Fibroblast-specific PRMT5 deficiency suppresses cardiac fibrosis and left ventricular dysfunction in male mice

Protein arginine methyltransferase 5 (PRMT5) is a well-known epigenetic regulatory enzyme. However, the role of PRMT5-mediated arginine methylation in gene transcription related to cardiac fibrosis is unknown. Here we show that fibroblast-specific deletion of PRMT5 significantly reduces pressure overload-induced cardiac fibrosis and improves cardiac dysfunction in male mice. Both the PRMT5-selective inhibitor EPZ015666 and knockdown of PRMT5 suppress α-smooth muscle actin (α-SMA) expression induced by transforming growth factor-β (TGF-β) in cultured cardiac fibroblasts. TGF-β stimulation promotes the recruitment of the PRMT5/Smad3 complex to the promoter site of α-SMA. It also increases PRMT5-mediated H3R2 symmetric dimethylation, and this increase is inhibited by Smad3 knockdown. TGF-β stimulation increases H3K4 tri-methylation mediated by the WDR5/MLL1 methyltransferase complex, which recognizes H3R2 dimethylation. Finally, treatment with EPZ015666 significantly improves pressure overload-induced cardiac fibrosis and dysfunction. These findings suggest that PRMT5 regulates TGF-β/Smad3-dependent fibrotic gene transcription, possibly through histone methylation crosstalk, and plays a critical role in cardiac fibrosis and dysfunction.

Anserine, a Histidine-Containing Dipeptide, Suppresses Pressure Overload-Induced Systolic Dysfunction by Inhibiting Histone Acetyltransferase Activity of p300 in Mice

Anserine, an imidazole dipeptide, is present in the muscles of birds and fish and has various bioactivities, such as anti-inflammatory and anti-fatigue effects. However, the effect of anserine on the development of heart failure remains unknown. We cultured primary cardiomyocytes with 0.03 mM to 10 mM anserine and stimulated them with phenylephrine for 48 h. Anserine significantly suppressed the phenylephrine-induced increases in cardiomyocyte hypertrophy, ANF and BNP mRNA levels, and histone H3K9 acetylation. An in vitro histone acetyltransferase (HAT) assay showed that anserine directly suppressed p300-HAT activity with an IC50 of 1.87 mM. Subsequently, 8-week-old male C57BL/6J mice were subjected to transverse aortic constriction (TAC) and were randomly assigned to receive daily oral treatment with anserine-containing material, Marine Active® (60 or 200 mg/kg anserine) or vehicle for 8 weeks. Echocardiography revealed that anserine 200 mg/kg significantly prevented the TAC-induced increase in left ventricular posterior wall thickness and the decrease in left ventricular fractional shortening. Moreover, anserine significantly suppressed the TAC-induced acetylation of histone H3K9. These results indicate that anserine suppresses TAC-induced systolic dysfunction, at least in part, by inhibiting p300-HAT activity. Anserine may be used as a pharmacological agent for human heart failure therapy.

Impact of smoking initiation age on nicotine dependency and cardiovascular risk factors: a retrospective cohort study in Japan

Aims

Initiating smoking in early adolescence results in challenges with smoking cessation and is associated with high risk of cardiovascular disease. Recently, the initiation of smoking has transitioned from adolescence to young adulthood. However, there are few reports on the impact of initiating smoking at a later age. This study investigated the impact of the age of smoking initiation on nicotine dependency, smoking cessation rates, and cardiovascular risk factors, using a cut-off point of 20 years, within the Japanese population.

Methods and results

This retrospective cohort study encompassed 1382 smokers who sought smoking cessation treatment at Kyoto Medical Centre Hospital between 2007 and 2019. Clinical indicators were evaluated by adjusting for age at the time of hospital visit and sex. The smoking cessation rate was further adjusted for treatment medication. The group with a smoking initiation age of <20 years reported a higher number of cigarettes/day (P = 0.002), higher respiratory carbon monoxide levels (P < 0.001), a higher Fagerström Test for Nicotine Dependence (FTND) score (P < 0.001), and a higher Self-rating Depression Scale score (P = 0.014). They also reported lower diastolic blood pressure (P = 0.020) and a lower successful smoking cessation rate [odds ratio: 0.736, 95% confidence interval (0.569, 0.951)] than the group with a smoking initiation age of ≥20 years. When smokers were divided into four groups based on the age they started smoking, the FTND score for those who started at 20-21 years was significantly higher than the score for those who started at 22 years or older.

Conclusion

In young adulthood, initiating smoking later (beyond 20 years old) was associated with lower nicotine dependency and fewer depressive tendencies, as well as a higher success rate in smoking cessation among Japanese smokers. The results might suggest that raising the legal smoking initiation age from 20 to 22 years old or older could be effective in reducing nicotine dependency in smokers.

Myogenetic Oligodeoxynucleotide Induces Myocardial Differentiation of Murine Pluripotent Stem Cells

An 18-base myogenetic oligodeoxynucleotide (myoDN), iSN04, acts as an anti-nucleolin aptamer and induces myogenic differentiation of skeletal muscle myoblasts. This study investigated the effect of iSN04 on murine embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). In the undifferentiated state, iSN04 inhibited the proliferation of ESCs and iPSCs but did not affect the expression of pluripotent markers. In the differentiating condition, iSN04 treatment of ESCs/iPSCs from day 5 onward dramatically induced differentiation into Nkx2-5+ beating cardiomyocytes with upregulation of Gata4, Isl1, and Nkx2-5, whereas iSN04 treatment from earlier stages completely inhibited cardiomyogenesis. RNA sequencing revealed that iSN04 treatment from day 5 onward contributes to the generation of cardiac progenitors by modulating the Wnt signaling pathway. Immunostaining showed that iSN04 suppressed the cytoplasmic translocation of nucleolin and restricted it to the nucleoli. These results demonstrate that nucleolin inhibition by iSN04 facilitates the terminal differentiation of cardiac mesoderm into cardiomyocytes but interferes with the differentiation of early mesoderm into the cardiac lineage. This is the first report on the generation of cardiomyocytes from pluripotent stem cells using a DNA aptamer. Since iSN04 did not induce hypertrophic responses in primary-cultured cardiomyocytes, iSN04 would be useful and safe for the regenerative therapy of heart failure using stem cell-derived cardiomyocytes.

Monodemethylated Metabolites of Orally Administered Nobiletin: Identification and Quantitation in Rat Plasma and Tissues

Although nobiletin (Nob) is a promising functional food component in view of its multifaceted physiological activity, the metabolism of this flavonoid remains underexplored. Herein, we examine the pharmacokinetics and tissue distribution of orally ingested Nob in rats, focusing on the six monodemethylnobiletin (MDNob) isomers as the main Nob metabolites. Two of these metabolites, namely, 6-MDNob and 8-MDNob, are chemically prepared for the first time, and a method for the simultaneous determination of all six MDNobs is developed. The obtained results demonstrate the production of 8-MDNob as a novel Nob metabolite and confirm the previously reported generation of 6-MDNob and 7-MDNob as oral metabolites of Nob in vivo. Finally, a quantitative relationship is established between the amount of metabolically generated MDNobs and that of administered Nob. Thus, this work paves the way for the broad applications and safe usage of Nob.

MEF2C/p300-mediated epigenetic remodeling promotes the maturation of induced cardiomyocytes

Cardiac transcription factors (TFs) directly reprogram fibroblasts into induced cardiomyocytes (iCMs), where MEF2C acts as a pioneer factor with GATA4 and TBX5 (GT). However, the generation of functional and mature iCMs is inefficient, and the molecular mechanisms underlying this process remain largely unknown. Here, we found that the overexpression of transcriptionally activated MEF2C via fusion of the powerful MYOD transactivation domain combined with GT increased the generation of beating iCMs by 30-fold. Activated MEF2C with GT generated iCMs that were transcriptionally, structurally, and functionally more mature than those generated by native MEF2C with GT. Mechanistically, activated MEF2C recruited p300 and multiple cardiogenic TFs to cardiac loci to induce chromatin remodeling. In contrast, p300 inhibition suppressed cardiac gene expression, inhibited iCM maturation, and decreased the beating iCM numbers. Splicing isoforms of MEF2C with similar transcriptional activities did not promote functional iCM generation. Thus, MEF2C/p300-mediated epigenetic remodeling promotes iCM maturation.

