Alcohol, insulin resistance and the liver-brain axis

Early life stress and body-mass-index modulate brain connectivity in alcohol use disorder

Early life stress (ELS) significantly increases susceptibility to alcohol use disorder (AUD) by affecting the interplay between the executive and the salience networks (SNs). The link between AUD and higher body-mass index (BMI) is known, but we lack understanding of how BMI impacts the relationship between ELS and brain connectivity in individuals with AUD. To bridge this gap, we investigated the main and interaction effects of ELS and BMI on brain connectivity in individuals with AUD compared to non-AUD participants (n = 77 sex-matched individuals per group). All participants underwent resting-state functional magnetic resonance imaging, revealing intriguing positive functional connectivity between SN seeds and brain regions involved in somatosensory processing, motor coordination and executive control. Examining the relationship of brain connectivity with ELS and BMI, we observed positive associations with the correlations of SN seeds, right anterior insula (RAIns) and supramarginal gyrus (SMG) with clusters in motor [occipital cortex, supplementary motor cortex]; anterior cingulate cortex (ACC) with clusters in frontal, or executive, control regions (middle frontal gyrus; MFG, precentral gyrus) that reportedly are involved in processing of emotionally salient stimuli (all |β | > 0.001, |p | < 0.05). Interestingly, a negative association of the interaction effect of ELS events and BMI measures with the functional connectivity of SN seeds ACC with decision-making (MFG, precentral gyrus), RAIns and RSMG with visuo-motor control regions (occipital cortex and supplementary motor cortex) (all |β | = -0.001, |p | < 0.05). These findings emphasize the moderating effect of BMI on ELS-associated SN seed brain connectivity in AUD. Understanding the neural mechanisms linking BMI, ELS and AUD can guide targeted interventions for this population.

Unravelling the liver-brain connection: A two-sample Mendelian randomization study investigating the causal relationship between NAFLD and cortical structure

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has been linked to cognitive decline and neuropsychiatric conditions, implying a potential connection between NAFLD and brain health. However, the causal association between NAFLD and cortical changes remains uncertain. This study aimed to examine the causal impact of NAFLD on cortical structures using a two-sample Mendelian randomization (MR) approach.

METHODS

Summary data from genome-wide association studies (GWAS) for NAFLD were gathered from large-scale cohorts. Surface area (SA) and cortical thickness (TH) measurements were derived from Enhancing Neuro Imaging Genetics through Meta-Analysis (ENIGMA) Consortium magnetic resonance imaging (MRI) data of 33,992 participants. Inverse-variance weighted (IVW) served as the primary method. Additional sensitivity analyses, including MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO), MR-Egger, and weighted median procedures, were conducted to detect heterogeneity and pleiotropy.

RESULTS

Our MR analysis revealed that NAFLD led to notable alterations in cortical structures, particularly in the pars orbitalis gyrus. Specifically, genetically predicted NAFLD was linked to a decrease in TH (β = -0.008 mm, 95 % CI: -0.013 mm to -0.004 mm, P = 3.00 × 10-4) within this region. No significant heterogeneity and pleiotropy were identified.

CONCLUSION

The two-sample MR study supports the existence of a liver-brain axis by demonstrating a causal association between NAFLD and changes in cortical structures. These findings emphasize the potential association between NAFLD and brain health, which could have implications for preventing and treating cognitive deficits and neuropsychiatric conditions in patients with NAFLD.

Dietary soy prevents fetal demise, intrauterine growth restriction, craniofacial dysmorphic features, and impairments in placentation linked to gestational alcohol exposure: Pivotal role of insulin and insulin-like growth factor signaling networks

INTRODUCTION

Prenatal alcohol exposure can impair placentation and cause intrauterine growth restriction (IUGR), fetal demise, and fetal alcohol spectrum disorder (FASD). Previous studies showed that ethanol's inhibition of placental insulin and insulin-like growth factor, type 1 (IGF-1) signaling compromises trophoblastic cell motility and maternal vascular transformation at the implantation site. Since soy isolate supports insulin responsiveness, we hypothesized that dietary soy could be used to normalize placentation and fetal growth in an experimental model of FASD.

METHODS

Pregnant Long-Evans rat dams were fed with isocaloric liquid diets containing 0% or 8.2% ethanol (v/v) from gestation day (GD) 6. Dietary protein sources were either 100% soy isolate or 100% casein (standard). Gestational sacs were harvested on GD19 to evaluate fetal resorption, fetal growth parameters, and placental morphology. Placental insulin/IGF-1 signaling through Akt pathways was assessed using commercial bead-based multiplex enzyme-linked immunosorbent assays.

RESULTS

Dietary soy markedly reduced or prevented the ethanol-associated fetal loss, IUGR, FASD dysmorphic features, and impairments in placentation/maturation. Furthermore, ethanol's inhibitory effects on the placental glycogen cell population at the junctional zone, invasive trophoblast populations at the implantation site, maternal vascular transformation, and signaling through the insulin and IGF1 receptors, Akt and PRAS40 were largely abrogated by co-administration of soy.

CONCLUSION

Dietary soy may provide an economically feasible and accessible means of reducing adverse pregnancy outcomes linked to gestational ethanol exposure.

The Influence of Insulin Resistance on Outcomes in Hospitalizations for Alcohol-Related Liver Disease: A Nationwide Study

Background Alcoholic liver disease (ALD) is known to contribute to the onset of insulin resistance (IR), which has been speculated to worsen the outcome of the disease. This study examines the impact of IR on the severity and outcomes of hospitalizations for ALD. Methods A retrospective study was performed using the combined 2016 to 2018 Nationwide Inpatient Sample. All admissions for ALD were included. The association between IR and the clinical and resource utilization of hospitalizations for ALD was analyzed using multivariate regression models to adjust for confounding variables. Results About 294,864 hospitalizations for ALD were analyzed. Of these, 383 cases (0.13%) included a secondary diagnosis of IR, while the remaining 294,481 hospitalizations (99.87%) were considered as controls. The incidence of IR in the study was 1.3 per 1000 admissions for ALD. IR was not associated with any significant difference in the likelihood of mortality (adjusted odds ratio (aOR): 1.10, 95% confidence interval (CI): 0.370-3.251, p=0.867), acute liver failure, or the incidence of complications (aOR: 0.83, 95% CI: 0.535-1.274, p<0.001). However, the study found that ALD hospitalizations with IR had longer hospital stays (7.3 days vs. 6.0 days: IRR, 1.17; 95% CI, 1.09-1.26; p<0.001) and higher mean hospital costs ($91,124 vs. $65,290: IRR, 1.32; 95% CI, 1.20-1.46; p<0.001) compared to patients without IR. Conclusion IR alone does not worsen the outcomes of patients with ALD, and its association with longer hospital stays and higher mean hospital costs could be due to other confounding factors.

Early Life Stress and Body-Mass Index Modulate Brain Connectivity in Alcohol Use Disorder

Early life stress (ELS) significantly increases susceptibility to alcohol use disorder (AUD) by affecting the interplay between executive and salience networks (SN). The link between AUD and higher body-mass index (BMI) is known, but we lack understanding of how BMI impacts the relationship between ELS and brain connectivity in individuals with AUD. To bridge this gap, we investigated the effects of ELS on brain connectivity in AUD participants, taking into account differences in BMI. The cohort included 401 individuals with AUD, with approximately 60% having a BMI ≥ 25. Within the overall cohort, 123 participants underwent resting-state functional magnetic resonance imaging, revealing intriguing anticorrelations between SN seeds and brain regions involved in somatosensory processing, motor coordination, and executive control as an effect of ELS. Examining the relationship between ELS-driven brain connectivity and BMI, we observed negative correlations in connectivity among low BMI (≤ 24.9) vs. high BMI (≥ 25) individuals. For example, the left supramarginal gyrus (SMG) seed exhibited decreased connectivity with emotion regulation and decision-making regions, including the right occipital cortex, posterior cingulate cortex, and precuneus clusters (all |β| < -0.03, |p| < 0.05). Additionally, the right SMG seed showed reduced connectivity with impulse control and executive function regions, such as the left postcentral/middle frontal gyrus cluster (β = 0.04, p = 0.02). These findings highlight the role of ELS-induced alterations in SN seed connectivity, influenced by BMI, in the neurobiology of AUD. Understanding the neural mechanisms linking obesity, AUD, and ELS can guide targeted interventions for this population.

