Three rats paralyzed due to spinal ischemia
returned to near normal ambulatory function six weeks after having received
human spinal stem cells (hSSCs) developed by Neuralstem, Inc. (OTC Bulletin
Board: NRLS), researchers reported online in the journal, NEUROSCIENCE
(neuroscience-ibro). Three other rats, while not able to
stand up two months after treatment, showed significant improvement in the
mobility of all three lower extremity joints and increased muscle tone. In
all the grafted animals, the majority of transplanted hSSCs cells survived
and became mature neurons. The study was conducted at the University of
California at San Diego.
The rats suffered from Ischemic Spastic Paraplegia (ISP), a painful
form of extreme spasticity and rigidity that causes permanent and
untreatable loss of motor function and paralysis. In humans, ISP can result
from surgery to repair aortic aneurysms, an operation that is performed on
thousands of patients a year in the United States.
"Other human stem cell transplants in the spinal cord have focused on
repairing the myelin-forming cells," commented Dr. Karl Johe, Neuralstem
Founding Scientist, and a study author. "In this breakthrough study, we are
reconstructing the neural circuitry, which has not been done before. This
novel approach is one for which our technology, which generates highly
neurogenic human stem cell lines, is uniquely suited." Dr. Johe went on to
say, "Human ISP patients, unlike the rat subjects of this study, will be
able to receive physical therapy once treated. We believe this will
accelerate integration of the grafted stem cells with the host tissue and
enhance the therapeutic benefit of the cells. The goal is to provide a
significant gain in functional mobility of the patient's legs."
According to lead investigator Dr. Martin Marsala, "In this study, we
demonstrated that grafting human neural cells directly into the spinal cord
leads to a progressive recovery of motor function. This could be an
effective treatment for patients suffering from the same kind of
ischemia-induced paralysis. We are currently studying hSSCs in paralyzed
mini-pigs, who have similar spinal cord anatomy as human spinal cords."
According to Neuralstem CEO, Richard Garr, "Neuralstem is a second
generation stem cell company, built primarily to optimize our discovery of
neural stem cells, and take them into the clinic and into patients. We
believe, as this study demonstrates, that our technology answers many of
the issues that have held the field back, and makes it possible to build a
stem cell company around a true product focus. We expect to file an IND for
our first human trial to treat paraplegic patients in 2007," he concluded.
About the study
In a two-month study of sixteen rats with induced spinal cord ischemia,
nine were injected with hSSCs 21 days after paralysis (ten injections,
30,000 cells per injection). Seven additional rats were injected with
medium containing no stem cells as the control group. The recovery of motor
function was evaluated in seven-day intervals using a well-accepted
locomotor scale and showed a progressive recovery of ambulatory functions
in the hSSC animals. Three of nine rats receiving hSSCs had returned to
walking at six weeks. Three others had improved mobility in all lower
extremity joints. All animals grafted with hSSCs achieved significantly
better motor scores than those in the control group. The hSSC-grafted
animals showed a consistent presence of transplanted cells in the spinal
area.
In an additional three-month study to assess the recovery of motor
function and spasticity, thirteen rats were grafted with the hSSCs (25-30
injections, 10,000 cells per injection). A control group of six was
injected with medium only. Seven of the grafted rats showed a
time-dependent improvement in motor function and were able to move their
lower extremities. This directly correlated with the degree of reduced
spasticity (measured by motor evoked potentials (MEPs)), although these
rats did not return to walking. Researchers speculate that response
differences could be due to the role of subtle differences such as graft
position. They further noted that, at the end of the study, transplanted
neurons were still maturing, leading them to speculate that a longer term
post-grafting period (6-12 months) and physical rehabilitation would likely
be associated with a higher degree of functional recovery. In contrast with
the grafted groups, no recovery was seen in any animals injected with
medium only.
About Neuralstem
Neuralstem's patent-protected technology enables, for the first time,
the ability to produce neural stem cells of the human brain and spinal cord
in commercial quantities, and the ability to control the differentiation of
these cells into mature, physiologically relevant human neurons and glia.
The Company expects that its first Investigational New Drug (IND)
application will be for the treatment of Ischemic Paraplegia, a form of
paraplegia that sometimes results from the surgery to repair aortic
aneurysms and for which there is no effective treatment The Company hopes
to submit its initial IND application to the FDA and begin its first human
trial during calendar year 2007.
Major Central Nervous System diseases targeted by the Company with
research programs currently underway include: Ischemic Paraplegia,
Traumatic Spinal Cord Injury, ALS, and Parkinson's Disease. The company's
cells recently extended the life of rats with ALS (Lou Gehrig's disease) in
a paper published in the journal TRANSPLANTATION, and were deemed viable
for continued work in neurodegenerative spinal conditions. The company has
also developed immortalized human neural stem cells for in-vitro use in
drug development for the academic and pharmaceutical markets. For further
information, please visit neuralstem.
This press release contains forward-looking statements. Neuralstem
wishes to caution the readers of this press release that actual results may
differ from those discussed in the forward-looking statements and may be
adversely affected by, among other things, US FDA responses, and responses
from other jurisdictions, to various regulatory submissions; SEC responses
to various registration submissions; changes in corporate strategy; the
need to raise additional capital; the success or failure of other private
and public organizations and/or academic and corporate institutions engaged
in stem cell research and development, and the market for stem cell
research in general. For further information, please review the company's
SB-2 filing with the Securities and Exchange Commission, and its 10-K for
the year ending December 31, 2006.
Neuralstem, Inc.
neuralstem