Tag: 2023

Mast Cells in the Autonomic Nervous System and Potential Role in Disorders with Dysautonomia and Neuroinflammation

Abstract:

Mast cells (MC) are ubiquitous in the body and are critical for allergic diseases, but also in immunity and inflammation, as well as potential involvement in the pathophysiology of dysautonomias and neuroinflammatory disorders. MC are located perivascularly close to nerve endings and sites such as the carotid bodies, heart, hypothalamus, the pineal and the adrenal glands that would allow them to regulate, but also be affected by the autonomic nervous system (ANS).

MC are stimulated not only by allergens, but also many other triggers including some from the ANS that can affect MC release of neurosensitizing, proinflammatory and vasoactive mediators. Hence MC may be able to regulate homeostatic functions that appear to be dysfunctional in many conditions, such as postural orthostatic hypertension syndrome (POTS), autism spectrum disorder (ASD), myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and Long-COVID syndrome.

The evidence indicates that there is a possible association between these conditions and diseases associated with mast cell activation, There is no effective treatment for any form of these conditions other than minimizing symptoms. Given the many ways MC could be activated and the numerous mediators released, it would be important to develop ways to inhibit stimulation of MC and the release of ANS-relevant mediators.

Source: Theoharides TC, Twahir A, Kempuraj D. Mast Cells in the Autonomic Nervous System and Potential Role in Disorders with Dysautonomia and Neuroinflammation. Ann Allergy Asthma Immunol. 2023 Nov 9:S1081-1206(23)01397-2. doi: 10.1016/j.anai.2023.10.032. Epub ahead of print. PMID: 37951572. https://pubmed.ncbi.nlm.nih.gov/37951572/

Senolytic therapy alleviates physiological human brain aging and COVID-19 neuropathology

Abstract:

Aging is a major risk factor for neurodegenerative diseases, and coronavirus disease 2019 (COVID-19) is linked to severe neurological manifestations. Senescent cells contribute to brain aging, but the impact of virus-induced senescence on neuropathologies is unknown. Here we show that senescent cells accumulate in aged human brain organoids and that senolytics reduce age-related inflammation and rejuvenate transcriptomic aging clocks.

In postmortem brains of patients with severe COVID-19 we observed increased senescent cell accumulation compared with age-matched controls. Exposure of human brain organoids to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induced cellular senescence, and transcriptomic analysis revealed a unique SARS-CoV-2 inflammatory signature. Senolytic treatment of infected brain organoids blocked viral replication and prevented senescence in distinct neuronal populations. In human-ACE2-overexpressing mice, senolytics improved COVID-19 clinical outcomes, promoted dopaminergic neuron survival and alleviated viral and proinflammatory gene expression.

Collectively our results demonstrate an important role for cellular senescence in driving brain aging and SARS-CoV-2-induced neuropathology, and a therapeutic benefit of senolytic treatments.

Source:Aguado, J., Amarilla, A.A., Taherian Fard, A. et al. Senolytic therapy alleviates physiological human brain aging and COVID-19 neuropathology. Nat Aging (2023). https://doi.org/10.1038/s43587-023-00519-6 https://www.nature.com/articles/s43587-023-00519-6 (Full text)

Senolytic drugs: from discovery to translation

Abstract:

Senolytics are a class of drugs that selectively clear senescent cells (SC). The first senolytic drugs Dasatinib, Quercetin, Fisetin and Navitoclax were discovered using a hypothesis-driven approach.

SC accumulate with ageing and at causal sites of multiple chronic disorders, including diseases accounting for the bulk of morbidity, mortality and health expenditures. The most deleterious SC are resistant to apoptosis and have up-regulation of anti-apoptotic pathways which defend SC against their own inflammatory senescence-associated secretory phenotype (SASP), allowing them to survive, despite killing neighbouring cells. Senolytics transiently disable these SCAPs, causing apoptosis of those SC with a tissue-destructive SASP.