System Biology Investigation Revealed Lipopolysaccharide and Alcohol-Induced Hepatocellular Carcinoma Resembled Hepatitis B Virus Immunobiology and Pathogenesis

Hepatitis B infection caused by the hepatitis B virus is a life-threatening cause of liver fibrosis, cirrhosis, and hepatocellular carcinoma. Researchers have produced multiple in vivo models for hepatitis B virus (HBV) and, currently, there are no specific laboratory animal models available to study HBV pathogenesis or immune response; nonetheless, their limitations prevent them from being used to study HBV pathogenesis, immune response, or therapeutic methods because HBV can only infect humans and chimpanzees. The current study is the first of its kind to identify a suitable chemically induced liver cirrhosis/HCC model that parallels HBV pathophysiology. Initially, data from the peer-reviewed literature and the GeneCards database were compiled to identify the genes that HBV and seven drugs (acetaminophen, isoniazid, alcohol, D-galactosamine, lipopolysaccharide, thioacetamide, and rifampicin) regulate. Functional enrichment analysis was performed in the STRING server. The network HBV/Chemical, genes, and pathways were constructed by Cytoscape 3.6.1. About 1546 genes were modulated by HBV, of which 25.2% and 17.6% of the genes were common for alcohol and lipopolysaccharide-induced hepatitis. In accordance with the enrichment analysis, HBV activates the signaling pathways for apoptosis, cell cycle, PI3K-Akt, TNF, JAK-STAT, MAPK, chemokines, NF-kappa B, and TGF-beta. In addition, alcohol and lipopolysaccharide significantly activated these pathways more than other chemicals, with higher gene counts and lower FDR scores. In conclusion, alcohol-induced hepatitis could be a suitable model to study chronic HBV infection and lipopolysaccharide-induced hepatitis for an acute inflammatory response to HBV.

Relationship between 25-hydroxyvitamin D and IGF1: a cross-sectional study of the Third National Health and Nutrition Examination Survey participants

BACKGROUND

25-Hydroxyvitamin D (25OHD) and insulin-like growth factor 1 (IGF1) are crucial for bone health. Some studies have shown that they interact, whereas others have indicated no association. However, it remains inconclusive whether the interaction between the two is dose dependent. Herein, we explored the relationship between 25OHD and IGF1 by conducting a cross-sectional study.

METHODS

This study involved 6,046 individuals from the Third National Health and Nutrition Examination Survey (NHANES III). The dependent and independent variables were IGF1 and 25OHD levels, respectively. The covariates included age, sex, race, BMI, exercise, smoking behavior, alcohol intake, diabetes, and serum calcium level. Multiple linear regression and generalized additive model were employed to analyze the relationship between 25OHD and IGF1. Interaction and hierarchical analyses were also performed.

RESULTS

The 25OHD and IGF1 levels positively correlated after adjusting for covariates (β = 0.16, 95% CI: 0.04-0.29, P = 0.0103). Smooth curve fitting demonstrated a curvilinear relationship. When the 25OHD level was < 75 nmol/L, a positive correlation (β = 0.43, 95% CI: 0.25-0.62, P < 0.0001) was observed. When the 25OHD level was > 75 nmol/L, a negative correlation was observed (β = -0.53, 95% CI: -0.90 to -0.15, P = 0.0057).

CONCLUSION

This study demonstrated a nonlinear relationship between 25OHD and IGF1. It suggests that keeping the 25OHD level within a specific range may be more conducive to bone health. Additionally, when IGF1 is used to evaluate the efficacy and safety of recombinant human growth hormone (rhGH) in growth hormone deficiency treatment, the effect of 25OHD on the actual IGF1 level should be taken into account.

Effects of alcohol and PARP inhibition on RNA ribosomal engagement in cortical excitatory neurons

We report on the effects of ethanol (EtOH) and Poly (ADP-ribose) polymerase (PARP) inhibition on RNA ribosomal engagement, as a proxy for protein translation, in prefrontal cortical (PFC) pyramidal neurons. We hypothesized that EtOH induces a shift in RNA ribosomal-engagement (RE) in PFC pyramidal neurons, and that many of these changes can be reversed using a PARP inhibitor. We utilized the translating ribosome affinity purification (TRAP) technique to isolate cell type-specific RNA. Transgenic mice with EGFP-tagged Rpl10a ribosomal protein expressed only in CaMKIIα-expressing pyramidal cells were administered EtOH or normal saline (CTL) i.p. twice a day, for four consecutive days. On the fourth day, a sub-group of mice that received EtOH in the previous three days received a combination of EtOH and the PARP inhibitor ABT-888 (EtOH + ABT-888). PFC tissue was processed to isolate both, CaMKIIα pyramidal cell-type specific ribosomal-engaged RNA (TRAP-RNA), as well as genomically expressed total-RNA from whole tissue, which were submitted for RNA-seq. We observed EtOH effects on RE transcripts in pyramidal cells and furthermore treatment with a PARP inhibitor "reversed" these effects. The PARP inhibitor ABT-888 reversed 82% of the EtOH-induced changes in RE (TRAP-RNA), and similarly 83% in the total-RNA transcripts. We identified Insulin Receptor Signaling as highly enriched in the ethanol-regulated and PARP-reverted RE pool and validated five participating genes from this pathway. To our knowledge, this is the first description of the effects of EtOH on excitatory neuron RE transcripts from total-RNA and provides insights into PARP-mediated regulation of EtOH effects.

Malignant Brain Aging: The Formidable Link Between Dysregulated Signaling Through Mechanistic Target of Rapamycin Pathways and Alzheimer's Disease (Type 3 Diabetes)

Malignant brain aging corresponds to accelerated age-related declines in brain functions eventually derailing the self-sustaining forces that govern independent vitality. Malignant brain aging establishes the path toward dementing neurodegeneration, including Alzheimer's disease (AD). The full spectrum of AD includes progressive dysfunction of neurons, oligodendrocytes, astrocytes, microglia, and the microvascular systems, and is mechanistically driven by insulin and insulin-like growth factor (IGF) deficiencies and resistances with accompanying deficits in energy balance, increased cellular stress, inflammation, and impaired perfusion, mimicking the core features of diabetes mellitus. The underlying pathophysiological derangements result in mitochondrial dysfunction, abnormal protein aggregation, increased oxidative and endoplasmic reticulum stress, aberrant autophagy, and abnormal post-translational modification of proteins, all of which are signature features of both AD and dysregulated insulin/IGF-1-mechanistic target of rapamycin (mTOR) signaling. This article connects the dots from benign to malignant aging to neurodegeneration by reviewing the salient pathologies associated with initially adaptive and later dysfunctional mTOR signaling in the brain. Effective therapeutic and preventive measures must be two-pronged and designed to 1) address complex and shifting impairments in mTOR signaling through the re-purpose of effective anti-diabetes therapeutics that target the brain, and 2) minimize the impact of extrinsic mediators of benign to malignant aging transitions, e.g., inflammatory states, obesity, systemic insulin resistance diseases, and repeated bouts of general anesthesia, by minimizing exposures or implementing neuroprotective measures.

Meta-analytic evidence for a sex-diverging association between alcohol use and body mass index

Alcohol use is an important health issue and has been suggested to contribute to the burden produced by obesity. Both alcohol use and obesity are subject to sex differences. The available studies on the relationship between alcohol use and body mass index (BMI) report inconsistent results with positive, negative, and null findings which requests a meta-analytic approach. Therefore, we conducted a meta-analysis of case-control, cohort, and cross-sectional studies. The systematic literature search and data extraction was performed by 3 independent raters. We conducted sex-separated meta-analyses and -regressions to investigate how alcohol consumption associates with BMI. Our systematic literature search resulted in 36 studies with 48 data sets (N_men = 172,254; k_men = 30; N_women = 24,164; k_women = 18; N_{unknown sex} = 672,344; k_{unknown sex} = 24). Alcohol use was associated with higher BMI in men (g = 0.08 [0.07; 0.09]) and lower BMI in women (g = - 0.26 [- 0.29; - 0.22]). Moreover, we found the amount of daily alcohol intake in men (β = 0.001 [0.0008; 0.0014]) and ethnicity in women (g[Caucasians] = - 0.45 versus g[Asians] = - 0.05; z = 11.5, p < 0.0001) to moderate these effects. We here identified sex-diverging relationships between alcohol use and BMI, found daily alcohol intake and ethnicity to sex-specifically moderate these effects, and argue that sex-specific choice of beverage type and higher amount of daily alcohol use in men than in women account for these observations. Future research is needed to provide empirical evidence for the underlying mechanisms.

Insulin resistance enhances binge ethanol-induced liver injury through promoting oxidative stress and up-regulation CYP2E1

Alcoholic liver disease (ALD) has caused a serious burden on public and personal health in crowd with ethanol abuse. The effects of insulin resistance (IR) on ALD and the mechanisms underlying these responses are still not well understood. In this study, we investigated the changes of liver injury, inflammation, apoptosis, mitochondrial dysfunction and CYP2E1 changes in liver of mice exposed to ethanol with IR or not. We found IR increased the sensitivity of liver injury in mice exposed to ethanol, manifested as the increase serum activities of AST and ALT, the accumulation of triglycerides, the deterioration of liver pathology and increase of inflammatory factors. IR also exacerbated apoptosis and mitochondrial dysfunction in liver of mice exposed to ethanol. The increase of oxidative stress and the decrease of antioxidant defense ability might be responsible for the sensitizing effects of IR on ethanol-induced liver injury, supported by the increase of MDA levels and the decline of GSH/GSSG, the inactivation of antioxidant enzymes SOD, GR through the inhibition of Nrf-2 pathway. The activation of CYP2E1 might be also involved in the sensitizing effects of IR on ethanol induced liver injury in mice. These results demonstrated that IR exhibited a significant pro-oxidative and pro-apoptosis effects to aggravate alcoholic liver injury. Our study helped us to better understand the sensitive role of IR on ALD and suggested that alcohol intake may be more harmful for people with IR.

