Impact of cocaine abuse on HIV pathogenesis

Non-Coding RNAs in HIV Infection, NeuroHIV, and Related Comorbidities

NeuroHIV affects approximately 30-60% of people living with HIV-1 (PLWH) and is characterized by varying degrees of cognitive impairments, presenting a multifaceted challenge, the underlying cause of which is chronic, low-level neuroinflammation. Such smoldering neuroinflammation is likely an outcome of lifelong reliance on antiretrovirals coupled with residual virus replication in the brains of PLWH. Despite advancements in antiretroviral therapeutics, our understanding of the molecular mechanism(s) driving inflammatory processes in the brain remains limited. Recent times have seen the emergence of non-coding RNAs (ncRNAs) as critical regulators of gene expression, underlying the neuroinflammatory processes in HIV infection, NeuroHIV, and their associated comorbidities. This review explores the role of various classes of ncRNAs and their regulatory functions implicated in HIV infection, neuropathogenesis, and related conditions. The dysregulated expression of ncRNAs is known to exacerbate the neuroinflammatory responses, thus contributing to neurocognitive impairments in PLWH. This review also discusses the diagnostic and therapeutic potential of ncRNAs in HIV infection and its comorbidities, suggesting their utility as non-invasive biomarkers and targets for modulating neuroinflammatory pathways. Understanding these regulatory roles could pave the way for novel diagnostic strategies and therapeutic interventions in the context of HIV and its comorbidities.

Examining the Intersection of Ethnoracial Disparities and HIV Status in Substance Use Risks among U.S. Adults

Black/African American and Hispanic Americans experience significant HIV-related disparities. Substance use might be a contributing factor to these disparities, but there is limited research on this topic. This study investigated various substance use risks by HIV status and race/ethnicity (Black, Hispanic, White) among U.S. adults. We used data from the 2005-2019 National Survey on Drug Use and Health (N = 541,921). In each racial/ethnic group, the prevalence rates of past-year and past-month tobacco, alcohol, cannabis, and cocaine use, and past-year alcohol and illicit drug use disorders were estimated by HIV status. A series of logistic regressions with the interaction term of HIV x race/ethnicity were performed to examine race/ethnicity's moderating effect on the HIV-substance use associations, while controlling for sociodemographic factors and survey year. Moderation analysis showed that HIV status's association with the risks of past-year tobacco use (AOR = 1.67, 95% CI = 1.01-2.75), past-year cocaine use (AOR = 3.80, 95% CI = 1.91-7.57), past-month cocaine use (AOR = 5.34, 95% CI = 2.10-13.60), and past-year alcohol use disorder (AOR = 2.52, 95% CI = 1.29-4.92) differed significantly between Black and White adults. Between the Hispanic and White groups, HIV status's association with the risks of past-year alcohol use (AOR = 2.00, 95% CI = 1.09-3.69), past-year cocaine use (AOR = 2.40, 95% CI = 1.06-5.39), and past-month cocaine use (AOR = 3.69, 95% CI = 1.36-10.02) also differed significantly. It is well-established that individuals with HIV face an elevated risk of substance use. Our study added valuable insights by highlighting that this phenomenon is particularly more significant among Black and Hispanic adults for several substances when compared to White adults. Implications for practice are discussed.

EcoHIV Infection Modulates the Effects of Cocaine Exposure Pattern and Abstinence on Cocaine Seeking and Neuroimmune Protein Expression in Male Mice

Cocaine use disorders (CUDs) and human immunodeficiency virus (HIV) remain persistent public health dilemmas throughout the world. One major hurdle for treating CUD is the increase in cocaine craving and seeking behavior that occurs over a protracted period of abstinence, an effect known as the incubation of craving. Little is known about how HIV may modulate this process. Thus, we sought to examine the impact of chronic HIV infection on the incubation of cocaine craving and associated changes in the central and peripheral immune systems. Here, mice were inoculated with EcoHIV, which is a chimeric HIV-1 construct that produces chronic HIV infection in mice. EcoHIV- and sham-infected mice were conditioned with cocaine daily or intermittently in a conditioned place preference (CPP) paradigm, followed by 1 or 21 days of forced abstinence prior to assessing preference for the cocaine-paired chamber. Under both conditioning regimens, sham mice exhibited incubation of cocaine CPP after 21 days of abstinence. EcoHIV-infected mice conditioned daily with cocaine showed enhanced cocaine seeking at both abstinence timepoints, whereas infected mice conditioned intermittently showed a reversal of the incubation effect, with higher cocaine seeking after 1 day of abstinence compared to 21 days. Analysis of corticolimbic CX3CL1-CX3CR1 and glutamate receptor expression revealed alterations in medial prefrontal cortex (mPFC) CX3CL1 and nucleus accumbens (NAc) GluN2A receptors that correlated with cocaine seeking following daily cocaine exposure. Moreover, examination of peripheral immune markers showed that the effect of abstinence and EcoHIV infection on these measures depended on the cocaine exposure regimen. Altogether, these results highlight the importance of cocaine abstinence and exposure pattern as critical variables that modulate HIV-associated neuroimmune outcomes and relapse vulnerability.

Polarization of HIV-1- and CMV-Specific IL-17-Producing T Cells among People with HIV under Antiretroviral Therapy with Cannabis and/or Cocaine Usage

OBJECTIVE

This study evaluated the influence of cannabis and/or cocaine use in human immunodeficiency virus (HIV)- and cytomegalovirus (CMV)-specific T-cell responses of people with HIV (PWH).

RESULTS

There was a higher percentage of IL-17-producing HIV-Gag-specific CD8+ T-cells in all drug users than that in PWH non-drug users. Stratifying the drug-user groups, increased percentages of IL-17-producing HIV-Gag-specific CD4+ and CD8+ T-cells were found in PWH cannabis plus cocaine users compared to PWH non-drug users. In response to CMV, there were higher percentage of IL-17-producing CMV-specific CD8+ T-cell in PWH cocaine users than that in PWH non-drug users. Considering all drug users together, there was a higher percentage of SEB-stimulated IL-17-producing CD4+ T-cells than that in PWH non-drug users, whereas cannabis users had higher percentages of IL-17-producing CD4+ T-cells compared to non-drug users.

METHODS

Cryopreserved peripheral blood mononuclear cells from 37 PWH undergoing antiretroviral therapy (ART) using cannabis (10), cocaine (7), or cannabis plus cocaine (10) and non-drug users (10) were stimulated with HIV-1 Gag or CMV-pp65 peptide pools, or staphylococcal enterotoxin B (SEB) and evaluated for IFN-γ- and/or IL-17A-producing CD4+ and CD8+ T-cells using flow cytometry.

CONCLUSIONS

Cannabis plus cocaine use increased HIV-specific IL-17 producing T-cells and cocaine use increased IL-17 CMV-specific CD8+ T-cell responses which could favor the inflammatory conditions associated with IL-17 overproduction.

Cocaine regulates antiretroviral therapy CNS access through pregnane-x receptor-mediated drug transporter and metabolizing enzyme modulation at the blood brain barrier

BACKGROUND

Appropriate interactions between antiretroviral therapies (ART) and drug transporters and metabolizing enzymes at the blood brain barrier (BBB) are critical to ensure adequate dosing of the brain to achieve HIV suppression. These proteins are modulated by demographic and lifestyle factors, including substance use. While understudied, illicit substances share drug transport and metabolism pathways with ART, increasing the potential for adverse drug:drug interactions. This is particularly important when considering the brain as it is relatively undertreated compared to peripheral organs and is vulnerable to substance use-mediated damage.

