7th October, 2013
A paper by Dr Anna Russ and co-authors describing laser microdissection of inflamed colon tissue has been published in the high-impact PLoS One journal.
Dr Russ successfully defended her PhD thesis through Massey University in March 2013, supervised by Professor Warren McNabb, Dr Nicole Roy, Dr Rachel Anderson, Dr Matthew Barnett (AgResearch) and Professor Gordon Reynolds (Massey University). During her PhD, she teamed up with Jason Peters, a Research Associate at AgResearchâ€™s Grasslands campus, to successfully apply laser microdissection technology to colon tissue samples. The technique involves cutting very thin sections from frozen samples, staining the sections to identify key cell types, and using a computer-guided laser to dissect these cells and separate them from the rest of the colon tissue.
In this study, the target of the laser was epithelial cells, which play important roles in absorption and secretion, protection from resident microbes, and maintenance of homeostasis within the intestine. Using high-density microarrays, and ably assisted by Kelly Armstrong (also a Research Associate at AgResearch), Dr Russ analysed the expression of genes within these cells, which gave a highly targeted view of molecular pathways in the mucosa, both before and during inflammation.
The key observation was that while epithelial cells showed similar results to intact colon tissue when inflammation was well established, gene set enrichment analysis (completed with assistance from AgResearch Scientist Dr Wayne Young and Bioinformatician Paul McLean, and one of several techniques used to analyse microarray data) identified more immune-related pathways in epithelial cells than in intact colon during the early phase of inflammation. This suggests that targeting epithelial cells using a technique such as laser microdissection could better detect important immune changes that take place early in the inflammatory process, enabling earlier intervention when inflammation does occur.
An important next step will be to establish whether the outcomes of this study can be applied in a non-invasive manner (for example, exfoliated epithelial cells in faecal samples) to the early diagnosis of intestinal inflammation in conditions such as human inflammatory bowel disease.
Link to the paper: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0063251