Boosting the circadian rhythm of tissue repair in osteoarthritic knees
Research type
Research Study
Full title
A pilot study to boost the endogenous circadian rhythm of tissue repair in osteoarthritic knees
IRAS ID
308561
Contact name
Qing-Jun Meng
Contact email
Sponsor organisation
University of Manchester
Clinicaltrials.gov Identifier
N/A, N/A
Duration of Study in the UK
0 years, 9 months, 30 days
Research summary
Osteoarthritis (OA) is a chronic condition that results from damage to joint cartilage. Approximately 20% of adults in the UK have OA in one or both of their knees. Knee OA causes long-term pain and functional disability. Consequently, it is a personal, societal, and economic burden.
The most effective treatment for knee OA is a knee replacement, but this procedure is only performed in end-stage disease. Thus, patients with OA must live with the condition for years until they are eligible for joint replacement. With OA prevalence increasing, a disease-modifying treatment for the condition is fast becoming necessary.
Treating OA is difficult because cartilage cannot repair itself well. One gene associated with cartilage repair is Bmal1. Professor Meng’s research on Bmal1 has shown that the gene has a circadian rhythm (body clock) and that this rhythm is disrupted and dampened in OA conditions. However, further research in animal cartilage showed that Bmal1 expression can be increased by raising the temperature of the tissue. These findings suggest that the cartilage repair process could be boosted in OA joints by increasing the temperature of the affected joint.
This pilot study, funded by the University of Manchester Wellcome Trust Institutional Translational Partnership Award, will translate Meng’s laboratory research into humans. The aims will be to confirm that Bmal1 and other genes can be extracted from OA tissue, and that people with OA find the sleeve acceptable to use.
Twenty participants from Trafford General Hospital (Manchester) will be randomized to wear a heated sleeve (intervention) or a non-heated sleeve (vehicle control) for one hour a day for six weeks before a knee replacement. Participants will complete questionnaires about their experience and donate the tissue removed during surgery to the University of Manchester for analysis.
The results will be used to inform future grant applications.
Lay Summary of Results
What was the purpose of the study?
Osteoarthritis (OA), the most common form of arthritis, affects 9 million people in the UK, causing severe joint pain and disability. The body cannot easily repair the damage done by OA, but studies done at the University of Manchester showed that heating an arthritic joint could switch on the body-clocks (circadian rhythms) of certain genes that are linked to repair. This means that heat has the potential to be used as a therapeutic treatment of OA.
Based on the results of these laboratory studies, the researchers wanted to see if a device that can be worn on the knee to warm the joint (known as a ‘sleeve’) could be used to increase the activity of genes linked to joint repair in people with knee OA.
The two aims of this study were:
1)To see if the activity of tissue repair genes could be measured in human bone and cartilage, a smooth, glass-like tissue that helps cushion joints.
To do this, tissue samples from people who used the sleeve at home before a knee replacement operation were tested in a laboratory.
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2) To determine if the sleeve was acceptable to people with arthritis.
To test this, we used a questionnaire. It asked the participant about the safety, comfort, and tolerability of the device.
To help us understand if heat plays a role in activating tissue repair genes in human arthritic knees, this study was randomised. This means that half of the people taking part in the study were asked to programme the knee sleeve to 42°C and the other half were asked to programme the sleeve to room temperature. The sleeve was attached to a pump which pumped water into the sleeve at the desired temperature.
At the first research appointment, participants were instructed to wear their allocated sleeve for one-hour each day for 6-weeks before their knee replacement surgery. A questionnaire was completed at this time. On the day of surgery, participants were asked to complete the questionnaire again and give feedback on the sleeve. Samples of their tissue were also taken from the operating room for analysis in the laboratory.
Who took part in this study?
This study was what researchers call a ‘pilot’ study. This means that it was a small-scale study to test whether we could do a similar study on a bigger scale, with more people.
Seventeen people signed up to the study, and 15 of these completed the research. The average age of the participants was 70 years old. Ten of the participants who completed the study were male (66.7%) and 5 were female (33.3%). Nine had a knee replacement on the left knee (60%), while 6 had the operation on the right knee (40%). Seven participants were randomised into the heated-sleeve group (46.7%) and the remaining 8 were randomised into the non-heated sleeve group (53.3%).
What did we learn from the tissue samples?
Bone and cartilage tissues that are removed from the knee during a total knee replacement operation are normally discarded. However, for this study we carefully collected and took these tissues to a laboratory at the University of Manchester for detailed study.
Looking closely at the cartilage
In the lab, we first focused on the cartilage. We took small samples of the cartilage to study it in different ways:
•
Studying Genes: Some of the cartilage was specially frozen. This allowed us to look at genes, which are like the instruction manuals inside cells. By studying these genes, we can learn more about what the cartilage cells were doing and how they might have responded to the knee heating treatment.
•
Examining Cells and Proteins: Another part of the cartilage was preserved so we could look at it under a microscope. This helped us see the structure of the cartilage and identify specific proteins. Proteins are like the workers in cells, carrying out important jobs.
