128 research outputs found

    Article microgravity induces transient emt in human keratinocytes by early down-regulation of e-cadherin and cell-adhesion remodeling

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    Changes in cell–matrix and cell-to-cell adhesion patterns are dramatically fostered by the microgravity exposure of living cells. The modification of adhesion properties could promote the emergence of a migrating and invasive phenotype. We previously demonstrated that short exposure to the simulated microgravity of human keratinocytes (HaCaT) promotes an early epithelial– mesenchymal transition (EMT). Herein, we developed this investigation to verify if the cells maintain the acquired invasive phenotype after an extended period of weightlessness exposure. We also evaluated cells’ capability in recovering epithelial characteristics when seeded again into a normal gravitational field after short microgravity exposure. We evaluated the ultra-structural junctional features of HaCaT cells by Transmission Electron Microscopy and the distribution pattern of vinculin and E-cadherin by confocal microscopy, observing a rearrangement in cell–cell and cell–matrix interactions. These results are mirrored by data provided by migration and invasion biological assay. Overall, our studies demonstrate that after extended periods of microgravity, HaCaT cells recover an epithelial phenotype by re-establishing E-cadherin-based junctions and cytoskeleton remodeling, both being instrumental in promoting a mesenchymal–epithelial transition (MET). Those findings suggest that cytoskeletal changes noticed during the first weightlessness period have a transitory character, given that they are later reversed and followed by adaptive modifications through which cells miss the acquired mesenchymal phenotype

    Microgravity Modifies the Phenotype of Fibroblast and Promotes Remodeling of the Fibroblast–Keratinocyte Interaction in a 3D Co-Culture Model

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    Microgravity impairs tissue organization and critical pathways involved in the cell– microenvironment interplay, where fibroblasts have a critical role. We exposed dermal fibroblasts to simulated microgravity by means of a Random Positioning Machine (RPM), a device that reproduces conditions of weightlessness. Molecular and structural changes were analyzed and compared to control samples growing in a normal gravity field. Simulated microgravity impairs fibroblast conversion into myofibroblast and inhibits their migratory properties. Consequently, the normal interplay between fibroblasts and keratinocytes were remarkably altered in 3D co-culture experiments, giving rise to several ultra-structural abnormalities. Such phenotypic changes are associated with down-regulation of α-SMA that translocate in the nucleoplasm, altogether with the concomitant modification of the actin-vinculin apparatus. Noticeably, the stress associated with weightlessness induced oxidative damage, which seemed to concur with such modifications. These findings disclose new opportunities to establish antioxidant strategies that counteract the microgravity-induced disruptive effects on fibroblasts and tissue organization

    The Hip Spine Relationship—What We Know and What We Don’t: A Narrative Review

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    Background and Objective: The hip-spine syndrome was first described in 1983. The premise of the report was that the hip and spine are closely related and patients can easily have overlapping conditions and misdiagnoses. Since that time, there has been considerable advancement in our understanding of spinopelvic parameters and how degenerative disc disease can affect the pelvis and subsequently the acetabulum. Our objective is to provide an updated review on the relationship between hip and spine degeneration, how we define the relationship, and what steps should be taken when planning surgical intervention for these patients. Methods: A literature review was conducted via the PubMed database. Articles were screened based on their relevancy, recency, and quality of analysis. Search items included the following MeSH terms: “lumbar spine” with free text items: “hip, arthroplasty, parameters, spinopelvic, sagittal alignment, fusion, total hip arthroplasty, hip-spine syndrome, surgical complications, and dislocation”. Key Content and Findings: Novel spinopelvic parameters such as the combined sagittal index (CSI) may be useful in predicting complications in patients undergoing total hip arthroplasty. A reasonable approach may be to perform hip arthroplasty prior to a multilevel spinal fusion, especially when the fusion includes the pelvis. However, for patients with radiculopathy requiring a simpler one- or two-level spinal fusion, the spine may be safely addressed first to relieve the patient of radiculopathy prior to proceeding with a hip arthroplasty. Conclusions: New interpretations and applications of these parameters may decrease risk, prevent complications, and improve outcomes for patients who experience these associated, and often concurrent, pathologies