METHODS

We used an in vitro model of the human BBB to determine the extravasation of three first-line ART drugs, emtricitabine (FTC), tenofovir (TFV), and dolutegravir (DTG), in the presence and absence of cocaine, which served as our illicit substance model. The impact of cocaine on BBB integrity and permeability, drug transporters, metabolizing enzymes, and their master transcriptional regulators were evaluated to determine the mechanisms by which substance use impacted ART central nervous system (CNS) availability.

RESULTS

We determined that cocaine had a selective impact on ART extravasation, where it increased FTC's ability to cross the BBB while decreasing TFV. DTG concentrations that passed the BBB were below quantifiable limits. Interestingly, the potent neuroinflammatory modulator, lipopolysaccharide, had no effect on ART transport, suggesting a specificity for cocaine. Unexpectedly, cocaine did not breach the BBB, as permeability to albumin and 4 kDa FITC-dextran, as well as tight junction proteins and adhesion molecules remained unchanged. Rather, cocaine selectively decreased the pregnane-x receptor (PXR), but not constitutive androstane receptor (CAR). Consequently, drug transporter expression and activity decreased in endothelial cells of the BBB, including p-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug resistance-associated protein 4 (MRP4). Further, cytochrome P450 3A4 (CYP3A4) enzymatic activity increased following cocaine treatment that coincided with decreased expression. Finally, cocaine modulated adenylate kinases that are required to facilitate biotransformation of ART prodrugs to their phosphorylated, pharmacologically active counterparts.

CONCLUSION

Our findings indicate that additional considerations are needed in CNS HIV treatment strategies for people who use cocaine, as it may limit ART efficacy through regulation of drug transport and metabolizing pathways at the BBB.

Cocaine Regulates Antiretroviral Therapy CNS Access Through Pregnane-X Receptor-Mediated Drug Transporter and Metabolizing Enzyme Modulation at the Blood Brain Barrier

Background

Appropriate interactions between antiretroviral therapies (ART) and drug transporters and metabolizing enzymes at the blood brain barrier (BBB) are critical to ensure adequate dosing of the brain to achieve HIV suppression. These proteins are modulated by demographic and lifestyle factors, including substance use. While understudied, illicit substances share drug transport and metabolism pathways with ART, increasing the potential for adverse drug:drug interactions. This is particularly important when considering the brain as it is relatively undertreated compared to peripheral organs and is vulnerable to substance use-mediated damage.

Methods

We used an in vitro model of the human BBB to determine the extravasation of three first-line ART drugs, emtricitabine (FTC), tenofovir (TFV), and dolutegravir (DTG), in the presence and absence of cocaine, which served as our illicit substance model. The impact of cocaine on BBB integrity and permeability, drug transporters, metabolizing enzymes, and their master transcriptional regulators were evaluated to determine the mechanisms by which substance use impacted ART central nervous system (CNS) availability.

Results

We determined that cocaine had a selective impact on ART extravasation, where it increased FTC's ability to cross the BBB while decreasing TFV. DTG concentrations that passed the BBB were below quantifiable limits. Interestingly, the potent neuroinflammatory modulator, lipopolysaccharide, had no effect on ART transport, suggesting a specificity for cocaine. Unexpectedly, cocaine did not breach the BBB, as permeability to albumin and tight junction proteins and adhesion molecules remained unchanged. Rather, cocaine selectively decreased the pregnane-x receptor (PXR), but not constitutive androstane receptor (CAR). Consequently, drug transporter expression and activity decreased in endothelial cells of the BBB, including p-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug resistance-associated protein 4 (MRP4). Further, cytochrome P450 3A4 (CYP3A4) enzymatic activity increased following cocaine treatment that coincided with decreased expression. Finally, cocaine modulated adenylate kinases are required to facilitate biotransformation of ART prodrugs to their phosphorylated, pharmacologically active counterparts.

Conclusion

Our findings indicate that additional considerations are needed in CNS HIV treatment strategies for people who use cocaine, as it may limit ART efficacy through regulation of drug transport and metabolizing pathways at the BBB.

Clinical management of psychostimulant withdrawal: review of the evidence

It is estimated that a majority of people who use psychostimulants, particularly methamphetamine (MA) and cocaine, experience withdrawal upon abstinence from sustained use. This review of clinical research reports the evidence regarding biomedical and behavioral treatments for psychostimulant withdrawal symptoms. It provides a framework for clinicians and scientists to increase impact on attenuating MA and cocaine withdrawal during initial and sustained abstinence. Articles reviewed included reports of controlled clinical trials (randomized or non-randomized) reporting at least one withdrawal symptom among the outcomes or specifically studying patients in withdrawal. Potential efficacy for MA withdrawal is noted for a few medications (mirtazapine, naltrexone, bupropion) and repetitive transcranial magnetic stimulation during acute (first week), early protracted (weeks 2-4) and late protracted (> 4 weeks) withdrawal phases. Topiramate shows mixed evidence of efficacy for cocaine withdrawal. In general, there is inconsistent signal for biomedical and behavioral treatments on MA and cocaine withdrawal.

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

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

Cocaine sensitizes the CD4+ T cells for HIV infection by co-stimulating NFAT and AP-1

The productive infection of HIV, which generates new viral progeny, depends on the activation status of the cell. In this study, we found cocaine exposure sensitizes partially active CD4+ T cells and makes them poised for productive HIV infection. We discovered that cocaine treatment enhances the metabolic state of the cells by co-stimulating several transcription factors, mainly NFAT and AP-1, the two transcription factors, which specifically play a crucial role in enhancing both HIV and the overall cellular gene expression in T cells. We found that cocaine-induced AP-1 works in tandem with NFAT to boost HIV transcription. The enhanced HIV transcription upon cocaine exposure was further confirmed through higher phosphorylation of the crucial serine residues at the carboxyl-terminal domain (CTD) of RNA polymerase II. The insights gained from this study could aid in developing highly specialized therapeutics combating the deleterious effects of cocaine on the cocaine-using HIV population.

Emerging trends in the nanomedicine applications of functionalized magnetic nanoparticles as novel therapies for acute and chronic diseases

High-quality point-of-care is critical for timely decision of disease diagnosis and healthcare management. In this regard, biosensors have revolutionized the field of rapid testing and screening, however, are confounded by several technical challenges including material cost, half-life, stability, site-specific targeting, analytes specificity, and detection sensitivity that affect the overall diagnostic potential and therapeutic profile. Despite their advances in point-of-care testing, very few classical biosensors have proven effective and commercially viable in situations of healthcare emergency including the recent COVID-19 pandemic. To overcome these challenges functionalized magnetic nanoparticles (MNPs) have emerged as key players in advancing the biomedical and healthcare sector with promising applications during the ongoing healthcare crises. This critical review focus on understanding recent developments in theranostic applications of functionalized magnetic nanoparticles (MNPs). Given the profound global economic and health burden, we discuss the therapeutic impact of functionalized MNPs in acute and chronic diseases like small RNA therapeutics, vascular diseases, neurological disorders, and cancer, as well as for COVID-19 testing. Lastly, we culminate with a futuristic perspective on the scope of this field and provide an insight into the emerging opportunities whose impact is anticipated to disrupt the healthcare industry.

Cocaine Self-Administration Influences Central Nervous System Immune Responses in Male HIV-1 Transgenic Rats

Cocaine use increases the neurotoxic severity of human immunodeficiency virus-1 (HIV-1) infection and the development of HIV-associated neurocognitive disorders (HAND). Among the studied cellular mechanisms promoting neurotoxicity in HIV-1 and cocaine use, central nervous system (CNS) immunity, such as neuroimmune signaling and reduced antiviral activity, are risk determinants; however, concrete evidence remains elusive. In the present study, we tested the hypothesis that cocaine self-administration by transgenic HIV-1 (HIV-1_Tg) rats promotes CNS inflammation. To test this hypothesis, we measured cytokine, chemokine, and growth factor protein levels in the frontal cortex (fCTX) and caudal striatum (cSTR). Our results demonstrated that cocaine self-administration significantly increased fCTX inflammation in HIV-1_Tg rats, but not in the cSTR. Accordingly, we postulate that cocaine synergizes with HIV-1 proteins to increase neuroinflammation in a region-selective manner, including the fCTX. Given the fCTX role in cognition, this interaction may contribute to the hyperimmunity and reduced antiviral activity associated with cocaine-mediated enhancement of HAND.

