CCDC115 inhibits autophagy-mediated degradation of YAP to promote cell proliferation.

Autophagy and Hippo signalling pathways both play important roles in cell homeostasis and are often involved in tumourigenesis. However, the crosstalk between these two signal pathways in response to stress conditions, such as nutrient deficiency, is incompletely understood. Here, we show that vesicular localised coiled-coil domain containing 115 (CCDC115) inhibits autophagy as well as Hippo signalling pathway under starvation. Moreover, we show that CCDC115 interacts with the HOPS complex. This interaction competes with STX17, thus inhibiting the fusion of autophagosomes with lysosomes. Hence, CCDC115 inhibits the autophagic degradation of yes-associated protein (YAP), thereby promoting cell proliferation in nutrient-restricted situation.

DIPK2A promotes STX17- and VAMP7-mediated autophagosome-lysosome fusion by binding to VAMP7B.

Autophagosome and lysosome fusion is an important macroautophagy/autophagy process for cargo degradation, and SNARE proteins, including STX17, SNAP29, VAMP7 and VAMP8, are key players in this process. However, the manner in which this process is precisely regulated is poorly understood. Here, we show that VAMP7B, a SNARE domain-disrupted isoform of R-SNARE protein VAMP7, competes with SNARE domain functional isoform VAMP7A to bind to STX17 and inhibits autophagosome-lysosome fusion. Moreover, we show that DIPK2A, a late endosome- and lysosome-localized protein, binds to VAMP7B, which inhibits the interaction of VAMP7B with STX17 and enhances the binding of STX17 to VAMP7A, thus enhancing autophagosome-lysosome fusion. Furthermore, DIPK2A participates in autophagic degradation of mitochondria proteins and alleviates apoptosis. Thus, we reveal a new aspect of autophagosome-lysosome fusion in which different isoforms of VAMP7 compete with STX17 and their regulation by DIPK2A.Abbreviations: DIPK2A: divergent protein kinase domain 2A; EEA1: early endosome antigen 1; GOLGA2: golgin A2; LAMP1: lysosomal associated membrane protein 1; MAP1LC3B/LC3: microtubule associated protein 1 light chain 3 beta; MFN2: mitofusin 2; MT-CO2: mitochondrially encoded cytochrome c oxidase II; PARP1: poly(ADP-ribose) polymerase 1; PRKN: parkin RBR E3 ubiquitin protein ligase; RAB5A: RAB5A, member RAS oncogene family; RAB7A: RAB7A, member RAS oncogene family; REEP: receptor accessory protein; RTN4: reticulon 4; SNARE: SNAP receptor; SQSTM1/p62: sequestosome 1; STX17: syntaxin 17; TOMM20: translocase of outer mitochondrial membrane 20; VAMP7: vesicle associated membrane protein 7; VAMP8: vesicle associated membrane protein 8.

8:2 Fluorotelomer alcohol causes G1 cell cycle arrest and blocks granulocytic differentiation in HL-60 cells.

Fluorotelomer alcohols (FTOHs) are fluorinated intermediates used in manufacturing specialty polymer and surfactants, with 8:2 FTOH the homologue of largest production. FTOHs were found to pose acute toxicity, hepatotoxicity, nephrotoxicity, developmental toxicity and endocrine-disrupting risks, whereas research regarding immunotoxicity and its underlying mechanism, especially on specific immune cells is limited. Here, we investigated the immunotoxicity of 8:2 FTOH on immature immune cells in an in vitro system. We observed that exposure of HL-60 cells, a human promyelocytic leukemic cell line, to 8:2 FTOH reduced cell viability in a dose- and time-dependent manner. In addition, 8:2 FTOH exposure caused G1 cell cycle arrest in HL-60 cells, while it showed no effect on apoptosis. Exposure to 8:2 FTOH inhibited the mRNA expression of cell cycle-related genes, including CCNA1, CCNA2, CCND1, and CCNE2. Moreover, exposure to 8:2 FTOH inhibited the mRNA expression of granulocytic differentiation-related genes of CD11b, CSF3R, PU.1, and C/EPBε in HL-60 cells . Furthermore, 8:2 FTOH exhibited no effect on intracellular ROS level, while hydralazine hydrochloride (Hyd), one reactive carbonyl species (RCS) scavenger, partially blocked 8:2 FTOH-caused cytotoxicity in HL-60 cells. Overall, the results obtained in the study show that 8:2 FTOH poses immunotoxicity in immature immune cells and RCS may partially underline its mechanism.

An Optimized Probabilistic Delay Tolerant Network (DTN) Routing Protocol Based on Scheduling Mechanism for Internet of Things (IoT).

Many applications of Internet of Things (IoT) have been implemented based on unreliable wireless or mobile networks like the delay tolerant network (DTN). Therefore, it is an important issue for IoT applications to achieve efficient data transmission in DTN. In order to improve delivery rate and optimize delivery delay with low overhead in DTN for IoT applications, we propose a new routing protocol, called Scheduling-Probabilistic Routing Protocol using History of Encounters and Transitivity (PROPHET). In this protocol, we calculate the delivery predictability according to the encountering frequency among nodes. Two scheduling mechanisms are proposed to extend the traditional PROPHET protocol and improve performance in both storage and transmission in DTN. In order to evaluate the proposed routing protocol, we perform simulations and compare it with other routing protocols in an Opportunistic Network Environment (ONE) simulator. The results demonstrate that the proposed Scheduling-PROPHET can achieve better performances in several key aspects compared with the existing protocols.

ß-Cypermethrin and its metabolite 3-phenoxybenzoic acid exhibit immunotoxicity in murine macrophages.

ß-Cypermethrin (ß-CYP), one of most important pyrethroids, is widely used to control insects, and has been detected in organisms, including human. Pyrethroids have been shown to pose neurotoxicity, hepatotoxicity, endocrine disruption and reproductive risks in mammals. However, research in immunotoxicity of pyrethroids, especially their metabolites, is limited. A common metabolite of pyrethroids is 3-phenoxybenzoic acid (3-PBA) in mammals. Thus, in this study, we evaluated the immunotoxicity of ß-CYP and 3-PBA in mouse macrophages, RAW 264.7 cells. MTT assays showed that both ß-CYP and 3-PBA reduced cell viability in a concentration- and time-dependent manner. Flow cytometry with Annexin-V/PI staining demonstrated that both ß-CYP and 3-PBA induced RAW 264.7 cell apoptosis. Furthermore, our results also showed that N-acetylcysteine partially blocked ß-CYP- and 3-PBA-induced cytotoxicity and apoptosis. Intrinsic apoptotic pathway was stimulated by both ß-CYP and 3-PBA exposure. In addition, we found that ß-CYP and 3-PBA inhibited mRNA levels of pro-inflammatory cytokines with or without LPS stimulation. Phagocytosis assay showed that both ß-CYP and 3-PBA inhibited phagocytic ability of macrophages. Moreover, it was also found that both ß-CYP and 3-PBA increased reactive oxygen species (ROS) levels in RAW 264.7 cells. Accordingly, both ß-CYP and 3-PBA were found to regulate the mRNA levels of oxidative stress-related genes in RAW 264.7 cells. Taken together, the results obtained in this study demonstrated that ß-CYP and 3-PBA may have immunotoxic effect on macrophages and that elevated ROS may underlie the mechanism. The present study will help to understand the health risks caused by ß-CYP and other pyrethroids.