A monocarboxylate transporter rescues frontotemporal dementia and Alzheimer's disease models.

Brains are highly metabolically active organs, consuming 20% of a person's energy at resting state. A decline in glucose metabolism is a common feature across a number of neurodegenerative diseases. Another common feature is the progressive accumulation of insoluble protein deposits, it's unclear if the two are linked. Glucose metabolism in the brain is highly coupled between neurons and glia, with glucose taken up by glia and metabolised to lactate, which is then shuttled via transporters to neurons, where it is converted back to pyruvate and fed into the TCA cycle for ATP production. Monocarboxylates are also involved in signalling, and play broad ranging roles in brain homeostasis and metabolic reprogramming. However, the role of monocarboxylates in dementia has not been tested. Here, we find that increasing pyruvate import in Drosophila neurons by over-expression of the transporter bumpel, leads to a rescue of lifespan and behavioural phenotypes in fly models of both frontotemporal dementia and Alzheimer's disease. The rescue is linked to a clearance of late stage autolysosomes, leading to degradation of toxic peptides associated with disease. We propose upregulation of pyruvate import into neurons as potentially a broad-scope therapeutic approach to increase neuronal autophagy, which could be beneficial for multiple dementias.

Osteopontin Depletion in Non-haematopoietic Cells Improves Outcomes in Septic Mice by Enhancing Antimicrobial Peptide Production.

Osteopontin (Opn) depletion can improve septic outcomes, but the underlying mechanism remains unknown. In this study, we demonstrated that non-haematopoietic but not haematopoietic Opn depletion improved septic outcomes. Compared to wild-type (WT) mice, co-housed Opn-/- mice displayed enhanced production of antibacterial peptides (AMPs), decreased bacterial loads, and a distinct bacterial composition of gut microbiota. Fecal microbiota transplantation (FMT) and OPN neutralization assay showed that Opn depletion could reduce the bacterial loads and improve septic inflammation. By employing an intestinal organoid culture system, we proved that OPN neutralization in WT organoids could inactivate AKT and decrease FOXO3a phosphorylation, resulting in enhanced AMP production, whereas OPN treatment in OPN deficient organoids could activate AKT and increase FOXO3a phosphorylation, leading to reduced AMP production. Our findings identified OPN as a novel regulatory factor of AMP production to modulate bacterial loads and composition of gut microbiota, in turn affecting sepsis outcomes.

The macrophage STING-YAP axis controls hepatic steatosis by promoting the autophagic degradation of lipid droplets.

BACKGROUND AND AIMS: The hallmark of NAFLD or hepatic steatosis is characterized by lipid droplet (LD) accumulation in hepatocytes. Autophagy may have profound effects on lipid metabolism and innate immune response. However, how innate immune activation may regulate the autophagic degradation of intracellular LDs remains elusive. APPROACH AND RESULTS: A mouse model of a high-fat diet-induced NASH was used in the myeloid-specific stimulator of interferon genes (STING) knockout or STING/yes-associated protein (YAP) double knockout mice. Liver injury, lipid accumulation, lipid droplet proteins, autophagic genes, chromatin immunoprecipitation coupled with massively parallel sequencing, and RNA-Seq were assessed in vivo and in vitro . We found that high-fat diet-induced oxidative stress activates STING and YAP pathways in hepatic macrophages. The acrophage STING deficiency (myeloid-specific STING knockout) enhances nuclear YAP activity, reduces lipid accumulation, and increases autophagy-related proteins ATG5, ATG7, and light chain 3B but diminishes LD protein perilipin 2 expression. However, disruption of STING and YAP (myeloid STING and YAP double knockout) increases serum alanine aminotransferase and triglyceride levels and reduces ß-fatty acid oxidation gene expression but augments perilipin 2 levels, exacerbating high-fat diet-induced lipid deposition. Chromatin immunoprecipitation coupled with massively parallel sequencing reveals that macrophage YAP targets transmembrane protein 205 and activates AMP-activated protein kinase α, which interacts with hepatocyte mitofusin 2 and induces protein disulfide isomerase activation. Protein disulfide isomerase activates hypoxia-inducible factor-1α signaling, increases autophagosome colocalization with LDs, and promotes the degradation of perilipin 2 by interacting with chaperone-mediated autophagy chaperone HSC70. CONCLUSIONS: The macrophage STING-YAP axis controls hepatic steatosis by reprogramming lipid metabolism in a transmembrane protein 205/mitofusin 2/protein disulfide isomerase-dependent pathway. These findings highlight the regulatory mechanism of the macrophage STING-driven YAP activity on lipid control.

