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Alterations in KRAS have been identified as the most recurring somatic variants in the multiple myeloma (MM) mutational landscape. Combining DNA and RNA sequencing, we studied 756 patients and observed KRAS as the most frequently mutated gene in patients at diagnosis; in addition, we demonstrated the persistence or de novo occurrence of the KRAS aberration at disease relapse. Small-molecule inhibitors targeting KRAS have been developed; however, they are selective for tumors carrying the KRASG12C mutation. Therefore, there is still a need to develop novel therapeutic approaches to target the KRAS mutational events found in other tumor types, including MM. We used AZD4785, a potent and selective antisense oligonucleotide that selectively targets and downregulates all KRAS isoforms, as a tool to dissect the functional sequelae secondary to KRAS silencing in MM within the context of the bone marrow niche and demonstrated its ability to significantly silence KRAS, leading to inhibition of MM tumor growth, both in vitro and in vivo, and confirming KRAS as a driver and therapeutic target in MM.

Prompt diagnosis of complex phenotypes is a challenging task in clinical genetics. Whole exome sequencing has proved to be effective in solving such conditions. Here, we report on an unpredictable presentation of Werner Syndrome (WRNS) in a 12-year-old girl carrying a homozygous truncating variant in RECQL2, the gene mutated in WRNS, and a de novo activating missense change in PTPN11, the major Noonan syndrome gene, encoding SHP2, a protein tyrosine phosphatase positively controlling RAS function and MAPK signaling, which have tightly been associated with senescence in primary cells. All the major WRNS clinical criteria were present with an extreme precocious onset and were associated with mild intellectual disability, severe growth retardation and facial dysmorphism. Compared to primary fibroblasts from adult subjects with WRNS, proband's fibroblasts showed a dramatically reduced proliferation rate and competence, and a more accelerated senescence, in line with the anticipated WRNS features occurring in the child. In vitro functional characterization of the SHP2 mutant documented its hyperactive behavior and a significantly enhanced activation of the MAPK pathway. Based on the functional interaction of WRN and MAPK signaling in processes relevant to replicative senescence, these findings disclose a unique phenotype likely resulting from negative genetic interaction.

The aim of this work was to retrospectively evaluate the influence of pimobendan on the survival time (ST) of dogs with myxomatous mitral valve disease at different stages using an Inverse Probability Weighting (IPW) analysis. An IPW method was used to minimize confounding and IPW weighted time-repeated logistic model was used to approximate survival curves (SCs) and calculate survival differences. Subjects were allocated into exposed (E) and unexposed (U). Dogs in the American College of Veterinary Internal Medicine (ACVIM) B2 class treated with pimobendan (± ACE-inhibitors) were selected for the E group, as well as symptomatic patients (ACVIM class C) treated with triple (furosemide, ACE-inhibitor, pimobendan) or quadruple (furosemide, ACE-inhibitor, pimobendan and spironolactone) therapy. The U group included ACVIM class B2 dogs not treated with any medication and ACVIM C dogs treated with a combination of furosemide and ACE-inhibitor/spironolactone without pimobendan. The survival curve (SC) of the E group crossed the U group at 1634 days. The difference between the two SCs at the time of maximum survival difference in favor of the U group was 11.3% (CI 1.7%-20.9%) (significant), in favor of the E group was 3.9% (CI -8.6%-16.4%) (not significant) and at the mean ST was 3.6% (CI -8.5%-15.7%) (not significant) in favor of the E group. For times greater than 1634 days the survival was in favor of the E group, but there were no statistically significant differences in survival in favor of the E group in this clinical population.

Maintenance of genome stability is crucial for cell survival and relies on accurate DNA replication. However, replication fork progression is under constant attack from different exogenous and endogenous factors that can give rise to replication stress, a source of genomic instability and a notable hallmark of pre-cancerous and cancerous cells. Notably, one of the major natural threats for DNA replication is transcription. Encounters or conflicts between replication and transcription are unavoidable, as they compete for the same DNA template, so that collisions occur quite frequently. The main harmful transcription-associated structures are R-loops. These are DNA structures consisting of a DNA–RNA hybrid and a displaced single-stranded DNA, which play important physiological roles. However, if their homeostasis is altered, they become a potent source of replication stress and genome instability giving rise to several human diseases, including cancer. To combat the deleterious consequences of pathological R-loop persistence, cells have evolved multiple mechanisms, and an ever growing number of replication fork protection factors have been implicated in preventing/removing these harmful structures; however, many others are perhaps still unknown. In this review, we report the current knowledge on how aberrant R-loops affect genome integrity and how they are handled, and we discuss our recent findings on the role played by two fork protection factors, the Werner syndrome protein (WRN) and the Werner helicase-interacting protein 1 (WRNIP1) in response to R-loop-induced genome instability.