Impaired verbal memory in individuals living with HIV and cocaine dependence

INTRODUCTION

Our study aimed to understand the independent and combined effects of cocaine dependence and HIV status across aspects of verbal memory.

METHOD

Our sample consisted of a total of 102 individuals: 28 individuals living with HIV and cocaine dependence (HIV+/CD), 28 individuals who are HIV-negative with cocaine dependence (HIV-/CD), 20 individuals living with HIV without cocaine dependence (HIV+/ND), and 26 individuals who are HIV-negative without cocaine dependence (HIV-/ND). We utilized the Hopkins Verbal Learning Test-Revised Version (HVLT-R) to assess components of verbal memory, including encoding, recall, and recognition. A 2 (HIV: Yes/No) × 2 (Cocaine: Yes/No) MANCOVA on Total and Delayed Recall while controlling for premorbid intelligence was conducted. We used a Kruskal-Wallis H test to examine retrieval and recognition.

RESULTS

The combination of HIV and cocaine dependence amplified deficits on Total Recall. We found comparably poor performance across Delayed Recall between all three clinical groups. People living with HIV without cocaine dependence demonstrated intact recognition, whereas those with cocaine dependence had poor recognition.

CONCLUSIONS

HIV and cocaine both impacted verbal memory. However, there are potential subtle differences in the role cocaine versus HIV has on the memory process. People living with HIV without cocaine dependence recognized significantly more words than they could freely recall. In contrast, cocaine dependence impacted recognition in HIV and non-HIV groups. These performance patterns suggest HIV may be associated with retrieval deficits, whereas cocaine dependence may be associated with encoding deficits. Further research assessing these specific components of the memory process will help clarify these potential differences.

Daily and near-daily cannabis use is associated with HIV viral load suppression in people living with HIV who use cocaine

Disparities remain in HIV viral load (VL) suppression between people living with HIV (PLWH) who use cocaine and those who do not. It is not known how cannabis use affects VL suppression in PLWH who use cocaine. We evaluated the relationship between cannabis use and VL suppression among PLWH who use cocaine. We conducted a secondary data analysis of 119 baseline interviews from a randomized controlled trial in the Bronx, NY (6/2012 to 1/2017). Participants were adult PLWH prescribed antiretrovirals for ≥16 weeks, who endorsed imperfect antiretroviral adherence and used cocaine in the past 30-days. In bivariate and multivariable regression analyses, we examined how cannabis use, is associated with VL suppression among PLWH who use cocaine. Participants were a mean age of 50 years; most were male (64%) and non-Hispanic black (55%). Participants with VL suppression used cocaine less frequently than those with no VL suppression (p < 0.01); cannabis use was not significantly different. In regression analysis, compared with no use, daily/near-daily cannabis use was associated with VL suppression (aOR = 4.2, 95% CI: 1.1-16.6, p < 0.05). Less-frequent cannabis use was not associated with VL suppression. Further investigation is needed to understand how cannabis use impacts HIV outcomes among PLWH who use cocaine.

Endocytosis and Transcytosis of SARS-CoV-2 Across the Intestinal Epithelium and Other Tissue Barriers

Since 2003, the world has been confronted with three new betacoronaviruses that cause human respiratory infections: SARS-CoV, which causes severe acute respiratory syndrome (SARS), MERS-CoV, which causes Middle East respiratory syndrome (MERS), and SARS-CoV-2, which causes Coronavirus Disease 2019 (COVID-19). The mechanisms of coronavirus transmission and dissemination in the human body determine the diagnostic and therapeutic strategies. An important problem is the possibility that viral particles overcome tissue barriers such as the intestine, respiratory tract, blood-brain barrier, and placenta. In this work, we will 1) consider the issue of endocytosis and the possibility of transcytosis and paracellular trafficking of coronaviruses across tissue barriers with an emphasis on the intestinal epithelium; 2) discuss the possibility of antibody-mediated transcytosis of opsonized viruses due to complexes of immunoglobulins with their receptors; 3) assess the possibility of the virus transfer into extracellular vesicles during intracellular transport; and 4) describe the clinical significance of these processes. Models of the intestinal epithelium and other barrier tissues for in vitro transcytosis studies will also be briefly characterized.

Therapeutic Significance of microRNA-Mediated Regulation of PARP-1 in SARS-CoV-2 Infection

The COVID-19 pandemic caused by the novel coronavirus SARS-CoV-2 (2019-nCoV) has devastated global healthcare and economies. Despite the stabilization of infectivity rates in some developed nations, several countries are still under the grip of the pathogenic viral mutants that are causing a significant increase in infections and hospitalization. Given this urgency, targeting of key host factors regulating SARS-CoV-2 life cycle is postulated as a novel strategy to counter the virus and its associated pathological outcomes. In this regard, Poly (ADP)-ribose polymerase-1 (PARP-1) is being increasingly recognized as a possible target. PARP-1 is well studied in human diseases such as cancer, central nervous system (CNS) disorders and pathology of RNA viruses. Emerging evidence indicates that regulation of PARP-1 by non-coding RNAs such as microRNAs is integral to cell survival, redox balance, DNA damage response, energy homeostasis, and several other cellular processes. In this short perspective, we summarize the recent findings on the microRNA/PARP-1 axis and its therapeutic potential for COVID-19 pathologies.

Cocaine augments neuro-inflammation via modulating extracellular vesicle release in HIV-1 infected immune cells

Background

Extracellular Vesicles (EV) recently have been implicated in the pathogenesis of HIV-1 syndromes, including neuroinflammation and HIV-1 associated neurological disorder (HAND). Cocaine, an illicit stimulant drug used worldwide is known to exacerbate these HIV-1 associated neurological syndromes. However, the effects of cocaine on EV biogenesis and roles of EVs in enhancing HIV-1 pathogenesis are not yet well defined.

Results

Here, we investigated the effects of cocaine on EV biogenesis and release in HIV-1 infected immune cells and explored their roles in elicitation of neuroinflammation. We found that cocaine significantly augmented the release of EVs from uninfected and HIV-1 infected T-cells, DCs and macrophages. Further analysis of the molecular components of EVs revealed enhanced expression of adhesion molecules integrin β1 and LFA-1 in those EVs derived from cocaine treated cells. Intriguingly, in EVs derived from HIV-1 infected cells, cocaine treatment significantly increased the levels of viral genes in EVs released from macrophages and DCs, but not in T-cells. Exploring the molecular mechanism to account for this, we found that DCs and macrophages showed enhanced expression of the cocaine receptor Sigma 1-Receptor compared to T-cells. In addition, we found that cocaine significantly altered the integrity of the RNA-induced silencing complex (RISC) in HIV-1 infected macrophages and DCs compared to untreated HIV-1 infected cells. Characterizing further the molecular mechanisms involved in how cocaine increased EV release, we found that cocaine decreased the expression of the interferon-inducible protein BST-2; this resulted in altered trafficking of intracellular virus containing vesicles and EV biogenesis and release. We also observed EVs released from cocaine treated HIV-1 infected macrophages and DCs enhanced HIV-1 trans-infection to T-cells compared to those from untreated and HIV-1 infected cells. These EVs triggered release of proinflammatory cytokines in human brain microvascular endothelial cells (HBMECs) and altered monolayer integrity.

