Presence and function of stress granules in atrial fibrillation.

AimsStress granules (SGs) are transient cytoplasmic mRNA and protein complexes that form in eukaryotic cells under stress. SGs are related to multiple diseases, but there are no reports of the existence of SGs in atrial fibrillation (AF).Methods and resultsCell models of AF were established by field stimulation at 600 times per minute. HL-1 cells, cardiomyocytes and cardiac fibroblasts were transfected with G3BP1-cDNA plasmid by Lipofectamine 2000. The presence of SGs was detected by immunofluorescence analysis against GTPase-activating protein SH3 domain binding protein 1 (G3BP1) and poly(A)-binding protein 1 (PABP-1) and electron microscopy. Stable HL-1 cell lines transfected with lentivirus overexpressing G3BP1were constructed to further induce the formation of SGs in AF. Reactive oxygen species (ROS) and calcium overload in tachypaced HL-1 cells were studied by flow cytometry. The effects of G3BP1 overexpression on cardiac fibroblast proliferation and the protein expression level of collagen I/III and fibronectin-1 were also studied. Additionally, we detected protein synthesis in general and in single cells by puromycin incorporation in paced HL-1 cells. Here, we first showed that SGs are present in both tachypaced mouse cardiomyocytes and HL-1 atrial cells, although the presence is partial and at a low level. G3BP1 overexpression promoted SG formation, inhibited the rapid pacing-induced increase in ROS level, and attenuated calcium overload in HL-1 cells (all PConclusionsSGs are rapidly induced and present partially in AF, and G3BP1 overexpression promotes SG formation and confers cytoprotection against oxidative stress, calcium overload and atrial fibrosis in AF

Plasma MicroRNAs as Potential Noninvasive Biomarkers for In-Stent Restenosis

<div><p>Objective</p><p>To investigate whether microRNAs (miRs) can serve as novel biomarkers for in-stent restenosis (ISR).</p><p>Methods</p><p>This retrospective, observational single-centre study was conducted at the cardiovascular department of a tertiary hospital centre in the north of China. Follow-up coronary angiography at 6 to 12 months was performed in 181 consecutive patients implanted with drug-eluting stents. Fifty-two healthy volunteers served as the control group. The plasma miRs levels were analyzed by quantitative real-time PCR. Receiver-operating characteristic curve (ROC) analysis was performed to investigate the characters of these miRs as potential biomarkers of ISR.</p><p>Results</p><p>MiR-21 levels in ISR patients were significantly higher than those in non-ISR patients and healthy controls (<i>P</i><0.05), while miR-100 (<i>P</i><0.05), miR-143 (<i>P</i><0.001) and miR-145 (<i>P</i><0.0001) levels were significantly decreased in ISR patients. Further analysis showed that miR-21 levels were remarkably increased (<i>P</i> = 0.045), while miR-100 (<i>P</i> = 0.041), miR-143 (<i>P</i> = 0.029) and miR-145 (<i>P</i><0.01) levels were dramatically decreased in patients with diffuse ISR compared to those with focal ISR. ROC analysis demonstrated that the area under curve of miR-145, miR-143, miR-100 and miR-21 were 0.880 (95% confidence interval; CI = 0.791–0.987, <i>P</i><0.001), 0.818 (95% confidence interval; CI = 0.755–0.963, <i>P</i><0.001), 0.608 (95% confidence interval; CI = 0.372–0.757, <i>P</i><0.05) and 0.568 (95% confidence interval; CI = 0.372–0.757, <i>P</i><0.05), with specificity of 83.1%, 80.1%, 68.9% and 68.6%, and sensitivity of 88.7%, 82.1%, 60.2% and 50.1%, respectively.</p><p>Conclusions</p><p>Circulating miR-143 and miR-145 levels are associated with the occurrence of ISR and can serve as novel noninvasive biomarkers for ISR.</p></div

Clinical characteristics of patients between ISR group and non-ISR group used for miRNAs profiling.

<p>Data are presented as means (±SD) or as numbers (percentages).</p><p>*<i>P</i><0.05 vs. Non-ISR.</p><p>Clinical characteristics of patients between ISR group and non-ISR group used for miRNAs profiling.</p

Clinical characteristics of patients between ISR group and non-ISR group.

<p>LDL-C, low density lipoprotein cholesterol; CCB, Calcium channel blockers;</p><p>ACEI, angiotensin converting enzyme inhibitor; ARB, angiotensin receptor blocker.</p><p>NA, not applicable.</p><p>Data are presented as means (±SD) or as numbers (percentages).</p>#<p>comparison among patients with ISR, non-ISR and control: P<0.05 for three groups.</p><p>*comparison between patients with ISR and non-ISR: P<0.05 for ISR vs. Non-ISR.</p><p>Clinical characteristics of patients between ISR group and non-ISR group.</p

Primers sequence.

<p>RT, RT primers; FP, forward primer; RP, reverse primer.</p><p>Primers sequence.</p

Relative expression of plasma miRNAs (qRT-PCR) in patients with focal ISR pattern group (n = 32) vs diffuse ISR pattern group (n = 19).

<p>Data are expressed as mean±SD.</p

Global view of the network.

<p>Global view of the network.</p