Extending Healthspan With Regenerative Medicine
The applications of Regenerative Medicine in Human Longevity
Joint pain. Brittle bones. Forgetfulness. Declining eyesight and hearing. Grey hair. Wrinkles. Weak immune system. Cell division slows. Decreased organ function. Death.
All of these symptoms and more. The cause? Aging.
What Causes Aging?
Aging is a complicated yet inevitable process, and there are many contributing factors to the reason why we age.
Diminished Stem Cells
When we are young, we have a large number of stem cells in our body, able to repair damage and produce more cells. Stem cells are the reason why we grow and heal. As we age, our stem cells begin to diminish and their ability to differentiate into specialized cells deteriorates, the repair of our body becomes slower and not as effective as it once was. This leads to the wear and tear we see in the elderly.
Shortening of Telomeres
Another factor of aging is the shortening of telomeres during mitosis (flashback to your high school science class). When the chromosomes (condensed forms of DNA), are formed, telomeres are on the end of them, acting as caps on a shoelace, protecting the ends of the chromosomes from degradation during mitosis. Each time the cell divides, a little bit of the telomeres disappear each time too. As we age and our cells continue to divide, these telomeres keep shortening and eventually, they are at a critical length, and they are supposed to die through a process called apoptosis because the cell can no longer replicate. Sometimes this doesn’t happen according to the plan and this causes the buildup of senescent cells.
Accumulating Senescent Cells
Senescent cells are cells that have stopped dividing due to critical telomere lengths and other factors. They are zombie cells sitting in your body and releasing signals that tell other cells to be like them. Senescent cells are not all bad. They help with tumour suppression and wound healing and when we are younger, eventually perform apoptosis to prevent buildup. During aging, our immune system weakens and more senescent cells escape their grasp. They inhibit tissue function, increase inflammation, and contribute to age-related diseases such as Alzheimer’s.
So How Can Regenerative Medicine Help?
Regenerative Medicine can help increase the amount of time we spend healthy in our lives (healthspan), and also increase lifespan.
Regenerative Medicine (RM) is a field of medicine that is designed to repair or replace cells, tissues, or organs to establish or restore function in the human body. This field of medicine is divided into three main subfields: stem cells, tissue engineering & gene therapy. Regenerative medicine restores function and regrows tissues from damage caused by trauma, disease, and normal wear and tear of aging.
So how can Regenerative medicine be used to combat the disease of aging? Replenishing the stem cells in our body and replacing damaged organs are two methods that can help increase healthspan.
Replenishing the Little Repair Cells in Our Body
The repair cells in our body have been working hard from day one. All the cells you currently have in your body originated from stem cells. Stem cells are undifferentiated and can develop into many different types of cells like cardiac cells, neurons, epithelial cells, and many more. There are many types of stem cells: embryonic stem cells, induced pluripotent stem cells (iPSCs), and adult stem cells.
Embryonic Stem Cells
Embryonic stem cells are the cells you and I came from. They are responsible for all the other cells in our body. Embryonic stem cells are pluripotent and can give rise to over 220 different cell types (except the placenta). Even though their pluripotent properties are valuable, there is some ethical controversy around them, because to obtain these cells involves killing a fertilized embryo.
Induced Pluripotent Stem Cells
Induced pluripotent stem cells (iPSCs) are also pluripotent, instead of harvesting them from an embryo, they are obtained by reprogramming human or animal differentiated cells. iPSCs are taken from specialized adult cells such as a blood cell or skin cell, and genetically reprogramming into an embryonic state. iPSCs are most commonly used in scientific studies as they are easiest to obtain in large quantities and face no ethical issues.
Adult Stem Cells
Adult stem cells are found in small quantities in adult tissue. They are multipotent and can only give rise to certain types of cells in the body. The main purpose of adult stem cells is to maintain a steady-state of function (homeostasis) and to replace dying cells in our body. These adult stem cells diminish as we age, and they go through mutations when they divide that eventually compromising their effectiveness.
Stem Cells in Neurodegenerative Diseases
The chances of developing neurodegenerative diseases such as Alzheimer’s increases as we age. But there has been research about using stem cells to treat these diseases. Alzheimer’s disease is a chronic neurodegenerative disease that causes cognitive decline in the brain. Alzheimer’s is irreversible and slowly deteriorates memory and thinking skills and causes brain cells(neurons) to die. Scientists are looking into how stem cells can introduce new neurons into the brain to reverse some of the effects of the disease. There is still some work to be done before it can be used. In the future stem cells could bring an effective treatment or cure for this debilitating disease.
