Bidirectional Associations among Nicotine and Tobacco Smoke, NeuroHIV, and Antiretroviral Therapy

Contributions of chronic tobacco smoking to HIV-associated brain atrophy and cognitive deficits

OBJECTIVES

Tobacco smoking is linked to cognitive deficits and greater white matter (WM) abnormalities in people with HIV disease (PWH). Whether tobacco smoking additionally contributes to brain atrophy in PWH is unknown and was evaluated in this study.

DESIGN

We used a 2 × 2 design that included 83 PWH (43 nonsmokers, 40 smokers) and 171 HIV-seronegative (SN, 106 nonsmokers, 65 smokers) participants and assessed their brain structure and cognitive function.

METHODS

Selected subcortical volumes, voxel-wise cortical volumes and thickness, and total WM volume were analyzed using FreeSurfer. Independent and interactive effects of HIV and smoking were evaluated with two-way analysis of covariance on cognitive domain Z-scores and morphometric measures on T1-weighted MRI.

RESULTS

Regardless of smoking status, relative to SN, PWH had smaller brain volumes [basal ganglia, thalami, hippocampi, subcortical gray matter (GM) and cerebral WM volumes (P = 0.002-0.042)], steeper age-related declines in the right superior-parietal (interaction: P < 0.001) volumes, and poorer attention/working memory and learning (P = 0.016-0.027). Regardless of HIV serostatus, smokers tended to have smaller hippocampi than nonsmokers (-0.6%, P = 0.055). PWH smokers had the smallest total and regional subcortical GM and cortical WM volume and poorest cognitive performance.

CONCLUSIONS

Tobacco smoking additionally contributed to brain atrophy and cognitive deficits in PWH. The greater brain atrophy in PWH smokers may be due to greater neuronal damage or myelin loss in various brain regions, leading to their poor cognitive performance. Therefore, tobacco smoking may exacerbate or increase the risk for HIV-associated neurocognitive disorders.

The effect of art therapy on reoccurring smoking among youths

OBJECTIVE

To evaluate the effect of art therapy on reoccurring smoking among youths.

METHODS

A total of 114 smokers admitted to the smoking cessation clinic of our hospital were enrolled and randomly divided into the control group (n=61) and the study group (n=53). The control group was given health education intervention, and the study group was given art therapy intervention. The blood lipid level, symptom checklist score, lung function, and high-density lipoprotein cholesterol (HDL-C) and serum total cholesterol (TC) levels of different length of smoking were compared between the two groups.

RESULTS

The levels of low-density lipoprotein cholesterol (LDL-C), TC, triglycerides (TG), HDL-C were significantly reduced in both groups, but compared with the control group, the LDL-C, TC, TG, and HDL-C levels of the study group were decreased more significantly, and the difference was statistically significant (P<0.05). The symptom checklist scores were significantly reduced in both groups, but compared with the control group, the study group decreased more significantly, and the difference was statistically significant (P<0.05). There were significant differences in HDL-C levels among young smokers who had different length of smoking (P<0.05), and with the continuous increase in smoking years, HDL-C levels were significantly reduced. After intervention, lung function was significantly improved, and the levels of vital capacity (VC%) and forced expiratory volume in the first second (FEV1%) were significantly increased (P<0.05). After intervention, the smoking reduction rate and the success rate of time-point smoking cessation were significantly reduced (P<0.05).

CONCLUSION

Art therapy intervention had an ideal effect on young smokers, which could improve blood lipid levels and lung function, reduce the rate of reoccurring smoking, and significantly increase patients' symptom checklist score.

Dolutegravir Inhibition of Matrix Metalloproteinases Affects Mouse Neurodevelopment

Dolutegravir (DTG) is a first-line antiretroviral drug (ARV) used in combination therapy for the treatment of human immunodeficiency virus type-1 (HIV-1) infection. The drug is effective, safe, and well tolerated. Nonetheless, concerns have recently emerged for its usage in pregnant women or those of child-bearing age. Notably, DTG-based ARV regimens have been linked to birth defects seen as a consequence of periconceptional usages. To this end, uncovering an underlying mechanism for DTG-associated adverse fetal development outcomes has gained clinical and basic research interest. We now report that DTG inhibits matrix metalloproteinases (MMPs) activities that could affect fetal neurodevelopment. DTG is a broad-spectrum MMPs inhibitor and binds to Zn⁺⁺ at the enzyme’s catalytic domain. Studies performed in pregnant mice show that DTG readily reaches the fetal central nervous system during gestation and inhibits MMP activity. Postnatal screenings of brain health in mice pups identified neuroinflammation and neuronal impairment. These abnormalities persist as a consequence of in utero DTG exposure. We conclude that DTG inhibition of MMPs activities during gestation has the potential to affect prenatal and postnatal neurodevelopment.