    Inositols: From established knowledge to novel approaches

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    Myo-inositol (myo-Ins) and D-chiro-inositol (D-chiro-Ins) are natural compounds involved in many biological pathways. Since the discovery of their involvement in endocrine signal transduction, myo-Ins and D-chiro-Ins supplementation has contributed to clinical approaches in ameliorating many gynecological and endocrinological diseases. Currently both myo-Ins and D-chiro-Ins are well-tolerated, effective alternative candidates to the classical insulin sensitizers, and are useful treatments in preventing and treating metabolic and reproductive disorders such as polycystic ovary syndrome (PCOS), gestational diabetes mellitus (GDM), and male fertility disturbances, like sperm abnormalities. Moreover, besides metabolic activity, myo-Ins and D-chiro-Ins deeply influence steroidogenesis, regulating the pools of androgens and estrogens, likely in opposite ways. Given the complexity of inositol-related mechanisms of action, many of their beneficial effects are still under scrutiny. Therefore, continuing research aims to discover new emerging roles and mechanisms that can allow clinicians to tailor inositol therapy and to use it in other medical areas, hitherto unexplored. The present paper outlines the established evidence on inositols and updates on recent research, namely concerning D-chiro-Ins involvement into steroidogenesis. In particular, D-chiro-Ins mediates insulin-induced testosterone biosynthesis from ovarian thecal cells and directly affects synthesis of estrogens by modulating the expression of the aromatase enzyme. Ovaries, as well as other organs and tissues, are characterized by a specific ratio of myo-Ins to D-chiro-Ins, which ensures their healthy state and proper functionality. Altered inositol ratios may account for pathological conditions, causing an imbalance in sex hormones. Such situations usually occur in association with medical conditions, such as PCOS, or as a consequence of some pharmacological treatments. Based on the physiological role of inositols and the pathological implications of altered myo-Ins to D-chiro-Ins ratios, inositol therapy may be designed with two different aims: (1) restoring the inositol physiological ratio; (2) altering the ratio in a controlled way to achieve specific effects

    When one size does not fit all: Reconsidering PCOS etiology, diagnosis, clinical subgroups, and subgroup-specific treatments

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    Polycystic Ovary Syndrome (PCOS) is a complex endocrine disorder that affects a large proportion of women. Due to its heterogeneity, the best diagnostic strategy has been a matter of contention. Since 1990 scientific societies in the field of human reproduction have tried to define the pivotal criteria for the diagnosis of PCOS. The consensus Rotterdam diagnostic criteria included the presence of hyperandrogenism, oligo/anovulation, and polycystic ovarian morphology (PCOM), and have now been updated to evidence based diagnostic criteria in the 2018 and 2023 International Guideline diagnostic criteria endorsed by 39 societies internationally. Within the Rotterdam Criteria, at least two out of three of the above-mentioned features are required to be present to diagnose PCOS, resulting in four phenotypes being identified: phenotype A, characterized by the presence of all the features, phenotype B, exhibiting hyperandrogenism and oligo-anovulation, phenotype C, presenting as hyperandrogenism and PCOM and finally the phenotype D that is characterized by oligo-anovulation and PCOM, lacking the hyperandrogenic component. However, it is the hypothesis of the EGOI group that the Rotterdam phenotypes A, B, and C have a different underlying causality to phenotype D. Recent studies have highlighted the strong correlation between insulin resistance and hyperandrogenism, and the pivotal role of these factors in driving ovarian alterations, such as oligo-anovulation and follicular functional cyst formation. This new understanding of PCOS pathogenesis has led the authors to hypothesis that phenotypes A, B, and C are endocrine-metabolic syndromes with a metabolic clinical onset. Conversely, the absence of hyperandrogenism and metabolic disturbances in phenotype D suggests a different origin of this condition, and point towards novel pathophysiological mechanisms; however, these are still not fully understood. Further questions have been raised regarding the suitability of the “phenotypes” described by the Rotterdam Criteria by the publication by recent GWAS studies, which demonstrated that these phenotypes should be considered clinical subtypes as they are not reflected in the genetic picture. Hence, by capturing the heterogeneity of this complex disorder, current diagnostic criteria may benefit from a reassessment and the evaluation of additional parameters such as insulin resistance and endometrial thickness, with the purpose of not only improving their diagnostic accuracy but also of assigning an appropriate and personalized treatment. In this framework, the present overview aims to analyze the diagnostic criteria currently recognized by the scientific community and assess the suitability of their application in clinical practice in light of the newly emerging evidence

    Stromal Vascular Fraction Transplantation as an Alternative Therapy for Ischemic Heart Failure: Anti-inflammatory Role

