Animal Experimental Study of Bioabsorbable Left Atrial Appendage Occluder.

Left atrial appendage (LAA) closure can prevent stroke in high-risk patients with atrial fibrillation.A bioabsorbable LAA occluder made of degradable polymer materials, such as polydioxanone (PDO) and poly-L-lactic acid (PLA), and nitinol wire was used. Occluders were successfully implanted in 18 Chinese rural dogs, 2 of which died within 48 hours after operation due to pericardial tamponade and hemorrhage, respectively. Follow-up observation was performed after transcatheter LAA closure. New tissue was found on the surface of the occluder 2 months after operation. No adjacent structures such as the mitral valve and the left superior pulmonary vein were affected by the occluder discs. Hematoxylin and eosin (HE) staining was performed at 3 months after operation, which showed intact intimal structure on the occluder surface, and unabsorbed PDO and PLA were observed. Scanning electron microscopy showed irregular arrangement of endothelial cells. New endothelial tissue was observed to completely cover the occluder at 6 months after operation. Most PDOs were replaced by fibrous connective tissue, and scanning electron microscopy showed regularly arranged endothelial cells. Pathological examination at 12 months showed only a small remnant of PDO. The gross specimens of the liver, spleen, and kidneys and pathological examination did not indicate thromboembolism.The bioabsorbable LAA occluder made of PDO, PLA, and nitinol wire was safe and effective for the occlusion of LAA in dogs. The surface of the occluder was endothelialized half a year after operation. The absorbable materials of the occluder were degraded after 1 year.

Epigenetic regulation of vascular smooth muscle cell phenotypic switch and neointimal formation by PRMT5.

AIMS: Phenotypic transition of vascular smooth muscle cells (VSMCs) from a contractile to a synthetic state is involved in the development of cardiovascular diseases, including atherosclerosis, hypertension, and post-angioplasty restenosis. Arginine methylation catalyzed by protein arginine methyltransferases (PRMTs) has been implicated in multiple cellular processes, however, its role in VSMC biology remains undetermined. The objective of this study was to determine the role of PRMTs in VSMC phenotypic switch and vascular remodelling after injury. METHODS AND RESULTS: Our results show that PRMT5 is the most abundantly expressed PRMT in human aortic SMCs, and its expression is up-regulated in platelet-derived growth factor (PDGF)-stimulated VSMCs, human atherosclerotic lesions, and rat carotid arteries after injury, as determined by western blot and immunohistochemical staining. PRMT5 overexpression inhibits the expression of SMC marker genes and promotes VSMC proliferation and migration, while silencing PRMT5 exerts the opposite effects. Mechanistically, we found that PRMT5 overexpression led to histone di-methylation of H3R8 and H4R3, which in turn attenuates acetylation of H3K9 and H4, thus limiting recruitment of the SRF/myocardin complexes to the CArG boxes of SMC marker genes. Furthermore, both SMC-specific deletion of PRMT5 in mice and local delivery of lentivirus expressing shPRMT5 to rat carotid arteries significantly attenuated neointimal formation after injury. Likewise, pharmacological inhibition of PRMT5 by EPZ015666 markedly inhibited carotid artery ligation-induced neointimal formation in mice. CONCLUSIONS: Our results identify PRMT5 as a novel regulator in VSMC phenotypic switch and suggest that inhibition of PRMT5 may represent an effective therapeutic strategy for proliferative vascular diseases.

Investigation of the Effects of Some Cardiovascular Drugs on Angiogenesis by Transgenic Zebrafish.

Introduction: Angiogenesis contributes to the pathophysiology of cardiovascular disease (CVD). Some cardiovascular drugs used in the treatment of CVD have an effect on the process of angiogenesis. Methods: Transgenic Tg (flk1: EGFP) zebrafish embryos were used to identify the effects of some cardiovascular drugs on angiogenesis during vertebral development in vivo. Zebrafish embryos at a one-cell stage or two-cell stage were cultured with embryo medium containing cardiovascular drugs at a final solvent concentration of 0.5% (V/V) dimethyl sulfoxide (DMSO) for 24 hours in 24-well plates. Results: We found that 6 drugs including isosorbide mononitrate, amlodipine, bisoprolol fumarate, carvedilol, irbesartan, and rosuvastatin calcium may affect angiogenesis by vascular endothelial growth factor (VEGF) signaling pathway. Conclusion: These new findings of some cardiovascular drugs should improve the treatment of cardiovascular diseases.

