Improvement of Symptoms and Quality of Life After Successful Percutaneous Coronary Intervention for Chronic Total Occlusion in Elderly Patients.

Background Data regarding the impact of successful chronic total occlusion treated with percutaneous coronary intervention (CTO-PCI) on symptoms and quality of life (QOL) in elderly patients (≥75 years) are unknown. This prospective study aimed to assess whether successful CTO-PCI could improve the symptoms and QOL in elderly patients (≥75 years). Methods and Results Consecutive patients who underwent elective CTO-PCI were prospectively enrolled and subdivided into 3 groups based on age: age<65 years, 65 years≤age<75 years, and age≥75 years. The primary outcomes included symptoms, as assessed with the New York Heart Association functional class and Seattle Angina Questionnaire, and QOL, as assessed with the 12-Item Short-Form Health Survey questionnaire, at baseline, 1 month, and 1 year after successful CTO-PCI. Of 1076 patients with CTO, 101 were age≥75 years (9.39%). Hemoglobin, estimated glomerular filtration rate, and left ventricular ejection fraction levels all decreased with increasing age, and NT-proBNP (N-terminal pro-B-type natriuretic peptide) increased. The proportion of dyspnea and coronary lesions, including multivessel disease, multi-CTO lesion, and calcification were higher in elderly patients. Procedural success rate, intraprocedural complications, and in-hospital major adverse cardiac events were not statistically different in the 3 groups. Importantly, symptoms, including dyspnea and angina, were markedly improved regardless of age at 1-month and 1-year follow-up (P<0.05). Likewise, successful CTO-PCI significantly improved QOL at 1-month and 1-year follow-up (P<0.01). Additionally, the incidence of major adverse cardiac events and all-cause mortality at 1-month and 1-year follow-up was not statistically different in the 3 groups. Conclusions Successful PCI was beneficial and feasible to improve symptoms and QOL in patients ≥75 years of age with CTO.

Elevated branched-chain amino acid promotes atherosclerosis progression by enhancing mitochondrial-to-nuclear H2O2-disulfide HMGB1 in macrophages.

As the essential amino acids, branched-chain amino acid (BCAA) from diets is indispensable for health. BCAA supplementation is often recommended for patients with consumptive diseases or healthy people who exercise regularly. Latest studies and ours reported that elevated BCAA level was positively correlated with metabolic syndrome, diabetes, thrombosis and heart failure. However, the adverse effect of BCAA in atherosclerosis (AS) and its underlying mechanism remain unknown. Here, we found elevated plasma BCAA level was an independent risk factor for CHD patients by a human cohort study. By employing the HCD-fed ApoE-/- mice of AS model, ingestion of BCAA significantly increased plaque volume, instability and inflammation in AS. Elevated BCAA due to high dietary BCAA intake or BCAA catabolic defects promoted AS progression. Furthermore, BCAA catabolic defects were found in the monocytes of patients with CHD and abdominal macrophages in AS mice. Improvement of BCAA catabolism in macrophages alleviated AS burden in mice. The protein screening assay revealed HMGB1 as a potential molecular target of BCAA in activating proinflammatory macrophages. Excessive BCAA induced the formation and secretion of disulfide HMGB1 as well as subsequent inflammatory cascade of macrophages in a mitochondrial-nuclear H2O2 dependent manner. Scavenging nuclear H2O2 by overexpression of nucleus-targeting catalase (nCAT) effectively inhibited BCAA-induced inflammation in macrophages. All of the results above illustrate that elevated BCAA promotes AS progression by inducing redox-regulated HMGB1 translocation and further proinflammatory macrophage activation. Our findings provide novel insights into the role of animo acids as the daily dietary nutrients in AS development, and also suggest that restricting excessive dietary BCAA consuming and promoting BCAA catabolism may serve as promising strategies to alleviate and prevent AS and its subsequent CHD.

Computing intracoronary blood flow rate under incomplete boundary conditions: Combing coronary anatomy and fractional flow reserve.

BACKGROUND: Accurate measurement of intracoronary blood flow rate is of great significance for the diagnosis of ischemic heart disease (IHD). Computational fluid dynamic (CFD) method, combining coronary angiography images and fractional flow reserve (FFR), provides a new way to calculate the mean flow rate. However, due to the incomplete boundary conditions obtained by FFR, side branches were ignored which was likely to have a significant impact on the accuracy. In this paper, a novel CFD based method for calculating the mean intracoronary flow rate under incomplete pressure boundary conditions was proposed, in order to improve the accuracy by including the side branches. METHODS: A pressure-flow curve based flow resistance model was employed to model resistance of the epicardial arteries. A series of steady flow simulations were performed to extract the parameters of the flow resistance model, which implicitly specified constraints for splitting flow between branches and thus enabled the mean intracoronary blood flow rate to be calculated in two or more branches under incomplete pressure boundary conditions. Simulation experiments were designed to validate the proposed method in both idealized and reconstructed 3D models of coronary branches, and the impact of the assumed coefficient of the Murray's Law for splitting flow between branches was also investigated. RESULTS: The mean percentage error of the proposed method was +2.05%±0.04% for idealized models and +2.24%±0.01% for reconstructed models, and it was much lower than that of the method ignoring side branches (+38.48%±10.45% for idealized models and +30.54%±6.12% for reconstructed models). When the assumed coefficient of the Murray's Law was inconsistent with the real blood flow condition, the percentage errors still maintained less than about 3.00%. CONCLUSIONS: The proposed method provided an easy and accurate way to measure the mean intracoronary flow rate and would facilitate the accurate diagnosis of IHD.

