Critical roles of the activation of ethylene pathway genes mediated by DNA demethylation in Arabidopsis hyperhydricity.

Hyperhydricity (HH) often occurs in plant tissue culture, seriously influencing the commercial micropropagation and genetic improvement. DNA methylation has been studied for its function in plant development and stress responses. However, its potential role in HH is unknown. In this study, we report the first comparative DNA methylome analysis of normal and hyperhydric Arabidopsis thaliana (L.) Heynh. seedlings using whole-genome bisulfite sequencing (BS-seq). We found that the global methylation level decreased in hyperhydric seedlings, and most of the differentially methylated genes were CHH hypomethylated genes. Moreover, the bisulfite sequencing results showed that hyperhydric seedlings displayed CHH demethylation patterns in the promoter of the ACS1 and ETR1 genes, resulting in upregulated expression of both genes and increased ethylene accumulation. Furthermore, hyperhydric seedling displayed reduced stomatal aperture accompanied by decreased water loss and increased phosphorylation of aquaporins accompanied by increased water uptake. While silver nitrate (AgNO3 ) prevented HH by maintained the degree of methylation in the promoter regions of ACS1 and ETR1 and downregulated the transcription of both genes. AgNO3 also reduced the content of ethylene together with the phosphorylation of aquaporins and water uptake. Taken together, this study suggested that DNA demethylation is a key switch that activates ethylene pathway genes to enable ethylene synthesis and signal transduction, which may subsequently influence aquaporin phosphorylation and stomatal aperture, eventually causing HH; thus, DNA demethylation plays a crucial role in HH. These results provide insights into the epigenetic regulation mechanism of HH and confirm the role of ethylene and AgNO3 in hyperhydricity control.

Bone marrow mesenchymal stem cell-derived exosomes promote plasminogen activator inhibitor 1 expression in vascular cells in the local microenvironment during rabbit osteonecrosis of the femoral head.

BACKGROUND: Nontraumatic osteonecrosis of the femoral head (NONFH) is a highly disabling orthopedic disease in young individuals. Plasminogen activator inhibitor 1 (PAI-1) has been reported to be positively associated with NONFH. We aimed to investigate the dysregulating PAI-1 in bone marrow mesenchymal stem cells (BMMSCs) and vascular cells in rabbit steroid-induced NONFH. METHODS: To verify the hypothesis that BMMSCs could promote thrombus formation in a paracrine manner, we collected exosomes from glucocorticoid-treated BMMSCs (GB-Exo) to determine their regulatory effects on vascular cells. microRNA sequencing was conducted to find potential regulators in GB-Exo. Utilizing gain-of-function and knockdown approaches, we testified the regulatory effect of microRNA in exosomes. RESULTS: The expression of PAI-1 was significantly increased in the local microenvironment of the femoral head in the ONFH model. GB-Exo promoted PAI-1 expression in vascular smooth muscle cells and vascular endothelial cells. We also revealed that miR-451-5p in GB-Exo plays a crucial role for the elevated PAI-1. Moreover, we identified miR-133b-3p and tested its role as a potential inhibitor of PAI-1. CONCLUSIONS: This study provided considerable evidence for BMMSC exosomal miR-mediated upregulation of the fibrinolytic regulator PAI-1 in vascular cells. The disruption of coagulation and low fibrinolysis in the femoral head will eventually lead to a disturbance in the microcirculation of NONFH. We believe that our findings could be of great significance for guiding clinical trials in the future.

The bacterial potassium transporter gene MbtrkH improves K+ uptake in yeast and tobacco.