Lifestyle in adulthood can modify the causal relationship between BMI and islet function: using Mendelian randomization analysis

BACKGROUND

Body mass index was intimately associated with islet function, which was affected by various confounding factors. Among all methods of statistical analysis, Mendelian randomization best ruled out bias to find the causal relationship. In the present study, we explored the relationship between 13 East Asian body mass index-related genes reported previously and islet function using the Mendelian randomization method.

METHODS

A total of 2892 participants residing in northern China were enrolled. Anthropological information, such as sex, age, drinking status, smoking status, weight, height and blood pressure, was recorded for all participants. Fasting glucose and insulin were detected, and the insulin sensitivity index was calculated. 13 single nucleotide polymorphismss in East Asian body mass index -related genes were analysed with the ABI7900HT system.

RESULTS

Five genetic locus mutations, CDKAL1, MAP2K5, BDNF, FTO and SEC16B, were found to be associated with body mass index and were used to estimate the genetic risk score. We found that the genetic risk score was negatively associated with the insulin sensitivity index. Even after adjusted of confounding factors, the relationship showed statistical significance. A subsequent interaction effect analysis suggested that the negative relationship between the genetic risk score and insulin sensitivity index no longer existed in the nondrinking population, and smokers had a stronger negative relationship than nonsmokers.

CONCLUSION

We found a negative causal relationship between body mass index-related genetic locus mutations and insulin resistance, which might be increased by acquired lifestyle factors, such as drinking and smoking status.

Comorbidity of osteoporosis and Alzheimer's disease: Is `AKT `-ing on cellular glucose uptake the missing link?

Osteoporosis and Alzheimer's disease (AD) are both degenerative diseases. Osteoporosis often proceeds cognitive deficits, and multiple studies have revealed common triggers that lead to energy deficits in brain and bone. Risk factors for osteoporosis and AD, such as obesity, type 2 diabetes, aging, chemotherapy, vitamin deficiency, alcohol abuse, and apolipoprotein Eε4 and/or Il-6 gene variants, reduce cellular glucose uptake, and protective factors, such as estrogen, insulin, exercise, mammalian target of rapamycin inhibitors, hydrogen sulfide, and most phytochemicals, increase uptake. Glucose uptake is a fine-tuned process that depends on an abundance of glucose transporters (Gluts) on the cell surface. Gluts are stored in vesicles under the plasma membrane, and protective factors cause these vesicles to fuse with the membrane, resulting in presentation of Gluts on the cell surface. This translocation depends mainly on AKT kinase signaling and can be affected by a range of factors. Reduced AKT kinase signaling results in intracellular glucose deprivation, which causes endoplasmic reticulum stress and iron depletion, leading to activation of HIF-1α, the transcription factor necessary for higher Glut expression. The link between diseases and aging is a topic of growing interest. Here, we show that diseases that affect the same biochemical pathways tend to co-occur, which may explain why osteoporosis and/or diabetes are often associated with AD.

Methyl ferulic acid ameliorates alcohol-induced hepatic insulin resistance via miR-378b-mediated activation of PI3K-AKT pathway

A previous study indicated that microRNA-378b (miR-378b) plays a critical role in controlling hepatic insulin resistance by targeting insulin receptor (IR) and p110α in alcoholic liver disease (ALD). Methyl ferulic acid (MFA), a bioactive ingredient in Securidaca inappendiculata Hassk rhizomes, exhibits multiple pharmacological activities. It has been reported that MFA ameliorates insulin resistance in ALD, whereas the underlying molecular mechanism remains unclear. The objective of study was to evaluate the influence of MFA on insulin sensitivity in ethanol-induced L-02 cells as well as alcohol-fed mice and illuminate the function of miR-378b-mediated phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway in system. MFA was found to remarkably down-regulate miR-378b level and increase IR and p110α expressions. Furthermore, the effect of MFA on modulating miR-378b/PI3K-AKT pathway to enhance insulin sensitivity was corroborated by overexpressing and inhibiting miR-378b. Taken together, MFA exhibited a positive effect against ALD by attenuating the inhibition of miR-378b on IR/p110α and partly activating the insulin signaling to alleviate alcohol-induced hepatic insulin resistance.

PCSK9 and the Gut-Liver-Brain Axis: A Novel Therapeutic Target for Immune Regulation in Alcohol Use Disorder

Alcohol use disorder (AUD) is a chronic relapsing disorder characterized by an impaired ability to control or stop alcohol intake and is associated with organ damage including alcohol-associated liver disease (ALD) and progressive neurodegeneration. The etiology of AUD is complex, but organ injury due to chronic alcohol use can be partially attributed to systemic and local inflammation along the gut-liver-brain axis. Excessive alcohol use can result in translocation of bacterial products into circulation, increased expression of pro-inflammatory cytokines, and activation of immune cells, including macrophages and/or microglia in the liver and brain. One potential mediator of this alcohol-induced inflammation is proprotein convertase subtilisin/kexin type 9 (PCSK9). PCSK9 is primarily known for its regulation of plasma low-density lipoprotein cholesterol but has more recently been shown to influence inflammatory responses in the liver and brain. In rodent and post-mortem brain studies, chronic alcohol use altered methylation of the PCSK9 gene and increased expression of PCSK9 in the liver and cerebral spinal fluid. Additionally, PCSK9 inhibition in a rat model of ALD attenuated liver inflammation and steatosis. PCSK9 may play an important role in alcohol-induced pathologies along the gut-liver-brain axis and may be a novel therapeutic target for AUD-related liver and brain inflammation.

S-Allylmercaptocysteine improves alcoholic liver disease partly through a direct modulation of insulin receptor signaling

Alcoholic liver disease (ALD) causes insulin resistance, lipid metabolism dysfunction, and inflammation. We investigated the protective effects and direct regulating target of S-allylmercaptocysteine (SAMC) from aged garlic on liver cell injury. A chronic ethanol-fed ALD in vivo model (the NIAAA model) was used to test the protective functions of SAMC. It was observed that SAMC (300 mg/kg, by gavage method) effectively ameliorated ALD-induced body weight reduction, steatosis, insulin resistance, and inflammation without affecting the health status of the control mice, as demonstrated by histological, biochemical, and molecular biology assays. By using biophysical assays and molecular docking, we demonstrated that SAMC directly targeted insulin receptor (INSR) protein on the cell membrane and then restored downstream IRS-1/AKT/GSK3β signaling. Liver-specific knock-down in mice and siRNA-mediated knock-down in AML-12 cells of Insr significantly impaired SAMC (250 μmol/L in cells)-mediated protection. Restoration of the IRS-1/AKT signaling partly recovered hepatic injury and further contributed to SAMC's beneficial effects. Continuous administration of AKT agonist and recombinant IGF-1 in combination with SAMC showed hepato-protection in the mice model. Long-term (90-day) administration of SAMC had no obvious adverse effect on healthy mice. We conclude that SAMC is an effective and safe hepato-protective complimentary agent against ALD partly through the direct binding of INSR and partial regulation of the IRS-1/AKT/GSK3β pathway.

The Placenta as a Target for Alcohol During Pregnancy: The Close Relation with IGFs Signaling Pathway

Alcohol is one of the most consumed drugs in the world, even during pregnancy. Its use is a risk factor for developing adverse outcomes, e.g. fetal death, miscarriage, fetal growth restriction, and premature birth, also resulting in fetal alcohol spectrum disorders. Ethanol metabolism induces an oxidative environment that promotes the oxidation of lipids and proteins, triggers DNA damage, and advocates mitochondrial dysfunction, all of them leading to apoptosis and cellular injury. Several organs are altered due to this harmful behavior, the brain being one of the most affected. Throughout pregnancy, the human placenta is one of the most important organs for women's health and fetal development, as it secretes numerous hormones necessary for a suitable intrauterine environment. However, our understanding of the human placenta is very limited and even more restricted is the knowledge of the impact of toxic substances in its development and fetal growth. So, could ethanol consumption during this period have wounding effects in the placenta, compromising proper fetal organ development? Several studies have demonstrated that alcohol impairs various signaling cascades within G protein-coupled receptors and tyrosine kinase receptors, mainly through its action on insulin and insulin-like growth factor 1 (IGF-1) signaling pathway. This last cascade is involved in cell proliferation, migration, and differentiation and in placentation. This review tries to examine the current knowledge and gaps in our existing understanding of the ethanol effects in insulin/IGFs signaling pathway, which can explain the mechanism to elucidate the adverse actions of ethanol in the maternal-fetal interface of mammals.

7,8-Dihydroxyflavone alleviated the high-fat diet and alcohol-induced memory impairment: behavioral, biochemical and molecular evidence

RATIONALE

Alcoholism and obesity impart a deleterious impact on human health and affects the quality of life. Chronic consumption of alcohol and western diet has been reported to cause memory deficits. 7,8-dihydroxyflavone (7,8-DHF), a TrkB agonist, comprises antioxidant and anti-inflammatory properties in treating various neurological disorders.

OBJECTIVES

The current study was aimed to determine the protective effect and molecular mechanism of 7,8-DHF against alcohol and high-fat diet (HFD)-induced memory deficits in rats.

METHODS

The adult male Wistar rats were given alcohol (3-15%) and HFD ad libitum for 12 weeks in different experimental groups. 7,8-DHF (5 mg/kg) was intraperitoneally injected daily for the last 4 weeks (9th-12th week).

