Tomio Umemoto

Cardioprotection by a nonerythropoietic, tissue-protective peptide mimicking the 3D structure of erythropoietin

Erythropoietin (EPO), originally identified for its critical hormonal role in regulating production and survival of erythrocytes, is a member of the type 1 cytokine superfamily. Recent studies have shown that EPO has cytoprotective effects in a wide variety of tissues, including the heart, by preventing apoptosis. However, EPO also has undesirable effects, such as thrombogenesis. In the present study, we investigated whether a helix B-surface peptide (HBSP), a nonerythropoietic, tissue-protective peptide mimicking the 3D structure of erythropoietin, protects cardiomyocytes from apoptosis in vitro and in vivo. In cultured neonatal rat cardiomyocytes, HBSP clearly inhibited apoptosis (≈80%) induced by TNF-α, which was comparable with the effect of EPO, and activated critical signaling pathways of cell survival, including Akt, ERK1/2, and STAT3. Among these pathways, Akt was shown to play an essential role in HBSP-induced prevention of apoptosis, as assessed by using a small interfering RNA approach. In the dilated cardiomyopathic hamster (J2N-k), whose cardiac tissues diffusely expressed TNF-α, HBSP also inhibited apoptosis (≈70%) and activated Akt in cardiomyocytes. Furthermore, the levels of serum creatine kinase activity and of cardiac expression of atrial natriuretic peptide, a marker of chronic heart failure, were down-regulated in animals treated with HBSP. These data demonstrate that HBSP protects cardiomyocytes from apoptosis and leads to a favorable outcome in failing hearts through an Akt-dependent pathway. Because HBSP does not have the undesirable effects of EPO, it could be a promising alternative for EPO to treat cardiovascular diseases, such as myocardial infarction and heart failure.

Eicosapentaenoic acid shows anti-inflammatory effect via GPR120 in 3T3-L1 adipocytes and attenuates adipose tissue inflammation in diet-induced obese mice

BackgroundSaturated fatty acids have been shown to cause insulin resistance and low-grade chronic inflammation, whereas unsaturated fatty acids suppress inflammation via G-protein coupled receptor 120 (GPR120) in macrophages. However, the anti-inflammatory effects of unsaturated fatty acids in adipocytes have yet to be elucidated. Hence, the aims of the present study were to evaluate the anti-inflammatory effects of eicosapentaenoic acid (EPA) via GPR120 in adipocytes.MethodsWe used 250 μM palmitate as a representative saturated fatty acid. 3T3-L1 adipocytes were used for in vitro studies. We further evaluated the effect of EPA supplementation in a high-fat/high-sucrose (HFHS) diet-induced adipose tissue inflammatory mouse model.ResultsEPA attenuated palmitate-induced increases in inflammatory gene expression and NF-κB phosphorylation in 3T3-L1 adipocytes. Silencing of GPR120 abolished the anti-inflammatory effects of EPA. In GPR120 downstream signal analysis, EPA was found to decrease palmitate-induced increases in TAK1/TAB1 complex expression. EPA supplementation suppressed HFHS-induced crown-like structure formation in epididymal adipose tissue and altered macrophage phenotypes from M1 to M2 in the stromal vascular fraction. Moreover, the EPA-containing diet attenuated increases in adipose p-JNK and phospho-p65 NF-κB levels.ConclusionsIn conclusion, the findings of the present study demonstrate that EPA suppresses palmitate-induced inflammation via GPR120 by inhibiting the TAK1/TAB1 interaction in adipocytes. EPA supplementation reduced HFHS diet-induced inflammatory changes in mouse adipose tissues. These results demonstrate adipose GPR120 as a potential therapeutic target for decreasing inflammation.

Determinants of Left Ventricular Systolic Function Improvement Following Coronary Artery Revascularization in Heart Failure Patients With Reduced Ejection Fraction (HFrEF)

Revascularization therapy such as percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) should be considered for heart failure with reduced ejection fraction (HFrEF). However, revascularization therapy does not always improve left ventricular ejection fraction (LVEF). The purpose of this study was to investigate the determinants of LVEF improvement following revascularization in HFrEF patients. From 2,229 consecutive decompensated heart failure patients, a total of 47 HFrEF patients who underwent revascularization were included in the analysis. Improvement of LVEF was defined as [(LVEF during chronic phase) - (LVEF during acute phase)] ≥ 10%. Univariate and multivariate logistic regression analyses were applied to investigate the determinants of LVEF improvement. The prevalence of revascularization by PCIs including chronic total occlusion (CTO) was significantly greater in the improved EF group (45.0%) as compared to the non-improved EF group (11.1%) (P = 0.02). Multivariate logistic regression analysis revealed that revascularization by PCIs including CTO was the significant determinant of the LVEF improvement after adjusting for confounding factors (OR 5.43, 95% CI 1.06-27.74, P = 0.04). Optimal medical therapy (angiotensin-converting enzyme (ACE) inhibitor and/or angiotensin II receptor blocker (ARB) and beta-blockers) was less frequently prescribed in patients with CABG (50.0% for ACE inhibitor and/or ARB and 41.7% for beta-blocker) than in patients without CABG (94.3% for both) (P < 0.01 and P < 0.001, respectively). In conclusion, revascularization by PCIs including CTO was the significant determinant of LVEF improvement in HFrEF patients. Our results underscore the importance of optimal medical therapy even if patients receive complete revascularization such as CABG.

