Neurodegenerative Processes Research Articles

A rapid review of differences in cerebrospinal neurofilament light levels in clinical subtypes of progressive multiple sclerosis.

Multiple sclerosis (MS) is divided into three clinical phenotypes: relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and primary progressive MS (PPMS). It is unknown to what extent SPMS and PPMS pathophysiology share inflammatory or neurodegenerative pathological processes. Cerebrospinal (CSF) neurofilament light (NfL) has been broadly studied in different MS phenotypes and is a candidate biomarker for comparing MS subtypes. Are CSF NfL levels different among clinical subtypes of progressive MS? A search strategy identifying original research investigating fluid neurodegenerative biomarkers in progressive forms of MS between 2010 and 2022 was applied to Medline. Identified articles underwent title and abstract screen and full text review against pre-specified criteria. Data abstraction was limited to studies that measured NfL levels in the CSF. Reported statistical comparisons of NfL levels between clinical phenotypes were abstracted qualitatively. 18 studies that focused on investigating direct comparisons of CSF NfL from people with MS were included in the final report. We found NfL levels were typically reported to be higher in relapsing and progressive MS compared to healthy controls. Notably, higher NfL levels were not clearly associated with progressive MS subtypes when compared to relapsing MS, and there was no observed difference in NfL levels between PPMS and SPMS in articles that separately assessed these phenotypes. CSF NfL levels distinguish individuals with MS from healthy controls but do not differentiate MS subtypes. Broad biological phenotyping is needed to overcome limitations of current clinical phenotyping and improve biomarker translatability to decision-making in the clinic.

Glial cell line-derived Neurotrophic factor GDNF Gene Expression Analysis: Unveiling Neuronal Protection Mechanisms in Alzheimer's Disease Management

Background: Alzheimer's disease (AD), accounting for a substantial proportion of dementia cases, presents a formidable challenge to healthcare systems worldwide. The pathogenesis of AD in patients with Type II Diabetes Mellitus (DM) is particularly complex due to the interplay of metabolic and neurodegenerative processes. Understanding the role of Glial Cell Line-Derived Neurotrophic Factor (GDNF) in this context is vital for elucidating potential therapeutic targets. Objective: This study aimed to assess the expression levels of the GDNF gene in patients with Type II DM and dementia and to explore the correlation between GDNF expression and cognitive function. Methods: Blood samples were collected from 88 diabetic patients with dementia and 12 healthy controls. GDNF serum levels were measured using Chemiluminescent Immunoassay (CLIA), and genomic DNA was isolated for expression analysis via RT-qPCR. Cognitive function was evaluated using the Mini Mental State Examination (MMSE). Statistical analysis, including t-tests and one-way ANOVA, was performed using Graphpad Prism version 9.0. Results: Diabetic dementia patients exhibited significantly lower GDNF serum levels (4.37±1.38 µg/mL) compared to healthy controls (11.37±3.64 µg/mL, p=0.014). MMSE scores were also lower in the patient group (12.26±4.56) than in controls (24.1±3.12, p=0.009). RT-qPCR results showed a relative fold decrease in GDNF expression of 4.1 in dementia patients, indicating underexpression of the GDNF gene.1 Conclusion: The reduced expression of GDNF in patients with Type II DM and dementia underscores its potential as a biomarker for cognitive impairment. These findings pave the way for further research into GDNF-targeted therapies, which could prove pivotal in early detection and management of dementia in diabetic populations.

Mitophagy Upregulation Occurs Early in the Neurodegenerative Process Mediated by α-Synuclein.