Benefits of successful percutaneous coronary intervention in chronic total occlusion patients with diabetes.

BACKGROUND: Diabetes was commonly seen in chronic total occlusion (CTO) patients but data regarding the impact of successful percutaneous coronary intervention (PCI) on clinical outcome of CTO patients with diabetes was controversial. And importantly, no studies have compared quality of life (QOL) after CTO-PCI in patients with and without diabetes. METHODS: Consecutive patients undergoing elective CTO-PCI were prospectively enrolled from Apr. 2018 to May 2021. Patients were subdivided into 2 groups: Diabetes and No Diabetes. Detailed baseline characteristics, assessment of symptoms and QOL, angiographic and procedural details, in-hospital complications, and 1 month and 1 year follow-up data were collected. These data were analyzed accordingly for risk predictors of clinical outcome in patients who have diabetes and received successful CTO-PCI. RESULTS: A total of 1076 patients underwent CTO-PCI attempts. Diabetes was present in 374 (34.76%) patients, who had more hypertension, previous PCI and stroke. Regarding the coronary lesions, diabetic patients suffered more LCX lesion, multivessel disease, number of lesions per patient, blunt stump, calcification and higher J-CTO score (p < 0.05). In-hospital major adverse cardiac event (MACE) (4.13% vs. 5.35%; p = 0.362) was similar in the two groups. At 1 month and 1 year follow-up after successful CTO-PCI, the incidence of MACE and all-cause mortality were also similar in the two groups (p > 0.05). Number of lesions per patient was an independent risk factor of MACE and all-cause mortality (p < 0.001) 1 year after successful CTO-PCI. Symptom and QOL were markedly improved regardless of diabetes both at 1 month and 1 year follow-up, and importantly, patients with diabetes showed similar degrees of improvement to those without diabetes (P > 0.05). CONCLUSIONS: Successful CTO-PCI could represent an effective strategy improving clinical outcome, symptoms and QOL in CTO patients with diabetes.

Comparative Effectiveness and Safety of Ticagrelor Versus Clopidogrel for Elderly Chinese Patients Undergoing Percutaneous Coronary Intervention: A Single-Center Retrospective Cohort Study.

BACKGROUND: Taking ischemic and bleeding risks into consideration, insufficient data exist on dual antiplatelet therapy after percutaneous coronary intervention in elderly Chinese patients with coronary artery disease. OBJECTIVE: We aimed to investigate the effectiveness and safety of ticagrelor in comparison with clopidogrel on a background of aspirin for elderly Chinese patients with coronary artery disease 12 months after percutaneous coronary intervention. METHODS: A single-center retrospective cohort study was conducted. Selected from patients with coronary artery disease aged ≥ 75 years from January 2010 to July 2019, 908 eligible subjects receiving dual antiplatelet therapy after percutaneous coronary intervention for up to 12 months were consecutively enrolled in the study. The included patients received ticagrelor in combination with aspirin (n = 264) or clopidogrel in combination with aspirin (n = 644). Effectiveness endpoints were evaluated by the major adverse cardiovascular events, encompassing all-cause death, non-fatal myocardial infarction, and clinically driven revascularization. The safety endpoints were recorded as the incidence of Bleeding Academic Research Consortium bleeding. RESULTS: The patients who were treated with ticagrelor were slightly younger than those who were treated with clopidogrel (79.1 ± 3.7 vs 80.7 ± 4.5 years, p < 0.01). The ticagrelor cohort contained a higher percentage of patients undergoing a prior percutaneous coronary intervention (37.9% vs 24.5%, p < 0.01), and a lower percentage of smokers (19.3% vs 27.2%, p < 0.05), compared with the clopidogrel cohort. The levels of glucose, total cholesterol, and low-density lipoprotein-cholesterol in the ticagrelor group were higher while the level of triglycerides and high-density lipoprotein-cholesterol were lower (p < 0.05) than those in the clopidogrel group. Left main percutaneous coronary intervention was performed more frequently among the ticagrelor-treated patients (23.5% vs 9.3%, p < 0.01), while patients in the clopidogrel group underwent more left circumflex percutaneous coronary intervention (34.3% vs 23.1%, p < 0.01). We found that ticagrelor was associated with a lower incidence of major adverse cardiovascular events than clopidogrel using the inverse probability of treatment weighting model (odds ratio, 0.493; 95% confidence interval 0.356-0.684). There was no difference in terms of the risk of Bleeding Academic Research Consortium bleeding between the two groups (p > 0.05). CONCLUSIONS: Ticagrelor was associated with a lower incidence of major adverse cardiovascular events than clopidogrel at 12 months in elderly Chinese patients with coronary artery disease, without a significant increase of Bleeding Academic Research Consortium bleeding events.

