Differential expression and clinical significance of COX6C in human diseases.

Mitochondria, independent double-membrane organelles, are intracellular power plants that feed most eukaryotic cells with the ATP produced via the oxidative phosphorylation (OXPHOS). Consistently, cytochrome c oxidase (COX) catalyzes the electron transfer chain's final step. Electrons are transferred from reduced cytochrome c to molecular oxygen and play an indispensable role in oxidative phosphorylation of cells. Cytochrome c oxidase subunit 6c (COX6C) is encoded by the nuclear genome in the ribosome after translation and is transported to mitochondria via different pathways, and eventually forms the COX complex. In recent years, many studies have shown the abnormal level of COX6C in familial hypercholesterolemia, chronic kidney disease, diabetes, breast cancer, prostate cancer, uterine leiomyoma, follicular thyroid cancer, melanoma tissues, and other conditions. Its underlying mechanism may be related to the cellular oxidative phosphorylation pathway in tissue injury disease. Here reviews the varied function of COX6C in non-tumor and tumor diseases.

The function of SEC22B and its role in human diseases.

Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins are a large protein complex that is involved in the membrane fusion in vesicle trafficking, cell growth, cytokinesis, membrane repair, and synaptic transmission. As one of the SNARE proteins, SEC22B functions in membrane fusion of vesicle trafficking between the endoplasmic reticulum and the Golgi apparatus, antigen cross-presentation, secretory autophagy, and other biological processes. However, apart from not being SNARE proteins, there is little knowledge known about its two homologs (SEC22A and SEC22C). SEC22B alterations have been reported in many human diseases, especially, many mutations of SEC22B in human cancers have been detected. In this review, we will introduce the specific functions of SEC22B, and summarize the researches about SEC22B in human cancers and other diseases. These findings have laid the foundation for further studies to clarify the exact mechanism of SEC22B in the pathological process and to seek new therapeutic targets and better treatment strategies.

The blockage of Notch signalling promoted the generation of polymorphonuclear myeloid-derived suppressor cells with lower immunosuppression.

Myeloid-derived suppressor cells (MDSCs) mostly consisting of polymorphonuclear (PMN)-MDSCs and mononuclear MDSCs have been considered to play critical roles in immunosuppression, angiogenesis, invasion and metastases of various tumours. However, it is still unclear the regulated mechanisms underlying the generation and immunosuppression of two major MDSC subsets. Here, we report Notch signalling was inhibited significantly in tumour-bearing mouse MDSCs, in which PMN-MDSCs were the major population. MDSCs without recombination signal binding protein-Jк (RBP-J), the critical transcription factor mediating signalling from all four mammalian Notch receptors, reduced their ability of inhibiting the proliferation and activation of allogenic T cells. RBP-J-deficient MDSCs could not down-regulate the expression of co-stimulation molecules on dendritic cells (DCs). The antigen presentation capacity of DCs co-cultured with RBP-J-deficient MDSCs was not impaired in contrast to controls. Moreover, we show the blockage of Notch signalling could improve the generation of PMN-MDSCs but inhibit the production of mononuclear MDSCs both in vitro and in vivo. Stat3 pathway was suppressed in MDSCs blocked Notch signalling and Stat3 activation by IL-6 could reverse the phenotype and immunosuppression of Notch signalling-deficient MDSCs. Therefore, targeting Notch signalling may be an effective therapeutic strategy in tumour therapy.

[TNF-α stimulates bone marrow mesenchymal stem cell VCAM-1 production by ERK signaling pathway].

