In this research article, the researchers show this interesting correlation with our adipose tissue (energy storage system) and our immune system. Naturally, we would never think that fat has anything to do with immune responses, but clearly seen here in this research, we see some beneficial anti-inflammatory occurrences.
Crohn's disease is known to affect any part of the GI tract, and in this study, they mainly examined the area around the small intestine, the mesenteric adipose tissue. Looking at the adipocytes in this area, they concentrated on one of the bioactive molecules that were secreted--adiponectin. Adiponectin has been shown to have a ton of biological effects, but more importantly, it has anti-inflammatory properties in endothelial cells and macrophages.
They looked at patients with Crohn's Disease (CD), ulcerative colitis (UC), and then for the control, patients who have had surgical resection due to colon cancer. With their samples from the patients, they imaged for adipocytes, immunohistologically stained for CD3, CD20 and CD68 (proteins seen on T cells), determined adiponectin and IL-6 concentrations, looked at short term adiponectin release, and looked at mRNA levels for adiponectin.
Overall, the observation was that adiponectin was prevalent in the mesenteric adipose tissue. The adipocytes were smaller, there was evidence of T cell presence in these areas, and adiponectin concentration, release, and mRNA levels were higher in the hypertrophied areas of Crohn's disease patients. Logically so, CRP levels and IL-6 (proinflammtory markers) both had an inverse relationship with the level of adiponectin.
One of the interesting things for me was that, in patients with UC, their adiponectin levels were the lowest, even lower than the controls. My thought process for this was based on the location of where they took the samples. UC usually manifests itself in the colon (large intestine) areas while a majority of the CD patients were afflicted in the ileal areas of their small intestine. The mesentery is also what holds up the parts of the small intestine to the back wall of the abdomen. As a result, the samples they got might have just been farther from the large intestine, and with less inflammation from UC.
I found this research article interesting, because it is one of the first to examine the role of adiponectin, and its anti-inflammatory properties in IBD. I think Leon brought up a great point regarding the differences between adiponectin levels in CD patients and UC patients. The article says that, “hypertrophied adipose tissue extending from the mesenteric attachment and partially covering the intestinal circumference, is common in both the small and large intestine and is also considered a hallmark of CD” (789). I wonder if adiponectin levels would be higher in patients if the samples were taken in areas where the UC was most active. It seems to me that adiponectin might be high in places healing might need to occur. If this is the case, it would explain why adiponectin levels are high in CD near the ileal region, why adiponectin is moderate in the control group, and low in that particular region for UC.
ReplyDeleteWhen I read this study for the first time, like Dr. Cohen, I found it interesting that the control group consisted of previous colon cancer patients. It seems to me that their adiponectin levels might be higher than those with UC, because they might have also experienced damage from the cancer. As a result, adiponectin might be higher in the control group making it hard to draw conclusions about a normal healthy individual, versus one with IBD.