Article

In utero exposure of female CD-1 Mice to AZT and/or 3TC: I. Persistence of microscopic lesions in cardiac tissue.

University of New Mexico, Albuquerque, 87131, USA.
Cardiovascular toxicology (Impact Factor: 2.06). 03/2010; 10(1):37-50. DOI: 10.1007/s12012-010-9061-3
Source: PubMed

ABSTRACT The current study was designed to delineate temporal changes in cardiomyocytes and mitochondria at the light and electron microscopic levels in hearts of mice exposed transplacentally to commonly used nucleoside analogs (NRTIs). Pregnant CD-1 mice were given 80 mg AZT/kg, 40 mg 3TC/kg, 80 mg AZT/kg plus 40 mg 3TC/kg, or vehicle alone during the last 7 days of gestation, and hearts from female mouse pups were examined at 13 and 26 weeks postpartum for histopathological or ultrastructural changes in cross-sections of both the ventricles and the interventricular septum. Using light microscopy and special staining techniques, transplacental exposure to AZT, 3TC, or AZT/3TC was shown to induce significant histopathological changes in myofibrils; these changes were more widespread at 13 weeks than at 26 weeks postpartum. While most light microscopic lesions resolved, some became more severe between 13 and 26 weeks postpartum. Transplacental NRTI exposure also resulted in progressive drug-specific changes in the number and ultrastructural integrity of cardiac mitochondria. These light and electron microscopic findings show that a subset of changes in cardiac mitochondria and myofibrils persisted and progressed months after transplacental exposure of an animal model to NRTIs, with combined AZT/3TC exposure yielding additive effects compared with either drug alone.

