During missions into outer space, galactic cosmic radiation (GCR) will penetrate current spacecraft shielding and thus pose a significant risk to human health. Previous studies have shown that GCR can cause short-term cognitive deficits in male rodents. Now a study published in the Journal of Neurochemistry reveals that GCR exposure can also cause long-lasting learning deficits in female rodents.
The impact of GCR on cognition was lessened when mice were fed an antioxidant and anti-inflammatory compound called CDDO-EA.
Beyond its immediate implications for space exploration, the findings contribute to a broader understanding of radiation’s long-term impact on cognitive health.
“Our study lays the groundwork for future causal delineation of how the brain responds to complex GCR exposure and how these brain adaptations result in altered behaviours,” said co-corresponding author Sanghee Yun, PhD, of the Children’s Hospital of Philadelphia Research Institute and the University of Pennsylvania Perelman School of Medicine.
The neurons of the brain are protected by an insulating layer called myelin. In certain diseases like multiple sclerosis, the protective myelin layer around neurons is damaged and lost, leading to death of neurons and disability. New research published in The FEBS Journal reveals the importance of a protein called C1QL1 for promoting the replacement of the specialised cells that produce myelin. The findings could have important implications for the ongoing effort to develop new and improved therapies for the treatment of demyelinating diseases.
In experiments conducted in mice, deleting the gene that codes for C1QL1 caused a delay in the rate at which oligodendrocytes (the cells that make myelin) mature, leading to reduced myelination of neurons.
After mice were fed a drug that destroys myelin, recovery of oligodendrocytes and myelination were delayed in mice lacking the C1QL1 protein. Causing mice to express more C1QL1, however, led to increased numbers of oligodendrocytes and more myelination upon drug withdrawal, suggesting that C1QL1 helps to restore the damaged myelin layer. Thus, investigational therapies that boost C1QL1 may hold promise against demyelinating diseases.
“Our basic research on C1QL1 is nascent, but there is potential that it is relevant for a novel treatment for multiple sclerosis,” said corresponding author David C. Martinelli, PhD, of the University of Connecticut Health Center. “New drug treatment options for patients with multiple sclerosis could have a large impact on their quality of life.”
Long term exposure to arsenic in water may increase cardiovascular disease and especially heart disease risk even at exposure levels below the US regulatory limit (10µg/L) according to a new study in Environmental Health Perspectives. This is the first study to describe exposure-response relationships at concentrations below the current regulatory limit and substantiates that prolonged exposure to arsenic in water contributes to the development of ischaemic heart disease.
The researchers, from Columbia University Mailman School of Public Health, compared various time windows of exposure, finding that the previous decade of water arsenic exposure up to the time of a cardiovascular disease event contributed the greatest risk.
“Our findings shed light on critical time windows of arsenic exposure that contribute to heart disease and inform the ongoing arsenic risk assessment by the EPA. It further reinforces the importance of considering non-cancer outcomes, and specifically cardiovascular disease, which is the number one cause of death in the US and globally,” said Danielle Medgyesi, a doctoral Fellow in the Department of Environmental Health Sciences at Columbia Mailman School. “This study offers resounding proof of the need for regulatory standards in protecting health and provides evidence in support of reducing the current limit to further eliminate significant risk.”
According to the American Heart Association and other leading health agencies, there is substantial evidence that arsenic exposure increases the risk of cardiovascular disease. This includes evidence of risk at high arsenic levels (> 100µg/L) in drinking water. The U.S. Environmental Protection Agency reduced the maximum contaminant level (MCL) for arsenic in community water supplies (CWS) from 50µg/L to 10µg/L beginning in 2006. Even so, drinking water remains an important source of arsenic exposure among CWS users. The natural occurrence of arsenic in groundwater is commonly observed in regions of New England, the upper Midwest, and the West, including California.
