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The deformation response of low Ti (<0.1%), MP35N alloy (35% Co-35% Ni-20% Cr-10% Mo, all in wt%) wire with a ~100µm diameter was assessed in monotonic and cyclic loading modes. The as-drawn wire exhibited a strong <111> fiber texture and consisted of a hierarchically twinned microstructure with twins spanning the micrometer to nanometer scale; when deformed in this condition in uniaxial tension at room temperature, high strengths up to 2GPa, limited tensile ductility of 3% and strain rate sensitivity in the quasi-static regime were noted. The deformed microstructure revealed evidence for slip, twinning and de-twinning, and in the necked region, in the vicinity where fracture had occurred, the fine twins appeared broken down into nanograins. The cyclic response of the as-drawn wire, evaluated using rotary beam bending (R=-1) and in tension-tension fatigue (R=0.3), appeared to be initiation-controlled and sensitive to the presence of extraneous second phase inclusions identified as Al=sub=2=/sub=O=sub=3=/sub= particles. Cyclically-deformed as=sub=-=/sub=drawn wire samples displayed extensive de-twinning and multiple twin variants formation. [ABSTRACT FROM AUTHOR]

The pancreatic islets are composed of discrete hormone-producing cells that orchestrate systemic glucose homeostasis. Here we identify subsets of beta cells using a single-cell transcriptomic approach. One subset of beta cells marked by high CD63 expression is enriched for the expression of mitochondrial metabolism genes and exhibits higher mitochondrial respiration compared with CD63 lo beta cells. Human and murine pseudo-islets derived from CD63 hi beta cells demonstrate enhanced glucose-stimulated insulin secretion compared with pseudo-islets from CD63 lo beta cells. We show that CD63 hi beta cells are diminished in mouse models of and in humans with type 2 diabetes. Finally, transplantation of pseudo-islets generated from CD63 hi but not CD63 lo beta cells into diabetic mice restores glucose homeostasis. These findings suggest that loss of a specific subset of beta cells may lead to diabetes. Strategies to reconstitute or maintain CD63 hi beta cells may represent a potential anti-diabetic therapy., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

In the mouse, feto-placental endothelial cells (FPEC) line the inner surface of the feto-placental blood vessels located within placental labyrinthine zone and play critical roles in placental development and function. Here, we present a detailed protocol for isolation and culture of primary mouse FPEC, as well as two complementary methods (immunohistochemistry staining and flow cytometry analysis) to assess their purity. These cells are suitable for downstream ex vivo studies to investigate their functional properties, both in normal and pathological contexts. For complete details on the use and execution of this protocol, please refer to Sandovici et al. (2022)., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Rising rates of obesity are intricately tied to the type 2 diabetes epidemic. The adipose tissues can play a central role in protection against or triggering metabolic diseases through the secretion of adipokines. Many adipokines may improve peripheral insulin sensitivity through a variety of mechanisms, thereby indirectly reducing the strain on beta cells and thus improving their viability and functionality. Such effects will not be the focus of this article. Rather, we will focus on adipocyte-secreted molecules that have a direct effect on pancreatic islets. By their nature, adipokines represent potential druggable targets that can reach the islets and improve beta-cell function or preserve beta cells in the face of metabolic stress. © 2022 American Physiological Society. Compr Physiol 12:1-27, 2022., (Copyright © 2022 American Physiological Society. All rights reserved.)

Organ function relies on microvascular networks to maintain homeostatic equilibrium, which varies widely in different organs and during different physiological challenges. The endothelium role in this critical process can only be evaluated in physiologically relevant contexts. Comparing the responses to oxygen flux in primary murine microvascular EC (MVEC) obtained from brain and lung tissue reveals that supra-physiological oxygen tensions can compromise MVEC viability. Brain MVEC lose mitochondrial activity and undergo significant alterations in electron transport chain (ETC) composition when cultured under standard, non-physiological atmospheric oxygen levels. While glycolytic capacity of both lung and brain MVEC are unchanged by environmental oxygen, the ability to trigger a metabolic shift when oxygen levels drop is greatly compromised following exposure to hyperoxia. This is particularly striking in MVEC from the brain. This work demonstrates that the unique metabolism and function of organ-specific MVEC (1) can be reprogrammed by external oxygen, (2) that this reprogramming can compromise MVEC survival and, importantly, (3) that ex vivo modelling of endothelial function is significantly affected by culture conditions. It further demonstrates that physiological, metabolic and functional studies performed in non-physiological environments do not represent cell function in situ, and this has serious implications in the interpretation of cell-based pre-clinical models.

