Medicine and Health Sciences Commons^™

Macrophage-Derived Netrin-1 Promotes Abdominal Aortic Aneurysm Formation By Activating Mmp3 In Vascular Smooth Muscle Cells, Tarik Hadi, Ludovic Boytard, Michele Silvestro, Dornazsadat Alebrahim, Samson Jacob, Jordyn Feinstein, Krista Barone, Wes Spiro, Susan Hutchison, Russell Simon, Debra L. Rateri, Florence Pinet, David Fenyo, Mark Adelman, Kathryn J. Moore, Holger K. Eltzschig, Alan Daugherty, Bhama Ramkhelawon

Physiology Faculty Publications

Abdominal aortic aneurysms (AAA) are characterized by extensive extracellular matrix (ECM) fragmentation and inflammation. However, the mechanisms by which these events are coupled thereby fueling focal vascular damage are undefined. Here we report through single-cell RNA-sequencing of diseased aorta that the neuronal guidance cue netrin-1 can act at the interface of macrophage-driven injury and ECM degradation. Netrin-1 expression peaks in human and murine aneurysmal macrophages. Targeted deletion of netrin-1 in macrophages protects mice from developing AAA. Through its receptor neogenin-1, netrin-1 induces a robust intracellular calcium flux necessary for the transcriptional regulation and persistent catalytic activation of matrix metalloproteinase-3 (MMP3) …

The Dual Role Of Group V Secretory Phospholipase A2 In Pancreatic Β-Cells, Preetha Shridas, Victoria P. Noffsinger, Andrea C. Trumbauer, Nancy R. Webb

Saha Cardiovascular Research Center Faculty Publications

Purpose

Group X (GX) and group V (GV) secretory phospholipase A₂ (sPLA₂) potently release arachidonic acid (AA) from the plasma membrane of intact cells. We previously demonstrated that GX sPLA₂ negatively regulates glucose-stimulated insulin secretion (GSIS) by a prostaglandin E2 (PGE2)-dependent mechanism. In this study we investigated whether GV sPLA₂ similarly regulates GSIS.

Methods

GSIS and pancreatic islet-size were assessed in wild-type (WT) and GV sPLA₂-knock out (GV KO) mice. GSIS was also assessed ex vivo in isolated islets and in vitro using MIN6 pancreatic beta cell lines with or without GV sPLA …

Tgf-Β Neutralization Enhances Angii-Induced Aortic Rupture And Aneurysm In Both Thoracic And Abdominal Regions, Xiaofeng Chen, Debra L. Rateri, Deborah A. Howatt, Anju Balakrishnan, Jessica J. Moorleghen, Lisa A. Cassis, Alan Daugherty

Saha Cardiovascular Research Center Faculty Publications

AngII and TGF-β interact in development of thoracic and abdominal aortic diseases, although there are many facets of this interaction that have not been clearly defined. The aim of the present study was to determine the effects of TGF-β neutralization on AngII induced-aortic pathologies. Male C57BL/6J mice were administered with either a rabbit or mouse TGF-β neutralizing antibody and then infused with AngII. The rabbit TGF-β antibody modestly reduced serum TGF-β concentrations, with no significant enhancements to AngII-induced aneurysm or rupture. Administration of this rabbit TGF-β antibody in mice led to high serum titers against rabbit IgG that may have …

Telemetric Blood Pressure Assessment In Angiotensin Ii-Infused Apoe-/- Mice: 28 Day Natural History And Comparison To Tail-Cuff Measurements, Christopher M. Haggerty, Andrea C. Mattingly, Ming C. Gong, Wen Su, Alan Daugherty, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

Abdominal aortic aneurysm (AAA) is a disease of the aortic wall, which can progress to catastrophic rupture. Assessment of mechanical characteristics of AAA, such as aortic distensibility, may provide important insights to help identify at-risk patients and understand disease progression. While the majority of studies on this topic have focused on retrospective patient data, recent studies have used mouse models of AAA to prospectively evaluate the evolution of aortic mechanics. Quantification of aortic distensibility requires accurate measurement of arterial blood pressure, particularly pulse pressure, which is challenging to perform accurately in murine models. We hypothesized that volume/pressure tail-cuff measurements of …

