Cardioprotective effects of asiaticoside against diabetic cardiomyopathy: Activation of the AMPK/Nrf2 pathway.

Diabetic cardiomyopathy (DCM) is a chronic microvascular complication of diabetes that is generally defined as ventricular dysfunction occurring in patients with diabetes and unrelated to known causes. Several mechanisms have been proposed to contribute to the occurrence and persistence of DCM, in which oxidative stress and autophagy play a non-negligible role. Diabetic cardiomyopathy is involved in a variety of physiological and pathological processes. The 5' adenosine monophosphate-activated protein kinase/nuclear factor-erythroid 2-related factor 2 (AMPK/Nrf2) are expressed in the heart, and studies have shown that asiaticoside (ASI) and activated AMPK/Nrf2 have a protective effect on the myocardium. However, the roles of ASI and AMPK/Nrf2 in DCM are unknown. The intraperitoneal injection of streptozotocin (STZ) and high-fat feed were used to establish the DCM models in 100 C57/BL mice. Asiaticoside and inhibitors of AMPK/Nrf2 were used for intervention. Cardiac function, oxidative stress, and autophagy were measured in mice. DCM mice displayed increased levels of oxidative stress while autophagy levels declined. In addition, AMPK/Nrf2 was activated in DCM mice with ASI intervention. Further, we discovered that AMPK/Nrf2 inhibition blocked the protective effect of ASI by compound C and treatment with ML-385. The present study demonstrates that ASI exerts a protective effect against DCM via the potential activation of the AMPK/Nrf2 pathway. Asiaticoside is a potential therapeutic target for DCM.

RIP3 orchestrates oxidative stress and pyroptosis in doxorubicin-induced cardiotoxicity through regulation of AKT/Nrf2 signaling cascade.

This study was designed to explore the role of RIP3 in DOX-induced cardiotoxicity and its underlying molecular mechanisms. Our results demonstrate that RIP3 exacerbates DOX-induced cardiotoxicity through promoting oxidative stress and pyroptosis by regulating the AKT/Nuclear factor erythroid 2-related factor 2 (Nrf2) signal pathway. Inhibition of RIP3 using GSK-872 attenuated DOX-induced cardiac remodeling and contractile dysfunction. Moreover, using GSK-872 in vivo, the results revealed that inhibition of RIP3 alleviated DOX-induced cardiotoxicity by the resulting inhibition of oxidative stress and pyroptosis. In addition, inhibition of RIP3 increased the protein levels of AKT and Nrf2 in DOX-treated mouse hearts. Furthermore, the AKT inhibitor LY294002 lessened RIP3 reduction-offered protection against DOX-induced H9c2 cell injury by moderating oxidative stress and pyroptosis. Taken together, these data demonstrate that RIP3 activation orchestrates DOX-induced cardiotoxicity through elevated oxidative stress and pyroptosis in an AKT/Nrf2-dependent manner. Those findings highlight the clinical relevance and therapeutic potential of targeting RIP3 for the treatment of DOX-induced cardiotoxicity.

The Potential Roles of CHI3L1 in Failed Autologous Arteriovenous Fistula in End-Stage Renal Disease.

Autologous arteriovenous fistula (AVF) is commonly placed for hemodialysis treatment. Recent studies show that increased baseline serum level of Chitinase-3-like protein 1 (CHI3L1) is independently associated with a higher risk of the early failure of forearm AVFs. However, the changes and mechanisms of CHI3LI in local vascular tissues of failed AVF have not be revealed. This study aims to conduct the expression and mechanism of CHI3L1 in vascular tissues from patients. Immunoreactivity of CHI3L1, matrix metalloproteinase 2 (MMP-2) and vascular endothelial growth factor-A (VEGF-A) were detected in vascular tissues collected from nine patients with AVF surgery. Due to the significant stenosis clinically, six of the nine patients received arteriovenous fistula reconstruction. The expression differences of CHI3L1 between the initial vascular tissues and failed AVF are significant (P < 0.05). Failed AVF due to stenosis shows intraluminal thrombus, collagen fiber rupture, fibrous connective tissue hyperplasia, tube wall thickening, neovascularization, scattered inflammatory cell infiltration in the tunica media as well as high CHI3L1 expression level, and the expression of MMP-2 (r = 0.9022, P = 0.0139) and VEGF-A (r = 0.8355, P = 0.0393) was positively correlated with CHI3L1. CHI3L1 expression in vascular tissues possibly plays an important role in AVF failure. MMP-2 and VEGF-A may participate in venous stenosis with CHI3L1.

