Links between COVID-19 and Parkinson's disease/Alzheimer's disease: reciprocal impacts, medical care strategies and underlying mechanisms

Ginsenoside Rg1 ameliorates stress-exacerbated Parkinson's disease in mice by eliminating RTP801 and α-synuclein autophagic degradation obstacle

Emerging evidence shows that psychological stress promotes the progression of Parkinson's disease (PD) and the onset of dyskinesia in non-PD individuals, highlighting a potential avenue for therapeutic intervention. We previously reported that chronic restraint-induced psychological stress precipitated the onset of parkinsonism in 10-month-old transgenic mice expressing mutant human α-synuclein (αSyn) (hαSyn A53T). We refer to these as chronic stress-genetic susceptibility (CSGS) PD model mice. In this study we investigated whether ginsenoside Rg1, a principal compound in ginseng notable for soothing the mind, could alleviate PD deterioration induced by psychological stress. Ten-month-old transgenic hαSyn A53T mice were subjected to 4 weeks' restraint stress to simulate chronic stress conditions that worsen PD, meanwhile the mice were treated with Rg1 (40 mg· kg-1 ·d-1, i.g.), and followed by functional magnetic resonance imaging (fMRI) and a variety of neurobehavioral tests. We showed that treatment with Rg1 significantly alleviated both motor and non-motor symptoms associated with PD. Functional MRI revealed that Rg1 treatment enhanced connectivity between brain regions implicated in PD, and in vivo multi-channel electrophysiological assay showed improvements in dyskinesia-related electrical activity. In addition, Rg1 treatment significantly attenuated the degeneration of dopaminergic neurons and reduced the pathological aggregation of αSyn in the striatum and SNc. We revealed that Rg1 treatment selectively reduced the level of the stress-sensitive protein RTP801 in SNc under chronic stress conditions, without impacting the acute stress response. HPLC-MS/MS analysis coupled with site-directed mutation showed that Rg1 promoted the ubiquitination and subsequent degradation of RTP801 at residues K188 and K218, a process mediated by the Parkin RING2 domain. Utilizing αSyn A53T+; RTP801-/- mice, we confirmed the critical role of RTP801 in stress-aggravated PD and its necessity for Rg1's protective effects. Moreover, Rg1 alleviated obstacles in αSyn autophagic degradation by ameliorating the RTP801-TXNIP-mediated deficiency of ATP13A2. Collectively, our results suggest that ginsenoside Rg1 holds promise as a therapeutic choice for treating PD-sensitive individuals who especially experience high levels of stress and self-imposed expectations.

Resting-state neural dynamics changes in older adults with post-COVID syndrome and the modulatory effect of cognitive training and sex

Post-COVID syndrome manifests with numerous neurological and cognitive symptoms, the precise origins of which are still not fully understood. As females and older adults are more susceptible to developing this condition, our study aimed to investigate how post-COVID syndrome alters intrinsic brain dynamics in older adults and whether biological sex and cognitive training might modulate these effects, with a specific focus on older females. The participants, aged between 60 and 75 years, were divided into three experimental groups: healthy old female, post-COVID old female and post-COVID old male. They underwent an adaptive task-switching training protocol. We analysed multiscale entropy and spectral power density of resting-state EEG data collected before and after the training to assess neural signal complexity and oscillatory power, respectively. We found no difference between post-COVID females and males before training, indicating that post-COVID similarly affected both sexes. However, cognitive training was effective only in post-COVID females and not in males, by modulating local neural processing capacity. This improvement was further evidenced by comparing healthy and post-COVID females, wherein the latter group showed increased finer timescale entropy (1-30 ms) and higher frequency band power (11-40 Hz) before training, but these differences disappeared following cognitive training. Our results suggest that in older adults with post-COVID syndrome, there is a pronounced shift from more global to local neural processing, potentially contributing to accelerated neural aging in this condition. However, cognitive training seems to offer a promising intervention method for modulating these changes in brain dynamics, especially among females.

