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-ß (TGF-ß) in cultured cardiac fibroblasts. TGF-ß 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-ß 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-ß/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.

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-ß)-induced increases in L-proline incorporation. It also blocked PE- and TGF-ß-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.

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.

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.

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.

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.

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.

Psychological Effects of Aromatherapy on Smokers With Depressive Tendencies During Smoking Cessation Treatment: Protocol for a Pre-Post Single-Arm Clinical Trial.

BACKGROUND: Cessation of smoking can markedly reduce the incidence of cardiovascular disease, improve health economics, and benefit society. Aromatherapy has the potential to be a novel option as an adjuvant therapy for smoking cessation that may alleviate depressive symptoms. However, research on the efficacy of aromatherapy as an adjuvant therapy for smoking cessation is scarce. OBJECTIVE: The aim of this study was to examine the potential effects of aromatherapy on psychological states in smokers with depressive tendencies and to determine if it is reasonable to proceed to the next step (ie, a phase III trial). METHODS: This is a pre-post single-arm clinical trial. Smokers with depression will be subjected to aromatherapy during smoking cessation treatment for 12 weeks. We will evaluate changes in scores on the Zung Self-Rating Depression Scale and the Profile of Mood States from pretreatment screening to 4 weeks and 12 weeks after the start of aromatherapy. Moreover, we will compare the group treated with aromatherapy with the group that received standard treatment in our previous randomized controlled trial (ie, the control group in that study). Furthermore, we will compare successful smoking cessation rates after 12 weeks. In addition, we will conduct an exploratory analysis of the efficacy of aromatherapy. The target sample size is 100, which is the number of subjects expected to be enrolled in this study during the 2-year study period. RESULTS: This study was approved by the Kyoto Medical Center Institutional Review Board (IRB approval No. 19-016). Enrollment started on July 1, 2019. As of May 2022, 76 patients have been recruited. In the original plan, recruitment should have been finished on June 30, 2021. However, the number of subjects decreased due to the COVID-19 pandemic, and the study inclusion period was extended by 1 year (ie, until the end of June 2022) with the approval of the IRB on May 17, 2021. Analyses of the results will be completed subsequently. CONCLUSIONS: This study has some limitations. This is not a rigorous validation study because it compares the same subjects who received standard treatment in a previous study. Moreover, the sample size and methods of statistical analysis were not fully set with prior consideration of statistical rigor. To address these limitations, we plan to conduct a phase III trial that will reflect the exploratory findings of this study. This is the first study to evaluate the psychological effects of aromatherapy during a smoking cessation program, and it may help improve the quality of treatment for smoking cessation in the future. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000043102; https://tinyurl.com/tn3hvt9w. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/38626.

Pyrazole-Curcumin Suppresses Cardiomyocyte Hypertrophy by Disrupting the CDK9/CyclinT1 Complex.

The intrinsic histone acetyltransferase (HAT), p300, has an important role in the development and progression of heart failure. Curcumin (CUR), a natural p300-specific HAT inhibitor, suppresses hypertrophic responses and prevents deterioration of left-ventricular systolic function in heart-failure models. However, few structure-activity relationship studies on cardiomyocyte hypertrophy using CUR have been conducted. To evaluate if prenylated pyrazolo curcumin (PPC) and curcumin pyrazole (PyrC) can suppress cardiomyocyte hypertrophy, cultured cardiomyocytes were treated with CUR, PPC, or PyrC and then stimulated with phenylephrine (PE). PE-induced cardiomyocyte hypertrophy was inhibited by PyrC but not PPC at a lower concentration than CUR. Western blotting showed that PyrC suppressed PE-induced histone acetylation. However, an in vitro HAT assay showed that PyrC did not directly inhibit p300-HAT activity. As Cdk9 phosphorylates both RNA polymerase II and p300 and increases p300-HAT activity, the effects of CUR and PyrC on the kinase activity of Cdk9 were examined. Phosphorylation of p300 by Cdk9 was suppressed by PyrC. Immunoprecipitation-WB showed that PyrC inhibits Cdk9 binding to CyclinT1 in cultured cardiomyocytes. PyrC may prevent cardiomyocyte hypertrophic responses by indirectly suppressing both p300-HAT activity and RNA polymerase II transcription elongation activity via inhibition of Cdk9 kinase activity.

The polyunsaturated fatty acids, EPA and DHA, ameliorate myocardial infarction-induced heart failure by inhibiting p300-HAT activity in rats.

While the cardioprotective functions of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and omega-3 unsaturated fatty acids have been previously demonstrated, little is known about their effects on cardiomyocyte hypertrophy. In this study, we compared the effects of EPA and DHA on hypertrophic responses in cardiomyocytes and development of heart failure in rats with myocardial infarction (MI). Both EPA and DHA significantly suppressed phenylephrine- and p300-induced cardiomyocyte hypertrophy, transcription of hypertrophy response genes, and acetylation of histone H3K9 in cardiomyocytes. EPA and DHA directly inhibited p300-histone acetyltransferase activity (IC50: 37.8 and 30.6 µM, respectively). Further, EPA- and DHA-induced allosteric inhibition of histones and competitive inhibition of acetyl-CoA, and significantly prevented p300-induced hypertrophic responses. Rats with moderate MI (left ventricular fractional shortening [FS] <40%) were randomly assigned to three groups, namely, vehicle (saline), EPA (1 g/kg), and DHA (1 g/kg). One week after the operation, rats were orally administrated with test agents for 6 weeks. Echocardiographic analysis demonstrated that both EPA and DHA treatments preserved FS and prevented MI-induced left ventricular remodeling. Furthermore, EPA and DHA significantly suppressed the MI-induced increase in myocardial cell diameter, perivascular fibrosis, mRNA levels of hypertrophic markers, fibrosis, and acetylation of histone H3K9. The effects on hypertrophic responses and the development of heart failure were not different between EPA and DHA groups. Both EPA and DHA suppressed hypertrophic responses and the development of heart failure to the same extent through the inhibition of p300-HAT activity.

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-1ß levels were evaluated by qRT-PCR and ELISA. The expression of ANGPTL4 (p = 0.0180) and IL-1ß (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-1ß 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-1ß (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.

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.

Multimerization of the GATA4 transcription factor regulates transcriptional activity and cardiomyocyte hypertrophic response.

The activation of the GATA-binding factor 4 (GATA4) transcription factor induces cardiac hypertrophy and heart failure. The multimerization of transcription factors often plays an important role in the regulation of transcriptional activity. Here, we report that the GATA4 transcription factor forms a homomultimer and that residues 308-326 of GATA4 are necessary for its multimerization. The acetylation of GATA4 by the transcriptional co-activator p300 induces the multimerization of GATA4 and activates its DNA binding activity. In addition, we found that the suppression of GATA4 multimerization did not reduce its acetylation, but repressed GATA4/p300-induced gene transcription. Furthermore, the inhibition of GATA4 multimerization suppressed phenylephrine (PE)-induced hypertrophic response in cardiomyocytes. This study demonstrates that the multimerization of GATA4 during the p300-induced acetylation of GATA4 activates the transcription of hypertrophic response genes, which leads to cardiomyocyte hypertrophy. Therefore, the inhibition of GATA4 homomultimerization could serve as a potential therapeutic strategy for the development of novel drugs against heart failure.

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.

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.