Mutation causing Dupuytren's? Or not?

Evaluation of a Mitochondrial DNA mutation in Maternally Inherited and Sporadic Cases of Dupuytren’s Disease: Anderson et al, CM&R, 2012. 

It has been a long time since I did any kind of science type post but I thought that there is no harm in one every so often and this is mainly inheritance. So…

In this paper they are looking into a previously reported mutation that has been linked to Dupuytren’s disease. The previous paper identified a mutation and reported that this specific mutation was present in 90% of their subjects who has maternally inherited Dupuytren’s disease but not in any of their controls. 

I am not going to go into the details of the mutation but please ask if you would like a more detailed explanation but what I will say is that this mutation was in the mitochondria. Of course most people don’t know what this is but basically it is the thing inside the cell that makes energy and it has been shown to accumulate mutations with aging (Dupuytren’s increases with age) and mitochondria are only passed from the mother to child meaning that it is only important in cases of maternal inheritance. There are several reasons why this might be interesting which I have tried to explain in the picture below for anyone who is interested. 

I think most of the above is self explanatory but I wil

Basically in their pool of patients they see nobody with the previously identified mutation but then they only have 2 cases where there is a maternal inheritance but the other explanation is that their patients are all German whereas the previously study was English so perhaps the difference could be that this mutation is present in the English population but not the German one. 

Clearly this paper is not ground breaking however it is good to see that there are still studies on-going into the genetic basis of Dupuytren’s and hopefully they manage to find something. I don’t think that there is a single source as I think that there are too many different pathways involved and it is far too common to be a single mutation. The above mutation may well be one of the causes in the UK and it could help explain why it increases with age but the work needs to continue. 

Key points: 

• Previous study saw 90% of maternal DD has specific mutation (study in UK). 
• This study did not see this same mutation but it was from a different region and only had 2 patient with maternally inherited cases of Dupuytren's.
• With me being a man one day looking to start a family I hope that this is also a mutation linked to Ledderhose and it is the one so that I cannot pass it on to any children. 

Why Ledderhose disease is not Cancer...

Why is it not cancer?

I have seen that I have had several visits on the blog from different people that are asking..."Is Ledderhose disease cancer?" Or at least something along those lines so I thought I would clear up the matter a little bit. To be best most of this is just a rehash or simple copy and paste from the Cancer Research UK website which is great. I thought it would be best to start off with a definition of cancer and a definition of Ledderhose.

Cancer:

"Cancer is a disease caused by normal cells changing so that they grow in an uncontrolled way. The uncontrolled growth causes a lump called a tumour to form. If not treated, the tumour can cause problems in one or more of the following ways

• Spreading into normal tissues nearby
• Causing pressure on other body structures
• Spreading to other parts of the body through the lymphatic system or bloodstream" [1]

Ledderhose:

Now for a description made up by me.

Ledderhose is the formation of nodules / tumours caused by cells in the foot changing so that they grow in an uncontrolled manner.

Comparison:

As you can see there are some similarities and both do result in a tumour but a tumour does not mean cancer and for this I am going to go back to the Cancer Research UK page as this really does have lots of useful information.

"Tumours (lumps) can be benign or malignant. Benign means it is not cancer. Benign tumours

• Usually grow quite slowly
• Do not spread to other parts of the body
• Usually have a covering made up of normal cells

Benign tumours are made up of cells that are quite similar to normal cells. They will only cause a problem if they

• Grow very large
• Become uncomfortable or unsightly
• Press on other body organs
• Take up space inside the skull (such as a brain tumour)
• Release hormones that affect how the body works

Malignant tumours are made up of cancer cells. They

• Usually grow faster than benign tumours
• Spread into and destroy surrounding tissues
• Spread to other parts of the body" [1]

So as I said that info is just from the Cancer research UK page and is not my work but theirs but I think that it does a great job of explaining my point. Ledderhose disease tumours are benign tumours and do not spread around the body, if you also get something like Dupuytren's that is not the spread of the disease but rather the same disease occuring in another part of the body.

So I hope that should anyone come here now looking for the answer to this question they have it answered and have a great link to go to for more information.

[1] http://cancerhelp.cancerresearchuk.org/about-cancer/what-is-cancer/cells/what-cancer-is

Xiaflex in cells - Trying to help you understand, maybe

So today I am going to try and review this paper In Vitro Study of Novel Collagenase (XIAFLEX®) on Dupuytren's Disease Fibroblasts Displays Unique Drug Related Properties. This paper is open access so you might like to take a look for yourself or have it open at the same time as you read this and it might help. I don't understand all of it so good luck!