The aim of this work was to retrospectively evaluate the influence of different therapeutic protocols (loop diuretics, ACE-inhibitors, spironolactone +/- pimobendan) on the survival time (ST) of dogs with myxomatous mitral valve disease at different stages using an Inverse Probability Weighting (IPW) analysis. An IPW method was used to minimize confounding and IPW weighted time-repeated logistic model was used to approximate survival curves (SCs) and calculate survival differences. Subjects were allocated into cases (CA) and controls (CO). Dogs in American College of Veterinary Internal Medicine (ACVIM) B2 class treated with pimobendan (+/- ACE-inhibitors) were selected for the CA group, as well as symptomatic patients (ACVIM class C) threated with triple (furosemide, ACE-inhibitor, pimobendan) or quadruple (furosemide, ACE-inhibitor, pimobendan and spironolactone) therapy. The CO group included ACVIM class B2 dogs not treated with any medication and ACVIM C dogs treated with a combination of furosemide and ACE-inhibitor/spironolactone without pimobendan.The SC of the CA group crossed the CO group at 1634 days. The difference between the two SCs at the time of maximum survival difference in favour of the CO group was 11.3% (CI 1.7%–20.9%) (significant), in favour of the CA group was 3.9% (CI -8.6%–16.4%) (not significant) and at the mean ST was 3.6% (CI -8.5%–15.7%) (not significant) in favour of the CA group. For times greater than 1634 days the survival was in favour of the CA group, there were no statistically significant differences in survival in favour of the CA group in this clinical population.

Werner syndrome (WS) is a cancer-prone disease caused by deficiency of Werner protein (WRN). WRN maintains genome integrity by promoting replication-fork stability after various forms of replication stress. Under mild replication stress, WS cells show impaired ATR-mediated CHK1 activation. However, it remains unclear if WS cells elicit other repair pathway. We demonstrate that loss of WRN leads to enhanced ATM phosphorylation upon prolonged exposure to aphidicolin, a specific inhibitor of DNA polymerases, resulting in CHK1 activation. Moreover, we find that loss of WRN sensitises cells to replication-transcription collisions and promotes accumulation of R-loops, which undergo XPG-dependent cleavage responsible for ATM signalling activation. Importantly, we observe that ATM pathway limits chromosomal instability in WS cells. Finally, we prove that, in WS cells, genomic instability enhanced upon chemical inhibition of ATM kinase activity is counteracted by direct or indirect suppression of R-loop formation or by XPG abrogation. Together, these findings suggest a potential role of WRN as regulator of R-loop-associated genomic instability, strengthening the notion that conflicts between replication and transcription can affect DNA replication, leading to human disease and cancer.

Local authorities’ efforts facing the climate challenge have been supported and endorsed by the European Commission since 2008 through the Covenant of Mayors initiative (CoM). Signatories voluntarily commit to planning and implementing sustainable energy and climate policies in their territories and reporting on their progresses. The initiative has evolved and, since 2015, the mitigation target has been increased to a reduction of 40% of CO2 by 2030 and the adaptation pillar has been integrated. Two key features characterize the composition of signatories to the CoM: population lower than 50,000 inhabitants (90%) and geographic location in Mediterranean countries regions (72%). This paper focuses on both the mitigation and adaptation pillars of the initiative and it analyses the most energy intensive sectors as well as the main hazards and vulnerabilities identified by signatories in the Mediterranean region. The data provided to the CoM by signatories belonging to the Mediterranean region is the basis of this study, whose results may contribute to increase the understanding of the strategies of cities in the region.