Changes in salivary proteome before and after cigarette smoking in smokers compared to sham smoking in nonsmokers: A pilot study

INTRODUCTION

Smoking is the leading cause of preventable disease. Although smoking results in an acute effect of relaxation and positive mood through dopamine release, smoking is thought to increase stress symptoms such as heart rate and blood pressure from nicotine-induced effects on the HPA axis and increased cortisol. Despite the importance in understanding the mechanisms in smoking maintenance, little is known about the overall protein and physiological response to smoking. There may be multiple functions involved that if identified might help in improving methods for behavioral and pharmacological interventions. Therefore, our goal for this pilot study was to identify proteins in the saliva that change in response to an acute smoking event versus acute sham smoking event in smokers and non-smokers, respectively.

METHODS

We employed the iTRAQ technique followed by Mass Spectrometry to identify differentially expressed proteins in saliva of smokers and non-smokers after smoking cigarettes and sham smoking, respectively. We also validated some of the salivary proteins by ELISA or western blotting. In addition, salivary cortisol and salivary amylase (sAA) activity were measured.

RESULTS

In all, 484 salivary proteins were identified. Several proteins were elevated as well as decreased in smokers compared to non-smokers. Among these were proteins associated with stress response including fibrinogen alpha, cystatin A and sAA. Our investigation also highlights methodological considerations in study design, sampling and iTRAQ analysis.

CONCLUSIONS

We suggest further investigation of other differentially expressed proteins in this study including ACBP, A2ML1, APOA4, BPIB1, BPIA2, CAH1, CAH6, CYTA, DSG1, EST1, GRP78, GSTO1, sAA, SAP, STAT, TCO1, and TGM3 that might assist in improving methods for behavioral and pharmacological interventions for smokers.

Evaluation of an integrated treatment to address smoking cessation and anxiety/depressive symptoms among people living with HIV: Study protocol for a randomized controlled trial

BACKGROUND

Interventions that target anxiety/depressive symptoms in the context of smoking treatment have shown promise irrespective of psychiatric diagnosis. Yet, these tailored treatments are largely absent for persons who smoke and are living with HIV (SLWH).

OBJECTIVE

To evaluate a novel, smoking cessation intervention that addresses anxiety/depression and HIV-related health (QUIT) against a time-matched control (TMC) and a standard of care (SOC) condition.

METHODS

SLWH (N = 180) will be recruited and enrolled from 3 medical clinics in Boston, MA, and Houston, TX. The trial will consist of a baseline assessment, a 10-week intervention/assessment period, and follow-up assessments, accounting for a total study duration of approximately 8 months. All participants will complete a baseline visit and a pre-randomization standardized psychoeducation visit, and will then be randomized to one of three conditions: QUIT, TMC, or SOC. QUIT and TMC will consist of nine 60-min, cognitive behavioral therapy-based, individual weekly counseling sessions using standard smoking cessation counseling; additionally, QUIT will target anxiety and depressive symptoms by addressing underlying mechanisms related to mood and quit difficulty. SOC participants will complete weekly self-report surveys for nine weeks. All participants will be encouraged to quit at Session 7 and will be offered nicotine replacement therapy to help.

CONCLUSIONS

QUIT is designed to improve smoking cessation in SLWH by addressing anxiety and depression and HIV-related health issues. If successful, the QUIT intervention would be ready for implementation and dissemination into "real-world" behavioral health and social service settings consistent with the four objectives outlined in NIDA's Strategic Plan.

Neuroimaging the Neuropathogenesis of HIV

PURPOSE OF REVIEW

This review highlights neuroimaging studies of HIV conducted over the last 2 years and discusses how relevant findings further our knowledge of the neuropathology of HIV. Three major avenues of neuroimaging research are covered with a particular emphasis on inflammation, aging, and substance use in persons living with HIV (PLWH).