K+ is an essential nutrient for plant growth and is responsible for many important physiological processes. K+ deficiency leads to crop yield losses, and overexpression of K+ transporter genes has been proven to be an effective way to resolve this problem. However, current research on the overexpression of K+ transporter genes is limited to plant sources. TrkH is a bacterial K+ transporter whose function generally depends on the regulation of TrkA. To date, whether TrkH can improve K+ uptake in eukaryotic organisms is still unknown. In this study, a novel MbtrkH gene was cloned from marine microbial metagenomic DNA. Functional complementation and K+-depletion analyses revealed that MbTrkH functions in K+ uptake in the K+-deficient yeast strain CY162. Moreover, K+-depletion assays revealed that MbtrkH overexpression improves plant K+ uptake. K+ hydroponic culture experiments showed that, compared with WT tobacco lines, MbtrkH transgenic tobacco lines had significantly greater fresh weights, dry weights and K+ contents. These results indicate that MbTrkH promotes K+ uptake independently of TrkA in eukaryotes and provide a new strategy for improving K+-use efficiency in plants.

Long-term Production of Glycogen and Hepatic-Derived, Cell-Invasion-Promoting Chemokines by Ultrasound-Driven Hepatic-Differentiated Human Bone Marrow Mesenchymal Stem Cells.

The current treatment for liver failure is restricted to surgical liver transplantation, which is technically complicated, limited by the shortage of available organs and presents major risks to the patient. Bone marrow mesenchymal stem cells (BMSCs) represent promising sources of hepatocyte-like cells for cell transplantation treatment. However, a safe and efficient induction method for their differentiation remains to be defined. Here we further optimized an effective technique by combining high-dose treatment with hepatocyte growth factor (HGF) and ultrasound stimulation. The optimized ultrasound parameter (1.0 W/cm2 intensity, 1 MHz frequency, 20% duty cycle, 100 Hz pulse repetition frequency, 60-s irradiation duration, triple times in three days) combined with different HGF doses (10, 20 and 50 ng/ml) was used to treat BMSCs. The results showed that the specific hepatic markers, including α-fetoprotein (αFP/AFP), cytokeratin 18 (CK18), albumin (ALB) and glycogen, were increased in a dose-dependent manner. Their concentration was then further increased when ultrasound irradiation was administered (P < 0.05), as indicated by PCR, Western blot and immunofluorescence staining as well as a glycogen synthesis test. Furthermore, analysis of the hepatocyte-derived chemokines showed elevated stromal cell-derived factor 1alpha (SDF-1α) and C-X-C chemokine receptor type 4 (CXCR4) after HGF treatment. Again, concentrations of those chemokines were further increased by ultrasound radiation (P < 0.05). The observed increased effect was sustained for 21 days. To summarize, we further defined the optimal combination of HGF and ultrasound treatment to increase the differentiation and chemotaxis of BMSCs in a safe, sustained and efficient manner. These findings provide a new perspective for stem cell orientation in the field of tissue engineering.

Potassium channels and their role in glioma: A mini review.

K+ channels regulate a multitude of biological processes and play important roles in a variety of diseases by controlling potassium flow across cell membranes. They are widely expressed in the central and peripheral nervous system. As a malignant tumor derived from nerve epithelium, glioma has the characteristics of high incidence, high recurrence rate, high mortality rate, and low cure rate. Since glioma cells show invasive growth, current surgical methods cannot completely remove tumors. Adjuvant chemotherapy is still needed after surgery. Because the blood-brain barrier and other factors lead to a lower effective concentration of chemotherapeutic drugs in the tumor, the recurrence rate of residual lesions is extremely high. Therefore, new therapeutic methods are needed. Numerous studies have shown that different K+ channel subtypes are differentially expressed in glioma cells and are involved in the regulation of the cell cycle of glioma cells to arrest them at different stages of the cell cycle. Increasing evidence suggests that K+ channels express in glioma cells and regulate glioma cell behaviors such as cell cycle, proliferation and apoptosis. This review article aims to summarize the current knowledge on the function of K+ channels in glioma, suggests K+ channels participating in the development of glioma.

Expression of KCNA5 Protein in Human Mammary Epithelial Cell Line Associated with Caveolin-1.