RESULTS

The alcohol and HFD administration caused cognitive impairment as evaluated through the Morris water maze (MWM) test in alcohol, HFD, and alcohol + HFD-fed animals. The last 4-week treatment of 7,8-DHF (5 mg/kg; i.p.) attenuated alcohol and HFD-induced memory loss. 7,8-DHF treatment also restored the glutathione (GSH) level along with attenuation of nitrite, malondialdehyde content (markers of oxidative and nitrosative stress), and reduction of the acetylcholinesterase activity in the hippocampus of alcohol and HFD-fed animals. Furthermore, the administration of 7,8-DHF caused downregulation of NF-κB, iNOS, and caspase-3 and upregulation of Nrf2, HO-1, and BDNF mRNA level in rat hippocampus.

CONCLUSION

7,8-DHF administration conferred beneficial effects against alcohol and HFD-induced memory deficit via its unique antioxidant, anti-inflammatory, anti-apoptotic potential, along with the activation of TrkB/BDNF signaling pathway in the hippocampus.

Lipidomic biomarkers and mechanisms of lipotoxicity in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) represents the most common form of chronic liver disease worldwide (about 25% of the general population) and 3-5% of patients develop non-alcoholic steatohepatitis (NASH), characterized by hepatocytes damage, inflammation and fibrosis, which increase the risk of developing liver failure, cirrhosis and hepatocellular carcinoma. The pathogenesis of NAFLD, particularly the mechanisms whereby a minority of patients develop a more severe phenotype, is still incompletely understood. In this review we examine the available literature on initial mechanisms of hepatocellular damage and inflammation, deriving from toxic effects of excess lipids. Accumulating data indicate that the total amount of triglycerides stored in the liver cells is not the main determinant of lipotoxicity and that specific lipid classes act as damaging agents. These lipotoxic species affect the cell behavior via multiple mechanisms, including activation of death receptors, endoplasmic reticulum stress, modification of mitochondrial function and oxidative stress. The gut microbiota, which provides signals through the intestine to the liver, is also reported to play a key role in lipotoxicity. Finally, we summarize the most recent lipidomic strategies utilized to explore the liver lipidome and its modifications in the course of NALFD. These include measures of lipid profiles in blood plasma and erythrocyte membranes that can surrogate to some extent lipid investigation in the liver.

Increased risk of chronic liver disease in patients with major depressive disorder: A population-based study

OBJECTIVE

This study investigated the prevalence and incidence of chronic liver disease in patients with major depressive disorder (MDD), and aimed to identify associated factors.

METHODS

Data of 766,427 adult subjects aged ≥18 years were randomly selected from the National Health Research Institute database from the year 2005. The study first searched for subjects with at least one primary diagnosis of MDD in 2005, and then for those with a primary or secondary diagnosis of chronic liver disease were also identified. The differences in the prevalence of chronic liver disease and its associated factors between patients with MDD and the general population in 2005 were then analyzed. We also compared the incidence of chronic liver disease in patients with MDD and in the general population from 2006 to 2010.

RESULTS

The prevalence of chronic liver disease in patients with MDD was 2.27 times as high as that of the general population in 2005 (12.4% vs. 5.8%; odds ratio (OR) = 2.27; 95% confidence interval (CI) = 2.07-2.48). The average annual incidence of chronic liver disease in patients with MDD during 2006-2010 was also higher than that of the general population (2.6% vs. 1.7%; risk ratio (RR) = 1.52; 95% CI = 1.37-1.7).

CONCLUSIONS

Patients with MDD had a significantly higher prevalence and incidence of chronic liver disease than the general population. Among patients with MDD, an older age, the male sex, diabetes, hyperlipidemia and first-generation antipsychotic use were factors associated with chronic liver disease.

Mulberry and dandelion water extracts prevent alcohol-induced steatosis with alleviating gut microbiome dysbiosis

Chronic alcohol intake causes hepatic steatosis and changes the body composition and glucose metabolism. We examined whether water extracts of mulberry (WMB) and white flower dandelion ( Taraxacum coreanum Nakai, WTC) can prevent and/or delay the symptoms of chronic ethanol-induced hepatic steatosis in male Sprague Dawley rats, and explored the mechanisms. Ethanol degradation was examined by orally administering 3 g ethanol/kg bw after giving them 0.3 g/kg bw WMB or WTC. All rats were continuously provided about 7 g ethanol/kg bw/day for four weeks and were given either of 0.1% dextrin (control), WMB, WTC, or water extracts of Hovenia dulcis Thunb fruit (positive-control) in high-fat diets. Area under the curve of serum ethanol levels was lowered in descending order of control, WTC and positive-control, and WMB in acute ethanol challenge. WMB and WTC prevented alcohol intake-related decrease in bone mineral density and lean body mass compared to the control. After glucose challenge, serum glucose levels increased more in the control group than other groups in the first part and the rate of decrease after 40 min was similar among all groups. These changes were associated with decreasing serum insulin levels. WMB had the greatest efficacy for decreasing triglyceride and increasing glycogen deposits. WMB and WTC prevented the disruption of the hepatic cells and nuclei while reducing malondialdehyde contents in rats fed alcohol, but the prevention was not as much as the normal-control. The ratio of Firmicutes to Bacteroidetes in the gut was much higher in the control than the normal-control, but WTC and WMB decreased the ratio compared to the control. WMB and WTC separated the gut microbiota community from the control. In conclusion, WMB and WTC protected against alcoholic liver steatosis by accelerating ethanol degradation and also improved body composition and glucose metabolism while alleviating the dysbiosis of gut microbiome by chronic alcohol intake. Impact statement Excessive alcohol consumption is associated with serious pathologies and is common in much of the world. Pathologies include liver damage, glucose intolerance, and loss of lean body mass and bone mass. These pathologies are mediated by changes in metabolism as well as toxic metabolic byproducts, and possibly by gut dysbiosis. In this study, we demonstrate that aqueous extracts of mulberry and dandelion protected rats against ethanol-induced losses in lean body and bone masses, improved glucose tolerance and partially normalized gut bacterial populations, with mulberry extract being generally more effective. This research suggests that mulberry and dandelion extracts may have the potential to improve some of the pathologies associated with excess alcohol consumption, and that further clinical research is warranted.

Insulin Resistance and Oxidative Stress in the Brain: What's New?

The latest studies have indicated a strong relationship between systemic insulin resistance (IR) and higher incidence of neurodegeneration, dementia, and mild cognitive impairment. Although some of these abnormalities could be explained by chronic hyperglycaemia, hyperinsulinemia, dyslipidaemia, and/or prolonged whole-body inflammation, the key role is attributed to the neuronal redox imbalance and oxidative damage. In this mini review, we provide a schematic overview of intracellular oxidative stress and mitochondrial abnormalities in the IR brain. We highlight important correlations found so far between brain oxidative stress, ceramide generation, β-amyloid accumulation, as well as neuronal apoptosis in the IR conditions.

Differential contribution of chronic binge alcohol and antiretroviral therapy to metabolic dysregulation in SIV-infected male macaques

The incidence of alcohol use disorder (AUD) is higher among people living with HIV (PLWH). The advent and continued development of antiretroviral therapy (ART) has significantly reduced mortality, shifting the course of HIV infection to a chronic illness. However, this is associated with an increased incidence of comorbid conditions, including type 2 diabetes mellitus, insulin resistance, and cardiovascular complications. Using a nonhuman primate model of simian immunodeficiency virus (SIV) infection, previous studies have demonstrated that chronic binge alcohol (CBA) administration decreases whole body insulin responsiveness, irrespective of ART administration. The objective of the current study was to determine the effects of CBA and ART on insulin-sensitive peripheral tissues before the development of overt clinical symptoms of SIV disease. Our results show that CBA reduced omental adipocyte cell size, increased collagen expression, and decreased the in vitro differentiation potential of adipose-derived stem cells. In contrast, it did not alter skeletal muscle or omental or hepatic expression of insulin signaling proteins. However, ART significantly decreased skeletal muscle expression of phosphatase and tensin homolog, total mechanistic target of rapamycin, and ribosomal protein S6. In addition, ART increased hepatic phosphorylation of AMP-activated protein kinase α and increased gene expression of key enzymes required for gluconeogenesis and fatty acid synthesis. These findings suggest that CBA and ART differentially promote adverse metabolic effects in an organ-specific manner that may underlie insulin resistance associated with alcohol, SIV, and ART. Whether this is translated in PLWH with AUD remains to be determined.

A Natural Dietary Supplement with a Combination of Nutrients Prevents Neurodegeneration Induced by a High Fat Diet in Mice

Obesity and metabolic disorders can be risk factors for the onset and development of neurodegenerative diseases. The aim of the present study was to investigate the protective effects of a natural dietary supplement (NDS), containing Curcuma longa, silymarin, guggul, chlorogenic acid and inulin, on dysmetabolism and neurodegeneration in the brains of high fat diet (HFD)-fed mice. Decrease in the expression of FACL-4, CerS-1, CerS-4, cholesterol concentration and increase in the insulin receptor expression and insulin signaling activation, were found in brains of NDS-treated HFD brains in comparison with HFD untreated-mice, suggesting that NDS is able to prevent brain lipid accumulation and central insulin resistance. In the brains of NDS-treated HFD mice, the levels of RNS, ROS and lipid peroxidation, the expression of p-ERK, H-Oxy, i-NOS, HSP60, NF-kB, GFAP, IL-1β, IL-6 and CD4 positive cell infiltration were lower than in untreated HFD mice, suggesting antioxidant and anti-inflammatory effects of NDS. The decreased expression of p-ERK and GFAP in NDS-treated HFD mice was confirmed by immunofluorescence. Lastly, a lower number of apoptotic nuclei was found in cortical sections of NDS-treated HFD mice. The present data indicate that NDS exerts neuroprotective effects in HFD mice by reducing brain fat accumulation, oxidative stress and inflammation and improving brain insulin resistance.