Opposite atom dependence of isotope engineering of thermal conductivity in bulk and 2D GaN.

Isotope engineering has been shown to be an effective means of regulating thermal conductivity. In this work, we studied the isotope engineering of thermal conductivity in bulk and 2D GaN, and diametrically opposite atom isotope dependence is found. That is, Ga isotope has a large effect (77%) on bulk GaN, while the effect of N isotope on the thermal conductivity is negligible. In 2D GaN, however, N isotope effect (20%) is more significant than that of Ga. Understanding of the different isotope dependence is achieved by deeper insight. Due to the relative magnitude of scattering rate, isotopic scattering influences the thermal conductivity of bulk and 2D GaN in different frequency regions, leading to the opposite atom dependence.

A Missing Traffic Data Imputation Method Based on a Diffusion Convolutional Neural Network-Generative Adversarial Network.

Traffic state data are key to the proper operation of intelligent transportation systems (ITS). However, traffic detectors often receive environmental factors that cause missing values in the collected traffic state data. Therefore, aiming at the above problem, a method for imputing missing traffic state data based on a Diffusion Convolutional Neural Network-Generative Adversarial Network (DCNN-GAN) is proposed in this paper. The proposed method uses a graph embedding algorithm to construct a road network structure based on spatial correlation instead of the original road network structure; through the use of a GAN for confrontation training, it is possible to generate missing traffic state data based on the known data of the road network. In the generator, the spatiotemporal features of the reconstructed road network are extracted by the DCNN to realize the imputation. Two real traffic datasets were used to verify the effectiveness of this method, with the results of the proposed model proving better than those of the other models used for comparison.

CT-based radiogenomic analysis dissects intratumor heterogeneity and predicts prognosis of colorectal cancer: a multi-institutional retrospective study.

BACKGROUND: This study aimed to develop a radiogenomic prognostic prediction model for colorectal cancer (CRC) by investigating the biological and clinical relevance of intratumoural heterogeneity. METHODS: This retrospective multi-cohort study was conducted in three steps. First, we identified genomic subclones using unsupervised deconvolution analysis. Second, we established radiogenomic signatures to link radiomic features with prognostic subclone compositions in an independent radiogenomic dataset containing matched imaging and gene expression data. Finally, the prognostic value of the identified radiogenomic signatures was validated using two testing datasets containing imaging and survival information collected from separate medical centres. RESULTS: This multi-institutional retrospective study included 1601 patients (714 females and 887 males; mean age, 65 years ± 14 [standard deviation]) with CRC from 5 datasets. Molecular heterogeneity was identified using unsupervised deconvolution analysis of gene expression data. The relative prevalence of the two subclones associated with cell cycle and extracellular matrix pathways identified patients with significantly different survival outcomes. A radiogenomic signature-based predictive model significantly stratified patients into high- and low-risk groups with disparate disease-free survival (HR = 1.74, P = 0.003). Radiogenomic signatures were revealed as an independent predictive factor for CRC by multivariable analysis (HR = 1.59, 95% CI:1.03-2.45, P = 0.034). Functional analysis demonstrated that the 11 radiogenomic signatures were predominantly associated with extracellular matrix and immune-related pathways. CONCLUSIONS: The identified radiogenomic signatures might be a surrogate for genomic signatures and could complement the current prognostic strategies.

CD47-Mediated Hedgehog/SMO/GLI1 Signaling Promotes Mesenchymal Stem Cell Immunomodulation in Mouse Liver Inflammation.

