Oxidative Stress and Antioxidant Capacity in Smoking and Nonsmoking Men With HIV/Acquired Immunodeficiency Syndrome

HIV-associated lung disease

Lung disease encompasses acute, infectious processes and chronic, non-infectious processes such as chronic obstructive pulmonary disease, asthma and lung cancer. People living with HIV are at increased risk of both acute and chronic lung diseases. Although the use of effective antiretroviral therapy has diminished the burden of infectious lung disease, people living with HIV experience growing morbidity and mortality from chronic lung diseases. A key risk factor for HIV-associated lung disease is cigarette smoking, which is more prevalent in people living with HIV than in uninfected people. Other risk factors include older age, history of bacterial pneumonia, Pneumocystis pneumonia, pulmonary tuberculosis and immunosuppression. Mechanistic investigations support roles for aberrant innate and adaptive immunity, local and systemic inflammation, oxidative stress, altered lung and gut microbiota, and environmental exposures such as biomass fuel burning in the development of HIV-associated lung disease. Assessment, prevention and treatment strategies are largely extrapolated from data from HIV-uninfected people. Smoking cessation is essential. Data on the long-term consequences of HIV-associated lung disease are limited. Efforts to continue quantifying the effects of HIV infection on the lung, especially in low-income and middle-income countries, are essential to advance our knowledge and optimize respiratory care in people living with HIV.

Trends in Comorbidities Among Human Immunodeficiency Virus-Infected Hospital Admissions in New York City from 2006-2016

BACKGROUND

Due to the advent and success of antiretroviral therapy, the number of people living and aging with human immunodeficiency virus (HIV) has grown substantially. Although people living with HIV (PLHIV) are experiencing longer life expectancies, this achievement may be undermined by increasing and disproportionate chronic disease burden among PLHIV.

METHODS

This study is a retrospective analysis of adult (≥18 years) inpatient hospital discharges from a large hospital system in the New York City, New York metropolitan area, between 1 January 2006 and 31 December 2016. We aimed to investigate (1) changes in the prevalence of Charlson-defined comorbidities among PLHIV hospitalized between 2006 and 2016 and (2) changes in the unadjusted prevalence ratio (PR) of comorbidities in HIV-positive versus HIV-negative admissions over time.

RESULTS

Of 898 139 hospital admissions from 2006-2016, 19 039 (2.1%) were HIV positive. Across all admissions during the study period, the greatest comorbidity disparities between HIV-positive and HIV-negative admissions were mild liver disease (PR, 4.9 [95% confidence interval, 4.8-5.1]), moderate or severe liver disease (PR, 2.2 [2.0-2.4]), and chronic pulmonary disease (PR, 1.8 [1.8-1.8]).

CONCLUSIONS

The prevalence and relative burden of comorbidities among hospitalized PLHIV are changing over time. Careful monitoring and intensive discharge planning may be effective strategies for addressing the evolving health needs of PLHIV.

Extracellular Vesicles in Smoking-Mediated HIV Pathogenesis and their Potential Role in Biomarker Discovery and Therapeutic Interventions

In the last two decades, the mortality rate in people living with HIV/AIDS (PLWHA) has decreased significantly, resulting in an almost normal longevity in this population. However, a large portion of this population still endures a poor quality of life, mostly due to an increased inclination for substance abuse, including tobacco smoking. The prevalence of smoking in PLWHA is consistently higher than in HIV negative persons. A predisposition to cigarette smoking in the setting of HIV potentially leads to exacerbated HIV replication and a higher risk for developing neurocognitive and other CNS disorders. Oxidative stress and inflammation have been identified as mechanistic pathways in smoking-mediated HIV pathogenesis and HIV-associated neuropathogenesis. Extracellular vesicles (EVs), packaged with oxidative stress and inflammatory agents, show promise in understanding the underlying mechanisms of smoking-induced HIV pathogenesis via cell-cell interactions. This review focuses on recent advances in the field of EVs with an emphasis on smoking-mediated HIV pathogenesis and HIV-associated neuropathogenesis. This review also provides an overview of the potential applications of EVs in developing novel therapeutic carriers for the treatment of HIV-infected individuals who smoke, and in the discovery of novel biomarkers that are associated with HIV-smoking interactions in the CNS.