Conclusions

Taken together, our results provide a novel mechanism which helps to elucidate the enhanced prevalence of neurological disorders in cocaine using HIV-1 infected individuals and offers insights into developing novel therapeutic strategies against HAND in these hosts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12977-021-00570-4.

Patterns of reduced use and abstinence in multi-site randomized controlled trials of pharmacotherapies for cocaine and methamphetamine use disorders

BACKGROUND

Many individuals with cocaine or methamphetamine use disorders who enter treatment do not achieve abstinence but reduce their use of the target drug. We aimed to compare change in pattern of drug use (i.e., achieving "abstinence", "reduced use" or no reduction in use) among participants in randomized controlled trials (RCTs) of treatment of cocaine and methamphetamine use disorder, irrespective of the type of treatment.

METHODS

The data were drawn from 10 multi-site pharmacotherapy RCTs of cocaine (n = 1,134) and methamphetamine (n = 555) use disorders. The outcome patterns and their sociodemographic and clinical correlates were compared in cocaine and methamphetamine RCTs, using multinomial logistic regression models. Analyses were adjusted for missing data, clustering within RCTs, socio-demographic and baseline clinical characteristics, and treatment arms.

RESULTS

Those in cocaine RCTs were more likely to experience reduced use compared to participants in methamphetamine RCTs (20.6% vs. 13.2%, respectively), but less likely to experience "abstinence" (7.6% vs. 20.3%; Chi-squared = 14.20, df = 2, P < 0.001). Differences in "abstinence" persisted after adjustment for baseline covariates. Association of sociodemographic and clinical correlates with outcomes differed in cocaine and methamphetamine RCTs.

CONCLUSION

A sizeable proportion of individuals in RCTs of pharmacological treatment for stimulant use disorder who do not attain "abstinence" nevertheless reduce their use. The outcome patterns of drug use are different for cocaine and methamphetamine use disorders and reliance on abstinence as the sole outcome may obscure these differences.

Co-receptor signaling in the pathogenesis of neuroHIV

The HIV co-receptors, CCR5 and CXCR4, are necessary for HIV entry into target cells, interacting with the HIV envelope protein, gp120, to initiate several signaling cascades thought to be important to the entry process. Co-receptor signaling may also promote the development of neuroHIV by contributing to both persistent neuroinflammation and indirect neurotoxicity. But despite the critical importance of CXCR4 and CCR5 signaling to HIV pathogenesis, there is only one therapeutic (the CCR5 inhibitor Maraviroc) that targets these receptors. Moreover, our understanding of co-receptor signaling in the specific context of neuroHIV is relatively poor. Research into co-receptor signaling has largely stalled in the past decade, possibly owing to the complexity of the signaling cascades and functions mediated by these receptors. Examining the many signaling pathways triggered by co-receptor activation has been challenging due to the lack of specific molecular tools targeting many of the proteins involved in these pathways and the wide array of model systems used across these experiments. Studies examining the impact of co-receptor signaling on HIV neuropathogenesis often show activation of multiple overlapping pathways by similar stimuli, leading to contradictory data on the effects of co-receptor activation. To address this, we will broadly review HIV infection and neuropathogenesis, examine different co-receptor mediated signaling pathways and functions, then discuss the HIV mediated signaling and the differences between activation induced by HIV and cognate ligands. We will assess the specific effects of co-receptor activation on neuropathogenesis, focusing on neuroinflammation. We will also explore how the use of substances of abuse, which are highly prevalent in people living with HIV, can exacerbate the neuropathogenic effects of co-receptor signaling. Finally, we will discuss the current state of therapeutics targeting co-receptors, highlighting challenges the field has faced and areas in which research into co-receptor signaling would yield the most therapeutic benefit in the context of HIV infection. This discussion will provide a comprehensive overview of what is known and what remains to be explored in regard to co-receptor signaling and HIV infection, and will emphasize the potential value of HIV co-receptors as a target for future therapeutic development.

HIV-1 Tat and cocaine impact astrocytic energy reservoir influence on miRNA epigenetic regulation

Astrocytes are the primary regulator of energy metabolism in the central nervous system (CNS), and impairment of astrocyte's energy resource may trigger neurodegeneration. HIV infections and cocaine use are known to alter epigenetic modification, including miRNAs, which can target gene expression post-transcriptionally. However, miRNA-mediated astrocyte energy metabolism has not been delineated in HIV infection and cocaine abuse. Using next-generation sequencing (NGS), we identified a total of 1900 miRNAs, 64 were upregulated and 68 miRNAs were downregulated in the astrocytes by HIV-1 Tat with cocaine exposure. Moreover, miR-4727-3p, miR-5189-5p, miR-5090, and miR-6810-5p expressions were significantly impacted, and their gene targets were identified as VAMP2, NFIB, PPM1H, MEIS1, and PSD93 through the bioinformatic approach. In addition, the astrocytes treated with the nootropic drug piracetam protects these miRNAs. These findings provide evidence that the miRNAs in the astrocytes may be a potential biomarker and therapeutic target for HIV and cocaine abuse-induced neurodegeneration.

Using mobile health technologies to test the association of cocaine use with sexual desire and risky sexual behaviors among people with and without HIV who use illicit stimulants

BACKGROUND

Cocaine use is broadly associated with risky sexual behavior potentially through elevated sexual desire. Understanding the within-person effects of cocaine on sexual desire and risky sexual behavior and the modification of HIV infection may inform primary and secondary HIV interventions.

METHODS

We conducted a mobile health (mHealth) study in a community sample of males and females with (n = 28) and without (n = 32) HIV who use illicit stimulant drugs. Participants completed ecological momentary assessments (EMAs) and daily diaries over 28 days. Mixed effects models were employed to examine the within-person association of cocaine use with sexual desire and risky sexual behavior.

RESULTS

Participants completed 3505 EMA responses, with 36 % involving recent cocaine use, including powder and/or crack cocaine. They completed 1427 daily diary responses, with cocaine use reported on 49 % of these days and sexual behavior on 21 % of these days. Sexual desire was highest in the first hour since cocaine use and gradually decreased with time. Sexual desire was lowest when participants had not used any cocaine in the past 6 h, and it correlated positively with the amount of use. Participants were more likely to have risky sexual behavior on days they used cocaine. These associations were similar for participants with and without HIV.

CONCLUSION

This study demonstrates the dynamic and proximal effects of cocaine use on sexual desire and risky sexual behavior. Our findings support the development of HIV prevention interventions that utilize mHealth technology to reduce sexual risk behavior among persons who use stimulant drugs.

Effects of cocaine and HIV on decision-making abilities

Our study aimed to understand the impact of cocaine dependence on high-risk decision-making abilities in individuals with the human immunodeficiency virus (HIV) and individuals with cocaine dependence. We recruited 99 participants (27 HIV/Cocaine, 20 HIV Only, 26 Cocaine Only, and 26 Healthy Controls). The Iowa Gambling Task (IGT) was applied to assess decision-making abilities. Independent and interactive effects of HIV status and cocaine dependence were examined using 2 × 2 factorial ANCOVA with premorbid IQ (WRAT-4: WR) as the covariate. We found cocaine dependence had a significant adverse effect on overall IGT performance (p = 0.015). We also found individuals who were HIV-positive tended to have less total money at the end of the game than individuals who were HIV-negative (p = 0.032), suggesting individuals living with HIV had less focus on long-term gains and more focus on short-term gains. Our findings highlight the significant impact of cocaine dependence on decision-making abilities and the difficulty individuals with HIV have in adequately weighing the cost and benefits of their decisions and making appropriate changes for the future.