CaMKII orchestrates endoplasmic reticulum stress and apoptosis in doxorubicin-induced cardiotoxicity by regulating the IRE1α/XBP1s pathway.

Doxorubicin (Dox), an anthracycline antibiotic with potent antitumor effects, has limited clinical applications due to cumulative cardiotoxicity. Ca2+ /calmodulin-dependent protein kinase II (CaMKII) is implicated in the pathological progression of Dox-induced cardiotoxicity. This study examined the hypothesis that CaMKII exacerbates Dox-induced cardiotoxicity by promoting endoplasmic reticulum stress and apoptosis through regulation of the inositol-requiring enzyme 1α (IRE1α)/spliced X-box binding protein 1 (XBP1s) pathway. Our results demonstrated that CaMKII activation and IRE1α/XBP1s pathway were involved in Dox-treated hearts. CaMKII inhibition with KN-93 ameliorated Dox-induced cardiac dysfunction and pathological myocardial changes. In addition, CaMKII inhibition prevented Dox-induced endoplasmic reticulum stress and apoptosis. Moreover, CaMKII inhibition increased the expression of IRE1α and XBP1s in Dox-treated hearts. The IRE1α inhibitor 4µ8C blocked the protective effect of CaMKII inhibition against Dox-induced cardiotoxicity. Mechanistically, 4µ8C prevented the effects of CaMKII inhibition on Dox-induced endoplasmic reticulum stress and apoptosis by inhibiting the expression of IRE1α and XBP1s. Additionally, treatment with rhADAMTS13 decreased the protein level of thrombospondin 1 (TSP1) and the phosphorylation of CaMKII in Dox-treated human AC16 cardiomyocytes. Taken together, these results demonstrate that the ADAMTS13-TSP1 axis regulates CaMKII activation and exacerbates Dox-induced cardiotoxicity by triggering endoplasmic reticulum stress and apoptosis by inhibiting the IRE1α/XBP1s pathway.

Cardioprotective effects of melatonin against myocardial ischaemia/reperfusion injury: Activation of AMPK/Nrf2 pathway.

Although reperfusion is the most effective therapy for patients with acute myocardial infarction, reperfusion injury limits the therapeutic effects of early reperfusion. Oxidative stress plays a crucial role in myocardial ischaemia/reperfusion (I/R) injury. Melatonin, a circulating hormone, is well-known as an antioxidant in cardiovascular diseases. In this short communication, we show that melatonin significantly improves post-ischaemic cardiac function, reduces infarct size and decreases oxidative stress. Furthermore, melatonin markedly increases AMPK activation and Nrf2 nuclear translocation. Nevertheless, these melatonin-induced changes are abrogated by compound C. In addition, ML-385, an Nrf2 inhibitor, also withdraws the antioxidative effects of melatonin but has little effect on AMPK activation. In conclusion, our results demonstrate that melatonin alleviates myocardial I/R injury by inhibiting oxidative stress via the AMPK/Nrf2 signalling pathway.

Transcatheter Closure of Mitral Paravalvular Leak via Multiple Approaches.

