Ethanol concentration-dependent alterations in gene expression during acute binge drinking in the HIV-1 transgenic rat

Involvement of TRPM7 in Alcohol-Induced Damage of the Blood-Brain Barrier in the Presence of HIV Viral Proteins

Ethanol (EtOH) exerts its effects through various protein targets, including transient receptor potential melastatin 7 (TRPM7) channels, which play an essential role in cellular homeostasis. We demonstrated that TRPM7 is expressed in rat brain microvascular endothelial cells (rBMVECs), the major cellular component of the blood-brain barrier (BBB). Heavy alcohol drinking is often associated with HIV infection, however mechanisms underlying alcohol-induced BBB damage and HIV proteins, are not fully understood. We utilized the HIV-1 transgenic (HIV-1Tg) rat to mimic HIV-1 patients on combination anti-retroviral therapy (cART) and demonstrated TRPM7 expression in rBMVECs wass lower in adolescent HIV-1Tg rats compared to control animals, however control and HIV-1Tg rats expressed similar levels at 9 weeks, indicating persistent presence of HIV-1 proteins delayed TRPM7 expression. Binge exposure to EtOH (binge EtOH) decreased TRPM7 expression in control rBMVECs in a concentration-dependent manner, and abolished TRPM7 expression in HIV-1Tg rats. In human BMVECs (hBMVECs), TRPM7 expression was downregulated after treatment with EtOH, HIV-1 proteins, and in combination. Next, we constructed in vitro BBB models using BMVECs and found TRPM7 antagonists enhanced EtOH-mediated BBB integrity changes. Our study demonstrated alcohol decreased TRPM7 expression, whereby TRPM7 could be involved in the mechanisms underlying BBB alcohol-induced damage in HIV-1 patients on cART.

The Impact of Alcohol-Induced Dysbiosis on Diseases and Disorders of the Central Nervous System

The human digestive tract contains a diverse and abundant microbiota that is important for health. Excessive alcohol use can disrupt the balance of these microbes (known as dysbiosis), leading to elevated blood endotoxin levels and systemic inflammation. Using QIAGEN Ingenuity Pathway Analysis (IPA) bioinformatics tool, we have confirmed that peripheral endotoxin (lipopolysaccharide) mediates various cytokines to enhance the neuroinflammation signaling pathway. The literature has identified alcohol-mediated neuroinflammation as a possible risk factor for the onset and progression of neurodegenerative diseases, including Alzheimer's disease (AD) and Parkinson's disease (PD), and psychiatric disorders such as addiction to alcohol and other drugs. In this review, we discuss alcohol-use-induced dysbiosis in the gut and other body parts as a causal factor in the progression of Central Nervous System (CNS) diseases including neurodegenerative disease and possibly alcohol use disorder.

Modulatory Effects of Nicotine on neuroHIV/neuroAIDS

Nicotine, one of the key active ingredients in tobacco smoke, exerts its effects via binding to nicotinic acetylcholine receptors (nAChRs). Although both negative and positive pharmacological effects of nicotine have been shown in numerous animals and human studies, its interaction with human immunodeficiency virus-1 (HIV-1) have not been fully elucidated. Even though combined anti-retroviral therapy (cART) limits the progression of HIV-1 to acquired immune deficiency syndrome (AIDS), HIV-associated neurocognitive disorders (HAND) remain prevalent. There is thus a compelling need to enhance our understanding of HAND-related neurologic dysfunction. Some biochemical pathways and physiological dysfunctions have been found to be shared by HAND and Alzheimer's (AD) or Parkinson's (PD) diseases, and nicotine may exert the same neuroprotection in HAND that has been observed in both AD and PD. In the past dozen years, various potential therapeutic effects of nicotine such as neuroprotection have been revealed in both in vivo and in vitro studies, including using HIV-1 transgenic (HIV-1Tg) rat model, which mimics HIV-infected patients receiving cART. In the current review, we describe recent progress in the prevalence of HIV/AIDS with and without cigarette smoking, some animal models for studying neural dysfunction associated with HIV-1 infection, elucidating the modulatory effects of cigarette smoking/nicotine on HIV/AIDS, the anti-inflammatory effects of nicotine, and the neuroprotective effects observed in HIV-1Tg rat model. Taken together, these findings suggest the following: although tobacco smoking does cause deleterious effects in both health and disease conditions such as HIV infection, nicotine, the significant component of tobacco smoke, has been shown to possess some neuroprotective effects in HIV patients, possible via its anti-inflammatory activities. It is therefore necessary to study nicotine's dual effects on neuroHIV/neuroAIDS in hope of better defining the potential medical uses of nicotine or its analogues, and to make them available in a purer and less dangerous form.

