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BioRxiv : the Preprint Server For... Jun 2024Our previous studies have indicated that insulin resistance, hyperglycemia, and hypertension in aged wild-type (WT) mice can be reversed in mice lacking chromogranin-A...
Our previous studies have indicated that insulin resistance, hyperglycemia, and hypertension in aged wild-type (WT) mice can be reversed in mice lacking chromogranin-A (CgA-KO mice). These health conditions are associated with a higher risk of Alzheimer's disease (AD). CgA, a neuroendocrine secretory protein has been detected in protein aggregates in the brains of AD patients. Here, we determined the role of CgA in tauopathies, including AD (secondary tauopathy) and corticobasal degeneration (CBD, primary tauopathy). We found elevated levels of CgA in both AD and CBD brains, which were positively correlated with increased phosphorylated tau in the frontal cortex. Furthermore, CgA ablation in a human P301S tau (hTau) transgenic mice (CgA-KO/hTau) exhibited reduced tau aggregation, resistance to tau spreading, and an extended lifespan, coupled with improved cognitive function. Transcriptomic analysis of mice cortices highlighted altered levels of alpha-adrenergic receptors (Adra) in hTau mice compared to WT mice, akin to AD patients. Since CgA regulates the release of the Adra ligands epinephrine (EPI) and norepinephrine (NE), we determined their levels and found elevated EPI levels in the cortices of hTau mice, AD and CBD patients. CgA-KO/hTau mice exhibited reversal of EPI levels in the cortex and the expression of several affected genes, including Adra1 and 2, nearly returning them to WT levels. Treatment of hippocampal slice cultures with EPI or an Adra1 agonist intensified, while an Adra1 antagonist inhibited, tau hyperphosphorylation and aggregation. These findings reveal a critical role of CgA in regulation of tau pathogenesis via the EPI-Adra signaling axis.
PubMed: 38915622
DOI: 10.1101/2024.06.11.598548 -
Allergy, Asthma & Immunology Research May 2024Concerns regarding the safety of beta-2 agonists have led to revisions of the major asthma guidelines to better address these issues. Although these updates allow for a... (Review)
Review
Concerns regarding the safety of beta-2 agonists have led to revisions of the major asthma guidelines to better address these issues. Although these updates allow for a combination of previous and current strategies, they may confuse clinical practitioners. Beta-2 agonists are vital for alleviating asthma symptoms by relaxing smooth muscles; however, they also pose significant risks by inducing pro-inflammatory mediators both and . In addition to the risks of overuse and symptom masking, the use of beta-agonists alone at therapeutic doses can worsen airway inflammation and enhance virus-induced inflammation during asthma exacerbation. Inhaled corticosteroids (ICS) can effectively prevent these adverse effects. With new insights into the mechanisms of these adverse events, reserving short-acting beta-agonists for acute symptom relief during exacerbations and only for those who are already on ICS or oral steroids represents a careful approach to using beta-agonists with least adverse effects in patients with asthma. However, a major drawback of this approach is the potential non-compliance with ICS, leading to beta-agonist use without the necessary counteraction by ICS. An optimal strategy, both during and outside exacerbations, would integrate beta-agonists into an anti-inflammatory regimen that includes ICS, ideally combined with the same inhaler to ensure their concurrent use where finances allow. This would maintain the beneficial effects of beta-agonists, such as bronchodilation, while preventing the adverse effects from the induction of inflammatory mediators. This method is aligned with diverse clinical settings, maximizes the safe use of beta-agonists, and supports a comprehensive guideline-compliant management strategy.
PubMed: 38910281
DOI: 10.4168/aair.2024.16.3.217 -
Biological & Pharmaceutical Bulletin 2024Guanfacine, used as a medication for attention-deficit/hyperactivity disorder (ADHD), leads to a high incidence of somnolence, in contrast to methylphenidate, which...
Guanfacine, used as a medication for attention-deficit/hyperactivity disorder (ADHD), leads to a high incidence of somnolence, in contrast to methylphenidate, which leads to a high incidence of insomnia. The impact of somnolence on continuing guanfacine treatment is unclear. Therefore, we investigated the reasons for discontinuing guanfacine and analyzed the factors associated with discontinuation caused by somnolence. We surveyed 96 patients under guanfacine from July 2017 to December 2021 at the Saga University Hospital. Patients who discontinued guanfacine by the end date of our study were divided into a median early and late group. We compared the reasons for discontinuation in both groups. Of all patients, 47 continued and 49 discontinued guanfacine. A higher percentage of patients discontinued guanfacine caused by somnolence for ≤70 d than for >70 d of treatment (44.0 vs. 8.3%; p = 0.008). When stratified by the concomitant use of other ADHD drugs, somnolence resulted in a higher discontinuation rate for ≤70 d than for >70 d of treatment without concomitant use (55.0 vs. 7.1%; p = 0.009). Nonetheless, concomitant use resulted in no difference. In conclusion, somnolence affects the early discontinuation of guanfacine as an ADHD drug. The combination of methylphenidate or atomoxetine may decrease withdrawal caused by somnolence.