The Feasibility and Long-Term Outcomes of the Crossboss/Stingray for Treating Coronary Chronic Total Occlusions Lesions with Distal Diffuse Disease Landing Zone.

BACKGROUND: The feasibility and long-term outcomes of the CrossBoss/Stingray for treating coronary chronic total occlusions (CTO) with distal diffuse disease landing zone remain unclear. METHODS: Consecutive CTO patients with distal diffuse lesions that underwent percutaneous coronary intervention by the CrossBoss/Stingray system at Xijing Hospital from April 2016 to October 2020, were included. Patients were analyzed by two groups according to the extent of stenosis in the distal landing zone: 50%-70% stenosis (moderate stenosis group) and >70% stenosis (severe stenosis group). The primary efficacy outcome was technical success, defined as the frequency of true lumen guidewire placement distal to the CTO. The composite endpoint of all-cause death, any stroke, or any revascularization was also explored. RESULTS: A total of 91 consecutive patients were included, with 32 patients in the moderate stenosis group and 59 patients in the severe stenosis group. The mean J-CTO score was 2.5 ± 1.1. The technical success rate was 79.1% (72/91) in the overall population and was similar between the 2 groups: 78.1% (25/32) and 79.7% (47/59) (p = 0.608). No coronary perforation occurred. With a median follow-up of 29 months (IQR: 53-92), the estimated rate of the composite endpoint of all-cause death, any stroke, or any revascularization was 50.4% (all-cause death: 16.6%, any stroke: 1.1%, any revascularization: 36.5%) in the overall population. No significant difference was observed in the rate of the composite endpoint between the moderate stenosis group and the severe stenosis group (45.1% vs. 54.3%, respectively, p = 0.797). CONCLUSIONS: In CTO lesions with distal diffuse disease landing zone, the technical success rates of CrossBoss/Stingray and the long-term clinical outcomes were not significantly different between the moderate stenosis group (50%-70%) and the severe stenosis group (>70%). However, the relatively high rate of long-term clinical outcomes, especially any revascularization, warrants further investigations on this indication in future studies.

Percutaneous coronary intervention improves quality of life of patients with chronic total occlusion and low estimated glomerular filtration rate.

Background: A low estimated glomerular filtration rate (eGFR <90 mL/min/1.73 m2) is widely recognized as a risk factor for major adverse cardiac events (MACE) after percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). However, the impact of successful CTO-PCI on quality of life (QOL) of patients with low eGFR remains unknown. Objectives: The aim of this prospective study was to assess the QOL of CTO patients with low eGFR after successful PCI. Methods: Consecutive patients undergoing elective CTO-PCI were prospectively enrolled and subdivided into four groups: eGFR ≥90 mL/min/1.73 m2 (n = 410), 90 > eGFR ≥ 60 mL/min/1.73 m2 (n = 482), 60 > eGFR ≥ 30 mL/min/1.73 m2 (n = 161), and eGFR <30 mL/min/1.73 m2 (n = 23). The primary outcomes included QOL, as assessed with the European Quality of Life-5 Dimensions (EQ-5D) questionnaire, and symptoms, as assessed with the Rose Dyspnea Scale (RDS) and Seattle Angina Questionnaire (SAQ), at 1 month and 1 year after successful PCI. Results: With the decline of eGFR, CTO patients were more likely to present with comorbidities of hypertension, diabetes, hyperuricemia, and previous stroke, in addition to lower hemoglobin levels and left ventricular ejection fraction (p < 0.05). Low eGFR was associated with greater incidences of in-hospital pericardiocentesis, major bleeding, acute renal failure, and subcutaneous hematoma, but not in-hospital MACE (p < 0.05). Symptoms of dyspnea and angina were alleviated in all CTO patients with eGFR ≥30 mL/min/1.73 m2 at 1 month and 1 year after successful CTO-PCI, but only at 1 month for those with eGFR <30 mL/min/1.73 m2 (p < 0.01). Importantly, QOL was markedly improved at 1 month and 1 year after successful PCI (p < 0.01), notably at a similar degree between patients with low eGFR and those with normal eGFR (p > 0.05). Conclusion: Successful PCI effectively improved symptoms and QOL of CTO patients with low eGFR.

High Glucose Attenuates Cardioprotective Effects of Glucagon-Like Peptide-1 Through Induction of Mitochondria Dysfunction via Inhibition of ß-Arrestin-Signaling.