Role of the pregnane X receptor in binge ethanol-induced steatosis and hepatotoxicity

The pregnane X receptor (PXR, NR1I2) is a xenobiotic-sensing nuclear receptor that defends against toxic agents. We have shown that PXR promotes chronic ethanol (EtOH)-induced steatosis. Therefore, we examined the role of PXR in binge EtOH-induced hepatotoxicity. Male wild type (WT) and Pxr-null mice were orally administered three binge doses of EtOH (4.5 g/kg, every 12 hours) and euthanized four hours after the final dose. Pxr-null mice displayed higher basal mRNA levels of hepatic lipogenic transcription factor sterol regulatory element binding protein 1c (Srebp-1c) and its target stearoyl-CoA desaturase 1 (Scd1) and the lipid peroxide detoxifying aldo-keto reductase 1b7 (Akr1b7) and higher protein levels of EtOH-metabolizing alcohol dehydrogenase 1 (ADH1). In both genotypes, binge EtOH-induced triglyceride accumulation was associated with inhibition of fatty acid β-oxidation and upregulation of Srebp-1c- regulated lipogenic genes and hepatic CYP2E1 protein. Unexpectedly, gene expression of Cyp2b10, a constitutive androstane receptor target gene, implicated in EtOH hepatotoxicity, was PXR-dependent upregulated by binge EtOH. Also, PXR-dependent was the binge EtOH-induced inhibition of hepatic Akr1b8 mRNA, and protein levels of aldehyde dehydrogenase (ALDH) 1A1 and anti-apoptotic Bcl-2, but increased pro-apoptotic Bax protein expression, leading to increases in residual EtOH concentration and the cellular oxidative stress marker, malondialdehyde. In contrast, Pxr-null mice displayed increased Akr1b7 gene and ADH1 protein expression and hypertriglyceridemia following binge EtOH exposure. Taken together, this study demonstrates that PXR ablation prevents EtOH induced upregulation of Cyp2b10 and that PXR potentiates binge EtOH-induced oxidative stress and inhibition of EtOH catabolism, but protects against alcoholic hyperlipidemia.

Analysis of the Association of Nonsynonymous Polymorphisms in ADH Genes with Hazardous Drinking in HIV-1-Positive Individuals

BACKGROUND

Hazardous drinking (HD) is a serious health problem in people infected with human immunodeficiency virus type 1 (HIV-1). Single nucleotide polymorphisms (SNPs) in alcohol dehydrogenase (ADH) genes have been associated with HD in different populations, but there were no data about this in HIV-1-positive individuals. This study investigated the association of 4 nonsynonymous SNPs in ADH genes (Arg48His and Arg370Cys in ADH1B gene; Arg272Gln and Ile350Val in ADH1C gene) with HD in people living with HIV-1.

METHODS

This case-control study included 365 HIV-1-positive individuals (121 with HD and 244 without HD). Sociodemographic variables were collected with a standardized individual questionnaire. HD (score ≥8) and binge drinking (BD) (drinks on the same occasion ≥5) were detected with the Alcohol Use Disorders Identification Test. The 4 SNPs were genotyped by the polymerase chain reaction-restriction fragment length polymorphism method. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated using logistic regression analysis. The Bonferroni correction was used (considering the 4 SNPs studied).