This study was aimed to explore the effect of TNF-α on the vascular cell adhesion molecule 1 (VCAM-1) expression of human bone marrow mesenchymal stem cells (BMMSC) and the relationship between this process and ERK signalling pathway. BMMSC were isolated by density gradient centrifugation combined with adherent culture method, and then identified by surface antigen expression and differentiation potential. Flow cytometry was used to detect expression of VCAM-1 on BMMSC exposed to TNF-α at different concentrations, and the effect of ERK inhibitor U0126 on VCAM-1 of BMMSC. ERK signaling pathway activation was analyzed by Western blot. The results showed that BMMSC positively expressed CD29, CD69, CD44, CD105, and negatively expressed CD34, CD45. BMMSC could be induced to differentiate into osteoblasts and adipocytes. Flow cytometry analysis showed that after the TNF-α stimulation, the expression of VCAM-1 on BMMSC increased in a dose-dependent manner. And this increase was inhibited by U0126. TNF-α caused activation of ERK signal pathway, and U0126 suppressed this effect induced by TNF-α. It is concluded that TNF-α can increase expression of VCAM-1 of BMMSC via ERK signaling pathway.

[The relationship of telomere and telomerase activity with outcome of aplastic anemia after immunosuppressive therapy].

OBJECTIVE: To observe the changes of telomere length and telomerase activity in patients with aplastic anemia (AA), and relationship with immunosuppressive therapy (IST) efficacy, to explore the pathogenesis of AA and the role of telomere length in evaluating immunosuppressive therapy efficacy. METHODS: 71 cases of AA patients between September 2010 and March 2013 were enrolled into this study. 3 ml peripheral blood specimens from this cohort of patients were collected to test the telomere length in peripheral blood mononuclear cell (PBMNC) with flow-FISH and detect telomerase activity with TRAP-PCR-ELISA method. RESULTS: Telomere length and age showed negative correlation (b=-0.387, P=0.001) in normal control, NSAA and SAA + VSAA groups, telomere length became shorter with the growth of age, and normal control group telomere length decreased along with the age growth slightly greater than the other two groups (NSAA, SAA+VSAA). Besides the effect of age on telomere length, no significant difference was observed between NSAA and SAA+VSAA groups (P=0.573), and NSAA, SAA+VSAA (30.957 ± 4.502,29.510 ± 5.911)groups were significantly shorter than normal control group (51.086±10.844) (P<0.01). Telomere length in NR group (25.357±4.848)was significantly lower than normal control group (51.086 ± 10.844) (P=0.005), telomere length in CR(32.808 ± 4.685)/PR groups (30.334±4.464) compared with normal control group had no significant difference (P=0.517, P=0.254). Telomere length below 29.21% obviously decreased outcomes of IST. Telomerase activity had significant difference (χ²=20.385, P<0.01). The telomerase activity had no significant difference in terms of age and gender in three groups, multiple comparison found that telomerase activities in SAA + VSAA (0.324±0.178) (P<0.01), and NSAA (0.234±0.175) groups (P=0.002) were significantly higher than normal control group (0.107±0.083). CONCLUSION: Telomere length of PBMNC in AA patients was significantly shortened than normal control group with telomerase activity increased, and telomere shorted more apparently in NR group, these patients should adjust the treatment as early as possible. Telomeres could predict the curative effect of IST.

Notch-RBP-J signaling is required by bone marrow stromal cells for the treatment of acute graft versus host disease.

Recent evidence has shown that bone marrow stromal cells (BMSCs) may exhibit immuno-suppression activities through soluble mediators and direct cell-cell contact, but how these processes are modulated has been poorly understood. In this study, we show that the Notch signaling pathway participates in the modulation of BMSCs to elicit their immuno-suppressive roles. In a murine lethal acute graft versus host disease (aGvHD) model, BMSCs deficient for RBP-J, the critical transcription factor mediating signaling from all four mammalian Notch receptors, failed to delay the development of the disease. RBP-J deficient BMSCs were not able to inhibit the proliferation and activation of allogenic T-cells. Moreover, RBP-J deficient BMSCs could not down-regulate the expression of MHC II and co-stimulation molecules CD80 and CD86 on dendritic cells (DCs). The antigen presentation capacity of DCs co-cultured with RBP-J deficient BMSCs was not impaired in contrast to wild type BMSCs. Furthermore, we showed that the productions of IL-6 and PGE2, two critical molecules mediating the immuno-suppressive activities of BMSCs, were reduced significantly in RBP-J deficient BMSCs. Both of the two molecules were importantly involved in the regulation of BMSCs by Notch signaling. In conclusion, our data suggests that the immuno-suppressive effects of BMSCs in aGvHD are dependent on Notch-RBP-J signaling, which regulates the productions of IL-6 and PGE2.

