The distinction between sporadic and genetic behavioural-variant frontotemporal dementia(bvFTD)regarding some neuropsychological(NP)features remains challenging.Specifically,progranulin(GRN)-associated bvFTD frequentl...The distinction between sporadic and genetic behavioural-variant frontotemporal dementia(bvFTD)regarding some neuropsychological(NP)features remains challenging.Specifically,progranulin(GRN)-associated bvFTD frequently presents with early episodic memory impairment and some degree of parietal dysfunction which are supporters of Alzheimer’s disease(AD)diagnosis.In this context,we aimed to characterize the NP profile of GRN-bvFTD as compared to sporadic-bvFTD and AD in patients with mild dementia(Mini-Mental State Examination score≥17 and Clinical Dementia Rating Scale score≤1.We identified 21 patients at Centro Hospitalar e Universitário de Coimbra,Portugal with GRN mutations belonging to fifteen different families.As our focus was bvFTD variants,FTD-related aphasic forms(3 patients)were excluded.The remaining 18 GRN-bvFTD were further matched with 18 sporadic-bvFTD and 18 AD patients according to disease staging,age and education.All patients completed the Mini-Mental State Examination,Montreal Cognitive Assessment(MoCA)and a comprehensive NP assessment battery.Results were converted into z-scores.Differences between groups in individual NP measures and NP domains were assessed through non-parametric tests(Kruskal-Wallis test analysis)and eta squared(ŋ2)was calculated as a measure of effect size.Group comparisons show that GRN patients have worse performances on verbal retrieval processes(P=0.039,ŋ2=0.110)and visuoconstructive abilities(P=0.039,ŋ2=0.190)than sporadic bvFTD forms.When compared to AD,GRN patients present a higher impairment in frontal(P=0.001,ŋ2=0.211)and parietal(P=0.041,ŋ2=0.129)measures and a better performance in memory tasks(P=0.020,ŋ2=0.120).Sporadic-bvFTD forms are worse than AD in frontal measures(P=0.032,ŋ2=0.200),being better in both memory(P=0.010,ŋ2=0.131)and visuospatial skills(P=0.023,ŋ2=0.231).Considering these results,we conclude that GRN-bvFTD patients present a NP profile that associates the typical patterns of FTD and AD deficits.This is particularly expressive in visuoconstructive abilities,which was the more discriminative feature between groups,followed by episodic verbal memory.This study was approved by the Institutional Ethics Committee of Centro Hospitalar e Universitário de Coimbra,Portugal(CE-029/2019)on June 24,2019.展开更多
Frontotemporal lobar degeneration describes a group of progressive brain disorders that primarily are associated with atrophy of the prefrontal and anterior temporal lobes.Frontotemporal lobar degeneration is consider...Frontotemporal lobar degeneration describes a group of progressive brain disorders that primarily are associated with atrophy of the prefrontal and anterior temporal lobes.Frontotemporal lobar degeneration is considered to be equivalent to frontotemporal dementia.Frontotemporal dementia is characterized by progressive impairments in behavior,executive function,and language.There are two main clinical subtypes:behavioral-variant frontotemporal dementia and primary progressive aphasia.The early diagnosis of frontotemporal dementia is critical for developing management strategies and interventions for these patients.Without validated biomarkers,the clinical diagnosis depends on recognizing all the core or necessary neuropsychiatric features,but misdiagnosis often occurs due to overlap with a range of neurologic and psychiatric disorders.In the studies reviewed a very large number of microRNAs were found to be dysregulated but with limited overlap between individual studies.Measurement of specific miRNAs singly or in combination,or as miRNA pairs(as a ratio)in blood plasma,serum,or cerebrospinal fluid enabled frontotemporal dementia to be discriminated from healthy controls,Alzheimer’s disease,and amyotrophic lateral sclerosis.Furthermore,upregulation of miR-223-3p and downregulation of miR-15a-5p,which occurred both in blood serum and cerebrospinal fluid,distinguished behavioral-variant frontotemporal dementia from healthy controls.Downregulation of miR-132-3p in frontal and temporal cortical tissue distinguished frontotemporal lobar degeneration and frontotemporal dementia,respectively,from healthy controls.Possible strong miRNA biofluid biomarker contenders for behavioral-variant frontotemporal dementia are miR-223-3p,miR-15a-5p,miR-22-3p in blood serum and cerebrospinal fluid,and miR-124 in cerebrospinal fluid.No miRNAs were identified able to distinguish between behavioral-variant frontotemporal dementia and primary progressive aphasia subtypes.Further studies are warranted on investigating miRNA expression in biofluids and frontal/temporal cortical tissue to validate and extend these findings.展开更多
Protein synthesis is essential for cells to perform life metabolic processes.Pathological alterations of protein content can lead to particular diseases.Cells have an intrinsic array of mechanisms and pathways that ar...Protein synthesis is essential for cells to perform life metabolic processes.Pathological alterations of protein content can lead to particular diseases.Cells have an intrinsic array of mechanisms and pathways that are activated when protein misfolding,accumulation,aggregation or mislocalization occur.Some of them(like the unfolded protein response)represent complex interactions between endoplasmic reticulum sensors and elongation factors that tend to increase expression of chaperone proteins and/or repress translation in order to restore protein homeostasis(also known as proteostasis).This is even more important in neurons,as they are very susceptible to harmful effects associated with protein overload and proteostatic mechanisms are less effective with age.Several neurodegenerative pathologies such as Alzheimer’s,Parkinson’s,and Huntington’s diseases,amyotrophic lateral sclerosis and frontotemporal dementia exhibit a particular molecular signature of distinct,unbalanced protein overload.In amyotrophic lateral sclerosis and frontotemporal dementia,the majority of cases present intracellular inclusions of ubiquitinated transactive response DNA-binding protein of 43 kDa(TDP-43).TDP-43 is an RNA binding protein that participates in RNA metabolism,among other functions.Dysregulation of TDP-43(e.g.aggregation and mislocalization)can dramatically affect neurons,and this has been linked to disease development.Expression of amyotrophic lateral sclerosis/frontotemporal dementia TDP-43-related mutations in cellular and animal models has been shown to recapitulate key features of the amyotrophic lateral sclerosis/frontotemporal dementia disease spectrum.These variants can be causative of degeneration onset and progression.Most neurodegenerative diseases(including amyotrophic lateral sclerosis and frontotemporal dementia)have no cure at the moment;however,modulating translation has recently emerged as an attractive approach that can be performed at several steps(i.e.regulating activation of initiation and elongation factors,inhibiting unfolded protein response activation or inducing chaperone expression and activity).This review focuses on the features of protein imbalance in neurodegenerative disorders and the relevance of developing therapeutical compounds aiming at restoring proteostasis.We strive to highlight the importance of research on drugs that,not only restore protein imbalance without compromising translational activity of cells,but are also as safe as possible for the patients.展开更多
Tauopathies,diseases characterized by neuropathological aggregates of tau including Alzheimer's disease and subtypes of fro ntotemporal dementia,make up the vast majority of dementia cases.Although there have been...Tauopathies,diseases characterized by neuropathological aggregates of tau including Alzheimer's disease and subtypes of fro ntotemporal dementia,make up the vast majority of dementia cases.Although there have been recent developments in tauopathy biomarkers and disease-modifying treatments,ongoing progress is required to ensure these are effective,economical,and accessible for the globally ageing population.As such,continued identification of new potential drug targets and biomarkers is critical."Big data"studies,such as proteomics,can generate information on thousands of possible new targets for dementia diagnostics and therapeutics,but currently remain underutilized due to the lack of a clear process by which targets are selected for future drug development.In this review,we discuss current tauopathy biomarkers and therapeutics,and highlight areas in need of improvement,particularly when addressing the needs of frail,comorbid and cognitively impaired populations.We highlight biomarkers which have been developed from proteomic data,and outline possible future directions in this field.We propose new criteria by which potential targets in proteomics studies can be objectively ranked as favorable for drug development,and demonstrate its application to our group's recent tau interactome dataset as an example.展开更多
