Notch-RBP-J Signaling Regulates the Mobilization and Function of Endothelial Progenitor Cells by Dynamic Modulation of CXCR4 Expression in Mice

Bone marrow (BM)-derived endothelial progenitor cells (EPC) have therapeutic potentials in promoting tissue regeneration, but how these cells are modulated in vivo has been elusive. Here, we report that RBP-J, the critical transcription factor mediating Notch signaling, modulates EPC through CXCR4. In a mouse partial hepatectomy (PHx) model, RBP-J deficient EPC showed attenuated capacities of homing and facilitating liver regeneration. In resting mice, the conditional deletion of RBP-J led to a decrease of BM EPC, with a concomitant increase of EPC in the peripheral blood. This was accompanied by a down-regulation of CXCR4 on EPC in BM, although CXCR4 expression on EPC in the circulation was up-regulated in the absence of RBP-J. PHx in RBP-J deficient mice induced stronger EPC mobilization. In vitro, RBP-J deficient EPC showed lowered capacities of adhering, migrating, and forming vessel-like structures in three-dimensional cultures. Over-expression of CXCR4 could at least rescue the defects in vessel formation by the RBP-J deficient EPC. These data suggested that the RBP-J-mediated Notch signaling regulated EPC mobilization and function, at least partially through dynamic modulation of CXCR4 expression. Our findings not only provide new insights into the regulation of EPC, but also have implications for clinical therapies using EPC in diseases

Statistical comparison of leaching behavior of incineration bottom ash using seawater and deionized water : significant findings based on several leaching methods

Bottom ashes generated from municipal solid waste incineration have gained increasing popularity as alternative construction materials, however, they contains elevated heavy metals posing a challenge for its free usage. Different leaching methods are developed to quantify leaching potential of incineration bottom ashes meanwhile guide its environmentally friendly application. Yet, there are diverse IBA applications while the in situ environment is always complicated, challenging its legislation. In this study, leaching tests were conveyed using batch and column leaching methods with seawater as opposed to deionized water, to unveil the metal leaching potential of IBA subjected to salty environment, which is commonly encountered when using IBA in land reclamation yet not well understood. Statistical analysis for different leaching methods suggested disparate performance between seawater and deionized water primarily ascribed to ionic strength. Impacts of leachant are metal-specific dependent on leaching methods and have a function of intrinsic characteristics of incineration bottom ashes. Leaching performances were further compared on additional perspectives, e.g. leaching approach and liquid to solid ratio, indicating sophisticated leaching potentials dominated by combined geochemistry. It is necessary to develop application-oriented leaching methods with corresponding leaching criteria to preclude discriminations between different applications, e.g., terrestrial applications vs. land reclamation.Accepted versio

Dual-time-point myocardial 18F-FDG imaging in the detection of coronary artery disease

Abstract Background Myocardial 18F-deoxyglucose (18F-FDG) uptake has been observed to be enhanced in patients with coronary artery disease (CAD) under fasting conditions. However, whether the increased 18F-FDG is induced by myocardial ischemia and how to discriminate ischemic from physiological 18F-FDG uptake have rarely been investigated. Methods Under fasting conditions, 18F-FDG PET imaging was performed in 52 patients with suspected CAD. Two 18F-FDG imaging sessions were conducted within two hours after a single administration of 18F-FDG (dual-time-point imaging), and with an intervention of an exercise test after the first imaging. Abnormal 18F-FDG uptake was determined by the classification of the 18F-FDG distribution pattern, and the changes of the 18F-FDG distribution between the two PET imaging sessions were analyzed. 99mTc-sestamibi was injected at peak exercise and myocardial perfusion imaging (MPI) was conducted after 18F-FDG imaging. Coronary angiography was considered the reference for diagnosing CAD. Results Overall, 54.8% (17/31) of CAD patients and 36.2% (21/58) of stenotic coronaries showed exercise-induced abnormal uptake of 18F-FDG. Based on the classification of the 18F-FDG distribution pattern, the sensitivity and specificity of exercise 18F-FDG imaging to diagnose CAD was 80.6% and 95.2% by patient analysis, 56.9% and 98.0% by vascular analysis, respectively. Compared with MPI, 18F-FDG imaging had a tendency to have higher sensitivity (80.6% vs 64.5%, P = 0.06) on the patient level. Conclusion Myocardial ischemia can induce 18F-FDG uptake. With the classification of the 18F-FDG distribution pattern, dual-time-point 18F-FDG imaging under fasting conditions is efficient in diagnosing CAD

