Aortic Explants Research Articles

Impact of dietary supplementation of glycocalyx precursors on vascular function in type 2 diabetes.

Degradation of the endothelial glycocalyx in type 2 diabetes (T2D) is thought to contribute to impaired shear stress mechanotransduction, leading to endothelial dysfunction and the development of cardiovascular disease. Herein, we tested the hypothesis that restoration of the endothelial glycocalyx with dietary supplementation of glycocalyx precursors (DSGP, containing glucosamine sulfate, fucoidan, superoxide dismutase, and high molecular weight hyaluronan) improves endothelial function and other indices of vascular function in T2D. First, in db/db mice, we showed that treatment with DSGP (100 mg/kg/day) for four weeks restored endothelial glycocalyx length, as assessed via atomic force microscopy in aortic explants. Restoration of the glycocalyx with DSGP was accompanied by improved flow-mediated dilation (FMD) and reduced arterial stiffness in isolated mesenteric arteries. Further corroborating these findings, treatment of cultured endothelial cells with that same mixture of glycocalyx precursors promoted glycocalyx growth. Next, as an initial step to investigate the translatability of these findings, we conducted a pilot (n=22) double-blinded randomized placebo-controlled clinical trial to assess the effects of DSGP (3,712.5 mg/day) for eight weeks on endothelial glycocalyx integrity and indices of vascular function, including FMD, in Veterans with T2D. Contrary to the hypothesis, DSGP neither enhanced endothelial glycocalyx integrity nor improved vascular function indices relative to placebo. Together, these findings conceptually support the notion that restoration of the endothelial glycocalyx can lead to improvements in vascular function in a mouse model of T2D; however, DSGP as a therapeutic strategy to enhance vascular function in individuals with T2D does not appear to be efficacious.

Aortic valve disease augments vesicular microRNA-145-5p to regulate the calcification of valvular interstitial cells via cellular crosstalk

Abstract Rationale: Aortic valve stenosis (AVS) is a major contributor to cardiovascular death in the elderly population worldwide. MicroRNAs (miRNAs) are highly dysregulated in patients with AVS undergoing surgical aortic valve replacement (SAVR). However, miRNA-dependent mechanisms regulating inflammation and calcification or miRNA-mediated cell-cell crossstalk during the pathogenesis of AVS are still poorly understood. Here, we explored the role of extracellular vesicles (EV)-associated miR-145-5p, which we showed to be highly upregulated upon valvular calcification in AVS in mice and humans. Methods Human TaqMan miRNA arrays identified dysregulated miRNAs in aortic valve tissue explants from AVS patients compared to non-calcified valvular tissue explants of patients undergoing SAVR. Echocardiographic parameters were measured in association with the quantification of dysregulated miRNAs in a murine AVS model. In vitro calcification experiments were performed to explore the effects of EV-miR-145-5p on calcification and crosstalk in valvular cells. To dissect molecular miRNA signatures and their effect on signaling pathways, integrated OMICS analyses were performed. RNA sequencing (RNA-seq), high-throughput transcription factor (TF) and proteome arrays showed that a number of genes, miRNAs, TFs, and proteins are crucial for calcification and apoptosis, which are involved in the pathogenesis of AVS. Results Among several miRNAs dysregulated in valve explants of AVS patients, miR-145-5p was the most highly gender-independently dysregulated miRNA (AUC, 0.780, p-value, 0.01). MiRNA arrays utilizing patient-derived- and murine aortic-stenosis samples demonstrated that the expression of miR-145-5p is significantly upregulated and correlates positively with cardiac function based on echocardiography. In vitro experiments confirmed that miR-145-5p is encapsulated into EVs and shuttled into valvular interstitial cells. Based on the integrated OMICs results, miR-145-5p interrelates with markers of inflammation, calcification, and apoptosis. In vitro calcification experiments demonstrated that miR-145-5p regulates the ALPL gene, a hallmark of calcification in vascular and valvular cells. EV-mediated shuttling of miR-145-5p suppressed the expression of ZEB2, a negative regulator of the ALPL gene, by binding to its 3' untranslated region to inhibit its translation, thereby diminishing the calcification of target valvular interstitial cells. Conclusion Elevated levels of pro-calcific and pro-apoptotic EV-associated miR-145-5p contribute to the progression of AVS via the ZEB2-ALPL axis, which could potentially be therapeutically targeted to minimize the burden of AVS.

