Tipifarnib prevents development of hypoxia-induced pulmonary hypertension

Aims. RhoB plays a key role in the pathogenesis of hypoxia - induced pulmonary hypertension. Farne sylated RhoB promotes growth responses in cancer cells and we investigated whether inhibition of protein farnesylation will have a protective effect. Methods and Results. The analysis of l ung tissues from rodent models and pulmonary hypertensive patients showed increased levels of protein farnesylation. Oral farnesyltransferase inhibitor tipifarnib prevented development of hypoxia - induced pulmonary hypertension in mice. Tipifarnib reduced hypoxia - induced vascular cell proliferation, increased endothelium - dependent vasodilatation and reduced vasoconstriction of intrapulmonary arteries without affecting cell viability. Protective effects of tipifarnib were associated with inhibition of Ras and RhoB, actin depolymerisation and increased eNOS expression in vi tro and in vivo . Farnesylated - only RhoB (F - RhoB) increased proliferative responses in cultured pulmonary vascular cells, mimicking the effects of hypoxia, while both geranylgeranylated - only RhoB (GG - RhoB) and tipifarnib had an inhibitory effect. Label - fre e proteomics linked F - RhoB with cell survival, activation of cell cycle and mitochondrial biogenesis. Hypoxia increased and tipifarnib reduced the levels of F - RhoB - regulated proteins in the lung, reinforcing the importance of RhoB as a signalling mediator. Unlike simvastatin, tipifarnib did not increase the expression levels of Rho proteins. Conclusions. Our study demonstrates the importance of protein farnesylation in pulmonary vascular remodeling and provides a rationale for selective targeting of this pa thway in pulmonary hypertension

SOX17 Enhancer Variants Disrupt Transcription Factor Binding And Enhancer Inactivity Drives Pulmonary Hypertension

BACKGROUND: Pulmonary arterial hypertension (PAH) is a rare disease characterized by remodeling of the pulmonary arteries, increased vascular resistance, and right-sided heart failure. Genome-wide association studies of idiopathic/heritable PAH established novel genetic risk variants, including conserved enhancers upstream of transcription factor (TF) SOX17 containing 2 independent signals. SOX17 is an important TF in embryonic development and in the homeostasis of pulmonary artery endothelial cells (hPAEC) in the adult. Rare pathogenic mutations in SOX17 cause heritable PAH. We hypothesized that PAH risk alleles in an enhancer region impair TF-binding upstream of SOX17, which in turn reduces SOX17 expression and contributes to disturbed endothelial cell function and PAH development. METHODS: CRISPR manipulation and siRNA were used to modulate SOX17 expression. Electromobility shift assays were used to confirm in silico–predicted TF differential binding to the SOX17 variants. Functional assays in hPAECs were used to establish the biological consequences of SOX17 loss. In silico analysis with the connectivity map was used to predict compounds that rescue disturbed SOX17 signaling. Mice with deletion of the SOX17 signal 1 enhancer region (SOX17-4593/enhKO) were phenotyped in response to chronic hypoxia and SU5416/hypoxia. RESULTS: CRISPR inhibition of SOX17-signal 2 and deletion of SOX17signal 1 specifically decreased SOX17 expression. Electromobility shift assays demonstrated differential binding of hPAEC nuclear proteins to the risk and nonrisk alleles from both SOX17 signals. Candidate TFs HOXA5 and ROR-α were identified through in silico analysis and antibody electromobility shift assays. Analysis of the hPAEC transcriptomes revealed alteration of PAH-relevant pathways on SOX17 silencing, including extracellular matrix regulation. SOX17 silencing in hPAECs resulted in increased apoptosis, proliferation, and disturbance of barrier function. With the use of the connectivity map, compounds were identified that reversed the SOX17-dysfunction transcriptomic signatures in hPAECs. SOX17 enhancer knockout in mice reduced lung SOX17 expression, resulting in more severe pulmonary vascular leak and hypoxia or SU5416/hypoxia-induced pulmonary hypertension. CONCLUSIONS: Common PAH risk variants upstream of the SOX17 promoter reduce endothelial SOX17 expression, at least in part, through differential binding of HOXA5 and ROR-α. Reduced SOX17 expression results in disturbed hPAEC function and PAH. Existing drug compounds can reverse the disturbed SOX17 pulmonary endothelial transcriptomic signature

An international working group consensus report for the prioritization of molecular biomarkers for Ewing sarcoma

The advent of dose intensified interval compressed therapy has improved event-free survival for patients with localized Ewing sarcoma (EwS) to 78% at 5 years. However, nearly a quarter of patients with localized tumors and 60-80% of patients with metastatic tumors suffer relapse and die of disease. In addition, those who survive are often left with debilitating late effects. Clinical features aside from stage have proven inadequate to meaningfully classify patients for risk-stratified therapy. Therefore, there is a critical need to develop approaches to risk stratify patients with EwS based on molecular features. Over the past decade, new technology has enabled the study of multiple molecular biomarkers in EwS. Preliminary evidence requiring validation supports copy number changes, and loss of function mutations in tumor suppressor genes as biomarkers of outcome in EwS. Initial studies of circulating tumor DNA demonstrated that diagnostic ctDNA burden and ctDNA clearance during induction are also associated with outcome. In addition, fusion partner should be a pre-requisite for enrollment on EwS clinical trials, and the fusion type and structure require further study to determine prognostic impact. These emerging biomarkers represent a new horizon in our understanding of disease risk and will enable future efforts to develop risk-adapted treatment