An increased vulnerability has been detected after ischemia/reperfusion injury in cardiomyocytes in diabetic patients. Glucagon-like peptide-1 (GLP-1) has been proven to have a notable cardioprotective effect in cardiomyocytes. However, in diabetic patients, the cardioprotective effects of GLP-1 are compromised, which is called GLP-1 resistance. ß-arrestin is one of the two main downstream effectors of GLP-1 and ß-arrestin signaling pathway exerts cardioprotective effects upon activation of GLP-1R. Our hypothesis is that the increased vulnerability of cardiomyocytes in diabetic patients is partly due to disruption of the ß-arrestin signaling pathway. To test this, we analyzed cardiomyocyte viability and survival in high glucose and normal glucose condition after hypoxia/reoxygenation injury in vitro, additional GLP-1 was used to determine whether ß-arrestin signaling pathway was involved. We also investigated the role of mitochondrial dysfunction in GLP-1 resistance. Our results showed that cardioprotective effects of GLP-1 were reduced in high glucose cultured H9C2 cells compared to normal glucose cultured H9C2, verifying the existence of GLP-1 resistance in high glucose cultured H9C2 cells. Further study suggested that ß-arrestin plays a key role in GLP-1 resistance: ß-arrestin expression is notably downregulated in high glucose condition and cardioprotective effects of GLP-1 can be diminished by downregulation of ß-arrestin in normal glucose condition while upregulation of ß-arrestin can restore cardioprotective effects of GLP-1 in high glucose condition. Then we explore how ß-arrestin affects the cardioprotective effects of GLP-1 and found that ß-arrestin exerts cardioprotective effects by improving mitochondria quality control via the PI3K/Akt signaling pathway. Thus, our study found out a new mechanism of GLP-1 resistance of cardiomyocytes in high glucose conditions that impaired ß-arrestin expression, caused mitochondria dysfunction and eventually cell death. Our study provided a new perspective in treating myocardial ischemia/reperfusion injury in diabetic patients.

Essential Role Of High Glucose-Induced Overexpression Of PKCß And PKCδ In GLP-1 Resistance In Rodent Cardiomyocytes.

PURPOSE: Myocardia in diabetic patients exhibit increased vulnerability after ischemia/reperfusion injury (IRI). It has been demonstrated that glucagon-like peptide-1 (GLP-1) has a protective effect on cardiomyocytes. Protein kinase C (PKC) acts as a key regulator of many signaling pathways including oxidative stress and apoptosis. Our hypothesis is that increased vulnerability of myocardia in diabetic patients is partly due to GLP-1 resistance. The aim of this study was to explore the role of PKC in GLP-1 resistance in diabetic cardiomyocytes. METHODS: Cardiac function of diabetic or non-diabetic mice after myocardial IRI was detected with or without administration of GLP-1 analog exendin-4. Impacts of diabetes mellitus on GLP-1R expression in myocardia after IRI were accessed by Western blot. By transfecting PKC isoforms siRNA, in vitro study helped to identify the exact PKC isoforms which contributed to the downregulatio n of GLP-1R or impaired post-receptor signaling pathways in rodent cardiomyocytes (H9C2 cells) cultured by high glucose. RESULTS: The cardioprotective effects of endogenous GLP-1 were impaired in diabetic mice after myocardial IRI and administration of exendin-4 had no significant effects in restoring cardiac function. GLP-1 receptor (GLP-1R) expression decreased in H9C2 cells cultured by high glucose and knockdown of PKCß partly restored GLP-1R expression. Overexpression of PKCδ induced by high glucose in H9C2 cells impaired GLP-1 post-receptor anti-apoptotic signaling pathways by inhibition of Akt phosphorylation. Knockdown of both PKCß and PKCδ significantly restored cardioprotective effects of GLP-1 in H9C2 cells cultured by high glucose. CONCLUSION: Our study found out a new mechanism of GLP-1 resistance that high glucose-induced overexpression of PKCß and PKCδ impaired cardioprotective effects of GLP-1 by downregulation of GLP-1R and inhibition of GLP-1 post-receptor anti-apoptotic signaling pathways, thus provided a new perspective in treating myocardial IRI in diabetic patients.

Pretreatment of Diabetic Adipose-derived Stem Cells with mitoTEMPO Reverses their Defective Proangiogenic Function in Diabetic Mice with Critical Limb Ischemia.

Adipose-derived stem cells (ADSCs) have the ability to migrate to injury sites and facilitate tissue repair by promoting angiogenesis. However, the therapeutic effect of ADSCs from patients with diabetes is impaired due to oxidative stress. Given that diabetes is a group of metabolic disorders and mitochondria are a major source of reactive oxygen species (ROS), it is possible that mitochondrial ROS plays an important role in the induction of diabetic ADSC (dADSC) dysfunction. ADSCs isolated from diabetic mice were treated with mitoTEMPO, a mitochondrial ROS scavenger, or TEMPO, a universal ROS scavenger, for three passages. The results showed that pretreatment with mitoTEMPO increased the proliferation, multidifferentiation potential, and the migration and proangiogenic capacities of dADSCs to levels similar to those of ADSCs from control mice, whereas pretreatment with TEMPO showed only minor effects. Mechanistically, mitoTEMPO pretreatment enhanced the mitochondrial antioxidant capacity of dADSCs, and knockdown of superoxide dismutase reduced the restored mitochondrial antioxidant capacity and attenuated the proangiogenic effects induced by mitoTEMPO pretreatment. In addition, mitoTEMPO pretreatment improved the survival of dADSCs in diabetic mice with critical limb ischemia, showing protective effects similar to those of control ADSCs. Pretreatment of dADSCs with mitoTEMPO decreased limb injury and improved angiogenesis in diabetic mice with critical limb ischemia. These findings suggested that short-term pretreatment of dADSCs with a mitochondrial ROS scavenger restored their normal functions, which may be an effective strategy for improving the therapeutic effects of ADSC-based therapies in patients with diabetes.