The dynamics behavior of Rh nanoclusters on boron nitride sheet.

The configurations and corresponding adsorption energies of Rh(n) (n = 4-13) nanoclusters on the boron nitride sheet are investigated by density functional theory (DFT). We use the force-matching method (FMM) to modify parameters of Morse and Tersoff potential functions. To elucidate the dynamical behaviors of Rh nanoclusters on the boron nitride sheet, molecular dynamics (MD) is applied with modified Morse potential function parameter. Finally, the square displacement (SD) is utilized the dynamics behavior of different size Rh nanoclusters at different temperatures.

Notch signaling regulates CXCR4 expression and the migration of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) have been used to repair injured tissues through immune-suppression and/or cell replace mechanisms. However, a significant barrier to MSC therapy is insufficient MSC engraftment in injured tissues after systemic administration. Here, we report that cell surface, total protein, and mRNA levels of CXCR4 were significantly increased in MSCs when Notch signaling was interrupted by γ-secretase inhibitor (GSI) or knockout of the transcription factor RBP-J, which mediates signaling from all four mammalian Notch receptors. The GSI-treated or RBP-J deficient MSCs showed stronger migration toward stromal cell-derived factor-1α (SDF-1α) than that of the control. In a mouse hepatic ischemia/reperfusion model, RBP-J deficient MSCs migrated into the injured liver tissues at a significantly higher efficiency than that of the control MSCs. Mice transfused with RBP-J deficient MSCs showed reduced liver damage. Therefore, Notch signaling regulates MSC migration and function, at least partially via the modulation of CXCR4 expression.

The balance between two isoforms of LEF-1 regulates colon carcinoma growth.

BACKGROUND: Colon cancer is one of the most aggressive human malignancies, with a very poor prognosis. Although it has been suggested that different isoforms of the lymphoid enhancer factor (LEF-1) have opposing biological activities, the biological outcome of aberrant LEF-1 activation in colon cancer is still unclear. The aim of this study was to evaluate the effect of the different LEF-1 phenotypes on the growth of colon carcinoma cell lines. A deeper understanding of these processes might improve the targeted therapies for colon cancer by regulating the expression of LEF-1. METHODS: The role of different isoforms of LEF-1 on the growth of human colon carcinoma cell lines (SW480 and HT-29) was studied using various in vitro and in vivo assays. In vitro proliferation, migration, adhesion and apoptosis of the cells stably transfected of different isoforms of LEF-1 were monitored by MTT assay, carboxyfluorescein diacetate-succinimidyl ester staining, annexin V staining, ECM adhesion assay and transwell assay, respectively. In nude mice, the formation of neovasculature in the tumors formed by our constructed cells was measured by immunohistochemistry. All the data were analyzed using a t test, and data were treated as significant when p < 0.05. RESULTS: Overexpression of truncated LEF-1 (LEF-1-ΔL) in the colon cell lines, SW480 and HT29, inhibited their growth significantly in vitro and in vivo, but the full-length LEF-1 (LEF-1-FL) promoted the proliferation of HT29. Inactivation of Wnt signaling by LEF-1-ΔL reduced the expression of CXCR4 in colon cell lines, which may lead to a decrease in activities such as migration, adhesion and survival. In nude mice, the formation of neovasculature as well as an increase in tumor volume were inhibited by the short isoform of LEF-1. LEF-1-FL, however, caused an increase in all these parameters compared with controls. CONCLUSIONS: These findings suggest that LEF-1 might play an important role in colon carcinogenesis by acting as a regulator. Enhanced expression of LEF-1-FL, which occurs frequently in colon cancer, may be a new target for clinical therapy.

