An occasional roundup of news items Vector finds noteworthy.
Zika’s surface in stunning detail; mosquito tactics
We haven’t curbed the Zika epidemic yet. But cryo-electron microscopy — a newer, faster alternative to X-ray crystallography — at least reveals the structure of the virus, which has been linked to microcephaly (though not yet definitively). The anatomy of the virus’s projections gives clues to how the virus is able to attach to and infect cells, and could provide toeholds for developing antiviral treatments and vaccines. Read coverage in the Washington Post and see the full paper in Science.
Meanwhile, as The New York Times reports, scientists are coming together in an effort to control Zika by genetically manipulating the mosquito that spreads it, Aedes aegypti. …
Second in a two-part series on nerve regeneration. Read part 1.
The search for therapies to spur regeneration after spinal cord injury, stroke and other central nervous system injuries hasn’t been all that successful to date. Getting nerve fibers (axons) to regenerate in mammals, typically lab mice, has often involved manipulating oncogenes or tumor suppressor genes to encourage growth, a move that could greatly increase a person’s risk of cancer.
Nerve regeneration. From Santiago Ramón y Cajal’s “Estudios sobre la degeneración y regeneración del sistema nervioso” (1913-14). Via Scholarpedia.
First in a two-part series on nerve regeneration. Read part 2.
Researchers have tried for a century to get injured nerves in the brain and spinal cord to regenerate. Various combinations of growth-promoting and growth-inhibiting molecules have been found helpful, but results have often been hard to replicate. There have been some notable glimmers of hope in recent years, but the goal of regenerating a nerve fiber enough to wire up properly in the brain and actually function again has been largely elusive.
“The majority of axons still cannot regenerate,” says Zhigang He, PhD, a member of the F.M. Kirby Neurobiology Center at Boston Children’s Hospital. “This suggests we need to find additional molecules, additional mechanisms.”
Microarray analyses—which show what genes are transcribed (turned on) in injured nerves—have helped to some extent, but the plentiful leads they turn up are hard to analyze and often don’t pan out. The problem, says Judith Steen, PhD, who runs a proteomics lab at the Kirby Center, is that even when the genes are transcribed, the cell may not actually build the proteins they encode.
That’s where proteomics comes in. “By measuring proteins, you get a more direct, downstream readout of the system,” Steen says. …
For more than a century, neuroscientists have been trying to figure out how to repair broken nerves in the spinal cord–and the rest of the central nervous system–after injury. They’ve produced a steady stream of promising discoveries–treatments that promote nerve growth in the laboratory dish and animals, even some reports of paralyzed rodents regaining motor function. So why are people with spinal cord injury (SCI) still without therapies that repair their nerve damage? …
Last Friday in Atlanta, a patient with spinal cord injuries, paralyzed from the waist down, became the first clinical trial subject to receive a treatment derived from embryonic stem cells. Despite widespread misreporting in the media, the patient didn’t receive embryonic stem cells directly — that’s well known to create teratomas. Instead, oligodendrocyte progenitor cells — precursors of the cells that form the insulating sheath around nerve fibers and have nerve growth-stimulating properties — were derived from embryonic stem cells and injected into the site of damage. …