6-Shogaol, an Active Component of Ginger, Inhibits p300 Histone Acetyltransferase Activity and Attenuates the Development of Pressure-Overload-Induced Heart Failure

Hypertrophic stress-induced cardiac remodeling is a compensatory mechanism associated with cardiomyocyte hypertrophy and cardiac fibrosis. Continuation of this response eventually leads to heart failure. The histone acetyltransferase p300 plays an important role in the development of heart failure, and may be a target for heart failure therapy. The phenolic phytochemical 6-shogaol, a pungent component of raw ginger, has various bioactive effects; however, its effect on cardiovascular diseases has not been investigated. One micromolar of 6-shogaol suppressed phenylephrine (PE)-induced increases in cardiomyocyte hypertrophy in rat primary cultured cardiomyocytes. In rat primary cultured cardiac fibroblasts, 6-shogaol suppressed transforming growth factor-beta (TGF-β)-induced increases in L-proline incorporation. It also blocked PE- and TGF-β-induced increases in histone H3K9 acetylation in the same cells and in vitro. An in vitro p300-HAT assay revealed that 6-shogaol suppressed histone acetylation. The mice underwent transverse aortic constriction (TAC) surgery, and were administered 0.2 or 1 mg/kg of 6-shogaol daily for 8 weeks. 6-shogaol prevented TAC-induced systolic dysfunction and cardiac hypertrophy in a dose-dependent manner. Furthermore, it also significantly inhibited TAC-induced increases in histone H3K9 acetylation. These results suggest that 6-shogaol may ameliorate heart failure through a variety of mechanisms, including the inhibition of p300-HAT activity.

CBMS-3 SEARCH FOR COMPOUNDS WITH ANTI-TUMOUR EFFECTS AGAINST GLIOBLASTOMA

Purpose

Glioblastoma (GBM) has a high risk of recurrence and a poor prognosis due to the difficulty of surgical resection and the resistance to temozolomide, the standard treatment for GBM. Therefore, the development of new therapeutic agents for GBM is desired. We searched our compound library for compounds with anti-tumor activity against GBM and identified Curcumin (Cur) derivatives, Compound A and B. The purpose of this study was to investigate the antitumor activity of Compound A and B against GBM.

Methods and Results

To evaluate the antitumor activity of Compound A and B against GBM, we performed the MTT assay. Human glioblastoma cell lines, U87-MG and U251 cells, were treated with Compound A and B. After 96 hours, cell viability was evaluated using CCK-8, and the IC50 values of Compound A and B were calculated. In U87-MG, the IC50 of Cur was 9.78 μM, whereas the that of Compound A was 2.42 μM and that of Compound B was 1.28 μM. In U251 cells, the IC50 of Cur was 9.50 μM, whereas that of Compound A was 2.27 μM and that of Compound B was 0.64 μM. Next, to examine the effects of Compound A and B on normal cells, we performed the same MTT assay using primary cultured rat astrocytes. At the concentrations at which antitumor effects were observed (Compound A; 3 μM, B; 1.5 μM), there was no reduction in cell viability in primary rat cultured astrocytes.

Discussion

The present study shows that Compound A and B exhibit antitumor activity against human glioblastoma cells at lower concentrations than Cur without affecting normal cells. We will examine the effects of Compound A and B in a mouse model of brain tumor transplanted with U87-RFP cells in the future, which may lead to the development of noble brain tumor therapeutics.

TB-3 A GINGER EXTRACT COMPOUND A REVEALED ANTITUMOR ACTIVITY AGAINST GLIOMA

Purpose

Malignant neoplasms arising in the brain and central nervous system have a poor prognosis and present with symptoms such as headache, epileptic seizures, and paralysis of the arms and legs. Treatment of glioma, the most frequent primary brain tumor, is based on surgical removal of the tumor, radiation therapy, and chemotherapy. However, since gliomas grow invasively, surgical removal of the entire tumor is considered difficult. In addition, the standard treatment, temozolomide, possesses the problem of resistance. Therefore, the risk of recurrence is high, and the development of noble therapeutic agents for Glioma is required. We have screened for compounds with anti-tumor activity against Glioma from our natural compound library and focused on ginger extract, Compound A. In this study, we investigated the effect of Compound A on Glioma cell lines.

Methods and Results

To evaluate the antitumor activity of Compound A on Glioma in vitro , MTT assay was performed. Human glioma cell lines U87-MG and U251 cells were treated with Compound A. After 96 hours, cell viability was evaluated using CCK-8. The IC50 value of Compound A in U87-MG cells was calculated to be 16.3 μM. The IC50 of Compound A in U251 cells was 10.8 μM. Next, to examine the effect of Compound A on normal cells, we performed the same MTT assay using primary cultured rat astrocytes. The MTT assay showed no decrease in cell viability in primary cultured rat astrocytes at 15 μM, whereas an antitumor effect was observed in a human glioma cell line.

Discussion

In this study, Compound A showed antitumor activity against Glioma without affecting normal cells. In the future, we will examine the effects of Compound A in an immunocompromised mouse brain in which U87-MG-RFP cells are implanted, which may lead to the development of therapeutic agents against Glioma.

Auraptene, a citrus peel-derived natural product, prevents myocardial infarction-induced heart failure by activating PPARα in rats

BACKGROUND

Auraptene derived from the peel of Citrus hassaku possesses anti-tumor, anti-inflammatory, and neuroprotective activities. Thus, it could be a valuable pharmacological alternative to treat some diseases. However, the therapeutic value of auraptene for heart failure (HF) is unknown.

STUDY DESIGN/METHODS

In cultured cardiomyocytes from neonatal rats, the effect of auraptene on phenylephrine-induced hypertrophic responses and peroxisome proliferator-activated receptor-alpha (PPARα)-dependent gene transcriptions. To investigate whether auraptene prevents the development of heart failure after myocardial infarction (MI) in vivo, Sprague-Dawley rats with moderate MI (fractional shortening < 40%) were randomly assigned for treatment with low- or high-dose auraptene (5 or 50 mg/kg/day, respectively) or vehicle for 6 weeks. The effects of auraptene were evaluated by echocardiography, histological analysis, and the measurement of mRNA levels of hypertrophy, fibrosis, and PPARα-associated genes.

RESULTS

In cultured cardiomyocytes, auraptene repressed phenylephrine-induced hypertrophic responses, such as increases in cell size and activities of atrial natriuretic factor and endothelin-1 promoters. Auraptene induced PPARα-dependent gene activation by enhancing cardiomyocyte peroxisome proliferator-responsive element reporter activity. The inhibition of PPARα abrogated the protective effect of auraptene on phenylephrine-induced hypertrophic responses. In rats with MI, auraptene significantly improved MI-induced systolic dysfunction and increased posterior wall thickness compared to the vehicle. Auraptene treatment also suppressed MI-induced increases in myocardial cell diameter, perivascular fibrosis, and expression of hypertrophy and fibrosis response markers at the mRNA level compared with vehicle treatment. MI-induced decreases in the expression of PPARα-dependent genes were improved by auraptene treatment.

CONCLUSIONS

Auraptene has beneficial effects on MI-induced cardiac hypertrophy and left ventricular systolic dysfunction in rats, at least partly due to PPARα activation. Further clinical studies are required to evaluate the efficacy of auraptene in patients with HF.

Randomized double-blind placebo-controlled multicenter trial for the effects of a polyherbal remedy, Yokukansan (YiganSan), in smokers with depressive tendencies

BACKGROUND

Smoking and depression are closely related and form a vicious cycle. Yokukansan (YiganSan) is a polyherbal remedy that has the effect of calming neuropsychiatric symptoms such as anger and irritation. To examine the efficacy of Yokukansan during smoking cessation (SC) therapy in smokers with depressive tendencies but without major depressive disorders requiring pharmacotherapy.