An inducible model for medial calcification based on matrix Gla protein deficiency

Calcific deposits in the arterial media have been associated with a number of metabolic and genetic disorders including diabetes, chronic kidney disease and generalized arterial calcification of infancy. The loss of Matrix Gla protein (MGP) leads to medial elastic lamina calcification (elastocalcinosis) in both humans and animal models. While MGP-deficient (Mgp-/-) mice have been used as a reliable model to study medial elastocalcinosis, these mice are difficult to maintain because of their fragility. Also, these mice are unsuitable for long-term calcification studies in relation to age and sex as most often they die prematurely. In order to circumvent these problems we generated Mgp-/-;ApoE-FGF23 mice, which in addition to the ablation of Mgp alleles, carries a transgene expressing the phosphaturic hormone FGF23. Increased FGF23 levels in the circulation and ensuing hypophosphatemia in these mice lead to a complete prevention of medial calcification until late adulthood. Interestingly, upon feeding a high phosphorus diet for 10 days, we were able to induce medial calcification in 3-week-old Mgp-/-;ApoE-FGF23 mice. Our mineral analyses showed that the calcific deposits in these mice were Our mineral analyses showed that the Ca/P % in the calcific deposits in these mice were comparable to that of 5-week-old Mgp-/- mice although the level of crystallinity differed. The aorta explants from Mgp-/-;ApoE-FGF23 mice resulted in elastocalcinosis in the presence of 2mM phosphate in the culture medium which was completely prevented by pyrophosphate analogue alendronate. Mgp-/-;ApoE-FGF23 mice will be suitable for future in vivo or ex vivo studies examining the effects of age, sex and mineralization inhibitors on medial elastocalcinosis.

Prenatal exposure to low doses of benzophenone-3 elicits disruption of cortical vasculature in fetuses through perturbations in Wnt/β-catenin signaling correlating with depression-like behavior in offspring mice

Benzophenone-3 (BP-3), commonly used in personal care products, is routinely detected in environmental and human matrices. Evidence delineates a correlation between gestational BP-3 exposure and emotional and social disorders in children and adolescents. However, sensitive target cells and the mode of action underlying the early responses to environmentally relevant level of BP-3 exposure remain unclear. In this study, 0.3 and 3 mg/kg of BP-3 were administered to pregnant mice. Compared with the control group, the cortical blood vessel development process manifested the highest susceptibility to BP-3 exposure using transcriptomic sequencing at embryonic day 14 (E14). Notably, the diminution in vascular density and tight junction proteins presence was observed in the fetal cortex at E14, concomitant with the suppressed transcriptional activity of genes essential to angiogenesis and barrier formation. Strikingly, the investigation revealed that BP-3 exposure impeded vascular sprouting in aortic ring explants and neuroendothelial migration, implicating the Wnt/β-catenin signaling pathway. Moreover, BP-3 exposure compromised perivascular neural stem cell differentiation. Cortical vascular injury correlated with the exhibition of depression-like behavior in four-week postnatal progeny. These insights underscore the cerebrovasculature as an early sensitive target for low doses of BP-3 exposure, fostering the development of biomarkers and the establishment of the adverse outcome pathway framework for BP-3 hazard evaluation.

1004 Urgent Explant of Infected Aortic Stent Graft in a Patient with Kidney Transplant Using Biological Aortoiliac Reconstruction and a Temporary Axillo-Femoral Perfusion Shunt: 6-Year Follow-Up and Literature Review

