Image Credits: Harvard Health – Harvard University
What is Degenerative Osteoarthritis?
Osteoarthritis is an acute or chronic inflammation of a joint. Arthritis symptoms are variable but often include pain and changes to the joint. Up to 10%–15% of all adults aged over 60 had some degree of symptomatic OA, with prevalence higher among females than males .
As a partially autoimmune condition, one of the best ways to control Osteoarthritis is via the appropriate diet and lifestyle changes. Statistically Osteoarthritis(OA) is one of the most commonly treated orthopaedic conditions. Many older adults suffer from this condition, due to the fact that joint components like cartilage, take a long time to heal. With advances in medicine, OA is now being combatted with conditions such as stem cell treatment.
In the progression of OA, patients often exhibit symptoms such as the capsule-bursa tissue inflammation, synovial fluid modifications, cartilage breakdown and erosions, osteochondral inflammatory damage leading to bone erosion and distortion.
One of the underlying reasons that medical treatments are being developed for conditions like OA is because the underlying mechanisms of propagation of the disease is identified. During the initial phases of the inflammatory-immunologic process, researchers have identified the pathways that contribute to this state. There are additional disease elements such as synoviocytes (A and B), chrondrocytes, extracellular matrix, local immune-inflammatory mediators and proteases. How these all interact in the generation process is still being investigated by medical researchers. With the advent of stem cell therapy however, mesenchymal stem cells (MSCs) have found immense use in the healing of OA. The MSCs counter the inflammatory-immunologic processes and facilitate healing.
How do Stem Cells or Growth Factors Regenerate the Body?
The stem cell has long been identified as the regenerative life force in our bodies. With their ability to divide and duplicate, as well as generate new and different stem cells that are relevant to a healing site, it is possible to regenerate cartilage cells and even bone cells. This is great news for the arthritic foot. Over time, the joint can wear away, and with the ability to rebuild it naturally, it will save the individual time from having to go through processes like harvesting.
How are Stem Cells Administered?
Stem cells are administered either surgically, or via injection into the arthritic joint. Much like the image above, your orthopaedic surgeon will utilize medical imaging in order to identify where on the body, the stem cells are to be administered. Depending on the severity of the injury, either of the two options will be applied. When the stem cells are being administered, your orthopaedic surgeon will more than likely utilize mesenchymal stem cells that have been harvested from the individual’s body.
Studies have identified that joint-resident MSC’s are integral to the facilitation of joint regeneration stability, and also regulate cell turn over and tissue repair. A regenerative microenvironment is the outcome of introduction of MSCs into an arthritic joint. The reversal of OA is now possible with these newly understood mechanisms.
With an understanding of OA biological processes that trigger OA, the primary aim now is to identify the means to minimise cartilage degeneration. Resident joint MSCs work to modulate local inflammatory and immunologic responses. Thus far, MSCs seem promising for both early stage OA all the way to more advanced joint degeneration.
RESTORATIVE SITES IN OA
The knee joint forms a joint capsule where all the bones meet in the hinge mechanism. Within the joint is a fibrous membrane that is composed of connective fibrous tissue. The nervous system permeates this area introducing feeling, while muscles and tendons facilitate the motion and flexibility of the joint. The synovial membrane in the joint, is the point where the special mesenchymal tissue resides. This is the point of regeneration. As a regenerative site, there is a dense net of capillary vessels that provide the nutrients that are distributed via processes such as diffusion. All joints have a fibrous membrane structure that varies in thickness in different parts of the body. For this reason, it is possible to transfer some of the MSCs from the fatty parts of the body into sites that need to be regenerated. They can’t always be generated in situ, but they can be transferred from a pre-existing site.
Within the synovial membrane complex is the important function of generating synovial fluid, as well as the sustenance of the Extracellular Matrix that is a cell host. Synovial fluid is a key element in the health of the cartilage. It supports the superficial and middle zones of the cartilage, and provides them with nutrients.
The General Properties of MSCs
MSCs are members of the stem cell family. The innate ability of all stem cells is to generate mesenchymal lineages such as fibroblasts, chondroblasts, adipocytes, muscle-cells, osteoblasts and other mesenchymal lineages . This ability of the stem cell to forge differing cell groups is what facilitates the in vivo proliferation and differentiation in the regenerative microenvironment that is the joint. Their mechanisms of action include autocrine and paracrine effects. Medical research is still delving into the various mechanisms of action of the MSC cells. They have various interactions with critical receptors in the joint capsule. One thing that activates the already resident MSCs in the joint is presence of tissue injury and inflammation. The regenerative mechanisms are activated once these conditions are induced. Local immune modulation and trophic effects are two of the primary functions of the MSCs. MSCs as a heterogenous stem cell population that generate the relevant cells needed for healing in a tissue-specific microenvironment. They adapt to their environment.
MSC Exosome Research
In the past decade, research in MSC has resulted in several experimental models that have ultimately led to clinical applications. Since the MSC’s show great promise in promotion of healing and tissue regeneration there is a lot of interest in their utilization. What is the current concern of researchers is to ensure that the survival rate of MSCS during and after transplants is understood. Survival rate verification is currently to be determined, and future research is still to understand the full mechanisms of action once the transplanted cells are placed in the host tissue. Unlike drugs whose concentrations and paths are traceable, there is still a lot to be learned from the Stem Cell research. Sometimes in the research process, when MSCs were intended for proliferation they would act in an immune-regenerative function instead. This inability to specify the mechanism is what is limiting the use of the MSCs and also the progress of usage in therapies. The root of this condition is linked to a process known as paracrine action. Studies have linked this outcome to the secretion of exosomes. These membrane-enclosed vesicles favor regeneration. Knowing how to adjust the lever to the right specificity will be the key to a successful future.