Pretransfer Aspirin Administration and Its Impact on Angiographic Outcomes for Patients with ST-Elevation Myocardial Infarction.

Although guidelines recommend early aspirin administration after diagnosis of ST-elevation myocardial infarction (STEMI), the decision of pretransfer aspirin administration is at the discretion of the primary physicians. Therefore, this study aimed to determine whether pretransfer aspirin administration was associated with better angiographical outcomes in patients with STEMI. This study compared the angiographic findings of thrombolysis in myocardial infarction (TIMI) flow grade in the infarct-related artery before percutaneous coronary intervention (PCI) between patients who received pretransfer aspirin and those who did not. In total, 28 patients (11.2%) were administered aspirin before transfer and 219 (88.8%) were administered aspirin upon arrival at the hospital. Propensity score matching yielded 135 patients [27 patients (20%) who were administered aspirin before transfer and 108 patients (80%) who were administered aspirin upon arrival at the hospital]. Patients who received pretransfer aspirin had a higher rate of TIMI-3 flow before PCI compared to those who did not receive pretransfer aspirin [8 (28.6%) versus 15 (6.8%), P < 0.01, in all study patients; 8 (26.6%) versus 7 (6.5%), P < 0.01, in propensity-score-matched patients]. Multivariable logistic regression analysis revealed that pretransfer aspirin administration was significantly associated with the presence of TIMI-3 flow before PCI, independent of age, gender, transfer time, and statin use (OR: 5.43, 95% CI: 1.94-15.2, P < 0.01, in all study patients; OR: 6.17, 95% CI: 1.86-20.46, P < 0.01, in propensity-score-matched patients). Pretransfer aspirin administration could lead to the early restoration of coronary blood flow in patients with STEMI, supporting its active use in STEMI care.

Prognostic Value of Novel Natriuretic Peptide Index After Percutaneous Coronary Intervention.

BACKGROUND: The predictive value of both atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) is well known. This study evaluated the prognostic value of a novel natriuretic peptide index (NPI) combining ANP and BNP. Methods and Results: This study included 849 consecutive patients with coronary artery disease who underwent successful percutaneous coronary intervention (PCI). Patients were followed up clinically for up to 3 years or until the occurrence of major adverse cardiac events (MACE). The primary endpoint was a composite of all-cause death and non-fatal myocardial infarction. The NPI (pg/mL) was defined as √ANP×BNP. MACE occurred in 73 patients (8.6%) during the follow-up period. Receiver operating characteristic curve analysis showed the highest area under the curve for NPI (0.779) compared with ANP and BNP (0.773 and 0.755, respectively). A risk analysis of MACE occurrence adjusted for the multivariable model showed the highest hazard ratio (HR) for NPI (1.33; 95% confidence interval [CI] 1.18-1.51; P<0.001) compared with ANP and BNP (HR 1.25 [95% CI 1.13-1.39] and 1.30 [95% CI 1.13-1.49], respectively; P<0.001). The NPI was a significant independent predictor of MACE, among other clinical parameters, in the multivariable analysis. CONCLUSIONS: Compared with ANP and BNP, the NPI was more effective in predicting future adverse events after PCI.

Protein S-glutathionylation stimulate adipogenesis by stabilizing C/EBPß in 3T3L1 cells.

Reactive oxygen species (ROS) increase during adipogenesis and in obesity. Oxidants react with cysteine residues of proteins to form glutathione (GSH) adducts, S-glutathionylation, that are selectively removed by glutaredoxin-1 (Glrx). We have previously reported that Glrx knockout mice had increased protein S-glutathionylation and developed obesity by an unknown mechanism. In this study, we demonstrated that 3T3L1 adipocytes differentiation increased ROS and protein S-glutathionylation. Glrx ablation elevated protein S-glutathionylation and lipid content in 3T3L1 cells. Glrx replenishment decreased the lipid content of Glrx KO 3T3L1 cells. Glrx KO also increased protein expression and protein S-glutathionylation of the adipogenic transcription factor CCAAT enhancer-binding protein (C/EBP) ß. Protein S-glutathionylation decreased the interaction of C/EBPß and protein inhibitor of activated STAT (PIAS) 1, a small ubiquitin-related modifier E3 ligase that facilitates C/EBPß degradation. Experiments with truncated mutant C/EBPß demonstrated that PIAS1 interacted with the liver-enriched inhibitory protein (LIP) region of C/EBPß. Furthermore, mass spectrometry analysis identified protein S-glutathionylation of Cys201 and Cys296 in the LIP region of C/EBPß. The C201S, C296S double-mutant C/EBPß prevented protein S-glutathionylation and preserved the interaction with PIAS1. In summary, Glrx ablation stimulated 3T3L1 cell differentiation and adipogenesis via increased protein S-glutathionylation of C/EBPß, stabilizing and increasing C/EBPß protein levels.

