Unraveling the mysteries of the mitochondria in Huntington’s disease – and getting fast, clear, and useful results from research studies

In the collaborative quest for Huntington’s disease treatments, deepening affected families’ understanding of the key scientific challenges is vital. It can demystify the process of research, inspire involvement in investigative studies and clinical trials, and ultimately bolster the chances of defeating this horrible malady.

Noting the global nature of HD research, last month I highlighted key work on the West Coast of the United States. Andrew F. Leuchter, M.D., and Michael Levine, Ph.D., plan to measure brain energy waves to decipher the signals emitting from HD-affected individuals. Their work could ultimately lead to new drugs (click here to read more).

On the East Coast, at the Magnetic Resonance Research Center (MRRC) of the Yale School of Medicine, Doug Rothman, Ph.D., and his collaborators will conduct two unique studies that seek to unravel long-standing mysteries about Huntington’s and the mitochondria, the complex powerhouses of most of our cells.

“All the brain cells depend on them very heavily,” Dr. Rothman said during an interview at the MRRC on April 12.

Mitochondria came onto the evolutionary path about a billion years ago, he noted. They use oxygen to burn fuels (such as glucose, or common sugar) to provide energy for brain cells. In focusing on the mitochondria, Dr. Rothman’s studies aim to shed light on the serious energy deficits caused in HD and to provide tools for improving clinical trials.

As the Huntington’s community ramps up to a growing number of those trials, the paramount work of these scientists can help insure clear and useful results.

A mitochondrian (Wikipedia diagram by Mariana Ruiz Villarreal)

Novel and unique human studies

In people carrying the HD genetic abnormality, why do so many brain cells become damaged and eventually die, leading to HD symptoms? For decades, scientists researching this question mainly in animals and cell cultures have found much evidence implicating the mitochondria in the cells’ problems. However, they still don’t know exactly what the problem is.

Using the latest brain-scan technology, Dr. Rothman’s studies will involve human participants. They will focus on the mitochondria and the decline in cellular energy production, one of the main characteristics of HD.

“Anything that impairs the energy supply will severely impact brain function and will eventually impact cellular health,” Dr. Rothman said, adding that researchers suspect that mitochondrial dysfunction plays a part in many other neurological disorders.

Doug Rothman, Ph.D. (photo by Gene Veritas)

The first study seeks to identify a mitochondria-linked biomarker (a sign of disease or a disease mechanism) that could lead to a faster, more efficient way of testing potential HD remedies. The second aims to answer a major question: are less active mitochondria a cause or an effect of the disease?

“There’s lots of preclinical studies that suggest mitochondrial alterations,” Dr. Rothman said, referring to animal studies. “What’s nice is that the MR [magnetic resonance] technology allows this aspect of mitochondrial function to be measured non-invasively in vivo.”

These studies are “novel” and “unique” because they will involve “patients who have the gene,” he added. “Before it would have to be done on a preclinical model. There was no way to directly study humans until the development of the MR technology.”

Described below, the specific types of MR scans in Dr. Rothman’s studies will be used on HD-affected individuals for the first time, he said.

Pioneering the technology

Dr. Rothman helped pioneer this technology. It is recognizable to most people in the form of the MRI scanners that became common in medical diagnostics worldwide over the past two decades.

In working toward his Ph.D. at Yale, received in 1987, Dr. Rothman specialized in a technique known as NMR, nuclear magnetic resonance.  When used in humans NMR is now referred to as MRS, magnetic resonance spectroscopy. He and other specialists have applied MRS to the study of disease. In 1989 he was appointed to the Yale Medical School faculty, and in 1995 he became the director of the Magnetic Resonance Research Center.

As researchers refine these techniques, they have become ever more capable of picking up the resonance – literally a radio frequency – of the chemicals that make up living organisms, including humans.

In both MRS and the more familiar MRI, radio pulses are given to subjects inside huge magnets.  The radio pulses excite (stimulate) chemicals in the body while a person lies in the machine, analogous to a bell being struck. Each compound then resonates (again analogous to a bell) at a characteristic radio frequency. By measuring the radio signal from the different resonating chemicals the chemical composition of different brain regions can be determined.

Dr. Rothman stressed that the technology is safe. “You’re not exposed to any radiation at all – literally just radio frequency,” he said of the scanners, which detect the radio frequencies coming out of the body.