BACKGROUND AND AIMS: The cluster of differentiation 47 (CD47)-signal regulatory protein alpha (SIRPα) signaling pathway plays important roles in immune homeostasis and tissue inflammatory response. Activation of the Hedgehog/smoothened (SMO)/GLI family zinc finger 1 (Gli1) pathway regulates cell growth, differentiation, and immune function. However, it remains unknown whether and how the CD47-SIRPα interaction may regulate Hedgehog/SMO/Gli1 signaling in mesenchymal stem cell (MSC)-mediated immune regulation during sterile inflammatory liver injury. APPROACH AND RESULTS: In a mouse model of ischemia/reperfusion (IR)-induced sterile inflammatory liver injury, we found that adoptive transfer of MSCs increased CD47 expression and ameliorated liver IR injury. However, deletion of CD47 in MSCs exacerbated IR-induced liver damage, with increased serum ALT levels, macrophage/neutrophil infiltration, and pro-inflammatory mediators. MSC treatment augmented SIRPα, Hedgehog/SMO/Gli1, and Notch1 intracellular domain (NICD), whereas CD47-deficient MSC treatment reduced these gene expressions in IR-stressed livers. Moreover, disruption of myeloid SMO or Notch1 increased IR-triggered liver inflammation with diminished Gli1 and NICD, but enhanced NIMA related kinase 7 (NEK7) and NLR family pyrin domain containing 3 (NLRP3) activation in MSC-transferred mice. Using a MSC/macrophage co-culture system, we found that MSC CD47 and macrophage SIRPα expression were increased after LPS stimulation. The CD47-SIRPα interaction increased macrophage Gli1 and NICD nuclear translocation, whereby NICD interacted with Gli1 and regulated its target gene Dvl2 (dishevelled segment polarity protein 2), which in turn inhibited NEK7/NLRP3 activity. CONCLUSIONS: The CD47-SIRPα signaling activates the Hedgehog/SMO/Gli1 pathway, which controls NEK7/NLRP3 activity through a direct interaction between Gli1 and NICD. NICD is a coactivator of Gli1, and the target gene Dvl2 regulated by the NICD-Gli1 complex is crucial for the modulation of NLRP3-driven inflammatory response in MSC-mediated immune regulation. Our findings provide potential therapeutic targets in MSC-mediated immunotherapy of sterile inflammatory liver injury.

Macrophage Notch1 inhibits TAK1 function and RIPK3-mediated hepatocyte necroptosis through activation of ß-catenin signaling in liver ischemia and reperfusion injury.

BACKGROUND: Notch signaling is highly conserved and critically involved in cell differentiation, immunity, and survival. Activation of the Notch pathway modulates immune cell functions during the inflammatory response. However, it remains unknown whether and how the macrophage Notch1 may control the innate immune signaling TAK1, and RIPK3-mediated hepatocyte necroptosis in liver ischemia and reperfusion injury (IRI). This study investigated the molecular mechanisms of macrophage Notch1 in modulating TAK1-mediated innate immune responses and RIPK3 functions in liver IRI. METHODS: Myeloid-specific Notch1 knockout (Notch1M-KO) and floxed Notch1 (Notch1FL/FL) mice (n = 6/group) were subjected to 90 min partial liver warm ischemia followed by 6 h of reperfusion. In a parallel in vitro study, bone marrow-derived macrophages (BMMs) were isolated from these conditional knockout mice and transfected with CRISPR/Cas9-mediated ß-catenin knockout (KO) vector followed by LPS (100 ng/ml) stimulation. RESULTS: IR stress-induced Notch1 activation evidenced by increased nuclear Notch intracellular domain (NICD) expression in liver macrophages. Myeloid Notch1 deficiency exacerbated IR-induced liver damage, with increased serum ALT levels, macrophage/neutrophil accumulation, and proinflammatory cytokines/chemokines production compared to the Notch1FL/FL controls. Unlike in the Notch1FL/FL controls, Notch1M-KO enhanced TRAF6, TAK1, NF-κB, RIPK3, and MLKL but reduced ß-catenin activation in ischemic livers. However, adoptive transfer of lentivirus ß-catenin-modified macrophages markedly improved liver function with reduced TRAF6, p-TAK1, RIPK3 and p-MLKL in IR-challenged livers. Moreover, disruption of RIPK3 in Notch1M-KO mice with an in vivo mannose-mediated RIPK3 siRNA delivery system diminished IR-triggered hepatocyte death. In vitro studies showed that macrophage NICD and ß-catenin co-localized in the nucleus, whereby ß-catenin interacted with NICD in response to LPS stimulation. Disruption of ß-catenin with a CRISPR/Cas9-mediated ß-catenin KO in Notch1FL/FL macrophage augmented TRAF6 activation leading to enhanced TAK1 function. While CRISPR/Cas9-mediated TRAF6 KO in Notch1M-KO macrophage inhibited RIPK3-mediated hepatocyte necroptosis after co-culture with primary hepatocytes. CONCLUSIONS: Macrophage Notch1 controls TAK1-mediated innate immune responses and RIPK3-mediated hepatocyte necroptosis through activation of ß-catenin. ß-catenin is required for the macrophage Notch1-mediated immune regulation in liver IRI. Our findings demonstrate that the macrophage Notch1-ß-catenin axis is a crucial regulatory mechanism in IR-triggered liver inflammation and provide novel therapeutic potential in organ IRI and transplant recipients. Video abstract.