METHODS

A multicenter, double-blind, randomized, placebo-controlled, parallel-group comparison trial was conducted between June 2016 and May 2020 at 12 centers of the National Hospital Organization, Japan. This trial targeted smokers who first visited the SC outpatient clinics, did not receive any pharmacological treatment at the psychiatric or psychosomatic department, and scored 39 or more on the self-rating depression scale (SDS). Participants (n = 198) were randomly assigned to either the Yokukansan or placebo groups. The trial drug was initiated with the start of the SC treatment and continued for 12 weeks. The primary outcome was the high success rate of the SC treatment, and the secondary outcomes included changes in scores of the SDS and the Profile of Mood States (POMS) instrument.

RESULTS

The success rate of the SC treatment was similar between the placebo (63%) and Yokukansan (67%) groups (P = .649). The SDS scores (placebo: mean difference [MD] = -3.5, 95% confidence interval [CI][-5.8, -1.2], d = 0.42; Yokukansan: MD = -4.6, 95%CI[-6.8, -2.3], d = 0.55), and the "tension-anxiety" POMS-subscale scores (placebo: MD = -1.6, 95%CI[-2.5, -0.7], d = 0.52; Yokukansan: MD = -1.6, 95%CI[-2.9, -0.3], d = 0.36) showed significant improvement in both groups after the SC treatment. However, "depression-dejection" improved in the Yokukansan group (MD = -1.9, 95%CI[-3.1, -0.7], d = 0.44) but not in the placebo group (MD = -0.1, 95%CI[-1.0, 0.7], d = 0.04). Significant improvement in "fatigue" was noted in the Yokukansan group (MD = -2.1, 95%CI[-3.4, -0.9], d = 0.47) but not in the placebo group (MD = -0.5, 95%CI[-1.8, 0.8], d = 0.11). The time × group interaction on the improvement in "depression-dejection" was significant (P = .019).

CONCLUSIONS

Yokukansan does not increase the SC treatment's success rate but has additional positive effects on the psychological states due to the SC treatment in smokers with depressive tendencies but without apparent mental disorders.

TRIAL REGISTRATION

ID: UMIN000027036. Retrospectively registered at UMIN on April 18, 2017.

Study protocol to determine the effects of highly absorbable oral curcumin on the indicators of cognitive functioning: a double-blind randomised controlled trial

INTRODUCTION

Mild cognitive impairment (MCI) refers to a state in which cognitive functions, such as memory, have diminished but daily activities are largely unhampered. MCI is often overlooked but carries the risk of leading to development of dementia later. Curcumin is the main component of the natural herbal medicine turmeric. Curcumin is widely used as a health food and is an antioxidant that has anti-inflammatory and anti-amyloid actions. The current trial was designed to determine the effects of curcumin on indicators of cognitive functioning.

METHODS AND ANALYSIS

The current trial will be a single-centre randomised placebo-controlled double-blind parallel group trial. The participants will be 60 members of the general public with potential MCI, based on dementia screening using the Japanese version of the Mini Mental State Examination (MMSE-J). The investigational health food used in this trial will be a recently developed preparation for highly absorbable oral curcumin. This trial will determine the effects of the highly absorbable oral curcumin (brand name: curcuRouge) on the indicators of cognitive functioning, including the scores obtained with the MMSE-J, which is an interview-based measure of cognitive functioning, and the blood biomarkers that have been reported to be associated with dementia.

ETHICS AND DISSEMINATION

Informed written consent will be obtained from all the participants. The Ethical Review Board of the National Hospital Organization Kyoto Medical Center approved the study protocol.

TRIAL REGISTRATION NUMBER

University Hospital Medical Information Network (UMIN000042471).

Effects of high-absorption curcumin for the prevention of hypertensive heart disease: a double-blind, placebo-controlled, randomized clinical study

Aims

Hypertension is a strong risk factor for heart failure with preserved ejection fraction. Curcumin has p300-specific histone acetyltransferase inhibitory activity, suppresses cardiomyocyte hypertrophy and fibrosis, and significantly reduces myocardial brain natriuretic peptide (BNP) expression without altering blood pressure in a rat model of hypertensive heart disease. This double-blind, placebo-controlled, randomized study, for the first time, aimed to examine the efficacy of a high-absorption curcumin for the prevention of hypertensive heart disease in humans.

Methods and results

Patients exhibiting initial signs of hypertensive heart disease with left ventricular ejection fraction ≥60% and stable blood pressure <140/90 mmHg orally took a double-blinded capsule (either a 90 mg curcumin capsule or placebo) twice daily for 24 weeks. The primary endpoint was per cent changes in left ventricular diastolic function (E/E′) from baseline to 6 months after administration. The secondary endpoint was the per cent change in plasma BNP levels. The E/E′ ratio per cent change from baseline to 6 months after administration was similar between the placebo (n = 69) and the curcumin (n = 73) groups. The per cent change in plasma BNP levels was significantly lower in the curcumin group than in the placebo group. In patients <65 years, BNP per cent changes were significantly lower in the curcumin group than in the placebo group, but similar between groups in ≥65 years (<65 vs. ≥65 years: P for interaction = 0.011).

Conclusions

A high-absorption curcumin agent did not affect the E/E′ ratio, rather it significantly inhibited the increase in plasma BNP levels in patients with initial signs of hypertensive heart disease.

Gingival bleeding and pocket depth among smokers and the related changes after short-term smoking cessation

BACKGROUND

Smoking is associated with the deteriorating health of the gingiva and periodontium. The long-term beneficial effects of smoking cessation on oral health are well known. However, the effects of short-term smoking cessation on gingival bleeding and periodontal pocket depth are unknown. The purpose of the present study was to determine the effects of short-term smoking cessation on gingival bleeding and periodontal pocket depth.

METHODS

Dentate smokers with a mean age of 56.9 ± 14.4 years at an outpatient smoking cessation clinic participated in this study. A professional dentist checked the periodontal pocket depth and gingival bleeding. Patients visited the smoking cessation clinic on their first visit and 2, 4, 8, and 12 weeks (three months). The gingival assessment was re-performed in those who succeeded in smoking cessation 3 months after the baseline.

RESULTS

The baseline data of 83 patients showed that an increase in pocket depth was associated with increasing age and the amount of smoking. A significant increase in gingival bleeding (p = .031) and increase in pocket depth (p = .046) were observed 3 months after the baseline in patients who successfully quit smoking (n = 14).

CONCLUSION

Short-term smoking cessation increased periodontal pocket depth and gingival bleeding. These findings may reflect healing processes that occur in the healthy gingiva.

IMPLICATIONS

Study findings will be useful to advise patients during smoking cessation programs. Dentists can inform patients that an initial increase in gingival bleeding and pocket depth could be associated with smoking cessation. Such advice will prevent patients from any apprehension that may cause them to recommence smoking.

ANGPTL4 Expression Is Increased in Epicardial Adipose Tissue of Patients with Coronary Artery Disease

Epicardial adipose tissue (EAT) is known to affect atherosclerosis and coronary artery disease (CAD) pathogenesis, persistently releasing pro-inflammatory adipokines that affect the myocardium and coronary arteries. Angiopoietin-like 4 (ANGPTL4) is a protein secreted from adipose tissue and plays a critical role in the progression of atherosclerosis. Here, the expression of ANGPTL4 in EAT was investigated in CAD subjects. Thirty-four consecutive patients (13 patients with significant CAD; 21 patients without CAD) undergoing elective open-heart surgery were recruited. EAT and pericardial fluid were obtained at the time of surgery. mRNA expression and ANGPTL4 and IL-1β levels were evaluated by qRT-PCR and ELISA. The expression of ANGPTL4 (p = 0.0180) and IL-1β (p < 0.0001) in EAT significantly increased in the CAD group compared to that in the non-CAD group and positively correlated (p = 0.004). Multiple regression analysis indicated that CAD is a contributing factor for ANGPTL4 expression in EAT. IL-1β level in the pericardial fluid was significantly increased in patients with CAD (p = 0.020). Moreover, the expression of ANGPTL4 (p = 0.004) and IL-1β (p < 0.001) in EAT was significantly increased in non-obese patients with CAD. In summary, ANGPTL4 expression in EAT was increased in CAD patients.

