Could SARS-CoV-2 Spike Protein Be Responsible for Long-COVID Syndrome?

Exploring the Pathophysiology of Long COVID: The Central Role of Low-Grade Inflammation and Multisystem Involvement

Long COVID (LC), also referred to as Post COVID-19 Condition, Post-Acute Sequelae of SARS-CoV-2 Infection (PASC), and other terms, represents a complex multisystem disease persisting after the acute phase of COVID-19. Characterized by a myriad of symptoms across different organ systems, LC presents significant diagnostic and management challenges. Central to the disorder is the role of low-grade inflammation, a non-classical inflammatory response that contributes to the chronicity and diversity of symptoms observed. This review explores the pathophysiological underpinnings of LC, emphasizing the importance of low-grade inflammation as a core component. By delineating the pathogenetic relationships and clinical manifestations of LC, this article highlights the necessity for an integrated approach that employs both personalized medicine and standardized protocols aimed at mitigating long-term consequences. The insights gained not only enhance our understanding of LC but also inform the development of therapeutic strategies that could be applicable to other chronic conditions with similar pathophysiological features.

Assessing the association between antibody status and symptoms of long COVID: A multisite study

The association between SARS-CoV-2 humoral immunity and post-acute sequelae of COVID-19 (long COVID) remains uncertain. The objective of this population-based cohort study was to assess the association between SARS-CoV-2 seropositivity and symptoms consistent with long COVID. English and Spanish-speaking members ≥ 18 years old with SARS-CoV-2 serologic testing conducted prior to August 2021 were recruited from Kaiser Permanente Southern California and Kaiser Permanente Colorado. Between November 2021 and April 2022, participants completed a survey assessing symptoms, physical health, mental health, and cognitive function consistent with long COVID. Survey results were linked to SARS-CoV-2 antibody (Ab) and viral (RNA) lab results in electronic health records. Weighted descriptive analyses were generated for five mutually exclusive patient groups: (1) +Ab/+RNA; (2) +Ab/- or missing RNA; (3) -Ab/+RNA; (4a) -Ab/-RNA reporting no prior infection; and (4b) -Ab/-RNA reporting prior infection. The proportions reporting symptoms between the +Ab/+RNA and -Ab/+RNA groups were compared, adjusted for covariates. Among 3,946 participants, the mean age was 52.1 years old (SD 15.6), 68.3% were female, 28.4% were Hispanic, and the serologic testing occurred a median of 15 months prior (IQR = 12-18). Three quarters (74.5%) reported having had COVID-19. Among people with laboratory-confirmed COVID-19, there was no association between antibody positivity (+Ab/+RNA vs. -Ab/+RNA) and any symptoms, physical health, mental health, or cognitive function. As expected, physical health, cognitive function, and fatigue were worse, and palpitations and headaches limiting the ability to work were more prevalent among people with laboratory-confirmed prior infection and positive serology (+Ab/+RNA) compared to those without reported or confirmed prior infection and negative serology (-Ab/-RNA/no reported COVID-19). Among people with laboratory-confirmed COVID-19, SARS-CoV-2 serology from practice settings were not associated with long COVID symptoms and health status suggesting limited utility of serology testing for long COVID.

Psychiatric adverse events following COVID-19 vaccination: a population-based cohort study in Seoul, South Korea

Evidence has suggested an increased risk of psychiatric manifestations following viral infections including coronavirus disease-2019 (COVID-19). However, psychiatric adverse events (AEs) after COVID-19 vaccination, which were documented in case reports and case series, remain unclear. This study is aimed to investigate the psychiatric AEs after COVID-19 vaccination from a large population-based cohort in Seoul, South Korea. We recruited 50% of the Seoul-resident population randomly selected from the Korean National Health Insurance Service (KNHIS) claims database on 1, January, 2021. The included participants (n = 2,027,353) from the Korean National Health Insurance Service claims database were divided into two groups according to COVID-19 vaccination. The cumulative incidences per 10,000 of psychiatric AEs were assessed on one week, two weeks, one month, and three months after COVID-19 vaccination. Hazard ratios (HRs) and 95% Confidence interval (CIs) of psychiatric AEs were measured for the vaccinated population. The cumulative incidence of depression, anxiety, dissociative, stress-related, and somatoform disorders, sleep disorders, and sexual disorders at three months following COVID-19 vaccination were higher in the vaccination group than no vaccination group. However, schizophrenia and bipolar disorders showed lower cumulative incidence in the vaccination group than in the non-vaccinated group. Depression (HR [95% CI] = 1.683 [1.520-1.863]), anxiety, dissociative, stress-related, and somatoform disorders (HR [95% CI] = 1.439 [1.322-1.568]), and sleep disorders (HR [95% CI] = 1.934 [1.738-2.152]) showed increased risks after COVID-19 vaccination, whereas the risks of schizophrenia (HR [95% CI] = 0.231 [0.164-0.326]) and bipolar disorder (HR [95% CI] = 0.672 [0.470-0.962]). COVID-19 vaccination increased the risks of depression, anxiety, dissociative, stress-related, and somatoform disorders, and sleep disorders while reducing the risk of schizophrenia and bipolar disorder. Therefore, special cautions are necessary for administering additional COVID-19 vaccinations to populations vulnerable to psychiatric AEs.

Inhibition of SARS-CoV-2-Induced NLRP3 Inflammasome-Mediated Lung Cell Inflammation by Triphala-Loaded Nanoparticle Targeting Spike Glycoprotein S1

The COVID-19 pandemic, caused by SARS-CoV-2, poses a significant global health threat. The spike glycoprotein S1 of the SARS-CoV-2 virus is known to induce the production of pro-inflammatory mediators, contributing to hyperinflammation in COVID-19 patients. Triphala, an ancient Ayurvedic remedy composed of dried fruits from three plant species-Emblica officinalis (Family Euphorbiaceae), Terminalia bellerica (Family Combretaceae), and Terminalia chebula (Family Combretaceae)-shows promise in addressing inflammation. However, the limited water solubility of its ethanolic extract impedes its bioavailability. In this study, we aimed to develop nanoparticles loaded with Triphala extract, termed "nanotriphala", as a drug delivery system. Additionally, we investigated the in vitro anti-inflammatory properties of nanotriphala and its major compounds, namely gallic acid, chebulagic acid, and chebulinic acid, in lung epithelial cells (A549) induced by CoV2-SP. The nanotriphala formulation was prepared using the solvent displacement method. The encapsulation efficiency of Triphala in nanotriphala was determined to be 87.96 ± 2.60% based on total phenolic content. In terms of in vitro release, nanotriphala exhibited a biphasic release profile with zero-order kinetics over 0-8 h. A549 cells were treated with nanotriphala or its active compounds and then induced with 100 ng/mL of spike S1 subunit (CoV2-SP). The results demonstrate that chebulagic acid and chebulinic acid are the active compounds in nanotriphala, which significantly reduced cytokine release (IL-6, IL-1β, and IL-18) and suppressed the expression of inflammatory genes (IL-6, IL-1β, IL-18, and NLRP3) (p < 0.05). Mechanistically, nanotriphala and its active compounds notably attenuated the expression of inflammasome machinery proteins (NLRP3, ASC, and Caspase-1) (p < 0.05). In conclusion, the nanoparticle formulation of Triphala enhances its stability and exhibits anti-inflammatory properties against CoV2-SP-induction. This was achieved by suppressing inflammatory mediators and the NLRP3 inflammasome machinery. Thus, nanotriphala holds promise as a supportive preventive anti-inflammatory therapy for COVID-19-related chronic inflammation.

What Role Does Microthrombosis Play in Long COVID?

Soon after the outbreak of coronavirus disease 2019 (COVID-19), unexplained sustained fatigue, cognitive disturbance, and muscle ache/weakness were reported in patients who had recovered from acute COVID-19 infection. This abnormal condition has been recognized as "long COVID (postacute sequelae of COVID-19 [PASC])" with a prevalence estimated to be from 10 to 20% of convalescent patients. Although the pathophysiology of PASC has been studied, the exact mechanism remains obscure. Microclots in circulation can represent one of the possible causes of PASC. Although hypercoagulability and thrombosis are critical mechanisms of acute COVID-19, recent studies have reported that thromboinflammation continues in some patients, even after the virus has cleared. Viral spike proteins and RNA can be detected months after patients have recovered, findings that may be responsible for persistent thromboinflammation and the development of microclots. Despite this theory, long-term results of anticoagulation, antiplatelet therapy, and vascular endothelial protection are inconsistent, and could not always show beneficial treatment effects. In summary, PASC reflects a heterogeneous condition, and microclots cannot explain all the presenting symptoms. After clarification of the pathomechanisms of each symptom, a symptom- or biomarker-based stratified approach should be considered for future studies.

Can inflammatory plasma proteins predict Long COVID or Fatigue severity after SARS-CoV-2 infection?

OBJECTIVE

To investigate whether specific immune response plasma proteins can predict an elevated risk of developing Long COVID symptoms or fatigue severity after SARS-CoV-2 infection.

METHODS

This study was based on 257 outpatients with test-confirmed SARS-CoV-2 infection between February 2020 and January 2021. At least 12 weeks after the acute infection, 92 plasma proteins were measured using the Olink Target 96 immune response panel (median time between acute infection and venous blood sampling was 38.8 [IQR: 24.0-48.0] weeks). The presence of Long COVID symptoms and fatigue severity was assessed 115.8 [92.5-118.6] weeks after the acute infection by a follow-up postal survey. Long COVID (yes/no) was defined as having one or more of the following symptoms: fatigue, shortness of breath, concentration or memory problems. The severity of fatigue was assessed using the Fatigue Assessment Scale (FAS). In multivariable-adjusted logistic and linear regression models the associations between each plasma protein (exposure) and Long COVID (yes/no) or severity of fatigue were investigated.