Voltage-gated potassium (Kv) channels are involved in the proliferation and transformation of mammary epithelial cells. They are thought to be related to the development of breast carcinoma, although the exact role they play in this event remains unclear. In this study, we investigated whether the expression and function of Kv channels is associated with Caveolin-1 (Cav-1, a principal component of caveolae) in different cell lines. We found that expression of Cav-1 correlated with the expression of Kv channels in mammary epithelial cells (MCF10A, MCF10A-ST1, and MCF7), and silencing of Cav-1 inhibited the expression of KCNA5 (voltage-gated shaker-related subfamily A, member 5). Immunofluorescence analysis indicated the colocalization of KCNA5 with Cav-1, whereas immunoprecipitation suggested a possible interaction between the two proteins. Overall, our finding indicated that KCNA5 protein may interact with Cav-1, thereby contributing to the proliferation and early transformation of mammary cells.

Restoration of S100A4 expression enhances invasive and metastatic potentials of COLO16 cutaneous squamous cancer cells.

BACKGROUND: S100A4 promotes cancer metastasis but is frequently silenced in human cutaneous squamous cell carcinomas/c-SCCs due to DNA methylation, which may explain the less metastasized property of c-SCCs. OBJECTIVE: This study aims to check 1) whether the metastatic potential of S100A4-negative human c-SCC cells could be enhanced when S100A4 expression is restored in COLO16 c-SCC cells with S100A4 methylation and 2) the correlation of S100A4 expression and the differentiation grades and invasiveness of human c-SCC tumors. METHODS: The motility and invasion of parent and transfected COLO16 cells are examined by the use of 24-well modified Boyden chambers, scratched wound healing assay and nude mouse transplantation tumor model. Meanwhile, the correlation of S100A4 expression with growth patterns and grade of differentiation of c-SCC surgical specimens are analyzed. RESULTS: S100A4 expression is successfully restored in COLO16 cells after plasmid lipofectamine transfection. Transwell and scratched wound healing assays shows that the invasion and migration activities of S100A4-expressing transfectants are higher than that of parent COLO16 cells. Subcutaneous and foot pad c-SCC models are established by injecting 5 × 10^{6}/100~l parental and S100A4-expressing COLO16 cells to BALB/c-nu/nude mice, respectively. Histological examination confirms the differences of invasiveness between the parent cells and the transfectants. Regional lymph node metastases are found only in the mice bearing S100A4-expressing tumors. S100A4 expression levels and frequencies are significantly different (P< 0.001) between the well and the poorly differentiated c-SCCs and closely correlated with tumor invasion (P< 0.05). CONCLUSIONS: S100A4 confers invasive and metastatic potentials on human c-SCCs. The low incidence of metastasis of c-SCCs, especially the well differentiated ones, might be due to the infrequent S100A4 expression. S100A4 can be regarded as a negative prognostic biomarker or a metastasis-risk factor of human c-SCCs.

Replica exchange Monte Carlo simulation of human serum albumin-catechin complexes.

Replica exchange Monte Carlo simulation equipped with an orientation-enhanced hydrophobic interaction was utilized to study the impacts of molar ratio and ionic strength on the complex formation of human serum albumin (HSA) and catechin. Only a small amount of catechins was found to act as bridges in the formation of HSA-catechin complexes. Selective binding behavior was observed at low catechin to HSA molar ratio (R). Increase of catechin amount can suppress HSA self-aggregation and diminish the selectivity of protein binding sites. Strong saturation binding with short-range interactions was found to level off at around 4.6 catechins per HSA on average, while this number slowly increased with R when long-range interactions were taken into account. Meanwhile, among the three rings of catechin, the 3,4-dihydroxyphenyl (B-ring) shows the strongest preference to bind HSA. Neither the aggregation nor the binding sites of the HSA-catechin complex was sensitive to ionic strength, suggesting that the electrostatic interaction is not a dominant force in such complexes. These results provide a further molecular level understanding of protein-polyphenol binding, and the strategy employed in this work shows a way to bridge phase behaviors at macroscale and the distribution of binding sites at residue level.

