ABSTRACT
The physical properties of nanoscale cell-extracellular matrix (ECM) ligands profoundly impact biological processes, such as adhesion, motility, and differentiation. While the mechanoresponse of cells to static ligands is well-studied, the effect of dynamic ligand presentation with "adaptive" properties on cell mechanotransduction remains less understood. Utilizing a controllable diffusible ligand interface, we demonstrated that cells on surfaces with rapid ligand mobility could recruit ligands through activating integrin α5ß1, leading to faster focal adhesion growth and spreading at the early adhesion stage. By leveraging UV-light-sensitive anchor molecules to trigger a "dynamic to static" transformation of ligands, we sequentially activated α5ß1 and αvß3 integrins, significantly promoting osteogenic differentiation of mesenchymal stem cells. This study illustrates how manipulating molecular dynamics can directly influence stem cell fate, suggesting the potential of "sequentially" controlled mobile surfaces as adaptable platforms for engineering smart biomaterial coatings.
Subject(s)
Cell Adhesion , Cell Differentiation , Mechanotransduction, Cellular , Mesenchymal Stem Cells , Surface Properties , Mesenchymal Stem Cells/cytology , Humans , Integrin alpha5beta1/metabolism , Osteogenesis , Extracellular Matrix/chemistry , Extracellular Matrix/metabolism , Integrin alphaVbeta3/metabolism , Ligands , Focal AdhesionsABSTRACT
Atmospheric resources provide important support for human economic and social systems through their unique ecosystem service functions. Implementing the off-office auditing of atmospheric resources for leading cadres holds great strategic significance for fundamentally solve air pollution problems. Exploring the compilation of an atmospheric resource balance sheet is a necessary pre-step in the implementation of outgoing audits. In this paper, atmospheric resources are innovatively divided into atmospheric capacity resources and atmospheric quality resources from the perspective of the ecosystem service functions of atmospheric resources. The value of atmospheric resource assets is calculated by combining the environmental capacity value method and the environmental loss evaluation method. This study evaluates atmospheric ecological achievements based on the atmospheric resources balance sheet and related accounts as the data carrier and opens up the key "blocking point" of the off-office auditing of atmospheric resources. This paper takes Anhui Province as an example and applies the accounting results of the prepared atmospheric resource balance sheet to evaluate the atmospheric resource ecological achievements of leading cadres from 2016 to 2020. The results clearly reflect the ecological achievements and shortcomings of local leading cadres during their tenure.
Subject(s)
Air Pollution , Ecosystem , Humans , Conservation of Natural Resources , Financial Statements , ChinaABSTRACT
Embryonic stem cells (ESCs) exhibit unique attributes of boundless self-renewal and pluripotency, making them invaluable for fundamental investigations and clinical endeavors. Previous examinations of microgravity effects on ESC self-renewal and differentiation have predominantly maintained a descriptive nature, constrained by limited experimental opportunities and techniques. In this investigation, we present compelling evidence derived from murine and human ESCs, demonstrating that simulated microgravity (SMG)-induced stress significantly impacts self-renewal and pluripotency through a previously unidentified conserved mechanism. Specifically, SMG induces the upregulation of heat shock protein genes, subsequently enhancing the expression of core pluripotency factors and activating the Wnt and/or LIF/STAT3 signaling pathways, thereby fostering ESC self-renewal. Notably, heightened Wnt pathway activity, facilitated by Tbx3 upregulation, prompts mesoendodermal differentiation in both murine and human ESCs under SMG conditions. Recognizing potential disparities between terrestrial SMG simulations and authentic microgravity, forthcoming space flight experiments are imperative to validate the impact of reduced gravity on ESC self-renewal and differentiation mechanisms.