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Alcohol Research : Current Reviews 2024By 2040, 21.6% of Americans will be over age 65, and the population of those older than age 85 is estimated to reach 14.4 million. Although not causative, older age is a... (Review)
Review
PURPOSE
By 2040, 21.6% of Americans will be over age 65, and the population of those older than age 85 is estimated to reach 14.4 million. Although not causative, older age is a risk factor for dementia: every 5 years beyond age 65, the risk doubles; approximately one-third of those older than age 85 are diagnosed with dementia. As current alcohol consumption among older adults is significantly higher compared to previous generations, a pressing question is whether drinking alcohol increases the risk for Alzheimer's disease or other forms of dementia.
SEARCH METHODS
Databases explored included PubMed, Web of Science, and ScienceDirect. To accomplish this narrative review on the effects of alcohol consumption on dementia risk, the literature covered included clinical diagnoses, epidemiology, neuropsychology, postmortem pathology, neuroimaging and other biomarkers, and translational studies. Searches conducted between January 12 and August 1, 2023, included the following terms and combinations: "aging," "alcoholism," "alcohol use disorder (AUD)," "brain," "CNS," "dementia," "Wernicke," "Korsakoff," "Alzheimer," "vascular," "frontotemporal," "Lewy body," "clinical," "diagnosis," "epidemiology," "pathology," "autopsy," "postmortem," "histology," "cognitive," "motor," "neuropsychological," "magnetic resonance," "imaging," "PET," "ligand," "degeneration," "atrophy," "translational," "rodent," "rat," "mouse," "model," "amyloid," "neurofibrillary tangles," "α-synuclein," or "presenilin." When relevant, "species" (i.e., "humans" or "other animals") was selected as an additional filter. Review articles were avoided when possible.
SEARCH RESULTS
The two terms "alcoholism" and "aging" retrieved about 1,350 papers; adding phrases-for example, "postmortem" or "magnetic resonance"-limited the number to fewer than 100 papers. Using the traditional term, "alcoholism" with "dementia" resulted in 876 citations, but using the currently accepted term "alcohol use disorder (AUD)" with "dementia" produced only 87 papers. Similarly, whereas the terms "Alzheimer's" and "alcoholism" yielded 318 results, "Alzheimer's" and "alcohol use disorder (AUD)" returned only 40 citations. As pertinent postmortem pathology papers were published in the 1950s and recent animal models of Alzheimer's disease were created in the early 2000s, articles referenced span the years 1957 to 2024. In total, more than 5,000 articles were considered; about 400 are herein referenced.
DISCUSSION AND CONCLUSIONS
Chronic alcohol misuse accelerates brain aging and contributes to cognitive impairments, including those in the mnemonic domain. The consensus among studies from multiple disciplines, however, is that alcohol misuse can increase the risk for dementia, but not necessarily Alzheimer's disease. Key issues to consider include the reversibility of brain damage following abstinence from chronic alcohol misuse compared to the degenerative and progressive course of Alzheimer's disease, and the characteristic presence of protein inclusions in the brains of people with Alzheimer's disease, which are absent in the brains of those with AUD.
Topics: Humans; Dementia; Alcoholism; Aged; Animals; Aged, 80 and over; Alcohol Drinking; Brain; Alzheimer Disease; Risk Factors
PubMed: 38812709
DOI: 10.35946/arcr.v44.1.03 -
PloS One 2024Benfotiamine provides an important novel therapeutic direction in Alzheimer's disease (AD) with possible additive or synergistic effects to amyloid targeting therapeutic... (Randomized Controlled Trial)
Randomized Controlled Trial
Protocol for a seamless phase 2A-phase 2B randomized double-blind placebo-controlled trial to evaluate the safety and efficacy of benfotiamine in patients with early Alzheimer's disease (BenfoTeam).
BACKGROUND
Benfotiamine provides an important novel therapeutic direction in Alzheimer's disease (AD) with possible additive or synergistic effects to amyloid targeting therapeutic approaches.
OBJECTIVE
To conduct a seamless phase 2A-2B proof of concept trial investigating tolerability, safety, and efficacy of benfotiamine, a prodrug of thiamine, as a first-in-class small molecule oral treatment for early AD.
