Sulfhydryl Modification Induces Calcium Entry through IP3-Sensitive Store-Operated Pathway in Activation-Dependent Human Neutrophils

As the first line of host defense, neutrophils are stimulated by pro-inflammatory cytokines from resting state, facilitating the execution of immunomodulatory functions in activation state. Sulfhydryl modification has a regulatory role in a wide variety of physiological functions through mediation of signaling transductions in various cell types. Recent research suggested that two kinds of sulfhydryl modification, S-nitrosylation by exogenous nitric oxide (NO) and alkylation by N-ethylmaleimide (NEM), could induce calcium entry through a non-store-operated pathway in resting rat neutrophils and DDT1MF-2 cells, while in active human neutrophils a different process has been observed by us. In the present work, data showed that NEM induced a sharp rising of cytosolic calcium concentration ([Ca2+]c) without external calcium, followed by a second [Ca2+]c increase with readdition of external calcium in phorbol 12-myristate 13-acetate (PMA)-activated human neutrophils. Meanwhile, addition of external calcium did not cause [Ca2+]c change of Ca2+-free PMA-activated neutrophils before application of NEM. These data indicated that NEM could induce believable store-operated calcium entry (SOCE) in PMA-activated neutrophils. Besides, we found that sodium nitroprusside (SNP), a donor of exogenous NO, resulted in believable SOCE in PMA-activated human neutrophils via S-nitrosylation modification. In contrast, NEM and SNP have no effect on [Ca2+]c of resting neutrophils which were performed in suspension. Furthermore, 2-Aminoethoxydiphenyl borate, a reliable blocker of SOCE and an inhibitor of inositol 1,4,5-trisphosphate (IP3) receptor, evidently abolished SNP and NEM-induced calcium entry at 75 µM, while preventing calcium release in a concentration-dependent manner. Considered together, these results demonstrated that NEM and SNP induced calcium entry through an IP3-sensitive store-operated pathway of human neutrophils via sulfhydryl modification in a PMA-induced activation-dependent manner

Super-Resolution Microscopy Reveals the Native Ultrastructure of the Erythrocyte Cytoskeleton

Summary: The erythrocyte cytoskeleton is a textbook prototype for the submembrane cytoskeleton of metazoan cells. While early experiments suggest a triangular network of actin-based junctional complexes connected by ∼200-nm-long spectrin tetramers, later studies indicate much smaller junction-to-junction distances in the range of 25-60 nm. Through super-resolution microscopy, we resolve the native ultrastructure of the cytoskeleton of membrane-preserved erythrocytes for the N and C termini of β-spectrin, F-actin, protein 4.1, tropomodulin, and adducin. This allows us to determine an ∼80-nm junction-to-junction distance, a length consistent with relaxed spectrin tetramers and theories based on spectrin abundance. Through two-color data, we further show that the cytoskeleton meshwork often contains nanoscale voids where the cell membrane remains intact and that actin filaments and capping proteins localize to a subset of, but not all, junctional complexes. Together, our results call for a reassessment of the structure and function of the submembrane cytoskeleton. : Pan et al. resolve the cytoskeletal organization in native erythrocytes using STORM super-resolution microscopy, revealing an ∼80-nm junction-to-junction distance that is in agreement with relaxed spectrin tetramers and showing that the junctional complexes are partially occupied by actin and its capping proteins. Keywords: erythrocyte, membrane cytoskeleton, spectrin-actin-based cytoskeleton, junctional complex, super-resolution microscopy, native ultrastructure, red blood cel

Reactivity of TiS2 Anode towards Electrolytes in Aqueous Li‐ion Batteries

Aqueous rechargeable batteries are appealing alternatives for large-scale energy storage. Reversible cycling of high-energy aqueous batteries has been showcased using highly concentrated aqueous electrolytes, which lead to a significantly suppressed water activity and formation of a stable solid-electrolyte interphase (SEI). However, the high salt concentration inevitably raises the cost and compromises the environmental sustainability. Herein, we use layered TiS2 as a model anode to explore the feasibility of cycling aqueous cells in dilute electrolytes. By coupling three-electrode cycling data with online electrochemical mass spectrometry measurements, we depict the potential-dependent gas evolution from the cell in the absence of a stable SEI. We offer a comprehensive mechanistic understanding of the complex interfacial chemistry in dilute electrolytes, taking into account material reactivity and interfacial compatibility. Design strategies and research directions of layered-type electrodes for sustainable aqueous batteries with dilute electrolytes are recommended, based on the scientific discovery presented in this work

Interfacial Chemistry in Aqueous Lithium‐Ion Batteries : A Case Study of V2O5 in Dilute Aqueous Electrolytes

