches, such as cytokine inhibitors and protein kinase inhibitors, are being investigated to protect β-cells from inflammation and glucotoxicity. Bariatric surgery emerges as an effective treatment for obesity and T2D by promoting β-cell survival and function. It improves insulin sensitivity, modulates gut hormones, and expands β-cell mass, leading to diabetes remission and better glycemic control. In conclusion, preserving β-cells offers a promising approach to managing both types of diabetes. By combining lifestyle modifications, targeted pharmacological interventions, and advanced therapies like stem cell transplantation and bariatric surgery, we have a significant chance to preserve β-cell function and enhance glucose regulation in diabetic patients.

Expert opinion on the prescription practice of antihistamines for the management of allergic rhinitis in Indian settings

Several clinical studies corroborate the synergistic effects of montelukast in conjunction with antihistamine for reducing the symptoms and quality of life of AR patients. Some studies also highlighted a significant quantitative differences in the prescribing patterns of antihistamines across different countries. So, this study aimed to gather expert opinions on the management of allergic rhinitis (AR) using antihistamines alone or in various combinations in Indian settings.The cross-sectional, multiple-response, 23-item survey was primarily focused on current practices, clinical observations, and experiences related to AR and the utilization of oral histamines for disease management. The study involved otorhinolaryngologist from diverse settings in India.Out of 435 participants, 29% reported sneezing as the common AR symptoms. The majority (84.83%) favoured antihistamine and leukotriene receptor antagonist combinations for AR treatment. Specifically, 52% preferred levocetirizine, while 43% favoured fexofenadine. About 63% opted for polytherapy with oral antihistamines and anti-leukotrienes for AR management. Of these, 48% chose levocetirizine and montelukast for various AR symptoms. According to 60% of participants, fexofenadine + montelukast effectively improved nasal and eye symptoms. Around 64% preferred levocetirizine + montelukast for nighttime nasal symptoms, while 55% chose fexofenadine + montelukast for daytime nasal symptoms. Around 64% of the respondents favoured levocetirizine + montelukast for improving all AR symptoms, and 69% favoured antihistamine + montelukast for its cost-effectiveness.Experts recommend antihistamine and leukotriene receptor antagonist combinations for managing AR symptoms, with levocetirizine and fexofenadine being popular choices. Polytherapy with these combinations was favoured, especially for managing nighttime and daytime nasal symptoms.

Standard technical specifications for methacholine chloride (Methacholine) bronchial challenge test (2023)

Standard technical specifications for methacholine chloride (Methacholine) bronchial challenge test (2023)

Insights from Overviewing Selective International Guidelines for Pediatric Asthma.

Asthma is a chronic atopic and inflammatory bronchial disease characterized by recurring symptoms and, episodic reversible bronchial obstruction and easily triggered bronchospasms. Asthma often begins in childhood. International guidelines are widely accepted and implemented; however, there are similarities and differences in the management approaches. There is no national guideline in many cities in Asia. This review aims to provide a practical perspective on current recommendations in the management of childhood asthma, specifically in the following aspects: diagnosis, classification of severity, treatment options, and asthma control, and to provide physicians with up-to-date information for the management of asthma. We used the PubMed function of Clinical Queries and searched keywords of "Asthma", "Pediatric," AND "Guidelines" as the search engine. "Clinical Prediction Guides", "Etiology", "Diagnosis", "Therapy," "Prognosis," and "Narrow" scope were used as filters. The search was conducted in November 2022. The information retrieved from this search was used in compiling the present article. Diagnosis is clinically based on symptom pattern, response to therapy with bronchodilators and inhaled corticosteroids, and spirometric pulmonary function testing (PFT). Asthma is classified in accordance with symptom frequency, peak expiratory flow rate (PEFR), forced expiratory volume in one second (FEV1), atopic versus nonatopic etiology, where atopy means a predisposition toward a type 1 hypersensitivity reaction. Asthma is also classified as intermittent or persistent (mild to severe). Unfortunately, there is no disease cure for asthma. However, symptoms can be prevented by trigger avoidance and suppressed with inhaled corticosteroids. Antileukotriene agents or long-acting beta-agonists (LABA) may be used together with inhaled corticosteroids if symptoms of asthma are not controlled. Rapidly worsening symptoms are usually treated with an inhaled short-acting beta-2 agonist (SABA, e.g., salbutamol) and oral corticosteroids. Intravenous corticosteroids and hospitalization are required in severe cases of asthma attacks. Some guidelines also provide recommendations on the use of biologics and immunotherapy. Asthma is diagnosed clinically, with supporting laboratory testing. Treatment is based on severity classification, from intermittent to persistent. Inhaled bronchodilator and steroid anti-inflammatory form the main stay of management.

