β-aminopropionitrile-induced thoracic aortopathy is refractory to cilostazol and sildenafil in mice.

Thoracic aortopathies are life-threatening diseases including aneurysm, dissection, and rupture. Cilostazol, a phosphodiesterase (PDE) 3 inhibitor, and sildenafil, a PDE5 inhibitor, have been used clinically for peripheral arterial disease and erectile dysfunction or pulmonary hypertension, respectively. Recent studies report their effects on abdominal aortic aneurysm formation.

Metformin Does Not Attenuate Angiotensin II-Induced Aortic Aneurysms in Low-Density Lipoprotein Receptor Deficient Mice.

Background: Metformin, a biguanide antihyperglycemic agent, prevents angiotensin II (AngII)-induced abdominal aortic aneurysm formation in apolipoprotein E-deficient (ApoE-/-) mice. Low-density lipoprotein receptor-deficient (LDLR-/-) mice are also widely used as a hypercholesterolemic model, which more closely mimics the lipoprotein profile of patients with hypercholesterolemia than ApoE-/- mice. In addition, LDLR-/- mice exhibit characteristics of glucose metabolism that are distinct from ApoE-/- mice.

Attenuation of Atherosclerosis With PAR4 Deficiency: A Potential Role of Hematopoietically Expressed PAR4 in Atherosclerosis-Brief Report.

Background: Cardiovascular disease is a significant burden globally and, despite current therapeutics, remains the leading cause of death. PAR (protease-activated receptor) 4 is a receptor highly expressed by hematopoietic cells, strongly activated by thrombin, and plays a vital role in platelet activation and aggregation. However, the role of PAR4 in atherothrombotic disease remains understudied.

β-aminopropionitrile-induced thoracic aortopathy is refractory to cilostazol and sildenafil in mice.

Thoracic aortopathies are life-threatening diseases including aneurysm, dissection, and rupture. Phosphodiesterases (PDEs) regulate intracellular cyclic nucleotide concentrations. Recent studies report the influences of cilostazol, a PDE3 inhibitor, and sildenafil, a PDE5 inhibitor, on abdominal aortic aneurysm formation.

Attenuation of Atherosclerosis with PAR4 Deficiency: Differential Platelet Outcomes in apoE vs. Ldlr Mice.

Objective: Cardiovascular disease (CVD) is a significant burden globally and, despite current therapeutics, remains the leading cause of death. Platelet inhibitors are of interest in CVD treatment to reduce thrombus formation post-plaque rupture as well their contribution to inflammation throughout the progression of atherosclerosis. Protease activated receptor 4 (PAR4) is a receptor highly expressed by platelets, strongly activated by thrombin, and plays a vital role in platelet activation and aggregation.

β-Aminopropionitrile Induces Distinct Pathologies in the Ascending and Descending Thoracic Aortic Regions of Mice.

Background: β-aminopropionitrile (BAPN) is a pharmacological inhibitor of LOX (lysyl oxidase) and LOXLs (LOX-like proteins). Administration of BAPN promotes aortopathies, although there is a paucity of data on experimental conditions to generate pathology. The objective of this study was to define experimental parameters and determine whether equivalent or variable aortopathies were generated throughout the aortic tree during BAPN administration in mice.

β-aminopropionitrile Induces Distinct Pathologies in the Ascending and Descending Thoracic Aortic Regions of Mice.

Background: β-aminopropionitrile (BAPN) is a pharmacological inhibitor of lysyl oxidase and lysyl oxidase-like proteins. Administration of BAPN promotes aortopathies, although there is a paucity of data on experimental conditions to generate pathology. The objective of this study was to define experimental parameters and determine whether equivalent or variable aortopathies were generated throughout the aortic tree during BAPN administration in mice.

Manipulation of components of the renin angiotensin system in renal proximal tubules fails to alter atherosclerosis in hypercholesterolemic mice.

Background And Objective: Whole body manipulation of the renin-angiotensin system (RAS) consistently exerts profound effects on experimental atherosclerosis development. A deficit in the literature has been a lack of attention to the effects of sex. Also, based on data with gene-deleted mice, the site of RAS activity that influences lesion formation is at an unknown distant location.

Functional Exploration of Conserved Sequences in the Distal Face of Angiotensinogen-Brief Report.

Background: Angiotensinogen (AGT) is an essential component in the renin-angiotensin system. AGT has highly conserved sequences in the loop and β-sheet regions among species; however, their functions have not been studied.

Methods: Adeno-associated viral vector (AAV) serotype 2/8 encoding mouse AGT with mutations of conserved sequences in the loop (AAV.

Antisense oligonucleotides targeting hepatic angiotensinogen reduce atherosclerosis and liver steatosis in hypercholesterolemic mice.

