Research news in brief

New map reveals genes that control the skeleton

Research led by the Garvan Institute of Medical Research has mapped the unique gene expression profile of the skeleton’s “master regulator” cells, known as osteocytes. The study, published in Nature Communications, outlines the genes that are switched on or off in osteocytes, a type of bone cell that controls how other types of cells make or break down parts of the skeleton to maintain strong and healthy bones. Osteocytes are the most abundant cell type in the bones but have proved difficult to study because they are embedded within the hard mineral structure of the skeleton. Inside the bone, osteocytes form a network similar in scale and complexity to the neurons in the brain (with over 23 trillion connections between 42 billion osteocytes) that monitors bone health and responds to ageing and damage by signalling other cells to build more bone or break down old bone. Diseases such as osteoporosis and rare genetic skeletal disorders arise from an imbalance in these processes. To understand what genes are involved in controlling bone build-up or breakdown, the researchers isolated bone samples from different skeletal sites of experimental models to measure the average gene activity in osteocytes. Through this, they mapped a comprehensive osteocyte “signature” of 1239 genes that are switched on in osteocytes and that distinguish them from other cells; 77% of these genes have no previously known role in the skeleton and many were completely novel, with expression only found in these critical cells. A comparison of the osteocyte signature genes with human genetic association studies of osteoporosis identify genes that may be associated with susceptibility to this common skeleton disease. Furthermore, many of the genes expressed in osteocytes were also shown to cause rare bone diseases.

COVID-19 vaccine delivery by age may mitigate deaths and severe health impacts

Strategic vaccine delivery is critical to reducing COVID-19 transmission, mortality, and long term health impacts, according to a UK study published in PLOS Computational Biology. The results suggest that prioritising vaccine delivery to older age groups and the medically vulnerable has the greatest impact in minimising loss of life. While older people are more likely to experience serious health outcomes related to COVID-19 infections, younger age groups contribute significantly to disease transmission and spread. In order to test the effectiveness of different vaccination strategies on minimising deaths and hospitalisations, researchers built an age-structured model that simulated the spread of SARS-CoV-2

within different regions in the UK. The authors then used the model to test multiple different scenarios, including variations in vaccine effectiveness using observational data on comorbidities and social-distancing measures in the UK. The models showed that vaccine strategies prioritising older age groups first most effectively mitigated deaths and lost quality of life years, despite the significant role of younger groups in disease spread. Since the study’s completion in 2020, data have become available for the key assumption on vaccine uptake and specific vaccine characteristics; however, the general conclusions of the study remain relevant. Additionally, the research has already helped guide UK policy makers in the development of an effective COVID-19 vaccination program, including the formation of the Joint Committee for Vaccination and Immunisation’s priority groups that have been used for vaccine delivery.

Robotics next frontier to combat bacterial resistance to medicines

Automation has significantly advanced a multitude of industries over the past century; now researchers are turning to robotics to modernise the way we monitor antimicrobial resistance (AMR). As it stands, the mortality rate of antimicrobial-resistant infections is on track to reach 10 million deaths per year by 2050. Researchers from Murdoch University, in an article published by the Journal of Antimicrobial Chemotherapy, wrote that surveillance of antimicrobial resistance is critical to reducing its wide-reaching impact. They developed a robotic platform (RASP) for high throughput AMR surveillance and validated it through a series of experiments. “Surveillance requires the large-scale sampling of indicator organisms – bacteria such as [Escherichia coli], that are common to a wide variety of humans and animals and which typically don’t cause disease – to determine what antimicrobial resistances they are carrying, and whether these resistances are being detected more frequently,” they wrote. “Conventional, human-centric methods have long dominated the way we survey antimicrobial resistance yet have seen very little improvement since their conception. These methods are hamstrung by high-processing costs and slow turnaround times, making them incompatible with the high volumes of sampling required to accurately depict a population’s AMR status. A consequence of continuing surveillance using conventional methods could mean that more serious, but less frequently occurring resistances may be slipping through the cracks. If these highly important resistances are not being detected, the necessary research into combatting them cannot be undertaken.” To overcome the limitations to scalability, RASP was developed to drastically increase processing power, cutting processing times by two thirds, while maintaining or improving upon the quality of results generated by human technicians. “This will be the next generation approach to surveillance of antimicrobial resistance and could be applied to other areas of bacterial resistance. It is critical that researchers harness robotic platforms like RASP if we are to resist the current mortality trajectory of antimicrobial resistance.”

Air pollution can negatively affect the brain power of older men

Short term exposure (up to 28 days) to higher levels of air pollution is associated with impaired cognitive function among older men, according to a study published in Nature Aging. The article also suggests that the negative impact of short term exposure to air pollution was lessened among participants who were prescribed common pain medications. A decline in cognitive function is common among older adults but can be accelerated by environmental factors, such as exposure to fine particulate matter no more than 2.5 micrometres (PM_2.5) in size in the air. Nevertheless, there is a lack of research examining the impacts of short term exposure to air pollution on cognitive function of older adults. Previous studies have also investigated the use of nonsteroidal anti-inflammatory drugs (NSAIDs) as a potential treatment for cognitive impairment and dementia. However, the use of NSAIDs as a potential intervention to limit the impact of air pollution on cognitive health had not been examined before. Researchers from Monash University and Peking University studied a cohort of 954 older white men (averaging 70 years of age) living in the Greater Boston area in the US who participated in the Veterans Affairs Normative Aging Study. The authors measured their cognitive performance using global cognitive function and Mini-Mental State Examination scores over several visits. They then compared this to the levels of PM_2.5 in the air of the local area on the day of each visit, and the average levels 1–4 weeks prior to each visit. The authors found that increased levels of PM_2.5 up to 28 days before testing was associated with lower global cognitive function scores among participants, even at levels below what is usually considered hazardous (approximately ≤ 10 μg m⁻³). They also found that those in the study who were prescribed NSAIDs were less affected by the adverse effects of short term exposure to air pollution. The authors conclude that multidisciplinary studies based on larger cohorts with more detailed NSAID usage information are required to validate the relationships between air pollution exposure and cognitive function, and the potential modifying effect of NSAIDs, identified in this study.