“You literally could set up an FM radio and pick these up,” he continued. “Really, the system’s main difference from a standard radio is just the sensitivity and stability, because we’re talking about very small differences of frequency, as opposed to say a megahertz, as you have in FM radio.”

The scanner sends the readings to a computer for analysis.

Understanding brain metabolism

Using MRS, Dr. Rothman and his colleagues at the MRRC contributed to breakthroughs in understanding the biochemistry of type 2 diabetes. He also helped make important discoveries about the biochemistry of the liver and muscles.

At the same time, he and others discovered ways to measure levels of chemicals in the brain. Those chemicals included metabolites, which provide energy, and neurotransmitters, which are involved in signaling between brain cells.

For the first time in human brain scans, Dr. Rothman and his colleagues detected key chemicals such as ethanol and glucose. They also saw the major neurotransmitters glutamate and GABA (gamma aminobutryric acid), substances mentioned frequently in the world of HD research.

This group of scientists made other important advances in the understanding of brain metabolism. Of particular potential importance for HD, they discovered the energy cost for supporting brain glutamate and GABA neurotransmitter activity, providing a direct link between mitochondrial health and brain function.

As a result of their discoveries, Dr. Rothman and a group of colleagues saw how levels of glutamate and GABA are altered in depression, epilepsy, and other psychiatric disorders, and how drugs can impact those levels.

Dysfunction seen in animals

Several years ago, Dr. Rothman added Huntington’s disease to his focus. Funded by CHDI Foundation, Inc., the multi-million-dollar nonprofit virtual biotech dedicated to finding HD treatments, Dr. Rothman and his lab staff conducted research on mitochondria and brain cell metabolism in two types of transgenic HD mice.

Using MRS scans, in both groups of mice the team found a decline in metabolism in three key regions of the brain (cortex, thalamus, and striatum). They also discovered a reduction in brain cell glutamate and GABA signaling activity.

“The changes were much more profound as the models reached the late premanifest or manifest stage,” Dr. Rothman said during a presentation of the research in February at the CHDI-sponsored 10th Annual HD Therapeutics Conference.

These findings suggested that mitochondrial dysfunction plays a role in HD. This and his upcoming studies are part of a larger group of biomarker studies necessitated by the advent of clinical trials.

You can watch Dr. Rothman’s presentation in the video below.

Evidence for Mitochondrial Dysfunction in Mouse Models of Huntington's Disease? from Gene Veritas on Vimeo.

High-powered brain scans

With CHDI support, Dr. Rothman hopes to carry out the human studies in the second half of this year.

Each study will require about 40 volunteers: 20 early-stage HD-affected individuals and 20 gene-negative volunteers to act as a comparison group. Each study will involve a brain scan and take two or three days, including travel time. The study will cover the cost of travel, food, and lodging. Volunteers can take part in both studies, if they wish.

In the first study participants will undergo a so-called proton scan lasting 60-90 minutes. The Rothman team will use Yale’s 7 Tesla scanner. The number of Teslas corresponds to the power of the magnet, with higher Tesla giving greater sensitivity (the ringing discussed above has a higher amplitude and frequency).

“Seven Tesla is about the highest magnetic field that can be used for human studies,” said Dr. Rothman. “Your molecules move around and jitter and release a radio signal that interferes with the measurement, and so we need as about as high a sensitivity as possible. Interestingly, within a chemical, the protons all have different frequencies. So you can actually identify a chemical based on the pattern of resonance frequencies.”

At this level, the scientists can measure more types of metabolites and with greater sensitivity, allowing them to distinguish between glutamate and another neurotransmitter, glutamine. Both are involved in a cycle involving GABA, brain cell signaling, and metabolism. The research team aims to determine whether glutamine or glutamate is most altered by the disease.

Yale's 7 Tesla scanner (photo by Gene Veritas)

Optimizing treatments

The researchers will focus primarily on glutamine, because it is the most sensitive chemical marker in the brain, but it’s not easily measured in humans at 3 Tesla or lower (scanners with less sensitivity), Dr. Rothman explained.

The more sensitive the biomarker, the better the chance of measuring the effects of the disease and potential treatments, he added.

This biological fine-tuning raises the possibility of studying the disease and testing therapies in small groups, perhaps even single subjects – a far more efficient, inexpensive, and faster way to treatments than the traditional, larger studies involving dozens or scores of individuals.

