15 Oct Stem cells have awesome potential to increase brain and spine health
Stem cells have awesome potential to increase brain and spine health
You have lots of different types of cells in your body. Often the cells are highly specialized and are not interchangeable. Most cells can only perform a specific job; blood cells deliver oxygen, retinal cells see, brain cells think. But the original you started out as a single cell in your mother’s belly. All the cells in your body differentiated from this single cell, which had nearly infinite potential.
Stem cells aren’t as powerful as the original you cell. But they’re still pretty awesome. They’re undifferentiated or partly differentiated cells. They’re biding their time all over your body, waiting for a day they might be called upon to change into a type of cell that your body may need. For instance, if you break a bone, mesenchymal stem cells (which have the potential to become cartilage, muscle, fat or bone) are called upon to differentiate into bone cells and knit together the fractured bone. Once a stem cell differentiates into a mature cell, it can’t go back to being a stem cell again.
The brain and spine are notoriously bad at healing. But even the central nervous system harbors a population of stem cells that maintain some limited activity. In particular, three areas of the adult brain, the olfactory bulb (sense of smell), the hypothalamus (regulation of essential body functions like temperature, thirst, etc.) and the hippocampus (memory and learning), maintain stem cells with some ability to replace worn out or damaged cells.
And stem cells from other parts of the body can sometimes migrate to the brain or spine to lend a hand. Chinese scientists recently discovered that brain injury or bleeding may induce bone marrow stem cells to differentiate into unique white blood cells, which have the ability to travel into the brain. Once the cells reach the site of damage, they have been shown to reduce inflammation (swelling). In 2020, a group of California scientists reported on methods to help precisely guide stem cells to where they’re needed most. It turns out that the central nervous system is a perplexing place to navigate and the blood-brain barrier is a tough rampart to scale. The researchers reported that a newly discovered molecule, called SDV1a, acts like a traffic cop and directs stem cells in mouse brains to repair degenerated neural tissue.
As science progresses, discoveries are being made about how stem cells may benefit you, both today and potentially down the road.
Stem cells and brain trauma or stroke:
Scientists are investigating the utility of stem cells for healing a stroke or brain injury. Current strategies being researched include activating neural stem cells (stem cells that are already present in the brain), coaxing other types of stem cells to travel to the brain or harvesting stem cells from other parts of the body and injecting them into the brain.
In 2021, Texan scientists reported promising results using stem cells for treatment of stroke. The scientists harvested bone marrow stem cells by boring a needle into the pelvis of certain patients who had suffered from a stroke. The doctors then injected the cells into a vein in the patients’ arms. Another group of stroke patients received an injection of saline (salt water). The doctors reported that the group who received an infusion of their own stem cells had superior outcomes after stroke, both in terms of MRI findings (the size of the stroke shrunk more) and clinical findings (the patients had better recovery). It is believed that the stem cells migrate to the site of injury. When the stem cells arrive at the damaged brain, they may differentiate to replace injured cells. And the stem cells also may release anti-inflammatory factors and growth factors that may help heal the stroke or traumatic injury.
In 2021, researchers at Stanford University in California secured funding to begin an experimental trial on patients who suffered disabling strokes that did not respond to traditional treatments. The doctors plan to use stem cells derived from human embryos. They plan to implant these cells directly in the brains of the neurologically devastated patients with the hope of restoring function.
Stem cells and memory:
Stem cells, with the ability to replace worn out or damaged neurons (brain cells) are present and active in only three areas of the adult brain: The olfactory bulb, which provides for the sense of smell. The hypothalamus, a small area in the center of the brain that is crucial for the regulation of essential body functions like temperature, thirst, etc. The hippocampus, which is vital in learning and creating and storing memory.
In 2020, German researchers reported that the small population of stem cells present in the hippocampus may be beneficially altered. The scientists currently work with experimental animals (mice). The scientists reported that after hippocampal stem cell stimulation, memory function and maze navigating abilities improved in the treated mice.
