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Cell Discovery Feb 2022Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening condition characterized by medial layer degeneration of the thoracic aorta. A thorough understanding...
Single-cell RNA sequencing identifies an Il1rn/Trem1 macrophage subpopulation as a cellular target for mitigating the progression of thoracic aortic aneurysm and dissection.
Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening condition characterized by medial layer degeneration of the thoracic aorta. A thorough understanding of the regulator changes during pathogenesis is essential for medical therapy development. To delineate the cellular and molecular changes during the development of TAAD, we performed single-cell RNA sequencing of thoracic aortic cells from β-aminopropionitrile-induced TAAD mouse models at three time points that spanned from the early to the advanced stages of the disease. Comparative analyses were performed to delineate the temporal dynamics of changes in cellular composition, lineage-specific regulation, and cell-cell communications. Excessive activation of stress-responsive and Toll-like receptor signaling pathways contributed to the smooth muscle cell senescence at the early stage. Three subpopulations of aortic macrophages were identified, i.e., Lyve1 resident-like, Cd74 antigen-presenting, and Il1rn/Trem1 pro-inflammatory macrophages. In both mice and humans, the pro-inflammatory macrophage subpopulation was found to represent the predominant source of most detrimental molecules. Suppression of macrophage accumulation in the aorta with Ki20227 could significantly decrease the incidence of TAAD and aortic rupture in mice. Targeting the Il1rn/Trem1 macrophage subpopulation via blockade of Trem1 using mLR12 could significantly decrease the aortic rupture rate in mice. We present the first comprehensive analysis of the cellular and molecular changes during the development of TAAD at single-cell resolution. Our results highlight the importance of anti-inflammation therapy in TAAD, and pinpoint the macrophage subpopulation as the predominant source of detrimental molecules for TAAD. Targeting the IL1RN/TREM1 macrophage subpopulation via blockade of TREM1 may represent a promising medical treatment.
PubMed: 35132073
DOI: 10.1038/s41421-021-00362-2 -
Cells Dec 2021When a large artery becomes occluded, hemodynamic changes stimulate remodeling of arterial networks to form collateral arteries in a process termed arteriogenesis....
When a large artery becomes occluded, hemodynamic changes stimulate remodeling of arterial networks to form collateral arteries in a process termed arteriogenesis. However, the structural changes necessary for collateral remodeling have not been defined. We hypothesize that deconstruction of the extracellular matrix is essential to remodel smaller arteries into effective collaterals. Using multiphoton microscopy, we analyzed collagen and elastin structure in maturing collateral arteries isolated from ischemic rat hindlimbs. Collateral arteries harvested at different timepoints showed progressive diameter expansion associated with striking rearrangement of internal elastic lamina (IEL) into a loose fibrous mesh, a pattern persisting at 8 weeks. Despite a 2.5-fold increase in luminal diameter, total elastin content remained unchanged in collaterals compared with control arteries. Among the collateral midzones, baseline elastic fiber content was low. Outward remodeling of these vessels with a 10-20 fold diameter increase was associated with fractures of the elastic fibers and evidence of increased wall tension, as demonstrated by the straightening of the adventitial collagen. Inhibition of lysyl oxidase (LOX) function with β-aminopropionitrile resulted in severe fragmentation or complete loss of continuity of the IEL in developing collaterals. Collateral artery development is associated with permanent redistribution of existing elastic fibers to accommodate diameter growth. We found no evidence of new elastic fiber formation. Stabilization of the arterial wall during outward remodeling is necessary and dependent on LOX activity.
Topics: Animals; Arteries; Collagen; Elasticity; Extracellular Matrix; Humans; Male; Organogenesis; Protein-Lysine 6-Oxidase; Rats, Sprague-Dawley; Tomography, X-Ray Computed; Vascular Remodeling; Rats
PubMed: 35011567
DOI: 10.3390/cells11010007 -
Cancers Jan 2022The biochemical composition and architecture of the extracellular matrix (ECM) is known to condition development and invasiveness of neoplasms. To clarify this point, we...