Benefit-risk profile of extended dual antiplatelet therapy beyond 1 year in patients with high risk of ischemic or bleeding events after PCI

The benefits and harms of dual antiplatelet therapy (DAPT) continuation with aspirin and clopidogrel beyond 1 year after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation for high ischemic or bleeding risk patients remain unclear. All consecutive patients undergoing PCI were prospectively included in the Fuwai PCI Registry from January 2013 to December 2013. We evaluated 7521 patients who were at high risk for thrombotic or hemorrhagic complications and were events free at 1 year after the index procedure. “TWILIGHT-like” patients with high risk of bleeding or ischemic events were defined by clinical and angiographic criteria. The primary ischemic outcome was major adverse cardiac and cerebrovascular events [MACCE] (a composite of all-cause death, myocardial infarction, or stroke). Median follow-up duration was 2.4 years. The risk of MACCE was significantly lower in DAPT>1-year group (n = 5252) than DAPT≤1-year group (n = 2269) (1.5% vs. 3.8%; hazard ratio [HR]: 0.37; 95% confidence interval [CI]: 0.27–0.50; P < .001). This difference was largely driven by a lower risk of all-cause death. In contrast, the risk of Bleeding Academic Research Consortium (BARC) type 2, 3 or 5 bleeding was statistically similar between the two groups (1.0% vs. 1.1%; HR: 0.80; 95% CI: 0.50–1.28; P = .346). Results were consistent after multivariable regression and propensity-score matching. Prolonged DAPT beyond 1 year after DES implantation resulted in a significantly lower rate of atherothrombotic events, including a mortality benefit, with no higher risk of clinically relevant bleeding in “TWILIGHT-like” patients who were at high-risk for ischemic or bleeding events

Prognostic Value of Machine‐Learning‐Based PRAISE Score for Ischemic and Bleeding Events in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Background The PRAISE (Prediction of Adverse Events Following an Acute Coronary Syndrome) score is a machine‐learning‐based model for predicting 1‐year all‐cause death, myocardial infarction, and Bleeding Academic Research Consortium (BARC) type 3/5 bleeding. Its utility in an unselected Asian population undergoing percutaneous coronary intervention for acute coronary syndrome remains unknown. We aimed to validate the PRAISE score in a real‐world Asian population. Methods and Results A total of 6412 consecutive patients undergoing percutaneous coronary intervention for acute coronary syndrome were prospectively included. The PRAISE scores were compared with established scoring systems (GRACE [Global Registry of Acute Coronary Events] 2.0, PRECISE‐DAPT (Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent Dual Antiplatelet Therapy), and PARIS [Patterns of Non‐Adherence to Anti‐Platelet Regimen in Stented Patients]) to evaluate their discrimination, calibration, and reclassification. The risk of all‐cause mortality (hazard ratio [HR], 12.24 [95% CI, 5.32–28.15]) and recurrent acute myocardial infarction (HR, 3.92 [95% CI, 1.76–8.73]) was greater in the high‐risk group than in the low‐risk group. The C‐statistics for death, myocardial infarction, and major bleeding were 0.75 (0.67–0.83), 0.61 (0.52–0.69), and 0.62 (0.46–0.77), respectively. The observed to expected ratio of death, myocardial infarction, and major bleeding was 0.427, 0.260, and 0.106, respectively. Based on the decision curve analysis, the PRAISE score displayed a slightly greater net benefit for the 1‐year risk of death (5%–10%) than the GRACE score did. Conclusions The PRAISE score showed limited potential for risk prediction in our validation cohort with acute coronary syndrome. As a result, new prediction models or model refitting are required with improved discrimination and accuracy in risk prediction

Insights into the structural and mechanistic basis of multifunctional S. cerevisiae Pif1p helicase

