161 research outputs found
Ankyrin repeat and Single KH domain 1 (ANKHD1) drives renal cancer cell proliferation via binding to and altering a subset of miRNAs
Clear cell Renal Cell Carcinoma (ccRCC) represents the most common kidney cancer worldwide. Increased cell proliferation associated with abnormal microRNA (miRNA) regulation are hallmarks of carcinogenesis. Ankyrin repeat and single KH domain 1 (ANKHD1) is a highly conserved protein found to interact with core cancer pathways in Drosophila, however its involvement in RCC is completely unexplored. Quantitative PCR studies coupled with large-scale genomics data analyses demonstrated that ANKHD1 is significantly upregulated in kidneys of RCC patients when compared to healthy controls. Cell cycle analyses revealed that ANKHD1 is an essential factor for RCC cell division. To understand the molecular mechanism(s) utilized by ANKHD1 to drive RCC cell proliferation we performed bioinformatics analyses which revealed that ANKHD1 contains a putative miRNA-binding motif. We screened 48 miRNAs with tumour-enhancing or suppressing activities, and found that ANKHD1 binds to and regulates three tumour-suppressing miRNAs (i.e. miR-29a, miR-205, and miR-196a). RNA-immunoprecipitation assays demonstrated that ANKHD1 physically interacts with its target miRNAs via a single K-Homology (KH)-domain, located in the c-terminus of the protein. Functionally we discovered that ANKHD1 positively drives ccRCC cell mitosis via binding to and suppressing mainly miR-29a and to a lesser degree via miR-196a/205, leading to an upregulation in pro-proliferative genes such as CCDN1. Collectively, these data identify ANKHD1 as a new regulator of ccRCC proliferation via specific miRNA interactions
The controversial role of fibrosis in Autosomal Dominant Polycystic Kidney Disease
Autosomal Dominant Polycystic Kidney Disease (ADPKD) is characterized by the progressive growth of cysts but it is also accompanied by diffuse tissue scarring or fibrosis. A number of recent studies have been published in this area, yet the role of fibrosis in ADPKD remains controversial. Here, we will discuss the stages of fibrosis progression in ADPKD, and how these compare with other common kidney diseases. We will also provide a detailed overview of some key mechanistic pathways to fibrosis in the polycystic kidney. Specifically, the role of the ‘chronic hypoxia hypothesis’, persistent inflammation, Transforming Growth Factor beta (TGFβ), Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT) and microRNAs will be examined. Evidence for and against a pathogenic role of extracellular matrix during ADPKD disease progression will be provided
Renal expression of JAK2 is high in polycystic kidney disease and its inhibition reduces cystogenesis.
Autosomal dominant polycystic kidney disease (ADPKD) is the most common renal genetic disorder, however it still lacks a cure. The discovery of new therapies heavily depends on understanding key signalling pathways that lead to ADPKD. The JAnus Kinase and Signal Transducers and Activators of Transcription (JAK/STAT) pathway is aberrantly activated and contributes to ADPKD pathogenesis via enhancing epithelial proliferation. Yet the mechanisms underlying the upregulation of JAK/STAT activity in this disease context is completely unknown. Here, we investigate the role of JAK2 in ADPKD using a murine model of ADPKD (Pkd1nl/nl). In normal kidneys, JAK2 expression is limited to tubular epithelial and vascular cells with lesser staining in bowman's capsule and remains below detection level in the interstitium. By contrast, in kidneys of mice with ADPKD, JAK2 is higher in cyst-lining cells when compared to normal tubules and critically, it is ectopically expressed in the interstitium, suggesting that ectopic JAK2 may contribute to ADPKD. JAK2 activity was inhibited using either curcumin, a natural compound with strong JAK2 inhibitor activity, or Tofacitinib, a clinically used selective JAK small molecule inhibitor. JAK2 inhibition led to significantly reduced tyrosine phosphorylation of STAT3 and markedly reduced cystic growth of human and mouse ADPKD-derived cells in cystogenesis assays. Taken together, our results indicate that blockade of JAK2 shows promise as a novel therapeutic target in ADPKD
The Bernard and Joan Marshall Early Career Investigators and Distinguished Investigator Award 2018
Data on CUX1 isoforms in idiopathic pulmonary fibrosis lung and systemic sclerosis skin tissue sections
This data article contains complementary figures related to the
research article entitled, “Transforming growth factor-β-induced
CUX1 isoforms are associated with fibrosis in systemic sclerosis
lung fibroblasts” (Ikeda et al. (2016) [2], http://dx.doi.org/10.1016/j.
