Assessment of blood-brain barrier leakage and brain oxygenation in Connexin-32 knockout mice with systemic neuroinflammation using pulse electron paramagnetic resonance imaging techniques

PURPOSE

The determination of blood-brain barrier (BBB) integrity and partial pressure of oxygen (pO2) in the brain is of substantial interest in several neurological applications. This study aimed to assess the feasibility of using trityl OX071-based pulse electron paramagnetic resonance imaging (pEPRI) to provide a quantitative estimate of BBB integrity and pO2 maps in mouse brains as a function of neuroinflammatory disease progression.

METHODS

Five Connexin-32 (Cx32)-knockout (KO) mice were injected with lipopolysaccharide to induce neuroinflammation for imaging. Three wild-type mice were also used to optimize the imaging procedure and as control animals. An additional seven Cx32-KO mice were used to establish the BBB leakage of trityl using the colorimetric assay. All pEPRI experiments were performed using a preclinical instrument, JIVA-25 (25 mT/720 MHz), at times t = 0, 4, and 6 h following lipopolysaccharide injection. Two pEPRI imaging techniques were used: (a) single-point imaging for obtaining spatial maps to outline the brain and calculate BBB leakage using the signal amplitude, and (b) inversion-recovery electron spin echo for obtaining pO2 maps.

RESULTS

A statistically significant change in BBB leakage was found using pEPRI with the progression of inflammation in Cx32 KO animals. However, the change in pO2 values with the progression of inflammation for these animals was not statistically significant.

CONCLUSIONS

For the first time, we show the ability of pEPRI to provide pO2 maps in mouse brains noninvasively, along with a quantitative assessment of BBB leakage. We expect this study to open new queries from the field to explore the pathology of many neurological diseases and provide a path to new treatments.

A review on the new age methodologies for early detection of Alzheimer's and Parkinson's disease

BACKGROUNDS

Neurodegenerative diseases (NDDs) such as Alzheimer's (AD) and Parkinson's (PD) are often diagnosed late, impeding effective treatment; therefore, early detection is imperative. Modern methodologies can serve a pivotal role in fulfilling the crucial need for timely detection and intervention in this context.

OBJECTIVES

Evaluate early detection's significance and summarize key technologies (biomarkers, neuroimaging, AI/ML, genetics, digital health) for enhanced diagnostic strategies in AD and PD.

METHODS

This study employs a focused descriptive review approach, encompassing analysis of peer-reviewed articles and clinical trials from existing literature, to provide a nuanced exploration of the subject matter.

FINDINGS

This review underscores the efficacy of non-invasive biomarkers, biosensors and emerging promising technologies for advancing early diagnosis of AD and PD.

CONCLUSION

The landscape of early NDD detection has been reshaped by technology, yet challenges persist, encompassing the domains of validation and ethics. A collaborative effort between medical professionals, researchers and technologists is imperative to effectively address and combat NDDs.

Utility of the INECO Frontal Screening and the Frontal Assessment Battery in detecting executive dysfunction in early-onset cognitive impairment and dementia

OBJECTIVE

The INECO Frontal Screening (IFS) and the Frontal Assessment Battery (FAB) are executive dysfunction (ED) screening tools that can distinguish patients with neurodegenerative disorders from healthy controls and, to some extent, between dementia subtypes. This paper aims to examine the suitability of these tests in assessing early-onset cognitive impairment and dementia patients.

METHOD

In a memory clinic patient cohort (age mean = 57.4 years) with symptom onset at ≤65 years, we analyzed the IFS and the FAB results of four groups: early-onset dementia (EOD, n = 49), mild cognitive impairment due to neurological causes (MCI-n, n = 34), MCI due to other causes such as depression (MCI-o, n = 99) and subjective cognitive decline (SCD, n = 14). Data were gathered at baseline and at 6 and 12 months. We also studied the tests' accuracy in distinguishing EOD from SCD patients and ED patients from those with intact executive functioning. Correlations with neuropsychological measures were also studied.

RESULTS

The EOD group had significantly (p < .05) lower IFS and FAB total scores than the MCI-o and SCD groups. Compared with the FAB, the IFS showed more statistically significant (p < .05) differences between diagnostic groups, greater accuracy (IFS AUC = .80, FAB AUC = .75, p = .036) in detecting ED and marginally stronger correlations with neuropsychological measures. We found no statistically significant differences in the EOD group scores from baseline up to 6- or 12-months follow-up.

CONCLUSIONS

While both tests can detect EOD among memory clinic patients, the IFS may be more reliable in detecting ED than the FAB.

Mechanism and structural dynamics of sulfur transfer during de novo [2Fe-2S] cluster assembly on ISCU2

Maturation of iron-sulfur proteins in eukaryotes is initiated in mitochondria by the core iron-sulfur cluster assembly (ISC) complex, consisting of the cysteine desulfurase sub-complex NFS1-ISD11-ACP1, the scaffold protein ISCU2, the electron donor ferredoxin FDX2, and frataxin, a protein dysfunctional in Friedreich's ataxia. The core ISC complex synthesizes [2Fe-2S] clusters de novo from Fe and a persulfide (SSH) bound at conserved cluster assembly site residues. Here, we elucidate the poorly understood Fe-dependent mechanism of persulfide transfer from cysteine desulfurase NFS1 to ISCU2. High-resolution cryo-EM structures obtained from anaerobically prepared samples provide snapshots that both visualize different stages of persulfide transfer from Cys381NFS1 to Cys138ISCU2 and clarify the molecular role of frataxin in optimally positioning assembly site residues for fast sulfur transfer. Biochemical analyses assign ISCU2 residues essential for sulfur transfer, and reveal that Cys138ISCU2 rapidly receives the persulfide without a detectable intermediate. Mössbauer spectroscopy assessing the Fe coordination of various sulfur transfer intermediates shows a dynamic equilibrium between pre- and post-sulfur-transfer states shifted by frataxin. Collectively, our study defines crucial mechanistic stages of physiological [2Fe-2S] cluster assembly and clarifies frataxin's molecular role in this fundamental process.

Grey matter networks in women and men with dementia with Lewy bodies

Sex differences permeate many aspects of dementia with Lewy bodies (DLB), yet sex differences in patterns of neurodegeneration in DLB remain largely unexplored. Here, we test whether grey matter networks differ between sexes in DLB and compare these findings to sex differences in healthy controls. In this cross-sectional study, we analysed clinical and neuroimaging data of patients with DLB and cognitively healthy controls matched for age and sex. Grey matter networks were constructed by pairwise correlations between 58 regional volumes after correction for age, intracranial volume, and centre. Network properties were compared between sexes and diagnostic groups. Additional analyses were conducted on w-scored data to identify DLB-specific sex differences. Data from 119 (68.7 ± 8.4 years) men and 45 women (69.9 ± 9.1 years) with DLB, and 164 healthy controls were included in this study. Networks of men had a lower nodal strength compared to women. In comparison to healthy women, the grey matter networks of healthy men showed a higher global efficiency, modularity, and fewer modules. None of the network measures showed significant sex differences in DLB. Comparing DLB patients with healthy controls revealed global differences in women and more local differences in men. Modular analyses showed a more distinct demarcation between cortical and subcortical regions in men compared with women. While topologies of grey matter networks differed between sexes in healthy controls, those sex differences were diluted in DLB patients. These findings suggest a disease-driven convergence of neurodegenerative patterns in women and men with DLB, which may inform precision medicine in DLB.

