People with high-level spinal cord injury develop what is known as spinal cord injury-induced immune suppression syndrome (SCI-IDS). As the body rushes to react to spinal cord damage, new but abnormal nervous system circuitry starts to form. Scientists have identified an underlying cause of dangerous immune suppression in people with high level spinal cord injuries and they propose a possible treatment.
In the journal Nature Neuroscience, researchers at Cincinnati Children's Hospital Medical Center and Wexner Medical Center at The Ohio State University write that spinal cord injuries higher than thoracic level 5 (T5) cause autonomic nervous system circuitry to develop a highly adaptable state of plasticity. The autonomic nervous system controls bodily functions that are not consciously directed - like breathing, heartbeat, digestion and immune function.
Autonomic Dysreflexia
Autonomic dysreflexia is a condition that occurs in patients with spinal cord injuries especially in the T5 and T6 levels. This condition is characterized by hyper activity of the autonomic nervous system.
Advertisement
‘Chemogenetic silencing - manipulating receptors that are on the surface of cells and silencing them - reverses the immune suppressive reflex in spinal injured mice.’
Tweet it Now
The researchers show that in mouse models of spinal cord injury, this aberrant nervous system circuitry causes responses that extend beyond thoracic spinal segments, which in uninjured mice would normally feed nerves to secondary lymphoid tissues that help generate immune cells. Because of this, abnormal spinal interneurons are activated by the bladder and/or bowel. This results in formation of an exaggerated network of neural circuitry that activates an anti-inflammatory and immune suppressive reflex.
"Infection, a consequence of immune suppression, is the leading cause of death for people with spinal cord injuries," said Yutaka Yoshida, co-lead author and a scientist in the Division of Developmental Biology at Cincinnati Children's. "Patients and mouse models of spinal injury also are subject to autonomic dysreflexia, a potentially fatal clinical syndrome marked by episodes of high blood pressure."
![Spinal Injury - Symptom Evaluation]( "Spinal Injury - Symptom Evaluation")
Spinal Injury refers to damage to spinal cord that runs below the brain through the back. Injury to spinal cord is a severe injury as the damage is irreversible and it can be life-threatening.
In the study, mouse models of high spinal cord injury have atrophied spleens (a secondary organ that produces white blood cells) and show signs of leukopenia (low white blood cell count).
Co-lead author Phillip Popovich, professor of Neuroscience and director of the Center for Brain and at Ohio State, said that this abnormal spinal cord circuitry likely causes chronic immune suppression and increases the chance that people with spinal cord injuries will suffer from complications caused by common infections, such as pneumonia.
In an effort to develop a possible treatment to stop immune suppression syndrome, the researchers tested chemogenetic agents in their laboratory mouse models. Chemogenetics involves manipulating receptors that are on the surface of cells and either activate or silence these cells. The use of chemogenetics creates the ability to exert very selective pharmacologic control over a variety of cell-signaling processes.
In the instance of mouse high spinal cord injury models, the researchers used chemogenetics to silence signaling transmissions from newly forming interneurons that trigger the immune suppression reflex. Because the newly forming nerves had specific genetic signatures, the scientists were able to control these neurons using a precisely targeted chemogenetic silencer (hM4Di-DREADD).
Chemogenetic silencing reversed the immune suppressive reflex in spinal injured mice. Atrophy in the animals' spleens was reversed and white blood cell counts increased, the researchers report.
The researchers continue to test and refine the use of chemogenetic silencing to treat SCI-IDS. They caution that the experimental treatment method remains years away from testing in people with spinal cord injury.
Source: Newswise
Spinal Injury - Symptom Evaluation
Spinal Injury refers to damage to spinal cord that runs below the brain through the back. Injury to spinal cord is a severe injury as the damage is irreversible and it can be life-threatening.
Advertisement
In the study, mouse models of high spinal cord injury have atrophied spleens (a secondary organ that produces white blood cells) and show signs of leukopenia (low white blood cell count).
Co-lead author Phillip Popovich, professor of Neuroscience and director of the Center for Brain and at Ohio State, said that this abnormal spinal cord circuitry likely causes chronic immune suppression and increases the chance that people with spinal cord injuries will suffer from complications caused by common infections, such as pneumonia.
In an effort to develop a possible treatment to stop immune suppression syndrome, the researchers tested chemogenetic agents in their laboratory mouse models. Chemogenetics involves manipulating receptors that are on the surface of cells and either activate or silence these cells. The use of chemogenetics creates the ability to exert very selective pharmacologic control over a variety of cell-signaling processes.
In the instance of mouse high spinal cord injury models, the researchers used chemogenetics to silence signaling transmissions from newly forming interneurons that trigger the immune suppression reflex. Because the newly forming nerves had specific genetic signatures, the scientists were able to control these neurons using a precisely targeted chemogenetic silencer (hM4Di-DREADD).
Chemogenetic silencing reversed the immune suppressive reflex in spinal injured mice. Atrophy in the animals' spleens was reversed and white blood cell counts increased, the researchers report.
The researchers continue to test and refine the use of chemogenetic silencing to treat SCI-IDS. They caution that the experimental treatment method remains years away from testing in people with spinal cord injury.
Source: Newswise
Stem Cells Mediate Immune Response to Spinal Cord Injury
A family of therapeutic stem cells called multipotent adult progenitor cells lessen the consequences of the immune system's damaging second wave response.
Advertisement
 Humans And Monkeys Recover Faster From Spinal Cord Injury Than RatsThe differences in anatomy and function of the corticospinal tract, that are the fibers through which the cortex communicates with the spinal cord is the reason. | Advertisement
|
Advertisement
Recommended Reading
Latest Research News
The International Space Station will be used to carry out experiments seeking to improve understanding of incurable child brain tumors and the muscle aging process.
How many people in the UK have misophonia? In a representative sample study, most people had at least some irritation upon hearing trigger sounds.
Routine eye-checkups and mass screenings enable early diagnosis and treatment of glaucoma. Late-stage glaucoma diagnosis leads to blindness.
Brain plasticity following blindness leads to superior ability in sensing signals from the heart, which has implications for bodily awareness and emotional processing.
A group of scientists were awarded £1.3 million to create a new “point of care testing” kit that detects Alzheimer's disease biomarkers.