Myeloid-specific knockout of Notch-1 inhibits MyD88- and TRIF-mediated TLR signaling pathways by regulating oxidative stress-SHP2 axis, thus restraining aneurysm progression.

OBJECTIVE: Notch-1 is a signal regulatory protein with extensive effects in myeloid cells, but its role in aneurysms remains to be fully clarified. In this study, therefore, the aneurysm mouse model with myeloid-specific knockout of Notch-1 was established to observe the role of Notch-1 in aneurysm progression. METHODS AND RESULTS: The effect of Notch-1 was assessed by pathological staining and Western blotting. It was found that after myeloid-specific knockout of Notch-1 in the aneurysm mouse model, the area of aneurysms and the macrophage infiltration were significantly reduced, the damage to arterial elastic plates was significantly relieved, and the oxidative stress level significantly declined. The results of Western blotting showed that after myeloid-specific knockout of Notch-1, the levels of oxidative stress-related proteins p22 and p47 in aneurysm tissues significantly declined, accompanied by a significant increase in the protein level of Src homology 2 domain-containing tyrosine phosphatase-2 (SHP2). In addition, the levels of phosphorylated myeloid differential protein-88 (MyD88), TIR domain-containing adaptor-inducing interferon-ß (TRIF) and nuclear factor-κB (NF-κB), and inflammatory cytokines interferon-γ (IFN-γ), interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) also significantly decreased after myeloid-specific knockout of Notch-1. Following myeloid-specific knockout of Notch-1, the phagocytic capacity of macrophages was enhanced by promoting the SHP2 signaling pathway. CONCLUSION: Notch-1 in monocytes/macrophages can activate the Toll-like receptor (TLR)-mediated inflammatory and stress responses by activating oxidative stress and inhibiting the SHP2 protein expression, thus facilitating aneurysm progression.

Correction to: Resveratrol prevents atrial fibrillation by inhibiting atrial structural and metabolic remodeling in collagen-induced arthritis rats.

There was a mistake of IL-6 blot in the Fig. 5 in the present paper, and authors had mistakenly pasted the blot of Bax for IL-6 when making Figure5.

Outlier analyses of the Protein Data Bank archive using a probability-density-ranking approach.

Outlier analyses are central to scientific data assessments. Conventional outlier identification methods do not work effectively for Protein Data Bank (PDB) data, which are characterized by heavy skewness and the presence of bounds and/or long tails. We have developed a data-driven nonparametric method to identify outliers in PDB data based on kernel probability density estimation. Unlike conventional outlier analyses based on location and scale, Probability Density Ranking can be used for robust assessments of distance from other observations. Analyzing PDB data from the vantage points of probability and frequency enables proper outlier identification, which is important for quality control during deposition-validation-biocuration of new three-dimensional structure data. Ranking of Probability Density also permits use of Most Probable Range as a robust measure of data dispersion that is more compact than Interquartile Range. The Probability-Density-Ranking approach can be employed to analyze outliers and data-spread on any large data set with continuous distribution.

Long non-coding RNA CCRR controls cardiac conduction via regulating intercellular coupling.

Long non-coding RNAs (lncRNAs) have emerged as a new class of gene expression regulators playing key roles in many biological and pathophysiological processes. Here, we identify cardiac conduction regulatory RNA (CCRR) as an antiarrhythmic lncRNA. CCRR is downregulated in a mouse model of heart failure (HF) and in patients with HF, and this downregulation slows cardiac conduction and enhances arrhythmogenicity. Moreover, CCRR silencing induces arrhythmias in healthy mice. CCRR overexpression eliminates these detrimental alterations. HF or CCRR knockdown causes destruction of intercalated discs and gap junctions to slow longitudinal cardiac conduction. CCRR overexpression improves cardiac conduction by blocking endocytic trafficking of connexin43 (Cx43) to prevent its degradation via binding to Cx43-interacting protein CIP85, whereas CCRR silence does the opposite. We identified the functional domain of CCRR, which can reproduce the functional roles and pertinent molecular events of full-length CCRR. Our study suggests CCRR replacement a potential therapeutic approach for pathological arrhythmias.