To evaluate the relationship between long-term arsenic exposure from CWS and cardiovascular disease, the researchers used statewide healthcare administrative and mortality records collected for the California Teachers Study cohort from enrollment through follow-up (1995-2018), identifying fatal and nonfatal cases of ischemic heart disease and cardiovascular disease. Working closely with collaborators at the California Office of Environmental Health Hazard Assessment (OEHHA), the team gathered water arsenic data from CWS for three decades (1990-2020).
The analysis included 98 250 participants, 6119 ischaemic heart disease cases and 9,936 CVD cases. Excluded were those 85 years of age or older and those with a history of CVD at enrolment. Similar to the proportion of California’s population that relies on CWS (over 90%), most participants resided in areas served by a CWS (92%). Leveraging the extensive years of arsenic data available, the team compared time windows of relatively short-term (3-years) to long-term (10-years to cumulative) average arsenic exposure. The study found decade-long arsenic exposure up to the time of a cardiovascular disease event was associated with the greatest risk, consistent with a study in Chile finding peak mortality of acute myocardial infarction around a decade after a period of very high arsenic exposure. This provides new insights into relevant exposure windows that are critical to the development of ischemic heart disease.
Nearly half (48%) of participants were exposed to an average arsenic concentration below California’s non-cancer public health goal < 1 µg/L. In comparison to this low-exposure group, those exposed to 1 to < 5 µg/L had modestly higher risk of ischaemic heart disease, with increases of 5 to 6%. Risk jumped to 20% among those in the exposure ranges of 5 to < 10 µg/L (or one-half to below the current regulatory limit), and more than doubled to 42% for those exposed to levels at and above the current EPA limit ≥ 10µg/L. The relationship was consistently stronger for ischemic heart disease compared to cardiovascular disease, and no evidence of risk for stroke was found, largely consistent with previous research and the conclusions of the current EPA risk assessment.
These results highlight the serious health consequences not only when community water systems do not meet the current EPA standard but also at levels below the current standard. The study found a substantial 20% risk at arsenic exposures ranging from 5 to < 10 µg/L which affected about 3.2% of participants, suggesting that stronger regulations would provide significant benefits to the population. In line with prior research, the study also found higher arsenic concentrations, including concentrations above the current standard, disproportionally affect Hispanic and Latina populations and residents of lower socioeconomic status neighbourhoods.
“Our results are novel and encourage a renewed discussion of current policy and regulatory standards,” said Tiffany Sanchez, senior author. “However, this also implies that much more research is needed to understand the risks associated with arsenic levels that CWS users currently experience. We believe that the data and methods developed in this study can be used to bolster and inform future studies and can be extended to evaluate other drinking water exposures and health outcomes.”
A new study from Karolinska Institutet and the Chinese Academy of Medical Sciences has identified an RNA molecule that is important for skin wound healing. The research, published in Nature Communications, may have implications for the treatment of hard-to-heal wounds.
The study focuses on the molecular processes in wound healing that regulate the transition from inflammation to a proliferative phase, where new cells form to repair damaged tissue. Researchers have now mapped lncRNA (long non-coding RNA molecules) in human skin wounds in tissue samples from Karolinska University Hospital, identifying a key regulator in wound healing.
“Our study reveals that the lncRNA molecule SNHG26 plays a pivotal role in guiding skin cells through the stages of wound healing, from an inflammatory stage to a healing phase,” explains Ning Xu Landén, docent at the Department of Medicine, Solna, Karolinska Institutet.
The researchers also used mouse models to uncover how this molecule interacts with genes involved in inflammation and tissue regeneration. In mice lacking SNHG26, wound healing was delayed, emphasising the molecule’s importance in the balance between inflammation and tissue repair. The discovery paves the way for new therapeutic approaches for acute and chronic wounds.
“By targeting SNHG26, we may be able to accelerate healing and reduce complications, particularly in chronic wounds where prolonged inflammation is a major problem,” says Ning Xu Landén.