Unearthing the Potential Therapeutic Effects of Oxyresveratrol Based on Intrinsic Links between Pharmacological Effects: Implications for the Gut-Liver-Brain Axis

Oxyresveratrol is a stilbene compound with a simple chemical structure and various therapeutic potentials. This study summarized and analyzed the multiple pharmacological effects and mechanisms of oxyresveratrol, identifying its prominent performance in neuroprotection, hepatoprotection, and anti-inflammatory activities in the intestines. By integrating the pharmacological effects of oxyresveratrol with insights from the network pharmacology and molecular docking of its interactions with targets linked to gut-liver-brain axis disorders, it has been shown that oxyresveratrol may hold promise for the treatment of gut-liver-brain axis-related disorders. The synergistic effect between various mechanisms has inspired further research and the development of oxyresveratrol's application value.

Ecofriendly micellar mediated spectrofluorimetric method for ultrasensitive quantification of the antiparkinsonian drug safinamide in pharmaceutical formulation and spiked human plasma

A novel, highly sensitive and eco-friendly micellar-mediated spectrofluorimetric method was developed and validated for the determination of the novel antiparkinsonian drug safinamide mesylate in the presence of its related precursor impurity, 4-hydroxybenzaldehyde. The proposed approach relies on increasing the inherent fluorescence emission at 296 nm of safinamide, by forming hydrogen bonds between the mentioned drug and sodium dodecyl sulfate in the micellar system using 0.1 N HCl as a solvent, following excitation at 226 nm. A thorough investigation was conducted into the experimental factors affecting spectrofluorimetric behavior of the studied drug. A linearity plot of safinamide over the concentration range of 10.0-1000.0 ng/mL against the relative fluorescence intensities was established. The proposed method demonstrated excellent sensitivity down to the nano-gram level with detection and quantitation limits of 1.91 and 5.79 ng/mL, respectively. The studied drug was effectively determined in Parkimedine® Tablets. Furthermore, the proposed method allows for ultrasensitive quantification of safinamide in spiked human plasma, with satisfactory percentage recovery (98.97-102.28%). Additionally, the greenness assessment using the advanced green certificate classification approach, the complementary green analytical procedure index (Complex-GAPI), and the analytical GREEness metric approach (AGREE), along with the practicality check using the Blue Applicability Grade Index in addition to the all-inclusive overall whiteness evaluation using the RGB-12 model were carried out. The outcomes demonstrated the effectiveness and whiteness of the proposed technique. Clearly, the suggested approach has the advantages of being simple, requiring no pretreatment steps, and relying solely on direct measuring procedures.

Case report: Dementia sensitivity to altitude changes and effective treatment with hyperbaric air and glutathione precursors

A 78-year-old man with dementia experienced waxing and waning of symptoms with changes in altitude as he traveled from his home in the Rocky Mountains to lower elevations and back. To replicate the improvement in his symptoms with travel to lower elevations (higher pressure), the patient was treated with a near-identical repressurization in a hyperbaric chamber using compressed air. With four 1-h treatments at 1.3 Atmospheres Absolute (ATA) and concurrent administration of low-dose oral glutathione amino acid precursors, he recovered speech and showed improvement in activities of daily living. Regional broadcast media had documented his novel recovery. Nosocomial COVID-19 and withdrawal of hyperbaric air therapy led to patient demise 7 months after initiation of treatment. It is theorized that hyperbaric air therapy stimulated mitochondrial biochemical and physical changes, which led to clinical improvement.

Persistent Neurological Deficits in Mouse PASC Reveal Antiviral Drug Limitations

Post-Acute Sequelae of COVID-19 (PASC) encompasses persistent neurological symptoms, including olfactory and autonomic dysfunction. Here, we report chronic neurological dysfunction in mice infected with a virulent mouse-adapted SARS-CoV-2 that does not infect the brain. Long after recovery from nasal infection, we observed loss of tyrosine hydroxylase (TH) expression in olfactory bulb glomeruli and neurotransmitter levels in the substantia nigra (SN) persisted. Vulnerability of dopaminergic neurons in these brain areas was accompanied by increased levels of proinflammatory cytokines and neurobehavioral changes. RNAseq analysis unveiled persistent microglia activation, as found in human neurodegenerative diseases. Early treatment with antivirals (nirmatrelvir and molnupiravir) reduced virus titers and lung inflammation but failed to prevent neurological abnormalities, as observed in patients. Together these results show that chronic deficiencies in neuronal function in SARS-CoV-2-infected mice are not directly linked to ongoing olfactory epithelium dysfunction. Rather, they bear similarity with neurodegenerative disease, the vulnerability of which is exacerbated by chronic inflammation.