International audienceThe Saccharomyces cerevisiae Pif1 protein (ScPif1p) is the prototypical member of the Pif1 family of DNA helicases. ScPif1p is involved in the maintenance of mitochondrial, ribosomal and telomeric DNA and suppresses genome instability at G-quadruplex motifs. Here, we report the crystal structures of a truncated ScPif1p (ScPif1p237−780) in complex with different ssDNAs. Our results have revealed that a yeast-specific insertion domain protruding from the 2B domain folds as a bundle bearing an α-helix, α16. The α16 helix regulates the helicase activities of ScPif1p through interactions with the previously identified loop3. Furthermore, a biologically relevant dimeric structure has been identified, which can be further specifically stabilized by G-quadruplex DNA. Basing on structural analyses and mutational studies with DNA binding and unwinding assays, a potential G-quadruplex DNA binding site in ScPif1p monomers is suggested. Our results also show that ScPif1p uses the Q-motif to preferentially hydrolyze ATP, and a G-rich tract is preferentially recognized by more residues, consistent with previous biochemical observations. These findings provide a structural and mechanistic basis for understanding the multifunctional ScPif1p

Comparison of Estimated LDL Cholesterol Equations with Direct Measurement in Patients with Angiographically Confirmed Coronary Artery Disease

Background and aims: Our goals in the study were to (1) quantify the discordance in LDL-C levels between equations (the Friedewald, Sampson, and Martin/Hopkins equations) and compare them with direct LDL-C (dLDL-C); and (2) explore the proportion of misclassified patients by calculated LDL-C using these three different equations. Methods: A total of 30,349 consecutive patients with angiographically confirmed coronary artery disease (CAD) were prospectively enrolled. Concordance was defined as if the LDL-C was &lt;1.8 mmol/L with each pairwise comparison of LDL-C equations. Estimated LDL-C that fell into the same category as dLDL-C at the following levels: &lt;1.4, 1.4 to 1.7, 1.8 to 2.5, 2.6 to 2.9, and &ge;3.0 mmol/L was considered to have been correctly categorized. Results: The concordance was 96.3% (Sampson vs. Martin/Hopkins), 95.0% (Friedewald vs. Sampson), and 91.4% (Friedewald vs. Martin/Hopkins), respectively. This proportion fell to 82.4% in those with hypertriglyceridemia (TG &ge; 1.7 mmol/L). With an accurate classification rate of 73.6%, the Martin/Hopkins equation outperformed the Sampson equation (69.5%) and the Friedewald equation (59.3%) by a wide margin. Conclusions: Comparing it to the validated Martin/Hopkins equation, the Friedewald equation produced the lowest levels of LDL-C, followed by the Sampson equation. In the classification of LDL-C, the Martin/Hopkins equation has also been shown to be more accurate. There is a significant difference between the equations and the direct measurement method, which may lead to overtreatment or undertreatment

Lowered recruitment of the <i>RBP-J</i>-deleted EPC into the regenerating liver after PHx.

<p>Normal mice were subjected to PHx. On the next day of the operation, mice were irradiated, and were transfused with Dio-labeled BM cells from the RBP-J deficient (KO-BMT) or the control (Con-BMT) mice. The recipient mice were analyzed 2 days after the BM transplantation (3 days after PHx). (A) The livers of the recipient mice suffering PHx were sectioned, stained for UEA-1, and were examined for Dio⁺ cells (upper) and UEA-1⁺Dio⁺ cells (lower). (B, C) Dio⁺ cells and UEA-1⁺Dio⁺ cells in (A) were quantitatively represented by corresponding pixels (bars = mean±SD; n = 4; ** <i>P</i><0.01; *** <i>P</i><0.001). (D) Livers were perfused with PBS. SECs were purified from the livers of the recipient mice using a kit, and were analyzed for Flk-1⁺Dio⁺ cells. The cytograph represented 4 independent experiments with the same results.</p

Effect of the RBP-J deletion on the in vitro cultured EPC.

<p>(A) The expression of CXCR4 on the cultured EPC was accessed by FACS analysis. (B, C) In vitro migration assay. Transwell culture was set up, with EPC from the RBP-J-deleted and the control mice in the upper chamber, and SDF-1α in the lower chamber. A photograph of EPC in the lower chamber (B) was taken, and cells in the lower chamber (C) were counted 18 h after the starting of the culture (bars = mean±SD; n = 4; ** <i>P</i><0.01). (D) The formation of colonies by the cultured RBP-J knockout and the control EPC. (E) The number of total EPC formed 7 days after the culture. (F) The number of EPC attached on the gelatin-coated dishes 3 days after the culture. (bars = mean±SD; n = 4; * <i>P</i><0.05).</p