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    <p>Abstract</p> <p>Background</p> <p>The aims of this study were: (1) to show the feasibility of using adipose-derived stromal vascular fraction (SVF) as an alternative to bone marrow mono nuclear cell (BM-MNC) for cell transplantation into chronic ischemic myocardium; and (2) to explore underlying mechanisms with focus on anti-inflammation role of engrafted SVF and BM-MNC post chronic myocardial infarction (MI) against left ventricular (LV) remodelling and cardiac dysfunction.</p> <p>Methods</p> <p>Four weeks after left anterior descending coronary artery ligation, 32 Male Lewis rats with moderate MI were divided into 3 groups. SVF group (n = 12) had SVF cell transplantation (6 × 10<sup>6 </sup>cells). BM-MNC group (n = 12) received BM-MNCs (6 × 10<sup>6</sup>) and the control (n = 10) had culture medium. At 4 weeks, after the final echocardiography, histological sections were stained with Styrus red and immunohistochemical staining was performed for α-smooth muscle actin, von Willebrand factor, CD3, CD8 and CD20.</p> <p>Results</p> <p>At 4 weeks, in SVF and BM-MNC groups, LV diastolic dimension and LV systolic dimension were smaller and fractional shortening was increased in echocardiography, compared to control group. Histology revealed highest vascular density, CD3+ and CD20+ cells in SVF transplanted group. SVF transplantation decreased myocardial mRNA expression of inflammatory cytokines TNF-α, IL-6, MMP-1, TIMP-1 and inhibited collagen deposition.</p> <p>Conclusions</p> <p>Transplantation of adipose derived SVF cells might be a useful therapeutic option for angiogenesis in chronic ischemic heart disease. Anti-inflammation role for SVF and BM transplantation might partly benefit for the cardioprotective effect for chronic ischemic myocardium.</p

    A programmable beam shaping system for tailoring the profile of high fluence laser beams

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    Customized spatial light modulators have been designed and fabricated for use as precision beam shaping devices in fusion class laser systems. By inserting this device in a low-fluence relay plane upstream of the amplifier chain, 'blocker' obscurations can be programmed into the beam profile to shadow small isolated flaws on downstream optical components that might otherwise limit the system operating energy. In this two stage system, 1920 x 1080 bitmap images are first imprinted on incoherent, 470 nm address beams via pixilated liquid crystal on silicon (LCoS) modulators. To realize defined masking functions with smooth apodized shapes and no pixelization artifacts, address beam images are projected onto custom fabricated optically-addressable light valves. Each valve consists of a large, single pixel liquid cell in series with a photoconductive Bismuth silicon Oxide (BSO) crystal. The BSO crystal enables bright and dark regions of the address image to locally control the voltage supplied to the liquid crystal layer which in turn modulates the amplitude of the coherent beams at 1053 nm. Valves as large as 24 mm x 36 mm have been fabricated with low wavefront distortion (&lt;0.5 waves) and antireflection coatings for high transmission (&gt;90%) and etalon suppression to avoid spectral and temporal ripple. This device in combination with a flaw inspection system and optic registration strategy represents a new approach for extending the operational lifetime of high fluence laser optics

    Programmable beam spatial shaping system for the National Ignition Facility

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    A system of customized spatial light modulators has been installed onto the front end of the laser system at the National Ignition Facility (NIF). The devices are capable of shaping the beam profile at a low-fluence relay plane upstream of the amplifier chain. Their primary function is to introduce 'blocker' obscurations at programmed locations within the beam profile. These obscurations are positioned to shadow small, isolated flaws on downstream optical components that might otherwise limit the system operating energy. The modulators were designed to enable a drop-in retrofit of each of the 48 existing Pre Amplifier Modules (PAMs) without compromising their original performance specifications. This was accomplished by use of transmissive Optically Addressable Light Valves (OALV) based on a Bismuth Silicon Oxide photoconductive layer in series with a twisted nematic liquid crystal (LC) layer. These Programmable Spatial Shaper packages in combination with a flaw inspection system and optic registration strategy have provided a robust approach for extending the operational lifetime of high fluence laser optics on NIF

    A network linking scene perception and spatial memory systems in posterior cerebral cortex

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    The neural systems supporting scene-perception and spatial-memory systems of the human brain are well-described. But how do these neural systems interact? Here, using fine-grained individual-subject fMRI, we report three cortical areas of the human brain, each lying immediately anterior to a region of the scene perception network in posterior cerebral cortex, that selectively activate when recalling familiar real-world locations. Despite their close proximity to the scene-perception areas, network analyses show that these regions constitute a distinct functional network that interfaces with spatial memory systems during naturalistic scene understanding. These “place-memory areas” offer a new framework for understanding how the brain implements memory-guided visual behaviors, including navigation
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