OBJECTIVES: The purpose of this study was to review the experiences with transcatheter closure of mitral PVL after surgical valve replacement. BACKGROUND: Transcatheter closure of paravalvular leak (PVL) is an intricate alternative to surgical closure. But it represents one of the most intricate procedures in the field of structural heart interventions, especially for patients with mitral PVL. METHODS: From January 2015 through January 2019, 35 patients with mitral PVL after valve replacement underwent transcatheter closure. We reviewed the catheter techniques, perioperative characteristics, and prognosis. The median follow-up was 26 (3-48) months. RESULTS: Acute procedural success was achieved in 33/35 (94.3%) patients. Twenty-five patients had single mitral prosthetic valve replacements; 10 had combined aortic and mitral prosthetic valve replacements previously; 28 had mechanical valves; and 7 had bioprosthetic valves. All percutaneous procedures were performed with local anesthesia except for seven transapical cases with general anesthesia. Multiple approaches were used: transfemoral, transapical, and transseptal via an arteriovenous loop. Multiple devices were deployed. There were no hospital deaths. The procedural time was 67-300 (124 ± 62) minutes. Fluoroscopic time was 17-50 (23.6 ± 12.1) minutes. The hospital stay was 5-17 (8.3 ± 3.2) days. Complications included recurrent hemolysis, residual regurgitation, acute renal insufficiency, and anemia. Twenty-seven (77.1%) patients improved by ≥1 New York Heart Association functional class at the 1-year follow-up. CONCLUSIONS: Transcatheter mitral PVL closure requires complex catheter techniques. However, this minimally invasive treatment could provide reliable outcomes and shorter hospital stays in selected patients. This trial is registered with NCT02917980.

Application of three-dimensional transesophageal echocardiography in preoperative evaluation of transcatheter aortic valve replacement.

BACKGROUND: Our goal was to determine the accuracy of 3-dimensional transesophageal echocardiography (3D-TEE) compared with that of computed tomography (CT) in the preoperative evaluation for transcatheter aortic valve replacement (TAVR) when the errors caused by inconsistent software and method have been eliminated and the representativeness of the sample has been improved. We also investigated the influence of aortic root calcification on the accuracy of 3D-TEE in aortic annulus evaluations. METHODS: Part I: 45 of 233 patients who underwent TAVR in the department of cardiovascular surgery at the Xijing hospital from January 2016 to August 2019 were studied retrospectively. Materialise Mimics software and the multiplanar reconstruction method were used for evaluation, based on 3D-TEE and CT. The annulus area-derived diameter, the annulus perimeter-derived diameter (Dp), the annulus mean diameter, the left ventricular outflow tract Dp diameter, the sinotubular junction (STJ) diameter-Dp, and the aortic sinus diameter were compared and analyzed. Part II: 31 of 233 patients whose 3D-TEE and CT data were well preserved and in the required format were included. HU450 and HU850 were used as indicators to measure the severity of calcification. The Spearman rank correlation and Linear regression were used to analyze the correlation between aortic root calcification and the accuracy of 3D-TEE in aortic annulus measurement. RESULTS: The measurement results based on 3D-TEE were significantly lower than those obtained using CT (P < 0.05), except for the STJ diameter-Dp in diastole (P = 0.11). The correlation coefficient of the two groups was 0.699-0.954 (P < 0.01), which also indicated a significant correlation between the two groups. A Bland-Altman plot showed that the ordinate values were mostly within the 95% consistency limit; the consistency of the two groups was good. By establishing the linear regression equation, the two groups can be inferred from each other. The Spearman rank correlation analysis and the Linear regression analysis showed that the influence of aortic calcification on the accuracy of the 3D-TEE annulus evaluation was limited. CONCLUSIONS: Although an evaluation based on 3D-TEE underestimated the results, we can deduce CT results from 3D-TEE because the two methods exhibit considerable correlation and consistency. TRIAL REGISTRATION: Name: Surgery and Transcatheter Intervention for Structural Heart Diseases. Number: NCT02917980. URL: https://clinicaltrials.gov/ct2/results?term=NCT02917980 .

Helix B surface peptide attenuates diabetic cardiomyopathy via AMPK-dependent autophagy.

