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Biochimica Et Biophysica Acta.... Feb 2022Stanford type A aortic dissection (TA-AD) is a life-threatening disease. Most cases of aortic dissection (AD) are sporadic rather than inherited. Unlike that of...
Stanford type A aortic dissection (TA-AD) is a life-threatening disease. Most cases of aortic dissection (AD) are sporadic rather than inherited. Unlike that of inherited AD, the pathogenesis of sporadic AD is still unclear. In the current study, we aimed to explore the pathogenesis of sporadic AD through transcriptome sequencing data analyses. We downloaded sporadic TA-AD transcriptome profiles from Gene Expression Omnibus (GEO) and found response to DNA damage stimulus was activated in AD. Furthermore, by conducting mouse AD tissue single cell RNA sequencing and immunostaining, we found that DNA damage mainly occurred in smooth muscle cells (SMCs) and fibroblasts. Next, we examined the repair patterns in response to DNA damage and found the linker molecules RBBP8/NOTCH1 between DNA damage/repair and extracellular matrix (ECM) organization through protein-protein interaction analysis. Thus, we proposed that DNA damage could contribute to AD by regulating ECM changes. To explore the underlying mechanism, we knocked down the DNA repair-related gene RBBP8 in aortic SMCs, which could exacerbate DNA damage, and observed decreased expression level of NOTCH1. Inhibition of NOTCH1 with crenigacestat in vivo accelerated β-aminopropionitrile-induced formation of AD and increased mortality. Meanwhile, phenotype switching of SMCs was induced by Notch1 knockdown or inhibition; this switching occurred via a pathway involving downregulation of contractile marker gene expression and upregulation of MMP2 expression, which might aggravate ECM degradation. In conclusion, excessive DNA damage is a characteristic pathological change of sporadic aortic dissection, which might contribute to ECM changes and AD development via action on the NOTCH1 pathway.
Topics: Aortic Dissection; Animals; DNA Damage; Endodeoxyribonucleases; Extracellular Matrix; Female; Humans; Male; Mice; Mice, Inbred C57BL; Muscle, Smooth, Vascular; Receptor, Notch1; Signal Transduction
PubMed: 34780912
DOI: 10.1016/j.bbadis.2021.166303 -
JVS-vascular Science 2021Abdominal aortic aneurysm (AAA) is a condition that has considerable socioeconomic impact and an eventual rupture is associated with high mortality and morbidity.... (Review)
Review
INTRODUCTION
Abdominal aortic aneurysm (AAA) is a condition that has considerable socioeconomic impact and an eventual rupture is associated with high mortality and morbidity. Despite decades of research, surgical repair remains the treatment of choice and no medical therapy is currently available. Animal models and, in particular, murine models, of AAA are a vital tool for experimental in vivo research. However, each of the different models has individual limitations and provide only partial mimicry of human disease. This narrative review addresses the translational potential of the available mouse models, highlighting unanswered questions from a clinical perspective. It is based on a thorough presentation of the available literature and more than a decade of personal experience, with most of the available models in experimental and translational AAA research.
RESULTS
From all the models published, only the four inducible models, namely the angiotensin II model (AngII), the porcine pancreatic elastase perfusion model (PPE), the external periadventitial elastase application (ePPE), and the CaCl model have been widely used by different independent research groups. Although the angiotensin II model provides features of dissection and aneurysm formation, the PPE model shows reliable features of human AAA, especially beyond day 7 after induction, but remains technically challenging. The translational value of ePPE as a model and the combination with β-aminopropionitrile to induce rupture and intraluminal thrombus formation is promising, but warrants further mechanistic insights. Finally, the external CaCl application is known to produce inflammatory vascular wall thickening. Unmet translational research questions include the origin of AAA development, monitoring aneurysm growth, gender issues, and novel surgical therapies as well as novel nonsurgical therapies.