Dopamine Levels Induced by Substance Abuse Alter Efficacy of Maraviroc and Expression of CCR5 Conformations on Myeloid Cells: Implications for NeuroHIV

Despite widespread use of antiretroviral therapy (ART), HIV remains a major public health issue. Even with effective ART many infected individuals still suffer from the constellation of neurological symptoms now known as neuroHIV. These symptoms can be exacerbated by substance abuse, a common comorbidity among HIV-infected individuals. The mechanism(s) by which different types of drugs impact neuroHIV remains unclear, but all drugs of abuse increase central nervous system (CNS) dopamine and elevated dopamine increases HIV infection and inflammation in human myeloid cells including macrophages and microglia, the primary targets for HIV in the brain. Thus, drug-induced increases in CNS dopamine may be a common mechanism by which distinct addictive substances alter neuroHIV. Myeloid cells are generally infected by HIV strains that use the chemokine receptor CCR5 as a co-receptor, and our data indicate that in a subset of individuals, drug-induced levels of dopamine could interfere with the effectiveness of the CCR5 inhibitor Maraviroc. CCR5 can adopt distinct conformations that differentially regulate the efficiency of HIV entry and subsequent replication and using qPCR, flow cytometry, Western blotting and high content fluorescent imaging, we show that dopamine alters the expression of specific CCR5 conformations of CCR5 on the surface of human macrophages. These changes are not affected by association with lipid rafts, but do correlate with dopamine receptor gene expression levels, specifically higher levels of D1-like dopamine receptors. These data also demonstrate that dopamine increases HIV replication and alters CCR5 conformations in human microglia similarly to macrophages. These data support the importance of dopamine in the development of neuroHIV and indicate that dopamine signaling pathways should be examined as a target in antiretroviral therapies specifically tailored to HIV-infected drug abusers. Further, these studies show the potential immunomodulatory role of dopamine, suggesting changes in this neurotransmitter may also affect the progression of other diseases.

Web-Based Cognitive Training to Improve Working Memory in Persons with Co-Occurring HIV Infection and Cocaine Use Disorder: Outcomes from a Randomized Controlled Trial

Neurocognitive impairment (NCI) remains a persistent complication of HIV disease that nearly half of persons with HIV experience, and rates are even higher in persons who use substances such as cocaine. Cognitive training is a promising intervention for HIV-associated NCI. In this randomized controlled trial, we examined the feasibility and effectiveness of a web-based cognitive training program to improve working memory in a sample of 58 persons with HIV and cocaine use disorder. Participants were randomly assigned to either the experimental working memory training arm or the attention control training arm and completed up to 48 daily sessions over 10 weeks. Overall, treatment completion (74%) and retention rates (97%) were high, and participant feedback indicated the intervention was acceptable. Our results show that the intervention successfully reduced working memory deficits in the experimental arm relative to the control arm. Our findings support both the feasibility and effectiveness of cognitive training in this population.

A "Drug-Dependent" Immune System Can Compromise Protection against Infection: The Relationships between Psychostimulants and HIV

Psychostimulant use is a major comorbidity in people living with HIV, which was initially explained by them adopting risky behaviors that facilitate HIV transmission. However, the effects of drug use on the immune system might also influence this phenomenon. Psychostimulants act on peripheral immune cells even before they reach the central nervous system (CNS) and their effects on immunity are likely to influence HIV infection. Beyond their canonical activities, classic neurotransmitters and neuromodulators are expressed by peripheral immune cells (e.g., dopamine and enkephalins), which display immunomodulatory properties and could be influenced by psychostimulants. Immune receptors, like Toll-like receptors (TLRs) on microglia, are modulated by cocaine and amphetamine exposure. Since peripheral immunocytes also express TLRs, they may be similarly affected by psychostimulants. In this review, we will summarize how psychostimulants are currently thought to influence peripheral immunity, mainly focusing on catecholamines, enkephalins and TLR4, and shed light on how these drugs might affect HIV infection. We will try to shift from the classic CNS perspective and adopt a more holistic view, addressing the potential impact of psychostimulants on the peripheral immune system and how their systemic effects could influence HIV infection.

HIV Neuropathogenesis in the Presence of a Disrupted Dopamine System

Antiretroviral therapy (ART) has transformed HIV into a chronic condition, lengthening and improving the lives of individuals living with this virus. Despite successful suppression of HIV replication, people living with HIV (PLWH) are susceptible to a growing number of comorbidities, including neuroHIV that results from infection of the central nervous system (CNS). Alterations in the dopaminergic system have long been associated with HIV infection of the CNS. Studies indicate that changes in dopamine concentrations not only alter neurotransmission, but also significantly impact the function of immune cells, contributing to neuroinflammation and neuronal dysfunction. Monocytes/macrophages, which are a major target for HIV in the CNS, are responsive to dopamine. Therefore, defining more precisely the mechanisms by which dopamine acts on these cells, and the changes in cellular function elicited by this neurotransmitter are necessary to develop therapeutic strategies to treat neuroHIV. This is especially important for vulnerable populations of PLWH with chemically altered dopamine concentrations, such as individuals with substance use disorder (SUD), or aging individuals using dopamine-altering medications. The specific neuropathologic and neurocognitive consequences of increased CNS dopamine remain unclear. This is due to the complex nature of HIV neuropathogenesis, and logistical and technical challenges that contribute to inconsistencies among cohort studies, animal models and in vitro studies, as well as lack of demographic data and access to human CNS samples and cells. This review summarizes current understanding of the impact of dopamine on HIV neuropathogenesis, and proposes new experimental approaches to examine the role of dopamine in CNS HIV infection. Graphical abstract HIV Neuropathogenesis in the Presence of a Disrupted Dopamine System. Both substance abuse disorders and the use of dopaminergic medications for age-related diseases are associated with changes in CNS dopamine concentrations and dopaminergic neurotransmission. These changes can lead to aberrant immune function, particularly in myeloid cells, which contributes to the neuroinflammation, neuropathology and dysfunctional neurotransmission observed in dopamine-rich regions in HIV+ individuals. These changes, which are seen despite the use antiretroviral therapy (ART), in turn lead to further dysregulation of the dopamine system. Thus, in individuals with elevated dopamine, the bi-directional interaction between aberrant dopaminergic neurotransmission and HIV infection creates a feedback loop contributing to HIV associated neurocognitive dysfunction and neuroHIV. However, the distinct contributions and interactions made by HIV infection, inflammatory mediators, ART, drugs of abuse, and age-related therapeutics are poorly understood. Defining more precisely the mechanisms by which these factors influence the development of neurological disease is critical to addressing the continued presence of neuroHIV in vulnerable populations, such as HIV-infected older adults or drug abusers. Due to the complexity of this system, understanding these effects will require a combination of novel experimental modalities in the context of ART. These will include more rigorous epidemiological studies, relevant animal models, and in vitro cellular and molecular mechanistic analysis.

DNA methylation mediates the effect of cocaine use on HIV severity

Background

Cocaine use accelerates human immunodeficiency virus (HIV) progression and worsens HIV outcomes. We assessed whether DNA methylation in blood mediates the association between cocaine use and HIV severity in a veteran population.

Methods

We analyzed 1435 HIV-positive participants from the Veterans Aging Cohort Study Biomarker Cohort (VACS-BC). HIV severity was measured by the Veteran Aging Cohort Study (VACS) index. We assessed the effect of cocaine use on VACS index and mortality among the HIV-positive participants. We selected candidate mediators that were associated with both persistent cocaine use and VACS index by epigenome-wide association (EWA) scans at a liberal p value cutoff of 0.001. Mediation analysis of the candidate CpG sites between cocaine’s effect and the VACS index was conducted, and the joint mediation effect of multiple CpGs was estimated. A two-step epigenetic Mendelian randomization (MR) analysis was conducted as validation.