Because SC take weeks to reaccumulate, senolytics can be administered intermittently – a ‘hit-and-run’ approach. In preclinical models, senolytics delay, prevent or alleviate frailty, cancers and cardiovascular, neuropsychiatric, liver, kidney, musculoskeletal, lung, eye, haematological, metabolic and skin disorders as well as complications of organ transplantation, radiation and cancer treatment.

As anticipated for agents targeting the fundamental ageing mechanisms that are ‘root cause’ contributors to multiple disorders, potential uses of senolytics are protean, potentially alleviating over 40 conditions in preclinical studies, opening a new route for treating age-related dysfunction and diseases. Early pilot trials of senolytics suggest they decrease senescent cells, reduce inflammation and alleviate frailty in humans.

Clinical trials for diabetes, idiopathic pulmonary fibrosis, Alzheimer’s disease, COVID-19, osteoarthritis, osteoporosis, eye diseases and bone marrow transplant and childhood cancer survivors are underway or beginning. Until such studies are done, it is too early for senolytics to be used outside of clinical trials.

Source: Kirkland JL, Tchkonia T. Senolytic drugs: from discovery to translation. J Intern Med. 2020 Nov;288(5):518-536. doi: 10.1111/joim.13141. Epub 2020 Aug 4. PMID: 32686219; PMCID: PMC7405395. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7405395/ (Full text)

Dry eye symptoms and signs in United States Gulf War era veterans with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: To examine ocular symptoms and signs of veterans with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) diagnosis, ME/CFS symptoms, and controls.

Methods: This was a prospective, cross-sectional study of 124 South Florida veterans in active duty during the Gulf War era. Participants were recruited at an ophthalmology clinic at the Miami Veterans Affairs Hospital and evaluated for a diagnosis of ME/CFS, or symptoms of ME/CFS (intermediate fatigue, IF) using the Canadian Consensus criteria. Ocular symptoms were assessed via standardised questionnaires and signs via comprehensive slit lamp examination. Inflammatory blood markers were analysed and compared across groups.

Results: Mean age was 55.1 ± 4.7 years, 88.7% identified as male, 58.1% as White, and 39.5% as Hispanic. Ocular symptoms were more severe in the ME/CFS (n = 32) and IF (n = 48) groups compared to controls (n = 44) across dry eye (DE; Ocular Surface Disease Index [OSDI]: 48.9 ± 22.3 vs. 38.8 ± 23.3 vs. 19.1 ± 17.8, p < 0.001; 5 item Dry Eye Questionnaire [DEQ-5]: 10.8 ± 3.9 vs. 10.0 ± 4.6 vs. 6.6 ± 4.2, p < 0.001) and pain-specific questionnaires (Numerical Rating Scale 1-10 [NRS] right now: 2.4 ± 2.8 vs. 2.4 ± 2.9 vs 0.9 ± 1.5; p = 0.007; Neuropathic Pain Symptom Inventory modified for the Eye [NPSI-E]: 23.0 ± 18.6 vs. 19.8 ± 19.1 vs. 6.5 ± 9.0, p < 0.001). Ocular surface parameters and blood markers of inflammation were generally similar across groups.

Conclusion: Individuals with ME/CFS report increased ocular pain but similar DE signs, suggesting that mechanisms beyond the ocular surface contribute to symptoms.

Source: Victor Sanchez BS, Colin K. Kim BS, Elyana V. T. Locatelli BS, Adam K. Cohen, Kimberly Cabrera MS, Kristina Aenlle PhD, Nancy G. Klimas MD, Robert O’Brien PhD, Anat Galor MD, MSPH. Dry eye symptoms and signs in United States Gulf War era veterans with myalgic encephalomyelitis/chronic fatigue syndrome. First published: 12 November 2023 https://doi.org/10.1111/ceo.14313 https://onlinelibrary.wiley.com/doi/10.1111/ceo.14313 (Full text)

Post-Vaccination Syndrome: A Descriptive Analysis of Reported Symptoms and Patient Experiences After Covid-19 Immunization

Abstract:

Introduction: A chronic post-vaccination syndrome (PVS) after covid-19 vaccination has been reported but has yet to be well characterized.