Supplementation of all trans retinoic acid ameliorates ethanol-induced endoplasmic reticulum stress

CONTEXT

Molecular pathogenesis of chronic alcoholism is linked to increased endoplasmic reticulum stress. Ethanol is a competitive inhibitor of vitamin A metabolism and vitamin A supplementation aggravates existing liver problems. Hence, we probed into the impact of supplementation of all trans retinoic acid (ATRA), the active metabolite of vitamin A on ethanol-induced endoplasmic reticulcum stress.

METHODS

Male Sprague-Dawley rats were divided into four groups - I: Control; II: Ethanol; III: ATRA; IV: ATRA + Ethanol. After 90 days the animals were sacrificed to study markers of lipid peroxidation in hepatic microsomal fraction and expression of ER stress proteins and apoptosis in liver.

RESULTS AND CONCLUSION

Ethanol caused hepatic hyperlipidemia, enhanced microsomal lipid peroxidation, upregulated expression of unfolded protein response associated proteins and that of apoptosis. Ethanol also led to downregulation of retinoid receptors. ATRA supplementation reversed all these alterations indicating the decrease in ethanol-induced endoplasmic reticulum stress.

Prevalence and risk factors of type 2 diabetes in insomnia sufferers: a study on 1311 individuals referred for sleep examinations

BACKGROUND

Several studies have investigated the particular relationship between insomnia and type 2 diabetes. However, few studies have investigated the prevalence and risk factors for type 2 diabetes in insomnia sufferers. The aim of this study was to examine the prevalence and risk factors of type 2 diabetes in a large sample of insomnia sufferers.

METHODS

Data from 1311 insomnia sufferers recruited from the research database of the Erasme Hospital sleep laboratory were analyzed. Only individuals with a diagnosis of type 2 diabetes according to the diagnostic criteria of the American Diabetes Association at admission were included in the diabetes group. Logistic regression analyses were conducted to examine clinical and demographic risk factors of type 2 diabetes in insomnia sufferers.

RESULTS

The prevalence of type 2 diabetes in insomnia sufferers is 21.13%. Multivariate logistic regression analysis revealed that significant risk factors of type 2 diabetes in insomnia sufferers were as follows: being male, Z-drugs use, high blood pressure, hypertriglyceridemia, alcohol consumption of ≥4 units/day, BMI ≥25 & <30 kg/m², BMI ≥30 kg/m², age ≥50 years, C-reactive protein ≥4.5 mg/L, a sleep duration of <6.5 h, apnea-hypopnea index ≥15/hour, periodic limb movements index ≥26/hour, and severe complaints of early morning awakening.

CONCLUSION

Type 2 diabetes is a common pathology in insomnia sufferers. In this subpopulation, most of the risk factors for type 2 diabetes are reversible, which justifies better prevention and management of this pathology in order to avoid its negative consequences.

Imaging mass spectrometry of frontal white matter lipid changes in human alcoholics

BACKGROUND

Chronic alcohol use disorders (AUD) are associated with white matter (WM) degeneration with altered myelin integrity. Matrix assisted laser desorption ionization-imaging mass spectrometry (MALDI-IMS) enables high throughput analysis of myelin lipid biochemical histopathology to help characterize disease mechanisms.

PURPOSE

This study utilized MALDI-IMS to investigate frontal lobe WM myelin lipid abnormalities in AUD.

METHODS

Standardized cores of formalin-fixed WM from Brodmann Area 4 (BA4) and BA8/9 of 20 postmortem AUD and 19 control adult human brains were embedded in carboxymethyl-cellulose, cryo-sectioned (8 μm), thaw-mounted onto indium tin oxide (ITO) -coated glass slides, and sublimed with 2,5-dihydroxybenzxoic acid (DHB) matrix. Lipids were imaged by MALDI-time of flight in the negative ionization mode. Data were visualized with FlexImaging software v4.0 and analyzed with ClinProTools v3.0.

RESULTS

Principal component analysis (PCA) and data bar plots of MALDI-IMS data differentiated AUD from control WM. The dominant effect of AUD was to broadly reduce expression of sphingolipids (sulfatides and ceramides) and phospholipids. Data bar plots demonstrated overall similar responses to AUD in BA4 and BA8/9. However, differential regional effects of AUD on WM lipid profiles were manifested by non-overlapping expression or discordant responses to AUD for a subset of lipid ions.

CONCLUSIONS

Human AUD is associated with substantial inhibition of frontal lobe WM lipid expression with regional variability in these effects. MALDI-IMS can be used to characterize the nature of AUD-associated lipid biochemical abnormalities for correlation with lifetime exposures and WM degeneration, altered gene expression, and responses to abstinence or treatment.

Alcohol Modulation of the Postburn Hepatic Response

The widespread and rapidly increasing trend of binge drinking is accompanied by a concomitant rise in the prevalence of trauma patients under the influence of alcohol at the time of their injury. Epidemiological evidence suggests up to half of all adult burn patients are intoxicated at the time of admission, and the presence of alcohol is an independent risk factor for death in the early stages post burn. As the major site of alcohol metabolism and toxicity, the liver is a critical determinant of postburn outcome, and experimental evidence implies an injury threshold exists beyond which burn-induced hepatic derangement is observed. Alcohol may lower this threshold for postburn hepatic damage through a variety of mechanisms including modulation of extrahepatic events, alteration of the gut-liver axis, and changes in signaling pathways. The direct and indirect effects of alcohol may prime the liver for the second-hit of many overlapping physiologic responses to burn injury. In an effort to gain a deeper understanding of how alcohol potentiates postburn hepatic damage, the authors summarize possible mechanisms by which alcohol modulates the postburn hepatic response.

Links Between Obesity-Induced Brain Insulin Resistance, Brain Mitochondrial Dysfunction, and Dementia

It is widely recognized that obesity and associated metabolic changes are considered a risk factor to age-associated cognitive decline. Inflammation and increased oxidative stress in peripheral areas, following obesity, are patently the major contributory factors to the degree of the severity of brain insulin resistance as well as the progression of cognitive impairment in the obese condition. Numerous studies have demonstrated that the alterations in brain mitochondria, including both functional and morphological changes, occurred following obesity. Several studies also suggested that brain mitochondrial dysfunction may be one of underlying mechanism contributing to brain insulin resistance and cognitive impairment in the obese condition. Thus, this review aimed to comprehensively summarize and discuss the current evidence from various in vitro, in vivo, and clinical studies that are associated with obesity, brain insulin resistance, brain mitochondrial dysfunction, and cognition. Contradictory findings and the mechanistic insights about the roles of obesity, brain insulin resistance, and brain mitochondrial dysfunction on cognition are also presented and discussed. In addition, the potential therapies for obese-insulin resistance are reported as the therapeutic strategies which exert the neuroprotective effects in the obese-insulin resistant condition.

Effects of Tobacco Nicotine-Derived Nitrosamine Ketone (NNK) Exposures on Brain Alcohol Metabolizing Enzyme Activities

BACKGROUND

The high levels of blood alcohol achieved with chronic plus binge alcohol exposures are somewhat reduced by co-administration of tobacco-specific Nicotine-Derived Nitrosamine Ketone (NNK) suggesting that NNK may alter alcohol metabolism.

OBJECTIVE

We examined ethanol and acetaldehyde-metabolizing enzyme activities and malondialdehyde adduct formation in rats exposed to ethanol (chronic + binge), NNK, or both.

METHODS

4-week old Long Evans rats were fed liquid diets containing 0% or 26% caloric ethanol for 8 weeks. Ethanol-fed rats were binge-administered ethanol (2 g/kg; on Mondays, Wednesdays, and Fridays) by intraperitoneal (i.p.) injection, while control group administered saline in weeks 7 and 8 (n=12/group). Six rats from each group were administered i.p. injections of NNK (2 mg/kg) or saline on Tuesdays, Thursdays, and Saturdays of weeks 3 through 8. Alcohol dehydrogenase, catalase, and aldehyde dehydrogenase activities were measured using commercial assays. Cytochrome P450 mRNA levels (17 isoforms) were measured by quantitative reverse transcription-polymerase chain reaction. Malondialdehyde immunoreactivity was measured by enzyme-linked immunosorbent assay.

RESULTS

Dual exposures to ethanol and NNK significantly increased frontal lobe ADH activity relative to control (P=0.01) and ethanol only (P=0.04) treatments, and ALDH relative to control (P=0.02). In contrast, malondialdehyde-protein expression was not significantly altered by ethanol+NNK. Ethanol decreased CYP1A1 mRNA expression relative to control (P=0.02), and combined ethanol+NNK exposures decreased the expression of CYP1A1 (P=0.01) and CYP2C6 (P=0.03).