Efficacy and safety of the combination nasal spray olopatadine hydrochloride-mometasone furoate in the treatment of allergic rhinitis

Abstract Introduction Pharmacotherapy is the main pillar in the treatment of allergic rhinitis. While antihistamines (AH) and intranasal glucocorticosteroids (INCS) have long been part of the therapeutic standard, a pharmacological combination of both active substances in a nasal spray has so far only been implemented and made available in two preparations in Germany. Recently, an intranasal olopatadine hydrochloride-mometasone furoate (Olo-Mom) combination was introduced as a nasal spray for the treatment of seasonal and perennial allergic rhinitis. Methods In a literature search, treatment options for allergic rhinitis were analyzed and the available evidence was determined by searching Medline, PubMed, and the national and international study (ClinicalTrials.gov) and guideline registers and the Cochrane Library. Human studies published on the topic in the period up to and including August 2023 were taken into account. Results Based on the international literature and previous experience, the results are summarized and recommendations are given. The drugs used in the pharmacotherapy of AR primarily include INCS, intranasal and oral AH, leukotriene antagonists, intranasal cromoglicic acid preparations, intranasal and oral vasoconstrictors, and nasal rinses. For patients with intermittent and persistent allergic rhinitis, INCS are the first-line therapy, but in many patients they do not work sufficiently or quickly enough. The fixed combination Olo-Mom nasal spray showed significant improvements in the Reflective Total Nasal Symptom Score (rTNSS) in two phase II clinical trials with twice-daily and once-daily administration. In phase III studies, Olo-Mom nasal spray administered twice daily showed significant improvements in rTNSS compared to placebo, olopatadine monotherapy, and mometasone monotherapy. Conclusion In summary, AH and INCS will remain the main groups of active ingredients in the treatment of allergic rhinitis in the future. In combination preparations such as the new combination nasal spray olopatadine hydrochloride-mometasone furoate, they are highly effective and safe, thus opening up new perspectives, especially for patients with moderate and severe allergic rhinitis from the age of 12 years.

Promising Effects of Montelukast for Critically Ill Asthma Patients via a Reduction in Delirium.

Background: Montelukast (MTK), a potent antagonist of cysteinyl leukotriene receptor 1, has shown therapeutic promise for the treatment of neuropsychiatric disorders. Delirium, a common complication in critically ill patients, lacks effective treatment. This study aims to explore the impact of pre-intensive care unit (ICU) MTK use on in-hospital delirium incidence and, subsequent, prognosis in critically ill patients. Methods: A retrospective cohort study (n = 6344) was conducted using the MIMIC-IV database. After propensity score matching, logistic/Cox regression, E-value sensitivity analysis, and causal mediation analysis were performed to assess associations between pre-ICU MTK exposure and delirium and prognosis in critically ill patients. Results: Pre-ICU MTK use was significantly associated with reduced in-hospital delirium (OR: 0.705; 95% CI 0.497-0.999; p = 0.049) and 90-day mortality (OR: 0.554; 95% CI 0.366-0.840; p = 0.005). The association was more significant in patients without myocardial infarction (OR: 0.856; 95% CI 0.383-0.896; p = 0.014) and could be increased by extending the duration of use. Causal mediation analysis showed that the reduction in delirium partially mediated the association between MTK and 90-day mortality (ACME: -0.053; 95% CI -0.0142 to 0.0002; p = 0.020). Conclusions: In critically ill patients, MTK has shown promising therapeutic benefits by reducing the incidence of delirium and 90-day mortality. This study highlights the potential of MTK, beyond its traditional use in respiratory disease, and may contribute to the development of novel therapeutic strategies for delirium.