BACKGROUND: Erythropoietin (EPO) has been reported to exert protective effects on a host of damaged tissues. However, the erythropoietic effect of this hormone can result in high risks of thrombosis, stroke, and hypertension, remarkably limiting the clinical use of EPO. Helix B surface peptide (HBSP) is a small peptide derived from the helix-B domain of EPO. Surprisingly, HBSP retains the tissue protective properties of EPO without altering the hematocrit. Thus, we evaluated the possible role of HBSP on diabetic cardiomyopathy. METHODS: Diabetes was induced in mice by intraperitoneal injections of streptozocin (STZ). Mice were randomly treated with normal saline or HBSP. Cardiac function, fibrosis, apoptosis, and myocardial mitochondrial morphology were examined. For in vitro experiments, H9C2 myoblast cells were randomly grouped as normal glucose (NG, 5 mM), NG+HBSP (100 nM), high glucose (HG, 33 mM), HG+HBSP (100 nM), HG+HBSP+3-methyladenine (3-MA, 10 mM), HG+rapamycin (Rapa, 100 nM), and HG+HBSP+Compound C (CC, 10 mM). Autophagosomes, LC3 dots, apoptosis and mitochondria membrane potential (MMP) of H9C2 cells were examined.The expressions of LC3, p62, p-AMPK (Thr172) and p-mTOR (Ser2448) were examined by Western blot. RESULTS: HBSP markedly improved cardiac function, attenuated cardiac interstitial fibrosis, inhibited myocardial apoptosis, and ameliorated mitochondrial ultrastructure in mice with diabetic cardiomyopathy. HG reduced autophagy in H9C2 cells. HBSP enhanced autophagy in HG-treated H9C2 cells. HBSP reduced the apoptosis index of HG-treated H9C2 cells. HBSP increased the MMP of HG-treated H9C2 cells. HBSP increased the levels of p-AMPK (Thr172), and reduced p-mTOR (Ser2448) in HG-treated H9C2 cells, and the increase of p-AMPK (Thr172) was accompanied by the stimulation of autophagy. Autophagy inhibitor 3-MA and AMPK inhibitor CC mitigated HBSP-induced beneficial effect, whereas autophagy inducer Rapa alleviated the HG-induced cell apoptosis. CONCLUSIONS: HBSP attenuates diabetic cardiomyopathy via autophagy mediated by AMPK-dependent pathway. HBSP may be a potential therapeutic intervention for diabetic cardiomyopathy.

Tetrahydrocurcumin ameliorates postinfarction cardiac dysfunction and remodeling by inhibiting oxidative stress and preserving mitochondrial function via SIRT3 signaling pathway.

BACKGROUND: Myocardial infarction (MI) often leads to sudden cardiac death. Persistent myocardial ischemia increases oxidative stress and impairs mitochondrial function, contributing significantly to postinfarction cardiac dysfunction and remodeling, and the subsequent progression to heart failure (HF). Tetrahydrocurcumin (THC), isolated from the rhizome of turmeric, has antioxidant properties and has been shown to protect against cardiovascular diseases. However, its effects on HF after MI are poorly understood. PURPOSE: The objective was the investigation of the pharmacological effects of THC and its associated mechanisms in the pathogenesis of HF after MI. METHODS: A total of 120 mice (C57BL/6, male) were used for the in vivo experiments. An MI mouse model was created by permanent ligation of the left anterior descending coronary artery. The mice received oral dose of THC at 120 mg/kg/d and the effects on MI-induced myocardial injury were evaluated by assessment of cardiac function, histopathology, myocardial oxidative levels, and mitochondrial function. Molecular mechanisms were investigated by intraperitoneal injection of 50 mg/kg of the SIRT3 selective inhibitor 3-TYP. Meanwhile, mouse neonatal cardiomyocytes were isolated and cultured in a hypoxic incubator to verify the effects of THC in vitro. Lastly, SIRT3 and Nrf2 were silenced using siRNAs to further explore the regulatory mechanism of key molecules in this process. RESULTS: The mouse hearts showed significant impairment in systolic function after MI, together with enlarged infarct size, increased myocardial fibrosis, cardiac hypertrophy, and apoptosis of cardiomyocytes. A significant reversal of these changes was seen after treatment with THC. Moreover, THC markedly reduced reactive oxygen species generation and protected mitochondrial function, thus mitigating oxidative stress in the post-MI myocardium. Mechanistically, THC counteracted reduced Nrf2 nuclear accumulation and SIRT3 signaling in the MI mice while inhibition of Nrf2 or SIRT3 reversed the effects of THC. Cell experiments showed that Nrf2 silencing markedly reduced SIRT3 levels and deacetylation activity while inhibition of SIRT3 signaling had little impact on Nrf2 expression. CONCLUSION: This is the first demonstration that THC protects against the effects of MI. THC reduced both oxidative stress and mitochondrial damage by regulating Nrf2-SIRT3 signaling. The results suggest the potential of THC in treating myocardial ischemic diseases.

