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Molecular Metabolism Jan 2024Retinol saturase (RetSat) is an endoplasmic reticulum-localized oxidoreductase highly expressed in organs involved in lipid metabolism such as white (WAT) and brown...
OBJECTIVE
Retinol saturase (RetSat) is an endoplasmic reticulum-localized oxidoreductase highly expressed in organs involved in lipid metabolism such as white (WAT) and brown adipose tissue (BAT). Cold exposure was shown to increase RETSAT protein in BAT but its relevance for non-shivering thermogenesis, a process with beneficial effects on metabolic health, is unknown.
METHODS
We analyzed the regulation of RetSat expression in white and brown adipocytes and different murine adipose tissue depots upon β-adrenergic stimulation and cold exposure. RetSat function during the differentiation and β-adrenergic stimulation of brown adipocytes was dissected by loss-of-function experiments. Mice with BAT-specific deletion of RetSat were generated and exposed to cold. Gene expression in human WAT was analyzed and the effect of RetSat depletion on adipocyte lipolysis investigated.
RESULTS
We show that cold exposure induces RetSat expression in both WAT and BAT of mice via β-adrenergic signaling. In brown adipocytes, RetSat has minor effects on differentiation but is required for maximal thermogenic gene and protein expression upon β-adrenergic stimulation and mitochondrial respiration. In mice, BAT-specific deletion of RetSat impaired acute but not long-term adaptation to cold exposure. RetSat expression in subcutaneous WAT of humans correlates with the expression of genes related to mitochondrial function. Mechanistically, we found that RetSat depletion impaired β-agonist-induced lipolysis, a major regulator of thermogenic gene expression in adipocytes.
CONCLUSIONS
Thus, RetSat expression is under β-adrenergic control and determines thermogenic capacity of brown adipocytes and acute cold tolerance in mice. Modulating RetSat activity may allow for therapeutic interventions towards pathologies with inadequate metabolic activity.
Topics: Mice; Humans; Animals; Vitamin A; Lipolysis; Adrenergic Agents; Adipose Tissue, Brown; Adipocytes, Brown; Obesity
PubMed: 38128827
DOI: 10.1016/j.molmet.2023.101855 -
Anesthesia and Analgesia Dec 2023The hypothesis "General anesthesia consists of producing both loss of consciousness and the inhibition of noxious stimuli reaching the brain and causing arousal" was... (Review)
Review
The hypothesis "General anesthesia consists of producing both loss of consciousness and the inhibition of noxious stimuli reaching the brain and causing arousal" was used as a basis for the review of published data on general anesthetic interactions with antinociceptive agents: opioids, α 2 adrenergic agonists, and systemic sodium channel blockers. This review is focused on a specific type of anesthetic interaction-the transformation of antinociceptive agents into general anesthetic adjuncts. The primary aim is to answer 2 questions. First, how does an antinociceptive agent transform the effect of an anesthetic in providing a certain component of anesthesia-hypnosis, immobility, or hemodynamic response to noxious stimulation? Second, does a combination of an anesthetic with an adjunct result in a simple summation of their respective effects or in a supra-additive or infra-additive interaction? The Medline database was searched for data describing the interactions of antinociceptive agents and general anesthetics. The following classes of antinociceptive agents were considered: opioids, α 2 adrenergic agonists, and systemic sodium channel blockers. Drugs used in combination with antinociceptive agents were general anesthetics and benzodiazepines. The following terms related to drug interactions were used: anesthetic interactions, synergy, antagonism, isobolographic analysis, response surface analysis, and fractional analysis. The interactions of antinociceptive agents with general anesthetics result in a decrease of general anesthetic requirements, which differ for each of the components of general anesthesia: hypnosis, immobility, and hemodynamic response to noxious stimulation. Most studies of the nature of anesthetic interactions are related to opioid-general anesthetic combinations, and their conclusions usually confirm supra-additivity.