bbrep.2016.06.022), which presents that TGF-β increased CUX1
binding in the proximal promoter and enhancer of the COL1A2 and
regulated COL1. Further, in the scleroderma (SSc) lung and diffuse
alveolar damage lung sections, CUX1 localized within the α-
smooth muscle actin (α-SMA) positive cells (Fragiadaki et al., 2011)
[1], “High doses of TGF-beta potently suppress type I collagen via
the transcription factor CUX1” (Ikeda et al., 2016) [2]. Here we
show that CUX1 isoforms are localized within α-smooth muscle
actin-positive cells in SSc skin and idiopathic pulmonary fibrosis
(IPF) lung tissue sections. In particular, at the granular and prickle
cell layers in the SSc skin sections, CUX1 and α-SMA are colocalized.
In addition, at the fibrotic loci in the IPF lung tissue
sections, CUX1 localized within the α-smooth muscle actin (α-
SMA) positive cells
Endothelial dysfunction in COVID-19: a position paper of the ESC Working Group for Atherosclerosis and Vascular Biology, and the ESC Council of Basic Cardiovascular Science
The COVID-19 pandemic is an unprecedented healthcare emergency causing mortality and illness across the world. Although primarily affecting the lungs, the SARS-CoV-2 virus also affects the cardiovascular system. In addition to cardiac effects, e.g. myocarditis, arrhythmias, and myocardial damage, the vasculature is affected in COVID-19, both directly by the SARS-CoV-2 virus, and indirectly as a result of a systemic inflammatory cytokine storm. This includes the role of the vascular endothelium in the recruitment of inflammatory leucocytes where they contribute to tissue damage and cytokine release, which are key drivers of acute respiratory distress syndrome (ARDS), in disseminated intravascular coagulation, and cardiovascular complications in COVID-19. There is also evidence linking endothelial cells (ECs) to SARS-CoV-2 infection including: (i) the expression and function of its receptor angiotensin-converting enzyme 2 (ACE2) in the vasculature; (ii) the prevalence of a Kawasaki disease-like syndrome (vasculitis) in COVID-19; and (iii) evidence of EC infection with SARS-CoV-2 in patients with fatal COVID-19. Here, the Working Group on Atherosclerosis and Vascular Biology together with the Council of Basic Cardiovascular Science of the European Society of Cardiology provide a Position Statement on the importance of the endothelium in the underlying pathophysiology behind the clinical presentation in COVID-19 and identify key questions for future research to address. We propose that endothelial biomarkers and tests of function (e.g. flow-mediated dilatation) should be evaluated for their usefulness in the risk stratification of COVID-19 patients. A better understanding of the effects of SARS-CoV-2 on endothelial biology in both the micro- and macrovasculature is required, and endothelial function testing should be considered in the follow-up of convalescent COVID-19 patients for early detection of long-term cardiovascular complications
Influence of high ambient temperature on reproductive performance and physiology of rabbit does in a commercial rabbitry in Greece
