Epilepsy drug therapies to be improved by new targeted approach

New research from the University of Liverpool, in collaboration with the Mario Negri Institute in Milan, published today in the Journal of Clinical Investigation, has identified a protein that could help patients with epilepsy respond more positively to drug therapies.

Epilepsy continues to be a serious health problem and is the most common serious neurological disease. Despite 30 years of drug development, approximately 30% of people with epilepsy do not become free of fits (also called seizures) with currently available drugs.

New, more effective drugs are therefore required for these individuals. We do not fully understand why some people develop seizures, why some go onto develop epilepsy (continuing seizures), and most importantly, why some patients cannot be controlled with current drugs.

Inflammation

There is now increasing body of evidence suggesting that local inflammation in the brain may be important in preventing control of seizures. Inflammation refers to the process by which the body reacts to insults such as having a fit. In most cases, the inflammation settles down, but in a small number of patients, the inflammation continues.

The aim of the research, undertaken by Dr Lauren Walker while she was a Medical Research Council (MRC) Clinical Training Fellow, was to address the important question of how can inflammation be detected by using blood samples, and whether this may provide us with new ways of treating patients in the future to reduce the inflammation and therefore improve seizure control.

The research focused on a protein called high mobility group box-1 (HMGB1), which exists in different forms in tissues and bloodstream (called isoforms), as it can provide a marker to gauge the level of inflammation present.

Predicting drug response

The results showed that there was a persistent increase in these isoforms in patients with newly-diagnosed epilepsy who had continuing seizure activity, despite anti-epileptic drug therapy, but not in those where the fits were controlled.

An accompanying drug study also found that HMGB1 isoforms may predict how an epilepsy patient’s seizures will respond to anti-inflammatory drugs.

Dr Lauren Walker, said: “Our data suggest that HMGB1 isoforms represent potential new drug targets, which could also identify which patients will respond to anti-inflammatory therapies. This will require evaluation in larger-scale prospective trials.”

Innovative scheme

Professor Sir Munir Pirmohamed, Director of the MRC Centre for Drug Safety Science and Programme lead for the MRC Clinical Pharmacology scheme, said: “The MRC Clinical Pharmacology scheme is a highly successful scheme to train “high flyers” who are likely to become future leaders in academia and industry.

“Dr Walker’s research is testament to this and shows how this innovative scheme, which was jointly funded by the MRC and Industry, can tackle areas of unmet clinical need, and identify new ways of treating patients with epilepsy using a personalised medicine approach”.

Antibiotics Weaken Alzheimer’s Disease Progression Through Changes in the Gut Microbiome

Long-term treatment with broad spectrum antibiotics decreased levels of amyloid plaques, a hallmark of Alzheimer’s disease, and activated inflammatory microglial cells in the brains of mice in a new study by neuroscientists from the University of Chicago.

The study, published July 21, 2016, in Scientific Reports, also showed significant changes in the gut microbiome after antibiotic treatment, suggesting the composition and diversity of bacteria in the gut play an important role in regulating immune system activity that impacts progression of Alzheimer’s disease.

“We’re exploring very new territory in how the gut influences brain health,” said Sangram Sisodia, PhD, Thomas Reynolds Sr. Family Professor of Neurosciences at the University of Chicago and senior author of the study. “This is an area that people who work with neurodegenerative diseases are going to be increasingly interested in, because it could have an influence down the road on treatments.”

Two of the key features of Alzheimer’s disease are the development of amyloidosis, accumulation of amyloid-ß (Aß) peptides in the brain, and inflammation of the microglia, brain cells that perform immune system functions in the central nervous system. Buildup of Aß into plaques plays a central role in the onset of Alzheimer’s, while the severity of neuro-inflammation is believed to influence the rate of cognitive decline from the disease.

For this study, Sisodia and his team administered high doses of broad-spectrum antibiotics to mice over five to six months. At the end of this period, genetic analysis of gut bacteria from the antibiotic-treated mice showed that while the total mass of microbes present was roughly the same as in controls, the diversity of the community changed dramatically. The antibiotic-treated mice also showed more than a two-fold decrease in Aß plaques compared to controls, and a significant elevation in the inflammatory state of microglia in the brain. Levels of important signaling chemicals circulating in the blood were also elevated in the treated mice.

While the mechanisms linking these changes is unclear, the study points to the potential in further research on the gut microbiome’s influence on the brain and nervous system.

“We don’t propose that a long-term course of antibiotics is going to be a treatment—that’s just absurd for a whole number of reasons,” said Myles Minter, PhD, a postdoctoral scholar in the Department of Neurobiology at UChicago and lead author of the study. “But what this study does is allow us to explore further, now that we’re clearly changing the gut microbial population and have new bugs that are more prevalent in mice with altered amyloid deposition after antibiotics.”

The study is the result of one the first collaborations from the Microbiome Center, a joint effort by the University of Chicago, the Marine Biological Laboratory and Argonne National Laboratory to support scientists at all three institutions who are developing new applications and tools to understand and harness the capabilities of microbial systems across different fields. Sisodia, Minter and their team worked with Eugene B. Chang, Martin Boyer Professor of Medicine at UChicago, and Vanessa Leone, PhD, a postdoctoral scholar in Chang’s lab, to analyze the gut microbes of the mice in this study.

Minter said the collaboration was enabling, and highlighted the cross-disciplinary thinking necessary to tackle a seemingly intractable disease like Alzheimer’s. “Once you put ideas together from different fields that have largely long been believed to be segregated from one another, the possibilities are really amazing,” he said.

Sisodia cautioned that while the current study opens new possibilities for understanding the role of the gut microbiome in Alzheimer’s disease, it’s just a beginning step.

“There’s probably not going to be a cure for Alzheimer’s disease for several generations, because we know there are changes occurring in the brain and central nervous system 15 to 20 years before clinical onset,” he said. “We have to find ways to intervene when a patient starts showing clinical signs, and if we learn how changes in gut bacteria affect onset or progression, or how the molecules they produce interact with the nervous system, we could use that to create a new kind of personalized medicine.”