Inhibition of circDGKZ ameliorates myocardial ischemia/reperfusion injury by targeting miR-345-5p/TLR4.

AIMS: This study aims to explore the molecular mechanism of circular RNAs' (circRNAs) potential involvement in myocardial ischaemia-reperfusion injury (MIRI). METHODS AND RESULTS: Differently expressed genes in myocardial infarction (MI) were identified by screening the GEO database. Serum was collected from MI patients and healthy volunteers (n = 5 for each group). AC16 cells were cultured and exposed to hypoxia/reperfusion (H/R) treatment for the cell experiments. Then candidate genes were validated in human serum and the H/R model. Quantitative real-time PCR and western blot were used to detect expression of key molecules such as circDGKZ, miR-345-5p, and Toll-like receptor 4 (TLR4), as well as pyroptosis markers such as NOD-like receptor thermal protein domain-associated protein 3 (NLRP3), ASC, C-caspase1, interleukin (IL)-1ß, and IL-18. CircDGKZ was positively correlated in human serum (P < 0.05) and in AC16 cells (P < 0.01). Knockdown of circDGKZ inhibited cardiomyocyte pyroptosis and the TLR4/nuclear factor kappa B (NF-κB) signalling pathway (all P < 0.05). A luciferase assay was used to detect the molecule interaction. MiR-345-5p was regulated by circDGKZ and regulated TLR4 in cardiomyocytes both through direct interaction (P < 0.01). The stability and distribution of circRNA or linear RNA were examined by subcellular localization and RNA decay assays. CircDGKZ was stably expressed in cardiomyocytes and mainly distributed in the cytoplasm (P < 0.01). Knockdown of circDGKZ also promoted the degradation of NLRP3 by inducing autophagy (P < 0.05). MIRI rat models were constructed (n = 5 for each group), and the cellular results were further confirmed in rat models (P < 0.05). CONCLUSIONS: Knockdown of circDGKZ interrupted pyroptosis and induced autophagy of cardiomyocytes via regulating miR-345-5p/TLR4/NF-κB.

Mesenchymal Stem Cells and Extracellular Vesicles: Therapeutic Potential in Organ Transplantation.

At present, organ transplantation remains the most appropriate therapy for patients with end-stage organ failure. However, the field of organ transplantation is still facing many challenges, including the shortage of organ donors, graft function damage caused by organ metastasis, and antibody-mediated immune rejection. It is therefore urgently necessary to find new and effective treatment. Stem cell therapy has been regarded as a "regenerative medicine technology." Mesenchymal stem cells (MSCs), as the most common source of cells for stem cell therapy, play an important role in regulating innate and adaptive immune responses and have been widely used in clinical trials for the treatment of autoimmune and inflammatory diseases. Increasing evidence has shown that MSCs mainly rely on paracrine pathways to exert immunomodulatory functions. In addition, mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) are the main components of paracrine substances of MSCs. Herein, an overview of the application of the function of MSCs and MSC-EVs in organ transplantation will focus on the progress reported in recent experimental and clinical findings and explore their uses for graft preconditioning and recipient immune tolerance regulation. Additionally, the limitations on the use of MSC and MSC-EVs are also discussed, covering the isolation of exosomes and preservation techniques. Finally, the opportunities and challenges for translating MSCs and MSC-EVs into clinical practice of organ transplantation are also evaluated.

The Impact of Valve Surgery on the Safety and Cardiac Function of Patients with Valvular Heart Disease Complicated by Pulmonary Arterial Hypertension.