Establishment of a lipid metabolism disorder model in ApoEb mutant zebrafish.

BACKGROUND AND AIMS: ApoEb is a zebrafish homologous to mammalian ApoE, whose deficiency would lead to lipid metabolism disorders (LMDs) like atherosclerosis. We attempted to knock out the zebrafish ApoEb, then establish a zebrafish model with LMD. METHODS: ApoEb was knocked out using the CRISPR/Cas9 system, and the accumulation of lipids was confirmed by Oil Red O staining, confocal imaging, and lipid measurements. The lipid-lowering effects of simvastatin (SIM), ezetimibe (EZE) and Xuezhikang (XZK), an extract derived from red yeast rice, were evaluated through in vivo imaging in zebrafish larvae. RESULTS: In the ApoEb mutant, significant vascular lipid deposition occurred, and lipid measurement performed in the whole-body homogenate of larvae and adult plasma showed significantly increased lipid levels. SIM, EZE and XZK apparently relieved hyperlipidemia in ApoEb mutants, and XZK had a significant inhibitory effect on the recruitment of neutrophils and macrophages. CONCLUSIONS: In this study, an LMD model has been established in ApoEb mutant zebrafish. We suggest that this versatile model could be applied in studying hypercholesterolemia and related vascular pathology in the context of early atherosclerosis, as well as the physiological function of ApoE.

A newly designed disk-lobe occluder with isogenous barbs for left atrial appendage closure: Initial multicenter experience.

Background: Although the implant success rate of left atrial appendage closure (LAAC) has increased and complications have decreased over time, there are still anatomically and technically complicated cases where novel LAA occluders may simplify the procedure and thus might potentially improve the clinical outcome. Objectives: This study aimed to assess the safety and efficacy of the newly designed device with isogenous barbs in LAAC. Methods: Eight centers in China participated in this prospective study from July 2016 to April 2018. Peri- and post-procedural safety and efficacy were evaluated through scheduled follow-ups and transesophageal echocardiography (TEE). Results: A total of 175 patients with a mean age of 68.4 ± 9.2 years old, a mean CHA2DS2-VASc score of 4.7 ± 1.8, and a mean HAS-BLED score of 3.2 ± 1.3, were included. The device was successfully implanted in 173 patients (98.9%). The device size ranged from 18 to 34 mm. Clinically relevant pericardial effusion (PEF) in the perioperative period, occurred in 3 patients (1.7%). TEE follow-up was available in 167 (96.5%) patients at 12-month. During follow-up, 9 patients suffered serious adverse event: 4 death (2.3%), 1 ischemic stroke (0.6%), and 2 gastro-intestinal bleeding (1.2%) and 2 device-related thrombus (DRT) (1.2%). Estimated annual thromboembolism rate reduced by 90% and estimated annual major bleeding rate reduced by 81% after LAAC with the newly designed device. Conclusion: The newly designed device with isogenous barbs for LAAC could be performed effectively with a low incidence of adverse events and a high incidence of anatomic closure.

An updated meta-analysis of device related thrombus following left atrial appendage closure in patients with atrial fibrillation.

Aims: Device related thrombus (DRT) is a known complication of left atrial appendage closure (LAAC). However, the relation between DRT and elevated risk of ischemic events remains controversial. This study is sought to reassessed the incidence of DRT following LAAC and the relation between DRT and elevated risk of ischemic stroke and systemic embolism (SE) with latest clinical trials included. Methods: The PubMed, Embase, and Cochrane Library databases were systematically searched from their inception until April 2022 for studies that reported the incidence of DRT and compared the incidence of both stroke and SE between DRT patients and non-DRT patients. Results: In 59 eligible studies, the incidence of DRT was 366/12,845 (2.8%, ranging from 0 to 11%, I 2 = 64%). The incidence of DRT was not statistically different between single-seal device (SS) and dual-seal device (DS) in subgroup analysis [171/6,190 (2.8%) vs. 78/3,023 (3.6%); p = 0.93]. The pooled incidence of stroke (26 studies, 7,827 patients) in patients with and without DRT was 11.5% in DRT patients and 2.9% among non-DRT patients (OR: 5.08; 95% CI = 3.47-7.44). In the sensitivity analysis, DRT was associated with higher rate of stroke (12.1 vs. 3.2%; OR: 4.14; 95% CI = 2.69-6.38) and SE (16.0 vs. 3.8%; OR: 4.48; 95% CI = 3.04-6.62). Conclusion: The incidence of DRT was low and similar between SS and DS devices. DRT was associated with increased rates of ischemic events. The occurrence rate of ischemic events associated DRT was comparable between two occlusion mechanism devices. Systematic review registration: [https://www.crd.york.ac.uk/], identifier [CRD42022326179].

