I3 Venture awards info

Emory is full of fledgling biomedical proto-companies. Some of them are actual corporations with employees, while others are ideas that need a push to get them to that point. Along with the companies highlighted by the Emory Biotech Consulting Club, Dean Sukhatme’s recent announcement of five I3 Venture research awards gives more examples of early stage research projects with commercial potential. This is the third round of the I3 awards; the first two were Wow! Read more

Take heart, Goldilocks -- and get more sleep

Sleeping too little or too much increases the risk of cardiovascular events and death in those with coronary artery disease, according to a new paper from Emory Clinical Cardiovascular Research Institute. Others have observed a similar U-shaped risk curve in the general population, with respect to sleep duration. The new study, published in American Journal of Cardiology, extends the finding to people who were being evaluated for coronary artery disease. Arshed Quyyumi, MD and colleagues analyzed Read more

Repurposing a transplant drug for bone growth

The transplant immunosuppressant drug FK506, also known as tacrolimus or Prograf, can stimulate bone formation in both cell culture and animal Read more

Andrew Escayg

Epilepsy pick up sticks

Imagine the game of pick up sticks. It’s hard to extract one stick from the pile without moving others. The same problem exists, in a much more complex way, in the brain. Pulling on one gene or neurotransmitter often nudges a lot of others.

Andrew Escayg, PhD

That’s why a recent paper from Andrew Escayg’s lab is so interesting. He studies genes involved in epilepsy. Several years ago, he showed that mice with mutations in the SCN8A gene have absence epilepsy, while also showing resistance to induced seizures. SCN8A is one of those sticks that touches many others. The gene encodes a voltage-gated sodium channel, involved in setting the thresholds for and triggering neurons’ action potentials. Mutating the gene in mice modifies sleep and even enhances spatial memory.

Escayg’s new paper, with first author Jennifer Wong, looks at the effect of “knocking down” SCN8A in the hippocampus in a mouse model of mesial temporal lobe epilepsy. This model doesn’t involve sodium channel genes; it’s generated by injection of a toxin (kainic acid) into the brain. The finding suggests that inhibiting SCN8A may be applicable to other forms of epilepsy. Escayg notes that mesial temporal lobe epilepsy is one of the most common forms of treatment-resistant epilepsy in adults.

Knocking down SCN8A in the hippocampus 24 hours after injection could prevent the development of seizures in 90 percent of the treated mice. “It is likely that selective reduction in Scn8a expression would have directly decreased neuronal excitability,” the authors write. It did not lead to increased anxiety levels or impaired learning/memory.

Currently, no available drugs target Scn8a specifically. However, antisense approaches for neurodegenerative diseases have been gaining ground – perhaps epilepsy could fit in.

Posted on by Quinn Eastman in Neuro Leave a comment

Nerve gas, angel dust and genetic epilepsy

Last week, Lab Land noticed similarities between two independent lines of research from the Escayg and Traynelis/Yuan labs at Emory. Both were published recently and deal with rare forms of genetic epilepsy, in which molecular understanding of the cause leads to individualized treatment, albeit with limited benefit.

Both conditions are linked to an excess of neuronal excitation, and both can be addressed using medications that have also been tested for Alzheimer’s. A critical difference is that memantine is FDA-approved for Alzheimer’s, but huperzine A is not.

What condition? Dravet syndrome/GEFS+ Epilepsy-aphasia syndrome
What gene is mutated? SCN1A – sodium ion channel GRIN2A – NMDA receptor subunit
What is the beneficial drug? Huperzine A Memantine
How does the drug work? Acetylcholinesterase inhibitor NMDA receptor antagonist
Other drugs that use the same mechanism Alzheimer’s medications such as donepezil

Irreversible + stronger: insecticides, nerve gas

Ketamine, phencyclidine (aka PCP)
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Four take-home thoughts on NGLY1

Please check out our feature in Emory Medicine magazine about two sisters with NGLY1 deficiency. This rare genetic disorder was identified only a few years ago, and now a surge of research is directed toward uncovering its mysteries.

  1. The Stinchcombs are amazing. Seth Mnookin’s July 2014 piece in the New Yorker, and especially, his comments at the end of an interview with The Open Notebook drove me to contact them. “The father cares for the two girls with this disease full time. The mother is working insane hours. And while all this is going on, they’re the most good-natured … I don’t know, they just seem like they’re happy.”
  1. Several research teams around the world are investigating NGLY1 deficiency and potential remedies. For the magazine article, I talked with Emory geneticist Michael Gambello, Hudson Freeze at Sanford Burnham and Lynne Wolfe at the NIH Undiagnosed Diseases Program. Even more: the Grace Science Foundation, established by the Wilsey family, is supporting research at Retrophin/Notre Dame and Gladstone/UCSF. The independent Perlstein lab is investigating NGLY1 deficiency in fruit flies (reminiscent of Emory research from a decade ago on Fragile X syndrome).
  1. There’s a long road ahead for rare genetic disorders such as NGLY1 deficiency. That’s why the title that EM editor Mary Loftus came up with, “In time to help Jessie,” is so poignant. When I read Abby Goodnough’s New York Times piece on RCDP, which is a rare inherited bone disease that also involves seizures, I thought: “That could be NGLY1 in ten years.” Still, progress is possible, as demonstrated by this recent NEJM report on exome sequencing and neurometabolic disorders from British Columbia.

Read more

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