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

Lessons from microRNA biology: top key cellular drivers of autosomal dominant polycystic kidney disease

Background: Numerous microRNAs (miRs), small RNAs targeting several pathways, have been implicated in the development of Autosomal Dominant Polycystic Kidney Disease (ADPKD), which is the most common genetic cause of Chronic Kidney Disease. The hallmark of ADPKD is tissue overgrowth and hyperproliferation, eventually leading to kidney failure. Scope of the review: Many miRs are dysregulated in disease, yet the intracellular pathways regulated by these are less well described in ADPKD. Here, I summarise all the differentially expressed miRs and highlight the top miR-regulated cellular driver of ADPKD. Major conclusions: Literature review has identified 35 abnormally expressed miRs in ADPKD. By performing bioinformatics analysis of their target genes I present 10 key intracellular pathways that drive ADPKD progression. The top key drivers are divided into three main areas: (i) hyperproliferation and the role of JAK/STAT and PI3K pathways (ii) DNA damage and (iii) inflammation and NFκB. General significance: The description of the 10 top cellular drivers of ADPKD, derived by analysis of miR signatures, is of paramount importance in better understanding the key processes resulting in pathophysiological changes that underlie disease

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

Connective tissue growth factor is a new ligand of epidermal growth factor receptor

Chronic kidney disease is reaching epidemic proportions worldwide and there is no effective treatment. Connective tissue growth factor (CCN2) has been suggested as a risk biomarker and a potential therapeutic target for renal diseases, but its specific receptor has not been identified. Epidermal growth factor receptor (EGFR) participates in kidney damage, but whether CCN2 activates the EGFR pathway is unknown. Here, we show that CCN2 is a novel EGFR ligand. CCN2 binding to EGFR extracellular domain was demonstrated by surface plasmon resonance. CCN2 contains four distinct structural modules. The carboxyl-terminal module (CCN2(IV)) showed a clear interaction with soluble EGFR, suggesting that EGFR-binding site is located in this module. Injection of CCN2(IV) in mice increased EGFR phosphorylation in the kidney, mainly in tubular epithelial cells. EGFR kinase inhibition decreased CCN2(IV)-induced renal changes (ERK activation and inflammation). Studies in cultured tubular epithelial cells showed that CCN2(IV) binds to EGFR leading to ERK activation and proinflammatory factors overexpression. CCN2 interacts with the neurotrophin receptor TrkA, and EGFR/TrkA receptor crosstalk was found in response to CCN2(IV) stimulation. Moreover, endogenous CCN2 blockade inhibited TGF-β-induced EGFR activation. These findings indicate that CCN2 is a novel EGFR ligand that contributes to renal damage through EGFR signalling. © 2013 The Author

Case of unilateral hypoplasia and atresia of the right uterine horn of a gilt

Περιγράφεται περίπτωση ετερόπλευρης υποπλασίας και ατρησίας κέρατος μήτρας νεαρής συός αναπαραγωγής, ηλικίας 19 μηνών. Στη συν εφαρμόσθηκε τεχνητή σπερματέγχυση στον τρίτο της οίστρο, η οποία υπήρξε ανεπιτυχής. Ακολούθησαν εννέα συνολικά τεχνητές σπερματεγχύσεις με το ίδιο αρνητικό αποτέλεσμα. Η συς οδηγήθηκε τελικά στο σφαγείο όπου κατά τη νεκροψία βρέθηκε ότι το δεξιό κέρας εμφάνιζε ατρησία στο όριο του με το σώμα της μήτρας και το μήκος του ήταν σχεδόν το ήμισυ του μήκους του αριστερού (110 cm vs. 190 cm). Αμφότερα τα κέρατα έφεραν διάχυτες και περιγεγραμμένες κύστεις. Το υποπλαστικό κέρας περιείχε 150 ml υγρού. Ιστολογικά το ενδομήτριο ήταν ανενεργό και παρουσίαζε σε μεγάλη έκταση θηλώδη διαμόρφωση. Πιστεύεται ότι η παραγωγή PGF2a από το υποπλαστικό και με ατρησία κέρας διέκοπτε την εγκυμοσύνη του φυσιολογικού κέρατος.A case of unilateral hypoplasia and atresia of the uterus horn was described in 19 months old gilt. After repeated returns and 9, in total, unsuccessful artificial inseminations, during and after the third oestrus, the gilt was slaughtered and the right horn of the uterus was found to be "blind" at the level of its borders with the uterus body. It contained 150ml of fluid and was about half the length of the left horn (110cm vs. 190cm). Diffused and welloutlined cysts were observed in both horns of the uterus. Histological examination revealed in the endometrium, edema with abundant loose cellular stroma that surrounded numerous hypoplastic glands and hyperaemic blood vessels with thick walls. It is suggested that the production of PGF2a by the hypoplastic and "blind" horn of the uterus interrupted the pregnancy in the left horn

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

Neuroendocrine and neurophysiological effects of interleukin 6 in rheumatoid arthritis

RA is a chronic, systemic, autoimmune disease characterized by inflammation and degradation of the joints, causing significant negative impact on quality of life. In addition to joint disease, symptoms and co-morbidities associated with RA—namely pain, fatigue and mood disorders—are often as debilitating as the disease itself. The pro-inflammatory cytokine IL-6 plays a critical role in RA-associated pathology. However, a greater understanding of the translational effects of IL-6 outside of the immune system is needed. This review discusses our current understanding of emerging aspects of IL-6 in RA-associated pain, fatigue and mood disorders such as depression and anxiety. This review also describes the clinical effects of IL-6 inhibition on these symptoms and co-morbidities in patients with RA

ANKHD1 promotes pathogenic proliferation in Autosomal Dominant Polycystic Kidney Disease via the Cyclin D1/CDK4 pathway

Background Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common genetic cause of renal failure. Uncontrolled proliferation drives ADPKD, which manifests with cystic kidney enlargement. Yet, the mechanisms by which renal epithelial cells lose cell cycle control are largely unknown. To investigate this, we examined the expression and function of the Ankyrin Repeat and single KH Domain 1 (ANKHD1), which positively regulates proliferation in cancer, yet its role in ADPKD is unexplored. Results We report elevated proliferation (Ki67 and Cyclin D1) in three independent mouse models of ADPKD, the Pkd1nl/nl, the Pax8-cre; Pkd1del/del and the KSP-cre; Pkd1del/del. We find that ANKHD1 protein localises in cyst lining cells of both aquaporin-1 and 2 (AQP1-AQP2) positive cysts. ANKHD1 knockdown in human cells or knockout in mouse tissues resulted in reduced proliferation, slower cystic growth in vitro and smaller kidneys in vivo; ultimately leading to improved renal function. Mechanistically, ANKHD1 binds to CDK4 and positively controls the Cyclin D1/CDK4 pathway. ANKHD1-mediated enhancement of Cyclin D1/CDK4 activity leads to increased retinoblastoma phosphorylation and proliferation, a mechanism that is p19-dependent but p21 independent. Conclusions We report a functional role for ANKHD1 in driving pathogenic proliferation in ADPKD via the Cyclin D1/CDK4 axis

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