Wednesday, April 2, 2025
4/2/2025
Immunometabolic Regulation of Adipose Tissue by CTRP6 - PROJECT SUMMARY Macrophages respond to stimuli in their microenvironments, altering their polarization to M1 pro- inflammatory or M2 anti-inflammatory phenotype. Targeting macrophage polarization provides a promising therapeutic strategy for obesity-related inflammation and insulin resistance. C1q/TNF-related protein 6 (CTRP6), a member of a highly conserved secreted protein family, has recently been found to be involved in the functional regulation of adipose tissue. In Ctrp6 knockout (KO) mice fed with high- fat diet, the expression level of M1 macrophage marker gene TNF-a was significantly down-regulated in white adipose tissue as well as in serum, suggesting the reduced inflammation. In RAW264.7 macrophage cell line, CTRP6 recombinant protein reduced the expression of M2 macrophage marker gene CD206 at lower doses while induced TNF-a expression at higher doses, indicating its important role in both suppressing M2 polarization and promoting M1 polarization. Interestingly, CTRP6 recombinant protein can be detected in the nuclear after it was added to the cell culture medium, indicating it is a secreted nuclear protein. Thus, the objective of the proposal is to confirm knocking out CTRP6 gene in macrophages polarizes them to anti-inflammatory phenotype and further develop a cell-based therapy to attenuate adipose tissue inflammation and insulin resistance via injecting CRISPR/Cas9-mediated CTRP6 KO macrophages. The program will be carried out in three specific aims: 1) determine the anti-inflammatory phenotype of CTRP6 KO macrophages by performing transcriptome profiling, functional analysis and metabolic analysis; 2) determine the impact of CTRP6 KO macrophages on adipocyte insulin sensitivity in a co-culture system by assessing glucose uptake, GLUT4 translocation, insulin and other signaling pathways; 3) develop cell-based therapy using CRISPR/Cas9-mediated CTRP6 KO macrophages to ameliorate insulin resistance by evaluating adipose tissue inflammation and systemic insulin sensitivity. The proposed research is significant, because it will not only contribute to a fundamental understanding of macrophage polarization in the setting of adipose tissue inflammation and insulin resistance, but also lay the groundwork for the development of potential cell therapy for obesity using genetically modified macrophages. In addition, this proposal will enhance the infrastructure of research and education at Oklahoma State University, introducing biomedical research to undergraduate students especially underrepresented minority and female students. This would allow them to experience a broad spectrum of techniques, and acquire skills such as molecular cloning, cell culture and mouse models, which are widely used in modern scientific investigations.
HHS’ Tracking Accountability in Government Grants System (TAGGS) website provides access to detailed descriptions of grants, loans, aggregated direct payments and other types of financial assistance awarded by the HHS Operating Divisions (OPDIVs) and the Office of the Secretary Staff Divisions (STAFFDIVs).