Trappc1 intrinsically prevents ferroptosis of naive T cells to avoid spontaneous autoinflammatory disease in mice.

T lymphocytes are pivotal in adaptive immunity. The role of the trafficking protein particle complex (TRAPPC) in regulating T-cell development and homeostasis is unknown. Using CD4cre -Trappc1flox/flox (Trappc1 cKO) mice, we found that Trappc1 deficiency in T cells significantly decreased cell number of naive T cells in the periphery, whereas thymic T-cell development in Trappc1 cKO mice was identical as WT mice. In the culture assays and mouse models with adoptive transfer of the sorted WT (CD45.1+ CD45.2+ ) and Trappc1 cKO naive T cells (CD45.2+ ) to CD45.1+ syngeneic mice, Trappc1-deficient naive T cells showed significantly reduced survival ability compared with WT cells. RNA-seq and molecular studies showed that Trappc1 deficiency in naive T cells reduced protein transport from the endoplasmic reticulum to the Golgi apparatus, enhanced unfolded protein responses, increased P53 transcription, intracellular Ca2+ , Atf4-CHOP, oxidative phosphorylation, and lipid peroxide accumulation, and subsequently led to ferroptosis. Trappc1 deficiency in naive T cells increased ferroptosis-related damage-associated molecular pattern molecules like high mobility group box 1 or lipid oxidation products like prostaglandin E2, leukotriene B4, leukotriene C4, and leukotriene D4. Functionally, the culture supernatant of Trappc1 cKO naive T cells significantly promoted neutrophils to express inflammatory cytokines like TNFα and IL-6, which was rescued by lipid peroxidation inhibitor Acetylcysteine. Importantly, Trappc1 cKO mice spontaneously developed severe autoinflammatory disease 4 weeks after birth. Thus, intrinsic expression of Trappc1 in naive T cells plays an integral role in maintaining T-cell homeostasis to avoid proinflammatory naive T-cell death-caused autoinflammatory syndrome in mice. This study highlights the importance of the TRAPPC in T-cell biology.

Sleep fragmentation disrupts Lyme arthritis resolution in mice

Study objectivesLyme arthritis is a common late-stage complication of infection by Borrelia burgdorferi, the agent of Lyme disease. Patients with Lyme arthritis report increased levels of sleep disturbance associated with pain. Using a mouse model of experimental Lyme arthritis, we investigated the effect of disrupted sleep on the development and resolution of joint inflammation. MethodsLyme arthritis-susceptible C3H/HeJ mice (n = 10/group) were infected with B. burgdorferi and were left either alone (control) or subjected to sleep fragmentation (SF). Arthritis development or resolution were monitored. The impact of SF on immune and inflammatory parameters such as arthritis severity scores, anti-borrelia antibody production, and bacterial clearance was measured. We also determined the effect of SF on arthritis resolution in C3H mice deficient in leukotriene (LT) B4 signaling (BLT1/2−/−) who display delayed Lyme arthritis resolution. ResultsSF had no significant impact on Lyme arthritis development or inflammatory parameters regardless of whether SF treatment began 1 week prior to or congruent with infection. However, initiation of SF at the peak of arthritis resulted in a significant delay in arthritis resolution as measured by joint edema, arthritis severity scores, and decreased bacterial clearance from the joint. This was accompanied by significant changes in joint cytokine transcription levels (e.g., increased TNFα and decreased IL-4). SF has no significant impact on Lyme arthritis resolution in the BLT1/2−/− mice. ConclusionsPoor sleep, especially near the peak of arthritis inflammation, may delay initiation of resolution programs possibly through altering cytokine production and host immune responses, leading to defects in spirochete clearance and prolonged disease.

