Searching for the Molecular Benchmark of Physiological Intestinal Anastomotic Healing in Rats: An Experimental Study

Abstract

Purpose: This investigation focuses on the physiological characteristics of gene transcription of intestinal tissue following anastomosis formation. Methods: In eight rats, end-to-end ileo-ileal anastomoses were performed (n = 2/group). The healthy intestinal tissue resected for this operation was used as a control. On days 0, 2, 4 and 8, 10-mm perianastomotic segments were resected. Control and perianastomotic segments were examined with an Affymetrix microarray chip to assess changes in gene regulation. Microarray findings were validated using real-time PCR for selected genes. In addition to screening global gene expression, we identified genes intensely regulated during healing and also subjected our data sets to an overrepresentation analysis using the Gene Ontology (GO) and Kyoto Encyclopedia for Genes and Genomes (KEGG). Results: Compared to the control group, we observed that the number of differentially regulated genes peaked on day 2 with a total of 2,238 genes, decreasing by day 4 to 1,687 genes and to 1,407 genes by day 8. PCR validation for matrix metalloproteinases-3 and -13 showed not only identical transcription patterns but also analogous regulation intensity. When setting the cutoff of upregulation at 10-fold to identify genes likely to be relevant, the total gene count was significantly lower with 55, 45 and 37 genes on days 2, 4 and 8, respectively. A total of 947 GO subcategories were significantly overrepresented during anastomotic healing. Furthermore, 23 overrepresented KEGG pathways were identified. Conclusion: This study is the first of its kind that focuses explicitly on gene transcription during intestinal anastomotic healing under standardized conditions. Our work sets a foundation for further studies toward a more profound understanding of the physiology of anastomotic healing.

The effect of pasireotide on intestinal anastomotic healing with and without whole-body irradiation in a rat model

“…However, various studies have convincingly suggested a positive effect of IGF-1 on the process of anastomotic healing. Furthermore, in a previous study, we observed a significant increase in local IGF-1 gene expression during intestinal anastomotic healing [ 22 ]. Therefore, it may not be excluded that pasireotide negatively impacts physiological anastomotic healing via decreasing systemic and/or local IGF-1 production.…”

“…This may be explained by local release mechanisms that bypass pasireotide dependent central nervous inhibition of the GH-IGF-1 axis. We have shown that a complex machinery of IGF-1, its receptors, and a large group of IGF-1 binding proteins is upregulated in the intestine during anastomotic healing [ 22 ]. It remains unclear how dependent this upregulation is of upstream hormonal stimulation and to which degree this is an autonomous, immune system–mediated effect.…”