Methods: We included 241 individuals aged 18 and older who self-reported PVS after covid-19 vaccination and who joined the online Yale Listen to Immune, Symptom and Treatment Experiences Now (LISTEN) Study from May 2022 to July 2023. We summarized their demographics, health status, symptoms, treatments tried, and overall experience.

Results: The median age of participants was 46 years (interquartile range [IQR]: 38 to 56), with 192 (80%) identifying as female, 209 (87%) as non-Hispanic White, and 211 (88%) from the United States. Among these participants with PVS, 127 (55%) had received the BNT162b2 [Pfizer-BioNTech] vaccine, and 86 (37%) received the mRNA-1273 [Moderna] vaccine. The median time from the day of index vaccination to symptom onset was three days (IQR: 1 day to 8 days). The time from vaccination to symptom survey completion was 595 days (IQR: 417 to 661 days). The median Euro-QoL visual analogue scale score was 50 (IQR: 39 to 70). The five most common symptoms were exercise intolerance (71%), excessive fatigue (69%), numbness (63%), brain fog (63%), and neuropathy (63%). In the week before survey completion, participants reported feeling unease (93%), fearfulness (82%), and overwhelmed by worries (81%), as well as feelings of helplessness (80%), anxiety (76%), depression (76%), hopelessness (72%), and worthlessness (49%) at least once. Participants reported a median of 20 (IQR: 13 to 30) interventions to treat their condition.

Conclusions: In this study, individuals who reported PVS after covid-19 vaccination had low health status, high symptom burden, and high psychosocial stress despite trying many treatments. There is a need for continued investigation to understand and treat this condition.

Source: Harlan M Krumholz, Yilun Wu, Mitsuaki Sawano, Rishi Shah, Tianna Zhou, Adith S Arun, Pavan Khosla, Shayaan Kaleem, Anushree Vashist, Bornali Bhattacharjee, Qinglan Ding, Yuan Lu, Cesar Caraballo, Frederick Warner, Chenxi Huang, Jeph Herrin, David Putrino, Danice Hertz, Brianne Dressen, Akiko Iwasaki. Post-Vaccination Syndrome: A Descriptive Analysis of Reported Symptoms and Patient Experiences After Covid-19 Immunization. medRxiv 2023.11.09.23298266; doi: https://doi.org/10.1101/2023.11.09.23298266 https://www.medrxiv.org/content/10.1101/2023.11.09.23298266v1 (Full text available as PDF file)

Increased risk of chronic fatigue syndrome following infection: a 17-year population-based cohort study

Abstract:

Background: Previous serological studies have indicated an association between viruses and atypical pathogens and Chronic Fatigue Syndrome (CFS). This study aims to investigate the correlation between infections from common pathogens, including typical bacteria, and the subsequent risk of developing CFS. The analysis is based on data from Taiwan’s National Health Insurance Research Database.

Methods: From 2000 to 2017, we included a total of 395,811 cases aged 20 years or older newly diagnosed with infection. The cases were matched 1:1 with controls using a propensity score and were followed up until diagnoses of CFS were made.

Results: The Cox proportional hazards regression analysis was used to estimate the relationship between infection and the subsequent risk of CFS. The incidence density rates among non-infection and infection population were 3.67 and 5.40 per 1000 person-years, respectively (adjusted hazard ratio [HR] = 1.5, with a 95% confidence interval [CI] 1.47-1.54). Patients infected with Varicella-zoster virus, Mycobacterium tuberculosis, Escherichia coli, Candida, Salmonella, Staphylococcus aureus and influenza virus had a significantly higher risk of CFS than those without these pathogens (p < 0.05). Patients taking doxycycline, azithromycin, moxifloxacin, levofloxacin, or ciprofloxacin had a significantly lower risk of CFS than patients in the corresponding control group (p < 0.05).

Conclusion: Our population-based retrospective cohort study found that infection with common pathogens, including bacteria, viruses, is associated with an increased risk of developing CFS.