Role of the soluble epoxide hydrolase in keratinocyte proliferation and sensitivity of skin to inflammatory stimuli

The lipid content of skin plays a determinant role in its barrier function with a particularly important role attributed to linoleic acid and its derivatives. Here we explored the consequences of interfering with the soluble epoxide hydrolase (sEH) on skin homeostasis. sEH; which converts fatty acid epoxides generated by cytochrome P450 enzymes to their corresponding diols, was largely restricted to the epidermis which was enriched in sEH-generated diols. Global deletion of the sEH increased levels of epoxides, including the linoleic acid-derived epoxide; 12,13-epoxyoctadecenoic acid (12,13-EpOME), and increased basal keratinocyte proliferation. sEH deletion (sEH-/- mice) resulted in thicker differentiated spinous and corneocyte layers compared to wild-type mice, a hyperkeratosis phenotype that was reproduced in wild-type mice treated with a sEH inhibitor. sEH deletion made the skin sensitive to inflammation and sEH-/- mice developed thicker imiquimod-induced psoriasis plaques than the control group and were more prone to inflammation triggered by mechanical stress with pronounced infiltration and activation of neutrophils as well as vascular leak and increased 12,13-EpOME and leukotriene (LT) B4 levels. Topical treatment of LTB4 antagonist after stripping successfully inhibited inflammation and neutrophil infiltration both in wild type and sEH-/- skin. While 12,13-EpoME had no effect on the trans-endothelial migration of neutrophils, like LTB4, it effectively induced neutrophil adhesion and activation. These observations indicate that while the increased accumulation of neutrophils in sEH-deficient skin could be attributed to the increase in LTB4 levels, both 12,13-EpOME and LTB4 contribute to neutrophil activation. Our observations identify a protective role of the sEH in the skin and should be taken into account when designing future clinical trials with sEH inhibitors.

Exercise-Induced Asthma: Managing Respiratory Issues in Athletes.

Asthma is a complex respiratory condition characterized by chronic airway inflammation and variable expiratory airflow limitation, affecting millions globally. Among athletes, particularly those competing at elite levels, the prevalence of respiratory conditions is notably heightened, varying between 20% and 70% across specific sports. Exercise-induced bronchoconstriction (EIB) is a common issue among athletes, impacting their performance and well-being. The prevalence rates vary based on the sport, training environment, and genetics. Exercise is a known trigger for asthma, but paradoxically, it can also improve pulmonary function and alleviate EIB severity. However, athletes' asthma phenotypes differ, leading to varied responses to medications and challenges in management. The unique aspects in athletes include heightened airway sensitivity, allergen, pollutant exposure, and temperature variations. This review addresses EIB in athletes, focusing on pathogenesis, diagnosis, and treatment. The pathogenesis of EIB involves complex interactions between physiological and environmental factors. Airway dehydration and cooling are key mechanisms, leading to osmotic and thermal theories. Airway inflammation and hyper-responsiveness are common factors. Elite athletes often exhibit distinct inflammatory responses and heightened airway sensitivity, influenced by sport type, training, and environment. Swimming and certain sports pose higher EIB risks, with chlorine exposure in pools being a notable factor. Immune responses, lung function changes, and individual variations contribute to EIB in athletes. Diagnosing EIB in athletes requires objective testing, as baseline lung function tests can yield normal results. Both EIB with asthma (EIBA) and without asthma (EIBwA) must be considered. Exercise and indirect bronchoprovocation tests provide reliable diagnoses. In athletes, exercise tests offer effectiveness in diagnosing EIB. Spirometry and bronchodilation tests are standard approaches, but the diagnostic emphasis is shifting toward provocation tests. Despite its challenges, achieving an optimal diagnosis of EIA constitutes the cornerstone for effective management, leading to improved performance, reduced risk of complications, and enhanced quality of life. The management of EIB in athletes aligns with the general principles for symptom control, prevention, and reducing complications. Non-pharmacological approaches, including trigger avoidance and warming up, are essential. Inhaled corticosteroids (ICS) are the cornerstone of asthma therapy in athletes. Short-acting beta agonists (SABA) are discouraged as sole treatments. Leukotriene receptor antagonists (LTRA) and mast cell stabilizing agents (MCSA) are potential options. Optimal management improves the athletes' quality of life and allows them to pursue competitive sports effectively.