Stem cells can help repair damage in the body, reduce inflammation, fight autoimmune diseases, and even regrow hair. These stem cells, either from your own body or from a donor, can be injected straight into joints or tissues or delivered intravenously to repair other organs and tissues in the body. By using stem cells, we can delay aging and increase health in older age.
Replacing Damaged Organs
73, 802 people. That is how many 50+ year-olds are on the organ transplant list in the US. The age group with the highest number of people on this list is the 50–64-year-old category. This age group doubles more than any other age group with 49, 768 individuals. Why? Well because aging has a detrimental effect on our bodies. The stem cells are declining, while senescent cells are building up in the body. The accumulating damage eventually causes organs to fail. Typically, people will have to wait years on the transplant list, and after receiving this transplant, must spend the rest of their lives on immunosuppressive and anti-rejection medications. These medications don’t help the already weak immune system. The combination of these immune-suppressing drugs means that they will be more susceptible to autoimmune diseases and viruses and will make it harder for them to fight it off.
With regenerative medicine, scientists hope to eliminate the organ transplant list, with tissue engineering and 3D bioprinting. Using stem cells, either harvested from the patient or a compatible donor, they can be seeded on a 3D printed scaffold made of collagen into the organ shape. With the right environment and growth factor proteins and nutrients, the goal is that it will grow into a functional organ. And because they are seeded with stem cells that are either from the patient or a matching donor, they are less likely for rejection, therefore eliminating the need for anti-rejection medications. With these bio-printed transplant organs, it improves the quality of life and their healthspan as the bio-printed organ will work like new.
Biobanking
Well, now you know that stem cells decline as we age but are important in increasing healthspan, there is still hope. Why not store our young cells for when we need them. They could help us live longer and in a healthier state. Companies like Acorn Biolabs, and Healthcord Cryogenics, are biobanking stem cells and cryogenically freezing them for later use. The process is relatively simple but varies depending on which company you use. Some harvest from hair, others from the umbilical cord from a baby, fat tissue, blood, etc. This is a great investment as it can save your cells until when you need them, whether it’s when you are fighting a disease or the effects of aging.
🔑Key Takeaways
- Aging is a process driven by many factors. Some of the factors are:
1. A reduction in stem cells: the little repair cells in our body that decrease and mutate as we age, making them less effective at repairing injury in our body
2. The shortening of telomeres: Telomeres are the little caps at the end of our chromosomes, protecting them from the imperfect process of mitosis. When they become too short, it typically stops replicating and performs programmed cell death (apoptosis)
3. The buildup of senescent cells: When these damaged cells don’t die, they become senescent cells, which are zombie-like and inhibit tissue function, increases inflammation, and contributes to age-related disease.
- Regenerative Medicine (RM) is a field of medicine that aims to replace or repair cells, tissues, or organs from damage that is caused by the wear and tear from aging.
- Stem cells are a promising treatment to delay the effects of aging and extend healthspan
Embryonic stem cells are pluripotent (they can give rise to over 220 cell types) but involve killing a fertilized embryo
Induced Pluripotent Stem Cells (iPSCs) are also pluripotent, but unlike embryonic stem cells, they originate from differentiated adult cells that are reprogrammed into an embryonic state
Adult stem cells are multipotent (they can only give rise to a specific set of cell types) and are in much smaller quantities. Their main goal is to repair damage in the body. Adult stem cells diminish over time and become less effective, leading to wear and tear.
Stem cells can help with some of the symptoms of aging by being delivered intravenously or injected directly into the site to repair joints and tissue, regrow hair, and repair other organs.
- There are over 73,000 people that are 50 years and older that are on the organ transplant list in the US. One of the contributing factors to such a high number is aging, as the stem cells begin to deteriorate, organs begin to take damage and eventually start to fail.
With tissue engineering, using a patient’s stem cell or a donor’s, scientists can soon be able to regrow organs through 3D bioprinting, eliminating the organ transplant list.
This would improve the healthspan of the elderly in need of these organs as they don’t need to be on anti-rejection medications, which leaves them more susceptible to immune diseases.
- Biobanking is the process of storing your young stem cells by cryogenically freezing them for future use, making all of these treatments for aging. possible.
Conclusion:
Aging. It’s a natural process. Eventually, our hair will go grey and the wrinkles will start to appear. But with regenerative medicine, we can hope to decrease the debilitating diseases and effects of aging, improving both our healthspan and lifespan.
