News Brief By Ursula Biba
In 2011, Yamuna Krishnan and her team at the National Centre for Biological Sciences in Banglore, India were the first to show a DNA nanomachine working in a living organism. This nanomachine, called the I- switch, measures subcellular pH levels much more accurately than other traditional methods. However, her team has not stopped there: they have developed multiple pH sensors specific to various organelles that emit fluorescent signals as pH concentration changes. More notably, though, is the team’s Clensor DNA nanosensor that measures physiological concentrations of chloride. Before Clensor, there was no effective way to measure cellular chloride levels—despite chloride being one of the most abundant charged molecules in the human body and integral in the neurobiological process of neuron excitation.
As well as this, Clensor’s use also brings potential for the treatment of various chloride ion channel diseases. Of these uses, one of the most promising is Clensor’s ability to measure and visualize the activity of proteins related to cystic fibrosis, a genetic disease in which a genetic mutation hinders the ability of chloride transport ions to make thin mucus in the lungs. With Clensor, scientists can create assays that screen for chemicals to restore the chloride channel and ease the symptoms of cystic fibrosis. As humans have nine different chloride ion channels, there are nine possible ailments that can be treated with nanosensors like Clensor. Krishnan and team’s work with pH sensors is also applicable to human health as there are a plethora of diseases spurred by environments with irregular pH levels, and their goal is to use these sensors to learn about fatal lysosomal storage disorders. Krishnan hopes that her team’s work creating small, simple molecule drugs can lead to more effective therapies for at least one of these diseases.
University of Chicago. "DNA devices perform bio-analytical chemistry inside live cells." ScienceDaily. ScienceDaily, 24 March 2016. <www.sciencedaily.com/releases/2016/03/160324133940.htm>.