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•
Growing Cartilage Cells: We also took a portion of the cartilage to isolate its living cells, called chondrocytes. We were able to grow these cells in special dishes in our lab. This allowed us to study them more closely.
Understanding the "Body Clock" in cartilage
One of the main things we were interested in was the circadian within the cartilage cells. To see the specific proteins that make up this clock, we used special tools called antibodies. Think of antibodies as tiny, highly specific detectors that can find and attach to only one type of protein.
•
In Living Cells (grown in the lab): We used these antibody "detectors" that were designed to find the body clock proteins. When these antibodies found their target proteins in the cartilage cells, they were made to light up (fluoresce) under a special microscope. This glowing allowed us to see exactly where these important clock proteins were located inside the individual cells.
•
In Tissue Samples (thin slices of cartilage): For the cartilage tissue samples, we again used these specific antibody "detectors." This time, when the antibodies attached to the clock proteins, they helped create a visible brown colour change right where the protein was located. This technique, called immunohistochemistry or IHC, allowed us to see which cells contained these clock components and how many of them there were in different areas of the cartilage. This helped us understand if the heating treatment had any effect on these proteins.
A deeper dive into gene activity and individual differences
We also used a powerful technique called RNA sequencing. Think of this like being able to read all the active instruction manuals (genes) in the cartilage cells at once. This not only helped us compare the general gene activity between those who
CartilageChondrocyte cellsCircadian Cloc GenesAntibody staining ofcartilage tissue detectingcircadian clock proteins.Brown dots are chondrocytecells with detectable clockproteins.Fluorescent antibody staining of livechondrocyte cells detectingcircadian clock proteins. reen areclock proteins; Blue is NA in thecell nucleus.Expression levels of circadianclock genes (rows) amongstudy participants (columns).Red high level; Blue lowlevel
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received the knee heating treatment and those who didn't, but it also allowed us to see how gene activity varied from one patient to another. Understanding these individual differences is very important, as it helps us see that people may respond differently to treatments like knee heating.
What did we learn from the questionnaires?
We asked participants several questions during this study to understand more about their symptoms before and after using the sleeve. This helped us understand whether participants felt that their symptoms had changed in any way after using the sleeve for 6 weeks.
It should be noted at this point that many factors contribute to the answers that people provide to these questions. This means that we cannot use these results to work out whether any of the changes in scores over time, or differences in scores between groups, are linked to the sleeves used in this study.
Oxford Knee Score
The first questionnaire that participants answered was the Oxford Knee Score. This asks participants questions on nee function and pain. It is commonly used before and after knee replacement. Lower scores mean less pain and better function.
Participants who had the heated sleeve started with a score of 20. This reduced by one mark to 19 after sleeve use. Participants who had the non-heated sleeve reported a worse score before sleeve use at 23 points. This improved to 15 points after use of the non-heated sleeve.
EQ-5 Score
The second questionnaire asked questions on quality of life. The first question was about mobility. On average, both groups chose the option “I have moderate problems in walking about” before using the sleeve. This worsened to “I have severe problems in walking about” in the non-heated sleeve group after use, but did not change in the heated sleeve group.
Similarly, for the next question on self-care. On average, both groups chose the option “I have slight problems washing or dressing myself” before using the sleeve. This worsened to “I have moderate problems washing or dressing myself” in the non-heated sleeve group after use, but did not change in the heated sleeve group.
The same pattern was seen for the third question on usual activities. On average, both groups chose the option “I have moderate problems doing my usual activities” before using the sleeve. This worsened to “I have severe problems doing my usual
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activities” in the non-heated sleeve group after use, but did not change in the heated sleeve group.
In the fourth question on pain and discomfort, the participants in the non-heated sleeve cohort started the study with moderate pain and ended the study with severe pain. No change was seen in the group which had the heated sleeve, who reported moderate pain at both time points.
Next, participants in both groups reported that they felt more anxious (moderately compared to slightly) after using the sleeve. It should be mentioned however, that the final questionnaires were completed on the morning of the operation; a time when it is not uncommon to be anxious.
Finally, participants were asked to rate on a scale from 0-100 their general health on that day, with 0 being the worst health they could image and 100 being the best health they could imagine. Participants in the non-heated sleeve group felt their overall health was 74% before using the sleeve. This improved to 78% after sleeve use. Participants in the heated sleeve started the study at 59% and improved to 73% at the end.
Knee Osteoarthritis Outcome Score (KOOS)
The KOOS is a questionnaire that is commonly used in hospitals to assess pain, and the impact that knee OA has on function, activities of daily living, sports and recreation and quality of life. Higher scores mean less pain and better function.