RECENT FINDINGS

Neuroimaging has been a critical tool for understanding the neuropathological underpinnings observed in HIV. Recent studies comparing levels of neuroinflammation in PLWH and HIV-negative controls show inconsistent results but report an association between elevated neuroinflammation and poorer cognition in PLWH. Other recent neuroimaging studies suggest that older PLWH are at increased risk for brain and cognitive compromise compared to their younger counterparts. Finally, recent findings also suggest that the effects of HIV may be exacerbated by alcohol and drug abuse. These neuroimaging studies provide insight into the structural, functional, and molecular changes occurring in the brain due to HIV. HIV triggers a strong neuroimmune response and may lead to a cascade of events including increased chronic inflammation and cognitive decline. These outcomes are further exacerbated by age and age-related comorbidities, as well as lifestyle factors such as drug use/abuse.

Cytochrome P450 2A6 is associated with macrophage polarization and is a potential biomarker for hepatocellular carcinoma

Cytochrome P450 2A6 (CYP2A6) is an important metabolic enzyme and is involved in the progression of hepatocellular carcinoma (HCC). However, its specific function and the mechanism of modulation remain to be elucidated. In this study, we found that CYP2A6 is dramatically downregulated in HCC. CYP2A6 expression is closely associated with pathological grading, histologic grade, hepatitis, vascular metastasis, liver inflammation, and worse prognosis. Reduced expression of CYP2A6 contributes to alternative activation of macrophage polarization and impairs macrophage maturation and phagocytosis. Mechanistically, CYP2A6 participates in arachidonic acid metabolism, initiates 20‐hydroxyeicosatetraenoic acid (HETE) generation, and inhibits epoxyeicosatrienoic acid (EET) generation. Disruption of the equilibrium between 20‐HETE and EETs can induce macrophage polarization, thereby modulating antitumor immunity.

The relationship of smoking and unhealthy alcohol use to the HIV care continuum among people with HIV in an integrated health care system

INTRODUCTION

Smoking tobacco and unhealthy alcohol use may negatively influence HIV care continuum outcomes but have not been examined in combination.

METHODS

Participants were people with HIV (PWH) in Kaiser Permanente Northern California. Predictors included smoking status and unhealthy alcohol use (exceeding daily and/or weekly limits) reported by patients during primary care screening (index date). Outcomes were based on not achieving the following steps in the care continuum: linkage to HIV care (≥1 visit within 90 days of newly identified HIV diagnosis), retention (2+ in-person visits, 60+ days apart) and HIV RNA control (<75 copies/mL). Adjusted odds ratios (ORs) were obtained from separate logistic regression models for each outcome associated with smoking and unhealthy alcohol use independently and combined.

RESULTS

The overall sample (N = 8958) had a mean age of 48.0 years; was 91.3 % male; 54.0 % white, 17.6 % Latino, 15.1 % black, and 9.6 % other race/ethnicity. Smoking was associated with higher odds of not being linked to HIV care (OR = 1.60 [95 % CI 1.03-2.48]), not retained (OR = 1.30 [95 % CI 1.13-1.50]), and HIV RNA not in control (OR = 1.91 [95 % CI 1.60-2.27]). Alcohol measures were not independently associated with outcomes. The combination of unhealthy alcohol use and smoking (versus neither) was associated with higher odds of not being linked to care (OR = 2.83 [95 % CI 1.40-5.71]), although the interaction did not reach significance (p = 0.18).

CONCLUSIONS

In this large sample of PWH in an integrated health care system, smoking, both independently and in combination with unhealthy alcohol use, was associated with worse HIV care continuum outcomes.

Unraveling neuroHIV in the Presence of Substance Use Disorders

This special issue contains 10 invited review papers that highlighted and extended the presentations at the NIDA-sponsored workshop "Unraveling NeuroAIDS in the Presence of Substance Use Disorders" at the 25th Society on NeuroImmune Pharmacology conference in 2019. The topics covered by these papers focused on the interactive, additive or synergistic effects of substance use disorders (SUD) with HIV infection on the immune system and on neuropathogenesis. These papers reviewed four categories of substances of abuse (opioids, tobacco, stimulants, and cannabis) and how comorbid HIV infection (including models with HIV proteins, HIV transgenic rodent models and SIV) might further impact the dysregulated dopaminergic and immune systems, and the subsequent neuropathogenesis and behavioral disorders known as HIV-associated neurological disorders (HAND). These reviews provided detailed background knowledge regarding how each of these addictive substances and HIV individually or collectively affected the immune system at the cellular, molecular and system levels, and the subsequent clinical and behavioral outcomes. The authors also identified gaps, confounds or constraints in the current disease models and approaches, and proposed future research directions.