Protein Corona Composition of Gold Nanocatalysts

The interaction between nanoparticles (NPs) and biological environments is profoundly influenced by a stable, strongly adsorbed "hard" protein corona. This corona significantly determines the NPs' pharmacokinetics and biological destiny. Our study delves into the mechanisms by which colloidal Au nanocrystals that are synthesized electrochemically without surface-capping organic ligands, known as CNM-Au8, traverse the blood-brain barrier (BBB) and target human brain tissue for treating neurodegenerative disorders. We discovered that upon interaction with human plasma, CNM-Au8 gold nanocrystals (AuNCs) effectively attract a variety of crucial apolipoproteins, notably apolipoproteins E, to their surfaces. This interaction likely facilitates their passage through the BBB. Furthermore, the coronas of these AuNCs exhibit a substantial presence of albumin and a notable absence of opsonin-based proteins, contributing to prolonged blood circulation. These characteristics align well with the clinical performance observed for the CNM-Au8 NCs. This study highlights that AuNCs with intentionally engineered structures and surfactant-free surfaces can create a distinct protein corona composition. This finding holds significant promise for the development of advanced therapeutic agents aimed at combating neurodegenerative diseases.

Detecting Abnormal Eye Movements in Patients with Neurodegenerative Diseases - Current Insights

This review delineates the ocular motor disturbances across a spectrum of neurodegenerative disorders, including Alzheimer's Disease (AD) and related disorders (ADRD), Parkinson's Disease (PD), atypical parkinsonism, and others, leveraging advancements in eye-tracking technology for enhanced diagnostic precision. We delve into the different classes of eye movements, their clinical assessment, and specific abnormalities manifesting in these diseases, highlighting the nuanced differences and shared patterns. For instance, AD and ADRD are characterized by increased saccadic latencies and instability in fixation, while PD features saccadic hypometria and mild smooth pursuit impairments. Atypical parkinsonism, notably Progressive Supranuclear Palsy (PSP) and Corticobasal Syndrome (CBS), presents with distinct ocular motor signatures such as vertical supranuclear gaze palsy and saccadic apraxia, respectively. Our review underscores the diagnostic value of eye movement analysis in differentiating between these disorders and also posits the existence of underlying common pathological mechanisms. We discuss how eye movements have potential as biomarkers for neurodegenerative diseases but also some of the existing limitations.

Endo-lysosomal dysfunction in neurodegenerative diseases: opinion on current progress and future direction in the use of exosomes as biomarkers

Over the past two decades, increased research has highlighted the connection between endosomal trafficking defects and neurodegeneration. The endo-lysosomal network is an important, complex cellular system specialized in the transport of proteins, lipids, and other metabolites, essential for cell homeostasis. Disruption of this pathway is linked to a wide range of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease and frontotemporal dementia. Furthermore, there is strong evidence that defects in this pathway create opportunities for diagnostic and therapeutic intervention. In this Opinion piece, we concisely address the role of endo-lysosomal dysfunction in five neurodegenerative diseases and discuss how future research can investigate this intracellular pathway, including extracellular vesicles with a specific focus on exosomes for the identification of novel disease biomarkers. This article is part of a discussion meeting issue 'Understanding the endo-lysosomal network in neurodegeneration'.

Potential Therapeutic Targets to Modulate the Endocannabinoid System in Alzheimer's Disease

Alzheimer's disease (AD), the most common neurodegenerative disease (NDD), is characterized by chronic neuronal cell death through progressive loss of cognitive function. Amyloid beta (Aβ) deposition, neuroinflammation, oxidative stress, and hyperphosphorylated tau proteins are considered the hallmarks of AD pathology. Different therapeutic approaches approved by the Food and Drug Administration can only target a single altered pathway instead of various mechanisms that are involved in AD pathology, resulting in limited symptomatic relief and almost no effect in slowing down the disease progression. Growing evidence on modulating the components of the endocannabinoid system (ECS) proclaimed their neuroprotective effects by reducing neurochemical alterations and preventing cellular dysfunction. Recent studies on AD mouse models have reported that the inhibitors of the fatty acid amide hydrolase (FAAH) and monoacylglycerol (MAGL), hydrolytic enzymes for N-arachidonoyl ethanolamine (AEA) and 2-arachidonoylglycerol (2-AG), respectively, might be promising candidates as therapeutical intervention. The FAAH and MAGL inhibitors alone or in combination seem to produce neuroprotection by reversing cognitive deficits along with Aβ-induced neuroinflammation, oxidative responses, and neuronal death, delaying AD progression. Their exact signaling mechanisms need to be elucidated for understanding the brain intrinsic repair mechanism. The aim of this review was to shed light on physiology and pathophysiology of AD and to summarize the experimental data on neuroprotective roles of FAAH and MAGL inhibitors. In this review, we have also included CB1R and CB2R modulators with their diverse roles to modulate ECS mediated responses such as anti-nociceptive, anxiolytic, and anti-inflammatory actions in AD. Future research would provide the directions in understanding the molecular mechanisms and development of new therapeutic interventions for the treatment of AD.

Gut microbiota: the indispensable player in neurodegenerative diseases

As one of the most urgent social and health problems in the world, neurodegenerative diseases have always been attracted by researchers. However, the pathological mechanisms and therapeutic approaches are not achieved. In addition to the established roles of oxidative stress, inflammation and immune response, the changes of gut microbiota are also closely related to the pathogenesis of neurodegenerative diseases. Gut microbiota is the central player of gut- brain axis, the dynamic bidirectional communication pathway between gut microbiota and central nervous system, and emerging insights have confirmed its indispensability in the development of neurodegenerative diseases. In this review, we discussed the complex relationship between gut microbiota and the central nervous system from the perspective of gut-brain axis, reviewed the mechanism of microbiota on the modulation different neurodegenerative diseases and concluded how different dietary patterns affected neurodegenerative diseases via gut microbiota, and prospected the employment of gut microbiota in the therapeutic approach of those diseases. This article is protected by copyright. All rights reserved.

Long COVID and its association with neurodegenerative diseases: pathogenesis, neuroimaging, and treatment

Corona Virus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has presented unprecedented challenges to the world. Changes after acute COVID-19 have had a significant impact on patients with neurodegenerative diseases. This study aims to explore the mechanism of neurodegenerative diseases by examining the main pathways of central nervous system infection of SARS-CoV-2. Research has indicated that chronic inflammation and abnormal immune response are the primary factors leading to neuronal damage and long-term consequences of COVID-19. In some COVID-19 patients, the concurrent inflammatory response leads to increased release of pro-inflammatory cytokines, which may significantly impact the prognosis. Molecular imaging can accurately assess the severity of neurodegenerative diseases in patients with COVID-19 after the acute phase. Furthermore, the use of FDG-PET is advocated to quantify the relationship between neuroinflammation and psychiatric and cognitive symptoms in patients who have recovered from COVID-19. Future development should focus on aggressive post-infection control of inflammation and the development of targeted therapies that target ACE2 receptors, ERK1/2, and Ca2+.

Performance of SOBA-AD blood test in discriminating Alzheimer's disease patients from cognitively unimpaired controls in two independent cohorts

Amyloid-beta (Aβ) toxic oligomers are critical early players in the molecular pathology of Alzheimer's disease (AD). We have developed a Soluble Oligomer Binding Assay (SOBA-AD) for detection of these Aβ oligomers that contain α-sheet secondary structure that discriminates plasma samples from patients on the AD continuum from non-AD controls. We tested 265 plasma samples from two independent cohorts to investigate the performance of SOBA-AD. Testing was performed at two different sites, with different personnel, reagents, and instrumentation. Across two cohorts, SOBA-AD discriminated AD patients from cognitively unimpaired (CU) subjects with 100% sensitivity, > 95% specificity, and > 98% area under the curve (AUC) (95% CI 0.95-1.00). A SOBA-AD positive readout, reflecting α-sheet toxic oligomer burden, was found in AD patients, and not in controls, providing separation of the two populations, aside from 5 SOBA-AD positive controls. Based on an earlier SOBA-AD study, the Aβ oligomers detected in these CU subjects may represent preclinical cases of AD. The results presented here support the value of SOBA-AD as a promising blood-based tool for the detection and confirmation of AD.