This data article relates to and complement the research paper: "Assessment of climate change mitigation policies in 315 cities in the Covenant of Mayors initiative" [1] . The reported data has been collected and elaborated within the framework of the Covenant of Mayors (CoM) initiative. The dataset is extracted from the overall database of the initiative reported through the platform MyCovenant. The data deals with the Monitoring Emission Inventories submitted by local authorities by 2016. Data has been processed and elaborated to highlights specific features of signatories and the policies they have adopted in the development of their Sustainable Energy Action Plans (SEAP). Available data relates to the mitigation policies in the SEAPs and includes their carbon reduction potential, the status of implementation and the class of governance. The CoM gathers together thousands of local authorities who voluntary committed to decarbonisation and increase resilience in their territory. Therefore, this data can be of interest for local policy makers and urban planners to identify successful examples in cities with comparable contexts and to identify possible measures in several sectors for climate change mitigation.

The Paris Agreement goals require net‐zero CO2 emissions by mid‐century. The European Commission in its recent proposal for climate and energy strategy for 2050 indicated the need for more intensified actions to substantially improve the energy performances of buildings. With the rate of new construction in Europe, the challenge is to increase both the pace and depth of building energy renovations. Several barriers inhibit the wide uptake of comprehensive energy renovations, including the inability or inertia to finance upfront costs of energy renovations. Despite various policies implemented to address some of these barriers, current investments in buildings remain at suboptimal levels. The paper reviews current financing practices for energy renovations and investigates some innovative instruments with a special focus on their applicability to residential buildings. In addition to “traditional” financial schemes such as subsidies, tax incentives, and loans, the paper assesses innovative financing schemes: On property tax and on‐bill financing, energy efficiency mortgages, and energy efficiency feed‐in tariffs. The paper also investigates the concept of one‐stop shops for building renovations and crowdfunding. The paper offers an assessment of the characteristics, benefits, and challenges of each analyzed financing instrument and provides policy recommendations for their successful implementation. In general, as financing instruments involve different stakeholders and due to complex nature of the sector, there is no single solution to accelerate energy renovation investment in buildings. The emerging financial models offer the potential to address the long‐standing barriers to investment in energy efficiency.

Energy demand and production of neighbourhoods are central issues in the development of integrated spatial-energy strategies in the framework of recent European Policies. This study provides a comprehensive tool that combines spatial and energy issues with optimization methods to support urban planners in the decision-making process for urban energy strategies. By adopting an integrated approach, optimized urban energy scenarios aimed at reducing CO2 emissions are developed and results are shown in spatial-energy maps. Through the application of the proposed method, current urban energy demand is determined and potential local production of electrical energy due to the introduction of renewable energy systems is assessed. The insertion of renewable energy systems allows configuring a network of energy exchanges where buildings are considered able to share energy through physical connections. The optimization of energy exchanges among buildings is carried out by using a model based on complex networks and is represented in maps, developed in GIS, allowing the integration between energy evaluations and spatial planning. As case study, the method has been applied to a neighbourhood of the municipality of Catania in Southern Italy.

Conflicts between replication and transcription are common source of genome instability and many factors participate in prevention or removal of harmful R-loops. Here, we demonstrate that a WRNIP1-mediated response plays an important role in counteracting accumulation of aberrant R-loops. Using human cellular models with compromised ATR-dependent checkpoint activation, we show that WRNIP1 is stabilised in chromatin and is needed for maintaining genome integrity by mediating the ATM-dependent phosphorylation of CHK1. Furthermore, we show that loss of WRN or ATR signalling leads to accumulation of R-loop-dependent parental ssDNA, which is covered by RAD51. We demonstrate that WRNIP1 chromatin retention is also required to stabilise the association of RAD51 with ssDNA in proximity of R-loops. Therefore, in these pathological contexts, ATM inhibition or WRNIP1 abrogation is accompanied by increased levels of genomic instability. Overall our findings reveal a novel function of WRNIP1 in preventing R-loop-driven genome instability, providing new clues to understand the way replication-transcription conflicts are resolved.