Chrysanthemum morifolium Extract Ameliorates Doxorubicin-Induced Cardiotoxicity by Decreasing Apoptosis

It is well known that the anthracycline anticancer drug doxorubicin (DOX) induces cardiotoxicity. Recently, Chrysanthemum morifolium extract (CME), an extract of the purple chrysanthemum flower, has been reported to possess various physiological activities such as antioxidant and anti-inflammatory effects. However, its effect on DOX-induced cardiotoxicity is still unknown. An 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT)assay revealed that 1 mg/mL of CME reduced DOX-induced cytotoxicity in H9C2 cells but not in MDA-MB-231 cells. A TUNEL assay indicated that CME treatment improved DOX-induced apoptosis in H9C2 cells. Moreover, DOX-induced increases in the expression levels of p53, phosphorylated p53, and cleaved caspase-3,9 were significantly suppressed by CME treatment. Next, we investigated the effect of CME in vivo. The results showed that CME treatment substantially reversed the DOX-induced decrease in survival rate. Echocardiography indicated that CME treatment also reduced DOX-induced left ventricular systolic dysfunction, and a TUNEL assay showed that CME treatment also suppressed apoptosis in the mouse heart. These results reveal that CME treatment ameliorated DOX-induced cardiotoxicity by suppressing apoptosis. Further study is needed to clarify the effect of CME on DOX-induced heart failure in humans.

Ecklonia stolonifera Okamura Extract Suppresses Myocardial Infarction-Induced Left Ventricular Systolic Dysfunction by Inhibiting p300-HAT Activity

Ecklonia stolonifera Okamura extract (ESE) has been reported to have various bioactive effects, but its effects on cardiovascular disease have not yet been investigated. First, primary neonatal rat cultured cardiomyocytes were treated with ESE and stimulated with phenylephrine (PE) for 48 h. ESE (1000 µg/mL) significantly suppressed PE-induced cardiomyocyte hypertrophy, hypertrophy-related gene transcription, and the acetylation of histone H3K9. An in vitro p300-HAT assay indicated that ESE directly inhibited p300-HAT activity. Next, one week after myocardial infarction (MI) surgery, rats (left ventricular fractional shortening (LVFS) < 40%) were randomly assigned to three groups: vehicle (saline, n = 9), ESE (0.3 g/kg, n = 10), or ESE (1 g/kg, n = 10). Daily oral administration was carried out for 8 weeks. After treatment, LVFS was significantly higher in the ESE (1 g/kg) group than in the vehicle group. The ESE treatments also significantly suppressed MI-induced increases in myocardial cell diameter, perivascular fibrosis, hypertrophy- and fibrosis-related gene transcription, and the acetylation of histone H3K9. These results suggest that ESE suppressed both hypertrophic responses in cardiomyocytes and the development of heart failure in rats by inhibiting p300-HAT activity. Thus, this dietary extract is a potential novel therapeutic strategy for heart failure in humans.

The Selective Serotonin 2A Receptor Antagonist Sarpogrelate Prevents Cardiac Hypertrophy and Systolic Dysfunction via Inhibition of the ERK1/2-GATA4 Signaling Pathway

Drug repositioning has recently emerged as a strategy for developing new treatments at low cost. In this study, we used a library of approved drugs to screen for compounds that suppress cardiomyocyte hypertrophy. We identified the antiplatelet drug sarpogrelate, a selective serotonin-2A (5-HT_2A) receptor antagonist, and investigated the drug's anti-hypertrophic effect in cultured cardiomyocytes and its effect on heart failure in vivo. Primary cultured cardiomyocytes pretreated with sarpogrelate were stimulated with angiotensin II, endothelin-1, or phenylephrine. Immunofluorescence staining showed that sarpogrelate suppressed the cardiomyocyte hypertrophy induced by each of the stimuli. Western blotting analysis revealed that 5-HT_2A receptor level was not changed by phenylephrine, and that sarpogrelate suppressed phenylephrine-induced phosphorylation of ERK1/2 and GATA4. C57BL/6J male mice were subjected to transverse aortic constriction (TAC) surgery followed by daily oral administration of sarpogrelate for 8 weeks. Echocardiography showed that 5 mg/kg of sarpogrelate suppressed TAC-induced cardiac hypertrophy and systolic dysfunction. Western blotting revealed that sarpogrelate suppressed TAC-induced phosphorylation of ERK1/2 and GATA4. These results indicate that sarpogrelate suppresses the development of heart failure and that it does so at least in part by inhibiting the ERK1/2-GATA4 signaling pathway.

Zerumbone prevents pressure overload-induced left ventricular systolic dysfunction by inhibiting cardiac hypertrophy and fibrosis

BACKGROUND

Cardiac hypertrophy and fibrosis are hallmarks of cardiac remodeling and are involved functionally in the development of heart failure (HF). However, it is unknown whether Zerumbone (Zer) prevents left ventricular (LV) systolic dysfunction by inhibiting cardiac hypertrophy and fibrosis.

PURPOSE

This study investigated the effect of Zer on cardiac hypertrophy and fibrosis in vitro and in vivo.

STUDY DESIGN/METHODS

In primary cultured cardiac cells from neonatal rats, the effect of Zer on phenylephrine (PE)-induced hypertrophic responses and transforming growth factor beta (TGF-β)-induced fibrotic responses was observed. To determine whether Zer prevents the development of pressure overload-induced HF in vivo, a transverse aortic constriction (TAC) mouse model was utilized. Cardiac function was evaluated by echocardiography. The changes of cardiomyocyte surface area were observed using immunofluorescence staining and histological analysis (HE and WGA staining). Collagen synthesis and fibrosis formation were measured by scintillation counter and picrosirius staining, respectively. The total mRNA levels of genes associated with hypertrophy (ANF and BNP) and fibrosis (Postn and α-SMA) were measured by qRT-PCR. The protein expressions (Akt and α-SMA) were assessed by western blotting.

RESULTS

Zer significantly suppressed PE-induced increase in cell size, mRNA levels of ANF and BNP, and Akt phosphorylation in cardiomyocytes. The TGF-β-induced increase in proline incorporation, mRNA levels of Postn and α-SMA, and protein expression of α-SMA were decreased by Zer in cultured cardiac fibroblasts. In the TAC male C57BL/6 mice, echocardiography results demonstrated that Zer improved cardiac function by increasing LV fractional shortening and reducing LV wall thickness compared with the vehicle group. ZER significantly reduced the level of phosphorylated Akt both in cultured cardiomyocytes treated with PE and in the hearts of TAC. Finally, Zer inhibited the pressure overload-induced cardiac hypertrophy and cardiac fibrosis.

CONCLUSION

Zer ameliorates pressure overload-induced LV dysfunction, at least in part by suppressing both cardiac hypertrophy and fibrosis.

Effect of Theaflavin on Oral Bacteria in Japanese Subjects: A Randomized, Placebo-Controlled, Double-Blind Study

Black tea is a popular beverage worldwide. Theaflavins (TFs), which are active functional components of black tea, are potentially valuable for preventing and/or treating the progression of periodontal diseases. Our previous pilot study showed that TF intake decreases the number of Porphyromonas gingivalis (P. gingivalis) bacteria in the saliva. In this study, we aimed to determine whether TF intake improves periodontal disease attributed to oral bacteria in a randomized, placebo-controlled, and double-blind study. A total of 56 healthy subjects without periodontal diseases were enrolled and assigned to the placebo and TF groups (n = 28). TF intake for 6 weeks did not significantly alter the clinical evaluation of subjects. There was no significant adverse effect among the subjects. The number of P. gingivalis and Fusobacterium nucleatum (F. nucleatum) bacteria, which was the primary endpoint in this study, was not impacted by TF intake. The change ratio of Prevotella intermedia was significantly decreased by TF intake (P = .043) when compared with the placebo group. Collectively, our findings suggest that TFs have beneficial effects on oral bacteria for the prevention of periodontal disease. The study protocol was registered in the University Hospital Medical Information Network (UMIN000020049).

