Kidney diseases are among the most expensive and most debilitating diseases. Total costs are in excess of $50 billion a year, with $30 billion spent on people with end-stage renal disease including hemodialysis and kidney transplantation. People with kidney diseases have diminished quality of life, and substantial amounts of their time are devoted to medical treatment. Not surprisingly, researchers are aggressively pursuing novel therapies to treat kidney diseases before they result in end-stage renal disease. Stem cells and exosomes are among the most exciting and the most promising research topics in this area.
Most cells release tiny packets called extracellular
vesicles. The most notable extracellular vesicles are exosomes. While small,
exosomes are filled with high concentrations of potentially helpful substances
such as RNA, DNA, and proteins. While most cells release exosomes, researchers
are particularly interested in exosomes released by stem cells. It is within
these exosomes that stem cells pass along the substances that make stem cells
helpful in tissue repair and regeneration.
coauthors reviewed the recent advances that have been made using exosomes
to treat kidney diseases. Most of the work has focused on acute kidney injury
or AKI. Acute kidney injury can lead to
chronic kidney disease and kidney failure. Thus, if one could stop AKI, they
could potentially reduce the risk of chronic kidney disease.
Many different research groups have shown the power of
exosomes and other extracellular vesicles in treating acute kidney injury.
Exosomes taken from mesenchymal stem cells protected kidney cells from cell
death and fibrosis and helped them repair themselves. The
same was true of exosomes derived human umbilical cord stem cells.
Even stem cells taken from human liver cells were
able to improve kidney function after injury. There are many other examples.
et al. reported that extracellular vesicles derived from human adult
mesenchymal stem cells could protect against acute kidney injury, but, most
impressively, also halted the progression of AKI to chronic kidney disease.
This finding has important implications for people who suffer from serious
acute kidney illnesses, such as kidney ischemia. It means that—if confirmed in
human studies—stem cell-derived extracellular vesicles can help treat kidney
disease in the short term and reduce the risk of that illness becoming a
chronic, debilitating problem.
Further research is needed in this field but, initial
results confirmed by many laboratories have created well-founded enthusiasm for
Reference: Zhang, W. et al. (2016). Extracellular vesicles
in diagnosis and therapy of kidney diseases. American Journal of Physiology – Renal Physiology. 2016, Nov 1;
Chronic pain, that is, pain lasting for more than 12 weeks, is extremely common. As many as 1 in 3 Americans struggle with chronic pain, making it perhaps the most common physical condition that afflicts humans. Chronic pain is a source of significant suffering; it makes daily tasks more difficult, limits people’s ability to do the things they enjoy, and greatly diminishes the quality of life.
Perhaps the most frustrating aspect of chronic pain is that
there are usually no good treatments. Because the pain is chronic, patients who
try to treat chronic pain with medications must take drugs every day.
Acetaminophen and non-steroidal anti-inflammatories (NSAIDs) like ibuprofen can
help take away some suffering, but they are usually only partially effective.
Opioids are stronger, of course, but have such a high risk of causing
dependence and addiction that few doctors will prescribe for chronic non-cancer
pain. Physical therapy helps some, but not most people. Surgery may be able to
treat people with certain types of chronic musculoskeletal pain; however, orthopedic surgery is a major ordeal with no guarantees of
success. Consequently, most people with chronic pain are left with very few
Perhaps this lack of chronic pain treatment options is what
makes recent stem cell research in chronic pain treatment so exciting.
Researchers are learning that mesenchymal
stem cells appear to be able to treat people with chronic pain. For
example, in a study of patients with low back pain who received treatment autologous
stem cells (their own stem cell populations purified, expanded, and
re-injected in their bodies), their pain and disability
decreased to the same levels as people who underwent major orthopedic
surgery (spinal fusion or total disc replacement). Another lab in Japan showed similar results.
The same benefit may occur in knee arthritis (osteoarthritis),
as well. Researchers showed that autologous stem cells were able to increase
the size of the knee
meniscus cartilage in a patient with severe knee arthritis. It should be
noted that damaged knee meniscus cartilage is one of the main sources of
chronic pain in knee osteoarthritis.
Of course, the number of patients treated in these studies is relatively small. Larger studies will be required to confirm that mesenchymal stem cells can treat chronic pain. However, these results are intriguing, since a staggering number of studies show autologous stem cell treatment to be safe. Indeed, mesenchymal stem cell treatment is now widely available in clinics and medical practices.
