Role of Alcohol Drinking in Alzheimer's Disease, Parkinson's Disease, and Amyotrophic Lateral Sclerosis

Intermittent hypoxia-hyperoxia training ameliorates cognitive impairment and neuroinflammation in a rat model of Alzheimer's disease

Alzheimer's disease (AD), characterized by severe and progressive cognitive decline, stands as one of the most prevalent and devastating forms of dementia. Based on our recent findings showing intermittent hypoxic conditioning improved neuronal function in patients with mild cognitive impairment, the present study aimed at investigating whether the neuroprotective effects of intermittent hypoxia can be replicated in a rat model of AD, which allows us to explore the underlying cellular mechanisms involving neuroinflammation, hypoxia inducible factor 1α (HIF1α), and cytochrome P450 family 2 subfamily E member 1 (CYP2E1). Forty-one adult male Wistar rats were randomly assigned to three groups: 1) Control group: received intracerebroventricular (ICV) injection of saline; 2) STZ group: received ICV injection of streptozotocin (STZ) to induce AD-like pathology; and 3) STZ + IHHT group received ICV injection of STZ as well as 15 daily sessions of intermittent hypoxia-hyperoxia training (IHHT). We observed that ICV injection of STZ inhibited spatial learning and memory in the rats assessed with Morris Water Maze test. The cognitive function declines were accompanied by increased expression of amyloid β peptide (Aβ), HIF1α, CYP2E1, and TNFα in hippocampus. Interestingly, IHHT significantly restored the STZ-induced cognitive dysfunction, while reduced expression of Aβ, CYP2E1, HIF1α and TNFα. We conclude that IHHT with mild hypoxia-hyperoxia can enhance spatial learning and memory and reduce the AD-like pathologic changes in rats. The neuroprotective outcome of IHHT may be related to anti-inflammatory effects in hippocampus.

Alcohol consumption confers lasting impacts on prefrontal cortical neuron intrinsic excitability and spontaneous neurotransmitter signaling in the aging brain in mice

Both alcohol use disorder (AUD) and cognitive decline include disruption in the balance of excitation and inhibition in the cortex, but the potential role of alcohol use on excitation and inhibition on the aging brain is unclear. We examined the effect of moderate voluntary binge alcohol consumption on the aged, pre-disease neuronal environment by measuring intrinsic excitability and spontaneous neurotransmission on prefrontal cortical pyramidal (excitatory, glutamatergic) and non-pyramidal (inhibitory, GABAergic) neurons following a prolonged period of abstinence from alcohol in mice. Results highlight that binge alcohol consumption has lasting impacts on the electrophysiological properties of prefrontal cortical neurons. A profound increase in excitatory events onto layer 2/3 non-pyramidal neurons following alcohol consumption was seen, along with altered intrinsic excitability of pyramidal neurons, which could have a range of effects on cognitive disorder progression, such as Alzheimer's Disease, in humans. These results indicate that moderate voluntary alcohol influences the pre-disease environment in aging and highlight the need for further mechanistic investigation into this risk factor.

Glutathione S-transferase: A keystone in Parkinson's disease pathogenesis and therapy

Parkinson's disease is a progressive neurodegenerative disorder that predominantly affects motor function due to the loss of dopaminergic neurons in the substantia nigra. It presents significant challenges, impacting millions worldwide with symptoms such as tremors, rigidity, bradykinesia, and postural instability, leading to decreased quality of life and increased morbidity. The pathogenesis of Parkinson's disease is multifaceted, involving complex interactions between genetic susceptibility, environmental factors, and aging, with oxidative stress playing a central role in neuronal degeneration. Glutathione S-Transferase enzymes are critical in the cellular defense mechanism against oxidative stress, catalysing the conjugation of the antioxidant glutathione to various toxic compounds, thereby facilitating their detoxification. Recent research underscores the importance of Glutathione S-Transferase in the pathophysiology of Parkinson's disease, revealing that genetic polymorphisms in Glutathione S-Transferase genes influence the risk and progression of the disease. These genetic variations can affect the enzymatic activity of Glutathione S-Transferase, thereby modulating an individual's capacity to detoxify reactive oxygen species and xenobiotics, which are implicated in Parkinson's disease neuropathological processes. Moreover, biochemical studies have elucidated the role of Glutathione S-Transferase in not only maintaining cellular redox balance but also in modulating various cellular signalling pathways, highlighting its neuroprotective potential. From a therapeutic perspective, targeting Glutathione S-Transferase pathways offers promising avenues for the development of novel treatments aimed at enhancing neuroprotection and mitigating disease progression. This review explores the evident and hypothesized roles of Glutathione S-Transferase in Parkinson's disease, providing a comprehensive overview of its importance and potential as a target for therapeutic intervention.

Effect of fecal microbiota transplantation on patients with sporadic amyotrophic lateral sclerosis: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder marked by the progressive loss of motor neurons. Recent insights into ALS pathogenesis underscore the pivotal role of the gut microbiome, prompting an investigation into the potential therapeutic impact of fecal microbiota transplantation (FMT) on sporadic ALS patients.

METHODS

Conducted as a double-blind, placebo-controlled, parallel-group, randomized clinical trial, the study enrolled 27 participants from October 2022 to April 2023. The participants were followed up for 6 months from February 2023 to October 2023, during in-person visits at baseline, week 15, week 23, and week 35. The participants, evenly randomized, received either healthy donor FMT (FMT, n = 14) or a mixture of 0.9% saline and food coloring (E150c) as sham transplantation (placebo, n = 13). The primary outcome measured the change in the ALS Functional Rating Scale-Revised (ALSFRS-R) total score from baseline to week 35. Secondary outcomes included changes in gastrointestinal and respiratory functions, muscle strength, autonomic function, cognition, quality of life, intestinal microbiome composition, and plasm neurofilament light chain protein (NFL). Efficacy and safety outcomes were assessed in the intention-to-treat population.

RESULTS

A total of 27 randomized patients (47% women; mean age, 67.2 years), 24 participants completed the entire study. Notably, ALSFRS-R score changes exhibited no significant differences between FMT (6.1 [SD, 3.11]) and placebo (6.41[SD, 2.73]) groups from baseline to week 35. Secondary efficacy outcomes, encompassing respiratory function, muscle strength, autonomic function, cognition, quality of life, and plasm NFL, showed no significant differences. Nevertheless, the FMT group exhibited improvements in constipation, depression, and anxiety symptoms. FMT induced a shift in gut microbiome community composition, marked by increased abundance of Bifidobacterium, which persisted until week 15 (95% CI, 0.04 to 0.28; p = 0.01). Gastrointestinal adverse events were the primary manifestations of FMT-related side effects.

CONCLUSIONS

In this clinical trial involving 27 sporadic ALS patients, FMT did not significantly slow the decline in ALSFRS-R score. Larger multicenter trials are needed to confirm the efficacy of FMT in sporadic ALS patients and to explore the underlying biological mechanisms.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR 2200064504.

Biochemical changes precede affective and cognitive anomalies in aging adult C57BL/6J mice with a prior history of adolescent alcohol binge-drinking

The early initiation of binge-drinking and biological sex are critical risk factors for the development of affective disturbances and cognitive decline, as well as neurodegenerative diseases including Alzheimer's disease. Further, a history of excessive alcohol consumption alters normal age-related changes in the pattern of protein expression in the brain, which may relate to an acceleration of cognitive decline. Here, we aimed to disentangle the interrelation between a history of binge-drinking during adolescence, biological sex and normal aging on the manifestation of negative affect, cognitive decline and associated biochemical pathology. To this end, adolescent male and female C57BL/6J mice (PND 28-29) underwent 30 days of alcohol binge-drinking using a modified drinking-in-the-dark (DID) paradigm. Then, mice were assayed for negative affect, sensorimotor gating and cognition at three developmental stages during adulthood-mature adulthood (6 months), pre-middle age (9 months) and middle age (12 months). Behavioural testing was then followed by immunoblotting to index the protein expression of glutamate receptors, neuropathological markers [Tau, p (Thr217)-Tau, p (Ser396)-Tau, BACE, APP, Aβ], as well as ERK activation within the entorhinal cortex, prefrontal cortex and amygdala. Across this age span, we detected only a few age-related changes in our measures of negative affect or spatial learning/memory in the Morris water maze and all of these changes were sex-specific. Prior adolescent binge-drinking impaired behaviour only during reversal learning in 9-month-old females and during radial arm maze testing in 12-month-old females. In contrast to behaviour, we detected a large number of protein changes related to prior binge-drinking history, several of which manifested as early as 6 months of age, with the prefrontal cortex particularly affected at this earlier age. While 6-month-old mice exhibited relatively few alcohol-related protein changes within the entorhinal cortex and amygdala, the number of alcohol-related protein changes within the entorhinal cortex increased with age, while the 12-month-old mice exhibited the largest number of protein changes within the amygdala. Approximately a third of the alcohol-related protein changes were sex-selective. Taken together, the results of our longitudinal study using a murine model of binge-drinking indicate that a prior history of heavy alcohol consumption, beginning in adolescence, is sufficient to induce what we presume to be latent changes in protein indices of cellular activity, glutamate transmission and neuropathology within key brain regions governing cognition, executive function and emotion that appear to precede the onset of robust behavioural signs of dysregulated affect and cognitive impairment.

The Effect of Alcohol Consumption on Progressive Supranuclear Palsy: A Cross-Sectional Study

AIMS

To investigate the effect of alcohol consumption on the clinical symptoms in a cohort of Progressive supranuclear palsy (PSP) patients.

