Evidence suggests an important link between immune cell activation and insulin resistance (IR) in states associated with increases in visceral adipose tissue (AT). The interleukin-12 (IL-12) family of cytokines is particularly relevant given their importance in cell-mediated immune responses and downstream inflammatory gene induction. IL-12 has been shown to be directly involved in the progression of atherosclerosis. Signal transducer and activator of transcription 4 (STAT4), which is activated by IL-12, induces the expression of several major genes linked to inflammation in atherosclerosis and the metabolic syndrome. The central hypothesis is that IL-12/Stat-4 pathway plays a critical role in the induction of IR in visceral and peri-aortic adipose tissue and this will affect the immune response in aortas and further accelerate atherosclerosis.
Aims to address this include:
Aim 1. Determine mechanisms related to IL-12/STAT4 deficiency in hematopoetic and non-hematopoetic cells on protection against obesity induced insulin resistance, and adipose tissue inflammation. Our hypothesis is that STAT4 deficiency prevents IR in diet-induced obesity by changes in T cell abundance and phenotype and macrophage polarization in adipose tissue and by reducing inflammation and improving insulin sensitivity in visceral adipocytes.
Aim 1. 1: Determine the in vivo effect of IL-12 or STAT4 deficiency in the hematopoietic (T cells, NK cells) vs. non-hematopoetic compartment (adipocyte) for the development of IR and obesity.
Aim 1. 2: Determine role of IL-12/STAT4 deficiency on in vivo and in vitro T cell migration in adipose tissue, T cell and macrophage phenotype and polarization and production of pro-inflammatory cytokines.
Aim 1. 3: Mechanistically investigate functional roles of IL-12/STAT4 deficiency in adipocytes on glucose uptake and insulin signaling in response to high fat diet and cytokine stimulation.
Aim 2. Determine effects of IL-12/Stat-4 pathway inhibition on AT inflammation-associated atherosclerosis. What is the specific role of peri-aortic and visceral AT in adipose tissue-related atherosclerosis? Aim 2.1: Examine effects of Stat-4 deficiency on atherosclerosis with and without AT inflammation in Stat -4-/- Ldlr-/- mice fed a diabetogenic diet (DD) to induce IR and DD with additional cholesterol (DDC) to induce atherosclerosis and AT inflammation.
Aim 2. 2: Test the effects of AT inflammation, Stat-4 deficiency on leukocyte recruitment into peri-aortic, visceral AT and aortas.
Aim 2. 3: Determine the involvement of AT inflammation, Stat-4 deficiency and the conditions of AT inflammation-related atherogenesis on local immune response in peri-aortic, visceral AT and aortas.
Aim 2. 4: Investigate effects and specificity of IL-12 inhibition on Stat-4+/+ and Stat-4 deficient model of AT- inflammation accelerated atherosclerosis in mice fed DDC diet. The completed project should identify an innovative therapeutic target that could lead to new treatment to reduce atherosclerosis associated with central obesity insulin resistance and diabetes.

Public Health Relevance

Central obesity is a major independent risk factor for development of serious cardiovascular disease and diabetes. However the mechanism why this occurs is not clear. The proposed research will identify a new target that could lead to new medications to halt the rise of heart attack risks due to obesity and diabetes.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
3R01HL112605-02S1
Application #
8587826
Study Section
Molecular and Cellular Endocrinology Study Section (MCE)
Program Officer
Hasan, Ahmed AK
Project Start
2011-12-01
Project End
2016-11-30
Budget Start
2012-12-01
Budget End
2013-11-30
Support Year
2
Fiscal Year
2013
Total Cost
$43,950
Indirect Cost
$13,950
Name
Eastern Virginia Medical School
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
058625146
City
Norfolk
State
VA
Country
United States
Zip Code
23501
Taghavie-Moghadam, Parésa L; Waseem, Tayab C; Hattler, Julian et al. (2017) STAT4 Regulates the CD8+ Regulatory T Cell/T Follicular Helper Cell Axis and Promotes Atherogenesis in Insulin-Resistant Ldlr-/- Mice. J Immunol 199:3453-3465
Ma, Kaiwen; Xiao, An; Park, So Hyun et al. (2017) 12-Lipoxygenase Inhibitor Improves Functions of Cytokine-Treated Human Islets and Type 2 Diabetic Islets. J Clin Endocrinol Metab 102:2789-2797
Imai, Yumi; Dobrian, Anca D; Morris, Margaret A et al. (2016) Lipids and immunoinflammatory pathways of beta cell destruction. Diabetologia 59:673-8
Dobrian, A D; Hatcher, M A; Brotman, J J et al. (2015) STAT4 contributes to adipose tissue inflammation and atherosclerosis. J Endocrinol 227:13-24
Taghavie-Moghadam, Parésa L; Gjurich, Breanne N; Jabeen, Rukhsana et al. (2015) STAT4 deficiency reduces the development of atherosclerosis in mice. Atherosclerosis 243:169-78
Weaver, Jessica R; Nadler, Jerry L; Taylor-Fishwick, David A (2015) Interleukin-12 (IL-12)/STAT4 Axis Is an Important Element for ?-Cell Dysfunction Induced by Inflammatory Cytokines. PLoS One 10:e0142735
Gjurich, Breanne N; Taghavie-Moghadam, Parésa L; Galkina, Elena V (2015) Flow Cytometric Analysis of Immune Cells Within Murine Aorta. Methods Mol Biol 1339:161-75
Tersey, Sarah A; Bolanis, Esther; Holman, Theodore R et al. (2015) Minireview: 12-Lipoxygenase and Islet ?-Cell Dysfunction in Diabetes. Mol Endocrinol 29:791-800
Butcher, Matthew J; Hallinger, Daniel; Garcia, Eden et al. (2014) Association of proinflammatory cytokines and islet resident leucocytes with islet dysfunction in type 2 diabetes. Diabetologia 57:491-501
Luci, Diane K; Jameson 2nd, J Brian; Yasgar, Adam et al. (2014) Synthesis and structure-activity relationship studies of 4-((2-hydroxy-3-methoxybenzyl)amino)benzenesulfonamide derivatives as potent and selective inhibitors of 12-lipoxygenase. J Med Chem 57:495-506

Showing the most recent 10 out of 20 publications