Kinetics and mechanisms for the adsorption, dissociation, and diffusion of hydrogen in Ni and Ni/YSZ slabs: a DFT study.

The adsorption, dissociation, and diffusion of hydrogen in Ni(100) and Ni(100)/YSZ(100) slabs with two different interfaces (Ni/cation and Ni/O interface) have been studied by the density functional theory (DFT) with the Perdew-Wang functional. The H(2) molecule is found to preferentially absorb on a Top (T) site with side-on configuration on the Ni(100) surface, while the H-atom is strongly bound at a fcc Hollow (H) site. The barrier for the H(2) dissociation on both surfaces is calculated to be only ~0.1 eV. The potential energy pathways of H diffusion on pure Ni and Ni/YSZ with the two different interfaces are studied. Our calculated results show that the H-atom diffusion occurs via surface path rather than the bulk path. For the bulk path in Ni/YSZ, H-atom migration can occur more readily at the Ni/cation interface compared to the Ni/O interface. The existence of vacancy in the interface region is found to improve the mobility of H-atoms at the interface of Ni/YSZ slab. The rate constants for hydrogen dissociation and diffusion in pure Ni and Ni/YSZ are predicted.

Monocyte to macrophage differentiation-associated (MMD) positively regulates ERK and Akt activation and TNF-α and NO production in macrophages.

Macrophage activation is modulated by both environmental cues and endogenous programs. In the present study, we investigated the role of a PAQR family protein, monocyte to macrophage differentiation-associated (MMD), in macrophage activation and unveiled its underlying molecular mechanism. Our results showed that while MMD expression could be detected in all tissues examined, its expression level is significantly up-regulated upon monocyte differentiation. Within cells, EGFP-MMD fusion protein could be co-localized to endoplasmic reticulum, mitochondria, Golgi apparatus, but not lysosomes and cytoplasm. MMD expression is up-regulated in macrophages after LPS stimulation, and this might be modulated by RBP-J, the critical transcription factor of Notch signaling. Overexpression of MMD in macrophages increased the production of TNF-α and NO upon LPS stimulation. We found that MMD overexpression enhanced ERK1/2 and Akt phosphorylation in macrophages after LPS stimulation. Blocking Erk or Akt by pharmacological agent reduced TNF-α or NO production in MMD-overexpressing macrophages, respectively. These results suggested that MMD modulates TNF-α and NO production in macrophages, and this process might involves Erk or Akt.

Tuning the electronic properties of boron nitride nanotube by mechanical uni-axial deformation: a DFT study.

The effect of uni-axial strain on the electronic properties of (8,0) zigzag and (5,5) armchair boron nitride nanotubes (BNNT) is addressed by density functional theory calculation. The stress-strain profiles indicate that these two BNNTS of differing types display very similar mechanical properties, but there are variations in HOMO-LUMO gaps at different strains, indicating that the electronic properties of BNNTs not only depend on uni-axial strain, but on BNNT type. The variations in nanotube geometries, partial density of states of B and N atoms, B and N charges are also discussed for (8,0) and (5,5) BNNTs at different strains.

Modeling of polyethylene, poly(l-lactide), and CNT composites: a dissipative particle dynamics study.

Dissipative particle dynamics (DPD), a mesoscopic simulation approach, is used to investigate the effect of volume fraction of polyethylene (PE) and poly(l-lactide) (PLLA) on the structural property of the immiscible PE/PLLA/carbon nanotube in a system. In this work, the interaction parameter in DPD simulation, related to the Flory-Huggins interaction parameter χ, is estimated by the calculation of mixing energy for each pair of components in molecular dynamics simulation. Volume fraction and mixing methods clearly affect the equilibrated structure. Even if the volume fraction is different, micro-structures are similar when the equilibrated structures are different. Unlike the blend system, where no relationship exists between the micro-structure and the equilibrated structure, in the di-block copolymer system, the micro-structure and equilibrated structure have specific relationships.