Genetic characterization of a novel Iflavirus associated with vomiting disease in the Chinese oak silkmoth Antheraea pernyi.

Larvae of the Chinese oak silkmoth (Antheraea pernyi) are often affected by AVD (A. pernyi vomiting disease), whose causative agent has long been suspected to be a virus. In an unrelated project we discovered a novel positive sense single-stranded RNA virus that could reproduce AVD symptoms upon injection into healthy A. pernyi larvae. The genome of this virus is 10,163 nucleotides long, has a natural poly-A tail, and contains a single, large open reading frame flanked at the 5' and 3' ends by untranslated regions containing putative structural elements for replication and translation of the virus genome. The open reading frame is predicted to encode a 3036 amino acid polyprotein with four viral structural proteins (VP1-VP4) located in the N-terminal end and the non-structural proteins, including a helicase, RNA-dependent RNA polymerase and 3C-protease, located in the C-terminal end of the polyprotein. Putative 3C-protease and autolytic cleavage sites were identified for processing the polyprotein into functional units. The genome organization, amino acid sequence and phylogenetic analyses suggest that the virus is a novel species of the genus Iflavirus, with the proposed name of Antheraea pernyi Iflavirus (ApIV).

Temporal modulation of sodium current kinetics in neuron cells by near-infrared laser.

Near-infrared laser provides a novel nerve stimulation modality to regulate the cell functions. Understanding its physiological effect is a prerequisite for clinic laser therapy applications. Here, the whole-cell sodium (Na) channel kinetics of neuron cell was employed to determine the temporal roles of infrared laser. The Na currents were elicited by electrical pulses that were synchronized at the rising and falling edges of the 980 nm laser pulses, respectively, to investigate the different infrared effect on cell functions. The time constants of activation (τ(m)) and inactivation (τ(h)) kinetics were extracted from fitting of the Na current (m(3)h) according to the Hodgkin-Huxley (HH) model. By comparing the time constants without and with the laser irradiation, we obtained that laser pulses changed the Na current kinetics by accelerating τ(h)-phase and slowing down τ m-phase at the beginning of the laser pulse, whereas both phases were accelerated at the end of the pulse. After relating the ratios of the time constants to the temperature characteristics of Na channel by Q10, we found that the accelerating in Na current kinetics could be related to the average temperature of extracellular solution in the corresponding time span by choosing Q10 = 2.6. The results of this study demonstrated that there was a positive correlation between the acceleration of the Na current kinetics and increases in temperature of the extracellular solution.

MDA-7/IL-24 suppresses tumor adhesion and invasive potential in hepatocellular carcinoma cell lines.

Melanoma differentiation associated gene-7 (MDA-7)/interleukin­24 (IL-24) has been considered as a tumor-suppressor gene, which suppresses the growth and induces the apoptosis of cancer cells. In the present study, we investigated the effect and mechanisms of MDA-7/IL-24 regarding the inhibition of metastasis of HepG2 and BEL-7402 human hepatocellular carcinoma (HCC) cells in vitro. We established MDA-7/IL-24-overexpressing HepG2 and BEL-7402 cell lines and found that MDA-7/IL-24 overexpression inhibited tumor cell adhesion and invasion, and induced G2/M arrest in tumor cells. To explore its mechanism of action, western blotting and real-time-PCR assay were used to investigate the expression of E-cadherin, CD44, ICAM-1, matrix metalloproteinase (MMP)-2 and -9, CyclinB, Twist, survivin, p-ERK and p-Akt. ELISA assay was used to measure the secretion of TGF-ß, and a reporter gene assay was used to detected the transcriptional activity of NF-κB and AP-1 in HepG2 and BEL-7402 cells. The results showed that MDA-7/IL-24 overexpression decreased the expression of CD44, ICAM-1, MMP-2/-9, CyclinB, Twist, survivin, TGF-ß and p-Akt, transcriptional activity of NF-κB, and increased the expression of E-cadherin and p-ERK and transcriptional activity of AP-1 in HepG2 and BEL-7402 cells. Our results revealed that MDA-7/IL-24 mediated the inhibition of adhesion and invasion in HepG2 and BEL-7402 cells by suppressing metastasis-related gene expression. Thus, MDA-7/IL-24 may be used as a novel cancer-suppressor gene for the therapy of human HCC.