Parkinson's disease (PD) is a progressive neurogenerative movement disorder characterized by dopaminergic cell death within the substantia nigra pars compacta (SNpc) due to the aggregation-prone protein α-synuclein. Accumulation of α-synuclein is implicated in mitochondrial dysfunction and disruption of the autophagic turnover of mitochondria, or mitophagy, which is an essential quality control mechanism proposed to preserve mitochondrial fidelity in response to aging and stress. Yet, the precise relationship between α-synuclein accumulation, mitochondrial autophagy, and dopaminergic cell loss remains unresolved. Here, we determine the kinetics of α-synuclein overexpression and mitophagy using the pH-sensitive fluorescent mito-QC reporter. We find that overexpression of mutant A53T α-synuclein in either human SH-SY5Y cells or rat primary cortical neurons induces mitophagy. Moreover, the accumulation of mutant A53T α-synuclein in the SNpc of rats results in mitophagy dysregulation that precedes the onset of dopaminergic neurodegeneration. This study reveals a role for mutant A53T α-synuclein in inducing mitochondrial dysfunction, which may be an early event contributing to neurodegeneration.

Deficits in force production during multifinger tasks demarcate cognitive dysfunction

BackgroundThe multifinger force deficit (MFFD) is the decline in force generated by each finger as the number of fingers contributing to an action is increased. It has been shown to associate with cognitive status.AimsThe aim was to establish whether a particularly challenging form of multifinger grip dynamometry, that provides minimal tactile feedback via cutaneous receptors and requires active compensation for reaction forces, will yield an MFFD that is more sensitive to cognitive status.MethodsAssociations between measures of motor function, and cognitive status (Montreal Cognitive Assessment [MoCA]) and latent components of cognitive function (derived from 11 tests using principal component analysis), were estimated cross-sectionally using generalized partial rank correlations. The participants (n = 62) were community dwelling, aged 65–87.ResultsApproximately half the participants were unable to complete the dynamometry task successfully. Cognitive status demarcated individuals who could perform the task from those who could not. Among those who complied with the task requirements, the MFFD was negatively correlated with MoCA scores—those with the highest MoCA scores tended to exhibit the smallest deficits, and vice versa. There were corresponding associations with latent components of cognitive function.DiscussionThe results support the view that neurodegenerative processes that are a feature of normal and pathological aging exert corresponding effects on expressions of motor coordination—in multifinger tasks, and cognitive sufficiency, due to their dependence on shared neural systems.ConclusionsThe outcomes add weight to the assertion that deficits in force production during multifinger tasks are sensitive to cognitive dysfunction.

Early altered directionality of resting brain network state transitions in the TgF344-AD rat model of Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disease resulting in memory loss and cognitive decline. Synaptic dysfunction is an early hallmark of the disease whose effects on whole-brain functional architecture can be identified using resting-state functional MRI (rsfMRI). Insights into mechanisms of early, whole-brain network alterations can help our understanding of the functional impact of AD's pathophysiology. Here, we obtained rsfMRI data in the TgF344-AD rat model at the pre- and early-plaque stages. This model recapitulates the major pathological and behavioral hallmarks of AD. We used co-activation pattern (CAP) analysis to investigate if and how the dynamic organization of intrinsic brain functional networks states, undetectable by earlier methods, is altered at these early stages. We identified and characterized six intrinsic brain states as CAPs, their spatial and temporal features, and the transitions between the different states. At the pre-plaque stage, the TgF344-AD rats showed reduced co-activation of hub regions in the CAPs corresponding to the default mode-like and lateral cortical network. Default mode-like network activity segregated into two distinct brain states, with one state characterized by high co-activation of the basal forebrain. This basal forebrain co-activation was reduced in TgF344-AD animals mainly at the pre-plaque stage. Brain state transition probabilities were altered at the pre-plaque stage between states involving the default mode-like network, lateral cortical network, and basal forebrain regions. Additionally, while the directionality preference in the network-state transitions observed in the wild-type animals at the pre-plaque stage had diminished at the early-plaque stage, TgF344-AD animals continued to show directionality preference at both stages. Our study enhances the understanding of intrinsic brain state dynamics and how they are impacted at the early stages of AD, providing a nuanced characterization of the early, functional impact of the disease's neurodegenerative process.