Investigating a Novel Neurodegenerative Disease Toxic Mechanism Involving Lipid Binding Specificity of Amyloid Oligomers

Exploring the mechanisms underlying the toxicity of amyloid oligomers (AOs) presents a significant opportunity for discovering cures and developing treatments for neurodegenerative diseases. Recently, using a combination of ion mobility spectrometry-mass spectrometry (IMS-MS) and X-ray crystallography (XRC), we showed that the peptide KVKVLWDVIEV, which is the G95W mutant of αB-Crystallin (90-100) and abbreviated as G6W, self-assembles up to a dodecamer that structurally resembles lipid transport proteins. The glycine to tryptophan mutation promotes not only larger oligomers and enhanced cytotoxicity in brain slices than the wild type but also a narrow hydrophobic cavity suitable for fatty acid or phospholipid binding. Here, we determine the plausibility of a novel cytotoxic mechanism where the G6W's structural motif could perturb lipid homeostasis by determining its lipid binding selectivity and specificity. We show that the G6W oligomers have a strong affinity toward unsaturated phospholipids with a preference toward phospholipids containing 16-C alkyl chains. Molecular dynamics simulations demonstrate how an unsaturated, 16-C phospholipid fits tightly inside and outside G6W's hydrophobic cavity. This binding is exclusive to the G6W peptide, as other amyloid oligomers with different atomic structures, including its wildtype αB-Crystallin (90-100) and several superoxide dismutase 1 (SOD1) peptides that are known to self-assemble into amyloid oligomers (SOD1P28K and SOD1WG-GW), do not experience the same strong binding affinity. While the existing chaperone-lipid hypothesis on amyloid toxicity suggests amyloid-lipid complexes perforate cell membranes, our work provides a new outlook, indicating that soluble amyloid oligomers disrupt lipid homeostasis via selective protein-ligand interactions. The toxic mechanisms may arise from the formation of unique amyloid oligomer structures assisted by lipid ligands or impaired lipid transports.

Assessing the perception of Parkinson's disease in Al-Ahsa, Saudi Arabia among the visitors of a public campaign: before and after survey

Introduction

Insufficient knowledge and beliefs hinder the early diagnosis and provision of adequate treatment and care for PD patients, causing socio-economic burdens. Raising public awareness and understanding the knowledge gap is crucial for effective educational programs and early detection. This study aims to assess the perception of Parkinson's disease (PD) among visitors of a public campaign conducted to raise PD awareness and knowledge to facilitate early detection and management.

Methods

A before-and-after study was conducted from May to June 2023, to assess the perception of PD among a public PD campaign visitors in Al-Ahsa, Saudi Arabia. The campaign included educational booths discussing PD symptoms, causes, diagnosis, management, and support. Participants completed a self-administered online questionnaire before and after the campaign. The data were analyzed using SPSS.

Results

The study included 48 eligible individuals. The mean knowledge score was significantly enhanced following the campaign, rising from 12 to 17.77 points (p < 0.05). The symptoms of PD that showed a significant difference were slow movement, tremors, depression, memory problems, and sleep problems. The campaign had a beneficial effect on participants' general understanding of PD.

Discussion

The study showed that public awareness campaigns successfully raised community awareness of PD. Participants' knowledge improved after the campaign, highlighting its positive effect. Further research could explore measuring the continuity of awareness over a longer period and its impact on improving patients' lives and could expand the sample size.

Toward diffusion tensor imaging as a biomarker in neurodegenerative diseases: technical considerations to optimize recordings and data processing

Neuroimaging biomarkers have shown high potential to map the disease processes in the application to neurodegenerative diseases (NDD), e.g., diffusion tensor imaging (DTI). For DTI, the implementation of a standardized scanning and analysis cascade in clinical trials has potential to be further optimized. Over the last few years, various approaches to improve DTI applications to NDD have been developed. The core issue of this review was to address considerations and limitations of DTI in NDD: we discuss suggestions for improvements of DTI applications to NDD. Based on this technical approach, a set of recommendations was proposed for a standardized DTI scan protocol and an analysis cascade of DTI data pre-and postprocessing and statistical analysis. In summary, considering advantages and limitations of the DTI in NDD we suggest improvements for a standardized framework for a DTI-based protocol to be applied to future imaging studies in NDD, towards the goal to proceed to establish DTI as a biomarker in clinical trials in neurodegeneration.

Alzheimer's disease cerebrospinal fluid biomarkers and kidney function in normal and cognitively impaired older adults

INTRODUCTION

Recent Alzheimer's disease (AD) clinical trials have used cerebrospinal fluid (CSF) biomarker levels for screening and enrollment. Preliminary evidence suggests that AD risk is related to impaired renal function. The impact of kidney function on commonly used AD biomarkers remains unknown.

METHODS

Participants in studies conducted at the Goizueta Alzheimer's Disease Research Center (N = 973) had measurements of serum creatinine and CSF AD biomarkers. General linear models and individual data were used to assess the relationships between biomarkers and eGFR.

RESULTS

Lower estimated glomerular filtration rate (eGFR) was associated with lower amyloid beta (Aβ)42/tau ratio (p < 0.0001) and Aβ42 (p = 0.002) and higher tau (p < 0.0001) and p-tau (p = 0.0002). The impact of eGFR on AD biomarker levels was more robust in individuals with cognitive impairment (all p-values were < 0.005).

DISCUSSION

The association between eGFR and CSF AD biomarkers has a significant impact that varies by cognitive status. Future studies exploring this impact on the pathogenesis of AD and related biomarkers are needed.

Highlights

There is a significant association between Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers and both estimated glomerular filtration rate (eGFR) and mild cognitive impairment (MCI).Kidney function influences CSF biomarker levels in individuals with normal cognitive function and those with MCI.The impact of kidney function on AD biomarker levels is more pronounced in individuals with cognitive impairment.The variation in CSF tau levels is independent of cardiovascular factors and is likely directly related to kidney function.Tau may have a possible role in both kidney and cognitive function.

Identification of gene fusions associated with amyotrophic lateral sclerosis

INTRODUCTION/AIMS

Genetics is an important risk factor for amyotrophic lateral sclerosis (ALS), a neurodegenerative disease affecting motor neurons. Recent findings demonstrate that in addition to specific genetic mutations, structural variants caused by genetic instability can also play a causative role in ALS. Genomic instability can lead to deletions, duplications, insertions, inversions, and translocations in the genome, and these changes can sometimes lead to fusion of distinct genes into a single transcript. Gene fusion events have been studied extensively in cancer; however, they have not been thoroughly investigated in ALS. The aim of this study was to determine whether gene fusions are present in ALS.

METHODS

Gene fusions were identified using STAR Fusion v1.10.0 software in bulk RNA-Seq data from human postmortem samples from publicly available data sets from Target ALS and the New York Genome Center ALS Consortium.

RESULTS

We report the presence of gene fusion events in several brain regions as well as in spinal cord samples in ALS. Although most gene fusions were intra-chromosomal events between neighboring genes and present in both ALS and control samples, there was a significantly greater number of unique gene fusions in ALS compared to controls. Lastly, we identified specific gene fusions with a significant burden in ALS, that were absent from both control samples and known cancer gene fusion databases.

DISCUSSION

Collectively, our findings reveal an enrichment of gene fusions in ALS and suggest that these events may be an additional genetic cause linked to ALS pathogenesis.

Molecular interplay between phytoconstituents of Ficus Racemosa and neurodegenerative diseases

Neurodegenerative diseases (NDs) are a significant global health concern, primarily affecting middle and older populations. Recently, there has been growing interest in herbal therapeutics as a potential approach to address diverse neuropathological conditions. Despite the widespread prevalence of NDs, limited phytochemical has been reported for their promising therapeutic potential with distinct underlying mechanisms. Additionally, the intricate molecular pathways influenced by herbal phytoconstituents, particularly in neurodegenerative disorders, are also not well documented. This report explores the phytoconstituents of Ficus racemosa (F. racemosa), an unfamiliar plant of the Moraceae family, for their potential interactions with pathological pathways of NDs. The influential phytoconstituents of F. racemosa, including polyphenols, glycosides, terpenoids, and furocoumarin, have been reported for targeting diverse pathological states. We proposed the most convincing molecular interplay between leading phytoconstituents and detrimental signalling cascades. However, extensive research is required to thoroughly understand the phytochemical persuaded intricate molecular pathway. The comprehensive evidence strongly suggests that F. racemosa and its natural compounds could be valuable in treating NDs. This points towards an exciting path for future research and the development of potential treatments based on a molecular level.