RESULTS

Nine plasma proteins were significantly associated with Long COVID before, but not after adjusting for multiple testing (FDR-adjustment): DFFA, TRIM5, TRIM21, HEXIM1, SRPK2, PRDX5, PIK3AP1, IFNLR1 and HCLS1. Moreover, a total of 10 proteins were significantly associated with severity of fatigue before FDR-adjustment: SRPK2, ITGA6, CLEC4G, HEXIM1, PPP1R9B, PLXNA4, PRDX5, DAPP1, STC1 and HCLS1. Only SRPK2 and ITGA6 remained significantly associated after FDR-adjustment.

CONCLUSIONS

This study demonstrates that certain immune response plasma proteins might play an important role in the pathophysiology of Long COVID and severity of fatigue after SARS-CoV-2 infection.

Toll like receptor 4 mediates the inhibitory effect of SARS-CoV-2 spike protein on proximal tubule albumin endocytosis

Tubular proteinuria is a common feature in COVID-19 patients, even in the absence of established acute kidney injury. SARS-CoV-2 spike protein (S protein) was shown to inhibit megalin-mediated albumin endocytosis in proximal tubule epithelial cells (PTECs). Angiotensin-converting enzyme type 2 (ACE2) was not directly involved. Since Toll-like receptor 4 (TLR4) mediates S protein effects in various cell types, we hypothesized that TLR4 could be participating in the inhibition of PTECs albumin endocytosis elicited by S protein. Two different models of PTECs were used: porcine proximal tubule cells (LLC-PK1) and human embryonic kidney cells (HEK-293). S protein reduced Akt activity by specifically inhibiting of threonine 308 (Thr308) phosphorylation, a process mediated by phosphoinositide-dependent kinase 1 (PDK1). GSK2334470, a PDK1 inhibitor, decreased albumin endocytosis and megalin expression mimicking S protein effect. S protein did not change total TLR4 expression but decreased its surface expression. LPS-RS, a TLR4 antagonist, also counteracted the effects of the S protein on Akt phosphorylation at Thr308, albumin endocytosis, and megalin expression. Conversely, these effects of the S protein were replicated by LPS, an agonist of TLR4. Incubation of PTECs with a pseudovirus containing S protein inhibited albumin endocytosis. Null or VSV-G pseudovirus, used as control, had no effect. LPS-RS prevented the inhibitory impact of pseudovirus containing the S protein on albumin endocytosis but had no influence on virus internalization. Our findings demonstrate that the inhibitory effect of the S protein on albumin endocytosis in PTECs is mediated through TLR4, resulting from a reduction in megalin expression.

SARS-CoV-2 Spike Protein 1 Causes Aggregation of α-Synuclein via Microglia-Induced Inflammation and Production of Mitochondrial ROS: Potential Therapeutic Applications of Metformin

Abnormal aggregation of α-synuclein is the hallmark of neurodegenerative diseases, classified as α-synucleinopathies, primarily occurring sporadically. Their onset is associated with an interaction between genetic susceptibility and environmental factors such as neurotoxins, oxidative stress, inflammation, and viral infections. Recently, evidence has suggested an association between neurological complications in long COVID (sometimes referred to as 'post-acute sequelae of COVID-19') and α-synucleinopathies, but its underlying mechanisms are not completely understood. In this study, we first showed that SARS-CoV-2 Spike protein 1 (S1) induces α-synuclein aggregation associated with activation of microglial cells in the rodent model. In vitro, we demonstrated that S1 increases aggregation of α-synuclein in BE(2)M-17 dopaminergic neurons via BV-2 microglia-mediated inflammatory responses. We also identified that S1 directly affects aggregation of α-synuclein in dopaminergic neurons through increasing mitochondrial ROS, though only under conditions of sufficient α-Syn accumulation. In addition, we observed a synergistic effect between S1 and the neurotoxin MPP+ S1 treatment. Combined with a low dose of MPP+, it boosted α-synuclein aggregation and mitochondrial ROS production compared to S1 or the MPP+ treatment group. Furthermore, we evaluated the therapeutic effects of metformin. The treatment of metformin suppressed the S1-induced inflammatory response and α-synucleinopathy. Our findings demonstrate that S1 promotes α-synucleinopathy via both microglia-mediated inflammation and mitochondrial ROS, and they provide pathological insights, as well as a foundation for the clinical management of α-synucleinopathies and the onset of neurological symptoms after the COVID-19 outbreak.

Therapeutic implications of quercetin and its derived-products in COVID-19 protection and prophylactic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel human coronavirus, which has triggered a global pandemic of the coronavirus infectious disease 2019 (COVID-19). Outbreaks of emerging infectious diseases continue to challenge human health worldwide. The virus conquers human cells through the angiotensin-converting enzyme 2 receptor-driven pathway by mostly targeting the human respiratory tract. Quercetin is a natural flavonoid widely represented in the plant kingdom. Cumulative evidence has demonstrated that quercetin and its derivatives have various pharmacological properties including anti-cancer, anti-hypertension, anti-hyperlipidemia, anti-hyperglycemia, anti-microbial, antiviral, neuroprotective, and cardio-protective effects, because it is a potential treatment for severe inflammation and acute respiratory distress syndrome. Furthermore, it is the main life-threatening condition in patients with COVID-19. This article provides a comprehensive review of the primary literature on the predictable effectiveness of quercetin and its derivatives docked to multi-target of SARS-CoV-2 and host cells via in silico and some of validation through in vitro, in vivo, and clinically to fight SARS-CoV-2 infections, contribute to the reduction of inflammation, which suggests the preventive and therapeutic latency of quercetin and its derived-products against COVID-19 pandemic, multisystem inflammatory syndromes (MIS), and long-COVID.

A murine model of post-acute neurological sequelae following SARS-CoV-2 variant infection

Viral variant is one known risk factor associated with post-acute sequelae of COVID-19 (PASC), yet the pathogenesis is largely unknown. Here, we studied SARS-CoV-2 Delta variant-induced PASC in K18-hACE2 mice. The virus replicated productively, induced robust inflammatory responses in lung and brain tissues, and caused weight loss and mortality during the acute infection. Longitudinal behavior studies in surviving mice up to 4 months post-acute infection revealed persistent abnormalities in neuropsychiatric state and motor behaviors, while reflex and sensory functions recovered over time. In the brain, no detectable viral RNA and minimal residential immune cell activation was observed in the surviving mice post-acute infection. Transcriptome analysis revealed persistent activation of immune pathways, including humoral responses, complement, and phagocytosis, and gene expression levels associated with ataxia telangiectasia, impaired cognitive function and memory recall, and neuronal dysfunction and degeneration. Furthermore, surviving mice maintained potent systemic T helper 1 prone cellular immune responses and strong sera neutralizing antibodies against Delta and Omicron variants months post-acute infection. Overall, our findings suggest that infection in K18-hACE2 mice recapitulates the persistent clinical symptoms reported in long-COVID patients and provides new insights into the role of systemic and brain residential immune factors in PASC pathogenesis.

Long COVID: plasma levels of neurofilament light chain in mild COVID-19 patients with neurocognitive symptoms

It is well known the potential of severe acute respiratory coronavirus type 2 (SARS-CoV-2) infection to induce post-acute sequelae, a condition called Long COVID. This syndrome includes several symptoms, but the central nervous system (CNS) main one is neurocognitive dysfunction. Recently it has been demonstrated the relevance of plasma levels of neurofilament light chain (pNfL), as a biomarker of early involvement of the CNS in COVID-19. The aim of this study was to investigate the relationship between pNfL in patients with post-acute neurocognitive symptoms and the potential of NfL as a prognostic biomarker in these cases. A group of 63 long COVID patients ranging from 18 to 59 years-old were evaluated, submitted to a neurocognitive battery assessment, and subdivided in different groups, according to results. Plasma samples were collected during the long COVID assessment and used for measurement of pNfL with the Single molecule array (SIMOA) assays. Levels of pNfL were significantly higher in long COVID patients with neurocognitive symptoms when compared to HC (p = 0.0031). Long COVID patients with cognitive impairment and fatigue symptoms presented higher pNfL levels when compared to long COVID patients without these symptoms, individually and combined (p = 0.0263, p = 0.0480, and 0.0142, respectively). Correlation analysis showed that levels of cognitive lost and exacerbation of fatigue in the neurocognitive evaluation had a significative correlation with higher pNfL levels (p = 0.0219 and 0.0255, respectively). Previous reports suggested that pNfL levels are related with higher risk of severity and predict lethality of COVID-19. Our findings demonstrate that SARS-CoV-2 infection seems to have a long-term impact on the brain, even in patients who presented mild acute disease. NfL measurements might be useful to identify CNS involvement in long COVID associated with neurocognitive symptoms and to identify who will need continuous monitoring and treatment support.

Mast cells in the autonomic nervous system and potential role in disorders with dysautonomia and neuroinflammation

Mast cells (MC) are ubiquitous in the body, and they are critical for not only in allergic diseases but also in immunity and inflammation, including having 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 gland, and the adrenal gland that would allow them not only to regulate but also to 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 seem to be dysfunctional in many conditions, such as postural orthostatic tachycardia syndrome, autism spectrum disorder, myalgic encephalomyelitis/chronic fatigue syndrome, and Long-COVID syndrome. The evidence indicates that there is a possible association between these conditions and diseases associated with MC 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.