Improvement of LV Reverse Remodeling Using Dynamic Programming of Fusion-Optimized Atrioventricular Intervals in Cardiac Resynchronization Therapy.

Background: The patient-tailored SyncAV algorithm shortens the QRS duration (QRSd) beyond what conventional biventricular (BiV) pacing can. However, evidence of the ability of SyncAV to improve the cardiac resynchronization therapy (CRT) response is lacking. The aim of this study was to evaluate the impact of CRT enhanced by SyncAV on echocardiographic and clinical responses. Methods and Results: Consecutive heart failure (HF) patients from three centers treated with a quadripolar CRT system (Abbott) were enrolled. The total of 122 patients were divided into BiV+SyncAV (n = 68) and BiV groups (n = 54) according to whether they underwent CRT with or without SyncAV. Electrocardiographic, echocardiographic, and clinical data were assessed at baseline and during follow-up. Echocardiographic response to CRT was defined as a ≥15% decrease in left ventricular end-systolic volume (LVESV), and clinical response was defined as a NYHA class reduction of ≥1. At the 6-month follow-up, the baseline QRSd and LVESV decreased more significantly in the BiV+SyncAV than in the BiV group (QRSd -36.25 ± 16.33 vs. -22.72 ± 18.75 ms, P < 0.001; LVESV -54.19 ± 38.87 vs. -25.37 ± 36.48 ml, P < 0.001). Compared to the BiV group, more patients in the BiV+SyncAV group were classified as echocardiographic (82.35 vs. 64.81%; P = 0.036) and clinical responders (83.82 vs. 66.67%; P = 0.033). During follow-up, no deaths due to HF deterioration or severe procedure related complications occurred. Conclusion: Compared to BiV pacing, BiV combined with SyncAV leads to a more significant reduction in QRSd and improves LV remodeling and long-term outcomes in HF patients treated with CRT.

MicroRNA-663 prevents monocrotaline-induced pulmonary arterial hypertension by targeting TGF-ß1/smad2/3 signaling.

OBJECTIVE: Pulmonary vascular remodeling due to excessive growth factor production and pulmonary artery smooth muscle cells (PASMCs) proliferation is the hallmark feature of pulmonary arterial hypertension (PAH). Recent studies suggest that miR-663 is a potent modulator for tumorigenesis and atherosclerosis. However, whether miR-663 involves in pulmonary vascular remodeling is still unclear. METHODS AND RESULTS: By using quantitative RT-PCR, we found that miR-663 was highly expressed in normal human PASMCs. In contrast, circulating level of miR-663 dramatically reduced in PAH patients. In addition, in situ hybridization showed that expression of miR-663 was decreased in pulmonary vasculature of PAH patients. Furthermore, MTT and cell scratch-wound assay showed that transfection of miR-663 mimics significantly inhibited platelet derived growth factor (PDGF)-induced PASMCs proliferation and migration, while knockdown of miR-663 expression enhanced these effects. Mechanistically, dual-luciferase reporter assay revealed that miR-663 directly targets the 3'UTR of TGF-ß1. Moreover, western blots and ELISA results showed that miR-663 decreased PDGF-induced TGF-ß1 expression and secretion, which in turn suppressed the downstream smad2/3 phosphorylation and collagen I expression. Finally, intratracheal instillation of adeno-miR-663 efficiently inhibited the development of pulmonary vascular remodeling and right ventricular hypertrophy in monocrotaline (MCT)-induced PAH rat models. CONCLUSION: These results indicate that miR-663 is a potential biomarker for PAH. MiR-663 decreases PDGF-BB-induced PASMCs proliferation and prevents pulmonary vascular remodeling and right ventricular hypertrophy in MCT-PAH by targeting TGF-ß1/smad2/3 signaling. These findings suggest that miR-663 may represent as an attractive approach for the diagnosis and treatment for PAH.