Impact of persistent endothelial dysfunction in an infarct-related coronary artery on future major adverse cardiovascular event occurrence in STEMI survivors.

Although coronary endothelial vasomotor dysfunction predicts future coronary events, few human studies have shown the relationship between persistent endothelial vasomotor dysfunction and major adverse cardiovascular events (MACE) using serial assessments in the same coronary artery. This study examined whether persistent endothelial vasomotor dysfunction is related to MACE occurrence in the infarct-related coronary artery (IRA) of ST-segment elevation myocardial infarction (STEMI) survivors using serial assessments of the coronary vasomotor response to acetylcholine (ACh). This study included 169 consecutive patients with a first acute STEMI due to left anterior descending coronary artery (LAD) occlusion and successful reperfusion therapy with percutaneous coronary intervention. Vasomotor response to ACh in the LAD was measured within 2 weeks of acute myocardial infarction (AMI) (first test) and repeated 6 months (second test) after AMI under optimal anti-atherosclerotic therapy. MACE was defined as the composite of all-cause death, non-fatal MI, angina recurrence requiring percutaneous intervention or surgical bypass, and hospitalization for heart failure. We followed up 126 patients for a period of ≤ 60 months until MACE occurrence after second test. Nineteen MACEs occurred during the follow-up. The log-rank test, Kaplan-Meier curves and univariate Cox proportional hazards regression analysis showed that MACE occurrence was significantly associated with the persistent impairment of epicardial coronary artery dilation and coronary blood flow increases in response to ACh (log-rank test, p < 0.001 and p < 0.001, respectively) (Hazard ratio, p = 0.001 and p = 0.002, respectively). Persistent impairment of endothelial vasomotor function in the infarct-related conduit arterial segment and resistance arteriole were the significant predictor of future MACE occurrence in STEMI survivors.

Wnt5a-Mediated Neutrophil Recruitment Has an Obligatory Role in Pressure Overload-Induced Cardiac Dysfunction.

BACKGROUND: Although the complex roles of macrophages in myocardial injury are widely appreciated, the function of neutrophils in nonischemic cardiac pathology has received relatively little attention. METHODS: To examine the regulation and function of neutrophils in pressure overload-induced cardiac hypertrophy, mice underwent treatment with Ly6G antibody to deplete neutrophils and then were subjected to transverse aortic constriction. RESULTS: Neutrophil depletion diminished transverse aortic constriction-induced hypertrophy and inflammation and preserved cardiac function. Myeloid deficiency of Wnt5a, a noncanonical Wnt, suppressed neutrophil infiltration to the hearts of transverse aortic constriction-treated mice and produced a phenotype that was similar to the neutropenic conditions. Conversely, mice overexpressing Wnt5a in myeloid cells displayed greater hypertrophic growth, inflammation, and cardiac dysfunction. Neutrophil depletion reversed the Wnt5a overexpression-induced cardiac pathology and eliminated differences in cardiac parameters between wild-type and myeloid-specific Wnt5a transgenic mice. CONCLUSIONS: These findings reveal that Wnt5a-regulated neutrophil infiltration has a critical role in pressure overload-induced heart failure.

Persistent Myocardial Production of Follistatin-like 1 Is Associated With Left Ventricular Adverse Remodeling in Patients With Myocardial Infarction: Myocardial production of FSTL1 in AMI patients.