CONCLUSION
New imaging techniques, experimental therapeutic alternatives, and endovascular treatment options provide a plethora of research topics to strengthen the individual features of currently available mouse models, creating the possibility of shedding new light on translational research questions.
PubMed: 34778850
DOI: 10.1016/j.jvssci.2021.01.002 -
International Journal of Molecular... Nov 2021Congenital clubfoot is a complex musculoskeletal deformity, in which a stiff, contracted tissue forms in the medial part of the foot. Fibrotic changes are associated...
Congenital clubfoot is a complex musculoskeletal deformity, in which a stiff, contracted tissue forms in the medial part of the foot. Fibrotic changes are associated with increased collagen deposition and lysyl oxidase (LOX)-mediated crosslinking, which impair collagen degradation and increase the tissue stiffness. First, we studied collagen deposition, as well as the expression of collagen and the amount of pyridinoline and deoxypyridinoline crosslinks in the tissue of relapsed clubfoot by immunohistochemistry, real-time PCR, and enzyme-linked immunosorbent assay (ELISA). We then isolated fibroblast-like cells from the contracted tissue to study the potential inhibition of these processes in vitro. We assessed the effects of a LOX inhibitor, β-aminopropionitrile (BAPN), on the cells by a hydroxyproline assay, ELISA, and Second Harmonic Generation imaging. We also evaluated the cell-mediated contraction of extracellular matrix in 3D cell-populated collagen gels. For the first time, we have confirmed significantly increased crosslinking and excessive collagen type I deposition in the clubfoot-contracted tissue. We successfully reduced these processes in vitro in a dose-dependent manner with 10-40 µg/mL of BAPN, and we observed an increasing trend in the inhibition of the cell-mediated contraction of collagen gels. The in vitro inhibitory effects indicate that BAPN has good potential for the treatment of relapsed and resistant clubfeet.
Topics: Aminopropionitrile; Child, Preschool; Clubfoot; Collagen; Cross-Linking Reagents; Female; Fibroblasts; Humans; Male; Protein-Lysine 6-Oxidase
PubMed: 34769331
DOI: 10.3390/ijms222111903 -
Journal of Immunology Research 2021Tobacco smoke is an established risk factor for thoracic aortic aneurysms and dissections (TAAD). However, little is known about its underlying mechanisms due to the...
Tobacco smoke is an established risk factor for thoracic aortic aneurysms and dissections (TAAD). However, little is known about its underlying mechanisms due to the lack of validated animal models. The present study developed a mouse model that may be utilized to investigate exacerbation of TAAD formation by mimetics of tobacco smoke. TAADs were created via inducible deletion of smooth muscle cell-specific receptors. Using this model, the first set of experiments evaluated the efficacy of nicotine salt (34.0 mg/kg/day), nicotine free base (NFB, 5.0 mg 90-day pellets), and cigarette smoke extract (0.1 ml/mouse/day). Compared with their respective control groups, only NFB pellets promoted TAAD dilation (23 ± 3% vs. 12 ± 2%, = 0.014), and this efficacy was achieved at a cost of >50% acute mortality. Infusion of NFB with osmotic minipumps at extremely high, but nonlethal, doses (15.0 or 45.0 mg/kg/day) failed to accelerate TAAD dilation. Interestingly, costimulation with -aminopropionitrile (BAPN) promoted TAAD dilation and aortic rupture at dosages of 3.0 and 45.0 mg/kg/day, respectively, indicating that BAPN sensitizes the response of TAADs to NFB. In subsequent analyses, the detrimental effects of NFB were associated with clustering of macrophages, neutrophils, and T-cells in areas with structural destruction, enhanced matrix metalloproteinase- (MMP-) 2 production, and pathological angiogenesis with attenuated fibrosis in the adventitia. In conclusion, modeling nicotine exacerbation of TAAD formation requires optimization of chemical form, route of delivery, and dosage of the drug as well as the pathologic complexity of TAADs. Under the optimized conditions of the present study, chronic inflammation and adventitial mal-remodeling serve as critical pathways through which NFB exacerbates TAAD formation.