Source: Chang H, Kuo CF, Yu TS, Ke LY, Hung CL, Tsai SY. Increased risk of chronic fatigue syndrome following infection: a 17-year population-based cohort study. J Transl Med. 2023 Nov 11;21(1):804. doi: 10.1186/s12967-023-04636-z. PMID: 37951920. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-04636-z (Full text)

Neurologic sequelae of COVID-19 are determined by immunologic imprinting from previous coronaviruses

Abstract:

Coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global public health emergency. Although SARS-CoV-2 is primarily a respiratory pathogen, extra-respiratory organs, including the CNS, can also be affected. Neurologic symptoms have been observed not only during acute SARS-CoV-2 infection, but also at distance from respiratory disease, also known as long-COVID or neurological post-acute sequelae of COVID-19 (neuroPASC). The pathogenesis of neuroPASC is not well understood, but hypotheses include SARS-CoV-2-induced immune dysfunctions, hormonal dysregulations and persistence of SARS-CoV-2 reservoirs.

In this prospective cohort study, we used a high throughput systems serology approach to dissect the humoral response to SARS-CoV-2 (and other common coronaviruses: 229E, HKU1, NL63 and OC43) in the serum and CSF from 112 infected individuals who developed (n = 18) or did not develop (n = 94) neuroPASC. Unique SARS-CoV-2 humoral profiles were observed in the CSF of neuroPASC compared with serum responses. All antibody isotypes (IgG, IgM, IgA) and subclasses (IgA1-2, IgG1-4) were detected in serum, whereas CSF was characterized by focused IgG1 (and absence of IgM).

These data argue in favour of compartmentalized brain-specific responses against SARS-CoV-2 through selective transfer of antibodies from the serum to the CSF across the blood-brain barrier, rather than intrathecal synthesis, where more diversity in antibody classes/subclasses would be expected.

Compared to individuals who did not develop post-acute complications following infection, individuals with neuroPASC had similar demographic features (median age 65 versus 66.5 years, respectively, P = 0.55; females 33% versus 44%, P = 0.52) but exhibited attenuated systemic antibody responses against SARS-CoV-2, characterized by decreased capacity to activate antibody-dependent complement deposition (ADCD), NK cell activation (ADNKA) and to bind Fcγ receptors. However, surprisingly, neuroPASC individuals showed significantly expanded antibody responses to other common coronaviruses, including 229E, HKU1, NL63 and OC43.

This biased humoral activation across coronaviruses was particularly enriched in neuroPASC individuals with poor outcome, suggesting an ‘original antigenic sin’ (or immunologic imprinting), where pre-existing immune responses against related viruses shape the response to the current infection, as a key prognostic marker of neuroPASC disease.

Overall, these findings point to a pathogenic role for compromised anti-SARS-CoV-2 responses in the CSF, likely resulting in incomplete virus clearance from the brain and persistent neuroinflammation, in the development of post-acute neurologic complications of SARS-CoV-2 infection.

Source: Spatola M, Nziza N, Jung W, Deng Y, Yuan D, Dinoto A, Bozzetti S, Chiodega V, Ferrari S, Lauffenburger DA, Mariotto S, Alter G. Neurologic sequelae of COVID-19 are determined by immunologic imprinting from previous coronaviruses. Brain. 2023 Oct 3;146(10):4292-4305. doi: 10.1093/brain/awad155. PMID: 37161609. https://academic.oup.com/brain/article/146/10/4292/7158783 (Full text)

Sequential multi-omics analysis identifies clinical phenotypes and predictive biomarkers for long COVID

Abstract:

The post-acute sequelae of COVID-19 (PASC), also known as long COVID, is often associated with debilitating symptoms and adverse multisystem consequences. We obtain plasma samples from 117 individuals during and 6 months following their acute phase of infection to comprehensively profile and assess changes in cytokines, proteome, and metabolome.

Network analysis reveals sustained inflammatory response, platelet degranulation, and cellular activation during convalescence accompanied by dysregulation in arginine biosynthesis, methionine metabolism, taurine metabolism, and tricarboxylic acid (TCA) cycle processes.

Furthermore, we develop a prognostic model composed of 20 molecules involved in regulating T cell exhaustion and energy metabolism that can reliably predict adverse clinical outcomes following discharge from acute infection with 83% accuracy and an area under the curve (AUC) of 0.96.