Possible Role of Cannabis in the Management of Neuroinflammation in Patients with Post-COVID Condition

The post-COVID condition (PCC) is a pathology stemming from COVID-19, and studying its pathophysiology, diagnosis, and treatment is crucial. Neuroinflammation causes the most common manifestations of this disease including headaches, fatigue, insomnia, depression, anxiety, among others. Currently, there are no specific management proposals; however, given that the inflammatory component involves cytokines and free radicals, these conditions must be treated to reduce the current symptoms and provide neuroprotection to reduce the risk of a long-term neurodegenerative disease. It has been shown that cannabis has compounds with immunomodulatory and antioxidant functions in other pathologies. Therefore, exploring this approach could provide a viable therapeutic option for PCC, which is the purpose of this review. This review involved an exhaustive search in specialized databases including PubMed, PubChem, ProQuest, EBSCO, Scopus, Science Direct, Web of Science, and Clinical Trials. Phytocannabinoids, including cannabidiol (CBD), cannabigerol (CBG), and Delta-9-tetrahydrocannabinol (THC), exhibit significant antioxidative and anti-inflammatory properties and have been shown to be an effective treatment for neuroinflammatory conditions. These compounds could be promising adjuvants for PCC alone or in combination with other antioxidants or therapies. PCC presents significant challenges to neurological health, and neuroinflammation and oxidative stress play central roles in its pathogenesis. Antioxidant therapy and cannabinoid-based approaches represent promising areas of research and treatment for mitigating adverse effects, but further studies are needed.

Murine alveolar macrophages rapidly accumulate intranasally administered SARS-CoV-2 Spike protein leading to neutrophil recruitment and damage

The trimeric SARS-CoV-2 Spike protein mediates viral attachment facilitating cell entry. Most COVID-19 vaccines direct mammalian cells to express the Spike protein or deliver it directly via inoculation to engender a protective immune response. The trafficking and cellular tropism of the Spike protein in vivo and its impact on immune cells remains incompletely elucidated. In this study, we inoculated mice intranasally, intravenously, and subcutaneously with fluorescently labeled recombinant SARS-CoV-2 Spike protein. Using flow cytometry and imaging techniques, we analyzed its localization, immune cell tropism, and acute functional impact. Intranasal administration led to rapid lung alveolar macrophage uptake, pulmonary vascular leakage, and neutrophil recruitment and damage. When injected near the inguinal lymph node medullary, but not subcapsular macrophages, captured the protein, while scrotal injection recruited and fragmented neutrophils. Widespread endothelial and liver Kupffer cell uptake followed intravenous administration. Human peripheral blood cells B cells, neutrophils, monocytes, and myeloid dendritic cells all efficiently bound Spike protein. Exposure to the Spike protein enhanced neutrophil NETosis and augmented human macrophage TNF-α (tumor necrosis factor-α) and IL-6 production. Human and murine immune cells employed C-type lectin receptors and Siglecs to help capture the Spike protein. This study highlights the potential toxicity of the SARS-CoV-2 Spike protein for mammalian cells and illustrates the central role for alveolar macrophage in pathogenic protein uptake.

[Interaction of somatic findings and psychiatric symptoms in COVID-19. A scoping review]

An infection with SARS-CoV‑2 can affect the central nervous system, leading to neurological as well as psychiatric symptoms. In this respect, mechanisms of inflammation seem to be of much greater importance than the virus itself. This paper deals with the possible contributions of organic changes to psychiatric symptomatology and deals especially with delirium, cognitive symptoms, depression, anxiety, posttraumatic stress disorder and psychosis. Processes of neuroinflammation with infection of capillary endothelial cells and activation of microglia and astrocytes releasing high amounts of cytokines seem to be of key importance in all kinds of disturbances. They can lead to damage in grey and white matter, impairment of cerebral metabolism and loss of connectivity. Such neuroimmunological processes have been described as a organic basis for many psychiatric disorders, as affective disorders, psychoses and dementia. As the activation of the glia cells can persist for a long time after the offending agent has been cleared, this can contribute to long term sequalae of the infection.

Pathophysiological, immunological, and inflammatory features of long COVID

The COVID-19 pandemic continues to cause severe global disruption, resulting in significant excess mortality, overwhelming healthcare systems, and imposing substantial social and economic burdens on nations. While most of the attention and therapeutic efforts have concentrated on the acute phase of the disease, a notable proportion of survivors experience persistent symptoms post-infection clearance. This diverse set of symptoms, loosely categorized as long COVID, presents a potential additional public health crisis. It is estimated that 1 in 5 COVID-19 survivors exhibit clinical manifestations consistent with long COVID. Despite this prevalence, the mechanisms and pathophysiology of long COVID remain poorly understood. Alarmingly, evidence suggests that a significant proportion of cases within this clinical condition develop debilitating or disabling symptoms. Hence, urgent priority should be given to further studies on this condition to equip global public health systems for its management. This review provides an overview of available information on this emerging clinical condition, focusing on the affected individuals' epidemiology, pathophysiological mechanisms, and immunological and inflammatory profiles.

Association of vaccine status, reinfections, and risk factors with Long COVID syndrome

The COVID-19 pandemic had a profound global impact, characterized by a high fatality rate and the emergence of enduring consequences known as Long COVID. Our study sought to determine the prevalence of Long COVID syndrome within a population of Northeastern Mexico, correlating it with patients' comorbidities, number of COVID-19 reinfection, and vaccination status. Employing an observational cross-sectional approach, we administered a comprehensive questionnaire covering medical history, demographics, vaccination status, COVID-related symptoms, and treatment. Our participant cohort included 807 patients, with an average age of 41.5 (SD 13.6) years, and women accounting 59.3% of the cohort. The follow-up was 488 (IQR 456) days. One hundred sixty-eight subjects (20.9%) met Long COVID criteria. Long COVID-19 was more prevalent when subjects had reinfections (p = 0.02) and less frequent when they had a complete vaccination scheme (p = 0.05). Through logistic regression, we found that male gender (OR 0.5, p ≤ 0.001), blood types of AB- (OR 0.48, p = 0.003) and O- (OR 0.27, p ≤ 0.001) in comparison with A+ and two doses of vaccines (OR 0.5, p = 006) to be protective factors against Long COVID; while higher BMI (OR 1.04, p = 0.005) was a risk factor. We saw that the prevalence of Long COVID was different within vaccinated patients and specific blood types, while being female and a higher BMI were associated with an increased risk of having long-COVID.

Omicron variant (B.1.1.529) challenge the integrity of blood brain barrier: Evidence from protein structural analysis

Studies on nonhuman primates, wild-type and transgenic mice have shown the presence of SARS-CoV-2 RNA components in the brains. Despite the Blood-Brain Barrier (BBB) provides protection there are less evidences on how the SARS-CoV-2 crosses the BBB. Given that there is an increase of Omicron reinfection rates, transmissibility rate and involvement to cause neurological dysfunctions, we hypothesized to investigate how the Omicron variant (B.1.1.529) binds structurally to key BBB-maintaining proteins and thus can possibly challenge the integrity and transportation to the brain. By using molecular dynamics simulation approaches we examined the interaction of Omicron variant (B.1.1.529) with different structural and transporter proteins located at the BBB. Our results show that in Zona Ocludin 1-RBD complex, we observe a distinct pattern. Omicron demonstrates a docking score of -88.9 ± 6.8 kcal/mol and six interactions, while the wild type (WT) presents a higher score of -94.0 ± 2.3 kcal/mol, forming eight interactions. Comparing affinities, the WT-RBD displays a stronger preference for Claudin-5, boasting a docking score of -110.2 ± 3.0 and nine interactions, versus Omicron-RBD's slightly reduced engagement, with a docking score of -105.6 ± 0.2 and seven interactions. Interestingly, the Omicron variant exhibits heightened stability in interactions with Glucose Transporter and ABC transporters, registering docking scores of -110.6 ± 1.9 and -112.0 ± 3.6 kcal/mol, respectively. This surpasses the WT's respective scores of -95.2 ± 2.2 and -104.0 ± 6.2 kcal/mol, reflecting a unique interaction profile. Rigorous molecular dynamics simulations validate our findings. Our study emphasizes the Omicron variant's increased affinity towards transporter proteins, illuminating potential implications for BBB integrity and brain transportation. While these insights offer a valuable framework, comprehensive experimental validation is indispensable for a comprehensive understanding.

Possible Role of Fibrinaloid Microclots in Postural Orthostatic Tachycardia Syndrome (POTS): Focus on Long COVID

Postural orthostatic tachycardia syndrome (POTS) is a common accompaniment of a variety of chronic, inflammatory diseases, including long COVID, as are small, insoluble, 'fibrinaloid' microclots. We here develop the argument, with accompanying evidence, that fibrinaloid microclots, through their ability to block the flow of blood through microcapillaries and thus cause tissue hypoxia, are not simply correlated with but in fact, by preceding it, may be a chief intermediary cause of POTS, in which tachycardia is simply the body's exaggerated 'physiological' response to hypoxia. Similar reasoning accounts for the symptoms bundled under the term 'fatigue'. Amyloids are known to be membrane disruptors, and when their targets are nerve membranes, this can explain neurotoxicity and hence the autonomic nervous system dysfunction that contributes to POTS. Taken together as a system view, we indicate that fibrinaloid microclots can serve to link POTS and fatigue in long COVID in a manner that is at once both mechanistic and explanatory. This has clear implications for the treatment of such diseases.