Molecular cross-talk between long COVID-19 and Alzheimer's disease

The long COVID (coronavirus disease), a multisystemic condition following severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, is one of the widespread problems. Some of its symptoms affect the nervous system and resemble symptoms of Alzheimer's disease (AD)-a neurodegenerative condition caused by the accumulation of amyloid beta and hyperphosphorylation of tau proteins. Multiple studies have found dependence between these two conditions. Patients with Alzheimer's disease have a greater risk of SARS-CoV-2 infection due to increased levels of angiotensin-converting enzyme 2 (ACE2), and the infection itself promotes amyloid beta generation which enhances the risk of AD. Also, the molecular pathways are alike-misregulations in folate-mediated one-carbon metabolism, a deficit of Cq10, and disease-associated microglia. Medical imaging in both of these diseases shows a decrease in the volume of gray matter, global brain size reduction, and hypometabolism in the parahippocampal gyrus, thalamus, and cingulate cortex. In some studies, a similar approach to applied medication can be seen, including the use of amino adamantanes and phenolic compounds of rosemary. The significance of these connections and their possible application in medical practice still needs further study but there is a possibility that they will help to better understand long COVID.

SARS-CoV-2 Spike Protein S1 Domain Accelerates α-Synuclein Phosphorylation and Aggregation in Cellular Models of Synucleinopathy

The 2019 novel coronavirus disease (COVID-19) is an infectious disease that began to spread globally since 2019. Some COVID-19 patients have neurological complications, such as olfactory disorders and movement disorders, which coincide with the symptoms of Parkinson's disease (PD). Increasing imaging and autopsy evidence supports that the density of dopaminergic neurons in the nigrostriatal pathway is damaged in some COVID-19 patients. However, the underlying mechanism that causes PD-like symptoms remains unclear. PD is an age-related neurodegenerative disease with Lewy bodies (LBs) as its histopathologic feature. The main component of LBs is abnormally aggregated α-synuclein (α-syn). The prion-like propagation of α-syn aggregates plays a key role in the onset and progression of PD. The spike protein (S protein) of SARS-CoV-2 is a heparin-binding protein that mediates the entry of the virus into host cells. Here we found that the S1 domain interacts with α-syn and promotes α-syn aggregation. The S1 domain induces mitochondrial dysfunction, oxidative stress, and cytotoxicity. The S1-seeded α-syn fibrils show enhanced seeding activity and induce synaptic damage and cytotoxicity. Thus, the S1 domain of SARS-CoV-2 promotes the aggregation of α-syn in the cellular model of synucleinopathy and may contribute to the pathogenesis of PD.

Protein-protein interactions regulating α-synuclein pathology

Parkinson's disease (PD) is a neurodegenerative disease characterized by the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and the formation of Lewy bodies (LBs). The main proteinaceous component of LBs is aggregated α-synuclein (α-syn). However, the mechanisms underlying α-syn aggregation are not yet fully understood. Converging lines of evidence indicate that, under certain pathological conditions, various proteins can interact with α-syn and regulate its aggregation. Understanding these protein-protein interactions is crucial for unraveling the molecular mechanisms contributing to PD pathogenesis. In this review we provide an overview of the current knowledge on protein-protein interactions that regulate α-syn aggregation. Additionally, we briefly summarize the methods used to investigate the influence of protein-protein interactions on α-syn aggregation and propagation.

Life and disease status of patients with Parkinson's disease during and after zero-COVID in China: an online survey

BACKGROUND

Little is known about the impact of the COVID-19 pandemic on patients with Parkinson's disease (PD) at different stages of the pandemic. This study aims to assess the lives and disease status of PD patients during the zero-COVID policy period and after ending the zero-COVID policy.

METHODS

This multicenter cross-sectional study included two online surveys among PD patients in China, from May 30 to June 30 in 2022 and from January 1 to February 28 in 2023, respectively. The survey questionnaires contained four sections: (1) status of COVID-19 infection; (2) impact on motor and non-motor symptoms; (3) impact on daily and social lives; and (4) impact on PD disease management.