Super-selective intracoronary injection of Rho-kinase inhibitor relieves refractory coronary vasospasms: A case report

Coronary spastic angina (CSA) may become refractory when pa-tients discontinue medication, resume smoking, are overworked, areunder mental stress, or are hyperventilation [1]. Calcium channelblockers (CCBs) are effective standard therapeutic agents for CSA. Insomecases,however,acombinationofmedicationssuchasCCBs,nitro-gen, and nicorandil fails to relieve CSA. We report a case of refractoryCSA,whichwaseventuallyrelievedbysuper-selectiveintracoronaryin-jection of a Rho-kinase inhibitor, fasudil.An84-year-oldmancomplainedofchestpainatrest,andwastrans-ferred to our hospital. He was diagnosed with CSA in 2008, and hadreceived treatment with two CCBs (diltiazem and nifedipine) andnicorandil. However, he discontinued these medications 2 days priorto the onset of his chest pain. An electrocardiogram (ECG) showed ST–T elevations in leads V3–V6 (Fig. 1A). Laboratory data showed a whiteblood cell count of 9250/mm

A Case of Pulmonary Hypertension Associated with Idiopathic Hypereosinophilic Syndrome

Hypereosinophilic syndrome (HES) is characterized by multi-organ damage that is associated with tissue hypereosinophilia. A persistently elevated eosinophilic count is also required for the diagnosis of HES. Although HES affects various organs, damage to pulmonary artery is rarely reported. We present a case of a 39-year-old man who was diagnosed with pulmonary hypertension (PH) associated with idiopathic HES. Although the pulmonary arterial hypertension specific drugs including intravenous epoprostenol could not control his PH, corticosteroid was effective for both hypereosinophilia and PH. Our case suggests the importance of steroid therapy as well as specific drugs for pulmonary arterial hypertension in the treatment of PH associated with HES.

Clinical characteristics associated with pacing-induced cardiac dysfunction: a high incidence of undiagnosed cardiac sarcoidosis before permanent pacemaker implantation

Previous studies suggested that right ventricular pacing was associated with pacing-induced cardiac dysfunction (PICD). The purpose of this study was to investigate the clinical characteristics including the incidence of undiagnosed cardiac sarcoidosis (CS) in patients with atrioventricular block (AVB) who manifest PICD. We retrospectively investigated consecutive patients with permanent pacemaker (PPM) undergoing a first-generator replacement surgery with a new PPM or an upgrade procedure to a cardiac resynchronization therapy (CRT) device between December 1, 2011 and June 30, 2017. Patients with AVB showing normal echocardiographic findings before PPM implantation were included and divided into 2 groups: patients with post-PPM left ventricular ejection fraction (LVEF) < 40% and/or undergoing an upgrade procedure to CRT (PICD group) and patients with post-PPM LVEF ≥ 40% who underwent replacement surgery with a new PPM (no-PICD group). There were 15 and 41 patients in the PICD and no-PICD groups, respectively. A wider-paced QRS duration just after the PPM implantation and/or lower pre-PPM LVEF was observed in the PICD group. Furthermore, 46.7% of the PICD patients (7/15) satisfied the diagnostic criteria for CS according to the guideline of the Japanese Circulation Society, although no patients fulfilled these criteria before PPM implantation. In conclusion, a high incidence of CS was observed in patients with AVB who had PICD. However, none of these patients was diagnosed with CS before PPM implantation.

Predictors of prolonged fluoroscopy time in diagnostic coronary angiography

BACKGROUND Prolonged fluoroscopy time during coronary angiography is a major concern for interventional cardiologists as well as for patients. It is unknown which factors affect the prolonged fluoroscopy time. METHODS A total of 458 patients who underwent diagnostic coronary angiography were included. The patients who had the highest decile of fluoroscopy time were assigned to the prolonged fluoroscopy group (fluoroscopy time ≥15.7min), while the other patients were assigned to the non-prolonged fluoroscopy group (fluoroscopy time <15.7min). We performed univariate and multivariate logistic regression analysis to identify the predictors of prolonged fluoroscopy time. RESULTS Mean fluoroscopy time in 458 patients was 8.5±5.8min. Median and ranges of fluoroscopy time were 19.0 [15.7-47.0]min in the prolonged fluoroscopy group and 6.0 [2.0-15.3]min in the non-prolonged fluoroscopy group, respectively. The multivariate logistic regression analysis showed that significant predictors of prolonged fluoroscopy time were prior surgery of ascending aorta replacement [odds ratios (OR) 11.46, 95% confidence intervals (CI) 1.53-85.74, p=0.02] and the prevalence of moderate to severe aortic regurgitation (OR 2.83, 95% CI 1.20-6.66, p=0.02). CONCLUSIONS The prior surgery of ascending aorta replacement and moderate to severe aortic regurgitation were significant predictors of the prolonged fluoroscopy time.

Reply to Abdelwahid and Smith: The effect on cardiomyocytes of helix B-surface peptide (HBSP), a peptide with cell-protective but not erythropoietic activities of erythropoietin

We thank Abdelwahid and Smith (1) for their interest and comments concerning our studies of the cardioprotective effects of a peptide designed to mimic the 3D surface structure of a portion of helix B [helix B-surface peptide (HBSP)] of erythropoietin (EPO) (2). This peptide has been shown to have similar tissue protective and regenerative activities as EPO, but lacks hematopoietic effects (3). On the basis of a variety of evidence (4), we believe different EPO receptor isoforms are responsible for these differences. In the study (2), a combination of in vivo and in vitro experiments were performed that confirmed antiapoptotic activity of HBSP in the …