Results

More frequent cocaine use was significantly associated with a higher VACS index (β = 1.00, p = 2.7E−04), and cocaine use increased the risk of 10-year mortality (hazard ratio = 1.10, p = 0.011) with adjustment for confounding factors. Fifteen candidate mediator CpGs were selected from the EWA scan. Twelve of these CpGs showed significant mediation effects, with each explaining 11.3–29.5% of the variation. The mediation effects for 3 of the 12 CpGs were validated by the two-step epigenetic MR analysis. The joint mediation effect of the 12 CpGs accounted for 47.2% of cocaine’s effect on HIV severity. Genes harboring these 12 CpGs are involved in the antiviral response (IFIT3, IFITM1, NLRC5, PLSCR1, PARP9) and HIV progression (CX3CR1, MX1).

Conclusions

We identified 12 DNA methylation CpG sites that appear to play a mediation role in the association between cocaine use and HIV severity.

Role of Inflammasomes in HIV-1 and Drug Abuse Mediated Neuroinflammaging

Despite the effectiveness of combined antiretroviral therapy (cART) in suppressing virus replication, chronic inflammation remains one of the cardinal features intersecting HIV-1, cART, drug abuse, and likely contributes to the accelerated neurocognitive decline and aging in people living with HIV-1 (PLWH) that abuse drugs. It is also estimated that ~30–60% of PLWH on cART develop cognitive deficits associated with HIV-1-associated neurocognitive disorders (HAND), with symptomatology ranging from asymptomatic to mild, neurocognitive impairments. Adding further complexity to HAND is the comorbidity of drug abuse in PLWH involving activated immune responses and the release of neurotoxins, which, in turn, mediate neuroinflammation. Premature or accelerated aging is another feature of drug abusing PLWH on cART regimes. Emerging studies implicate the role of HIV-1/HIV-1 proteins, cART, and abused drugs in altering the inflammasome signaling in the central nervous system (CNS) cells. It is thus likely that exposure of these cells to HIV-1/HIV-1 proteins, cART, and/or abused drugs could have synergistic/additive effects on the activation of inflammasomes, in turn, leading to exacerbated neuroinflammation, ultimately resulting in premature aging referred to as “inflammaging” In this review, we summarize the current knowledge of inflammasome activation, neuroinflammation, and aging in central nervous system (CNS) cells such as microglia, astrocytes, and neurons in the context of HIV-1 and drug abuse.

Longitudinal patterns of illicit drug use, antiretroviral therapy exposure and plasma HIV-1 RNA viral load among HIV-positive people who use illicit drugs

OBJECTIVES

HIV-positive people who use illicit drugs (PWUD) experience elevated rates of HIV-associated morbidity and mortality compared with members of other key affected populations. Although suboptimal levels of access and adherence to antiretroviral therapy (ART) are common among HIV-positive PWUD, there is a need for studies investigating the possible biological impacts of noninjection illicit drug use among people living with HIV in real-world settings.

METHODS

We accessed data from the ACCESS study, an ongoing prospective cohort of illicit drug users with systematic HIV viral load monitoring in a setting with universal care and ART dispensation records. We used multivariable generalized linear mixed models to estimate the longitudinal associations between noninjection use of crack cocaine, powder cocaine, opioids, methamphetamine, cannabis and alcohol on plasma HIV-1 RNA viral load, adjusted for ART exposure and relevant confounders.

RESULTS

Between 2005 and 2018, 843 individuals from the ACCESS cohort were included and contributed to 8698 interviews. At baseline, the mean age was 43 years, 566 (67%) reported male sex and 659 (78%) used crack cocaine in the previous 6 months. In multivariable models adjusted for ART exposure, only crack cocaine use in the last 6 months was found to be significantly associated with higher HIV viral load.

CONCLUSION

We observed significantly higher HIV viral load during periods of crack cocaine use independent of ART exposure. Our findings support further research to investigate the possible biological mechanisms of this effect.

Inhibition of the Dead Box RNA Helicase 3 Prevents HIV-1 Tat and Cocaine-Induced Neurotoxicity by Targeting Microglia Activation

HIV-1 Associated Neurocognitive Disorder (HAND) is a common and clinically detrimental complication of HIV infection. Viral proteins, including Tat, released from infected cells, cause neuronal toxicity. Substance abuse in HIV-infected patients greatly influences the severity of neuronal damage. To repurpose small molecule inhibitors for anti-HAND therapy, we employed MOLIERE, an AI-based literature mining system that we developed. All human genes were analyzed and prioritized by MOLIERE to find previously unknown targets connected to HAND. From the identified high priority genes, we narrowed the list to those with known small molecule ligands developed for other applications and lacking systemic toxicity in animal models. To validate the AI-based process, the selective small molecule inhibitor of DDX3 helicase activity, RK-33, was chosen and tested for neuroprotective activity. The compound, previously developed for cancer treatment, was tested for the prevention of combined neurotoxicity of HIV Tat and cocaine. Rodent cortical cultures were treated with 6 or 60 ng/ml of HIV Tat and 10 or 25 μM of cocaine, which caused substantial toxicity. RK-33 at doses as low as 1 μM greatly reduced the neurotoxicity of Tat and cocaine. Transcriptome analysis showed that most Tat-activated transcripts are microglia-specific genes and that RK-33 blocks their activation. Treatment with RK-33 inhibits the Tat and cocaine-dependent increase in the number and size of microglia and the proinflammatory cytokines IL-6, TNF-α, MCP-1/CCL2, MIP-2, IL-1α and IL-1β. These findings reveal that inhibition of DDX3 may have the potential to treat not only HAND but other neurodegenerative diseases. Graphical Abstract RK-33, selective inhibitor of Dead Box RNA helicase 3 (DDX3) protects neurons from combined Tat and cocaine neurotoxicity by inhibition of microglia activation and production of proinflammatory cytokines.

A client-centered relational framework on barriers to the integration of HIV and substance use services: a systematic review

Background

Given the close connection between human immunodeficiency virus (HIV) infection and substance use disorder (SUD), access to integrated HIV and SUD services is critical for individuals experiencing both challenges and their biopsychosocial conditions.

Method

Adopting an integrative method, this systematic review included 23 empirical studies published between 2000 and 2018. Articles investigated providers’ and clients’ perspectives on barriers to accessing integrated HIV and SUD services in various service settings (e.g., HIV primary care, SUD treatment, pharmacy).

Results

Using a client-centered relational framework, we identified barriers in three relational domains with “the client” as the focus of each: client-provider, client-organization, and client-system. The review shows that (1) barriers to HIV and SUD services do not exist in isolation, but in the dynamics within and across three relational domains; (2) service providers and clients often have different perceptions about what constitutes a barrier and the origin of such barriers; and (3) interprofessional and interorganizational collaborations are crucial for integrating HIV and SUD services.

Conclusion

This review points out the limitations of the conventional paradigm grouping barriers to service integration into isolated domains (client, provider, organization, or system). Reforms in service arrangements and provider training are recommended to address barriers to integrated services.

Distinct inflammatory profiles in HIV-infected individuals under antiretroviral therapy using cannabis, cocaine or cannabis plus cocaine

OBJECTIVES

To evaluate the effects of cannabis and/or cocaine use on inflammatory, oxidative stress status and circulating monocyte subsets in HIV-infected individuals under antiretroviral therapy.

DESIGN

Soluble CD14 (sCD14), intestinal fatty acid-binding protein (IFABP), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-8, IL-10, C-reactive protein (CRP) and oxidative stress markers were examined. The monocyte subsets and their activation and cytokine production by peripheral blood mononuclear cells (PBMCs) of HIV-1 infected individuals upon lipopolysaccharide (LPS)-stimulation were also investigated.