Transcatheter Closure of a Paravalvular Leak Guided by Transesophageal Echocardiography and Three-Dimensional Printing.

Background: Closure of a percutaneous paravalvular leak (PVL) is a technically challenging procedure because of the specific anatomy postoperatively and the complex catheter techniques required. Transesophageal echocardiography (TEE) and three-dimensional (3D) printing might be helpful in identifying complex anatomical structures and the procedural design. Objectives: The purpose of this study was to review our experiences with transcatheter closure of PVL guided by TEE and 3D (TEE&3D) printing. Methods: A total of 166 patients with PVL after surgical valve replacement underwent transcatheter closure, from January 2015 through December 2020. Among these patients, 68 had preoperative guidance from TEE&3D printing. We reviewed the catheter techniques, perioperative characteristics, and prognosis. The median follow-up period was 36 (3-70) months. Results: Acute procedural success was achieved in 154/166 (92.8%) patients; of these, 64/68 (94.1%) had TEE&3D guidance and 90/98 (91.8%) had transthoracic echocardiography (TTE) guidance. No hospital deaths occurred. All patients having percutaneous procedures were given local anesthesia, while 13 patients having transapical procedures were given general anesthesia. Multiple approaches were used, including transfemoral, transapical, and transseptal via the arteriovenous loop. We also deployed multiple devices, including the Amplatzer Vascular Plug II (AVP II), the Amplatzer duct occluder II, the patent ductus arteriosus (PDA) occluder, and the Amplatzer muscular ventricular septal defect occluder. Those cases guided by TEE&3D printing had shorter procedural times compared with those guided by TTE [(61.2 ± 23.4) vs. (105.7 ± 53.9) min, p < 0.05]. The fluoroscopic time was also shorter for operations guided by TEE&3D printing compared with those guided by TTE alone [(18.5 ± 11.4) vs. (27.3 ± 5.6) min, p < 0.05]. The complications included recurrent hemolysis, residual regurgitation, acute renal insufficiency, and anemia. There was no significant difference in the incidence of complications between the 2 groups. Conclusion: Transesophageal echocardiography and 3D printing show advantages compared with standalone TTE in guiding the transcatheter closure of PVL with shorter procedural and fluoroscopic times. This minimally invasive treatment could provide reliable outcomes in selected patients. Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [NCT02917980].

Effects of berbamine against myocardial ischemia/reperfusion injury: Activation of the 5' adenosine monophosphate-activated protein kinase/nuclear factor erythroid 2-related factor pathway and changes in the mitochondrial state.

This study was designed to investigate whether berbamine (BA)-induced cardioprotective effects were related to 5' adenosine monophosphate-activated protein kinase (AMPK)/nuclear factor erythroid 2-related factor (Nrf2) signaling and changes in the mitochondria in myocardial ischemia/reperfusion (I/R) injury. C57/BL6 mice were exposed to BA (10 mg/kg/d), with or without administration of the AMPK specific inhibitor compound C (5 mg/kg/d) or the Nrf2 specific inhibitor ML-385 (30 mg/kg/d), and then subjected to a myocardial I/R operation. As expected, BA significantly improved post-ischemic cardiac function, reduced infarct size and apoptotic cell death, decreased oxidative stress, and improved the mitochondrial state. Furthermore, BA markedly increased AMPK activation, Nrf2 nuclear translocation, and the levels of NAD(P)H quinone dehydrogenase and heme oxygenase-1. Nevertheless, these BA-induced changes were abrogated by compound C. In addition, ML-385 also canceled the cardioprotective effects of BA but had little effect on AMPK activation. Our results demonstrate that BA alleviates myocardial I/R injury and the mitochondrial state by inhibiting apoptosis and oxidative stress via the AMPK/Nrf2 signaling pathway.

Safety, efficacy, and clinical outcomes of transcatheter tricuspid valve replacement: One-year follow-up.