Since the discovery of the C9ORF72 gene in2011,great advances have been achieved in its genetics and in identifying its role in disease models and pathological mechanisms;it is the most common genetic cause of amyotro...Since the discovery of the C9ORF72 gene in2011,great advances have been achieved in its genetics and in identifying its role in disease models and pathological mechanisms;it is the most common genetic cause of amyotrophic lateral sclerosis(ALS) and frontotemporal dementia(FTD).ALS patients with C9ORF72 expansion show heterogeneous symptoms.Those who are C9ORF72 expansion carriers have shorter survival after disease onset than non-C9ORF72 expansion patients.Pathological and clinical features of C9ORF72 patients have been well mimicked via several models,including induced pluripotent stem cell-derived neurons and transgenic mice that were embedded with bacterial artificial chromosome construct and that overexpressing dipeptide repeat proteins.The mechanisms implicated in C9ORF72 pathology include DNA damage,changes of RNA metabolism,alteration of phase separation,and impairment of nucleocytoplasmic transport,which may underlie C9ORF72 expansion-related ALS/FTD and provide insight into nonC9ORF72 expansion-related ALS,FTD,and other neurodegenerative diseases.展开更多
Cardiovascular risk factors(CRF)were widely described as related to dementia.There are very few studies regarding this association in FTD.The objective of the study was to compare the frequency of CRF in our populatio...Cardiovascular risk factors(CRF)were widely described as related to dementia.There are very few studies regarding this association in FTD.The objective of the study was to compare the frequency of CRF in our population with FTD and controls.100 consecutive subjects with FTD diagnosis according to Lund-Manchester clinical criteria and 200 controls matched by age and sex were included between January 2003 to February 2007 at the Cognitive and Behavior Unit of Hospital Italiano de Buenos Aires.Clinical evaluation,laboratory tests,brain images(CT/MRI),neuropsychological and neuropsychiatric assessment were performed.Multiple regression analysis was performed to analyze the association in CRF between FTD patients vs.controls.The mean age in FTD was 69.7±0.9 vs.70.1±0.8 in controls(p 0.12).No difference in gender was observed between cases and controls.No differences were identified between patients and controls regarding hypertension(HTA)(65%vs.67,3%p 0.44);dyslipidemia(57%vs.54.7%p 0.74);obesity(39%vs.27.6%p 0.14)and hypothyroidism(26%vs.17.1%p 0.1).A significant difference was observed for Diabetes Mellitus(39%vs.22.6%p 0.001).In our population,Diabetes Mellitus was associated as an independent risk factor for FTD.To our knowledge this is the first report in which CRF were evaluated prospectively in FTD patients.More studies are needed to confirm this finding in larger populations.展开更多
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease mainly involving motor neurons in spinal cord,brain stem,and motor cortex of brain,characterized by variable combinations of limb weakness,muscle at...Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease mainly involving motor neurons in spinal cord,brain stem,and motor cortex of brain,characterized by variable combinations of limb weakness,muscle atrophy,and pyramidal signs.TAR DNA-binding protein 43 (TDP-43) serves as the pathological protein for both ALS and a proportion of frontotemporal dementia (FTD),where lies the foundation of a disease complex,ALS-FTD.Delusion and hallucination,core features of schizophrenia,are also regarded as common symptoms in the context of neurodegenerative dementia,including Alzheimer disease and dementia with Lewy body.Although rare in the course of FTD,these manifestations could be rather notable,causing a great challenge to differentiate FTD from schizophrenia.Emphasis of psychotic phenomenon also lies in its importance of predicting the progression to ALS-FTD and its underlying genetic mutation.Herein we report two cases of ALS-FTD presented with psychosis.展开更多
Background:Astrocytes play an essential role in neuroinflammation and are involved in the pathogenesis of neurodenegerative diseases.Studies of glial fibrillary acidic protein(GFAP),an astrocytic damage marker,may hel...Background:Astrocytes play an essential role in neuroinflammation and are involved in the pathogenesis of neurodenegerative diseases.Studies of glial fibrillary acidic protein(GFAP),an astrocytic damage marker,may help advance our understanding of different neurodegenerative diseases.In this study,we investigated the diagnostic performance of plasma GFAP(pGFAP),plasma neurofilament light chain(pNfL)and their combination for frontotemporal dementia(FTD)and Alzheimer's disease(AD)and their clinical utility in predicting disease progression.Methods:pGFAP and pNfL concentrations were measured in 72 FTD,56 AD and 83 cognitively normal(CN)participants using the Single Molecule Array technology.Of the 211 participants,199 underwent cerebrospinal(CSF)analysis and 122 had magnetic resonance imaging.We compared cross-sectional biomarker levels between groups,studied their diagnostic performance and assessed correlation between CSF biomarkers,cognitive performance and cortical thickness.The prognostic performance was investigated,analyzing cognitive decline through group comparisons by tertile.Results:Unlike pNfL,which was increased similarly in both clinical groups,pGFAP was increased in FTD but lower than in AD(all P<0.01).Combination of both plasma markers improved the diagnostic performance to discriminate FTD from AD(area under the curve[AUC]:combination 0.78;pGFAP 0.7;pNfL 0.61,all P<0.05).In FTD,pGFAP correlated with cognition,CSF and plasma NfL,and cortical thickness(all P<0.05).The higher tertile of pGFAP was associated with greater change in MMSE score and poor cognitive outcome during follow-up both in FTD(1.40 points annually,hazard ratio[HR]3.82,P<0.005)and in AD(1.20 points annually,HR 2.26,P<0.005).Conclusions:pGFAP and pNfL levels differ in FTD and AD;and their combination is useful for distinguishing between the two diseases.pGFAP could also be used to track disease severity and predict greater cognitive decline during follow-up in patients with FTD.展开更多
Progress has been made in understanding the genetics and molecular biology of frontotemporal dementia(FTD).Targets for intervention have been identified,therapies are being developed,and clinical trials are advancing....Progress has been made in understanding the genetics and molecular biology of frontotemporal dementia(FTD).Targets for intervention have been identified,therapies are being developed,and clinical trials are advancing.A major challenge for FTD research is that multiple underlying pathologies can be associated with heterogeneous phenotypes.The neuropsychological profiles associated with FTD spectrum disorders often include executive dysfunction,language impairments and behavioral disturbance.Behavioral variant FTD is characterized by an initial presentation of changes in personality,behavior and/or emotion,which are often difficult to objectively capture using traditional neuropsychological measures.The two principal language variants of FTD are Progressive Nonfluent Aphasia(PNFA)with predominant agrammatic/non-fluent impairments and Semantic Dementia(SD)with semantic impairments and visual agnosia.Selection of appropriate endpoints for clinical trials is critical to ensure that the measures are adequately sensitive to detect change,yet specific enough to isolate signal from noise,and acceptable to regulatory agencies.Given the anticipated potential for small effect sizes,measures must be able to identify small incremental changes over time.It is also imperative that the measures provide adequate coverage of the constructs or behaviors of interest.Selected outcome measures should be suitable for repeat administration,yet relatively robust to practice effects to ensure that observed changes reflect true signal variance and not residual effects due to repeated measurement or poor reliability.To facilitate widespread adoption as an endpoint,measures should be readily accessible.We provide several examples of potential global,composite,and individual cognitive measures,as well as behavioral measures promising for FTD trials.Development and application of appropriate trial outcomes is critically important to success in advancing new treatments for FTD patients.展开更多
Objective To investigate the changes in cortical excitability and inhibitory circuits of patients with Alzheimer’s disease(AD)or behavioral variant frontotemporal dementia(bv FTD)using transcranial magnetic stimulati...Objective To investigate the changes in cortical excitability and inhibitory circuits of patients with Alzheimer’s disease(AD)or behavioral variant frontotemporal dementia(bv FTD)using transcranial magnetic stimulation(TMS).Methods Forty-four patients with AD,30 patients with bv FTD and 44 healthy controls were enrolled in the study.The epidemiological data展开更多