Topics: Aortic Dissection; Animals; Aorta, Thoracic; Aortic Aneurysm, Thoracic; Cigarette Smoking; Disease Models, Animal; Humans; Male; Mice; Mice, Knockout; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Nicotine; Receptor, Transforming Growth Factor-beta Type II
PubMed: 34646889
DOI: 10.1155/2021/6880036 -
Scientific Reports Sep 2021Although well investigated, the importance of collagen fibers in supporting angiogenesis is not well understood. In this study, we demonstrate that extracellular...
Although well investigated, the importance of collagen fibers in supporting angiogenesis is not well understood. In this study, we demonstrate that extracellular collagen fibers provide guidance cues for endothelial cell migration during regenerative angiogenesis in the caudal zebrafish fin. Inhibition of collagen cross-linking by β-Aminopropionitrile results in a 70% shorter regeneration area with 50% reduced vessel growth and disintegrated collagen fibers. The disrupted collagen scaffold impedes endothelial cell migration and induces formation of abnormal angioma-like blood vessels. Treatment of the Fli//colRN zebrafish line with the prodrug Nifurpirinol, which selectively damages the active collagen-producing 1α2 cells, reduced the regeneration area and vascular growth by 50% with wider, but less inter-connected, capillary segments. The regenerated area contained larger vessels partially covered by endothelial cells embedded in atypical extracellular matrix containing cell debris and apoptotic bodies, macrophages and granulocytes. Similar experiments performed in early embryonic zebrafish suggested that collagens are important also during embryonic angiogenesis. In vitro assays revealed that collagen I allows for the most efficient endothelial cell migration, followed by collagen IV relative to the complete absence of exogenous matrix support. Our data demonstrates severe vascular defects and restricted fin regeneration when collagens are impaired. Collagen I therefore, provides support and guidance for endothelial cell migration while collagen IV is responsible for proper lumen formation and vascular integrity.
Topics: Animal Fins; Animals; Biomarkers; Capillaries; Cell Line; Collagen Type IV; Endothelial Cells; Fibrillar Collagens; Fluorescent Antibody Technique; Gene Expression; Gene Knockdown Techniques; Humans; Neovascularization, Physiologic; Regeneration; Wound Healing; Zebrafish
PubMed: 34593884
DOI: 10.1038/s41598-021-98852-6 -
Arteriosclerosis, Thrombosis, and... Nov 2021
Topics: Aminopropionitrile; Aortic Dissection; Animals; Aorta, Thoracic; Aortic Aneurysm, Thoracic; Cefixime; Disease Models, Animal; Fluoroquinolones; Histone Deacetylase Inhibitors; Male; Mice, Inbred C57BL; Panobinostat; Risk Assessment; Risk Factors; Severity of Illness Index; Mice
PubMed: 34525846
DOI: 10.1161/ATVBAHA.121.316808 -
Molecular Therapy. Nucleic Acids Dec 2021Accumulating evidence shows that tRNA-derived fragments are a novel class of functional small non-coding RNA; however, their roles in aortic dissection (AD) are still...
Accumulating evidence shows that tRNA-derived fragments are a novel class of functional small non-coding RNA; however, their roles in aortic dissection (AD) are still unknown. In this study, we found that 5'-tiRNA-Cys-GCA was significantly downregulated in human and mouse models of aortic dissection. The abnormal proliferation, migration, and phenotypic transition of vascular smooth muscle cells (VSMCs) played a crucial role in the initiation and progression of aortic dissection, with 5'-tiRNA-Cys-GCA as a potential phenotypic switching regulator, because its overexpression inhibited the proliferation and migration of VSMCs and increased the expression of contractile markers. In addition, we verified that signal transducer and activator of transcription 4 (STAT4) was a direct downstream target of 5'-tiRNA-Cys-GCA. We found that the STAT4 upregulation in oxidized low-density lipoprotein (ox-LDL)-treated VSMCs, which promoted cell proliferation, migration, and phenotypic transformation, was reversed by 5'-tiRNA-Cys-GCA. Furthermore, 5'-tiRNA-Cys-GCA treatment reduced the incidence and prevented the malignant process of angiotensin II- and β-aminopropionitrile-induced AD in mice. In conclusion, our findings reveal that 5'-tiRNA-Cys-GCA is a potential regulator of the AD pathological process via the STAT4 signaling pathway, providing a novel clinical target for the development of future treatment strategies for aortic dissection.
