Researchers unlock new mechanism in pain management

It’s in the brain where we perceive the unpleasant sensations of pain, and researchers have long been examining how calcium channels in the brain and peripheral nervous system contribute to the development of chronic pain conditions.

Neuroscientist Gerald Zamponi, PhD, and his team at the University of Calgary’s Hotchkiss Brain Institute have discovered a new mechanism that can reverse chronic pain. Using an animal model, their research has found that pain signals in nerve cells can be shut off by interfering with the communication of a specific enzyme with calcium channels, a group of important proteins that control nerve impulses.

Their Canadian Institutes of Health Research-funded study was published in the September issue of Neuron — one of the most influential journals in the field of neuroscience.

Zamponi is now applying his research and partnering with the Centre for Drug Research and Development (CDRD) in Vancouver to develop a drug that could one day improve the lives of those with inflammatory pain such as arthritis, irritable bowel disease or neuropathic pain. Their approach may be able to reduce the pain associated with these conditions.

Opening the door to new treatments

“Chronic pain can be a debilitating condition that affects many people and is often poorly controlled by currently available treatments.  Therefore, new treatment avenues are needed. Our discovery opens the door towards new treatments, and based on the data that we have so far, it is a viable strategy,” says Zamponi, the lead author of the study and senior associate dean of research at the Cumming School of Medicine.

With CDRD, Zamponi and his team are screening more than 100,000 molecules in hopes of finding one that would stop the enzyme from communicating with the calcium channel. If they can isolate the right molecule, they can potentially turn it into a drug. So far, they have already found two viable molecules that have been validated by his group as painkillers in animals.

Promising innovation from basic research

Commercialization of the project Zamponi and his team are working on is one of six funded through the competition of the Alberta/Pfizer Translational Research Fund Opportunity. “AIHS is delighted that the strong partnership created with Pfizer, Western Economic Diversification, and Alberta Innovation and Advanced Education is helping to develop promising innovations from basic research into technologies, drugs, and tools to improve health,” says Dr. Cy Frank, president and CEO of Alberta Innovates – Health Solutions.

The Alberta/Pfizer Translational Research Fund Opportunity is a partnership between Pfizer Canada Inc., Alberta Innovates – Health Solutions, Alberta’s Ministry of Innovation and Advanced Education, and Western Economic Diversification Canada. This partnership will provide opportunities to focus on the development and commercialization of innovations in health. More than $3.25 million has been committed to identify and support promising health-care innovations with market potential.

Learning how the brain takes out its trash may help decode neurological diseases

Imagine that garbage haulers don’t exist. Slowly, the trash accumulates in our offices, our homes, it clogs the streets and damages our cars, causes illness and renders normal life impossible.

Garbage in the brain, in the form of dead cells, must also be removed before it accumulates, because it can cause both rare and common neurological diseases, such as Parkinson’s. Now, University of Michigan researchers are a leap closer to decoding the critical process of how the brain clears dead cells, said Haoxing Xu, associate professor in the U-M Department of Molecular, Cellular and Developmental Biology.

A new U-M study identified two critical components of this cell clearing process: an essential calcium channel protein, TRPML1, that helps the so-called garbage collecting cells, called microphages or microglia, to clear out the dead cells; and alipid molecule, which helps activate TRPML1 and the process that allows the microphages to remove these dead cells.

Moreover, the Xu lab identified a synthetic chemical compound that can activate TRPML1. Because this chemical compound ultimately helps activate this cell-clearing process, it provides a drug target that could help combat these neurological diseases.

"This is clearly a drug target," Xu said. "What this paper picks out is exactly what is going wrong in this process."

Scientists began by looking at a very rare neurodegenerative disease called Type IV Mucolipidosis, a childhood neurodegenerative disease characterized by multiple disabilities.

Xu’s group found that lack of TRPML1 function, which is the channel through which calcium is released from the lysosome—the cell’s recycling center—into the microphage cells, contributes to these neurodegenerative conditions. If this calcium channel doesn’t work, calcium cannot be released, and dead cells aren’t removed, Xu said. The synthetic chemical compound stimulates the TRPML1 calcium channel to release the calcium into the cell.

Further, dead cells “are bad for live cells,” Xu said. An excess of dead cells leads the macrophage cells to also kill healthy neurons necessary for neurological function, which in turn can lead to these neurodegenerative diseases.

There are many neurodegenerative diseases, some very rare and some more common, such as Parkinson’s and ALS. The common thread among them is the dearth of live and functioning neurons, which prevents the neurological system from carrying out normal functions, Xu said.

Thus, identifying a lipid molecule and also chemical compounds that stimulates proper function of the TRMPL1 function could revolutionize the treatment of these neurodegenerative diseases.

