05 April 2011

Adiponectin: Friend or Foe?

So a couple weeks ago we were discussing Inflammatory Bowel Disease (IBD)and the possible role adiponectin played in its pathogenesis. As a just a quick recap, adiponectin is an adipocyte specific secretory protein that plays many different roles in the innate humoral immune system; in relation to IBD, and more specifically Crohn's Disease, it was proposed in one of the papers that it also has anti-inflammatory effects. In the study conducted, it was concluded that the adiponectin secreted from adipocytes in hypertrophied mesenteric adipose tissue could serve as a barrier, preventing the inflammation from spreading into the intra-abdominal space. In this case, adiponectin plays a positive role, limiting the damage done by the inflammation.

As is the case with many different inflammatory and anti-inflammatory proteins, adiponectin's roles are not limited of course to its actions in Crohn's Disease. What I wanted to know, however, was if adiponectin also has possible positive effects, if any, when it came to arthritis. When i did a little research, I was surprised to find out that in the case of Rheumatoid Arthritis (RA), adiponectin may actually play a significant role in the pathogenesis of RA. What was demonstrated in the study I found was that adiponectin stimulated the production of vascular endothelial growth factor (VEGF) and MMPS, which could lead to an increase in the joint inflammation and destruction. This study did state, however, that there must be more research conducted to prove these findings.

2 comments:

  1. Hi Clifford. Did the paper mention which form (high molecular weight, hexamer, trimer, dimer, etc.) of adiponectin played that pathogenic role? It would be interesting to know that because there are studies that show that levels of the high molecular weight form are decreased in obesity.

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  2. After seeing your comment, I reread the article again, unfortunately the form of adiponectin was not mentioned. They did mention that in the experiment they treated the RA synovial cells with 1 and 10 μg/mL adiponectin and it was only the 10 μg/mL adiponectin that raised the MMP and VEGF levels significantly. If the chances of an obese individual having RA are increased, since adiponectin may play a role in the pathogenesis of RA, it might have been a form of adiponectin other than the high molecular weight if in obese people the high molecular weight form are decreased.

    If you would like to read the article, the link is http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3003518/

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