Mild cognitive impairment in Parkinson's disease: current view

Parkinson's disease (PD), the most common motor movement disorder and second most common neurodegenerative disorder after Alzheimer's disease (AD), is often preceded by a period of mild cognitive impairment (MCI), which is associated with impairment of a variety of cognitive domains including executive function, attention, visuospatial abilities and memory. MCI, a risk factor for developing dementia, affects around 30% of de novo PD patients and can increase to 75% after more than 10 years. While 30–40% remain in the MCI state, up to 60% will convert to dementia. Characteristic findings are slowing of EEG rhythms, frontotemporal hypoperfusion, decreased functional connectivity in the default mode and attentional networks, prefrontal and basal-ganglia-cortical circuits, which often manifests prior to clinical symptoms and overt brain atrophy. The heterogeneity of cognitive phenotypes suggests that a common neurodegenerative process affects multiple functional neuronal networks and neuromodulatory systems that may be superimposed by Lewy body and Alzheimer's-related or other co-pathologies. Sparse neuropathological data for PD-MCI revealed a heterogenous picture with various morphological changes similar to MCI in other diseases. This review highlights the essential epidemiological, clinical, neuroimaging and morphological changes in PD-MCI, available biomarkers, and discusses the heterogenous pathobiological mechanisms involved in its development. In view of its complex pathogenesis, well-designed longitudinal clinico-pathological studies are warranted to clarify the alterations leading to MCI in PD, which may be supported by fluid and neuroimaging biomarkers as a basis for early diagnosis and future adequate treatment modalities of this debilitating disorder.

Spinocerebellar Ataxia Type 3 Pathophysiology-Implications for Translational Research and Clinical Studies.

The spinocerebellar ataxias (SCA) comprise a group of inherited neurodegenerative diseases. Machado-Joseph Disease (MJD) or spinocerebellar ataxia 3 (SCA3) is the most common autosomal dominant form, caused by the expansion of CAG repeats within the ataxin-3 (ATXN3) gene. This mutation results in the expression of an abnormal protein containing long polyglutamine (polyQ) stretches that confers a toxic gain of function and leads to misfolding and aggregation of ATXN3 in neurons. As a result of the neurodegenerative process, SCA3 patients are severely disabled and die prematurely. Several screening approaches, e.g., druggable genome-wide and drug library screenings have been performed, focussing on the reduction in stably overexpressed ATXN3(polyQ) protein and improvement in the resultant toxicity. Transgenic overexpression models of toxic ATXN3, however, missed potential modulators of endogenous ATXN3 regulation. In another approach to identify modifiers of endogenous ATXN3 expression using a CRISPR/Cas9-modified SK-N-SH wild-type cell line with a GFP-T2A-luciferase (LUC) cassette under the control of the endogenous ATXN3 promotor, four statins were identified as potential activators of expression. We here provide an overview of the high throughput screening approaches yet performed to find compounds or genomic modifiers of ATXN3(polyQ) toxicity in different SCA3 model organisms and cell lines to ameliorate and halt SCA3 progression in patients. Furthermore, the putative role of cholesterol in neurodegenerative diseases (NDDs) in general and SCA3 in particular is discussed.

Intranasal Administration of GRP78 Protein (HSPA5) Confers Neuroprotection in a Lactacystin-Induced Rat Model of Parkinson's Disease.

The accumulation of misfolded and aggregated α-synuclein can trigger endoplasmic reticulum (ER) stress and the unfolded protein response (UPR), leading to apoptotic cell death in patients with Parkinson's disease (PD). As the major ER chaperone, glucose-regulated protein 78 (GRP78/BiP/HSPA5) plays a key role in UPR regulation. GRP78 overexpression can modulate the UPR, block apoptosis, and promote the survival of nigral dopamine neurons in a rat model of α-synuclein pathology. Here, we explore the therapeutic potential of intranasal exogenous GRP78 for preventing or slowing PD-like neurodegeneration in a lactacystin-induced rat model. We show that intranasally-administered GRP78 rapidly enters the substantia nigra pars compacta (SNpc) and other afflicted brain regions. It is then internalized by neurons and microglia, preventing the development of the neurodegenerative process in the nigrostriatal system. Lactacystin-induced disturbances, such as the abnormal accumulation of phosphorylated pS129-α-synuclein and activation of the pro-apoptotic GRP78/PERK/eIF2α/CHOP/caspase-3,9 signaling pathway of the UPR, are substantially reversed upon GRP78 administration. Moreover, exogenous GRP78 inhibits both microglia activation and the production of proinflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), via the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway in model animals. The neuroprotective and anti-inflammatory potential of exogenous GRP78 may inform the development of effective therapeutic agents for PD and other synucleinopathies.