Dementia is a contemporary global health issue with far reaching consequences, not only for affected individuals and their families, but for national and global socio-economic conditions. The hallmark feature of demen...Dementia is a contemporary global health issue with far reaching consequences, not only for affected individuals and their families, but for national and global socio-economic conditions. The hallmark feature of dementia is that of irreversible cognitive decline, usually affecting memory, and impaired activities of daily living. Advances in healthcare worldwide have facilitated longer life spans, increasing the risks of developing cognitive decline and dementia in late life. Dementia remains a clinical diagnosis. The role of structural and molecular neuroimaging in patients with dementia is primarily supportive role rather than diagnostic, American and European guidelines recommending imaging to exclude treatable causes of dementia, such as tumor, hydrocephalus or intracranial haemorrhage, but also to distinguish between different dementia subtypes, the commonest of which is Alzheimer’s disease. However, this depends on the availability of these imaging techniques at individual centres. Advanced magnetic resonance imaging (MRI) techniques, such as functional connectivity MRI, diffusion tensor imaging and magnetic resonance spectroscopy, and molecular imaging techniques, such as 18F fluoro-deoxy glucose positron emission tomography (PET), amyloid PET, tau PET, are currently within the realm of dementia research but are available for clinical use. Increasingly the research focus is on earlier identification of at risk preclinical individuals, for example due to family history. Intervention at the preclinical stages before irreversible brain damage occurs is currently the best hope of reducing the impact of dementia.展开更多
BACKGROUND Antipsychotic medications such as risperidone,olanzapine and aripiprazole are used to treat psychological and behavioural symptoms among dementia patients.Current evidence indicate prescription rates for an...BACKGROUND Antipsychotic medications such as risperidone,olanzapine and aripiprazole are used to treat psychological and behavioural symptoms among dementia patients.Current evidence indicate prescription rates for antipsychotics vary and wider consensus to evaluate clinical epidemiological outcomes is limited.AIM To investigate the potential impact of atypical antipsychotics on the mortality of patients with dementia.METHODS A retrospective clinical cohort study was developed to review United Kingdom Clinical Record Interactive Search system based data between January 1,2013 to December 31,2017.A descriptive statistical method was used to analyse the data.Mini Mental State Examination(MMSE)scores were used to assess the severity and stage of disease progression.A cox proportional hazards model was developed to evaluate the relationship between survival following diagnosis and other variables.RESULTS A total of 1692 patients were identified using natural language processing of which,587 were prescribed olanzapine,quetiapine or risperidone(common group)whilst 893(control group)were not prescribed any antipsychotics.Patients prescribed olanzapine showed an increased risk of death[hazard ratio(HR)=1.32;95%confidence interval(CI):1.08-1.60;P<0.01],as did those with risperidone(HR=1.35;95%CI:1.18-1.54;P<0.001).Patients prescribed quetiapine showed no significant association(HR=1.09;95%CI:0.90-1.34;P=0.38).Factors associated with a lower risk of death were:High MMSE score at diagnosis(HR=0.72;95%CI:0.62-0.83;P<0.001),identifying as female(HR=0.73;95%CI:0.64-0.82;P<0.001),and being of a White-British ethnic group(HR=0.82;95%CI:0.72-0.94;P<0.01).CONCLUSION A significant mortality risk was identified among those prescribed olanzapine and risperidone which contradicts previous findings although the study designs used were different.Comprehensive research should be conducted to better assess clinical epidemiological outcomes associated with diagnosis and therapies to improve clinical management of these patients.展开更多
In the last years, some studies have shown that behavior disorder seems in frontotemporal dementia is related to dysfunction in the fronto-subcortical circuitry. <strong>Objectives:</strong> We did a narra...In the last years, some studies have shown that behavior disorder seems in frontotemporal dementia is related to dysfunction in the fronto-subcortical circuitry. <strong>Objectives:</strong> We did a narrative literature review concerning fronto-subcortical circuitry and frontotemporal dementia (FTD). <strong>Methods:</strong> Manuscripts related to fronto-subcortical network and frontotemporal dementia were selected for further analysis. <strong>Results:</strong> From the executions of simple motor actions to the most complex behaviors like goal-direct behavior and social cognition, the fronto-subcortical circuitry involves an intrigued network of fibers that reaches to basal ganglia nuclei. Recently, researchers have shown five parallel fronto-subcortical circuits integrating and segregating information from the frontal cortex to basal ganglia. Understanding the relationship between the fronto-subcortical circuit dysfunctions and neurodegenerative diseases requires studying the functional anatomy and neurochemical basis involved.<strong> Conclusions:</strong> In this view, it is essential to review the functional anatomy of the fronto-subcortical network, and it’s correlated with clinical aspects to pursuing a better therapeutic approach.展开更多
Advances in experimental and computational technologies continue to grow rapidly to provide novel avenues for the treatment of neurodegenerative disorders. Despite this, there remain only a handful of drugs that have ...Advances in experimental and computational technologies continue to grow rapidly to provide novel avenues for the treatment of neurodegenerative disorders. Despite this, there remain only a handful of drugs that have shown success in late-stage clinical trials for Tau-associated neurodegenerative disorders. The most commonly prescribed treatments are symptomatic treatments such as cholinesterase inhibitors and N-methyl-D-aspartate receptor blockers that were approved for use in Alzheimer's disease. As diagnostic screening can detect disorders at earlier time points, the field needs pre-symptomatic treatments that can prevent, or significantly delay the progression of these disorders(Koychev et al., 2019). These approaches may be different from late-stage treatments that may help to ameliorate symptoms and slow progression once symptoms have become more advanced should early diagnostic screening fail. This mini-review will highlight five key avenues of academic and industrial research for identifying therapeutic strategies to treat Tau-associated neurodegenerative disorders. These avenues include investigating(1) the broad class of chemicals termed “small molecules”;(2) adaptive immunity through both passive and active antibody treatments;(3) innate immunity with an emphasis on microglial modulation;(4) synaptic compartments with the view that Tau-associated neurodegenerative disorders are synaptopathies. Although this mini-review will focus on Alzheimer's disease due to its prevalence, it will also argue the need to target other tauopathies, as through understanding Alzheimer's disease as a Tau-associated neurodegenerative disorder, we may be able to generalize treatment options. For this reason, added detail linking back specifically to Tau protein as a direct therapeutic target will be added to each topic.展开更多
The infectious template-mediated protein conversion is a unique mechanism for the onset of rare and fatal neurodegenerative disorders known as transmissible spongiform encephalopathies, or prion diseases, which affect...The infectious template-mediated protein conversion is a unique mechanism for the onset of rare and fatal neurodegenerative disorders known as transmissible spongiform encephalopathies, or prion diseases, which affect humans and other animal species. However, emerging studies are now demonstrating prion-like mechanisms of self-propagation of protein misfolding in a number of common, non-infectious neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. It has been proposed that distinct and unrelated proteins(beta-amyloid, tau, α-synuclein, TAR DNA-binding protein 43 and huntingtin, etc.) associated with common neurodegenerative disorders can seed conversion and spread via cellto-cell transfer, sustaining the transmission of neurotoxic agents along a stereotypic route, sharing features at the heart of the intrinsic nature of prions. Here we review the most recent development on both the molecular mechanisms underlying the pathogenesis of prion-like neurodegenerative diseases as well as innovative methods and strategies for potential therapeutic applications.展开更多