Alpha Mangostin Derived from Garcinia magostana Linn Ameliorates Cardiomyocyte Hypertrophy and Fibroblast Phenotypes in Vitro

Cardiac hypertrophy and fibrosis are significant risk factors for chronic heart failure (HF). Since pharmacotherapy agents targeting these processes have not been established, we investigated the effect of alpha-magostin (α-man) on cardiomyocyte hypertrophy and fibrosis in vitro. Primary cultured cardiomyocytes and cardiac fibroblasts were prepared from neonatal rats. After α-man treatment, phenylephrine (PE) and transforming growth factor-beta (TGF-β) were added to the cardiomyocytes and cardiac fibroblasts to induce hypertrophic and fibrotic responses, respectively. Hypertrophic responses were assessed by measuring the cardiomyocyte surface area and hypertrophic gene expression levels. PE-induced phosphorylation of Akt, extracellular signal-regulated kinase (ERK)1/2, and p38 was examined by Western blotting. Fibrotic responses were assessed by measuring collagen synthesis, fibrotic gene expression levels, and myofibroblast differentiation. In addition, TGF-β-induced reactive oxygen species (ROS) production was investigated. In cultured cardiomyocytes, α-man significantly suppressed PE-induced increases in the cardiomyocyte surface area, and the mRNA levels (atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP)). Treatment with α-man significantly suppressed PE-induced Akt phosphorylation, but not ERK and p38 phosphorylation. In cultured cardiac fibroblasts, α-man significantly suppressed TGF-β-induced increases in L-proline incorporation, mRNA levels (POSTN and alpha-smooth muscle actin (α-SMA)), and myofibroblast differentiation. Additionally, it significantly inhibited TGF-β-induced reduced nicotinamide adenine dinucleotide phosphate oxidase4 (NOX4) expression and ROS production in cardiac fibroblasts. Treatment with α-man significantly ameliorates hypertrophy by inhibiting Akt phosphorylation in cardiomyocytes and fibrosis by inhibiting NOX4-generating ROS in fibroblasts. These findings suggest that α-man is a possible natural product for the prevention of cardiac hypertrophy and fibrosis.

Metformin suppresses phenylephrine-induced hypertrophic responses by inhibiting p300-HAT activity in cardiomyocytes

INTRODUCTION

Heart failure is the final pathway for a wide spectrum of myocardial stress, including hypertension and myocardial infarction. However, the potential effects of metformin on cardiac hypertrophy are still unclear.

PURPOSE

The purpose of this study was to investigate whether metformin leads to suppression of hypertrophic responses in cardiomyocytes.

METHODS AND RESULTS

To investigate whether metformin inhibited p300-histone acetyltransferase (HAT), we performed an in vitro HAT assay. Metformin directly inhibited p300-mediated acetylation of histone-H3K9. To examine the effects of metformin on hypertrophic responses, cardiomyocytes prepared from neonatal rats were treated with metformin and stimulated with saline or phenylephrine (PE), a α1-adrenergic agonist for 48 h. PE stimulus showed an increase in cell size, myofibrillar organization, expression of the endogenous atrial natriuretic factor and brain natriuretic peptide genes, and acetylation of histone-H3K9 compared with saline-treated cells. These PE-induced changes were inhibited by metformin. Next, to examine the effect of metformin on p300-mediated hypertrophy, cardiomyocytes were transfected with expression vector of p300. Metformin significantly suppressed p300-induced hypertrophic responses and acetylation of histone-H3K9.

CONCLUSIONS

The study demonstrates that metformin can suppress PE-induced and p300-mediated hypertrophic responses. Metformin may be useful for the treatment of patients with diabetes and heart failure.

Abstract P381: Ecklonia Stolonifera Okamura Extract Suppresses Hypertrophic Responses In Cardiomyocytes And Development Of Heart Failure By Inhibiting P300-HAT Activity

Introduction: Heart failure is the leading cause of death in the world. Cardiomyocyte hypertrophy is observed during the development of heart failure, suggesting that its inhibition is a potential target for the prevention and treatment of heart failure. In this study, we screened a natural compound library using cultured cardiomyocytes and found that Ecklonia stolonifera Okamura extract (ESE) suppressed cardiomyocyte hypertrophy. ESE, a perennial brown alga, has been reported to have various bioactive effects, such as antioxidant and anti-inflammatory activity, but its effect on heart failure is still unclear. Therefore, we investigated whether ESE has an inhibitory effect on cardiomyocyte hypertrophic response and on the progression of heart failure in post-myocardial infarction (MI) rats.

Methods and Results: First, primary cultured cardiomyocytes from neonatal rats were treated with ESE and then stimulated with phenylephrine (PE) for 48 hours. ESE (1000 μg/mL) significantly suppressed PE-induced increases in cardiomyocyte surface area, hypertrophic response gene transcription, and acetylation of histone H3K9. An in vitro p300-HAT assay indicated that ESE directly inhibited p300-HAT activity (IC50: 505 μg/mL). Next, one week after the ligation of the left anterior descending artery, rats with moderate MI (left ventricular fractioning shorting (LVFS) <40%) were randomly assigned to three groups: vehicle (saline) (n=9), ESE (0.3 g/kg) (n=10), or ESE (1 g/kg) (n=10). Daily oral administration was repeated for 8 weeks. After treatment, LVFS was significantly higher in the ESE (1 g/kg) group (23.3 ± 0.7%, p<0.05) than in the vehicle group (16.6 ± 1.3%). Next, the hearts were isolated and histological analysis, evaluation of gene transcription, and measurement of histone H3K9 acetylation. were performed. ESE treatment significantly suppressed MI-induced increases both in myocardial cell diameter and in the mRNA levels of hypertrophic response genes. ESE also inhibited MI-induced perivascular fibrosis and the acetylation of histone H3K9.

Conclusion: These results suggest that ESE suppresses both hypertrophic responses in cardiomyocytes and the development of heart failure by inhibiting p300-HAT activity. Further studies are needed to clarify the effectiveness of ESE for heart failure therapy.

Abstract P352: An Antiplatelet Agent Sarpogrelate Suppresses Pressure Overload-induced Development Of Heart Failure In A 5-ht 2a Receptor-independent Manner

Purpose: The cost of new drug development is increasing year by year, and drug repositioning is being used as a strategy to develop new treatments at low-cost. We used a library of approved drugs to screen for compounds that suppress cardiomyocyte hypertrophy, and identified as a candidate the antiplatelet drug sarpogrelate, a selective serotonin-2A (5-HT 2A ) receptor antagonist. In this study, we examined the effect of sarpogrelate on cultured cardiomyocyte hypertrophy and development of heart failure.

Methods & Results: First, primary cultured cardiomyocytes were treated with 1 μM sarpogrelate and then stimulated with various hypertrophic stimuli (30 μM phenylephrine (PE), 0.1 μM angiotensin II and 0.1 μM endothelin 1). The results of immunofluorescence staining with anti-MHC antibody showed that sarpogrelate significantly suppressed cardiomyocyte hypertrophy induced by each stimulus. Western blotting and qPCR analysis showed that the mRNA and protein levels of 5-HT 2A receptor did not change by PE, and sarpogrelate significantly suppressed PE-induced phosphorylation of ERK1/2 and GATA4. Next, C57BL/6j male mice were subjected to a transverse aortic constriction (TAC) and sham operation. One day after the operation, the mice were randomly divided into 3 groups: sarpogrelate at 1 mg/kg or 5 mg/kg, and vehicle as a control. Daily oral administration was repeated for 8 weeks. Echocardiographic analysis showed that 5 mg/kg sarpogrelate significantly prevented a TAC-induced increase in posterior left ventricular wall thickness and a decrease in fractional shortening at 8 weeks after the operation. Five mg/kg sarpogrelate also suppressed TAC-induced increase in HW/BW ratio, cross-sectional areas, perivascular fibrosis, and mRNA levels of ANF and BNP. Moreover, the western blotting analysis showed that 5 mg/kg sarpogrelate significantly suppressed TAC-induced phosphorylation of ERK1/2.

