LncRNA XIST knockdown reduces myocardial damage in myocarditis by targeting the miR-140-3p/RIPK1 axis.

Viral myocarditis (MC) is caused by Coxsackie virus B3 (CVB3)-induced cardiomyocyte apoptosis and inflammation, and changes in miRNA and lncRNA are linked to cardiac remodeling. The long non-coding RNA XIST (XIST) has been identified as a regulator in various pathological processes in heart diseases, but its role in CVB3-induced MC is not well understood. This research aimed to evaluate the impact that XIST has on CVB3-induced MC as well as the mechanism behind this effect. XIST expression in CVB3-exposed H9c2 cells (H9c2 cells) was evaluated by qRT-PCR. In CVB3-exposed H9c2 cells, reactive oxygen species production, inflammatory mediators, and apoptosis were experimentally observed. An investigation into and confirmation of the existence of an interaction involving XIST, miR-140-3p, and RIPK1 were carried out. The findings showed that CVB3 induced upregulation of XIST in H9c2 cells. However, XIST knockdown reduced oxidative stress, inflammation, and apoptosis of CVB3-exposed H9c2 cells. XIST was specifically bound to miR-140-3p, and there was mutual negative regulation between the two. Moreover, XIST downregulated RIPK1, which was mediated by miR-140-3p. The study suggests that downregulating XIST can alleviate inflammatory injury in CVB3-exposed H9c2 cells through the miR-140-3p/RIPK1 axis. These findings provide novel insights into the underlying mechanisms of MC.

A Multi-Centre Prospective Study of the Efficacy and Safety of Alglucosidase Alfa in Chinese Patients With Infantile-Onset Pompe Disease.

Background: A high prevalence of infantile-onset Pompe disease (IOPD) in the Chinese population has been noted, but there are currently no reported clinical trials of enzyme replacement therapy (ERT) for IOPD in this population. The purpose of this study was to evaluate the efficacy and safety of alglucosidase alfa in Chinese patients with IOPD. Materials and Methods: A multicentre, single-arm, prospective, open-label clinical trial was performed at 4 sites in China. Eligible Chinese subjects with IOPD received an infusion of alglucosidase alfa at a dose of 20 mg/kg every 2 weeks for up to 52 weeks. The primary endpoints of clinical efficacy were the survival rate and changes in the left ventricular mass index (LVMI). The safety assessment was based on the incidence of adverse events (AEs). Results: A total of 10 eligible subjects were enrolled in the study. The mean age at the start of ERT was 5.36 ± 1.56 months. Nine subjects had survived after 52 weeks of treatment. One subject discontinued the study and died after mechanical ventilation was withdrawn. The intent-to-treat analysis demonstrated that the survival rate was 90.0% (95% confidence interval: 55.5-99.7%). The mean LVMI at week 52 was 70.59 ± 39.93 g/m2 compared to that of 298.02 ± 178.43 g/m2 at baseline, with a difference of -227.60 ± 155.99 g/m2. All subjects had left ventricular mass (LVM) Z scores >10 at baseline, and eight subjects (80%) achieved Z scores <5 at week 52. No treatment-related AEs were observed, and no AEs led to the discontinuation of treatment. Conclusions: This clinical trial is the first study of ERT for IOPD in China, indicating that alglucosidase alfa has favourable efficacy and safety for the treatment of Chinese patients with IOPD (ClinicalTrials.gov number, NCT03687333).

Left ventricular epicardial pacing achieved hyper-responsiveness in young children with dilated cardiomyopathy with left bundle branch block.