Topics: Analgesics; Analgesics, Opioid; Drug Interactions; Anesthetics, General; Sodium Channel Blockers; Adrenergic Agonists; Dose-Response Relationship, Drug
PubMed: 37851902
DOI: 10.1213/ANE.0000000000006737 -
JAMA Cardiology Apr 2024Increasing the patient's heart rate (HR) has emerged as a therapeutic option in patients with heart failure with preserved ejection fraction (HFpEF). However, the... (Randomized Controlled Trial)
Randomized Controlled Trial
IMPORTANCE
Increasing the patient's heart rate (HR) has emerged as a therapeutic option in patients with heart failure with preserved ejection fraction (HFpEF). However, the evidence is conflicting, and the profile of patients who benefit most from this strategy remains unclear.
OBJECTIVE
To assess the association of β-blocker treatment withdrawal with changes in the percentage of predicted peak oxygen consumption (VO2) across indexed left ventricular diastolic (iLVEDV) and indexed left ventricular systolic volumes (iLVESV), and left ventricular ejection fraction (LVEF) in patients with HFpEF and chronotropic incompetence.
DESIGN, SETTING, AND PARTICIPANTS
This post hoc analysis was conducted using data from the investigator-blinded multicenter, randomized, and crossover clinical trial, PRESERVE-HR, that took place from October 1, 2018, through December 31, 2020, to investigate the short-term effects (2 weeks) of β-blocker withdrawal on peak oxygen consumption (peak VO2). Patients with stable HFpEF (New York Heart Association functional class II to III) receiving treatment with β-blocker and chronotropic incompetence were included.
INTERVENTION
Participants in the PRESERVE-HR trial were randomized to withdraw vs continue with β-blocker treatment. After 2 weeks, they were crossed over to receive the opposite intervention. This crossover randomized clinical trial examined the short-term effect of β-blocker withdrawal on peak VO2.
MAIN OUTCOMES AND MEASURES
The primary outcome was to evaluate the association between β-blocker withdrawal and short-term changes in percentage of peak VO2 across iLVEDV, iLVESV, and LVEF in patients with HFpEF and chronotropic incompetence treated with β-blocker.
RESULTS
A total of 52 patients (mean age, 73 [SD, 13] years; 60% female) were randomized. The mean resting HR, peak HR, peak VO2, and percentage of peak VO2 were 65 (SD, 9) beats per minute (bpm), 97 (SD, 15) bpm, 12.4 (SD, 2.9) mL/kg per minute, and 72.4% (SD, 17.7%), respectively. The medians (minimum-maximum) of iLVEDV, iLVESV, and LVEF were 44 mL/m2 (IQR, 19-82), 15 mL/m2 (IQR, 7-32), and 64% (IQR, 52%-78%), respectively. After stopping β-blocker treatment, the median increase in peak HR was plus 30 bpm (95% CI, 25-35; P < .001). β-Blocker cessation was differentially associated with change of percentage of peak VO2 across the continuum of iLVESV (P for interaction = .02), indicating a greater benefit in those with lower iLVESV.
CONCLUSIONS AND RELEVANCE
In this study, results showed that in patients with HFpEF and chronotropic incompetence receiving treatment with β-blocker, lower iLVESV may identify those with a greater short-term improvement in maximal functional capacity after stopping β-blocker treatment. Further studies are warranted for further investigation.
TRIAL REGISTRATION
ClinicalTrials.gov (NCT03871803).
