A diastrophic dysplasia sulfate transporter (SLC26A2) mutant mouse: morphological and biochemical characterization of the resulting chondrodysplasia phenotype.

Mutations in the diastrophic dysplasia sulfate transporter (DTDST or SLC26A2) cause a family of recessively inherited chondrodysplasias including, in order of decreasing severity, achondrogenesis 1B, atelosteogenesis 2, diastrophic dysplasia (DTD) and recessive multiple epiphyseal dysplasia. The gene encodes a widely distributed sulfate/chloride antiporter of the cell membrane whose function is crucial for the uptake of inorganic sulfate, which is needed for proteoglycan sulfation. To provide new insights in the pathogenetic mechanisms leading to skeletal and connective tissue dysplasia and to obtain an in vivo model for therapeutic approaches to DTD, we generated a Dtdst knock-in mouse with a partial loss of function of the sulfate transporter. In addition, the intronic neomycine cassette in the mutant allele contributed to the hypomorphic phenotype by inducing abnormal splicing. Homozygous mutant mice were characterized by growth retardation, skeletal dysplasia and joint contractures, thereby recapitulating essential aspects of the DTD phenotype in man. The skeletal phenotype included reduced toluidine blue staining of cartilage, chondrocytes of irregular size, delay in the formation of the secondary ossification center and osteoporosis of long bones. Impaired sulfate uptake was demonstrated in chondrocytes, osteoblasts and fibroblasts. In spite of the generalized nature of the sulfate uptake defect, significant proteoglycan undersulfation was detected only in cartilage. Chondrocyte proliferation and apoptosis studies suggested that reduced proliferation and/or lack of terminal chondrocyte differentiation might contribute to reduced bone growth. The similarity with human DTD makes this mouse strain a useful model to explore pathogenetic and therapeutic aspects of DTDST-related disorders

Tumor-derived microRNAs induce myeloid suppressor cells and predict immunotherapy resistance in melanoma

The accrual of myeloid-derived suppressor cells (MDSCs) represents a major obstacle to effective immunotherapy in cancer patients, but the mechanisms underlying this process in the human setting remain elusive. Here, we describe a set of microRNAs (miR-146a, miR-155, miR-125b, miR-100, let-7e, miR-125a, miR-146b, miR-99b) that are associated with MDSCs and with resistance to treatment with immune checkpoint inhibitors in melanoma patients. The miRs were identified by transcriptional analyses as being responsible for the conversion of monocytes into MDSCs (CD14+HLA-DRneg cells) mediated by melanoma extracellular vesicles (EVs) and were shown to recreate MDSC features upon transfection. In melanoma patients, these miRs are increased in circulating CD14+ monocytes, plasma and tumor samples, where they correlate with the myeloid cell infiltrate. In plasma, their baseline level clusters with the clinical efficacy of CTLA-4 or PD-1 blockade. Hence, MDSC-related miRs represent an indicator of MDSC activity in cancer patients and a potential blood marker of a poor immunotherapy outcome

Increased classical endoplasmic reticulum stress is sufficient to reduce chondrocyte proliferation rate in the growth plate and decrease bone growth

Copyright: © 2015 Kung et al. Mutations in genes encoding cartilage oligomeric matrix protein and matrilin-3 cause a spectrum of chondrodysplasias called multiple epiphyseal dysplasia (MED) and pseudoachondroplasia (PSACH). The majority of these diseases feature classical endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) as a result of misfolding of the mutant protein. However, the importance and the pathological contribution of ER stress in the disease pathogenesis are unknown. The aim of this study was to investigate the generic role of ER stress and the UPR in the pathogenesis of these diseases. A transgenic mouse line (ColIITgcog) was generated using the collagen II promoter to drive expression of an ER stress-inducing protein (Tgcog) in chondrocytes. The skeletal and histological phenotypes of these ColIITgcog mice were characterised. The expression and intracellular retention of Tgcog induced ER stress and activated the UPR as characterised by increased BiP expression, phosphorylation of eIF2á and spliced Xbp1. ColIITgcog mice exhibited decreased long bone growth and decreased chondrocyte proliferation rate. However, there was no disruption of chondrocyte morphology or growth plate architecture and perturbations in apoptosis were not apparent. Our data demonstrate that the targeted induction of ER stress in chondrocytes was sufficient to reduce the rate of bone growth, a key clinical feature associated with MED and PSACH, in the absence of any growth plate dysplasia. This study establishes that classical ER stress is a pathogenic factor that contributes to the disease mechanism of MED and PSACH. However, not all the pathological features of MED and PSACH were recapitulated, suggesting that a combination of intra- and extra-cellular factors are likely to be responsible for the disease pathology as a whole