BACKGROUND: Although animal studies showed that Follistatin-like 1 (FSTL1) exerts cardioprotective effects against ischemic injury, little is known in humans. We examined whether FSTL1 is secreted in an infarcted myocardium and whether its production is associated with left ventricular (LV) remodeling in survivors of acute myocardial infarction. METHODS AND RESULTS: FSTL1 levels were measured by enzyme-linked immunosorbent assay in plasma collected from the aortic root and the anterior interventricular vein in 93 patients with anterior acute myocardial infarction. Measurement of FSTL1 levels and left ventriculography were repeated during the early phase (2 weeks) and the chronic phase (6 months) after MI. A persistent increment in FSTL1 levels from the aortic root to the anterior interventricular vein, reflecting FSTL1 production in the infarcted myocardium at both the early and chronic phases, was seen in 22 patients (24%). A linear regression analysis revealed that a persistent transmyocardial increment in FSTL1 levels was significantly associated with percent changes in LV end-diastolic volume index, LV end-systolic volume index, and LV ejection fraction from the early to the chronic phase (r = 0.44, 0.51, and -0.43, respectively, all P < .001). CONCLUSIONS: The persistent production of FSTL1 in the infarcted myocardium was associated with adverse LV remodeling in survivors of acute myocardial infarction.

Endothelial cell-specific redox gene modulation inhibits angiogenesis but promotes B16F0 tumor growth in mice.

Glutaredoxin-1 (Glrx) is a small cytosolic enzyme that removes S-glutathionylation, glutathione adducts of protein cysteine residues, thus modulating redox signaling and gene transcription. Although Glrx up-regulation prevented endothelial cell (EC) migration and global Glrx transgenic mice had impaired ischemic vascularization, the effects of cell-specific Glrx overexpression remained unknown. Here, we examined the role of EC-specific Glrx up-regulation in distinct models of angiogenesis; namely, hind limb ischemia and tumor angiogenesis. EC-specific Glrx transgenic (EC-Glrx TG) overexpression in mice significantly impaired EC migration in Matrigel implants and hind limb revascularization after femoral artery ligation. Additionally, ECs migrated less into subcutaneously implanted B16F0 melanoma tumors as assessed by decreased staining of EC markers. Despite reduced angiogenesis, EC-Glrx TG mice unexpectedly developed larger tumors compared with control mice. EC-Glrx TG mice showed higher levels of VEGF-A in the tumors, indicating hypoxia, which may stimulate tumor cells to form vascular channels without EC, referred to as vasculogenic mimicry. These data suggest that impaired ischemic vascularization does not necessarily associate with suppression of tumor growth, and that antiangiogenic therapies may be ineffective for melanoma tumors because of their ability to implement vasculogenic mimicry during hypoxia.-Yura, Y., Chong, B. S. H., Johnson, R. D., Watanabe, Y., Tsukahara, Y., Ferran, B., Murdoch, C. E., Behring, J. B., McComb, M. E., Costello, C. E., Janssen-Heininger, Y. M. W., Cohen, R. A., Bachschmid, M. M., Matsui, R. Endothelial cell-specific redox gene modulation inhibits angiogenesis but promotes B16F0 tumor growth in mice.

[A Case of Synchronous Double Lung Cancer Including Intestinal Adenocarcinoma Complicated with Colonic Adenoma].

The patient was a 73-year-old man who was referred to our hospital for increasing bilateral lung nodules. Video-assisted left S9-10 segmentectomy and right S1, S3 partial resection were performed separately for suspect of synchronous double lung cancer. Colonoscopy was performed because left lung tumor was difficult to distinguish between primary lung cancer and metastatic lung cancer. Colonoscopy did not find advanced cancer lesion. We diagnosed the left lung tumor as pT1b, cN0, cM0, Stage ⅠA2 intestinal adenocarcinoma. The right lung tumor was diagnosed as pT1c, cN0, cM0, Stage ⅠA3 papillary adenocarcinoma. Intestinal adenocarcinoma is a rare tissue subtype of lung adenocarcinoma and colonoscopy is useful modality for ruling out metastatic colorectal cancer.