The leukotriene receptor antagonist montelukast as a potential therapeutic adjuvant in multiple sclerosis - a review.

Multiple Sclerosis (MS) is a multifactorial autoimmune disease of the central nervous system (CNS). It is characterized by a heightened activation of the immune system with ensuing inflammation, demyelination and neurodegeneration with consequences such as motor, sensory, cognitive, as well as autonomic dysfunctions. While a range of immune-modulatory drugs have shown certain efficacy in alleviating pathology and symptoms, none of the currently available therapeutics regenerates the damaged CNS to restore function. There is emerging evidence for leukotrienes and leukotriene receptors being involved in the various aspects of the MS pathology including neuroinflammation and de/remyelination. Moreover, leukotriene receptor antagonists such as the asthma drug montelukast diminish inflammation and promote regeneration/remyelination. Indeed, montelukast has successfully been tested in animal models of MS and a recent retrospective case-control study suggests that montelukast treatment reduces relapses in patients with MS. Therefore, we propose montelukast as a therapeutic adjuvant to the standard immune-modulatory drugs with the potential to reduce pathology and promote structural and functional restoration. Here, we review the current knowledge on MS, its pathology, and on the potential of leukotriene receptor antagonists as therapeutics for MS.

Modern approaches to rational combination pharmacotherapy of allergic rhinitis

Allergic rhinitis (AR) can significantly reduce the quality of life of patients leading to increased fatigue, mood changes, cognitive impairment, and depression. In clinical practice, insufficient effectiveness of initial AR monotherapy is often noted, and a significant proportion of patients referring for medical care have moderate-severe AR. In this regard, the issues of optimization of combined pharmacological treatment of AR are becoming more and more urgent. This paper provides analysis of the opportunities of combined pharmacotherapy within the framework of current management strategy of AR. Based on the results of some studies and known pharmacological properties of medications it is being discussed the advantages of combined use of intranasal corticosteroids and leukotriene receptor antagonists, in particular mometasone furoate and montelukast, in the therapy of AR, including such comorbidities as bronchial asthma, chronic polyposis rhinosinusitis and pharyngeal tonsil hyperplasia. Some aspects of combination therapy with montelukast and second-generation systemic antihistamines as an alternative approach in case of inability to take intranasal corticosteroids, including the reasonability of using a fixed combination of montelukast and levocetirizine, are analyzed from the perspective of rational pharmacotherapy. The problem of interchangeability of brand-name and generic drugs for the treatment of AR is discussed, considering the almost complete absence of studies of their therapeutic equivalence.

Prescription pattern of anti-asthmatic drugs for adults in asthma outpatient department in a tertiary care hospital

Background: Various groups of drugs are prescribed for the management of bronchial asthma. Choosing correct group is necessary for compliance and good outcome. Aims and Objectives: The aims and objectives of the study are to know the prescribing pattern of anti-asthmatic drugs for adults. Materials and Methods: 500 asthma patients prescription were analyzed from the MMC/RGGGH, Chennai. Results: 654 prescriptions were screened and 500 prescriptions were taken for data analysis. The data showed 67% men and 33% women. Most of them received combination therapy (85%) than monotherapy (15%). Beta 2 agonists (salbutamol) formed major anti-asthmatic group (68%). Steroids group formed next (47%). Deriphyllin was prescribed for 108 patients (22%), cetrizine (anti-histamine) for 55 patients (11%), and montelukast (leukotriene antagonists) for 45 patients (9%). About 76% patients took oral tablet and 24% took inhalers. Conclusion: β 2 agonists were preferred more than steroids group. Combination therapy is given more than monotherapy. Majority patients in our study were given oral route when compared to inhalational route.

A Fully Decentralized Randomized Controlled Study of As-Needed Albuterol-Budesonide Fixed-Dose Inhaler in Mild Asthma: The BATURA Study Design.