LiMn2O4 cathodes with F anion doping for superior performance of lithium-ion batteries.

Although considered as promising candidates for lithium-ion secondary batteries, spinel LiMn2O4 cathodes suffer from significant capacity decay owing to the Jahn-Teller effect, dissolution of Mn and lattice oxygen loss during the charge/discharge process, preventing their wider use. In this work, we realize that F-doping at small concentrations could improve the battery voltage and reduce the capacity decay using an atomistic model. For voltage, F-doping improves the voltage to about 4.4 eV under large delithiation. For capacity decay, it retards capacity decay owing to the reduced lattice oxygen loss. The larger Gibbs free energy of oxygen release after F-doping indicates harder lattice oxygen loss. In addition, although F-doping makes the average valence of Mn lower, the existence of Mn4+ during delithiation exerts a positive effect by reducing the Jahn-Teller effect. However, since the Mn3+ ions in the spinel structure could induce Jahn-Teller distortion, the effect of F-doping on Jahn-Teller distortion is determined by the competition between Mn4+ and Mn3+. The atomistic mechanism of F-doping in the performance of LiMn2O4 offers new insight in developing spinel lithium manganese oxide cathode materials with superior performance.

CLPVG: Circular limited penetrable visibility graph as a new network model for time series.

A visibility graph transforms time series into graphs, facilitating signal processing by advanced graph data mining algorithms. In this paper, based on the classic limited penetrable visibility graph method, we propose a novel mapping method named circular limited penetrable visibility graph, which replaces the linear visibility line in limited penetrable visibility graph with nonlinear visibility arc for pursuing more flexible and reasonable mapping of time series. Tests on degree distribution and some common network features of the generated graphs from typical time series demonstrate that our circular limited penetrable visibility graph can effectively capture the important features of time series and show higher robust classification performance than the traditional limited penetrable visibility graph in the presence of noise. The experiments on real-world time-series datasets of radio and electroencephalogram signals also suggest that the structural features provided by a circular limited penetrable visibility graph, rather than a limited penetrable visibility graph, are more useful for time-series classification, leading to higher accuracy. This classification performance can be further enhanced through structural feature expansion by adopting subgraph networks. All of these results demonstrate the effectiveness of our circular limited penetrable visibility graph model.

Metformin suppresses interleukin-22 induced hepatocellular carcinoma by upregulating Hippo signaling pathway.