Ozone protects the rat lung from ischemia-reperfusion injury by attenuating NLRP3-mediated inflammation, enhancing Nrf2 antioxidant activity and inhibiting apoptosis.

Ischemia-reperfusion injury (IRI) is a major cause of lung dysfunction during cardiovascular surgery, heart transplantation and cardiopulmonary bypass procedures, and the inflammatory response, oxidative stress, and apoptosis play key and allegedly maladaptive roles in its pathogenesis. The aim of this study was to initially elucidate whether ozone induces oxidative preconditioning by activating nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and secondly to determine whether ozone oxidative preconditioning (OzoneOP) protects the lung from IRI by attenuating nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3)-mediated inflammation, enhancing the antioxidant activity of Nrf2 and inhibiting apoptosis. Rats treated with or without OzoneOP (2 ml containing 100 µg/kg/day) were subjected to 1 h of lung ischemia followed by 2 h of reperfusion for 10 days. Lung damage, antioxidant capacity, inflammation and apoptosis were evaluated and compared among different groups after reperfusion. OzoneOP significantly ameliorated changes in lung morphology and protected the lung from IRI by attenuating oxidative stress, inflammation-induced injury and lung apoptosis. Moreover, OzoneOP increased the expression of Nrf2 and decreased the levels of NLRP3, apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), un-cleavable cysteine-requiring aspartate protease-1 (procaspase-1), cysteine-requiring aspartate protease-1 (caspase-1) and interleukin-1ß (IL-1ß) in the rat lungs. In summary, these results provide new insights into the molecular events modulated by ozone and suggest that ozone therapy may be an integrative support for patients with lung IRI.

Resveratrol prevents atrial fibrillation by inhibiting atrial structural and metabolic remodeling in collagen-induced arthritis rats.

Rheumatoid arthritis (RA) causes atrial remodeling that induces the occurrence and maintenance of atrial fibrillation (AF). In this study, we explored the influence of RA on atrial fibrillation and the potential therapeutic effects of resveratrol in a rat model. The following three groups of female Wistar rats (8 weeks old) were used in this study: control, collagen-induced arthritis (CIA), and resveratrol. Rats in the CIA and resveratrol groups were injected twice with type II collagen in Freund's incomplete adjuvant. Three weeks after the second injection, resveratrol (10 mg kg-1 day-1) was administered for 4 weeks. Subsequently, atrial electrophysiological parameters were measured. Levels of inflammatory factors in the atria and serum were measured. Atrial histopathological changes were assessed using microscopy, and cardiomyocyte apoptosis and fibrosis were assessed using TUNEL and Masson's staining. Apoptosis-related and fibrosis-related proteins were assessed using Western blotting. Atrial adenosine triphosphate (ATP) and free fatty acid (FFA) levels were tested using ELISA. Glycogen accumulation and metabolism-related protein expression were assessed. AF inducibility and duration were markedly increased in CIA rats and were reduced by resveratrol. CIA also increased the atrial and serum IL-6 and TNF-a levels and induced atrial apoptosis and fibrosis, which were attenuated by resveratrol. Moreover, CIA induced the impairment of atrial energy metabolism by inhibiting the AMPK/PGC-1α pathway, which was reversed by resveratrol. Resveratrol protects against RA-induced atrial structural and metabolic remodeling, which may provide a new potential therapeutic treatment for RA-related AF.

Expression of platelet-derived growth factor B is upregulated in patients with thoracic aortic dissection.

