Search Results (11)

Background/Objectives: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition with not fully understood causes, though evidence points to immune system involvement and possible autoimmunity. ME/CFS could be triggered by various infectious pathogens, like SARS-CoV-2; furthermore, a subset of the post-COVID-19 condition (PCC) patients fulfill the diagnostic criteria of ME/CFS. According to the Canadian Consensus Criteria (CCC), the presence of specific symptoms such as fatigue, post-exertional malaise, sleep dysfunction, pain, neurological/cognitive manifestations, and symptoms from at least two of the following categories lead to the diagnosis of ME/CFS: autonomic, neuroendocrine, and immune manifestation. In this study, the patient selection was based on the identification of ME/CFS patients with elevated autoantibodies, regardless of the triggering factor of their condition. Methods: The aim of this study was to identify ME/CFS patients among long COVID patients with elevated autoantibodies. In seven cases, plasmapheresis (PE) and intravenous immunoglobulins (IVIGs) with repetitive autoantibody measurements were applied: four PE sessions on days 1, 5, 30, and 60, and a low-dose IVIG therapy after each treatment. Antibodies were measured before the first PE and two weeks after the last PE session. To monitor clinical outcomes, the following somatic and psychometric follow-up assessments were conducted before the first PE, 2 weeks after the second, and 2 weeks after the last PE: the Schellong test, ISI (insomnia), FSS (fatigue), HADS (depression and anxiety), and EQ-5D-5L (quality of life) questionnaires. Results: There was a negative association between both the β2-adrenergic and M3-muscarinic receptor autoantibody concentration and the quality of life measurements assessed with the EQ-5D-5L questionnaire. Per 1 U/mL increase in the concentration levels of β2-adrenergic receptor antibodies or M3-muscarinic acetylcholine receptor antibodies, the EQ-5D-5L index score [−0.59 to 1] decreased by 0.01 (0.63%) or 0.02 (1.26%), respectively. There were no significant associations between the ISI, HADS, and FSS questionnaires and the β1-adrenergic and M4-muscarinic receptor antibodies titers. Conclusions: After a thorough selection of patients with present autoantibodies, this pilot study found negative associations concerning autoantibody concentration and somatic, as well as psychological wellbeing. To validate these promising feasibility study results—indicating the potential therapeutic potential of antibody-lowering methods—further investigation with larger sample sizes is needed. Full article

High-mobility group box 1 (HMGB1) is a nuclear protein that can be secreted or released into the extracellular environment during cellular stress, functioning as a damage-associated molecular pattern molecule. This study investigates the role of HMGB1 in adipocyte development and metabolism, explicitly examining its interaction with β3-adrenergic receptor-mediated lipolysis and caveolin-1 (CAV1) regulation, which may influence cardiovascular risk factors. Using 3T3-L1 preadipocytes and mouse embryonic fibroblasts, we demonstrated that HMGB1 expression increases progressively during adipogenesis, reaching peak levels in mature adipocytes. While exogenous HMGB1 treatment did not affect preadipocyte proliferation or differentiation, it inhibited lipolysis in mature adipocytes. Mechanistically, HMGB1 suppressed β3-adrenergic receptor agonist CL-316,243-induced hormone-sensitive lipase activation by reducing protein kinase A-mediated phosphorylation and attenuating extracellular signal-regulated kinase signaling without affecting upstream cyclic AMP levels. We discovered a novel regulatory mechanism wherein CAV1 physically interacts with HMGB1 in mature adipocytes, with c-Src-dependent CAV1 phosphorylation functioning as a negative regulator of HMGB1 secretion. This finding was confirmed in CAV1-deficient models, which displayed increased HMGB1 secretion and diminished lipolytic activity both in vitro and in vivo. Furthermore, administering HMGB1-neutralizing antibodies to wild-type mice enhanced fasting-induced lipolysis, establishing circulating HMGB1 as a crucial antilipolytic factor. These findings reveal HMGB1’s previously uncharacterized role in adipose tissue metabolism as a negative regulator of lipolysis through CAV1-dependent mechanisms. This work provides new insights into adipose tissue metabolism regulation and identifies potential therapeutic targets for obesity-related metabolic disorders and cardiovascular diseases. Full article

