Whole-exome sequencing reveals MYH7 p.R671C mutation in three different phenotypes of familial hypertrophic cardiomyopathy.

Familial hypertrophic cardiomyopathy (HCM) is one of the most common types of genetic heart disorder and features high genetic heterogeneity. HCM is a major cause of sudden cardiac death and also an important cause of heart failure-related disability. A pedigree with suspected familial HCM was recruited for the present study to identify genetic abnormalities. HCM was confirmed by echocardiography and clinical data of the family members were collected. Genomic DNA was extracted from the peripheral blood and sequenced based on standard whole-exome sequencing (WES) protocols. Sanger sequencing was further performed to verify mutation sites and their association with HCM. WES and Sanger sequencing revealed a heterozygous missense mutation (c.2011C>T p.R671C) in myosin heavy chain 7 (MYH7) that was identified in three family members. The Arg671Cys mutation was located in exon 18 and, to the best of our knowledge, has not been previously reported in familial HCM. Furthermore, family members carrying the same mutated gene were of different sexes and clinical phenotypes. They included the proband, a 17-year-old survivor of sudden cardiac arrest with ventricular systolic dysfunction, the proband's maternal uncle, who presented with ventricular diastolic dysfunction and the proband's mother, who had no obvious clinical symptoms and did not present with cardiac dysfunction. However, echocardiology indicated that the proband's mother had an enlarged left atrium, slightly thicker right anterior wall and anterior septum and an expanded atrial septum. Therefore, HCM exhibited obvious genetic and phenotypic heterogeneity. To the best of our knowledge, the present study was the first to report such a mutation in the MYH7 gene in familial HCM. In addition, the present study demonstrated that WES is a powerful tool for identifying genetic variants in HCM.

Structural characterisation and ACE-inhibitory activities of polysaccharide from Gastrodia elata Blume.

The structural properties and Angiotensin-I converting enzyme (ACE) inhibition activities of a polysaccharide (PGE) extracted from Gastrodia elata Blume were investigated. PGE was extracted using hot water and purified by Sephadex G-200 followed by ultra-filtration. The structural characterisation of PGE was analysed by FT-IR, NMR spectroscopy, specific rotation determination, periodate oxidation-smith degradation, methylation analysis, GC-MS and Congo red test. The results revealed that PGE was composed by glucose, with an average molecular weight of 1.54 × 103 kDa. The structure of PGE was 1→3 and 1→4,6-branched-glucopyranose that had a linear backbone of (1 → 4)-linked-d-glucopyranose (Glcp). ACE-inhibitory activity results showed that PGE was efficient to inhibit ACE and the IC50 value was 0.66 mg/mL.

SIRT3 protects cardiomyocytes from oxidative stress-mediated cell death by activating NF-κB.

Oxidative stress-mediated cell death in cardiomyocytes reportedly plays an important role in many cardiac pathologies. Our previous report demonstrated that mitochondrial SIRT3 plays an essential role in mediating cell survival in cardiac myocytes, and that resveratrol protects cardiomyocytes from oxidative stress-induced apoptosis by activating SIRT3. However, the exact mechanism by which SIRT3 prevents oxidative stress remains unknown. Here, we show that exposure of H9c2 cells to 50 µM H(2)O(2) for 6h caused a significant increase in cell death and the down-regulation of SIRT3. Reactive oxygen species (ROS)-mediated NF-κB activation was involved in this SIRT3 down-regulation. The SIRT3 activator, resveratrol, which is considered an important antioxidant, protected against H(2)O(2)-induced cell death, whereas the SIRT inhibitor, nicotinamide, enhanced cell death. Moreover, resveratrol negatively regulated H(2)O(2)-induced NF-κB activation, whereas nicotinamide enhanced H(2)O(2)-induced NF-κB activation. We also found that SOD2, Bcl-2 and Bax, the downstream genes of NF-κB, were involved in this pathological process. These results suggest that SIRT3 protects cardiomyocytes exposed to oxidative stress from apoptosis via a mechanism that may involve the NF-κB pathway.