METHODS

We conducted a cross-sectional study focusing on possible and probable PSP patients in Qilu Hospital of Shandong University. Diagnoses and clinical phenotypes were confirmed using the 2017 Movement Disorder Society criteria and the Multiple Allocations eXtinction (MAX) rules. Data on drinking habits and demographics were collected via face-to-face interviews and medical records reviews. Clinical scales assessed motor and nonmotor symptoms. Alcohol consumption was categorized into light, moderate, and heavy status. Using multivariate linear regression and adjusting for confounding factors, we analyzed the relationship between alcohol consumption and clinical symptoms.

RESULTS

The study comprised 128 participants (59.4% male and 45.31% drinkers). Alcohol consumption has been associated with severe PSP clinical symptoms, particularly among male patients. Compared with nondrinkers, consumers of alcohol exhibit significantly more severe motor symptoms and cognitive impairments, particularly in the domains of visuospatial and executive abilities, memory, and language. Moreover, when categorizing individuals based on their intake of alcohol weekly, those with heavy consumption show significantly higher PSP Rating Scale (PSPRS) and the Unified Parkinson's Disease Rating Scale (UPDRS) scores, as well as significantly lower Montreal Cognitive Assessment Scale (MoCA) and Mini Mental State Examination (MMSE) scores compared to nonconsumers.

CONCLUSION

Our findings indicate an association between heavy alcohol consumption and more pronounced symptoms of PSP, especially cognitive function. It raises the possibility that alcohol intake may play a role in modulating the clinical course of PSP.

Association between added sugars intake and Parkinson's disease status in U.S. adults: a cross-sectional study from NHANES 1990-2020

BACKGROUND

Added sugars intake is common among individuals with Parkinson's disease (PD), yet the link between added sugars intake and PD is not well understood. Our study aims to investigate the association between added sugars intake and PD.

METHODS

This study utilized data from the National Health and Nutrition Examination Survey (NHANES) from1990 to 2020. Added sugars intake was estimated based on a 24-hour dietary recall from participants. Multivariable logistic regression analysis was employed to explore the relationship between added sugars intake and the prevalence of PD. Restricted cubic spline (RCS) was used to explore the nonlinear association between added sugars intake and PD. To further observe whether the conclusions were consistent across different subgroups, we conducted subgroup analyses to investigate the association of added sugars intake with PD in different populations.

RESULTS

The study included 12,489 participants, of which 100 had PD. When weighted, the data represented 136,959,144 participants. The study revealed a positive association between added sugars intake and the prevalence of PD. In multivariable regression models adjusted for all confounding factors, compared with the lowest quartile of added sugars intake, the third quartile (OR = 2.99; 95% CI: 1.43-6.26) and those consuming more than 25% of their calories from added sugars (OR = 3.34; 95% CI: 1.03-10.86) had the highest risk of PD. The RCS curve showed an L-shaped nonlinear association between added sugars intake and PD. Two-segment linear regression by sex revealed that PD prevalence in women was linearly related to sugar intake (nonlinear P = 0.465), while men exhibited an L-shaped nonlinear relationship (nonlinear P = 0.03). Additionally, subgroup analysis showed that alcohol consumption and diabetes significantly influenced the association between added sugars intake and the prevalence of PD.

CONCLUSION

These results highlight a positive association between added sugars intake and the prevalence of PD, particularly among women, heavy drinkers, and individuals with diabetes.

Probiotics alleviate chronic ethanol exposure-induced anxiety-like behavior and hippocampal neuroinflammation in male mice through gut microbiota-derived extracellular vesicles

BACKGROUND

Probiotics can colonize both the human and animal bodies and consist of active microorganisms that are beneficial to health. The use of probiotics has been shown to alleviate certain neurological diseases and disturbances in gut microbiota resulting from chronic ethanol exposure. Research indicates that probiotics can influence the nervous system via the microbial-gut-brain axis, wherein extracellular vesicles secreted by the gut microbiota play a significant role in this process.

RESULTS

In this study, we first established a 30-day ethanol exposure and probiotic gavage mouse model, both of which influenced behavior and the composition of gut microbiota. We then extracted gut microbiota-derived extracellular vesicles from the feces of these model mice and injected them into new mice via the tail vein to assess the role of each set of extracellular vesicles. The results indicated that the extracellular vesicles derived from the intestinal microbiota in the ethanol group induced anxiety-like behavior and hippocampal neuroinflammation in the recipient mice. In contrast, the extracellular vesicles secreted by the gut microbiota from the probiotic group mitigated the anxiety-like behavior and neuroinflammation induced by ethanol-influenced extracellular vesicles.

CONCLUSIONS

Our study demonstrates that extracellular vesicles secreted by the gut microbiota can influence the nervous system via the microbial-gut-brain axis. Furthermore, we found that the extracellular vesicles secreted by the gut microbiota from the probiotic group exert a beneficial therapeutic effect on anxiety and hippocampal neuroinflammation.

Transgenic expression of human cytochrome P450 2E1 in C. elegans and rat PC-12 cells sensitizes to ethanol-induced locomotor and mitochondrial effects

Chronic alcohol (ethanol) use is increasing in the United States and has been linked to numerous health issues in multiple organ systems including neurological dysfunction and diseases. Ethanol toxicity is mainly driven by the metabolite acetaldehyde, which is generated through three pathways: alcohol dehydrogenase (ADH2), catalase (CAT), and cytochrome P450 2E1 (CYP2E1). ADH2, while the main ethanol clearance pathway in the liver, is not expressed in the mammalian brain, resulting in CAT and CYP2E1 driving local metabolism of ethanol in the central nervous system. CYP2E1 is known to generate reactive metabolites and reactive oxygen species and localizes to the mitochondria (mtCYP2E1) and endoplasmic reticulum (erCYP2E1). We sought to understand the consequences of mtCYP2E1 and erCYP2E1 in the nervous system during acute ethanol exposure. To answer this question, we generated transgenic Caenorhabditis elegans roundworms expressing human CYP2E1 in the mitochondria, endoplasmic reticulum, or both and exposed them to ethanol. We found that at lower concentrations, wild-type and mtCYP2E1-expressing worms had a small but significant inhibition of locomotion, whereas the erCYP2E1-expressing worms showed protection from this inhibition. At higher doses, all strains had reduced locomotion, but the erCYP2E1-expressing worms recovered faster than wild-type controls. CYP2E1 expression, regardless of organellar targeting, reduced mitochondrial respiration in response to ethanol. Similarly, transgenic expression of CYP2E1 in either organelle in PC-12 rat neuronal cell lines sensitized them to ethanol-induced cell death. Together, these findings suggest that subcellular localization of CYP2E1 impacts behavioral effects of ethanol and should be further studied in the mammalian central nervous system.

Alcohol consumption and its association with cancer, cardiovascular, liver and brain diseases: a systematic review of Mendelian randomization studies

Background

The health effects of alcohol consumption, particularly regarding potential protective benefits of light to moderate intake compared to abstinence, remain a subject of ongoing debate. However, epidemiological studies face limitations due to imprecise exposure measurements and the potential for bias through residual confounding and reverse causation. To address these limitations, we conducted a systematic review of Mendelian Randomization (MR) studies examining the causal relationship between alcohol consumption and cancers, cardiovascular, liver, and neurological diseases.

Methodology

We searched PubMed, ScienceDirect and Embase and Europe PMC up to 05/2024 for MR studies investigating the association of genetically predicted alcohol consumption with cancers, cardiovascular, liver and neurological diseases. We assessed methodological quality based on key elements of the MR design a genetic association studies tool.

Results

We included 70 MR studies that matched our inclusion criteria. Our review showed a significant association of alcohol consumption with multiple cancers such as oral and oropharyngeal, esophageal, colorectal cancers, hepatocellular carcinoma and cutaneous melanoma. While the available studies did not consistently confirm the adverse or protective effects of alcohol on other cancers, such as lung cancer, as suggested by observational studies. Additionally, MR studies confirmed a likely causal effect of alcohol on the risk of hypertension, atrial fibrillation, myocardial infraction and vessels disease. However, there was no evidence to support the protective effects of light to moderate alcohol consumption on cognitive function, Alzheimer's disease, and amyotrophic lateral sclerosis, as reported in observational studies while our review revealed an increased risk of epilepsy and multiple sclerosis. The available studies provided limited results on the link between alcohol consumption and liver disease.

Conclusions

Despite the valuable insights into the causal relationship between alcohol consumption and various health outcomes that MR studies provided, it is worth noting that the inconsistent ability of genetic instrumental variables to distinguish between abstainers, light and moderate drinkers makes it difficult to differentiate between U or J-shaped vs. linear relationships between exposure and outcome. Additional research is necessary to establish formal quality assessment tools for MR studies and to conduct more studies in diverse populations, including non-European ancestries.

Systematic Review Registration

www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021246154, Identifier: PROSPERO (CRD42021246154).