Topics: Guanfacine; Humans; Attention Deficit Disorder with Hyperactivity; Male; Female; Child; Adolescent; Sleepiness; Adrenergic alpha-2 Receptor Agonists; Methylphenidate
PubMed: 38910124
DOI: 10.1248/bpb.b24-00147 -
American Family Physician Jun 2024Rosacea is a chronic inflammatory skin disease of the central face, affecting 5% of the population. The exact etiology is unknown. A diagnosis is made based on the... (Review)
Review
Rosacea is a chronic inflammatory skin disease of the central face, affecting 5% of the population. The exact etiology is unknown. A diagnosis is made based on the updated 2017 National Rosacea Society Expert Committee guidelines, including fixed erythema, phymatous changes of skin thickening due to sebaceous gland hyperplasia and fibrosis, papules, pustules, telangiectasia, and flushing. Delays in an accurate diagnosis and treatment may occur in skin of color due to difficulty visualizing erythema and telangiectasia. The daily use of sunscreen, moisturizers, and mild skin cleansers and avoidance of triggers are essential aspects of maintenance treatment. Effective topical treatment options include alpha-adrenergic receptor agonists for flushing and ivermectin, metronidazole, and azelaic acid for papules and pustules. Systemic treatments include nonselective beta blockers for flushing, low-dose doxycycline, and isotretinoin for papules and pustules. Rosacea can significantly affect a patient's emotional health and quality of life. A referral for care is recommended for fixed phymatous changes and ocular rosacea. (Am Fam Physician. 2024;109(6):533-542.
Topics: Rosacea; Humans; Dermatologic Agents; Quality of Life; Dicarboxylic Acids
PubMed: 38905551
DOI: No ID Found -
Indian Journal of Anaesthesia Jun 2024Electroconvulsive therapy (ECT) is an effective intervention for psychiatric patients. Succinylcholine is considered the drug of choice for muscle relaxation for ECT....
BACKGROUND AND AIM
Electroconvulsive therapy (ECT) is an effective intervention for psychiatric patients. Succinylcholine is considered the drug of choice for muscle relaxation for ECT. Significant adverse effects of succinylcholine include fasciculation and myalgia. Dexmedetomidine is a highly selective α-2 adrenergic agonist. This study aims to determine the efficacy of a low dose of dexmedetomidine in reducing succinylcholine-induced myalgia in patients receiving ECT.
METHODS
This randomised controlled trial was conducted on 100 patients, aged 18-65 years, undergoing ECT, who were randomly allocated into two groups with an allocation ratio of 1:1. Group D received intravenous (IV) dexmedetomidine 0.25 µg/kg, and Group C received IV normal saline (0.9%). Patients' self-reported myalgia scores were measured after 60 min of the procedure. Fasciculations were noted after IV succinylcholine administration. Heart rate (HR) and mean blood pressure (MBP) were measured at baseline, after infusion (5 min) and after ECT (0, 2.5, 5, 10, 15, 30 min). Continuous data were analysed using a Student's -test for two-group comparisons, a mixed model analysis of variance for group comparisons and various time point analyses. Categorical data were analysed using the Chi-square/Fisher's exact test.
RESULTS
There were no differences between the groups regarding demographics. Myalgia and fasciculations were less in Group D than in Group C ( < 0.001). MBP and HR changes were comparable ( > 0.05).
CONCLUSION
A low dose of dexmedetomidine (0.25 µg/kg) effectively reduces myalgia and fasciculations due to succinylcholine in patients undergoing electroconvulsive therapy.
PubMed: 38903251
DOI: 10.4103/ija.ija_1159_23 -
Chemico-biological Interactions Jun 2024Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS): Life-threatening medical conditions characterized by high morbidity and mortality rates, where...
Dexmedetomidine mitigates lipopolysaccharide-induced acute lung injury by modulating heat shock protein A12B to inhibit the toll-like receptor 4/nuclear factor-kappa B signaling pathway.