Decentralized clinical trials, where trial-related activities occur at locations other than traditional clinical sites(eg participant homes, local healthcare facilities), have the potential to improve trial access for people for whom time and/or distance constraints may impede participation. Albuterol-budesonide 180/160 µg pressurized metered-dose inhaler (pMDI) is FDA approved for the as-needed treatment or prevention of bronchoconstriction and to reduce the risk of exacerbations in patients with asthma 18 years or older. BATURA (NCT05505734) is a fully decentralized study, investigating as-needed albuterol-budesonide in participants with mild asthma. BATURA is a fully decentralized, phase 3b, randomized, double-blind, event-driven exacerbation study conducted in the United States. Participants aged ≥12 years using as-needed short-acting β2-agonist (SABA), alone or with low-dose inhaled corticosteroid or leukotriene receptor antagonist maintenance, are randomized 1:1 to as-needed albuterol-budesonide 180/160 µg or albuterol 180 µg pMDI for up to 52 weeks (minimum 12 weeks). Participants continue their current maintenance therapy, if applicable. Participants must have used SABA for ≥2 days in the 2 weeks pre-enrollment and have an Asthma Impairment Risk Questionnaire score ≥2 at screening and randomization. All trial-related visits, including screening and consent, are conducted virtually, with study medication shipped directly to each participant's residence. The primary objective is to evaluate the efficacy of as-needed albuterol-budesonide versus albuterol on severe asthma exacerbation risk, measured by time-to-first severe asthma exacerbation (primary endpoint). Secondary endpoints include annualized rate of severe asthma exacerbation and total systemic corticosteroid exposure. Study medication use is captured via a Hailie sensor attached to the study medication pMDI. The intended sample size is 2500 participants. BATURA evaluates as-needed albuterol-budesonide in participants with mild asthma. The decentralized study model enables the trial to move out of research sites into participant homes, reducing participant burden and improving access.

Comparative efficacy of combined antihistamine and montelukast therapy in adult patients with atopic dermatitis.

Atopic dermatitis (AD) is one of the most common chronic skin conditions affecting about 20% of children and 5% of adults. However, the studies assessing novel therapies for AD have been focused mainly on paediatric patients and only few studies have involved adult participants. To compare the treatment outcomes between the antihistamine monotherapy and combined intervention with an antihistamine agent and a cysteinyl leukotriene receptor antagonist in adult patients with atopic dermatitis. Patients were randomized into two groups to receive 5 mg oral desloratadine or the combined therapy with 5 mg oral desloratadine and 10 mg montelukast. Both groups were also administered topical treatment using the same protocol (topical Elocon and moisturizer). To estimate the efficacy of the implemented therapy methods, different skin health scores (SCORAD, GISS, EASI, PPNRS and DLQI) and skin functional assessment outcomes (corneometry, pH and transepidermal water loss) were evaluated before and after the treatment. Significant differences were revealed in compared measurement results for scales of the Extent and Severity of Eczema assessment, Global Individual Signs Score, Eczema Area and Severity Index, Pruritus Numerical Rating Scale, Dermatology Life Quality Index and Skin Functional Properties (p > 0.05). Comparison of data presenting the therapy outcomes in two groups showed that administration of the combined therapy was significantly more effective compared to the antihistamine monotherapy. The results revealed considerable efficacy of the combined therapy reinforced by the use of cysteinyl leukotriene receptor antagonist, montelukast.

A review of the therapeutic potential of the cysteinyl leukotriene antagonist Montelukast in the treatment of bronchiolitis obliterans syndrome following lung and hematopoietic-stem cell transplantation and its possible mechanisms.