Acute Myocardial Infarction during the COVID-19 Pandemic: Long-Term Outcomes and Prognosis-A Systematic Review

Coronavirus disease 2019 (COVID-19) was a global pandemic with high mortality and morbidity that led to an increased health burden all over the world. Although the virus mostly affects the pulmonary tract, cardiovascular implications are often observed among COVID-19 patients and are predictive of poor outcomes. Increased values of myocardial biomarkers such as troponin I or NT-proBNP were proven to be risk factors for respiratory failure. Although the risk of acute coronary syndromes (ACSs) was greater in the acute phase of COVID-19, there were lower rates of hospitalization for ACSs, due to patients' hesitation in presenting at the hospital. Hospitalized ACSs patients with COVID-19 infection had a prolonged symptom-to-first-medical-contact time, and longer door-to-balloon time. The mechanisms of myocardial injury in COVID-19 patients are still not entirely clear; however, the most frequently implicated factors include the downregulation of ACE2 receptors, endothelial dysfunction, pro-coagulant status, and increased levels of pro-inflammatory cytokines. The aim of this paper is to evaluate the long-term outcomes and prognosis of COVID-19 survivors that presented an acute myocardial infarction, by reviewing existing data. The importance of the association between this infectious disease and myocardial infarction arises from the increased mortality of patients with SARS-CoV-2 infection and AMI (10-76%, compared with 4.6% for NSTEMI patients and 7% for STEMI patients without COVID-19). The literature review showed an increased risk of cardiovascular events in COVID-19 survivors compared with the general population, even after the acute phase of the disease, with poorer long-term outcomes.

A Murine Model of Post-acute Neurological Sequelae Following SARS-CoV-2 Variant Infection

Viral variant is one known risk factor associated with post-acute sequelae of COVID-19 (PASC), yet the pathogenesis is largely unknown. Here, we studied SARS-CoV-2 Delta variant-induced PASC in K18-hACE2 mice. The virus replicated productively, induced robust inflammatory responses in lung and brain tissues, and caused weight loss and mortality during the acute infection. Longitudinal behavior studies in surviving mice up to 4 months post-acute infection revealed persistent abnormalities in neuropsychiatric state and motor behaviors, while reflex and sensory functions recovered over time. Surviving mice showed no detectable viral RNA in the brain and minimal neuroinflammation post-acute infection. Transcriptome analysis revealed persistent activation of immune pathways, including humoral responses, complement, and phagocytosis, and reduced levels of genes associated with ataxia telangiectasia, impaired cognitive function and memory recall, and neuronal dysfunction and degeneration. Furthermore, surviving mice maintained potent T helper 1 prone cellular immune responses and high neutralizing antibodies against Delta and Omicron variants in the periphery for months post-acute infection. Overall, infection in K18-hACE2 mice recapitulates the persistent clinical symptoms reported in long COVID patients and may be useful for future assessment of the efficacy of vaccines and therapeutics against SARS-CoV-2 variants.

Efficacies of S-nitrosoglutathione (GSNO) and GSNO reductase inhibitor in SARS-CoV-2 spike protein induced acute lung disease in mice

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which initially surfaced in late 2019, often triggers severe pulmonary complications, encompassing various disease mechanisms such as intense lung inflammation, vascular dysfunction, and pulmonary embolism. Currently, however, there's no drug addressing all these mechanisms simultaneously. This study explored the multi-targeting potential of S-nitrosoglutathione (GSNO) and N6022, an inhibitor of GSNO reductase (GSNOR) on markers of inflammatory, vascular, and thrombotic diseases related to COVID-19-induced acute lung disease. For this, acute lung disease was induced in C57BL/6 mice through intranasal administration of recombinant SARS-CoV-2 spike protein S1 domain (SP-S1). The mice exhibited fever, body weight loss, and increased blood levels and lung expression of proinflammatory cytokines (e.g., TNF-α and IL-6) as well as increased vascular inflammation mediated by ICAM-1 and VCAM-1 and lung infiltration by immune cells (e.g., neutrophils, monocytes, and activated cytotoxic and helper T cells). Further, the mice exhibited increased lung hyperpermeability (lung Evans blue extravasation) leading to lung edema development as well as elevated blood coagulation factors (e.g., fibrinogen, thrombin, activated platelets, and von Willebrand factor) and lung fibrin deposition. Similar to the patients with COVID-19, male mice showed more severe disease than female mice, along with higher GSNOR expression in the lungs. Optimization of GSNO by treatment with exogenous GSNO or inhibition of GSNOR by N6022 (or GSNO knockout) protects against SP-S1-induced lung diseases in both genders. These findings provide evidence for the potential efficacies of GSNO and GSNOR inhibitors in addressing the multi-mechanistic nature of SARS-CoV-2 SP-associated acute-lung disease.

Murine Alveolar Macrophages Rapidly Accumulate Intranasally Administered SARS-CoV-2 Spike Protein leading to Neutrophil Recruitment and Damage

The trimeric SARS-CoV-2 Spike protein mediates viral attachment facilitating cell entry. Most COVID-19 vaccines direct mammalian cells to express the Spike protein or deliver it directly via inoculation to engender a protective immune response. The trafficking and cellular tropism of the Spike protein in vivo and its impact on immune cells remains incompletely elucidated. In this study we inoculated mice intranasally, intravenously, and subcutaneously with fluorescently labeled recombinant SARS-CoV-2 Spike protein. Using flow cytometry and imaging techniques we analyzed its localization, immune cell tropism, and acute functional impact. Intranasal administration led to rapid lung alveolar macrophage uptake, pulmonary vascular leakage, and neutrophil recruitment and damage. When injected near the inguinal lymph node medullary, but not subcapsular macrophages, captured the protein, while scrotal injection recruited and fragmented neutrophils. Wide-spread endothelial and liver Kupffer cell uptake followed intravenous administration. Human peripheral blood cells B cells, neutrophils, monocytes, and myeloid dendritic cells all efficiently bound Spike protein. Exposure to the Spike protein enhanced neutrophil NETosis and augmented human macrophage TNF-α and IL-6 production. Human and murine immune cells employed C-type lectin receptors and Siglecs to help capture the Spike protein. This study highlights the potential toxicity of the SARS-CoV-2 Spike protein for mammalian cells and illustrates the central role for alveolar macrophage in pathogenic protein uptake.

Nutritional and Wellness Strategies for Neurological and Psychiatric Recovery From Post-COVID Syndrome and Post-acute Sequelae of COVID-19

The post-COVID syndrome was officially recognized as a disability under the Americans with Disabilities Act, indicating that this syndrome has made a significant impact on our populace. Also, post-acute sequelae of COVID-19 (PASC) is a term that describes the long-term health problems that some people experience after being infected with the virus that causes COVID-19. These problems can last for weeks, months, or even years, and can affect various parts of the body, such as the heart, lungs, brain, and blood vessels. This narrative review paper utilized the PubMed database to explore the pathophysiology of post-COVID syndrome's neurological and psychiatric symptoms and PASC and make therapeutic connections to the known mechanisms of various nutritional, supplemental, and wellness approaches. Searches were queried on the PubMed database between March 29 and April 16, 2022, using the phrases "long-covid," "post-COVID syndrome," "Vitamin D covid," "vitamin C covid," "omega-3 covid," "kynurenine covid," "whole-body hyperthermia," "mushrooms immunity," "n-acetyl cysteine covid," "mushrooms cognition," "sugar consumption inflammation," and "covid microbiome." Articles were screened for their relevance to the discussion of post-COVID syndrome's neurological and psychiatric pathophysiology at the discretion of the principal researcher. There were no limitations regarding publication years, but articles from 2005 to April 2022 were cited. Micro-ischemic disease, neuropathy, autoimmune processes, mast-cell activation, and impaired blood-brain barriers have all been implicated in the pathological processes of this syndrome with varying degrees of supportive evidence. The common denominators, however, are inflammation and oxidative stress. Therefore, a beneficial approach to dealing with the complications of post-COVID syndrome would be to reduce the exacerbations of these common denominators with lifestyle and nutritional changes. Replenishing nutritional deficiencies, supplementing with N-acetylcysteine, decreasing consumption of refined sugars, preventing dysbiosis of the microbiome, performing exercises, increasing dietary intake of mushrooms, utilizing beneficial herbs such as rosemary, and increasing the core body temperature through whole-body hyperthermia seem to show potential for efficacy in this pursuit. Considering the safety and evidence-based connections of the therapies explored for dealing with the post-Covid syndrome, it could be of great benefit and of little harm to our patients to include these considerations in formulating post-Covid treatment plans.

Photobiomodulation, Transmucosal Laser Irradiation of Blood, or B complex as alternatives to treat Covid-19 Related Long-Term Taste Impairment: double-blind randomized clinical trial

COVID-19 Related Long-Term Taste Impairment (CRLTTI) is a condition that can be expressed after COVID-19 contagion, lasting for months or even years, affecting the routine and quality of life of individuals. Participants expressing CRLTTI, with a minimum of 2 months, attested by PCR-RT test were assessed for taste and smell, and underwent experimental treatments in 6 distinct groups: Photobiomodulation (PBM) in tongue dorsum and lateral (660 nm, 808 nm, association of 660 and 808 nm), Transmucosal Laser Irradiation of Blood (TLIB)-ventral surface of tongue (660 nm), B complex supplementation, and Sham laser. No intergroup statistical differences were observed at the final evaluation, despite the tendencies of better results with PBM and TLIB observed. PBM, TLIB, and B complex might be treatment options in the management of CRLTTI, despite the lack of total remission of taste and smell perception after 8 sessions (PBM and TLIB) or 30 days of B complex supplementation.