Bridging Gaps in Sleep Health and Dementia: Linking Sleep Disorders and Neurocognitive Health

There is growing evidence of a bidirectional relationship between sleep disturbances and disorders and cognitive function in normal and pathological aging. Not only do sleep disturbances and disorders predict and contribute to a decline in neurocognitive function, but neurodegenerative disorders impair sleep. Furthermore, sleep and rhythm disturbances may be some of the earliest symptoms of neurodegenerative disorders such as MCI, AD, and Parkinson's disease. However, the potential effects of improving sleep on mitigating decline in cognitive function are still unknown. While some of the classes of pharmaceutical agents may improve subjective sleep, they have variable effects on sleep oscillations and cognition. The effects of other approaches, such as cognitive behavioral therapy and neuromodulation, on neurodegenerative processes are not yet fully understood.The goal of this session and panel is to educate participants about changes in sleep patterns and sleep oscillations that occur in aging and neurodegenerative disorders, mechanisms for associations between poor sleep and sleep disorders and cognitive decline and contribution to dementia, and the potential benefits of identifying and treating sleep disorders in older adults who may be at risk of developing dementia. In addition, the discussion will highlight the lack of standardized care pathways for diagnosing and treating sleep problems in older adults.

Hyperoxia and brain: the link between necessity and injury from a molecular perspective.

Oxygen (O2) supplementation is commonly used to treat hypoxia in patients with respiratory failure. However, indiscriminate use can lead to hyperoxia, a condition detrimental to living tissues, particularly the brain. The brain is sensitive to reactive oxygen species (ROS) and inflammation caused by high concentrations of O2, which can result in brain damage and mitochondrial dysfunction, common features of neurodegenerative disorders. Hyperoxia leads to increased production of ROS, causing oxidative stress, an imbalance between oxidants and antioxidants, which can damage tissues. The brain is particularly vulnerable to oxidative stress due to its lipid composition, high O2 consumption rate, and low levels of antioxidant enzymes. Moreover, hyperoxia can cause vasoconstriction and decreased O2 supply to the brain, posing a challenge to redox balance and neurodegenerative processes. Studies have shown that the severity of hyperoxia-induced brain damage varies with inspired O2 concentration and duration of exposure. Therefore, careful evaluation of the balance between benefits and risks of O2 supplementation, especially in clinical settings, is crucial.

Assessment of Stx-1A gene polymorphism (rs1569061) in relation to the development of multiple sclerosis in Egyptian patients

Multiple sclerosis (MS) is a multifactorial polygenic disease; results from autoimmune and neurodegenerative processes which lead to multifocal lesions of the central nervous system. Axonal degeneration was found to be prominent in the inflammation period of MS and contribute to the progression of disability. Soluble N-ethylmaleimide sensitive factor attachment receptor (SNARE) complex plays a vital role in the release of neurotransmitter by synaptic vesicle fusion. Stx-1A protein (Stx-1A), a major component of the SNARE complex, is widely expressed in brain tissue. This study intended to evaluate the prevalence of the Stx-1A gene polymorphism (rs1569061) in the Egyptian population with MS and to investigate its association with various clinical factors. This study included 65 adult Egyptian MS patients and 35 age- and sex-matched normal control subjects. Diagnosis of MS was made by an experienced neurologist according to revised McDonald criteria. All Patients underwent full history taking, included Age of onset of MS, disease duration, disease course and degree of disability according to the Expanded Disability Status Scale (EDSS) and family history of neurological diseases. Stx-1A gene polymorphism (rs1569061) genotyping was performed by TaqMan assay based quantitative real time (qPCR) and verified by sanger sequencer. Genotype and allele frequencies of (rs1569061) did not differ significantly between case and control groups. No difference was detected when comparing the genotype frequency and the allele frequency to different disease parameters. Discrepancy of the minor allele frequency (MAF) of Stx-1A gene (rs1569061) between different populations was noted. In conclusion, our study in Stx-1A gene polymorphism (rs1569061) and MS showed that no difference between the patient and control as regards gene frequency and allele frequency. Predicting no association between the studied polymorphism and MS in the Egyptian population. However, discrepancy between different population was noted as regards the MAF for Stx-1A gene (rs1569061).