Lung and hematopoietic stem cell transplantation are therapeutic modalities in chronic pulmonary and hematological diseases, respectively. One of the complications in these patients is the development of bronchiolitis obliterans syndrome (BOS). The efficacy and safety of available treatment strategies in BOS remain a challenge. A few mechanisms have been recognized for BOS in lung transplant and graft-versus-host disease (GVHD) patients involving the TH-1 and TH-2 cells, NF-kappa B, TGF-b, several cytokines and chemokines, and cysteinyl leukotrienes (CysLT). Montelukast is a highly selective CysLT receptor antagonist that has been demonstrated to exert anti-inflammatory and anti-fibrotic effects in abundant experiments. One area of interest for the use of montelukast is lung transplants or GVHD-associated BOS. Herein, we briefly review data regarding the mechanisms involved in BOS development and montelukast administration as a treatment modality for BOS, and finally, the possible relationship between CysLTs antagonism and BOS improvement will be discussed.

Higher risk of osteoporosis in adult-onset asthma than childhood-onset asthma: from genetic and prospective evidence.

Childhood-onset asthma (COA) differs with adult-onset asthma (AOA) on genetic susceptibility, severity, and co-morbidities. Whether COA or AOA is independently associated with osteoporosis is unexplored. We aimed to determine the effects of COA and AOA on osteoporosis at genetic and individual level. We used two-sample Mendelian randomization analysis to explore the causal effects of COA and AOA on osteoporosis. In the UK Biobank cohort, we included 478,289 osteoporosis-free participants at baseline (2006-2010). Participants were classified as non-asthma, COA, and AOA at recruitment. Multivariate Cox regression analysis was used to evaluate the effects of COA, AOA, and multiple asthma medications on incident osteoporosis risk. COA and AOA were causally related to osteoporosis, with odds ratio of 1.007 (95% confidence interval (CI), 1.0003-1.0132) and 1.012 (95% CI, 1.002-1.023), respectively. Multivariate Cox regression analysis suggested that COA (hazard ratio (HR), 1.46; 95% CI, 1.32-1.61) and AOA (HR, 1.70; 95% CI, 1.61-1.80) were independently associated with incident osteoporosis, and the risk was greatly higher in AOA (HR, 1.51; 95% CI, 1.34-1.70). In addition to corticosteroids, monotherapy with leukotriene modifiers (HR, 1.70; 95% CI, 1.20-2.42), long-acting beta agonists (HR, 1.49; 95% CI, 1.18-1.87), and short-acting beta agonists (HR, 1.72; 95% CI1.01-2.93) were independently associated with a higher risk of osteoporosis. Both COA and AOA have a genetically causal effect on osteoporosis, and the risk of osteoporosis is greatly higher in AOA. Besides corticosteroids, the increased risk of osteoporosis among asthma patients should be attributed to genetic susceptibility and other asthma medications.

Integrated transcriptomics and metabolomics reveal the toxic mechanisms of mercury exposure to an endangered species Tachypleus tridentatus

Mercury (Hg) pollution is threatening the health of endangered Tachypleus tridentatus whereas the toxic mechanism is still unclear. This study combined transcriptomic and metabolomics technology to reveal the toxic mechanisms of mercury (Hg 2+, 0.025 mg/L) exposing to T. tridentatus larvae for 15 days. Mercury induced cellular toxicity and cardiovascular dysfunction by dysregulating the genes related to endocrine system, such as polyubiquitin-A, cathepsin B, atrial natriuretic peptide, etc. Mercury induced lipid metabolic disorder with the abnormal increase of lysoPC, leukotriene D4, and prostaglandin E2. Cytochrome P450 pathway was activated to produce anti-inflammatory substances to reconstruct the homeostasis. Mercury also inhibited arginine generation, which may affect the development of T. tridentatus by disrupting the crucial signaling pathway. The mercury methylation caused enhancement of S-adenosylmethionine to meet the need of methyl donor. The mechanisms described in present study provide new insight into the risk assessment of mercury exposure to T. tridentatus.