CONCLUSION

Dual exposures to ethanol and NNK increase brain ethanol metabolism and inhibit the expression of CYP450s that regulate xenobiotic metabolism.

Progressive white matter atrophy with altered lipid profiles is partially reversed by short-term abstinence in an experimental model of alcohol-related neurodegeneration

Chronic ethanol exposure causes white matter (WM) atrophy and degeneration with major impairments in the structural integrity of myelin. Since myelin is composed of oligodendrocyte lipid-rich membranes, understanding the consequences and reversibility of alcohol-related oligodendrocyte dysfunction in relation to myelin structure could provide new insights into the pathogenesis of WM degeneration and potential strategies for treatment. Adult male Long Evans rats were pair-fed with isocaloric liquid diets containing 0% or 26% ethanol (caloric) for 3 or 8 weeks. During the last 2 weeks of feeding, the ethanol groups were binged with 2 g/kg of ethanol by intraperitoneal (i.p.) injection on Mondays, Wednesdays, and Fridays; controls were treated with i.p. saline. For recovery effects, at the 6-week time point, ethanol exposures were tapered over 2 days, and then discontinued, rendering the rats ethanol-free for 12 days. Anterior corpus callosum WM lipid ion profiles were analyzed using matrix-assisted laser desorption ionization-imaging mass spectrometry (MALDI-IMS) and correlated with histopathology. Ethanol exposures caused progressive atrophy and reductions in myelin staining intensity within the corpus callosum, whereas short-term recovery partially reversed those effects. MALDI-IMS demonstrated striking ethanol-associated alterations in WM lipid profiles characterized by reduced levels of phosphatidylinositols, phosphatidylserines, phosphatidylethanolamines, and sulfatides, and partial "normalization" of lipid expression with recovery. Ethanol exposure duration and recovery responses were further distinguished by heatmap hierarchical dendrogram and PCA plots. In conclusion, chronic+binge ethanol exposures caused progressive, partially reversible WM atrophy with myelin loss associated with reduced expression of WM phospholipids and sulfatides. The extent of WM lipid abnormalities suggests that ethanol broadly impairs molecular and biochemical functions regulating myelin synthesis, degradation, and maintenance in oligodendrocytes.

Critical assessment of health disparities across subpopulation groups through a social determinants of health perspective: The case of type 2 diabetes patients

BACKGROUND

Studies on diabetes have shown that population subgroups have varying rates of medical events and related procedures; however, existing studies have investigated either medical events or procedures, and hence, it is unknown whether disparities exist between medical events and procedures.

PURPOSE

The objective of this study is to investigate how diabetes-related medical events and procedures are different across population subgroups through a social determinants of health (SDH) perspective.

METHODS

Because the purpose of this manuscript is to explore whether statistically significant health disparities exist across population subgroups regarding diabetes patients' medical events and procedures, group difference test methods were employed. Diabetes patients' data were drawn from the Cerner Health Facts® data warehouse.

RESULTS

The study revealed systematic disparities across population subgroups regarding medical events and procedures. The most significant disparities were connected with smoking status, alcohol use, type of insurance, age, marital status, and gender.

CONCLUSIONS

Some population subgroups have higher rates of medical events and yet receive lower rates of treatments, and such disparities are systematic. Socially constructed behaviors and structurally discriminating public policies in part contribute to such systematic health disparities across population subgroups.

The role of melatonin in the onset and progression of type 3 diabetes

Alzheimer’s disease (AD) is defined by the excessive accumulation of toxic peptides, such as beta amyloid (Aβ) plaques and intracellular neurofibrillary tangles (NFT). The risk factors associated with AD include genetic mutations, aging, insulin resistance, and oxidative stress. To date, several studies that have demonstrated an association between AD and diabetes have revealed that the common risk factors include insulin resistance, sleep disturbances, blood brain barrier (BBB) disruption, and altered glucose homeostasis. Many researchers have discovered that there are mechanisms common to both diabetes and AD. AD that results from insulin resistance in the brain is termed “type 3 diabetes”. Melatonin synthesized by the pineal gland is known to contribute to circadian rhythms, insulin resistance, protection of the BBB, and cell survival mechanisms. Here, we review the relationship between melatonin and type 3 diabetes, and suggest that melatonin might regulate the risk factors for type 3 diabetes. We suggest that melatonin is crucial for attenuating the onset of type 3 diabetes by intervening in Aβ accumulation, insulin resistance, glucose metabolism, and BBB permeability.

Phosphorylation Modulates Aspartyl-(Asparaginyl)-β Hydroxylase Protein Expression, Catalytic Activity and Migration in Human Immature Neuronal Cerebellar Cells

Background

Abundant aspartyl-asparaginyl-β-hydroxylase (ASPH) expression supports robust neuronal migration during development, and reduced ASPH expression and function, as occur in fetal alcohol spectrum disorder, impair cerebellar neuron migration. ASPH mediates its effects on cell migration via hydroxylation-dependent activation of Notch signaling networks. Insulin and Insulin-like growth factor (IGF-1) stimulate ASPH mRNA transcription and enhance ASPH protein expression by inhibiting Glycogen Synthase Kinase-3β (GSK-3β). This study examines the role of direct GSK-3β phosphorylation as a modulator of ASPH protein expression and function in human cerebellar-derived PNET2 cells.

Methods

Predicted phosphorylation sites encoded by human ASPH were ablated by S/T→A site-directed mutagenesis of an N-Myc-tagged wildtype (WT) cDNA regulated by a CMV promoter. Phenotypic and functional features were assessed in transiently transfected PNET2 cells.

Results

Cells transfected with WT ASPH had increased ASPH protein expression, directional motility, Notch-1 and Jagged-1 expression, and catalytic activity relative to control. Although most single- and multi-point ASPH mutants also had increased ASPH protein expression, their effects on Notch and Jagged expression, directional motility and adhesion, and catalytic activity varied such that only a few of the cDNA constructs conferred functional advantages over WT. Immunofluorescence studies showed that ASPH phosphorylation site deletions can alter the subcellular distribution of ASPH and therefore its potential interactions with Notch/Jagged at the cell surface.

Conclusions

Inhibition of ASPH phosphorylation enhances ASPH protein expression, but attendant alterations in intra-cellular trafficking may govern the functional consequences in relation to neuronal migration, adhesion and Notch activated signaling.

Effects of selection for ethanol preference on gene expression in the nucleus accumbens of HS-CC mice

Previous studies on changes in murine brain gene expression associated with the selection for ethanol preference have used F₂ intercross or heterogeneous stock (HS) founders, derived from standard laboratory strains. However, these populations represent only a small proportion of the genetic variance available in Mus musculus. To investigate a wider range of genetic diversity, we selected mice for ethanol preference using an HS derived from the eight strains of the collaborative cross. These HS mice were selectively bred (four generations) for high and low ethanol preference. The nucleus accumbens shell of naive S₄ mice was interrogated using RNA sequencing (RNA-Seq). Gene networks were constructed using the weighted gene coexpression network analysis assessing both coexpression and cosplicing. Selection targeted one of the network coexpression modules (greenyellow) that was significantly enriched in genes associated with receptor signaling activity including Chrna7, Grin2a, Htr2a and Oprd1. Connectivity in the module as measured by changes in the hub nodes was significantly reduced in the low preference line. Of particular interest was the observation that selection had marked effects on a large number of cell adhesion molecules, including cadherins and protocadherins. In addition, the coexpression data showed that selection had marked effects on long non-coding RNA hub nodes. Analysis of the cosplicing network data showed a significant effect of selection on a large cluster of Ras GTPase-binding genes including Cdkl5, Cyfip1, Ndrg1, Sod1 and Stxbp5. These data in part support the earlier observation that preference is linked to Ras/Mapk pathways.

Alcohol's Effects on the Brain: Neuroimaging Results in Humans and Animal Models

Brain imaging technology has allowed researchers to conduct rigorous studies of the dynamic course of alcoholism through periods of drinking, sobriety, and relapse and to gain insights into the effects of chronic alcoholism on the human brain. Magnetic resonance imaging (MRI) studies have distinguished alcohol-related brain effects that are permanent from those that are reversible with abstinence. In support of postmortem neuropathological studies showing degeneration of white matter, MRI studies have shown a specific vulnerability of white matter to chronic alcohol exposure. Such studies have demonstrated white-matter volume deficits as well as damage to selective gray-matter structures. Diffusion tensor imaging (DTI), by permitting microstructural characterization of white matter, has extended MRI findings in alcoholics. MR spectroscopy (MRS) allows quantification of several metabolites that shed light on brain biochemical alterations caused by alcoholism. This article focuses on MRI, DTI, and MRS findings in neurological disorders that commonly co-occur with alcoholism, including Wernicke's encephalopathy, Korsakoff's syndrome, and hepatic encephalopathy. Also reviewed are neuroimaging findings in animal models of alcoholism and related neurological disorders. This report also suggests that the dynamic course of alcoholism presents a unique opportunity to examine brain structural and functional repair and recovery.

Protective Role of the Hepatic Vagus Nerve against Liver Metastasis in Mice

OBJECTIVE(S)

Although accumulating evidence has shown that the autonomic nervous system is involved in liver pathology, its role in regulating cancer development remains unclear. The purpose of this study was to elucidate its detailed mechanisms.