AIMS: The management of heart failure (HF) in young children is challenging. The present study aimed to clarify the effect of left univentricular epicardial pacing on dilated cardiomyopathy with left bundle branch block (LBBB) in children. METHODS AND RESULTS: A total of five cases (30.86 ± 16.39 months, three female) of children weighing 5.8-15 kg with dilated cardiomyopathy and LBBB were included in this study. LBBB in one child occurred after device closure of peri-membranous ventricular septal defects, and the remaining four were idiopathically discovered early after birth. Before implantation, all children suffered from refractory HF and cardiac dilatation; the left ventricular ejection fraction was 33.48 ± 5.84% with Ross Heart Failure Classification III-IV. Electrical and mechanical dyssynchrony were observed in all children with QRS duration >140 ms and prolonged septal-to-left posterior wall motion delay. Left univentricular epicardial pacing was successfully implanted via left axillary minithoracotomy in the five children. Sensed atrioventricular delays (83 ± 15 ms) were optimized by velocity time integral of aortic blood flow before discharge. During the follow-up period (10.8 ± 2.68 months), the dilated failing heart was reversed significantly in terms of decreased left ventricular dimension (55.62 ± 3.46 vs. 38.94 ± 3.69 mm, P = 0.005), while the left ventricular ejection fraction improved to 60.18 ± 8.78% (P = 0.006). CONCLUSIONS: In young children with low body weight, if HF is caused by or related to LBBB, left ventricular epicardial pacing still has an excellent effect.

An Avascular Niche Created by Axitinib-Loaded PCL/Collagen Nanofibrous Membrane Stabilized Subcutaneous Chondrogenesis of Mesenchymal Stromal Cells.

Engineered cartilage derived from mesenchymal stromal cells (MSCs) always fails to maintain the cartilaginous phenotype in the subcutaneous environment due to the ossification tendency. Vascular invasion is a prerequisite for endochondral ossification during the development of long bone. As an oral antitumor medicine, Inlyta (axitinib) possesses pronounced antiangiogenic activity, owing to the inactivation of the vascular endothelial growth factor (VEGF) signaling pathway. In this study, axitinib-loaded poly(ε-caprolactone) (PCL)/collagen nanofibrous membranes are fabricated by electrospinning for the first time. Rabbit-derived MSCs-engineered cartilage is encapsulated in the axitinib-loaded nanofibrous membrane and subcutaneously implanted into nude mice. The sustained and localized release of axitinib successfully inhibits vascular invasion, stabilizes cartilaginous phenotype, and helps cartilage maturation. RNA sequence further reveals that axitinib creates an avascular, hypoxic, and low immune response niche. Timp1 is remarkably upregulated in this niche, which probably plays a functional role in inhibiting the activity of matrix metalloproteinases and stabilizing the engineered cartilage. This study provides a novel strategy for stable subcutaneous chondrogenesis of mesenchymal stromal cells, which is also suitable for other medical applications, such as arthritis treatment, local treatment of tumors, and regeneration of other avascular tissues (cornea and tendon).

Clinical and imaging characteristics of isolated subclavian artery in pediatric patients.

OBJECTIVES: To describe clinical and imaging characteristics of an isolated subclavian artery (ISA) in pediatric patients. BACKGROUND: ISA is a rare congenital aortic arch anomaly defined as a loss of connection between the subclavian artery and aorta. The clinical manifestations and complications of ISA in children are unclear. METHODS: This retrospective study included clinical and imaging data of ISA patients younger than 18 years whose data were recorded in the electronic radiology database during January 2006-August 2019. RESULTS: Of 102 enrolled patients, 59 had been diagnosed in the first year of life. The majority of the patients also had congenital heart diseases, of which tetralogy of Fallot was the most common. The vertebral artery and collateral branch of the descending aorta served as blood flow supplies in 94 and 8 patients with ISA, respectively, as confirmed using computed tomography or magnetic resonance imaging. However, the blood supply did not influence the development of ISA. Eleven patients exhibited mild or moderate stenosis of the ISA, although only two exhibited coldness or a blood pressure gradient in the upper extremities. These two symptomatic patients also presented with patent ductus arteriosus, and this association was significant (P = 0.008). CONCLUSION: ISA management is often determined based on symptoms and associated congenital heart diseases. The ISA is prone to stenosis in patients with ipsilateral patent ductus arteriosus. We recommend early surgical ligation or percutaneous closure of the ductus arteriosus in patients with ISA.

Knockdown of KCNQ1OT1 attenuates cardiac hypertrophy through modulation of the miR-2054/AKT3 axis.