Preliminary evaluation of 18F­AlF­NOTA­MAL­Cys40­Exendin­4 in rodent heart after myocardial ischemia and reperfusion.

Glucagon­like peptide­1 (GLP­1) and its receptor (GLP­1R) exert cardioprotective effects after myocardial ischemia and reperfusion (MI/R) in animal models and human clinical trials. Receptor imaging with positron emission tomography (PET) provides a non­invasive method for monitoring GLP­1R expression. In the present study, a fluorine­18­labeled aluminum fluoride exendin­4 analog [18F­AlF conjugated with 1,4,7­triazacyclononanetriacetic acid (NOTA)­maleimide (MAL)­Cys40­exendin­4] was synthesized and evaluated in a rat MI/R model for GLP­1R imaging. NOTA­MAL­Cys40­exendin­4 was synthesized by coupling Cys40­exendin­4 with NOTA­MAL. NOTA­MAL­Cys40­exendin­4 was then conjugated with 18F­AlF to obtain 18F­AlF­NOTA­MAL­Cys40­exendin­4. The yield of 18F­AlF­NOTA­MAL­Cys40­exendin­4 was 18.5±3.4% (not decay corrected). The process was completed within ~30 min. In rat MI/R models, the tracer exhibited specific binding to GLP­1R and an appropriate signal­to­noise ratio. At 8 h post­MI/R, tracer uptake reached its peak [0.35±0.053% of injected dose (%ID)/g; n=6] in ischemic myocardium. Localized tracer uptake decreased 1 day (0.20±0.032 %ID/g; n=6) and 3 days (0.16±0.017 %ID/g; n=6) post­MI/R compared with 8 h post­MI/R, but still remained higher compared with sham­operated groups (0.06±0.012 %ID/g; n=6). Pre­injected unlabeled exendin­4 effectively blocked tracer accumulation (0.09±0.041 %ID/g; n=6). In conclusion, 18F­AlF­NOTA­MAL­Cys40­exendin­4 demonstrated favorable characteristics for GLP­1R imaging following MI/R. PET imaging using 18F­AlF­NOTA­MAL­Cys40­exendin­4 in rodent hearts after MI/R revealed a dynamic pattern of GLP­1R upregulation.

Preclinical modeling and multimodality imaging of chronic myocardial infarction in minipigs induced by novel interventional embolization technique.

BACKGROUND: This study was designed to establish a chronic myocardial infarction (MI) model in minipigs with a novel coronary sequential balloons-sponge embolism technique. METHODS: Eighteen healthy minipigs (25-30 kg) were randomly divided into three groups for left anterior descending artery (LAD) occlusion: conventional balloon occlusion group (BO group, temporary balloon occlusion for 60 mins), half-balloon embolism group (HB group), and sequential balloon-balloon-sponge embolism group (BBS group, two half-balloons with one sponge as the embolism clot). The incidence of ventricular fibrillation (VF), total mortality, operating time, and vascular recanalization 3 months post-MI was recorded and compared. Echocardiography, multimodality nuclear medical imaging, and histology staining were applied for the evaluation of infarction. RESULTS: Thirteen out of 18 minipigs survived after the operation, while 5 animals died with VF (3 in the BO group, 1 in the HB group, and 1 in the BBS group), with an 83.3 % (5/6 minipigs) acute procedural survival rate in embolism groups. The operating duration was 60.0 ± 0.5 mins, 21.4 ± 5.2 mins, and 31.2 ± 4.7 mins in the three groups, respectively. LAD recanalization was found in three animals of the HB group but none in the BBS group by angiography follow-up. The infarct sizes were more stable and larger in the HB group and BBS group than that in the BO group (P < 0.05, n = 13). CONCLUSIONS: The method of sequential balloons-sponge embolization could induce myocardial infarction with consistent and sustained embolization and gain higher operation success rate and better repeatability in minipigs, which holds a promising method for preclinical MI study.

Notch3/Akt signaling contributes to OSM-induced protection against cardiac ischemia/reperfusion injury.