METHODS

A mouse model of liver metastasis of colorectal cancer was used. To elucidate the potential mechanisms involved, we examined the effect of selective hepatic vagotomy on the survival rate and liver-to-body weight. We further evaluated the possible involvement of the hepatic sympathetic nerve fibers in this model.

RESULTS

The mortality rate and the liver-to-body weight ratio after cancer inoculation were significantly higher in the vagotomized mice than in the sham-operated mice. The vagotomized mice exhibited a transient decrease in hepatic norepinephrine levels following cancer inoculation. Interestingly, the vagotomy-induced exacerbation of liver metastasis was attenuated by supplementary norepinephrine or phenylephrine, a selective α1-adrenoceptor agonist, but not by clonidine, a selective α2-adrenoceptor agonist.

CONCLUSION

Collectively, these results suggest that the hepatic vagus nerve may play a protective role against liver metastasis. Hepatic sympathetic nerves may also be involved as a protective efferent loop, possibly acting through the α1-adrenoceptor.

Differential Sphingolipid and Phospholipid Profiles in Alcohol and Nicotine-Derived Nitrosamine Ketone-Associated White Matter Degeneration

BACKGROUND

Alcohol-mediated neurodegeneration is associated with white matter (WM) atrophy due to targeting of myelin and oligodendrocytes. However, variability in disease severity suggests cofactors contribute to WM degeneration. We examined the potential cofactor role of the tobacco-specific nitrosamine, nicotine-derived nitrosamine ketone (NNK), because smoking causes WM atrophy and most heavy drinkers consume tobacco products.

METHODS

This 8-week study of Long Evans rats had 4 treatment groups: control; NNK-2 mg/kg, 3×/wk in weeks 3 to 8; ethanol (EtOH) (chronic-26% caloric + binge-2 g/kg, 3×/wk in weeks 7 to 8); and EtOH + NNK. Exposure effects on WM lipid biochemical profiles and in situ distributions were examined using matrix-assisted laser desorption/ionization imaging mass spectrometry and tandem mass spectrometry.

RESULTS

NNK mainly caused WM fiber degeneration and fiber loss, EtOH caused demyelination, and dual exposures had additive effects. EtOH and EtOH + NNK decreased WM (including corpus callosum) and/or gray matter (hypothalamus, cortex, medial temporal) levels of several phosphatidylserine, phosphatidylinositol, and sphingolipid (sulfatide [ST]) species, while NNK increased or had minimal effect on these lipids. EtOH + NNK had broader and larger inhibitory effects on phospholipids and ST than EtOH or NNK alone. Principal component analysis clustered control with NNK, and EtOH with EtOH + NNK groups, highlighting the independent EtOH- rather than NNK-driven responses.

CONCLUSIONS

Chronic EtOH exposures decreased several phospholipid and sphingolipid species in brain, while concomitant NNK exposures exacerbated these effects. These findings support our hypothesis that tobacco smoking is a pathogenic cofactor in alcohol-mediated WM degeneration.

Increased risk of chronic liver disease in patients with bipolar disorder: A population-based study

OBJECTIVE

This study aimed to investigate the prevalence and incidence of chronic liver disease in patients with bipolar disorder.

METHODS

We used a random sample of 766,427 subjects aged ≥18 years from the National Health Research Institute database in the year 2005. Subjects with at least one primary diagnosis of bipolar disorder in 2005 were identified. Patients with a primary or secondary diagnosis of chronic liver disease were also defined. We compared the prevalence and associated factors of chronic liver disease between patients with bipolar disorder and the general population in 2005. We also compared the incidence of chronic liver disease in patients with bipolar disorder and the general population from 2006 to 2010.

RESULTS

The prevalence of chronic liver disease in patients with bipolar disorder (13.9%) was 2.68 times higher than that of the general population (5.8%) in 2005. The average annual incidence of chronic liver disease in patients with bipolar disorder from 2006 to 2010 was also higher than that of the general population (2.95% vs. 1.73%; risk ratio: 1.71; 95% confidence interval: 1.46-2.01).

CONCLUSIONS

Patients with bipolar disorder had a significantly higher prevalence and incidence of chronic liver disease than those in the general population, and younger patients with bipolar disorder have a much higher prevalence and incidence than those in the general population. Male sex, second-generation antipsychotic or antidepressant use, and hyperlipidemia were associated factors for chronic liver disease in patients with bipolar disorder.

Relation of insulin resistance with social-demographics, adiposity and behavioral factors in non-diabetic adult Canadians

BACKGROUND

Insulin resistance is a pathogenic factor for type II diabetes and has been associated with metabolic abnormalities and adverse clinical outcomes. The purpose of this study was to examine the relationship between insulin resistance and socio-demographics, adiposity and behavioral factors in the general, non-diabetic adult Canadian population.

METHODS

Data for 3515 non-diabetic adults aged 18 to 79 years from the Canadian Health Measures Survey (cycles 1 and 2, 2007-2011) were analyzed. Insulin resistance index was measured by the homeostasis model assessment of insulin resistance (HOMA-IR), and insulin resistance (IR) was defined as individuals in the highest quartile of the HOMA-IR index. Logistic regression models were used to examine the effect of demographics, lifestyle factors and adiposity measurements on HOMA-IR.

RESULTS

The risk of IR increased with age, particularly in men. Individuals had adjusted odds ratio (OR) (with corresponding 95 % confidence interval) of 5.97 (2.90-8.52) and 25.12 (15.20-41.51) associated with a body-mass-index (BMI) between 25.0 and < 30.0, or ≥30.0, of 9.23 (6.52-13.07) with abdominal obesity (waist circumstance ≥102 cm for men and ≥ 88 cm for women), of 8.72 (6.13-12.39) with a high waist-to-height ratio (>0.57), and of 6.30 (4.33-9.16) with a high waist-to-hip ratio (>0.90 for men and >0.85 for women). Physically inactive people and non-alcohol consumer also had a significantly higher odd of IR.

CONCLUSIONS

This study found that men and older, obese and physically inactive people were at increased risk for IR. Adiposity indices including BMI, waist circumstance, waist-to-height ratio and waist-to-hip ratio were highly associated with IR with similar magnitude of association.

Animal models of insulin resistance: A review

Insulin resistance can be seen as a molecular and genetic mystery, with a role in the pathophysiology of type 2 diabetes mellitus. It is a basis for a number of chronic diseases like hypertension, dyslipidemia, glucose intolerance, coronary heart disease, cerebral vascular disease along with T2DM, thus the key is to cure and prevent insulin resistance. Critical perspicacity into the etiology of insulin resistance have been gained by the use of animal models where insulin action has been modulated by various transgenic and non-transgenic models which is not possible in human studies. The following review comprises the pathophysiology involved in insulin resistance, various factors causing insulin resistance, their screening and various genetic and non-genetic animal models highlighting the pathological and metabolic characteristics of each.

Structural and microstructral imaging of the brain in alcohol use disorders

Magnetic resonance imaging (MRI), by enabling rigorous in vivo study of the longitudinal, dynamic course of alcoholism through periods of drinking, sobriety, and relapse, has enabled characterization of the effects of chronic alcoholism on the brain in the human condition. Importantly, MRI has distinguished alcohol-related brain effects that are permanent versus those that are reversible with abstinence. In support of postmortem neuropathologic studies showing degeneration of white matter, MRI has shown a specific vulnerability of brain white matter to chronic alcohol exposure by demonstrating white-matter volume deficits, yet not leaving selective gray-matter structures unscathed. Diffusion tensor imaging (DTI), by permitting microstructural characterization of white matter, has extended MRI findings in alcoholics. This review focuses on MRI and DTI findings in common concomitants of alcoholism, including Wernicke's encephalopathy, Korsakoff's syndrome, hepatic encephalopathy, central pontine myelinolysis, alcoholic cerebellar degeneration, alcoholic dementia, and Marchiafava-Bignami disease as a framework for findings in so-called "uncomplicated alcoholism," and also covers findings in abstinence and relapse.

Potential Contributions of the Tobacco Nicotine-Derived Nitrosamine Ketone to White Matter Molecular Pathology in Fetal Alcohol Spectrum Disorder

Background

Fetal alcohol spectrum disorder (FASD) is associated with long-term deficits in cognitive and motor functions. Previous studies linked neurodevelopmental abnormalities to increased oxidative stress and white matter hypotrophy. However, similar effects occur with low-dose nitrosamine exposures, alcohol abuse correlates with cigarette smoking, and tobacco smoke contains tobacco-specific nitrosamines, including NNK.

Hypothesis

Tobacco smoke exposure is a co-factor in FASD.

Design

Long Evans rat pups were i.p. administered ethanol (2 g/kg) on postnatal days (P) 2, 4, 6 and/or NNK (2 mg/kg) on P3, P5, and P7 to simulate third trimester human exposures. Oligodendroglial myelin-associated, neuroglial, and relevant transcription factor mRNA transcripts were measured using targeted PCR arrays.

Results

Ethanol and NNK differentially altered the expression of immature and mature oligodendroglial, neuronal and astrocytic structural and plasticity-associated, and various transcription factor genes. NNK’s effects were broader and more pronounced than ethanol’s, and additive or synergistic effects of dual exposures impacted expression of all four categories of genes investigated.

