mRNA expression in ileal CD: Effect of the coding rare rs2302685 variant on the expression levels of HD-5 and LRP6.
We excluded individuals with mutations in the pattern recognition receptor NOD2 as well as patients with a neoterminal ileum. All cohort samples were sub-grouped according to the disease state and analysed with respect to the LRP6 genotype. A) As previously reported, HD-5 mRNA levels are diminished in ileal CD as compared to controls and colonic CD. We saw no difference between ileal CD samples that came from inflamed tissue at the time of biopsy taking and material from 6 uninflamed biopsy specimens (left panel). The mRNA expression of HD-5 seems to be influenced by the coding rare LRP6 rs2302685 allele (C- allele) in ileal CD patients as carriers of the variant show the lowest HD-5 levels. B) Similar to the diminished HD-5, we found significantly decreased LRP6 transcriptional expression in ileal CD patients as compared to controls as well as to patients with exclusive colonic CD. Again similar to HD-5, we found no difference between inflamed compared to uninflamed ileal CD samples. The presence of the functional LRP6 mutation however, seems to have, as expected, no effect on LRP6 mRNA level.