RESULTS

There were no significant differences in the frequencies of Arg370Cys, Arg272Gln, and Ile350Val polymorphisms between HD cases and controls. Otherwise, Arg/His genotype (rs1229984) in ADH1B gene showed a protective effect against HD (aOR = 0.36; 95% CI: 0.14 to 0.90) and BD (aOR = 0.49; 95% CI: 0.21 to 0.95). Nevertheless, these differences were no longer significant after Bonferroni correction.

CONCLUSIONS

The results of this study suggest a possible effect of the Arg48His genotype on the protection against HD in HIV-1-positive individuals.

HIV-1 Proteins Influence Novelty-Seeking Behavior and Alter Region-Specific Transcriptional Responses to Chronic Nicotine Treatment in HIV-1Tg Rats

INTRODUCTION

Clinical studies suggest that HIV-1-infected patients are more likely to use or abuse addictive drugs than is the general population. We hypothesized that HIV-1 proteins impact novelty-seeking behavior and enhance the transcriptional response to nicotine in genes implicated in both novelty-seeking behavior and drug addiction.

METHODS

We assessed the effects of HIV-1 proteins on novelty-seeking behavior by comparing baseline activity differences of HIV-1Tg and F344 control rats in the open-field test. One day after behavioral testing, all rats began daily subcutaneous injections of either nicotine (0.4 mg/kg, base) or saline (the same for each rat) for 27 days. At the end of treatment, the prefrontal cortex, nucleus accumbens, and ventral tegmental area were collected for RNA expression analysis of genes in the receptor families for dopamine, GABA, glutamate, and serotonin.

RESULTS

Significant strain difference was detected in the distance moved in the center, such that HIV-1Tg rats traveled greater distance in the center of the arena than did F344 rats. Quantitative RT-PCR analysis showed that mRNA from Drd3 and Grm2 in the prefrontal cortex and Drd5 and Gabra6 in the ventral tegmental area was significantly upregulated, whereas that of Drd5 in the nucleus accumbens was downregulated in HIV-1Tg rats compared with F344 rats. Further, more addiction-related genes were significantly modulated by nicotine in each brain region in the HIV-1Tg rats than in the control animals.

CONCLUSIONS

HIV-1 proteins may affect novelty-seeking behavior and modulate the expression of genes related to drug addiction and novelty-seeking behavior.

IMPLICATIONS

HIV-1 viral proteins and chronic nicotine treatment impact the expression of genes involved in novelty-seeking behavior and addiction in three brain regions of the HIV-1 transgenic rat. These findings implicate that HIV-1 proteins may be involved in novelty-seeking behavior and in modulating the expression of genes related to drug addiction and novelty seeking.

Interactive Effects of Ethanol and HIV-1 Proteins on Novelty-Seeking Behaviors and Addiction-Related Gene Expression

BACKGROUND

Novelty-seeking behavior is related to the reward system in the brain and can predict the potential for addiction. Alcohol use is prevalent in HIV-1-infected patients and adversely affects antiretroviral medication. The difference in vulnerability to alcohol addiction between HIV-1-infected and noninfected populations has not been fully investigated. This study was designed to determine whether HIV-1 proteins alter the effects of ethanol (EtOH) on novelty-seeking behavior using the HIV-1 transgenic (HIV-1Tg) rat as the study model and to examine the molecular mechanisms responsible for this behavior.

METHODS

Both HIV-1Tg and F344 control rats were tested for baseline novelty-seeking behavior, then received either EtOH (1 g/kg) at a concentration of 20% v/v or saline treatment for 13 days, and then were retested for novelty seeking. Quantitative real-time polymerase chain reaction was conducted to examine the differences in expression of 65 genes implicated in novelty seeking and alcohol addiction between strains and treatment groups.

