Health Journal Online

Tag: Brain

  • Exposure To Air Pollution During Pregnancy And Childhood Have Lasting Effects On Brain: Study

    Exposure To Air Pollution During Pregnancy And Childhood Have Lasting Effects On Brain: Study

    Long-term exposure to air pollutants is known to affect physical well-being, increasing the risk of respiratory illnesses, cardiovascular diseases, and cancers. A recent study revealed that early-life exposure to air pollution has lasting effects on the brain.

    According to the research led by the Barcelona Institute for Global Health (ISGlobal), exposure to fine particles (PM2.5) and nitrogen oxides (NOx) during pregnancy and childhood can lead to significant changes in the microstructure of the brain’s white matter. Alarmingly, these alterations can persist into adolescence, raising concerns about the long-term impact of air pollution on brain development.

    Earlier studies have explored the impact of air pollutants on the brain’s white matter, but most were limited to a single time point and did not track participants throughout childhood.

    The latest study published in Environmental Research involved 4,000 participants in Rotterdam, the Netherlands who were part of the Generation R Study and were followed up since birth. Based on the participants’ location, the team estimated the amount of exposure to 14 different air pollutants during pregnancy and childhood.

    To examine changes in white matter microstructure, researchers conducted brain scans on 1,314 children, once around the age of 10 and again around 14.

    “Following participants throughout childhood and including two neuroimaging assessments for each child would shed new light on whether the effects of air pollution on white matter persist, attenuate, or worsen,” said ISGlobal researcher Mònica Guxens in a news release.

    The results revealed that higher exposure to PM2.5 during pregnancy, as well as elevated levels of PM2.5, PM10, PM2.5-10, and NOx during childhood, led to a reduction in fractional anisotropy, a measure of how water molecules diffuse within the brain. In more mature brains, water tends to flow more in one direction, resulting in higher values for this marker. This association persisted into adolescence, indicating a long-term impact of air pollution on brain development.

    “Every increase in exposure level to air pollution corresponded to more than a 5-month delay in the development of fractional anisotropy,” the researchers wrote.

    “We think that the lower fractional anisotropy is likely the result of changes in myelin, the protective sheath that forms around the nerves, rather than in the structure or packaging of the nerve fibers,” said first author of the study, Michelle Kusters.

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  • New drug shows promise in clearing HIV from brain

    New drug shows promise in clearing HIV from brain

    An experimental drug originally developed to treat cancer may help clear HIV from infected cells in the brain, according to a new Tulane University study.

    For the first time, researchers at Tulane National Primate Research Center found that a cancer drug significantly reduced levels of SIV, the nonhuman primate equivalent of HIV, in the brain by targeting and depleting certain immune cells that harbor the virus.

    Published in the journal Brain, this discovery marks a significant step toward eliminating HIV from hard-to-reach reservoirs where the virus evades otherwise effective treatment.

    “This research is an important step in tackling brain-related issues caused by HIV, which still affect people even when they are on effective HIV medication,” said lead study author Woong-Ki Kim, PhD, associate director for research at Tulane National Primate Research Center. “By specifically targeting the infected cells in the brain, we may be able to clear the virus from these hidden areas, which has been a major challenge in HIV treatment.”

    Antiretroviral therapy (ART) is an essential component of successful HIV treatment, maintaining the virus at undetectable levels in the blood and transforming HIV from a terminal illness into a manageable condition. However, ART does not completely eradicate HIV, necessitating lifelong treatment. The virus persists in “viral reservoirs” in the brain, liver, and lymph nodes, where it remains out of reach of ART.

    The brain has been a particularly challenging area for treatment due to the blood-brain barrier — a protective membrane that shields it from harmful substances but also blocks treatments, allowing the virus to persist. In addition, cells in the brain known as macrophages are extremely long-lived, making them difficult to eradicate once they become infected.

    Infection of macrophages is thought to contribute to neurocognitive dysfunction, experienced by nearly half of those living with HIV. Eradicating the virus from the brain is critical for comprehensive HIV treatment and could significantly improve the quality of life for those with HIV-related neurocognitive problems.

    Researchers focused on macrophages, a type of white blood cell that harbors HIV in the brain. By using a small molecule inhibitor to block a receptor that increases in HIV-infected macrophages, the team successfully reduced the viral load in the brain. This approach essentially cleared the virus from brain tissue, providing a potential new treatment avenue for HIV.

    The small molecule inhibitor used, BLZ945, has previously been studied for therapeutic use in amyotrophic lateral sclerosis (ALS) and brain cancer, but never before in the context of clearing HIV from the brain.

    The study, which took place at the Tulane National Primate Research Center, utilized three groups to model human HIV infection and treatment: an untreated control group, and two groups treated with either a low or high dose of the small molecule inhibitor for 30 days. The high-dose treatment lead to a notable reduction in cells expressing HIV receptor sites, as well as a 95-99% decrease in viral DNA loads in the brain .

    In addition to reducing viral loads, the treatment did not significantly impact microglia, the brain’s resident immune cells, which are essential for maintaining a healthy neuroimmune environment. It also did not show signs of liver toxicity at the doses tested.

    The next step for the research team is to test this therapy in conjunction with ART to assess its efficacy in a combined treatment approach. This could pave the way for more comprehensive strategies to eradicate HIV from the body entirely.

    This research was funded by the National Institutes of Health, including grants from the National Institute of Mental Health and the National Institute of Neurological Disorders and Stroke, and was supported with resources from the Tulane National Primate Research Center base grant of the National Institutes of Health, P51 OD011104.

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