Objective: The aim was to evaluate the safety and efficacy of TTVR in patients with severe TR at the 1-year follow-up. Materials and methods: This project was a single-center, observational study. From September 2020 to May 2021, 15 patients with severe or extremely severe TR at high risk of traditional surgery were enrolled. All patients had preoperative imaging assessments to evaluate the tricuspid valve and the anatomy of the right heart. All patients were planned to treated with the LuX-Valve (Ningbo Jenscare Biotechnology, Ningbo, China). The LuX-Valve was implanted under the intraoperative guidance of TEE and X-ray fluoroscopy. Data were collected at baseline, before discharge, and at 30 days, 6 months, and 1 year postoperatively. Results: The LuX-Valves were successfully implanted in all 15 patients. TR was significantly reduced to ≤ 2 +. One patient died on postoperative day 12 of a pulmonary infection that was considered unrelated to the procedures or the devices. The remaining 14 patients (100.0%) reached the primary end point. One patient (7.1%) was rehospitalized during 1-year follow-up because of device thrombosis. The number of patients who survived at 1 year with New York Heart Association (NYHA) functional class II was higher than that before TTVR (11/14 vs. 0/15, P = 9.11 × 10-4). Patients with peripheral edema and ascites decreased from 100.0 to 46.7% at baseline to 28.6% and 14.3% at 1 year (P = 1.57 × 10-3 and 2.53 × 10-2). Conclusion: TTVR is associated with RV remodeling, increased cardiac output, and improvement in NYHA functional class. Using the LuX-Valve for TTVR to treat patients with severe TR is a feasible and relatively safe method with reliable clinical results. Further studies are needed to determine long-term outcomes.

Transcatheter aortic valve replacement in patients with quadricuspid aortic valve in a single center.

Background: Quadricuspid aortic valve (QAV) is a rare congenital malformation that can present with aortic regurgitation or aortic stenosis (AS)), requiring surgical treatment. Transcatheter aortic valve replacement (TAVR) is an alternative treatment for older patients and its prognosis for QAV therapy remains challenging. We sought to examine our early experience with TAVR in patients with QAV. Materials and methods: Prospectively collected data were retrospectively reviewed in patients with QAV undergoing TAVR in our institution. Results: Five patients with QAV and AR or AS were treated with TAVR between January 2016 and January 2022. The mean age was 73.8 years (range 69-82 years), and the median Society of Thoracic Surgeons score was 7.51% (range 2.668-18.138%). Two patients had type B and three had either type A, D, or F according to the Hurwitz and Roberts classification for QAV. Four patients with pure aortic regurgitation underwent transapical TAVR using the J-Valve system, and the patient with severe AS underwent transfemoral TAVR using the Venus-A system. Procedural success was achieved in all five patients. Trivial paravalvular leak was only detected in one case after the procedure, and one patient received a permanent pacemaker due to high-degree atrioventricular block three days later. The median follow-up period was 18 (12-56) months. After discharge, no deaths occurred during the 1 year follow-up. All patients improved by ≥1 New York Heart Association functional class at 30 days; four patients were in functional class ≤II later in the follow-up period. All patients' heart failure symptoms improved considerably. Conclusion: Our early experience with TAVR in QAV demonstrates these procedures to be feasible with acceptable early results. Further follow-up is necessary to determine the long-term outcomes of this modality. Clinical trial registration: [ClinicalTrials.gov], identifier [NCT02917980].

Activation of cannabinoid receptor 2 attenuates Angiotensin II-induced atrial fibrillation via a potential NOX/CaMKII mechanism.

Background: Atrial fibrillation (AF) is the most frequent arrythmia managed in clinical practice. Several mechanisms have been proposed to contribute to the occurrence and persistence of AF, in which oxidative stress plays a non-negligible role. The endocannabinoid system (ECS) is involved in a variety physiological and pathological processes. Cannabinoid receptor 1 (CB1R) and cannabinoid receptor 2 (CB2R) are expressed in the heart, and studies have shown that activating CB2R has a protective effect on the myocardium. However, the role of CB2R in AF is unknown. Materials and methods: Angiotensin II (Ang II)-infused mice were treated with the CB2R agonist AM1241 intraperitoneally for 21 days. Atrial structural remodeling, AF inducibility, electrical transmission, oxidative stress and fibrosis were measured in mice. Results: The susceptibility to AF and the level of oxidative stress were increased significantly in Ang II-infused mice. In addition, nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2), NOX4, and oxidized Ca2+/calmodulin-dependent protein kinase II (ox-CaMKII) were highly expressed. More importantly, treatment with AM1241 activated CB2R, resulting in a protective effect. Conclusion: The present study demonstrates that pharmacological activation of CB2R exerts a protective effect against AF via a potential NOX/CaMKII mechanism. CB2R is a potential therapeutic target for AF.