Climate change mitigation in urban areas requires a portfolio of policies and practices that are implemented across a range of scales and sectors. The local scale allows the development and implementation of site specific strategies to address climate change in urban areas that have been proven to be more efficient, especially within buildings. But these must be within the wider context of transport and other energy consumption. A unique integrated assessment methodology for the analysis of energy at the neighbourhood scale that considers the key sectors of buildings, transport and outdoor lighting has been developed. The influence of key drivers of energy consumption: land use, technology, infrastructure design, are considered to assess how neighbourhood choices impact upon wider energy usage, such as transport emissions. Applied to a neighbourhood in Italy, results show that building retrofit has the greatest benefit, of up to 60%. However, by transitioning to a mixed land use neighbourhood, growing local employment and improving the transit network, reductions of 80% can be achieved in line with the requirements of the Paris Agreement. The method highlights the importance of taking a multi-sector and multi-scale approach to considering neighbourhood mitigation.

Non-urbanized areas (NUAs) play an important role in reducing the effects of climate change by providing both carbon storage and sequestration. Urban areas are responsible for the emission of 60% o...

The Schimke immuno-osseous dysplasia is an autosomal recessive genetic osteochondrodysplasia characterized by dysmorphism, spondyloepiphyseal dysplasia, nephrotic syndrome and frequently T cell immunodeficiency. Several hypotheses have been proposed to explain pathophysiology of the disease, however, the mechanism by which SMARCAL1 mutations cause the syndrome is elusive. Indeed, animal models of the disease are absent or useless to provide insight into the disease mechanism, since they do not recapitulate the phenotype. We generated a conditional knockdown model of SMARCAL1 in iPSCs to mimic conditions of cells with severe form the disease. Here, we characterize this model for the presence of phenotype linked to the replication caretaker role of SMARCAL1 using multiple cellular endpoints. Our data show that conditional knockdown of SMARCAL1 in human iPSCs induces replication-dependent and chronic accumulation of DNA damage triggering the DNA damage response. Furthermore, they indicate that accumulation of DNA damage and activation of the DNA damage response correlates with increased levels of R-loops and replication-transcription interference. Finally, we provide data showing that, in SMARCAL1-deficient iPSCs, DNA damage response can be maintained active also after differentiation, possibly contributing to the observed altered expression of a subset of germ layer-specific master genes. In conclusion, our conditional SMARCAL1 iPSCs may represent a powerful model where studying pathogenetic mechanisms of severe Schimke immuno-osseous dysplasia, thus overcoming the reported inability of different model systems to recapitulate the disease.

Schimke immuno-osseous dysplasia is an autosomal recessive genetic osteochondrodysplasia characterized by dysmorphism, spondyloepiphyseal dysplasia, nephrotic syndrome and frequently T cell immunodeficiency. Several hypotheses have been proposed to explain the pathophysiology of the disease; however, the mechanism by which SMARCAL1 mutations cause the syndrome is elusive. Here, we generated a conditional SMARCAL1 knockdown model in induced pluripotent stem cells (iPSCs) to mimic conditions associated with the severe form the disease. Using multiple cellular endpoints, we characterized this model for the presence of phenotypes linked to the replication caretaker role of SMARCAL1. Our data show that conditional knockdown of SMARCAL1 in human iPSCs induces replication-dependent and chronic accumulation of DNA damage triggering the DNA damage response. Furthermore, they indicate that accumulation of DNA damage and activation of the DNA damage response correlates with increased levels of R-loops and replication-transcription interference. Finally, we provide evidence that SMARCAL1-deficient iPSCs maintain active DNA damage response beyond differentiation, possibly contributing to the observed altered expression of a subset of germ layer-specific master genes. Confirming the relevance of SMARCAL1 loss for the observed phenotypes, they are prevented or rescued after re-expression of wild-type SMARCAL1 in our iPSC model. In conclusion, our conditional SMARCAL1 knockdown model in iPSCs may represent a powerful model when studying pathogenetic mechanisms of severe Schimke immuno-osseous dysplasia., Summary: This study reports the generation of an iPSC model to investigate phenotypic changes associated with loss of SMARCAL1, as found in severe forms of the genetic disease Schimke immuno-osseous dysplasia.