Pulmonary Vascular Resistance Is Associated With Brachial-Ankle Pulse-Wave Velocity and Adverse Clinical Outcomes in Patients With Heart Failure With Preserved Ejection Fraction.

BACKGROUND: The precise mechanisms underlying the high prevalence of pulmonary hypertension (PH) with increased pulmonary vascular resistance (PVR) in heart failure with preserved ejection fraction (HFpEF) remain largely unknown. Measurements of brachial-ankle pulse wave velocity (baPWV) have been shown to be useful for risk assessment in HF patients. Thus, this study sought to define the association of PVR with baPWV and clinical outcomes in HFpEF. METHODS AND RESULTS: Patients with HFpEF (n = 198) had measurements of baPWV and PVR by right heart catheterization, and were prospectively followed-up for <96 months or until the occurrence of a composite of all-cause death, hospitalization with worsening HF, and nonfatal acute coronary syndrome. RESULTS: Multivariate logistic analysis showed that baPWV was independently associated with PH with increased PVR (P < .001). During the follow-up period, 46 clinical events occurred. Multivariate Cox proportional hazards analysis showed that PH with increased PVR was a significant predictor of adverse outcomes after adjustment for conventional risk factors (HR 1.96, 95% CI 1.03-3.76, P = .04). CONCLUSIONS: PH with increased PVR was associated with increased baPWV and adverse clinical outcomes in HFpEF. Thus, increased arterial stiffness may contribute to increased risk predictability of PVR for patients with HFpEF.

Remnant Lipoproteins Are Residual Risk Factor for Future Cardiovascular Events in Patients With Stable Coronary Artery Disease and On-Statin Low-Density Lipoprotein Cholesterol Levels <70 mg/dL.

BACKGROUND: This study examined the predictive value of remnant lipoprotein levels for cardiovascular events (CVEs) in patients with stable coronary artery disease (CAD) and low-density lipoprotein cholesterol (LDL-C) levels <70 mg/dL on statin treatment.Methods and Results:Serum levels of remnant lipoproteins (remnant-like lipoprotein particles cholesterol: RLP-C) were measured by an immunoseparation method in 247 consecutive patients with CAD who had on-statin LDL-C levels <70 mg/dL. All the patients were followed prospectively for a period of ≤60 months or until the occurrence of the primary composite endpoint of cardiac death, nonfatal myocardial infarction, unstable angina requiring coronary revascularization, worsening heart failure, peripheral artery disease, aortic event, and ischemic stroke. During a mean follow-up period of 38 months, 33 CVEs occurred. Kaplan-Meier analysis demonstrated that higher RLP-C levels (≥3.9 mg/dL, determined by ROC curve) resulted in a significantly higher probability for the primary endpoint than did lower RLP-C levels (<3.9 mg/dL) (P<0.01 by log-rank test). Stepwise multivariate Cox proportional hazard analysis showed that RLP-C was a significant predictor of the primary endpoint after adjustment for known risk factors and lipid variables including triglycerides, and total apolipoprotein B (hazard ratio 1.62, 95% confidence interval 1.26-2.07, P<0.01). CONCLUSIONS: RLP-C levels are a residual risk factor for future CVEs in patients with CAD and on-statin LDL-C <70 mg/dL.

High levels of stromal cell-derived factor-1α predict short-term progression of renal dysfunction in patients with coronary artery disease.

