Beta2-adrenergic agonist use and the risk of multiple sclerosis: a total population-based case-control study

Evidence from a mouse model supports repurposing an anti-asthmatic drug, bambuterol, against Alzheimer's disease by administration through an intranasal route

Bambuterol is a long-acting anti-asthmatic prodrug which releases terbutaline. Terbutaline is an agonist of the β2-adrenergic receptors which is formed by decarbamoylation of bambuterol by butyrylcholinesterase. Inhibition of the latter, as well as activation of β2-AR, are of interest for the treatment of Alzheimer's disease (AD). Combining these two activities, bambuterol could express a good clinical efficacy against AD. The present work firstly confirmed the capacity of bambuterol to display in cellulo neuroprotective activities, reduction of Tau hyperphosphorylation and preservation of synapses in rat hippocampal neuronal cultures intoxicated with Aβ peptides. Further, bambuterol, in the form of a liposomal gel, showed a good bioavailability in CNS after intranasal administration, which should reduce any side effects linked to peripheral terbutaline release. Indeed, even if the latter is more selective than other β2-mimetics towards bronchial β2-AR, cardiovascular effects (tachycardia, arrhythmias…) could occur upon cardiac β1-AR activation. Finally, intranasal administration of low doses of bambuterol gel in mice intoxicated with Aβ peptides, prevented long-term spatial memory impairment and showed beneficial effects on the survival of neurons and on synapse preservation.

Asthma and chronic obstructive pulmonary disease (COPD) in people with multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

Studies have found that multiple sclerosis (MS) has an impact on the initiation or the course of asthma and chronic obstructive pulmonary disease (COPD). This review amied to investigate the prevalence and odds of asthma and COPD among people with MS (pwMS).

METHOD

PubMed, Embase, Scopus, and Web of Science were systemically searched from inception to May 2023. R version 4.3.2 and random-effect model were used to calculate the pooled prevalence and odds ratio (OR), with their 95 % confidence interval (CI), in pwMS.

RESULTS

A total of 40 studies consisting of 287,702 pwMS were included. 37 studies indicated that the pooled prevalences of asthma and COPD among pwMS were 5.97 % (95 % CI: 4.62 %-7.69 %, I2=99 %) and 3.03 % (95 % CI: 1.82 %-5.00 %, I2=99 %), respectively. 24 studies on 236,469 pwMS and 85,328,673 healthy controls revealed that the overall odds of asthma and COPD in MS were 1.14 (95 % CI: 0.76-1.71, p-value=0.53, I2=97 %) and 1.28 (95 % CI: 1.11-1.47, p-value<0.01, I2=70 %), respectively.

CONCLUSION

MS can increased the risk of developing COPD, while asthma does not exhibit a significant relationship with MS. Our study highlights the importance of identifying pwMS who face greater risks of respiratory issues to monitor efficiently and initiate suitable preventative actions.

Activation of β2-adrenergic receptors prevents AD-type synaptotoxicity via epigenetic mechanisms

We previously reported that prolonged exposure to an enriched environment (EE) enhances hippocampal synaptic plasticity, with one of the significant mechanistic pathways being activation of β2-adrenergic receptor (β2-AR) signaling, thereby mitigating the synaptotoxic effects of soluble oligomers of amyloid β-protein (oAβ). However, the detailed mechanism remained elusive. In this work, we recorded field excitatory postsynaptic potentials (fEPSP) in the CA1 region of mouse hippocampal slices treated with or without toxic Aβ-species. We found that pharmacological activation of β2-AR, but not β1-AR, selectively mimicked the effects of EE in enhancing LTP and preventing oAβ-induced synaptic dysfunction. Mechanistic analyses showed that certain histone deacetylase (HDAC) inhibitors mimicked the benefits of EE, but this was not seen in β2-AR knockout mice, suggesting that activating β2-AR prevents oAβ-mediated synaptic dysfunction via changes in histone acetylation. EE or activation of β-ARs each decreased HDAC2, whereas Aβ oligomers increased HDAC2 levels in the hippocampus. Further, oAβ-induced inflammatory effects and neurite degeneration were prevented by either β2-AR agonists or certain specific HDAC inhibitors. These preclinical results suggest that activation of β2-AR is a novel potential therapeutic strategy to mitigate oAβ-mediated features of AD.