RESULTS

The HIV-1 proteins significantly enhanced baseline novelty-seeking behaviors in both the hole-board and open-field tests. Chronic EtOH treatment significantly increased baseline novelty-seeking behavior in both strains, but the effects of EtOH appeared to be more robust and prominent in HIV-1Tg rats. Strain-specific patterns of altered gene expression were observed for dopaminergic, cholinergic, and glutamatergic signaling in the nucleus accumbens, suggesting the effects of HIV-1 proteins on the brain's reward system. Chronic EtOH treatment was shown to greatly modulate the effects of HIV-1 proteins in these neurotransmitter systems.

CONCLUSIONS

Taken together, our findings indicate that HIV-1 proteins could modify novelty-seeking behavior at the gene expression level, and EtOH treatment may enhance this behavior in both strains but to a greater extent in HIV-1Tg rats.

Expression profile of nicotinic acetylcholine receptor subunits in the brain of HIV-1 transgenic rats given chronic nicotine treatment

Abuse of addictive substances, including cigarettes, is much greater in HIV-1-infected individuals than in the general population and challenges the efficiency of highly active anti-retroviral therapy (HAART). The HIV-1 transgenic (HIV-1Tg) rat, an animal model used to study drug addiction in HIV-1-infected patients on HAART, displays abnormal neurobehavioral responses to addictive substances. Given that the cholinergic system plays an essential part in the central reward circuitry, we evaluated the expression profile of nine nicotinic acetylcholine receptor (nAChR) subunit genes in the central nervous system (CNS) of HIV-1Tg rats. We found that nAChR subunits were differentially expressed in various brain regions in HIV-1Tg rats compared to F344 control rats, with more subunits altered in the ventral tegmental area (VTA) and nucleus accumbens (NAc) of the HIV-1Tg rats than in other brain regions. We also found that chronic nicotine treatment (0.4 mg/kg/day) decreased the mRNA expression of nAChR subunits α6, β3, and β4 in the VTA of HIV-1Tg rats, whereas expression of α4 and α6 subunits in the NAc increased. No such changes were observed in F344 rats. Together, our data suggest that HIV-1 proteins alter the expression of nAChRs, which may contribute to the vulnerability to cigarette smoking addiction in HIV-1 patients.

Role of Autophagy in HIV Pathogenesis and Drug Abuse

Autophagy is a highly regulated process in which excessive cytoplasmic materials are captured and degraded during deprivation conditions. The unique nature of autophagy that clears invasive microorganisms has made it an important cellular defense mechanism in a variety of clinical situations. In recent years, it has become increasingly clear that autophagy is extensively involved in the pathology of HIV-1. To ensure survival of the virus, HIV-1 viral proteins modulate and utilize the autophagy pathway so that biosynthesis of the virus is maximized. At the same time, the abuse of illicit drugs such as methamphetamine, cocaine, morphine, and alcohol is thought to be a significant risk factor for the acquirement and progression of HIV-1. During drug-induced toxicity, autophagic activity has been proved to be altered in various cell types. Here, we review the current literature on the interaction between autophagy, HIV-1, and drug abuse and discuss the complex role of autophagy during HIV-1 pathogenesis in co-exposure to illicit drugs.

Profile of Class I Histone Deacetylases (HDAC) by Human Dendritic Cells after Alcohol Consumption and In Vitro Alcohol Treatment and Their Implication in Oxidative Stress: Role of HDAC Inhibitors Trichostatin A and Mocetinostat

Epigenetic mechanisms have been shown to play a role in alcohol use disorders (AUDs) and may prove to be valuable therapeutic targets. However, the involvement of histone deacetylases (HDACs) on alcohol-induced oxidative stress of human primary monocyte-derived dendritic cells (MDDCs) has not been elucidated. In the current study, we took a novel approach combining ex vivo, in vitro and in silico analyses to elucidate the mechanisms of alcohol-induced oxidative stress and role of HDACs in the periphery. ex vivo and in vitro analyses of alcohol-modulation of class I HDACs and activity by MDDCs from self-reported alcohol users and non-alcohol users was performed. Additionally, MDDCs treated with alcohol were assessed using qRT-PCR, western blot, and fluorometric assay. The functional effects of alcohol-induce oxidative stress were measured in vitro using PCR array and in silico using gene expression network analysis. Our findings show, for the first time, that MDDCs from self-reported alcohol users have higher levels of class I HDACs compare to controls and alcohol treatment in vitro differentially modulates HDACs expression. Further, HDAC inhibitors (HDACi) blocked alcohol-induction of class I HDACs and modulated alcohol-induced oxidative stress related genes expressed by MDDCs. In silico analysis revealed new target genes and pathways on the mode of action of alcohol and HDACi. Findings elucidating the ability of alcohol to modulate class I HDACs may be useful for the treatment of alcohol-induced oxidative damage and may delineate new potential immune-modulatory mechanisms.