Red wine may be used in the therapy of myocarditis.

Myocarditis is one of the most commonly cardiovascular diseases in clinical practice, but the treatment is always limited at present. Considering the multifactorial etiology of myocarditis, a novel therapeutic agent with multi-bioactivties should be presented. Red wine has been recognized as a favorable natural medicine against a large number of pathologic conditions. Recent results indicate that red wine could effectively decrease inflammatory factors secretion, reduce the migration of neutrophils, antagonize oxidation, and regulate immunity. By these bioactivities of anti-inflammation, anti-oxidation, and immunomodulation, red wine may be an effective therapeutic candidate to manage the symptoms and prevent the recurrence of myocarditis.

SIRT1: a novel target to prevent atherosclerosis.

Atherosclerosis is a chronic immuno-inflammatory disease associated with blood lipids disorder. Many studies have demonstrated that caloric restriction (CR) can prevent atherosclerosis and extend lifespan. Sir2 protein, mammal's SIRT1, has been reported to at least partly contribute to the protective effect of CR. Hence, we hypothesize that SIRT1 is a key regulator in the pathogenesis of atherosclerosis and that upregulation of SIRT1 in endothelial cells may mimic CR's beneficial effect on vascular health. The recent studies have demonstrated that endothelial SIRT1 is an anti-atherosclerosis factor and the possible mechanism may be related to inhibit oxidized low-density lipoprotein (oxLDL)-induced apoptosis, upregulate endothelial nitric oxide synthase (eNOS) expression, and improve endothelium relaxation function. We infer that SIRT1 may be a novel target for atherosclerosis prevention and treatment.

Effects of resveratrol on H(2)O(2)-induced apoptosis and expression of SIRTs in H9c2 cells.

Resveratrol, a polyphenol found in fruits, has been demonstrated to activate Sir2. Though many studies have demonstrated that resveratrol can activate SIRT1, whether it has effect on other sirtuins (SIRT2-7) are unknown. The present study shows that exposure of H9c2 cells to 50 microM H(2)O(2) for 6 h caused a significant increase in apoptosis, as evaluated by TUNEL and flow cytometry (FCM), but pretreatment of resveratrol (20 microM) eliminated H(2)O(2)-induced apoptosis. Resveratrol also prevented H(2)O(2)-induced caspase-3 activation. Exposure of cells to resveratrol caused rapid activation of SIRT1,3,4,7. Sirtuin inhibitor, nicotinamide (20 mM) attenuated resveratrol's inhibitory effect on cell apoptosis and caspase-3 activity. These results suggest that resveratrol protects cardiomyocytes from H(2)O(2)-induced apoptosis by activating SIRT1,3,4,7.

Resveratrol protects cardiomyocytes from hypoxia-induced apoptosis through the SIRT1-FoxO1 pathway.

Loss of cardiomyocytes through apoptosis has been proposed as a cause of ventricular remodeling and heart failure. Ischemia- and hypoxia-induced apoptosis of cardiomyocytes reportedly plays an important role in many cardiac pathologies. We investigated whether resveratrol (Res) has direct cytoprotective effects against ischemia/hypoxia for cardiomyocytes. Exposure of H9c2 embryonic rat heart-derived cells to hypoxia for 24h caused a significant increase in apoptosis, as evaluated by TUNEL and flow cytometry, while treatment with 20 microM Res greatly decreased hypoxia-induced apoptosis in these cells. Exposure of the cells to Res (20 microM) caused rapid activation of SIRT1, which had a dual effect on FoxO1 function: SIRT1 increased FoxO1's ability to induce cell cycle arrest, but inhibited FoxO1's ability to induce cell death. This effect could be reversed by SIRT1 inhibition. Results of our study indicate that Res inhibits hypoxia-induced apoptosis via the SIRT1-FoxO1 pathway in H9c2 cells. This polyphenol may have potential in preventing cardiovascular disease, especially in coronary artery disease (CAD) patients.