Brain-Region-Specific Differences in Protein Citrullination/Deimination in a Pre-Motor Parkinson's Disease Rat Model

The detection of early molecular mechanisms and potential biomarkers in Parkinson's disease (PD) remains a challenge. Recent research has pointed to novel roles for post-translational citrullination/deimination caused by peptidylarginine deiminases (PADs), a family of calcium-activated enzymes, in the early stages of the disease. The current study assessed brain-region-specific citrullinated protein targets and their associated protein-protein interaction networks alongside PAD isozymes in the 6-hydroxydopamine (6-OHDA) induced rat model of pre-motor PD. Six brain regions (cortex, hippocampus, striatum, midbrain, cerebellum and olfactory bulb) were compared between controls/shams and the pre-motor PD model. For all brain regions, there was a significant difference in citrullinated protein IDs between the PD model and the controls. Citrullinated protein hits were most abundant in cortex and hippocampus, followed by cerebellum, midbrain, olfactory bulb and striatum. Citrullinome-associated pathway enrichment analysis showed correspondingly considerable differences between the six brain regions; some were overlapping for controls and PD, some were identified for the PD model only, and some were identified in control brains only. The KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways identified in PD brains only were associated with neurological, metabolic, immune and hormonal functions and included the following: "Axon guidance"; "Spinocerebellar ataxia"; "Hippo signalling pathway"; "NOD-like receptor signalling pathway"; "Phosphatidylinositol signalling system"; "Rap1 signalling pathway"; "Platelet activation"; "Yersinia infection"; "Fc gamma R-mediated phagocytosis"; "Human cytomegalovirus infection"; "Inositol phosphate metabolism"; "Thyroid hormone signalling pathway"; "Progesterone-mediated oocyte maturation"; "Oocyte meiosis"; and "Choline metabolism in cancer". Some brain-region-specific differences were furthermore observed for the five PAD isozymes (PADs 1, 2, 3, 4 and 6), with most changes in PAD 2, 3 and 4 when comparing control and PD brain regions. Our findings indicate that PAD-mediated protein citrullination plays roles in metabolic, immune, cell signalling and neurodegenerative disease-related pathways across brain regions in early pre-motor stages of PD, highlighting PADs as targets for future therapeutic avenues.

Low to moderate ethanol exposure reduces astrocyte-induced neuroinflammatory signaling and cognitive decline in presymptomatic APP/PS1 mice

Alcohol use disorder has been associated with the development of neurodegenerative diseases, including Alzheimer's disease (AD). However, recent studies demonstrate that moderate alcohol consumption may be protective against dementia and cognitive decline. We examined astrocyte function, low-density lipoprotein (LDL) receptor-related protein 1 (LRP1), and the NF-κB p65 and IKK-α/β signaling pathways in modulating neuroinflammation and amyloid beta (Aβ) deposition. We assessed apolipoprotein E (ApoE) in the brain of APP/PS1 mice using IHC and ELISA in response to low to moderate ethanol exposure (MEE). First, to confirm the intracerebral distribution of ApoE, we co-stained with GFAP, a marker for astrocytes that biosynthesize ApoE. We sought to investigate whether the ethanol-induced upregulation of LRP1 could potentially inhibit the activity of IL-1β and TNF-α induced IKK-α/β towards NF-κB p65, resulting in a reduction of pro-inflammatory cytokines. To evaluate the actual Aβ load in the brains of APP/PS1 mice, we performed with a specific antibody Aβ (Thioflavin S) on both air- and ethanol-exposed groups, subsequently analyzing Aβ levels. We also measured glucose uptake using 18F- fluorodeoxyglucose (FDG)-positron emission tomography (PET). Finally, we investigated whether MEE induced cognitive and memory changes using the Y maze, noble object recognition test, and Morris water maze. Our findings demonstrate that MEE reduced astrocytic glial fibrillary acidic protein (GFAP) and ApoE levels in the cortex and hippocampus in presymptomatic APP/PS1 mice. Interestingly, increased LRP1 protein expression was accompanied by dampening the IKK-α/β-NF-κB p65 pathway, resulting in decreased IL-1β and TNF-α levels in male mice. Notably, female mice show reduced levels of anti-inflammatory cytokines IL-4, and IL-10 without altering IL-1β and TNF-α concentrations. In both males and females, Aβ plaques, a hallmark of AD, were reduced in the cortex and hippocampus of APP/PS1 mice exposed to ethanol starting at pre-symptomatic stage. Consistently, MEE increased FDG-PET-based brain activities and normalized cognitive and memory deficits in the APP/PS1 mice. Our findings suggest that MEE may benefit AD pathology via modulating LRP1 expression, potentially reducing neuroinflammation and attenuating Aβ deposition. Our study implies that reduced astrocyte-derived ApoE and LDL cholesterol levels are critical for attenuating AD pathology.

The role of ALDH2 rs671 polymorphism and C-reactive protein in the phenotypes of male ALS patients

Background

The aldehyde dehydrogenase 2 (ALDH2) rs671 (A) allele has been implicated in neurodegeneration, potentially through oxidative and inflammatory pathways. The study aims to investigate the effects of the ALDH2 rs671 (A) allele and high sensitivity C-reactive protein (hs-CRP) on the clinical phenotypes of amyotrophic lateral sclerosis (ALS) in male and female patients.

Methods

Clinical data and ALDH2 rs671 genotype of 143 ALS patients, including 85 males and 58 females, were collected from January 2018 to December 2022. All patients underwent assessment using the Chinese version of the Edinburgh Cognitive and Behavioral ALS Screen (ECAS). Complete blood count and metabolic profiles were measured. Clinical and laboratory parameters were compared between carriers and non-carriers of the rs671 (A) allele in males and females, respectively. The significant parameters and rs671 (A) Allele were included in multivariate linear regression models to identify potential contributors to motor and cognitive impairment. Mediation analysis was employed to evaluate any mediation effects.

Results

Male patients carrying rs671 (A) allele exhibited higher levels of hs-CRP than non-carriers (1.70 mg/L vs. 0.50 mg/L, p = 0.006). The rs671 (A) allele was identified as an independent risk factor for faster disease progression only in male patients (β = 0.274, 95% CI = 0.048-0.499, p = 0.018). The effect of the rs671 (A) allele on the executive function in male patients was fully mediated by hs-CRP (Indirect effect = -1.790, 95% CI = -4.555--0.225). No effects of the rs671 (A) allele or hs-CRP were observed in female ALS patients. The effects of the ALDH2 rs671 (A) allele and the mediating role of hs-CRP in male patients remained significant in the sensitivity analyses.

Conclusion

The ALDH2 rs671 (A) allele contributed to faster disease progression and hs-CRP mediated cognitive impairment in male ALS patients.

Neurological Disorders Induced by Drug Use: Effects of Adolescent and Embryonic Drug Exposure on Behavioral Neurodevelopment

Clinical studies demonstrate that the risk of developing neurological disorders is increased by overconsumption of the commonly used drugs, alcohol, nicotine and cannabis. These drug-induced neurological disorders, which include substance use disorder (SUD) and its co-occurring emotional conditions such as anxiety and depression, are observed not only in adults but also with drug use during adolescence and after prenatal exposure to these drugs, and they are accompanied by long-lasting disturbances in brain development. This report provides overviews of clinical and preclinical studies, which confirm these adverse effects in adolescents and the offspring prenatally exposed to the drugs and include a more in-depth description of specific neuronal systems, their neurocircuitry and molecular mechanisms, affected by drug exposure and of specific techniques used to determine if these effects in the brain are causally related to the behavioral disturbances. With analysis of further studies, this review then addresses four specific questions that are important for fully understanding the impact that drug use in young individuals can have on future pregnancies and their offspring. Evidence demonstrates that the adverse effects on their brain and behavior can occur: (1) at low doses with short periods of drug exposure during pregnancy; (2) after pre-conception drug use by both females and males; (3) in subsequent generations following the initial drug exposure; and (4) in a sex-dependent manner, with drug use producing a greater risk in females than males of developing SUDs with emotional conditions and female offspring after prenatal drug exposure responding more adversely than male offspring. With the recent rise in drug use by adolescents and pregnant women that has occurred in association with the legalization of cannabis and increased availability of vaping tools, these conclusions from the clinical and preclinical literature are particularly alarming and underscore the urgent need to educate young women and men about the possible harmful effects of early drug use and to seek novel therapeutic strategies that might help to limit drug use in young individuals.

Secondary Bioactive Metabolites from Foods of Plant Origin as Theravention Agents against Neurodegenerative Disorders

Neurodegenerative disorders (NDDs) such as Alzheimer's (AD) and Parkinson's (PD) are on the rise, robbing people of their memories and independence. While risk factors such as age and genetics play an important role, exciting studies suggest that a diet rich in foods from plant origin may offer a line of defense. These kinds of foods, namely fruits and vegetables, are packed with a plethora of powerful bioactive secondary metabolites (SBMs), including terpenoids, polyphenols, glucosinolates, phytosterols and capsaicinoids, which exhibit a wide range of biological activities including antioxidant, antidiabetic, antihypertensive, anti-Alzheimer's, antiproliferative, and antimicrobial properties, associated with preventive effects in the development of chronic diseases mediated by oxidative stress such as type 2 diabetes mellitus, respiratory diseases, cancer, cardiovascular diseases, and NDDs. This review explores the potential of SBMs as theravention agents (metabolites with therapeutic and preventive action) against NDDs. By understanding the science behind plant-based prevention, we may be able to develop new strategies to promote brain health and prevent the rise in NDDs. The proposed review stands out by emphasizing the integration of multiple SBMs in plant-based foods and their potential in preventing NDDs. Previous research has often focused on individual compounds or specific foods, but this review aims to present a comprehensive fingerprint of how a diet rich in various SBMs can synergistically contribute to brain health. The risk factors related to NDD development and the diagnostic process, in addition to some examples of food-related products and medicinal plants that significantly reduce the inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), are highlighted.

Whole exome sequencing analysis identifies genes for alcohol consumption

Alcohol consumption is a heritable behavior seriously endangers human health. However, genetic studies on alcohol consumption primarily focuses on common variants, while insights from rare coding variants are lacking. Here we leverage whole exome sequencing data across 304,119 white British individuals from UK Biobank to identify protein-coding variants associated with alcohol consumption. Twenty-five variants are associated with alcohol consumption through single variant analysis and thirteen genes through gene-based analysis, ten of which have not been reported previously. Notably, the two unreported alcohol consumption-related genes GIGYF1 and ANKRD12 show enrichment in brain function-related pathways including glial cell differentiation and are strongly expressed in the cerebellum. Phenome-wide association analyses reveal that alcohol consumption-related genes are associated with brain white matter integrity and risk of digestive and neuropsychiatric diseases. In summary, this study enhances the comprehension of the genetic architecture of alcohol consumption and implies biological mechanisms underlying alcohol-related adverse outcomes.