Objective: This study evaluates the effects of valve surgery on safety and cardiac function in patients with valvular heart disease complicated by pulmonary arterial hypertension (PAH), focusing on postoperative outcomes influenced by age, heart function grade, and PAH severity. Methods: A retrospective analysis was conducted on 307 valve surgery patients from April 2017 to April 2022. The cohort had a mean age of 57.6 years, with 56.9% males, and was stratified by NYHA functional class II-IV. Outcomes assessed included mortality, complication rates, left ventricular ejection fraction (LVEF), and pulmonary artery systolic pressure (PASP), with statistical analysis performed using t-tests and chi-square tests for continuous and categorical data, respectively. Results: Postoperative outcomes varied significantly with age, NYHA class, and PASP grade. Patients aged ≤60 exhibited an average PASP reduction of 44.46% in the male group and 44.44% in the female group and an LVEF improvement of 5.28% in the male group and 5.80% in the female group. However, these patients showed a higher risk of postoperative complications, such as renal failure, arrhythmia, low cardiac output syndrome, respiratory insufficiency, (23.31%), and a higher mortality rate (13.53%)(P < .05). Higher NYHA classes correlated with increased postoperative risks of complications and mortality rates, and elevated PASP grades were associated with larger improvements in PASP and LVEF but also higher postoperative risks. Conclusion: Valve surgery in valvular heart disease with PAH is influenced by patient age, functional status, and PAH severity. Despite advances in surgical techniques, there remains a notable gap in understanding the nuanced interplay between these conditions and the variable outcomes of valve surgery. This study addresses this research gap, offering comprehensive insights into how age, heart function, and PAH severity influence postoperative outcomes. These findings are crucial for clinicians, providing a more informed basis for tailored treatment strategies, and ultimately enhancing patient care in this complex clinical scenario.Healthcare providers should consider the age-specific benefits and risks of valve surgery in patients with valvular heart disease and pulmonary arterial hypertension. Tailored decision-making, particularly for those aged ≤60, higher NYHA classes, or severe PAH, is essential for optimizing individual outcomes.

Preservation solution Custodiol containing human alpha-1-antitrypsin improves graft recovery after prolonged cold ischemic storage in a rat model of heart transplantation.

Introduction: The shortage of available donor hearts and the risk of ischemia/reperfusion injury restrict heart transplantation (HTX). Alpha-1-antitrypsin (AAT), a well-characterized inhibitor of neutrophil serine protease, is used in augmentation therapy to treat emphysema due to severe AAT deficiency. Evidence demonstrates its additional anti-inflammatory and tissue-protective effects. We hypothesized that adding human AAT in a preservation solution reduces graft dysfunction in a rat model of HTX following extended cold ischemic storage. Methods: The hearts from isogenic Lewis donor rats were explanted, stored for either 1h or 5h in cold Custodiol supplemented with either vehicle (1h ischemia, n=7 or 5h ischemia, n=7 groups) or 1 mg/ml AAT (1h ischemia+AAT, n=7 or 5h ischemia+AAT, n=9 groups) before heterotopic HTX. Left-ventricular (LV) graft function was evaluated in vivo 1.5h after HTX. Immunohistochemical detection of myeloperoxydase (MPO) was performed in myocardial tissue and expression of 88 gene quantified with PCR was analyzed both statistical and with machine-learning methods. Results: After HTX, LV systolic function (dP/dtmax 1h ischemia+AAT 4197 ± 256 vs 1h ischemia 3123 ± 110; 5h ischemia+AAT 2858 ± 154 vs 5h ischemia 1843 ± 104mmHg/s, p<0.05) and diastolic function (dP/dtmin 5h ischemia+AAT 1516 ± 68 vs 5h ischemia 1095 ± 67mmHg/s, p<0.05) at an intraventricular volume of 90µl were improved in the AAT groups compared with the corresponding vehicle groups. In addition, the rate pressure product (1h ischemia+AAT 53 ± 4 vs 1h ischemia 26 ± 1; 5h ischemia+AAT 37 ± 3 vs 5h ischemia 21 ± 1mmHg*beats/min at an intraventricular volume of 90µl; p<0.05) was increased in the AAT groups compared with the corresponding vehicle groups. Moreover, the 5h ischemia+AAT hearts exhibited a significant reduction in MPO-positive cell infiltration in comparison to the 5h ischemia group. Our computational analysis shows that ischemia+AAT network displays higher homogeneity, more positive and fewer negative gene correlations than the ischemia+placebo network. Discussion: We provided experimental evidence that AAT protects cardiac grafts from prolonged cold ischemia during HTX in rats.

Upregulation of P2Y14 receptor in neutrophils promotes inflammation after myocardial ischemia/reperfusion injury.