The abnormal expansion of G-rich hexanucleotide repeat,GGGGCC(G4C2),in chromosome 9 open reading frame 72(C9orf72)is known to be the prevailing genetic cause of two fatal degenerative neurological diseases,amyotrophi...The abnormal expansion of G-rich hexanucleotide repeat,GGGGCC(G4C2),in chromosome 9 open reading frame 72(C9orf72)is known to be the prevailing genetic cause of two fatal degenerative neurological diseases,amyotrophic lateral sclerosis(ALS)and frontotemporal dementia(FTD).It is well known that the DNA G4C2 repeat expansion with different lengths can form G-quadruplexes which affect gene transcription related to ALS/FTD,therefore it is crucial to understand DNA G4C2 G-quadruplex structures.Herein,by utilizing nuclear magnetic resonance(NMR)spectroscopy,we examined DNA G-quadruplex structure adopted by two G4C2 hexanucleotide repeats with an inosine substitution at position 4,d(G4C2)2-I4.We show that d(G4C2)2-I4 folds into an eight-layer parallel tetrameric G-quadruplex containing two parallel dimeric G-quadruplexes stacking together through p-p interaction via 50-to-50 mode in solution.Each dimeric G-quadruplex unit involves two propeller loops composed of two cytosine bases.This result is consistent with the observation in the crystal structure of d(G4C2)2.Our work not only sheds light on the structural diversity of G-quadruplexes adopted by d(G4C2)n but also provides a structural basis for drug design in treatment of ALS and FTD.展开更多
The hexanucleotide repeat mutation in the intron-1 of the chromosome 9 open reading frame (C9orf72) is a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Altered RNA folding pla...The hexanucleotide repeat mutation in the intron-1 of the chromosome 9 open reading frame (C9orf72) is a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Altered RNA folding plays a role in ALS pathogenesis in two ways: non-ATG translation of the repeat can lead to aggregates of the known C9orf72 specific dipeptide polymer, whereas the repeat also can form neurotoxic RNA inclusions that dose-responsively kill motor neurons. We report the presence of a homology in the 5’untranslated region (UTR) of the messenger RNA encoding C9orf72 with the iron responsive elements (IRE) that control expression of iron-associated transcripts and predict that this RNA structure may iron-dependently regulate C9orf72 translation. We previously report altered serum ferritin levels track with severity of ALS in patients. Here, we conduct bioinformatics analyses to determine the secondary structure of the 5’UTR in C9orf72 mRNA and find it aligned with IREs in the human mitochondrial cis-aconitase and L and H-ferritin transcripts. Comparison of the role of RNA repeats in Friedriech’s ataxia and fragile X mental retardation suggests the utility of RNA based therapies for treatment of ALS. Antisense oligonucleotides (ASO) have been reported to therapeutically target these GGGGCC repeats. At the same time, because the function of C9orf72 is unknown, knockdown strategies carry some risk of inducing or compounding haploinsufficiency. We propose, for consideration, an approach that may enhance its therapeutic dynamic range by increasing the 5’UTR driven translation of C9orf72 protein to compensate for any potential ALS-specific or ASO-induced haploinsufficieny.展开更多
Growing evidences indicate that dysfunction of autophagy contributes to the disease pathogenesis of amyotrophic lateral sclerosis(ALS)and frontotemporal dementia(FTD),two neurodegenerative disorders.The GGGGCC·GG...Growing evidences indicate that dysfunction of autophagy contributes to the disease pathogenesis of amyotrophic lateral sclerosis(ALS)and frontotemporal dementia(FTD),two neurodegenerative disorders.The GGGGCC·GGCCCC repeat RNA expansion in chromosome 9 open reading frame 72(C9orf72)is the most genetic cause of both ALS and FTD.According to the previous studies,GGGGCC·GGCCCC repeat undergoes the unconventional repeat-associated non-ATG translation,which produces dipeptide repeat(DPR)proteins.Although there is a growing understanding that C9orf72 DPRs have a strong ability to harm neurons and induce C9orf72-linked ALS/FTD,whether these DPRs can affect autophagy remains unclear.In the present study,we find that poly-GR and poly-PR,two arginine-containing DPRs which display the most cytotoxic properties according to the previous studies,strongly inhibit starvation-induced autophagy.Moreover,our data indicate that arginine-rich DPRs enhance the interaction between BCL2 and BECN1/Beclin 1 by inhibiting BCL2 phosphorylation,therefore they can impair autophagic clearance of neurodegenerative disease-associated protein aggregates under starvation condition in cells.Importantly,our study not only highlights the role of C9orf72 DPR in autophagy dysfunction,but also provides novel insight that pharmacological intervention of autophagy using SW063058,a small molecule compound that can disrupt the interaction between BECN1 and BCL2,may reduce C9orf72 DPR-induced neurotoxicity.展开更多
Background:Disease modifying therapies(DMTs)are urgently needed for neurodegenerative diseases(NDD)such as Alzheimer’s disease(AD)and many other disorders characterized by protein aggregation and neurodegeneration.De...Background:Disease modifying therapies(DMTs)are urgently needed for neurodegenerative diseases(NDD)such as Alzheimer’s disease(AD)and many other disorders characterized by protein aggregation and neurodegeneration.Despite advances in understanding the neurobiology of NDD,there are no approved DMTs.Discussion:Defining disease-modification is critical to drug-development programs.A DMT is an intervention that produces an enduring change in the trajectory of clinical decline of an NDD by impacting the disease processes leading to nerve cell death.A DMT is neuroprotective,and neuroprotection will result in disease modification.Disease modification can be demonstrated in clinical trials by a drug-placebo difference in clinical outcomes supported by a drug-placebo difference on biomarkers reflective of the fundamental pathophysiology of the NDD.Alternatively,disease modification can be supported by findings on a staggered start or delayed withdrawal clinical trial design.Collecting multiple biomarkers is necessary to support a comprehensive view of disease modification.Conclusion:Disease modification is established by demonstrating an enduring change in the clinical trajectory of an NDD based on intervention in the fundamental pathophysiology of the disease leading to nerve cell death.Supporting data are collected in clinical trials.Effectively defining a DMT will assist in NDD drug development programs.展开更多
Background The clinical presentations of frontotemporal dementia(FTD)are diverse and overlap with other neurological disorders.There are,as of today,no biomarkers in clinical practice for diagnosing the disorders.Here...Background The clinical presentations of frontotemporal dementia(FTD)are diverse and overlap with other neurological disorders.There are,as of today,no biomarkers in clinical practice for diagnosing the disorders.Here,we aimed to find protein markers in cerebrospinal fluid(CSF)from patients with FTD,presymptomatic mutation carriers and non-carriers.Methods Antibody suspension bead arrays were used to analyse 328 proteins in CSF from patients with behavioural variant FTD(bvFTD,n=16)and progressive primary aphasia(PPA,n=13),as well as presymptomatic mutation carriers(PMC,n=16)and non-carriers(NC,n=8).A total of 492 antibodies were used to measure protein levels by direct labelling of the CSF samples.The findings were further examined in an independent cohort including 13 FTD patients,79 patients with Alzheimer’s disease and 18 healthy controls.Results We found significantly altered protein levels in CSF from FTD patients compared to unaffected individuals(PMC and NC)for 26 proteins.The analysis show patterns of separation between unaffected individuals and FTD patients,especially for those with a clinical diagnosis of bvFTD.The most statistically significant differences in protein levels were found for VGF,TN-R,NPTXR,TMEM132D,PDYN and NF-M.Patients with FTD were found to have higher levels of TN-R and NF-M,and lower levels of VGF,NPTXR,TMEM132D and PDYN,compared to unaffected individuals.The main findings were reproduced in the independent cohort.Conclusion In this pilot study,we show a separation of FTD patients from unaffected individuals based on protein levels in CSF.Further investigation is required to explore the CSF profiles in larger cohorts,but the results presented here has the potential to enable future clinical utilization of these potential biomarkers within FTD.展开更多
基金ML was supported by Portuguese Foundation for Science and Technology(FCT),No.SFRH/BD/144001/2019.
