Browsing by Author "Salazar, Ethan A."

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    Impact of human immunodeficiency virus on pulmonary vascular disease
    (Magdi Yacoub Institute, 2021-06-30) Kumar, Ashok; Mahajan, Aatish; Salazar, Ethan A.; Pruitt, Kevin; Guzman, Christian Arce; Clauss, Matthias A.; Almodovar, Sharilyn; Dhillon, Navneet K.; Medicine, School of Medicine
    With the advent of anti-retroviral therapy, non-AIDS-related comorbidities have increased in people living with HIV. Among these comorbidities, pulmonary hypertension (PH) is one of the most common causes of morbidity and mortality. Although chronic HIV-1 infection is independently associated with the development of pulmonary arterial hypertension, PH in people living with HIV may also be the outcome of various co-morbidities commonly observed in these individuals including chronic obstructive pulmonary disease, left heart disease and co-infections. In addition, the association of these co-morbidities and other risk factors, such as illicit drug use, can exacerbate the development of pulmonary vascular disease. This review will focus on these complex interactions contributing to PH development and exacerbation in HIV patients. We also examine the interactions of HIV proteins, including Nef, Tat, and gp120 in the pulmonary vasculature and how these proteins alter the endothelial and smooth muscle function by transforming them into susceptible PH phenotype. The review also discusses the available infectious and non-infectious animal models to study HIV-associated PAH, highlighting the advantages and disadvantages of each model, along with their ability to mimic the clinical manifestations of HIV-PAH.
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    Mice with humanized immune system as novel models to study HIV-associated pulmonary hypertension
    (Frontiers Media, 2022-08-05) Rodriguez-Irizarry, Valerie J.; Schneider, Alina C.; Ahle, Daniel; Smith, Justin M.; Suarez-Martinez, Edu B.; Salazar, Ethan A.; McDaniel Mims, Brianyell; Rasha, Fahmida; Moussa, Hanna; Moustaïd-Moussa, Naima; Pruitt, Kevin; Fonseca, Marcelo; Henriquez, Mauricio; Clauss, Matthias A.; Grisham, Matthew B.; Almodovar, Sharilyn; Medicine, School of Medicine
    People living with HIV and who receive antiretroviral therapy have a significantly improved lifespan, compared to the early days without therapy. Unfortunately, persisting viral replication in the lungs sustains chronic inflammation, which may cause pulmonary vascular dysfunction and ultimate life-threatening Pulmonary Hypertension (PH). The mechanisms involved in the progression of HIV and PH remain unclear. The study of HIV-PH is limited due to the lack of tractable animal models that recapitulate infection and pathobiological aspects of PH. On one hand, mice with humanized immune systems (hu-mice) are highly relevant to HIV research but their suitability for HIV-PH research deserves investigation. On another hand, the Hypoxia-Sugen is a well-established model for experimental PH that combines hypoxia with the VEGF antagonist SU5416. To test the suitability of hu-mice, we combined HIV with either SU5416 or hypoxia. Using right heart catheterization, we found that combining HIV+SU5416 exacerbated PH. HIV infection increases human pro-inflammatory cytokines in the lungs, compared to uninfected mice. Histopathological examinations showed pulmonary vascular inflammation with arterial muscularization in HIV-PH. We also found an increase in endothelial-monocyte activating polypeptide II (EMAP II) when combining HIV+SU5416. Therefore, combinations of HIV with SU5416 or hypoxia recapitulate PH in hu-mice, creating well-suited models for infectious mechanistic pulmonary vascular research in small animals.