Conclusions: These results indicate that sarpogrelate significantly suppresses cardiomyocyte hypertrophy and the development of heart failure via at least, in part, by inhibition of ERK1/2-GATA4 pathway. These findings suggest that sarpogrelate may be an effective agent for heart failure therapy.

Abstract P362: Gata4 Dimerization May Be A Target For Heart Failure Therapy

Introduction: Cardiac hypertrophy is regulated by activation of GATA4. Although GATA4 post-translational modification such as acetylation by p300 is well examined, the details of the activation mechanism of GATA4 are still unclear. The purpose of this study is to investigate whether GATA4 dimerization involved in transcriptional activation and cardiomyocyte hypertrophic responses.

Methods and Results: A GST pull-down assay using GST fusion GATA4 full-length and deletion mutants demonstrated that GATA4 308-326, including the acetylation site, was required for the dimerization of GATA4. A DNA pull down assay showed that the C-zinc finger motif (256-295) and the acetylation site were required for the DNA binding capacity of GATA4. IP-WB using nuclear extract from HEK293T cells expressing FLAG- or HA-tagged GATA4 showed that co-expression of p300 increased the formation of the homo-dimer as well as acetylation of GATA4. The GATA4 homo-dimer was disrupted by both acetyl-deficient GATA4 and HAT-deficient p300. This result indicates that acetylation of GATA4 is important for dimerization of GATA4. Overexpression of the deletion mutant containing a GATA4 308-326 (G4D) prevented p300-induced GATA4 dimerization but not the p300 binding nor acetylation of GATA4. ChIP assay and DNA pulldown assay showed that G4D did not inhibit the p300-induced DNA binding of GATA4. In cardiomyocytes, the G4D inhibited phenylephrine-induced ANF and ET-1 promoter activities and cardiomyocyte hypertrophy. To perform the X-ray crystal structure analysis, recombinant GATA4 fragment including GATA4 308-326 was highly purified. The X-ray diffraction data of obtained crystals was collected. Resolution of the crystal was 3.1Å, which was insufficient for phase determine. To obtain a high-quality crystal, GATA4 fragment was crystallized in international space station, in collaboration with JAXA. Resolution of the crystal was 3.16Å, which was similar to the best data before obtained.

Conclusions: These results suggest that GATA4 dimerization may play an important role in hypertrophy-response gene transcription. It is expected to elucidate the GATA4 dimerization mechanism and targeted this dimerization will lead to the development of a noble heart failure therapy.

Neutrophil/lymphocyte ratio is correlated with levels of inflammatory markers and is significantly reduced by smoking cessation

Previous studies have reported that the neutrophil to lymphocyte ratio (NLR) is associated with onset and prognosis of cardiovascular disease (CVD). Smoking is a major risk factor for CVD and smoking cessation significantly reduces CVD risk. However, the effects of smoking cessation on the NLR remain unknown. Among smokers visiting our smoking cessation clinics, we examined changes in the NLR and CVD biomarkers before and after smoking cessation. A total of 389 individuals (301 men and 88 women) were enrolled in the study. The median NLR was significantly reduced after successful smoking cessation (before: 1.8, interquartile range [IQR] 1.5, 2.5; after: 1.7, IQR 1.3, 2.4). In a linear regression model adjusted for sex, percent change in NLR comparing before and after smoking cessation was significantly and positively correlated with percent changes in C-reactive protein (β = 0.260), α1-antitrypsin-low density lipoprotein (β = 0.151, p < 0.05), and serum amyloid A-low density lipoprotein (β = 0.325). Our study demonstrated for the first time that smoking cessation significantly reduces the NLR in tandem with markers of inflammation and oxidative stress.

The Curcumin Analog GO-Y030 Controls the Generation and Stability of Regulatory T Cells

Regulatory T cells (Tregs) play a crucial role in preventing antitumor immune responses in cancer tissues. Cancer tissues produce large amounts of transforming growth factor beta (TGF-β), which promotes the generation of Foxp3+ Tregs from naïve CD4+ T cells in the local tumor microenvironment. TGF-β activates nuclear factor kappa B (NF-κB)/p300 and SMAD signaling, which increases the number of acetylated histones at the Foxp3 locus and induces Foxp3 gene expression. TGF-β also helps stabilize Foxp3 expression. The curcumin analog and antitumor agent, GO-Y030, prevented the TGF-β-induced generation of Tregs by preventing p300 from accelerating NF-κB-induced Foxp3 expression. Moreover, the addition of GO-Y030 resulted in a significant reduction in the number of acetylated histones at the Foxp3 promoter and at the conserved noncoding sequence 1 regions that are generated in response to TGF-β. In vivo tumor models demonstrated that GO-Y030-treatment prevented tumor growth and reduced the Foxp3+ Tregs population in tumor-infiltrating lymphocytes. Therefore, GO-Y030 exerts a potent anticancer effect by controlling Treg generation and stability.

Histone Acetylation Domains Are Differentially Induced during Development of Heart Failure in Dahl Salt-Sensitive Rats

Histone acetylation by epigenetic regulators has been shown to activate the transcription of hypertrophic response genes, which subsequently leads to the development and progression of heart failure. However, nothing is known about the acetylation of the histone tail and globular domains in left ventricular hypertrophy or in heart failure. The acetylation of H3K9 on the promoter of the hypertrophic response gene was significantly increased in the left ventricular hypertrophy stage, whereas the acetylation of H3K122 did not increase in the left ventricular hypertrophy stage but did significantly increase in the heart failure stage. Interestingly, the interaction between the chromatin remodeling factor BRG1 and p300 was significantly increased in the heart failure stage, but not in the left ventricular hypertrophy stage. This study demonstrates that stage-specific acetylation of the histone tail and globular domains occurs during the development and progression of heart failure, providing novel insights into the epigenetic regulatory mechanism governing transcriptional activity in these processes.

Clinically Administered Doses of Pitavastatin and Rosuvastatin

Clinical studies have indicated that 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, also known as statins, can potentially inhibit chronic heart failure. In the Stat-LVDF study, a difference was noted in terms of the effect of lipophilic pitavastatin (PTV) and hydrophilic rosuvastatin (RSV) on plasma BNP, suggesting that statin lipophilicity and pharmacokinetics change the pleiotropic effect on heart failure in humans. Therefore, we assessed the beneficial effects of PTV on hypertrophy in cardiac myocytes compared with RSV at clinically used doses. Cultured cardiomyocytes were stimulated with 30 μM phenylephrine (PE) in the presence of PTV (250 nM) or RSV (50 nM). These doses were calculated based on the maximum blood concentration of statins used in clinical situations in Japan. The results showed that PTV, but not RSV, significantly inhibits the PE-induced increase in cell size and leucine incorporation without causing cell toxicity. In addition, PTV significantly suppressed PE-induced mRNA expression of hypertrophic response genes. PE-induced ERK phosphorylation was inhibited by PTV, but not by RSV. Furthermore, PTV significantly suppressed the angiotensin-II-induced proline incorporation in primary cultured cardiac fibroblasts. In conclusion, a clinical dose of PTV was noted to directly inhibit cardiomyocyte hypertrophy and cardiac fibrosis, suggesting that lipophilic PTV can be a potential drug candidate against chronic heart failure.