Effect of Eccentric Calcification of an Aortic Valve on the Implant Depth of a Venus-A Prosthesis During Transcatheter Aortic Valve Replacement: A Retrospective Study.

OBJECT: Our goal was to assess the implant depth of a Venus-A prosthesis during transcatheter aortic valve replacement (TAVR) when the areas of eccentric calcification were distributed in different sections of the aortic valve. METHODS: A total of 53 patients with eccentric calcification of the aortic valve who underwent TAVR with a Venus-A prosthesis from January 2018 to November 2019 were retrospectively analyzed. The patients were divided into three groups (A, B, and C) according to the location of the eccentric calcification, which was determined by preprocedural computerized tomography angiography (CTA) images. The prosthesis release process and position were evaluated by contrast aortography during TAVR, and the differences in valve implant depths were compared among the three groups. The effects of different aortic root structures and procedural strategies on prosthesis implant depth were analyzed. RESULTS: Eleven patients had eccentric calcification in region A; 19 patients, in region B; and 23 patients, in region C. The patients with eccentric calcification in region B had a higher risk of prosthesis migration (10.5% upward and 21.1% downward), and the position of the prosthesis after TAVR in group B was the deepest among the three groups. When eccentric calcification was located in region A or C, the prosthesis was released at the standard position with more stability, and the location of the prosthesis was less deep after TAVR (region A: 4.12 ± 3.4 mm; region B: 10.2 ± 5.3 mm; region C: 8.4 ± 4.0 mm; region A vs. region B, P = 0.0004; region C vs. region B; and P = 0.0360). In addition, the left ventricular outflow tract (LVOT) (P = 0.0213) and aortic root angulation (P = 0.0263) also had a significant effect on implant depth in the aortic root structure of the patients. The prosthesis size was 28.3 ± 2.4 in the deep implant group and 26.4 ± 2.0 in the appropriate implant group (P = 0.0068). CONCLUSION: The implant depth of the Venus-A prosthesis is closely related to the distribution of eccentric calcification in the aortic valve during TAVR. Surgeons should adjust the surgical strategy according to aortic root morphology to prevent prosthesis migration.

CaMKIIδ inhibition protects against myocardial ischemia/reperfusion injury: Role of Beclin-1-dependent autophagy.

Ca2+/calmodulin-dependent protein kinase II δ (CaMKIIδ) has been shown to play a vital role in pathological events in myocardial ischemia/reperfusion (IR) injury. Dysregulation of autophagy in cardiomyocytes is implicated in myocardial IR injury. Here, we examined whether CaMKIIδ inhibition could protect against myocardial IR injury through alleviating autophagy dysfunction and evaluated the potential role of CaMKIIδ in Beclin-1-dependent autophagy in ischemia/reperfused hearts. This study was performed using isolated perfused rat hearts and H9c2 cardiac myoblasts. KN-93, but not KN-92, inhibited the phosphorylation of CaMKIIδ at Thr286 and its substrate phospholamban at Thr17 besides the CaMKIIδ activity in myocardial IR. KN-93, but not KN-92 significantly improved post-ischemic cardiac function and reduced cell death. In cultured H9c2 cardiac myoblasts, KN-93 or CaMKIIδ siRNA, but not KN-92, attenuated simulated IR (SIR)-induced cell death. Moreover, CaMKIIδ inhibition could alleviate IR-induced autophagic dysfunction as evidenced in reduced levels of Atg5, p62, and LC3BII in isolated rat hearts and H9c2 cardiac myoblasts. Furthermore, co-treatment with bafilomycin A1, a lysosomal inhibitor, in CaMKII inhibition-treated cells suggested that CaMKII inhibition alleviated autophagic flux. CaMKIIδ inhibition mitigated the phosphorylation of Beclin-1 at Ser90. As expected, Beclin-1 siRNA significantly decreased the levels of Beclin-1 and Beclin-1 phosphorylation accompanied by partial reductions in Atg5, LC3BII, p62, cleaved caspase-3 and cytochrome c. However, Beclin-1 siRNA had little effect on CaMKIIδ phosphorylation. Taken together, these results demonstrated that CaMKIIδ inhibition reduced myocardial IR injury by improving autophagy dysfunction, and that CaMKIIδ-induced autophagy dysfunction partially depended on the phosphorylation of Beclin-1.

