News briefs

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 are completely novel, with expression only found in these critical cells. A comparison of the osteocyte signature genes with human genetic association studies of osteoporosis identified 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.

https://www.nature.com/articles/s41467-021-22517-1

Robotics next frontier to combat bacterial resistance

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 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.”

https://academic.oup.com/jac/advance-article/doi/10.1093/jac/dkab107/6248215