Kosen-cha, a Polymerized Catechin-Rich Green Tea, as a Potential Functional Beverage for the Reduction of Body Weight and Cardiovascular Risk Factors: A Pilot Study in Obese Patients

Previous studies have shown that green tea catechins (GTCs) have beneficial effects on obesity and metabolic syndromes. In this study, we prepared kosen-cha from green tea using high pressure extraction, to reduce the astringent taste of the green tea. We identified a large quantity of polymerized GTCs in kosen-cha. To investigate the effects of kosen-cha containing polymerized GTCs in obese Japanese patients, we designed an open-label pilot study in which 6 obese subjects (body mass index (BMI) >25 kg/m²) were administered kosen-cha (5 g/L/d) for 12 weeks. Body composition, serum lipids, insulin resistance, vascular functions, and cardiac hypertrophy were measured before and 12 weeks after kosen-cha administration. Kosen-cha showed no significant adverse effects on the patients. Body weights, BMI, waist circumferences, serum triglyceride (TG) levels, and homeostasis model assessment as an index of insulin resistance (HOMA-IR) levels were significantly decreased after the 12 weeks of administration. Flow-mediated dilation (FMD) (p = 0.0214), brachial-ankle pulse wave velocity (baPWV)(p = 0.0141), left ventricular mass indexes (p = 0.0120), and plasma brain natriuretic peptide (BNP) (p = 0.0144) were significantly improved. Overall, kosen-cha reduced obesity and improved insulin resistance, vascular function, and cardiac hypertrophy, indicating its preventive potential in obesity and metabolic syndrome.

Cacao Bean Polyphenols Inhibit Cardiac Hypertrophy and Systolic Dysfunction in Pressure Overload-induced Heart Failure Model Mice

Pathological stresses such as pressure overload and myocardial infarction induce cardiac hypertrophy, which increases the risk of heart failure. Cacao bean polyphenols have recently gained considerable attention for their beneficial effects on cardiovascular diseases. This study investigated the effect of cacao bean polyphenols on the development of cardiac hypertrophy and heart failure. Cardiomyocytes from neonatal rats were pre-treated with cacao bean polyphenols and then stimulated with 30 µM phenylephrine. C57BL/6j male mice were subjected to sham or transverse aortic constriction surgery and then orally administered with vehicle or cacao bean polyphenols. Cardiac hypertrophy and function were examined by echocardiography. In cardiomyocytes, cacao bean polyphenols significantly suppressed phenylephrine-induced cardiomyocyte hypertrophy and hypertrophic gene transcription. Extracellular signal-regulated kinase 1/2 and GATA binding protein 4 phosphorylation induced by phenylephrine was inhibited by cacao bean polyphenols treatment in the cardiomyocytes. Cacao bean polyphenols treatment at 1200 mg/kg significantly ameliorated left ventricular posterior wall thickness, fractional shortening, hypertrophic gene transcription, cardiac hypertrophy, cardiac fibrosis, and extracellular signal-regulated kinase 1/2 phosphorylation induced by pressure overload. In conclusion, these findings suggest that cacao bean polyphenols prevent pressure overload-induced cardiac hypertrophy and systolic dysfunction by inhibiting the extracellular signal-regulated kinase 1/2-GATA binding protein 4 pathway in cardiomyocytes. Thus, cacao bean polyphenols may be useful for heart failure therapy in humans.

The Synthetic Curcumin Analogue GO-Y030 Effectively Suppresses the Development of Pressure Overload-induced Heart Failure in Mice

Curcumin is a naturally occurring p300-histone acetyltransferase (p300-HAT) inhibitor that suppresses cardiomyocyte hypertrophy and the development of heart failure in experimental animal models. To enhance the therapeutic potential of curcumin against heart failure, we produced a series of synthetic curcumin analogues and investigated their inhibitory activity against p300-HAT. The compound with the strongest activity was further evaluated to determine its effects on cardiomyocyte hypertrophy and pressure overload-induced heart failure in mice. We synthesised five synthetic curcumin analogues and found that a compound we have named GO-Y030 most strongly inhibited p300-HAT activity. Furthermore, 1 μM GO-Y030, in a manner equivalent to 10 µM curcumin, suppressed phenylephrine-induced hypertrophic responses in cultured cardiomyocytes. In mice undergoing transverse aortic constriction surgery, administration of GO-Y030 at a mere 1% of an equivalently-effective dose of curcumin significantly attenuated cardiac hypertrophy and systolic dysfunction. In addition, this low dose of GO-Y030 almost completely blocked histone H3K9 acetylation and eliminated left ventricular fibrosis. A low dose of the synthetic curcumin analogue GO-Y030 effectively inhibits p300-HAT activity and markedly suppresses the development of heart failure in mice.

[The Therapeutic Potency of Natural Products against Heart Failure]

Chronic heart failure is the final stage of such heart diseases as hypertension, cardiomyopathy, and myocardial infarction. Since the incidence of heart failure has increased in recent decades, heart failure is now a major public health problem in developed countries, including Japan. Recently, some studies have demonstrated that natural products, used as nutritional supplements, play an important role in preventing the development of heart failure in animal studies. In our previous study, we showed that curcumin, a natural polyphenol compound derived from Curcuma longa, exhibits therapeutic potency against heart failure. To establish the pharmacological therapeutic value of curcumin in heart failure, we have investigated the translational research of curcumin. This report reviews our basic studies and clinical trials using curcumin therapeutically to prevent heart failure, as well as the possibility of clinical applications of curcumin.

Role of SIRT1 in Modulating Acetylation of the Sarco-Endoplasmic Reticulum Ca2+-ATPase in Heart Failure

RATIONALE

SERCA2a, sarco-endoplasmic reticulum Ca²⁺-ATPase, is a critical determinant of cardiac function. Reduced level and activity of SERCA2a are major features of heart failure. Accordingly, intensive efforts have been made to develop efficient modalities for SERCA2a activation. We showed that the activity of SERCA2a is enhanced by post-translational modification with SUMO1 (small ubiquitin-like modifier 1). However, the roles of other post-translational modifications on SERCA2a are still unknown.

OBJECTIVE

In this study, we aim to assess the role of lysine acetylation on SERCA2a function and determine whether inhibition of lysine acetylation can improve cardiac function in the setting of heart failure.

METHODS AND RESULTS

The acetylation of SERCA2a was significantly increased in failing hearts of humans, mice, and pigs, which is associated with the reduced level of SIRT1 (sirtuin 1), a class III histone deacetylase. Downregulation of SIRT1 increased the SERCA2a acetylation, which in turn led to SERCA2a dysfunction and cardiac defects at baseline. In contrast, pharmacological activation of SIRT1 reduced the SERCA2a acetylation, which was accompanied by recovery of SERCA2a function and cardiac defects in failing hearts. Lysine 492 (K492) was of critical importance for the regulation of SERCA2a activity via acetylation. Acetylation at K492 significantly reduced the SERCA2a activity, presumably through interfering with the binding of ATP to SERCA2a. In failing hearts, acetylation at K492 appeared to be mediated by p300 (histone acetyltransferase p300), a histone acetyltransferase.

CONCLUSIONS

These results indicate that acetylation/deacetylation at K492, which is regulated by SIRT1 and p300, is critical for the regulation of SERCA2a activity in hearts. Pharmacological activation of SIRT1 can restore SERCA2a activity through deacetylation at K492. These findings might provide a novel strategy for the treatment of heart failure.

Serum Cystatin C, a Sensitive Marker of Renal Function and Cardiovascular Disease, Decreases After Smoking Cessation

Background: Smoking exerts detrimental effects during the progression of atherosclerotic vascular disease. Serum cystatin C is useful in the evaluation of early renal dysfunction and serves as a cardiovascular prognostic marker. This study measured changes in serum cystatin C after smoking cessation (SC). Methods and Results: In this study, patients who visited the SC clinic for the first time and succeeded in SC for 1 year were enrolled. In the entire cohort of 86 patients, body mass index (BMI, P<0.001) and waist circumference (WC, P<0.001) increased significantly at 3 months after SC compared with baseline. These values were further increased significantly (BMI, P<0.001; WC, P<0.001) from 3 months to 1 year after SC. Serum cystatin C decreased significantly at 3 months (P=0.045) after SC, and remained unchanged (P=0.482) from 3 months to 1 year after SC. Percent change from baseline to 3 months after SC in serum cystatin C was correlated with the percent change in serum monocyte chemoattractant protein 1 (P=0.047). Conclusions: Serum cystatin C, a marker of chronic kidney disease, was significantly reduced at 3 months after SC.

