Life Sciences & Biotechnology
Title : | Macrophage polarization in colorectal inflammation: A study of intervention by Vitamin D and Short Chain Fatty Acids |
Area of research : | Life Sciences & Biotechnology |
Principal Investigator : | Dr. Jayasree Saha, Indian Institute Of Technology (IIT) Kharagpur, West Bengal |
Timeline Start Year : | 2023 |
Timeline End Year : | 2025 |
Contact info : | jayee21@gmail.com |
Details
Executive Summary : | Inflammatory Bowel Disease (IBD) and associated colorectal cancer (CRC) are of significant concern as the colon is continually being exposed to foreign microbes and subsequent immune homeostasis as well as inflammation. Macrophage polarization is one of the defining factors of the fate of an inflammatory microenvironment due to their abundance and extensive cytokine secretory potential that regulates other immune and non-immune cell functionality. Short Chain Fatty Acids (SCFAs-acetate, butyrate, propionate) and Vitamin D are currently under scientific scrutiny for their role in suppression of inflammation. The knowledge related to possible alleviating effects of SCFAs and Vitamin D in colon inflammation resolution by regulation of polarization and activation of intestinal macrophages is still obscure. This project proposes to study macrophage function in disease progression of IBD and related colon cancer primarily in murine models.
The study of secretory cytokines like IL-10, IL-12, IL-6, TNF-α, TGF-β that determines M1/M2 activation state of macrophages would be assessed upon SCFA and Vitamin D administration in vitro and in vivo models both. For IBD model we propose to establish AOM-DSS (Azoxymethane-dextran sodium sulphate) induced colitis model and CT26 colon cancer in BALB/c animals. Intestinal macrophages would be isolated from colon tissues by antibody-mediated cell separation methods and studied for polarization and activation by their cytokine secretion status, and cytokine gene expression studies in both in vitro and in vivo methods. This would determine the differences in putative ameliorating role of the three SCFAs in combination or when administered individually. Gene-expression profiling of the cytokine genes as well as Macrophage-inflammatory protein 1 & 2 (MIP-1 & MIP-2) under SCFA and Vitamin D stimulation would be enlightening upon fatty acid uptake and metabolism by the steroid receptor in macrophages.
Histochemical analysis of colon tissues would determine the extent of inflammatory breach and subsequent attenuation by SCFA and Vitamin D administration from in vivo studies. Detailed experiments including chromatin immunoprecipitation, molecular cloning using plasmids that overexpresses vitamin D receptor protein and silencing SCFA receptor expression by shRNA constructs would help to dissect the mechanism of how might Vitamin D receptor interacts with SCFAs in macrophages to produce discernible antagonising effects in resolution of macrophage-mediated colorectal inflammation. Breaching of immune homeostasis due to inflammation in colon and ensuing M1/M2 polarization are one of the significant facets of colorectal disease prognosis and associated risks. Studies emphasizing the differences in the mode of action of SCFAs and their possible interaction with vitamin D receptor in intestinal macrophages can be explored to identify efficient drug targets and augment therapeutic interventions in colon related disorders. |
Organizations involved