Extracellular Vesicles Secreted by Corneal Myofibroblasts Promote Corneal Epithelial Cell Migration

Corneal epithelial wound healing is a multifaceted process that encompasses cell proliferation, migration, and communication from the corneal stroma. Upon corneal injury, bidirectional crosstalk between the epithelium and stroma via extracellular vesicles (EVs) has been reported. However, the mechanisms by which the EVs from human corneal keratocytes (HCKs), fibroblasts (HCFs), and/or myofibroblasts (HCMs) exert their effects on the corneal epithelium remain unclear. In this study, HCK-, HCF-, and HCM-EVs were isolated and characterized, and human corneal epithelial (HCE) cell migration was assessed in a scratch assay following PKH26-labeled HCK-, HCF-, or HCM-EV treatment. HCE cells proliferative and apoptotic activity following EV treatment was assessed. HCF-/HCM-EVs were enriched for CD63, CD81, ITGAV, and THBS1 compared to HCK-EV. All EVs were negative for GM130 and showed minimal differences in biophysical properties. At the proteomic level, we showed HCM-EV with a log >two-fold change in CXCL6, CXCL12, MMP1, and MMP2 expression compared to HCK-/HCF-EVs; these proteins are associated with cellular movement pathways. Upon HCM-EV treatment, HCE cell migration, velocity, and proliferation were significantly increased compared to HCK-/HCF-EVs. This study concludes that the HCM-EV protein cargo influences HCE cell migration and proliferation, and understanding these elements may provide a novel therapeutic avenue for corneal wound healing

MULTI-LEVEL POLICY COALITIONS AN INTERPRETATIVE MODEL OF WATER CONFLICTS IN THE AMERICAS

ABSTRACT This article proposes an analytical approach to conflicts and policy-making related to urban water management based on multi-level policy coalitions. This is necessary to articulate four main issues. First, the repositioning of social and political struggles for access to water, along with policy variables. Second, the analysis of the effects of ecological transition, including climate change. Third, the reincorporation of these struggles and challenges in a multi-level approach. Finally, the enquiry into the apparent contradiction, in contemporary policymaking. The article proposes a definition of multi-level coalitions as collective preference systems that influence the content of policies (ideas/advocacy, decisions, policy tools) and their implementation, groups of actors that arise from engagement in policy issues. In the first section, the article presents the objectives of research on urban water management in the Americas, within the framework of which this analytical approach by multi-level coalitions is fashioned. In the second section, the article details four analytical issues. In the third section, it gives a definition of multi-level coalitions