RESULTS

A total of 1764 PD patients participated in the first online survey, with 200 patients having lockdown experience and 3 being COVID-19-positive (0.17%). In addition, 537 patients participated in the second online survey, with 467 patients having COVID-19 infection (86.96%). (1) During zero-COVID, all of the COVID-19-positive patients had mild symptoms of COVID-19 and no death was reported. After zero-COVID, 83.51% of the COVID-19-positive patients had mild symptoms. The overall death rate and inpatient mortality rate of COVID-19-positive PD patients were 3.21% and 30.00%, respectively. (2) During zero-COVID, 49.43% of PD patients reported worsening of PD-related symptoms (lockdown vs. unlockdown, 60.50% vs. 48.02%, P = 0.0009). After zero-COVID, 54.93% of PD patients reported worsening of PD-related symptoms (COVID-19 positive vs. COVID-19 negative, 59.31% vs. 25.71%, P < 0.0001). (3) During zero-COVID, 62.36% of patients felt worried, and 'limited outdoor activities' (55.39%) was the top reason for mental health problems. After zero-COVID, 59.03% of patients felt worried, with 'poor health' (58.10%) being the top reason. The PD patients tended to change their daily activities from offline to online, and their economic and caregiver burdens increased both during and after zero-COVID. (4) Most PD patients would like to choose online rehabilitation during (69.56%) and after zero-COVID (69.27%). The demand for online medication purchasing also increased during (47.00%) and after zero-COVID (26.63%).

CONCLUSIONS

The COVID-19 pandemic aggravated the motor and non-motor symptoms of PD patients either during or after the zero-COVID policy period. The PD patients also experienced prominent mental health problems, changes in daily activities, and increases in economic and caregiver burdens. The COVID-19 pandemic has changed ways of PD management with increasing demands for online medication purchasing and rehabilitation.

Unraveling the brain's response to COVID-19: How SARS-CoV-2 afflicts dopaminergic neurons

COVID-19 patients often display dysfunctions of the nervous system, indicating an effect of SARS-CoV-2 on neural cells. Yang et al. now show that human stem-cell-derived dopaminergic neurons are susceptible to SARS-CoV-2, triggering inflammation and senescence. The study further identifies three FDA-approved drugs capable of reversing these cellular phenotypes.

Update on Central Nervous System Effects of the Intersection of HIV-1 and SARS-CoV-2

PURPOSE OF REVIEW

Research has shown myriad neurologic and mental health manifestations during the acute and subsequent stages of COVID-19 in people with HIV (PWH). This review summarizes the updates on central nervous system (CNS) outcomes following SARS-CoV-2 infection in PWH and highlight the existing knowledge gaps in this area.

RECENT FINDINGS

Studies leveraging electronic record systems have highlighted the excess risk of developing acute and lingering neurological complications of COVID-19 in PWH compared to people without HIV (PWoH). However, there is a notable scarcity of neuroimaging as well as blood and cerebrospinal fluid (CSF) marker studies that can confirm the potential synergy between these two infections, particularly in PWH receiving suppressive antiretroviral therapy. Considering the unclear potential interaction between SARS-CoV-2 and HIV, clinicians should remain vigilant regarding new-onset or worsening neurological symptoms in PWH following COVID-19, as they could be linked to either infection.

Evaluation and treatment approaches for neurological post-acute sequelae of COVID-19: A consensus statement and scoping review from the global COVID-19 neuro research coalition

Post-acute neurological sequelae of COVID-19 affect millions of people worldwide, yet little data is available to guide treatment strategies for the most common symptoms. We conducted a scoping review of PubMed/Medline from 1/1/2020-4/1/2023 to identify studies addressing diagnosis and treatment of the most common post-acute neurological sequelae of COVID-19 including: cognitive impairment, sleep disorders, headache, dizziness/lightheadedness, fatigue, weakness, numbness/pain, anxiety, depression and post-traumatic stress disorder. Utilizing the available literature and international disease-specific society guidelines, we constructed symptom-based differential diagnoses, evaluation and management paradigms. This pragmatic, evidence-based consensus document may serve as a guide for a holistic approach to post-COVID neurological care and will complement future clinical trials by outlining best practices in the evaluation and treatment of post-acute neurological signs/symptoms.