Manganese induces oxidative damage in the hippocampus by regulating the expression of oxidative stress-related genes via modulation of H3K18 acetylation

Prolonged exposure to manganese (Mn) contributes to hippocampal Mn accumulation, which leads to neurodegenerative diseases called manganese poisoning. However, the underlying molecular mechanisms remain unclear and there are no ideal biomarkers. Oxidative stress is the essential mechanisms of Mn-related neurotoxicity. Furthermore, histone acetylation has been identified as being engaged in the onset and development of neurodegenerative diseases. Therefore, the work aims to understand the molecular mechanisms of oxidative damage in the hippocampus due to Mn exposure from the aspect of histone acetylation modification and to assess whether H3K18 acetylation (H3K18ac) modification level in peripheral blood reflect Mn-induced oxidative damage in the hippocampus. Here, we randomly divided 60 male rats into four groups and injected them intraperitoneally with sterile pure water and MnCl2 ⋅4H2 O (5, 10, and 15 mg/kg) for 16 weeks, 5 days a week, once a day. The data confirmed that Mn exposure down-regulated superoxide dismutase activity and glutathione level as well as up-regulated malondialdehyde level in the hippocampus and plasma, and that there was a positive correlation between these indicators in the hippocampus and plasma. Besides, we noted that Mn treatment upregulated H3K18ac modification levels in the hippocampus and peripheral blood and that H3K18ac modification levels correlated with oxidative stress. Further studies demonstrated that Mn treatment decreased the amounts of H3K18ac enrichment in the manganese superoxide dismutase (SOD2) and glutathione transferase omega 1 (GSTO1) gene promoter regions, contributing to oxidative damage in the hippocampus. In short, our results demonstrate that Mn induces oxidative damage in the hippocampus by inhibiting the expression of SOD2 and GSTO1 genes via modulation of H3K18ac. In assessing Mn-induced hippocampal neurotoxicity, oxidative damage in plasma may reflect hippocampal oxidative damage in Mn-exposed groups.

Regulatory mechanism of circular RNAs in neurodegenerative diseases

BACKGROUND

Neurodegenerative disease is a collective term for a category of diseases that are caused by neuronal dysfunction, such as Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). Circular RNAs (circRNAs) are a class of non-coding RNAs without the 3' cap and 5' poly(A) and are linked by covalent bonds. CircRNAs are highly expressed in brain neurons and can regulate the pathological process of neurodegenerative diseases by affecting the levels of various deposition proteins.

AIMS

This review is aiming to suggest that the majority of circRNAs influence neurodegenerative pathologies mainly by affecting the abnormal deposition of proteins in neurodegenerative diseases.

METHODS

We systematically summarized the pathological features of neurodegenerative diseases and the regulatory mechanisms of circRNAs in various types of neurodegenerative diseases.

RESULTS

Neurodegenerative disease main features include intercellular ubiquitin-proteasome system abnormalities, changes in cytoskeletal proteins, and the continuous deposition of insoluble protein fragments and inclusion bodies in the cytoplasm or nucleus, resulting in impairment of the normal physiological processes of the neuronal system. CircRNAs have multiple mechanisms, such as acting as microRNA sponges, binding to proteins, and regulating transcription. CircRNAs, which are highly stable molecules, are expected to be potential biomarkers for the pathological detection of neurodegenerative diseases such as AD and PD.

CONCLUSIONS

In this review, we describe the regulatory roles and mechanisms of circRNAs in neurodegenerative diseases and aim to employ circRNAs as biomarkers for the diagnosis and treatment of neurodegenerative diseases.

Optogenetics in chronic neurodegenerative diseases, controlling the brain with light: A systematic review

Neurodegenerative diseases are progressive disorders characterized by synaptic loss and neuronal death. Optogenetics combines optical and genetic methods to control the activity of specific cell types. The efficacy of this approach in neurodegenerative diseases has been investigated in many reviews, however, none of them tackled it systematically. Our study aimed to review systematically the findings of optogenetics and its potential applications in animal models of chronic neurodegenerative diseases and compare it with deep brain stimulation and designer receptors exclusively activated by designer drugs techniques. The search strategy was performed based on the PRISMA guidelines and the risk of bias was assessed following the Systematic Review Centre for Laboratory Animal Experimentation tool. A total of 247 articles were found, of which 53 were suitable for the qualitative analysis. Our data revealed that optogenetic manipulation of distinct neurons in the brain is efficient in rescuing memory impairment, alleviating neuroinflammation, and reducing plaque pathology in Alzheimer's disease. Similarly, this technique shows an advanced understanding of the contribution of various neurons involved in the basal ganglia pathways with Parkinson's disease motor symptoms and pathology. However, the optogenetic application using animal models of Huntington's disease, multiple sclerosis, and amyotrophic lateral sclerosis was limited. Optogenetics is a promising technique that enhanced our knowledge in the research of neurodegenerative diseases and addressed potential therapeutic solutions for managing these diseases' symptoms and delaying their progression. Nevertheless, advanced investigations should be considered to improve optogenetic tools' efficacy and safety to pave the way for their translatability to the clinic.

Autophagy in neural stem cells and glia for brain health and diseases

Autophagy is a multifaceted cellular process that not only maintains the homeostatic and adaptive responses of the brain but is also dynamically involved in the regulation of neural cell generation, maturation, and survival. Autophagy facilities the utilization of energy and the microenvironment for developing neural stem cells. Autophagy arbitrates structural and functional remodeling during the cell differentiation process. Autophagy also plays an indispensable role in the maintenance of stemness and homeostasis in neural stem cells during essential brain physiology and also in the instigation and progression of diseases. Only recently, studies have begun to shed light on autophagy regulation in glia (microglia, astrocyte, and oligodendrocyte) in the brain. Glial cells have attained relatively less consideration despite their unquestioned influence on various aspects of neural development, synaptic function, brain metabolism, cellular debris clearing, and restoration of damaged or injured tissues. Thus, this review composes pertinent information regarding the involvement of autophagy in neural stem cells and glial regulation and the role of this connexion in normal brain functions, neurodevelopmental disorders, and neurodegenerative diseases. This review will provide insight into establishing a concrete strategic approach for investigating pathological mechanisms and developing therapies for brain diseases.

Increasing Risk of Dementia Among Patients with Subsequent Epilepsy Within 2 Years Post-Traumatic Brain Injury: A Population-Based Case-Control Study

Background

Although the association between neurodegenerative diseases, such as dementia, and traumatic brain injury (TBI) has long been known, the association between dementia and TBI with epilepsy has been controversial.

Aim

This data-driven population-based study is designed to investigate the association between dementia and epilepsy after TBI within a 2-year period.

Methods

This case-control cohort study was conducted using the Longitudinal Health Insurance Database 2000 (LHID2000). We included 784 individuals ambulatory or hospitalized for TBI with epilepsy from 2001 to 2011, compared with 2992 patients with TBI without epilepsy who were matched for characteristics including sex, age, and healthcare resource use index date. Every participant was followed up for 5 years to ascertain any dementia development. Data were stratified and analyzed using the Cox proportional hazards regression.

Results

Through the 5-year follow-up period, 39 patients (5.21%) with TBI with epilepsy and 55 (1.53%) with TBI without epilepsy developed dementia. TBI with epilepsy was independently associated with a >3.03 times risk of dementia after correcting for age, sex, and comorbidities.