The role of captopril in leukotriene deficient type 1 diabetic mice

T1D can be associated with metabolic disorders and several impaired pathways, including insulin signaling, and development of insulin resistance through the renin-angiotensin system (RAS). The main precursor of RAS is angiotensinogen (Agt) and this system is often linked to autophagy dysregulation. Dysregulated autophagy has been described in T1D and linked to impairments in both glucose metabolism, and leukotrienes (LTs) production. Here, we have investigated the role of RAS and LTs in both muscle and liver from T1D mice, and its effects on insulin and autophagy pathways. We have chemically induced T1D in 129sve and 129sve 5LO−/− mice (lacking LTs) with streptozotocin (STZ). To further inhibit ACE activity, mice were treated with captopril (Cap). In muscle of T1D mice, treatment with Cap increased the expression of RAS (angiotensinogen and angiotensin II receptor), insulin signaling, and autophagy markers, regardless of the genotype. In the liver of T1D mice, the treatment with Cap increased the expression of RAS and insulin signaling markers, mostly when LTs were absent. 5LO−/− T1D mice showed increased insulin sensitivity, and decreased NEFA, after the Cap treatment. Cap treatment impacted both insulin signaling and autophagy pathways at the mRNA levels in muscle and liver, indicating the potential role of ACE inhibition on insulin sensitivity and autophagy in T1D.

Epigenomic Profiling Advises Therapeutic Potential of Leukotriene Receptor Inhibitors for a Subset of Triple-Negative Breast Tumors.

Triple-negative breast cancer (TNBC) is the most aggressive molecular subtype, with a poor survival rate compared to others subtypes. For a long time, chemotherapy was the only systemic treatment for TNBC, and the identification of actionable molecular targets might ultimately improve the prognosis for TNBC patients. We performed a genome-wide analysis of DNA methylation at CpG islands on a collection of one hundred ten breast carcinoma samples and six normal breast tissue samples using reduced representation bisulfite sequencing with the XmaI restriction enzyme (XmaI-RRBS) and identified a subset of TNBC samples with significant hypomethylation at the LTB4R/LTB4R2 genes' CpG islands, including CpG dinucleotides covered with cg12853742 and cg21886367 HumanMethylation 450K microarray probes. Abnormal DNA hypomethylation of this region in TNBC compared to normal samples was confirmed by bisulfite Sanger sequencing. Gene expression generally anticorrelates with promoter methylation, and thus, the promoter hypomethylation detected and confirmed in our study might be revealed as an indirect marker of high LTB4R/LTB4R2 expression using a simple methylation-sensitive PCR test. Analysis of RNA-seq expression and DNA methylation data from the TCGA dataset demonstrates that the expression of the LTB4R and LTB4R2 genes significantly negatively correlates with DNA methylation at both CpG sites cg12853742 (R = -0.4, p = 2.6 × 10-6; R = -0.21, p = 0.015) and cg21886367 (R = -0.45, p = 7.3 × 10-8; R = -0.24, p = 0.005), suggesting the upregulation of these genes in tumors with abnormal hypomethylation of their CpG island. Kaplan-Meier analysis using the TCGA-BRCA gene expression and clinical data revealed poorer overall survival for TNBC patients with an upregulated LTB4R. To this day, only the leukotriene inhibitor LY255283 has been tested on an MCF-7/DOX cell line, which is a luminal A breast cancer molecular subtype. Other studies compare the effects of Montelukast and Zafirlukast (inhibitors of the cysteinyl leukotriene receptor, which is different from LTB4R/LTB4R2) on the MDA-MB-231 (TNBC) cell line, with high methylation and low expression levels of LTB4R. In our study, we assess the therapeutic effects of various drugs (including leukotriene receptor inhibitors) with the DepMap gene effect and drug sensitivity data for TNBC cell lines with hypomethylated and upregulated LTB4R/LTB4R2 genes. LY255283, Minocycline, Silibinin, Piceatannol, Mitiglinide, 1-Azakenpaullone, Carbetocin, and Pim-1-inhibitor-2 can be considered as candidates for the additional treatment of TNBC patients with tumors demonstrating LTB4R/LTB4R2 hypomethylation/upregulation. Finally, our results suggest that the epigenetic status of leukotriene B4 receptors is a novel, potential, predictive, and prognostic biomarker for TNBC. These findings might improve individualized therapy for TNBC patients by introducing new therapeutic adjuncts as anticancer agents.