The frequency and intensity of extreme climate events are increasing all around the world, due to climate change. Climate adaptation strategies are therefore needed, since mitigation strategies alone are not sufficient to avoid serious impacts of climate change. However, adaptation to climate change is not straightforward, as it is highly influenced by diverse and conflicting interests as well as epistemological (or scientific) uncertainties. Therefore, a minimum requirement for its success is the active participation of stakeholders and citizens in the adaptation policy cycle. This paper presents a case study on a participatory process involving civil servants from different municipalities in Malaysia, in Southeast Asia, with a view to considering the optimal level of engagement that is required for climate adaptation planning. The exercise consisted of a Focus Group session, where participants were asked to discuss the level of stakeholder and citizen participation that should be adopted within the Global Covenant of Mayors for Climate and Energy initiative. Contrary to authors' expectations, the participants tended to suggest medium to high levels of participation in the planning process. During the dialogues, a walking activity through the city, aimed at identifying hotspots of climate risks and defined as “safety walks”, was one of the ideas proposed as a high-potential participatory method, spreading in the adaptation framework. Safety walks could complement climate modelling and enhance the robustness of climate risk assessments., Highlights • A focus group session on stakeholders participation in adaptation planning • Medium-high levels of participation in the planning process were suggested. • Technical expertise from local community is needed • "Safety walks" suggested as a high-potential stakeholder-involving participatory technique • Site-specific challenging issues were addressed through active discussion and best practices

The Paris agreement recognises the key role of local authorities in reaching the 1,5 °C target. The Covenant of Mayors (CoM) has been an unprecedented phenomenon in the arena of transnational initiatives in climate action at local level. The initiative has expanded tremendously over the past 10 years, covering more than 9 600 local authorities and 327 million inhabitants as of June 2019. This study analyses policies and measures adopted and implemented by local authorities, signatories to the CoM, as reported in their Monitoring Emission Inventories (MEI). More than 12 000 policies reported in 315 MEIs have been assessed. The policies adopted in municipalities across Europe have been classified according to two criteria: (1) the type of policy tool and (2) the field of action. The aggregated policies have then be correlated with the grouping of signatories according to three "contextual" drivers. The contextual drivers allow identifying the factors that may influence the distribution of climate and energy policies and successful examples and methodologies that may be replicated in other cities with comparable characteristics and similar contexts. Overall, results show that the most common policies cover municipal assets and structures. The policies adopted by local governments do change with the population and, therefore, the focus on municipal assets changes with the increase of population, while local authorities’ Gross Domestic Products and climatic conditions have limited influence on the selection and distribution of policies in the framework of this study.

Conflicts between replication and transcription are a common source of genomic instability, a characteristic of almost all human cancers. Aberrant R-loops can cause a block to replication fork progression. A growing number of factors are involved in the resolution of these harmful structures and many perhaps are still unknown. Here, we reveal that the Werner interacting protein 1 (WRNIP1)-mediated response is implicated in counteracting aberrant R-loop accumulation. Using human cellular models with compromised Ataxia-Telangiectasia and Rad3-Related (ATR)-dependent checkpoint activation, we show that WRNIP1 is stabilized in chromatin and is needed for maintaining genome integrity by mediating the Ataxia Telangiectasia Mutated (ATM)-dependent phosphorylation of Checkpoint kinase 1 (CHK1). Furthermore, we demonstrated that loss of Werner Syndrome protein (WRN) or ATR signaling leads to formation of R-loop-dependent parental ssDNA upon mild replication stress, which is covered by Radiorestistance protein 51 (RAD51). We prove that Werner helicase-interacting protein 1 (WRNIP1) chromatin retention is also required to stabilize the association of RAD51 with ssDNA in proximity of R-loops. Therefore, in these pathological contexts, ATM inhibition or WRNIP1 abrogation is accompanied by increased levels of genomic instability. Overall, our findings suggest a novel function for WRNIP1 in preventing R-loop-driven genome instability, providing new clues to understand the way replication&ndash, transcription conflicts are handled.

Regulation of end-processing is critical for accurate repair and to switch between homologous recombination (HR) and non-homologous end joining (NHEJ). End resection is a two-stage process but very little is known about regulation of the long-range resection, especially in humans. WRN participates in one of the two alternative long-range resection pathways mediated by DNA2 or EXO1. Here we demonstrate that phosphorylation of WRN by CDK1 is essential to perform DNA2-dependent end resection at replication-related DSBs, promoting HR, replication recovery and chromosome stability. Mechanistically, S1133 phosphorylation of WRN is dispensable for relocalization in foci but is involved in the interaction with the MRE11 complex. Loss of WRN phosphorylation negatively affects MRE11 foci formation and acts in a dominant negative manner to prevent long-range resection altogether, thereby licensing NHEJ at collapsed forks. Collectively, we unveil a CDK1-dependent regulation of the WRN-DNA2-mediated resection and identify an undescribed function of WRN as a DSB repair pathway switch., End-resection of double strand DNA breaks is essential for pathway choice between non-homologous end-joining and homologous recombination. Here the authors show that phosphorylation of WRN helicase by CDK1 is essential for resection at replication-related breaks.