LSST Science Book, Version 2.0

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo

LSST: from Science Drivers to Reference Design and Anticipated Data Products

(Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg$^2$ field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5$\sigma$ point-source depth in a single visit in $r$ will be $\sim 24.5$ (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg$^2$ with $\delta<+34.5^\circ$, and will be imaged multiple times in six bands, $ugrizy$, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg$^2$ region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to $r\sim27.5$. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

Consensus classification of posterior cortical atrophy

INTRODUCTION: A classification framework for posterior cortical atrophy (PCA) is proposed to improve the uniformity of definition of the syndrome in a variety of research settings. METHODS: Consensus statements about PCA were developed through a detailed literature review, the formation of an international multidisciplinary working party which convened on four occasions, and a Web-based quantitative survey regarding symptom frequency and the conceptualization of PCA. RESULTS: A three-level classification framework for PCA is described comprising both syndrome- and disease-level descriptions. Classification level 1 (PCA) defines the core clinical, cognitive, and neuroimaging features and exclusion criteria of the clinico-radiological syndrome. Classification level 2 (PCA-pure, PCA-plus) establishes whether, in addition to the core PCA syndrome, the core features of any other neurodegenerative syndromes are present. Classification level 3 (PCA attributable to AD [PCA-AD], Lewy body disease [PCA-LBD], corticobasal degeneration [PCA-CBD], prion disease [PCA-prion]) provides a more formal determination of the underlying cause of the PCA syndrome, based on available pathophysiological biomarker evidence. The issue of additional syndrome-level descriptors is discussed in relation to the challenges of defining stages of syndrome severity and characterizing phenotypic heterogeneity within the PCA spectrum. DISCUSSION: There was strong agreement regarding the definition of the core clinico-radiological syndrome, meaning that the current consensus statement should be regarded as a refinement, development, and extension of previous single-center PCA criteria rather than any wholesale alteration or redescription of the syndrome. The framework and terminology may facilitate the interpretation of research data across studies, be applicable across a broad range of research scenarios (e.g., behavioral interventions, pharmacological trials), and provide a foundation for future collaborative work

Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.

Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis

The Clinical Variability of Maternally Inherited Diabetes and Deafness Is Associated with the Degree of Heteroplasmy in Blood Leukocytes

Context: Maternally inherited diabetes and deafness (MIDD) is a rare form of diabetes with a matrilineal transmission, sensorineural hearing loss, and macular pattern dystrophy due to an A to G transition at position 3243 of mitochondrial DNA (mtDNA) (m.3243A&gt;G). The phenotypic heterogeneity of MIDD may be the consequence of different levels of mutated mtDNA among mitochondria in a given tissue. Objective: The aim of the present study was thus to ascertain the correlation between the severity of the phenotype in patients with MIDD and the level of heteroplasmy in the blood leukocytes. Participants: The GEDIAM prospective multicenter register was initiated in 1995. Eighty-nine Europid patients from this register, with MIDD and the mtDNA 3243A&gt;G mutation, were included. Patients with MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) or with mitochondrial diabetes related to other mutations or to deletions of mtDNA were excluded. Results: A significant negative correlation was found between levels of heteroplasmy and age of the patients at the time of sampling for molecular analysis, age at the diagnosis of diabetes, and body mass index. After adjustment for age at sampling for molecular study and gender, the correlation between heteroplasmy levels and age at the diagnosis of diabetes was no more significant. The two other correlations remained significant. A significant positive correlation between levels of heteroplasmy and HbA1c was also found and remained significant after adjustment for age at molecular sampling and gender. Conclusions: These results support the hypothesis that heteroplasmy levels are at least one of the determinants of the severity of the phenotype in MIDD. Heteroplasmy levels are at least one of the determinants of the severity of the phenotype of maternally inherited diabetes and deafness

Immune Responses Elicited in Tertiary Lymphoid Tissues Display Distinctive Features

During chronic inflammation, immune effectors progressively organize themselves into a functional tertiary lymphoid tissue (TLT) within the targeted organ. TLT has been observed in a wide range of chronic inflammatory conditions but its pathophysiological significance remains unknown. We used the rat aortic interposition model in which a TLT has been evidenced in the adventitia of chronically rejected allografts one month after transplantation. The immune responses elicited in adventitial TLT and those taking place in spleen and draining lymph nodes (LN) were compared in terms of antibody production, T cell activation and repertoire perturbations. The anti-MHC humoral response was more intense and more diverse in TLT. This difference was associated with an increased percentage of activated CD4+ T cells and a symmetric reduction of regulatory T cell subsets. Moreover, TCR repertoire perturbations in TLT were not only increased and different from the common pattern observed in spleen and LN but also “stochastic,” since each recipient displayed a specific pattern. We propose that the abnormal activation of CD4+ T cells promotes the development of an exaggerated pathogenic immune humoral response in TLT. Preliminary findings suggest that this phenomenon i) is due to a defective immune regulation in this non-professional inflammatory-induced lymphoid tissue, and ii) also occurs in human chronically rejected grafts