The impact of aging and oxidative stress in metabolic and nervous system disorders: programmed cell death and molecular signal transduction crosstalk

Life expectancy is increasing throughout the world and coincides with a rise in non-communicable diseases (NCDs), especially for metabolic disease that includes diabetes mellitus (DM) and neurodegenerative disorders. The debilitating effects of metabolic disorders influence the entire body and significantly affect the nervous system impacting greater than one billion people with disability in the peripheral nervous system as well as with cognitive loss, now the seventh leading cause of death worldwide. Metabolic disorders, such as DM, and neurologic disease remain a significant challenge for the treatment and care of individuals since present therapies may limit symptoms but do not halt overall disease progression. These clinical challenges to address the interplay between metabolic and neurodegenerative disorders warrant innovative strategies that can focus upon the underlying mechanisms of aging-related disorders, oxidative stress, cell senescence, and cell death. Programmed cell death pathways that involve autophagy, apoptosis, ferroptosis, and pyroptosis can play a critical role in metabolic and neurodegenerative disorders and oversee processes that include insulin resistance, β-cell function, mitochondrial integrity, reactive oxygen species release, and inflammatory cell activation. The silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), AMP activated protein kinase (AMPK), and Wnt1 inducible signaling pathway protein 1 (WISP1) are novel targets that can oversee programmed cell death pathways tied to β-nicotinamide adenine dinucleotide (NAD+), nicotinamide, apolipoprotein E (APOE), severe acute respiratory syndrome (SARS-CoV-2) exposure with coronavirus disease 2019 (COVID-19), and trophic factors, such as erythropoietin (EPO). The pathways of programmed cell death, SIRT1, AMPK, and WISP1 offer exciting prospects for maintaining metabolic homeostasis and nervous system function that can be compromised during aging-related disorders and lead to cognitive impairment, but these pathways have dual roles in determining the ultimate fate of cells and organ systems that warrant thoughtful insight into complex autofeedback mechanisms.

High unrecognized SARS-CoV-2 exposure of newly admitted and hospitalized psychiatric patients

BACKGROUND

Patients with pre-existing mental disorders are at higher risk for SARS-CoV-2 infection and adverse outcomes, and severe mental illness, including mood and psychosis spectrum disorders, is associated with increased mortality risk. Despite their increased risk profile, patients with severe mental illness have been understudied during the pandemic, with limited estimates of exposure in inpatient settings.

OBJECTIVE

The aim of this study was to describe the SARS-CoV-2 seroprevalence and antibody titers, and pro-inflammatory cytokine concentrations of newly admitted or hospitalized psychiatric inpatients without known history of COVID-19 infection, using robust quantitative multi-antigen assessments, and compare patients' exposure to that of hospital staff.

METHODS

This multi-centric, cross-sectional study compared SARS-CoV-2 seroprevalence and titers of 285 patients (University Psychiatric Centre Duffel [UPCD] N = 194; Assistance-Publique-Hopitaux de Paris [AP-HP] N = 91), and 192 hospital caregivers (UPCD N = 130; AP-HP N = 62) at two large psychiatric care facilities between January 1st and the May 30th 2021. Serum levels of SARS-CoV-2 antibodies against Spike proteins (full length), spike subunit 1 (S1), spike subunit 2 (S2), spike subunit 1 receptor binding domain (S1-RBD) and Nucleocapsid proteins were quantitatively determined using an advanced capillary Western Blot technique. To assess the robustness of the between-group seroprevalence differences, we performed sensitivity analyses with stringent cut-offs for seropositivity. We also assessed peripheral concentrations of IL-6, IL-8 and TNF-a using ELLA assays. Secondary analyses included comparisons of SARS-CoV-2 seroprevalence and titers between patient diagnostic subgroups, and between newly admitted (hospitalization ≤ 7 days) and hospitalized patients (hospitalization > 7 days) and correlations between serological and cytokines.

RESULTS

Patients had a significantly higher SARS-CoV-2 seroprevalence (67.85 % [95% CI 62.20-73.02]) than hospital caregivers (27.08% [95% CI 21.29-33.77]), and had significantly higher global SARS-CoV-2 titers (F = 29.40, df = 2, p < 0.0001). Moreover, patients had a 2.51-fold (95% CI 1.95-3.20) higher SARS-CoV-2 exposure risk compared to hospital caregivers (Fisher's exact test, P < 0.0001). No difference was found in SARS-CoV-2 seroprevalence and titers between patient subgroups. Patients could be differentiated most accurately from hospital caregivers by their higher Spike protein titers (OR 136.54 [95% CI 43.08-481.98], P < 0.0001), lower S1 (OR 0.06 [95% CI 0.02-0.15], P < 0.0001) titers and higher IL-6 (OR 3.41 [95% CI 1.73-7.24], P < 0.0001) and TNF-α (OR 34.29 [95% CI 5.00-258.87], P < 0.0001) and lower titers of IL-8 (OR 0.13 [95% CI 0.05-0.30], P < 0.0001). Seropositive patients had significantly higher SARS-COV-2 antibody titers compared to seropositive hospital caregivers (F = 19.53, df = 2, P < 0.0001), while titers were not different in seronegative individuals. Pro-inflammatory cytokine concentrations were not associated with serological status.

CONCLUSION

Our work demonstrated a very high unrecognized exposure to SARS-CoV-2 among newly admitted and hospitalized psychiatric inpatients, which is cause for concern in the context of highly robust evidence of adverse outcomes following COVID-19 in psychiatric patients. Attention should be directed toward monitoring and mitigating exposure to infectious agents within psychiatric hospitals.

Clinical Approach to Post-acute Sequelae After COVID-19 Infection and Vaccination

The spike protein of SARS-CoV-2 has been found to exhibit pathogenic characteristics and be a possible cause of post-acute sequelae after SARS-CoV-2 infection or COVID-19 vaccination. COVID-19 vaccines utilize a modified, stabilized prefusion spike protein that may share similar toxic effects with its viral counterpart. The aim of this study is to investigate possible mechanisms of harm to biological systems from SARS-CoV-2 spike protein and vaccine-encoded spike protein and to propose possible mitigation strategies. We searched PubMed, Google Scholar, and 'grey literature' to find studies that (1) investigated the effects of the spike protein on biological systems, (2) helped differentiate between viral and vaccine-generated spike proteins, and (3) identified possible spike protein detoxification protocols and compounds that had signals of benefit and acceptable safety profiles. We found abundant evidence that SARS-CoV-2 spike protein may cause damage in the cardiovascular, hematological, neurological, respiratory, gastrointestinal, and immunological systems. Viral and vaccine-encoded spike proteins have been shown to play a direct role in cardiovascular and thrombotic injuries from both SARS-CoV-2 and vaccination. Detection of spike protein for at least 6-15 months after vaccination and infection in those with post-acute sequelae indicates spike protein as a possible primary contributing factor to long COVID. We rationalized that these findings give support to the potential benefit of spike protein detoxification protocols in those with long-term post-infection and/or vaccine-induced complications. We propose a base spike detoxification protocol, composed of oral nattokinase, bromelain, and curcumin. This approach holds immense promise as a base of clinical care, upon which additional therapeutic agents are applied with the goal of aiding in the resolution of post-acute sequelae after SARS-CoV-2 infection and COVID-19 vaccination. Large-scale, prospective, randomized, double-blind, placebo-controlled trials are warranted in order to determine the relative risks and benefits of the base spike detoxification protocol.

Vaccination after developing long COVID: Impact on clinical presentation, viral persistence, and immune responses

BACKGROUND

Vaccination protects against severe COVID-19 manifestations. For those with post-COVID-19 conditions (PCC) or long COVID, the impact of COVID-19 vaccination on the evolution of symptoms, immune responses, and viral persistence is unclear.

METHODS

In this prospective observational cohort study, we evaluated the number of PCC symptoms, affected organ systems, and psychological well-being scores before and after patients with PCC received COVID-19 vaccination. We simultaneously evaluated biomarkers of systemic inflammation and levels of plasma cytokines/chemokines. We measured plasma and intracellular levels of SARS-CoV-2 antigens, and immunoreactivity to SARS-CoV-2 antigens in blood.

RESULTS

COVID-19 vaccination was associated with decreases in number of PCC symptoms (pre-vaccination: 6.56 ± 3.1 vs post-vaccination: 3.92 ± 4.02; P <0.001) and affected organ systems (pre-vaccination: 3.19 ± 1.04 vs post-vaccination: 1.89 ± 1.12; P <0.001), and increases in World Health Organization (WHO)-5 Well-Being Index Scores (pre-vaccination: 42.67 ± 22.76 vs post-vaccination: 56.15 ± 22.83; P <0.001). Patients with PCC also had significantly decreased levels of several pro-inflammatory plasma cytokines/chemokines after COVID-19 vaccination including sCD40L, GRO-⍺, macrophage inflammatory protein (MIP)-1⍺, interleukin (IL)-12p40, G-colony stimulating factor (CSF), M-CSF, IL-1β, and stem cell factor (SCF). PCC participants presented a certain level of immunoreactivity toward SARS-CoV-2, that was boosted with vaccination. SARS-CoV-2 S1 antigen persisted in the blood of PCC participants, mostly in non-classical monocytes, regardless of participants receiving vaccination.