Conclusion

Developmental exposures to alcohol and NNK (via tobacco smoke) contribute to sustained abnormalities in brain white matter structure and function via distinct but overlapping alterations in the expression of genes that regulate oligodendrocyte survival, maturation and function, neuroglial structural integrity, and synaptic plasticity. The results support the hypothesis that smoking may contribute to brain abnormalities associated with FASD.

Differential Effects of 3rd Trimester-Equivalent Binge Ethanol and Tobacco-Specific Nitrosamine Ketone Exposures on Brain Insulin Signaling in Adolescence

BACKGROUND

Fetal alcohol spectrum disorder (FASD) is associated with impairments in insulin and insulin-like growth factor (IGF) signaling through Akt pathways and altered expression of neuro-glial proteins needed for structural and functional integrity of the brain. However, alcohol abuse correlates with smoking, and tobacco smoke contains 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), which like other nitrosamines, impairs insulin and IGF signaling.

HYPOTHESIS

NNK exposure can serve as a co-factor in mediating long-term neuro-developmental abnormalities associated with FASD.

DESIGN

Long Evans rat pups were IP administered ethanol (2 g/kg) on postnatal days (P) 2, 4, 6 and/or NNK (2 mg/kg) on P3, P5, and P7, simulating third trimester human exposures. Temporal lobes from P30 rats (young adolescent) were used to measure signaling through the insulin/IGF-1/Akt pathways by multiplex ELISAs, and expression of neuroglial proteins by duplex ELISAs.

RESULTS

Ethanol, NNK, and ethanol + NNK exposures significantly inhibited insulin receptor tyrosine phosphorylation, and IRS-1 and myelin-associated glycoprotein expression. However, the major long-term adverse effects on Akt pathway downstream signaling and its targeted proteins including choline acetyltransferase, Tau, pTau, ubiquitin, and aspartate-β-hydroxylase were due to NNK rather than ethanol.

CONCLUSION

Alcohol and tobacco exposures can both contribute to long-term brain abnormalities currently regarded fetal ethanol effects. However, the findings suggest that many of the adverse effects on brain function are attributable to smoking, including impairments in signaling through survival and metabolic pathways, and altered expression of genes that regulate myelin synthesis, maturation and integrity and synaptic plasticity. Therefore, public health measures should address both substances of abuse to prevent "FASD".

Cigarette Smoke-Induced Alterations in Frontal White Matter Lipid Profiles Demonstrated by MALDI-Imaging Mass Spectrometry: Relevance to Alzheimer's Disease

BACKGROUND

Meta-analysis has shown that smokers have significantly increased risks for Alzheimer's disease (AD), and neuroimaging studies showed that smoking alters white matter (WM) structural integrity.

OBJECTIVE

Herein, we characterize the effects of cigarette smoke (CS) exposures and withdrawal on WM myelin lipid composition using matrix assisted laser desorption and ionization-imaging mass spectrometry (MALDI-IMS).

METHODS

Young adult male A/J mice were exposed to air (8 weeks; A8), CS (4 or 8 weeks; CS4, CS8), or CS8 followed by 2 weeks recovery (CS8 + R). Frontal lobe WM was examined for indices of lipid and protein oxidation and lipid profile alterations by MALDI-IMS. Lipid ions were identified by MS/MS with the LIPID MAPS prediction tools database. Inter-group comparisons were made using principal component analysis and R-generated heatmap.

RESULTS

CS increased lipid and protein adducts such that higher levels were present in CS8 compared with CS4 samples. CS8 + R reversed CS8 effects and normalized the levels of oxidative stress. MALDI-IMS demonstrated striking CS-associated alterations in WM lipid profiles characterized by either reductions or increases in phospholipids (phosphatidylinositol, phosphatidylserine, phosphatidylcholine, or phosphatidylethanolamine) and sphingolipids (sulfatides), and partial reversal of CS's inhibitory effects with recovery. The heatmap hierarchical dendrogram and PCA distinguished CS exposure, duration, and withdrawal effects on WM lipid profiles.

CONCLUSION

CS-mediated WM degeneration is associated with lipid peroxidation, protein oxidative injury, and alterations in myelin lipid composition, including shifts in phospholipids and sphingolipids needed for membrane integrity, plasticity, and intracellular signaling. Future goals are to delineate WM abnormalities in AD using MALDI-IMS, and couple the findings with MRI-mass spectroscopy to improve in vivo diagnostics and early detection of brain biochemical responses to treatment.

Impact of Alcohol on Glycemic Control and Insulin Action

Alcohol has profound effects on tissue and whole-body fuel metabolism which contribute to the increased morbidity and mortality in individuals with alcohol use disorder. This review focuses on the glucose metabolic effects of alcohol, primarily in the muscle, liver and adipose tissue, under basal postabsorptive conditions and in response to insulin stimulation. While there is a relatively extensive literature in this area, results are often discordant and extrapolating between models and tissues is fraught with uncertainty. Comparisons between data generated in experimental cell and animals systems will be contrasted with that obtained from human subjects as often times results differ. Further, the nutritional status is also an important component of the sometimes divergent findings pertaining to the effects of alcohol on the regulation of insulin and glucose metabolism. This work is relevant as the contribution of alcohol intake to the development or exacerbation of type 2 diabetes remains ill-defined and a multi-systems approach is likely needed as both alcohol and diabetes affect multiple targets within the body.

Mitochondrial function in ageing: coordination with signalling and transcriptional pathways

Mitochondrial dysfunction entailing decreased energy-transducing capacity and perturbed redox homeostasis is an early and sometimes initiating event in ageing and age-related disorders involving tissues with high metabolic rate such as brain, liver and heart. In the central nervous system (CNS), recent findings from our and other groups suggest that the mitochondrion-centred hypometabolism is a key feature of ageing brains and Alzheimer's disease. This hypometabolic state is manifested by lowered neuronal glucose uptake, metabolic shift in the astrocytes, and alternations in mitochondrial tricarboxylic acid cycle function. Similarly, in liver and adipose tissue, mitochondrial capacity around glucose and fatty acid metabolism and thermogenesis is found to decline with age and is implicated in age-related metabolic disorders such as obesity and type 2 diabetes mellitus. These mitochondrion-related disorders in peripheral tissues can impact on brain functions through metabolic, hormonal and inflammatory signals. At the cellular level, studies in CNS and non-CNS tissues support the notion that instead of being viewed as autonomous organelles, mitochondria are part of a dynamic network with close interactions with other cellular components through energy- or redox-sensitive cytosolic kinase signalling and transcriptional pathways. Hence, it would be critical to further understand the molecular mechanisms involved in the communication between mitochondria and the rest of the cell. Therapeutic strategies that effectively preserves or improve mitochondrial function by targeting key component of these signalling cascades could represent a novel direction for numerous mitochondrion-implicated, age-related disorders.

Advances and New Concepts in Alcohol-Induced Organelle Stress, Unfolded Protein Responses and Organ Damage

Alcohol is a simple and consumable biomolecule yet its excessive consumption disturbs numerous biological pathways damaging nearly all organs of the human body. One of the essential biological processes affected by the harmful effects of alcohol is proteostasis, which regulates the balance between biogenesis and turnover of proteins within and outside the cell. A significant amount of published evidence indicates that alcohol and its metabolites directly or indirectly interfere with protein homeostasis in the endoplasmic reticulum (ER) causing an accumulation of unfolded or misfolded proteins, which triggers the unfolded protein response (UPR) leading to either restoration of homeostasis or cell death, inflammation and other pathologies under severe and chronic alcohol conditions. The UPR senses the abnormal protein accumulation and activates transcription factors that regulate nuclear transcription of genes related to ER function. Similarly, this kind of protein stress response can occur in other cellular organelles, which is an evolving field of interest. Here, I review recent advances in the alcohol-induced ER stress response as well as discuss new concepts on alcohol-induced mitochondrial, Golgi and lysosomal stress responses and injuries.

Behavioral, Metabolic, and Immune Consequences of Chronic Alcohol or Cannabinoids on HIV/AIDs: Studies in the Non-Human Primate SIV Model

HIV-associated mortality has been significantly reduced with antiretroviral therapy (ART), and HIV infection has become a chronic disease that frequently coexists with many disorders, including substance abuse (Azar et al. Drug Alcohol Depend 112:178-193, 2010; Phillips et al. J Gen Int Med 16:165, 2001). Alcohol and drugs of abuse may modify host-pathogen interactions at various levels including behavioral, metabolic, and immune consequences of HIV infection, as well as the ability of the virus to integrate into the genome and replicate in host cells. Identifying mechanisms responsible for these interactions is complicated by many factors, such as the tissue specific responses to viral infection, multiple cellular mechanisms involved in inflammatory responses, neuroendocrine and localized responses to infection, and kinetics of viral replication. An integrated physiological analysis of the biomedical consequences of chronic alcohol and drug use or abuse on disease progression is possible using rhesus macaques infected with simian immunodeficiency virus (SIV), a relevant model of HIV infection. This review will provide an overview of the data gathered using this model to show that chronic administration of two of the most commonly abused substances, alcohol and cannabinoids (Δ(9)-Tetrahydrocannabinol; THC), affect host-pathogen interactions.