PubMed: 34513311
DOI: 10.1016/j.omtn.2021.07.013 -
Acta Biomaterialia Oct 2021Abdominal aortic aneurysms (AAAs) are characterized histopathologically by compromised elastic fiber integrity, lost smooth muscle cells or their function, and remodeled...
Abdominal aortic aneurysms (AAAs) are characterized histopathologically by compromised elastic fiber integrity, lost smooth muscle cells or their function, and remodeled collagen. We used a recently introduced mouse model of AAAs that combines enzymatic degradation of elastic fibers and blocking of lysyl oxidase, and thus matrix cross-linking, to study progressive dilatation of the infrarenal abdominal aorta, including development of intraluminal thrombus. We quantified changes in biomaterial properties and biomechanical functionality within the aneurysmal segment as a function of time of enlargement and degree of thrombosis. Towards this end, we combined multi-modality imaging with state-of-the art biomechanical testing and histology to quantify regional heterogeneities for the first time and we used a computational model of arterial growth and remodeling to test multiple hypotheses, suggested by the data, regarding the degree of lost elastin, accumulation of glycosaminoglycans, and rates of collagen turnover. We found that standard histopathological findings can be misleading, while combining advanced experimental and computational methods revealed that glycosaminoglycan accumulation is pathologic, not adaptive, and that heightened collagen deposition is ineffective if not cross-linked. In conclusion, loss of elastic fiber integrity can be a strong initiator of aortic aneurysms, but it is the rate and effectiveness of fibrillar collagen remodeling that dictates enlargement. STATEMENT OF SIGNIFICANCE: Precise mechanisms by which abdominal aortic aneurysms enlarge remain unclear, but a recent elastase plus β-aminopropionitrile mouse model provides new insight into disease progression. As in the human condition, the aortic degeneration and adverse remodeling are highly heterogeneous in this model. Our multi-modality experiments quantify and contrast the heterogeneities in geometry and biomaterial properties, and our computational modeling shows that standard histopathology can be misleading. Neither accumulating glycosaminoglycans nor frustrated collagen synthesis slow disease progression, thus highlighting the importance of stimulating adaptive collagen remodeling to limit lesion enlargement.
Topics: Aminopropionitrile; Animals; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Disease Models, Animal; Elastic Tissue; Elastin; Mice; Pancreatic Elastase
PubMed: 34332103
DOI: 10.1016/j.actbio.2021.07.059 -
Kidney360 Feb 2021The arteriovenous fistula (AVF) is the preferred hemodialysis access for end-stage renal disease (ESRD) patients. Yet, establishment of a functional AVF presents a...
BACKGROUND
The arteriovenous fistula (AVF) is the preferred hemodialysis access for end-stage renal disease (ESRD) patients. Yet, establishment of a functional AVF presents a challenge, even for the most experienced surgeons, since postoperative stenosis frequently occludes the AVF. Stenosis results from the loss of compliance in fibrotic areas of the fistula which turns intimal hyperplasia into an occlusive feature. Fibrotic remodeling depends on deposition and crosslinking of collagen by lysyl oxidase (LOX), an enzyme that catalyzes the deamination of lysine and hydroxylysine residues, facilitating intra/intermolecular covalent bonds. We postulate that pharmacological inhibition of lysyl oxidase (LOX) increases postoperative venous compliance and prevents stenosis in a rat AVF model.