CONCLUSIONS

Our study shows higher pro-inflammatory responses associated with PCC symptoms and brings forward a possible role for vaccination in mitigating PCC symptoms by decreasing systemic inflammation. We also observed persistence of viral products independent of vaccination that could be involved in perpetuating inflammation through non-classical monocytes.

SARS-CoV-2 spike protein S1 activates Cx43 hemichannels and disturbs intracellular Ca2+ dynamics

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the ongoing coronavirus disease 2019 (COVID-19). An aspect of high uncertainty is whether the SARS-CoV-2 per se or the systemic inflammation induced by viral infection directly affects cellular function and survival in different tissues. It has been postulated that tissue dysfunction and damage observed in COVID-19 patients may rely on the direct effects of SARS-CoV-2 viral proteins. Previous evidence indicates that the human immunodeficiency virus and its envelope protein gp120 increase the activity of connexin 43 (Cx43) hemichannels with negative repercussions for cellular function and survival. Here, we evaluated whether the spike protein S1 of SARS-CoV-2 could impact the activity of Cx43 hemichannels.

RESULTS

We found that spike S1 time and dose-dependently increased the activity of Cx43 hemichannels in HeLa-Cx43 cells, as measured by dye uptake experiments. These responses were potentiated when the angiotensin-converting enzyme 2 (ACE2) was expressed in HeLa-Cx43 cells. Patch clamp experiments revealed that spike S1 increased unitary current events with conductances compatible with Cx43 hemichannels. In addition, Cx43 hemichannel opening evoked by spike S1 triggered the release of ATP and increased the [Ca2+]i dynamics elicited by ATP.

CONCLUSIONS

We hypothesize that Cx43 hemichannels could represent potential pharmacological targets for developing therapies to counteract SARS-CoV-2 infection and their long-term consequences.

Gut-brain pathogenesis of post-acute COVID-19 neurocognitive symptoms

Approximately one third of non-hospitalized coronavirus disease of 2019 (COVID-19) patients report chronic symptoms after recovering from the acute stage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Some of the most persistent and common complaints of this post-acute COVID-19 syndrome (PACS) are cognitive in nature, described subjectively as "brain fog" and also objectively measured as deficits in executive function, working memory, attention, and processing speed. The mechanisms of these chronic cognitive sequelae are currently not understood. SARS-CoV-2 inflicts damage to cerebral blood vessels and the intestinal wall by binding to angiotensin-converting enzyme 2 (ACE2) receptors and also by evoking production of high levels of systemic cytokines, compromising the brain's neurovascular unit, degrading the intestinal barrier, and potentially increasing the permeability of both to harmful substances. Such substances are hypothesized to be produced in the gut by pathogenic microbiota that, given the profound effects COVID-19 has on the gastrointestinal system, may fourish as a result of intestinal post-COVID-19 dysbiosis. COVID-19 may therefore create a scenario in which neurotoxic and neuroinflammatory substances readily proliferate from the gut lumen and encounter a weakened neurovascular unit, gaining access to the brain and subsequently producing cognitive deficits. Here, we review this proposed PACS pathogenesis along the gut-brain axis, while also identifying specific methodologies that are currently available to experimentally measure each individual component of the model.

COVID-19 and Long COVID: Disruption of the Neurovascular Unit, Blood-Brain Barrier, and Tight Junctions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), could affect brain structure and function. SARS-CoV-2 can enter the brain through different routes, including the olfactory, trigeminal, and vagus nerves, and through blood and immunocytes. SARS-CoV-2 may also enter the brain from the peripheral blood through a disrupted blood-brain barrier (BBB). The neurovascular unit in the brain, composed of neurons, astrocytes, endothelial cells, and pericytes, protects brain parenchyma by regulating the entry of substances from the blood. The endothelial cells, pericytes, and astrocytes highly express angiotensin converting enzyme 2 (ACE2), indicating that the BBB can be disturbed by SARS-CoV-2 and lead to derangements of tight junction and adherens junction proteins. This leads to increased BBB permeability, leakage of blood components, and movement of immune cells into the brain parenchyma. SARS-CoV-2 may also cross microvascular endothelial cells through an ACE2 receptor-associated pathway. The exact mechanism of BBB dysregulation in COVID-19/neuro-COVID is not clearly known, nor is the development of long COVID. Various blood biomarkers could indicate disease severity and neurologic complications in COVID-19 and help objectively diagnose those developing long COVID. This review highlights the importance of neurovascular and BBB disruption, as well as some potentially useful biomarkers in COVID-19, and long COVID/neuro-COVID.

Cardiovascular autonomic dysfunction in "Long COVID": pathophysiology, heart rate variability, and inflammatory markers

Long COVID is characterized by persistent signs and symptoms that continue or develop for more than 4 weeks after acute COVID-19 infection. Patients with Long COVID experience a cardiovascular autonomic imbalance known as dysautonomia. However, the underlying autonomic pathophysiological mechanisms behind this remain unclear. Current hypotheses include neurotropism, cytokine storms, and inflammatory persistence. Certain immunological factors indicate autoimmune dysfunction, which can be used to identify patients at a higher risk of Long COVID. Heart rate variability can indicate autonomic imbalances in individuals suffering from Long COVID, and measurement is a non-invasive and low-cost method for assessing cardiovascular autonomic modulation. Additionally, biochemical inflammatory markers are used for diagnosing and monitoring Long COVID. These inflammatory markers can be used to improve the understanding of the mechanisms driving the inflammatory response and its effects on the sympathetic and parasympathetic pathways of the autonomic nervous system. Autonomic imbalances in patients with Long COVID may result in lower heart rate variability, impaired vagal activity, and substantial sympathovagal imbalance. New research on this subject must be encouraged to enhance the understanding of the long-term risks that cardiovascular autonomic imbalances can cause in individuals with Long COVID.

Luteolin inhibits spike protein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) binding to angiotensin-converting enzyme 2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), a respiratory illness that poses a serious threat to global public health. In an essential step during infection, SARS-CoV-2 uses the receptor-binding domain (RBD) of the spike (S) protein to engage with angiotensin-converting enzyme 2 (ACE2) in host cells. Chinese herbal medicines and their active components exhibit antiviral activity, with luteolin being a flavonoid that can significantly inhibit SARS-CoV infection. However, whether it can block the interaction between the S-protein RBD of SARS-CoV-2 and ACE2 has not yet been elucidated. Here, we investigated the effects of luteolin on the binding of the S-protein RBD to ACE2. By employing a competitive binding assay in vitro, we found that luteolin significantly blocked the binding of S-protein RBD to ACE2 with IC50 values of 0.61 mM, which was confirmed by the neutralized infection with SARS-CoV-2 pseudovirus in vivo. A surface plasmon resonance-based competition assay revealed that luteolin significantly affects the binding of the S-protein RBD to the ACE2 receptor. Molecular docking was performed to predict the binding sites of luteolin to the S-protein RBD-ACE2 complex. The active binding sites were defined based on published literature, and we found that luteolin might interfere with the mixture at residues including LYS353, ASP30, and TYR83 in the cellular ACE2 receptor and GLY496, GLN498, TYR505, LEU455, GLN493, and GLU484 in the S-protein RBD. These residues may together form attractive charges and destroy the stable interaction of S-protein RBD-ACE2. Luteolin also inhibits SARS-CoV-2 spike protein-induced platelet spreading, thereby inhibiting the binding of the spike protein to ACE2. Our results are the first to provide evidence that luteolin is an anti-SARS-CoV-2 agent associated with interference between viral S-protein RBD-ACE2 interactions.

Potential Role of Moesin in Regulating Mast Cell Secretion

Mast cells have existed for millions of years in species that never suffer from allergic reactions. Hence, in addition to allergies, mast cells can play a critical role in homeostasis and inflammation via secretion of numerous vasoactive, pro-inflammatory and neuro-sensitizing mediators. Secretion may utilize different modes that involve the cytoskeleton, but our understanding of the molecular mechanisms regulating secretion is still not well understood. The Ezrin/Radixin/Moesin (ERM) family of proteins is involved in linking cell surface-initiated signaling to the actin cytoskeleton. However, how ERMs may regulate secretion from mast cells is still poorly understood. ERMs contain two functional domains connected through a long α-helix region, the N-terminal FERM (band 4.1 protein-ERM) domain and the C-terminal ERM association domain (C-ERMAD). The FERM domain and the C-ERMAD can bind to each other in a head-to-tail manner, leading to a closed/inactive conformation. Typically, phosphorylation on the C-terminus Thr has been associated with the activation of ERMs, including secretion from macrophages and platelets. It has previously been shown that the ability of the so-called mast cell "stabilizer" disodium cromoglycate (cromolyn) to inhibit secretion from rat mast cells closely paralleled the phosphorylation of a 78 kDa protein, which was subsequently shown to be moesin, a member of ERMs. Interestingly, the phosphorylation of moesin during the inhibition of mast cell secretion was on the N-terminal Ser56/74 and Thr66 residues. This phosphorylation pattern could lock moesin in its inactive state and render it inaccessible to binding to the Soluble NSF attachment protein receptors (SNAREs) and synaptosomal-associated proteins (SNAPs) critical for exocytosis. Using confocal microscopic imaging, we showed moesin was found to colocalize with actin and cluster around secretory granules during inhibition of secretion. In conclusion, the phosphorylation pattern and localization of moesin may be important in the regulation of mast cell secretion and could be targeted for the development of effective inhibitors of secretion of allergic and inflammatory mediators from mast cells.