OBJECTIVE: Thoracic aortic dissection (TAD) is a serious condition requiring urgent treatment to avoid catastrophic consequences. The inflammatory response is involved in the occurrence and development of TAD, possibly potentiated by platelet-derived growth factors (PDGFs). This study aimed to determine whether expression of PDGF-B (a subunit of PDGF-BB) was increased in TAD patients and to explore the factors responsible for its upregulation and subsequent effects on TAD. METHODS: Full-thickness ascending aorta wall specimens from TAD patients (n = 15) and control patients (n = 10) were examined for expression of PDGF-B and its receptor (PDGFRB) and in terms of morphology, inflammation, and fibrosis. Blood samples from TAD and control patients were collected to detect plasma levels of PDGF-BB and soluble elastins. RESULTS: Expression levels of PDGF-B, PDGFRB, and collagen I were significantly enhanced in ascending aorta wall specimens from TAD patients compared with controls. Furthermore, soluble elastic fragments and PDGF-BB were significantly increased in plasma from TAD patients compared with controls, and numerous irregular elastic fibers and macrophages were seen in the ascending aorta wall in TAD patients. CONCLUSIONS: An increase in elastic fragments in the aorta wall might be responsible for inducing the activation and migration of macrophages to injured sites, leading to elevated expression of PDGF-B, which in turn induces deposition of collagen, disrupts extracellular matrix homeostasis, and increases the stiffness of the aorta wall, resulting in compromised aorta compliance.

Overexpression of microRNA-138 alleviates human coronary artery endothelial cell injury and inflammatory response by inhibiting the PI3K/Akt/eNOS pathway.

This study aimed to investigate the role of miR-138 in human coronary artery endothelial cell (HCAEC) injury and inflammatory response and the involvement of the PI3K/Akt/eNOS signalling pathway. Oxidized low-density lipoprotein (OX-LDL)-induced HCAEC injury models were established and assigned to blank, miR-138 mimic, miR-138 inhibitor, LY294002 (an inhibitor of the PI3K/Akt/eNOS pathway), miR-138 inhibitor + LY294002 and negative control (NC) groups. qRT-PCR and Western blotting were performed to detect the miR-138, PI3K, Akt and eNOS levels and the protein expressions of PI3K, Akt, eNOS, p-Akt, p-eNOS, Bcl-2, Bax and caspase-3. ELISAs were employed to measure the expressions of TNF-α, IL-4, IL-6, IL-8, IL-10 and nitric oxide (NO) and the activities of lactate dehydrogenase (LDH) and eNOS. MTT and flow cytometry were performed to assess the proliferation and apoptosis of HCAECs. Compared to the blank group, PI3K, Akt and eNOS were down-regulated in the miR-138 mimic and LY294002 groups but were up-regulated in the miR-138 inhibitor group. The miR-138 mimic and LY294002 groups showed decreased concentrations of TNF-α, IL-6, IL-8 and NO and reduced activities of LDH and eNOS, while opposite trends were observed in the miR-138 inhibitor group. The concentrations of IL-4 and IL-10 increased in the miR-138 mimic and LY294002 groups but decreased in the miR-138 inhibitor group. The miR-138 mimic and LY294002 groups had significantly decreased cell proliferation and increased cell apoptosis compared to the blank group. These findings indicate that up-regulation of miR-138 alleviates HCAEC injury and inflammatory response by inhibiting the PI3K/Akt/eNOS signalling pathway.

Ozone protects rat heart against ischemia-reperfusion injury: A role for oxidative preconditioning in attenuating mitochondrial injury.

Ischemia-reperfusion injury (IRI) is a major cause of cardiac dysfunction during cardiovascular surgery, heart transplantation and cardiopulmonary bypass procedures. The purpose of the present study was to explore, firstly, whether ozone induces oxidative preconditioning by activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and, secondly, whether ozone oxidative preconditioning (OzoneOP) can protect the heart against IRI by attenuating mitochondrial damage. Rats were subjected to 30min of cardiac ischemia followed by 2h of reperfusion, with or without prior OzoneOP (100µg/kg/day) for 5 days. Antioxidant capacity, myocardial apoptosis and mitochondrial damage were evaluated and compared at the end of reperfusion. OzoneOP was found to increase antioxidant capacity and to protect the myocardium against IRI by attenuating mitochondrial damage and myocardial apoptosis. The study suggests a potential role for OzoneOP in protecting the heart against IRI during cardiovascular surgery, cardiopulmonary bypass procedures or transplantation.

Keeping the heart empty and beating: an alternative technique to preserve hypertrophied hearts during valvular surgery.