Topics: Aged; Female; Humans; Male; Adrenergic beta-Antagonists; Heart Failure; Heart Rate; Stroke Volume; Ventricular Function, Left; Middle Aged; Aged, 80 and over
PubMed: 38324280
DOI: 10.1001/jamacardio.2023.5500 -
Discovery Medicine May 2024Cardiovascular disease stands as the leading cause of death globally, with hypertension emerging as an independent risk factor for its development. The worldwide... (Review)
Review
Cardiovascular disease stands as the leading cause of death globally, with hypertension emerging as an independent risk factor for its development. The worldwide prevalence of hypertension hovers around 30%, encompassing a staggering 1.2 billion patients, and continues to escalate annually. Medication plays a pivotal role in managing hypertension, not only effectively regulating blood pressure (BP) but also substantially mitigating the occurrence of cardiovascular and cerebrovascular diseases. This review comprehensively outlines the categories, mechanisms, clinical applications, and drawbacks of conventional antihypertensive drugs. It delves into the five primary pharmacological classifications, namely β-receptor blockers, calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), and diuretics. The emphasis is placed on elucidating the mechanisms, advantages, and research progress of novel antihypertensive drugs targeting emerging areas. These include mineralocorticoid receptor antagonists (MRAs), atrial natriuretic peptides (ANPs), neutral endopeptidase inhibitors (NEPIs), sodium-dependent glucose transporter 2 inhibitors (SGLT-2Is), glucagon-like peptide-1 receptor agonists (GLP-1RAs), endothelin receptor antagonists (ERAs), soluble guanylate cyclase (sGC) agonists, brain aminopeptidase A inhibitors (APAIs), and small interfering ribonucleic acids (siRNAs) targeting hepatic angiotensinogen. Compared to conventional antihypertensive drugs, these novel alternatives exhibit favorable antihypertensive effects with minimal adverse reactions. This review serves as a valuable reference for future research and the clinical application of antihypertensive drugs.
Topics: Humans; Antihypertensive Agents; Hypertension; Angiotensin-Converting Enzyme Inhibitors; Angiotensin Receptor Antagonists; Calcium Channel Blockers; Animals; Adrenergic beta-Antagonists; Diuretics; Mineralocorticoid Receptor Antagonists
PubMed: 38798249
DOI: 10.24976/Discov.Med.202436184.83 -
BMJ Open Aug 2023Bronchiectasis is a long-term lung condition, with dilated bronchi, chronic inflammation, chronic infection and acute exacerbations. Recurrent exacerbations are...
Dual bronchodilators in Bronchiectasis study (DIBS): protocol for a pragmatic, multicentre, placebo-controlled, three-arm, double-blinded, randomised controlled trial studying bronchodilators in preventing exacerbations of bronchiectasis.
INTRODUCTION
Bronchiectasis is a long-term lung condition, with dilated bronchi, chronic inflammation, chronic infection and acute exacerbations. Recurrent exacerbations are associated with poorer clinical outcomes such as increased severity of lung disease, further exacerbations, hospitalisations, reduced quality of life and increased risk of death. Despite an increasing prevalence of bronchiectasis, there is a critical lack of high-quality studies into the disease and no treatments specifically approved for its treatment. This trial aims to establish whether inhaled dual bronchodilators (long acting beta agonist (LABA) and long acting muscarinic antagonist (LAMA)) taken as either a stand-alone therapy or in combination with inhaled corticosteroid (ICS) reduce the number of exacerbations of bronchiectasis requiring treatment with antibiotics during a 12 month treatment period.
METHODS
This is a multicentre, pragmatic, double-blind, randomised controlled trial, incorporating an internal pilot and embedded economic evaluation. 600 adult patients (≥18 years) with CT confirmed bronchiectasis will be recruited and randomised to either inhaled dual therapy (LABA+LAMA), triple therapy (LABA+LAMA+ICS) or matched placebo, in a 2:2:1 ratio (respectively). The primary outcome is the number of protocol defined exacerbations requiring treatment with antibiotics during the 12 month treatment period.
ETHICS AND DISSEMINATION
Favourable ethical opinion was received from the North East-Newcastle and North Tyneside 2 Research Ethics Committee (reference: 21/NE/0020). Results will be disseminated in peer-reviewed publications, at national and international conferences, in the NIHR journal and to participants and the public (using lay language).
TRIAL REGISTRATION NUMBER
ISRCTN15988757.
