Experimental diabetes exacerbates autophagic flux impairment during myocardial I/R injury through calpain-mediated cleavage of Atg5/LAMP2.

To explore the role of autophagic flux in the increased susceptibility of the experimental diabetic heart to ischaemia-reperfusion (I/R) injury, we established STZ-induced diabetic mice and performed I/R. In vitro, neonatal mouse cardiomyocytes were subjected to high glucose and hypoxia/reoxygenation challenge to mimic diabetic I/R injury. We found that experimental diabetes aggravated I/R-induced injury than compared with nondiabetic mice. Autophagic flux was impaired in I/R hearts, and the impairment was exacerbated in diabetic mice subjected to I/R with defective autophagosome formation and clearance. Calpains, calcium-dependent thiol proteases, were upregulated and highly activated after I/R of diabetes, while calpain inhibition attenuated cardiac function and cell death and partially restored autophagic flux. The expression levels of Atg5 and LAMP2, two crucial autophagy-related proteins, were significantly degraded in diabetic I/R hearts, alterations that were associated with calpain activation and could be reversed by calpain inhibition. Co-overexpression of Atg5 and LAMP2 reduced myocardial injury and normalized autophagic flux. In conclusion, experimental diabetes exacerbates autophagic flux impairment of cardiomyocytes under I/R stress, resulting in worse I/R-induced injury. Calpain activation and cleavage of Atg5 and LAMP2 at least partially account for the deterioration of autophagic flux impairment.

Clinical presentation and in-hospital outcomes of intraoperative red blood cell transfusion in non-anemic patients undergoing elective valve replacement.

Background: Intraoperative transfusion is associated with adverse clinical outcomes in cardiac surgery. However, few studies have shown the impact of intraoperative red blood cell (RBC) transfusion on non-anemic patients undergoing cardiac surgery. We assessed the in-hospital clinical outcomes of non-anemic patients undergoing isolated valve replacements and investigated the predictors associated with intraoperative RBC transfusion. Methods: We enrolled 345 non-anemic patients undergoing isolated valve replacements in our department from January 2015 to December 2019. The patients were stratified by the receipt of intraoperative RBC transfusion. Baseline characteristics were compared between groups and multiple logistic regression was used to identify the predictors for intraoperative RBC transfusion. The association between intraoperative RBC transfusion and in-hospital outcomes was also evaluated. Results: Intraoperative RBC transfusion developed in 84 of the 345 enrolled patients (24.3%). Three independent predictors for intraoperative RBC transfusion of non-anemic patients undergoing isolated valve replacements were identified by multivariate logistic analysis, including female, iron deficiency and hemoglobin level. When the two groups were compared, a significant tendency of higher in-hospital mortality (6.0% vs. 1.1%, P = 0.033) and higher incidence of postoperative hypoxemia (9.5% vs. 2.7%, P = 0.007) were observed in the intraoperative RBC transfusion group. After adjustment, the presence of intraoperative RBC transfusion was associated with an increase in postoperative hypoxemia (OR = 3.36, 95% CI: 1.16-9.71, P = 0.026). Conclusion: Intraoperative RBC transfusion was associated with poorer clinical outcomes in non-anemic adults undergoing isolated valve replacements, which significantly increased the risk of postoperative hypoxemia. The independent predictors of intraoperative RBC transfusion, such as iron deficiency and female, were identified, which may be helpful for risk assessment and perioperative management.

MiR-375-3p Promotes Cardiac Fibrosis by Regulating the Ferroptosis Mediated by GPX4.