Αντικείμενο της παρούσας εργασίας υπήρξε η μελέτη των αναπαραγωγικών και φυσιολογικών παραμέτρων των κονικλομητέρων υπό τις φυσικές συνθήκες εκτροφής τους στηνΕλλάδα, κατά τη θερινή (Ιούλιος 2000-Οκτώβριος 2000 και Μάϊος 2001-Ιούνιος 2001) και χειμερινή (Νοέμβριος-Απρίλιος 2001) περίοδο (μέση θερμοκρασία θαλάμων εκτροφής 19,5°C και 12,4°C αντίστοιχα). Για τους σκοπούς της μελέτης χρησιμοποιήθηκαν 809 ενήλικα θηλυκά και 20 ενήλικα αρσενικά κουνέλια διασταυρωμένα Νέας Ζηλανδίας χ Καλιφόρνιας. Οι φυσιολογικές παράμετροι που μελετήθηκαν ήταν: το σύνολο των γεννηθέντων κονικλιδίων (ζωντανών,νεκρών, θνησιγενών) ανά κονικλομητέρα, το βάρος της το-κετοομάδας, το μέσο ατομικό βάρος γέννησης και ο αριθμός απογαλακτισθέντων και το ποσοστό θνησιμότητας των θηλαζόντων κονικλιδίων με βάση τον αριθμό των ζωντανών γεννηθέντων και των υιοθετημένων ανά τοκετοομάδα. Ελήφθη η θερμοκρασία απευθυσμένου και ο ρυθμός αναπνοών των κονικλομητέρων. Η δυσμενής επίδραση των υψηλών θερινών θερμοκρασιών ήταν σημαντική στο μέγεθος της τοκετοομάδας κατά τη γέννηση (7,38 συνολικά γεννηθέντα τη θερινή περίοδο έναντι 8,05 τη χειμερινή Ρ0,05, και 68g έναντι 65g το χειμώνα, Ρ>0,05, αντίστοιχα).(Στις κονικλομητέρες κατά τη θερινή περίοδο παρατηρήθηκε στατιστικά μη σημαντική αύξηση της θερμοκρασίας απευθυσμένου (39,09°C έναντι 38,93°C χο χειμώνα), καθώς και στατιστικά σημαντική αύξηση του αριθμού των αναπνοών/λεπτό (128,08 αναπνοές/λεπτό έναντι 115,37 αναπνοές/ λεπτό το χειμώνα, Ρ<0,001). Πέρα από την επίδραση της θερμοκρασίας του περιβάλλοντος μελετήθηκε τόσο η επίδραση του αριθμού τοκετών ανά κονικλομητέρα όσο και η ατομικότητα της κάθε κονικλομητέρας στις αναπαραγωγικές παραμέτρους. Σημαντική ήταν η επίδραση του αριθμού τοκετών ανά κονικλομητέρα στο σύνολο των γεννηθέντων κονικλιδίων, στα ζωντανά, νεκρά και απογαλακτισθέντα κονικλίδια, στο βάροςτης τοκετοομάδας κατά τη γέννηση, στο μέσο ατομικό βάρος γέννησης των κονικλιδίων και τέλος στον αριθμό αναπνοών/λεπτό των κονικλομητέρων. Συμπερασματικά διαπιστώθηκε η αρνητική επίδραση των υψηλών θερμοκρασιών του περιβάλλοντος στις αναπαραγωγικές και φυσιολογικές παραμέτρους των κονικλομητέρων.The reproductive performance and physiological traits of intensively raised does were evaluated under farm conditions in Greece, during the hot (average farm temperature 19.5°C) and cold period (average farm temperature 12.4°C). The size of litter at birth (6.94 vs. 7.84 alive pups, P<0.001), the size of litter at weaning (5.95 vs. 7.06, P<0.001), the pre-weaning mortality rate (16.94% vs. 9.60%, P<0.001, the number of born dead (0.39 vs. 0.19, P<0.001) and the number of stillborn (0,05 vs 0,02 P<0.01) were significantly affected during the hot period, while litter weight and individual weight at birth did not seem to differ between hot and cold period (461 g vs. 466 g (P<0.05) and 68 vs. 65 g (P<0.05), respectively). Rectal temperature of does and respiration rate were higher in the hot period (39.09°C vs. 38.93°C (NS) and 128.08 respirations/min vs. 115.37 respirations/min; P<0.001). The effects of parity order and animals were also studied revealing that parity order influenced significantly total born, born alive, stillborn and weaned rabbits, litter weight and individual weight at birth, as well as the does' respiration rate. The interaction between parity and period was not significant for any of the recorded parameters. In conclusion, high ambient temperature impaired does' reproductive and physiological traits under those conditions, similar to most natural environmental conditions in Greece
Mechanical Activation of Hypoxia-Inducible Factor 1α Drives Endothelial Dysfunction at Atheroprone Sites
