January 4 Research Roundup: DNA Origami, Cannabis Potency, Immune System Fountain of Youth and More
There are plenty of great scientific research stories out this week. Here’s a look at just a few of them.
DNA Origami Used to Play Tic-Tac-Toe
A year ago, researchers with California Institute of Technology developed a technique called DNA origami, which is used to create tiles that could then self-assemble into larger nanostructures. They created the world’s smallest version of the Mona Lisa painting. One problem was it could not be easily changed. The same researchers in the laboratory of Lulu Qian, assistant professor of bioengineering, now used the technology to play a game of tic-tac-toe. The work was published in the journal Nature Communications.
“We developed a mechanism to program the dynamic interactions between complex DNA nanostructures,” stated Qian. “Using this mechanism, we created the world’s smallest game board for playing tic-tac-toe, where every move involves molecular self-reconfiguration for swapping in and out hundreds of DNA strands at once.”
Obviously, tic-tac-toe is not the goal. The object is to develop nanomachines that can be modified or repaired after they have been built, but this is a big step in that direction.
Cannabis Potency Doubled in the Last 11 Years
A study published in the journal Addiction by researchers from the University of Bath and King's College London noted that cannabis resin and herbal cannabis’ potency has more than doubled across Europe in the past 11 years. The scientists drew on data from across 28 European Union countries, including Norway and Turkey. Concentrations of THC, the main psychoactive ingredient in marijuana, grew by about 5 percent in 2006 to about 10 percent in 2016. The same applied to cannabis resin (hash). THC concentrations were stable from 2006 to 2011, from 8 to 10 percent, then increased from 2011 to 2016 from 10 percent to 17 percent.
“CBD has the potential to make cannabis safer, without limiting the positive effects users seek,” stated lead author Tom Freeman. “What we are seeing in Europe is an increase in THC and either stable or decreasing levels of CBD, potentially making cannabis more harmful. These changes in the illicit market are largely hidden from scientific investigation and are difficult to target by policy-makers. An alternative option could be attempt to control THC and CBD content through regulation.”
Development of a Wireless Brain Pacemaker
Engineers at the University of California, Berkeley (CAL) developed the technology for a neurostimulator that can listen to and stimulate electric current in the brain, which could possibly deliver finely-tuned treatments to patients with diseases like epilepsy and Parkinson’s. The device is dubbed the WAND, which stands for wireless artifact-free neuromodulation device. They published their research in the journal Nature Biomedical Engineering.
The WAND can record electrical activity across 128 channels, or from 128 points in the brain, compared to the more typical eight in other closed-loop systems. Deep brain stimulators currently in use either stop recording while delivering electrical stimulation, or record at a different location than where the stimulation is occurring.
“In order to deliver closed-loop stimulation-based therapies, which is a big goal for people treating Parkinson’s and epilepsy and a variety of neurological disorders, it is very important to both perform neural recordings and stimulation simultaneously, which currently no single commercial device does,” stated Samantha Santacruz, assistant professor at the University of Texas in Austin, formerly postdoctoral associate at UC Berkeley.
Finding the Immune System’s Fountain of Youth
Scientists at the Weizmann Institute of Science published research in Nature Communications that describes possible approaches to boosting the immune system as we age. One of the immune system’s duties as we age is clearing older, senescent cells, which accumulate, take up space, and are implicated in inflammation. As we age, our ability to clear these living but inactive cells weakens.
Working with mice where a gene important in clearing senescent cells was missing, the researchers used a drug that blocks the activity of proteins that help senescent cells survive. The mice responded very well, with their tissues appearing much closer to those of young mice.
The authors concluded, “Elimination of senescent cells in mice was shown to reduce incidence of age-related disorders and increase median survival. Both ABT-737 and its paralog ABT-263 induce clearance of senescent cells in variety of in vivo systems. This study shows for the first time that regardless of the functionality of the immune system, and with no genetic manipulation, it is possible to eliminate senescent cells in vivo and to modulate aging in mice by treating them with BCL-2 family inhibitors.”
Evidence that Type 2 Diabetes Causes Erectile Dysfunction
Although long-observed that male patients with type 2 diabetes have erectile dysfunction (ED), the link hasn’t been completely made because not many clinical trials have linked ED as an outcome of improved glucose control. Now, researchers with the University of Exeter and the University of Oxford published a large-scale genomic analysis in the American Journal of Human Genetics that suggests a genetic link between ED and type 2 diabetes.
The study looked at data on 220,000 men across three cohorts, 6,000 with ED. The data was drawn from the UK Biobank, the Estonian Genome Center of the University of Tartu cohort, and hospital-recruited Partners HealthCare Biobank.
“Erectile dysfunction affects at least one in five men over 60, yet up until now little has been known about its cause,” stated Anna Murray, lead author of the study, with the University of Exeter Medical School. “Our paper echoes recent findings that the cause can be genetic, and it goes further. We found that a genetic predisposition to type 2 diabetes is linked to erectile dysfunction. That may mean that if people can reduce their risk of diabetes through healthier lifestyles, they may also avoid developing erectile dysfunction.”
A New Atlas of Osteoporosis Genetic Influences
Researchers at McGill University published an atlas in the journal Nature Genetics that identified 518 genome-wide loci, 301 that are newly discovered, that explain 20 percent of the genetic variance associated with osteoporosis.
“Our findings represent significant progress in highlighting drug development opportunities,” stated Brent Richards, lead investigator, geneticist at the Lady Davis Institute (LDI) at the Jewish General Hospital (JGH)’s Centre for Clinical Epidemiology. “This set of genetic changes that influence BMD provides drug targets that are likely to be helpful for osteoporotic fracture prevention.”
The researchers looked at more than 426,000 people in the UK Biobank. They analyzed the data, refining their search to isolate a set of genes that very strongly enriched for known drug targets.
John Morris, lead author of the study, also from the LDI and McGill University, stated, “Although we found many genetic factors associated with BMD, the kind of precision medicine that genetics offers should allow us to home in on those factors that can have the greatest effect on improving bone density and lessening the risk of fracture.”