Evidence for genetic causality between iron homeostasis and Parkinson's disease: A two-sample Mendelian randomization study

BACKGROUND

Parkinson's disease (PD) is a degenerative disease of the central nervous system, and its specific etiology is still unclear. At present, it is believed that the main pathological basis is the reduction of dopamine concentration in the brain striatum. Although many previous studies have believed that iron as an important nutrient element participates in the occurrence and development of PD, whether there is a causal correlation between total iron binding capacity(TIBC), transferring saturation(TSAT), ferritin and serum iron in iron homeostasis indicators and PD, there has been a lack of effective genetic evidence.

METHODS

We used Mendelian randomization (MR) as an analytical method to effectively evaluate the genetic association between exposure and outcome, based on the largest genome-wide association study (GWAS) data to date. By using randomly assigned genetic instrumental variables (SNPs, Single Nucleotide Polymorphisms) that are not affected by any causal relationship, we effectively evaluated the causal relationship between iron homeostasis indicators and PD while controlling for confounding factors.

RESULTS

By coordinated analysis of 86 SNPs associated with iron homeostasis markers and 12,858,066 SNPs associated with PD, a total of 56 SNPs were finally screened for genome-wide significance of iron homeostasis associated with PD. The results of inverse variance weighting(IVW) analysis suggested that iron（ β = - 0.524; 95%cl=-0.046 to -0.002; P=0.032) was considered to have a genetic causal relationship with PD. Cochran's Q, Egger intercept and MR-PRESSO global tests did not detect the existence of heterogeneity and pleiotropy (P>0.05). Mr Steiger directionality test further confirmed our estimation of the potential causal direction of iron and PD (P=0.001). In addition, TIBC (β=-0.142; 95%Cl=-0.197-0.481; P=0.414), TSAT (β=-0.316; 95%Cl=-0.861-0.229; P=0.255), and ferritin (β=-0.387; 95%Cl=-1.179-0.405; P=0.338) did not have genetic causal relationships with PD, and the results were not heterogeneous and pleiotropic (P>0.05). In addition, TIBC (β=-0.142; 95%Cl=-0.197-0.481; P=0.414), TSAT (β=-0.316; 95%Cl=-0.861-0.229; P=0.255), and ferritin (β=-0.101; 95%Cl=--0.987 to -0.405; P=0.823) did not have genetic causal relationships with PD, and the results were not heterogeneous and pleiotropic (P>0.05). TIBC (P=0.008), TSAT (P=0.000) and ferritin (P=0.013) were all consistent with the estimation of MR Steiger directivity test.

CONCLUSION

Our study found that among the four iron homeostasis markers, there was a genetic causal association between serum iron and PD, and the serum iron level was negatively correlated with the risk of PD. In addition, TIBC, TSAT, ferritin had no genetic causal relationship with PD.

Alcohol: Epigenome alteration and inter/transgenerational effect

While DNA serves as the fundamental genetic blueprint for an organism, it is not a static entity. Gene expression, the process by which genetic information is utilized to create functional products like proteins, can be modulated by a diverse range of environmental factors. Epigenetic mechanisms, including DNA methylation, histone modification, and microRNAs, play a pivotal role in mediating the intricate interplay between the environment and gene expression. Intriguingly, alterations in the epigenome have the potential to be inherited across generations. Alcohol use disorder (AUD) poses significant health issues worldwide. Alcohol has the capability to induce changes in the epigenome, which can be inherited by offspring, thus impacting them even in the absence of direct alcohol exposure. This review delves into the impact of alcohol on the epigenome, examining how its effects vary based on factors such as the age of exposure (adolescence or adulthood), the duration of exposure (chronic or acute), and the specific sample collected (brain, blood, or sperm). The literature underscores that alcohol exposure can elicit diverse effects on the epigenome during different life stages. Furthermore, compelling evidence from human and animal studies demonstrates that alcohol induces alterations in epigenome content, affecting both the brain and blood. Notably, rodent studies suggest that these epigenetic changes can result in lasting phenotype alterations that extend across at least two generations. In conclusion, the comprehensive literature analysis supports the notion that alcohol exposure induces lasting epigenetic alterations, influencing the behavior and health of future generations. This knowledge emphasizes the significance of addressing the potential transgenerational effects of alcohol and highlights the importance of preventive measures to minimize the adverse impact on offspring.

Protein Kinase C (PKC) in Neurological Health: Implications for Alzheimer's Disease and Chronic Alcohol Consumption

Protein kinase C (PKC) is a diverse enzyme family crucial for cell signalling in various organs. Its dysregulation is linked to numerous diseases, including cancer, cardiovascular disorders, and neurological problems. In the brain, PKC plays pivotal roles in synaptic plasticity, learning, memory, and neuronal survival. Specifically, PKC's involvement in Alzheimer's Disease (AD) pathogenesis is of significant interest. The dysregulation of PKC signalling has been linked to neurological disorders, including AD. This review elucidates PKC's pivotal role in neurological health, particularly its implications in AD pathogenesis and chronic alcohol addiction. AD, characterised by neurodegeneration, implicates PKC dysregulation in synaptic dysfunction and cognitive decline. Conversely, chronic alcohol consumption elicits neural adaptations intertwined with PKC signalling, exacerbating addictive behaviours. By unravelling PKC's involvement in these afflictions, potential therapeutic avenues emerge, offering promise for ameliorating their debilitating effects. This review navigates the complex interplay between PKC, AD pathology, and alcohol addiction, illuminating pathways for future neurotherapeutic interventions.

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.

Bioinformatics and Systems Biology Approaches to Identify the Synergistic Effects of Alcohol Use Disorder on the Progression of Neurological Diseases

Clinical investigations showed that individuals with Alcohol Use Disorder (AUD) have worse Neurological Disease (ND) development, pointing to possible pathogenic relationships between AUD and NDs. It remains difficult to identify risk factors that are predisposing between AUD and NDs. In order to fix these issues, we created the bioinformatics pipeline and network-based approaches for employing unbiased methods to discover genes abnormally stated in both AUD and NDs and to pinpoint some of the common molecular pathways that might underlie AUD and ND interaction. We found 100 differentially expressed genes (DEGs) in both the AUD and ND patient's tissue samples. The most important Gene Ontology (GO) terms and metabolic pathways, including positive control of cytotoxicity caused by T cells, proinflammatory responses, antigen processing and presentation, and platelet-triggered interactions with vascular and circulating cell pathways were then extracted using the overlapped DEGs. Protein-protein interaction analysis was used to identify hub proteins, including CCL2, IL1B, TH, MYCN, HLA-DRB1, SLC17A7, and HNF4A, in the pathways that have been reported as playing a function in these disorders. We determined several TFs (HNF4A, C4A, HLA-B, SNCA, HLA-DMB, SLC17A7, HLA-DRB1, HLA-C, HLA-A, and HLA-DPB1) and potential miRNAs (hsa-mir-34a-5p, hsa-mir-34c-5p, hsa-mir-449a, hsa-mir-155-5p, and hsa-mir-1-3p) were crucial for regulating the expression of AUD and ND which could serve as prospective targets for treatment. Our methodologies discovered unique putative biomarkers that point to the interaction between AUD and various neurological disorders, as well as pathways that could one day be the focus of therapeutic intervention.

MODERATE ALCOHOL CONSUMPTION INDUCES LASTING IMPACTS ON PREFRONTAL CORTICAL SIGNALING IN MICE

Both alcohol use disorder (AUD) and Alzheimer's Disease and Related Dementias (ADRD) appear to include disruption in the balance of excitation and inhibition in the cortex, but their potential interactions are unclear. We examined the effect of moderate voluntary binge alcohol consumption on the aged, pre-disease neuronal environment by measuring intrinsic excitability and spontaneous neurotransmission on prefrontal cortical pyramidal (excitatory, glutamatergic) and non-pyramidal (inhibitory, GABAergic) neurons following a prolonged period of abstinence from alcohol in mice. Results highlight that binge alcohol consumption has lasting impacts on the electrophysiological properties of prefrontal cortical neurons. A profound increase in excitatory events onto layer 2/3 non-pyramidal neurons following alcohol consumption was seen, along with altered intrinsic excitability of pyramidal neurons, which could have a range of effects on Alzheimer's Disease progression in humans. These results indicate that moderate voluntary alcohol influences the pre-disease environment in aging and highlight the need for further mechanistic investigation into this risk factor.

The aldehyde dehydrogenase 2 rs671 variant enhances amyloid β pathology

In the ALDH2 rs671 variant, a guanine changes to an adenine, resulting in a dramatic decrease in the catalytic activity of the enzyme. Population-based data are contradictory about whether this variant increases the risk of Alzheimer's disease. In East Asian populations, the prevalence of the ALDH2 rs671 variant is 30-50%, making the National Human Brain Bank for Development and Function (the largest brain bank in East Asia) an important resource to explore the link between the ALDH2 rs671 polymorphism and Alzheimer's disease pathology. Here, using 469 postmortem brains, we find that while the ALDH2 rs671 variant is associated with increased plaque deposits and a higher Aβ40/42 ratio, it is not an independent risk factor for Alzheimer's disease. Mechanistically, we show that lower ALDH2 activity leads to 4-HNE accumulation in the brain. The (R)-4-HNE enantiomer adducts to residue Lys53 of C99, favoring Aβ40 generation in the Golgi apparatus. Decreased ALDH2 activity also lowers inflammatory factor secretion, as well as amyloid β phagocytosis and spread in brains of patients with Alzheimer's disease. We thus define the relationship between the ALDH2 rs671 polymorphism and amyloid β pathology, and find that ALDH2 rs671 is a key regulator of Aβ40 or Aβ42 generation.