Topics: Adult; Humans; Bronchodilator Agents; Quality of Life; Adrenergic beta-2 Receptor Agonists; Muscarinic Antagonists; Bronchiectasis; Pulmonary Disease, Chronic Obstructive; Administration, Inhalation; Drug Therapy, Combination; Adrenal Cortex Hormones; Anti-Bacterial Agents; Randomized Controlled Trials as Topic; Multicenter Studies as Topic
PubMed: 37562935
DOI: 10.1136/bmjopen-2023-071906 -
Heart Failure Reviews May 2024Despite major advances in prevention and medical therapy, heart failure (HF) remains associated with high morbidity and mortality, especially in older and frailer... (Review)
Review
Despite major advances in prevention and medical therapy, heart failure (HF) remains associated with high morbidity and mortality, especially in older and frailer patients. Therefore, a complete, guideline-based treatment is essential, even in HF patients with conditions traditionally associated with a problematic initiation and escalation of the medical HF therapy, such as chronic kidney disease and arterial hypotension, as the potential adverse effects are overcome by the overall decrease of the absolute risk. Furthermore, since the latest data suggest that the benefit of a combined medical therapy (MRA, ARNI, SGLT2i, beta-blocker) may extend up to a LVEF of 65%, further trials on these subgroups of patients (HFmrEF, HFpEF) are needed to re-evaluate the guideline-directed medical therapy across the HF spectrum. In particular, the use of SGLT2i was recently extended to HFpEF patients, as evidenced by the DELIVER and EMPEROR-preserved trials. Moreover, the indication for other conservative treatments in HF patients, such as the intravenous iron supplementation, was accordingly strengthened in the latest guidelines. Finally, the possible implementation of newer substances, such as finerenone, in guideline-directed medical practice for HF is anticipated with great interest.
Topics: Humans; Heart Failure; Sodium-Glucose Transporter 2 Inhibitors; Stroke Volume; Adrenergic beta-Antagonists; Practice Guidelines as Topic
PubMed: 38349462
DOI: 10.1007/s10741-024-10389-8 -
Acta Physiologica (Oxford, England) Apr 2024Exercise intolerance is the central symptom in patients with heart failure with preserved ejection fraction. In the present study, we investigated the adrenergic reserve...
AIM
Exercise intolerance is the central symptom in patients with heart failure with preserved ejection fraction. In the present study, we investigated the adrenergic reserve both in vivo and in cardiomyocytes of a murine cardiometabolic HFpEF model.
METHODS
12-week-old male C57BL/6J mice were fed regular chow (control) or a high-fat diet and L-NAME (HFpEF) for 15 weeks. At 27 weeks, we performed (stress) echocardiography and exercise testing and measured the adrenergic reserve and its modulation by nitric oxide and reactive oxygen species in left ventricular cardiomyocytes.
RESULTS
HFpEF mice (preserved left ventricular ejection fraction, increased E/e', pulmonary congestion [wet lung weight/TL]) exhibited reduced exercise capacity and a reduction of stroke volume and cardiac output with adrenergic stress. In ventricular cardiomyocytes isolated from HFpEF mice, sarcomere shortening had a higher amplitude and faster relaxation compared to control animals. Increased shortening was caused by a shift of myofilament calcium sensitivity. With addition of isoproterenol, there were no differences in sarcomere function between HFpEF and control mice. This resulted in a reduced inotropic and lusitropic reserve in HFpEF cardiomyocytes. Preincubation with inhibitors of nitric oxide synthases or glutathione partially restored the adrenergic reserve in cardiomyocytes in HFpEF.
CONCLUSION
In this murine HFpEF model, the cardiac output reserve on adrenergic stimulation is impaired. In ventricular cardiomyocytes, we found a congruent loss of the adrenergic inotropic and lusitropic reserve. This was caused by increased contractility and faster relaxation at rest, partially mediated by nitro-oxidative signaling.
Topics: Humans; Male; Animals; Mice; Stroke Volume; Ventricular Function, Left; Heart Failure; Adrenergic Agents; Disease Models, Animal; Nitric Oxide; Mice, Inbred C57BL
PubMed: 38436094
DOI: 10.1111/apha.14124 -
JAMA Cardiology Aug 2023Syncope is the most powerful predictor for subsequent life-threatening events (LTEs) in patients with congenital long QT syndrome (LQTS). Whether distinct syncope...