Abstract Background Written consent obtained for case report. A 59-year-old male who was 3-months post-EVAR repair under immunosuppression for kidney transplantation and anti-retroviral HIV treatment presented to ED in 2017 with abdominal pain and fever. CTAP revealed pyelonephritis in renal allograft. Blood cultures were positive for staphylococcus epidermidis. PETCT showed high-intensity uptake around endograft. Urgent explant of endograft and insitu biological aorto-biiliac graft reconstruction with bench prepared bilateral long saphenous veins were performed. Results The predicted challenges were locating source of infection, immunosuppressed state, and allograft preservation. Dacron graft was used as temporary perfusion shunt (left axillary artery to right superficial femoral artery) for renal allograft on right external iliac vessels. Endograft was removed via rooftop incision with visceral rotation. Supra-celiac and supra-superior mesenteric artery clamping times were 15 and 35 minutes. The source of infection was from infected appendix proximal to graft with erosion of right external iliac artery resulting in appendectomy in the same operation. Following 12-weeks of OPAT antibiotic-therapy, repeat PETCT revealed low-grade uptake around aortic graft and inflammatory markers were back to baseline. At 6 years in 2023, patient remains clinically well with ∼20% allograft function. Maintaining kidney allograft perfusion in the setting of elective non-infected aortic graft explant was previously reported, but with ENROUTE system (Rasheed et al., 2018). Conclusions The satisfactory long-term outcomes discussed here demonstrated with MDT planning involving vascular surgery, infectious diseases, renal medicine and patient, explant of infected graft with insitu biological graft reconstruction in renal transplant patients presenting with complex aortic-graft infection is feasible.

Impact of aortic root surgery during transcatheter aortic valve explant

BackgroundTranscatheter aortic valve replacement (TAVR) explantation is currently the fastest-growing cardiac surgery procedure. Issues surrounding TAVR explantation and subsequent surgical aortic valve replacement (SAVR), specifically aortic root surgery, merit further investigation. MethodsA retrospective review of an institutional database identified cases of SAVR after TAVR, with or without concomitant aortic root operations, performed between January 1, 2014, and July 1, 2023, identifying 26 patients. Conventional statistical methods were used to compare groups. ResultsThe mean Society of Thoracic Surgeons predicted risk of mortality for aortic valve replacement was 11.1 ± 6.0% in our cohort. Eight of 26 patients (30.8%) had undergone prior cardiac surgery. Concomitant aortic root enlargement or replacement was required in 12 of the 26 patients (46.2%). The time from TAVR to removal was longer for those requiring root operations compared to those who did not (mean, 783 ± 908 days vs 492 ± 486 days; P = .046). There was a trend toward more frequent infective endocarditis in patients requiring root operations (46.2% [n = 5/12] vs 21.4% [n = 3/14]; P = .155). The 30-day mortality was 19.2% (n = 5/26), with an observed-to-expected ratio of 1.72. Mortality was not significantly different between the 2 groups. ConclusionsTAVR explant remains a high-risk procedure, although adding aortic root enlargement/replacement does not appear to amplify the short-term mortality risk when performed at an experienced institution. These results are important when considering lifetime management of aortic stenosis, particularly in low-risk patients likely to require multiple interventions.

Nitric oxide releasing nanofiber stimulates revascularization in response to ischemia via cGMP-dependent protein kinase.

Nitric oxide (NO) promotes angiogenesis via various mechanisms; however, the effective transmission of NO in ischemic diseases is unclear. Herein, we tested whether NO-releasing nanofibers modulate therapeutic angiogenesis in an animal hindlimb ischemia model. Male wild-type C57BL/6 mice with surgically-induced hindlimb ischemia were treated with NO-releasing 3-methylaminopropyltrimethoxysilane (MAP3)-derived or control (i.e., non-NO-releasing) nanofibers, by applying them to the wound for 20 min, three times every two days. The amount of NO from the nanofiber into tissues was assessed by NO fluorometric assay. The activity of cGMP-dependent protein kinase (PKG) was determined by western blot analysis. Perfusion ratios were measured 2, 4, and 14 days after inducing ischemia using laser doppler imaging. On day 4, Immunohistochemistry (IHC) with F4/80 and gelatin zymography were performed. IHC with CD31 was performed on day 14. To determine the angiogenic potential of NO-releasing nanofibers, aorta-ring explants were treated with MAP3 or control fiber for 20 min, and the sprout lengths were examined after 6 days. As per either LDPI (Laser doppler perfusion image) ratio or CD31 capillary density measurement, angiogenesis in the ischemic hindlimb was improved in the MAP3 nanofiber group; further, the total nitrate/nitrite concentration in the adduct muscle increased. The number of macrophage infiltrations and matrix metalloproteinase-9 (MMP-9) activity decreased. Vasodilator-stimulated phosphoprotein (VASP), one of the major substrates for PKG, increased phosphorylation in the MAP3 group. MAP3 nanofiber or NO donor SNAP (s-nitroso-n-acetyl penicillamine)-treated aortic explants showed enhanced sprouting in an ex vivo aortic ring assay, which was partially abrogated by KT5823, a potent inhibitor of PKG. These findings suggest that the novel NO-releasing nanofiber, MAP3 activates PKG and promotes therapeutic angiogenesis in response to hindlimb ischemia.