“The hope is that it would be possible to get immediate feedback before any behavioral-motor changes and use that to optimize individual subjects’ therapy,” Dr. Rothman elaborated.

Tracing the journey of sugar

In the second study Dr. Rothman will use ¹³C (carbon-13) MRS, the same technique used in the HD-mouse mitochondria project (discussed above) and in human scans for a variety of conditions. Carbon-13 is a natural, stable isotope that makes up about 1.1 percent of all the carbon on earth. Researchers use it to label substances so they can be tracked through the body.

Participants will lie in a 4 Tesla scanner for about two hours. They will be continuously injected with ¹³C-labeled glucose through a catheter in one arm. From a catheter in the other arm small blood samples will be taken to read levels of ¹³C and glucose. Glucose is used because it is the main fuel that the mitochondria burn to provide the brain with energy.

Lab assistants will monitor participants’ glucose levels to make sure they remain stable. Afterwards, the participants will receive orange juice and lunch in a standard recovery room, where assistants will make sure that their glucose levels have returned to normal.

As Dr. Rothman explained, the ¹³C MRS technique will allow his team to watch the glucose go through the various stages of the energy cycle in the brain. This metabolic process includes the transformation of glucose into lactate, then into glutamate by way of what is known as the TCA (tricarboxylic acid) cycle in mitochondria. The rate of flow of glucose into the mitochondria is proportional to the amount of energy the mitochondria produce.

“We can also measure the flow from glutamate to glutamine, which gives us the rate of glutamate neurotransmission, a direct measure of brain function,” he added.

As a result, the team can measure the rate of energy production in individual brain cells, as well as the rate of brain signaling (neurotransmission).

Dr. Rothman summarized: “We have a measure of both the energetics of the neuron – how much energy is the mitochondria making – and a measure of the function of the neuron – how much it’s signaling, how much glutamate it’s releasing through the flow into glutamine.”

The team will attempt to answer two questions: whether energy production decreases in early-stage HD individuals, and, if so, whether the drop results from impairments in the mitochondria.

Based on animal studies and previous human studies using other techniques, Dr. Rothman and his team believe they will find diminished energy production in the mitochondria.

“But that doesn’t, by itself, tell us that the mitochondria are causing it,” he said. “It could be many other things.”

Dr. Rothman making an adjustment on Yale's 4 Tesla scanner (above) and standing the in recovery room where ¹³C study volunteers will have glucose readings monitored afterwards (below) (photos by Gene Veritas)

Verifying the impairment

The ¹³C experiment will examine the rate of energy production of the mitochondria. To further tease out the questions about the role of the mitochondria in HD, Dr. Rothman and his team want to measure the demand on the mitochondria for energy production. 

To do so, they will run a second experiment during the ¹³C scans. Using phosphorous magnetic resonance spectroscopy, they will analyze the level of other compounds used for brain cell energy. Specifically, they will measure the synthesis of ATP (adenosine triphosphate) from ADP (adenosine diphosphate) (click here to learn about this process). The breakdown of ATP back into ADP by the mitochondria releases energy to fuel cellular processes, he said.

“In the muscle it fuels contraction,” Dr. Rothman said. “In the brain it fuels neurotransmission. If the mitochondria have a defect or have a low number or activity, they have to be driven harder for the same amount of energy production.”

For this measurement to occur, the participants must have their brains stimulated. “So both people with HD and control subjects will be given visual scenes in the magnet that will force the visual cortex we’re measuring to be active,” Dr. Rothman explained.

If the HD subjects have a mitochondrial impairment, the team will be able to determine whether the mitochondria “are being forced to work harder, because their capacity is less,” he said.

In combination with the ¹³C MRS readings, this experiment will help the scientists conclude whether “the problem is at the mitochondria,” Dr. Rothman said. This knowledge will help in the design of potential remedies and the clinical trials to test them.

The ¹³C study will measure energetics and signaling, as shown in this rendition of the glutamatergic synapse (image courtesy of Dr. Rothman)

Gratitude for the scientists’ work

Dr. Rothman said he expects the proton study to take about 18 months and the ¹³C study about 24 months. Once the studies commence, a call for volunteers will go out from the MRRC. If recruitment goes well, the studies may finish sooner, he said.