Modulation Effect of HIV-1 Viral Proteins and Nicotine on Expression of the Immune-Related Genes in Brain of the HIV-1 Transgenic Rats

The human immunodeficiency virus-1 transgenic (HIV-1Tg) rat is a non-infectious rodent model for HIV-1 infection which develops altered immune-responses similar to those in persons infected with HIV-1. HIV-1Tg and F344 rats respond significantly different to morphine, ethanol, nicotine and other psychostimulants, although the molecular mechanisms underlying these differences remain largely undetermined. Here, we compared expression of 52 immune-related genes in the prefrontal cortex (PFC), nucleus accumbens (NAc), and ventral tegmental area (VTA) of HIV-1Tg and F344 rats treated with either nicotine (0.4 mg/kg nicotine, base, s.c.) or saline for 27 days, to identify differentially expressed genes in the presence of HIV-1 with and without nicotine treatment. Using quantitative RT-PCR array, we measured RNA expression levels. Results showed that RNA expression of CASP3, CCL5, CX3CL1, CX3CR1, IL1α, LRF4, LFR7, TGFβ1 and TLR4 in NAc, CCL2, CCL5, TGFβ1 and TLR4 in PFC, and CASP3, CX3CR1, IFNα1, IL1β and IL6 in VTA was significantly modulated in HIV-1Tg rats compared with F344 rats. IL1α showed a 58 % (P = 0.000072) decrease and IRF6 showed a 93.7 % increase (P = 0.000227) in the NAc of HIV-1Tg compared with F344 rats; results remained significant after correction for multiple testing. We also found that several genes were significantly modulated by nicotine in HIV-1Tg rats while only a small number of immune-related genes were altered by nicotine in F344 rats. These findings imply that HIV-1 viral proteins greatly impact immune function and alter responsiveness to nicotine in certain immune-related genes.

Alcohol and Cannabinoids Differentially Affect HIV Infection and Function of Human Monocyte-Derived Dendritic Cells (MDDC)

During human immunodeficiency virus (HIV) infection, alcohol has been known to induce inflammation while cannabinoids have been shown to have an anti-inflammatory role. For instance cannabinoids have been shown to reduce susceptibility to HIV-1 infection and attenuate HIV replication in macrophages. Recently, we demonstrated that alcohol induces cannabinoid receptors and regulates cytokine production by monocyte-derived dendritic cells (MDDC). However, the ability of alcohol and cannabinoids to alter MDDC function during HIV infection has not been clearly elucidated yet. In order to study the potential impact of alcohol and cannabinoids on differentiated MDDC infected with HIV, monocytes were cultured for 7 days with GM-CSF and IL-4, differentiated MDDC were infected with HIV-1Ba-L and treated with EtOH (0.1 and 0.2%), THC (5 and 10 μM), or JWH-015 (5 and 10 μM) for 4–7 days. HIV infection of MDDC was confirmed by p24 and Long Terminal Repeats (LTR) estimation. MDDC endocytosis assay and cytokine array profiles were measured to investigate the effects of HIV and substances of abuse on MDDC function. Our results show the HIV + EtOH treated MDDC had the highest levels of p24 production and expression when compared with the HIV positive controls and the cannabinoid treated cells. Although both cannabinoids, THC and JWH-015 had lower levels of p24 production and expression, the HIV + JWH-015 treated MDDC had the lowest levels of p24 when compared to the HIV + THC treated cells. In addition, MDDC endocytic function and cytokine production were also differentially altered after alcohol and cannabinoid treatments. Our results show a differential effect of alcohol and cannabinoids, which may provide insights into the divergent inflammatory role of alcohol and cannabinoids to modulate MDDC function in the context of HIV infection.

