Publications by authors named "Hisashi Sawada"

Article Synopsis
  • Pharmacological inhibition of megalin in mice helps reduce atherosclerosis, but the study aimed to see if specifically deleting megalin in renal proximal tubule cells (PTCs) could have similar effects against hypercholesterolemia-induced atherosclerosis.
  • The experiments involved creating mice with and without megalin (PTC-LRP2 -/-) and inducing atherosclerosis by using a Western diet, but results showed that deleting megalin did not reduce atherosclerosis in any mice.
  • Instead, male PTC-LRP2 -/- mice exhibited severe kidney issues, including CD68+ cell infiltration and tubular atrophy, indicating that high-fat diets can lead to kidney damage independent of cholesterol levels, while female P
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Article Synopsis
  • A study was conducted to examine if deleting megalin from renal proximal tubule cells (PTCs) would reduce atherosclerosis in mice with high cholesterol levels.
  • The results showed that this deletion did not reduce atherosclerosis but caused kidney issues, such as inflammation and tubular atrophy, particularly in male mice on a Western diet.
  • Overall, the findings suggest that while megalin deletion doesn’t impact atherosclerosis, it leads to specific kidney problems influenced by diet, especially in males.
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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.

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AGT (angiotensinogen) is the unique precursor for the generation of all the peptides of the renin-angiotensin system, but it has received relatively scant attention compared to many other renin-angiotensin system components. Focus on AGT has increased recently, particularly with the evolution of drugs to target the synthesis of the protein. AGT is a noninhibitory serpin that has several conserved domains in addition to the angiotensin II sequences at the N terminus.

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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.

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Background: The regional heterogeneity of vascular components and transcriptomes is an important determinant of aortic biology. This notion has been explored in multiple mouse studies. In the present study, we examined the regional heterogeneity of aortas in nonhuman primates.

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Background: The regional heterogeneity of vascular components and transcriptomes is an important determinant of aortic biology. This notion has been explored in multiple mouse studies. In the present study, we examined the regional heterogeneity of aortas in non-human primates.

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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.

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Article Synopsis
  • The renin-angiotensin system (RAS) is a key hormonal system that regulates water and sodium balance, blood flow to the kidneys, and blood vessel constriction, impacting overall blood pressure levels.
  • When RAS is overactive, such as through increased angiotensin II (Ang II), it can lead to hypertension and damage to organs, with Ang II receptors also contributing to cardiovascular and kidney diseases independently of blood pressure.
  • Recent research highlights the complex roles of various RAS components, showing that some can have protective effects (like angiotensin 1-7) against the harmful effects of Ang II, while studies on gene-deleted mice reveal specific functions of Ang II receptors in different cell types in the cardiovascular
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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.

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  • Vascular smooth muscle cells (vSMCs) help keep blood vessels healthy and are involved in various signaling processes, particularly through a receptor called LRP1, which recognizes multiple biological signals.
  • Mice lacking LRP1 in their vSMCs developed aneurysms in a specific artery, indicating that the absence of this receptor disrupts normal vascular function and signaling related to blood pressure regulation.
  • Treating these mice with a medication that blocks angiotensin II signaling successfully reversed vascular issues and prevented aneurysm formation, highlighting the importance of LRP1 in maintaining blood vessel integrity.
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Article Synopsis
  • * They pose a significant risk of aortic rupture, resulting in severe bleeding that can be fatal.
  • * Understanding and managing AAD is crucial for preventing these dangerous outcomes and improving patient survival rates.
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Smooth muscle cells (SMCs) are the major cell type of the aortic wall and play a pivotal role in the pathophysiology of thoracic aortic aneurysms (TAAs). TAAs occur in a region-specific manner with the proximal region being a common location. In this region, SMCs are derived embryonically from either the cardiac neural crest or the second heart field.

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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.

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Article Synopsis
  • Atherosclerosis is a major health issue worldwide, contributing to high rates of illness and death.
  • Mice are commonly used in research to understand the causes and mechanisms of atherosclerosis, with the aorta and cross-sections of the aortic root being the main methods for measuring severity.
  • This review highlights the strengths and weaknesses of these methods and offers improvements to make quantification more reliable in preclinical studies.
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Angiotensin II (AngII) infusion in mice has been used widely to investigate mechanisms of abdominal aortic aneurysms (AAAs). To achieve a high incidence of AngII-induced AAAs, mice should be hypercholesterolemic. Therefore, either low-density lipoprotein receptor (LDLR) or apolipoprotein E deficiency have been used as a hypercholesterolemic background.

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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.

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Aortic aneurysms and dissections are life-threatening conditions that have a high risk for lethal bleeding and organ malperfusion. Many studies have investigated the molecular basis of these diseases using mouse models. In mice, ex vivo, in situ, and ultrasound imaging are major approaches to evaluate aortic diameters, a common parameter to determine the severity of aortic aneurysms.

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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.

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