Although coronary artery recanalization after myocardial infarction improves patient outcomes, inadequate ventricular remodeling following ischemia-reperfusion (IR) injury and secondary cardiac fibrosis (CF) are common and can lead to heart failure. MicroRNAs (miRNAs) play an important role in cardiovascular disorders. However, the underlying molecular mechanism of miRNAs in the occurrence and progression of CF has not been fully elucidated. Herein, through the construction of an I/R rat model and an angiotensin II-induced CF cell model, we evaluated the role of miR-375-3p in the progression of CF. In the I/R rat model and CF cell model, miR-375-3p promoted fibrosis by accelerating the ferroptosis of cardiomyocytes through mediating glutathione peroxidase 4 (GPX4). Furthermore, we treated the rats or cell model with miR-375-3p antagomir (or inhibitor) and ferroptosis inhibitor Ferrostatin-1 (Fer-1). The results showed that miR-375-3p antagomir (or inhibitor) and Fer-1 promoted the antioxidant capacity of cardiac fibroblasts, reduced GPX4-mediated ferroptosis process and alleviated I/R-induced CF. In conclusion, this study revealed that miR-375-3p directly targeted GPX4-an inhibitor of the ferroptosis pathway. Meanwhile, miR-375-3p can be a new potential biomarker for the prevention and treatment of CF.

Protective Effect of Dihydrokaempferol on Acetaminophen-Induced Liver Injury by Activating the SIRT1 Pathway.

Acetaminophen (APAP) overdose is the leading cause of acute liver failure (ALF) in the Western world, with limited treatment opportunities. 3,5,7,4[Formula: see text]-Tetrahydroxyflavanone (Dihydrokaempferol, DHK, Aromadendrin) is a flavonoid isolated from Chinese herbs and displays high anti-oxidant and anti-inflammatory capacities. In this study, we investigated the protective effect by DHK against APAP-induced liver injury in vitro and in vivo and the potential mechanism of action. Cell viability assays were used to determine the effects of DHK against APAP-induced liver injury. The levels of reactive oxygen species (ROS), serum alanine/aspartate aminotransferases (ALT/AST), liver myeloperoxidase (MPO), and malondialdehyde (MDA) were measured and analyzed to evaluate the effects of DHK on APAP-induced liver injury. Western blotting, immunofluorescence staining, RT-PCR, and Transmission Electron Microscope were carried out to detect the signaling pathways affected by DHK. Here, we found that DHK owned a protective effect on APAP-induced liver injury with a dose-dependent manner. Meanwhile, Western blotting showed that DHK promoted SIRT1 expression and autophagy, activated the NRF2 pathway, and inhibited the translocation of nuclear p65 (NF-[Formula: see text]B) in the presence of APAP. Furthermore, SIRT1 inhibitor EX-527 aggravated APAP-induced hepatotoxicity when treating with DHK. Molecular docking results suggested potential interaction between DHK and SIRT1. Taken together, our study demonstrates that DHK protects against APAP-induced liver injury by activating the SIRT1 pathway, thereby promoting autophagy, reducing oxidative stress injury, and inhibiting inflammatory responses.

Low Concentrations of Zinc Oxide Nanoparticles Cause Severe Cytotoxicity Through Increased Intracellular Reactive Oxygen Species.

With wide application of Zinc oxide (ZnO) nanoparticles, their biological toxicity has received more and more attention in recent years. In this research, two ZnO dispersions with different particle sizes, small size Zinc oxide (S-ZnO) and big size Zinc oxide (B-ZnO), were prepared using polycarboxylic acid as dispersant. We found that the S-ZnO nanoparticles showed stronger toxicity on Human Pulmonary Alveolar Epithelial Cells (HPAEpiC) under same concentration. Only 9 ppm S-ZnO could decrease HPAEpiC viability to about 50%, which means that, a small amount of well-dispersed ZnO nanoparticles in industrial production process may cause serious damage to the human body through oral inhalation. Focusing on mechanism for cytotoxicity, ZnO nanoparticles promoted generation and accumulation of Reactive Oxygen Species (ROS) in mitochondria via inhibiting Superoxide Dismutase (SOD) enzyme activity and reducing Glutathione (GSH) content. ROS in turn opened the mitochondrial Ca2+ pathway and lowered the Mitochondrial Membrane Potentials (MMP), leading to cell death. To simulate the lung environment in vitro, mixed dipalmitoyl phosphatidylcholine (DPPC) and ZnO nanoparticles (1:1) were incubated for 72 hours and then cytotoxicity was evaluated on HPAEpiC. Results showed that the cell viability was significantly increased, which proved that the DPPC effectively inhibited the toxicity of ZnO nanoparticles.