Long Term Cognitive Impact of Electroconvulsive Therapy in Patients with Early Frontotemporal Lobar Degeneration

Frontotemporal lobar degeneration (FTLD) is the umbrella term to describe several overlapping neurodegenerative syndromes including progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and behavioral variant frontotemporal dementia (bvFTD). Most patients with FTLD present initially with psychiatric symptoms such as apathy, depressed mood, and fatigue (often with a mild Parkinsonism) that almost always prove refractory to medication interventions and psychotherapy. Some patients may be recommended for electroconvulsive therapy (ECT), which in our clinical experience, is not effective and potentially harmful. Electroconvulsive therapy has a well-known risk of cognitive impairment and memory loss but the full impact and long-term effects of this intervention are not well studied in individuals with neurodegenerative disease.For this clinical case presentation, we will discuss the case of a 69-year-old left-handed female who presented to our memory and cognitive disorders clinic after several years of apathy, depressed mood, and irritability. Due to the refractory nature of her treatment, she had undergone several rounds to ECT; an intervention that did not help her behavioral symptoms and appeared to accelerate her cognitive decline. Volumetric MRI and neuropsychological testing confirmed the diagnosis of corticobasal degeneration, a FTLD spectrum disease. Implications for course and management of this patient's neurodegenerative process, particularly neuropsychiatric sequelae, will be discussed.

Hippocampus under Pressure: Molecular Mechanisms of Development of Cognitive Impairments in SHR Rats.

Data from clinical trials and animal experiments demonstrate relationship between chronic hypertension and development of cognitive impairments. Here, we review structural and biochemical alterations in the hippocampus of SHR rats with genetic hypertension, which are used as a model of essential hypertension and vascular dementia. In addition to hypertension, dysfunction of the hypothalamic-pituitary-adrenal system observed in SHR rats already at an early age may be a key factor of changes in the hippocampus at the structural and molecular levels. Global changes at the body level, such as hypertension and neurohumoral dysfunction, are associated with the development of vascular pathology and impairment of the blood-brain barrier. Changes in multiple biochemical glucocorticoid-dependent processes in the hippocampus, including dysfunction of steroid hormones receptors, impairments of neurotransmitter systems, BDNF deficiency, oxidative stress, and neuroinflammation are accompanied by the structural alterations, such as cellular signs of neuroinflammation micro- and astrogliosis, impairments of neurogenesis in the subgranular neurogenic zone, and neurodegenerative processes at the level of synapses, axons, and dendrites up to the death of neurons. The consequence of this is dysfunction of hippocampus, a key structure of the limbic system necessary for cognitive functions. Taking into account the available results at various levels starting from the body and brain structure (hippocampus) levels to molecular one, we can confirm translational validity of SHR rats for modeling mechanisms of vascular dementia.