The term "In Silico Trial" indicates the use of computer modelling and simulation to evaluate the safety and efficacy of a medical product, whether a drug, a medical device, a diagnostic product or an advanced therapy medicinal product. Predictive models are positioned as new methodologies for the development and the regulatory evaluation of medical products. New methodologies are qualified by regulators such as FDA and EMA through formal processes, where a first step is the definition of the Context of Use (CoU), which is a concise description of how the new methodology is intended to be used in the development and regulatory assessment process. As In Silico Trials are a disruptively innovative class of new methodologies, it is important to have a list of possible CoUs highlighting potential applications for the development of the relative regulatory science. This review paper presents the result of a consensus process that took place in the InSilicoWorld Community of Practice, an online forum for experts in in silico medicine. The experts involved identified 46 descriptions of possible CoUs which were organised into a candidate taxonomy of nine CoU categories. Examples of 31 CoUs were identified in the available literature; the remaining 15 should, for now, be considered speculative.

Oxidative stress has been acknowledged as a major factor in aging, senescence and neurodegenerative conditions. Mammalian models are susceptible to these stresses following the restoration of oxygen after anoxia; however, some organisms including the freshwater turtle Trachemys scripta can withstand repeated anoxia and reoxygenation without apparent pathology. T. scripta thus provides us with an alternate vertebrate model to investigate physiological mechanisms of neuroprotection. The objective of this study was to investigate the antioxidant methionine sulfoxide reductase system (Msr) in turtle neuronal tissue. We examined brain transcript and protein levels of MsrA and MsrB and examined the potential for the transcription factor FOXO3a to regulate the oxygen-responsive changes in Msr in vitro. We found that Msr mRNA and protein levels are differentially upregulated during anoxia and reoxygenation, and when cells were exposed to chemical oxidative stress. However, while MsrA and MsrB3 levels increased when cell cultures were exposed to chemical oxidative stress, this induction was not enhanced by treatment with epigallocatechin gallate (EGCG), which has previously been shown to enhance FOXO3a levels in the turtle. These results suggest that FOXO3a and Msr protect the cells from oxidative stress through different molecular pathways, and that both the Msr pathway and EGCG may be therapeutic targets to treat diseases related to oxidative damage.

We report an enantioselective Nazarov cyclization catalyzed by chiral hydrogen-bond-donors in concert with silyl Lewis acids. The developed transformation provides access to tri-substituted cyclopentenones in high levels of enantioselectivity (up to 95% e.e.) from a variety of simple unactivated dienones. Kinetic and mechanistic studies are consistent with a reversible 4π-electrocyclization C-C bond-forming step followed by rate- and enantio-determining proton-transfer as the mode of catalysis.

The detrimental effects of oxidative stress caused by the accumulation of Reactive Oxygen Species (ROS) factor into aging, senescence and several neurodegenerative diseases. Mammalian models are extremely susceptible to the stresses that follow the restoration of oxygen after anoxia; however some organisms including the freshwater turtle Trachemys scripta can withstand extended anoxia and reoxygenation without apparent pathology. The ability of the turtle to withstand these conditions is thought to be linked to the upregulation of protective mechanisms such as heat shock proteins (HSP) as well as the suppression of ROS formation and the upregulation of antioxidant defenses. One such antioxidant mechanism is the transcription factor Forkhead box O3a (FOXO3a), that has been shown to be activated in several animal models during oxidative stress. In this study, we utilized both the transfection of a plasmid carrying foxo3a and the pharmacological manipulation of foxo3a using the green tea extract Epigallocatechin-3-gallate (EGCG) to investigate the protective role of FOXO3a in the turtle brain. Our studies found that transcript levels of foxo3a were upregulated significantly during reoxygenation with greater increases during chemical oxidative stress. Induction of foxo3a by direct transfection significantly decreased cell death during chemical oxidative stress. Cells treated with EGCG also showed increased foxo3a expression and decreased cell death in the presence of H 2 O 2 . These results agree with results seen in other animal models and suggest that EGCG (through the upregulation of foxo3a) may be a therapeutic target against oxidative stress damage that warrants further investigation., Competing Interests: Declaration of Competing Interest None, (Copyright © 2020 Elsevier Inc. All rights reserved.)