Upon the completion of the proton study, CHDI will evaluate the feasibility of glutamine as a treatment biomarker in comparison with glutamate and other MRS biomarkers under study, he added. Later Dr. Rothman’s team will file a report on the studies with CHDI, and they aim to submit their work to a scientific journal.

The engagement of Dr. Rothman and Yale Medical School in HD science exemplifies the seriousness of CHDI and HD researchers in the quest for treatments.

With the goal of unraveling the mysteries of the mitochondria, Dr. Rothman’s experiments can potentially complete key parts of the HD treatment puzzle. The search for effective biomarkers and increased knowledge about the role of the mitochondria can speed the movement of discoveries from scientific bench to patient’s bedside.

As a Yale graduate and carrier of the HD genetic defect, I was especially thrilled to interview Dr. Rothman. My alma mater may very well be helping to save me and thousands of others from the ravages of HD.

I am grateful each day for the commitment of Dr. Rothman and scientists around the globe to defeat HD.

Gene Veritas (aka Kenneth P. Serbin) at Yale University in New Haven, CT, April 2015 (photo by Gene Veritas)

‘Predicting’ Huntington’s disease in the heartland

To develop treatments for a disease, researchers and physicians first need to understand how its symptoms evolve and how they affect people’s lives.

In early August, I traveled to the University of Iowa in Iowa City to donate blood, urine, and saliva samples, undergo a motor coordination exam and brain MRI scan, and perform a battery of cognitive and mood tests for the long-term research study Neurobiological Predictors of Huntington’s Disease, best known as PREDICT-HD, one of the largest public-private research projects in the history of the quest to defeat the disease.

My biological samples will become part of a bio-repository at the National Institute of Neurological Disorders and Stroke (NINDS), a division of the National Institutes of Health (NIH) located just outside Washington, D.C. Researchers from around the world can apply for access to these materials.

In studying gene-positive, asymptomatic people like me, the scores of researchers working at the University of Iowa, 26 other PREDICT centers in the U.S. and abroad, and many other institutions can try to analyze how the early symptoms of HD develop.

They are also seeking to identify HD “biomarkers” in the blood, cerebral spinal fluid (CSF), and brains of the study participants, who include formerly at-risk individuals who tested negative for HD. These individuals serve as a control, or comparison, group to ascertain which changes in the gene-positive people are specifically caused by HD.

Gene Veritas in preparation for PREDICT-HD MRI scan (photo by Sarah Petitt)

With biomarkers and other study data, researchers can effectively measure the effectiveness of potential treatments in upcoming clinical trials.

Patients: study us!

The lead scientist and administrator of the multi-million-dollar PREDICT study is Jane Paulsen, Ph.D., the co-director of the University of Iowa Huntington’s Disease Society of America Center of Excellence and Professor of Psychiatry, Neurology, Psychology, and Neuroscience. From 1991-96, she was a postdoctoral neuropsychology fellow at the University of California, San Diego (UCSD), where she directed the HD clinical research program and came into close contact with the local HD community.

“The desire to move towards earlier detection and identification was really brought forth at UCSD from the families,” Dr. Paulsen recalled in an August 6 interview. Such families, she noted, told her: “‘You know, I’ve been dealing with this for years, and it isn’t validated by the professional community. I don’t have a diagnosis. A lot of people just think I’m exaggerating.’

“So just that sense of so many people who are at risk, who might be having subtle symptoms. When we would see them, we could detect maybe cognitive or certainly emotional changes that might occur. There’s a lot of stages that occur before you get the motor signs and diagnosis.

“So the whole PREDICT project was sparked by families in San Diego saying, ‘I’ve seen this forever, and we need to detect it sooner, before I lose my job or blow up at my kids or I don’t take care of my home responsibilities the same or my friends don’t understand me the same or my family doesn’t understand me the same. If we could move it back and better understand it, then we could maintain all those additional components of my life.’ So that was really the motivating factor – trying to get people to look at it this presymptomatically, before that diagnosis.”

The decision to start PREDICT occurred in 1998 at an executive meeting of the physician-researcher collective known as the Huntington Study Group, of which Dr. Paulsen was a founding member. PREDICT formally began in 2001.

With its focus on the asymptomatic, PREDICT could help identify and test preventative treatments – the “holy grail” of HD research.

“Eventually, when they have a treatment, we want to intervene as soon as possible, because the sooner we intervene in the brain, the less tissue loss, the less dysfunction, the less toxicity has occurred,” Dr. Paulsen explained. “Even if we slow it 15 percent, which is all that they’ve done in other brain diseases, since HD lasts so many years – we’re thinking 40 years now – 15 percent could be many years where you could maintain a higher level of functioning.”