INTRODUCTION: To determine whether keeping the heart empty and beating is an effective technique to preserve hypertrophied pig hearts, and to investigate the underlying mechanism. METHODS: Ten Bama Miniature pigs with hypertrophied hearts were divided into 2 groups (n = 5 in each group). One group underwent normothermic normokalemic simultaneous perfusion (NNSP). The other group was subjected to normothermic hypermokalemic simultaneous perfusion (NHSP) and used as controls. Cardiac contractive function, myocardial energy metabolism and myocardial perfusion were assessed using magnetic resonance imaging. Western blot analysis was carried out to determine the expression of Troponin I (cTnI), Troponin T (cTnT), SM-MHC, Casapase-3 and PARP4. TUNEL assay was used to detect apoptotic cardiomyocytes. RESULTS: Keeping the heart empty and beating with NNSP improved the preservation of contractile function in comparison with cardioplegic arrest using NHSP. No significant differences existed in the effects of NNSP and NHSP in maintaining myocardial energy metabolism. 13 % perfusion defects areas were found in one heart in the NHSP group, whereas none was found in all other hearts in both groups. The expressions of cTnI, cTnT, Casapase-3 and PARP4 in NHSP group were abundantly increased compared to NNSP group as measured by Western blotting. Conversely, the expression of SM-MHC in NHSP group was reduced compared with NNSP group. The number of TUNEL positive nuclei per mm(2) area was significantly increased in NHSP group compared with NNSP group. CONCLUSIONS: Keeping the heart beating with NNSP is an alternative technique to preserve hypertrophied hearts during valvular surgery.

Uric acid as a predictor of in-hospital mortality in acute myocardial infarction: a meta-analysis.

Uric acid (UA) is generalized as a byproduct the terminal steps of purine catabolism, which are catalyzed by xanthine oxidoreductase. Xanthine oxidase activity and uric acid synthesis are reported to be increased under tissue ischemia. Therefore, elevated uric acid may act as a prognostic marker of acute myocardial infarction (AMI). A few studies have showed that UA is associated with therapeutic outcomes in patients with acute myocardial infarction. The purpose of this meta-analysis is to evaluate the prognostic significance of the UA as a predictor of in-hospital mortality. We performed a systematic review and included studies that used both UA and in-hospital mortality from Embase and PubMed. Six studies have been included in this review with totally 5,686 patients. During the follow-up, high UA level was found to be associated with an increased risk of in-hospital mortality [risk ratios (RR) 2.10 (1.03-4.26), number needed to harm (NNH) 37], MACE [RR 3.44 (2.33-5.08), NNH 17]. High UA level has the potential to be an important prognostic marker for in-hospital mortality in individuals with AMI.

Microvascular damage after coronary artery bypass surgery: assessment using dobutamine stress myocardial contrast echocardiography.

BACKGROUND: Although dobutamine stress myocardial contrast echocardiography (DSMCE) has been widely used for the prediction of myocardial functional recovery, dynamic changes that occur at the microcirculatory level during stress have been studied limitedly. The objective of the present study was to use low-dose DSMCE to assess microvascular damage and predict myocardial functional recovery in coronary artery disease (CAD) patients receiving coronary artery bypass grafting. METHODS: Forty-six CAD patients were subjected to low-dose DSMCE, as well as echocardiography and coronary computed tomography angiography before revascularization, 1 year after coronary artery bypass grafting. Dynamic changes occurring at the microcirculatory level during stress were analyzed for the ability to predict functional recovery. Quantitative assessment of functional recovery was determined using myocardial blood flow (MBF) via receiver operating characteristic curve analyses. RESULTS: Patients who failed to recover had fewer changes in MBF (ΔMBF) at rest and with stress compared with the segments showing functional recovery. Semiquantitative changes (enhanced or reduced) of the myocardial perfusion score (ΔMPS) and quantitative changes in ΔMBF of stress myocardial contrast echocardiography enhanced the specificity of resting MPS and the sensitivity of wall motion scores (P < 0.05) for the prediction of functional recovery. CONCLUSIONS: Specific stress ΔMBF more accurately reflected the extent of microvascular damage compared with wall motion scores and resting MPS. ΔMBF and ΔMPS under stress myocardial contrast echocardiography provided higher accuracy than wall motion scores and resting MPS in predicting functional recovery in CAD patients after revascularization.