Reference: Waterman R. et al. (2011). Treating Chronic Pain with Mesenchymal Stem Cells: A Therapeutic Approach Worthy of Continued Investigation. Journal of Stem Cell Research & Therapy. 2011, S2 DOI: 10.4172/2157-7633.S2-001.
stem cell treatments offer several advantages over other forms of stem cell
treatment. In autologous stem cell treatment, a patient’s own stem cells are
retrieved, processed, and injected back into the patient’s body. There is no
need for a stem cell donor, and the entire procedure can take place in the same
medical office. Since the patient’s own cells are used for an autologous stem
cell treatment, there is no risk of disease transmission from a donor (because
there is no donor) and no risk of rejection (because they are the patient’s own stem cells).
Unfortunately, younger stem cells are better for
regenerative medicine than older stem cells are. Moreover, older people have
fewer stem cells that can be harvested than they did when they were younger. So
while autologous stem cell treatment is still advantageous, it becomes more difficult
to achieve as patients get older because their stem cells are fewer and less potent.
Making matters worse, older stem cells compete against more youthful stem
cells, making autologous stem cell treatments potentially even less effective
in older patients.
Fortunately, stem cell researchers are coming up with ways to make the most out of the stem cells that older patients still have. They still take a sample of tissue, such as fat, and harvest the stem cells contained within it. However, instead of injecting all stem cells from the sample (both older and youthful stem cells), researchers select and use only youthful stem cells. Furthermore, they make the treatments even more effective by injecting other substances (e.g. extracellular matrix) that help youthful stem cells survive, grow, and thrive.
To demonstrate the effectiveness of their approach,
researchers collected mesenchymal
stem cells from about a dozen older individuals aged 65 to 86 years old.
They then assorted the stem cells into different groups, separating youthful
from older stem cells. They then used special factors to help the youthful stem
cells grow, increasing the numbers by an impressive 17,000 times. So while only
8% of stem cells produced by older individuals are “youthful,” this laboratory
process increased those numbers to a point that they can be used for stem cell
treatments—even stored for future use!
The next phase of the research will be to inject these youthful stem cells into older patients and assess their effectiveness. However, even these preliminary results are exciting because they suggest that people of all ages can potentially benefit from autologous stem cell treatments, not just middle age and younger individuals.
Reference: Block, TJ et al. (2017). Restoring the quantity and quality of elderly human mesenchymal stem cells for autologous cell-based therapies. Stem Cell Research & Therapy. 2017 Oct 27;8(1):239.
lateral sclerosis or ALS is a devastating, progressive neurological
disease. While the precise cause is unknown, ALS does destroy nerve cells in
the spinal cord, which causes several debilitating symptoms. Often the first
symptom of ALS is weakness in the hands or arms that is usually more pronounced
on one side of the body. As more spinal cord nerve cells become dysfunctional
and die, patients with ALS become weaker, their movements grow slower, and
their muscles begin to atrophy (i.e. break down). At the same time, some
muscles in the limbs become spastic, which means they are constantly in a contracted
state. In later stages of ALS, patients have difficulty swallowing and
The only drug to have any known survival benefit in ALS is riluzole. Patients who take riluzole live longer than those who do not; however, the drug does not improve function or meaningfully reduce symptoms. The only other approved ALS treatment, edaravone, may slow the rate at which ALS gets worse. However, neither of these drugs is a cure—far from it, in fact. Indeed, doctors and patients are left with virtually no effective treatment options for ALS.
Because ALS is caused by the destruction of nerve cells in the spinal cord, the regenerative properties of stem cells may offer a solution. The hypothesis is that stem cells—and exosomes collected from stem cells—can help protect, preserve, or even regenerate cells that are affected by ALS.
A flurry of research has been published over the last decade documenting the safety and possible effectiveness of mesenchymal stem cells for the treatment of ALS. In 2009, Deda et al. showed bone marrow stem cells injected into the spinal area were safe in patients with ALS, even showing that some patients had improvements in neuromuscular testing. The research groups of Karussis, Mazzini, Blanquer, and Baek showed similar safety results. Martinez et al. showed that stem cells derived from bone marrow could improve survival in patients with ALS. Rushkevich et al. showed that stem cell infusion improved the quality of life in patients with ALS.
