miR-376b-3p attenuates mitochondrial fission and cardiac hypertrophy by targeting mitochondrial fission factor.

Mitochondrial dysfunction contributes to the pathogenesis of cardiac hypertrophy. The disequilibrium of mitochondrial dynamic, which refers to mitochondrial fusion and fission, leads to mitochondrial morphology alteration and dysfunction. Enhanced understanding of the molecular mechanisms in depth may shed light on the therapy of the disease. In this study, we show that mitochondrial fission factor (MFF) is up-regulated upon hypertrophic agonist noradrenaline (NA) treatment. Knockdown of MFF attenuated NA induced mitochondrial fission and cardiac hypertrophy. Mitochondrial fission factor is a direct target of miR-376b-3p, which attenuated expression enhanced MFF expression through binding to its 3'UTR. Expression of miR-376b-3p weakened the fragmentation of mitochondria as well as decreased hypertrophic response through regulating MFF in NA treated neonatal rat ventricular cells (NRVCs). This study suggested that miR-376b-3p is a novel modulator affecting mitochondrial morphology through targeting MFF.

Serum erythropoietin level predicts the prognosis of chronic heart failure with or without anemia.

The aim of this study was to explore the correlation of erythropoietin (EPO) with N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high sensitivity C-reactive protein (hs-CRP) in patients with chronic heart failure (CHF) or CHF complicated with anemia, in addition to its correlation with the prognosis of the patient. A total of 217 CHF patients were enrolled in this study. The patients were graded according to the cardiac function criteria of the New York Heart Association (NYHA). The serum EPO, NT-proBNP and hs-CRP levels of the patients were determined. The patients were followed up for ≥24 months. The EPO expression level in patients with NYHA II-IV CHF was significantly higher compared with that in the control group (P<0.05). EPO expression increased with the aggravation of CHF, exhibiting significant differences amongst the various NYHA graded groups (P<0.05). The EPO expression level increased significantly with an increase in NHA grade in addition to the severity of the anemia in the patients with CHF complicated by anemia (P<0.05). In the patients who succumbed (mortality group), the expression level of EPO was significantly higher and the hemoglobin level was significantly lower compared with those of the survival group (P<0.05). The EPO expression levels were elevated in CHF patients and patients with CHF and anemia. The level of expression correlated positively with the severity of CHF as well as that of anemia. Serum EPO measurements were successful in predicting the mortality and re-hospitalization rates of CHF patients at the end point, within two years of follow-up.

Effect of polysaccharides extract of rhizoma atractylodis macrocephalae on thymus, spleen and cardiac indexes, caspase-3 activity ratio, Smac/DIABLO and HtrA2/Omi protein and mRNA expression levels in aged rats.

This study was designed to determine the possible protective effect of polysaccharides extract of rhizoma atractylodis macrocephalae on heart function in aged rats. Polysaccharides extract of rhizoma atractylodis macrocephalae was administered to aged rats. Results showed that thymus, spleen and cardiac indexs were significantly increased, whereas caspase-3 activity ratio, Smac/DIABLO and HtrA2/Omi protein expression, Smac/DIABLO and HtrA2/Omi mRNA expression levels were markedly reduced. It can be concluded that polysaccharides extract of rhizoma atractylodis macrocephalae may enhance immunity and improve heart function in aged rats.

Cd-induced changes in leaf proteome of the hyperaccumulator plant Phytolacca americana.

Cadmium (Cd) is highly toxic to all organisms. Soil contamination by Cd has become an increasing problem worldwide due to the intensive use of Cd-containing phosphate fertilizers and industrial zinc mining. Phytolacca americana L. is a Cd hyperaccumulator plant that can grow in Cd-polluted areas. However, the molecular basis for its remarkable Cd resistance is not known. In this study, the effects of Cd exposure on protein expression patterns in P.americana was investigated by 2-dimensional gel electrophoresis (2-DE). 2-DE profiles of leaf proteins from both control and Cd-treated (400µM, 48h) seedlings were compared quantitatively using ImageMaster software. In total, 32 differentially expressed protein spots were identified using MALDI-TOF/TOF mass spectrometry coupled to protein database search, corresponding to 25 unique gene products. Of those 14 were enhanced/induced while 11 reduced under Cd treatment. The alteration pattern of protein expression was verified for several key proteins involved in distinct metabolic pathways by immuno-blot analysis. Major changes were found for the proteins involved in photosynthetic pathways as well as in the sulfur- and GSH-related metabolisms. One-third of the up-regulated proteins were attributed to transcription, translation and molecular chaperones including a protein belonging to the calreticulin family. Other proteins include antioxidative enzymes such as 2-cys-peroxidase and oxidoreductases. The results of this proteomic analysis provide the first and primary information regarding the molecular basis of Cd hypertolerance in P. americana.

Proteomic analysis of hydrogen photoproduction in sulfur-deprived Chlamydomonas cells.

The green alga Chlamydomonas reinhardtii is a model organism to study H(2) metabolism in photosynthetic eukaryotes. To understand the molecular mechanism of H(2) metabolism, we used 2-DE coupled with MALDI-TOF and MALDI-TOF/TOF-MS to investigate proteomic changes of Chlamydomonas cells that undergo sulfur-depleted H(2) photoproduction process. In this report, we obtained 2-D PAGE soluble protein profiles of Chlamydomonas at three time points representing different phases leading to H(2) production. We found over 105 Coomassie-stained protein spots, corresponding to 82 unique gene products, changed in abundance throughout the process. Major changes included photosynthetic machinery, protein biosynthetic apparatus, molecular chaperones, and 20S proteasomal components. A number of proteins related to sulfate, nitrogen and acetate assimilation, and antioxidative reactions were also changed significantly. Other proteins showing alteration during the sulfur-depleted H(2) photoproduction process were proteins involved in cell wall and flagella metabolisms. In addition, among these differentially expressed proteins, 11 were found to be predicted proteins without functional annotation in the Chlamydomonas genome database. The results of this proteomic analysis provide new insight into molecular basis of H(2) photoproduction in Chlamydomonas under sulfur depletion.