Using single-cell RNA sequencing of deer antler at different stages of their annual cycle of regeneration, Chinese researchers have identified a progenitor cell population that drove antler regeneration. The authors of an accompanying editorial wrote the findings, which were published in the Feb. 24, 2023, issue of Science, “add to the emerging idea that blastema progenitor cells are a common stem cell type in mammalian appendage regeneration.”

In the larger picture, the fight against HIV has been a triumph of modern medicine. A patient diagnosed with HIV in the 1980s had a remaining life expectancy of 1 to 2 years. In 2023, they can expect to live another half century. But so far, an HIV vaccine has remained elusive. In the newest phase III failure, Janssen Pharmaceutical Cos. of Johnson and Johnson closed down its Mosaico trial more than a year ahead of schedule, following a data and safety monitoring board’s (DSMB) report saying the study was not expected to hit its primary endpoint.

Psychedelic drugs may exert their effects at intracellular serotonin receptors that serotonin itself, which does not cross cell membranes, cannot reach. The findings were published in the Feb. 17, 2023, issue of Science by researchers from the University of California at Davis.

Psychedelic drugs may exert their effects at intracellular serotonin receptors that serotonin itself, which does not cross cell membranes, cannot reach. The findings were published in the Feb. 17, 2023, issue of Science by researchers from the University of California at Davis. An accompanying editorial by Evan Hess and Todd Gould at the University of Maryland School of Medicine called them “a key achievement in the understanding of the mechanism of action of psychedelics” and “an important step forward for a rapidly ex­panding and much-needed field of study.”

Heart failure is a common condition: according to a new study in 11 high-income countries, an estimated 1-2% of the population has heart failure. One feature of late-stage heart failure is nicotine adenine dinucleotide (NAD+), which leaves heart muscle cells unable to generate sufficient ATP to meet their energy needs. Now, investigators at The Hospital for Sick Children and the University of Toronto have shown that this metabolic dysfunction is present early in heart failure, and precedes any sign of clinical dysfunction in the heart.

Compared to the issues that come with, say, a failing liver, skin aging can look like more of a vanity problem. But aging in both tissues, and multiple others, is driven by the same underlying molecular mechanisms. One of those mechanisms is fibrosis, the cross-linking of extracellular matrix (ECM) proteins that leads to tissue stiffening. Anti-aging company Cambrian Biopharma Inc. has argued that stiffening of the ECM should be considered one of the formal hallmarks of aging.

The shunt towards, or away from, cognitive decline may happen decades before such decline becomes clinically evident. And known risk factors explain very little of that decline. That is the conclusion reached by researchers from the Ohio State University, who published their results in the Feb. 8, 2023, issue of PLOS ONE.

In their analysis, the team looked at both the absolute level of cognitive function in about 7,000 participants of the U.S. Health and Retirement Study at age 54, and at the decline in cognitive function from age 54 to 85. The study participants that were analyzed were born between 1931 and 1941. The results were reminiscent of the adage that the way to make a silk purse out a sow’s ear is to start with a silk sow.