90 research outputs found

    Disaster risk reduction and protracted violent conflict

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    While technical experts and donors profess an ambition to adapt conventional disaster risk reduction (DRR) approaches to conflict contexts, they struggle to overcome the long-held perception that this is not a viable option. Conflict can undermine national disaster risk governance and the implementation of DRR strategies, and conflict contexts are often considered too difficult an environment in which to deliver DRR. In such conditions, disaster risk management is likely to be a low government priority, with action limited to protection and response. Afghanistan presents a contrasting picture, where a national strategy has been formulated and includes explicit consideration of the conflict environment, and where some local DRR interventions are linking with conflict prevention ambitions. Afghanistan has been beset by numerous disasters in recent years, with a high toll of death and displacement. Thousands have been injured, killed or forced to flee their homes as a resu

    Renal cyst growth is attenuated by a combination treatment of tolvaptan and pioglitazone, while pioglitazone treatment alone is not effective

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    Autosomal Dominant Polycystic Kidney Disease (ADPKD) is one of the most common monogenic disorders, characterized by the progressive formation of fluid-filled cysts. Tolvaptan is an approved drug for ADPKD patients, but is also associated with multiple side effects. The peroxisome proliferator-activator receptor gamma (PPAR gamma) agonist pioglitazone slows disease progression in the PCK rat model for PKD. Here, we tested whether a combination treatment of relevant doses of tolvaptan and pioglitazone leads to improved efficacy in an adult-onset PKD mouse model. Tolvaptan indeed slowed PKD progression, but the combination treatment was not more effective than tolvaptan alone. In addition, although pioglitazone raised plasma levels of its surrogate drug marker adiponectin, the drug unexpectedly failed to slow PKD progression. The pioglitazone target PPAR. was expressed at surprisingly low levels in mouse, rat and human kidneys. Other pioglitazone targets were more abundantly expressed, but this pattern was comparable across various species. The data suggest that several potential pharmacokinetic and pharmacodynamic (PK/PD) differences between different species may underlie whether or not pioglitazone is able to slow PKD progression. The ongoing phase II clinical trial with low-dose pioglitazone treatment (NCT02697617) will show whether pioglitazone is a suitable drug candidate for ADPKD treatment.Functional Genomics of Systemic Disorder

    The positive effect of selective prostaglandin E2 receptor EP2 and EP4 blockade on cystogenesis in vitro is counteracted by increased kidney inflammation in vivo

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    Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a major cause of end-stage kidney disease in man. The central role of cyclic adenosine monophosphate (cAMP) in ADPKD pathogenesis has been confirmed by numerous studies including positive clinical trial data. Here, we investigated the potential role of another major regulator of renal cAMP, prostaglandin E2 (PGE2), in modifying disease progression in ADPKD models using selective receptor modulators to all four PGE2 receptor subtypes (EP1-4). In 3D-culture model systems utilizing dog (MDCK) and patient-derived (UCL93, OX161-C1) kidney cell lines, PGE2 strikingly promoted cystogenesis and inhibited tubulogenesis by stimulating proliferation while reducing apoptosis. The effect of PGE2 on tubulogenesis and cystogenesis in 3D-culture was mimicked or abolished by selective EP2 and EP4 agonists or antagonists but not those specific to EP1 or EP3. In a Pkd1 mouse model (Pkd1nl/nl), kidney PGE2 and COX-2 expression were increased by two-fold at the peak of disease (week four). However, Pkd1nl/nl mice treated with selective EP2 (PF-04418948) or EP4 (ONO-AE3-208) antagonists from birth for three weeks had more severe cystic disease and fibrosis associated with increased cell proliferation and macrophage infiltration. A similar effect was observed for the EP4 antagonist ONO-AE3-208 in a second Pkd1 model (Pax8rtTA-TetO-Cre-Pkd1f/f). Thus, despite the positive effects of slowing cyst growth in vitro, the more complex effects of inhibiting EP2 or EP4 in vivo resulted in a worse outcome, possibly related to unexpected pro-inflammatory effects

    Parallel microarray profiling identifies ErbB4 as a determinant of cyst growth in ADPKD and a prognostic biomarker for disease progression.