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disorder characterized by serious physical and cognitive impairments. Recent research underscores the role of immune dysfunction, including the role of autoantibodies, in ME/CFS pathophysiology. Expanding on previous studies, we analyzed 7542 antibody–antigen interactions in ME/CFS patients using two advanced platforms: a 1134 autoantibody Luminex panel from Oncimmune and Augmenta Bioworks, along with Rapid Extracellular Antigen Profiling (REAP), a validated high-throughput method that measures autoantibody reactivity against 6183 extracellular human proteins and 225 human viral pathogen proteins. Unlike earlier reports, our analysis of 172 participants revealed no significant differences in autoantibody reactivities between ME/CFS patients and controls, including against GPCRs such as β-adrenergic receptors. However, subtle trends in autoantibody ratios between male and female ME/CFS subgroups, along with patterns of herpesvirus reactivation, suggest the need for broader and more detailed exploration. Full article

There is a preliminary record suggesting that β₂-adrenergic agonists may have therapeutic value in Parkinson’s disease; recent studies have proposed a possible role of these agents in suppressing the formation of α-synuclein protein, a component of Lewy bodies. The present study focuses on the importance of the prototypical β₂-adrenergic agonist epinephrine in relation to the incidence of Parkinson’s disease in humans, and its further investigation via synthetic selective β₂-receptor agonists, such as levalbuterol. Levalbuterol exerts significant anti-inflammatory activity, a property that may suppress cytokine-mediated degeneration of dopaminergic neurons and progression of Parkinsonism. In a completely novel finding, epinephrine and certain other adrenergic agents modeled in the Harvard/MIT Broad Institute genomic database, CLUE, demonstrated strong associations with the gene-expression signatures of anti-inflammatory glucocorticoids. This prompted in vivo confirmation in mice engrafted with human peripheral blood mononuclear cells (PBMCs). Upon toxic activation with mononuclear antibodies, levalbuterol inhibited (1) the release of the eosinophil attractant chemokine eotaxin-1, which is implicated in CNS and peripheral inflammatory disorders, (2) elaboration of the tumor-promoting angiogenic factor VEGFa, and (3) release of the pro-inflammatory cytokine IL-13 from activated PBMCs. These observations suggest possible translation to Parkinson’s disease, other neurodegenerative syndromes, and malignancies, via several mechanisms. Full article

In addition to binding to nicotinic acetylcholine receptors (nAChRs), nicotine is known to regulate the β-adrenergic receptors (β-ARs) promoting oncogenic signaling. Using A549 (p53 wild-type) and H1299 (p53-null) lung cancer cells, we show that nicotine treatment led to: increased adrenaline/noradrenaline levels, an effect blocked by treatment with the α7nAChR inhibitor (α-BTX) but not by the β-blocker (propranolol) or the α4β2nAChR antagonist (DhβE); decreased GABA levels in A549 and H1299 cell media, an effect blocked by treatment with DhβE; increased VEGF levels and PI3K/AKT activities, an effect diminished by cell co-treatment with α-BTX, propranolol, and/or DhβE; and inhibited p53 activity in A549 cells, that was reversed, upon cell co-treatment with α-BTX, propranolol, and/or DhβE or by VEGF immunodepletion. VEGF levels increased upon cell treatment with nicotine, adrenaline/noradrenaline, and decreased with GABA treatment. On the other hand, the p53 activity decreased in A549 cells treated with nicotine, adrenaline/noradrenaline and increased upon cell incubation with GABA. Knockdown of p53 led to increased VEGF levels in the media of A549 cells. The addition of anti-VEGF antibodies to A549 and H1299 cells decreased cell viability and increased apoptosis; blocked the activities of PI3K, AKT, and NFκB in the absence or presence of nicotine; and resulted in increased p53 activation in A549 cells. We conclude that VEGF can be upregulated via α7nAChR and/or β-ARs and downregulated via GABA and/or p53 in response to the nicotine treatment of NSCLC cells. Full article