I say try because there is a lot of scientific content in this paper, a lot of stuff that I have not done in the lab before and this makes it harder for me to work out exactly what it means, I will however try my best to understand it and where possible try and explain it in as simple terms as possible.

To start with for those who don't know Xiaflex is a treatment for Dupuytren's disease (DD) and potentially Ledderhose disease (LD), it is a collagenase and the main component of the lumps in DD and LD is collagen and so it breaks them down.

Right onto the paper, where possible I shall try and bullet point it and I am going to place a summary at the end where I will put what I consider to be the key points.

Introduction:

• DD is a common and benign disorder. 
• The cause(s) of DD and LD are unknown however DD has been linked to genetics, smoking, diabetes, alcohol, anti-epilepsy medication, occupation and local trauma (so all the usual stuff). 
• The group of people at the most risk are Caucasian men of North European descent that are 40 or over with highest incidence in USA, Scandinavia, Britain and Australia. 
• The disease shows cell proliferation, high levels of collagen and extra-cellular matrix remodelling. 

They also make a key point which is what frustrates many of us with the disease and this is that:

"Treatment of DD is not curative" and this means that rather than trying to rid the body of the disease they are just trying to remove the symptoms.

One current treatment that is showing promise is Xiaflex which is a collagenase that digest the triple helical structure of collagen and therefore removal the lumps and whilst this is significantly less invasive than surgery it does have a much higher level of recurrence.

Aim: Their aim is to investigate the functional effects of Xiaflex in comparison to Collagenase A when used on cells cultured from DD nodules, cord, fat and skin. They look into various different aspects of the cells including looking at the cell growth and at gene expression.

So I am going to try and go through this and explain the key points one figure at a time to make it easier to follow.

Figure 1: Here they just show the process through which they have derived the cells and then the experiments that they are planning to do on them.

Figure 2 (and Figure 3): Here they are measuring the ability of the cells from the DD nodules and cords to grow in the presence of  Xiaflex / Collagenase A and whether they are able to recover from this treatment in 24 hours by removing the drug and continuing to monitor the cells. In Figure 3: They also look at fat and skin cells from DD patients in a similar way.

• They find that without treatment there is no significant different between the nodules and cords compared to the skin and fat although the DD nodules and cords do show a faster growth rate. This makes sense as it is a proliferative disease.
• Treatment with  Xiaflex / Collagenase A decreases all of the things that they are measuring in ALL cell types in a dose dependent manner. 
• 24 hours after removal of the drug the cells recover, this happens even at the highest dose and may help to explain why DD comes back so frequently when treated with  Xiaflex. 

Figure 4: I can't really follow this figure very well so rather than get it wrong and make mistakes I am going to leave this figure out but their key point from this seems to be that Xiaflex / Collagenase A induce membrane leakage and reduce cellular viability and metabolic activity in DD cells.

Figure 5: Here they are looking at the toxicity of the 2 different drugs and want to see which is more toxic to cells and if there is any specificity towards DD nodules and cords. 

• Xiaflex / Collagenase A both cause cells to die. 
• Collagenase A causes both necrosis (premature cell death) and apoptosis (programmed cell death) 
• Xiaflex only causes necrosis.

As far as I can tell from reading this (and correct me if I am wrong) they do not comment on whether this is a big deal or anything? But I think they say in the discussion that it may mean that there are likely to be viable DD cells and therefore there is an increased chance of disease recurrence. 

Figure 6: Here they are looking in the different types of cells at the levels of mRNA for key components in the production of collagen to see if this is altered by the presence of Xiaflex / Collagenase A. For those who don't know about the central dogma of life I have tried to outline it in the diagram below. But the key thing you need to know to understand these results are that mRNA is produced from DNA and that the levels of mRNA vary so that it can be used as an indicator of protein levels in the cell as protein is produced from mRNA. (Below image is VERY simplified)

The central dogma: DNA is where the information is stored and this is processed into RNA and then proteins. 

• They are looking in DD disease and see that  Xiaflex treatment causes a decrease in levels of collagen I and collagen III as well as fibronectin (forms part of ECM and interacts with collagen), alpha SMA and TGF-B1. If you remember from my previous post a decrease in TGFB1 would be useful. Explained in the image below. 