The β-adrenergic hypothesis of synaptic and microglial impairment in Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease originating partly from amyloid β protein-induced synaptic failure. As damaging of noradrenergic neurons in the locus coeruleus (LC) occurs at the prodromal stage of AD, activation of adrenergic receptors could serve as the first line of defense against the onset of the disease. Activation of β₂ -ARs strengthens long-term potentiation (LTP) and synaptic activity, thus improving learning and memory. Physical stimulation of animals exposed to an enriched environment (EE) leads to the activation of β₂ -ARs and prevents synaptic dysfunction. EE also suppresses neuroinflammation, suggesting that β₂ -AR agonists may play a neuroprotective role. The β₂ -AR agonists used for respiratory diseases have been shown to have an anti-inflammatory effect. Epidemiological studies further support the beneficial effects of β₂ -AR agonists on several neurodegenerative diseases. Thus, I propose that β₂ -AR agonists may provide therapeutic value in combination with novel treatments for AD.

Application of an evidence-based, out-patient treatment strategy for COVID-19: Multidisciplinary medical practice principles to prevent severe disease

The COVID-19 pandemic has devastated individuals, families, and institutions throughout the world. Despite the breakneck speed of vaccine development, the human population remains at risk of further devastation. The decision to not become vaccinated, the protracted rollout of available vaccine, vaccine failure, mutational forms of the SARS virus, which may exhibit mounting resistance to our molecular strike at only one form of the viral family, and the rapid ability of the virus(es) to hitch a ride on our global transportation systems, means that we are will likely continue to confront an invisible, yet devastating foe. The enemy targets one of our human physiology's most important and vulnerable life-preserving body tissues, our broncho-alveolar gas exchange apparatus. Notwithstanding the fear and the fury of this microbe's potential to raise existential questions across the entire spectrum of human endeavor, the application of an early treatment intervention initiative may represent a crucial tool in our defensive strategy. This strategy is driven by evidence-based medical practice principles, those not likely to become antiquated, given the molecular diversity and mutational evolution of this very clever "world traveler".

Role of adrenergic receptor signalling in neuroimmune communication

Neuroimmune communication plays a crucial role in maintaining homeostasis and promptly responding to any foreign insults. Sympathetic nerve fibres are innervated into all the lymphoid organs (bone marrow, thymus, spleen, and lymph nodes) and provide a communication link between the central nervous system (CNS) and ongoing immune response in the tissue microenvironment. Neurotransmitters such as catecholamines (epinephrine and norepinephrine) bind to adrenergic receptors present on most immune and non-immune cells, establish a local neuroimmune-communication system, and help regulate the ongoing immune response. The activation of these receptors varies with the type of receptor-activated, target cell, the activation status of the cells, and timing of activation. Activating adrenergic receptors, specifically β-adrenergic signalling in immune cells leads to activation of the cAMP-PKA pathway or other non-canonical pathways. It predominantly leads to immune suppression such as inhibition of IL-2 secretion and a decrease in macrophages phagocytosis. This review discusses the expression of different adrenergic receptors in various immune cells, signalling, and how it modulates immune cell function and contributes to health and diseases. Understanding the neuroimmune communication through adrenergic receptor signalling in immune cells could help to design better strategies to control inflammation and autoimmunity.

•

Primary and secondary lymphoid organs are innervated with sympathetic nerve fibres.

•

Adrenergic receptor expression on immune and non-immune cells establishes a local neuroimmune communication system.

•

Adrenergic receptor signalling in immune cells controls the differentiation and function of various immune cells.

•

Modulating adrenergic receptor signalling with a specific agonist or antagonist also affect the immune response.

Part II. high-dose methotrexate with leucovorin rescue for severe COVID-19: An immune stabilization strategy for SARS-CoV-2 induced 'PANIC' attack

Here, in Part II of a duology on the characterization and potential treatment for COVID-19, we characterize the application of an innovative treatment regimen for the prevention of the transition from mild to severe COVID-19, as well as detail an intensive immunotherapy intervention hypothesis.

We propose as a putative randomized controlled trial that high-dose methotrexate with leucovorin (HDMTX-LR) rescue can abolish ‘PANIC’, thereby ‘left-shifting’ severe COVID-19 patients to the group majority of those infected with SARS-CoV-2, who are designated as having mild, even asymptomatic, disease. HDMTX-LR is endowed with broadly pleiotropic properties and is a repurposed, generic, inexpensive, and widely available agent which can be administered early in the course of severe COVID-19 thus rescuing the critical and irreplaceable gas-exchange alveoli.

Further, we describe a preventative treatment intervention regimen for those designated as having mild to moderate COVID-19 disease, but who exhibit features which herald the transition to the severe variant of this disease. Both of our proposed hypothesis-driven questions should be urgently subjected to rigorous assessment in the context of randomized controlled trials, in order to confirm or refute the contention that the approaches characterized herein, are in fact capable of exerting mitigating, if not abolishing, effects upon SARS-CoV-2 triggered ‘PANIC Attack’. Confirmation of our immunotherapy hypothesis would have far-reaching ramifications for the current pandemic, along with yielding invaluable lessons which could be leveraged to more effectively prepare for the next challenge to global health.