Conclusion

These findings suggest an increased risk of dementia in patients with TBI with epilepsy. Our research recommends that individuals with TBI and epilepsy be monitored more intensively.

The Role of Cardiolipin in Mitochondrial Function and Neurodegenerative Diseases

Cardiolipin (CL) is a mitochondria-exclusive phospholipid synthesized in the inner mitochondrial membrane. CL plays a key role in mitochondrial membranes, impacting a plethora of functions this organelle performs. Consequently, it is conceivable that abnormalities in the CL content, composition, and level of oxidation may negatively impact mitochondrial function and dynamics, with important implications in a variety of diseases. This review concentrates on papers published in recent years, combined with basic and underexplored research in CL. We capture new findings on its biological functions in the mitochondria, as well as its association with neurodegenerative diseases such as Alzheimer's disease or Parkinson's disease. Lastly, we explore the potential applications of CL as a biomarker and pharmacological target to mitigate mitochondrial dysfunction.

The Influence of Microglia on Neuroplasticity and Long-Term Cognitive Sequelae in Long COVID: Impacts on Brain Development and Beyond

Microglial cells, the immune cells of the central nervous system, are key elements regulating brain development and brain health. These cells are fully responsive to stressors, microenvironmental alterations and are actively involved in the construction of neural circuits in children and the ability to undergo full experience-dependent plasticity in adults. Since neuroinflammation is a known key element in the pathogenesis of COVID-19, one might expect the dysregulation of microglial function to severely impact both functional and structural plasticity, leading to the cognitive sequelae that appear in the pathogenesis of Long COVID. Therefore, understanding this complex scenario is mandatory for establishing the possible molecular mechanisms related to these symptoms. In the present review, we will discuss Long COVID and its association with reduced levels of BDNF, altered crosstalk between circulating immune cells and microglia, increased levels of inflammasomes, cytokines and chemokines, as well as the alterations in signaling pathways that impact neural synaptic remodeling and plasticity, such as fractalkines, the complement system, the expression of SIRPα and CD47 molecules and altered matrix remodeling. Together, these complex mechanisms may help us understand consequences of Long COVID for brain development and its association with altered brain plasticity, impacting learning disabilities, neurodevelopmental disorders, as well as cognitive decline in adults.

Down-sampling in diffusion MRI: a bundle-specific DTI and NODDI study

Introduction

Multi-shell diffusion Magnetic Resonance Imaging (dMRI) data has been widely used to characterise white matter microstructure in several neurodegenerative diseases. The lack of standardised dMRI protocols often implies the acquisition of redundant measurements, resulting in prolonged acquisition times. In this study, we investigate the impact of the number of gradient directions on Diffusion Tensor Imaging (DTI) and on Neurite Orientation Dispersion and Density Imaging (NODDI) metrics.

Methods

Data from 124 healthy controls collected in three different longitudinal studies were included. Using an in-house algorithm, we reduced the number of gradient directions in each data shell. We estimated DTI and NODDI measures on six white matter bundles clinically relevant for neurodegenerative diseases.

Results

Fractional Anisotropy (FA) measures on bundles where data were sampled at the 30% rate, showed a median L1 distance of up to 3.92% and a 95% CI of (1.74, 8.97)% when compared to those obtained at reference sampling. Mean Diffusivity (MD) reached up to 4.31% and a 95% CI of (1.60, 16.98)% on the same premises. At a sampling rate of 50%, we obtained a median of 3.90% and a 95% CI of (1.99, 16.65)% in FA, and 5.49% with a 95% CI of (2.14, 21.68)% in MD. The Intra-Cellular volume fraction (ICvf) median L1 distance was up to 2.83% with a 95% CI of (1.98, 4.82)% at a 30% sampling rate and 3.95% with a 95% CI of (2.39, 7.81)% at a 50% sampling rate. The volume difference of the reconstructed white matter at reference and 50% sampling reached a maximum of (2.09 ± 0.81)%.

Discussion

In conclusion, DTI and NODDI measures reported at reference sampling were comparable to those obtained when the number of dMRI volumes was reduced by up to 30%. Close to reference DTI and NODDI metrics were estimated with a significant reduction in acquisition time using three shells, respectively with: 4 directions at a b value of 700 s/mm2, 14 at 1000 s/mm2, and 32 at 2000 s/mm2. The study revealed aspects that can be important for large-scale clinical studies on bundle-specific diffusion MRI.

Nervonic Acid Synthesis Substrates as Essential Components in Profiled Lipid Supplementation for More Effective Central Nervous System Regeneration

Central nervous system (CNS) damage leads to severe neurological dysfunction as a result of neuronal cell death and axonal degeneration. As, in the mature CNS, neurons have little ability to regenerate their axons and reconstruct neural loss, demyelination is one of the hallmarks of neurological disorders such as multiple sclerosis (MS). Unfortunately, remyelination, as a regenerative process, is often insufficient to prevent axonal loss and improve neurological deficits after demyelination. Currently, there are still no effective therapeutic tools to restore neurological function, but interestingly, emerging studies prove the beneficial effects of lipid supplementation in a wide variety of pathological processes in the human body. In the future, available lipids with a proven beneficial effect on CNS regeneration could be included in supportive therapy, but this topic still requires further studies. Based on our and others' research, we review the role of exogenous lipids, pointing to substrates that are crucial in the remyelination process but are omitted in available studies, justifying the properly profiled supply of lipids in the human diet as a supportive therapy during CNS regeneration.

Targeting N-Methyl-d-Aspartate Receptors in Neurodegenerative Diseases

N-methyl-d-aspartate receptors (NMDARs) are the main class of ionotropic receptors for the excitatory neurotransmitter glutamate. They play a crucial role in the permeability of Ca2+ ions and excitatory neurotransmission in the brain. Being heteromeric receptors, they are composed of several subunits, including two obligatory GluN1 subunits (eight splice variants) and regulatory GluN2 (GluN2A~D) or GluN3 (GluN3A~B) subunits. Widely distributed in the brain, they regulate other neurotransmission systems and are therefore involved in essential functions such as synaptic transmission, learning and memory, plasticity, and excitotoxicity. The present review will detail the structure, composition, and localization of NMDARs, their role and regulation at the glutamatergic synapse, and their impact on cognitive processes and in neurodegenerative diseases (Alzheimer's, Huntington's, and Parkinson's disease). The pharmacology of different NMDAR antagonists and their therapeutic potentialities will be presented. In particular, a focus will be given on fluoroethylnormemantine (FENM), an investigational drug with very promising development as a neuroprotective agent in Alzheimer's disease, in complement to its reported efficacy as a tomography radiotracer for NMDARs and an anxiolytic drug in post-traumatic stress disorder.

Antineoplastics for treating Alzheimer's disease and dementia: Evidence from preclinical and observational studies

As the world population ages, there will be an increasing need for effective therapies for aging-associated neurodegenerative disorders, which remain untreatable. Dementia due to Alzheimer's disease (AD) is one of the leading neurological diseases in the aging population. Current therapeutic approaches to treat this disorder are solely symptomatic, making the need for new molecular entities acting on the causes of the disease extremely urgent. One of the potential solutions is to use compounds that are already in the market. The structures have known pharmacokinetics, pharmacodynamics, toxicity profiles, and patient data available in several countries. Several drugs have been used successfully to treat diseases different from their original purposes, such as autoimmunity and peripheral inflammation. Herein, we divulge the repurposing of drugs in the area of neurodegenerative diseases, focusing on the therapeutic potential of antineoplastics to treat dementia due to AD and dementia. We briefly touch upon the shared pathological mechanism between AD and cancer and drug repurposing strategies, with a focus on artificial intelligence. Next, we bring out the current status of research on the development of drugs, provide supporting evidence from retrospective, clinical, and preclinical studies on antineoplastic use, and bring in new areas, such as repurposing drugs for the prion-like spreading of pathologies in treating AD.