You can watch the entire interview with Dr. Paulsen in the video below.

Maximizing research

PREDICT seeks to “maximize” HD research, Dr. Paulsen said. “We work with anybody who wants to work on a particular aspect of the disease.”

As the PREDICT flagship, the University of Iowa has collaborated with its sister PREDICT centers and also partners and subcontractors at other academic institutions in the U.S. and abroad. The partners focus on cognitive testing, brain imaging, and motor studies. They include leading universities such as Johns Hopkins University, Brown University, and the Massachusetts Institute of Technology. On protein studies, PREDICT collaborates with Caprion, a private firm.

PREDICT had as many as 33 centers but currently has 27 active sites. Worldwide some 1,500 individuals, including 1,200 gene-positive, have participated in PREDICT. The study seeks to follow 1,000 individuals on a regular basis.

Stimulated largely by PREDICT, Iowa alone has produced a critical mass of innovative HD research in what Dr. Paulsen described as an “explosion” in knowledge about the disease over the past decade.

Among the 20-plus projects at Iowa over the past decade, Dr. Paulsen described research on clinical markers of the disease; biomarkers; proteomics (the study of HD-associated proteins); bone mass and metabolism; MRI scans; PET scans; full genome-wide scans (looking at all the genes in study participants); comparisons of symptoms among people with the same level of genetic mutation; the impact of discrimination and stigmatization on gene-positive people; and the possibility that HD might have vascular, immunological, or inflammatory components.

PREDICT researchers and their collaborators have published numerous scientific articles on presymptomatic HD and other aspects of the disease. These include studies seeking to refine cognitive testing; measure the relationship between estimated disease onset and the likelihood of the use of antidepressants; detect brain cell loss as an early HD imaging biomarker; and gauge the loss of perception and processing time in individuals.

Under Dr. Paulsen’s leadership, Iowa has also taken a key role in the study of juvenile Huntington’s disease, a form of the condition often given little attention by researchers because it accounts for just 10 percent of all HD cases.

Crunching the data

To help form research questions, search for useful biomarkers among the large amounts of data collected by PREDICT-HD, and help plan their use in clinical trials, the project enlists the skills of biostatistician Jeffrey Long, Ph.D., a professor of psychiatry.

“I mainly focus in tracking progression over time,” said Dr. Long, the author of a textbook on the open-source computer program known as R, used widely by statisticians and in the PREDICT research. “We try to make use of every piece of data because we are appreciative of the time you all devoted to the study and want to make sure that we maximize the relevant information for the community.”

Gene Veritas (left) interviewing Dr. Jeffrey Long (photo by Sean Thompson)

The seven-member bio-statistical team led by Dr. Long analyzes the different kinds of data collected individually and in combination. The team also helps draw comparisons between data from gene-positive and gene-negative individuals to account for factors such as cognitive loss due to natural aging.

Additionally, the scientists seek to understand the key relationship between the level of genetic mutation and the age of onset and severity of the disease. They have helped identify one key imaging biomarker: the diminishing size of the brain region known as the putamen before disease onset. They have also noted an abundance of a particular kind of protein in the bloodstream of gene-positive individuals.

A special connection

To coordinate visits by PREDICT participants and administer questionnaires and cognitive testing, the project employs several study coordinators, including research associate Stephen Cross.

“I’ve fallen in love with the population,” said Cross. “They talk about the ‘HD bug.’ I’ve got the bug. There’s something unique about this population. I think it’s the family aspect of it. I would feel like I was abandoning the cause to work with another group.”

With PREDICT since 2008, Cross currently has a caseload of some 80 individuals and their families.

PREDICT-HD study coordinator Stephen Cross (left) conversing with Gene Veritas (photo by Sarah Petitt)

“All of them have their lives changed by the genetic testing, regardless of the results, whether it’s positive or negative,” he observed.

He said that, in the case of gene-positive individuals, especially those from families who can trace the disease back a number of generations, “I think it changes their souls, when you know what’s coming in the family, when it’s in yourself. There’s some kind of interaction in this triad of symptoms – the movement, the psychiatric and the cognitive. I think you’re special because of this disease. I feel a spiritual connection with my participants.”