The dynamic behavior of ethanol and water mixtures inside an Au nanotube molecule filter.

Molecular dynamics (MD) simulation was used to investigate the behavior of water and ethanol molecules, which were mixed with five water-ethanol weight fractions (100:0, 0:100, 25:75, 50:50, and 75:25) inside the Au nanotube. To investigate the nano-confinement effect on water and ethanol molecules, the data of both molecules were analyzed by the probability of the number H-bonds per water and ethanol molecule and radial density distribution. Our results reveal that the radial density distributions and the number of H-bonds are significantly influenced by the Au nanotube, and the molecules also display different behavior from those in the bulk environment. In addition, the interaction between water molecules and the Au nanotube is stronger than that between ethanol molecules and the Au nanotube, from the profile of radial density distribution. Finally, both the number of H-bonds per water and per ethanol will be affected by the weight fraction, because the H-bond not only forms between the same material, but also between different materials.

The interfacial behavior of water/PMMA thin film under normal compression.

Molecular dynamics simulation (MD) has been used to investigate the structure property of water/PMMA interface under compression and compression release. A virtual repulsive wall was employed to generate a normal compression strain on the simulation model, leading a compressive system. In order to understand the difference of interfacial phenomenon between the system under strain and under release, the hydrogen bond and density distributions of water and PMMA along the normal direction are calculated. The results show that the hydrogen bond distribution profile of compressive system is different from that of the release system at the same strain. It demonstrates that the characteristic structure of water/PMMA interface under a compression-release cycle is not reversible.

Notch signaling determines the M1 versus M2 polarization of macrophages in antitumor immune responses.

Macrophages are important tumor-infiltrating cells and play pivotal roles in tumor growth and metastasis. Macrophages participate in immune responses to tumors in a polarized manner: classic M1 macrophages produce interleukin (IL) 12 to promote tumoricidal responses, whereas M2 macrophages produce IL10 and help tumor progression. The mechanisms governing macrophage polarization are unclear. Here, we show that the M2-like tumor-associated macrophages (TAM) have a lower level of Notch pathway activation in mouse tumor models. Forced activation of Notch signaling increased M1 macrophages which produce IL12, no matter whether M1 or M2 inducers were applied. When Notch signaling was blocked, the M1 inducers induced M2 response in the expense of M1. Macrophages deficient in canonical Notch signaling showed TAM phenotypes. Forced activation of Notch signaling in macrophages enhanced their antitumor capacity. We further show that RBP-J-mediated Notch signaling regulates the M1 versus M2 polarization through SOCS3. Therefore, Notch signaling plays critical roles in the determination of M1 versus M2 polarization of macrophages, and compromised Notch pathway activation will lead to the M2-like TAMs. These results provide new insights into the molecular mechanisms of macrophage polarization and shed light on new therapies for cancers through the modulation of macrophage polarization through the Notch signaling.

The transcription factor RBP-J-mediated signaling is essential for dendritic cells to evoke efficient anti-tumor immune responses in mice.

BACKGROUND: Dendritic cells (DCs) are professional antigen presenting cells that initiate specific immune responses against tumor cells. Transcription factor RBP-J-mediated Notch signaling regulates DC genesis, but whether this pathway regulates DC function in anti-tumor immunity remains unclear. In the present work we attempted to identify the role of Notch signaling in DC-mediated anti-tumor immune response. RESULTS: When DCs were co-inoculated together with tumor cells, while the control DCs repressed tumor growth, the RBP-J deficient DCs had lost tumor repression activity. This was most likely due to that DCs with the conditionally ablated RBP-J were unable to evoke anti-tumor immune responses in the solid tumors. Indeed, tumors containing the RBP-J deficient DCs had fewer infiltrating T-cells, B-cells and NK-cells. Similarly, the draining lymph nodes of the tumors with RBP-J-/- DCs were smaller in size, and contained fewer cells of the T, B and NK lineages, as compared with the controls. At the molecular level, the RBP-J deficient DCs expressed lower MHC II, CD80, CD86, and CCR7, resulting in inefficient DC migration and T-cell activation in vitro and in vivo. T-cells stimulated by the RBP-J deficient DCs did not possess efficient cytotoxicity against tumor cells, in contrast to the control DCs. CONCLUSION: The RBP-J-mediated Notch signaling is essential for DC-dependent anti-tumor immune responses. The deficiency of RBP-J impairs the DC-based anti-tumor immunity through affecting series of processes including maturation, migration, antigen presentation and T-cell activation. The Notch signaling pathway might be a target for the establishment of the DC-based anti-tumor immunotherapies.