Linguistic changes in neurodegenerative diseases relate to clinical symptoms

Background

The detection and characterization of speech changes may help in the identification and monitoring of neurodegenerative diseases. However, there is limited research validating the relationship between speech changes and clinical symptoms across a wide range of neurodegenerative diseases.

Method

We analyzed speech recordings from 109 patients who were diagnosed with various neurodegenerative diseases, including Alzheimer's disease, Frontotemporal Dementia, and Vascular Cognitive Impairment, in a cognitive neurology memory clinic. Speech recordings of an open-ended picture description task were processed using the Winterlight speech analysis platform which generates >500 speech features, including the acoustics of speech and linguistic properties of spoken language. We investigated the relationship between the speech features and clinical assessments including the Mini Mental State Examination (MMSE), Mattis Dementia Rating Scale (DRS), Western Aphasia Battery (WAB), and Boston Naming Task (BNT) in a heterogeneous patient population.

Result

Linguistic features including lexical and syntactic features were significantly correlated with clinical assessments in patients, across diagnoses. Lower MMSE and DRS scores were associated with the use of shorter words and fewer prepositional phrases. Increased impairment on WAB and BNT was correlated with the use of fewer nouns but more pronouns. Patients also differed from healthy adults as their speech duration was significantly shorter with more pauses.

Conclusion

Linguistic changes such as the use of simpler vocabularies and syntax were detectable in patients with different neurodegenerative diseases and correlated with cognitive decline. Speech has the potential to be a sensitive measure for detecting cognitive impairments across various neurodegenerative diseases.

Effects of Aerobic Exercise on Executive and Memory Functions in Patients With Alzheimer's Disease: A Systematic Review

BACKGROUND

Alzheimer's disease threatens the health of older adults, particularly by disrupting executive and memory functions, and many studies have shown that aerobic exercise prevents and improves the symptoms associated with the disease.

OBJECTIVE

The objective was to systematically review the effects of aerobic exercise on executive and memory functions in patients with Alzheimer's disease and to determine the effect factors and mechanisms of the design of aerobic exercise intervention programs.

METHOD

Relevant literature was searched in three databases (PubMed, Web of Science, and EBSCO) from January 1, 2014 to March 1, 2023, using a subject-word search method. Data on 10 items, including author and country, were extracted from the literature after screening. The quality of the literature was evaluated using the Physiotherapy Evidence Database scale, and a systematic review was performed.

RESULTS

Twelve papers from seven countries were ultimately included, embodying 11 randomized controlled trials and one study with a repeated-measures design. The overall quality of the studies was good as 657 study participants, aged 45 years and older who had varying degrees of Alzheimer's disease and significant symptoms, were included. Aerobic exercise was found to have a significant positive impact on executive and memory functions in people with Alzheimer's disease.

CONCLUSION

The effects of aerobic exercise on aspects of executive function were mainly characterized by improvements in inhibitory control, working memory, and cognitive flexibility, whereas the effects on aspects of memory function were mainly characterized by improvements in logical memory, situational memory, and short-term memory.

Familial Alzheimer's disease associated with heterozygous NPC1 mutation

INTRODUCTION

NPC1 mutations are responsible for Niemann-Pick disease type C (NPC), a rare autosomal recessive neurodegenerative disease. Patients harbouring heterozygous NPC1 mutations may rarely show parkinsonism or dementia. Here, we describe for the first time a large family with an apparently autosomal dominant late-onset Alzheimer's disease (AD) harbouring a novel heterozygous NPC1 mutation.

METHODS

All the five living siblings belonging to the family were evaluated. We performed clinical evaluation, neuropsychological tests, assessment of cerebrospinal fluid markers of amyloid deposition, tau pathology and neurodegeneration (ATN), structural neuroimaging and brain amyloid-positron emission tomography. Oxysterol serum levels were also tested. A wide next-generation sequencing panel of genes associated with neurodegenerative diseases and a whole exome sequencing analysis were performed.

RESULTS

We detected the novel heterozygous c.3034G>T (p.Gly1012Cys) mutation in NPC1, shared by all the siblings. No other point mutations or deletions in NPC1 or NPC2 were found. In four siblings, a diagnosis of late-onset AD was defined according to clinical characterisation and ATN biomarkers (A+, T+, N+) and serum oxysterol analysis showed increased 7-ketocholesterol and cholestane-3β,5α,6β-triol.

DISCUSSION

We describe a novel NPC1 heterozygous mutation harboured by different members of a family with autosomal dominant late-onset amnesic AD without NPC-associated features. A missense mutation in homozygous state in the same aminoacidic position has been previously reported in a patient with NPC with severe phenotype. The alteration of serum oxysterols in our family corroborates the pathogenic role of our NPC1 mutation. Our work, illustrating clinical and biochemical disease hallmarks associated with NPC1 heterozygosity in patients affected by AD, provides relevant insights into the pathogenetic mechanisms underlying this possible novel association.

Distinctive whole-brain cell types predict tissue damage patterns in thirteen neurodegenerative conditions

For over a century, brain research narrative has mainly centered on neuron cells. Accordingly, most neurodegenerative studies focus on neuronal dysfunction and their selective vulnerability, while we lack comprehensive analyses of other major cell types' contribution. By unifying spatial gene expression, structural MRI, and cell deconvolution, here we describe how the human brain distribution of canonical cell types extensively predicts tissue damage in 13 neurodegenerative conditions, including early- and late-onset Alzheimer's disease, Parkinson's disease, dementia with Lewy bodies, amyotrophic lateral sclerosis, mutations in presenilin-1, and 3 clinical variants of frontotemporal lobar degeneration (behavioral variant, semantic and non-fluent primary progressive aphasia) along with associated three-repeat and four-repeat tauopathies and TDP43 proteinopathies types A and C. We reconstructed comprehensive whole-brain reference maps of cellular abundance for six major cell types and identified characteristic axes of spatial overlapping with atrophy. Our results support the strong mediating role of non-neuronal cells, primarily microglia and astrocytes, in spatial vulnerability to tissue loss in neurodegeneration, with distinct and shared across-disorder pathomechanisms. These observations provide critical insights into the multicellular pathophysiology underlying spatiotemporal advance in neurodegeneration. Notably, they also emphasize the need to exceed the current neuro-centric view of brain diseases, supporting the imperative for cell-specific therapeutic targets in neurodegeneration.

Senescence: A DNA damage response and its role in aging and Neurodegenerative Diseases

Senescence is a complicated, multi-factorial, irreversible cell cycle halt that has a tumor-suppressing effect in addition to being a significant factor in aging and neurological diseases. Damaged DNA, neuroinflammation, oxidative stress and disrupted proteostasis are a few of the factors that cause senescence. Senescence is triggered by DNA damage which initiates DNA damage response. The DNA damage response, which includes the formation of DNA damage foci containing activated H2AX, which is a key factor in cellular senescence, is provoked by a double strand DNA break. Oxidative stress impairs cognition, inhibits neurogenesis, and has an accelerated aging effect. Senescent cells generate pro-inflammatory mediators known as senescence-associated secretory phenotype (SASP). These pro-inflammatory cytokines and chemokines have an impact on neuroinflammation, neuronal death, and cell proliferation. While it is tempting to think of neurodegenerative diseases as manifestations of accelerated aging and senescence, this review will present information on brain ageing and neurodegeneration as a result of senescence and DNA damage response.

Generalizing Parkinson's disease detection using keystroke dynamics: a self-supervised approach

OBJECTIVE

Passive monitoring of touchscreen interactions generates keystroke dynamic signals that can be used to detect and track neurological conditions such as Parkinson's disease (PD) and psychomotor impairment with minimal burden on the user. However, this typically requires datasets with clinically confirmed labels collected in standardized environments, which is challenging, especially for a large subject pool. This study validates the efficacy of a self-supervised learning method in reducing the reliance on labels and evaluates its generalizability.

