Home › Blog › Is Joint Arthritis All About the Fibroblasts?

While there’s a focus on the cartilage and bone spurs, there’s much more to arthritis. For example, your joint connective tissue is a large part of the tissues impacted by arthritis. Researchers are now only starting to understand how the cells in the joint covering are impacted in different ways in different types of arthritis.

What is Arthritis?

We think of arthritis as a breakdown of the cartilage and bone spurs. However, there’s quite a bit more to understand. For example, nerves, the fluid inside the joint, and the connective tissue covering of the joint all have roles to play.

If you have arthritis, your treatment options may be limited. Both osteoarthritis and rheumatoid arthritis, the most common forms of the disease, affect the joints of the body and cause pain, inflammation, and loss of mobility.

Rheumatoid Arthritis

In rheumatoid arthritis (RA), the body’s immune system attacks its own joints. As this onslaught occurs, the lining of the joints is invaded by immune cells. This buildup of immune cells in the joints makes them chronically inflamed—painful and swollen—and, over time, the joints become severely damaged and crippled.

Current treatments for RA target the immune cells, either by altering the cells directly or by attempting to interrupt the signals that attract the cells to the joints. The recent analogy used by researchers compares current therapies for arthritis to applying weed killer; the weeds die, but unless you continue to apply the treatment, the weeds come back.

Osteoarthritis

Osteoarthritis is the typical wear and tear type arthritis. Here, there is damage to cartilage and bone and the area loses cartilage. Over time, bone spurs develop. All of this gets worse if the joint ligaments are loose causing too much movement inside the joint or if there is more wear and tear in general. Also, total body inflammation can make this worse as can having a problem with a nerve that innervates the joint.

Arthritis Treatments

Medications usually reduce the swelling in the joint. However, no treatments are currently available that directly target the fibroblasts (connective tissues cells) found in the joint which respond to the incoming attack.  But new research could change that.

Researchers at the Universities of Birmingham and Oxford have uncovered new information about tissue cells that can help pave the way for more effective treatments for arthritis.  Their study found that various types of fibroblasts are arranged in different layers within the coverings of our joints.

The scientists compared these layers to different types of soil in your garden; the makeup of all the layers is not identical. Just as there are layers of soil (for example, subsoil and topsoil) in your garden, there are also layers of different types of fibroblasts in your joints tissues.

Different types of fibroblasts are responsible for two very different types of arthritis—rheumatoid arthritis and osteoarthritis. The scientists say that, (still comparing the tissue cells to the soil), in rheumatoid arthritis, the subsoil is where the problem occurs. In contrast, the topsoil is the source of the problem in osteoarthritis.

The researchers found that removing the aberrant fibroblasts decreased the flood of immune cells to the joint, and this, in turn, decreased inflammation and joint destruction.  

The upshot? This new research opens up a whole new avenue in drug management and regenerative medicine. For example, you could try to inhibit one set of these fibroblasts. That, however, may have unintended consequences. Better would be using cellular therapies to replace the bad fibroblasts with new and healthy ones. That’s not too different than what we do with stem cell injections today by replacing the worn out stem cell reserve in the joint. Hence, I suspect we’ll see that type of treatment at some point.

Chris Centeno, MD is a specialist in regenerative medicine and the new field of Interventional Orthopedics. Centeno pioneered orthopedic stem cell procedures in 2005 and is responsible for a large amount of the published research on stem cell use for orthopedic applications. View Profile