Improved phosphorus acquisition by tobacco through transgenic expression of mitochondrial malate dehydrogenase from Penicillium oxalicum.

Phosphorus (P) is an essential nutrient for plant growth and development, but is generally unavailable and inaccessible in soil, since applied P is mostly fixed to aluminium (Al) and ferrum (Fe) in acidic soils and to calcium (Ca) in alkaline soils. Increased organic acid excretion is thought to be one mechanism by which plants use to enhance P uptake. In this study, we overexpressed a mitochondrial malate dehydrogenase (MDH) gene from the mycorrhizal fungi Penicillium oxalicum in tobacco. The MDH activity of transgenic lines was significantly increased compared to that of wild type. Malate content in root exudation of transgenic lines induced in response to P deficiency was 1.3- to 2.9-fold greater than that of wild type under the same condition. Among the transgenic lines that were selected for analysis, one line (M1) showed the highest level of MDH activity and malate exudate. M1 showed a significant increase in growth over wild type, with 149.0, 128.5, and 127.9% increases in biomass, when grown in Al-phosphate, Fe-phosphate, and Ca-phosphate media, respectively. M1 also had better P uptake compared to wild type, with total P content increased by 287.3, 243.5, and 223.4% when grown in Al-phosphate, Fe-phosphate, and Ca-phosphate media, respectively. To our knowledge, this is the first study on improving the ability of a plant to utilize P from Al-phosphate, Fe-phosphate, and Ca-phosphate by manipulating the organic acid metabolism of the plant through genetic engineering.

A choline monooxygenase gene promoter from Salicornia europaea increases expression of the beta-glucuronidase gene under abiotic stresses in tobacco (Nicotiana tabacum L.).

A 1312 bp 5' flanking region of Salicornia europaea choline monooxygenase (SeCMO) gene was isolated using the anchored PCR. To investigate the mechanism of regulation for this stress-induced gene, the SeCMO promoter-beta-glucuronidase (GUS) chimeric gene constructs containing five deletions F1, F2, F3, F4 and F5 were introduced into tobacco (Nicotiana tabacum L.) by Agrobacterium-mediated transformation. The functional properties of each promoter fragment were examined by assaying GUS activity in the leaves of transgenic tobacco treated with abiotic stresses (NaCl, PEG6000 and low temperature). The GUS activity in transgenic tobacco with F2 (-1056 to +8) construct showed highest increase under all the three abiotic stresses. Thus, the study provided a potential promoter induced by the salt, dehydration and cold for the plant genetic manipulation.

Cytotoxicity of single-walled carbon nanotubes on PC12 cells.

The increasing use of carbon nanotubes (CNTs) in biomedical applications underlines the importance of its potential toxic effects to human health. In the present study, we first exposed PC12 cells, a commonly used in vitro model for neurotoxicity study, to two kinds of commercially available single-walled carbon nanotubes (SWCNTs), to investigate the effect of SWCNTs on nervous system in vitro. The decrease of PC12 cells viability was time and dose-dependent with exposure to SWCNTs demonstrated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, lactate dehydrogenase (LDH) release and morphological observation. Flow cytometry analysis showed that the PC12 cells' cycle was arrested in the G2/M phase, and their apoptotic rate induced by SWCNTs was dose-dependent. Further studies revealed SWCNTs decreased mitochondrial membrane potential (MMP), induced the formation of reactive oxygen species (ROS) and increased the level of lipid peroxide and decreased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and the content of glutathione (GSH) in a time and dose-dependent manner. These findings reveal that SWCNTs may induce oxidative stress to nervous system in vivo, causing the occurrence of diseases related to cellular injuries of neuronal cells, such as neurodegenerative disorders, and demonstrating the necessity of further research in vivo.