Oncostatin M (OSM) exhibits many unique biological activities by activating the Oß receptor. However, its role in myocardial ischemia/reperfusion injury (I/R injury) in mice remains unknown. We investigated whether Notch3/Akt signaling is involved in the regulation of OSM-induced protection against cardiac I/R injury. The effects of OSM were assessed in mice that underwent myocardial I/R injury by OSM treatment or by genetic deficiency of the OSM receptor Oß. We investigated its effects on cardiomyocyte apoptosis and mitochondrial biogenesis and whether Notch3/Akt signaling was involved in the regulation of OSM-induced protection against cardiac I/R injury. The mice underwent 30 min of ischemia followed by 3 h of reperfusion and were randomized to be treated with Notch3 siRNA (siNotch3) or lentivirus carrying Notch3 cDNA (Notch3) 72 h before coronary artery ligation. Myocardial infarct size, cardiac function, cardiomyocyte apoptosis and mitochondria morphology in mice that underwent cardiac I/R injury were compared between groups. OSM alleviated cardiac I/R injury by inhibiting cardiomyocyte apoptosis through promotion of Notch3 production, thus activating the PI3K/Akt pathway. OSM enhanced mitochondrial biogenesis and mitochondrial function in mice subjected to cardiac I/R injury. In contrast, OSM receptor Oß knock out exacerbated cardiac I/R injury, decreased Notch3 production, enhanced cardiomyocyte apoptosis, and impaired mitochondrial biogenesis in cardiac I/R injured mice. The mechanism of OSM on cardiac I/R injury is partly mediated by the Notch3/Akt pathway. These results suggest a novel role of Notch3/Akt signaling that contributes to OSM-induced protection against cardiac I/R injury.

Anti-oxidative stress effect of loading-dose rosuvastatin prior to percutaneous coronary intervention in patients with acute coronary syndrome: a prospective randomized controlled clinical trial.

BACKGROUND AND OBJECTIVES: Administration of a loading dose of a statin (HMG-CoA reductase inhibitor) prior to percutaneous coronary intervention (PCI) contributes to protection from myocardial ischemic-reperfusion injury. This trial was designed to investigate the effect and mechanism of loading-dose rosuvastatin therapy before PCI in patients with acute coronary syndrome. METHODS: One hundred and forty-three patients with acute coronary syndrome were randomized to either the loading-dose (rosuvastatin 40 mg given 4 h before PCI) or conventional-dose (rosuvastatin 10 mg given 4 h before PCI) group. Blood samples were collected before and 0, 24, and 72 h post-PCI for measurement of serum cardiac troponin-I (cTn I), creatine kinase-MB (CK-MB), superoxide dismutase (SOD), reactive oxygen species (ROS), and malondialdehyde (MDA). Echocardiography and the major adverse cardiac/cerebrovascular events (MACCE) rate were followed up for 6 months post-PCI. RESULTS: Blood serum CK-MB and cTn I were significantly lower in the loading-dose group than in the conventional-dose group at 24 and 72 h post-PCI [CK-MB: 26.90 ± 3.22 vs. 32.96 ± 2.65 IU/L, P = 0.024; 10.79 ± 4.65 vs. 15.18 ± 5.39 IU/L, P = 0.021. cTn I: 0.046 ± 0.007 vs. 0.055 ± 0.002 ng/mL, P = 0.015; 0.027 ± 0.006 vs. 0.041 ± 0.006 ng/mL, P = 0.026]. Echocardiography at 6 months after PCI revealed significant improvement in cardiac function in the loading-dose group compared with the conventional-dose group (P < 0.05). The MACCE rate at 6 months after PCI in the loading-dose group was lower than in the conventional-dose group (P = 0.0428). The levels of MDA and ROS were decreased and the SOD level was significantly higher in the loading-dose group than in the conventional-dose group at 0, 24, and 72 h post-PCI (P < 0.05). CONCLUSION: Administration of loading-dose rosuvastatin in patients with acute coronary syndrome prior to PCI exerts myocardial protection by inhibition of oxidative stress.

Myocardial protective effect of extracellular superoxide dismutase gene modified bone marrow mesenchymal stromal cells on infarcted mice hearts.

AIM: Extracellular superoxide dismutase (ecSOD) is a unique scavenger of superoxide anions and a promising target of gene therapy for ischemia/reperfusion injury (I/R). However, conventional gene therapies have limitation in effectiveness and efficiency. This study aimed to investigate the protective effects of ecSOD gene modified bone marrow mesenchymal stromal cells (BMSCs) on cardiac function improvement in mice infarcted heart. METHODS & RESULTS: BMSCs were isolated from Fluc(+) transgenic mice (Tg FVB[Fluc(+)]) and transfected by adenovirus combined with human ecSOD gene. ELISA was performed to determine ecSOD protein level. Female syngeneic FVB mice were randomized into 5 groups: (1) Sham group (sham); (2) MI group (MI); (3) MI+BMSCs group (BMSC); (4) MI+BMSCs-vector group (BMSC-vector); (5) MI+ BMSCs-ecSOD group (BMSC-ecSOD). MI was accomplished by ligation of the left anterior descending artery. BMSCs (2 x 10(6)) were injected into the border zone of infarction. In vivo bioluminescence imaging (BLI) was performed to monitor transplanted BMSCs viability. Echocardiography and histological staining revealed that BMSCs-ecSOD significantly reduced myocardial infarction size and improved cardiac function. Lucigenin chemiluminescence, DHE and TUNEL staining demonstrated that BMSCs-ecSOD delivery reduced ROS level and cell apoptosis both in vivo and in vitro. Western blot assay revealed that ecSOD supplementation increased FoxO3a phosphorylation in cardiomyocytes. Moreover, quantitative real-time PCR showed that pro-apoptotic factors (bim and bax) were decreased while the anti-apoptotic factor mir-21 expression was increased after ecSOD intervention. CONCLUSION: Intra-myocardial transplantation of adenovirus-ecSOD transfected BMSCs could exert potential cardiac protection against MI, which may be partly through reduction of oxidative stress and improvement of BMSCs survival.