METHODS
LOX gene expression and vascular localization were assayed in rat AVFs and human pre-access veins, respectively. Collagen crosslinking was measured in humans AVFs that matured or failed, and in rat AVFs treated with β-aminopropionitrile (BAPN), an irreversible LOX inhibitor. BAPN was either injected systemically or delivered locally around rat AVFs using nanofiber scaffolds. The major endpoints were AVF blood flow, wall fibrosis, collagen crosslinking, and vascular distensibility.
RESULTS
Non-maturation of human AVFs was associated with higher LOX deposition in pre-access veins (N=20, P=0.029), and increased trivalent crosslinks (N=18, P=0.027) in human AVF tissues. Systemic and local inhibition of LOX increased AVF distensibility, while reducing wall fibrosis and collagen crosslinking in rat fistulas.
CONCLUSIONS
Our results demonstrate that BAPN-mediated inhibition of LOX significantly improves vascular remodeling in experimental fistulas.
Topics: Aminopropionitrile; Animals; Arteriovenous Fistula; Arteriovenous Shunt, Surgical; Humans; Protein-Lysine 6-Oxidase; Rats; Veins
PubMed: 34322674
DOI: 10.34067/KID.0005012020 -
PloS One 2021Aortic dissection (AD) is a life-threatening emergency, and lumican (LUM) is a potential Biomarker for AD diagnosis. We investigated LUM expression patterns in patients...
INTRODUCTION
Aortic dissection (AD) is a life-threatening emergency, and lumican (LUM) is a potential Biomarker for AD diagnosis. We investigated LUM expression patterns in patients with AD and explored the molecular functions of Lum in AD mice model.
METHODS
LUM expression patterns were analyzed using aortic tissues of AD patients, and serum soluble LUM (s-LUM) levels were compared between patients with acute AD (AAD) and chronic AD (CAD). Lum-knockout (Lum-/-) mice were challenged with β-aminopropionitrile (BAPN) and angiotensin II (Ang II) to induce AD. The survival rate, AD incidence, and aortic aneurysm (AA) in these mice were compared with those in BAPN-Ang II-challenged wildtype (WT) mice. Tgf-β/Smad2, Mmps, Lum, and Nox expression patterns were examined.
RESULTS
LUM expression was detected in the intima and media of the ascending aorta in patients with AAD. Serum s-LUM levels were significantly higher in patients with AAD than CAD. Furthermore, AD-associated mortality and thoracic aortic rupture incidence were significantly higher in the Lum-/- AD mice than in the WT AD mice. However, no significant pathologic changes in AA were observed in the Lum-/- AD mice compared with the WT AD mice. The BAPN-Ang II-challenged WT and Lum-/- AD mice had higher Tgf-β, p-Smad2, Mmp2, Mmp9, and Nox4 levels than those of non-AD mice. We also found that Lum expression was significantly higher in the BAPN-Ang II-challenged WT in comparison to the unchallenged WT mice.
CONCLUSION
LUM expression was altered in patients with AD display increased s-LUM in blood, and Lum-/- mice exhibited augmented AD pathogenesis. These findings support the notion that LUM is a biomarker signifying the pathogenesis of injured aorta seen in AAD. The presence of LUM is essential for maintenance of connective tissue integrity. Future studies should elucidate the mechanisms underlying LUM association in aortic changes.
Topics: Acute Disease; Aminopropionitrile; Aortic Dissection; Angiotensin II; Animals; Aorta; Aortic Rupture; Biomarkers; Chronic Disease; Disease Models, Animal; Humans; Incidence; Kaplan-Meier Estimate; Lumican; Mice; Mice, Inbred C57BL; Mice, Knockout; Smad2 Protein; Transforming Growth Factor beta; Up-Regulation
PubMed: 34310653
DOI: 10.1371/journal.pone.0255238