Life-saving predictions from the ICU

Similar to the “precogs” who predict crime in the movie Minority Report, but for sepsis, the deadly response to infection. Read more

Five hot projects at Emory in 2017

Five hot projects at Emory in 2017: CRISPR gene editing for HD, cancer immunotherapy mechanics, memory enhancement, Zika immunology, and antivirals from Read more

Shaking up thermostable proteins

Imagine a shaker table, where kids can assemble a structure out of LEGO bricks and then subject it to a simulated earthquake. Biochemists face a similar task when they are attempting to design thermostable proteins, with heat analogous to shaking. Read more

Ray Dingledine

A push for reproducibility in biomedical research

Editor’s note: guest post from Neuroscience graduate student Erica Landis.

Neuroscience graduate student Erica Landis

Evidence is increasing that lack of reproducibility, whatever the cause, is a systemic problem in biomedical science. While institutions like the NIH and concerned journal editors are making efforts to implement more stringent requirements for rigorous and reproducible research, scientists themselves must make conscious efforts to avoid common pitfalls of scientific research. Here at Emory, several scientists are making greater efforts to push forward to improve scientific research and combat what is being called “the reproducibility crisis.”

In 2012, C. Glenn Begley, then a scientist with the pharmaceutical company Amgen, published a commentary in Nature on his growing concern for the reproducibility of preclinical research. Begley and his colleagues had attempted to replicate 53 published studies they identified as relevant to their own research into potential pharmaceuticals. They found that only 6 of the 53 publications could be replicated; even with help from the original authors. Similar studies have consistently found that greater than 50 percent of published studies could not be replicated. This sparked a period of great concern and questioning for scientists. It seemed to Begley and others that experimenter bias, carelessness, poor understanding of statistics, and the career-dependent scramble to publish contributes to a misuse of the scientific method. These factors contribute to what is now called the reproducibility crisis. In April 2017, Richard Harris published Rigor Mortis, a survey of the problem in preclinical research, which has kept the conversation going and left many wondering what the best solution to these issues could be. To combat the reproducibility crisis, Harris argues that funding agencies, journal editors and reviewers, research institutions, and scientists themselves all have a role to play.

Read more

Posted on by Quinn Eastman in Uncategorized Leave a comment

Insane in the membrane – inflamed in the brain

Inflammation in the brain is a feature of several neurological diseases, ranging from Parkinson’s and Alzheimer’s to epilepsy. Nick Varvel, a postdoc with Ray Dingledine’s lab at Emory, was recently presenting his research and showed some photos illustrating the phenomenon of brain inflammation in status epilepticus (prolonged life-threatening seizures).

The presentation was at a Center for Neurodegenerative Disease seminar; his research was also published in PNAS and at the 2016 Society for Neuroscience meeting.green-red-brain

Varvel was working with mice in which two different types of cells are marked by fluorescent proteins. Both of the cell types come originally from the blood and can be considered immune cells. However, one kind – marked with green — is in the brain all the time, and the red kind enters the brain only when there is an inflammatory breach of the blood brain barrier.

Both markers, CX3CR1 (green) and CCR2 (red), are chemokine receptors. Green fluorescent protein is selectively produced in microglia, which settle in the brain before birth and are thought to have important housekeeping/maintenance functions.

Monocytes, a distinct type of cell that is not usually in the brain in large numbers, are lit up red. Monocytes rush into the brain in status epilepticus, and in traumatic brain injury, hemorrhagic stroke and West Nile virus encephalitis, to name some other conditions where brain inflammation is also seen.

In the PNAS paper, Varvel and his colleagues include a cautionary note about using these mice for studying situations of more prolonged brain inflammation, such as neurodegenerative diseases: the monocytes may turn down production of the red protein over time, so it’s hard to tell if they’re still in the brain after several days.

Targeting CCR2 – good or bad? Depends on the disease model

The researchers make the case that “inhibiting brain invasion of CCR2+ monocytes could represent a viable method for alleviating several deleterious consequences of status epilepticus.” Read more

Posted on by Quinn Eastman in Immunology, Neuro Leave a comment

COX-2 and epilepsy: it’s complicated

How much is the development of epilepsy like arthritis?

More than you might expect. Inflammation, or the overactivation of the immune system, appears to be involved in both. In addition, for both diseases, inhibiting the enzyme COX-2 initially looked like a promising approach.

Ray Dingledine, PhD

COX-2 (cyclooxygenase 2) is a target of traditional non-steroid anti-inflammatory drugs like aspirin and ibuprofen, as well as more selective drugs such as Celebrex. With arthritis, selectively inhibiting COX-2 relieves pain and inflammation, but turns out to have the side effect of increasing the risk of heart attack and stroke.

In the development of epilepsy, inhibiting COX-2 turns out to be complicated as well. Ray Dingledine, chair of pharmacology at Emory, and colleagues have a new paper showing that COX-2 has both protective and harmful effects in mice after status epilepticus, depending on the timing and what cells the enzyme comes from. Status epilepticus is a period of continuous seizures leading to neurodegeneration, used as a model for the development of epilepsy.

Postdoc Geidy Serrano, now at the Banner Sun Health Research Institute in Arizona, is first author of the paper in Journal of Neuroscience. She and Dingledine were able to dissect COX-2’s effects because they engineered mice to have a deletion of the COX-2 gene, but only in some parts of the brain.
They show that deleting COX-2 in the brain reduces the level of inflammatory molecules produced by neurons, but this is the reverse effect of deleting it all over the body or inhibiting the enzyme with drugs.

Four days after status epilepticus, fewer neurons are damaged (bright green) in the neuronal COX-2 knockout mice.

Dingledine identified two take-home messages from the paper:
First, COX-2 itself is probably not a good target for antiepileptic therapy, and it may be better to go downstream, to prostaglandin receptors like EP2.
Second, the timing of intervention will be important, because the same enzyme has opposing actions a few hours after status epilepticus compared to a couple days later.

More of Dingledine’s thinking about inflammation in the development of epilepsy can be found in a recent review.

Posted on by Quinn Eastman in Neuro Leave a comment