Infection, Dysbiosis and Inflammation Interplay in the COVID Era in Children

For over three years, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children and adolescents has generated repercussions, especially a few weeks after infection, for symptomatic patients who tested positive, for asymptomatic ones, or even just the contacts of an infected person, and evolved from severe forms such as multisystem inflammatory syndrome in children (MIS-C) to multifarious clinical manifestations in long COVID (LC). Referred to under the umbrella term LC, the onset of persistent and highly heterogeneous symptoms such as fatigue, post-exertion malaise, cognitive dysfunction, and others have a major impact on the child's daily quality of life for months. The first aim of this review was to highlight the circumstances of the pathophysiological changes produced by COVID-19 in children and to better understand the hyperinflammation in COVID-19 and how MIS-C, as a life-threatening condition, could have been avoided in some patients. Another goal was to better identify the interplay between infection, dysbiosis, and inflammation at a molecular and cellular level, to better guide scientists, physicians, and pediatricians to advance new lines of medical action to avoid the post-acute sequelae of SARS-CoV-2 infection. The third objective was to identify symptoms and their connection to molecular pathways to recognize LC more easily. The fourth purpose was to connect the triggering factors of LC with related sequelae following acute SARS-CoV-2 injuries to systems and organs, the persistence of the virus, and some of its components in hidden reservoirs, including the gut and the central nervous system. The reactivation of other latent infectious agents in the host's immune environments, the interaction of this virus with the microbiome, immune hyperactivation, and autoimmunity generated by molecular mimicry between viral agents and host proteins, could initiate a targeted and individualized management. New high-tech solutions, molecules, probiotics, and others should be discovered to innovatively solve the interplay between RNA persistent viruses, microbiota, and our immune system.

Clinical Evolution and Risk Factors in Patients Infected during the First Wave of COVID-19: A Two-Year Longitudinal Study

A limited number of longitudinal studies have examined the symptoms associated with long-COVID-19. We conducted an assessment of symptom onset, severity and patient recovery, and determined the percentage of patients who experienced reinfection up to 2 years after the initial onset of the disease. Our cohort comprises 377 patients (≥18 years) with laboratory-confirmed COVID-19 in a secondary hospital (Madrid, Spain), throughout March 3-16, 2020. Disease outcomes and clinical data were followed-up until August 12, 2022. We reviewed the evolution of the 253 patients who had survived as of April 2020 (67.1%). Nine died between April 2020 and August 2022. A multivariate regression analysis performed to detect the risk factors associated with long-COVID-19 revealed that the increased likelihood was associated with chronic obstructive lung disease (OR 14.35, 95% CI 1.89-109.09; p = 0.010), dyspnea (5.02, 1.02-24.75; p = 0.048), higher LDH (3.23, 1.34-7.52; p = 0.006), and lower D-dimer levels (0.164, 0.04-0.678; p = 0.012). Reinfected patients (n = 45) (47.8 years; 39.7-67.2) were younger than non-reinfected patients (64.1 years; 48.6-74.4)) (p < 0.001). Patients who received a combination of vaccines exhibited fewer symptoms (44.4%) compared to those who received a single type of vaccine (77.8%) (p = 0.048). Long-COVID-19 was detected in 27.05% (66/244) of patients. The early detection of risk factors helps predict the clinical course of patients with COVID-19. Middle-aged adults could be susceptible to reinfection, highlighting the importance of prevention and control measures regardless of vaccination status.

Recombinant SARS-CoV-2 Spike Protein Stimulates Secretion of Chymase, Tryptase, and IL-1β from Human Mast Cells, Augmented by IL-33

SARS-CoV-2 infects cells via its spike (S) protein binding to its surface receptor angiotensin-converting enzyme 2 (ACE2) and results in the production of multiple proinflammatory cytokines, especially in the lungs, leading to what is known as COVID-19. However, the cell source and the mechanism of secretion of such cytokines have not been adequately characterized. In this study, we used human cultured mast cells that are plentiful in the lungs and showed that recombinant SARS-CoV-2 full-length S protein (1-10 ng/mL), but not its receptor-binding domain (RBD), stimulates the secretion of the proinflammatory cytokine interleukin-1β (IL-1β) as well as the proteolytic enzymes chymase and tryptase. The secretion of IL-1β, chymase, and tryptase is augmented by the co-administration of interleukin-33 (IL-33) (30 ng/mL). This effect is mediated via toll-like receptor 4 (TLR4) for IL-1β and via ACE2 for chymase and tryptase. These results provide evidence that the SARS-CoV-2 S protein contributes to inflammation by stimulating mast cells through different receptors and could lead to new targeted treatment approaches.

Psychophysiologic Symptom Relief Therapy (PSRT) for Post-acute Sequelae of COVID-19

Objective

To determine if psychophysiologic symptom relief therapy (PSRT) will reduce symptom burden in patients suffering from post-acute sequelae of COVID-19 (PASC) who had mild/moderate acute COVID-19 disease without objective evidence of organ injury.

Patients and Methods

Twenty-three adults under the age of 60 with PASC for at least 12 weeks following COVID-19 infection were enrolled in an interventional cohort study conducted via virtual platform between May 18, 2021 and August 7, 2022. Participants received PSRT during a 13 week (approximately 44 hour) course. Participants were administered validated questionnaires at baseline and at 4, 8, and 13 weeks. The primary outcome was change in somatic symptoms from baseline, measured using the Somatic Symptom Scale-8 (SSS-8), at 13 weeks.

Results

The median duration of symptoms prior to joining the study was 267 days (IQR: 144, 460). The mean SSS-8 score of the cohort decreased from baseline by 8.5 (95% CI: 5.7-11.4), 9.4 (95% CI: 6.9-11.9), and 10.9 (95% CI: 8.3-13.5) at 4, 8, and 13 weeks respectively (all p<.001). Participants also experienced statistically significant improvements across other secondary outcomes including changes in dyspnea, fatigue, and pain (all p<.001).

Conclusion

PSRT may effectively decrease symptom burden in patients suffering from PASC without evidence of organ injury. The study was registered on clinicaltrials.gov (NCT04854772).

Cellular Metabolism: A Fundamental Component of Degeneration in the Nervous System

It is estimated that, at minimum, 500 million individuals suffer from cellular metabolic dysfunction, such as diabetes mellitus (DM), throughout the world. Even more concerning is the knowledge that metabolic disease is intimately tied to neurodegenerative disorders, affecting both the central and peripheral nervous systems as well as leading to dementia, the seventh leading cause of death. New and innovative therapeutic strategies that address cellular metabolism, apoptosis, autophagy, and pyroptosis, the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), growth factor signaling with erythropoietin (EPO), and risk factors such as the apolipoprotein E (APOE-ε4) gene and coronavirus disease 2019 (COVID-19) can offer valuable insights for the clinical care and treatment of neurodegenerative disorders impacted by cellular metabolic disease. Critical insight into and modulation of these complex pathways are required since mTOR signaling pathways, such as AMPK activation, can improve memory retention in Alzheimer's disease (AD) and DM, promote healthy aging, facilitate clearance of β-amyloid (Aß) and tau in the brain, and control inflammation, but also may lead to cognitive loss and long-COVID syndrome through mechanisms that can include oxidative stress, mitochondrial dysfunction, cytokine release, and APOE-ε4 if pathways such as autophagy and other mechanisms of programmed cell death are left unchecked.

Aged brain and neuroimmune responses to COVID-19: post-acute sequelae and modulatory effects of behavioral and nutritional interventions

Advanced age is one of the significant risk determinants for coronavirus disease 2019 (COVID-19)-related mortality and for long COVID complications. The contributing factors may include the age-related dynamical remodeling of the immune system, known as immunosenescence and chronic low-grade systemic inflammation. Both of these factors may induce an inflammatory milieu in the aged brain and drive the changes in the microenvironment of neurons and microglia, which are characterized by a general condition of chronic inflammation, so-called neuroinflammation. Emerging evidence reveals that the immune privilege in the aging brain may be compromised. Resident brain cells, such as astrocytes, neurons, oligodendrocytes and microglia, but also infiltrating immune cells, such as monocytes, T cells and macrophages participate in the complex intercellular networks and multiple reciprocal interactions. Especially changes in microglia playing a regulatory role in inflammation, contribute to disturbing of the brain homeostasis and to impairments of the neuroimmune responses. Neuroinflammation may trigger structural damage, diminish regeneration, induce neuronal cell death, modulate synaptic remodeling and in this manner negatively interfere with the brain functions.In this review article, we give insights into neuroimmune interactions in the aged brain and highlight the impact of COVID-19 on the functional systems already modulated by immunosenescence and neuroinflammation. We discuss the potential ways of these interactions with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and review proposed neuroimmune mechanisms and biological factors that may contribute to the development of persisting long COVID conditions. We summarize the potential mechanisms responsible for long COVID, including inflammation, autoimmunity, direct virus-mediated cytotoxicity, hypercoagulation, mitochondrial failure, dysbiosis, and the reactivation of other persisting viruses, such as the Cytomegalovirus (CMV). Finally, we discuss the effects of various interventional options that can decrease the propagation of biological, physiological, and psychosocial stressors that are responsible for neuroimmune activation and which may inhibit the triggering of unbalanced inflammatory responses. We highlight the modulatory effects of bioactive nutritional compounds along with the multimodal benefits of behavioral interventions and moderate exercise, which can be applied as postinfectious interventions in order to improve brain health.