A wide range of anti-myocardial autoantibodies have been reported since the 1970s. Among them, autoantibodies against the β₁-adrenergic receptor (β₁AR-AAb) have been the most thoroughly investigated, especially in dilated cardiomyopathy (DCM). Β₁AR-Aabs have agonist effects inducing desensitization of β₁AR, cardiomyocyte apoptosis, and sustained calcium influx which lead to cardiac dysfunction and arrhythmias. Β₁AR-Aab has been reported to be detected in approximately 40% of patients with DCM, and the presence of the antibody has been associated with worse clinical outcomes. The removal of anti-myocardial autoantibodies including β₁AR-AAb by immunoadsorption is beneficial for the improvement of cardiac function for DCM patients. However, several studies have suggested that its efficacy depended on the removal of AAbs belonging to the IgG3 subclass, not total IgG. IgG subclasses differ in the structure of the Fc region, suggesting that the mechanism of action of β₁AR-AAb differs depending on the IgG subclasses. Our previous clinical research demonstrated that the patients with β₁AR-AAb better responded to β-blocker therapy, but the following studies found that its response also differed among IgG subclasses. Further studies are needed to elucidate the possible pathogenic role of IgG subclasses of β1AR-AAbs in DCM, and the broad spectrum of cardiovascular diseases including HF with preserved ejection fraction. Full article

Research on cancer therapies focuses on processes such as angiogenesis, cell signaling, stemness, metastasis, and drug resistance and inflammation, all of which are influenced by the cellular and molecular microenvironment of the tumor. Different strategies, such as antibodies, small chemicals, hormones, cytokines, and, recently, gene editing techniques, have been tested to reduce the malignancy and generate a harmful microenvironment for the tumor. Few therapeutic agents have shown benefits when administered alone, but a few more have demonstrated clear improvement when administered in combination with other therapeutic molecules. In 2008 (and for the first time in the clinic), the therapeutic benefits of the β-adrenergic receptor antagonist, propranolol, were described in benign tumors, such as infantile hemangioma. Propranolol, initially prescribed for high blood pressure, irregular heart rate, essential tremor, and anxiety, has shown, in the last decade, increasing evidence of its antitumoral properties in more than a dozen different types of cancer. Moreover, the use of propranolol in combination therapies with other drugs has shown synergistic antitumor effects. This review highlights the clinical trials in which propranolol is taking part as adjuvant therapy at single administration or in combinatorial human trials, arising as a good pick and roll partner in anticancer strategies. Full article

Potential activation of β2 adrenergic receptors (β2AR) by specific autoreactive antibodies (Abs) that arise during the host reaction to Trypanosoma cruzi, could contribute to the elevated prevalence of metabolic disturbances described in patients with chronic Chagas disease (CCD). This study aimed to determine the prevalence of anti-β2AR Abs in patients with CCD, as well as the correlation of these Abs with the presence of glucose and lipid metabolism disturbances, in order to explore their association with an insulin resistance profile. Additionally, we tested the functional effects of anti-β2AR Abs employing an in vitro bioassay with neuroendocrine cells expressing β2AR. A clinical and metabolic evaluation including an OGTT was performed in 80 CCD patients and 40 controls. Anti-β2AR Abs were measured by an in-house-developed ELISA, and the β2 adrenergic activity of affinity-purified IgG fractions from patient’ sera were assayed in CRE-Luc and POMCLuc transfected AtT-20 cells. A higher proportion of dysglycemia (72.5% vs. 37.5%; p = 0.001) was observed in the CCD group, accompanied by increased HOMA2-IR (p = 0.019), especially in subjects with Abs (+). Anti-β2AR Abs reactivity (7.01 (2.39–20.5); p = 0.0004) and age >50 years (3.83 (1.30–11.25); p = 0.014) resulted as relevant for IR prediction (AUC: 0.786). Concordantly, Abs (+) CCD patients showed elevated metabolic risk scores and an increased prevalence of atherogenic dyslipidemia (p = 0.040), as compared to Abs (−) patients and controls. On functional bioassays, Abs exerted specific and dose-dependent β2-agonist effects. Our findings suggest that anti-β2AR Abs may induce the activation of β2AR in other tissues besides the heart; furthermore, we show that in patients with CCD these Abs are associated with an insulin resistance profile and atherogenic dyslipidemia, providing biological plausibility to the hypothesis that adrenergic activation by anti-β2AR Abs could contribute to the pathogenesis of metabolic disturbances described in CCD patients, increasing their cardiovascular risk. Full article