Alcohol and stress exposure across the lifespan are key risk factors for Alzheimer's Disease and cognitive decline

Alzheimer's Disease and related dementias (ADRD) are an increasing threat to global health initiatives. Efforts to prevent the development of ADRD require understanding behaviors that increase and decrease risk of neurodegeneration and cognitive decline, in addition to uncovering the underlying biological mechanisms behind these effects. Stress exposure and alcohol consumption have both been associated with increased risk for ADRD in human populations. However, our ability to understand causal mechanisms of ADRD requires substantial preclinical research. In this review, we summarize existing human and animal research investigating the connections between lifetime stress and alcohol exposures and ADRD.

Clinical and Neuropathological Correlates of Substance Use in American Football Players

Background

Chronic traumatic encephalopathy (CTE) is a neurodegenerative tauopathy more frequently found in deceased former football players. CTE has heterogeneous clinical presentations with multifactorial causes. Previous literature has shown substance use (alcohol/drug) can contribute to Alzheimer's disease and related tauopathies pathologically and clinically.

Objective

To examine the association between substance use and clinical and neuropathological endpoints of CTE.

Methods

Our sample included 429 deceased male football players. CTE was neuropathologically diagnosed. Informant interviews assessed features of substance use and history of treatment for substance use to define indicators: history of substance use treatment (yes vs no, primary variable), alcohol severity, and drug severity. Outcomes included scales that were completed by informants to assess cognition (Cognitive Difficulties Scale, BRIEF-A Metacognition Index), mood (Geriatric Depression Scale-15), behavioral regulation (BRIEF-A Behavioral Regulation Index, Barratt Impulsiveness Scale-11), functional ability (Functional Activities Questionnaire), as well as CTE status and cumulative p-tau burden. Regression models tested associations between substance use indicators and outcomes.

Results

Of the 429 football players (mean age = 62.07), 313 (73%) had autopsy confirmed CTE and 100 (23%) had substance use treatment history. Substance use treatment and alcohol/drug severity were associated with measures of behavioral regulation (FDR-p-values<0.05, ΔR2 = 0.04-0.18) and depression (FDR-p-values<0.05, ΔR2 = 0.02-0.05). Substance use indicators had minimal associations with cognitive scales, whereas p-tau burden was associated with all cognitive scales (p-values <0.05). Substance use treatment had no associations with neuropathological endpoints (FDR-p-values>0.05).

Conclusions

Among deceased football players, substance use was common and associated with clinical symptoms.

Equilibrium of Dietary Patterns Between Alzheimer's Disease Patients and Healthy People: A Comprehensive Analysis Using Multiple Factor Analysis and Classification Modeling

BACKGROUND

Alzheimer's disease (AD) is a particular type of dementia that currently lacks a definitive treatment and cure. It is possible to reduce the risk of developing AD and mitigate its severity through modifications to one's lifestyle, regular diet, and alcohol-drinking habits.

OBJECTIVE

The objective of this study is to examine the daily dietary patterns of individuals with AD compared to healthy controls, with a focus on nutritional balance and its impact on AD.

METHODS

This study incorporated multiple-factor analysis (MFA) to evaluate dietary patterns and employed Random Forest (RF) classifier and Sparse Logistic Regression (SLR) for Variable Importance analysis to identify food items significantly associated with AD.

RESULTS

MFA revealed trends in the data and a strong correlation (Lg = 0.92, RV = 0.65) between the daily consumption of processed food and meat items in AD patients. In contrast, no significant relationship was found for any daily consumed food categories within the healthy control (HC) group. Food items such as meat pie, hamburger, ham, sausages, beef, capsicum, and cabbage were identified as important variables associated with AD in RF and SLR analyses.

CONCLUSIONS

The findings from MFA indicated that the diversity or equilibrium of daily diet might play a potential role in AD development. RF and SLR classifications exhibit among the processed foods, especially deli meats and food made with meat items, are associated with AD.

Association of a healthy beverage score with total mortality in the adult population of Spain: A nationwide cohort study

BACKGROUND

Despite the substantial evidence of the relationship between diet and mortality, the role of beverage consumption patterns is not well known. The aim of this study was to assess the association of the adherence to a Healthy Beverage Score (HBS) and all-cause mortality in a representative sample of the Spanish adult population.

METHODS AND FINDINGS

We conducted an observational cohort study using data from the Study on Nutrition and Cardiovascular Risk in Spain (ENRICA), which included 12,161 community-dwelling individuals aged ≥18 years recruited in 2008 to 2010 and followed until January 2022. At baseline, food consumption was collected using a validated diet history. The HBS consists of 7 items, each of which is scored from 1 to 4 (highest adherence). The HBS ranges from 7 to 28 points with a higher score representing a healthier pattern. Adherence was assigned as a higher consumption of low-fat milk, and coffee and tea, a lower consumption of whole-fat milk, no consumption of fruit juice, artificially sweetened beverages, or sugar-sweetened beverages, and no or moderate consumption of alcohol. Total mortality was ascertained by linkage to the Spanish National Death Index. Statistical analyses were performed with Cox models and adjusted for the main confounders, including sociodemographic, lifestyle, dietary variables, and morbidity. After a mean follow-up of 12.5 years (SD: 1.7; range: 0.5 to 12.9), a total of 967 deaths occurred. For all-cause mortality, the fully adjusted hazard ratio (HR) for the highest versus lowest sex-specific quartiles of HBS was 0.72 (95% confidence interval [0.57, 0.91], p linear-trend = 0.015), corresponding to an 8.3% reduction in the absolute risk of death. A linear relationship between the risk of death and the adherence to the HBS was observed using restricted cubic splines. The results were robust to sensitivity analyses. The main limitation was that repeated measurements on beverage consumption were not available and beverage consumption could have changed during follow-up.

CONCLUSIONS

In this study, we observed that higher adherence to the HBS was associated with lower total mortality. Adherence to a healthy beverage pattern could play a role in the prevention of premature mortality.

Moderate ethanol exposure reduces astrocyte-induced neuroinflammatorysignaling and cognitive decline in presymptomatic APP/PS1 mice

Background

Alcohol use disorder (AUD) has been associated with the development of neurodegenerative diseases, including Alzheimer's disease (AD). However, recent studies demonstrate that moderate alcohol consumption may be protective against dementia and cognitive decline.

Methods

We examined astrocyte function, low-density lipoprotein (LDL) receptor-related protein 1 (LRP1), and the NF-κB p65 and IKK-α/β signaling pathways in modulating neuroinflammation and amyloid beta (Aβ) deposition. We assessed apolipoprotein E (ApoE) in the mouse brain using IHC and ELISA in response to moderate ethanol exposure (MEE). First, to confirm the intracerebral distribution of ApoE, we co-stained with GFAP, a marker for astrocytes that biosynthesize ApoE. We sought to investigate whether the ethanol-induced upregulation of LRP1 could potentially inhibit the activity of IL-1β and TNF-α induced IKK-α/β towards NF-κB p65, resulting in a reduction of pro-inflammatory cytokines. To evaluate the actual Aβ load in the brains of APP/PS1 mice, we performed with a specific antibody Aβ (Thioflavin S) on both air- and ethanol-exposed groups, subsequently analyzing Aβ levels. We also measured glucose uptake activity using 18F-FDG in APP/PS1 mice. Finally, we investigated whether MEE induced cognitive and memory changes using the Y maze, noble objective recognition (NOR) test, and Morris water maze (MWM).

Results

Our findings demonstrate that MEE reduced astrocytic glial fibrillary acidic protein (GFAP) and ApoE levels in the cortex and hippocampus in presymptomatic APP/PS1 mice. Interestingly, increased LRP1 protein expression is accompanied by dampening the IKK-α/β-NF-κB p65 pathway, resulting in decreased IL-1β and TNF-α levels in male mice. Notably, female mice show reduced anti-inflammatory cytokines, IL-4, and IL-10 levels without altering IL-1β and TNF-α concentrations. In both males and females, Aβ plaques, a hallmark of AD, were reduced in the cortex and hippocampus of ethanol-exposed presymptomatic APP/PS1 mice. Consistently, MEE increased fluorodeoxyglucose (FDG)-positron emission tomography (PET)-based brain activities and normalized cognitive and memory deficits in the APP/PS1 mice.

Conclusions

Our findings suggest that MEE may benefit AD pathology via modulating LRP1 expression, potentially reducing neuroinflammation and attenuating Aβ deposition. Our study implies that reduced astrocyte derived ApoE and LDL cholesterol levels are critical for attenuating AD pathology.

In silico SNP prediction of selected protein orthologues in insect models for Alzheimer's, Parkinson's, and Huntington's diseases

Alzheimer's, Parkinson's, and Huntington's are the most common neurodegenerative diseases that are incurable and affect the elderly population. Discovery of effective treatments for these diseases is often difficult, expensive, and serendipitous. Previous comparative studies on different model organisms have revealed that most animals share similar cellular and molecular characteristics. The meta-SNP tool includes four different integrated tools (SIFT, PANTHER, SNAP, and PhD-SNP) was used to identify non synonymous single nucleotide polymorphism (nsSNPs). Prediction of nsSNPs was conducted on three representative proteins for Alzheimer's, Parkinson's, and Huntington's diseases; APPl in Drosophila melanogaster, LRRK1 in Aedes aegypti, and VCPl in Tribolium castaneum. With the possibility of using insect models to investigate neurodegenerative diseases. We conclude from the protein comparative analysis between different insect models and nsSNP analyses that D. melanogaster is the best model for Alzheimer's representing five nsSNPs of the 21 suggested mutations in the APPl protein. Aedes aegypti is the best model for Parkinson's representing three nsSNPs in the LRRK1 protein. Tribolium castaneum is the best model for Huntington's disease representing 13 SNPs of 37 suggested mutations in the VCPl protein. This study aimed to improve human neural health by identifying the best insect to model Alzheimer's, Parkinson's, and Huntington's.