0 Followers
 · 
100 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: IMPORTANCE Prior to contemporary antiretroviral therapies (ARTs), children infected with human immunodeficiency virus (HIV) were more likely to have heart failure. This study suggests that highly active ART (HAART) does not appear to impair heart function. OBJECTIVE To determine the cardiac effects of prolonged exposure to HAART on HIV-infected children. DESIGN In the National Institutes of Health-funded Pediatric HIV/AIDS Cohort Study's Adolescent Master Protocol (AMP), we used linear regression models to compare echocardiographic measures. SETTING A total of 14 US pediatric HIV clinics. PARTICIPANTS Perinatally HIV-infected children receiving HAART (n = 325), HIV-exposed but uninfected children (n = 189), and HIV-infected (mostly HAART-unexposed) historical pediatric controls from the National Institutes of Health-funded Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV Infection (P2C2-HIV) Study (n = 70). EXPOSURE Long-term HAART. MAIN OUTCOMES AND MEASURES Echocardiographic measures of left ventricular (LV) function and structure. RESULTS The 325 AMP HIV-infected children had lower viral loads, higher CD4 counts, and longer durations of ART than did the 70 HIV-infected children from the P2C2-HIV Study (all P < .001). The z scores for LV fractional shortening (a measure of cardiac function) were significantly lower among HIV-infected children from the P2C2-HIV Study than among the AMP HIV-infected group or the 189 AMP HIV-exposed but uninfected controls (P < .05). For HIV-infected children, a lower nadir CD4 percentage and a higher current viral load were associated with significantly lower cardiac function (LV contractility and LV fractional shortening z scores; all P = .001) and an increased LV end-systolic dimension z score (all P < .03). In an interaction analysis by HIV-infected cohort, the HIV-infected children from the P2C2-HIV Study with a longer ART exposure or a lower nadir CD4 percentage had lower mean LV fractional shortening z scores, whereas the mean z scores were relatively constant among AMP HIV-infected children (P < .05 for all interactions). CONCLUSIONS AND RELEVANCE Long-term HAART appears to be cardioprotective for HIV-infected children and adolescents.
    04/2013; 167(6):1-8. DOI:10.1001/jamapediatrics.2013.1206
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Exposure to fine particulate air pollution (PM2.5) is strongly associated with cardiovascular morbidity and mortality. Exposure to PM2.5 during pregnancy promotes reduced birthweight, and the associated adverse intrauterine conditions may also promote adult risk of cardiovascular disease. Here, we investigated the potential for in utero exposure to diesel exhaust (DE) air pollution, a major source of urban PM2.5, to promote adverse intrauterine conditions and influence adult susceptibility to disease. We exposed pregnant female C57Bl/6J mice to DE (≈300 µg/m(3) PM2.5, 6 hrs/day, 5 days/week) from embryonic day (E) 0.5 to 17.5. At E17.5 embryos were collected for gravimetric analysis and assessed for evidence of resorption. Placental tissues underwent pathological examination to assess the extent of injury, inflammatory cell infiltration, and oxidative stress. In addition, some dams that were exposed to DE were allowed to give birth to pups and raise offspring in filtered air (FA) conditions. At 10-weeks of age, body weight and blood pressure were measured. At 12-weeks of age, cardiac function was assessed by echocardiography. Susceptibility to pressure overload-induced heart failure was then determined after transverse aortic constriction surgery. We found that in utero exposure to DE increases embryo resorption, and promotes placental hemorrhage, focal necrosis, compaction of labyrinth vascular spaces, inflammatory cell infiltration and oxidative stress. In addition, we observed that in utero DE exposure increased body weight, but counterintuitively reduced blood pressure without any changes in baseline cardiac function in adult male mice. Importantly, we observed these mice to have increased susceptibility to pressure-overload induced heart failure, suggesting this in utero exposure to DE 'reprograms' the heart to a heightened susceptibility to failure. These observations provide important data to suggest that developmental exposure to air pollution may strongly influence adult susceptibility to cardiovascular disease.
    PLoS ONE 02/2014; 9(2):e88582. DOI:10.1371/journal.pone.0088582 · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Maternal-fetal HIV-1 transmission can be prevented by administration of AZT, alone or in combination with other antiretroviral drugs to pregnant HIV-1-infected women and their newborns. In spite of the benefits deriving from this life-saving prophylactic therapy, there is still considerable uncertainty on the potential long-term adverse effects of antiretroviral drugs on exposed children. Clinical and experimental studies have consistently shown the occurrence of mitochondrial dysfunction and increased oxidative stress following prenatal treatment with antiretroviral drugs, and clinical evidence suggests that the developing brain is one of the targets of the toxic action of these compounds possibly resulting in behavioral problems. We intended to verify the effects on brain and behavior of mice exposed during gestation to AZT, the backbone of antiretroviral therapy during human pregnancy. We hypothesized that glutamate, a neurotransmitter involved in excitotoxicity and behavioral plasticity, could be one of the major actors in AZT-induced neurochemical and behavioral alterations. We also assessed the antioxidant and neuroprotective effect of L-acetylcarnitine, a compound that improves mitochondrial function and is successfully used to treat antiretroviral-induced polyneuropathy in HIV-1 patients. We found that transplacental exposure to AZT given per os to pregnant mice from day 10 of pregnancy to delivery impaired in the adult offspring spatial learning and memory, enhanced corticosterone release in response to acute stress, increased brain oxidative stress also at birth and markedly reduced expression of mGluR1 and mGluR5 subtypes and GluR1 subunit of AMPA receptors in the hippocampus. Notably, administration during the entire pregnancy of L-acetylcarnitine was effective in preventing/ameliorating the neurochemical, neuroendocrine and behavioral adverse effects induced by AZT in the offspring. The present preclinical findings provide a mechanistic hypothesis for the neurobehavioral effects of AZT and strongly suggest that preventive administration of L-acetylcarnitine might be effective in reducing the neurological side-effects of antiretroviral therapy in fetus/newborn.
    PLoS ONE 10/2013; 8(2):e55753. DOI:10.1371/journal.pone.0055753 · 3.53 Impact Factor

Full-text (2 Sources)

Download
29 Downloads
Available from
May 30, 2014