Oxidation of the actin cytoskeleton regulator cofilin-1 as a mediator of endothelial stiffening and dysfunction in type 2 diabetes

Vascular disease is a feature of type 2 diabetes (T2D) that is caused in part by oxidative stress and endothelial dysfunction. An emerging instigator of endothelial dysfunction is stiffening of the cell, which is mediated by enhanced polymerization of filamentous actin (F-actin). Actin polymerization is regulated by cofilin-1, an actin severing protein that can be phosphorylated or oxidized, leading to its inactivation and loss of severing capability. Yet, the mechanisms contributing to endothelial stiffening in T2D remain largely unknown. Herein, we tested the hypothesis that endothelial stiffening in T2D is mediated by inactivation of cofilin-1, leading to actin polymerization. In support of this hypothesis, human umbilical vein endothelial cells (HUVECs) treated with plasma from subjects with T2D, and the aortic endothelium of diabetic mice (db/db), demonstrate increased cellular stiffness and F-actin presence. Of note, these findings were not associated with enhanced phosphorylation of cofilin-1, suggesting that its inactivation may instead occur through oxidation. Indeed, we show that cofilin-1 can be oxidized by H2O2, a strong oxidizing agent, and that exposure of HUVECs to H2O2 induces F-actin formation. These findings implicate oxidation and inactivation of cofilin-1 as a putative driver of endothelial F-actin formation and cellular stiffening. In further support of the notion that inactivation of cofilin-1 in endothelial cells promotes cytoskeletal remodeling, we show that genetic silencing or pharmacological inhibition of LIM kinase-1 (LIMK-1), a key enzyme responsible for phosphorylating and thus inactivating cofilin-1, reduces F-actin content and cellular stiffness. Congruently, we show that LIMK inhibition reduces endothelial stiffness in aortic explants from db/db mice. It is conceivable that increased endothelial actin polymerization and stiffening impact vasomotor function. As proof-of-concept, we show that intraluminal exposure of isolated arteries to jasplakinolide, a pharmacological inducer of actin polymerization, impairs endothelial-dependent vasodilation, as assessed via flow-mediated dilation (FMD), while endothelium-independent vasodilation remains unaffected. Conversely, cytochalasin D, an inhibitor of actin polymerization, improves FMD, without influencing endothelium-independent vasodilation. Taken together, these findings suggest the existence of a potential new paradigm of T2D-associated endothelial dysfunction whereby oxidative stress inactivates cofilin-1, contributing to F-actin-dependent endothelial stiffening. Moreover, this work supports the idea that LIMK-1 may be considered a potential target for reducing cofilin-1 inactivation and reversing endothelial stiffening in T2D. Funding: R01HL151384, R01HL153264, R01HL137769, and AHA23PRE1020897. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Neuraminidase-3 Inhibition Improves Vascular Function in Diabetic Mice