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    Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the fourth most common cause of end-stage renal disease. The disease course can be highly variable and treatment options are limited. To identify new therapeutic targets and prognostic biomarkers of disease, we conducted parallel discovery microarray profiling in normal and diseased human PKD1 cystic kidney cells. A total of 1515 genes and 5 miRNA were differentially expressed by more than two-fold in PKD1 cells. Functional enrichment analysis identified 30 dysregulated signalling pathways including the epidermal growth factor (EGF) receptor pathway. In this paper, we report that the EGF family receptor, ErbB4, is a major factor driving cyst growth in ADPKD. Expression of ErbB4 in vivo was increased in human ADPKD and Pkd1 cystic kidneys, both transcriptionally and post-transcriptionally by mir-193b-3p. Ligand-induced activation of ErbB4 drives cystic proliferation and expansion suggesting a pathogenic role in cystogenesis. Our results implicate ErbB4 activation as functionally relevant in ADPKD, both as a marker of disease activity and as a new therapeutic target in this major kidney disease

    Somatostatin in renal physiology and autosomal dominant polycystic kidney disease

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    Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive cyst formation, leading to growth in kidney volume and renal function decline. Although therapies have emerged, there is still an important unmet need for slowing the rate of disease progression in ADPKD. High intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) are involved in cell proliferation and fluid secretion, resulting in cyst formation. Somatostatin (SST), a hormone that is involved in many cell processes, has the ability to inhibit intracellular cAMP production. However, SST itself has limited therapeutic potential since it is rapidly eliminated in vivo. Therefore analogues have been synthesized, which have a longer half-life and may be promising agents in the treatment of ADPKD. This review provides an overview of the complex physiological effects of SST, in particular renal, and the potential therapeutic role of SST analogues in ADPKD.Nephrolog

    In vitro 3D phenotypic drug screen identifies celastrol as an effective in vivo inhibitor of polycystic kidney disease

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    Polycystic kidney disease (PKD) is a prevalent genetic disorder, characterized by the formation of kidney cysts that progressively lead to kidney failure. The currently available drug tolvaptan is not well tolerated by all patients and there remains a strong need for alternative treatments. The signaling rewiring in PKD that drives cyst formation is highly complex and not fully understood. As a consequence, the effects of drugs are sometimes difficult to predict. We previously established a high throughput microscopy phenotypic screening method for quantitative assessment of renal cyst growth. Here, we applied this 3D cyst growth phenotypic assay and screened 2320 small drug-like molecules, including approved drugs. We identified 81 active molecules that inhibit cyst growth. Multi-parametric phenotypic profiling of the effects on 3D cultured cysts discriminated molecules that showed preferred pharmacological effects above genuine toxicological properties. Celastrol, a triterpenoid from Tripterygium Wilfordii, was identified as a potent inhibitor of cyst growth in vitro. In an in vivo iKspCre-Pkd1lox,lox mouse model for PKD, celastrol inhibited the growth of renal cysts and maintained kidney function.Medicinal Chemistr

    Hepatic Cyst Infection During Use of the Somatostatin Analog Lanreotide in Autosomal Dominant Polycystic Kidney Disease: An Interim Analysis of the Randomized Open-Label Multicenter DIPAK-1 Study