Increased Sensitivity to Binge Alcohol-Induced Gut Leakiness and Inflammatory Liver Disease in HIV Transgenic Rats

The mechanisms of alcohol-mediated advanced liver injury in HIV-infected individuals are poorly understood. Thus, this study was aimed to investigate the effect of binge alcohol on the inflammatory liver disease in HIV transgenic rats as a model for simulating human conditions. Female wild-type (WT) or HIV transgenic rats were treated with three consecutive doses of binge ethanol (EtOH) (3.5 g/kg/dose oral gavages at 12-h intervals) or dextrose (Control). Blood and liver tissues were collected at 1 or 6-h following the last dose of ethanol or dextrose for the measurements of serum endotoxin and liver pathology, respectively. Compared to the WT, the HIV rats showed increased sensitivity to alcohol-mediated gut leakiness, hepatic steatosis and inflammation, as evidenced with the significantly elevated levels of serum endotoxin, hepatic triglycerides, histological fat accumulation and F4/80 staining. Real-time PCR analysis revealed that hepatic levels of toll-like receptor-4 (TLR4), leptin and the downstream target monocyte chemoattractant protein-1 (MCP-1) were significantly up-regulated in the HIV-EtOH rats, compared to all other groups. Subsequent experiments with primary cultured cells showed that both hepatocytes and hepatic Kupffer cells were the sources of the elevated MCP-1 in HIV-EtOH rats. Further, TLR4 and MCP-1 were found to be upregulated by leptin. Collectively, these results show that HIV rats, similar to HIV-infected people being treated with the highly active anti-retroviral therapy (HAART), are more susceptible to binge alcohol-induced gut leakiness and inflammatory liver disease than the corresponding WT, possibly due to additive or synergistic interaction between binge alcohol exposure and HIV infection. Based on these results, HIV transgenic rats can be used as a surrogate model to study the molecular mechanisms of many disease states caused by heavy alcohol intake in HIV-infected people on HAART.

Alcohol Versus Cannabinoids: A Review of Their Opposite Neuro-Immunomodulatory Effects and Future Therapeutic Potentials

Due to the legalization of marijuana and the increased demand for cannabis and alcohol consumption, research efforts highlighting the biomedical consequences of the use of alcohol and cannabinoids are not only relevant to the substance abuse scientific field, but are also of public health interest. Moreover, an overview of the recent literature about alcohol and cannabinoids neuro-immunomodulatory effects highlighting their future therapeutic potentials will provide a significant contribution to science and medicine. Therefore, in the current review, we will first discuss briefly the prevalence of alcohol and marijuana abuse, followed by a discussion on the individual effects of alcohol and cannabinoids on the immune system; then, we will focus on the role of endocannabinoids on the alcohol-induced inflammatory effects. In addition, the review also incorporates cytokine array data obtained from human monocyte-derived dendritic cells, providing a different perspective on the alcohol and cannabinoid abuse divergent effects on cytokine production. The final section will highlight the therapeutic potential of cannabinoid receptors and the novel strategies to treat alcohol dependence as determined by in vitro, in vivo and clinical studies.

Alcohol and inflammatory responses: summary of the 2013 Alcohol and Immunology Research Interest Group (AIRIG) meeting

Loyola University Chicago, Health Sciences Campus in Maywood, Illinois hosted the 18th annual Alcohol and Immunology Research Interest Group (AIRIG) meeting on November 22, 2013. This year's meeting emphasized alcohol's effect on inflammatory responses in diverse disease states and injury conditions. The meeting consisted of three plenary sessions demonstrating the adverse effects of alcohol, specifically, liver inflammation, adverse systemic effects, and alcohol's role in infection and immunology. Researchers also presented insight on modulation of microRNAs and stress proteins following alcohol consumption. Additionally, researchers revealed sex- and concentration-dependent differences in alcohol-mediated pathologies.