The evidence from post-mortem biochemical studies conducted on cortisol and catecholamines suggest that analysis of the adrenal gland could provide useful information about its role in human pathophysiology and the stress response. Authors designed an immunohistochemical study on the expression of the adrenal β2-adrenergic receptor (β2-AR), a receptor with high-affinity for catecholamines, with the aim to show which zones it is expressed in and how its expression differs in relation to the cause of death. The immunohistochemical study was performed on adrenal glands obtained from 48 forensic autopsies of subjects that died as a result of different pathogenic mechanisms using a mouse monoclonal β2-AR antibody. The results show that immunoreactivity for β2-AR was observed in all adrenal zones. Furthermore, immunoreactivity for β2-AR has shown variation in the localization and intensity of different patterns in relation to the original cause of death. To the best of our knowledge, this is the first study that demonstrates β2-AR expression in the human cortex and provides suggestions on the possible involvement of β2-AR in human cortex hormonal stimulation. In conclusion, the authors provide a possible explanation for the observed differences in expression in relation to the cause of death. Full article

The implementation of rotating-wall vessels (RWVs) for studying the effect of lack of gravity has attracted attention, especially in the fields of stem cells, tissue regeneration, and cancer research. Immune cells incubated in RWVs exhibit several features of immunosuppression including impaired leukocyte proliferation, cytokine responses, and antibody production. Interestingly, stress hormones influence cellular immune pathways affected by microgravity, such as cell proliferation, apoptosis, DNA repair, and T cell activation. These pathways are crucial defense mechanisms that protect the cell from toxins, pathogens, and radiation. Despite the importance of the adrenergic receptor in regulating the immune system, the effect of microgravity on the adrenergic system has been poorly studied. Thus, we elected to investigate the synergistic effects of isoproterenol (a sympathomimetic drug), radiation, and microgravity in nonstimulated immune cells. Peripheral blood mononuclear cells were treated with the sympathomimetic drug isoproterenol, exposed to 0.8 or 2 Gy γ-radiation, and incubated in RWVs. Mixed model regression analyses showed significant synergistic effects on the expression of the β2-adrenergic receptor gene (ADRB2). Radiation alone increased ADRB2 expression, and cells incubated in microgravity had more DNA strand breaks than cells incubated in normal gravity. We observed radiation-induced cytokine production only in microgravity. Prior treatment with isoproterenol clearly prevents most of the microgravity-mediated effects. RWVs may be a useful tool to provide insight into novel regulatory pathways, providing benefit not only to astronauts but also to patients suffering from immune disorders or undergoing radiotherapy. Full article

Protein function is mainly modulated by dynamic reversible or irreversible post-translational modifications. Among them, the identification of protein phosphorylation sites and changes in phosphorylation levels in vivo are of considerable interest for a better understanding of the protein function. Thus, effective strategies for the quantitative determination of phosphorylation degrees for low abundant proteins, for which antibodies are not available, are required in order to evaluate the functional regulation of proteins attributed to phosphorylation. In this study, we used the heart β1-adrenergic receptor (Adrb1) as a model protein and developed FLAG-Adrb1 knock-in mice, in which the FLAG tag was inserted at the N-terminus of Adrb1. The phosphorylation sites and levels of Adrb1 in the heart were elucidated by immuno-affinity purification followed by quantitative mass spectrometry analysis using ion intensity ratio of the phosphorylated peptide versus corresponding unphosphorylated peptide. The phosphorylation levels at Ser274 and Ser462 of Adrb1 were approximately 0.25 and 0.0023. This effective strategy should be useful for not only analyzing site-specific phosphorylation levels of target proteins, but also quantifying the expression levels of proteins of interest when appropriate antibodies are not available. Full article