Long non-coding RNA plasmacytoma variant translocation 1 linked to hypoxia-induced cardiomyocyte injury of H9c2 cells by targeting miR-135a-5p/forkhead box O1 axis / 中华医学杂志(英文版)

BACKGROUND@#Myocardial infarction occurs due to insufficient (ischemia) blood supply to heart for long time; plasmacytoma variant translocation 1 (PVT1) is a long non-coding RNAs (lncRNAs) involved in the pathogenesis of various diseases, including heart disease; However, few studies have explored its role. The present study evaluated the effects of lncRNA PVT1 on hypoxic rat H9c2 cells.@*METHODS@#Hypoxic injury was examined by measuring cell viability and apoptosis by using cell counting kit-8 activity and flow cytometry assays. Gene expressions after hypoxia were estimated by quantitative real time polymerase chain reaction and the signaling pathway were explored by Western blot analysis. RNA immunoprecipitation and luciferase reporter assays were applied to examine the interactions among genes. Data were analyzed using t-test with one-way or two-way analysis of variance.@*RESULTS@#The lncRNA PVT1 is up-regulated in hypoxia-stressed H9c2 cells and knockdown of PVT1 mitigates hypoxia-induced injury in H9c2 cells. PVT1 acts as a sponge for miR-135a-5p and knockdown of PVT1 attenuated the increased hypoxia-induced injury by up-regulating miR-135a-5p. Forkhead box O1 (FOXO1) was identified as a target of miR-135a-5p, and the expression was negatively regulated by miR-135a-5p. The exploration of the underlying mechanism demonstrated that knockdown of FOXO1 reversed PVT1/miR-135a-5p mediated hypoxia-induced injury in H9c2 cells.@*CONCLUSIONS@#PVT1 plays a crucial role in hypoxia-injured H9c2 cells through sponging miR-135a-5p and then positively regulating FOXO1.

Dual role of polyamines in heart ischemia/reperfusion injury through regulation of mitochondrial permeability transition pore / 生理学报

Polyamines (putrescine, spermidine, and spermine) are essential polycations that play important roles in various physiological and pathophysiological processes in mammalian cells. The study was to investigate their role in cardioprotection against ischemia/reperfusion (I/R) injury and the underlying mechanism. Isolated hearts from male Sprague-Dawley rats were Langendorff-perfused and cardiac I/R was achieved by 30 min of global ischemia followed by 120 min of reperfusion. Different concentrations of polyamines (0.1, 1, 10, and 15 μmol/L of putrescine, spermidine, and spermine), cyclosporin A (0.2 μmol/L), or atractyloside (20 μmol/L) were given 10 min before the onset of reperfusion. The hemodynamics were monitored; the lactate dehydrogenase (LDH) levels in the coronary effluent were measured spectrophotometrically; infarct size was determined by the 2,3,5-triphenyltetrazolium chloride staining method; and mitochondrial permeability transition pore (MPTP) opening was determined spectrophotometrically by the Ca-induced swelling of isolated cardiac mitochondria. The results showed that compared to I/R alone, 0.1 and 1 μmol/L polyamines treatment improved heart function, reduced LDH release, decreased infarct size, and these effects were inhibited by atractyloside (MPTP activator). In isolated mitochondria from normal rats, 0.1 and 1 μmol/L polyamines treatment inhibited MPTP opening. However, 10 and 15 μmol/L polyamines treatment had the opposite effects, and these effects were inhibited by cyclosporin A (MPTP inhibitor). Our findings showed that polyamines may have either protective or damaging effects on hearts suffering from I/R by inhibiting or activating MPTP opening.

The microbiology of chronic rhinosinusitis with and without nasal polyps.

OBJECTIVE: To compare the microbiological features in middle meatus samples from chronic rhinosinusitis (CRS) patients with nasal polyps (CRSwNP) and those without nasal polyps (CRSsNP), and control subjects. METHODS: A total of 136 CRSwNP patients, 66 CRSsNP patients, and 49 control subjects who underwent endoscopic surgery in Beijing TongRen Hospital were enrolled between January 2014 and January 2016. Swab samples were obtained from the middle meatus during surgery and processed for the presence of aerobic and non-aerobic bacteria and fungi. Information on the allergic rhinitis, asthma, the percentage of eosinophils in peripheral blood, and the history of smoking and surgery was collected. RESULTS: The overall isolation rate for bacteria was 81.3% for the three groups, with the lowest in the CRSsNP group (77.3%) and the highest in the CRSwNP group (88.4%). There were no significant differences in isolation rates among the three groups (P = 0.349). The three most common bacterial species were: Coagulase-negative Staphylococcus (24.3%), Corynebacterium (19.9%), and Staphylococcus epidermidis (19.1%) in the CRSwNP group; S. epidermidis (21.2%), Corynebacterium (21.2%), Coagulase-negative staphylococcus (18.2%), and Staphylococcus aureus (13.6%) in the CRSsNP group; S. epidermidis (30.6%), Coagulase-negative Staphylococcus (28.6%), and S. aureus (14.3%) in the control group. For the bacterial species with high isolation rates, no significant difference in the microbial cultures was observed among the three groups; whereas in the CRSwNP group, a relatively high proportion of Citrobacter (5.9%, a bacterium with low isolation rate) was observed compared with the CRSsNP and control groups (all 0.0%). Furthermore, when samples were categorized into subgroups according to the percentage of eosinophils, some bacterial species showed different rates in the CRSwNP group (e.g., S. aureus, 3.3% in the subgroup with normal percentage of eosinophils, 17.2% in the subgroup with increased percentage of eosinophils, P = 0.011). CONCLUSIONS: There were no significant differences in the microbiological features (except Citrobacter) in middle meatus samples from CRSwNP patients, CRSsNP patients, and control subjects. S. aureus may promote eosinophilic inflammatory response, while S. epidermidis may promote non-eosinophilic inflammatory response.