38 research outputs found

    Long non-coding RNA PCAT19 safeguards DNA in quiescent endothelial cells by preventing uncontrolled phosphorylation of replication protein A2

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    In healthy vessels, endothelial cells maintain a stable, differentiated, and growth-arrested phenotype for years. Upon injury, a rapid phenotypic switch facilitates proliferation to restore tissue perfusion. Here we report the identification of the endothelial cell-enriched long non-coding RNA (lncRNA) PCAT19, which contributes to the proliferative switch and acts as a safeguard for the endothelial genome. PCAT19 is enriched in confluent, quiescent endothelial cells and binds to the full replication protein A (RPA) complex in a DNA damage- and cell-cycle-related manner. Our results suggest that PCAT19 limits the phosphorylation of RPA2, primarily on the serine 33 (S33) residue, and thereby facilitates an appropriate DNA damage response while slowing cell cycle progression. Reduction in PCAT19 levels in response to either loss of cell contacts or knockdown promotes endothelial proliferation and angiogenesis. Collectively, PCAT19 acts as a dynamic guardian of the endothelial genome and facilitates rapid switching from quiescence to proliferation

    Effective detection of proteins following electrophoresis using extracts of locally available food species

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    Procedures in life sciences research laboratories often require chemicals and plasticware that are costly, toxic or pose a risk to the environment. Therefore, sustainable alternatives would be of interest, provided that they generate suitable data quality. Coomassie blue and silver staining are the most widely used methods for detecting proteins following electrophoresis in the laboratory. However, their use presents challenges in terms of safety and waste management. In the current study, aqueous extracts were prepared from a series of common food species and evaluated as alternative stains for protein detection. Beets, blueberries, purple cabbage, raspberries and strawberries were employed to stain identical proteins separated under the same conditions in electrophoresis gels. Extracts of the first two species resulted in protein bands that were detectable through visible light transillumination, whereas extracts from all five species generated specific protein bands under ultraviolet light. The raspberry-derived extract was selected for further study based on the brightness of the fluorescent protein bands and minimal background staining. For both bovine serum albumin and lysozyme at 2.5 μg and 0.5 μg protein per band, the mean signal intensities obtained with raspberry extract staining were just below half of those obtained with Coomassie blue. Furthermore, the mean intensities using raspberry extract were equivalent to those obtained using Coomassie blue in the detection of 0.1 μg protein. Therefore, raspberry could be used to produce an effective stain for the routine laboratory analysis of proteins

    The endothelial-enriched lncRNA LINC00607 mediates angiogenic function

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    Long non-coding RNAs (lncRNAs) can act as regulatory RNAs which, by altering the expression of target genes, impact on the cellular phenotype and cardiovascular disease development. Endothelial lncRNAs and their vascular functions are largely undefined. Deep RNA-Seq and FANTOM5 CAGE analysis revealed the lncRNA LINC00607 to be highly enriched in human endothelial cells. LINC00607 was induced in response to hypoxia, arteriosclerosis regression in non-human primates, post-atherosclerotic cultured endothelial cells from patients and also in response to propranolol used to induce regression of human arteriovenous malformations. siRNA knockdown or CRISPR/Cas9 knockout of LINC00607 attenuated VEGF-A-induced angiogenic sprouting. LINC00607 knockout in endothelial cells also integrated less into newly formed vascular networks in an in vivo assay in SCID mice. Overexpression of LINC00607 in CRISPR knockout cells restored normal endothelial function. RNA- and ATAC-Seq after LINC00607 knockout revealed changes in the transcription of endothelial gene sets linked to the endothelial phenotype and in chromatin accessibility around ERG-binding sites. Mechanistically, LINC00607 interacted with the SWI/SNF chromatin remodeling protein BRG1. CRISPR/Cas9-mediated knockout of BRG1 in HUVEC followed by CUT&RUN revealed that BRG1 is required to secure a stable chromatin state, mainly on ERG-binding sites. In conclusion, LINC00607 is an endothelial-enriched lncRNA that maintains ERG target gene transcription by interacting with the chromatin remodeler BRG1 to ultimately mediate angiogenesis

    The global retinoblastoma outcome study : a prospective, cluster-based analysis of 4064 patients from 149 countries

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    DATA SHARING : The study data will become available online once all analyses are complete.BACKGROUND : Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. METHODS : We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. FINDINGS : The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope). INTERPRETATION : This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.The Queen Elizabeth Diamond Jubilee Trust and the Wellcome Trust.https://www.thelancet.com/journals/langlo/homeam2023Paediatrics and Child Healt

    Short-term exercise improves myocardial tolerance to in vivo ischemia-reperfusion in the rat

