Inflammatory Responses and Barrier Function of Endothelial Cells Derived from Human Induced Pluripotent Stem Cells

Several studies have reported endothelial cell (EC) derivation from human induced pluripotent stem cells (hiPSCs). However, few have explored their functional properties in depth with respect to line-to-line and batch-to-batch variability and how they relate to primary ECs. We therefore carried out accurate characterization of hiPSC-derived ECs (hiPSC-ECs) from multiple (non-integrating) hiPSC lines and compared them with primary ECs in various functional assays, which included barrier function using real-time impedance spectroscopy with an integrated assay of electric wound healing, endothelia-leukocyte interaction under physiological flow to mimic inflammation and angiogenic responses in in vitro and in vivo assays. Overall, we found many similarities but also some important differences between hiPSC-derived and primary ECs. Assessment of vasculogenic responses in vivo showed little difference between primary ECs and hiPSC-ECs with regard to functional blood vessel formation, which may be important in future regenerative medicine applications requiring vascularization. In this article, Orlova and colleagues show that hiPSC-ECs have similar features to primary ECs but also show some differences. hiPSC-ECs exhibited higher barrier function, lower expression of pro-inflammatory adhesive receptors, and more stringent stromal cell requirements. Importantly, healthy control CD31+ hiPSC-ECs showed high consistency between different batches and lines, forming a good basis for disease modeling applications

Junctional adhesion molecule-C regulates vascular endothelial permeability by modulating VE-cadherin–mediated cell–cell contacts

We recently reported that junctional adhesion molecule (JAM)-C plays a role in leukocyte transendothelial migration. Here, the role of JAM-C in vascular permeability was investigated in vitro and in vivo. As opposed to macrovascular endothelial cells that constitutively expressed JAM-C in cell–cell contacts, in quiescent microvascular endothelial cells, JAM-C localized mainly intracellularly, and was recruited to junctions upon short-term stimulation with vascular endothelial growth factor (VEGF) or histamine. Strikingly, disruption of JAM-C function decreased basal permeability and prevented the VEGF- and histamine-induced increases in human dermal microvascular endothelial cell permeability in vitro and skin permeability in mice. Permeability increases are essential in angiogenesis, and JAM-C blockade reduced hyperpermeability and neovascularization in hypoxia-induced retinal angiogenesis in mice. The underlying mechanisms of the JAM-C–mediated increase in endothelial permeability were studied. JAM-C was essential for the regulation of endothelial actomyosin, as revealed by decreased F-actin, reduced myosin light chain phosphorylation, and actin stress fiber formation due to JAM-C knockdown. Moreover, the loss of JAM-C expression resulted in stabilization of VE-cadherin–mediated interendothelial adhesion in a manner dependent on the small GTPase Rap1. Together, through modulation of endothelial contractility and VE-cadherin–mediated adhesion, JAM-C helps to regulate vascular permeability and pathologic angiogenesis

Magnetic proximity-induced energy gap of topological surface states

Topological crystalline insulator surface states can acquire an energy gap when time reversal symmetry is broken by interfacing with a magnetic insulator. Such hybrid topological-magnetic insulator structures can be used to generate novel anomalous Hall effects and to control the magnetic state of the insulator in a spintronic device. In this work, the energy gap of topological surface states in proximity with a magnetic insulator is measured using Landau level spectroscopy. The measurements are carried out on Pb1-xSnxSe/EuSe heterostructures grown by molecular beam epitaxy exhibiting record mobility and a low Fermi energy enabling this measurement. We find an energy gap that does not exceed 20meV and we show that is due to the combined effect of quantum confinement and magnetic proximity. The presence of magnetism at the interface is confirmed by magnetometry and neutron reflectivity. The recovered energy gap sets an upper limit for the Fermi level needed to observe the quantized anomalous Hall effect using magnetic proximity heterostructures

Discovery of a high-temperature antiferromagnetic state and transport signatures of exchange interactions in a Bi2Se3/EuSe heterostructure

Spatial confinement of electronic topological surface states (TSS) in topological insulators poses a formidable challenge because TSS are protected by time-reversal symmetry. In previous works formation of a gap in the electronic spectrum of TSS has been successfully demonstrated in topological insulator/magnetic material heterostructures, where ferromagnetic exchange interactions locally lifts the time-reversal symmetry. Here we report an experimental evidence of exchange interaction between a topological insulator Bi2Se3 and a magnetic insulator EuSe. Spin-polarized neutron reflectometry reveals a reduction of the in-plane magnetic susceptibility within a 2 nm interfacial layer of EuSe, and the combination of SQUID magnetometry and Hall measurements points to the formation of an antiferromagnetic layer with at least five-fold enhancement of N\'eel's temperature. Abrupt resistance changes in high magnetic fields indicate interfacial exchange coupling that affects transport in a TSS. High temperature local control of TSS with zero net magnetization unlocks new opportunities for the design of electronic, spintronic and quantum computation devices, ranging from quantization of Hall conductance in zero fields to spatial localization of non-Abelian excitations in superconducting topological qubits

Human induced pluripotent stem cell-derived endothelial cells in thrombosis-on-a-chip devices