OBJECTIVE: Atherosclerosis develops near branches and bends of arteries that are exposed to low shear stress (mechanical drag). These sites are characterized by excessive endothelial cell (EC) proliferation and inflammation that promote lesion initiation. The transcription factor HIF1α (hypoxia-inducible factor 1α) is canonically activated by hypoxia and has a role in plaque neovascularization. We studied the influence of shear stress on HIF1α activation and the contribution of this noncanonical pathway to lesion initiation. APPROACH AND RESULTS: Quantitative polymerase chain reaction and en face staining revealed that HIF1α was expressed preferentially at low shear stress regions of porcine and murine arteries. Low shear stress induced HIF1α in cultured EC in the presence of atmospheric oxygen. The mechanism involves the transcription factor nuclear factor-κB that induced HIF1α transcripts and induction of the deubiquitinating enzyme Cezanne that stabilized HIF1α protein. Gene silencing revealed that HIF1α enhanced proliferation and inflammatory activation in EC exposed to low shear stress via induction of glycolysis enzymes. We validated this observation by imposing low shear stress in murine carotid arteries (partial ligation) that upregulated the expression of HIF1α, glycolysis enzymes, and inflammatory genes and enhanced EC proliferation. EC-specific genetic deletion of HIF1α in hypercholesterolemic apolipoprotein E-defecient mice reduced inflammation and endothelial proliferation in partially ligated arteries, indicating that HIF1α drives inflammation and vascular dysfunction at low shear stress regions. CONCLUSIONS: Mechanical low shear stress activates HIF1α at atheroprone regions of arteries via nuclear factor-κB and Cezanne. HIF1α promotes atherosclerosis initiation at these sites by inducing excessive EC proliferation and inflammation via the induction of glycolysis enzymes
Transforming growth factor-β-induced CUX1 isoforms are associated with fibrosis in systemic sclerosis lung fibroblasts
In the enhancer region of the human type I collagen alpha 2 (COL1A2) gene, we identified cis-elements for the transcription factor CUX1. However, the role of CUX1 in fibrosis remains unclear. Here we investigated the role of CUX1 in the regulation of COL1 expression and delineated the mechanisms underlying the regulation of COL1A2 expression by CUX1 in systemic sclerosis (SSc) lung fibroblasts. The binding of CUX1 to the COL1A2 enhancer region was assessed using electrophoretic mobility shift assays after treatment with transforming growth factor (TGF)-β. Subsequently, the protein expression levels of CUX1 isoforms were determined using Western blotting. Finally, the expression levels of COL1 and fibrosis-related cytokines, including CTGF, ET-1, Wnt1 and β-catenin were determined. The binding of CUX1 isoforms to the COL1A2 enhancer region increased after TGF-β treatment. TGF-β also increased the protein levels of the CUX1 isoforms p200, p150, p110, p75, p30 and p28. Moreover, SSc lung fibroblasts showed higher levels of CUX1 isoforms than normal lung fibroblasts, and treatment of SSc lung fibroblasts with a cathepsin L inhibitor (IW-CHO) decreased COL1 protein expression and reduced cell size, as measured using immunocytochemistry. In SSc and diffuse alveolar damage lung tissue sections, CUX1 localised within α-smooth muscle actin-positive cells. Our results suggested that CUX1 isoforms play vital roles in connective tissue deposition during wound repair and fibrosis
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