文摘The distinction between sporadic and genetic behavioural-variant frontotemporal dementia(bvFTD)regarding some neuropsychological(NP)features remains challenging.Specifically,progranulin(GRN)-associated bvFTD frequently presents with early episodic memory impairment and some degree of parietal dysfunction which are supporters of Alzheimer’s disease(AD)diagnosis.In this context,we aimed to characterize the NP profile of GRN-bvFTD as compared to sporadic-bvFTD and AD in patients with mild dementia(Mini-Mental State Examination score≥17 and Clinical Dementia Rating Scale score≤1.We identified 21 patients at Centro Hospitalar e Universitário de Coimbra,Portugal with GRN mutations belonging to fifteen different families.As our focus was bvFTD variants,FTD-related aphasic forms(3 patients)were excluded.The remaining 18 GRN-bvFTD were further matched with 18 sporadic-bvFTD and 18 AD patients according to disease staging,age and education.All patients completed the Mini-Mental State Examination,Montreal Cognitive Assessment(MoCA)and a comprehensive NP assessment battery.Results were converted into z-scores.Differences between groups in individual NP measures and NP domains were assessed through non-parametric tests(Kruskal-Wallis test analysis)and eta squared(ŋ2)was calculated as a measure of effect size.Group comparisons show that GRN patients have worse performances on verbal retrieval processes(P=0.039,ŋ2=0.110)and visuoconstructive abilities(P=0.039,ŋ2=0.190)than sporadic bvFTD forms.When compared to AD,GRN patients present a higher impairment in frontal(P=0.001,ŋ2=0.211)and parietal(P=0.041,ŋ2=0.129)measures and a better performance in memory tasks(P=0.020,ŋ2=0.120).Sporadic-bvFTD forms are worse than AD in frontal measures(P=0.032,ŋ2=0.200),being better in both memory(P=0.010,ŋ2=0.131)and visuospatial skills(P=0.023,ŋ2=0.231).Considering these results,we conclude that GRN-bvFTD patients present a NP profile that associates the typical patterns of FTD and AD deficits.This is particularly expressive in visuoconstructive abilities,which was the more discriminative feature between groups,followed by episodic verbal memory.This study was approved by the Institutional Ethics Committee of Centro Hospitalar e Universitário de Coimbra,Portugal(CE-029/2019)on June 24,2019.
文摘Frontotemporal lobar degeneration describes a group of progressive brain disorders that primarily are associated with atrophy of the prefrontal and anterior temporal lobes.Frontotemporal lobar degeneration is considered to be equivalent to frontotemporal dementia.Frontotemporal dementia is characterized by progressive impairments in behavior,executive function,and language.There are two main clinical subtypes:behavioral-variant frontotemporal dementia and primary progressive aphasia.The early diagnosis of frontotemporal dementia is critical for developing management strategies and interventions for these patients.Without validated biomarkers,the clinical diagnosis depends on recognizing all the core or necessary neuropsychiatric features,but misdiagnosis often occurs due to overlap with a range of neurologic and psychiatric disorders.In the studies reviewed a very large number of microRNAs were found to be dysregulated but with limited overlap between individual studies.Measurement of specific miRNAs singly or in combination,or as miRNA pairs(as a ratio)in blood plasma,serum,or cerebrospinal fluid enabled frontotemporal dementia to be discriminated from healthy controls,Alzheimer’s disease,and amyotrophic lateral sclerosis.Furthermore,upregulation of miR-223-3p and downregulation of miR-15a-5p,which occurred both in blood serum and cerebrospinal fluid,distinguished behavioral-variant frontotemporal dementia from healthy controls.Downregulation of miR-132-3p in frontal and temporal cortical tissue distinguished frontotemporal lobar degeneration and frontotemporal dementia,respectively,from healthy controls.Possible strong miRNA biofluid biomarker contenders for behavioral-variant frontotemporal dementia are miR-223-3p,miR-15a-5p,miR-22-3p in blood serum and cerebrospinal fluid,and miR-124 in cerebrospinal fluid.No miRNAs were identified able to distinguish between behavioral-variant frontotemporal dementia and primary progressive aphasia subtypes.Further studies are warranted on investigating miRNA expression in biofluids and frontal/temporal cortical tissue to validate and extend these findings.
基金supported by research grants to LMI from University of Buenos Aires(UBACyT)the Agencia Nacional de Promoción Científica y Tecnológica(ANPCyT)under grants PICT 2015-0975 and PICT 2017-2140。
文摘Protein synthesis is essential for cells to perform life metabolic processes.Pathological alterations of protein content can lead to particular diseases.Cells have an intrinsic array of mechanisms and pathways that are activated when protein misfolding,accumulation,aggregation or mislocalization occur.Some of them(like the unfolded protein response)represent complex interactions between endoplasmic reticulum sensors and elongation factors that tend to increase expression of chaperone proteins and/or repress translation in order to restore protein homeostasis(also known as proteostasis).This is even more important in neurons,as they are very susceptible to harmful effects associated with protein overload and proteostatic mechanisms are less effective with age.Several neurodegenerative pathologies such as Alzheimer’s,Parkinson’s,and Huntington’s diseases,amyotrophic lateral sclerosis and frontotemporal dementia exhibit a particular molecular signature of distinct,unbalanced protein overload.In amyotrophic lateral sclerosis and frontotemporal dementia,the majority of cases present intracellular inclusions of ubiquitinated transactive response DNA-binding protein of 43 kDa(TDP-43).TDP-43 is an RNA binding protein that participates in RNA metabolism,among other functions.Dysregulation of TDP-43(e.g.aggregation and mislocalization)can dramatically affect neurons,and this has been linked to disease development.Expression of amyotrophic lateral sclerosis/frontotemporal dementia TDP-43-related mutations in cellular and animal models has been shown to recapitulate key features of the amyotrophic lateral sclerosis/frontotemporal dementia disease spectrum.These variants can be causative of degeneration onset and progression.Most neurodegenerative diseases(including amyotrophic lateral sclerosis and frontotemporal dementia)have no cure at the moment;however,modulating translation has recently emerged as an attractive approach that can be performed at several steps(i.e.regulating activation of initiation and elongation factors,inhibiting unfolded protein response activation or inducing chaperone expression and activity).This review focuses on the features of protein imbalance in neurodegenerative disorders and the relevance of developing therapeutical compounds aiming at restoring proteostasis.We strive to highlight the importance of research on drugs that,not only restore protein imbalance without compromising translational activity of cells,but are also as safe as possible for the patients.
基金supported by funding from the Bluesand Foundation,Alzheimer's Association(AARG-21-852072 and Bias Frangione Early Career Achievement Award)to EDan Australian Government Research Training Program scholarship and the University of Sydney's Brain and Mind Centre fellowship to AH。
文摘Tauopathies,diseases characterized by neuropathological aggregates of tau including Alzheimer's disease and subtypes of fro ntotemporal dementia,make up the vast majority of dementia cases.Although there have been recent developments in tauopathy biomarkers and disease-modifying treatments,ongoing progress is required to ensure these are effective,economical,and accessible for the globally ageing population.As such,continued identification of new potential drug targets and biomarkers is critical."Big data"studies,such as proteomics,can generate information on thousands of possible new targets for dementia diagnostics and therapeutics,but currently remain underutilized due to the lack of a clear process by which targets are selected for future drug development.In this review,we discuss current tauopathy biomarkers and therapeutics,and highlight areas in need of improvement,particularly when addressing the needs of frail,comorbid and cognitively impaired populations.We highlight biomarkers which have been developed from proteomic data,and outline possible future directions in this field.We propose new criteria by which potential targets in proteomics studies can be objectively ranked as favorable for drug development,and demonstrate its application to our group's recent tau interactome dataset as an example.