METHODS
This is the protocol for a randomized, double-blind, placebo-controlled 72-week clinical trial of benfotiamine in 406 participants with early AD. Phase 2A determines the highest safe and well-tolerated dose of benfotiamine to be carried forward to phase 2B. During phase 2A, real-time monitoring of pre-defined safety stopping criteria in the first approximately 150 enrollees will help determine which dose (600 mg or 1200 mg) will be carried forward into phase 2B. The phase 2A primary analysis will test whether the rate of tolerability events (TEs) is unacceptably high in the high-dose arm compared to placebo. The primary safety endpoint in phase 2A is the rate of TEs compared between active and placebo arms, at each dose. The completion of phase 2A will seamlessly transition to phase 2B without pausing or stopping the trial. Phase 2B will assess efficacy and longer-term safety of benfotiamine in a larger group of participants through 72 weeks of treatment, at the selected dose. The co-primary efficacy endpoints in phase 2B are CDR-Sum of Boxes and ADAS-Cog13. Secondary endpoints include safety and tolerability measures; pharmacokinetic measures of thiamine and its esters, erythrocyte transketolase activity as blood markers of efficacy of drug delivery; ADCS-ADL-MCI; and MoCA.
CONCLUSION
The BenfoTeam trial utilizes an innovative seamless phase 2A-2B design to achieve proof of concept. It includes an adaptive dose decision rule, thus optimizing exposure to the highest and best-tolerated dose.
TRIAL REGISTRATION
ClinicalTrials.gov identifier: NCT06223360, registered on January 25, 2024. https://classic.clinicaltrials.gov/ct2/show/NCT06223360.
Topics: Humans; Alzheimer Disease; Thiamine; Double-Blind Method; Male; Female; Aged; Middle Aged; Treatment Outcome; Prodrugs
PubMed: 38809849
DOI: 10.1371/journal.pone.0302998 -
BMC Medicine May 2024In 2020, the Lancet Commission identified 12 risk factors as priorities for prevention of dementia, and other studies identified APOE e4/e4 genotype and family history...
BACKGROUND
In 2020, the Lancet Commission identified 12 risk factors as priorities for prevention of dementia, and other studies identified APOE e4/e4 genotype and family history of Alzheimer's disease strongly associated with dementia outcomes; however, it is unclear how robust these relationships are across dementia subtypes and analytic scenarios. Specification curve analysis (SCA) is a new tool to probe how plausible analytical scenarios influence outcomes.
METHODS
We evaluated the heterogeneity of odds ratios for 12 risk factors reported from the Lancet 2020 report and two additional strong associated non-modifiable factors (APOE e4/e4 genotype and family history of Alzheimer's disease) with dementia outcomes across 450,707 UK Biobank participants using SCA with 5357 specifications across dementia subtypes (outcomes) and analytic models (e.g., standard demographic covariates such as age or sex and/or 14 correlated risk factors).
RESULTS
SCA revealed variable dementia risks by subtype and age, with associations for TBI and APOE e4/e4 robust to model specification; in contrast, diabetes showed fluctuating links with dementia subtypes. We found that unattributed dementia participants had similar risk factor profiles to participants with defined subtypes.
CONCLUSIONS
We observed heterogeneity in the risk of dementia, and estimates of risk were influenced by the inclusion of a combination of other modifiable risk factors; non-modifiable demographic factors had a minimal role in analytic heterogeneity. Future studies should report multiple plausible analytic scenarios to test the robustness of their association. Considering these combinations of risk factors could be advantageous for the clinical development and evaluation of novel screening models for different types of dementia.
Topics: Humans; Dementia; Risk Factors; United Kingdom; Female; Male; Aged; Biological Specimen Banks; Middle Aged; Aged, 80 and over; UK Biobank
PubMed: 38807092
DOI: 10.1186/s12916-024-03424-w -
Translational Psychiatry May 2024Previous observational investigations suggest that structural and diffusion imaging-derived phenotypes (IDPs) are associated with major neurodegenerative diseases;...
Bidirectional two-sample Mendelian randomization analyses support causal relationships between structural and diffusion imaging-derived phenotypes and the risk of major neurodegenerative diseases.
