Background and Purpose
Oat β‐glucan could ameliorate epidermal hyperplasia and accelerate epidermal barrier repair. Dectin‐1 is one of the receptors of β‐glucan and many biological functions of ...β‐glucan are mediated by Dectin‐1. Dectin‐1 promotes wound healing through regulating the proliferation and migration of skin cells. Thus, this study aimed to investigate the role of oat β‐glucan and Dectin‐1 in epidermal barrier repair.
Experimental Approach
To investigate the role of Dectin‐1 in the epidermal barrier, indicators associated with the recovery of a damaged epidermal barrier, including histopathological changes, keratinization, proliferation, apoptosis, differentiation, cell–cell junctions and lipid content were compared between WT and Dectin‐1−/− mice. Further, the effect of oat β‐glucan on the disruption of the epidermal barrier was also compared between WT and Dectin‐1−/− mice.
Key Results
Dectin‐1 deficiency resulted in delayed recovery and marked keratinization, as well as abnormal levels of keratinocyte differentiation, cell–cell junctions and lipid synthesis during the restoration of the epidermal barrier. Oat β‐glucan significantly reduces epidermal hyperplasia, promotes epidermal differentiation, increases cell–cell junction expression, promotes lipid synthesis and ultimately accelerates the recovery of damaged epidermal barriers via Dectin‐1. Oat β‐glucan could promote CaS receptor expression and activate the PPAR‐γ signalling pathway via Dectin‐1.
Conclusion and Implications
Oat β‐glucan promote the recovery of damaged epidermal barriers through promoting epidermal differentiation, increasing the expression of cell–cell junctions and lipid synthesis through Dectin‐1. Dectin‐1 deficiency delay the recovery of epidermal barriers, which indicated that Dectin‐1 may be a potential target in epidermal barrier repair.
SARS-CoV-2 has caused the COVID-19 pandemic. There is an urgent need for physiological models to study SARS-CoV-2 infection using human disease-relevant cells. COVID-19 pathophysiology includes ...respiratory failure but involves other organ systems including gut, liver, heart, and pancreas. We present an experimental platform comprised of cell and organoid derivatives from human pluripotent stem cells (hPSCs). A Spike-enabled pseudo-entry virus infects pancreatic endocrine cells, liver organoids, cardiomyocytes, and dopaminergic neurons. Recent clinical studies show a strong association with COVID-19 and diabetes. We find that human pancreatic beta cells and liver organoids are highly permissive to SARS-CoV-2 infection, further validated using adult primary human islets and adult hepatocyte and cholangiocyte organoids. SARS-CoV-2 infection caused striking expression of chemokines, as also seen in primary human COVID-19 pulmonary autopsy samples. hPSC-derived cells/organoids provide valuable models for understanding the cellular responses of human tissues to SARS-CoV-2 infection and for disease modeling of COVID-19.
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•A hPSC-derived cell and organoid platform is used to study SARS-CoV-2 tissue tropism•Human pancreatic alpha and beta cells are permissive to SARS-CoV-2 infection•Human hepatocyte and cholangiocyte organoids are permissive to SARS-CoV-2 infection•hPSC-derived cells/organoids show similar chemokine responses as COVID-19 tissues
Yang et al. show that hPSC-derived cells and organoids provide valuable models to study SARS-CoV-2 tropism and to model COVID-19. They find that hPSC-derived pancreatic endocrine cells and human adult hepatocyte and cholangiocyte organoids are permissive to SARS-CoV-2 infection.
Abstract
The problem of bag boundary conditions within a field‐theoretic approach is revisited to study confinement of massless Dirac quasispinors in monolayer graphene. While no‐flux bag boundaries ...have previously been used to model lattice termination sites in graphene nanoribbons, a generalized setting is considered in which the confining boundaries are envisaged as arbitrary straight lines drawn across a graphene sheet and the quasispinor currents are allowed to partially permeate (leak) through such boundaries. Specifically focus is on rectangular nanolanes defined as areas confined between a pair of parallel lines at arbitrary separation on an unbounded lattice. It is shown that such nanolanes exhibit a considerable range of bandgap tunability depending on their widths and armchair, zigzag, or intermediate orientation. The case of nanoribbons can be derived as a special limit from the nanolane model. In this case, certain inconsistencies are clarified in previous implementations of no‐flux bag boundaries and show that the continuum approach reproduces the tight‐binding bandgaps accurately (within just a few percent in relative deviation) even as the nanoribbon width is decreased to just a couple of lattice spacings. This accentuates the proper use of boundary conditions when field‐theoretic approaches are applied to graphene systems.
Using Brownian Dynamics simulations, we study effective interactions mediated between two identical and impermeable disks (inclusions) immersed in a bath of identical, active (self-propelled), ...Brownian rods in two spatial dimensions, by assuming that the self-propulsion axis of the rods may generally deviate from their longitudinal axis. When the self-propulsion is transverse (perpendicular to the rod axis), the accumulation of active rods around the inclusions is significantly enhanced, causing a more expansive steric layering (ring formation) of the rods around the inclusions, as compared with the reference case of longitudinally self-propelling rods. As a result, the transversally self-propelling rods also mediate a significantly longer ranged effective interaction between the inclusions. The bath-mediated interaction arises due to the overlaps between the active-rod rings formed around the inclusions, as they are brought into small separations. When the self-propulsion axis is tilted relative to the rod axis, we find an asymmetric imbalance of active-rod accumulation around the inclusion dimer. This leads to a noncentral interaction, featuring an anti-parallel pair of transverse force components and, hence, a bath-mediated torque on the dimer.
While almost any kind of face mask offers some protection against particles and pathogens of different sizes, the most efficient ones make use of a layered structure where one or more layers are ...electrically charged. These electret layers are essential for the efficient filtration of difficult-to-capture small particles, yet the exact nature of electrostatic capture with respect to the charge on both the particles and the electret fibres as well as the effect of the immediate environment remain unclear. Here, we explore in detail the electrostatic interactions between the surface of a single charged electret fibre and a model of the SARS-CoV-2 virus. Using Poisson-Boltzmann electrostatics coupled to a detailed spike protein charge regulation model, we show how pH and salt concentration drastically change both the scale and the sign of the interaction. Furthermore, the configuration of the few spike proteins closest to the electret fibre turns out to be as important for the strength of the interaction as their total number on the virus envelope, a direct consequence of spike protein charge regulation. The results of our work elucidate the details of virus electrostatics and contribute to the general understanding of efficient virus filtration mechanisms.
Despite new immunotherapies aimed at B and T cells, plasma cells and their lifelong antibody secretion constitute a major immune barrier to long‐term graft survival. In this mini‐review, we survey ...the recent advances that have been made in the biology and immunometabolism of long‐lived plasma cells, and outline aspects of plasma cell function that can be exploited for clinical benefit in recipients of solid organ transplants. A handful of ongoing studies are already targeting plasma cells to achieve desensitization and reduce the alloantibody burden in individuals posttransplant. In reviewing the recent strides made in our understanding of the molecular basis of plasma cell survival, we will place our discussions in the context of existing preclinical and clinical studies.
The authors review recent advances in the biology and immunometabolism of plasma cells and outline aspects of plasma cell function that can be exploited for clinical benefit in recipients of solid organ transplants.
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