Biomacromolecules have transformed our capacity to effectively treat diseases; however, their rapid degradation and poor absorption in the gastrointestinal (GI) tract generally limit their administration to parenteral routes. An oral biologic delivery system must aid in both localization and permeation to achieve systemic drug uptake. Inspired by the leopard tortoise’s ability to passively reorient, we developed an ingestible self-orienting millimeter-scale applicator (SOMA) that autonomously positions itself to engage with GI tissue. It then deploys milliposts fabricated from active pharmaceutical ingredients directly through the gastric mucosa while avoiding perforation. We conducted in vivo studies in rats and swine that support the applicator’s safety and, using insulin as a model drug, demonstrated that the SOMA delivers active pharmaceutical ingredient plasma levels comparable to those achieved with subcutaneous millipost administration.

Actin has well established functions in cellular morphogenesis. However, it is not well understood how the various actin assemblies in a cell are kept in a dynamic equilibrium, in particular when cells have to respond to acute signals. Here, we characterize a rapid and transient actin reset in response to increased intracellular calcium levels. Within seconds of calcium influx, the formin INF2 stimulates filament polymerization at the endoplasmic reticulum (ER), while cortical actin is disassembled. The reaction is then reversed within a few minutes. This Calcium-mediated actin reset (CaAR) occurs in a wide range of mammalian cell types and in response to many physiological cues. CaAR leads to transient immobilization of organelles, drives reorganization of actin during cell cortex repair, cell spreading and wound healing, and induces long-lasting changes in gene expression. Our findings suggest that CaAR acts as fundamental facilitator of cellular adaptations in response to acute signals and stress.DOI: http://dx.doi.org/10.7554/eLife.19850.001

Cell encapsulation has been shown to hold promise for effective, long-term treatment of type 1 diabetes (T1D). However, challenges remain for its clinical applications. For example, there is an unmet need for an encapsulation system that is capable of delivering sufficient cell mass while still allowing convenient retrieval or replacement. Here, we report a simple cell encapsulation design that is readily scalable and conveniently retrievable. The key to this design was to engineer a highly wettable, Ca-releasing nanoporous polymer thread that promoted uniform in situ cross-linking and strong adhesion of a thin layer of alginate hydrogel around the thread. The device provided immunoprotection of rat islets in immunocompetent C57BL/6 mice in a short-term (1-mo) study, similar to neat alginate fibers. However, the mechanical property of the device, critical for handling and retrieval, was much more robust than the neat alginate fibers due to the reinforcement of the central thread. It also had facile mass transfer due to the short diffusion distance. We demonstrated the therapeutic potential of the device through the correction of chemically induced diabetes in C57BL/6 mice using rat islets for 3 mo as well as in immunodeficient SCID-Beige mice using human islets for 4 mo. We further showed, as a proof of concept, the scalability and retrievability in dogs. After 1 mo of implantation in dogs, the device could be rapidly retrieved through a minimally invasive laparoscopic procedure. This encapsulation device may contribute to a cellular therapy for T1D because of its retrievability and scale-up potential.

Insulin and other injectable biologic drugs have transformed the treatment of patients suffering from diabetes. Patients and healthcare providers, however, prefer the oral route of administration, yet macromolecule drugs are not readily absorbed into the bloodstream through the gastrointestinal tract. We developed an ingestible capsule, termed the luminal unfolding

Abstract-Liddle syndrome, an inherited form of hypertension, is caused by gain-of-function mutations in the epithelial Na + channel (ENaC), the principal mediator of Na + reabsorption in the kidney. Accordingly, the disease pathology was ascribed to a primary renal mechanism. Whether this is the sole responsible mechanism, however, remains uncertain as dysregulation of ENaC in other tissues may also be involved. Previous work indicates that ENaC in the vascular endothelium is crucial for the regulation of cellular mechanics and thus vascular function. The hormone aldosterone has been shown to concomitantly increase ENaC surface expression and stiffness of the cell cortex in vascular endothelial cells. The latter entails a reduced release of the vasodilator nitric oxide, which eventually leads to an increase in vascular tone and blood pressure. Using atomic force microscopy, we have found a direct correlation between ENaC surface expression and the formation of cortical stiffness in endothelial cells. Stable knockdown of αENaC in endothelial cells evoked a reduced channel surface density and a lower cortical stiffness compared with the mock control. In turn, an increased αENaC expression induced an elevated cortical stiffness. More importantly, using ex vivo preparations from a mouse model for Liddle syndrome, we show that this disorder evokes enhanced ENaC expression and increased cortical stiffness in vascular endothelial cells in situ. We conclude that ENaC in the vascular endothelium determines cellular