Bisphenol A Increases Atherosclerosis In Pregnane X Receptor-Humanized Apoe Deficient Mice, Yipeng Sui, Se-Hyung Park, Robert N. Helsley, Manjula Sunkara, Frank J. Gonzalez, Andrew J. Morris, Changcheng Zhou

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: Bisphenol A (BPA) is a base chemical used extensively in many consumer products. BPA has recently been associated with increased risk of cardiovascular disease (CVD) in multiple large-scale human population studies, but the underlying mechanisms remain elusive. We previously reported that BPA activates the pregnane X receptor (PXR), which acts as a xenobiotic sensor to regulate xenobiotic metabolism and has pro-atherogenic effects in animal models upon activation. Interestingly, BPA is a potent agonist of human PXR but does not activate mouse or rat PXR signaling, which confounds the use of rodent models to evaluate mechanisms of BPA-mediated CVD risk. …

Characterization Of Secretory Sphingomyelinase Activity, Lipoprotein Sphingolipid Content And Ldl Aggregation In Ldlr-/- Mice Fed On A High-Fat Diet, Gergana M. Deevska, Manjula Sunkara, Andrew J. Morris, Mariana N. Nikolova‑Karakashian

Physiology Faculty Publications

The propensity of LDLs (low-density lipoproteins) for aggregation and/or oxidation has been linked to their sphingolipid content, specifically the levels of SM (sphingomyelin) and ceramide. To investigate this association in vivo, ldlr (LDL receptor)-null mice (ldlr-/-) were fed on a modified (atherogenic) diet containing saturated fats and cholesterol. The diet led to significantly elevated SM content in all serum lipoproteins. In contrast, ceramide increased only in the LDL particles. MS-based analyses of the lipid acyl chain composition revealed a marked elevation in C16:0 fatty acid in SM and ceramide, consistent with the prevalence of palmitic acid in the modified diet. …

Oxidative Stress Accumulates In Adipose Tissue During Aging And Inhibits Adipogenesis, Hannes M. Findeisen, Kevin J. Pearson, Florence Gizard, Yue Zhao, Hua Qing, Karrie L Jones, Dianne Cohn, Elizabeth B. Heywood, Rafael De Cabo, Dennis Bruemmer

Saha Cardiovascular Research Center Faculty Publications

Aging constitutes a major independent risk factor for the development of type 2 diabetes and is accompanied by insulin resistance and adipose tissue dysfunction. One of the most important factors implicitly linked to aging and age-related chronic diseases is the accumulation of oxidative stress. However, the effect of increased oxidative stress on adipose tissue biology remains elusive. In this study, we demonstrate that aging in mice results in a loss of fat mass and the accumulation of oxidative stress in adipose tissue. In vitro, increased oxidative stress through glutathione depletion inhibits preadipocyte differentiation. This inhibition of adipogenesis is at …

Renin Inhibition Reduces Hypercholesterolemia-Induced Atherosclerosis In Mice, Hong Lu, Debra L. Rateri, David L. Feldman, Richard Charnigo, Akiyoshi Fukamizu, Junji Ishida, Elizabeth Grace Oesterling, Lisa A. Cassis, Alan Daugherty

Saha Cardiovascular Research Center Faculty Publications

The role of the renin angiotensin system (RAS) in atherosclerosis is complex because of the involvement of multiple peptides and receptors. Renin is the rate-limiting enzyme in the production of all angiotensin peptides. To determine the effects of renin inhibition on atherosclerosis, we administered the novel renin inhibitor aliskiren over a broad dose range to fat-fed LDL receptor-deficient (Ldlr^-/-) mice. Renin inhibition resulted in striking reductions of atherosclerotic lesion size in both the aortic arch and the root. Subsequent studies demonstrated that cultured macrophages expressed all components of the RAS. To determine the role of macrophage-derived angiotensin in …