Like the EQ-5 results, pain was found to worsen more in the non-heated sleeve group (44% to 31%) than the heated sleeve group (39% to 34%). Knee function also worsened in both groups, but more so in the group with the non-heated sleeve (49% to 42% compared to 41% to 39%). Interestingly both groups saw their score in the sports and recreation section of the questionnaire improve (9% to 12% for the non-heated sleeve group, and 22% to 24% in the heated sleeve group). Finally, both groups reported a reduction in quality of life over time, although the reduction was greater in the group which received the non-heated sleeve (30% to 20% compared to 23% to 20%).
Sleeve Questionnaire
We also asked participants to complete a questionnaire on their opinion of the sleeve and its use. This helped us understand whether we need to make any changes to how the equipment is used, or indeed the type of equipment used in future.
Q1 - How easy was it to attach the sleeve to your knee?
For this question, study participants rated this 8/10 on average, with 10 being ‘extremely easy’.
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Q2 - How easy was the sleeve to remove?
For this question, study participants rated this 10/10 on average, with 10 being ‘extremely easy’.
Q3 – How easy was it to use the device (fill it with water/switch it on/off etc.)?
For this question, study participants rated this 9/10 on average, with 10 being ‘extremely easy’.
Q4 – How comfortable was the material of the sleeve against your skin?
For this question, study participants rated this 9/10 on average, with 10 being ‘extremely comfortable’.
Q5 - Did you experience any problems associated with the material of the sleeve whilst wearing it e.g. rubbing or chafing against the skin?
All participants stated ‘No’ to this question.
Q6 – Did the sleeve stay in place when you used it i.e. was it secure enough?
All participants stated ‘Yes’ to this question.
Q7 – How aware were you of the sleeve when you were wearing it?
For this question, study participants rated this 6/10 on average, with 10 being ‘not at all aware’.
Q8 – How did you feel about the temperature of the sleeve?
All participants across both groups chose ‘Just right’ for this question.
Q9 – Did you ever experience any pain or discomfort when using the sleeve?
One participant described slight irritation when using the sleeve. All others stated ‘No’ to this question.
Q10 – How safe did you feel when using the sleeve?
For this question, study participants rated this 10/10 on average, with 10 being ‘extremely safe’.
Q11 – What did you think about the length of time each day (1-hour) the sleeve had to be worn for?
One participant chose ‘Too long’ for this question and declared that they had sometimes taken the sleeve off before the 1-hour mark. All others stated ‘Just right’ and confirmed they had worn the sleeve for the full hour each time.
Q12 – What time of day did you tend to wear the sleeve?
7-8am – One participant
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8-9am – One participant
9-10am – Two participants
Sometime in the morning – Two participants
2-3pm – One participant
4-5pm – Two participants
Sometime in the evening – Two participants
Unknown – Four participants
Q12 – What did you think about the duration of time (6-weeks) you had to use the sleeve for?
Four participants chose ‘Too long’ for this question. All others stated ‘Just right’.
Q13 – Did you use the sleeve every day for 6-weeks as instructed?
Four participants chose ‘No’ for this question. All others stated ‘Yes’. Reasons for not using the sleeve each day included going away on holiday, the surgery date being moved forward, and problems with getting the equipment to work effectively part-way through the study.
Overall, the findings of this questionnaire were positive, suggesting that people with OA would be willing and happy to use such a device in future research. However, there were significant problems with some of the sleeves which were highlighted by participants in the questionnaire. Some of them leaked water, and others failed to turn on or work properly. There were also multiple complaints about the water not travelling properly from the pump into the sleeve, and the sleeve itself failing to sit well on the knee. Suggested improvements included the use of sleeves of different sizes in future.
We have taken on board the feedback from participants. iven the magnitude of the problems with some of the devices, we have decided to stop using the sleeve that was used in this pilot study. For our future research, we will look to use novel battery-powered sleeves that can be worn under clothing and during everyday activities. As these are battery-powered, future participants would not need to be near a power outlet to use them, nor would they need to fill the devices with water; they could simply charge them overnight and wear them at any convenient time. These sleeves are also more easily adjustable for different knee sizes and may therefore suit more patients.
Why was this study important?
At this point in time, we are unable to draw any conclusions on how effective heat is at repairing damaged tissue in the knee, as this was a pilot study. However, this study was crucial for the following reasons:
1.
It helped us learn more about the effects of heating on knee cartilage, particularly on the cells' natural body clocks.
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2.
It helped us understand the kinds of equipment people are happy to use at home, which will help us develop future studies and therapeutic devices.
3.
It allowed us to improve and refine our methods for collecting cartilage samples after surgery, preparing them for study, and accurately detecting these subtle changes in proteins and genes.
4.
Importantly, by looking at differences in gene activity between participants (using RNA sequencing and our other methods), we started to understand how varied the response to heating can be from person to person. This is critical information that will help us design better and more effective larger studies in the future, with many more participants.
Has the registry been updated to include summary results?
N/A
Did you follow your dissemination plan submitted on the IRAS form?
Yes
Have participants been informed of the results of the study?
YesREC name
London - Stanmore Research Ethics Committee
REC reference
22/LO/0102
Date of REC Opinion
6 Apr 2022
REC opinion
Further Information Favourable Opinion