A novel BH3 mimetic S1 potently induces Bax/Bak-dependent apoptosis by targeting both Bcl-2 and Mcl-1.

Broad spectrum Bcl-2 small molecule inhibitors act as BH3 mimetics are effective antitumor agents. Herein, we have identified S1, a previously discovered small molecule Bcl-2 inhibitor, as the first authentic BH3 mimetic as well as a dual, nanomolar inhibitor of Bcl-2 and Mcl-1 (K(i) = 310 nM and 58 nM, respectively). The results of fluorescence polarization assays, coimmunoprecipitation, fluorescent resonance energy transfer, and shRNA indicated that S1 can disrupt Bcl-2/Bax, Mcl-1/Bak and Bcl-2/Bim heterodimerization in multiple cell lines, activate Bax accompanied by its translocation to mitochondrial, activate caspase 3 completely dependent on Bax/Bak, and in turn induce a Bim-independent apoptosis. Moreover, S1 could induce apoptosis on the primary acute lymphoblastic leukemia cells regardless of Mcl-1 level. Mechanism-based single agent antitumor activity in a mouse xenograft H22 (mouse liver carcinoma) model ascertain its therapeutic potential. S1 represents a novel chemical class of antitumor leads that function solely as BH3 mimetics and pan-Bcl-2 inhibitors. In the meanwhile, S1 could become a unique tool for interactions between Bcl-2 family proteins.

Involvement of TLR21 in baculovirus-induced interleukin-12 gene expression in avian macrophage-like cell line HD11.

Our previous work showed that baculovirus (Antheraea pernyi nuclear polyhedrosis virus [ApNPV]) induced a strong innate immunity and protected chicken from a lethal challenge of bronchitis virus. The purpose of present study was to determine the chicken Toll-like receptors (TLRs) used by BV-infected immune cells to induce this immune response. We first investigated the expression of the Toll-like receptor (TLR) genes in resting and BV-infected HD11 (chicken macrophage-like cell line) and DT40 (chicken B cell-like cell line) cells. Expressions of TLRs were detected in both cell types. After BV stimulation, TLR21 was the only upregulated TLR in HD11 cells, and all the TLRs were down-regulated in DT40 cells. Since TLR activation generally leads to cytokine induction, we then determined the expression of IL-12 in the two cell lines following treatment with BV or oligodeoxynucleotides (ODN) containing CpG dinucleotides (CpG-ODN). BV and CpG-ODN treatment induced the expression of IL-12 in HD11 but not in DT40 cells. HD11 cells transfected with siRNA specific for TLR21 significantly diminished BV- and CpG-ODN-induced IL-12 expression. Therefore, BV and CpG-ODN stimulated IL-12 expression involved TLR21 signaling and chicken TLR21 may have similar functions to the mammalian TLR9.

Dendritic superstructures and structure transitions of asymmetric poly(L-lactide-b-ethylene oxide) diblock copolymer thin films.

The evolution of morphologies of isothermally crystallized thin films with different thicknesses of poly(L-lactide-b-ethylene oxide) diblock copolymer was observed by optical microscopy (OM) and atomic force microscopy (AFM). Dendritic superstructures stacked with lamellae were investigated in thin films with approximately 200 nm to approximately 400 nm thickness. The lamellar structure was a lozenge- or truncated-lozenge-shaped single crystal of PLLA confirmed by AFM observations. The contour of the dendritic superstructures is hexagonal, and two types of sectors, [110] and [100], can be classified in terms of the chain-folding and crystal growth directions. These phenomena are due to the interplay of the crystallization of the PLLA block, the microphase separation of the block copolymer, and the effect of the film thickness. The growth process of the superstructure can be classified into three steps: the growth of the main branches, the growth of the secondary side branches along the main branch, and the tertiary side branches. PLLA growth rates decrease in copolymer films thinner than 1 microm. Layer-layer phase structure of the copolymer driven by the crystallization of PLLA and the microphase separation of the copolymer appears to be a key factor explaining the crystallization and morphological behavior of this system.