BACKGROUND: Persistent cardiac hypertrophy threatens health worldwide. Long non-coding RNAs (lncRNAs) attracted lots of attention in cardiac diseases such as cardiac hypertrophy. In this study, we aimed to study the function of KCNQ1OT1 in cardiac hypertrophy. METHODS: We first used qRT-PCR to detect the expression of KCNQ1OT1 in Ang-II-induced cardiomyocytes and mouse cardiac hypertrophy models. The function of KCNQ1OT1 was investigated by a loss-of-function test. Analysis of the luciferase reporter gene and RNA pulldown confirmed the interaction between KCNQ1OT1 and miR-2054. The target gene of miR-2054 was predicted by bioinformatics analysis and confirmed by luciferase reporter gene detection. Rescue experiments were performed to evaluate the role of miR-2054/AKT3 in the function of KCNQ1OT1. RESULTS: Our results suggested that KCNQ1OT1 was up-regulated in Ang-II-induced cardiomyocytes and transverse aortic constriction (TAC) mice. Knocking down of KCNQ1OT1 can reduce cell size and downregulate the expression of ANF, BNP and α-MHC in response to Ang-II. KCNQ1OT1 has been shown to compete competitively with miR-2054 and has a negative correlation with its expression. The combination of miR-2054 can reverse the effect of the KCNQ1OT1 combination in Ang-II-induced cardiomyocytes. In addition, AKT3 is a target of miR-2054 and mediates its effect on Ang-II-induced cardiomyocytes. CONCLUSIONS: Knockdown of KCNQ1OT1 could attenuate cardiac hypertrophy through modulation of the miR-2054/AKT3 axis.

Left bundle branch pacing improved heart function in a 10-year-old child after a 3-month follow-up.

AIMS: As a physiological pacing strategy, left bundle branch pacing (LBBP) were used to correct left bundle branch block (LBBB), however, there is no relevant report in children. We aimed to evaluate the feasibility of LBBP in children. METHODS AND RESULTS: Left bundle branch pacing was performed in a 10-year-old girl with a second-degree atrioventricular and LBBB. Under the guide of fluoroscopy, the pacing lead was deeply screwed into the interventricular septum to gain right bundle branch block (RBBB) pattern of paced QRS. Selective LBBP was achieved with a typical RBBB pattern of paced morphology and a discrete component between stimulus and ventricular activation in intracardiac electrogram and reached the standard of the stimulus to left ventricular activation time of 56 ms. At a 3-month follow-up, the LBBP acquired the reduction of left ventricular size and enhancement of left ventricular ejection fraction. CONCLUSION: The application of LBBP in a child was first achieved with inspiring preliminary results. The LBBP can be carried out in children by cautiousness under the premise of strict grasp of indications.

Characteristics and toxicity assessment of electrospun gelatin/PCL nanofibrous scaffold loaded with graphene in vitro and in vivo.

Background: Electrospun gelatin/polycaprolactone (Gt/PCL) nanofibrous scaffolds loaded with graphene are novel nanomaterials with the uniquely strong property of electrical conductivity, which have been widely investigated for their potential applications in cardiovascular tissue engineering, including in bypass tracts for atrioventricular block. Purpose: Electrospun Gt/PCL/graphene nanofibrous mats were successfully produced. Scanning electron micrography showed that the fibers with graphene were smooth and homogeneous. In vitro, to determine the biocompatibility of the scaffolds, hybrid scaffolds with different fractions of graphene were seeded with neonatal rat ventricular myocytes. In vivo, Gt/PCL scaffolds with different concentrations of graphene were implanted into rats for 4, 8 and 12 weeks. Results: CCK-8 assays and histopathological staining (including DAPI, cTNT, and CX43) indicated that cells grew and survived well on the hybrid scaffolds if the mass fraction of graphene was lower than 0.5%. After implanting into rats for 4, 8 or 12 weeks, there was no gathering of inflammatory cells around the nanomaterials according to the HE staining results. Conclusion: The results indicate that Gt/PCL nanofibrous scaffolds loaded with graphene have favorable electrical conductivity and biological properties and may be suitable scaffolds for use in the treatment of atrioventricular block. These findings alleviate safety concerns and provide novel insights into the potential applications of Gt/PCL loaded with graphene, offering a solid foundation for comprehensive in vivo studies.