PURPOSE
The biochemical composition and architecture of the extracellular matrix (ECM) is known to condition development and invasiveness of neoplasms. To clarify this point, we analyzed ECM stiffness, collagen cross-linking and anisotropy in lymph nodes (LN) of Hodgkin lymphomas (HL), follicular lymphomas (FL) and diffuse large B-cell lymphomas (DLBCL), compared with non-neoplastic LN (LDN).
METHODS AND RESULTS
We found increased elastic (Young's) modulus in HL and advanced FL (grade 3A) over LDN, FL grade 1-2 and DLBCL. Digital imaging evidenced larger stromal areas in HL, where increased collagen cross-linking was found; in turn, architectural modifications were documented in FL3A by scanning electron microscopy and enhanced anisotropy by polarized light microscopy. Interestingly, HL expressed high levels of lysyl oxidase (LOX), an enzyme responsible for collagen cross-linking. Using gelatin scaffolds fabricated with a low elastic modulus, comparable to that of non-neoplastic tissues, we demonstrated that HL LN-derived mesenchymal stromal cells and HL cells increased the Young's modulus of the extracellular microenvironment through the expression of LOX. Indeed, LOX inhibition by β-aminopropionitrile prevented the gelatin stiffness increase.
CONCLUSIONS
These data indicate that different mechanical, topographical and/or architectural modifications of ECM are detectable in human lymphomas and are related to their histotype and grading.
PubMed: 35008423
DOI: 10.3390/cancers14010259 -
Scientific Reports Jan 2022Abdominal aortic aneurysm (AAA) formation and expansion is highly complex and multifactorial, and the improvement of animal models is an important step to enhance our...
Abdominal aortic aneurysm (AAA) formation and expansion is highly complex and multifactorial, and the improvement of animal models is an important step to enhance our understanding of AAA pathophysiology. In this study, we explore our ability to influence aneurysm growth in a topical elastase plus β-Aminopropionitrile (BAPN) mouse model by varying elastase concentration and by altering the cross-linking capability of the tissue. To do so, we assess both chronic and acute effects of elastase concentration using volumetric ultrasound. Our results suggest that the applied elastase concentration affects initial elastin degradation, as well as long-term vessel expansion. Additionally, we assessed the effects of BAPN by (1) removing it to restore the cross-linking capability of tissue after aneurysm formation and (2) adding it to animals with stable aneurysms to interrupt cross-linking. These results demonstrate that, even after aneurysm formation, lysyl oxidase inhibition remains necessary for continued expansion. Removing BAPN reduces the aneurysm growth rate to near zero, resulting in a stable aneurysm. In contrast, adding BAPN causes a stable aneurysm to expand. Altogether, these results demonstrate the ability of elastase concentration and BAPN to modulate aneurysm growth rate and severity. The findings open several new areas of investigation in a murine model that mimics many aspects of human AAA.
Topics: Administration, Topical; Aminopropionitrile; Animals; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Dilatation, Pathologic; Disease Models, Animal; Disease Progression; Female; Male; Mice, Inbred C57BL; Pancreatic Elastase; Protein-Lysine 6-Oxidase; Severity of Illness Index; Mice
PubMed: 34997075
DOI: 10.1038/s41598-021-04089-8 -
Journal of the American Heart... Jan 2022Background cGMP-hydrolyzing phosphodiesterase type 5 (PDE5) regulates vascular smooth muscle cell (SMC) contraction by antagonizing cGMP-dependent protein kinase I...