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS): Life-threatening medical conditions characterized by high morbidity and mortality rates, where the inflammatory process plays a crucial role in lung tissue damage, especially in models induced by lipopolysaccharide (LPS). Heat shock protein A12B (HSPA12B) has strong anti-infammatory properties However, it is unknown whether increased HSPA12B is protective against LPS-induced ALI. And Dexmedetomidine (DEX) is a potent α-adrenergic receptor (α-AR) agonist that has been shown to protect against sepsis-induced lung injury, however, the underlying mechanisms of this protection are not fully understood. This study utilized bioinformatics analysis and an LPS-induced ALI model to explore how DEX alleviates lung injury by modulating HSPA12B and inhibiting the Toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-κB) signaling pathway. Results indicate that HSPA12B overexpression and DEX pre-treatment markedly mitigated LPS-induced lung injury, which was evaluated by the deterioration of histopathology, histologic scores, the W/D weight ratio, and total protein expression, tumor necrosis factor-alpha (TNF-α), and interleukin-1β (IL-1β) in the BALF, and the levels of NO, MDA,SOD and MPO in the lung. Moreover, HSPA12B overexpression and DEX pre-treatment significantly reduces lung injury and inflammation levels by upregulating HSPA12B and inhibiting the activation of the TLR4/NF-κB signaling pathway. On the contrary, when the expression of HSPA12B is inhibited, the protective effect of DEX pre-treatment on lung tissue is significantly weakened.In summary, our research demonstrated that the increased expression of AAV-mediated HSPA12B in the lungs of mice inhibits acute inflammation and suppresses the activation of TLR4/NF-κB pathway in a murine model of LPS-induced ALI. DEX could enhance HSPA12B and inhibit the initiation and development of inflammation through down-regulating TLR4/NF-κB pathway.These findings highlight the potential of DEX as a therapeutic agent for treating ALI and ARDS, offering new strategies for clinical intervention.
PubMed: 38901789
DOI: 10.1016/j.cbi.2024.111112 -
Circulation Research Jun 2024GPCRs (G protein-coupled receptors), also known as 7 transmembrane domain receptors, are the largest receptor family in the human genome, with ≈800 members. GPCRs... (Review)
Review
GPCRs (G protein-coupled receptors), also known as 7 transmembrane domain receptors, are the largest receptor family in the human genome, with ≈800 members. GPCRs regulate nearly every aspect of human physiology and disease, thus serving as important drug targets in cardiovascular disease. Sharing a conserved structure comprised of 7 transmembrane α-helices, GPCRs couple to heterotrimeric G-proteins, GPCR kinases, and β-arrestins, promoting downstream signaling through second messengers and other intracellular signaling pathways. GPCR drug development has led to important cardiovascular therapies, such as antagonists of β-adrenergic and angiotensin II receptors for heart failure and hypertension, and agonists of the glucagon-like peptide-1 receptor for reducing adverse cardiovascular events and other emerging indications. There continues to be a major interest in GPCR drug development in cardiovascular and cardiometabolic disease, driven by advances in GPCR mechanistic studies and structure-based drug design. This review recounts the rich history of GPCR research, including the current state of clinically used GPCR drugs, and highlights newly discovered aspects of GPCR biology and promising directions for future investigation. As additional mechanisms for regulating GPCR signaling are uncovered, new strategies for targeting these ubiquitous receptors hold tremendous promise for the field of cardiovascular medicine.
Topics: Humans; Receptors, G-Protein-Coupled; Animals; Cardiovascular Diseases; Signal Transduction; Drug Discovery; History, 21st Century; History, 20th Century
PubMed: 38900852
DOI: 10.1161/CIRCRESAHA.124.323067 -
PPAR Research 2024Partial and full PPAR- agonists have shown promising effects and antihypertensive and antidiabetic agents through increased plasma adiponectin concentration. This study...
Partial and full PPAR- agonists have shown promising effects and antihypertensive and antidiabetic agents through increased plasma adiponectin concentration. This study is aimed at examining the role of PPAR-, alpha-adrenoceptors, and adiponectin receptors in the modulation of vasopressor responses to angiotensin II (Ang II) and adrenergic agonists, after a subset treatment of partial and full PPAR- agonists, each individually, and also when coupled with adiponectin in SHRs. The antioxidant potential and metabolic indices for these animals were also determined. Group I (WKY) and group II (SHR) were designated as normotensive control and hypertensive control, respectively. Groups III (SHR) and IV (SHR) received irbesartan (30 mg/kg) and pioglitazone (10 mg/kg) orally for 28 days, and groups V (SHR), VI (SHR), and VII (SHR) were treated with adiponectin (2.5 g/kg) intraperitoneally alone, in combination with irbesartan, and in combination with pioglitazone, respectively, from days 21 to 28 only. On day 29, sodium pentobarbitone (60 mg/kg) was used to anesthetize all test animals, and systemic hemodynamic and plasma adiponectin concentrations and and antioxidant potential were measured. As compared to the WKY control, the SHR control group's noninvasive blood pressure and basal mean arterial pressure were significantly greater, along with increased arterial stiffness, lower plasma nitric oxide, adiponectin concentration, and antioxidant enzyme levels (all < 0.05). However, they were gradually normalized by single drug treatments in all groups, and to a greater extent in the SHR + Irb + Adp group ( < 0.05). In the acute study, the dose dependant mean arterial pressure responses to intravenously administered adrenergic agonists and angiotensin-II were significantly larger in SHRs as compared to WKY by 20-25%. Adiponectin alone and in combination significantly blunted vasopressor responses to these alpha-adrenergic agonists in the SHR + Pio + Adp group by 63%, whereas attenuated responses to ANG-II administration to 70% in SHR + Irb + Adp. In conclusion, the combined treatment of adiponectin with PPAR-agonists reduced the systemic vascular responses to adrenergic agonists and improved arterial stiffness. This an evidence of the interaction of adiponectin receptors, PPAR-, alpha-adrenoceptors, and ANG-II in the systemic vasculature of SHRs. A significant level of synergism has also been proved among full PPAR- agonists and adiponectin receptors.