IMPORTANCE
Syncope is the most powerful predictor for subsequent life-threatening events (LTEs) in patients with congenital long QT syndrome (LQTS). Whether distinct syncope triggers are associated with differential subsequent risk of LTEs is unknown.
OBJECTIVE
To evaluate the association between adrenergic (AD)- and nonadrenergic (non-AD)-triggered syncopal events and the risk of subsequent LTEs in patients with LQT types 1 to 3 (LQT1-3).
DESIGN, SETTING, AND PARTICIPANTS
This retrospective cohort study included data from 5 international LQTS registries (Rochester, New York; the Mayo Clinic, Rochester, Minnesota; Israel, the Netherlands, and Japan). The study population comprised 2938 patients with genetically confirmed LQT1, LQT2, or LQT3 stemming from a single LQTS-causative variant. Patients were enrolled from July 1979 to July 2021.
EXPOSURES
Syncope by AD and non-AD triggers.
MAIN OUTCOMES AND MEASURES
The primary end point was the first occurrence of an LTE. Multivariate Cox regression was used to determine the association of AD- or non-AD-triggered syncope on the risk of subsequent LTE by genotype. Separate analysis was performed in patients with β-blockers.
RESULTS
A total of 2938 patients were included (mean [SD] age at enrollment, 29 [7] years; 1645 [56%] female). In 1331 patients with LQT1, a first syncope occurred in 365 (27%) and was induced mostly with AD triggers (243 [67%]). Syncope preceded 43 subsequent LTEs (68%). Syncopal episodes associated with AD triggers were associated with the highest risk of subsequent LTE (hazard ratio [HR], 7.61; 95% CI, 4.18-14.20; P < .001), whereas the risk associated with syncopal events due to non-AD triggers was statistically nonsignificant (HR, 1.50; 95% CI, 0.21-4.77; P = .97). In 1106 patients with LQT2, a first syncope occurred in 283 (26%) and was associated with AD and non-AD triggers in 106 (37%) and 177 (63%), respectively. Syncope preceded 55 LTEs (56%). Both AD- and non-AD-triggered syncope were associated with a greater than 3-fold increased risk of subsequent LTE (HR, 3.07; 95% CI, 1.66-5.67; P ≤ .001 and HR, 3.45, 95% CI, 1.96-6.06; P ≤ .001, respectively). In contrast, in 501 patients with LQT3, LTE was preceded by a syncopal episode in 7 (12%). In patients with LQT1 and LQT2, treatment with β-blockers following a syncopal event was associated with a significant reduction in the risk of subsequent LTEs. The rate of breakthrough events during treatment with β-blockers was significantly higher among those treated with selective agents vs nonselective agents.
CONCLUSION AND RELEVANCE
In this study, trigger-specific syncope in LQTS patients was associated with differential risk of subsequent LTE and response to β-blocker therapy.
Topics: Humans; Female; Child; Male; Retrospective Studies; Risk Factors; Long QT Syndrome; Syncope; Adrenergic beta-Antagonists
PubMed: 37436769
DOI: 10.1001/jamacardio.2023.1951 -
PloS One 2023Chronic stress among young patients (≤ 45 years old) could result in autonomic dysfunction. Autonomic dysfunction could be exhibited via sympathetic hyperactivity,...