In type 2 diabetes (T2D), endothelial dysfunction and arterial stiffening play a significant role in the development of cardiovascular disease. A central mediator of vascular dysfunction is degradation of the endothelial glycocalyx, a semipermeable mechanosensitive structure that separates the endothelium from the flow of blood and shear forces associated with it. Neuraminidase, a sialidase that cleaves sialic acid from the terminal branches of glycoproteins and glycolipids, is implicated in glycocalyx degradation. However, its role in mediating vascular dysfunction in the setting of T2D remains relatively unexplored. Herein, we tested the hypothesis that pharmacological inhibition of neuraminidase-3 (Neu3i) improves glycocalyx integrity, ameliorates endothelial dysfunction, and reduces arterial stiffness in diabetes. In support of this hypothesis, we report that, relative to vehicle-treated cells, endothelial cells exposed to Neu3i for 24hr have increased glycocalyx components including sialic acid and N-acetylglucosamine (GlcNAc), one of the amino sugars comprising the N-acetyllactosaminoglycans chains within the glycocalyx, as assessed with fluorescent lectin staining using MAA/Mal I+2 and WGA, respectively. We further show that treatment of diabetic ( i.e., db/db) mice with Neu3i for 28 days reduced aortic pulse wave velocity, with no change in blood pressure, when compared to vehicle-treated mice. Neu3i also reduced the stiffness of aortic explants, as assessed via atomic force microscopy. Excised arteries were also assessed for flow-mediated dilation and vascular stiffness using pressure myography. Diabetic mice treated with Neu3i had increased flow-mediated dilation and reduced incremental modulus of elasticity, indicative of improved endothelial function and reduced arterial stiffness. Collectively, these data support the hypothesis that Neu3 is a potential therapeutic target for the amelioration of vascular dysfunction in T2D. National Institutes of Health grant: R01HL153264 to LM-L and JP. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Bonanza of Transcatheter Aortic Valve Explants Contributes to Surgeon Misery

Bonanza of Transcatheter Aortic Valve Explants Contributes to Surgeon Misery

Twenty-three Years of Experience in Aortic Endograft Explantation

Twenty-three Years of Experience in Aortic Endograft Explantation

FRI131 Abrogation Of Transglutaminase 2 In Myeloid Cells Ameliorates Angiotensin II Induced Vascular Stiffness In Female Mice

Abstract Disclosure: H. Naz: None. A.R. Aroor: None. A.T. Whaley-Connell: None. J. Guanghong: None. J.L. Hulse: None. C.M. Manrique Acevedo: None. G. Lastra: None. Introduction: Chronic low-grade inflammation and vascular stiffening contribute to cardiovascular disease (CVD) in obese and insulin-resistant women. Under these conditions, inappropriate activation of the renin angiotensin aldosterone system (RAAS) stimulates Transglutaminase 2 (TG2), a ubiquitously expressed enzyme that promotes vascular stiffening and remodeling. Additionally, Th17 cells contribute to CVD development in the setting of RAAS activation. However, it is unclear how TG2 activation mediates maladaptive immune responses associated with vascular stiffening in women. In this study, we hypothesize that TG2 abrogation inhibits Ang II-induced vascular stiffness in females by modulating Th17 immunity. Methods: 12-week-old female mice lacking TG2 expression (MyTG2KO) in myeloid cells, and control littermates (LM) were infused with Ang-II (1.4 mg/kg/day) for 2 weeks (n=4-8 per group). Prior to sacrifice, systolic blood pressure (SBP) was measured by tail-cuff method. Aortic stiffness was assessed by atomic force microscopy of thoracic aorta explants, and TG2 activity was examined by Alexa FluorTM 488 cadaverine. Analysis of Th17 cells in blood, spleen and epididymal fat (epi-fat) was done by flow cytometry. Cytokine bead array was used to measure cytokine levels in serum, RT-PCR was used to analyze cytokines in aortic tissue and TG2 knockdown efficiency in myeloid cells. Immunohistochemistry was used to examine fibrosis in aorta. Results: SBP was decreased in MyTG2KO-Ang-II as compared to LM-Ang-II cohort (129.6±5.6 vs 152.5 ±2 mmHg; p=0.04). TG2 mRNA expression in macrophages was lower in MyTG2KO mice as compared to LM (p=0.002). TG2 activity in aortic tissue increased in LM-Ang-II as compared to LM-saline (p=0.004) but was significantly lower in MyTG2KO-Ang-II mice (p=0.02). Aortic stiffness was lower in MyTG2KO-Ang-II mice relative to LM-Ang-II (4.0±0.6 vs 10.3±2.4 kPa; p=0.02). Compared to LM-Ang-II, MyTG2KO-Ang-II mice also had decreased Th17 lymphocytes (CD4+IL-17A+) in blood (3.5±0.2 vs 5.8 ±0.4 %; p=<0.0001), spleen (4.7±0.4 vs 7.1 ±0.5 %; p=0.004) and epi-fat (4.7±0.6 vs 6.8 ±0.5 %; p=0.02). MyTG2KO-Ang II mice also had significant lower levels of proinflammatory cytokines (TNF-a, IL6, IL17A, INF-g) in serum and mRNA expression of proinflammatory cytokines compared to LM-Ang-II mice and decreased total macrophage infiltration (CD68+) in the aorta. Ang-II treated MyTG2KO mice group also exhibited reduced fibrosis in the aorta relative to LM-Ang-II (p=0.003). Conclusion: The results demonstrate that abrogating TG2 in myeloid cells in female mice substantially reduces blood pressure, proinflammatory cytokines, and Th17 immune responses induced by Ang-II. Our findings have potential clinical implications for the prevention and management of CVD in women. Presentation: Friday, June 16, 2023