Previous observational investigations suggest that structural and diffusion imaging-derived phenotypes (IDPs) are associated with major neurodegenerative diseases; however, whether these associations are causal remains largely uncertain. Herein we conducted bidirectional two-sample Mendelian randomization analyses to infer the causal relationships between structural and diffusion IDPs and major neurodegenerative diseases using common genetic variants-single nucleotide polymorphism (SNPs) as instrumental variables. Summary statistics of genome-wide association study (GWAS) for structural and diffusion IDPs were obtained from 33,224 individuals in the UK Biobank cohort. Summary statistics of GWAS for seven major neurodegenerative diseases were obtained from the largest GWAS for each disease to date. The forward MR analyses identified significant or suggestively statistical causal effects of genetically predicted three structural IDPs on Alzheimer's disease (AD), frontotemporal dementia (FTD), and multiple sclerosis. For example, the reduction in the surface area of the left superior temporal gyrus was associated with a higher risk of AD. The reverse MR analyses identified significantly or suggestively statistical causal effects of genetically predicted AD, Lewy body dementia (LBD), and FTD on nine structural and diffusion IDPs. For example, LBD was associated with increased mean diffusivity in the right superior longitudinal fasciculus and AD was associated with decreased gray matter volume in the right ventral striatum. Our findings might contribute to shedding light on the prediction and therapeutic intervention for the major neurodegenerative diseases at the neuroimaging level.
Topics: Humans; Mendelian Randomization Analysis; Genome-Wide Association Study; Neurodegenerative Diseases; Polymorphism, Single Nucleotide; Alzheimer Disease; Phenotype; Frontotemporal Dementia; Male; Female; Diffusion Magnetic Resonance Imaging; Multiple Sclerosis; Brain; Aged; Lewy Body Disease; Middle Aged; Magnetic Resonance Imaging; United Kingdom
PubMed: 38806463
DOI: 10.1038/s41398-024-02939-3 -
Fluids and Barriers of the CNS May 2024Choroid plexus (ChP), the brain structure primarily responsible for cerebrospinal fluid production, contains a robust circadian clock, whose role remains to be...
Choroid plexus (ChP), the brain structure primarily responsible for cerebrospinal fluid production, contains a robust circadian clock, whose role remains to be elucidated. The aim of our study was to [1] identify rhythmically controlled cellular processes in the mouse ChP and [2] assess the role and nature of signals derived from the master clock in the suprachiasmatic nuclei (SCN) that control ChP rhythms. To accomplish this goal, we used various mouse models (WT, mPer2, ChP-specific Bmal1 knockout) and combined multiple experimental approaches, including surgical lesion of the SCN (SCNx), time-resolved transcriptomics, and single cell luminescence microscopy. In ChP of control (Ctrl) mice collected every 4 h over 2 circadian cycles in darkness, we found that the ChP clock regulates many processes, including the cerebrospinal fluid circadian secretome, precisely times endoplasmic reticulum stress response, and controls genes involved in neurodegenerative diseases (Alzheimer's disease, Huntington's disease, and frontotemporal dementia). In ChP of SCNx mice, the rhythmicity detected in vivo and ex vivo was severely dampened to a comparable extent as in mice with ChP-specific Bmal1 knockout, and the dampened cellular rhythms were restored by daily injections of dexamethasone in mice. Our data demonstrate that the ChP clock controls tissue-specific gene expression and is strongly dependent on the presence of a functional connection with the SCN. The results may contribute to the search for a novel link between ChP clock disruption and impaired brain health.
Topics: Animals; Suprachiasmatic Nucleus; Choroid Plexus; Circadian Clocks; Mice; Mice, Inbred C57BL; Circadian Rhythm; Male; Mice, Knockout; ARNTL Transcription Factors
PubMed: 38802875
DOI: 10.1186/s12987-024-00547-3 -
Acta Pharmaceutica Sinica. B May 2024Growing evidences indicate that dysfunction of autophagy contributes to the disease pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia...
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 () 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 DPRs have a strong ability to harm neurons and induce -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 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 DPR-induced neurotoxicity.
PubMed: 38799643
DOI: 10.1016/j.apsb.2024.02.004 -
Alpha Psychiatry Mar 2024Undiagnosed underlying medical conditions can cause many patients to be followed, for years, by a diagnosis of a primary psychiatric disorder and to receive...
BACKGROUND
Undiagnosed underlying medical conditions can cause many patients to be followed, for years, by a diagnosis of a primary psychiatric disorder and to receive inappropriate treatment. The aim of this study was to determine the prevalence of patients initially diagnosed with a primary psychiatric disorder but whose symptoms were later attributed to medical conditions. These patients' initial and final diagnoses were also examined.
METHODS
The records of 1843 patients hospitalized in Gazi University Faculty of Medicine Psychiatric Inpatient Clinic between 2015 and 2020 were examined in this retrospective and descriptive study. Thirteen patients were excluded from the study due to insufficient data. Descriptive statistics were performed on the data of 30 patients diagnosed with an underlying medical condition.