Brain and body scans

“We have many imaging studies,” said Dr. Paulsen. “We’re looking at the shape changes in the brain.”

Imaging provides a picture of HD without the “need to poke around in the brain,” Dr. Paulsen noted.

 “We already have a very good imaging marker,” she continued. “We can measure the volume of the part that’s particularly sensitive to Huntington’s disease, the striata or the basal ganglia. We can see that it changes a percentage every year of the disease. Even as far back as ten, 15 years prior to diagnosis. But we want to get are even better imaging markers, maybe ones that are earlier or maybe one that gives us a more robust signal. So that’s why we have a lot of projects right now that are really trying to challenge what we can learn from brain imaging.”

Gene Veritas (above) walks through a metal detector in preparation for a PREDICT-HD MRI scan performed after MRI radiology technician Marla Kleingartner (below) secures his head to prevent movement during the scan (photos by Sarah Petitt).

In addition to markers, imaging has revealed new information about the extent of the disease, Dr. Paulsen added. Scientists long thought HD affected only the basal ganglia, the area of the brain responsible for motor function.

“The imaging data that’s been published over the last decade shows that it’s much more widespread in the brain,” she said.

With the lack so far of significant HD biomarkers in the blood and urine, PREDICT is now starting to study CSF collected from a number of its previous and current participants by way of a spinal tap.

(I could not donate CSF because a previous lower back injury made the procedure too risky for me.)

A full-body scan

As a registered nurse, Nancy Downing, Ph.D., takes a holistic approach to HD-affected individuals, always seeking to improve their quality of life.

Several years ago, an NIH seminar on genetics helped solidify Dr. Downing’s interest in HD, she said. Today she seeks to integrate genetics and efforts to improve patients’ quality of life. As a PREDICT researcher, she has especially focused on the effects of diet and exercise and the way in which lifestyle affects the expression of genes.

Just two months ago she helped complete a pioneering twelve-month study in which a group of PREDICT participants underwent dual x-ray absorptiometry, a scan that reveals the composition of a person’s body mass (lean, fat, and bone). This same machine is used to detect osteoporosis.

Nancy Downing, Ph.D., RN, SANE-A (photo courtesy of HDSA Center of Excellence at the University of Iowa)

Dr. Downing hopes to triangulate the data from this study to help understand what HD does to areas of the body other than the brain such as muscle tissue. Evidence already suggests that gene-positive individuals have a shortage of branched-chain amino acids, necessary for muscle building and repair, she said.

Dr. Downing’s work supports the growing notion that HD must be seen as a disease of the body and not just the brain.

Preparing for clinical trials

PREDICT can have an impact on clinical trials and the approach treatments might take, Dr. Paulsen said.

“It’s kind of a when, where, how question,” she said. “I don’t think any of those questions is fully answered, so we have more work to do. But we have answers to those questions that we didn’t have before.

“We didn’t know that there was a when, where, how. We thought that once they get a diagnosis, we’re going to try to treat them with something that we’ve learned from other neurodegenerative diseases. I think in many ways Huntington’s has opened up that box and made it much larger. It’s a very exciting time. And I think it will continue. We’re not even close to the end of the possibilities on where we intervene, (and on) the changes of Huntington’s disease.”

PREDICT, with its unique database of long-term data on presymptomatic individuals, could potentially furnish important data for clinical trials, she added.

“We have this entire cohort,” she explained. “We know exactly how much change they have over time. If we do an intervention, we will be able to determine how much change has occurred. No other study can do that, because if you recruit someone new, you don’t know that individual’s trajectory. We have each individual’s trajectory. We know what type of progression they have. If there was a treatment today, this is the group we should put it in, because we tell exactly what’s going on with that person.”

A potential key treatment

In collaboration with PREDICT and other HD projects at Iowa, the lab of Beverly Davidson, Ph.D., is engaged in research aiming for a clinical trial to test a gene-silencing drug that could at least partially halt HD at its root cause.

This approach would involve the use of RNA interference (RNAi) molecules permanently introduced into the brain via the injection of a virus by a neurosurgeon.

Similar to two separate gene-silencing clinical trials planned by Isis Pharmaceuticals, Inc., and Roche and a team involving Medtronic and the non-profit CHDI Foundation, Inc., the potential Davidson lab therapy aims to reduce the production of harmful huntingtin protein by interrupting the natural translation of the gene into protein.

