Week in Review: July 13–17

Removing mtDNA mutations; mini brains for studying autism; HIV vaccine selectivity; “speed cells” in rat brain; more

Tracy Vence
Jul 17, 2015

Fixing mtDNA in stem cells

WIKIMEDIA, LOUISA HOWARDScientists from Oregon Health & Science University (OHSU) and their colleagues have effectively repaired mitochondrial DNA (mtDNA) defects in patient-derived induced pluripotent stem cells (iPSCs). Their work was published in Nature this week (July 15).

It may be a long path to the clinic, however, noted Robin Lovell-Badge of the Francis Crick Institute in London who was not involved in the study. “It’s going to be difficult to introduce cells in a way that you would help a patient,” he said. “You’ve got to substantially replace the cells of that patient.”

“It’s a first step, but we will follow up with further research,” agreed study coauthor Shoukhrat Mitalipov of OHSU’s Center for Embryonic Cell and Gene Therapy.

ASD mini brains

JESSICA MARIANILab-made miniature brains composed of patient-derived iPSCs could help researchers better understand the molecular mechanisms underlying the development of autism spectrum disorder (ASD), according to a study published in Cell this week (July 16). Researchers from Yale University and their colleagues have already gleaned new insights from these organoid models, including an association between ASD and an overproduction of inhibitory neurons.

“These are patients with idiopathic autism that do not share any genetic causes, and yet the authors find phenotypes shared between their cells. That’s impressive,” said neuroscientist and stem cell biologist Alysson Muotri of the University of California, San Diego, who was not involved in the study. “[There] seem to be key things that are dysregulated in all of them.”

Selective HIV vax

SCIENCE TRANSLATIONAL MEDICINE, C. BICKELThe mixed results of an HIV vaccination trial may have in part been the result of genetic differences among participants, according to a study published in Science Translational Medicine this week (July 16). Researchers from the Walter Reed Army Institute of Research and their colleagues identified a human leukocyte antigen (HLA) allele linked to reduced risk of HIV infection after vaccination among carriers.

“Understanding why [the vaccine] appeared to work in some individuals and may not have worked in others is really paramount to moving the field closer to an effective [HIV] vaccine,” said Bruce Walker, director at the Ragon Institute of Massachusetts General Hospital, MIT, and Harvard who was not involved in the work.

Adipocyte progenitors from marrow

WIKIMEDIA, OPENSTAX COLLEGEScientists at Sweden’s Karolinska Institute and their colleagues have found that donor-derived fat cells accounted for around 10 percent of all adipocytes examined in patients who received bone marrow transplants. The team’s results, which point to bone marrow as a source of adipocyte progenitors, were published in Cell Metabolism this week (July 16).

“In these bone marrow-transplanted individuals, they can actually find fat cells with genomic information from the donor and not from the recipient,” said Philipp Scherer, director of the Touchstone Diabetes Center at the University of Texas Southwestern Medical Center in Dallas who was not involved in the study.

Speedometer neurons

PIXABAY, GERALTIt took building motorized miniature cars for rats and manipulating the animals’ speeds in different environmental conditions for researchers at Norwegian University of Science and Technology (NTNU) and their colleagues to be able to identify a set of speed-linked neurons. The team’s results were published in Nature this week (July 15).

The next step, said study coauthor Edvard Moser, a neuroscientist at the Kavli Institute for Systems Neuroscience at NTNU, is to characterize the neurons. “We know that the cells are there; we don’t actually know which cells they are and how they interact with other cells.”

Salicylic acid shapes root microbiome

WIKIMEDIA, ALBERTO SALGUEROThe Arabidopsis thaliana defense hormone salicylic acid appears to promote the colonization of commensal microbes on the plant’s roots while warding off pathogens, according to a study published in Science this week (July 16). Investigators from the University of Tennessee, Knoxville, and their colleagues found evidence to suggest the hormone is a key regulator of root microbiome composition.

“This is the first study that really tied this phytohormone to the microbiome associated with the root,” said Xinnian Dong, a professor of biology at Duke University who was not affiliated with the work.

Other news in life science:

Krebs Nobel Auctioned
Proceeds from the sale of Hans Krebs’s Nobel Prize medal will support refugee scientists and student researchers.

Report: Plant Biologist Guilty of Misconduct
Investigators find that RNAi researcher Olivier Voinnet willfully misrepresented data published in several journals.

More Transparency in IRB-Industry Ties
Conflicts of interest among institutional review board members are disclosed more often than they were a decade ago, according to a survey of academics.

A Smaller World for Bumblebees
Warming temperatures have shrunk the bumblebee’s geographic range in Europe and North America, a study shows.