Longitudinal bioluminescence imaging of the dynamics of Doxorubicin induced apoptosis.

OBJECTIVES: Most chemotherapy agents cause tumor cell death primarily by the induction of apoptosis. The ability to noninvasively image apoptosis in vivo could dramatically benefit pre-clinical and clinical evaluation of chemotherapeutics targeting the apoptotic pathway. This study aims to visualize the dynamics of apoptotic process with temporal bioluminescence imaging (BLI) using an apoptosis specific bioluminescence reporter gene. METHODS: Both UM-SCC-22B human head and neck squamous carcinoma cells and 4T1 murine breast cancer cells were genetically modified with a caspase-3 specific cyclic firefly luciferase reporter gene (pcFluc-DEVD). Apoptosis induced by different concentrations of doxorubicin in the transfected cells was evaluated by both annexin V staining and BLI. Longitudinal BLI was performed in xenografted tumor models at different time points after doxorubicin or Doxil treatment, to evaluate apoptosis. After imaging, DNA fragmentation in apoptotic cells was assessed in frozen tumor sections using TUNEL staining. RESULTS: Dose- and time-dependent apoptosis induced by doxorubicin in pcFluc-DEVD transfected UM-SCC-22B and 4T1 cells was visualized and quantified by BLI. Caspase-3 activation was confirmed by both caspase activity assay and Glo(TM) luciferase assay. One dose of doxorubicin treatment induced a dramatic increase in BLI intensity as early as 24 h after treatment in 22B-pcFluc-DEVD xenografted tumors. Sustained signal increase was observed for the first 3 days and the fluorescent signal from ex vivo TUNEL staining was consistent with BLI imaging results. Long-term imaging revealed that BLI signal consistently increased and reached a maximum at around day 12 after the treatment with one dose of Doxil. CONCLUSIONS: BLI of apoptosis with pcFluc-DEVD as a reporter gene facilitates the determination of kinetics of the apoptotic process in a real-time manner, which provides a unique tool for drug development and therapy response monitoring.

Mesenchymal stem cell-based cell engineering with multifunctional mesoporous silica nanoparticles for tumor delivery.

Stem cell engineering, the manipulation and control of cells, harnesses tremendous potential for diagnosis and therapy of disease; however, it is still challenging to impart multifunctionalization onto stem cells to achieve both. Here we describe a mesenchymal stem cell (MSC)-based multifunctional platform to target orthotopic glioblastoma by integrating the tumor targeted delivery of mesenchymal stem cells and the multimodal imaging advantage of mesoporous silica nanoparticles (MSNs). Rapid cellular uptake, long retention time and stability of particles exemplify the potential that the combination of MSNs and MSCs has as a stem cell-based multifunctional platform. Using such a platform, we verified tumor-targeted delivery of MSCs by in vivo multimodal imaging in an orthotopic U87MG glioblastoma model, displaying higher tumor uptake than particles without MSCs. As a proof-of-concept, this MSC platform opens a new vision for multifunctional applications of cell products by combining the superiority of stem cells and nanoparticles for actively targeted delivery.

Evaluation of an [(18)F]AlF-NOTA Analog of Exendin-4 for Imaging of GLP-1 Receptor in Insulinoma.

INTRODUCTION: The GLP-1 receptor plays an important role in glucose homeostasis and thus is a very important target for diabetes therapy. The receptor is also overexpressed in insulinoma, a tumor of pancreatic beta-cells. We previously evaluated two fluorine-18-labeled analogs of exendin-4 prepared by conjugation with [(18)F]FBEM (N-[2-(4-[(18)F]fluorobenzamide)ethyl]maleimide). Both compounds demonstrated good tumor uptake, but the synthesis of the radiotracers was time consuming. To overcome this challenge, we developed a NOTA analog and performed radiolabeling using aluminum [(18)F]fluoride complexation. METHODS: Cys(40)-exendin-4 was conjugated with NOTA mono N-ethylmaleimide. [(18)F]AlF conjugation was conducted and the radiolabeled product purified by preparative HPLC. Dynamic and static PET imaging scans were conducted on nude mice with established INS-1 xenografts. Uptake of tumor and other major organs in static images was quantitated (%ID/g) and comparison with blocking studies was made. PET quantification was also compared with ex vivo biodistribution results. RESULTS: The radiosynthesis provided [(18)F]AlF-NOTA-MAL-cys(40)-exendin-4 in 23.6 ± 2.4 % radiochemical yield (uncorrected, n = 3) after HPLC; the process required about 55 min. The specific activity at time of injection ranged from 19.6 to 31.4 GBq (0.53-0.85 Ci)/µmol. Tumor uptake had reached its maximum (16.09 ± 1.18% ID/g, n = 4) by 5 min and remained nearly constant for the duration of the study. Kidney uptake continued to increase throughout the entire one hour time course. Pre-injection of exendin-4 caused a marked reduction in tissue uptake with the major exception of liver and kidneys, in which uptake was not affected. HPLC analysis of the radioactive components in extracts of the tumor and plasma showed primarily parent compound at 60 min post-injection, whereas extracts of kidney and urine contained exclusively one polar radioactive component. CONCLUSION: The radiotracer is prepared in a simple one-step procedure and obtained in high specific activity after HPLC purification. [(18)F]AlF-NOTA-MAL-exendin-4 shows high tumor uptake and highly selective GLP-1 tissue uptake (INS-1 tumor, lung, pancreas), but still suffers from high kidney uptake.

