Title: MiR-155 differentially regulates atherosclerosis and metabolically healthy obesity According to the Centers for Disease Control and Prevention, the prevalence of obesity (Ob) has increased to over 35% of the U.S. adult population, or more than 85 million adults (www.cdc.gov/obesity/data/adult.html). Ob is an important risk factor for type 2 diabetes mellitus (T2DM), various cancers, nonalcoholic fatty liver disease (NAFLD); cardiovascular disease (CVD), and mortality. In contrast to the classical Ob associated CVD (COB), evidence has shown that some obese individuals are metabolically healthy, termed metabolically healthy obesity (MHO) , and counts for 18-44% of obese adults and 10% adult population. Unlike COB, MHO reports less incidence of atherosclerosis, no insulin resistance (IR) but Ob. MHO is not truly ?healthy? since MHO significantly increase incidences of T2DM, hypertension, and metabolic syndrome (MetS). Therefore, novel therapies are urgently needed to inhibit MHO transition to COB. However, the mechanisms underlying MHO transition to COB remain poorly characterized due to lack of appropriate animal models for MHO transition to COB. The goal of this project is to determine the underlying mechanisms and establish new models of MHO transition to COB. We have long-standing interest in studying metabolic CVD and published many papers on endothelial cell (EC) activation, EC dysfunction, VSMC phenotypic switching, monocyte (MC)/macrophage (M?) recruitment, Foxp3+ Treg in inhibiting CV inflammation, atherosclerosis, Ob/diabetes, chronic kidney disease (CKD), and the roles of caspase-1(Casp1)/inflammmasome in CVD. Therefore, we have sufficient expertise in carrying out this proposal. Our strong preliminary data, new publications showed that: 1) miR155 is significantly upregulated in atherosclerosis aorta and in TNF?-, IL-1?- and lipopolysaccharide (LPS)-stimulated aortic EC; 2) miR155-/-/ApoE-/- mice (DKO) have decreased atherosclerosis, but increase high fat diet (HF)- induced white adipose tissue (WAT) hypertrophy; 3) miR155 KO M? produce less TNF? and IL-1? as others reported; 4) HF significantly increased DKO WAT M? (ATM), proinflammatory adipokines resistin and leptin, which creates systemic proinflammatory conditions and promote MHO transition to COB. These findings suggest that a single cell type, miR155-/- M?, in two different tissue contexts (aorta and WAT), regulates MHO; 5) DKO have no IR and no glucose intolerance, suggesting a MHO status; and 6) we obtained miR155fl/fl mice and are generating cell-specific miR155-/- mice. Our data/publications strongly suggest that DKO have decreased atherosclerosis but have increased HF-induced Ob and ATM without IR, which make DKO as the first model for studying MHO transition to COB. Therefore, the central to be tested is that extended HF feeding transitions MHO to COB by increasing adipose tissue inflammation via increased saturated fatty acids (SFA)-/proinflammatory adipokines - triggered caspase-1 (Casp1) activation in ATM. We will test this hypothesis in three linked aims:
Aim 1 To determine whether with 24 week extended HF-fed DKO aortic m? are less inflammatory, but 24 week HF fed DKO WAT and ATM are more inflammatory than ApoE-/- counterparts (relevant studies);
Aim 2 : To determine whether 24 week extended HF-induced DKO WAT increase SFA, resistin, and leptin, which polarize to M1 ATM by upregulating Casp1/TNF? pathways (mechanistic studies);
Aim 3 : To determine whether 24 week extended HF-induced DKO mice develop more atherosclerosis than 12 week HF DKO mice; whether HF-induced Casp1-/-/miR155-/-/ApoE-/- triple KO (Casp1 TKO)- and NLRP3-/-/miR155-/-/ApoE-/- (NLRP3 TKO)- WAT produce less resistin52/leptin; whether ATM in two TKO mice produce less IL-1?/TNF?; and whether two TKO mice less Ob and atherosclerotic with extended HF than DKO (verification studies). hypothesis