Pathogenesis of HIV-Related Lung Disease: Immunity, Infection, and Inflammation

Despite anti-retroviral therapy (ART), human immunodeficiency virus-1 (HIV)-related pulmonary disease continues to be a major cause of morbidity and mortality for people living with HIV (PLWH). The spectrum of lung diseases has changed from acute opportunistic infections resulting in death to chronic lung diseases for those with access to ART. Chronic immune activation and suppression can result in impairment of innate immunity and progressive loss of T cell and B cell functionality with aberrant cytokine and chemokine responses systemically as well as in the lung. HIV can be detected in the lungs of PLWH and has profound effects on cellular immune functions. In addition, HIV-related lung injury and disease can occur secondary to a number of mechanisms including altered pulmonary and systemic inflammatory pathways, viral persistence in the lung, oxidative stress with additive effects of smoke exposure, microbial translocation, and alterations in the lung and gut microbiome. Although ART has had profound effects on systemic viral suppression in HIV, the impact of ART on lung immunology still needs to be fully elucidated. Understanding of the mechanisms by which HIV-related lung diseases continue to occur is critical to the development of new preventive and therapeutic strategies to improve lung health in PLWH.

Impact of Tobacco Smoke in HIV Progression: a Major Risk Factor for the Development of NeuroAIDS and Associated of CNS Disorders

Aim

With the advent of highly active and combination antiretroviral therapy have substantially increased the life expectancy of patients infected with human immunodeficiency virus (HIV). However, this has brought into sharp contrast the incidence of several 'Non-acquired immunodeficiency syndrome (AIDS) diseases such as NeuroAIDS which identifies a group of neurological disorders caused primarily by HIV-mediated damage to the central and peripheral nervous systems. Given the patients depleted immune condition, the use and abuse of drug and addictive substances such as tobacco smoking can further deteriorates their overall health and accelerate the progression and severity of the disease. In this review we detail the pathogenesis, progression and characteristics of HIV and the impact of tobacco smoking as a risk factor for the progression of the disease to NeuroAIDS. This is a poorly understood aspect of HIV-related complications that needs to be addressed.

Subjects and methods

Review of theoretical approaches and knowledge synthesis.

Results

Tobacco smoking is highly prevalent in HIV patients when compared to the general population. The oxidative damage and inflammatory stress caused by chronic smoking on the cerebrovascular system have been well established. Considering that HIV patients have an impaired immune system and smokers per se are more susceptible to viral and bacterial inflammatory neuropathologies than non-smokers, it is conceivable that tobacco smoking as a risk factor for the progression of HIV into NeuroAIDS and related neurological impairments.

Conclusion

Tobacco smoke (TS) may bring about a synergistic effect in the context of persistent inflammatory state and cerebrovascular damage which facilitate HIV infection and progression to NeuroAIDS when compared to non-smokers.

Lung function abnormalities in HIV-infected adults and children

Despite the advent of antiretroviral therapy (ART), the human immunodeficiency virus (HIV) epidemic remains a global health crisis with a high burden of respiratory disease among infected persons. While the early complications of the epidemic were dominated by opportunistic infections, improved survival has led to the emergence of non-infectious conditions that are associated with chronic respiratory symptoms and pulmonary disability. Obstructive ventilatory defects and reduced diffusing capacity are common findings in adults, and the association between HIV and chronic obstructive pulmonary disease is increasingly recognized. There is synergism between viral factors, opportunistic infections, conventional influences like tobacco smoke and biomass fuel exposure, and potentially, the immunological effects of ART on the development of HIV-associated chronic obstructive lung disease. Pulmonary function data for HIV-infected infants and children are scarce, but shows that bronchiectasis and obliterative bronchiolitis with severe airflow limitation are major problems, particularly in the developing world. However, studies from these regions are sorely lacking. There is thus a major unmet need to understand the influences of chronic HIV infection on the lung in both adults and children, and to devise strategies to manage and prevent these diseases in HIV-infected individuals. It is important for clinicians working with HIV-infected individuals to have an appreciation of their effects on measurements of lung function. This review therefore summarizes the lung function abnormalities described in HIV-positive adults and children, with an emphasis on obstructive lung disease, and examines potential pathogenic links between HIV and the development of chronic pulmonary disability.

Antioxidant activity in HIV and malaria co-infected subjects in Anambra State, southeastern Nigeria

OBJECTIVE

To determine the antioxidant status of HIV and malaria co-infected participants.

METHODS

Blood samples collected from the 193 randomly recruited participants were used for HIV screening, Plasmodium falciparum antigen screening, malaria parasite density count, CD4(+) T cell count, glutathione reductase, glutathione peroxidase and total antioxidant status measurement. Standard laboratory methods were used for the analysis.