Central blue boxes show state in DD cells, right hand side is reported influence of Xiapex in DD cells

• They also say that levels of collagen are at their highest in the DD nodule which is exactly what you would expect. 

Figures 7 & 8: In figures 7 and 8 they are looking at the protein levels of Collagen I and III in the different cells types to see a) is there any difference in their profiles between the different sources (skin, fat, nodule and cord) and b) does Xiaflex / Collagenase A treatment cause any changes to these levels. 

• They show that the levels of Collagen I and III in the nodules are very high with Collagen III in particular very, very high (basically two times more than seen in anywhere else). 
• When looking at the effects of Xiaflex and Collagenase A they see that: 
• Collagenase A has an influence on Collagen I by causing a decrease on all samples at the highest dose only. 
•  Collagenase A only decreases Collagen III at the highest 2 doses in the nodules, cords and fat.
• Xiaflex causes a large decrease on all samples at all doses for both Collagen I & III with the largest decrease observed in the Nodules and cords.  

Figure 9: Here they are trying to show that the decreased levels of Collagen and other ECM factors was not just at the mRNA level but that they were also decreased at the protein level when DD tissue was treated with Xiaflex. 

• Xiaflex does down regulate the protein levels of fibronectin, Collagen and CTGF (and more) at  the protein level. 

Figure 10: I am just going to say that they see that Xiaflex and Collagenase causes a decrease in cell cycle markers. This makes sense as when the drug is added you see a slowing on cell growth and this means that the cell cycle is slower and therefore you should have a decrease in cell cycle related proteins (though in this case they are look at mRNA).

Right so that is all that I am going to cover for this paper, as I said it is a long post and it is very science based so here is the summary for all those who just want the key points or who are just too lazy to read it all (which is fair enough). 

Summary: 

• DD nodules and cords do show a faster growth rate.
• Xiaflex and collagenase A both decrease the growth rate in DD cells. 
• Xiaflex treatment causes a decrease in levels of collagen I and collagen III as well as fibronectin  and TGF-B1 (see the diagram as to why this might be good). 
• Levels of Collagen I and III in the DD nodules.

Reference:
Syed F, Thomas AN, Singh S, Kolluru V, Emeigh Hart SG, et al. (2012) In Vitro Study of Novel Collagenase (XIAFLEX®) on Dupuytren's Disease Fibroblasts Displays Unique Drug Related Properties. PLoS ONE 7(2): e31430. doi:10.1371/journal.pone.0031430

Interesting things to post about

I hope to do 2 posts today, this one and the one I promised on Thursday about the Dupuytren’s review. This post is going to be a bit about the kind of research that I have been looking for and failing majorly over the last few weeks. But first (very quickly) for anyone that is interested in Collagenase injections please look at this open publication about it which I hope to cover tomorrow but it is very big and scientific so might take some time for me to read and be able to explain.

See the paper here 

Anyway onto some failed research….

1) How do Plantar fibroma’s naturally regress

So as far as I can tell there is very little information out there on how either DD or LD lumps naturally go away, this information would surely be invaluable. I mean imagine if research manages to find out that a group of changes within the lump or surrounding tissue cause it to go away as that same set of changes could then be induced in patients and woo it has gone away.

There are of course many major problems with this. I mean for starts you do not know who will and who won’t naturally regress and on top of that I think that from what I have heard it going away by itself is not all that common. Another major factor would be that not only would you need some tissue from before it regressing but you would also need to have a tissue sample from after the lump and gone. I don’t know about anyone else but I would have serious concerns that if they wanted to take some tissue after it has gone as it would likely trigger it to come back and there would be no way that I would want to take that risk.

2) How common is lack of flexibility of toes?

It is well documented that in Dupuytren’s you get a bending of the fingers but what happens in LD. I mean as I posted about the other day there have been some cases where the toes have bent but what I am more interested in is what I have where you are unable to properly bend your toes and I cannot find anything out there on it. This could be for several reasons, it could be because it is rare and so there are few cases of it documented or it could just be that few people notice it so it doesn’t get documented. This is not really something that can be researched but rather than something that needs to be documented and I am only really interested in it because I show this problem.

I think that is everything that I wanted to post about this morning, I hope to be back later with the DD review and then again tomorrow with the paper I have mentioned above.