BACKGROUND AND AIMS: Epidemiological studies have shown direct associations between type 2 diabetes and the risk of cancers. Accumulating evidence indicates that metformin is profoundly implicated in preventing tumor development. However, the exact mechanism underlying the antitumor effects of metformin in hepatocellular carcinoma (HCC) is still not clear. METHODS: In this study, we investigated the effects of metformin on a mouse HCC model and interleukin-22 (IL-22)-associated carcinogenesis in vitro. RESULTS: We found that metformin significantly suppressed the incidence and tumor burden of HCC in the diethyl-nitrosamine-induced HCC mouse model. As expected, the expression of IL-22, an important factor involved in HCC progression, was markedly reduced by metformin. Treatment of HCC cells with metformin inhibited IL-22 induced cell proliferation, migration, and invasion, and promoted cell apoptosis. Furthermore, ectopic expression of IL-22 makes HCC more aggressive, whereas metformin largely compromised it in vitro and in vivo. Mechanistically, the whole transcriptome analysis and functional analysis revealed that Hippo signaling pathway was involved in the antitumor ability of metformin. Consistent with this, metformin directly inhibited LATS1/2 and activated Mst1/2, phosphorylated YAP1 in vitro. After blocking the Hippo pathway by XMU-MP-1, the inhibitor of MST1/2, the inhibitory effects by metformin were dramatically attenuated as shown by in vitro study. CONCLUSIONS: Collectively, our findings illuminate a new regulatory mechanism, metformin activates Hippo signaling pathway to regulate IL-22 mediated HCC progression and provide new insights into its tumor-suppressive roles.

Effect of hydrogenation on the thermal conductivity of 2D gallium nitride.

The indirect bandgap of two-dimensional GaN hinders its application in the optical field. Hydrogenation can convert the bandgap type of the GaN monolayer from an indirect to a direct one and also tune the bandgap size. The thermal transport, an important property in the application of two-dimensional materials, is also influenced by hydrogenation. By performing first-principles calculations and solving the phonon Boltzmann equation, we investigate the effect of hydrogenation on the thermal conductivity of the GaN monolayer. The results show that hydrogenation will slightly increase the thermal conductivity of the GaN monolayer from 70.62 Wm-1 K-1 to 76.23 Wm-1 K-1 at 300 K. The little effect of hydrogenation on thermal conductivity is mainly dominated by two competing factors: (1) the reduction of ZA mode lifetime due to the breaking of reflection symmetry after hydrogenation and (2) the increased contribution from TA and LA modes due to the reduction of anharmonic scattering caused by the enlarged phonon bandgap after hydrogenation. The results are compared with other two-dimensional materials with hexagonal monolayer structures.

Structure and electronic bandgap tunability of m-plane GaN multilayers.

Two-dimensional (2D) gallium nitride (GaN) has attracted a lot of attention due to its promising applications in photoelectric nano-devices. Most previous research studies have focused on polar c-plane 2D structures. Here, by employing first principles calculations, we systematically investigate the structural and electronic properties of non-polar m-plane GaN with different numbers of atomic layers. The results show a layer-dependent structure transition and electronic band variation for m-plane GaN. It is found that the monolayer keeps a planar hexagonal structure due to sp2 hybridization, whereas the multilayers are formed by stacking of buckled hexagonal monolayers with unsaturated coordination number at the surface sublayer and bulk-like inner layers. These discrepancies in the structure further induce an indirect to direct transition of the band gap type when the layer number reaches twelve. By carefully examining the relationship between the structure and electronic bandgap, we find that the indirect bandgap comes from the unsaturated surface with a planar like structure. On surface modification, saturation of the surface dangling bonds results in an indirect to direct band gap transition.

Mortality and serum hepcidin are associated with persistent and transient acute kidney injury in septic patients.