Degradable calcium deficient hydroxyapatite/poly(lactic-glycolic acid copolymer) bilayer scaffold through integral molding 3D printing for bone defect repair.

A novel method was developed for calcium deficient hydroxyapatite (CDHA) scaffold 3D printing, through which a bilayer scaffold was fabricated by the integral molding of individual CDHA and poly(lactic-glycolic acid copolymer) (PLGA). The hydration reaction ofα-tricalcium phosphate (TCP) was utilized to form CDHA, and a mixed solution of gelatin, glycerine and glutaraldehyde was applied as the dispersant and adhesive. The concentration of the glutaraldehyde (1‰(v/v)) and the mixing ratio ofα-TCP (0.6, 0.8, 1.0 and 1.2 g ml-1) were studied with regard to the effect on the forming ability of the CDHA ink. The influence ofα-TCP proportion (0.6, 0.8, 1.0 and 1.2 g ml-1) on the formation of CDHA was also researched in phase analysis, morphology and compressive strength measurements. The CDHA/PLGA bilayer scaffold was fabricated with a good combination of the two components by 3D printing. Thein vitrodegradation, cytotoxicity and cell proliferation behavior were studied. Meanwhile, thein-vivoperformances in terms of surgical safety, biodegradation and osteogenic capacity were investigated with a cortical bone defect model in a rabbit femur. The results showed that the CDHA/PLGA bilayer scaffold had excellent biocompatibility and no cytotoxicity. The scaffolds were successfully implanted and presented remarkable osteogenic capacity within 6 months through analyses in radiography and histology. In conclusion, the method has a potential clinical application in diverse bone repair practices by varied 3D-printing fabrication.

Effects of inhaled nitric oxide for postoperative hypoxemia in acute type A aortic dissection: a retrospective observational study.

BACKGROUND: Postoperative hypoxemia in acute type A aortic dissection (AADA) is a common complication and is associated with negative outcomes. This study aimed to analyze the efficacy of low-dose (5-10 ppm) inhaled nitric oxide (iNO) in the management of hypoxemia after AADA surgery. METHODS: In this retrospective observational study, Medical records of patients who underwent AADA surgery at two institutions between January 2015 and January 2018 were collected. Patients with postoperative hypoxemia were classified as iNO and control groups. Clinical characteristics and outcomes were compared using a propensity score-matched (PSM) analysis. RESULTS: Among 436 patients who underwent surgical repair, 187 (42.9%) had hypoxemia and 43 were treated with low-dose iNO. After PSM, patients were included in the iNO treatment (n = 40) and PSM control (n = 94) groups in a 1:3 ratio. iNO ameliorated hypoxemia at 6, 24, 48, and 72 h after initiation, and shortened the durations of ventilator support (39.0 h (31.3-47.8) vs. 69.0 h (47.8-110.3), p < 0.001) and ICU stay (122.0 h (80.8-155.0) vs 179.5 h (114.0-258.0), p < 0.001). There were no significant between-group differences in mortality, complications, or length of hospital stay. CONCLUSIONS: In this study, we found that low-dose iNO improved oxygenation in patients with hypoxemia after AADA surgery and shortened the durations of mechanical ventilation and ICU stay. No significant side effects or increase in postoperative mortality or morbidities were observed with iNO treatment. These findings warrant a randomized multicenter controlled trial to assess the exact efficiency of iNO for hypoxemia after AADA.

Nestin Promotes Peritoneal Fibrosis by Protecting HIF1-α From Proteasomal Degradation.

