Grant: Master's Award: Canada Graduate Scholarships

Hyperglycemia & diabetes cause chronic inflammation. Insulin (INS) lowers glucose levels, reducing hyperglycemia. INS counters hyperglycemic inflammation and activates the P13K/Akt and MAP kinase pathways, inducing an anti-inflammatory response. This results in glucose homeostasis, down-regulation of pro-inflammatory regulators, and up-regulation of anti-inflammatory regulators. INSL5 is secreted by enteroendocrine epithelial cells (EECs) in the colon. It binds to a relaxin family peptide 4 (RXFP4), found in many cells. Hypothesis: INSL5 induces anti-inflammatory effects by altering the immune response in macrophages. H1: Hyperglycemic mice will exhibit high levels of inflammatory markers after 30 days. H2: ISL5 treatment of macrophages and dendritic cells (DCs) will release altered LPS-induced cytokine levels in non-diabetic mice. H3: The anti-inflammatory effect of INSL5 is mediated by the ERK1/2, MAPK, or mTOR pathways. Objective 1: To compare markers of inflammation and gut microbial diversity in C57/B16 mice. Objective 2: To identify if INSL5 affects LPS-induced cytokine release in DCs and macrophages. Objective 3: To identify signalling pathways initiated by ISL5-RXFP4. Methods: Diabetes will be induced in mice. Mice will be euthanized, and blood, intestine, feces, spleen, and bone marrow will be collected. Macrophages and DCs will be cultured and either pre-treated with INSL5 followed by LPS, INSL5 and LPS co-treatment, solely LPS, or vehicle. RT-PCR will be used to compare cytokine levels in cells without inhibitors. Immunoblotting of proteins will be assessed via t-tests or ANOVA to identify INSL5-RXFP4-initiated signalling pathways. Significance: If INSL5 has anti-inflammatory effects in the gut, it could result in health related funding.