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.

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.

Efficient Colored de Bruijn Graph for Indexing Reads.

The colored de Bruijn graph is a variation of the de Bruijn graph that has recently been utilized for indexing sequencing reads. Although state-of-the-art methods have achieved small index sizes, they produce many read-incoherent paths that tend to cover the same regions in the source genome sequence. To solve this problem, we propose an accurate coloring method that can reduce the generation of read-incoherent paths by utilizing different colors for a single read depending on the position in the read, which reduces ambiguous coloring in cases where a node has two successors, and both of the successors have the same color. To avoid having to memorize the order of the colors, we utilize a hash function to generate and reproduce the series of colors from the initial color and then apply a Bloom filter for storing the colors to reduce the index size. Experimental results using simulated data and real data demonstrate that our method reduces the occurrence of read-incoherent paths from 149,556 to only 2 and 5596 to 0 respectively. Moreover, the depths of coverage for the reconstructed reads are equal to those for the input reads for the simulated data, whereas the previous method decreases the depth of coverage at many positions in the source genome. Our method achieves quite a high accuracy with a comparable construction time, peak memory size, and index size to the previous method.

Ozone ultrafine bubble water exhibits bactericidal activity against pathogenic bacteria in the oral cavity and upper airway and disinfects contaminated healthcare equipment.

Ozone is strong oxidizing agent that is applied in aqueous form for sanitation. However, ozonated water is unstable and has a short half-life. Ultrafine bubble technology is promising to overcome these issues. Ultrafine bubble is nanoscale bubble and can exist in water for a considerable duration of time. This study aims to investigate the application of ozone ultrafine bubble water (OUFBW) as a disinfectant. We produced an OUFBW generator which generates OUFBW containing 4-6 ppm of ozone. Thereafter, we examined the bactericidal activity of the OUFBW against various pathogenic bacteria in oral cavity and upper airway, including antibiotic-susceptible and antibiotic-resistant Streptococcus pneumoniae, Pseudomonas aeruginosa, Streptococcus mutans, Streptococcus sobrinus, Fusobacterium nucleatum, Prevotella intermedia, and Porphyromonas gingivalis. Exposure of planktonic culture of these bacterial species to OUFBW reduced viable bacteria by > 99% within 30s. Additionally, OUFBW exerted bactericidal activity against S. pneumoniae and P. aeruginosa adhered to toothbrush and gauze, respectively. We also observed disruption of bacterial cell wall of S. pneumoniae exposed to OUFBW by transmission electron microscope. Additionally, OUFB did not show any significant cytotoxicity toward the human gingival epithelial cell line Ca9-22. These results suggest that OUFBW exhibits bactericidal activity against broad spectrum of bacteria and has low toxicity towards human cells.

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.

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.

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.

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.

Efficient privacy-preserving variable-length substring match for genome sequence.

The development of a privacy-preserving technology is important for accelerating genome data sharing. This study proposes an algorithm that securely searches a variable-length substring match between a query and a database sequence. Our concept hinges on a technique that efficiently applies FM-index for a secret-sharing scheme. More precisely, we developed an algorithm that can achieve a secure table lookup in such a way that [Formula: see text] is computed for a given depth of recursion where [Formula: see text] is an initial position, and V is a vector. We used the secure table lookup for vectors created based on FM-index. The notable feature of the secure table lookup is that time, communication, and round complexities are not dependent on the table length N, after the query input. Therefore, a substring match by reference to the FM-index-based table can also be conducted independently against the database length, and the entire search time is dramatically improved compared to previous approaches. We conducted an experiment using a human genome sequence with the length of 10 million as the database and a query with the length of 100 and found that the query response time of our protocol was at least three orders of magnitude faster than a non-indexed database search protocol under the realistic computation/network environment.

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.

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.

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-HT2A) 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-HT2A 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.

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-ß) 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-ß-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-ß-induced increases in L-proline incorporation, mRNA levels (POSTN and alpha-smooth muscle actin (α-SMA)), and myofibroblast differentiation. Additionally, it significantly inhibited TGF-ß-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.

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-ß)-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-ß-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.

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.