BACKGROUND: Peritoneal dialysis (PD) is a treatment for end stage renal disease patients, but it can also cause peritoneal fibrosis. Nestin is known as a neural stem cell marker and it has many functions. The hypoxia induced factor (HIF) signaling pathway can be activated under hypoxia conditions, leading to the overexpression of some angiogenesis related genes. The aim of our study is to demonstrate Nestin's role in the development of peritoneal fibrosis (PF), and to provide a new target (Nestin) to treat PF. METHODS: PD mice models were constructed by an intraperitoneal administration of PDS at 10 ml/100g/d for 4 weeks. Nestin-positive cells were isolated from peritonea of Nestin-GFP mice by flow cytometry. The relationship of Nestin and HIF1-α-VEGFA pathway was detected by Nestin knockdown, Co-immunoprecipitation and immunofluorescence. Also, proteasomal activity was demonstrated by CHX and MG132 application, followed by Western blotting and Co-immunoprecipitation. RESULTS: In our experiments, we found that Nestin expression resulted in PF. Also, HIF1-α/VEGFA pathway was activated in PF. Nestin knockdown reduced the level of HIF1-α. Nestin directly bound to HIF1-α and protected HIF1-α from proteasomal degradation. Overexpression of HIF1-α reverts the fibrosis levels in Nestin-knockdown cells. In brief, Nestin inhibited the degradation of HIF1-α by mitigating its ubiquitination level, leading to the activation of HIF1-α signaling pathway, and eventually promoted PF. CONCLUSION: We found a novel mechanism of PF that Nestin promotes by protecting HIF1-α from proteasomal degradation. Taken together, our key findings highlight a novel mechanism by which the silencing of Nestin hinders HIF1- α -induced PF.

MCU Up-regulation contributes to myocardial ischemia-reperfusion Injury through calpain/OPA-1-mediated mitochondrial fusion/mitophagy Inhibition.

Mitochondrial dynamic disorder is involved in myocardial ischemia/reperfusion (I/R) injury. To explore the effect of mitochondrial calcium uniporter (MCU) on mitochondrial dynamic imbalance under I/R and its related signal pathways, a mouse myocardial I/R model and hypoxia/reoxygenation model of mouse cardiomyocytes were established. The expression of MCU during I/R increased and related to myocardial injury, enhancement of mitochondrial fission, inhibition of mitochondrial fusion and mitophagy. Suppressing MCU functions by Ru360 during I/R could reduce myocardial infarction area and cardiomyocyte apoptosis, alleviate mitochondrial fission and restore mitochondrial fusion and mitophagy. However, spermine administration, which could enhance MCU function, deteriorated the above-mentioned myocardial cell injury and mitochondrial dynamic imbalanced. In addition, up-regulation of MCU promoted the expression and activation of calpain-1/2 and down-regulated the expression of Optic atrophy type 1 (OPA1). Meantime, in transgenic mice (overexpression calpastatin, the endogenous inhibitor of calpain) I/R model and OPA1 knock-down cultured cell. In I/R models of transgenic mice over-expressing calpastatin, which is the endogenous inhibitor of calpain, and in H/R models with siOPA1 transfection, inhibition of calpains could enhance mitochondrial fusion and mitophagy, and inhibit excessive mitochondrion fission and apoptosis through OPA1. Therefore, we conclude that during I/R, MCU up-regulation induces calpain activation, which down-regulates OPA1, consequently leading to mitochondrial dynamic imbalance.

Characterization of an α-Calcium Sulfate Hemihydrates/α-Tricalcium Phosphate Combined Injectable Bone Cement.

The artificial bone-repair materials have received extensive attention. In this study, we have prepared new α-calcium sulfate hemihydrates (α-CSH) and gelatin modified α-tricalcium phosphate (α-TCP) combined injectable bone cement (α-CSH/α-TCP bone cement). The solidification, mechanical behavior, in vitro biocompatibility and degradation were studied and a spine bone trabecular defect model in swine vertebral body was constructed to evaluate its in vivo performance. The results demonstrated that the bone cement has the appropriate in vitro initial setting time of 6-10 min and final setting time within 20 min, excellent mechanical properties up to 35 M Pa in compressive strength, no in vitro cytotoxicity and appropriate in vivo biodegradation with good bone regeneration ability as the radiological and histological examination showed. Therefore, the α-CSH/α-TCP bone cement has broad application prospects in minimally invasive surgery for the bone defects treatment.

Overexpression of vasostatin-1 protects hypoxia/reoxygenation injuries in cardiomyocytes-endothelial cells transwell co-culture system.