KCNJ2 inhibition mitigates mechanical injury in a human brain organoid model of traumatic brain injury

Traumatic brain injury (TBI) strongly correlates with neurodegenerative disease. However, it remains unclear which neurodegenerative mechanisms are intrinsic to the brain and which strategies most potently mitigate these processes. We developed a high-intensity ultrasound platform to inflict mechanical injury to induced pluripotent stem cell (iPSC)-derived cortical organoids. Mechanically injured organoids elicit classic hallmarks of TBI, including neuronal death, tau phosphorylation, and TDP-43 nuclear egress. We found that deep-layer neurons were particularly vulnerable to injury and that TDP-43 proteinopathy promotes cell death. Injured organoids derived from C9ORF72 amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) patients displayed exacerbated TDP-43 dysfunction. Using genome-wide CRISPR interference screening, we identified a mechanosensory channel, KCNJ2, whose inhibition potently mitigated neurodegenerative processes invitro and invivo, including in C9ORF72 ALS/FTD organoids. Thus, targeting KCNJ2 may reduce acute neuronal death after brain injury, and we present a scalable, genetically flexible cerebral organoid model that may enable the identification of additional modifiers of mechanical stress.

The Role of Alcohol Use Disorders in the Development and Progression of Dementia

IntroductionIn recent years, there has been an increase in interest and research into the link between alcohol use disorders (AUD) and dementia. Alcohol use disorders, which are characterised by excessive and problematic alcohol consumption, have been associated to a variety of detrimental health effects, including liver disease, cardiovascular difficulties, and cognitive impairments.ObjectivesTo explore the link between alcohol use disorders and dementia onset and progression, explaining probable causes and emphasising preventive approaches.Methods The present study involved a thorough examination of relevant research papers, with a specific emphasis on longitudinal cohort studies, neuropathological observations, and biochemical interactions pertaining to the effects of alcohol on the brain. In addition to the aforementioned criteria, the review also took into account other complicating factors, including choices regarding lifestyle, genetic predisposition, and coexisting medical conditions.Results The results indicate a strong association between prolonged and excessive alcohol consumption and a heightened susceptibility to the early onset of dementia. The mechanisms underlying alcohol-related neurological damage encompass direct neurotoxic effects of alcohol, thiamine shortage, and alcohol-related cerebrovascular illness. Moreover, it is worth noting that alcohol use disorder (AUD) has the potential to worsen the advancement of neurodegenerative processes in individuals already diagnosed with dementia.ConclusionsThe association between AUD (Alcohol Use Disorder) and dementia is complex and involves multiple factors, presenting considerable difficulties in terms of clinical intervention and treatment. The use of early intervention strategies and public health initiatives focused on addressing alcohol use disorder (AUD) could have a significant impact on preventing or reducing the development of dementia.Disclosure of InterestNone Declared

Chrysin bonded to β-d-glucose tetraacetate enhances its protective effects against the neurotoxicity induced by aluminum in Swiss mice.

To evaluate whether the glycosylation of chrysin (CHR) enhances its protective effects against aluminum-induced neurotoxicity. To compare the antioxidant, anticholinesterase, and behavioral effects of CHR with its glycosylated form (CHR bonded to β-d-glucose tetraacetate, denoted as LQFM280), we employed an integrated approach using both in vitro (SH-SY5Y cells) and in vivo (aluminum-induced neurotoxicity in Swiss mice) models. LQFM280 demonstrated higher antioxidant activity than CHR in both models. Specifically, LQFM280 exhibited the ability to exert antioxidant effects in the cytoplasm of SH-SY5Y cells, indicating its competence in traversing neuronal membranes. Remarkably, LQFM280 proved more effective than CHR in recovering memory loss and counteracting neuronal death in the aluminum chloride mice model, suggesting its increased bioavailability at the brain level. The glycosylation of CHR with β-d-glucose tetraacetate amplifies its neuroprotective effects, positioning LQFM280 as a promising lead compound for safeguarding against neurodegenerative processes involving oxidative stress.

Prenylated Flavanone Isolated from Dalea Species as a Potential Multitarget-Neuroprotector in an In Vitro Alzheimer's Disease Mice Model.