Background cGMP-hydrolyzing phosphodiesterase type 5 (PDE5) regulates vascular smooth muscle cell (SMC) contraction by antagonizing cGMP-dependent protein kinase I (PKGI)-dependent SMC relaxation. SMC contractile dysfunction is implicated in the pathogenesis of aortic aneurysm. PDE5 inhibitors have been used for treating erectile dysfunction, such as drug Viagra (sildenafil). However, a few clinical cases have reported the association of Viagra usage with aortic dissection, and reduced PDE5A expression was found in human aortic aneurysm tissues. Therefore, we aimed to investigate the effect of sildenafil on experimental abdominal aortic aneurysm (AAA), the most common form of aortic aneurysm in elderly men. Methods and Results AAA was induced in C57BL/6J male mice by periaortic elastase in combination with blocking elastin/collagen formation via 3-aminopropionitrile fumarate salt for 35 days. PDE5A protein levels detected by immunostaining were significantly reduced in mouse AAA. Sildenafil application in drinking water significantly aggravated aortic wall dilation and elastin degradation with pre-existing moderate AAA. The phosphorylation level of myosin light chain 2 at Ser19, a biochemical marker of SMC contraction, was significantly reduced by sildenafil in AAA. Proximity ligation assay further revealed that the interaction between cGMP and PKGI was significantly increased by sildenafil in AAA, suggesting an elevation of PKGI activation in AAA. Conclusions Sildenafil treatment aggravated the degradation of elastin fibers and progression of experimental AAA by dysregulating cGMP and contractile signaling in SMCs. Our findings may raise the caution of clinical usage of Viagra in aneurysmal patients.
Topics: Aged; Animals; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Disease Models, Animal; Elastin; Humans; Male; Mice; Mice, Inbred C57BL; Sildenafil Citrate
PubMed: 34984916
DOI: 10.1161/JAHA.121.023053 -
Frontiers in Cardiovascular Medicine 2021Numerous pieces of evidence have indicated that thoracic aortic dissection (TAD) is an inflammatory disease. Sphingosine-1-phosphate receptor 2 (S1PR2) signaling is a...
Numerous pieces of evidence have indicated that thoracic aortic dissection (TAD) is an inflammatory disease. Sphingosine-1-phosphate receptor 2 (S1PR2) signaling is a driver in multiple inflammatory diseases. Here, we examined the S1PR2 expression in TAD lesions and explored the effect of interfering with S1PR2 on TAD formation and progression. Aorta specimens and blood samples were collected from patients with TAD and matched controls. The expression of S1PR1, S1PR2, and S1PR3 was examined. The effect of inhibiting S1PR2 on TAD was evaluated in a TAD mouse model induced by β-aminopropionitrile fumarate (BAPN) and AngII. The presence of sphingosine kinase 1 (SPHK1), S1P, and neutrophil extracellular traps (NETs) was investigated. Further, the possible association between S1PR2 signaling and NETs in TAD was analyzed. In the aortic tissues of patients with TAD and a mouse model, the S1PR2 expression was significantly up-regulated. In the TAD mouse model, JTE013, a specific S1PR2 antagonist, not only blunted the TAD formation and aortic rupture, but also preserved the elastic fiber architecture, reduced the smooth muscle cells apoptosis level, and mitigated the aortic wall inflammation. Augmented tissue protein expression of SPHK1, citrullinated histone H3 (CitH3, a specific marker of NETs), and serum S1P, CitH3 were detected in TAD patients. Surgical repair normalized the serum S1P and CitH3 levels. Immunofluorescence staining revealed that S1PR2 colocalized with NETs. The protein expression levels of SPHK1 and serum S1P levels positively correlated with the protein expression and serum levels of CitH3, separately. Furthermore, JTE013 treatment reduced NETs accumulation. Inhibiting S1PR2 attenuates TAD formation and prevents aortic rupture. Targeting S1PR2 may provide a promising treatment strategy against TAD.
PubMed: 34977175
DOI: 10.3389/fcvm.2021.748486 -
Frontiers in Cardiovascular Medicine 2021Inflammation plays an important role in aortic dissection (AD). Macrophages are critically involved in the inflammation after aortic injury. Neuraminidases (NEUs) are a...