PURPOSE: Acute kidney injury (AKI) is a common complication of sepsis and has high mortality. The 2017 Acute Disease Quality Initiative (AQDI) workgroup proposed new definitions for AKI - transient AKI and persistent AKI; however, very little is known about the effect of transient and persistent septic AKI on short-term mortality among critically ill patients with sepsis. The purpose of this study was to assess the impact of persistent AKI on mortality and to evaluate whether serum hepcidin can predict the occurrence of persistent AKI in critically ill patients with sepsis. MATERIALS AND METHODS: This prospective observational study was performed in a general hospital mixed surgical-medical ICU in Pudong, China. Consecutive adults with sepsis admitted to the ICU with absence of chronic kidney disease, renal transplant, and AKI were included. AKI was defined according to the KDIGO criteria and classified as transient (< 48-hour duration) or persistent (48-hour duration). Blood samples were obtained within 6 hours from when AKI was diagnosed. RESULTS: A total of 90 patients with sepsis or septic shock were included in the analysis. 44 (48.89%) patients developed AKI during ICU stay: 20 (45.45%) had transient and 24 (54.55%) had persistent AKI. Persistent AKI has a higher mortality than transient AKI (66.7 vs. 30.0%, p = 0.002). Persistent AKI and sequential organ failure assessment (SOFA) scores were an independent predictor of 60-day mortality. Patients with persistent AKI had higher concentrations of serum creatinine (SCr) and hepcidin than transient AKI patients when AKI was diagnosed. Logistic regression indicated that serum hepcidin was an independent predictor of persistent AKI in septic patients, with a fairly predictive value (AUC 0.71, 95% CI: 0.47 - 0.87; p = 0.02). CONCLUSION: Persistent AKI was associated with increased 60-day mortality compared with transient AKI in septic patients. The serum hepcidin levels measured when AKI was diagnosed have a fair predictive value to predict the occurrence of persistent AKI in septic patients.

Kinetic changes in serum procalcitonin predict persistent acute kidney injury in critical patients.

PURPOSE: Persistent acute kidney injury (AKI) has been shown to be closely associated with poor prognosis in critical patients. Recent studies have shown that procalcitonin (PCT) is valuable for the early prediction of AKI in critically patients. Our aim was to determine whether PCT and its kinetic changes could predict the occurrence of persistent AKI in critical patients. METHODS: This is a prospective observational study. The definition of AKI was based on the Kidney Disease: Improving Global Outcomes criteria. Persistent AKI was defined as renal function that does not return to baseline serum creatinine levels within 48 h. Blood samples were obtained at the onset of AKI and two subsequent days of hospital stay. 24-h PCT change (ΔPCT-24 h) was defined as 24 h PCT minus baseline PCT (day 0). RESULTS: A total of 91 critical patients with AKI were included in this study. The persistent AKI group had a stepwise increase in PCT concentration. ΔPCT-24 h was higher in the persistent AKI group (p < .01). Logistic regression analysis showed that ΔPCT-24 h (p = .04) was independent predictors of persistent AKI. The receiver operating characteristic curves showed that area under the curve of ΔPCT-24 h was 0.84 (p < .01), and the cut-off value for PCT to predict persistent AKI was 0.56 ng/ml. CONCLUSION: Our study showed that the observation of kinetic changes in PCT is more significant for the early prediction of persistent AKI than the index of PCT at a single time point. ΔPCT-24 h is a good predictor of persistent AKI in critical patients.

An urban commuters' OD hybrid prediction method based on big GPS data.

With the quick development of mobile Internet and communication technology, the use of Global Position System (GPS)-enabled devices is rapidly increasing, which facilitates the collection of huge volumes of movement data in the form of trajectories. Trajectory data contain a lot of commuters' travel information, which offer convenience for researchers to study traffic problems and to mine urban commuters' travel information. In this paper, we represent an urban commuters' origin-destination (OD) hybrid prediction method based on big GPS data, which considers the temporal and spatial dependencies of OD volume data simultaneously. The regional division was performed based on a simple grid map, and the data for each grid can be obtained. Based on the grids, the OD pairs can be constructed and the network topology of OD pairs can be established. A graph convolutional network and a long short-term memory deep learning method were introduced to capture the temporal and spatial dependencies, respectively. In addition, an attention mechanism was used to learn the weights of input data. The numerical experiment was performed based on the GPS data in Chengdu, China, and some comparisons were made. The results demonstrated that the proposed hybrid OD prediction method was significant and the accuracy was reasonable.