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    These experiments examined the independent effects of short-term exercise and heat stress on myocardial responses during in vivo ischemia-reperfusion (I/R). Female Sprague-Dawley rats (4 mo old) were randomly assigned to one of four experimental groups: 1) control, 2) 3 consecutive days of treadmill exercise [60 min/day at 60-70% maximal O-2 uptake ((V) over dot O-2 max)], 3) 5 consecutive days of treadmill exercise (60 min/day at 60-70% (V) over dot O-2 max), and 4) whole body heat stress (15 min at 42 degreesC). Twenty-four hours after heat stress or exercise, animals were anesthetized and mechanically ventilated, and the chest was opened by thoracotomy. Coronary occlusion was maintained for 30-min followed by a 30-min period of reperfusion. Compared with control, both heat-stressed animals and exercised animals (3 and 5 days) maintained higher (P < 0.05) left ventricular developed pressure (LVDP), maximum rate of left venticular pressure development (?), and maximum rate of left ventricular pressure decline (-dP/dt) at all measurement periods during both ischemia and reperfusion. No differences existed between heat-stressed and exercise groups in LVDP, ?, and -dP/dt at any time during ischemia or reperfusion. Both heat stress and exercise resulted in an increase (P < 0.05) in the relative levels of left ventricular heat shock protein 72 (HSP72). Furthermore, exercise (3 and 5 days) increased (P < 0.05) myocardial glutathione levels and manganese superoxide dismutase activity. These data indicate that 3-5 consecutive days of exercise improves myocardial contractile performance during in vivo I/R and that this exercise-induced myocardial protection is associated with an increase in both myocardial HSP72 and cardiac antioxidant defenses

    Exercise training improves myocardial tolerance to in vivo ischemia-reperfusion in the rat

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    Experimental studies examining the effects of regular exercise on cardiac responses to ischemia and reperfusion (I/R) are limited. Therefore, these experiments examined the effects of endurance exercise training on myocardial biochemical and physiological responses during in vivo I/R. Female Sprague-Dawley rats (4 mo old) were randomly assigned to either a sedentary control group or to an exercise training group. After a 10-wk endurance exercise training program, animals were anesthetized and mechanically ventilated, and the chest was opened by thoracotomy. Coronary occlusion was achieved by a ligature around the left coronary artery; occlusion was maintained for 20 min, followed by a 10-min period of reperfusion. Compared with untrained, exercise-trained animals maintained higher (P < 0.05) peak systolic blood pressure throughout I/R. Training resulted in a significant (P < 0.05) increase in ventricular nonprotein thiols, heat shock protein (HSP) 72, and the activities of superoxide dismutase (SOD), phosphofructokinase (PFK), and lactate dehydrogenase. Furthermore, compared with untrained controls, left ventricles from trained animals exhibited lower levels (P < 0.05) of lipid peroxidation after I/R. These data demonstrate that endurance exercise training improves myocardial contractile performance and reduces lipid peroxidation during I/R in the rat in vivo. It appears likely that the improvement in the myocardial responses to I/R was related to training-induced increases in nonprotein thiols, HSP72, and the activities of SOD and PFK in the myocardium

    Heart transplant survival outcomes for adriamycin-dilated cardiomyopathy.

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    In 2015, there will be an estimated 11.3 million cancer survivors. With an increasing population of cancer survivors, it is imperative to understand the treatment options available and outcomes for chemotherapy-related cardiomyopathy. Anthracycline-based chemotherapy causes heart failure in approximately 5% of patients. Orthotopic heart transplantation (OHT) is an option for cancer survivors in complete remission who develop end-stage heart failure. We examined retrospective OHT data collected from the United Network of Organ Sharing from 1987 to 2011. The primary aim was to characterize the survival in patients with either the primary diagnosis of dilated cardiomyopathy: Adriamycin (DCA) versus all other causes of cardiomyopathy. The secondary aim was to define the differences in the primary cause of death and to describe the temporal relationship of DCA OHT. The United Network of Organ Sharing database identified 453 OHTs for the diagnosis of DCA and 51,312 OHTs for all other causes of cardiomyopathy. The DCA group was significantly younger with a greater percentage of women. After adjusting for age, gender, and history of malignancy, the 10-year survival curves showed that patients with DCA have an improved survival compared to those with all other causes of cardiomyopathy (hazard ratio 1.28, p = 0.026). No difference was found in the primary cause of death between the 2 groups. A statistically significant increasing temporal trend was seen in the number of OHTs for the diagnosis DCA. In conclusion, patients who undergo OHT for DCA have favorable 10-year survival, making OHT a good therapeutic option for end-stage heart failure due to anthracyclines. Additionally, no increased risk of cancer-related deaths was found in the DCA group, demonstrating that recurrent malignancy does not affect long-term survival. The temporal trends demonstrated that DCA remains a significant problem for cancer survivors
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