Ohio – In a new study, researchers at The Center for Brain and Spinal Cord
Repair at The Ohio State University
Wexner Medical Center
show that is possible to restore immune function in spinal injured mice.
with spinal cord injury often are immune compromised, which makes them more
susceptible to infections. Why these people become immune-suppressed is not
known, but the Ohio State study found that a disorder called autonomic
dysreflexia can cause immune suppression.
Autonomic dysreflexia is a potentially dangerous complication of
high-level spinal cord injury characterized by exaggerated activation of spinal
autonomic (sympathetic) reflexes. This can cause an abrupt onset of excessively
high blood pressure that can cause pulmonary embolism, stroke and in severe
research offers an explanation for why people with spinal cord injuries develop
a condition referred to as ‘central immune depression syndrome.’ Their immune
systems, which are required to fight off infection, are suppressed due to
damage or malfunction in regions of the spinal cord that help control immune
function,” said principal investigator Phillip G.
Popovich, Ph.D., Professor of Neuroscience in Ohio State’s College of
Medicine and Director of Ohio State’s Center for Brain and Spinal Cord Repair.
The study is published in The Journal of Neuroscience.
found that autonomic dysreflexia develops spontaneously in spinal cord injured
mice, and becomes more frequent as time passes from the initial spinal cord
also found that simple, everyday occurrences that activate normal spinal
autonomic reflexes, such as having bowel movements or emptying the bladder, become
hyperactive and suppress immune function in people with spinal cord injury.
the study, Popovich and colleagues were able to restore immune function in mice
with spinal cord injuries using drugs that inhibit norepinephrine and glucocorticoids,
immune modulatory hormones that are produced during the onset and progression
of AD. They also observed in a patient with a high-level spinal cord injury
that briefly inducing autonomic dysreflexia impaired immune function,
confirming that their findings in mice have relevance to humans.
we don't know how to fix this yet, we also show that it is possible to restore
immune function in spinal injured mice,” Popovich said. “After spinal cord
injury, the ability of the spinal cord to control the immune system is
impaired. As result, these individuals become susceptible to infection, and
often die from these infections. For those that survive, the infections can
impair what little function they have left after the spinal cord injury.”
The study found that autonomic dysreflexia causes immune
suppression in part by releasing into blood and immune organs high levels of
immune modulatory hormones that non-selectively kill mature and immature white
blood cells in the spleen, said first author Yi Zhang, a post-doctoral
neuroscience researcher at Ohio State.
“Our research is laying the groundwork for potential therapeutic
targets for reversing central immune depression syndrome,” Zhang said, adding
that further research is needed.
State’s Center for Brain and Spinal Cord Repair is an
interdisciplinary collaboration of basic and clinical scientists working to
promote recovery and repair and to discover new treatments for individuals who
suffer from brain or spinal cord injuries.
State researchers involved in this study are Zhen Guan, Brenda Reader, Todd
Shawler, Shweta Mandrekar-Colucci, Kun Huang, Zachary Weil, Anna Bratasz,
Jonathan Wells, Nicole Powell, John Sheridan and Caroline Whitacre. Other
researchers involved in this study include Alexander Rabchevsky, University of
Kentucky and Mark Nash, University of Miami Miller School of Medicine.
research was supported by the National Institutes of Health (R21 NS067260) and
the Ray W. Poppleton Endowment.
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Eileen Scahill, Wexner Medical Center Public Affairs and Media Relations,
614-293-3737, or Eileen.Scahill@osumc.edu