Alzheimer's disease (AD) involves a neurodegenerative process that has not yet been prevented, reversed, or stopped. Continuing with the search for natural pharmacological treatments, flavonoids are a family of compounds with proven neuroprotective effects and multi-targeting behavior. The American genus Dalea L. (Fabaceae) is an important source of bioactive flavonoids. In this opportunity, we tested the neuroprotective potential of three prenylated flavanones isolated from Dalea species in a new in vitro pre-clinical AD model previously developed by us. Our approach consisted in exposing neural cells to conditioned media (3xTg-AD ACM) from neurotoxic astrocytes derived from hippocampi and cortices of old 3xTg-AD mice, mimicking a local neurodegenerative microenvironment. Flavanone 1 and 3 showed a neuroprotective effect against 3xTg-AD ACM, being 1 more active than 3. The structural requirements to afford neuroprotective activity in this model are a 5'-dimethylallyl and 4'-hydroxy at the B ring. In order to search the mechanistic performance of the most active flavanone, we focus on the flavonoid-mediated regulation of GSK-3β-mediated tau phosphorylation previously reported. Flavanone 1 treatment decreased the rise of hyperphosphorylated tau protein neuronal levels induced after 3xTg-AD ACM exposure and inhibited the activity of GSK-3β. Finally, direct exposure of these neurotoxic 3xTg-AD astrocytes to flavanone 1 resulted in toxicity to these cells and reduced the neurotoxicity of 3xTg-AD ACM as well. Our results allow us to present compound 1 as a natural prenylated flavanone that could be used as a precursor to development and design of future drug therapies for AD.

Presumptive Molecular Interconnections Between COVID-19 And Huntington’s Disease

Objective: The healthcare system worldwide has faced unparalleled challenges as a result of the coronavirus disease of 2019 (COVID-19) pandemic. While respiratory tract disease is the most common symptom of COVID-19, there is increasing evidence of neurological damage caused by the virus. To guide the clinical management of the disease, it is essential to elucidate the mechanisms underlying the
 pathophysiology of COVID-19. Various research indicate that COVID-19 patients exhibit reduced levels of brain-derived neurotrophic factor (BDNF), which is also a hallmark of Huntington’s disease, a neurodegenerative disorder. The objective of this study is to investigate the possible links between COVID-19 and Huntington’s disease. This aim is motivated by the need to guide the clinical management of COVID-19, especially given the increasing evidence of neurological damage caused by the virus, including reduced levels of BDNF, a hallmark also observed in Huntington’s disease.
 Methods: The comprehensive literature review conducted for both COVID-19 and Huntington’s disease, focusing on the genes associated with both conditions. These genes were then analyzed using the STRING database to determine protein-protein interactions, aiming to elucidate the mechanisms underlying the pathophysiology of COVID-19 and its potential connections to Huntington’s disease.
 Results: The outcomes of the study indicate that there could be molecular-level interactions between COVID-19 and Huntington’s disease, based on the literature research and STRING database analysis. Although the primary mechanism behind these interactions is not yet fully understood, the hypothesis suggests that BDNF and its high-affinity receptor TrkB may play a crucial role. Additionally, the study highlights olfactory dysfunction as a common symptom of COVID-19, which is also linked with various neurodegenerative conditions, including Huntington’s disease.
 Conclusion: This work emphasizes the connection between COVID-19 and neurodegenerative diseases, particularly through the lens of olfactory dysfunction, a common symptom shared by COVID-19 and Huntington’s disease. The potential molecular interactions observed suggest that COVID-19 could exacerbate neurodegenerative processes. This underscores the critical need for further research focused on olfactory dysfunction as a key symptom, to better understand and manage the implications of COVID-19 in patients with neurodegenerative conditions.

Methylene blue and its potential in the treatment of traumatic brain injury, brain ischemia, and Alzheimer's disease.