The Application and Teaching Value of a Ventricular Septal Defect Canine Model Established by Transcatheter Puncture.

This study aimed to improve and further explore a ventricular septal defect (VSD) canine model on the basis of the transcatheter puncture method and to evaluate its application and teaching value.In order to lessen the complications of VSD closure, it is necessary to improve the currently available treatment devices using appropriate animal models.In this study, we used 16 healthy adult canines as our models. After anesthesia, the VSD puncture was performed, followed by balloon dilatation of the perforation. VSD was confirmed by angiography. The venous-artery orbit was established, and the VSD was then closed once the catheter and occluder were across the defect.Of the experimental canines, 14 of the 16 canines were successfully modeled, giving a success rate of 87.5%. The canines underwent an immediate creation of a venous-artery orbit for teaching practice and were implanted with an occluder during the procedure. After 4 weeks, 13 canines survived. As per our findings, most VSD types established by the puncture were perimembranous (10 of 13, 77%).The current model has a high success rate. The model can not only avoid the risk of infection and hemodynamic disorders associated with an open thoracotomy, but can also be effectively used in evaluating the impact of occluders. It can also directly measure the parameters of the devices during the procedure, thus having a very high experimental and teaching value.

OCT4 regulated neointimal formation in injured mouse arteries by matrix metalloproteinase 2-mediated smooth muscle cells proliferation and migration.

The excessive proliferation and migration of vascular smooth muscle cells (VSMCs) play vital roles in neointimal hyperplasia and vascular restenosis. In the present study, we aimed to investigate the function and mechanism of octamer-binding transcription factor 4 (OCT4, a key transcription factor for maintaining stem cells in de-differentiated state) on neointima formation in response to vascular injury. Quantitative reverse-transcription polymerase chain reaction and western blot results displayed a significant increase of OCT4 levels in injured carotid arteries. Immunohistochemistry and immunofluorescence assays confirmed that the increased OCT4 expression was primarily localized in α-SMA-positive VSMCs from neointima, and colocalized with PCNA in the nuclei of VSMCs. Adenovirus-mediated OCT4 overexpression in injured carotid arteries exacerbated intimal thickening, while OCT4 knockdown significantly inhibited intimal thickening. In-vitro experiments confirmed that the increased OCT4 expression in VMSCs could be induced by platelet-derived growth factor-BB (PDGF-BB) in a time-dependent manner. Overexpression of OCT4 greatly promoted VSMCs proliferation and migration, while OCT4 knockdown significantly retarded the PDGF-BB-induced excessive proliferation and migration of VSMCs. Bioinformatics analysis, dual-luciferase reporter assay, and chromatin immunoprecipitation assay confirmed that OCT4 could upregulate matrix metalloproteinases 2 (MMP2) expression through promoting its transcription. Moreover, knockdown of MMP2 significantly attenuated OCT4-mediated VSMCs proliferation and migration. These results indicated that OCT4 facilitated neointimal formation in response to vascular injury by MMP2-mediated VSMCs proliferation and migration, and targeting OCT4 in VSMCs might be a novel therapeutic strategy for vascular restenosis.

Zfp36l1b protects angiogenesis through Notch1b/Dll4 and Vegfa regulation in zebrafish.