BACKGROUND: Stromal cell-derived factor-1α (SDF-1α) is an inflammatory chemokine that plays a critical role in cardiovascular disease. Although persistent inflammation causes renal dysfunction, it remains unclear whether SDF-1α is related to progression of chronic kidney disease. This study examined whether high levels of SDF-1α are associated with future declines in renal function in patients with coronary artery disease (CAD). METHODS: Plasma levels of SDF-1α in the peripheral blood were measured by enzyme-linked immunosorbent assay in 344 patients with CAD. All patients were followed for 24 months or until the occurrence of renal dysfunction, defined as ≥ 25% decrease in estimated glomerular filtration rate (eGFR) from baseline. RESULTS: During the follow-up period, 36 patients developed renal dysfunction. Multivariate logistic regression analysis showed that high plasma levels of SDF-1α were significantly associated with progression of renal dysfunction (odds ratio 1.65; 95% confidence intervals 1.07-2.35, p = 0.03). In addition, high plasma levels of SDF-1α had a significant incremental effect on the predictive value of known risk factors for renal dysfunction in analyses using net reclassification improvement (NRI) and integrated discrimination improvement (IDI) (NRI 0.58 [0.07-1.02], p < 0.01; and IDI 0.030 [0.001-0.085], p = 0.02). CONCLUSION: High plasma levels of SDF-1α were associated with the short-term decline of eGFR in patients with CAD. Thus, SDF-1α may be useful for predicting the progression of renal dysfunction in patients with CAD.

Glutathione adducts induced by ischemia and deletion of glutaredoxin-1 stabilize HIF-1α and improve limb revascularization.

Reactive oxygen species (ROS) are increased in ischemic tissues and necessary for revascularization; however, the mechanism remains unclear. Exposure of cysteine residues to ROS in the presence of glutathione (GSH) generates GSH-protein adducts that are specifically reversed by the cytosolic thioltransferase, glutaredoxin-1 (Glrx). Here, we show that a key angiogenic transcriptional factor hypoxia-inducible factor (HIF)-1α is stabilized by GSH adducts, and the genetic deletion of Glrx improves ischemic revascularization. In mouse muscle C2C12 cells, HIF-1α protein levels are increased by increasing GSH adducts with cell-permeable oxidized GSH (GSSG-ethyl ester) or 2-acetylamino-3-[4-(2-acetylamino-2-carboxyethylsulfanyl thiocarbonylamino) phenylthiocarbamoylsulfanyl] propionic acid (2-AAPA), an inhibitor of glutathione reductase. A biotin switch assay shows that GSSG-ester-induced HIF-1α contains reversibly modified thiols, and MS confirms GSH adducts on Cys(520) (mouse Cys(533)). In addition, an HIF-1α Cys(520) serine mutant is resistant to 2-AAPA-induced HIF-1α stabilization. Furthermore, Glrx overexpression prevents HIF-1α stabilization, whereas Glrx ablation by siRNA increases HIF-1α protein and expression of downstream angiogenic genes. Blood flow recovery after femoral artery ligation is significantly improved in Glrx KO mice, associated with increased levels of GSH-protein adducts, capillary density, vascular endothelial growth factor (VEGF)-A, and HIF-1α in the ischemic muscles. Therefore, Glrx ablation stabilizes HIF-1α by increasing GSH adducts on Cys(520) promoting in vivo HIF-1α stabilization, VEGF-A production, and revascularization in the ischemic muscles.

[A Case of Appendiceal Neuroendocrine Tumor Diagnosed after Appendectomy].

A 25-year-old woman visited our hospital with a complaint of right lower abdominal pain. As a result of the examination, she was diagnosed as having acute appendicitis. After conservative treatment, we planned an elective surgery. At 3 months after discharge, laparoscopic appendectomy was performed. We found a mass of 10mm in diameter at the body of the appendix. Histopathological examination revealed the proliferation of heteromorphic cells with small round nuclei. It was positive for chromogranin A and synaptophysin in immunostaining, so we made a diagnosis of NET G1. Tumor cells infiltrated beyond the intrinsic muscle layer, but no vascular invasion was observed, and the margin was negative. In accordance with the guidelines, we followed up the patient with imaging examination and did not find any signs of recurrence.

Human soluble phospholipase A2 receptor is an inhibitor of the integrin-mediated cell migratory response to collagen-I.