Alcohol and the Brain-Gut Axis: The Involvement of Microglia and Enteric Glia in the Process of Neuro-Enteric Inflammation

Binge or chronic alcohol consumption causes neuroinflammation and leads to alcohol use disorder (AUD). AUD not only affects the central nervous system (CNS) but also leads to pathologies in the peripheral and enteric nervous systems (ENS). Thus, understanding the mechanism of the immune signaling to target the effector molecules in the signaling pathway is necessary to alleviate AUD. Growing evidence shows that excessive alcohol consumption can activate neuroimmune cells, including microglia, and change the status of neurotransmitters, affecting the neuroimmune system. Microglia, like peripheral macrophages, are an integral part of the immune defense and represent the reticuloendothelial system in the CNS. Microglia constantly survey the CNS to scavenge the neuronal debris. These cells also protect parenchymal cells in the brain and spinal cord by repairing nerve circuits to keep the nervous system healthy against infectious and stress-derived agents. In an activated state, they become highly dynamic and mobile and can modulate the levels of neurotransmitters in the CNS. In several ways, microglia, enteric glial cells, and macrophages are similar in terms of causing inflammation. Microglia also express most of the receptors that are constitutively present in macrophages. Several receptors on microglia respond to the inflammatory signals that arise from danger-associated molecular patterns (DAMPs), pathogen-associated molecular patterns (PAMPs), endotoxins (e.g., lipopolysaccharides), and stress-causing molecules (e.g., alcohol). Therefore, this review article presents the latest findings, describing the roles of microglia and enteric glial cells in the brain and gut, respectively, and their association with neurotransmitters, neurotrophic factors, and receptors under the influence of binge and chronic alcohol use, and AUD.

Development and Psychometric Evaluation of a Lifestyle Evaluation Instrument for Older Adults

Brazil is experiencing an accelerated period of population aging, with important implications for individuals, families, and the society at large. Lifestyles for the elderly can have both positive and negative health effects and are characterized by behaviors that individuals constantly reproduce in day-to-day life. However, few assessment instruments are aimed at evaluating lifestyles, and this has hampered research development. Thus, our aim in this study was to develop and evaluate the psychometric qualities of a new instrument to assess older adults' lifestyles. We developed this single scale to assess the lifestyles of older men and women using the sequential mixed method. Individuals over 60 years old of both sexes participated in this study of several phases. In Phase 1, we produced a 96-item single scale instrument, based on a literature review, previous scales, and qualitative research. In Phase 2, we verified the scale's content validity with help from 12 experts and 20 members of a target audience, aged between 60-84 years, deleting some items and reworking others. In Phase 3, we analyzed the psychometric qualities of the new scale in a sample of 700 older adults, aged 60 and above, from the five regions of Brazil, using both exploratory and confirmatory factor analysis. Our completed "Older Adult Lifestyle Scale" (OALS) is composed of 19 items divided into four subscales. The OALS has shown good psychometric qualities for Brazilian older adults over 60 years of age, and we can now recommend its use in this population.

Changes in smoking, alcohol consumption, and the risk of Parkinson's disease

Objective

There have been no studies on the association between changes in smoking and alcohol consumption or combined changes in smoking and alcohol consumption frequencies and PD risk. To assess the influence of changes in smoking and alcohol consumption on the risk of Parkinson's disease (PD).

Methods

National Health Insurance Service (NHIS) database between January 2009 to December 2011 was analyzed. A total of 3,931,741 patients were included. Study participants were followed up for the incidence of PD until December 2017.

Results

Compared to the sustained non-smokers, sustained light smokers (adjusted hazard ratio [aHR] 0.80, 95% confidence interval [CI] 0.75-0.85), sustained moderate smokers (aHR 0.54, 95% CI 0.47-0.61), and sustained heavy smokers (aHR 0.49, 95% CI 0.44-0.55) had a lower risk of PD. Compared to those who sustained non-drinking, sustained light drinkers (aHR 0.85 95% CI 0.89-0.91), sustained moderate drinkers (aHR 0.68, 95% CI 0.60-0.78), and sustained heavy drinkers (aHR 0.77, 95% CI 0.68-0.87) showed decreased risk of PD. Among non-drinkers, those who started drinking to a light level were at decreased risk of PD (aHR 0.84, 95% CI 0.77-0.91). Among non-smoking and non-drinking participants, those who initiated smoking only (aHR 0.78, 95% CI 0.70-0.86), drinking only (aHR 0.77, 95% CI 0.68-0.87), and both smoking and drinking (aHR 0.69, 95% CI 0.58-0.82) showed decreased risk of PD.

Conclusion

Smoking is associated with decreased risk of PD with a dose-response relationship. Alcohol consumption at a light level may also be associated with decreased risk of PD. Further studies are warranted to find the possible mechanisms for the protective effects of smoking and drinking on PD, which may present insights into the etiology of PD.

Animal models of Alzheimer's disease: An originof innovativetreatments and insight to the disease's etiology

Alzheimer's disease (AD) is a progressive neurodegenerative disorder. The main pathogenic features are the development and depositionof senile plaques and neurofibrillary tangles in brain. Recent developments in the knowledge of the pathophysiological mechanisms behind Alzheimer's disease and other cognitive disorders have suggested new approaches to treatment development. These advancements have been significantly aided by the use of animal models, which are also essential for the assessment of therapies. Various approaches as transgenic animal model, chemical models, brain injury are used. This review will presentAD pathophysiology and emphasize several Alzheimer like dementia causingchemical substances, transgenic animal model and stereotaxy in order to enhance our existing knowledge of their mechanism of AD induction, dose, and treatment duration.

Impact of common ALDH2 inactivating mutation and alcohol consumption on Alzheimer's disease

Aldehyde dehydrogenase 2 (ALDH2) is an enzyme found in the mitochondrial matrix that plays a central role in alcohol and aldehyde metabolism. A common ALDH2 polymorphism in East Asians descent (called ALDH2*2 or E504K missense variant, SNP ID: rs671), present in approximately 8% of the world's population, has been associated with a variety of diseases. Recent meta-analyses support the relationship between this ALDH2 polymorphism and Alzheimer's disease (AD). And AD-like pathology observed in ALDH2-/- null mice and ALDH2*2 overexpressing transgenic mice indicate that ALDH2 deficiency plays an important role in the pathogenesis of AD. Recently, the worldwide increase in alcohol consumption has drawn attention to the relationship between heavy alcohol consumption and AD. Of potential clinical significance, chronic administration of alcohol in ALDH2*2/*2 knock-in mice exacerbates the pathogenesis of AD-like symptoms. Therefore, ALDH2 polymorphism and alcohol consumption likely play an important role in the onset and progression of AD. Here, we review the data on the relationship between ALDH2 polymorphism, alcohol, and AD, and summarize what is currently known about the role of the common ALDH2 inactivating mutation, ALDH2*2, and alcohol in the onset and progression of AD.

Associations of cardiovascular risk factors and lifestyle behaviors with neurodegenerative disease: a Mendelian randomization study

Previous observational studies reported that midlife clustering of cardiovascular risk factors and lifestyle behaviors were associated with neurodegenerative disease; however, these findings might be biased by confounding and reverse causality. This study aimed to investigate the causal associations of cardiovascular risk factors and lifestyle behaviors with neurodegenerative disease, using the two-sample Mendelian randomization design. Genetic variants for the modifiable risk factors and neurodegenerative disease were extracted from large-scale genome-wide association studies. The inverse-variance weighted method was used as the main analysis method, and MR-Egger regression and leave-one-out analyses were performed to identify potential violations. Genetically predicted diastolic blood pressure (DBP: OR per 1 mmHg, 0.990 [0.979-1.000]), body mass index (BMI: OR per 1 SD, 0.880 [0.825-0.939]), and educational level (OR per 1 SD, 0.698 [0.602-0.810]) were associated with lower risk of late-onset Alzheimer's disease (LOAD), while genetically predicted low-density lipoprotein (LDL: OR per 1 SD, 1.302 [1.066-1.590]) might increase LOAD risk. Genetically predicted exposures (including LDL and BMI) applied to familial AD showed the same effect. The association of LDL was also found with Amyotrophic lateral sclerosis (ALS) (LDL: OR per 1 SD, 1.180 [1.080-1.289]). This MR analysis showed that LDL, BMI, BP, and educational level were causally related to AD; a significant association between LDL and ALS risk, as well as the potential effect of sleep duration on PD risk, were also revealed. Targeting these modifiable factors was a promising strategy of neurodegenerative disease prevention.

Cell Death and Neurodegenerative Diseases: Mechanisms and Cytoprotective Molecules

A neurodegenerative disease is a pathological condition affecting neurons, condemning them to death [...].

A perspective on autophagy and transcription factor EB in Alcohol-Associated Alzheimer's disease

Alzheimer's disease (AD) is the most common form of progressive dementia and there is no truly efficacious treatment. Accumulating evidence indicates that impaired autophagic function for removal of damaged mitochondria and protein aggregates such as amyloid and tau protein aggregates may contribute to the pathogenesis of AD. Epidemiologic studies have implicated alcohol abuse in promoting AD, yet the underlying mechanisms are poorly understood. In this review, we discuss mechanisms of selective autophagy for mitochondria and protein aggregates and how these mechanisms are impaired by aging and alcohol consumption. We also discuss potential genetic and pharmacological approaches for targeting autophagy/mitophagy, as well as lysosomal and mitochondrial biogenesis, for the potential prevention and treatment of AD.