The next step in Xu’s research is to test how these general observations are helpful to the neurological diseases and whether the compound is effective in animal models of neurological diseases.

The paper, “A TRP channel in the lysosome regulates large particle phagocytosis via focal exocytosis,” appeared Aug. 29 online in Developmental Cell.

5 Disorders Share Genetic Risk Factors, Study Finds

The psychiatric illnesses seem very different — schizophrenia, bipolar disorder, autism, major depression and attention deficit hyperactivity disorder. Yet they share several genetic glitches that can nudge the brain along a path to mental illness, researchers report. Which disease, if any, develops is thought to depend on other genetic or environmental factors.

Their study, published online Wednesday in the Lancet, was based on an examination of genetic data from more than 60,000 people worldwide. Its authors say it is the largest genetic study yet of psychiatric disorders. The findings strengthen an emerging view of mental illness that aims to make diagnoses based on the genetic aberrations underlying diseases instead of on the disease symptoms.

Two of the aberrations discovered in the new study were in genes used in a major signaling system in the brain, giving clues to processes that might go awry and suggestions of how to treat the diseases.

“What we identified here is probably just the tip of an iceberg,” said Dr. Jordan Smoller, lead author of the paper and a professor of psychiatry at Harvard Medical School and Massachusetts General Hospital. “As these studies grow we expect to find additional genes that might overlap.”

The new study does not mean that the genetics of psychiatric disorders are simple. Researchers say there seem to be hundreds of genes involved and the gene variations discovered in the new study confer only a small risk of psychiatric disease.

Steven McCarroll, director of genetics for the Stanley Center for Psychiatric Research at the Broad Institute of Harvard and M.I.T., said it was significant that the researchers had found common genetic factors that pointed to a specific signaling system.

“It is very important that these were not just random hits on the dartboard of the genome,” said Dr. McCarroll, who was not involved in the new study.

The work began in 2007 when a large group of researchers began investigating genetic data generated by studies in 19 countries and including 33,332 people with psychiatric illnesses and 27,888 people free of the illnesses for comparison. The researchers studied scans of people’s DNA, looking for variations in any of several million places along the long stretch of genetic material containing three billion DNA letters. The question: Did people with psychiatric illnesses tend to have a distinctive DNA pattern in any of those locations?

Researchers had already seen some clues of overlapping genetic effects in identical twins. One twin might have schizophrenia while the other had bipolar disorder. About six years ago, around the time the new study began, researchers had examined the genes of a few rare families in which psychiatric disorders seemed especially prevalent. They found a few unusual disruptions of chromosomes that were linked to psychiatric illnesses. But what surprised them was that while one person with the aberration might get one disorder, a relative with the same mutation got a different one.

Jonathan Sebat, chief of the Beyster Center for Molecular Genomics of Neuropsychiatric Diseases at the University of California, San Diego, and one of the discoverers of this effect, said that work on these rare genetic aberrations had opened his eyes. “Two different diagnoses can have the same genetic risk factor,” he said.

In fact, the new paper reports, distinguishing psychiatric diseases by their symptoms has long been difficult. Autism, for example, was once called childhood schizophrenia. It was not until the 1970s that autism was distinguished as a separate disorder.

But Dr. Sebat, who did not work on the new study, said that until now it was not clear whether the rare families he and others had studied were an exception or whether they were pointing to a rule about multiple disorders arising from a single genetic glitch.

“No one had systematically looked at the common variations,” in DNA, he said. “We didn’t know if this was particularly true for rare mutations or if it would be true for all genetic risk.” The new study, he said, “shows all genetic risk is of this nature.”

The new study found four DNA regions that conferred a small risk of psychiatric disorders. For two of them, it is not clear what genes are involved or what they do, Dr. Smoller said. The other two, though, involve genes that are part of calcium channels, which are used when neurons send signals in the brain.

“The calcium channel findings suggest that perhaps — and this is a big if — treatments to affect calcium channel functioning might have effects across a range of disorders,” Dr. Smoller said.

There are drugs on the market that block calcium channels — they are used to treat high blood pressure — and researchers had already postulated that they might be useful for bipolar disorder even before the current findings.

One investigator, Dr. Roy Perlis of Massachusetts General Hospital, just completed a small study of a calcium channel blocker in 10 people with bipolar disorder and is about to expand it to a large randomized clinical trial. He also wants to study the drug in people with schizophrenia, in light of the new findings. He cautions, though, that people should not rush out to take a calcium channel blocker on their own.

“We need to be sure it is safe and we need to be sure it works,” Dr. Perlis said.