A microfluidic thrombosis-on-a-chip platform was developed to compare the pro-thrombotic response of healthy and inflamed monolayers of human umbilical vein endothelial cells (HUVECs) and human induced pluripotent stem cell-derived endothelial cells (hiPSC-ECs). Inflammation was induced by exposing the endothelial cells (ECs) to an inflammatory cytokine Tumor Necrosis Factor-α (TNF-α). After human whole blood perfusion at an arterial shear rate, the platelet coverage and average clot size were determined. Healthy endothelium showed a lower platelet coverage than inflamed endothelium. A minor difference was measured for both platelet coverage and average clot sizes on inflamed HUVECs versus hiPSC-ECs

ОСОБЕННОСТИ ОБРАЗОВАТЕЛЬНОГО ПРОЦЕССА В СОВРЕМЕННОМ ВЫСШЕМ ОБРАЗОВАНИИ

Background. The article presents the results of a study of the educational process in modern higher education, which is due to the problems of improving the quality and effectiveness of Russian education, which the last two decades have been discussing at all levels: from the cabinet to the townsfolk. However, concrete solutions have not yet been worked out, which testifies not so much to the insolubility of these problems as to the lack of a unified methodological platform that would serve as a basis at all levels of Russian higher education.Research methods: the heuristic technology “Cater” was used in the research process, which implies an open-ended question “What problems do you most often encounter in the learning process?”Research results: as a result of the study, problems that are conditionally divided into groups are identified and investigated: organizational, technical, the learning process, the personality of the student, the personality of the teacher. Discussion: analysis and grouping of problems made it possible to highlight the features of the educational process in modern higher education.Conclusion: a local analysis of the features of the educational process allows us to conclude that it is necessary to study the turbulence of the information environment and to clarify the features of its influence on the effectiveness of student learning, as well as the goal-setting of educational activities in close connection with the identified problems.Состояние вопроса: в статье представлены результаты исследования образовательного процесса в современном высшем образовании, что обусловлено проблемами повышения качества и результативности российского образования, которые последние два десятилетия обсуждают на всех уровнях: от кабинета министров до обывателей. Однако конкретных решений до сих пор не выработано, что свидетельствует не столько о неразрешимости этих проблем, сколько об отсутствии единой методологической платформы, которая бы выступила базисом на всех уровнях российского высшего образования.Методы исследования: в процессе исследования была применена эвристическая технология «Катер», которая подразумевает постановку открытого вопроса «С какими проблемами Вы чаще всего сталкиваетесь в процессе обучения?»Результаты исследования: в результате исследования выделены и исследованы проблемы, которые условно разделены на группы: организационные, технические, процесс обучения, личность обучающегося, личность преподавателя.Обсуждение: анализ и группировка проблем позволила выделить особенности образовательного процесса в современном высшем образовании.Заключение: проведенный локальный анализ особенностей образовательного процесса позволяет заключить о необходимости исследования турбулентности информационной среды и уточнения особенностей ее влияния на результативность обучения студентов, а также проведения целеполагания образовательной деятельности в тесной взаимосвязи с выявленными проблемами

STAT3/LKB1 controls metastatic prostate cancer by regulating mTORC1/CREB pathway

Prostate cancer (PCa) is a common and fatal type of cancer in men. Metastatic PCa (mPCa) is a major factor contributing to its lethality, although the mechanisms remain poorly understood. PTEN is one of the most frequently deleted genes in mPCa. Here we show a frequent genomic co-deletion of PTEN and STAT3 in liquid biopsies of patients with mPCa. Loss of Stat3 in a Pten-null mouse prostate model leads to a reduction of LKB1/pAMPK with simultaneous activation of mTOR/CREB, resulting in metastatic disease. However, constitutive activation of Stat3 led to high LKB1/pAMPK levels and suppressed mTORC1/CREB pathway, preventing mPCa development. Metformin, one of the most widely prescribed therapeutics against type 2 diabetes, inhibits mTORC1 in liver and requires LKB1 to mediate glucose homeostasis. We find that metformin treatment of STAT3/AR-expressing PCa xenografts resulted in significantly reduced tumor growth accompanied by diminished mTORC1/CREB, AR and PSA levels. PCa xenografts with deletion of STAT3/AR nearly completely abrogated mTORC1/CREB inhibition mediated by metformin. Moreover, metformin treatment of PCa patients with high Gleason grade and type 2 diabetes resulted in undetectable mTORC1 levels and upregulated STAT3 expression. Furthermore, PCa patients with high CREB expression have worse clinical outcomes and a significantly increased risk of PCa relapse and metastatic recurrence. In summary, we have shown that STAT3 controls mPCa via LKB1/pAMPK/mTORC1/CREB signaling, which we have identified as a promising novel downstream target for the treatment of lethal mPCa

Generation of 3 human induced pluripotent stem cell lines LUMCi005-A, B and C from a Hereditary Cerebral Hemorrhage with Amyloidosis-Dutch type patient

Hereditary Cerebral Hemorrhage with Amyloidosis-Dutch type (HCHWA-D) is an autosomal dominant hereditary disease caused by a point mutation in exon 17 of the APP gene. We generated human induced pluripotent stem cells (hiPSCs) from a symptomatic HCHWA-D patient by using non-integrating Sendai virus (SeV). The newly generated hiPSCs express all pluripotency markers, have a normal karyotype, carry the Dutch mutation, can differentiate in the three germ layers in vitro and are SeV free