BACKGROUND: P2Y14 receptor is expressed in neutrophils and is involved in activation of inflammatory signaling. However, the expression and function of P2Y14 receptor in neutrophils after myocardial infarction/reperfusion (MIR) injury remain to be elucidated. METHODS: In this research, rodent and cellular models of MIR were used to detect the involvement and function of P2Y14 receptor, as well as the regulation of inflammatory signaling via P2Y14 receptor in neutrophils post-MIR. RESULTS: In the early stage post MIR, the expression of P2Y14 receptor was upregulated in CD4+Ly-6G+ neutrophils. Additionally, the expression of P2Y14 receptor was highly induced in neutrophils subjected to uridine 5'-diphosphoglucose (UDP-Glu), which is proven to be secreted by cardiomyocytes during ischemia and reperfusion. Our results also showed the beneficial role of P2Y14 receptor antagonist PPTN in counteracting inflammation via promoting polarization of neutrophils to N2 phenotype in the infarct area of the heart tissue after MIR. CONCLUSION: These findings prove that the P2Y14 receptor is involved in the regulation of inflammation in the infarct area after MIR, and establish a novel signaling pathway concerning the interplay between cardiomyocytes and neutrophils in the heart tissue.

LncRNA KCNQ1OT1 Participates in Ox-LDL-Induced Proliferation/Apoptosis Imbalance in Vascular Smooth Muscle Cells by Regulating the MiR-196a-5p/FOXO1 Axis.

Backgroud The present study aimed to investigate the function and regulatory mechanisms of lncRNA KCNQ1OT1 in vascular smooth muscle cells under oxidation low lipoprotein stimulation. Methods RNA sequencing was used to detect transcriptome changes of vascular smooth muscle cells treated with oxidation low lipoprotein. KCNQ1OT1, miR-196a-5p, and FOXO1 expression levels in VSMCs after oxidation low lipoprotein treatment were assessed using qRT-PCR and western blotting. RNA immunoprecipitation, RNA pull-down, and dual-luciferase reporter assay were used to confirm the interaction among lncRNA KCNQ1OT1, miR-196a-5p, and FOXO1. The functions of KCNQ1OT1, miR-196a-5p, and FOXO1 were analyzed by CCK-8 and flow cytometry. The serum samples of high fat-feeding mice and atherosclerosis patients were collected, and the levels of KCNQ1OT1 and miR-196a-5p were analyzed. Results In vitro expression of KCNQ1OT1 and FOXO1 decreased in VSMCs treated with oxidation low lipoprotein, accompanied by overexpression of miR-196a-5p. As a ceRNA, KCNQ1OT1 positively regulated FOXO1 and imparted a negative regulatory effect on miR-196a-5p. Interference KCNQ1OT1/miR-196a-5p/FOXO1 could change roliferation/apoptosis imbalance in VSMCs under oxidation low lipoprotein stimulation. Higher levels of KCNQ1OT1 and lower levels of miR-196a-5p can be found in the thoracic aorta tissues of high fat-feeding mice and serum samples from individuals with carotid atherosclerosis. Conclusion Aberrant expression of KCNQ1OT1/miR-196a-5p/FOXO1 pathway mediated oxidation low lipoprotein-induced proliferation/apoptosis imbalance in VSMCs.

ox-LDL regulates proliferation and apoptosis in VSMCs by controlling the miR-183-5p/FOXO1.

BACKGROUND: microRNA-mRNA axes that are involved in oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs) proliferation/apoptosis imbalance need to be further investigated. OBJECTIVE: To investigate the functional role of miR-183-5p/FOXO1 in VSMCs and its interaction with ox-LDL. METHODS: RNA sequencing was used to detect transcriptome changes of VSMCs treated with ox-LDL. miR-183-5p and FOXO1 expression levels in VSMCs after ox-LDL treatment were assessed using qRT-PCR and western blotting. The regulatory effect of miR-183-5p on FOXO1 has been tried to prove using a dual-luciferase reporter assay. The functions of miR-183-5p, and FOXO1 were analyzed by CCK-8 assay and flow cytometry assay. The tissue samples or serum samples of high fat-feeding mice and carotid atherosclerosis patients were collected, and the levels of miR-183-5p/FOXO1 were analyzed. RESULTS: RNA sequencing data showed 81 miRNAs including miR-183-5p was significantly changed after ox-LDL treatment in VSMCs. FOXO1, a miR-183-5p's potential target, was also down-regulated in ox-LDL treated cells. qRT-PCR and western blot found that expression of FOXO1 mRNA and protein significantly reduced in VSMCs treated with ox-LDL, accompanied by overexpression of miR-183-5p. miR-183-5p inhibited FOXO1 mRNA by binding to its 3' UTR. Interference miR-183-5p/FOXO1 could change proliferation/apoptosis imbalance in VSMCs under ox-LDL stimulation. Higher levels of miR-183-5p but reduced FOXO1 can be found in the thoracic aorta tissues of high fat-feeding mice. In serum samples from individuals with carotid atherosclerosis, Higher levels of miR-183-5p were observed. the miR-183-5p level was positively related to the level of serum ox-LDL in patients. CONCLUSIONS: Aberrant expression of miR-183-5p/FOXO1 pathway mediated ox-LDL-induced proliferation/apoptosis imbalance in VSMCs. The miR-183-5p/FOXO1 axis can potentially be utilized as the target in the treatment of patients with atherosclerosis.