BACKGROUND AND AIMS: Angiogenesis is a key process for establishing functional vasculature during embryogenesis and involves different signaling mechanisms. The RNA binding protein Zfp36l1 was reported to be involved in various diseases in different species, including cardiovascular diseases. However, whether Zfp36l1b, one of the 2 paralogs of Zfp36l1 in zebrafish, works like mammalian Zfp36l1, and if the molecular mechanisms are different remains unclear. Here, we show that Zfp36l1b plays a crucial protective role in angiogenesis of zebrafish embryos. METHODS: We used transparent transgenic and wild-type zebrafish larvae to dynamically investigate the early stage of angiogenesis with confocal in vivo, after the knockdown of Zfp36l1b by morpholinos (MOs). In situ hybridization and fluorescence-activated cell sorting were performed to detect Zfp36l1b expression. mRNA rescue and CRISPR/Cas9 knockdown, and luciferase reporter experiments were performed to further explore the role of Zfp36l1b in angiogenesis. RESULTS: We found that knockdown of Zfp36l1b led to defected angiogenesis in intersomitic vessels and sub-intestinal veins (SIVs), which could be rescued by the addition of Zfp36l1b mRNA. Moreover, knockdown of Zfp36l1b suppressed Notch1b expression, while knockdown of Notch1b resulted in a partial relief of angiogenesis defects induced by Zfp36l1b down-regulation. Besides, Zfp36l1b knockdown alleviated the excessive branch of SIVs caused by Vegfa over-expression. CONCLUSIONS: Our results show that Zfp36l1b is responsible for establishing normal vessel circuits by affecting the extension of endothelial tip cells filopodia and the proliferation of endothelial cells partly through Notch1b/Fll4 suppression and synergistic function with Vegfa.

Isosorbide mononitrate promotes angiogenesis in embryonic development of zebrafish.

Coronary heart disease (CHD) is a leading cause of death worldwide, and angiogenesis plays important roles in CHD. Thus, in the present study, the angiogenic efficacy of four common cardiovascular medicines (aspirin, pravastatin, metoprolol and isosorbide mononitrate (ISMN)) was determined by the number and length of zebrafish intersegmental vessels (ISVs) after immersing zebrafish embryos in different medicines. Results showed that ISMN significantly increased the length and number of ISVs. ISMN is a long-acting nitrate ester drug. It has been used as a vasodilator to dilate arteries and veins to reduce the cardiac preload and postload. However, the effect of ISMN on angiogenesis remains unclear. Thus, by in vitro experiments, the angiogenic mechanism of ISMN was evaluated through detecting the viability and proliferation of human umbilical vein endothelial cells (HUVECs) and the expression of angiogenesis-related genes and miRNAs. Results indicated that ISMN could increase the viability and proliferation of HUVECs by decreasing apoptosis, and elevated the expressions of vedf, kdrl, pdgfr in zebrafish embryos. Furthermore, the expressions of miR-126, miR-130a and miR-210 were also regulated in ISMN-treated HUVECs. In conclusion, ISMN could promote angiogenesis in zebrafish embryos and HUVECs, implying ISMN may be a potential therapeutic in treating angiogenesis-related diseases.

Long-Term Follow-Up of Transthoracic Echocardiography-Guided Transcatheter Closure of Large Atrial Septal Defects (≥ 30 mm) Using the SHSMA Occluder.

Transcatheter closure of large atrial septal defects (ASDs) remains controversial. The aim of this study was to evaluate the feasibility and safety of transthoracic echocardiography (TTE)-guided transcatheter closure of large ASDs. Patients with large secundum ASDs (≥ 30 mm) who underwent device closure were retrospectively reviewed. TTE was performed to guide ASD occluder positioning and assess the immediate and long-term outcomes. A total of 60 patients (median age 43.5 years, range 15-78 years) were enrolled in the study. The median ASD size was 35 mm (range 30-42 mm). Mild to moderate pulmonary hypertension was observed in 36 patients (60%). Thirty-one patients (51.7%) had one short rim, and 18 patients (30.0%) had two deficient rims. Placement of the device was successful in 57 patients (95%), and the median device size was 42 mm (range 40-50 mm). Dislodgement of the device occurred in three patients with two deficient rims: a larger device was redeployed in one case, and two patients required surgical repair. During a median follow-up of 37 months (range 6-83 months), no residual shunts, erosion, or embolization were noted, and pulmonary hypertension resolved in 75% of the patients. Thus t vast majority (95%) of large ASDs can be successfully closed percutaneously using the Chinese-made Shanghai Shape Memory Alloy (SHSMA) occluder under TTE guidance. Long-term follow-up showed that transcatheter closure could become a safe and effective alternative to surgery in select large ASDs.

miR­20b inhibits the senescence of human umbilical vein endothelial cells through regulating the Wnt/ß­catenin pathway via the TXNIP/NLRP3 axis.