基金supported by the National Natural Science Foundation of China (31871023 and 31970966)the National Key Scientific R&D Program of China (2016YFC1306000)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Since the discovery of the C9ORF72 gene in2011,great advances have been achieved in its genetics and in identifying its role in disease models and pathological mechanisms;it is the most common genetic cause of amyotrophic lateral sclerosis(ALS) and frontotemporal dementia(FTD).ALS patients with C9ORF72 expansion show heterogeneous symptoms.Those who are C9ORF72 expansion carriers have shorter survival after disease onset than non-C9ORF72 expansion patients.Pathological and clinical features of C9ORF72 patients have been well mimicked via several models,including induced pluripotent stem cell-derived neurons and transgenic mice that were embedded with bacterial artificial chromosome construct and that overexpressing dipeptide repeat proteins.The mechanisms implicated in C9ORF72 pathology include DNA damage,changes of RNA metabolism,alteration of phase separation,and impairment of nucleocytoplasmic transport,which may underlie C9ORF72 expansion-related ALS/FTD and provide insight into nonC9ORF72 expansion-related ALS,FTD,and other neurodegenerative diseases.
文摘Cardiovascular risk factors(CRF)were widely described as related to dementia.There are very few studies regarding this association in FTD.The objective of the study was to compare the frequency of CRF in our population with FTD and controls.100 consecutive subjects with FTD diagnosis according to Lund-Manchester clinical criteria and 200 controls matched by age and sex were included between January 2003 to February 2007 at the Cognitive and Behavior Unit of Hospital Italiano de Buenos Aires.Clinical evaluation,laboratory tests,brain images(CT/MRI),neuropsychological and neuropsychiatric assessment were performed.Multiple regression analysis was performed to analyze the association in CRF between FTD patients vs.controls.The mean age in FTD was 69.7±0.9 vs.70.1±0.8 in controls(p 0.12).No difference in gender was observed between cases and controls.No differences were identified between patients and controls regarding hypertension(HTA)(65%vs.67,3%p 0.44);dyslipidemia(57%vs.54.7%p 0.74);obesity(39%vs.27.6%p 0.14)and hypothyroidism(26%vs.17.1%p 0.1).A significant difference was observed for Diabetes Mellitus(39%vs.22.6%p 0.001).In our population,Diabetes Mellitus was associated as an independent risk factor for FTD.To our knowledge this is the first report in which CRF were evaluated prospectively in FTD patients.More studies are needed to confirm this finding in larger populations.
文摘Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease mainly involving motor neurons in spinal cord,brain stem,and motor cortex of brain,characterized by variable combinations of limb weakness,muscle atrophy,and pyramidal signs.TAR DNA-binding protein 43 (TDP-43) serves as the pathological protein for both ALS and a proportion of frontotemporal dementia (FTD),where lies the foundation of a disease complex,ALS-FTD.Delusion and hallucination,core features of schizophrenia,are also regarded as common symptoms in the context of neurodegenerative dementia,including Alzheimer disease and dementia with Lewy body.Although rare in the course of FTD,these manifestations could be rather notable,causing a great challenge to differentiate FTD from schizophrenia.Emphasis of psychotic phenomenon also lies in its importance of predicting the progression to ALS-FTD and its underlying genetic mutation.Herein we report two cases of ALS-FTD presented with psychosis.
基金supported by the Fondo de Investigaciones Sanitario(FIS)Institute de Salud Carlos III(P114/01126,P117/01019 and PI20/01473 to JF,PI13/01532 and PI16/01825 to RB,PI18/00335 to MCI,PI18/00435 and INT19/00016 to DA,PI17/01896 and AC19/00103to AL)+4 种基金the CIBERNED program(Program 1,Alzheimer Disease to AL)jointly funded by Fondo Europeo de Desarrollo Regional,Unión Europea,"Una manera de hacer Europa"supported by Generalitat de Catalunya(2017-SGR-547,SLT006/17/125 to DA,SLT006/17/119 to JF,SLT002/16/408 to AL)"MaratóTV3"foundation grants 20141210 to JF,044412 to RB and 20142610 to ALsupported by a grant from the Fundacio Bancaria La Caixa to RB(DABNI project).
文摘Background:Astrocytes play an essential role in neuroinflammation and are involved in the pathogenesis of neurodenegerative diseases.Studies of glial fibrillary acidic protein(GFAP),an astrocytic damage marker,may help advance our understanding of different neurodegenerative diseases.In this study,we investigated the diagnostic performance of plasma GFAP(pGFAP),plasma neurofilament light chain(pNfL)and their combination for frontotemporal dementia(FTD)and Alzheimer's disease(AD)and their clinical utility in predicting disease progression.Methods:pGFAP and pNfL concentrations were measured in 72 FTD,56 AD and 83 cognitively normal(CN)participants using the Single Molecule Array technology.Of the 211 participants,199 underwent cerebrospinal(CSF)analysis and 122 had magnetic resonance imaging.We compared cross-sectional biomarker levels between groups,studied their diagnostic performance and assessed correlation between CSF biomarkers,cognitive performance and cortical thickness.The prognostic performance was investigated,analyzing cognitive decline through group comparisons by tertile.Results:Unlike pNfL,which was increased similarly in both clinical groups,pGFAP was increased in FTD but lower than in AD(all P<0.01).Combination of both plasma markers improved the diagnostic performance to discriminate FTD from AD(area under the curve[AUC]:combination 0.78;pGFAP 0.7;pNfL 0.61,all P<0.05).In FTD,pGFAP correlated with cognition,CSF and plasma NfL,and cortical thickness(all P<0.05).The higher tertile of pGFAP was associated with greater change in MMSE score and poor cognitive outcome during follow-up both in FTD(1.40 points annually,hazard ratio[HR]3.82,P<0.005)and in AD(1.20 points annually,HR 2.26,P<0.005).Conclusions:pGFAP and pNfL levels differ in FTD and AD;and their combination is useful for distinguishing between the two diseases.pGFAP could also be used to track disease severity and predict greater cognitive decline during follow-up in patients with FTD.
文摘Progress has been made in understanding the genetics and molecular biology of frontotemporal dementia(FTD).Targets for intervention have been identified,therapies are being developed,and clinical trials are advancing.A major challenge for FTD research is that multiple underlying pathologies can be associated with heterogeneous phenotypes.The neuropsychological profiles associated with FTD spectrum disorders often include executive dysfunction,language impairments and behavioral disturbance.Behavioral variant FTD is characterized by an initial presentation of changes in personality,behavior and/or emotion,which are often difficult to objectively capture using traditional neuropsychological measures.The two principal language variants of FTD are Progressive Nonfluent Aphasia(PNFA)with predominant agrammatic/non-fluent impairments and Semantic Dementia(SD)with semantic impairments and visual agnosia.Selection of appropriate endpoints for clinical trials is critical to ensure that the measures are adequately sensitive to detect change,yet specific enough to isolate signal from noise,and acceptable to regulatory agencies.Given the anticipated potential for small effect sizes,measures must be able to identify small incremental changes over time.It is also imperative that the measures provide adequate coverage of the constructs or behaviors of interest.Selected outcome measures should be suitable for repeat administration,yet relatively robust to practice effects to ensure that observed changes reflect true signal variance and not residual effects due to repeated measurement or poor reliability.To facilitate widespread adoption as an endpoint,measures should be readily accessible.We provide several examples of potential global,composite,and individual cognitive measures,as well as behavioral measures promising for FTD trials.Development and application of appropriate trial outcomes is critically important to success in advancing new treatments for FTD patients.