Protection of PC12 cells against superoxide-induced damage by isoflavonoids from Astragalus mongholicus.

OBJECTIVE: To further investigate the neuroprotective effects of five isoflavonoids from Astragalus mongholicus on xanthine (XA)/ xanthine oxidase (XO)-induced injury to PC12 cells. METHODS: PC12 cells were damaged by XA/XO. The activities of antioxidant enzymes, MTT, LDH, and GSH assays were used to evaluate the protection of these five isoflavonoids. Contents of Bcl-2 family proteins were determined with flow cytometry. RESULTS: Among the five isoflavonoids including formononetin, ononin, 9, 10-dimethoxypterocarpan-3-O-beta-D-glucoside, calycosin and calycosin-7-O-glucoside, calycosin and calycosin-7-O-glucoside were found to inhibit XA/ XO-induced injury to PC12 cells. Their EC50 values of formononetin and calycosin were 0.05 microg/mL. Moreover, treatment with these three isoflavonoids prevented a decrease in the activities of antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), while formononetin and calycosin could prevent a significant deletion of GSH. In addition, only calycosin and calycosin-7-O-glucoside were shown to inhibit XO activity in cell-free system, with an approximate IC50 value of 10 microg/mL and 50 microg/mL. Formononetin and calycosin had no significant influence on Bcl-2 or Bax protein contents. CONCLUSION: Neuroprotection of formononetin, calycosin and calycosin-7-O-glucoside may be mediated by increasing endogenous antioxidants, rather by inhibiting XO activities or by scavenging free radicals.

Synchrotron investigation on the sheared structure evolution of syndiotactic polypropylene crystallization process.

The final structure of molten syndiotactic polypropylene (sPP) sheared under different conditions was investigated by synchrotron small-angle x-ray scattering (SAXS) and wide-angle x-ray diffraction (WAXD) techniques to elucidate the shear effects on sPP crystalline structure. The results obtained from the WAXD show that there is no variation on crystalline form but a little difference on the orientation of the 200 reflection. The SAXS data indicate that the lamellar thickness and long period have not been affected by shear but the lamellar orientation is dependent on shear. The experimental data of sPP crystallization from sheared melt may indicate a mesophase structure that is crucial to the shear effects on the final polymer multiscale crystalline structures.

Upregulation of proinflammatory cytokines and NO production in BV-activated avian macrophage-like cell line (HD11) requires MAPK and NF-kappaB pathways.

The budded virus (BV) of Antheraea pernyi is a nuclear polyhedrosis virus (ApNPV), that belongs to the baculovirus family. It is capable of stimulating innate immune response in avian macrophage-like cells (HD11). In this study, we used the expression of proinflammatory cytokines (IFN-gamma and IL-12p40) and production of nitric oxide (NO) as indicators to evaluate the involvement of the signaling cascades in the activation of HD11 cells by BV. Western blot analysis revealed that ERK1/2, p38 MAPK and JNK were phosphorylated followed by activation of p65-NF-kappaB after HD11 cells were challenged with BV. Inhibition of p38 MAPK and NF-kappaB by their respective inhibitors abolished BV-induced expression of IL-12p40, IFN-gamma and production of NO, whereas inhibition of JNK abolished only the induction of cytokines. Additionally, inhibition of ERK1/2 resulted in unexpected increases in both cytokine expression and NO production. Taken together, these findings indicated that in BV-induced HD11 cells, the induction of cytokines was mediated by the p38 MAPK, JNK and NF-kappaB pathways, and NO production was mediated through the p38 MAPK/NF-kappaB pathways.