The microvasculature is a heterogeneous, dynamic and versatile component of the systemic circulation, with a unique ability to locally self-regulate and to respond to organ demand and environmental stimuli. Endothelial cells from different organs display considerable variation, but it is currently unclear to what extent functional properties of organ-specific endothelial cells are intrinsic, acquired and/or reprogrammable. Vascular function is a fundamental pillar of homeostasis, and dysfunction results in systemic consequences for the organism. Additionally, vascular failure can occur downstream of organ disease or environmental stress, often driving an exacerbation of symptoms and pathologies originally independent of the local circulation. The understanding of the molecular mechanisms underlying endothelial physiology and metabolism holds the promise to inform and improve diagnosis, prognosis and treatment options for a myriad of conditions as unrelated as cancer, neurodegeneration or pulmonary hypertension, and likely everything in between, if we consider that also treatments for such conditions are primarily distributed via the bloodstream. However, studying endothelial function has its challenges: the origin, isolation, culture conditions and preconditioning stimuli make this an extremely variable cell type to study and difficult to source. Animal models exist but are neither trivial to generate, nor necessarily adequately translatable to human disease. In this article, we aim to illustrate the breadth of microvascular functions in different environments, highlighting current and pioneering studies that have advanced our insight into the importance of the integrity of this tissue, as well as the limitations posed by its heterogeneity and plasticity., (© 2019 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Extensive research has shown that oxidative stress is strongly associated with aging, senescence and several diseases, including neurodegenerative and psychiatric disorders. Oxidative stress is caused by the overproduction of reactive oxygen species (ROS) that can be counteracted by both enzymatic and nonenzymatic antioxidants. One of these antioxidant mechanisms is the widely studied methionine sulfoxide reductase system (Msr). Methionine is one of the most easily oxidized amino acids and Msr can reverse this oxidation and restore protein function, with MsrA and MsrB reducing different stereoisomers. This article focuses on experimental and genetic research performed on Msr and its link to brain diseases. Studies on several model systems as well as genome-wide association studies are compiled to highlight the role of MSRA in schizophrenia, Alzheimer's disease, and Parkinson's disease. Genetic variation of MSRA may also contribute to the risk of psychosis, personality traits, and metabolic factors.

Oscillations in oxygen levels affect malignant cell growth, survival, and metastasis, but also somatic cell behaviour. In this work, we studied the effect of the differential expression of the two primary hypoxia inducible transcription factor isoforms, HIF-1α and HIF-2α, and pulmonary hypoxia to investigate how the hypoxia response of the vascular endothelium remodels the lung pre-metastatic niche. Molecular responses to acute versus chronic tissue hypoxia have been proposed to involve dynamic HIF stabilization, but the downstream consequences and the extent to which differential lengths of exposure to hypoxia can affect HIF-isoform activation and secondary organ pre-disposition for metastasis is unknown. We used primary pulmonary endothelial cells and mouse models with pulmonary endothelium-specific deletion of HIF-1α or HIF-2α, to characterise their roles in vascular integrity, inflammation and metastatic take after acute and chronic hypoxia. We found that acute hypoxic response results in increased lung metastatic tumours, caused by HIF-1α-dependent endothelial cell death and increased microvascular permeability, in turn facilitating extravasation. This is potentiated by the recruitment and retention of specific myeloid cells that further support a pro-metastatic environment. We also found that chronic hypoxia delays tumour growth to levels similar to those seen in normoxia, and in a HIF-2α-specific fashion, correlating with increased endothelial cell viability and vascular integrity. Deletion of endothelial HIF-2α rendered the lung environment more vulnerable to tumour cell seeding and growth. These results demonstrate that the nature of the hypoxic challenge strongly influences the nature of the endothelial cell response, and affects critical parameters of the pulmonary microenvironment, significantly impacting metastatic burden. Additionally, this work establishes endothelial cells as important players in lung remodelling and metastatic progression.

A 52-year old patient presented with lymphedema, protein loosing enteropathy, and sclerosing cholangitis and was diagnosed with lymphedema cholestasis syndrome (LCS). Cholangioscopy revealed dilated lymphatic vessels obstructing the bile duct and compound heterozygosity for collagen and calcium-binding epidermal growth factor domain-containing protein 1 (CCBE1) mutations was identified defining a novel type of LCS. (Hepatology 2017;66:286-288)., (© 2017 by the American Association for the Study of Liver Diseases.)