Independent and Combined Effects of Nicotine or Chronic Tobacco Smoking and HIV on the Brain: A Review of Preclinical and Clinical Studies

Tobacco smoking is highly prevalent among HIV-infected individuals. Chronic smokers with HIV showed greater cognitive deficits and impulsivity, and had more psychopathological symptoms and greater neuroinflammation than HIV non-smokers or smokers without HIV infection. However, preclinical studies that evaluated the combined effects of HIV-infection and tobacco smoking are scare. The preclinical models typically used cell cultures or animal models that involved specific HIV viral proteins or the administration of nicotine to rodents. These preclinical models consistently demonstrated that nicotine had neuroprotective and anti-inflammatory effects, leading to cognitive enhancement. Although the major addictive ingredient in tobacco smoking is nicotine, chronic smoking does not lead to improved cognitive function in humans. Therefore, preclinical studies designed to unravel the interactive effects of chronic tobacco smoking and HIV infection are needed. In this review, we summarized the preclinical studies that demonstrated the neuroprotective effects of nicotine, the neurotoxic effects of the HIV viral proteins, and the scant literature on nicotine or tobacco smoke in HIV transgenic rat models. We also reviewed the clinical studies that evaluated the neurotoxic effects of tobacco smoking, HIV infection and their combined effects on the brain, including studies that evaluated the cognitive and behavioral assessments, as well as neuroimaging measures. Lastly, we compared the different approaches between preclinical and clinical studies, identified some gaps and proposed some future directions. Graphical abstract Independent and combined effects of HIV and tobacco/nicotine. Left top and bottom panels: Both clinical studies of HIV infected persons and preclinical studies using viral proteins in vitro or in vivo in animal models showed that HIV infection could lead to neurotoxicity and neuroinflammation. Right top and bottom panels: While clinical studies of tobacco smoking consistently showed deleterious effects of smoking, clinical and preclinical studies that used nicotine show mild cognitive enhancement, neuroprotective and possibly anti-inflammatory effects. In the developing brain, however, nicotine is neurotoxic. Middle overlapping panels: Clinical studies of persons with HIV who were smokers typically showed additive deleterious effects of HIV and tobacco smoking. However, in the preclinical studies, when nicotine was administered to the HIV-1 Tg rats, the neurotoxic effects of HIV were attenuated, but tobacco smoke worsened the inflammatory cascade.

An update on drug-drug interactions between antiretroviral therapies and drugs of abuse in HIV systems

INTRODUCTION

While considerable progress has been made in the fight against HIV/AIDS, to date there has not been a cure, and millions of people around the world are currently living with HIV/AIDS. People living with HIV/AIDS have substance abuse disorders at higher rates than non-infected individuals, which puts them at an increased risk of drug-drug interactions.

AREAS COVERED

Potential drug-drug interactions are reviewed for a variety of potential drugs of abuse, both licit and illicit. These drugs include alcohol, cigarettes or other nicotine delivery systems, methamphetamine, cocaine, opioids, and marijuana. Potential interactions include decreased adherence, modulation of drug transporters, or modulation of metabolic enzymes. We also review the relative incidence of the use of these drugs of abuse in People living with HIV/AIDS.

EXPERT OPINION

Despite considerable improvements in outcomes, disparities in outcomes between PLWHA who use drugs of abuse, vs those who do not still exist. It is of critical necessity to improve outcomes in these patients and to work with them to stop abusing drugs of abuse.

Tobacco smoke and morphine alter peripheral and CNS inflammation following HIV infection in a humanized mouse model

Tobacco smoking is common in HIV-infected patients, and is prevalent among intravenous opiate abusers. Conversely, intravenous opiate abusers are more likely HIV-infected, and opiate abuse is associated with more severe neuroinflammation. Given the coincident use of tobacco smoking among HIV-infected intravenous drug users (IVDUs), we set out to study the effects of smoke exposure, chronic morphine administration, and HIV infection using the NSG humanized mouse model. Our results show that smoke, morphine, and the combination promotes the decline in CD4+ T cells in HIV-infected mice. Further, chronic morphine administration increases the numbers of circulating CD8+ T cells which express the inhibitory receptor PD-1, as well as the cytolytic proteins perforin and granzyme B in the infected mice. We also found that the combination of smoke and morphine inhibited the expression of IL-1α, IL-4 and IL-17A. Finally, the combination of smoke and morphine exposure induces microglial activation following infection, as well as in the absence of HIV infection. To our knowledge, this is the first report to assess the combined effects of smoke and chronic morphine exposure on the inflammation associated with HIV infection, and demonstrate that these two insults exert significant neuroinflammatory activity.