Murine membrane-bound phospholipase A2 receptor 1 (PLA2R) is shed and released into plasma in a soluble form that retains all of the extracellular domains. Relatively little is known about human PLA2R. This study examined whether human soluble PLA2R has biological functions and whether soluble PLA2R exists in human plasma. Here, we showed that human recombinant soluble PLA2R (rsPLA2R) bound to collagen-I and inhibited interaction of collagen-I with the extracellular domain of integrin ß1 on the cell surface of human embryonic kidney 293 (HEK293) cells. As a result, rsPLA2R suppressed integrin ß1-mediated migratory responses of HEK293 cells to collagen-I in Boyden chamber experiments. Inhibition of phosphorylation of FAK Tyr397 was also observed. Similar results were obtained with experiments using soluble PLA2R released from HEK293 cells transfected with a construct encoding human soluble PLA2R. rsPLA2R lacking the fibronectin-like type II (FNII) domain had no inhibitory effects on cell responses to collagen-I, suggesting an important role of the FNII domain in the interaction of rsPLA2R with collagen-I. In addition, rsPLA2R suppressed the migratory response to collagen-IV and binding of collagen-IV to the cell surface of human podocytes that endogenously express membrane-bound, full-length PLA2R. Immunoprecipitation and Western blotting showed the existence of immunoreactive PLA2R in human plasma. In conclusion, human recombinant soluble PLA2R inhibits integrin ß1-mediated cell responses to collagens. Further studies are warranted to elucidate whether immunoreactive PLA2R in human plasma has the same properties as rsPLA2R.

[A Case of Gallbladder Jejunal Anastomosis and Duodenal Jejunal Anastomosis to Maintain QOL for an Elderly Patient with Pancreatic Cancer].

An 87-year-oldwoman was admittedto our hospital with abdominal pain andfever. Computedtomography showeda 25 mm tumor mass in the pancreatic headandshowedd ilatation of the pancreatic duct andcommon bile duct. She was diagnosed with obstructive cholangitis due to pancreatic head cancer. An endoscopic naso-biliary drainage(EUS)tube was inserted, and an endoscopic ultrasound(ENBD)examination was performed. At this time, duodenal perforation occurred, and an emergency operation was performed. During the laparotomy, perforation was found in the anterior wall of the duodenum. The contamination in the abdominal cavity and the degree of tissue damage in the duodenum were mild. Gall bladder jejunal andd uodenal jejunal anastomoses were performedfor biliary bypass andto close the perforation andbypass the gastrointestinal tract, respectively. She hadno postoperative complications andwas discharged 13 days postoperatively. Oral intake was possible after discharge, andthe patient returnedhome without complications. She died 5 months postoperatively. In this case, we performedbile duct andgastrointestinal bypass surgery prophylactically. Although this surgery will not be effective for all patients, we thought that it wouldbe useful for predicting the patient's future condition and for increasing the procedural options, even in case of emergency surgery.

[A Case of Colon Metastasis from Invasive Lobular Carcinoma of the Breast].

The patient was a 48-year-old woman. She consulted our hospital with a chief complaint of vomiting. Colonoscopy showed stenosis and edematous mucosa, and biopsy was performed. Histological examination demonstrated the lesion to be colonic metastasis of breast cancer, invasive lobular carcinoma. Although colorectal metastasis of breast cancer has a poor prognosis and chemotherapy is considered as the main treatment modality, hormone therapy is also a treatment option depending on the condition.

[A Case of HER2 Positive Locally Advanced Breast Cancer Successfully Treated with a Combination Therapy of Eribulin, Trastuzumab and Pertuzumab].

The patient was an 82-year-oldwoman. She consultedour hospital with a chief complaint of left breast mass. MRI showed enhancedtumor with skin andextensive pectoral muscle invasion, so it was unresectable. Immunohistopathological analysis revealeda HER2-positive lesion. We administerederibulin, trastuzumab andpertuzumab, after which the tumor became resectable. Histological examination revealedremarkable response. Combination therapy of eribulin, trastuzumab andpertuzumab was well toleratedandconsid eredto be effective.

[A Comparison of the Treatment Methods for Obstructive Colorectal Cancer].