PubMed: 38899161
DOI: 10.1155/2024/5868010 -
Journal of Oral Rehabilitation Jun 2024Activation of β adrenergic receptors reduces cutaneous mechanical pain thresholds in rats. While β adrenergic receptor activation may contribute to mechanisms that...
BACKGROUND
Activation of β adrenergic receptors reduces cutaneous mechanical pain thresholds in rats. While β adrenergic receptor activation may contribute to mechanisms that underlie temporomandibular joint pain, its effect on masticatory muscle pain sensitivity is uncertain.
OBJECTIVES
The current study sought to determine the extent to which β adrenergic receptors are expressed by masticatory muscle afferent fibres, and to assess the effect of local activation of these receptors on the mechanical sensitivity of masticatory muscle afferent fibres in rats.
METHODS
Trigeminal ganglion neurons that innervate the rat (n = 12) masseter muscle and lower lip were identified by tissue injection of fluorescent dyes and were then stained with antibodies against β or β adrenergic receptors. Extracellular recordings from 60 trigeminal ganglion neurons that innervate the masticatory muscle were undertaken in a second group of anaesthetised rats of both sexes (n = 37) to assess afferent mechanical activation thresholds. Thresholds were assessed before and after injection of the β adrenergic receptor agonists into masticatory muscle.
RESULTS
β and β adrenergic receptor expression was greater in labial skin than in masticatory muscle ganglion neurons (p < .05, one-way ANOVA, Holm-Sidak test). There was a higher expression of β adrenergic receptors in masticatory muscle ganglion neurons in males than in females. The mixed β agonist isoproterenol increased afferent mechanical activation threshold in male but not female rats (p < .05, Mann-Whitney test). In male rats, salbutamol, a β selective agonist, also increased afferent mechanical activation threshold but hydralazine, a vasodilator, did not (p < .05, Mann-Whitney test).
CONCLUSION
Activation of β adrenergic receptors decreases the mechanical sensitivity of masticatory muscle afferent fibres in a sex-related manner.
PubMed: 38894554
DOI: 10.1111/joor.13787 -
Nutrients May 2024Pre-workout supplements are popular among sport athletes and overweight individuals. Phenethylamines (PEAs) and alkylamines (AA) are widely present in these supplements....
Pre-workout supplements are popular among sport athletes and overweight individuals. Phenethylamines (PEAs) and alkylamines (AA) are widely present in these supplements. Although the health effects of these analogues are not well understood yet, they are hypothesised to be agonists of adrenergic (ADR) and trace amine-associated receptors (TAARs). Therefore, we aimed to pharmacologically characterise these compounds by investigating their activating properties of ADRs and TAAR1 . The potency and efficacy of the selected PEAs and AAs was studied by using cell lines overexpressing human ADRα/α/α/α/α/β/β or TAAR1. Concentration-response relationships are expressed as percentages of the maximal signal obtained by the full ADR agonist adrenaline or the full TAAR1 agonist phenethylamine. Multiple PEAs activated ADRs (EC = 34 nM-690 µM; E = 8-105%). Almost all PEAs activated TAAR1 (EC = 1.8-92 µM; E = 40-104%). Our results reveal the pharmacological profile of PEAs and AAs that are often used in food supplements. Several PEAs have strong agonistic properties on multiple receptors and resemble potencies of the endogenous ligands, indicating that they might further stimulate the already activated sympathetic nervous system in exercising athletes via multiple mechanisms. The use of supplements containing one, or a combination of, PEA(s) may pose a health risk for their consumers.
Topics: Phenethylamines; Humans; Receptors, G-Protein-Coupled; Dietary Supplements; Receptors, Adrenergic; HEK293 Cells
PubMed: 38892500
DOI: 10.3390/nu16111567