COVID-19 and Alzheimer's Disease Share Common Neurological and Ophthalmological Manifestations: A Bidirectional Risk in the Post-Pandemic Future

A growing body of evidence indicates that a neuropathological cross-talk takes place between the coronavirus disease 2019 (COVID-19) -the pandemic severe pneumonia that has had a tremendous impact on the global economy and health since three years after its outbreak in December 2019- and Alzheimer's Disease (AD), the leading cause of dementia among human beings, reaching 139 million by the year 2050. Even though COVID-19 is a primary respiratory disease, its causative agent, the so-called Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), is also endowed with high neuro-invasive potential (Neurocovid). The neurological complications of COVID-19, resulting from the direct viral entry into the Central Nervous System (CNS) and/or indirect systemic inflammation and dysregulated activation of immune response, encompass memory decline and anosmia which are typically associated with AD symptomatology. In addition, patients diagnosed with AD are more vulnerable to SARS-CoV-2 infection and are inclined to more severe clinical outcomes. In the present review, we better elucidate the intimate connection between COVID-19 and AD by summarizing the involved risk factors/targets and the underlying biological mechanisms shared by these two disorders with a particular focus on the Angiotensin-Converting Enzyme 2 (ACE2) receptor, APOlipoprotein E (APOE), aging, neuroinflammation and cellular pathways associated with the Amyloid Precursor Protein (APP)/Amyloid beta (Aβ) and tau neuropathologies. Finally, the involvement of ophthalmological manifestations, including vitreo-retinal abnormalities and visual deficits, in both COVID-19 and AD are also discussed. Understanding the common physiopathological aspects linking COVID-19 and AD will pave the way to novel management and diagnostic/therapeutic approaches to cope with them in the post-pandemic future.

A large survey on COVID-19 vaccination in patients with Parkinson's disease and healthy population

BACKGROUND

A full rollout of COVID-19 vaccination offers the most promising prospect of bringing the pandemic to an end. This study aimed to compare the coverage, safety, and confidence of COVID-19 vaccination between patients with Parkinson's disease (PD) and healthy individuals so as to give suggestions for future immunization programs.

METHODS

A web-based, nationwide, multicenter survey was carried out in China from 2021 to 2022. The age and sex-standardized vaccination rate was calculated. Multivariate stepwise logistic regression models were used to estimate the influencing factors of vaccination status. We also investigated vaccination safety, willingness, confidence, and reasons for hesitancy with some ad hoc questions.

RESULTS

A total of 962 PD patients and 1208 healthy individuals participated in this survey with a vaccination rate of 71.1% vs 94.4% respectively. PD patients living in first-tier cities, with comorbidities, experiencing unstable PD with a longer course and levodopa use were less likely to get vaccinated, while healthy individuals living in first-tier cities and feeling physically poor exhibited a lower vaccination rate. For PD patients, concern about the adverse impact on existing illness and disagreement from doctors were the most common reasons for vaccination hesitancy. Whereas, no evidence was present that they experienced any local or systematic adverse events more frequently or seriously than healthy individuals, or their state of PD and comorbidities was seriously exacerbated after vaccination. A prominent transition from a little concerned to unconcerned about the security and efficacy of vaccines was evident among both two populations from pre-vaccination to post-vaccination.

CONCLUSIONS

The COVID-19 vaccination rate was remarkably lower in PD patients than healthy individuals in China. The approved vaccines have shown an acceptable safety profile. Our findings would offer a reference to guide future clinical decision-making of COVID-19 vaccination and improve the immunization management of PD patients.

COVID-19 in Relation to Alzheimer's Disease: Mendelian Randomization Analyses Add to Multiple Lines of Evidence

The potential link between COVID-19 and Alzheimer's disease (AD) has been an intriguing topic in the global pandemic. Whether the susceptibility and severity of COVID-19 affects the onset and progression of AD is of great concern. Clinical studies suggested an increased risk of AD occurrence or cognitive deficit after COVID-19. Basic research found that severe COVID-19 induced changes resembling AD. Evidence synthesis should always take into account diverse study designs, both traditional and novel. The recent study by Ding et al. aimed to investigate the association of COVID-19 with AD using a non-overlapping two-sample Mendelian randomization analysis.