RESULTS
In follow-up, 49 patients' diagnoses changed. 19 patients had a diagnosis unrelated to an underlying medical condition, and 30 had a diagnosis related to an underlying medical condition. Five (16.7%) of the patients, previously known to have psychiatric disorders, were found to have Alzheimer's disease. Brain space-occupying lesions, frontotemporal dementia, epilepsy, Parkinson's disease, and Arnold-Chiari malformation followed Alzheimer's disease at 6.7% (n = 2). The mean time until the diagnosis of the patients was revised was 4.95 years (standard deviation [SD] = 7.78). It was observed that psychotropic medications (90%) were used more than non-psychotropic drugs until the diagnosis was revised.
CONCLUSION
During the diagnostic process, we believe that clinicians should be aware of potential underlying medical conditions and that the multidisciplinary work of psychiatry and neurology is also crucial.
PubMed: 38798811
DOI: 10.5152/alphapsychiatry.2024.231274 -
Frontiers in Genetics 2024
PubMed: 38798695
DOI: 10.3389/fgene.2024.1420029 -
MedRxiv : the Preprint Server For... May 2024Neuronal dysfunction has been extensively studied as a central feature of neurodegenerative tauopathies. However, across neurodegenerative diseases, there is strong...
Neuronal dysfunction has been extensively studied as a central feature of neurodegenerative tauopathies. However, across neurodegenerative diseases, there is strong evidence for active involvement of immune cells like microglia in driving disease pathophysiology. Here, we demonstrate that tau mRNA and protein are expressed in microglia in human brains and in human induced pluripotent stem cell (iPSC)-derived microglia like cells (iMGLs). Using iMGLs harboring the IVS10+16 mutation and isogenic controls, we demonstrate that a tau mutation is sufficient to alter microglial transcriptional states. We discovered that IVS10+16 microglia exhibit cytoskeletal abnormalities, stalled phagocytosis, disrupted TREM2/TYROBP networks, and altered metabolism. Additionally, we found that secretory factors from IVS10+16 iMGLs impact neuronal health, reducing synaptic density in neurons. Key features observed were recapitulated in human brain tissue and cerebrospinal fluid from mutations carriers. Together, our findings that IVS10+16 drives cell-intrinsic dysfunction in microglia that impacts neuronal health has major implications for development of therapeutic strategies.
PubMed: 38798451
DOI: 10.1101/2024.05.15.24307444 -
BioRxiv : the Preprint Server For... May 2024TDP43 is an RNA/DNA binding protein increasingly recognized for its role in neurodegenerative conditions including amyotrophic lateral sclerosis (ALS) and frontotemporal...
TDP43 is an RNA/DNA binding protein increasingly recognized for its role in neurodegenerative conditions including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). As characterized by its aberrant nuclear export and cytoplasmic aggregation, TDP43 proteinopathy is a hallmark feature in over 95% of ALS/FTD cases, leading to the formation of detrimental cytosolic aggregates and a reduction in nuclear functionality within neurons. Building on our prior work linking TDP43 proteinopathy to the accumulation of DNA double-strand breaks (DSBs) in neurons, the present investigation uncovers a novel regulatory relationship between TDP43 and DNA mismatch repair (MMR) gene expressions. Here, we show that TDP43 depletion or overexpression directly affects the expression of key MMR genes. Alterations include MLH1, MSH2, MSH3, MSH6, and PMS2 levels across various primary cell lines, independent of their proliferative status. Our results specifically establish that TDP43 selectively influences the expression of MLH1 and MSH6 by influencing their alternative transcript splicing patterns and stability. We furthermore find aberrant MMR gene expression is linked to TDP43 proteinopathy in two distinct ALS mouse models and post-mortem brain and spinal cord tissues of ALS patients. Notably, MMR depletion resulted in the partial rescue of TDP43 proteinopathy-induced DNA damage and signaling. Moreover, bioinformatics analysis of the TCGA cancer database reveals significant associations between TDP43 expression, MMR gene expression, and mutational burden across multiple cancers. Collectively, our findings implicate TDP43 as a critical regulator of the MMR pathway and unveil its broad impact on the etiology of both neurodegenerative and neoplastic pathologies.
PubMed: 38798341
DOI: 10.1101/2024.05.16.594552