Q: How are scientists using menstruation blood for osteoarthritis treatment?
Krishna: Millions suffer from osteoarthritis—a progressive, degenerative joint disorder resulting in cartilage damage, loss of joint function, and chronic pain.
Treatments very often manage only pain.
Now a potential regenerative therapy comes from a source - the menstrual blood.
Researchers had long hypothesized that the endometrium contained stem cells, given its remarkable capacity to regrow itself each month. The tissue, which provides a site for an embryo to implant during pregnancy and is shed during menstruation, undergoes roughly 400 rounds of shedding and regrowth before a woman reaches menopause.
In a recent study published in Scientific Reports, researchers found that bioactive molecules from menstrual blood stem cells promoted cartilage regeneration in cultured cells and in human damaged cartilage samples, presenting a potential non-invasive treatment avenue for osteoarthritis (1).
Extracellular vesicles from menstrual blood stem cells promote cartilage production in human tissues.
Menstrual blood is rich in mesenchymal stromal cells, which are stem cells that can generate bone, cartilage, blood vessels, and lymphatics. These cells are very active because they rebuild endometrial lining every month in women, so their activeness can also stimulate other tissue cells to regenerate.
Another advantage of menstrual blood is that researchers can obtain samples non-invasively, compared to sources like bone marrow that require invasive procedures. Importantly, menstrual blood samples can be obtained consensually, which bypasses ethical issues that stem cell researchers face while working with embryonic stem cells.
So researchers collected period blood from three healthy donors and isolated mesenchymal stromal cells from the purified samples. From the secretions of these cells, they isolated extracellular vesicles (EVs), which are “small particles in the nanometer range that contain lipids, proteins, microRNAs, and cytosolic or nuclear proteins.
EVs perform important functions like cellular communication, immune roles, and crucially, tissue repair and regeneration.
The researchers cultured chondrocytes—the only cells in cartilage—and treated them with EVs from menstrual blood stromal cells. They found that the treated chondrocytes were not only able to uptake the vesicles, but also regenerate cartilage components.
Cartilage is composed of a dense scaffolding called the extracellular matrix (ECM), which is produced by chondrocytes. The ECM consists of proteoglycans which preserve the biomechanical properties of cartilage (2). Additionally, a lubricant fluid bathes the cartilage to absorb shock and prevent damage.
During osteoarthritis, the lubricant becomes loaded with pro‑inflammatory and death‑signalling molecules. The cartilage is continuously bathed in this ‘bad’ lubricant, and over time the chondrocytes become apoptotic, ECM breaks down, leading to loss of structural integrity of cartilage.
In the study, the researchers used a 3D cell culture system to mimic the human cartilage tissue environment. In this system, chondrocytes treated with EVs from menstrual blood stromal cells synthesized more of the ECM compared to untreated controls. The treated chondrocytes also exhibited increased proteoglycan levels.
To find out whether this works with human tissue, the team obtained damaged cartilage tissue discarded as waste during patients’ cartilage replacement surgeries. To these tissue explants, the team added a pro-inflammatory molecule that exacerbates ECM loss. Upon adding EVs from menstrual blood stromal cells to tissue explants in this inflammatory context, the ECM loss was notably reduced.
The cartilage explants were from patients with advanced osteoarthritis. The fact that they still see a clear beneficial effect of the vesicles on such severely damaged tissue is very, very important.
In addition to reducing ECM loss, EV-treated chondrocytes also over-expressed cartilage-specific genes, along with increased expression of chemical signals like interleukin (IL) (2). These results indicate a coordinated improvement of ECM synthesis through multiple mechanisms.
The researchers view this study as the starting point for developing a cell-free therapy for osteoarthritis, where secreted factors of stem cells, such as EVs, are used instead of stem cells themselves.
Other advantages include easier dosage adjustment and avoiding graft rejections.
But you should understand that this is still in the experimental stage. You have to wait for a few years more to get treated by this method.
Stem cells from the endometrium can be collected through a biopsy or in menstrual blood. Under the right conditions, they can differentiate into cell types including neurons and cartilage, fat, bone, heart, liver and skin cells.
Image source: Stem cell international
Research in lab animals suggests that menstrual stem cells could have therapeutic potential beyond osteoarthritis and gynecological diseases. In a couple of studies, for example, injecting menstrual stem cells into diabetic mice stimulated regeneration of insulin-producing cells and improved blood sugar levels. In another, treating injuries with stem cells or their secretions helped heal wounds in mice.
Scientists are experimenting with several other possibilities too.
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