文摘Objective To investigate the changes in cortical excitability and inhibitory circuits of patients with Alzheimer’s disease(AD)or behavioral variant frontotemporal dementia(bv FTD)using transcranial magnetic stimulation(TMS).Methods Forty-four patients with AD,30 patients with bv FTD and 44 healthy controls were enrolled in the study.The epidemiological data
文摘Dementia is a contemporary global health issue with far reaching consequences, not only for affected individuals and their families, but for national and global socio-economic conditions. The hallmark feature of dementia is that of irreversible cognitive decline, usually affecting memory, and impaired activities of daily living. Advances in healthcare worldwide have facilitated longer life spans, increasing the risks of developing cognitive decline and dementia in late life. Dementia remains a clinical diagnosis. The role of structural and molecular neuroimaging in patients with dementia is primarily supportive role rather than diagnostic, American and European guidelines recommending imaging to exclude treatable causes of dementia, such as tumor, hydrocephalus or intracranial haemorrhage, but also to distinguish between different dementia subtypes, the commonest of which is Alzheimer’s disease. However, this depends on the availability of these imaging techniques at individual centres. Advanced magnetic resonance imaging (MRI) techniques, such as functional connectivity MRI, diffusion tensor imaging and magnetic resonance spectroscopy, and molecular imaging techniques, such as 18F fluoro-deoxy glucose positron emission tomography (PET), amyloid PET, tau PET, are currently within the realm of dementia research but are available for clinical use. Increasingly the research focus is on earlier identification of at risk preclinical individuals, for example due to family history. Intervention at the preclinical stages before irreversible brain damage occurs is currently the best hope of reducing the impact of dementia.
文摘BACKGROUND Antipsychotic medications such as risperidone,olanzapine and aripiprazole are used to treat psychological and behavioural symptoms among dementia patients.Current evidence indicate prescription rates for antipsychotics vary and wider consensus to evaluate clinical epidemiological outcomes is limited.AIM To investigate the potential impact of atypical antipsychotics on the mortality of patients with dementia.METHODS A retrospective clinical cohort study was developed to review United Kingdom Clinical Record Interactive Search system based data between January 1,2013 to December 31,2017.A descriptive statistical method was used to analyse the data.Mini Mental State Examination(MMSE)scores were used to assess the severity and stage of disease progression.A cox proportional hazards model was developed to evaluate the relationship between survival following diagnosis and other variables.RESULTS A total of 1692 patients were identified using natural language processing of which,587 were prescribed olanzapine,quetiapine or risperidone(common group)whilst 893(control group)were not prescribed any antipsychotics.Patients prescribed olanzapine showed an increased risk of death[hazard ratio(HR)=1.32;95%confidence interval(CI):1.08-1.60;P<0.01],as did those with risperidone(HR=1.35;95%CI:1.18-1.54;P<0.001).Patients prescribed quetiapine showed no significant association(HR=1.09;95%CI:0.90-1.34;P=0.38).Factors associated with a lower risk of death were:High MMSE score at diagnosis(HR=0.72;95%CI:0.62-0.83;P<0.001),identifying as female(HR=0.73;95%CI:0.64-0.82;P<0.001),and being of a White-British ethnic group(HR=0.82;95%CI:0.72-0.94;P<0.01).CONCLUSION A significant mortality risk was identified among those prescribed olanzapine and risperidone which contradicts previous findings although the study designs used were different.Comprehensive research should be conducted to better assess clinical epidemiological outcomes associated with diagnosis and therapies to improve clinical management of these patients.
文摘In the last years, some studies have shown that behavior disorder seems in frontotemporal dementia is related to dysfunction in the fronto-subcortical circuitry. <strong>Objectives:</strong> We did a narrative literature review concerning fronto-subcortical circuitry and frontotemporal dementia (FTD). <strong>Methods:</strong> Manuscripts related to fronto-subcortical network and frontotemporal dementia were selected for further analysis. <strong>Results:</strong> From the executions of simple motor actions to the most complex behaviors like goal-direct behavior and social cognition, the fronto-subcortical circuitry involves an intrigued network of fibers that reaches to basal ganglia nuclei. Recently, researchers have shown five parallel fronto-subcortical circuits integrating and segregating information from the frontal cortex to basal ganglia. Understanding the relationship between the fronto-subcortical circuit dysfunctions and neurodegenerative diseases requires studying the functional anatomy and neurochemical basis involved.<strong> Conclusions:</strong> In this view, it is essential to review the functional anatomy of the fronto-subcortical network, and it’s correlated with clinical aspects to pursuing a better therapeutic approach.
基金the MRC Laboratory of Molecular Biology (to MR)。
文摘Advances in experimental and computational technologies continue to grow rapidly to provide novel avenues for the treatment of neurodegenerative disorders. Despite this, there remain only a handful of drugs that have shown success in late-stage clinical trials for Tau-associated neurodegenerative disorders. The most commonly prescribed treatments are symptomatic treatments such as cholinesterase inhibitors and N-methyl-D-aspartate receptor blockers that were approved for use in Alzheimer's disease. As diagnostic screening can detect disorders at earlier time points, the field needs pre-symptomatic treatments that can prevent, or significantly delay the progression of these disorders(Koychev et al., 2019). These approaches may be different from late-stage treatments that may help to ameliorate symptoms and slow progression once symptoms have become more advanced should early diagnostic screening fail. This mini-review will highlight five key avenues of academic and industrial research for identifying therapeutic strategies to treat Tau-associated neurodegenerative disorders. These avenues include investigating(1) the broad class of chemicals termed “small molecules”;(2) adaptive immunity through both passive and active antibody treatments;(3) innate immunity with an emphasis on microglial modulation;(4) synaptic compartments with the view that Tau-associated neurodegenerative disorders are synaptopathies. Although this mini-review will focus on Alzheimer's disease due to its prevalence, it will also argue the need to target other tauopathies, as through understanding Alzheimer's disease as a Tau-associated neurodegenerative disorder, we may be able to generalize treatment options. For this reason, added detail linking back specifically to Tau protein as a direct therapeutic target will be added to each topic.
文摘The infectious template-mediated protein conversion is a unique mechanism for the onset of rare and fatal neurodegenerative disorders known as transmissible spongiform encephalopathies, or prion diseases, which affect humans and other animal species. However, emerging studies are now demonstrating prion-like mechanisms of self-propagation of protein misfolding in a number of common, non-infectious neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. It has been proposed that distinct and unrelated proteins(beta-amyloid, tau, α-synuclein, TAR DNA-binding protein 43 and huntingtin, etc.) associated with common neurodegenerative disorders can seed conversion and spread via cellto-cell transfer, sustaining the transmission of neurotoxic agents along a stereotypic route, sharing features at the heart of the intrinsic nature of prions. Here we review the most recent development on both the molecular mechanisms underlying the pathogenesis of prion-like neurodegenerative diseases as well as innovative methods and strategies for potential therapeutic applications.
基金the National Natural Science Foundation of China to C.L.(No.32071188)Guangdong Basic and Applied Basic Research Foundation to C.L.(No.2020A1515010034)+1 种基金the Research Grants Council of the Hong Kong Special Administrative Region,China to G.Z.(Project No.16103719,16101120,and 161011121,AoE/M-403-16,AOE/M-401/20)Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)to G.Z.(Project No.SMSEGL20SC01eH)and VPRDO19RD03-6.
文摘The abnormal expansion of G-rich hexanucleotide repeat,GGGGCC(G4C2),in chromosome 9 open reading frame 72(C9orf72)is known to be the prevailing genetic cause of two fatal degenerative neurological diseases,amyotrophic lateral sclerosis(ALS)and frontotemporal dementia(FTD).It is well known that the DNA G4C2 repeat expansion with different lengths can form G-quadruplexes which affect gene transcription related to ALS/FTD,therefore it is crucial to understand DNA G4C2 G-quadruplex structures.Herein,by utilizing nuclear magnetic resonance(NMR)spectroscopy,we examined DNA G-quadruplex structure adopted by two G4C2 hexanucleotide repeats with an inosine substitution at position 4,d(G4C2)2-I4.We show that d(G4C2)2-I4 folds into an eight-layer parallel tetrameric G-quadruplex containing two parallel dimeric G-quadruplexes stacking together through p-p interaction via 50-to-50 mode in solution.Each dimeric G-quadruplex unit involves two propeller loops composed of two cytosine bases.This result is consistent with the observation in the crystal structure of d(G4C2)2.Our work not only sheds light on the structural diversity of G-quadruplexes adopted by d(G4C2)n but also provides a structural basis for drug design in treatment of ALS and FTD.