While more work is clearly needed to determine the full effectiveness of stem cell treatment for ALS, the number of researchers working on this topic and the number of successful studies published in this area are reasons for hope. These clinical studies show that stem cell treatment for ALS is clearly safe and feasible. What is needed are larger clinical trials that specifically focus on the effectiveness of treatment, both in the near- and long-term.
Reference: Roberta Bonafede and Raffaella Mariotti. (2017). Stem cell mobilizers: ALS Pathogenesis and Therapeutic Approaches: The Role of Mesenchymal Stem Cells and Extracellular Vesicles. Frontiers in Cellular Neuroscience. 2017; 11:80.
Over the past few years, data have accumulated showing the promise for cell-based therapies to help with the treatment of perianal Crohn’s disease. Specifically, stem cells appear to offer the opportunity to overcome several weaknesses associated with conventional therapies that have targeted perianal Crohn’s disease.
Based on these positive results, scientists and healthcare providers have become more adamant about understanding the broader role stem cells could play in the treatment of all inflammatory bowel disease. A new review published in Current Gastroenterology Reports discusses this specific issue and offers insights into the direction of stem cell research as it relates to inflammatory bowel disease.
The authors of this review discuss data from over a dozen clinical trials that have already been conducted on the impact of stem cell therapies in Crohn’s disease. Thus far, much of the success of regenerative medicine for the treatment of Crohn’s disease has been for the specific treatment of perianal Crohn’s disease, which occurs when the digestive and gastrointestinal inflammation associated with Crohn’s disease extends to the anal area.
Given the frequency with which the lining of the intestine is inflamed in inflammatory bowel disease, including both perianal Crohn’s disease and non-perianal Crohn’s disease, research efforts are focusing more and more on how stem cells may be able to combat this type of luminal disease. The authors put forth suggestions for the types of information that researchers should aim to obtain if we are to adequately treat intraluminal disease with regenerative medicine.
The potential of stem cells to address inflammatory bowel disease that has been demonstrated so far provides hope that this type of strategy will help not only patients with perianal Crohn’s disease but those with other forms of inflammatory bowel disease as well. More research should help to determine if and how these therapies can be deployed to help this patient population.
Reference: Lightner, A.L. (2019). Stem cell therapies for inflammatory bowel disease. Current Gastroenterology Reports, 21(4), 16.
Researchers have recently established that a hallmark of Amyotrophic Lateral Sclerosis (ALS) is endothelial cell degeneration that leads to vascular pathology. When this vascular pathology occurs, damage develops to the barrier between the blood and the central nervous system. Given this new understanding of the pathophysiology of ALS, researchers have begun looking at the potential of repairing this barrier as a strategy for treating the disease.
A recent study, published in Scientific Reports, addressed this issue by testing how human bone marrow cells may impact blood-spinal cord barrier repair by transplanting these cells in an ALS model. The researchers hypothesized that the cells should help to repair the barrier, reversing the damage accompanying ALS. They were also interested in whether this type of repair may improve not only the integrity of the barrier between the blood and central nervous system but also improve symptoms of ALS.
What the researchers found was that the human bone marrow cells differentiated into the type of endothelial cells that were needed for repair and successfully engrafted into the capillaries of the spinal cord in their model. Several specific observations led the scientists to conclude that these stem cells helped to effectively restore the barrier between the blood and the spinal cord.
The stem cells improved the integrity and survival of nervous system cells, including astrocytes and spinal cord motor neurons, preventing problematic changes in these cells that are associated with the breakdown of the blood-central nervous system barrier. Critically, the implantation of the stem cells also led to improvements in behaviors associated with ALS.
While there is still a lot of research to be done to establish whether bone marrow stem cells can help repair the blood-spinal cord barrier in patients with ALS, this study provides promising data. Given that there is no cure for ALS and limited treatment options, there is likely to be an emphasis on cell-based therapies for the disease. As more data become available, we will get a clearer picture as to if and how stem cells can help ALS patients.
Reference: Garbuzova-Davis,S. (2017). Endothelial and astrocytic support by human bone marrow stem cell grafts into symptomatic ALS mice towards blood-spinal cord barrier repair. Scientific Reports, 7(884).