COVID-19 Induced Postural Orthostatic Tachycardia Syndrome (POTS): A Review

POTS (Postural Orthostatic Tachycardia Syndrome) is a multisystem disorder characterized by the abnormal autonomic response to an upright posture, causing orthostatic intolerance and excessive tachycardia without hypotension. Recent reports suggest that a significant percentage of COVID-19 survivors develop POTS within 6 to 8 months of infection. Prominent symptoms of POTS include fatigue, orthostatic intolerance, tachycardia, and cognitive impairment. The exact mechanisms of post-COVID-19 POTS are unclear. Still, different hypotheses have been given, including autoantibody production against autonomic nerve fibers, direct toxic effects of SARS-CoV-2, or sympathetic nervous system stimulation secondary to infection. Physicians should have a high suspicion of POTS in COVID-19 survival when presented with symptoms of autonomic dysfunction and should conduct diagnostic tests like the Tilt table and others to confirm it. The management of COVID-19-related POTS requires a comprehensive approach. Most patients respond to initial non-pharmacological options, but when the symptoms become more severe and they do not respond to the non-pharmacological approach, pharmacological options are considered. We have limited understanding and knowledge of post-COVID-19 POTS, and further research is warranted to improve our understanding and formulate a better management plan.

Blood-brain barrier penetration of non-replicating SARS-CoV-2 and S1 variants of concern induce neuroinflammation which is accentuated in a mouse model of Alzheimer's disease

COVID-19 and especially Long COVID are associated with severe CNS symptoms and may place persons at risk to develop long-term cognitive impairments. Here, we show that two non-infective models of SARS-CoV-2 can cross the blood-brain barrier (BBB) and induce neuroinflammation, a major mechanism underpinning CNS and cognitive impairments, even in the absence of productive infection. The viral models cross the BBB by the mechanism of adsorptive transcytosis with the sugar N-acetylglucosamine being key. The delta and omicron variants cross the BB B faster than the other variants of concern, with peripheral tissue uptake rates also differing for the variants. Neuroinflammation induced by icv injection of S1 protein was greatly enhanced in young and especially in aged SAMP8 mice, a model of Alzheimer's disease, whereas sex and obesity had little effect.

COVID-19 Biogenesis and Intracellular Transport

SARS-CoV-2 is responsible for the COVID-19 pandemic. The structure of SARS-CoV-2 and most of its proteins of have been deciphered. SARS-CoV-2 enters cells through the endocytic pathway and perforates the endosomes' membranes, and its (+) RNA appears in the cytosol. Then, SARS-CoV-2 starts to use the protein machines of host cells and their membranes for its biogenesis. SARS-CoV-2 generates a replication organelle in the reticulo-vesicular network of the zippered endoplasmic reticulum and double membrane vesicles. Then, viral proteins start to oligomerize and are subjected to budding within the ER exit sites, and its virions are passed through the Golgi complex, where the proteins are subjected to glycosylation and appear in post-Golgi carriers. After their fusion with the plasma membrane, glycosylated virions are secreted into the lumen of airways or (seemingly rarely) into the space between epithelial cells. This review focuses on the biology of SARS-CoV-2's interactions with cells and its transport within cells. Our analysis revealed a significant number of unclear points related to intracellular transport in SARS-CoV-2-infected cells.

Role of SARS-CoV-2 Spike-Protein-Induced Activation of Microglia and Mast Cells in the Pathogenesis of Neuro-COVID

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). About 45% of COVID-19 patients experience several symptoms a few months after the initial infection and develop post-acute sequelae of SARS-CoV-2 (PASC), referred to as "Long-COVID," characterized by persistent physical and mental fatigue. However, the exact pathogenetic mechanisms affecting the brain are still not well-understood. There is increasing evidence of neurovascular inflammation in the brain. However, the precise role of the neuroinflammatory response that contributes to the disease severity of COVID-19 and long COVID pathogenesis is not clearly understood. Here, we review the reports that the SARS-CoV-2 spike protein can cause blood-brain barrier (BBB) dysfunction and damage neurons either directly, or via activation of brain mast cells and microglia and the release of various neuroinflammatory molecules. Moreover, we provide recent evidence that the novel flavanol eriodictyol is particularly suited for development as an effective treatment alone or together with oleuropein and sulforaphane (ViralProtek®), all of which have potent anti-viral and anti-inflammatory actions.

SARS-CoV-2 Spike Protein Downregulates Cell Surface α7nAChR through a Helical Motif in the Spike Neck

A deficiency of the functional α7 nicotinic acetylcholine receptor (α7nAChR) impairs neuronal and immune systems. The SARS-CoV-2 spike protein (S12) facilitates virus cell entry during COVID-19 infection and can also independently disrupt cellular functions. Here, we found that S12 expression significantly downregulated surface expression of α7nAChR in mammalian cells. A helical segment of S12 (L1145-L1152) in the spike neck was identified to be responsible for the downregulation of α7nAChR, as the mutant S12AAA (L1145A-F1148A-L1152A) had minimal effects on surface α7nAChR expression. This S12 segment is homologous to the α7nAChR intracellular helical motif known for binding chaperone proteins RIC3 and Bcl-2 to promote α7nAChR surface expression. Competition from S12 for binding these proteins likely underlies suppression of surface α7nAChR. Considering the critical roles of α7nAChR in cellular functions, these findings provide a new perspective for improving mRNA vaccines and developing treatment options for certain symptoms related to long COVID.

Safety of COVID-19 Vaccines in Patients with Autoimmune Diseases, in Patients with Cardiac Issues, and in the Healthy Population

The coronavirus disease 2019 (COVID-19) has been a challenge for the whole world since the beginning of 2020, and COVID-19 vaccines were considered crucial for disease eradication. Instead of producing classic vaccines, some companies pointed to develop products that mainly function by inducing, into the host, the production of the antigenic protein of SARS-CoV-2 called Spike, injecting an instruction based on RNA or a DNA sequence. Here, we aim to give an overview of the safety profile and the actual known adverse effects of these products in relationship with their mechanism of action. We discuss the use and safety of these products in at-risk people, especially those with autoimmune diseases or with previously reported myocarditis, but also in the general population. We debate the real necessity of administering these products with unclear long-term effects to at-risk people with autoimmune conditions, as well as to healthy people, at the time of omicron variants. This, considering the existence of therapeutic interventions, much more clearly assessed at present compared to the past, and the relatively lower aggressive nature of the new viral variants.

COVID-19 Vaccination and Alcohol Consumption: Justification of Risks

Since the beginning of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, pharmaceutical companies and research institutions have been actively working to develop vaccines, and the mass roll-out of vaccinations against COVID-19 began in January 2021. At the same time, during lockdowns, the consumption of alcoholic beverages increased. During the peak of vaccination, consumption remained at high levels around the world, despite the gradual relaxation of quarantine restrictions. Two of the popular queries on search engines were whether it is safe to drink alcohol after vaccination and whether this will affect the effectiveness of vaccines. Over the past two years, many studies have been published suggesting that excessive drinking not only worsens the course of an acute respiratory distress syndrome caused by the SARS-CoV-2 virus but can also exacerbate post-COVID-19 syndrome. Despite all sorts of online speculation, there is no specific scientific data on alcohol-induced complications after vaccination in the literature. Most of the published vaccine clinical trials do not include groups of patients with a history of alcohol-use disorders. This review analyzed the well-known and new mechanisms of action of COVID-19 vaccines on the immune system and the effects of alcohol and its metabolites on these mechanisms.

Overview of the potential use of fluvoxamine for COVID-19 and long COVID

Coronavirus disease 2019 (COVID-19) has presented a serious worldwide threat to public health since its emergence in late 2019. From a safety point of view, drug repurposing has received particular attention. Several clinical studies have demonstrated that the use of fluvoxamine, a selective serotonin reuptake inhibitor with potent sigma-1 receptor agonism, in the early-stage of infection might be associated with the prevention of clinical deterioration in individuals with SARS-CoV-2 infection, although several reports have shown that a low dose of fluvoxamine may be ineffective. There is increasing evidence that SARS-CoV-2 can cross the blood–brain barrier, resulting in a number of psychiatric and neurologic symptoms in COVID-19 survivors. Importantly, about half of COVID-19 survivors experience a variety of long-term sequelae, including psychiatric and neurologic symptoms, known as long COVID. In this priority review, the author presents an overview of the potential use of fluvoxamine in the treatment of COVID-19 and long COVID.

The Metabolic Basis for Nervous System Dysfunction in Alzheimer's Disease, Parkinson's Disease, and Huntington's Disease

Disorders of metabolism affect multiple systems throughout the body but may have the greatest impact on both central and peripheral nervous systems. Currently available treatments and behavior changes for disorders that include diabetes mellitus (DM) and nervous system diseases are limited and cannot reverse the disease burden. Greater access to healthcare and a longer lifespan have led to an increased prevalence of metabolic and neurodegenerative disorders. In light of these challenges, innovative studies into the underlying disease pathways offer new treatment perspectives for Alzheimer's Disease, Parkinson's Disease, and Huntington's Disease. Metabolic disorders are intimately tied to neurodegenerative diseases and can lead to debilitating outcomes, such as multi-nervous system disease, susceptibility to viral pathogens, and long-term cognitive disability. Novel strategies that can robustly address metabolic disease and neurodegenerative disorders involve a careful consideration of cellular metabolism, programmed cell death pathways, the mechanistic target of rapamycin (mTOR) and its associated pathways of mTOR Complex 1 (mTORC1), mTOR Complex 2 (mTORC2), AMP-activated protein kinase (AMPK), growth factor signaling, and underlying risk factors such as the apolipoprotein E (APOE-ε4) gene. Yet, these complex pathways necessitate comprehensive understanding to achieve clinical outcomes that target disease susceptibility, onset, and progression.