Public Health Relevance

Atherosclerosis and its complications, such as myocardial infarction, stroke, and peripheral artery disease, are still the leading cause of morbidity and mortality in the U.S., regardless of recent progress in lipid lowering therapy including statins. In addition, the prevalence of obesity has increased to 30% of the U.S. adult population. Obesity is an important risk factor for type 2 diabetes mellitus, sleep apnea, various cancers, and nonalcoholic fatty liver disease; and is an increased risk of all-cause and cause-specific mortality and cardiovascular disease. In contrast to the classical obesity associated cardiovascular disease, evidence has shown that some obese individuals are metabolically healthy, termed metabolically healthy obesity, and counts for 18-44% of obese adults and 10% adult population. Metabolically healthy obesity increases significantly incidences of type 2 diabetes, hypertension, and metabolic syndrome. Therefore, novel therapies are urgently needed to inhibit metabolically healthy obesity, classical obesity and atherosclerosis. However, the mechanisms underlying the suppression of atherosclerosis and obesity by microRNAs (miRs), a type of short non- coding RNA molecules, remain poorly defined. The proposed studies will examine the contribution and mechanisms underlying deficiency or downregulation of miR-155 in inhibiting atherosclerosis but accelerating metabolically healthy obesity. Success of this study would characterize miR-155 suppression in inhibiting molecular signaling in atherosclerosis and caspase-1 inhibition in suppressing metabolically healthy obesity, which will lead to the development of new therapeutics for the treatment of cardiovascular disease, stroke, peripheral vascular disease, metabolically healthy obesity and classical obesity.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL138749-04
Application #
9938613
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Chen, Jue
Project Start
2017-07-01
Project End
2021-05-31
Budget Start
2020-06-01
Budget End
2021-05-31
Support Year
4
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Temple University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
057123192
City
Philadelphia
State
PA
Country
United States
Zip Code
19122
Fang, Pu; Li, Xinyuan; Dai, Jin et al. (2018) Immune cell subset differentiation and tissue inflammation. J Hematol Oncol 11:97
Li, Xinyuan; Wang, Luqiao; Fang, Pu et al. (2018) Lysophospholipids induce innate immune transdifferentiation of endothelial cells, resulting in prolonged endothelial activation. J Biol Chem 293:11033-11045
Li, Xinyuan; Shao, Ying; Sha, Xiaojin et al. (2018) IL-35 (Interleukin-35) Suppresses Endothelial Cell Activation by Inhibiting Mitochondrial Reactive Oxygen Species-Mediated Site-Specific Acetylation of H3K14 (Histone 3 Lysine 14). Arterioscler Thromb Vasc Biol 38:599-609
Li, Xinyuan; Fang, Pu; Yang, William Y et al. (2017) Mitochondrial ROS, uncoupled from ATP synthesis, determine endothelial activation for both physiological recruitment of patrolling cells and pathological recruitment of inflammatory cells. Can J Physiol Pharmacol 95:247-252
Virtue, Anthony; Johnson, Candice; Lopez-PastraƱa, Jahaira et al. (2017) MicroRNA-155 Deficiency Leads to Decreased Atherosclerosis, Increased White Adipose Tissue Obesity, and Non-alcoholic Fatty Liver Disease: A NOVEL MOUSE MODEL OF OBESITY PARADOX. J Biol Chem 292:1267-1287
Li, Xinyuan; Fang, Pu; Yang, William Y et al. (2017) IL-35, as a newly proposed homeostasis-associated molecular pattern, plays three major functions including anti-inflammatory initiator, effector, and blocker in cardiovascular diseases. Cytokine :
Shao, Ying; Nanayakkara, Gayani; Cheng, Jiali et al. (2017) Lysophospholipids and Their Receptors Serve as Conditional DAMPs and DAMP Receptors in Tissue Oxidative and Inflammatory Injury. Antioxid Redox Signal :
Xu, Yanjie; Xia, Jixiang; Liu, Suxuan et al. (2017) Endocytosis and membrane receptor internalization: implication of F-BAR protein Carom. Front Biosci (Landmark Ed) 22:1439-1457
Dai, Jin; Fang, Pu; Saredy, Jason et al. (2017) Metabolism-associated danger signal-induced immune response and reverse immune checkpoint-activated CD40+ monocyte differentiation. J Hematol Oncol 10:141
Fu, Hangfei; Vadalia, Nish; Xue, Eric R et al. (2017) Thrombus leukocytes exhibit more endothelial cell-specific angiogenic markers than peripheral blood leukocytes do in acute coronary syndrome patients, suggesting a possibility of trans-differentiation: a comprehensive database mining study. J Hematol Oncol 10:74

Showing the most recent 10 out of 11 publications