Chronic stress among young patients (≤ 45 years old) could result in autonomic dysfunction. Autonomic dysfunction could be exhibited via sympathetic hyperactivity, sympathetic nerve sprouting, and diffuse adrenergic stimulation in the atria. Adrenergic spatial densities could alter atrial electrophysiology and increase arrhythmic susceptibility. Therefore, we examined the role of adrenergic spatial densities in creating arrhythmogenic substrates in silico. We simulated three 25 cm2 atrial sheets with varying adrenergic spatial densities (ASD), activation rates, and external transmembrane currents. We measured their effects on spatial and temporal heterogeneity of action potential durations (APD) at 50% and 20%. Increasing ASD shortens overall APD, and maximum spatial heterogeneity (31%) is achieved at 15% ASD. The addition of a few (5% to 10%) adrenergic elements decreases the excitation threshold, below 18 μA/cm2, while ASDs greater than 10% increase their excitation threshold up to 22 μA/cm2. Increase in ASD during rapid activation increases APD50 and APD20 by 21% and 41%, respectively. Activation times of captured beats during rapid activation could change by as much as 120 ms from the baseline cycle length. Rapidly activated atrial sheets with high ASDs significantly increase temporal heterogeneity of APD50 and APD20. Rapidly activated atrial sheets with 10% ASD have a high likelihood (0.7 ± 0.06) of fragmenting otherwise uniform wavefronts due to the transient inexcitability of adrenergically stimulated elements, producing an effective functional block. The likelihood of wave fragmentation due to ASD highly correlates with the spatial variations of APD20 (ρ = 0.90, p = 0.04). Our simulations provide a novel insight into the contributions of ASD to spatial and temporal heterogeneities of APDs, changes in excitation thresholds, and a potential explanation for wave fragmentation in the human atria due to sympathetic hyperactivity. Our work may aid in elucidating an electrophysiological link to arrhythmia initiation due to chronic stress among young patients.
Topics: Humans; Middle Aged; Adrenergic Agents; Atrial Fibrillation; Action Potentials; Autism Spectrum Disorder; Heart Septal Defects, Atrial; Primary Dysautonomias
PubMed: 37624832
DOI: 10.1371/journal.pone.0290676 -
Respiratory Investigation Nov 2023Chronic obstructive pulmonary disease (COPD) is characterized by airflow obstruction on spirometry and symptoms such as dyspnea on exertion and chronic cough with sputum... (Review)
Review
Management goals and stable phase management of patients with chronic obstructive pulmonary disease in the Japanese respiratory society guideline for the management of chronic obstructive pulmonary disease 2022 (6th edition).
Chronic obstructive pulmonary disease (COPD) is characterized by airflow obstruction on spirometry and symptoms such as dyspnea on exertion and chronic cough with sputum production, thus making it a significant healthcare issue worldwide. Japanese patients with COPD have unique characteristics compared to patients in Western countries, including older age and lower exacerbation frequency. The Japanese Respiratory Society (JRS) published the 6th edition of the COPD guideline in June 2022. This article introduces the management goals of COPD and describes its management during the stable phase, as outlined in the guideline. Management goals include improving the current status, such as the symptoms, quality of life (QOL), exercise tolerance, and physical activity, and reducing future risks through prevention of exacerbation and suppression of disease progression to prevent shortening of healthy life expectancy. Management plans should include avoidance of causative substances, assessment of disease severity, and personalized treatment plans. Pharmacotherapy using inhalation bronchodilators is a key component of the treatment of stable COPD. Bronchodilators, including short- and long-acting dilators, are commonly used to relieve symptoms and improve QOL. Inhaled corticosteroids (ICSs) are used in combination with long-acting bronchodilators, especially in patients with asthma and COPD overlap, or those experiencing frequent exacerbation of eosinophilia. Combination therapy with a long-acting muscarinic antagonist (LAMA), a long-acting beta 2 agonist (LABA), and ICS is expected to improve QOL and respiratory function and reduce mortality and exacerbation compared to the LAMA + LABA combination. Non-pharmacological therapies, including smoking cessation and pulmonary rehabilitation, should also be considered.
Topics: Humans; Administration, Inhalation; Adrenal Cortex Hormones; Adrenergic beta-2 Receptor Agonists; Bronchodilator Agents; Drug Therapy, Combination; East Asian People; Goals; Muscarinic Antagonists; Pulmonary Disease, Chronic Obstructive; Quality of Life
PubMed: 37741092
DOI: 10.1016/j.resinv.2023.08.007