Traumatic brain injury (TBI) and brain ischemia/reperfusion cause neurodegenerative processes that can continue after the acute stage with the development of severe brain atrophy with dementia. In this case, the long-term neurodegeneration of the brain is similar to the neurodegeneration characteristic of Alzheimer's disease (AD) and is associated with the accumulation of beta amyloid and tau protein. In the pathogenesis of AD as well as in the pathogenesis of cerebral ischemia and TBI oxidative stress, progressive inflammation, glial activation, blood-brain barrier dysfunction, and excessive activation of autophagy are involved, which implies the presence of many targets that can be affected by neuroprotectors. That is, multivariate cascades of nerve tissue damage represent many potential targets for therapeutic interventions. One of such substances that can be used in multi-purpose therapeutic strategies is methylene blue (MB). This drug can have an antiapoptotic and anti-inflammatory effect, activate autophagy, inhibit the aggregation of proteins with an irregular shape, inhibit NO synthase, and bypass impaired electron transfer in the respiratory chain of mitochondria. MB is a well-described treatment for methemoglobinemia, malaria, and encephalopathy caused by ifosfamide. In recent years, this drug has attracted great interest as a potential treatment for a number of neurodegenerative disorders, including the effects of TBI, ischemia, and AD.

Dietary vitamin A modifies the gut microbiota and intestinal tissue transcriptome, impacting intestinal permeability and the release of inflammatory factors, thereby influencing Aβ pathology.

Alzheimer's disease (AD) is an age-related neurodegenerative disorder with no effective interventions for curing or modifying its progression. However, emerging research suggests that vitamin A in the diet may play a role in both the prevention and treatment of AD, although the exact mechanisms are not fully understood. This study aims to investigate the dietary vitamin A modifies the gut microbiota and intestinal tissue transcriptome, impacting intestinal permeability and the release of inflammatory factors, thereby influencing Aβ pathology shedding light on its potential as a dietary intervention for AD prevention and treatment. The APP/PS1-AD mouse model was employed and divided into three dietary groups: vitamin A-deficient (VAD), normal vitamin A (VAN), and vitamin A-supplemented (VAS) for a 12-week study. Neurobehavioral functions were assessed using the Morris Water Maze Test (MWM). Enzyme-linked immunosorbent assay (ELISA) was used to quantify levels of Diamine Oxidase (DAO), D-lactate, IL-6, IL-1β, and TNF-a cytokines. Serum vitamin A levels were analyzed via LC-MS/MS analysis. Immunohistochemical analysis and morphometry were performed to evaluate the deposition of Aβ in brain tissue. The gut microbiota of APP/PS1 mice was analyzed using 16S rRNA sequencing analysis. Additionally, transcriptomic analysis was conducted on intestinal tissue from APP/PS1 mice. No significant changes in food intake and body weight were observed among the groups. However, the VAD and VAS groups showed reduced food intake compared to the VAN group at various time points. In terms of cognitive function, the VAN group performed better in the Morris Water Maze Test, indicating superior learning and memory abilities. The VAD and VAS groups exhibited impaired performance, with the VAS group performing relatively better than the VAD group. Serum vitamin A concentrations differed significantly among the groups, with the VAS group having the highest concentration. Aβ levels were significantly higher in the VAD group compared to both the VAN and VAS groups. Microbial analysis revealed that the VAS and VAN groups had higher microbial diversity than the VAD group, with specific taxa characterizing each group. The VAN group was characterized by taxa such as Actinohacteriota and Desulfovibrionaceae, while the VAD group was characterized by Parabacteroides and Tannerellaceae. The VAS group showed similarities with both VAN and VAD groups, with taxa like Desulfobacterota and Desulfovibrionaceae being present. The VAD vs. VAS, VAD vs. VAN, and VAS vs. VAN comparisons identified 571, 313, and 243 differentially expressed genes, respectively, which associated with cellular and metabolic processes, and pathway analysis revealed enrichment in pathways related to chemical carcinogenesis, drug metabolism, glutathione metabolism, and immune-related processes. The VAD group exhibited higher levels of D-lactate, diamine oxidase, and inflammatory cytokines (TNF-a, IL-1β, IL-6) compared to the VAN and VAS groups. Dietary vitamin A supplementation modulates the gut microbiota, intestinal permeability, inflammatory factors, and Aβ protein formation, offering insights into the pathogenesis of AD and potential therapeutic avenues for further exploration. This research highlights the intricate interplay between diet, gut microbiota, and neurodegenerative processes, emphasizing the importance of dietary interventions in managing AD-related pathologies.