Inflammation plays an important role in aortic dissection (AD). Macrophages are critically involved in the inflammation after aortic injury. Neuraminidases (NEUs) are a family of enzymes that catalyze the cleavage of terminal sialic acids from glycoproteins or glycolipids, which is emerging as a regulator of macrophage-associated immune responses. However, the role of neuraminidase 1 (NEU1) in pathological vascular remodeling of AD remains largely unknown. This study sought to characterize the role and identify the potential mechanism of NEU1 in pathological aortic degeneration. After β-aminopropionitrile monofumarate (BAPN) administration, NEU1 elevated significantly in the lesion zone of the aorta. Global or macrophage-specific NEU1 knockout (NEU1 CKO) mice had no baseline aortic defects but manifested improved aorta function, and decreased mortality due to aortic rupture. Improved outcomes in NEU1 CKO mice subjected to BAPN treatment were associated with the ameliorated vascular inflammation, lowered apoptosis, decreased reactive oxygen species production, mitigated extracellular matrix degradation, and improved M2 macrophage polarization. Furthermore, macrophages sorted from the aorta of NEU1 CKO mice displayed a significant increase of M2 macrophage markers and a marked decrease of M1 macrophage markers compared with the controls. To summarize, the present study demonstrated that macrophage-derived NEU1 is critical for vascular homeostasis. NEU1 exacerbates BAPN-induced pathological vascular remodeling. NEU1 may therefore represent a potential therapeutic target for the treatment of AD.
PubMed: 34869700
DOI: 10.3389/fcvm.2021.788645 -
Annals of Translational Medicine Oct 2021To investigate the protective effect of resolvin D1 (RvD1) on aortic dissection (AD) in mice and explore the related mechanisms.
BACKGROUND
To investigate the protective effect of resolvin D1 (RvD1) on aortic dissection (AD) in mice and explore the related mechanisms.
METHODS
Mice were randomly divided into a blank group, model group, and RvD1 group. The RvD1 and model groups were administered 0.4% β-aminopropionitrile (BAPN) solution, while the blank group was administered distilled water. When the experiment began, whether mice had AD was determined by echocardiogram. The RvD1 group was also administered RvD1 (30 µg/kg), while the model and blank groups were administered saline intraperitoneally. After 21 d, body weight trend and survival rate in the three groups were compared. The diameter of the ascending aorta of mice was detected by echocardiography. Then, the mice were sacrificed, and histopathological staining procedures were performed. Enzyme-linked immunosorbent assay (ELISA) was used to detect cytokines and chemokines in blood and tissue, respectively.
RESULTS
At 21 d, there was no statistically significant difference in body weight between three groups (P>0.05). The survival rate showed a significant difference between the RvD1 and model group (P<0.05). Echocardiography revealed that compared with the RvD1 and blank groups, aortic dilatation was significant in the model group. Pathological staining showed that the destruction of the aortic wall structure and inflammatory cell infiltration were more noticeable in the model group than in the RvD1 group. A slight disintegration of elastic fibers and collagen in the aorta was observed in the RvD1 group, and the aortic structure was clear. The results of ELISA showed that the inflammatory factors levels in the RvD1 group, although higher than those in blank group, were significantly decreased compared with the model group. The ELISA results of AD tissue showed that at 21 d, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels in the aorta were significantly decreased in the RvD1 group compared with the model group (P<0.05).
CONCLUSIONS
Administration of RvD1 significantly delayed aortic dilation and disintegration and inhibited local macrophage and neutrophil infiltration in the early stages of aortic injury. Moreover, RvD1 significantly downregulated the expression of cytokines and chemokines in aortic tissues and serum and improved aortic remodeling.
PubMed: 34805360
DOI: 10.21037/atm-21-3986 -
Journal of Inflammation Research 2021Aortic dissection (AD) is a threatening and catastrophic vascular disease with high mortality rate and limited therapeutic strategies. There is emerging evidence showing...