Aqueous lithium-ion batteries (ALIBs) are promising for large-scale energy storage systems because of the cost-effective, intrinsically safe, and environmentally friendly properties of aqueous electrolytes. Practical application is however impeded by interfacial side-reactions and the narrow electrochemical stability window (ESW) of aqueous electrolytes. Even though higher electrolyte salt concentrations (e.g., water-in-salt electrolyte) enhance performance by widening the ESW, the nature and extent of side-reaction processes are debated and more fundamental understanding thereof is needed. Herein, the interfacial chemistry of one of the most popular electrode materials, V2O5, for aqueous batteries is systematically explored by a unique set of operando analytical techniques. By monitoring electrode/electrolyte interphase deposition, electrolyte pH, and gas evolution, the highly dynamic formation/dissolution of V2O5/V2O4, Li2CO3 and LiF during dis-/charge is demonstrated and shown to be coupled with electrolyte decomposition and conductive carbon oxidation, regardless of electrolyte salt concentration. The study provides deeper understanding of interfacial chemistry of active materials under variable proton activity in aqueous electrolytes, hence guiding the design of more effective electrode/electrolyte interfaces for ALIBs and beyond

Collective Cell Radial Ordered Migration in Spatial Confinement

Abstract Collective cells, a typical active matter system, exhibit complex coordinated behaviors fundamental for various developmental and physiological processes. The present work discovers a collective radial ordered migration behavior of NIH3T3 fibroblasts that depends on persistent top‐down regulation with 2D spatial confinement. Remarkably, individual cells move in a weak‐oriented, diffusive‐like rather than strong‐oriented ballistic manner. Despite this, the collective movement is spatiotemporal heterogeneous and radial ordering at supracellular scale, manifesting as a radial ordered wavefront originated from the boundary and propagated toward the center of pattern. Combining bottom‐up cell‐to‐extracellular matrix (ECM) interaction strategy, numerical simulations based on a developed mechanical model well reproduce and explain above observations. The model further predicts the independence of geometric features on this ordering behavior, which is validated by experiments. These results together indicate such radial ordered collective migration is ascribed to the couple of top‐down regulation with spatial restriction and bottom‐up cellular endogenous nature

Identity-based provable data possession revisited: Security analysis and generic construction

2016 Elsevier B.V.Provable Data Possession (PDP), which enables cloud users to verify the data integrity without retrieving the entire file, is highly essential for cloud storage. Observing all the existing PDP schemes rely on the Public Key Infrastructure (PKI), Wang proposed an identity-based distributed provable data possession (ID-DPDP) scheme that can (1) eliminate the complex certificate management and (2) be applied to the multi-cloud scenario. The scheme is efficient, flexible and supports private verification, delegated verification and public verification. In this paper, we find that ID-DPDP is flawed since it fails to achieve soundness. We then fix the flaw by presenting a generic construction for identity-based PDP (ID-PDP) protocol, derived from secure digital signature schemes and traditional PDP protocols. We prove that the soundness of the generic ID-PDP construction depends on the security of the underlying PDP protocols and the signature schemes. An instance of the generic construction by utilizing a state-of-the-art PDP protocol due to Shacham and Waters and BLS short signature scheme is given. Moreover, a new ID-DPDP protocol is obtained by extending the basic ID-PDP to multiple clouds environment. The implementation shows that the proposed ID-PDP protocol is efficient

Ultraviolet light A irradiation induces immunosuppression associated with the generation of reactive oxygen species in human neutrophils

Ultraviolet blood irradiation has been used as a physical therapy to treat many nonspecific diseases in clinics; however, the underlying mechanisms remain largely unclear. Neutrophils, the first line of host defense, play a crucial role in a variety of inflammatory responses. In the present work, we investigated the effects of ultraviolet light A (UVA) on the immune functions of human neutrophils at the single-cell level by using an inverted fluorescence microscope. N-Formyl-methionyl-leucyl-phenylalanine (FMLP), a classic physiological chemotactic peptide, was used to induce a series of immune responses in neutrophils in vitro. FMLP-induced calcium mobilization, migration, and phagocytosis in human neutrophils was significantly blocked after treatment with 365nm UVA irradiation, demonstrating the immunosuppressive effects of UVA irradiation on neutrophils. Similar responses were also observed when the cells were pretreated with H2O2, a type of reactive oxygen species (ROS). Furthermore, UVA irradiation resulted in an increase in NAD(P)H, a member of host oxidative stress in cells. Taken together, our data indicate that UVA irradiation results in immunosuppression associated with the production of ROS in human neutrophils