Long non-coding RNA MEG3 serves as a ceRNA for microRNA-145 to induce apoptosis of AC16 cardiomyocytes under high glucose condition.

Diabetic cardiomyopathy (DCM) is one of the most serious complications of diabetes, but its pathogenesis remains largely unclear. In the present study, we aimed to explore the potential role of long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) and to investigate the underlying mechanisms in human AC16 cardiomyocytes under high glucose (HG) condition. The results demonstrated that MEG3 was overexpressed in HG-treated AC16 cells, and MEG3 knockdown suppressed the HG-induced apoptosis in AC16 cells. Mechanistically, MEG3 directly binds to miR-145 in AC16 cells, thereby up-regulating the expression of PDCD4. Rescue experiments showed that the role of MEG3 in HG-treated AC16 cells was partly dependent on its suppression on miR-145. In summary, our findings suggested that the role of MEG3 in HG-treated human cardiomyocytes is to serve as a competing endogenous RNA (ceRNA), which negatively regulates miR-145. These findings may provide a valuable and promising therapeutic target for the treatment of DCM in the future.

Dapagliflozin Attenuates Cardiac Remodeling in Mice Model of Cardiac Pressure Overload.

BACKGROUND: Dapagliflozin (DAPA) is an inhibitor of sodium-glucose cotransporter 2 prescribed for type 2 diabetes mellitus. DAPA plays a protective role against cardiovascular diseases. Nevertheless, the effect and mechanism of DAPA on pressure-overload-induced cardiac remodeling has not been determined. METHODS: We used a transverse aortic constriction (TAC) induced cardiac remodeling model to evaluate the effect of DAPA. Twenty-four C57BL/6J mice were divided into 3 groups: Sham, TAC, and TAC + DAPA groups (n = 8, each). DAPA was administered by gavage (1.0 mg/kg/day) for 4 weeks in the TAC + DAPA group, and then the myocardial hypertrophy, cardiac systolic function, myocardial fibrosis, and cardiomyocyte apoptosis were evaluated. RESULTS: Mice in TAC group showed increased heart weight/body weight, left ventricular (LV) diameter, LV posterior wall thickness, and decreased LV ejection fraction and LV fractional shortening. The collagen volume fraction and perivascular collagen area/luminal area ratio were significantly greater in the TAC group; the TUNEL-positive cell number and PARP level were also increased. We found that DAPA treatment reduced myocardial hypertrophy, myocardial interstitial and perivascular fibrosis, and cardiomyocyte apoptosis. Furthermore, DAPA administration inhibited phosphorylation of P38 and JNK in TAC group. In addition, the inhibited phosphorylation of FoxO1 in the TAC mice was upregulated by DAPA administration. CONCLUSION: DAPA administration had a cardioprotective effect by improving cardiac systolic function, inhibiting myocardial fibrosis and cardiomyocyte apoptosis in a TAC mouse model, indicating that it could serve as a new therapy to prevent pathological cardiac remodeling in nondiabetics.

Tfap2b mutation in mice results in patent ductus arteriosus and renal malformation.

BACKGROUND: Transcription factor TFAP2B is associated with Char syndrome in humans and is characterized by patent ductus arteriosus (PDA) and facial and finger abnormalities. In a previous study, we detected a c.435_438delCCGG TFAP2B mutation in a family with PDA, and no facial dysmorphism or finger abnormalities were observed. This 4-base pair (bp) deletion in exon 2 resulted in a truncated protein of about 21 kDa in cultured cells in vitro. However, it is not clear why c.435_438delCCGG mutation carriers are present with isolated PDA instead of Char syndrome. MATERIALS AND METHODS: We successfully established a mouse model bearing Tfap2b c.435_438delCCGG mutation using CRISPR/Cas9 technology. The mutant mice were phenotyped using histological analysis, and the development of ductus smooth muscles in mutant mice was examined by immunohistochemistry. RESULTS: The c.435_438delCCGG homozygous mutant mice were characterized by delayed closure of the ductus arteriosus (DA) and renal malformation. Furthermore, the c.435_438delCCGG mutation might result in PDA by affecting the development of ductus arterious smooth muscle cells. CONCLUSIONS: Using the c.435_438delCCGG homozygous mice, we verified the nature of the c.435_438delCCGG mutation and established a new and useful animal model to explore the function of Tfap2b and the mechanisms of PDA and renal formation. These findings may be useful for the development of therapies for those rare disorder.