HIV-1 transgenic female rat: synaptodendritic alterations of medium spiny neurons in the nucleus accumbens

HIV-1 associated neurocognitive deficits are increasing in prevalence, although the neuronal basis for these deficits is unclear. HIV-1 Tg rats constitutively express 7 of 9 HIV-associated proteins, and may be useful for studying the neuropathological substrates of HIV-1 associated neurocognitive disorders (HAND). In this study, adult female HIV-1 Tg rats and F344 control rats had similar growth rates, estrous cyclicity and startle reflex inhibition to a visual prepulse stimulus. Medium spiny neurons (MSNs) in the nucleus accumbens (NAcc) were ballistically-labeled utilizing the indocarbocyanine dye DiI. The branching complexity of MSNs in the NAcc was significantly decreased in HIV-1 Tg rats, relative to controls; moreover, the shorter length and decreased volume of dendritic spines, but unchanged head diameter, in HIV-1 Tg rats suggested a reduction of longer spines and an increase in shorter, less projected spines, indicating a population shift to a more immature spine phenotype. Collectively, these results from HIV-1 Tg female rats indicated significant synaptodendritic alterations of MSNs in the NAcc occur as a consequence of chronic, low-level, exposure to HIV-1 associated proteins.

Problematic alcohol use among individuals with HIV: relations with everyday memory functioning and HIV symptom severity

Problematic alcohol use has been shown to negatively impact cognitive functions germane to achieving optimal HIV health outcomes. The present study, a secondary data analysis, examined the impact of problematic alcohol use on aspects of everyday memory functioning in a sample of 172 HIV-infected individuals (22 % female; Mage = 48.37 years, SD = 8.64; 39 % Black/non-Hispanic). Additionally, we tested whether self-reported memory functioning explained the relation between problematic alcohol use and HIV symptom severity. Results indicated that problematic patterns of alcohol use were associated with lower total memory functioning, retrieval (e.g., recall-difficulty) and memory for activity (e.g., what you did yesterday) and greater HIV symptom severity. Memory functioning mediated the relation between problematic alcohol use and HIV symptom severity. However, the direction of this relation was unclear as HIV symptom severity also mediated the relation between problematic alcohol use and memory functioning. Findings highlight the importance of integrated care for HIV and alcohol use disorders and suggest that routine alcohol and cognitive screenings may bolster health outcomes among this vulnerable population.

Alcohol abuse and HIV infection: role of DRD2

According to a survey from the HIV Cost and Services Utilization Study (HCSUS), approximately 53% of HIV-infected patients reported drinking alcohol and 8% were classified as heavy drinkers. The role of alcohol as a risk factor for HIV infection has been widely studied and recent research has found a significant association between heavy alcohol consumption and lower levels of CD4 T cells among HIV-infected alcoholics. Although there is evidence on the role of alcohol as a risk factor for HIV transmission and disease progression, there is a need for population studies to determine the genetic mechanisms that affect alcohol's role in HIV disease progression. One of the mechanisms of interest is the dopaminergic system. To date, the effects of dopamine on HIV neuroimmune pathogenesis are not well understood; however, dopaminergic neural degeneration due to HIV is known to occur by viral invasion into the brain via immune cells, and modulation of dopamine in the CNS may be a common mechanism by which different types of substances of abuse impact HIV disease progression. Although previous studies have shown an association of D(2) dopamine receptor (DRD2) polymorphisms with severity of alcohol dependence, the expression of this allele risk on HIV patients with alcohol dependence has not been systematically explored. In the current study, DRD2 Taq1A and C957T SNP genotyping analyses were performed in 165 HIV-infected alcohol abusers and the results were examined with immune status and CD4 counts.