In HD mouse testing, the lab has demonstrated that RNAi reduces the toxicity of the bad gene in the brain and alleviates symptoms, Dr. Davidson said.

She explained that RNAi is currently under study in a clinical trial for Leber congenital amaurosis, a retinal disorder that leads to blindness in children.

“They put this into the eyes of these children, and the children are showing remarkable, remarkable results,” Dr. Davidson said.

Two of the Leber pioneers, Katherine High, M.D., and Jean Bennet,M.D., Ph.D., are “collaborating with us to develop the gene therapy vectors for Huntington’s disease,” Dr. Davidson noted.

Dr. Davidson said her team hopes to start a clinical trial within the next two years. “That might be aggressive, but we’ve been putting in a lot of effort in the background in the last year or so,” she said.

To learn more about this project watch my interview with Dr. Davidson in the video below.

PREDICT’s ending, gratitude to funders

Although currently operating at full steam, at least in its current form PREDICT is scheduled to end on July 1, 2014.

From 2001-2013, PREDICT received a total of $46.8 million in National Institute of Neurological Disorders and Stroke (NINDS) funding. Additional support has come from the National Human Genome Research Institute and the National Institute of Mental Health. The CHDI Foundation has also infused $15.5 million into the project and is providing further assistance.

In the last five years of the study, PREDICT received $5.6 million annually in federal funds from NINDS. The 2013-2014 fiscal year costs are being covered from funds incurred from previous years.

“I was told that NINDS won’t consider any more budgets over $1 million,” said Dr. Paulsen, noting the high cost of this kind of research. She said Iowa would be unable to continue the PREDICT study in its current form with so little money. Just bringing patients to Iowa is a major expense.

NINDS has experienced cuts in recent years. For fiscal year 2013, the federal government cut five percent of the NINDS budget as part of the $85 billion in overall spending cuts determined by Congress, including the sequestration provisions legislated in 2011.

In addition, CHDI is now shifting its priorities to implementing a new worldwide HD patient study and database known as Enroll-HD.

Nevertheless, Dr. Paulsen recognized the significance of NINDS funding, described by one observer as the largest HD project ever funded by the agency.

“I understand NINDS,” Dr. Paulsen said. “They’ve been cut every year. We’ve been fortunate to receive funding from them for years, and CHDI has supplemented us. They had us expand and train some sites to expand. They have supplemented us when we ran into obstacles. CHDI has been very forthcoming in assisting. So they’re just always there in the wings saying, ‘What can we do to make this go better?’ They really want to push things forward.”

Assessing PREDICT’s impact

Asked to reflect on the ultimate causes of PREDICT’s expected termination, Dr. Paulsen stated that she’s “not sure I have the right answer. I have my opinion. There are centers that have followed research projects for decades.”

The federal government has supported such ongoing centers for AIDS, Alzheimer’s, Parkinson’s, and alcoholism, she noted.

However, once again, HD’s status as a rare disease might be leading officials to treat it as insignificant, Dr. Paulsen indicated. Others might have misunderstood PREDICT to have failed to innovate.

She rebuts those notions.

“The output of this project has been far greater than many other of the ongoing centers,” she observed, adding that HD research has contributed significantly to the study of other conditions. “It’s definitely been a project that has morphed and kept up and pushed the envelope. It would be nice to be funded like other centers that just are kind of automatically rolled over.

“We have to be protective of our resources, but the amount we are learning has just become exponential. It has grown so much and it isn’t stopping. Most of the projects I’m talking about are brand new. They’re just starting to look at CSF, at new imaging markers, at trajectories.”

Despite these setbacks, Dr. Paulsen said that HD research would continue at Iowa. New grant applications are already in the works, she said.

The Iowa HDSA Center of Excellence will also continue its activities.

My future in PREDICT

In line with PREDICT’s goal of tracking patients over time, the Iowa team has already notified me that I should return next year for a follow-up examination, before the July 1, 2014, end date.

Ideally, I should also make a third visit at a later date for the researchers to have sufficient data points. The uncertain budgetary situation has cast doubt on that possibility.

Regardless, I feel privileged to have contributed as an HD-positive individual to the quest for treatments, and I am thankful to the numerous researchers and support staff of PREDICT-HD and the public and for the private funding that has made this initiative possible.

(Next time: advocacy meets science and medicine in Iowa and beyond.)