MATERIALS AND METHODS

We propose a new type of self-supervised loss combining Barlow Twins loss, which attempts to create similar feature representations with reduced feature redundancy for samples coming from the same subject, and a Dissimilarity loss, which promotes uncorrelated features for samples generated by different subjects. An encoder is first pre-trained using this loss on unlabeled data from an uncontrolled setting, then fine-tuned with clinically validated data. Our experiments test the model generalizability with controls and subjects with PD on 2 independent datasets.

RESULTS

Our approach showed better generalization compared to previous methods, including a feature engineering strategy, a deep learning model pre-trained on Parkinsonian signs, and a traditional supervised model.

DISCUSSION

The absence of standardized data acquisition protocols and the limited availability of annotated datasets compromise the generalizability of supervised models. In these contexts, self-supervised models offer the advantage of learning more robust patterns from the data, bypassing the need for ground truth labels.

CONCLUSION

This approach has the potential to accelerate the clinical validation of touchscreen typing software for neurodegenerative diseases.

The SCF-FBW7β E3 ligase mediates ubiquitination and degradation of the serine/threonine protein kinase PINK1

Understanding the mechanisms that govern the stability of functionally crucial proteins is essential for various cellular processes, development, and overall cell viability. Disturbances in protein homeostasis are linked to the pathogenesis of neurodegenerative diseases. PTEN-induced kinase 1 (PINK1), a protein kinase, plays a significant role in mitochondrial quality control and cellular stress response, and its mutated forms lead to early-onset Parkinson's disease. Despite its importance, the specific mechanisms regulating PINK1 protein stability have remained unclear. This study reveals a cytoplasmic interaction between PINK1 and F-box and WD repeat domain-containing 7β (FBW7β) in mammalian cells. FBW7β, a component of the Skp1-Cullin-1-F-box protein complex-type ubiquitin ligase, is instrumental in recognizing substrates. Our findings demonstrate that FBW7β regulates PINK1 stability through the Skp1-Cullin-1-F-box protein complex and the proteasome pathway. It facilitates the K48-linked polyubiquitination of PINK1, marking it for degradation. When FBW7 is absent, PINK1 accumulates, leading to heightened mitophagy triggered by carbonyl cyanide 3-chlorophenylhydrazone treatment. Moreover, exposure to the toxic compound staurosporine accelerates PINK1 degradation via FBW7β, correlating with increased cell death. This study unravels the intricate mechanisms controlling PINK1 protein stability and sheds light on the novel role of FBW7β. These findings deepen our understanding of PINK1-related pathologies and potentially pave the way for therapeutic interventions.

Genotoxic and neurotoxic potential of intracellular nanoplastics: A review

Plastic waste comprises polymers of different chemicals that disintegrate into nanoplastic particles (NPLs) of 1-100-nm size, thereby littering the environment and posing a threat to wildlife and human health. Research on NPL contamination has up to now focused on the ecotoxicology effects of the pollution rather than the health risks. This review aimed to speculate about the possible properties of carcinogenic and neurotoxic NPL as pollutants. Given their low-dimensional size and high surface size ratio, NPLs can easily penetrate biological membranes to cause functional and structural damage in cells. Once inside the cell, NPLs can interrupt the autophagy flux of cellular debris, alter proteostasis, provoke mitochondrial dysfunctions, and induce endoplasmic reticulum stress. Harmful metabolic and biological processes induced by NPLs include oxidative stress (OS), ROS generation, and pro-inflammatory reactions. Depending on the cell cycle status, NPLs may direct DNA damage, tumorigenesis, and lately carcinogenesis in tissues with high self-renewal capabilities like epithelia. In cells able to live the longest like neurons, NPLs could trigger neurodegeneration by promoting toxic proteinaceous aggregates, OS, and chronic inflammation. NPL genotoxicity and neurotoxicity are discussed based on the gathered evidence, when available, within the context of the intracellular uptake of these newcomer nanoparticles. In summary, this review explains how the risk evaluation of NPL pollution for human health may benefit from accurately monitoring NPL toxicokinetics and toxicodynamics at the intracellular resolution level.

Bearded capuchin monkeys as a model for Alzheimer's disease

The absence of a natural animal model is one of the main challenges in Alzheimer's disease research. Despite the challenges of using nonhuman primates in studies, these animals can bridge mouse models and humans, as nonhuman primates are phylogenetically closer to humans and can spontaneously develop AD-type pathology. The capuchin monkey, a New World primate, has recently attracted attention due to its skill in creating and using instruments. We analyzed one capuchin brain using structural 7 T MRI and performed a neuropathological evaluation of three animals. Alzheimer-type pathology was found in the two of the capuchins. Widespread β-amyloid pathology was observed, mainly in focal deposits with variable morphology and a high density of mature plaques. Notably, plaque-associated dystrophic neurites associated with disruption of axonal transport and early cytoskeletal alteration were frequently found. Unlike in other species of New World monkeys, cerebral arterial angiopathy was not the predominant form of β-amyloid pathology. Additionally, abnormal aggregates of hyperphosphorylated tau, resembling neurofibrillary pathology, were observed in the temporal and frontal cortex. Astrocyte hypertrophy surrounding plaques was found, suggesting a neuroinflammatory response. These findings indicate that aged capuchin monkeys can spontaneously develop Alzheimer-type pathology, indicating that they may be an advantageous animal model for research in Alzheimer's disease.

Neuroinflammatory Response and Redox-regulation Activity of Hyperoside in Manganese-induced Neurotoxicity Model of Wistar Rats

BACKGROUND

Excessive manganese exposure can lead to neurotoxicity with detrimental effects on the brain. Neuroinflammatory responses and redox regulation play pivotal roles in this process. Exploring the impact of hyperoside in a Wistar rat model offers insights into potential neuroprotective strategies against manganese-induced neurotoxicity.

OBJECTIVE

The study investigated the neuroprotective efficacy of hyperoside isolated from the ethanol leaf extract of Gongronema latifolium (HELEGL), in the brain tissue of Wistar rats following 15 consecutive days of exposure to 30 mg/L of MnCl2.

METHODS

Control animals in Group 1 had access to regular drinking water, while animals in groups 2-4 were exposed to MnCl2 in their drinking water. Groups 3 and 4 also received additional HELEGL at doses of 100 mg/kg and 200 mg/kg of body weight, respectively. In Group 5, HELEGL at a dose of 100 mg/kg of body weight was administered alone. Treatment with HELEGL commenced on day 8 via oral administration.

RESULTS

HELEGL effectively mitigated MnCl2-induced memory impairment, organ-body weight discrepancies, and fluid intake deficits. Exposure to MnCl2 increased the activities or levels of various markers such as acyl peptide hydrolase, tumour necrosis factor-α, dipeptidyl peptidase IV, nitric oxide, IL-1β, prolyl oligopeptidase, caspase-3, myeloperoxidase, H2O2, and malondialdehyde, while it decreased the activities or levels of others, including AChE, BChE, DOPA, serotonin, epinephrine, norepinephrine, GST, GPx, CAT, SOD, GSH, and T-SH (p < 0.05). In contrast, HELEGL effectively counteracted the adverse effects of MnCl2 by alleviating oxidative stress, inflammation, apoptosis, mitochondrial dysfunction, cognitive deficits, and bolstering the antioxidant status. Moreover, HELEGL restored the normal histoarchitecture of the brain, which had been distorted by MnCl2.

CONCLUSION

In summary, HELEGL reversed the causative factors of neurodegenerative diseases induced by MnCl2 exposure, suggesting its potential for further exploration as a prospective therapeutic agent in the management of Alzheimer's disease and related forms of dementia.

Mechanosensory neurons under pressure

A build-up of eggs in the uterus of the nematode C. elegans triggers the release of large extracellular vesicles, called exophers, from neurons that are sensitive to mechanical forces.