Vasostatin-1 (VS-1) plays important roles in myocardial ischemia/reperfusion injury. We have explored the protective effects of VS-1 on cardiomyocytes using cardiomyocyte-endothelial cells Transwell Co-culture System. Cardiomyocytes and rat aortic endothelial cells (RAECs) were prepared from ventricles and thoraco-abdominal aorta of Sprague-Dawley rats. The experiment used cardiomyocytes alone culture group (C) and cardiomyocytes-RAECs co-culture group (T), each with three subgroups: C-Ad-Null, C-Ad-VS-1, C-Hb (Ad-VS-1 + NO scavenger Hb), or T-Ad-Null, T-Ad-VS-1 transfection, T-Hb. After 48 h incubation, all groups were treated with hypoxia for 60 min and then reoxygenated for 120 min. We also investigated endothelial cells-mediated cardiomyocytes protection. RAECs were treated with hypoxia for 30 min and reoxygenated with normal cardiomyocytes for 120 min. The cardiomyocytes apoptosis rate, aspartate aminotransferase (AST) and creatine kinase isozyme MB (CK-MB) were recorded. As expected, cardiomyocytes apoptosis, AST and CK-MB were significantly increased in the T-Ad-Null group than in the C-Ad-Null group. VS transfection significantly reduced these levels. However, apoptosis, AST and CK-MB levels were increased again after Hb treatment, returning to the similar level of the C-Ad-null group in the C-Hb group, but still significantly lower in the T-Hb group compared with the T-Ad-null group. RAEC injury caused cardiomyocyte injury, and VS-1 transfection of the RAEC decreased apoptosis and the levels of AST and CK-MB. The findings suggest that VS-1 exerts protective effects on the cardiomyocytes directly or indirectly by cardiomyocyte-endothelial cells interaction.

Effect of hormone replacement therapy on cardiovascular outcomes: a meta-analysis of randomized controlled trials.

BACKGROUND: Hormone replacement therapy (HRT) is widely used to controlling menopausal symptoms and prevent adverse cardiovascular events. However, the benefit and risk of HRT on cardiovascular outcomes remains controversial. METHODOLOGY AND PRINCIPAL FINDINGS: We systematically searched the PubMed, EmBase, and Cochrane Central Register of Controlled Trials databases for obtaining relevant literature. All eligible trials reported on the effects of HRT on cardiovascular outcomes. We did a random effects meta-analysis to obtain summary effect estimates for the clinical outcomes with use of relative risks calculated from the raw data of included trials. Of 1903 identified studies, we included 10 trials reporting data on 38908 postmenopausal women. Overall, we noted that estrogen combined with medroxyprogesterone acetate therapy as compared to placebo had no effect on coronary events (RR, 1.07; 95%CI: 0.91-1.26; P = 0.41), myocardial infarction (RR, 1.09; 95%CI: 0.85-1.41; P = 0.48), stroke (RR, 1.21; 95%CI: 1.00-1.46; P = 0.06), cardiac death (RR, 1.19; 95%CI: 0.91-1.56; P = 0.21), total death (RR, 1.06; 95%CI: 0.81-1.39; P = 0.66), and revascularization (RR, 0.95; 95%CI: 0.83-1.08; P = 0.43). In addition, estrogen therapy alone had no effect on coronary events (RR, 0.93; 95%CI: 0.80-1.08; P = 0.33), myocardial infarction (RR, 0.95; 95%CI: 0.78-1.15; P = 0.57), cardiac death (RR, 0.86; 95%CI: 0.65-1.13; P = 0.27), total mortality (RR, 1.02; 95%CI: 0.89-1.18; P = 0.73), and revascularization (RR, 0.77; 95%CI: 0.45-1.31; P = 0.34), but associated with a 27% increased risk for incident stroke (RR, 1.27; 95%CI: 1.06-1.53; P = 0.01). CONCLUSION/SIGNIFICANCE: Hormone replacement therapy does not effect on the incidence of coronary events, myocardial infarction, cardiac death, total mortality or revascularization. However, it might contributed an important role on the risk of incident stroke.