Oral Probiotic Expressing Human Ethanol Dehydrogenase Attenuates Damage Caused by Acute Alcohol Consumption in Mice

Alcohol is an essential drug in human life with multiple medical functions, but excessive alcohol intake, even a single episode of binge drinking, can cause serious damage. Reducing alcohol consumption or absorption is a direct way to alleviate the related harm. Alcohol is decomposed successively by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in the liver. Here, we produced a human ADH1B (hADH1B)-expressing probiotic, a recombinant Lactococcus lactis, that aimed to enhance alcohol degradation in the intestinal tract after oral administration. Our results showed that the oral hADH1B-expressing probiotic reduced alcohol absorption, prolonged the alcohol tolerance time, and shortened the recovery time after acute alcohol challenge. More importantly, the liver and intestine were protected from acute injury caused by alcohol challenge. Therefore, the engineered probiotic has the potential to protect organ damage from alcohol consumption. Furthermore, this engineered probiotic may have beneficial effects on alcohol-related diseases such as alcoholic fatty liver disease. IMPORTANCE Alcohol plays an important role in medical treatment, culture, and social interaction. However, excessive alcohol consumption or improper alcohol intake patterns can lead to serious damage to health. Aiming to reduce the harm of alcohol consumption, we designed a recombinant probiotic expressing hADH1B. Our results showed that this recombinant probiotic can reduce alcohol absorption and protect the body from alcohol damage, including hangover, liver, and intestinal damage. Reducing alcohol damage is helpful to the health of people with difficulty in abstinence. The engineered probiotic may provide new strategies for treatment and prevention of the negative effects of alcohol, and it also has the potential for widespread application.

miR-9 utilizes precursor pathways in adaptation to alcohol in mouse striatal neurons

microRNA-9 (miR-9) is one of the most abundant microRNAs in the mammalian brain, essential for its development and normal function. In neurons, it regulates the expression of several key molecules, ranging from ion channels to enzymes, to transcription factors broadly affecting the expression of many genes. The neuronal effects of alcohol, one of the most abused drugs in the world, seem to be at least partially dependent on regulating the expression of miR-9. We previously observed that molecular mechanisms of the development of alcohol tolerance are miR-9 dependent. Since a critical feature of alcohol action is temporal exposure to the drug, we decided to better understand the time dependence of alcohol regulation of miR-9 biogenesis and expression. We measured the effect of intoxicating concentration of alcohol (20 mM ethanol) on the expression of all major elements of miR-9 biogenesis: three pri-precursors (pri-mir-9-1, pri-mir-9-2, pri-mir-9-3), three pre-precursors (pre-mir-9-1, pre-mir-9-2, pre-mir-9-3), and two mature microRNAs: miR-9-5p and miR-9-3p, using digital PCR and RT-qPCR, and murine primary medium spiny neurons (MSN) cultures. We subjected the neurons to alcohol based on an exposure/withdrawal matrix of different exposure times (from 15 min to 24 h) followed by different withdrawal times (from 0 h to 24 h). We observed that a short exposure increased mature miR-9-5p expression, which was followed by a gradual decrease and subsequent increase of the expression, returning to pre-exposure levels within 24 h. Temporal changes of miR-9-3p expression were complementing miR-9-5p changes. Interestingly, an extended, continuous presence of the drug caused a similar pattern. These results suggest the presence of the adaptive mechanisms of miR-9 expression in the presence and absence of alcohol. Measurement of miR-9 pre- and pri-precursors showed further that the primary effect of alcohol on miR-9 is through the mir-9-2 precursor pathway with a smaller contribution of mir-9-1 and mir-9-3 precursors. Our results provide new insight into the adaptive mechanisms of neurons to alcohol exposure. It would be of interest to determine next which microRNA-based mechanisms are involved in a transition from the acute, intoxicating effects of alcohol to the chronic, addictive effects of the drug.

Alcohol as a Modifiable Risk Factor for Alzheimer's Disease-Evidence from Experimental Studies

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by cognitive impairment and memory loss. Epidemiological evidence suggests that heavy alcohol consumption aggravates AD pathology, whereas low alcohol intake may be protective. However, these observations have been inconsistent, and because of methodological discrepancies, the findings remain controversial. Alcohol-feeding studies in AD mice support the notion that high alcohol intake promotes AD, while also hinting that low alcohol doses may be protective against AD. Chronic alcohol feeding to AD mice that delivers alcohol doses sufficient to cause liver injury largely promotes and accelerates AD pathology. The mechanisms by which alcohol can modulate cerebral AD pathology include Toll-like receptors, protein kinase-B (Akt)/mammalian target of rapamycin (mTOR) pathway, cyclic adenosine monophosphate (cAMP) response element-binding protein phosphorylation pathway, glycogen synthase kinase 3-β, cyclin-dependent kinase-5, insulin-like growth factor type-1 receptor, modulation of β-amyloid (Aβ) synthesis and clearance, microglial mediated, and brain endothelial alterations. Besides these brain-centric pathways, alcohol-mediated liver injury may significantly affect brain Aβ levels through alterations in the peripheral-to-central Aβ homeostasis. This article reviews published experimental studies (cell culture and AD rodent models) to summarize the scientific evidence and probable mechanisms (both cerebral and hepatic) by which alcohol promotes or protects against AD progression.

Mechanisms underlying phenotypic variation in neurogenetic disorders

Neurological diseases associated with pathogenic variants in a specific gene, or even with a specific pathogenic variant, can show profound phenotypic variation with regard to symptom presentation, age at onset and disease course. Highlighting examples from a range of neurogenetic disorders, this Review explores emerging mechanisms that are involved in this variability, including environmental, genetic and epigenetic factors that influence the expressivity and penetrance of pathogenic variants. Environmental factors, some of which can potentially be modified to prevent disease, include trauma, stress and metabolic changes. Dynamic patterns of pathogenic variants might explain some of the phenotypic variations, for example, in the case of disorders caused by DNA repeat expansions such as Huntington disease (HD). An important role for modifier genes has also been identified in some neurogenetic disorders, including HD, spinocerebellar ataxia and X-linked dystonia-parkinsonism. In other disorders, such as spastic paraplegia, the basis for most of the phenotypic variability remains unclear. Epigenetic factors have been implicated in disorders such as SGCE-related myoclonus-dystonia and HD. Knowledge of the mechanisms underlying phenotypic variation is already starting to influence management strategies and clinical trials for neurogenetic disorders.

Aerobic Physical Training Attenuates Oxidative Stress in the Spinal Cord of Adult Rats Induced by Binge-like Ethanol Intake

Binge drinking is the most frequent consumption pattern among young adults and remarkably changes the central nervous system; thus, research on strategies to protect it is relevant. This study aimed to investigate the detrimental effects of binge-like EtOH intake on the spinal cord of male rats and the potential neuroprotective effects provided by moderate-intensity aerobic physical training. Male Wistar rats were distributed into the 'control group', 'training group', 'EtOH group', and 'training + EtOH'. The physical training protocol consisted of daily 30-min exercise on a treadmill for 5 consecutive days followed by 2 days off during 4 weeks. After the fifth day of each week, distilled water ('control group' and 'training group') or 3 g/kg of EtOH diluted at 20% w/v ('EtOH group' and 'training + EtOH group') was administered for 3 consecutive days through intragastric gavage to simulate compulsive consumption. Spinal cord samples were collected for oxidative biochemistry and morphometric analyses. The binge-like EtOH intake induced oxidative and tissue damage by decreasing reduced glutathione (GSH) levels, increasing lipid peroxidation (LPO), and reducing motor neurons (MN) density in the cervical segment. Even under EtOH exposure, physical training maintained GSH levels, reduced LPO, and prevented MN reduction at the cervical segment. Physical training is a non-pharmacological strategy to neuroprotect the spinal cord against oxidative damage induced by binge-like EtOH intake.

Therapeutic strategies of small molecules in the microbiota-gut-brain axis for alcohol use disorder

The microbiota-gut-brain axis (MGBA) is important in maintaining the structure and function of the central nervous system (CNS) and is regulated by the CNS environment and signals from the peripheral tissues. However, the mechanism and function of the MGBA in alcohol use disorder (AUD) are still not completely understood. In this review, we investigate the underlying mechanisms involved in the onset of AUD and/or associated neuronal deficits and create a foundation for better treatment (and prevention) strategies. We summarize recent reports focusing on the alteration of the MGBA in AUD. Importantly, we highlight the properties of small-molecule short-chain fatty acids (SCFAs), neurotransmitters, hormones, and peptides in the MGBA and discusses their usage as therapeutic agents against AUD.

Chemical Genetic Identification of PKC Epsilon Substrates in Mouse Brain

PKC epsilon (PKCε) plays important roles in behavioral responses to alcohol and in anxiety-like behavior in rodents, making it a potential drug target for reducing alcohol consumption and anxiety. Identifying signals downstream of PKCε could reveal additional targets and strategies for interfering with PKCε signaling. We used a chemical genetic screen combined with mass spectrometry to identify direct substrates of PKCε in mouse brain and validated findings for 39 of them using peptide arrays and in vitro kinase assays. Prioritizing substrates with several public databases such as LINCS-L1000, STRING, GeneFriends, and GeneMAINA predicted interactions between these putative substrates and PKCε and identified substrates associated with alcohol-related behaviors, actions of benzodiazepines, and chronic stress. The 39 substrates could be broadly classified in three functional categories: cytoskeletal regulation, morphogenesis, and synaptic function. These results provide a list of brain PKCε substrates, many of which are novel, for future investigation to determine the role of PKCε signaling in alcohol responses, anxiety, responses to stress, and other related behaviors.