Role of the End-Point Mediators of Sympathoadrenal and Sympathoneural Stress Axes in the Pathogenesis of Experimental Autoimmune Encephalomyelitis and Multiple Sclerosis

The role of stress effector systems in the initiation and progression of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), the most commonly used experimental model of MS, has strongly been suggested. To corroborate this notion, alterations in activity of the sympathoadrenal and sympathoneural axes of sympathoadrenal system (a major communication pathway between the central nervous system and the immune system), mirrored in altered release of their end-point mediators (adrenaline and noradrenaline, respectively), are shown to precede (in MS) and/or occur during development of MS and EAE in response to immune cell activation (in early phase of disease) and disease-related damage of sympathoadrenal system neurons and their projections (in late phase of disease). To add to the complexity, innate immunity cells and T-lymphocytes synthesize noradrenaline that may be implicated in a local autocrine/paracrine self-amplifying feed-forward loop to enhance myeloid-cell synthesis of proinflammatory cytokines and inflammatory injury. Furthermore, experimental manipulations targeting noradrenaline/adrenaline action are shown to influence clinical outcome of EAE, in a disease phase-specific manner. This is partly related to the fact that virtually all types of cells involved in the instigation and progression of autoimmune inflammation and target tissue damage in EAE/MS express functional adrenoceptors. Although catecholamines exert majority of immunomodulatory effects through β₂-adrenoceptor, a role for α-adrenoceptors in EAE pathogenesis has also been indicated. In this review, we summarize all aforementioned aspects of immunopathogenetic action of catecholamines in EAE/MS as possibly important for designing new strategies targeting their action to prevent/mitigate autoimmune neuroinflammation and tissue damage.

Bidirectional Role of β2-Adrenergic Receptor in Autoimmune Diseases

Disorder of the sympathetic nervous system (SNS) is closely related to the pathogenesis of various autoimmune diseases (ADs). Catecholamine triggered beta2-adrenergic receptor (β2-AR) signaling is important in creating a bidirectional response in the progression of ADs due to factors including diverse expression patterns, single nucleotide polymorphisms (SNPs), biased signals, and desensitization of β2-AR, as well as different subtypes of Gα binding to β2-AR. In this review, we summarize the actions of β2-AR signaling in regulating the functions of immunocytes and in the pathogenesis of ADs, and the application of β2-AR agonists or antagonists in treating major types of ADs is also discussed. We suggest that restoring the immune balance via a soft regulation of the expression or activation of β2-AR is one of the promising therapeutic strategies for systematic ADs.

Drug exposure and the risk of multiple sclerosis: A systematic review

BACKGROUND

Several environmental and lifestyle factors have been associated with multiple sclerosis (MS) risk, including some pharmacological treatments. We systematically reviewed the literature on prescription drug exposure and MS risk.

METHODS

Six databases were searched for original observational studies reporting drug exposure and MS risk published before 2017.

RESULTS

Thirteen articles fulfilled inclusion criteria. Exposure to neither amiloride nor valproic acid was associated with MS (adjusted hazard ratio (adj.HR = 1.34;95% CI:0.81-2.20; adj.HR = 1.30;95%CI:0.44-3.80, respectively). Four studies explored oral contraceptive exposure and reported no association with MS; while a single study found an increased risk (odds ratio [adj.OR] = 1.52;95%CI:1.21-1.91). While penicillin exposure was associated with reduced risk of developing MS (adj.OR = 0.5;95%CI:0.3-0.9), a later study observed an elevated risk for penicillin (adj.OR = 1.21;95%CI:1.10-1.27) and all antibiotics (adj.OR = 1.41;95%CI:1.29-1.53), which was potentially attributed to underlying infection. Anti-tumor necrosis factor-alpha (TNFα) was not associated with MS risk in persons with inflammatory bowel disease (standard morbidity ratio = 4.2;95%CI:0.1-23.0) and arthritis (standardized incidence ratio = 1.38;95%CI:0.69-2.77); however, men exposed to anti-TNFα who also had arthritis and individuals with ankylosing spondylitis were at an increased risk (standardized incidence ratios = 3.91;95%CI:1.47-10.42 and 3.48;95%CI:1.45-8.37, respectively). A reduced risk of MS was observed with exposure to the beta2-adrenergic agonist fenoterol (adj.OR = 0.58;95%CI:0.45-0.76), and the sedating histamine 1-receptor antagonists (adj.OR = 0.2;95%CI:0.1-0.8), but not the non-sedating equivalent (adj.OR = 0.8;95%CI:0.4-1.6).

CONCLUSIONS

The suggestion that some drugs may prevent MS is intriguing and warrants further study. In addition, further pharmacovigilance is needed to assess the safety of anti-TNFα drugs in specific populations in the context of MS risk.