Modeling of the polyethylene and poly(L-lactide) triblock copolymer: a dissipative particle dynamics study.

Dissipative particle dynamics (DPD), a mesoscopic simulation approach, has been used to investigate the effect of the arrangement of the microstructure and the effect of the volume fraction on the structural properties of the immiscible polyethylene (PE)/poly(L-lactide) (PLLA) polymer in the triblock copolymer system. In this work, the interaction parameter in DPD simulation, related to the Flory-Huggins interaction parameter chi, is estimated by the calculation of mixing energy for each pair of components in molecular dynamics simulation. The immiscibility property of PE and PLLA polymers induces phase separation and exhibits different architectures at different volume fractions. In order to obtain the structural property, the radius of gyration and the end-to-end distance are used to observe the detailed arrangement of the triblock copolymer. The results show first that the relative volume fractions of PE and PLLA directly affect the bridge and loop fraction, and, second, that whether or not the arrangement is symmetrical or asymmetrical affects the equilibrium structure in the triblock copolymer system. Moreover, as the chain length of the component chains within the PE-PLLA-PE triblock copolymer increase, those component chains become softer; therefore, this directly affects the bridge and loop fraction.

Notch-RBP-J signaling regulates the mobilization and function of endothelial progenitor cells by dynamic modulation of CXCR4 expression in mice.

Bone marrow (BM)-derived endothelial progenitor cells (EPC) have therapeutic potentials in promoting tissue regeneration, but how these cells are modulated in vivo has been elusive. Here, we report that RBP-J, the critical transcription factor mediating Notch signaling, modulates EPC through CXCR4. In a mouse partial hepatectomy (PHx) model, RBP-J deficient EPC showed attenuated capacities of homing and facilitating liver regeneration. In resting mice, the conditional deletion of RBP-J led to a decrease of BM EPC, with a concomitant increase of EPC in the peripheral blood. This was accompanied by a down-regulation of CXCR4 on EPC in BM, although CXCR4 expression on EPC in the circulation was up-regulated in the absence of RBP-J. PHx in RBP-J deficient mice induced stronger EPC mobilization. In vitro, RBP-J deficient EPC showed lowered capacities of adhering, migrating, and forming vessel-like structures in three-dimensional cultures. Over-expression of CXCR4 could at least rescue the defects in vessel formation by the RBP-J deficient EPC. These data suggested that the RBP-J-mediated Notch signaling regulated EPC mobilization and function, at least partially through dynamic modulation of CXCR4 expression. Our findings not only provide new insights into the regulation of EPC, but also have implications for clinical therapies using EPC in diseases.

Endothelial cells promote the proliferation of lymphocytes partly through the Wnt pathway via LEF-1.

The function of T cells and B cells is to recognize specific "non-self" antigens, during a process known as antigen presentation. Once they have identified an invader, the cells generate specific responses that are tailored to maximally eliminate specific pathogens or pathogen-infected cells. Endothelial cells (ECs) can trigger the activation of T cells through their class I and class II MHC molecules. In this study, we examined the effect of ECs on the proliferation of lymphocytes. We report that the proliferation of T and B cells can be improved by interaction with ECs. LEF-1 is one of the main molecular mediators in this process, and the inhibition of LEF-1 induces apoptosis. These results suggest that LEF-1 modulates positively the proliferation of lymphocytes induced by their interaction with ECs.