PET of glucagonlike peptide receptor upregulation after myocardial ischemia or reperfusion injury.

UNLABELLED: Glucagonlike peptide (GLP-1) and its receptor (GLP-1R) exhibit cardioprotective effects after myocardial ischemia and reperfusion (MI/R) in both animal studies and clinical trials. However, the kinetics of GLP-1R expression in the infarcted/ischemic myocardium has not yet been explored. The purpose of this study was to monitor the presence and time course of regional myocardial GLP-1R expression after MI/R with noninvasive PET. METHODS: Male Sprague-Dawley rats underwent a 45-min transient left coronary artery occlusion, followed by reperfusion. The myocardial infarction was confirmed by electrocardiogram and cardiac ultrasound. In vivo PET was performed to determine myocardial uptake of (18)F-FBEM-Cys(40)-exendin-4 at different time points after reperfusion. The localization of (18)F-FBEM-Cys(40)-exendin-4 accumulation was determined by coregistering (18)F-FDG PET and CT images. Ex vivo autoradiography, GLP-1R immunohistochemical staining, and Western blot analysis were performed to confirm the PET results. RESULTS: Myocardial origin and infarcted/ischemic area localization of (18)F-FBEM-Cys(40)-exendin-4 accumulation was confirmed by coregistration of small-animal CT and (18)F-FDG images. At 8 h after MI/R, tracer uptake in the infarcted/ischemic region was 0.37 ± 0.05 percentage injected dose per gram, significantly higher than that in the control group (P < 0.01). The localized tracer uptake decreased, relative to the 8-h time point, but was still significantly higher than the control group on days 1 and 3 after MI/R. At 2 wk after MI/R, the tracer uptake in the affected area showed no significant difference, compared with that in the healthy myocardium. Autoradiography showed the same trend of (18)F-FBEM-Cys(40)-exendin-4 uptake in the myocardial infarcted/ischemic area. The specificity of tracer uptake into ischemic myocardium was supported by decreased tracer uptake after the rats were pretreated with an excess amount of unlabeled exendin-4. Immunohistochemical staining and Western blotting of GLP-1R protein of excised cardiac sections confirmed that the change in uptake observed by PET corresponded to a change in GLP-1R expression. CONCLUSION: Noninvasive PET using (18)F-FBEM-Cys(40)-exendin-4 revealed a dynamic pattern of GLP-1R upregulation in the infarcted/ischemic area after MI/R. The imaging results will deepen our understanding of the mechanism of the cardioprotective effect of GLP-1 and its analogs and potentially provide guidance for optimization of the time frame of therapeutic intervention.

Pharmacodynamics, tissue distribution, toxicity studies and antitumor efficacy of the vascular targeting fusion toxin VEGF121/rGel.

As a part of an ongoing assessment of its mechanism of action, we evaluated the in vivo pharmacokinetics, tissue distribution, toxicity and antitumor efficacy of VEGF(121)/rGel, a novel fusion protein. Pharmacokinetic studies showed that VEGF(121)/rGel cleared from the circulation in a biphasic manner with calculated half-lives of 0.3 and 6h for the alpha and beta phases, respectively. Pharmacokinetic evaluation of (64)Cu-DOTA-VEGF(121)/rGel showed relatively high blood retention 30 min after injection (26.6 ± 1.73% ID/g), dropping to 11.8 ± 2.83% and 0.82 ± 0.11% ID/g at 60 and 240 min post injection, respectively. Tissue uptake studies showed that kidneys, liver and tumor had the highest drug concentrations 48 h after administration. The maximum tolerated dose (MTD), based on a QOD×5 i.v. administration schedule, was found to be 18 mg/kg with an LD(50) of 25mg/kg. Treatment of BALB/c mice with VEGF(121)/rGel at doses up to the MTD caused no alterations in hematologic parameters. However, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) parameters increased in a dose-related manner. The no-observable-adverse-effect-level (NOAEL) was determined to be 20% of the MTD (3.6 mg/kg). VEGF(121)/rGel treatment of mice bearing orthotopically-placed MDA-MB-231 breast tumors caused increased vascular permeability of tumor tissue by 53% compared to saline-treated controls. Immunohistochemical analysis showed significant tumor hypoxia and necrosis as a consequence of vascular damage. In summary, VEGF(121)/rGel appears to be an effective therapeutic agent causing focused damage to tumor vasculature with minimal toxic effects to normal organs. This agent appears to be an excellent candidate for further clinical development.