Vegfa signaling regulates diverse artery/vein formation in vertebrate vasculatures.

Vascular endothelial growth factor A (Vegfa) signaling regulates vascular development during embryogenesis and organ formation. However, the signaling mechanisms that govern the formation of various arteries/veins in various tissues are incompletely understood. In this study, we utilized transcription activator-like effector nuclease (TALEN) to generate zebrafish vegfaa mutants. vegfaa-/- embryos are embryonic lethal, and display a complete loss of the dorsal aorta (DA) and expansion of the cardinal vein. Activation of Vegfa signaling expands the arterial cell population at the expense of venous cells during vasculogenesis of the axial vessels in the trunk. Vegfa signaling regulates endothelial cell (EC) proliferation after arterial-venous specification. Vegfa deficiency and overexpression inhibit the formation of tip cell filopodia and interfere with the pathfinding of intersegmental vessels (ISVs). In the head vasculature, vegfaa‒/‒ causes loss of a pair of mesencephalic veins (MsVs) and central arteries (CtAs), both of which usually develop via sprouting angiogenesis. Our results indicate that Vegfa signaling induces the formation of the DA at the expense of the cardinal vein during the trunk vasculogenesis, and that Vegfa is required for the angiogenic formation of MsVs and CtAs in the brain. These findings suggest that Vegfa signaling governs the formation of diverse arteries/veins by distinct cellular mechanisms in vertebrate vasculatures.

Vegfa Impacts Early Myocardium Development in Zebrafish.

Vascular endothelial growth factor A (Vegfa) signaling regulates cardiovascular development. However, the cellular mechanisms of Vegfa signaling in early cardiogenesis remain poorly understood. The present study aimed to understand the differential functions and mechanisms of Vegfa signaling in cardiac development. A loss-of-function approach was utilized to study the effect of Vegfa signaling in cardiogenesis. Both morphants and mutants for vegfaa display defects in cardiac looping and chamber formation, especially the ventricle. Vegfa regulates the heart morphogenesis in a dose-dependent manner. Furthermore, the initial fusion of the bilateral myocardium population is delayed rather than endocardium. The results demonstrate that Vegfa signaling plays a direct impact on myocardium fusion, indicating that it is the initial cause of the heart defects. The heart morphogenesis is regulated by Vegfa in a dose-dependent manner, and later endocardium defects may be secondary to impaired myocardium-endocardium crosstalk.

Isolated cleft of the mitral valve: clinical spectrum and course.

We have reviewed the clinical presentations, courses, and outcomes of 90 patients seen at Texas Children's Hospital from 1983 through 2008 who had an isolated cleft of the mitral valve without some form of endocardial cushion defect. Additional congenital cardiac defects were present in 61 of the 90 patients, 35 of whom had a congenital syndrome. Seven patients had isolated cleft of the mitral valve without other intracardiac defects, and in these 7 there was a progressive increase in the degree of mitral regurgitation during a median time of 26.5 months from diagnosis to surgery. The patients ranged from a gestational age of approximately 32 weeks to 21.9 years of age. No death was observed among the 39 surgical patients, including 32 who had additional cardiac defects. There was a significant reduction in the degree of mitral regurgitation in all patients who underwent surgery. Among the 51 patients who did not have surgery, the degree of regurgitation did not change significantly over the course of 1 to 27 years' observation. Isolated cleft of the mitral valve is an uncommon (but not rare) congenital malformation of the mitral valve that can cause all degrees of mitral regurgitation but can be managed medically or surgically.