Type 1 Diabetes Impairs Endothelium-Dependent Relaxation Via Increasing Endothelial Cell Glycolysis Through Advanced Glycation End Products, PFKFB3, and Nox1-Mediated Mechanisms.

Type 1 diabetes (T1D) is a major cause of endothelial dysfunction. Although cellular bioenergetics has been identified as a new regulator of vascular function, whether glycolysis, the primary bioenergetic pathway in endothelial cells (EC), regulates vascular tone and contributes to impaired endothelium-dependent relaxation (EDR) in T1D remains unknown. Experiments were conducted in Akita mice with intact or selective deficiency in EC PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3), the main regulator of glycolysis. Seahorse analyzer and myography were employed to measure glycolysis and mitochondrial respiration, and EDR, respectively, in aortic explants. EC PFKFB3 (Ad-PFKFB3) and glycolysis (Ad-GlycoHi) were increased in situ via adenoviral transduction. T1D increased EC glycolysis and elevated EC expression of PFKFB3 and NADPH oxidase Nox1 (NADPH oxidase homolog 1). Functionally, pharmacological and genetic inhibition of PFKFB3 restored EDR in T1D, while in situ aorta EC transduction with Ad-PFKFB3 or Ad-GlycoHi reproduced the impaired EDR associated with T1D. Nox1 inhibition restored EDR in aortic rings from Akita mice, as well as in Ad-PFKFB3-transduced aorta EC and lactate-treated wild-type aortas. T1D increased the expression of the advanced glycation end product precursor methylglyoxal in the aortas. Exposure of the aortas to methylglyoxal impaired EDR, which was prevented by PFKFB3 inhibition. T1D and exposure to methylglyoxal increased EC expression of HIF1α (hypoxia-inducible factor 1α), whose inhibition blunted methylglyoxal-mediated EC PFKFB3 upregulation. EC bioenergetics, namely glycolysis, is a new regulator of vasomotion and excess glycolysis, a novel mechanism of endothelial dysfunction in T1D. We introduce excess methylglyoxal, HIF1α, and PFKFB3 as major effectors in T1D-mediated increased EC glycolysis.

A computational bridge between traction force microscopy and tissue contraction.

Arterial wall active mechanics are driven by resident smooth muscle cells, which respond to biological, chemical, and mechanical stimuli and activate their cytoskeletal machinery to generate contractile stresses. The cellular mechanoresponse is sensitive to environmental perturbations, often leading to maladaptation and disease progression. When investigated at the single cell scale, however, these perturbations do not consistently result in phenotypes observed at the tissue scale. Here, a multiscale model is introduced that translates microscale contractility signaling into a macroscale, tissue-level response. The microscale framework incorporates a biochemical signaling network along with characterization of fiber networks that govern the anisotropic mechanics of vascular tissue. By incorporating both biochemical and mechanical components, the model is more flexible and more broadly applicable to physiological and pathological conditions. The model can be applied to both cell and tissue scale systems, allowing for the analysis of in vitro, traction force microscopy and ex vivo, isometric contraction experiments in parallel. When applied to aortic explant rings and isolated smooth muscle cells, the model predicts that active contractility is not a function of stretch at intermediate strain. The model also successfully predicts cell-scale and tissue-scale contractility and matches experimentally observed behaviors, including the hypercontractile phenotype caused by chronic hyperglycemia. The connection of the microscale framework to the macroscale through the multiscale model presents a framework that can translate the wealth of information already collected at the cell scale to tissue scale phenotypes, potentially easing the development of smooth muscle cell-targeting therapeutics.