Higher serum Lp-PLA2 is associated with cognitive impairment in Parkinson's disease patients

Objective

To explore the association between lipoprotein-associated phospholipase A2 (Lp-PLA2) and the risk of cognitive impairment in Parkinson's disease (PD-CI).

Methods

A case-control study involving 100 hospitalized PD patients and 60 healthy controls was carried out. Serum Lp-PLA2 level was detected by automatic biochemical analyzer. Based on whether Parkinson's patients have cognitive impairment, PD patients were subdivided to analyze the clinical value of Lp-PLA2. Relationship between Lp-PLA2 and PD-CI risk was analyzed by logistic regression. Diagnostic value of Lp-PLA2 in PD-CI patients was investigated using receiver's operator characteristic curves.

Results

The levels of serum Lp-PLA2 activity in Parkinson's disease with normal cognition (PD-NC) and PD-CI patients were significantly higher than those in healthy controls (HCs), respectively. Furthermore, compared to the PD-NC group, the serum Lp-PLA2 activity level was significantly higher in PD-CI patients. Multivariable logistic regression analysis indicated that higher Lp-PLA2 level was an independent risk factor for PD patients with cognitive impairment. Moreover, the area under the efficacy curve of Lp-PLA2 for predicting PD-CI is 0.659.

Conclusion

Our study shows that higher levels of Lp-PLA2 activity in PD patients are associated with the risk of developing cognitive impairment. Therefore, given the wide availability, safety, and convenience of monitoring serum Lp-PLA2 activity, it may serve as an early biomarker for cognitive impairment in PD patients.

Link among apolipoprotein E E4, gait, and cognition in neurodegenerative diseases: ONDRI study

INTRODUCTION

Apolipoprotein E E4 allele (APOE E4) and slow gait are independently associated with cognitive impairment and dementia. However, it is unknown whether their coexistence is associated with poorer cognitive performance and its underlying mechanism in neurodegenerative diseases.

METHODS

Gait speed, APOE E4, cognition, and neuroimaging were assessed in 480 older adults with neurodegeneration. Participants were grouped by APOE E4 presence and slow gait. Mediation analyses were conducted to determine if brain structures could explain the link between these factors and cognitive performance.

RESULTS

APOE E4 carriers with slow gait had the lowest global cognitive performance and smaller gray matter volumes compared to non-APOE E4 carriers with normal gait. Coexistence of APOE E4 and slow gait best predicted global and domain-specific poorer cognitive performances, mediated by smaller gray matter volume.

DISCUSSION

Gait slowness in APOE E4 carriers with neurodegenerative diseases may indicate extensive gray matter changes associated with poor cognition.

HIGHLIGHTS

APOE E4 and slow gait are risk factors for cognitive decline in neurodegenerative diseases. Slow gait and smaller gray matter volumes are associated, independently of APOE E4. Worse cognition in APOE E4 carriers with slow gait is explained by smaller GM volume. Gait slowness in APOE E4 carriers indicates poorer cognition-related brain changes.

U1 snRNP Biogenesis Defects in Neurodegenerative Diseases

The U1 small ribonucleoprotein (U1 snRNP) plays a pivotal role in the intricate process of gene expression, specifically within nuclear RNA processing. By initiating the splicing reaction and modulating 3'-end processing, U1 snRNP exerts precise control over RNA metabolism and gene expression. This ribonucleoparticle is abundantly present, and its complex biogenesis necessitates shuttling between the nuclear and cytoplasmic compartments. Over the past three decades, extensive research has illuminated the crucial connection between disrupted U snRNP biogenesis and several prominent human diseases, notably various neurodegenerative conditions. The perturbation of U1 snRNP homeostasis has been firmly established in diseases such as Spinal Muscular Atrophy, Pontocerebellar hypoplasia, and FUS-mediated Amyotrophic Lateral Sclerosis. Intriguingly, compelling evidence suggests a potential correlation in Fronto-temporal dementia and Alzheimer's disease as well. Although the U snRNP biogenesis pathway is conserved across all eukaryotic cells, neurons, in particular, appear to be highly susceptible to alterations in spliceosome homeostasis. In contrast, other cell types exhibit a greater resilience to such disturbances. This vulnerability underscores the intricate relationship between U1 snRNP dynamics and the health of neuronal cells, shedding light on potential avenues for understanding and addressing neurodegenerative disorders.

Injectable Hydrogels for Nervous Tissue Repair-A Brief Review

The repair of nervous tissue is a critical research field in tissue engineering because of the degenerative process in the injured nervous system. In this review, we summarize the progress of injectable hydrogels using in vitro and in vivo studies for the regeneration and repair of nervous tissue. Traditional treatments have not been favorable for patients, as they are invasive and inefficient; therefore, injectable hydrogels are promising for the treatment of damaged tissue. This review will contribute to a better understanding of injectable hydrogels as potential scaffolds and drug delivery system for neural tissue engineering applications.

Dissecting genetic architecture of rare dystonia: genetic, molecular and clinical insights

BACKGROUND

Dystonia is one of the most common movement disorders. To date, the genetic causes of dystonia in populations of European descent have been extensively studied. However, other populations, particularly those from the Middle East, have not been adequately studied. The purpose of this study is to discover the genetic basis of dystonia in a clinically and genetically well-characterised dystonia cohort from Turkey, which harbours poorly studied populations.

METHODS

Exome sequencing analysis was performed in 42 Turkish dystonia families. Using co-expression network (CEN) analysis, identified candidate genes were interrogated for the networks including known dystonia-associated genes and genes further associated with the protein-protein interaction, animal model-based characteristics and clinical findings.

RESULTS

We identified potentially disease-causing variants in the established dystonia genes (PRKRA, SGCE, KMT2B, SLC2A1, GCH1, THAP1, HPCA, TSPOAP1, AOPEP; n=11 families (26%)), in the uncommon forms of dystonia-associated genes (PCCB, CACNA1A, ALDH5A1, PRKN; n=4 families (10%)) and in the candidate genes prioritised based on the pathogenicity of the variants and CEN-based analyses (n=11 families (21%)). The diagnostic yield was found to be 36%. Several pathways and gene ontologies implicated in immune system, transcription, metabolic pathways, endosomal-lysosomal and neurodevelopmental mechanisms were over-represented in our CEN analysis.

CONCLUSIONS

Here, using a structured approach, we have characterised a clinically and genetically well-defined dystonia cohort from Turkey, where dystonia has not been widely studied, and provided an uncovered genetic basis, which will facilitate diagnostic dystonia research.

Identification of a novel drug molecule for neurodegenerative disease from marine algae through in-silico analysis

Cognitive functions are lost due to the rapid hydrolysis of acetylcholine including Acetylcholinesterase (AChE) and Butyrylcholinesterase (BChE). Marine algae-derived compounds were reported for their neuroprotective activities and hence they can be utilised for treating neurodegenerative ailments like Alzheimer's Disease and Parkinson's Disease which are due to the loss of cognitive functions. Major attention is currently paid to seaweeds due to their health benefits and high nutritional values. Sea weeds are of a rich sense of natural bioactive compounds which antioxidants, pharmaceutical compounds, flavonoids and alkaloids. They also contain a high amount of vitamins A, D, E, C and Ca, K, Mg and Fe. Regular consumption of a marine algae-based diet may boost immunities. In searching for natural cholinesterase inhibitors, the present study is focussed on some marine bioactive compounds reported from brown, red and green algae. Molecular docking studies have been carried out along with molecular dynamics simulations studies and binding energy calculations resulting in three best bioactive compounds when AChE is used as the target. The results are compared with cocrystal studies. Two best compounds, namely, Diphlorethohydroxycarmalol and Phlorofucofuroeckol from the brown seaweeds are identified as the potential lead compounds for neurodegenerative diseases, Alzheimer's and Parkinson's.Communicated by Ramaswamy H. Sarma.