Gene expression analysis in cardiac tissues from infants identifies candidate agents for Tetralogy of Fallot.

Tetralogy of Fallot (TOF) is the most common cyanotic heart defect and the most common cause of blue baby syndrome. Although great progress has been made, the molecular mechanisms of TOF are far from being fully understood, and treatment of this disease remains palliative. In this study, we downloaded gene expression data of TOF subjects with those of normally developing subjects from the Gene Expression Omnibus database and employed computational bioinformatics analyses to compare their gene expression patterns. Furthermore, small molecules that induce inverse gene changes to TOF were identified. A total of 2,274 genes involved in energy metabolism and protein binding were differentially expressed in TOF samples compared with samples from normal controls. Pathways associated with cellular oxygen tension were dysfunctional. In addition, we identified a group of small molecules that may be exploited as adjuvant drug to alleviate some symptoms for TOF patients. These drugs are clearly a direction that warrants additional consideration.

Overexpression of vasostatin-1 protects hypoxia/reoxygenation injuries in cardiomyocytes independent of endothelial cells.

INTRODUCTION: Vasostatin-1 (VS-1) has been suggested in protecting hypoxia/reoxygenation (H/R) injuries in isolated hearts. However, the molecular mechanisms remained to be elucidated. METHODS: Cardiomyocytes were treated with recombinant Ad-VS-1 adenoviral vector before H/R. Cell viability was studied using MTT methods and annexin V-FITC flow cytometry. Intracellular oxidative stress was measured by superoxide dismutase (SOD) and malondialdehyde (MDA), and inflammatory reactions by enzyme-linked immunosorbent assay (ELISA). Measurement of myocardial nitrous oxide synthase (NOS) was determined by serum nitric oxide (NO) concentrations using nitrite reductase and endothelial nitric oxide synthase (eNOS) by Western blotting. Inhibitors of the NOS system, including hemoglobin and KT5823, were applied to verify the results. RESULTS: In comparison of the blank group, cardiac myocytes overexpressing VS-1 showed significant decrease in apoptosis, intracellular oxidative stress, and inflammatory reactions (P < 0.05). In addition, serum NO concentrations and expression of eNOS were notably enhanced (P < 0.05). These protective effects of VS-1 were suppressed in the presence of apoptosis-inducing agents. CONCLUSIONS: Overexpression of VS-1 in cardiomyocytes could limit the H/R injuries at molecular levels. The protective effects were independent of endothelial cell function, suggestive of a potential therapeutic target for patients with myocardial ischemia in the future.

Significance of Jab1 expression in human esophageal squamous cell carcinoma.

GOAL: The aim of the present study was to examine the expression of Jun activation domain-binding protein 1(Jab1) and p27 and to elucidate its clinicopathologic significance in a larger series of squamous cell carcinoma (SCC) of the esophagus. BACKGROUND: Reduced expression of p27 has been associated with poor prognosis in most human cancers, including esophageal SCCs. Jab1 is known as a coactivator of AP-1 transcription factor, which contributes to tumor progression by degrading the p27 protein. STUDY: Immunohistochemical and Western blot analysis were performed in 90 cases of esophageal SCCs and ECA109 cells. Survival analyses were performed by using the Kaplan-Meier method. RESULTS: Immunohistochemical analysis showed that Jab1 expression was negatively associated with p27 level and significantly associated with unfavorable clinicopathologic variables. Overexpression of Jab1 in ECA109 cells resulted in decreased p27 level and this decrease was sensitive to 26S proteasome inhibitors. Subcellular fractionation confirmed Jab1 could lead to nuclear export of p27. Survival analysis revealed that Jab1 overexpression was significantly associated with overall survival (P<0.001). When Jab1 and p27 are combined, patients with Jab1(+)/p27(-) revealed poorer overall survival (P<0.001), what's more, patients with the phenotype of Jab1(+)/lymph node(+) had poorer disease-free and overall survival than others (P<0.001). CONCLUSIONS: These findings suggest that Jab1 is involved in the pathogenesis of esophageal SCC and that elevated levels of Jab1 expression may indicate a poor prognosis for patients with esophageal SCC.