Stem cells and Psychiatric disease:
Psychological problems may arise years after brain trauma such as multiple concussions. A syndrome called CTE (chronic traumatic encephalopathy) may result in emotional lability, impulse control problems, aggression, depression and paranoia. A similar constellation of psychological problems may occur years after a severe trauma that does not involve the brain; PTSD (post traumatic stress disorder). There is early evidence that stem cells may be of benefit. These stem cells are derived from donated umbilical cords (mesenchymal stem cells) and may be injected into the veins of affected individuals.
Stem cells and neurodegenerative disease:
Doctors have reported that stem cells are helpful in mitigating some neurodegenerative diseases (such as Alzheimer’s and Parkinson’s) and researchers are investigating whether they may be useful in alleviating other similar maladies.
In 2021, a start-up company called Tree Frog Therapeutics raised $75 million. They aim to use Stem cells in the fight against Parkinson’s disease. The scientists harvest cells from a human subject and bioengineer the mature cells (e.g. skin cells) into stem cells. They plan to recruit volunteers with severe Parkinson’s that have failed to improve despite standard treatment and reinject the engineered stem cells into the donor’s brain. They hope to start human trials by 2024. In an animal study (monkeys) of Parkinson’s disease published in 2021, scientists reported that stem cells provided benefits. The researchers injected stem cells into the brains of monkeys who were suffering from Parkinson’s disease. The scientists discovered that the stem cells differentiated into health neurons (brain cells), which replaced the diseased cells. Additionally, the symptoms of Parkinson’s disease (problems with movement, anxiety and depression) improved in the treated monkeys.
An NIH study is currently investigating whether stem cells may improve neurological function in people with dementia from Alzheimer’s disease. Doctors involved in the research harvest stem cells (mesenchymal stem cells) through a needle placed in the pelvis. The stem cells are then injected into a vein in the arm. The researchers hope that the stem cells will fight Alzheimer’s by migrating to the brain and decreasing inflammation. The scientists plan to enroll thirty patients in the study, which is expected to be completed in 2021.
Stem cells and spinal injury:
You have five vertebrae (bones), in your lower back, twelve behind your chest and seven in your neck. In between each of these bones is a spinal disc, which acts like a shock absorber. With time or injury, these discs can wear away (become damaged or degenerated). Walking around with a degenerated spinal disc can feel like driving around in a car with no shock absorbers. Every step you take causes an agonizing jolt of pain. In the near future, stem cells and bioengineered scaffolds may be injected into your back to regenerate and repair damaged discs.
Although degenerated discs may cause pain, they rarely cause paralysis. On the other hand an injury to your spinal cord can cause difficulty in moving your arms or legs. But, hope is on the horizon for repair of spinal cord injury. Scientists are studying animal models of spinal cord injury (mice). In 2018, one group of researchers reported on tissue engineering techniques that have provided promise in the repair of a damaged spinal cord. These doctors transplanted stem cells into the injured spine. They discovered that these stem cells differentiated into nerve cells (neurons) and replaced the damaged spinal cells. The stem cells decreased inflammation in the injured spine, which prevented scar formation (scar could otherwise block the growth of neurons). The researchers went a step further and used a special gelatin (hydrogel), which acted as a scaffold and provided structure to bridge across the injured site.
Stem cells and cancer:
Stem cells exhibit properties which may make them promising in the fight against brain tumors. Scientists have reported that they seem to be naturally drawn towards the area of cancer (like the roots of a tree seeking water) and they have the ability to migrate through the body.
Cellular engineering may supercharge stem cells for battle against cancer. They may be induced to carry chemotherapy or immunotherapy which can kill cancer cells. Under certain circumstances, stem cells also may engulf tiny magnetic particles. An external magnet may then be employed to guide the weaponized cell to the brain, where it can stealthily attack a tumor.
Stem cells and artificial brains
Just like the original you cell differentiated into the countless unique cell lines that formed the myriad organs and organ systems in the grown up you, a stem cell in the laboratory may be encouraged to differentiate into a cell line that will become an entire brain. It wouldn’t be a thinking brain like the one in your head, of course. But scientists have used this technique to build miniature brain “organoids” from stem cells.
The potential is like sci-fi nirvana. The mini stem cell brains have already revealed novel insights into molecular and genetic mechanisms of certain complex human neurological disorders such as microcephaly (a medical condition that causes a newborn to have a tiny, malfunctioning brain), autism, and Alzheimer’s disease.