MicroRNA-29b reduces myocardial ischemia-reperfusion injury in rats via down-regulating PTEN and activating the Akt/eNOS signaling pathway.

Reperfusion may cause injuries to the myocardium in ischemia situation, which is called ischemia/reperfusion (I/R) injury. The study aimed to explore the roles of microRNA-29b (miR-29b) in myocardial I/R injury. Myocardial I/R injury rat model was established. Differentially expressed miRNAs between the model rats and the sham-operated rats were analyzed. miR-29b expression in myocardial tissues was measured. Gain-of-function of miR-29b was performed, and then the morphological changes, infarct size, myocardial function, oxidative stress, and the cell apoptosis in myocardial tissues were detected. The target relation between miR-29b and PTEN was detected through bio-information prediction and dual luciferase reporter gene assay. Activation of Akt/eNOS signaling was detected. H9C2 cells were subjected to hypoxia/reoxygenation treatment to perform in vitro experiments. I/R rats presented severe inflammatory infiltration, increased infarct size and cell apoptosis, increased oxidative stress and decreased myocardial function. miR-29b was downregulated in I/R rats, and up-regulation of miR-29b reversed the above changes. miR-29b directly bound to PTEN, and overexpression of miR-29b reduced PTEN expression level and increased the protein levels of p-Akt/Akt and p-eNOS/eNOS. In vivo results were confirmed in in vitro experiments. This study provided evidence that miR-29b could alleviate the myocardial I/R injury in vivo and in vitro by inhibiting PTEN expression and activating the Akt/eNOS signaling pathway.

Circ_nuclear factor I X (circNfix) attenuates pressure overload-induced cardiac hypertrophy via regulating miR-145-5p/ATF3 axis.

Cardiac hypertrophy can cause heart failure. However, the mechanisms underlying the progression of cardiac hypertrophy remain unclear. Emerging evidence suggests that circular RNAs (circRNAs) play a critical role in cardiac hypertrophy. However, the association between circ_nuclear factor I X (circNfix) and cardiac hypertrophy remain largely unknown. Therefore, the aim of the present study was to explore the role of circNfix in cardiac hypertrophy. In order to detect the function of circNfix in cardiac hypertrophy, cardiomyocytes were stimulated with angiotensin II (Ang II) to mimic the pathogenesis of the disease. In addition, pressure overload-induced cardiac hypertrophy in a mouse model was established using transverse aortic constriction (TAC) surgery. The mechanism via which circNfix regulated cardiac hypertrophy was investigated using RNA pull-down and luciferase reporter assays, and fluorescence in situ hybridization (FISH). circNfix was downregulated in Ang II-treated cardiomyocytes. Similarly, circNfix expression was markedly downregulated in mice following TAC surgery. In addition, circNfix overexpression significantly prevented the progression of cardiac hypertrophy in TAC-treated mice. Luciferase activity and RNA pull-down assays indicated that circNfix could indirectly target activating transcription factor 3 (ATF3) by binding with microRNA (miR)-145-5p in cardiomyocytes. miR-145-5p overexpression or ATF3 knockdown could reverse the effects of circNfix in Ang II-treated mouse cardiomyocytes. circNfix attenuated pressure overload-induced cardiac hypertrophy by regulating the miR-145-5p/ATF3 axis. Therefore, circNfix may serve as a molecular target for cardiac hypertrophy treatment.

A Novel Rat Model of Cardiac Donation After Circulatory Death Combined With Normothermic ex situ Heart Perfusion.

