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Lamin A/C (LMNA) is one of the most frequently mutated genes associated with dilated cardiomyopathy (DCM). DCM related to mutations in LMNA is a common inherited cardiomyopathy that is associated with systolic dysfunction and cardiac arrhythmias. Here we modelled the LMNA-related DCM in vitro using patient-specific induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). Electrophysiological studies showed that the mutant iPSC-CMs displayed aberrant calcium homeostasis that led to arrhythmias at the single-cell level. Mechanistically, we show that the platelet-derived growth factor (PDGF) signalling pathway is activated in mutant iPSC-CMs compared to isogenic control iPSC-CMs. Conversely, pharmacological and molecular inhibition of the PDGF signalling pathway ameliorated the arrhythmic phenotypes of mutant iPSC-CMs in vitro. Taken together, our findings suggest that the activation of the PDGF pathway contributes to the pathogenesis of LMNA-related DCM and point to PDGF receptor-β (PDGFRB) as a potential therapeutic target.

This study demonstrates that significantly shortened telomeres are a hallmark of cardiomyocytes (CMs) from individuals with end-stage hypertrophic cardiomyopathy (HCM) or dilated cardiomyopathy (DCM) as a result of heritable defects in cardiac proteins critical to contractile function. Positioned at the ends of chromosomes, telomeres are DNA repeats that serve as protective caps that shorten with each cell division, a marker of aging. CMs are a known exception in which telomeres remain relatively stable throughout life in healthy individuals. We found that, relative to healthy controls, telomeres are significantly shorter in CMs of genetic HCM and DCM patient tissues harboring pathogenic mutations: TNNI3, MYBPC3, MYH7, DMD, TNNT2, and TTN Quantitative FISH (Q-FISH) of single cells revealed that telomeres were significantly reduced by 26% in HCM and 40% in DCM patient CMs in fixed tissue sections compared with CMs from age- and sex-matched healthy controls. In the cardiac tissues of the same patients, telomere shortening was not evident in vascular smooth muscle cells that do not express or require the contractile proteins, an important control. Telomere shortening was recapitulated in DCM and HCM CMs differentiated from patient-derived human-induced pluripotent stem cells (hiPSCs) measured by two independent assays. This study reveals telomere shortening as a hallmark of genetic HCM and DCM and demonstrates that this shortening can be modeled in vitro by using the hiPSC platform, enabling drug discovery.

Data suggest that clinical applications of human induced pluripotent stem cells (hiPSCs) will be realized. Nonetheless, clinical applications will require hiPSCs that are free of exogenous DNA and that can be manufactured through Good Manufacturing Practice (GMP). Optimally, derivation of hiPSCs should be rapid and efficient in order to minimize manipulations, reduce potential for accumulation of mutations and minimize financial costs. Previous studies reported the use of modified synthetic mRNAs to reprogram fibroblasts to a pluripotent state. Here, we provide an optimized, fully chemically defined and feeder-free protocol for the derivation of hiPSCs using synthetic mRNAs. The protocol results in derivation of fully reprogrammed hiPSC lines from adult dermal fibroblasts in less than two weeks. The hiPSC lines were successfully tested for their identity, purity, stability and safety at a GMP facility and cryopreserved. To our knowledge, as a proof of principle, these are the first integration-free iPSCs lines that were reproducibly generated through synthetic mRNA reprogramming that could be putatively used for clinical purposes.

The current paper aim is to present the technique of demand data modelling for microscopic simulation of the traffic flows. Traffic microscopic simulation is a powerful decision supporting tool, which could be applied for a wide range of tasks. In a past microscopic traffic simulation was used to test local changes in transport infrastructure, but the growth of computers performance allows now to simulate wide-scale fragments of the traffic network and to apply more advanced traffic flow simulation approaches, like an example dynamic assignment (DA). The results, obtained in the frame of this research are part of the project completed for one of the shopping malls (Riga, Latvia). The goal of the project was to evaluate different development scenarios of the transport network to raise the accessibility of the shopping mall. The number of practical issues in the frame of this project pushed to develop a new technique to model the demand data for the simulation model. As a traffic flow simulation tool, the PTV VISSIM simulation software was applied. The developed model was based on dynamic assignment approach. To complete the simulation the demand data was represented in two forms: 1) OD matrix for regular traffic in the transport network; 2) trip-chain file for a description of the pass-by and targeted trips.

The salient scope of this paper is to enable the knowledge and understanding of urban freight transportation and provide guidance for implementing sustainable policies and measures in a city. To achieve this goal, an evaluation framework for city logistics policies and measures is developed, which demonstrates the complexity of urban freight transportation systems, through selected performance indicators, taking into account divergent stakeholders’ interests, conflicting business models and operations. Evaluation follows a hierarchical process; sustainability disciplines (economy and energy, environment, transportation and mobility, society), applicability enablers (policy and measure maturity, social acceptance and users’ uptake), multiple criteria and indicators, capturing the lifecycle impact of policies and measures and multiple stakeholders. Apart from the multicriteria context, the framework embeds methodologies, including, Impact Assessment, Social Cost Benefit Analysis, Transferability and Adaptability, and Risk Analysis. To demonstrate its applicability a case study is set for the City of Graz assessing the establishment of an Urban Consolidation Center. Results show that there is an overall improvement of 2.2% in the Logistics Sustainability Index when comparing before and after implementation cases of the Urban Consolidation Center.