Neutrophil extracellular traps promote angiogenesis in gastric cancer

Although antiangiogenic therapy has been used in gastric cancer, disease progression due to drug resistance remains common. Neutrophils play an important role in the occurrence and progression of cancer via neutrophil extracellular traps (NETs). However, few studies have investigated angiogenic regulation in gastric cancer. We aimed to determine the role of NETs in promoting angiogenesis in gastric cancer. Multiple immunohistochemical staining was used to analyze the spatial distribution of NETs and microvessels in patient tissue samples. A mouse subcutaneous tumor model was established to determine the effect of NETs on tumor growth, and changes in microvessel density were observed via immunohistochemical staining. We screened differentially expressed proteins in HUVECs stimulated by NETs via proteomics. Cell Counting Kit-8, EdU labeling, and tubule formation assays were used to verify the effect of NETs on HUVEC proliferation, migration, and tubule formation. Blocking NETs, which was related to decreased microvessel density, significantly inhibited tumor growth in the murine subcutaneous tumor model. Compared with those of the control group, tumor volume and mass among mice in the inhibition group decreased by 61.3% and 77.9%, respectively. The NET-DNA receptor CCDC25 was expressed in HUVECs, providing a platform for NETs to promote HUVEC proliferation, migration, and tubulation. In an in vitro rat aortic explant model, NETs induced HUVEC proliferation, survival, and chemotaxis, which were not significantly different from those observed in the VEGF stimulation group. Our results confirm that NETs promote angiogenesis in gastric cancer, providing a theoretical basis for identifying new anti-vascular therapeutic targets.Graphical 1Sf8jYXSegxbAWaiHcqZYYVideo

P228 MINOCA/TYPE 2 IMA: WHEN WE HAVE TO EXIT FROM STANDARD DIAGNOSTIC FLOW–CHART

Abstract MINOCA is an Acute Myocardial Infarction (AMI), defined on the basis of Fouth Universal Definition, in absence of epicardial coronaries stenosis >50%. This definition is very broad, including typical mechanisms of type 1 and type 2 AMI. Diagnostic flow–chart recommended by ESC and AHA includes imaging tests, coronary physiology and cardiac MRI. Here we present the case of 71–year–old man who underwent aortic bioprosthesis implantation (Trifecta n.25) and atrial septal defect (ASD) closure in 2019. In December 2022, the patient arrived in the Emergency Department (ED) with anterior STEMI, apical akinesia and angiographic evidence of distal left anterior descending (LAD) artery occlusion. Whereas angiographic feature was compatible with an embolic phenomenon, we performed in the 1st day transesophageal echocardiogram (TEE) that showed a voluminous, rounded mass (maximum diameter 1.2 cm) isoechoic, mobile, adherent to the aortic side of left coronary cusp. Despite the absence of clinical features of an acute infection (apyrexia and negative CRP/PCT) and the atypical mass localization for endocarditis, we took 3 sets of blood cultures and we required an immediate cardiac surgical consultation. In consideration of high estimated embolic risk, patient underwent urgent cardiac surgery with aortic bioprosthesis explantation, annular malacia (probable abscess) explantation and Carpentier n.23 biological prosthesis implant. Histological examination of the removed mass showed exudative material with intense acute inflammation. According to counseling of infectious disease specialist, we started an empiric antibiotic therapy with intravenous vancomycin and gentamicin. Given persistence of 3rd degree atrioventrocular block, patient underwent definitive pacemaker implantation. Cultures on blood and on explanted valve were negative and patient was discharged without further complications after 4 weeks of antibiotic therapy. In our opinion, this clinical case underlines the importance of an individualized diagnostic–therapeutic approach in patients with MINOCA, also considering rare etiologies and involving various medical specialist (clinical cardiologist, echocardiographer, surgeon).