Effect of graft patency on the prediction of myocardial viability by dobutamine stress and myocardial contrast echocardiography before coronary artery bypass surgery.

BACKGROUND: Myocardial functional recovery after revascularization is considered the "gold standard" for myocardial viability (MV) assessment. However, the patency of the revascularized coronary artery affects myocardial functional recovery in patients subjected to coronary artery bypass grafting (CABG). The influence of graft patency on viability results has not been widely studied. PURPOSE: We evaluated the effect of graft patency on the prediction of MV after CABG by myocardial contrast echocardiography (MCE) and low-dose dobutamine stress echocardiography (LD-DSE). METHODS: Fifty-three subjects with chronic ischemic heart disease scheduled for CABG were divided randomly into groups A (n = 26) and B (n = 27). They underwent MCE and LD-DSE preoperatively. Patients were followed up 12 months after CABG. Group B patients underwent multislice computed tomography angiography to assess CABG patency, and patients with obstructed grafts were excluded. Group A patients were not subjected to multislice CT angiography. The accuracy of MCE and LD-DSE for assessing MV between the two groups was compared. RESULTS: The accuracy and positive predictive values of MCE and LD-DSE for predicting MV were higher in group B than in group A (p < 0.05). CONCLUSIONS: Preoperative LD-DSE and MCE ability to predict MV depends on the patency of CABG.

Celecoxib plays a multiple role to peripheral blood lymphocytes and allografts in acute rejection in rats after cardiac transplantation.

BACKGROUND: Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, is a non-steroidal anti-inflammatory drug used as an adjuvant to sensitize cancer cells to apoptosis. However, in rats suffering from acute rejection, celecoxib reduced apoptosis of myocardial cells. We hypothesize that celecoxib reduces myocardial apoptosis either by inducing apoptosis in peripheral blood lymphocytes (PBLs) or by altering the percentage of CD4(+) and CD8(+) lymphocytes. METHODS: After cardiac transplantation, rats were administered intragastrically with celecoxib (50 mg/kg per day) for 3, 5 or 7 days, at which time the graft was excised and evaluated for organ rejection. In addition, PBLs were isolated from the blood to determine PBLs apoptosis, and the percentage of CD4(+) and CD8(+) lymphocytes. RESULTS: Celecoxib induced PBLs apoptosis in 3 days, but protected the cells from apoptosis at 5 and 7 days. Also, the percentage of CD4(+) lymphocytes decreased only at 3 days, but a reduction in the percentage of CD8(+) lymphocytes was not seen until 7 days after the transplant surgery. Celecoxib only decreased acute rejection at 5 days, with no discernible difference in rejection after 3 and 7 days. CONCLUSIONS: The results suggested that celecoxib displayed a multiple physiological function in a time-dependent manner.

Pachymic acid, a novel compound for anti-rejection: effect in rats following cardiac allograft transplantation.

BACKGROUND: Pachymic acid (PA), a natural triterpenoid, is known to significantly reduce cell proliferation and induce apoptosis in vitro through initiation of mitochondria dysfunction. However, its effect on immune cells and anti-rejection following organ transplantation remains unknown. METHODS: In this study, we investigated PA as a treatment to control acute rejection occurred in rats which had accepted cardiac transplantation. We measured apoptosis of peripheral blood lymphocyte (PBLs), and CD4(+) lymphocyte, as well as the number of CD4(+) and CD8(+) lymphocytes and the effect of PA on acute rejection in rats 7 days after cardiac transplantation. RESULTS: PA treatment might decrease allograft rejection, protect PBLs from apoptosis, and reduce the percentage of CD8(+) lymphocyte. PA neither regulated the number nor the apoptosis rate of CD4(+) lymphocyte. CONCLUSIONS: Our findings indicated that PA has an anti-apoptotic effect acting on PBLs through a novel mechanism involving stabilization of the PBLs mitochondrial transmembrane potential, an anti-rejection effect in rats after cardiac transplantation and an inhibiting effect to CD8(+) lymphocyte.