BACKGROUND
Aortic dissection (AD) is a threatening and catastrophic vascular disease with high mortality rate and limited therapeutic strategies. There is emerging evidence showing that circular RNAs play crucial role in regulating various cardiovascular diseases. However, the biological functions and molecular mechanisms of circRNAs in AD still remains elusive. The purpose of this study was to illustrate the potential functional roles and mechanisms of hsa_circ_TGFBR2 in vitro and in vivo.
METHODS
The vascular smooth muscle cells (VSMCs) and AD-VSMCs were isolated from normal aorta and AD tissues. The expression of circ_TGFBR2, miR-29a and KLF4 were detected by realtime polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH). Cell proliferation was assessed by CCK-8 assay, colony formation and EDU assay. Cell migration was evaluated through transwell assay. Dual-luciferase reporter assay and RNA pulldown were performed to identify the interaction between circ_TGFBR2 and miR-29a or between miR-29a and KLF4. The wild-type sequence of circ_TGFBR2 or KLF4 were cloned into the luciferase reporter plasmid, and the activity was measured using dual-luciferase reporter assay system. And for RNA pulldown, the relative RNA enrichment of circ_TGFBR2 and miR-29a were confirmed using RT-PCR. Western Blot measured the expression of phenotype switch-related proteins. AD rat model induced by β-aminopropionitrile monofumarate (BAPN) was used to verify the role and mechanism of circ_TGFBR2.
RESULTS
Circ_TGFBR2 inhibited cell proliferation and migration of AD-VSMCs cells. Overexpression of circ_TGFBR2 promoted the expression of contractile markers (α-SMA, SM22α) and inhibited the expression of synthetic markers (MGP, OPN) in AD-VSMCs cells. Circ_TGFBR2 served as a sponge for miR-29a targeting KLF4. MiR-29a mimics rescued biological roles induced by circ_TGFBR2 overexpression. The in vivo experiments revealed that overexpression of TGFBR2 suppressed the progression of AD and increased the expression of contractile markers while inhibited the expression of synthetic markers.
CONCLUSION
Our study revealed that circ_TGFBR2 regulated VSMCs phenotype switch and suppressed the progression of AD.
PubMed: 34795497
DOI: 10.2147/JIR.S336094 -
Annals of Translational Medicine Oct 2021The precise role collagen plays in acute aortic dissection (AAD) was investigated in an animal model of β-aminopropinitrile (BAPN)-induced AAD.
BACKGROUND
The precise role collagen plays in acute aortic dissection (AAD) was investigated in an animal model of β-aminopropinitrile (BAPN)-induced AAD.
METHODS
The 30 3-week-old male specific-pathogen free (SPF)-grade Sprague-Dawley (SD) rats were randomly divided into two groups: 10 in the Control group and 20 in the Model group. The Model group was treated with 0.1% BAPN for 4 weeks, while the Control group received untreated water. Histopathological staining and western blot were used to detect changes of the extracellular matrix (ECM) and collagen content in the aorta.
RESULTS
At the end of the experiment, the incidence of AAD was 25%, the aortic ECM of surviving rats was severely damaged, and the arrangement was disordered. Fibroblast cells are unevenly distributed, with wide gaps, collagen fibers were also distributed unevenly in a disordered arrangement and their thickness was uneven. The elastic membrane disappeared over a large area. Compare to Control group, the Collagen types I, III and their subunits were upregulated (P<0.05), while matrix metalloproteinase (MMP) 2 and MMP9 were downregulated in the aorta of Model group (P<0.05).
CONCLUSIONS
In the animal model of BAPN-induced AAD, collagen types I, III and subunits were increased, while MMP2 and MMP9 were decreased in thoracic aorta, which may lead to stiffness of the aorta and be the cause of dissection.
PubMed: 34790780
DOI: 10.21037/atm-21-4933