RESULTS

The results showed that glutathione reductase, glutathione peroxidase, total antioxidant status and CD4(+) T cell count were significantly lowered in symptomatic HIV participants with and without malaria co-infection (P<0.01) in each case compared with control participants. Also, glutathione reductase, glutathione peroxidise, total antioxidant status and CD4(+) T cell count were significantly lowered in asymptomatic HIV participants with and without malaria co-infection (P<0.05) in each case, compared with control participants without malaria. Similarly, these antioxidants were significantly lowered in control participants with malaria infection (P<0.05) compared with control participants without malaria. The malaria parasite density in symptomatic HIV infected participants was negatively associated with glutathione reductase (r = -0.906, P<0.01), glutathione peroxidase (r = -0.719, P<0.01) and total antioxidant status (r = -0.824, P<0.01).

CONCLUSIONS

The antioxidant activity was affected in HIV infected participants with malaria co-infection. Malaria co-infection in HIV seems to exert additional burden on antioxidants. This calls for concern in malaria endemic areas with increasing prevalence of HIV infection.

HIV and chronic obstructive pulmonary disease: is it worse and why?

Smoking-related diseases, such as chronic obstructive pulmonary disease (COPD), are of particular concern in the HIV-infected population. Smoking rates are high in this population, and long-term exposure to cigarette smoke in the setting of HIV infection may increase the number of complications seen. Before the era of combination antiretroviral therapy, HIV-infected persons were noted to have an accelerated form of COPD, with significant emphysematous disease seen in individuals less than 40 years old. Unlike many of the AIDS-defining opportunistic infections, HIV-associated COPD may be more common in the current era of HIV because it is frequently reported in patients without a history of AIDS-related pulmonary complications and because many aging HIV-infected individuals have had a longer exposure to smoking and HIV. In this review, we document the epidemiology of HIV-associated COPD before and after the institution of combination antiretroviral therapy, review data suggesting that COPD is accelerated in those with HIV, and discuss possible mechanisms of HIV-associated COPD, including an increased susceptibility to chronic, latent infections; an aberrant inflammatory response; altered oxidant-antioxidant balance; increased apoptosis associated with HIV; and the effects of antiretroviral therapy.

Mechanisms and genes involved in enhancement of HIV infectivity by tobacco smoke

HIV infection is more common among smokers than nonsmokers, and, remarkably, HIV-infected individuals are about 3 times more likely to smoke than the uninfected general population. However, the relationship between tobacco smoking and HIV/AIDS disease progression remains controversial. In this study, we demonstrate a potent enhancing effect of aqueous tobacco smoke extract (TSE) on HIV infectivity that is nicotine-independent. This increased infectivity is neither NF-κB mediated nor a direct result of oxidative stress, as it cannot be blocked by antioxidants. On the contrary, TSE itself was found to possess significant antioxidant potential, enabling it to protect the viability of both infected cells and HIV virions in the presence of peroxide. Assessment of TSE-induced alterations in cellular gene expression that may be involved in increasing HIV infectivity in T cells showed that TSE up-regulates some genes known to be capable of enhancing HIV and HCV infection, or protecting HIV, but down-regulates several genes involved in cellular defense and antigen presentation. These results demonstrate that tobacco smoke can enhance HIV infectivity, possibly by a combination of direct (antioxidant) and indirect (gene-based) mechanisms. This raises the concern that smoking may thereby increase the risk of acquisition or progression of HIV infection.

HIV infection and risk for incident pulmonary diseases in the combination antiretroviral therapy era

RATIONALE

In aging HIV-infected populations comorbid diseases are important determinants of morbidity and mortality. Pulmonary diseases have not been systematically assessed in the combination antiretroviral therapy (ART) era.

OBJECTIVES

To determine the incidence of pulmonary diseases in HIV-infected persons compared with HIV-uninfected persons.

METHODS

We analyzed data from the Veterans Aging Cohort Study Virtual Cohort, consisting of 33,420 HIV-infected veterans and 66,840 age, sex, race and ethnicity, and site-matched HIV-uninfected veterans. Using Poisson regression, incidence rates and adjusted incidence rate ratios were calculated to determine the association of HIV with pulmonary disease. The Virtual Cohort was merged with the 1999 Veterans Large Health Survey to adjust for self-reported smoking in a nested sample (14%).