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    Introduction and Aims: The DIPAK-1 Study investigates the reno- and hepatoprotective efficacy of the somatostatin analog lanreotide compared with standard care in patients with later stage autosomal dominant polycystic kidney disease (ADPKD). During this trial, we witnessed several episodes of hepatic cyst infection, all during lanreotide treatment. We describe these events and provide a review of the literature. Methods: The DIPAK-1 Study is an ongoing investigator-driven, randomized, controlled, open-label multicenter trial. Patients (ADPKD, ages 18–60 years, estimated glomerular filtration rate 30–60 mL/min/1.73 m2) were randomized 1:1 to receive lanreotide 120 mg subcutaneously every 28 days or standard care during 120 weeks. Hepatic cyst infection was diagnosed by local physicians. Results: We included 309 ADPKD patients of which seven (median age 53 years [interquartile range: 48–55], 71% female, median estimated glomerular filtration rate 42 mL/min/1.73 m2 [interquartile range: 41–58]) developed eight episodes of hepatic cyst infection during 342 patient-years of lanreotide use (0.23 cases per 10 patient-years). These events were limited to patients receiving lanreotide (p < 0.001 vs. standard care). Baseline characteristics were similar between subjects who did or did not develop a hepatic cyst infection during lanreotide use, except for a history of hepatic cyst infection (29 vs. 0.7%, p < 0.001). Previous studies with somatostatin analogs reported cyst infections, but did not identify a causal relationship. Conclusions: These data suggest an increased risk for hepatic cyst infection during use of somatostatin analogs, especially in ADPKD patients with a history of hepatic cyst infection. The main results are still awaited to fully appreciate the risk–benefit ratio. ClinicalTrials.gov identifier: NCT 01616927

    CREBBP mutations in individuals without Rubinstein-Taybi syndrome phenotype

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    Item does not contain fulltextMutations in CREBBP cause Rubinstein-Taybi syndrome. By using exome sequencing, and by using Sanger in one patient, CREBBP mutations were detected in 11 patients who did not, or only in a very limited manner, resemble Rubinstein-Taybi syndrome. The combined facial signs typical for Rubinstein-Taybi syndrome were absent, none had broad thumbs, and three had only somewhat broad halluces. All had apparent developmental delay (being the reason for molecular analysis); five had short stature and seven had microcephaly. The facial characteristics were variable; main characteristics were short palpebral fissures, telecanthi, depressed nasal ridge, short nose, anteverted nares, short columella, and long philtrum. Six patients had autistic behavior, and two had self-injurious behavior. Other symptoms were recurrent upper airway infections (n = 5), feeding problems (n = 7) and impaired hearing (n = 7). Major malformations occurred infrequently. All patients had a de novo missense mutation in the last part of exon 30 or beginning of exon 31 of CREBBP, between base pairs 5,128 and 5,614 (codons 1,710 and 1,872). No missense or truncating mutations in this region have been described to be associated with the classical Rubinstein-Taybi syndrome phenotype. No functional studies have (yet) been performed, but we hypothesize that the mutations disturb protein-protein interactions by altering zinc finger function. We conclude that patients with missense mutations in this specific CREBBP region show a phenotype that differs substantially from that in patients with Rubinstein-Taybi syndrome, and may prove to constitute one (or more) separate entities. (c) 2016 Wiley Periodicals, Inc

    Molecular pathways involved in injury-repair and ADPKD progression

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    The major hallmark of Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the formation of many fluid-filled cysts in the kidneys, which ultimately impairs the normal renal structure and function, leading to end-stage renal disease (ESRD). A large body of evidence suggests that injury-repair mechanisms are part of ADPKD progression. Once cysts have been formed, proliferation and fluid secretion contribute to the cyst size increase, which eventually causes stress on the surrounding tissue resulting in local injury and fibrosis. In addition, renal injury can cause or accelerate cyst formation.In this review, we will describe the various mechanisms activated during renal injury and tissue repair and show how they largely overlap with the molecular mechanisms activated during PKD progression. In particular, we will discuss molecular mechanisms such as proliferation, inflammation, cell differentiation, cytokines and growth factors secretion, which are activated following the renal injury to allow the remodelling of the tissue and a proper organ repair. We will also underline how, in a context of PKD-related gene mutations, aberrant or chronic activation of these developmental pathways and repair/remodelling mechanisms results in exacerbation of the disease.Functional Genomics of Systemic Disorder
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