Cardiomyocyte Sirt (Sirtuin) 7 Ameliorates Stress-Induced Cardiac Hypertrophy by Interacting With and Deacetylating GATA4

Sirt (Sirtuin) 7, the most recently identified mammalian sirtuin, has been shown to contribute to appropriate wound healing processes after acute cardiovascular insult. However, its role in the development of cardiac remodeling after pressure overload is unclear. Cardiomyocyte-specific Sirt7-knockout and control mice were subjected to pressure overload induced by transverse aortic constriction. Cardiac hypertrophy and functions were then examined in these mice. Sirt7 protein expression was increased in myocardial tissue after pressure overload. Transverse aortic constriction-induced increases in heart weight/tibial length were significantly augmented in cardiomyocyte-specific Sirt7-knockout mice compared with those of control mice. Histological analysis showed that the cardiomyocyte cross-sectional area and fibrosis area were significantly larger in cardiomyocyte-specific Sirt7-deficient mice. Cardiac contractile functions were markedly decreased in cardiomyocyte-specific Sirt7-deficient mice. Mechanistically, we found that Sirt7 interacted directly with GATA4 and that the exacerbation of phenylephrine-induced cardiac hypertrophy by Sirt7 knockdown was decreased by GATA4 knockdown. Sirt7 deacetylated GATA4 in cardiomyocytes and regulated its transcriptional activity. Interestingly, we demonstrated that treatment with nicotinamide mononucleotide, a known key NAD⁺ intermediate, ameliorated agonist-induced cardiac hypertrophies in a Sirt7-dependent manner in vitro. Sirt7 deficiency in cardiomyocytes promotes cardiomyocyte hypertrophy in response to pressure overload. Sirt7 exerts its antihypertrophic effect by interacting with and promoting deacetylation of GATA4.

Identification and characterization of ferulic acid esterase from Penicillium chrysogenum 31B: de-esterification of ferulic acid decorated with l-arabinofuranoses and d-galactopyranoses in sugar beet pectin

We previously described the fungus Penicillium chrysogenum 31B, which has high performance to produce the ferulic acid esterase (FAE) for de-esterifying ferulic acids (FAs) from sugar beet pulp. However, the characteristics of this fungus have not yet been determined. Therefore, in this study, we evaluated the molecular characteristics and natural substrate specificity of the Pcfae1 gene from Penicillium chrysogenum and examined its synergistic effects on sugar beet pectin. The Pcfae1 gene was cloned and overexpressed in Pichia pastoris KM71H, and the recombinant enzyme, named PcFAE1, was characterized. The 505 amino acids of PcFAE1 possessed a GCSTG motif (Gly164 to Gly168), characteristic of the serine esterase family. By comparing the amino acid sequence of PcFAE1 with that of the FAE (AoFaeB) of Aspergillus oryzae, Ser166, Asp379, and His419 were identified as the catalytic triad. PcFAE1 was purified through two steps using anion-exchange column chromatography. Its molecular mass without the signal peptide was 75 kDa. Maximum PcFAE1 activity was achieved at pH 6.0-7.0 and 50 °C. The enzyme was stable up to 37 °C and at a pH range of 3-8. PcFAE1 activity was only inhibited by Hg²⁺, and the enzyme had activity toward methyl FA, methyl caffeic acid, and methyl p-coumaric acid, with specific activities of 6.97, 4.65, and 9.32 U/mg, respectively, but not on methyl sinapinic acid. These results indicated that PcFAE1 acted similar to FaeB type according the Crepin classification. PcFAE1 de-esterified O-[6-O-feruloyl-β-d-galactopyranosyl-(1→4)]-d-galactopyranose, O-[2-O-feruloyl-α-l-arabinofuranosyl-(1→5)]-l-arabinofuranose, and O-[5-O-feruloyl-α-l-arabinofuranosyl-(1→3)]-O-β-d-xylopyranosyl-(1→4)-d-xylopyranose, indicating that the enzyme could de-esterify FAs decorated with both β-d-galactopyranosidic and α-l-arabinofuranosidic residues in pectin and xylan. PcFAE1 acted in synergy with endo-α-1,5-arabinanase and α-l-arabinofuranosidase, which releases FA linked to arabinan, to digest the sugar beet pectin. Moreover, when PcFAE1 was allowed to act on sugar beet pectin together with Driselase, approximately 90% of total FA in the substrate was released. Therefore, PcFAE1 may be an interesting candidate for hydrolysis of lignocellulosic materials and could have applications as a tool for production of FA from natural substrates.

P1618A polymethoxy flavonoid, Nobiletin, Has a therapeutic potency against the development of heart failure through NBP1 activation

Introduction

Maladaptive hypertrophy is being recognized as a critical event during the development of heart failure. The control of cardiac hypertrophy may be one of the therapeutic strategy for heart failure therapy. In our previous study, we screened natural compound library and found that a natural compound, Nobiletin, could inhibit cardiomyocyte hypertrophy in culture. Nobiletin has various useful effects such as anti-cancer, anti-inflammation, and anti-oxidant and may be applicable to pharmacological therapy for heart failure.

Hypothesis

We thought that nobiletin might prevent the development of heart failure in vivo and investigated the target molecule of Nobiletin in the heart.

Methods and results

In primary cardiomyocytes, Nobiletin significantly inhibited phenylephrine (PE)-induced hypertrophic responses such as increases in cell size and hypertrophic gene transcription, such as ANF and BNP. C57BL6 mice were subjected to sham or transarotic constriction (TAC). Oral administrations of Nobiletin (20 mg/kg/day) or vehicle were repeated for 8 weeks. Nobiletin treatment significantly prevented TAC-induced increases in PWT and systolic dysfunction. Nobiletin also suppressed TAC-induced myocardial cell hypertrophy, perivascular fibrosis, and hypertrophic gene transcriptions. To investigate the target molecule of Nobiletin, Nobiletin-binding proteins were purified from rat heart using biotin-conjugated Nobiletin. We identified 162 novel binding protein of Nobiletin by LC/MS-MS. One of them, Nobiletin-binding protein 1 (NBP1) related to cellular metabolic pathway. Pulldown assay demonstrated that biotin-conjugated Nobiletin, but not biotin, directly interacted with recombinant NBP1. In vitro enzyme assay showed that Nobiletin enhanced NBP1 activity. Although NBP1 knockdown could not affect PE-induced hypertrophic response gene transcriptions and cardiomyocyte hypertrophy, NBP1 knockdown failed to exhibit Nobiletin-mediated anti-hypertrophic effects. NBP1-KO mice and WT mice were subjected to sham or TAC and randomly divided into two groups: Nobiletin (20 mg/kg/day) and vehicle. After 8 weeks, Nobiletin significantly improved TAC-induced cardiac hypertrophy and systolic dysfunction in WT mice but not in NBP1-KO mice. Nobiletin also prevented TAC-induced increases in HW/BW rate, myocardial cell hypertrophy, and mRNA levels of ANF and β-MHC in WT mice but not in NBP1-KO mice.

Conclusions

In this study, we demonstrate that Nobiletin inhibits cardiomyocyte hypertrophy and the development of heart failure in vivo. NBP1 activity is required to exhibit therapeutic potency of Nobiletin for heart failure. These finding suggest that a natural compound, nobiletin, might be a candidate for heart failure agent in human.

Acknowledgement/Funding

This work was supported by JSPS KAKENHI Grant.