Aims/hypothesis The hormone glucagon-like peptide 1 (GLP-1) is released in response to a meal from the intestinal L-cells, where it is processed from proglucagon by the proconvertase (PC)1/3. In contrast, in the adult islets proglucagon is processed to glucagon by the PC2 enzyme.

ObjectiveTo characterize the EndoC-βH1 cell line as a model for human beta cells and evaluate its beta cell functionality, focusing on insulin secretion, proliferation, apoptosis and ER stress, with the objective to assess its potential as a screening platform for identification of novel anti-diabetic drug candidates.MethodsEndoC-βH1 was transplanted into mice for validation of in vivo functionality. Insulin secretion was evaluated in cells cultured as monolayer and as pseudoislets, as well as in diabetic mice. Cytokine induced apoptosis, glucolipotoxicity, and ER stress responses were assessed. Beta cell relevant mRNA and protein expression were investigated by qPCR and antibody staining. Hundreds of proteins or peptides were tested for their effect on insulin secretion and proliferation.ResultsTransplantation of EndoC-βH1 cells restored normoglycemia in streptozotocin induced diabetic mice. Both in vitro and in vivo, we observed a clear insulin response to glucose, and, in vitro, we found a significant increase in insulin secretion from EndoC-βH1 pseudoislets compared to monolayer cultures for both glucose and incretins.Apoptosis and ER stress were inducible in the cells and caspase 3/7 activity was elevated in response to cytokines, but not affected by the saturated fatty acid palmitate.By screening of various proteins and peptides, we found Bombesin (BB) receptor agonists and Pituitary Adenylate Cyclase-Activating Polypeptides (PACAP) to significantly induce insulin secretion and the proteins SerpinA6, STC1, and APOH to significantly stimulate proliferation.ER stress was readily induced by Tunicamycin and resulted in a reduction of insulin mRNA. Somatostatin (SST) was found to be expressed by 1% of the cells and manipulation of the SST receptors was found to significantly affect insulin secretion.ConclusionsOverall, the EndoC-βH1 cells strongly resemble human islet beta cells in terms of glucose and incretin stimulated insulin secretion capabilities. The cell line has an active cytokine induced caspase 3/7 apoptotic pathway and is responsive to ER stress initiation factors. The cells' ability to proliferate can be further increased by already known compounds as well as by novel peptides and proteins. Based on its robust performance during the functionality assessment assays, the EndoC-βH1 cell line was successfully used as a screening platform for identification of novel anti-diabetic drug candidates.

The stiffness of vascular endothelial cells is crucial to mechanically withstand blood flow and, at the same time, to control deformation-dependent nitric oxide release. However, the regulation of mechanical stiffness is not yet understood. There is evidence that a possible regulator is the electrical plasma membrane potential difference. Using a novel technique that combines fluorescence-based membrane potential recordings with atomic force microscopy (AFM)-based stiffness measurements, the present study shows that membrane depolarization is associated with a decrease in the stiffness of endothelial cells. Three different depolarization protocols were applied, all of which led to a similar and significant decrease in cell stiffness, independently of changes in cell volume. Moreover, experiments using the actin-destabilizing agent cytochalasin D indicated that depolarization acts by affecting the cortical actin cytoskeleton. A model is proposed whereby a change of the electrical field across the plasma membrane is directly sensed by the submembranous actin network, regulating the actin polymerization:depolymerization ratio and thus cell stiffness. This depolarization-induced decrease in the stiffness of endothelial cells could play a role in flow-mediated nitric-oxide-dependent vasodilation.