METHODS

sCD14, IFABP, TNF-α, IL-6, IL-8 and IL-10 levels were evaluated using ELISA, CRP by turbidimetry; lipid peroxidation (TBARS) spectrofluometrically and total thiol levels by using 5-5'-dithio-bis (2-nitrobenzoic acid) reagent. Monocyte subsets and activation were assessed by flow cytometry.

RESULTS

All HIV-infected drug user groups showed higher sCD14 levels compared with HIV+ nondrug users. IFABP was increased in HIV+ drug-users in relation to healthy individuals. Cannabis use lowered the percentages of inflammatory, nonclassical, activated-classic and activated-inflammatory monocytes. Cocaine users showed increased plasmatic TNF-α and TBARS levels, decreased thiols content and lower activated-classic and inflammatory-monocyte percentages. Cannabis-plus-cocaine use increased CRP, IL-8 and IL-6/IL-10 ratio, but decreased thiol content, and inflammatory and activated-classic monocyte percentages. PBMCs of cannabis and cannabis-plus-cocaine users showed low-potential cytokine production either spontaneously or under LPS-stimulation.

CONCLUSION

In HIV infection, the use of cannabis induces predominantly an anti-inflammatory profile. The use of cocaine and cannabis-plus-cocaine showed a mixed pro-inflammatory and anti-inflammatory profile, with predominance of inflammatory status. Further studies are required to better understand the action of these drugs in HIV infection.

Double dissociation of HIV and substance use disorder effects on neurocognitive tasks dependent on striatal integrity

OBJECTIVE

Substance use is common among individuals infected with HIV, yet whether neurocognitive effects of HIV can be distinguished from more nonspecific effects of drug dependence and associated comorbidities is not known.

DESIGN

Cross-sectional observational study of neurocognitive function among HIV-infected and uninfected individuals with and without substance use disorders (SUDs).

METHODS

We compared the performance of 458 (31% HIV-infected) substance-dependent individuals (SDIs) and 90 individuals (23% HIV-infected) with no history of SUDs on measures of delay discounting and probability learning, tasks, which are differentially sensitive to addictive processes and HIV serostatus, respectively.

RESULTS

In factorial analyses of covariance adjusted for age, years of education, and sex, we found that SDIs showed significantly higher rates of delay discounting, regardless of HIV serostatus (P < 0.05). Conversely, HIV-infected individuals performed significantly more poorly on probability learning compared with uninfected groups, regardless of SUD history (P < 0.05).

CONCLUSION

Theory-driven cognitive neuropsychological tasks may have the capacity to detect neurocognitive effects of HIV not attributable solely to substance use; evidence from functional neuroimaging studies with more selective neurocognitive probes will be critical for hypothesis testing and mapping underlying brain systems more precisely.

A Mechanistic and Pathophysiological Approach for Stroke Associated with Drugs of Abuse

Drugs of abuse are associated with stroke, especially in young individuals. The major classes of drugs linked to stroke are cocaine, amphetamines, heroin, morphine, cannabis, and new synthetic cannabinoids, along with androgenic anabolic steroids (AASs). Both ischemic and hemorrhagic stroke have been reported due to drug abuse. Several common mechanisms have been identified, such as arrhythmias and cardioembolism, hypoxia, vascular toxicity, vascular spasm and effects on the thrombotic mechanism, as causes for ischemic stroke. For hemorrhagic stroke, acute hypertension, aneurysm formation/rupture and angiitis-like changes have been implicated. In AAS abuse, the effect of blood pressure is rather substance specific, whereas increased erythropoiesis usually leads to thromboembolism. Transient vasospasm, caused by synthetic cannabinoids, could lead to ischemic stroke. Opiates often cause infective endocarditis, resulting in ischemic stroke and hypereosinophilia accompanied by pyogenic arthritis, provoking hemorrhagic stroke. Genetic variants are linked to increased risk for stroke in cocaine abuse. The fact that case reports on cannabis-induced stroke usually refer to the young population is very alarming.

Cocaine Mediated Neuroinflammation: Role of Dysregulated Autophagy in Pericytes

Cocaine, a known psychostimulant, results in oxidative stress and inflammation. Recent studies from our group have shown that cocaine induces inflammation in glial cells. Our current study was aimed at investigating whether cocaine exposure could also induce inflammation in non-glial cells such as the pericytes with a focus on the endoplasmic reticulum (ER) stress/autophagy axis. Our in vitro findings demonstrated that exposure of pericytes to cocaine resulted in upregulation of the pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in both the intracellular as well as extracellular compartments, thus underpinning pericytes as yet another source of neuroinflammation. Cocaine exposure of pericytes resulted in increased formation of autophagosomes as demonstrated by a time-dependent increase of autophagy markers, with a concomitant defect in the fusion of the autophagosome with the lysosomes. Pharmacological blocking of the sigma 1 receptor underscored its role in cocaine-mediated activation of pericytes. Furthermore, it was also demonstrated that cocaine-mediated dysregulation of autophagy involved upstream activation of the ER stress pathways, with a subsequent downstream production of pro-inflammatory cytokines in pericytes. These findings were also validated in an in vivo model wherein pericytes in the isolated brain microvessels of cocaine injected mice (7 days) exhibited increased expression of both the autophagy marker-LC3 as well as the pro-inflammatory cytokine, IL-6. This is the first report describing the role of pericytes in cocaine-mediated neuroinflammation. Interventions aimed at blocking either the sigma-1 receptor or the upstream ER stress mediators could likely be envisioned as promising therapeutic targets for abrogating cocaine-mediated inflammation in pericytes.

Heart failure and adverse heart failure outcomes among persons living with HIV in a US tertiary medical center

BACKGROUND

Persons living with HIV (PLHIV) have an increased risk of heart failure (HF). However, little is known about outcomes among PLHIV with HF. The study aim was to compare HF outcomes among PLHIV with HF versus individuals without HIV with HF.

METHODS

Our cohort included 2,308 individuals admitted with decompensated HF. We compared baseline characteristics, 30-day HF readmission, and cardiovascular (CV) and all-cause mortality. Within PLHIV, we assessed outcomes stratified between CD4 count and viral load (VL), and tested the association between traditional and HIV-specific parameters with 30-day HF readmission.

RESULTS

There were 374 (16%) PLHIV with HF. Among PLHIV, 92% were on antiretroviral therapy and 63% had a VL <200 copies/mL. Groups were similar with respect to age, sex, race/ethnicity, and CV risk factors. In follow-up, PLHIV had increased 30-day HF readmission (49% vs 32%) and CV (26% vs 13.5%) and all-cause mortality rates (38% vs 22%). Among PLHIV, cocaine use, HIV-specific parameters (CD4, VL), and coronary artery disease were predictors of 30-day HF readmission. Specifically, among PLHIV, those with detectable VL had higher 30-day HF readmission and CV mortality, whereas PLHIV with undetectable VL had a similar 30-day HF readmission rate and CV mortality to uninfected controls with HF. Similar outcomes were observed across strata of left ventricular ejection fraction and by CD4.

CONCLUSIONS

PLHIV with a low CD4 count or detectable VL have an increased 30-day HF readmission rate as well as increased CV and all-cause mortality. In contrast, PLHIV with a higher CD4 count and undetectable VL have similar HF outcomes to uninfected controls.