Background: In heart transplantation, the adoption of hearts from donation after circulatory death (DCD) is considered to be a promising approach to expanding the donor pool. Normothermic ex situ heart perfusion (ESHP) is emerging as a novel preservation strategy for DCD hearts. Therefore, pre-clinical animal models of ESHP are essential to address some key issues before efficient clinical translation. We aim to develop a novel, reproducible, and economical rat model of DCD protocol combined with normothermic ESHP. Methods: Circulatory death of the anesthetized rats in the DCD group was declared when systolic blood pressure below 30 mmHg or asystole was observed after asphyxiation. Additional 15 min of standoff period was allowed to elapse. After perfusion of cold cardioplegia, the DCD hearts were excised and perfused with allogenic blood-based perfusate at constant flow for 90 min in the normothermic ESHP system. Functional assessment and blood gas analysis were performed every 30 min during ESHP. The alteration of DCD hearts submitted to different durations of ESHP (30, 60, and 90 min) in oxidative stress, apoptosis, tissue energy state, inflammatory response, histopathology, cell swelling, and myocardial infarction during ESHP was evaluated. Rats in the non-DCD group were treated similarly but not exposed to warm ischemia and preserved by the normothermic ESHP system for 90 min. Results: The DCD hearts showed compromised function at the beginning of ESHP and recovered over time, while non-DCD hearts presented better cardiac function during ESHP. The alteration of DCD hearts in oxidative stress, apoptosis, tissue energy state, histopathological changes, cell swelling, and inflammatory response didn't differ among different durations of ESHP. At the end of 90-min ESHP, DCD, and non-DCD hearts presented similarly in apoptosis, oxidative stress, inflammatory response, myocardial infarction, and histopathological changes. Moreover, the DCD hearts had lower energy storage and more evident cell swelling compared to the non-DCD hearts. Conclusion: We established a reproducible, clinically relevant, and economical rat model of DCD protocol combined with normothermic ESHP, where the DCD hearts can maintain a stable state during 90-min ESHP.

Two New Alkaloids from Fuzi and Their Metabolites Study.

Former study suggests alkaloids from herbs of Aconitum genus plants possess excellent bioactivities, which exert great value for related deeper chemical constituent investigation. Herein, chemical isolation was performed and four alkaloids were isolated from Fuzi, of which two were new ones, and the other two were reported NMR data for the first time. Their chemical structures were identified by NMR data, high resolution MS, UV and IR analysis. Additionally, the MS fragmentation patterns were explored, formerly, that of hetisane alkaloid was rarely reported, and fragmentation mechanism of the diagnostic ion was proposed. Based on these fragment pathway, metabolites and metabolic pathways of four compounds were investigated in rat liver microsomes using UPLC-Q/TOF-MS, and dehydrogenation product was firstly found from metabolites of hetisane alkaloid.

LncRNA HCP5 in hBMSC-derived exosomes alleviates myocardial ischemia reperfusion injury by sponging miR-497 to activate IGF1/PI3K/AKT pathway.

Ischemia/reperfusion (I/R) injury is an inevitable process during heart transplant and suppressing I/R injury could greatly improve the survival rate of recipients. Mesenchymal stem cells (MSCs) have positive effects on I/R. We aimed to investigate the mechanisms underlying the protective roles of MSCs in I/R. Both cell model and rat model of myocardial I/R were used. MTT assay and flow cytometry were used to measure cell viability and apoptosis, respectively. QRT-PCR and western blotting were employed to measure levels of lncRNA HCP5 (HLA complex P5), miR-497, apoptosis-related proteins, and insulin-like growth factor (IGF1)/PI3K/AKT pathway. Dual luciferase assay was used to validate interactions of HCP5 and miR-497, miR-497 and IGF1. Echocardiography was performed to evaluate cardiac function of rats. Serum levels of CK-MB and LDH were measured. H&E and Masson staining were used to examine morphology of myocardial tissues. hBMSC-derived exosomes (hBMSC-Exos) increased the viability of cardiomyocytes following hypoxia/reperfusion (H/R) and decreased apoptosis. H/R diminished HCP5 expression in cardiomyocytes while hBMSC-Exos recovered the level. Overexpression of HCP5 in hBMSC-Exos further enhanced the protective effects in H/R while HCP5 knockdown suppressed. HCP5 directly bound miR-497 and miR-497 targeted IGF1. miR-497 mimics or si-IGF1 blocked the effects of HCP5 overexpression. Further, hBMSC-Exos alleviated I/R injury in vivo and knockdown of HCP5 in hBMSC-Exos decreased the beneficial effects. AntagomiR-497 blocked the effects of HCP5 knockdown. HCP5 from hBMSC-Exos protects cardiomyocytes against I/R injury via sponging miR-497 to disinhibit IGF1/PI3K/AKT pathway. These results shed light on mechanisms underlying the protective role of hBMSC-Exos in I/R.