Animal model for high consumption and preference of ethanol and its interplay with high sugar and butter diet, behavior, and neuroimmune system

Introduction

Mechanisms that dictate the preference for ethanol and its addiction are not only restricted to the central nervous system (CNS). An increasing body of evidence has suggested that abusive ethanol consumption directly affects the immune system, which in turn interacts with the CNS, triggering neuronal responses and changes, resulting in dependence on the drug. It is known that neuroinflammation and greater immune system reactivity are observed in behavioral disorders and that these can regulate gene transcription. However, there is little information about these findings of the transcriptional profile of reward system genes in high consumption and alcohol preference. In this regard, there is a belief that, in the striatum, an integrating region of the brain reward system, the interaction of the immune response and the transcriptional profile of the Lrrk2 gene that is associated with loss of control and addiction to ethanol may influence the alcohol consumption and preference. Given this information, this study aimed to assess whether problematic alcohol consumption affects the transcriptional profile of the Lrrk2 gene, neuroinflammation, and behavior and whether these changes are interconnected.

Methods

An animal model developed by our research group has been used in which male C57BL/6 mice and knockouts for the Il6 and Nfat genes were subjected to a protocol of high fat and sugar diet intake and free choice of ethanol in the following stages: Stage 1 (T1)-Dietary treatment, for 8 weeks, in which the animals receive high-calorie diet, High Sugar and Butter (HSB group), or standard diet, American Institute of Nutrition 93-Growth (AIN93G group); and Stage 2 (T2)-Ethanol consumption, in which the animals are submitted, for 4 weeks, to alcohol within the free choice paradigm, being each of them divided into 10 groups, four groups continued with the same diet and in the other six the HSB diet is substituted by the AIN93G diet. Five groups had access to only water, while the five others had a free choice between water and a 10% ethanol solution. The weight of the animals was evaluated weekly and the consumption of water and ethanol daily. At the end of the 12-week experiment, anxiety-like behavior was evaluated by the light/dark box test; compulsive-like behavior by Marble burying, transcriptional regulation of genes Lrrk2, Tlr4, Nfat, Drd1, Drd2, Il6, Il1β, Il10, and iNOS by RT-qPCR; and inflammatory markers by flow cytometry. Animals that the diet was replaced had an ethanol high preference and consumption.

Results and discussion

We observed that high consumption and preference for ethanol resulted in (1) elevation of inflammatory cells in the brain, (2) upregulation of genes associated with cytokines (Il6 and Il1β) and pro-inflammatory signals (iNOS and Nfat), downregulation of anti-inflammatory cytokine (Il10), dopamine receptor (Drd2), and the Lrrk2 gene in the striatum, and (3) behavioral changes such as decreased anxiety-like behavior, and increased compulsive-like behavior. Our findings suggest that interactions between the immune system, behavior, and transcriptional profile of the Lrrk2 gene influence the ethanol preferential and abusive consumption.

Bacteria-Loaded Gastro-Retention Oral Delivery System for Alcohol Abuse

Alcohol abuse is harmful to human health, and many strategies have been developed to retard this harm through protecting liver or activating relative enzymes. In this study, a new strategy of decreasing the alcohol absorption directly depending on the dealcoholization by the bacteria in the upper gastrointestinal (GI) tract was reported. To realize this, a bacteria-loaded gastro-retention oral delivery system with pore structure was constructed through emulsification/internal gelation, which could relieve acute alcohol intoxication in mice successfully. It was found that this bacteria-loaded system kept the above 30% suspension ratio in the simulated gastric fluid for 4 min, displayed good protection effect for the bacteria, and decreased the alcohol concentration from 50 to 30% below within 24 h in vitro. The in vivo imaging results demonstrated that it remained in the upper GI tract until 24 h and reduced 41.9% alcohol absorption. The mice with oral administration of the bacteria-loaded system were found with normal gait, smooth coat, and less liver damage. Although the intestinal flora distribution was influenced slightly during the oral administration, it could restore to normal levels only one day after stopping oral administration quickly, suggesting good biosafety. In conclusion, these results revealed that the bacteria-loaded gastro-retention oral delivery system might intake alcohol molecules rapidly and has huge potential in the treatment of alcohol abuse.

Role of the gut-brain axis in HIV and drug abuse-mediated neuroinflammation

Drug abuse and related disorders are a global public health crisis affecting millions, but to date, limited treatment options are available. Abused drugs include but are not limited to opioids, cocaine, nicotine, methamphetamine, and alcohol. Drug abuse and human immunodeficiency virus-1/acquired immune deficiency syndrome (HIV-1/AIDS) are inextricably linked. Extensive research has been done to understand the effect of prolonged drug use on neuronal signaling networks and gut microbiota. Recently, there has been rising interest in exploring the interactions between the central nervous system and the gut microbiome. This review summarizes the existing research that points toward the potential role of the gut microbiome in the pathogenesis of HIV-1-linked drug abuse and subsequent neuroinflammation and neurodegenerative disorders. Preclinical data about gut dysbiosis as a consequence of drug abuse in the context of HIV-1 has been discussed in detail, along with its implications in various neurodegenerative disorders. Understanding this interplay will help elucidate the etiology and progression of drug abuse-induced neurodegenerative disorders. This will consequently be beneficial in developing possible interventions and therapeutic options for these drug abuse-related disorders.

Precocious emergence of cognitive and synaptic dysfunction in 3xTg-AD mice exposed prenatally to ethanol

Alzheimer's disease (AD) is the most common cause of dementia, affecting approximately 50 million people worldwide. Early life risk factors for AD, including prenatal exposures, remain underexplored. Exposure of the fetus to alcohol (ethanol) is not uncommon during pregnancy, and may result in physical, behavioral, and cognitive changes that are first detected during childhood but result in lifelong challenges. Whether or not prenatal ethanol exposure may contribute to Alzheimer's disease risk is not yet known. Here we exposed a mouse model of Alzheimer's disease (3xTg-AD), bearing three dementia-associated transgenes, presenilin1 (PS1M146V), human amyloid precursor protein (APPSwe), and human tau (TauP301S), to ethanol on gestational days 13.5-16.5 using an established binge-type maternal ethanol exposure paradigm. We sought to investigate whether prenatal ethanol exposure resulted in a precocious onset or increased severity of AD progression, or both. We found that a brief binge-type gestational exposure to ethanol during a period of peak neuronal migration to the developing cortex resulted in an earlier onset of spatial memory deficits and behavioral inflexibility in the progeny, as assessed by performance on the modified Barnes maze task. The observed cognitive changes coincided with alterations to both GABAergic and glutamatergic synaptic transmission in layer V/VI neurons, diminished GABAergic interneurons, and increased β-amyloid accumulation in the medial prefrontal cortex. These findings provide the first preclinical evidence for prenatal ethanol exposure as a potential factor for modifying the onset of AD-like behavioral dysfunction and set the groundwork for more comprehensive investigations into the underpinnings of AD-like cognitive changes in individuals with fetal alcohol spectrum disorders.

Tauopathy and alcohol consumption interact to alter locus coeruleus excitatory transmission and excitability in male and female mice

Alcohol use disorder is a major public health concern in the United States. Recent work has suggested a link between chronic alcohol consumption and the development of tauopathy disorders, such as Alzheimer's disease and frontotemporal dementia. However, relatively little work has investigated changes in neural circuitry involved in both tauopathy disorders and alcohol use disorder. The locus coeruleus (LC) is the major noradrenergic nucleus in the brain and is one of the earliest sites to be affected by tau lesions. The LC is also implicated in the rewarding effects of ethanol and alcohol withdrawal. In this study we assessed effects of long-term ethanol consumption and tauopathy on the physiology of LC neurons. Male and female P301S mice, a humanized transgenic mouse model of tauopathy, underwent 16 weeks of intermittent access to 20% ethanol from 3 to 7 months of age. We observed higher total alcohol consumption in female mice regardless of genotype. Male P301S mice consumed more ethanol and had a greater preference for ethanol than wild-type (WT) males. At the end of the drinking study, LC function was assessed using ex vivo whole cell electrophysiology. We found significant changes in excitatory inputs to the LC due to both ethanol and genotype. We found significantly increased excitability of the LC due to ethanol with greater effects in female P301S mice than in female WT mice. Our study identifies significant changes in the LC due to interactions between tauopathy and long-term ethanol use. These findings could have important implications regarding LC activity and changes in behavior due to both ethanol- and tauopathy-related dementia.

Dysregulation of tryptophan metabolism and distortion of cell signaling after oral exposure to ethanol and Kynurenic acid

Kynurenic acid (KYNA), an unavoidable tryptophan metabolite during fermentation is naturally blended with alcohol in all alcoholic beverages. Thus, alcohol drinking inevitably results in co-intake of KYNA. Effects of alcohol or KYNA on human health have been widely studied. However, the combined effects of both remain unknown. Here we report that alcohol and KYNA have a synergistic impact of on global gene expression, especially the gene sets related to tryptophan metabolism and cell signaling. Adult mice were exposed to alcohol (ethanol) and/or KYNA daily for a week. Transcriptomes of the brain, kidney and liver were profiled via bulk RNA sequencing. Results indicate that while KYNA alone largely promotes, and alcohol alone mostly inhibits gene expression, alcohol and KYNA co-administration has a stronger inhibition of global gene expression. Tryptophan metabolism is severely skewed towards kynurenine pathway by decreasing tryptophan hydroxylase 2 and increasing tryptophan dioxygenase. Quantification of tryptophan metabolic enzymes corroborates the transcriptional changes of these enzymes. Furthermore, the co-administration greatly enhances the GnRH signaling pathway. This research provides critical data to better understand the effects of alcohol and KYNA in mix on human health.