文摘The hexanucleotide repeat mutation in the intron-1 of the chromosome 9 open reading frame (C9orf72) is a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Altered RNA folding plays a role in ALS pathogenesis in two ways: non-ATG translation of the repeat can lead to aggregates of the known C9orf72 specific dipeptide polymer, whereas the repeat also can form neurotoxic RNA inclusions that dose-responsively kill motor neurons. We report the presence of a homology in the 5’untranslated region (UTR) of the messenger RNA encoding C9orf72 with the iron responsive elements (IRE) that control expression of iron-associated transcripts and predict that this RNA structure may iron-dependently regulate C9orf72 translation. We previously report altered serum ferritin levels track with severity of ALS in patients. Here, we conduct bioinformatics analyses to determine the secondary structure of the 5’UTR in C9orf72 mRNA and find it aligned with IREs in the human mitochondrial cis-aconitase and L and H-ferritin transcripts. Comparison of the role of RNA repeats in Friedriech’s ataxia and fragile X mental retardation suggests the utility of RNA based therapies for treatment of ALS. Antisense oligonucleotides (ASO) have been reported to therapeutically target these GGGGCC repeats. At the same time, because the function of C9orf72 is unknown, knockdown strategies carry some risk of inducing or compounding haploinsufficiency. We propose, for consideration, an approach that may enhance its therapeutic dynamic range by increasing the 5’UTR driven translation of C9orf72 protein to compensate for any potential ALS-specific or ASO-induced haploinsufficieny.
基金This work was supported by the National Natural Science Foundation of China(Nos.82022022,32371018 and 82071274)a Project Funded by Jiangsu Key Laboratory of Neuropsychiatric Diseases(BM2013003,China)+4 种基金a Key Project of Natural Science Foundation of Jiangsu Provincial Higher Education Institutions(23KJA310005,China)a Project Funded by the Interdisciplinary Basic Frontier Innovation Program of Suzhou Medical College of Soochow University(MP13202823,China)a Project Funded by the Suzhou International Joint Laboratory for Diagnosis and Treatment of Brain Diseases,and a Project Funded by the Priority Academic Program Development of the Jiangsu Higher Education Institutes(PAPD).J.H.M.P.was supported Science Foundation Ireland(17/COEN/3474,17/JPND/3455)Q.M.is a recipient of an RCSI International StAR Ph.D.scholarship.N.L.was supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province.K.Y.T.,was supported by the financial support from the Science and Technology Development Fund,Macao SAR(File no.0062/2021/A,China)University of Macao(File no.MYRG2022-00171-FHS,China).
文摘Growing evidences indicate that dysfunction of autophagy contributes to the disease pathogenesis of amyotrophic lateral sclerosis(ALS)and frontotemporal dementia(FTD),two neurodegenerative disorders.The GGGGCC·GGCCCC repeat RNA expansion in chromosome 9 open reading frame 72(C9orf72)is the most genetic cause of both ALS and FTD.According to the previous studies,GGGGCC·GGCCCC repeat undergoes the unconventional repeat-associated non-ATG translation,which produces dipeptide repeat(DPR)proteins.Although there is a growing understanding that C9orf72 DPRs have a strong ability to harm neurons and induce C9orf72-linked ALS/FTD,whether these DPRs can affect autophagy remains unclear.In the present study,we find that poly-GR and poly-PR,two arginine-containing DPRs which display the most cytotoxic properties according to the previous studies,strongly inhibit starvation-induced autophagy.Moreover,our data indicate that arginine-rich DPRs enhance the interaction between BCL2 and BECN1/Beclin 1 by inhibiting BCL2 phosphorylation,therefore they can impair autophagic clearance of neurodegenerative disease-associated protein aggregates under starvation condition in cells.Importantly,our study not only highlights the role of C9orf72 DPR in autophagy dysfunction,but also provides novel insight that pharmacological intervention of autophagy using SW063058,a small molecule compound that can disrupt the interaction between BECN1 and BCL2,may reduce C9orf72 DPR-induced neurotoxicity.
基金JC acknowledges funding from the National Institute of General Medical Sciences(Grant:P20GM109025)and support from Keep Memory Alive.
文摘Background:Disease modifying therapies(DMTs)are urgently needed for neurodegenerative diseases(NDD)such as Alzheimer’s disease(AD)and many other disorders characterized by protein aggregation and neurodegeneration.Despite advances in understanding the neurobiology of NDD,there are no approved DMTs.Discussion:Defining disease-modification is critical to drug-development programs.A DMT is an intervention that produces an enduring change in the trajectory of clinical decline of an NDD by impacting the disease processes leading to nerve cell death.A DMT is neuroprotective,and neuroprotection will result in disease modification.Disease modification can be demonstrated in clinical trials by a drug-placebo difference in clinical outcomes supported by a drug-placebo difference on biomarkers reflective of the fundamental pathophysiology of the NDD.Alternatively,disease modification can be supported by findings on a staggered start or delayed withdrawal clinical trial design.Collecting multiple biomarkers is necessary to support a comprehensive view of disease modification.Conclusion:Disease modification is established by demonstrating an enduring change in the clinical trajectory of an NDD based on intervention in the fundamental pathophysiology of the disease leading to nerve cell death.Supporting data are collected in clinical trials.Effectively defining a DMT will assist in NDD drug development programs.
基金This study was supported by grants from the Swedish FTD initiative funded by the Schörling Family Foundation and the KTH Center for Applied Precision Medicine(KCAP)funded by the Erling-Persson Family Foundation.CG,LO and AU were further supported by grants from JPND Prefrontals Swedish Research Council(VR)529-2014-7504,Swedish Research Council(VR)2015-02926,Swedish Research Council(VR)2018-02754,Swedish Brain Foundation,Swedish Alzheimer Foundation,Stockholm County Council ALF,Karolinska Institutet Doctoral Funding and StratNeuro,Swedish Demensfonden.The authors acknowledge support from the National Genomics Infrastructure in Stockholm/Uppsala funded by Science for Life Laboratory,the Knut and Alice Wallenberg Foundation and the Swedish Research Council,and SNIC/Uppsala Multidisciplinary Center for Advanced Computational Science for assistance with massively parallel sequencing and access to the UPPMAX computational infrastructure.Open access funding provided by Royal Institute of Technology.
文摘Background The clinical presentations of frontotemporal dementia(FTD)are diverse and overlap with other neurological disorders.There are,as of today,no biomarkers in clinical practice for diagnosing the disorders.Here,we aimed to find protein markers in cerebrospinal fluid(CSF)from patients with FTD,presymptomatic mutation carriers and non-carriers.Methods Antibody suspension bead arrays were used to analyse 328 proteins in CSF from patients with behavioural variant FTD(bvFTD,n=16)and progressive primary aphasia(PPA,n=13),as well as presymptomatic mutation carriers(PMC,n=16)and non-carriers(NC,n=8).A total of 492 antibodies were used to measure protein levels by direct labelling of the CSF samples.The findings were further examined in an independent cohort including 13 FTD patients,79 patients with Alzheimer’s disease and 18 healthy controls.Results We found significantly altered protein levels in CSF from FTD patients compared to unaffected individuals(PMC and NC)for 26 proteins.The analysis show patterns of separation between unaffected individuals and FTD patients,especially for those with a clinical diagnosis of bvFTD.The most statistically significant differences in protein levels were found for VGF,TN-R,NPTXR,TMEM132D,PDYN and NF-M.Patients with FTD were found to have higher levels of TN-R and NF-M,and lower levels of VGF,NPTXR,TMEM132D and PDYN,compared to unaffected individuals.The main findings were reproduced in the independent cohort.Conclusion In this pilot study,we show a separation of FTD patients from unaffected individuals based on protein levels in CSF.Further investigation is required to explore the CSF profiles in larger cohorts,but the results presented here has the potential to enable future clinical utilization of these potential biomarkers within FTD.