Our study reveals pertinent biological processes during convalescence that differ from acute infection, and it supports the development of specific therapies and biomarkers for patients suffering from long COVID.

Source: Wang K, Khoramjoo M, Srinivasan K, Gordon PMK, Mandal R, Jackson D, Sligl W, Grant MB, Penninger JM, Borchers CH, Wishart DS, Prasad V, Oudit GY. Sequential multi-omics analysis identifies clinical phenotypes and predictive biomarkers for long COVID. Cell Rep Med. 2023 Oct 18:101254. doi: 10.1016/j.xcrm.2023.101254. Epub ahead of print. PMID: 37890487. https://www.cell.com/cell-reports-medicine/fulltext/S2666-3791(23)00431-7 (Full text)

“It was almost like it’s set up for people to fail” A qualitative analysis of experiences and unmet supportive needs of people with Long COVID

Abstract:

Background: Almost twenty percent of adults with COVID-19 develop Long COVID, leading to prolonged symptoms and disability. Understanding the supportive needs of people with Long COVID is vital to enacting effective models of care and policies.

Design/methods: This qualitative sub-study explored the experiences of people with Long COVID and their unmet needs. Participants enrolled in a larger study to evaluate the post-acute cardiovascular impacts of COVID-19 were invited to participate in subsequent in-depth interviews. Participants were enrolled purposively until saturation at 24 participants. Data were analyzed using thematic content analysis.

Results: Participants focused on adaptations to life with Long COVID and their unmet needs in different life spheres. Three domains, 1) occupational and financial; 2) healthcare-related; and 3) social and emotional support, emerged as areas affecting quality of life. Although participants were motivated to return to work for financial and personal reasons, Long COVID symptoms often resulted in the inability to perform tasks required by their existing jobs, and unemployment. Those who maintained employment through employer accommodations still needed additional support. Participants encountered diagnostic challenges, challenges in accessing specialty appointments, insurance loopholes, high healthcare costs, and medical skepticism. Existing social networks provided support for completing daily tasks; however, those with Long COVID typically turned to others with similar lived experiences for emotional support. Participants found government support programs inadequate and difficult to access in all three domains.

Discussion: We propose a five-pronged policy approach to support persons with Long COVID. These overarching recommendations are (1) improve public awareness of Long COVID; (2) improve clinical care quality and access; (3) implement additional school and workplace accommodations; (4) strengthen socioeconomic benefits and social services; and (5) improve research on Long COVID.

Source: McNabb, K.C., Bergman, A.J., Smith-Wright, R. et al. “It was almost like it’s set up for people to fail” A qualitative analysis of experiences and unmet supportive needs of people with Long COVID. BMC Public Health 23, 2131 (2023). https://doi.org/10.1186/s12889-023-17033-4 https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-023-17033-4 (Full text)

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (Me/Cfs): The Biology of a Neglected Disease

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic disease with debilitating symptoms that impact all aspects of life. The diverse symptom presentation indicates that ME/CFS is likely to have a multifactorial origin. However, it is an extremely understudied disease with no standardised diagnostic criteria or proven treatment avenues. It is hypothesised that environmental insults (such as acute infection, mainly viral) or stress in genetically susceptible individuals may trigger the development of ME/CFS.

These insults result in acute inflammatory responses, along with aberrant immune activation. A spiralling disruption of homeostasis promotes subsequent patho-mechanisms including gut dysbiosis and systemic inflammation, and eventually a pathological clotting system, chronic endothelialitis, vasoconstriction, and hypoxia. Additionally, dysfunctional energy metabolism including oxidative stress is also present in the development of ME/CFS. Since the exact pathophysiology of ME/CFS remains unclear, additional research is required to reveal further insight into this “neglected” disease.

Source: Arron, Hayley and Marsh, Benamin and Khan, M. Asad and Jaeger, Beate and Kell, Douglas and Pretorius, Etheresia, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (Me/Cfs): The Biology of a Neglected Disease. Available at SSRN: https://ssrn.com/abstract=4622074 or http://dx.doi.org/10.2139/ssrn.4622074 (Full text available as PDF file)