1,721,049 research outputs found

    Pin1 inhibitor Juglone prevents diabetic vascular dysfunction

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    Background Atherosclerosis is a major cause of mortality in patients with diabetes. However, novel breakthrough therapies have yet to be approved in this setting. Prolyl-isomerase-1 (Pin1) is emerging as a key molecule implicated in vascular oxidative stress and inflammation. In the present study, we investigate whether pharmacological inhibition of Pin1 may protect against diabetes-induced oxidative stress, endothelial dysfunction and vascular inflammation. Methods and Results Experiments were performed in human aortic endothelial cells (HAECs) exposed to normal (5 mmol/L) or high glucose (25 mmol/L) concentrations, in the presence of Pin1 inhibitor Juglone (10 μM) or vehicle (< 1% ethanol). In parallel, streptozotocin-induced diabetic mice were treated with Juglone i.p. every other day for 30 days (1 mg/Kg). Organ chamber experiments were performed in aortic rings to assess endothelium-dependent relaxations to acetylcholine (Ach 10- 9 to 10- 6 mol/L). Mitochondrial oxidative stress, organelle integrity as well as NF-kB-dependent inflammatory signatures were determined both in HAECs and aortas from diabetic mice. In HAECs, ambient hyperglycemia increased mitochondrial superoxide anion generation while treatment with Juglone prevented this phenomenon. Pharmacological inhibition of Pin1 also preserved mitochondrial integrity, nitric oxide availability and endothelial expression of adhesion molecules. Interestingly enough, endothelial dysfunction, oxidative stress and NF-kB-driven inflammation were significantly attenuated in diabetic mice chronically treated with Juglone as compared to vehicle-treated animals. Conclusion Pharmacological inhibition of Pin1 by Juglone prevents hyperglycemia-induced vascular dysfunction. Taken together, our findings may set the stage for novel therapeutic approaches to prevent vascular complications in patients with diabetes

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Reprogramming ageing and longevity genes restores paracrine angiogenic properties of early outgrowth cells

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    AIMS: Impaired tissue vascularization is a major determinant of cardiovascular disease (CVD) in the elderly. Accumulation of reactive oxygen species (ROS) may interfere with vascular repair, but the underlying mechanisms remain unknown. Early outgrowth cells (EOCs) play an important role in endothelial repair. We investigated whether key lifespan genes involved in ROS, i.e. the mitochondrial adaptor p66(Shc) and the AP-1 transcription factor JunD, contribute to age-related EOCs dysfunction in humans. METHODS AND RESULTS: Early outgrowth cells were isolated and cultured from peripheral blood mononuclear cells of young and old healthy volunteers. Early outgrowth cells isolated from aged individuals displayed p66(Shc) gene up-regulation and reduced JunD expression. Deregulation of p66(Shc) and JunD in aged EOCs led to up-regulation of NADPH oxidase, reduced expression of manganese superoxide dismutase (MnSOD) and increased O2 (-) generation. This was associated with an impairment of EOCs-induced migration of mature endothelial cells. Secretome profiling revealed that angiogenic chemokines such as stromal-derived factor-1 and monocyte chemoattractant protein-1 were deregulated in conditioned medium collected from aged EOCs. Interestingly, p66(Shc) silencing or JunD overexpression blunted age-related O2 (-) production via the NADPH/MnSOD axis, and restored paracrine angiogenic potential of aged EOCs. CONCLUSION: Reprogramming ageing and longevity genes preserves EOCs functionality by affecting their paracrine properties. These findings set the basis for novel therapeutic strategies to improve for vascular repair after injury and in CVD in the elderly

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    MicroRNA profiling unveils hyperglycaemic memory in the diabetic heart

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    AIMS Recent randomized trials suggest that intensive glycaemic control fails to reduce heart failure-related events in patients with diabetes. The molecular cues underlying persistent myocardial damage despite normoglycaemia restoration remain elusive. MicroRNAs (miRNAs), a class of small non-coding RNAs, orchestrate transcriptional programs implicated in adverse cardiac remodelling. The present study investigates whether miRNAs participate to hyperglycaemic memory in the diabetic heart. METHODS AND RESULTS miRNA landscape was assessed by Mouse miRNome miRNA PCR Arrays in left ventricular specimens collected from 4-month-old streptozotocin-induced diabetic mice, with or without intensive glycaemic control by slow-release insulin implants. A dysregulation of 316 out of 1008 total miRNAs was observed in the diabetic hearts when compared with controls. Of these, 209 were up-regulated and 107 were down-regulated by >2.0-fold. Interestingly enough, the expression of 268 of those miRNAs remained significantly altered in diabetic mice even after subsequent normoglycaemia. Ingenuity pathway analysis revealed that dysregulated miRNAs were implicated in myocardial signalling networks triggering apoptosis (miR-320b, miR-378, miR-34a), fibrosis (miR-125b, miR-150, miR-199a, miR-29b, miR30a), hypertrophic growth (miR-1, miR-150, miR-199a, miR-133a, miR-214, miR-29a, miR-125b, miR-221, miR-212), autophagy (miR-133a, miR-221, miR-212, miR30a), oxidative stress (miR-221, miR-146a, miR-34a, miR-210, miR-19b, miR-125b, miR27a, miR-155), and heart failure (miR-423, miR-499, miR-199a), respectively. CONCLUSIONS Glycaemic control is not able to rescue hyperglycaemia-induced alterations of miRNA landscape in the diabetic heart. These findings may provide novel insights to understand why diabetic cardiomyopathy progresses despite normalization of blood glucose levels
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