Application of Mesenchymal Stem Cells During Machine Perfusion: An Emerging Novel Strategy for Organ Preservation.

Although solid organ transplantation remains the definitive management for patients with end-stage organ failure, this ultimate treatment has been limited by the number of acceptable donor organs. Therefore, efforts have been made to expand the donor pool by utilizing marginal organs from donation after circulatory death or extended criteria donors. However, marginal organs are susceptible to ischemia-reperfusion injury (IRI) and entail higher requirements for organ preservation. Recently, machine perfusion has emerged as a novel preservation strategy for marginal grafts. This technique continually perfuses the organs to mimic the physiologic condition, allows the evaluation of pretransplant graft function, and more excitingly facilitates organ reconditioning during perfusion with pharmacological, gene, and stem cell therapy. As mesenchymal stem cells (MSCs) have anti-oxidative, immunomodulatory, and regenerative properties, mounting studies have demonstrated the therapeutic effects of MSCs on organ IRI and solid organ transplantation. Therefore, MSCs are promising candidates for organ reconditioning during machine perfusion. This review provides an overview of the application of MSCs combined with machine perfusion for lung, kidney, liver, and heart preservation and reconditioning. Promising preclinical results highlight the potential clinical translation of this innovative strategy to improve the quality of marginal grafts.

The MicroRNA-210/Casp8ap2 Pathway Alleviates Hypoxia-Induced Injury in Myocardial Cells by Regulating Apoptosis and Autophagy.

AIM: This study was conducted to investigate the role of the miR-210/Caspase8ap2 pathway in apoptosis and autophagy in hypoxic myocardial cells. METHODS: The miR-control, miR-210 mimic, and miR-210 inhibitor were transfected into rat myocardial H9C2 cells. The transfection efficiency of exogenous miR-210 was determined by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). H9C2 cells were then treated with CoCl2 for 24, 48, and 72 h to generate a myocardial injury model. The apoptosis of H9C2 cells was assessed by flow cytometry. Additionally, a western blot assay was used to determine the expression of the autophagy-associated proteins light chain 3 (LC3), p62 and Beclin-1, and apoptosis-associated proteins Caspase8ap2, cleaved caspase 8, and cleaved caspase 3. RESULTS: We determined that a 48 h hypoxia treatment duration in H9C2 cardiomyocytes induced myocardial injury. Additionally, the overexpression of miR-210 significantly inhibited cell apoptosis. MiR-210 suppressed autophagy by upregulating p62 and downregulating LC3II/I in hypoxic H9C2 cells. Caspase8ap2 was a putative target of miR-210, miR-210 mediated apoptosis, and autophagy of H9C2 cells via suppressing Caspase8ap2. Furthermore, the expression of caspase 8, caspase 3, and Beclin-1 were decreased in response to miR-210. CONCLUSION: miR-210 exhibits anti-apoptosis and anti-autophagy effects, which alleviate myocardial injury in response to hypoxia.

Risk factors and long-term outcomes of elderly patients complicating with acute kidney injury after type A acute aortic dissection surgery: a retrospective study.

BACKGROUND: To identify risk factors and long-term outcomes for acute kidney injury (AKI) in elderly patients who underwent type A acute aortic dissection (TA-AAD) emergency surgeries. METHODS: This retrospective study enrolled 214 consecutive patients who underwent TA-AAD emergency surgeries between January 2014 to December 2018 in Nanjing Drum Tower hospital. The diagnosis of AKI was made based on the Kidney Disease: Improving Global Outcomes definition (KDIGO) criteria. Multivariable regression analysis was performed to identify risk factors for postoperative AKI. Kaplan-Meier curves were generated to compare the long-term outcomes between patients with and without AKI complication after TA-AAD surgeries. RESULTS: Among all enrolled patients, 114 (53.3%) developed AKI during postoperative period. The median age of patients with or without AKI was 68.0 (64.0, 74.0) and 66.0 (62.0, 72.8) years respectively. Renal replacement therapy (RRT) was required in 43 patients (20.1%). The 30-day mortality rate was 21.5% in all enrolled patients with 26.3% in AKI group and 16.0% in non-AKI group (P=0.067) respectively. Longer mechanical ventilation duration was identified as the only independent risk factor for developing AKI by multivariable logistic regression analysis. In addition, our data suggested that the long-term cumulative survival rate was different between two groups. CONCLUSIONS: Postoperative AKI after TA-AAD surgeries was common and associated with worsened long-term mortality in elderly patients. Longer postoperative mechanical ventilation duration was identified as the only independent risk factor for the development of AKI.