MEASUREMENTS AND MAIN RESULTS

Incident chronic obstructive pulmonary disease, lung cancer, pulmonary hypertension, and pulmonary fibrosis, as well as pulmonary infections, were significantly more likely among HIV-infected patients compared with uninfected patients in adjusted analyses, although rates of asthma did not differ by HIV status. Bacterial pneumonia and chronic obstructive pulmonary disease were the two most common incident pulmonary diseases, whereas opportunistic pneumonias were less common. Absolute rates of most pulmonary diseases increased with age, although the relative differences between those with and without HIV infection were greatest in younger persons. Chronic obstructive pulmonary disease and asthma, as well as pulmonary infections, were less likely in those with lower HIV RNA levels and use of ART at baseline.

CONCLUSIONS

Pulmonary diseases among HIV-infected patients receiving care within the Veterans Affairs Healthcare System in the combination ART era reflect a substantial burden of non-AIDS-defining and chronic conditions, many of which are associated with aging.

Distal airways in mice exposed to cigarette smoke: Nrf2-regulated genes are increased in Clara cells

Cigarette smoke (CS) is the main risk factor for chronic obstructive pulmonary disease (COPD). Terminal bronchioles are critical zones in the pathophysiology of COPD, but little is known about the cellular and molecular changes that occur in cells lining terminal bronchioles in response to CS. We subjected C57BL/6 mice to CS (6 d/wk, up to 6 mo), looked for morphologic changes lining the terminal bronchioles, and used laser capture microdissection to selectively isolate cells in terminal bronchioles to study gene expression. Morphologic and immunohistochemical analyses showed that Clara cell predominance remained despite 6 months of CS exposure. Since Clara cells have a role in protection against oxidative stress, we focused on the expression of antioxidant/detoxification genes using microarray analysis. Of the 35 antioxidant/detoxification genes with at least 2.5-fold increased expression in response to 6 months of CS exposure, 21 were NF-E2-related factor 2 (Nrf2)-regulated genes. Among these were cytochrome P450 1b1, glutathione reductase, thioredoxin reductase, and members of the glutathione S-transferase family, as well as Nrf2 itself. In vitro studies using immortalized murine Clara cells (C22) showed that CS induced the stabilization and nuclear translocation of Nrf2, which correlated with the induction of antioxidant and detoxification genes. Furthermore, decreasing Nrf2 expression by siRNA resulted in a corresponding decrease in CS-induced expression of several antioxidant and detoxification genes by C22 cells. These data suggest that the protective response by Clara cells to CS exposure is predominantly regulated by the transcription factor Nrf2.

The anti-inflammatory effects of selenium are mediated through 15-deoxy-Delta12,14-prostaglandin J2 in macrophages

Selenium is an essential micronutrient that suppresses the redox-sensitive transcription factor NF-kappaB-dependent pro-inflammatory gene expression. To understand the molecular mechanisms underlying the anti-inflammatory property of selenium, we examined the activity of a key kinase of the NF-kappaB cascade, IkappaB-kinase beta (IKKbeta) subunit, as a function of cellular selenium status in murine primary bone marrow-derived macrophages and RAW264.7 macrophage-like cell line. In vitro kinase assays revealed that selenium supplementation decreased the activity of IKKbeta in lipopolysaccharide (LPS)-treated macrophages. Stimulation by LPS of selenium-supplemented macrophages resulted in a time-dependent increase in 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) formation, an endogenous inhibitor of IKKbeta activity. Further analysis revealed that inhibition of IKKbeta activity in selenium-supplemented cells correlated with the Michael addition product of 15d-PGJ2 with Cys-179 of IKKbeta, while the formation of such an adduct was significantly decreased in the selenium-deficient macrophages. In addition, anti-inflammatory activities of selenium were also mediated by the 15d-PGJ2-dependent activation of the peroxisome proliferator-activated nuclear receptor-gamma in macrophages. Experiments using specific cyclooxygenase (COX) inhibitors and genetic knockdown approaches indicated that COX-1, and not the COX-2 pathway, was responsible for the increased synthesis of 15d-PGJ2 in selenium-supplemented macrophages. Taken together, our results suggest that selenium supplementation increases the production of 15d-PGJ2 as an adaptive response to protect cells against oxidative stress-induced pro-inflammatory gene expression. More specifically, modification of protein thiols by 15d-PGJ2 represents a previously undescribed code for redox regulation of gene expression by selenium.