Endothelial cell senescence is closely related to the occurrence of cardiovascular diseases and microRNAs (miRNAs/miRs) are considered as therapeutic targets for cardiovascular disease. The current study aimed to investigate the role of miR­20b in the senescence process of endothelial cells and its underlying mechanism. Cell viability, proportion of senescent cells and the cell cycle were respectively determined by Cell Counting Kit­8, SA­ß­galactosidase and flow cytometry. The relative expressions of mRNA and protein were detected by reverse transcription­quantitative polymerase chain reaction and western blotting, respectively. The possible target genes and binding sites of miR­20b were predicted using Targetscan and further verified by dual luciferase reporter assay. The present study found that H2O2 inhibited cell viability, caused cell cycle arrest in G1 phase, decreased miR­20b level and induced cell senescence. Moreover, high expression of miR­20b promoted cell viability and reduced H2O2­induced cell senescence, whereas low expression of miR­20b produced the opposite effects. Thioredoxin interacting protein (TXNIP) was predicted as a target gene for miR­20b and knockdown of TXNIP increased cell viability, inhibited cell senescence, reduced the expression of p16, p21, TXNIP, NLR family pyrin domain containing 3 (NLRP3) and cleaved Caspase­1 and reversed the promoting effects of the miR­20b inhibitor and H2O2 on cell senescence. Furthermore, the knockdown of TXNIP inhibited the Wnt/ß­catenin pathway. The finding reveals that high expression of miR­20b inhibits the senescence of human umbilical vein endothelial cells through regulating the Wnt/ß­catenin pathway via the TXNIP/NLRP3 axis.

Percutaneous occlusion of transseptal puncture-related free wall perforation at the coronary sinus with a ventricular septal occluder during left atrial appendage closure: A case report.

Coronary sinus perforation is a life-threatening complication of transseptal puncture and needs to be repaired immediately. In this study, we report a case of a 74-year-old female patient with nonvalvular atrial fibrillation, who is a poor long-term anticoagulation candidate. During the manipulation of transseptal puncture, a perforation of the free right atrial wall at the coronary sinus ostium occurred, which was caused by the Brockenbrough needle and followed by the immediate advancement of an 8.5-French transseptal sheath. In consideration of the danger of cardiac tamponade after sheath removal, we decided to leave the 8.5-French sheath in the pericardial cavity. Then, we advanced a 6 mm ventricular septal occluder through the sheath. Finally, we achieved successful deployment of the device and closure of the perforation under the guidance of fluoroscopy and transthoracic echocardiography. Subsequently, the left atrial appendage orifice was occluded with a 21 mm Watchman device. This case illustrates that percutaneous device closure is feasible for inadvertent perforation of the free right atrial wall at the coronary sinus during transseptal puncture and should be considered as an alternative to surgery.

Neoblast-enriched zinc finger protein FIR1 triggers local proliferation during planarian regeneration.

Regeneration, relying mainly on resident adult stem cells, is widespread. However, the mechanism by which stem cells initiate proliferation during this process in vivo is unclear. Using planarian as a model, we screened 46 transcripts showing potential function in the regulation of local stem cell proliferation following 48 h regeneration. By analyzing the regeneration defects and the mitotic activity of animals under administration of RNA interference (RNAi), we identified factor for initiating regeneration 1 (Fir1) required for local proliferation. Our findings reveal that Fir1, enriched in neoblasts, promotes planarian regeneration in any tissue-missing context. Further, we demonstrate that DIS3 like 3'-5' exoribonuclease 2 (Dis3l2) is required for Fir1 phenotype. Besides, RNAi knockdown of Fir1 causes a decrease of neoblast wound response genes following amputation. These findings suggest that Fir1 recognizes regenerative signals and promotes DIS3L2 proteins to trigger neoblast proliferation following amputation and provide a mechanism critical for stem cell response to injury.

Watch out for the Thrombus Adhering to the Puncture Site of the Atrial Septum during Left Atrial Appendage Closure.

We present a rare case of thrombus adhering to the puncture site of the atrial septum during left atrial appendage closure. By discussing the case, we suggest that some preventive measurements be taken during left atrial appendage closure and that conventional transesophageal echocardiography for the atrial septal puncture site be performed after the delivery sheath is removed.