MicroRNA­132 promotes oxidative stress­induced pyroptosis by targeting sirtuin 1 in myocardial ischaemia­reperfusion injury.

The present study aimed to investigate the roles of miR­132 in myocardial ischaemia/reperfusion (I/R) injury and the underlying mechanisms. The myocardial I/R model was established using C57BL/J6 mice. Haematoxylin and eosin staining was performed to observe the injury of myocardial tissues. Commercial kits were used to measure the levels of serum myocardial enzymes and inflammatory factors. The in vitro I/R model was established by the hypoxia/reoxygenation method using H9C2 cells. A dual luciferase reporter assay was used to confirm the binding of miR­132 and sirtuin 1 (SIRT1). Cell pyroptosis was determined using flow cytometry. Reverse transcription­quantitative PCR was performed to determine the expression of miR­132, SIRT1 and inflammatory factors. The levels of peroxisome proliferator­activated receptor gamma coactivator (PGC)­1α/nuclear factor erythroid­2­related factor 2 (Nrf2) signalling, oxidative stress and pyroptosis­related proteins were detected by western blotting. Apparent histologic injury and elevated levels of serum myocardial enzymes and inflammatory factors were observed in the myocardial I/R model. miR­132 was significantly upregulated and SIRT1 was markedly downregulated in I/R myocardial tissues. miR­132 directly targeted SIRT1 and negatively regulated the expression of SIRT1. PGC­1α, Nrf2, endothelial nitric oxide synthase and superoxide dismutase levels were significantly decreased, while inducible nitric oxide synthase and malondialdehyde levels were significantly increased by I/R induction. The pyroptosis­related proteins NLRP3, caspase­1 and interleukin (IL)­1ß were also significantly elevated by I/R induction. Inhibition of miR­132 activated PGC­1α/Nrf2 signalling and inhibited oxidative stress and the expression of the pyroptosis­related proteins NLRP3, caspase­1 and IL­1ß, which were all reversed by inhibiting SIRT1 with EX527. The findings of the present study indicated that inhibition of miR­132 may ameliorate myocardial I/R injury by inhibiting oxidative stress and pyroptosis through activation of PGC­1α/Nrf2 signalling by targeting SIRT1.

Brain-dead donor heart conservation with a preservation solution supplemented by a conditioned medium from mesenchymal stem cells improves graft contractility after transplantation.

Hearts are usually procured from brain-dead (BD) donors. However, brain death may induce hemodynamic instability, which may contribute to posttransplant graft dysfunction. We hypothesized that BD-donor heart preservation with a conditioned medium (CM) from mesenchymal stem cells (MSCs) would improve graft function after transplantation. Additionally, we explored the PI3K pathway's potential role. Rat MSCs-derived CM was used for conservation purposes. Donor rats were either exposed to sham operation or brain death by inflation of a subdural balloon-catheter for 5.5 hours. Then, the hearts were explanted, stored in cardioplegic solution-supplemented with either a medium vehicle (BD and sham), CM (BD + CM), or LY294002, an inhibitor of PI3K (BD + CM + LY), and finally transplanted. Systolic performance and relaxation parameters were significantly reduced in BD-donors compared to sham. After transplantation, systolic and diastolic functions were significantly decreased, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells and endonuclease G positive cells were increased in the BD-group compared to sham. Preservation of BD-donor hearts with CM resulted in a recovery of systolic graft function (dP/dtmax : BD + CM: 3148 ± 178 vs BD: 2192 ± 94 mm Hg/s at 110 µL, P < .05) and reduced apoptosis. LY294002 partially lowered graft protection afforded by CM in the BD group. Our data suggest that PI3K/Akt pathway is not the primary mechanism of action of CM in improving posttransplant cardiac contractility and preventing caspase-independent apoptosis.

MiR-29a in mesenchymal stem cells inhibits FSTL1 secretion and promotes cardiac myocyte apoptosis in hypoxia-reoxygenation injury.