Substance use is independently associated with pneumonia severity in persons living with the human immunodeficiency virus (HIV)

Background: Pneumonia is common in persons living with the human immunodeficiency virus (HIV) (PLWH). Alcohol, cocaine, and marijuana impact pneumonia pathogenesis. We hypothesized that substance use was independently associated with pneumonia severity in PLWH and modified the effect of alcohol on pneumonia severity. Methods: Retrospective data analysis of PLWH admitted with a diagnosis of pneumonia was conducted. Alcohol use disorder was defined by the Alcohol Use Disorders Identification Test score ≥14. Drug use was quantified by self-report. Pneumonia severity was defined by the pneumonia severity index (PSI). Multivariable linear regression was used to test independent associations with pneumonia severity and effect modification by sex. Results: Of 196 PLWH, the mean age was 44 (SD = 9) years and the majority were men (71%). Ten percent (n = 19) of subjects met criteria for an alcohol use disorder (AUD). In subjects reporting alcohol use, 25% reported concomitant crack/cocaine use and 16% reported marijuana use. PSI scores were higher with lifetime use of crack/cocaine (mean PSI: 63.1 vs. 57.3, P = .06) and/or injection drug use (68.4 vs. 54.9, P = .04). PSI scores were lower with active marijuana use (51.5 vs. 62.2, P = .01). There was no significant difference in clinical outcomes. Sex modified the effect of drug use on PSI, with greater PSI scores in women with an AUD (β = 58.1, 95% confidence interval [CI]: 46.7 to 69.5, P < .01), whereas active marijuana use mitigated the effect of AUD on PSI in men (β = -12.7, 95% CI: -18.8 to -6.6, P < .01). Conclusions: Active alcohol and/or crack/cocaine use was associated with increased pneumonia severity in PLWH, with less severe pneumonia with marijuana use. Alcohol and marijuana effects on pneumonia severity differed by sex, with increased PSI in women and decreased PSI in men with concomitant marijuana and AUD.

A Novel Role of Prolidase in Cocaine-Mediated Breach in the Barrier of Brain Microvascular Endothelial Cells

Cocaine use is associated with breach in the blood brain barrier (BBB) and increased HIV-1 neuro-invasion. We show that the cellular enzyme "Prolidase" plays a key role in cocaine-induced disruption of the BBB. We established a barrier model to mimic the BBB by culturing human brain microvascular endothelial cells (HBMECs) in transwell inserts. In this model, cocaine treatment enhanced permeability of FITC-dextran suggesting a breach in the barrier. Interestingly, cocaine treatment increased the activity of matrix metallo-proteinases that initiate degradation of the BBB-associated collagen. Cocaine exposure also induced prolidase expression and activity in HBMECs. Prolidase catalyzes the final and rate-limiting step of collagen degradation during BBB remodeling. Knock-down of prolidase abrogated cocaine-mediated increased permeability suggesting a direct role of prolidase in BBB breach. To decipher the mechanism by which cocaine regulates prolidase, we probed the inducible nitric oxide synthase (iNOS) mediated phosphorylation of prolidase since mRNA levels of the protein were not altered upon cocaine treatment. We observed increased iNOS expression concurrent with increased prolidase phosphorylation in cocaine treated cells. Subsequently, inhibition of iNOS decreased prolidase phosphorylation and reduced cocaine-mediated permeability. Finally, cocaine treatment increased transmigration of monocytic cells through the HBMEC barrier. Knock-down of prolidase reduced cocaine-mediated monocyte transmigration, establishing a key role of prolidase in cocaine-induced breach in endothelial cell barrier.

Cocaine-induced release of CXCL10 from pericytes regulates monocyte transmigration into the CNS

Cocaine is known to facilitate the transmigration of inflammatory leukocytes into the brain, an important mechanism underlying neuroinflammation. Pericytes are well-recognized as important constituents of the blood-brain barrier (BBB), playing a key role in maintaining barrier integrity. In the present study, we demonstrate for the first time that exposure of human brain vascular pericytes to cocaine results in enhanced secretion of CXCL10, leading, in turn, to increased monocyte transmigration across the BBB both in vitro and in vivo. This process involved translocation of σ-1 receptor (σ-1R) and interaction of σ-1R with c-Src kinase, leading to activation of the Src-PDGFR-β-NF-κB pathway. These findings imply a novel role for pericytes as a source of CXCL10 in the pericyte-monocyte cross talk in cocaine-mediated neuroinflammation, underpinning their role as active components of the innate immune responses.

Baseline Cigarette Smoking Status as a Predictor of Virologic Suppression and CD4 Cell Count During One-Year Follow-Up in Substance Users with Uncontrolled HIV Infection

Cigarette smoking is prevalent in people living with HIV/AIDS (PLHIV) who abuse alcohol and/or illicit substances. This study evaluated whether smoking is predictive of virologic non-suppression (> 200 copies/mL) and low CD4 count (< 200 cells/mm³) during 1-year follow-up in medically hospitalized, substance-using PLHIV recruited for a multi-site trial. Smoking status was assessed with the Heaviness of Smoking Index (HSI). Analyses revealed that, controlling for baseline differences and adherence to antiretroviral therapy, non-smokers (n = 237), compared to smokers scoring in the medium-to-high range on the HSI (n = 386), were significantly more likely to achieve viral suppression (OR 1.50, 95% CI 1.02, 2.20). There was a significant smoking-by-time interaction for CD4 cell count (χ²(1) = 4.08, p < .05), with smokers less likely to have low CD4 count at baseline and 6-month follow-up, but more likely to have low CD4 count at 12-month follow-up. The results suggest that smoking may play a role in immunological functioning in HIV-infected substance users. ClinicalTrials.gov Identifier: NCT01612169.

Granulocyte-colony stimulating factor controls neural and behavioral plasticity in response to cocaine

Cocaine addiction is characterized by dysfunction in reward-related brain circuits, leading to maladaptive motivation to seek and take the drug. There are currently no clinically available pharmacotherapies to treat cocaine addiction. Through a broad screen of innate immune mediators, we identify granulocyte-colony stimulating factor (G-CSF) as a potent mediator of cocaine-induced adaptations. Here we report that G-CSF potentiates cocaine-induced increases in neural activity in the nucleus accumbens (NAc) and prefrontal cortex. In addition, G-CSF injections potentiate cocaine place preference and enhance motivation to self-administer cocaine, while not affecting responses to natural rewards. Infusion of G-CSF neutralizing antibody into NAc blocks the ability of G-CSF to modulate cocaine's behavioral effects, providing a direct link between central G-CSF action in NAc and cocaine reward. These results demonstrate that manipulating G-CSF is sufficient to alter the motivation for cocaine, but not natural rewards, providing a pharmacotherapeutic avenue to manipulate addictive behaviors without abuse potential.

Cocaine Enhances DC to T-cell HIV-1 Transmission by Activating DC-SIGN/LARG/LSP1 Complex and Facilitating Infectious Synapse Formation

DC-SIGN is a dendritic cell surface structure which participates in binding and transmission of HIV-1. Here, for the first time we demonstrate that cocaine induces over expression of DC-SIGN and significantly enhances virus transfer from DCs to T-cells by increasing the binding and internalization of HIV-1 in DCs. We found that cocaine activates a DC-SIGN mediated 'signalosome' complex by enhancing its association with LARG and LSP1. Further, LARG was observed to participate in DC-SIGN mediated internalization of HIV-1 in DCs. Intracellular trafficking studies of HIV-1 in cocaine treated DCs revealed increased co-localization of HIV-1 with endosomal or multi vesicular body (MVB) markers such as CD81 and VPS4 and decreased co-localization with the phagolysomal marker LAMP1; this signified altered intracellular trafficking and decreased degradation of HIV-1 in cocaine treated DCs. Furthermore, we found that cocaine induced activation of LARG which in turn activated Rho A and the focal adhesion molecules FAK, Pyk2 and paxillin. This signaling cascade enhanced the formation of an infectious synapse between DCs and T-cells. Our study provides insight into the molecular mechanisms of cocaine's contribution to key components in HIV pathogenesis and highlights novel targets for interrupting the virus life cycle in substance using hosts.