The week’s most astounding developments from the neobiological frontier.

May 19, 2022

Urolithin A increases muscle strength in clinical trial

A small, 4-month clinical trial of 88 middle-aged people randomized to swallow either placebo pills or oral doses of a compound known as urolithin A showed those taking the supplements had a 12 percent increase in muscle strength and clinically meaningful improvements in aerobic endurance—according to researchers at the company Amazentis in Lausanne, Switzerland, who conducted the trial. The study tested the company’s own urolithin A product, which is marketed as Mitopure. Urolithin A is a metabolite produced by gut microbes when fed specific precursor chemicals found in foods like pomegranates and pistachios. The researchers claim it improves the health of mitochondria in muscle cells by activating mitophagy and removing dysfunctional mitochondria. Improving mitochondrial health, the researchers write, is a “viable strategy to improve muscle health.” Cell Reports Medicine

Two more pig kidneys transplanted into humans

Doctors at New York University announced this week they successfully connected two kidneys from genetically modified pigs to the circulatory systems of two people who were already brain dead and being kept alive by ventilators. Once attached, the kidneys remained viable and functioning for more than two days, with no signs of rejection. They took on a healthy pink color, and immediately began filtering the blood and producing urine. Supplied by Revivicor, a subsidiary of the Silver Spring, Maryland-based biotech company United Therapeutics, the pigs were genetically engineered to remove a key gene called alpha-1,3-galactosyltransferase, which is responsible for hyper-acute rejection. All mammals except humans, apes, and old-world monkeys carry this gene, so the human immune system will strongly recognize a transplanted organ from another species as “non-self” and vigorously reject it unless the gene is removed. New England Journal of Medicine

First AI to predict risk of mental health emergencies

Researchers at Koa Health in Barcelona, Spain, have designed a machine learning algorithm that can predict a person’s mental health crisis on the basis of electronic health records alone and details like the severity of someone’s symptoms, their age, how long they have been in treatment, their history of past mental health crises, and evidence of any missed or unplanned hospital appointments. The results of a test analyzing almost 6 million medical records of 17,122 people showed the algorithm largely agreed with the professional assessments of human doctors and that its evaluations could be clinically useful. Designed to flag at-risk people on the verge of a deteriorating crisis, the tool could help identify people who might otherwise fall through the cracks, and help prioritize those most at-risk patients for clinicians. Nature Medicine

The stress-buffering effects of hugging—for women

A 20-second embrace of a romantic partner prior to a stressful situation was shown to reduce the release of the stress hormone cortisol in women in a clinical trial involving 76 people. The same effect was not seen in men, or the cohort of women who did not hug their partner. According to psychologists at Ruhr University Bochum in Germany, who conducted the study, the sex difference could be related to varying levels of oxytocin released by men and women following an embrace. Previous studies have demonstrated that oxytocin levels are increased in the human body by social touch, and this is hypothesized to drive the decreased cortisol secretion. The researchers say their new results confirm that a quick hug from their partner prior to something like a major test or job interview could reduce their cortisol response and lower their stress—to which some men will respond, “You call a 20 second-long hug quick?!” PLOS ONE

The longevity secrets of lowly rodents

Despite how diligently we try to therapeutically extend the lifespans or healthspans of humans by a few years, our best efforts are likely to pale in comparison to Mother Nature, which has endowed some mammals with extraordinarily long maximum lifespans, sometimes 100-fold longer than other, similar mammals. Hoping to tease out the genetic secrets of mammalian longevity, scientists at the University of Rochester in New York conducted a comparative transcriptomics analysis of 26 species of mice, moles, and other rodent-like creatures with diverse lifespans. They cataloged thousands of genes with expression levels negatively or positively correlated with an individual species’ maximum lifespan. In general they found genes negatively correlated with lifespan were involved in energy metabolism and inflammation—and conversely those linked to longer life were involved in things like DNA repair. Cell Metabolism

Evidence of self-medicating among dolphins

After several wild Indo-Pacific bottlenose dolphins were observed queuing up and repeatedly swimming by and rubbing their backs on leather corals and Incinia sponges in the Northern Red Sea across from Egypt, researchers at Justus Liebig University in Giessen, Germany, took samples of those sea invertebrates and chemically analyzed them. They found seventeen active metabolites in the corals and sponges, which they say is a newfound example of what’s called “zoopharmacognosy,” where animals self-medicate by eating or topically applying plants, soils, insects, or other matter. Repeated rubbing against the corals and sponges with their skin releases the active metabolites which researchers hypothesize could be a protection or treatment against microbial infections. The same sort of unexplained rubbing behavior has been observed in killer whales and beluga whales. iScience

A dolphin with a fungal infection on its dorsal fin. Angela Ziltener CC BY-SA