Melatonin ameliorates pressure overload-induced cardiac hypertrophy by attenuating Atg5-dependent autophagy and activating the Akt/mTOR pathway.

Cardiac hypertrophy, including hypertension and valvular dysfunction, is a pathological feature of many cardiac diseases that ultimately leads to heart failure. Melatonin confers a protective role against pathological cardiac hypertrophy, but the underlying mechanisms remain elusive. In the present study, we hypothesized that melatonin protects against pressure overload-induced cardiac hypertrophy by attenuating Atg5-dependent autophagy and activating the Akt/mTOR pathway. Male C57BL/6 mice that received adenovirus carrying cardiac-specific Atg5 (under the cTNT promoter; Ad-cTNT-Atg5) underwent transverse aortic constriction (TAC) or sham operation and received an intraperitoneal injection of melatonin (10 mg/kg/d), vehicle or LY294002 (10 mg/kg/d) for 8 weeks. Melatonin treatment for 8 weeks markedly attenuated cardiac hypertrophy and restored impaired cardiac function, as indicated by a decreased HW/BW ratio, reduced cell cross-sectional area and fibrosis, downregulated the mRNA levels of ANP, BNP, and ß-MHC and ameliorated adverse effects on the LVEF and LVFS. Melatonin treatment also inhibited apoptosis and alleviated autophagy dysfunction. Furthermore, melatonin inhibited Akt/mTOR pathway activation, while these effects were blocked by LY294002. In addition, the effect of melatonin regulation on TAC-induced autophagy dysfunction was inhibited by LY294002 or cardiac-specific Atg5 overexpression. As expected, Akt/mTOR pathway inhibition or cardiac-specific Atg5 overexpression restrained melatonin alleviation of pressure overload-induced cardiac hypertrophy. These results demonstrated that melatonin ameliorated pressure overload-induced cardiac hypertrophy by attenuating Atg5-dependent autophagy and activating the Akt/mTOR pathway.

Asprosin improves the survival of mesenchymal stromal cells in myocardial infarction by inhibiting apoptosis via the activated ERK1/2-SOD2 pathway.

AIMS: Several adipokines have been proven to improve the therapeutic efficacy of mesenchymal stromal cells (MSCs) when used to treat ischemic heart disease. Asprosin (ASP) is a newly-discovered adipokine. ASP might also predict the severity of coronary pathology. We investigated the role of ASP on MSCs and the effects of ASP-pretreated MSCs on myocardial infarction (MI). MAIN METHODS: MSCs were labelled with a lentivirus carrying green fluorescent protein (GFP). For in vivo study, after pretreatment with vehicle or ASP, MSCs were injected into infarcted hearts. Cardiac function and fibrosis were then evaluated 4 weeks after the induction of MI and survival of MSCs evaluated after 1 week. MSCs proliferation and migration were investigated after ASP treatment in vitro. MSCs apoptosis induced by hydrogen peroxide (H2O2) was assessed using flow cytometry. KEY FINDINGS: Compared to vehicle-pretreated MSCs, ASP-pretreated MSCs significantly improved the left ventricular ejection fraction (LVEF), and inhibited myocardial fibrosis 4 weeks after MI. ASP pretreatment may have promoted homing of transplanted MSCs. In vitro results showed that ASP had no significant effect on MSC proliferation and migration, but protected these cells from H2O2-induced apoptosis. Among 21 molecules associated with antioxidation and cell death, the antioxidant enzyme SOD2 was significantly upregulated by ASP. Furthermore, ASP treatment inhibited H2O2-induced ROS generation and apoptosis via the activated ERK1/2-SOD2 pathway. SIGNIFICANCE: This is the first evidence that ASP can regulate MSCs function and enhance MSCs therapy for ischemic heart disease. Furthermore, we demonstrate that ASP protects MSCs from oxidative stress-induced apoptosis via the ERK1/2-SOD2 pathway.