PURPOSE: Emergency surgery for obstructive colorectal cancer is considered to be associated with a high degree of risk, and surgery may after decompression is considered to be safer. In cases of obstructive colorectal cancer, decompression can be achieved with surgery, an ileus tube, or a stent, depending on the disease condition. We herein compare the treatment methods for obstructive colorectal cancer. METHODS: Forty-two patients with obstructive colorectal cancer underwent emergency treatment between January 2012 and December 2016. RESULTS: Among the patients with obstructive colorectal cancer, 18 receiveda stent, 10 receiveda nasal ileus tube, 6 receiveda transanal ileus tube, 5 underwent stoma construction, and 3 underwent emergency surgery without decompression. The stent group showed the highest laparoscopic operation rate. There was no significant difference in the overall survival of the treatment groups. One patient in the stent group developed duplicated cancer. CONCLUSION: Stent placement can be considered to be a viable option in the emergency treatment for obstructive colorectal cancer because laparoscopic surgery anda preoperative examination can be performed.

Lack of phospholipase A2 receptor increases susceptibility to cardiac rupture after myocardial infarction.

RATIONALE: Recent evidence indicates that the biological effects of secretory phospholipase A2 (sPLA2) cannot be fully explained by its catalytic activity. A cell surface receptor for sPLA2 (PLA2 receptor 1 [PLA2R]) and its high-affinity ligands (including sPLA2-IB, sPLA2-IIE, and sPLA2-X) are expressed in the infarcted myocardium. OBJECTIVE: This study asked whether PLA2R might play a pathogenic role in myocardial infarction (MI) using mice lacking PLA2R (PLA2R(-/-)). METHODS AND RESULTS: MI was induced by permanent ligation of the left coronary artery. PLA2R(-/-) mice exhibited higher rates of cardiac rupture after MI compared with PLA2R wild-type (PLA2R(+/+)) mice (46% versus 21%, respectively; P=0.015). PLA2R(-/-) mice had a 31% decrease in collagen content and a 45% decrease in the number of α-smooth muscle actin-positive fibroblasts in the infarcted region compared with PLA2R(+/+) mice. PLA2R was primarily found in myofibroblasts in the infarcted region. PLA2R(-/-) myofibroblasts were impaired in collagen-dependent migration, proliferation, and activation of focal adhesion kinase in response to sPLA2-IB. Binding of sPLA2-IB to PLA2R promoted migration and proliferation of myofibroblasts through functional interaction with integrin ß1, independent of the catalytic activity of sPLA2-IB. In rescue experiments, the injection of PLA2R(+/+) myofibroblasts into the infarcted myocardium prevented post-MI cardiac rupture and reversed the decrease in collagen content in the infarcted region in PLA2R(-/-) mice. CONCLUSIONS: PLA2R deficiency increased the susceptibility to post-MI cardiac rupture through impaired healing of the infarcted region. This might be partly explained by a reduction in integrin ß1-mediated migratory and proliferative responses of PLA2R(-/-) myofibroblasts.

Endothelial Cell Redox Regulation of Ischemic Angiogenesis.

The endothelium produces and responds to reactive oxygen and nitrogen species (RONS), providing important redox regulation to the cardiovascular system in physiology and disease. In no other situation are RONS more critical than in the response to tissue ischemia. Here, tissue healing requires growth factor-mediated angiogenesis that is in part dependent on low levels of RONS, which paradoxically must overcome the damaging effects of high levels of RONS generated as a result of ischemia. Although the generation of endothelial cell RONS in hypoxia/reoxygenation is acknowledged, the mechanism for their role in angiogenesis is still poorly understood. During ischemia, the major low molecular weight thiol glutathione (GSH) reacts with RONS and protein cysteines, producing GSH-protein adducts. Recent data indicate that GSH adducts on certain proteins are essential to growth factor responses in endothelial cells. Genetic deletion of the enzyme glutaredoxin-1, which selectively removes GSH protein adducts, improves, whereas its overexpression impairs revascularization of the ischemic hindlimb of mice. Ischemia-induced GSH adducts on specific cysteine residues of several proteins, including p65 NF-kB and the sarcoplasmic reticulum calcium ATPase 2, evidently promote ischemic angiogenesis. Identifying the specific proteins in the redox response to ischemia has provided therapeutic opportunities to improve clinical outcomes of ischemia.