This study proposes the application of a model for the evaluation of the overall energy demand of existing urban neighborhoods, which can be useful when planning energy enhancement strategies at urban scale. The application of this model can be interconnected with the use of a GIS software tool, thus providing the opportunity to perform the energy mapping of city neighborhoods. In the proposed model, the overall energy demand of existing urban neighborhoods is evaluated by considering the three most energy intensive sectors: buildings, transport and urban lighting. However, in this paper the application of the model is only focused on the assessment of the energy demand in the building sector. The proposed methodology is applied to a neighborhood of the municipality of Catania in Southern Italy. The preliminary results are reported in this study: first, the existing energy consumption for space heating and electric appliances is assessed, then the effectiveness of a series of energy-saving strategies is considered, thus providing a tool to implement effective energy planning policies at urban scale.

Energy consumption of urban areas is a relevant theme for sustainable spatial planning. Through the integration of energy and urban planning issues, it can be identified a suitable strategy to face climate change. This study aims to evaluate overall energy demand of existing urban neighbourhoods, considering the most energy intensive sectors within a city. Using GIS software, the method provides energy mapping of neighbourhoods, allowing to improve the insight of energy demand of cities and to develop a preliminary assessment for future scenarios. The method has been applied to a neighbourhood of the municipality of Catania in southern Italy. Methodology and earliest results are discussed in this paper.

Cities are responsible for the 70% of the world's energy demand and represent the largest source of GHG emissions. The constant growth of cities encourages towards the configuration of urban energy plans in order to make urban areas more sustainable places. In this direction, Decentralized Energy Systems (DES) play an important role in order to improve the efficiency in urban energy consumptions. However, the decentralization of urban energy systems requires a comprehensive evaluation of the energy interactions that can occur among consumers. To this aim, proper mathematical models need to be defined in order to take into account how those interactions occur. In this paper, a mathematical procedure based on the complex network theory is introduced and tested to a neighborhood within the city of Catania.

To retrospectively compare and contrast the clinical presentation, diagnostic findings and survival in Boxer dogs with cardiomyopathy, with or without left ventricular (LV) systolic failure.Medical records of Boxers referred between 1993 and 2008 in which a diagnosis of ventricular arrhythmias and/or cardiomyopathy was made, were reviewed. Dogs were divided into two groups according to their left ventricular (LV) systolic diameter, group A normal (20 dogs) or group B dilated (59 dogs).Dogs in group A had a better outcome than dogs in group B (median survival time of 124 and 17 weeks respectively, p 0.001). In group B, dogs with a history of collapse had a worse outcome (median survival time of 10 weeks) compared with dogs not showing collapse (median survival time 24 weeks) (p = 0.031).The majority of dogs, in this UK study, presented with the myocardial dysfunction form of the disease, with LV dilation and congestive heart failure signs. The prognosis was worse in dogs with LV dilation compared to dogs with a normal LV and ventricular arrhythmias. In the Boxers with LV dilation, dogs with collapse had a worse prognosis than those without.

In this work we investigated which mitral valve leaflet was most often involved in mitral valve prolapse with degenerative mitral valve disease and whether there was an association with breed, age, gender, or weight. Five hundred and thirty-seven dogs with mitral valve prolapse-degenerative mitral valve disease were assessed; the cross-breed dog was the most represented breed (248 dogs, 46.2%). Mitral valve prolapse was more common in male dogs, and the average age was 11.3 +/- 2.8 years. Prolapse of the anterior leaflet was present in 48.4% of dogs, prolapse of the the posterior leaflet in 7.1%, and bileaflet prolapse was present in 44.5%; this distribution is different than that typically found in humans. There was a significant correlation between severity of mitral regurgitation and severity of mitral valve prolapse or ISACHC class, and between severity of mitral valve prolapse and ISACHC class. There was no relationship between the particular affected leaflet(s) and severity of mitral regurgitation, severity of mitral valve prolapse, or ISACHC class. Our findings suggest that the susceptibility to the mitral valve prolapse-degenerative mitral valve disease is not confined to a specific breeds and that the specific leaflet prolapsing is different in dogs compared with humans.