Hepatocyte-derived angiotensinogen (AGT) is the precursor of angiotensin II (AngII). We determined the effects of hepatocyte-specific (-acetylgalactosamine-conjugated) antisense oligonucleotides targeting AGT (GalNAc AGT ASO) on AngII-mediated blood pressure (BP) regulation and atherosclerosis and compared its effects with losartan, an AngII type 1 (AT1) receptor blocker, in hypercholesterolemic mice. Eight-week-old male low-density lipoprotein (LDL) receptor deficient mice were administered vehicle or GalNAc AGT ASO (1, 2.

Chronic environmental circadian disruption increases atherosclerosis and dyslipidemia in female, but not male, -deficient mice.

Shift work chronically disrupts circadian rhythms and increases the risk of developing cardiovascular disease. However, the mechanisms linking shift work and cardiovascular disease are largely unknown. The goal of this study was to investigate the effects of chronically shifting the light-dark (LD) cycle, which models the disordered exposure to light that may occur during shift work, on atherosclerosis.

Inhibition of the Renin-Angiotensin System Fails to Suppress β-Aminopropionitrile-Induced Thoracic Aortopathy in Mice-Brief Report.

Background: Cross-linking of lysine residues in elastic and collagen fibers is a vital process in aortic development. Inhibition of lysyl oxidase by BAPN (β-aminopropionitrile) leads to thoracic aortopathies in mice. Although the renin-angiotensin system contributes to several types of thoracic aortopathies, it remains unclear whether inhibition of the renin-angiotensin system protects against aortopathy caused by the impairment of elastic fiber/collagen crosslinking.

Fludrocortisone Induces Aortic Pathologies in Mice.

Background And Objective: In an experiment designed to explore the mechanisms of fludrocortisone-induced high blood pressure, we serendipitously observed aortic aneurysms in mice infused with fludrocortisone. The purpose of this study was to investigate whether fludrocortisone induces aortic pathologies in both normocholesterolemic and hypercholesterolemic mice.

Methods And Results: Male adult C57BL/6J mice were infused with either vehicle (85% polyethylene glycol 400 (PEG-400) and 15% dimethyl sulfoxide (DMSO); = 5) or fludrocortisone (12 mg/kg/day dissolved in 85% PEG-400 and 15% DMSO; = 15) for 28 days.

Second Heart Field-Derived Cells Contribute to Angiotensin II-Mediated Ascending Aortopathies.

Background: The ascending aorta is a common location for aneurysm and dissection. This aortic region is populated by a mosaic of medial and adventitial cells that are embryonically derived from either the second heart field (SHF) or the cardiac neural crest. SHF-derived cells populate areas that coincide with the spatial specificity of thoracic aortopathies.

Deletion of AT1a (Angiotensin II Type 1a) Receptor or Inhibition of Angiotensinogen Synthesis Attenuates Thoracic Aortopathies in Fibrillin1 Mice.

Objective: A cardinal feature of Marfan syndrome is thoracic aortic aneurysm. The contribution of the renin-angiotensin system via AT1aR (Ang II [angiotensin II] receptor type 1a) to thoracic aortic aneurysm progression remains controversial because the beneficial effects of angiotensin receptor blockers have been ascribed to off-target effects. This study used genetic and pharmacological modes of attenuating angiotensin receptor and ligand, respectively, to determine their roles on thoracic aortic aneurysm in mice with fibrillin-1 haploinsufficiency (Fbn1C1041G/+).

Inducible Depletion of Calpain-2 Mitigates Abdominal Aortic Aneurysm in Mice.

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Bitter Melon ( L.) Supplementation Has No Effect on Hypercholesterolemia and Atherosclerosis in Mice.

Bitter melon (BM; L.) has been reported to ameliorate diet-induced obesity and dyslipidemia. However, the effects of BM on atherosclerosis have not been determined.

Two Amino Acids Proximate to the Renin Cleavage Site of Human Angiotensinogen Do Not Affect Blood Pressure and Atherosclerosis in Mice-Brief Report.

Objective: Renin cleavage of angiotensinogen has species specificity. As the residues at positions 11 and 12 are different between human angiotensinogen and mouse angiotensinogen, we determined whether these 2 residues in angiotensinogen affect renin cleavage and angiotensin II-mediated blood pressure regulation and atherosclerosis using an adenoassociated viral approach for manipulating angiotensinogen in vivo. Approach and Results: Hepatocyte-specific angiotensinogen deficient (hepAGT) mice in an LDL receptor-deficient background were infected with adenoassociated virals containing a null insert, human angiotensinogen, or mouse angiotensinogen expressing the same residues of the human protein at positions 11 and 12 (mouse angiotensinogen [L11V;Y12I]).