The Application of a Ship Synthesis Model (SSM) for the Trade-off Study of Offshore Patrol Vessel

In the naval ship design and acquisition process, especially at an early stage, is increasingly crucial the application of computational tools, able to tackle the main ship characteristics and their interactions for the assessment of different design solutions in a reasonable time. The most comprehensive use of such computational tools is, undeniably, the possible interface with a cost estimating module and a performance evaluator with the aim to better lead the concept exploration process. The Ship Synthesis Model (SSM) can be an useful computational tools/approach in this exploration process: it allows to select a subset of feasible ship configurations which satisfy the settled requirement, evidencing the balancing of different functions, often affected by conflicting constraints. In fact, beside design requirements (speed, endurance, crew members, payload\u2026), it permits to identify several design parameters (L,B, form coefficients, propulsion and diesel enerator plants,\u2026), together with their functional relations and functional constraints. Then different balances in terms of propulsion and electric power, weights, volumes and areas are worked out. In the proposed paper an SSM code is presented together with an application case, in terms of trade off analysis for an offshore patrol vessel design. The sensitivity analysis of the SSM tool has been performed in relation with different ship requirements

Resilience dynamic assessment based on precursor events: Application to ship lng bunkering operations

The focus of the present paper is the development of a resilience framework suitable to be applied in assessing the safety of ship LNG (Liquefied Natural Gas) bunkering process. Ship propulsion considering LNG as a possible fuel (with dual fuel marine engines installed on board) has favored important discussions about the LNG supply chain and delivery on board to the ship power plant. Within this context, a resilience methodological approach is outlined, including a case study application, to demonstrate its actual effectiveness. With specific reference to the operative steps for LNG bunkering operations in the maritime field, a dynamic model based on Bayesian inference and MCMC simulations can be built, involving the probability of operational perturbations, together with their updates based on the hard (failures) and soft (process variables deviations) evidence emerging during LNG bunkering operations. The approach developed in this work, based on advanced Markov Models and variational fitting algorithms, has proven to be a useful and flexible tool to study, analyze and verify how much the perturbations of systems and subsystems can be absorbed without leading to failure

Resilience assessment of bunkering operations for a lng fuelled ship

In the present paper, a methodological framework to move from risk assessment to resilience assessment is described. In order to demonstrate the practical capability of the outlined methodology reference is made to a LNG (Liquefied Natural Gas) bunker activity for a cruise ship. The focal point to assess the resilience of a system is the identification of precursor events, which refers to early detection of \u201cweak\u201d signals from the system during the operations. In order to identify the precursors, a large amount of data analytics is needed. By data processing, validation and analysis, it is possible to predict the behaviour of the system, thus catching the guide-words for a resilient performance. Starting from the operative steps of LNG bunker activity in the maritime field, various coupled Data Driven BNs can be built, which involve the probability of operational perturbations, and their updates based on the hard and soft evidences during the operation. Ship propulsion by LNG as a possible fuel (with dual fuel engines installed on board) implies to deepen safety issues that might be involved in the LNG bunkering operations. Not so many investigations are available in literature at present and the paper is aimed to frame the most significant critical aspects about this topic

Numerical Approaches for Submarine Hydrodynamic Design and Performance Analysis

Submarines bring many interesting hydrodynamic challenges that need to be properly addressed to provide precise and reliable information about their performance. Hydrodynamic performance must be evaluated at least in two main operating conditions, namely when it is deeply submerged and at snorkel depth. There are relevant differences in terms of hydrodynamic since the forward speed in the latter condition is typically much lower and of interaction with the free surface. Moreover, submarines used to sail at snorkel depth if they need to accomplish specific tasks, such as communication, that involves the use of surface piercing masts. The proposed study analyses the opportunity provided by different Computational Fluid Dynamic (CFD) approaches to correctly address submarine performance. The resistance in both conditions, masts free surface hydrodynamics and maneuvering behaviors are addressed. Ad-hoc approaches based on in-house developed numerical procedures and open-source software are presented. Different CFD techniques have been used, including Reynolds Averaged Navire Stokes (RANS), Detached Eddy Simulation (DES) and Smoothed Particle Hydrodynamics (SPH), according to the particular physics that need to be studied