The WRN helicase/exonuclease protein is required for proper replication fork recovery and maintenance of genome stability. However, whether the different catalytic activities of WRN cooperate to recover replication forks in vivo is unknown. Here, we show that, in response to replication perturbation induced by low doses of the TOP1 inhibitor camptothecin, loss of the WRN exonuclease resulted in enhanced degradation and ssDNA formation at nascent strands by the combined action of MRE11 and EXO1, as opposed to the limited processing of nascent strands performed by DNA2 in wild-type cells. Nascent strand degradation by MRE11/EXO1 took place downstream of RAD51 and affected the ability to resume replication, which correlated with slow replication rates in WRN exonuclease-deficient cells. In contrast, loss of the WRN helicase reduced exonucleolytic processing at nascent strands and led to severe genome instability. Our findings identify a novel role of the WRN exonuclease at perturbed forks, thus providing the first in vivo evidence for a distinct action of the two WRN enzymatic activities upon fork stalling and providing insights into the pathological mechanisms underlying the processing of perturbed forks.

The objective of this study was to determine the demographic, clinical and survival characteristics and to identify risk factors for mortality due to tricuspid valve dysplasia in UK dogs. Records of client-owned dogs diagnosed with tricuspid valve dysplasia at a referral centre were retrospectively reviewed. Only dogs diagnosed with tricuspid valve dysplasia based on the presence of a right-sided heart murmur identified prior to one year of age, and confirmed with Doppler echocardiography, were included. Dogs with concomitant cardiac diseases, pulmonary hypertension and/or trivial tricuspid regurgitation were excluded. Analysed data included signalment, reason for presentation, clinical signs, electrocardiographic and echocardiographic features, survival status and cause of death. Survival times and risk factors for mortality were evaluated using Kaplan-Meier curves and Cox regression. Eighteen dogs met inclusion criteria. Border collies were over-represented (p= 0.014). Dogs were most frequently referred for investigation of heart murmur. The most common arrhythmia was atrial fibrillation (n=3). Median survival time from diagnosis of tricuspid valve dysplasia was 2775 days (range 1-3696 days; 95% CI 1542.41-4007.59) and from onset of right-sided congestive heart failure was 181 days (range 1-2130 days; 95% CI 0-455.59). Syncope was the sole risk factor for cardiac death. In this population of UK dogs, tricuspid valve dysplasia was uncommon but, when severe, frequently led to right-sided congestive heart failure. Prognosis was favourable for mild and moderate tricuspid dysplasia. Survival time was reduced with right-sided congestive heart failure but varied widely. Risk of cardiac death was significantly increased if syncope had occurred.Keywords: Tricuspid valve dysplasia, Congestive heart failure, Atrial fibrillation, Survival time, Canine congenital heart disease.

Replication-dependent double-strand breaks (DSBs) are the main source of genomic instability as their inaccurate repair stimulates chromosomal rearrangements. In a recent work, we uncover a novel regulatory circuit that involves the Werner's syndrome helicase and CDK1, and that is essential for repair pathway choice at replication-dependent DSBs.

Objectives: To assess the influence of body surface area, age and gender on echocardiographic parameters and to establish echocardiographic reference values for dogue de Bordeaux dogs. Methods: Thirty-nine healthy dogue de Bordeaux dogs of both sexes, older than one year, were recruited and 31 of these were included in the study. The classic linear regression model proved to be the best way to analyse the data. The reference limits of the echocardiographic measurements were calculated using the regression equations. The difference between the mean values of body surface area in both gender groups was evaluated by using one-way ANOVA. Results: A significant correlation was seen between several echocardiographic parameters and body surface area or body surface area and age, and high coefficients of determination (R2) were found. No effect of gender was detected on echocardiographic variables, except for the thickness of the left ventricular posterior wall at end diastole. Clinical Significance: The echocardiographic parameters related to body surface area, in the absence of correlation with other independent variables (gender and age) should be interpreted with caution because their variation could be significant for the presence of heart disease. The proposed statistical model allows estimation of echocardiographic parameters in dogue de Bordeaux dogs with different body surface areas and ages.