Road traffic state prediction based on a graph embedding recurrent neural network under the SCATS.

Road traffic state prediction is one of the essential and vital issues in intelligence transportation system, but it is difficult to get high accuracy due to the complicated spatiotemporal characteristics of traffic flow data, especially under the Sydney coordinated adaptive traffic system. In this work, we represent the traffic road network as a graph and propose a novel traffic flow prediction framework named the graph embedding recurrent neural network (GERNN). It could tackle the difficulty in the road traffic state prediction. We conduct numerical tests to compare GERNN with other existing methods using a real-world dataset.

Rictor Deficiency Aggravates Hepatic Ischemia/Reperfusion Injury in Mice by Suppressing Autophagy and Regulating MAPK Signaling.

BACKGROUND/AIMS: The role of Rictor in hepatic ischemia/reperfusion (I/R) injury remains unknown. Here, we comprehensively examined the role of Rictor in hepatic I/R injury. METHODS: We studied the expression of Rictor during hepatic I/R injury. The regulatory effects of Rictor on inflammatory responses, cytokine and chemokine release, apoptotic and anti-apoptotic responses, and autophagy induction during hepatic I/R injury were identified via the shRNA-mediated knockdown of Rictor. Subsequently, we collected the liver and blood samples of these mice to evaluate liver injury, mRNA and protein levels. Additionally, the signaling pathways induced by Rictor were investigated. Furthermore, the extent of activation of MAPKs in response to Rictor deficiency was investigated in lipopolysaccharide (LPS)-treated RAW264.7 cells. The mRNA expression levels were analyzed by real-time PCR, and the protein expression levels were analyzed using Western blot, immunofluorescence staining and enzyme-linked immunosorbent assay (ELISA). RESULTS: The expression of Rictor was increased during hepatic I/R injury in vivo and hypoxia/reoxygenation (H/R) injury in vitro. Rictor deficiency enhanced the extent of liver injury by increasing macrophage and neutrophil infiltration, promoting cytokine and chemokine release, aggravating hepatocyte apoptosis, suppressing anti-apoptotic responses, and inhibiting autophagy induction during both hepatic I/R and H/R injury. Rictor was associated with the activation of hepatic I/R injury-induced MAPK signaling. In addition, Rictor deficiency affected MAPK activation in LPS-treated RAW264.7 cells. CONCLUSION: Rictor can substantially ameliorate I/R-induced liver injury. Therefore, our findings strongly suggest a therapeutic value of the Rictor/mTORC2 axis in hepatic I/R injury.

Kinetic Monte Carlo simulations of GaN homoepitaxy on c- and m-plane surfaces.

The surface orientation can have profound effects on the atomic-scale processes of crystal growth and is essential to such technologies as GaN-based light-emitting diodes and high-power electronics. We investigate the dependence of homoepitaxial growth mechanisms on the surface orientation of a hexagonal crystal using kinetic Monte Carlo simulations. To model GaN metal-organic vapor phase epitaxy, in which N species are supplied in excess, only Ga atoms on a hexagonal close-packed (HCP) lattice are considered. The results are thus potentially applicable to any HCP material. Growth behaviors on c-plane (0001) and m-plane (011¯0) surfaces are compared. We present a reciprocal space analysis of the surface morphology, which allows extraction of growth mode boundaries and direct comparison with surface X-ray diffraction experiments. For each orientation, we map the boundaries between 3-dimensional, layer-by-layer, and step flow growth modes as a function of temperature and growth rate. Two models for surface diffusion are used, which produce different effective Ehrlich-Schwoebel step-edge barriers and different adatom diffusion anisotropies on m-plane surfaces. Simulation results in agreement with observed GaN island morphologies and growth mode boundaries are obtained. These indicate that anisotropy of step edge energy, rather than adatom diffusion, is responsible for the elongated islands observed on m-plane surfaces. Island nucleation spacing obeys a power-law dependence on growth rate, with exponents of -0.24 and -0.29 for the m- and c-plane, respectively.