Targeted pharmacological inhibition of neuraminidase-3 ameliorates vascular dysfunction in diabetic mice

In type 2 diabetes (T2D), endothelial dysfunction and arterial stiffening play a significant role in the development of cardiovascular disease. A central mediator of vascular dysfunction is degradation of the endothelial glycocalyx, a semipermeable mechanosensitive structure that separates the endothelium from the flow of blood and shear forces associated with it. Neuraminidase, a sialidase that cleaves sialic acid from the terminal branches of glycoproteins and glycolipids, is implicated in glycocalyx degradation. However, its role in mediating vascular dysfunction in the setting of T2D remains relatively unexplored. Herein we tested the hypothesis that increased neuraminidase-3 (Neu3) activity impairs vascular function, while its targeted inhibition improves it in diabetes. In support of this hypothesis, we report that mice overexpressing Neu3 exhibit increased blood pressure and pulse wave velocity, indicative of increased arterial stiffness. Furthermore, we show that pharmacological inhibition of Neu3 for 28 days in diabetic ( i.e., db/db) mice (vs. vehicle control) resulted in reduced pulse wave velocity, with no change in blood pressure. Neu3 inhibition also reduced stiffness in aortic explants, as assessed via atomic force microscopy. Excised arteries were also assessed for flow-mediated dilation and vascular stiffness using pressure myography. Arteries from diabetic mice treated with the Neu3 inhibitor had increased flow-mediated dilation and reduced incremental modulus of elasticity, indicative of improved endothelial function and reduced arterial stiffness. Collectively, these data support the hypothesis that Neu3 is a potential therapeutic target for the amelioration of vascular dysfunction in T2D. National Institutes of Health grant: R01HL153264 to LM-L and JP This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Single Centre Experience with Infected Abdominal Aortic Endograft Explantation

Single Centre Experience with Infected Abdominal Aortic Endograft Explantation

A Straightforward Cytometry-Based Protocol for the Comprehensive Analysis of the Inflammatory Valve Infiltrate in Aortic Stenosis.

Aortic stenosis (AS) is a frequent cardiac disease in old individuals, characterized by valvular calcification, fibrosis, and inflammation. Recent studies suggest that AS is an active inflammatory atherosclerotic-like process. Particularly, it has been suggested that several immune cell types, present in the valve infiltrate, contribute to its degeneration and to the progression toward stenosis. Furthermore, the infiltrating T cell subpopulations mainly consist of oligoclonal expansions, probably specific for persistent antigens. Thus, the characterization of the cells implicated in the aortic valve calcification and the analysis of the antigens to which those cells respond to is of utmost importance to develop new therapies alternative to the replacement of the valve itself. However, calcified aortic valves have been only studied so far by histological and immunohistochemical methods, unable to render an in-depth phenotypical and functional cell profiling. Here we present, for the first time, a simple and efficient cytometry-based protocol that allows the identification and quantification of infiltrating inflammatory leukocytes in aortic valve explants. Our cytometry protocol saves time and facilitates the simultaneous analysis of numerous surface and intracellular cell markers and may well be also applied to the study of other cardiac diseases with an inflammatory component.

Clinical outcomes of in situ graft reconstruction in treating infected abdominal aortic stent grafts following endovascular aortic aneurysm repair: a single-center experience.

This study aimed to review our experience with the explantation of infected endovascular aneurysm repair (EVAR) grafts. This single-center, retrospective, observational study analyzed the data of 12 consecutive patients who underwent infected aortic stent graft explantation following EVAR between January 1, 2010 and December 31, 2019, of which 11 underwent in situ graft reconstruction following graft removal. The presentation symptoms, infection route, original pathology of abdominal aortic aneurysms (AAA), graft materials, and clinical outcomes were analyzed. Six patients underwent total explantation, whereas 5 underwent removal of only the fabric portions. For in situ reconstructions, prosthetic grafts and banked allografts were used in 8 and 3 patients, respectively. Four mechanisms of graft infection were noted in 11 patients: 4 had bacteremia from systemic infections, 3 had persistent infections following EVAR of primary infected AAA, 3 had ascending infections from adjacent abscesses, and 1 had an aneurysm sac erosion resulting in an aortoenteric fistula. No infection-related postoperative complications or reinfections occurred during the mean 65.27-month (standard deviation, ±52.51) follow-up period. One patient died postoperatively because of the rupture of the proximal aortic wall pseudoaneurysm that had occurred during forceful bare stent removal. Regardless of graft material, in situ graft reconstruction is safe for interposition in treating an infected aortic stent graft following EVAR. In our experience, the residual bare stent is no longer a risk factor for reinfection. Therefore, it is important not to injure the proximal aortic wall when removing the bare stent by force.