BACKGROUND: Mesenchymal stem cells (MSCs) are under consideration for myocardial ischemia-reperfusion (I/R) injury therapy, but their mechanism remains to be evaluated. In this article, we aimed to study the effects of the miR-29a/follistatin-like 1 axis in bone marrow-derived mesenchymal stem cells on modulating myocyte apoptosis after hypoxia-reoxygenation (H/R) injury. METHODS: An in vitro myocardial ischemia-reperfusion injury model of H9c2 cells was developed by hypoxia-reoxygenation injury. The mRNA levels of follistatin-like 1, Bcl-2, Bax, and miR-29a and the protein levels of Bcl-2, Bax, cleaved caspase-3, and components of the JAK2/STAT3 pathway were detected by qRT-PCR and western blotting, respectively. Secretion of follistatin-like 1 was evaluated by enzyme-linked immunosorbent assay. Cell apoptosis was evaluated by flow cytometry. The interaction between miR-29a and follistatin-like 1 was evaluated by dual luciferase reporter assay. RESULTS: MiR-29a suppressed the expression and secretion of follistatin-like 1 in bone marrow-derived mesenchymal stem cells. Overexpression of follistatin-like 1 in bone marrow-derived mesenchymal stem cells decreased apoptosis of myocytes induced by hypoxia-reoxygenation. Cell apoptosis in myocytes was promoted by conditioned medium from bone marrow-derived mesenchymal stem cells with ectopic miR-29a expression. Conditioned medium of miR-29a-overexpressing bone marrow-derived mesenchymal stem cells inhibited the JAK2/STAT3 pathway in myocytes to promote apoptosis of myocytes. CONCLUSIONS: MiR-29a in bone marrow-derived mesenchymal stem cells inhibits follistatin-like 1 secretion and promotes myocyte apoptosis by suppressing the JAK2/STAT3 pathway in hypoxia-reoxygenation injury.

Modulation of the Proliferation/Apoptosis Balance of Vascular Smooth Muscle Cells in Atherosclerosis by lncRNA-MEG3 via Regulation of miR-26a/Smad1 Axis.

The balance between proliferation and apoptosis of vascular smooth muscle cells (VSMCs) plays a critical role in the initiation of atherosclerosis. LncRNA-MEG3 is involved in the pathophysiology of atherosclerosis through regulation of endothelial cell proliferation and migration. Its effect on the dysfunction of VSMCs and the corresponding mechanisms are actively researched. In this study, we observed that downregulated lncRNA-MEG3 expression was inversely correlated with the microRNA-26a level in coronary artery disease tissues. The overexpression of lncRNA-MEG3 could inhibit VSMCs proliferation while facilitating apoptosis. Moreover, alteration in the miR-26a/Smad1 axis could antagonize this effect. Bioinformatic analysis indicated that lncRNA-MEG3 could interact with miR-26a via complementary binding sites. The enforced expression of lncRNA-MEG3 could reduce the level of miR-26a in VSMCs, while the expression of Smad1 increases. Further, the direct binding between lncRNA-MEG3 and miR-26a was confirmed via dual-luciferase reporter assay, which indicated that lnc-MEG3 could sponge miR-26a as a competing endogenous RNA. In summary, we propose that lncRNA-MEG3 modulates the proliferation/apoptosis balance of VSMCs in atherosclerosis by regulating the miR-26a/Smad1 axis.

Luteolin exerts an anticancer effect on NCI-H460 human non-small cell lung cancer cells through the induction of Sirt1-mediated apoptosis.

Luteolin is a falconoid compound, which exhibits anticancer properties, however, its contribution to Sirt1-mediated apoptosis in human non-small cell lung cancer remains to be elucidated. The present study confirmed that the anticancer effect of luteolin on NCI­H460 cells was through Sirt1­mediated apoptosis. The NCI­H460 cells were treated with different concentrations of luteolin, and a 3­(4,5­dimethyl­2­thiazolyl)­2,5­diphnyl­2H­tetrazolium bromide assay, cell cycle analysis and annexin­V/fluorescein isothiocyanate and propidium double staining were performed to assess the apoptotic effect of luteolin. Wound healing and Transwell assays were performed to confirm the inhibition of NCI­H460 cell migration. The protein levels of Sirt1 were knocked down in the NCI­H460 cells using a lentivirus to further investigate the role of this protein, and the expression levels of the apoptotic associated proteins, Bad, Bcl­2, Bax, caspase­3 and Sirt1, were measured using western blotting. The results of the present study demonstrated that luteolin exerted an anticancer effect against NCI­H460 cells through Sirt1­mediated apoptosis and the inhibition of cell migration.