The day that patients with osteoarthritis can ease their painful joints by using stem cell therapy to regenerate damaged cartilage took a step closer recently when researchers reported successfully producing cartilage in rats using embryonic stem cells.
The success is attributed to a new procedure or protocol fur using human embryonic stem cells, developed under strict laboratory conditions, by the researchers at the University of Manchester in the UK.
The researchers report a study about their work – funded by Arthritis Research UK – in the journal Stem Cells Translational Medicine. The study shows how they used the new protocol to grow and transform human embryonic stem cells into cartilage cells.
Leading the research is Sue Kimber, a professor in the Faculty of Life Sciences at Manchester, who, with her colleagues, hopes their approach could in future be used to treat the painful joint condition osteoarthritis. She notes:
“This work represents an important step forward in treating cartilage damage by using embryonic stem cells to form new tissue, although it’s still in its early experimental stages.”
Osteoarthritis mainly affects people over the age of 60, and is a major cause of disability. It is a degenerative disease caused by wearing away of cartilage in joints that have been continually stressed during a person’s lifetime, including the knees, hips, fingers and lower spine region.
The World Health Organization estimates that around 9.6% of men and 18.0% of women aged over 60 years have symptomatic osteoarthritis.
Researchers generated precursor cartilage cells from embryonic stem cells
Cartilage cells – also known as chondrocytes – are formed from precursor cells called chondroprogenitors. In their study, the team describes how they used the new protocol to generate chondroprogenitors from human embryonic stem cells.
They implanted the precursor cartilage cells into damaged cartilage in the knee joints of rats.
After 4 weeks the cartilage was partially repaired. After 12 weeks, the cartilage surface was smooth and similar in appearance to normal cartilage.
Later examination of the regenerated cartilage showed that cartilage cells from the embryonic stem cells were still present and active in the tissue.
The study is promising because not only did the new protocol lead to regenerated, healthy-looking cartilage, but there were none of the adverse side-effects that have since dashed the high hopes raised in the early days of stem cell research – the growth of abnormal or disorganized tissue or tumors.
Testing the new protocol is the first step toward trials in human arthritis patients
Testing the new protocol in rats is the first step toward running trials in people with arthritis. But before this can happen a lot more needs to be done to show the protocol works and is safe. The team is already planning their next step to build on their findings.
Another approach to using human embryonic stem cells to generate new cartilage cells is using adult stem cells. Adult stem cells are found in certain “niches” in the body and are not as controversial as embryonic stem cells but their potential is not so great. Also, note the authors, they cannot currently be produced in large amounts and the procedure is expensive.
Dr. Stephen Simpson, director of research at Arthritis Research UK, says he is encouraged by the new study because:
“Embryonic stem cells offer an alternative source of cartilage cells to adult stem cells, and we’re excited about the immense potential of Professor Kimber’s work and the impact it could have for people with osteoarthritis.”
He explains that current treatments for osteoarthritis can only relieve painful symptoms, and there are no effective therapies that delay or reverse cartilage degeneration. Joint replacements are successful in older people, but these options are not effective in younger people or athletes with sports injuries.
In January 2015, Medical News Today learned about a new project that is going to test a newbone growth-accelerating therapy in space. Astronauts aboard the International Space Station and scientists stationed on Earth are going to assess how well a bone-forming molecule called NELL-1 promotes bone formation and protects against bone degeneration.
Written by Catharine Paddock PhD