Department of Radiation Oncology Works

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Browsing Department of Radiation Oncology Works by Subject "Abdominal aortic aneurysm"

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    Single-cell RNA Sequencing Technology Revealed the Pivotal Role of Fibroblast Heterogeneity in Ang II-Induced Abdominal Aortic Aneurysms
    (Research Square, 2021-11-02) Weng, Yingzheng; Lou, Jiangjie; Bao, Yizong; Cai, Changhong; Zhu, Kefu; Du, Changqing; Chen, Xiaofeng; Tang, Lijiang; Radiation Oncology, School of Medicine
    The mechanism of abdominal aortic aneurysm (AAA) has not been fully elucidated. In this study, we aimed to map the cellular heterogeneity, molecular alteration, and functional transformation of angiotensin (Ang) II-induced AAA in mice based on single-cell RNA sequencing (sc-RNA seq) technology. sc-RNA seq was performed on suprarenal abdominal aorta tissue from male Apoe-/- C57BL/6 mice of Ang II-induced AAA and shame models to determine the heterogeneity and phenotypic transformation of all cells. Immunohistochemistry was used to determine the pathophysiological characteristics of AAA. The single-cell trajectory was performed to predict the differentiation of fibroblasts. Finally ligand-receptor analysis was used to evaluate intercellular communication between fibroblasts and smooth muscle cells (SMCs). More than 27,000 cells were isolated and 25 clusters representing 8 types of cells were identified, including fibroblasts, macrophages, endothelial cells, SMCs, T lymphocytes, B lymphocytes, granulocytes, and natural killer cells. During AAA progression, the function and phenotype of different type cells altered separately, including activation of inflammatory cells, alternations of macrophage polarization, phenotypic transformation of vascular smooth muscle cells, and endothelial to mesenchymal transformation. The alterations of fibroblasts were the most conspicuous. Single-cell trajectory revealed the critical reprogramming genes of fibroblasts mainly enriched in regulation of immune system. Finally, the ligand-receptor analysis confirmed that disorder of collagen metabolism led by fibroblasts was one of the most prominent characteristics of Ang II-induced AAA. Our study revealed the cellular heterogeneity of Ang II-induced AAA. Fibroblasts may play a critical role in Ang II-induced AAA progression according to multiple biological functions, including immune regulation and extracellular matrix metabolic balance. Our study may provide us with a different perspective on the etiology and pathogenesis of AAA.
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    Treatment With Small Molecule Inhibitors of Advanced Glycation End‐Products Formation and Advanced Glycation End‐Products‐Mediated Collagen Cross‐Linking Promotes Experimental Aortic Aneurysm Progression in Diabetic Mice
    (American Heart Association, 2023) Li, Yankui; Zheng, Xiaoya; Guo, Jia; Samura, Makoto; Ge, Yingbin; Zhao, Sihai; Li, Gang; Chen, Xiaofeng; Shoji, Takahiro; Ikezoe, Toru; Miyata, Masaaki; Xu, Baohui; Dalman, Ronald L.; Radiation Oncology, School of Medicine
    Background: Although diabetes attenuates abdominal aortic aneurysms (AAAs), the mechanisms by which diabetes suppresses AAAs remain incompletely understood. Accumulation of advanced glycation end‐ (AGEs) reduces extracellular matrix (ECM) degradation in diabetes. Because ECM degradation is critical for AAA pathogenesis, we investigated whether AGEs mediate experimental AAA suppression in diabetes by blocking AGE formation or disrupting AGE‐ECM cross‐linking using small molecule inhibitors. Methods and Results: Male C57BL/6J mice were treated with streptozotocin and intra‐aortic elastase infusion to induce diabetes and experimental AAAs, respectively. Aminoguanidine (AGE formation inhibitor, 200 mg/kg), alagebrium (AGE‐ECM cross‐linking disrupter, 20 mg/kg), or vehicle was administered daily to mice from the last day following streptozotocin injection. AAAs were assessed via serial aortic diameter measurements, histopathology, and in vitro medial elastolysis assays. Treatment with aminoguanidine, not alagebrium, diminished AGEs in diabetic AAAs. Treatment with both inhibitors enhanced aortic enlargement in diabetic mice as compared with vehicle treatment. Neither enhanced AAA enlargement in nondiabetic mice. AAA enhancement in diabetic mice by aminoguanidine or alagebrium treatment promoted elastin degradation, smooth muscle cell depletion, mural macrophage accumulation, and neoangiogenesis without affecting matrix metalloproteinases, C‐C motif chemokine ligand 2, or serum glucose concentration. Additionally, treatment with both inhibitors reversed suppression of diabetic aortic medial elastolysis by porcine pancreatic elastase in vitro. Conclusions: Inhibiting AGE formation or AGE‐ECM cross‐linking enhances experimental AAAs in diabetes. These findings support the hypothesis that AGEs attenuate experimental AAAs in diabetes. These findings underscore the potential translational value of enhanced ECM cross‐linking as an inhibitory strategy for early AAA disease.