Chaperone-mediated autophagy degrade Dicer to promote breast cancer metastasis.

Metastasis in breast cancer usually lead to the majority of deaths on clinical patients. Accordingly, diagnosis of metastasis at the early stage in breast cancer is important to improve the prognosis. We observed that Dicer protein levels are significant decrease in highly invasive breast cancer cells and usually correlated with poor clinical outcomes. Following, we aim to clarify the molecular regulatory mechanism of this phenomenon in breast cancer to provide a new therapeutic target. In this study, we obtained that Dicer expression correlated with metastasis and invasion without affect cell stability in breast cancer cells. Importantly, we identified the regulatory mechanism of Dicer protein degradation, the chaperone-mediated autophagy (CMA)-mediated degradation that is major mechanism to decrease Dicer protein expression and lead to cancer metastasis. We discovered that heat shock cognate 71-kDa protein (Hsc70) which as a CMA-related factor interacts with the CMA-targeting motif I333A/K334A on Dicer to promote degradation through CMA. Taken together, our findings hint that Dicer highly correlated with cancer metastasis, we reveal the tumor-promoting effect of CMA-mediated Dicer degradation in breast cancer.

KOtBu-Promoted, Three-Component Domino Reaction of Arenes(indoles/phenols), C60, and (Per/poly)fluoroarenes: Achieving Direct C-C Cross-Coupling of Fullerene with (Per/poly)fluoroarenes.

A KOtBu-promoted, three-component cross-coupling of arenes(indoles/phenols), C60, and (per/poly)fluoroarenes has been established for the one-pot efficient synthesis of various 1,4-arene-bridged bis(polyfluoroaryl)-functionalized [60]fullerenes. This developed reaction system demonstrates good functional group compatibilities with broad substrate scope, which exhibits high regio- and chemoselectivities. Further control experiment succeeded in providing a one-pot protocol for the synthesis of various 1,2-N-(per/poly)fluoroarene-substituted 1,2-(3-indole)(hydro)fullerenes.

Combination of Modified NS1 and NS3 as a Novel Vaccine Strategy against Dengue Virus Infection.

Dengue virus (DENV) causes a range of illness, including dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. DENV nonstructural protein (NS) 1 has been considered to be a desirable vaccine candidate for its ability to induce Ab and complement-dependent cytolysis of DENV-infected cells as well as to block the pathogenic effects of NS1. However a potential drawback of NS1 as a vaccine is that anti-DENV NS1 Abs can lead to endothelial cell damage and platelet dysfunction by antigenic cross-reactivity. Therefore, we modified the DENV NS1 by replacing the C-terminal cross-reactive epitopes with the corresponding region of Japanese encephalitis virus NS1 to generate a chimeric DJ NS1 protein. Active immunization with DJ NS1 induced a strong Ab response. To enhance cellular immunity, we further combined DJ NS1 with DENV NS3 to immunize mice and showed activation of Ag-specific CD4+ and CD8+ T cells in addition to Ab responses. We further detected NS3-specific CTL activities as well as CD107a expression of effector cells. Importantly, the protective effects attributed by DJ NS1 and NS3 immunization were demonstrated in a DENV-infected mouse model by reduced viral titers, soluble NS1 levels, mouse tail bleeding time, and vascular leakage at skin injection sites. Collectively, the results from this study reveal the humoral and cellular immune responses and the protective effects conferred by DJ NS1 and NS3 immunization in the mouse model of DENV infection and provide a potential strategy for dengue vaccine design.

Long-term and short-term surgical outcomes of single-incision laparoscopic hepatectomy on anterolateral liver segments.

BACKGROUND: Laparoscopic liver resection yields improved short-term surgical outcomes, whereas the reports about clinical benefits of single-incision laparoscopic hepatectomy (SILH) are scarce. This retrospective study is to compare the surgical outcomes of SILH with those of multi-incision laparoscopic hepatectomy (MILH). METHODS: The study included 54 patients who had undergone SILH and 184 patients who had undergone MILH between January 2010 and December 2017. Short-term outcomes were compared in those of patients who underwent left lateral sectionectomy and partial hepatectomy of segment 5-6. A subgroup analysis of hepatocellular carcinoma (HCC) was also performed for long-term outcome comparisons. RESULTS: In those of patients who underwent left lateral sectionectomy, SILH group had less chronic hepatitis B (15.2 vs. 45.8%; p = 0.004), less liver cirrhosis (12.1 vs. 50.0%; p = 0.002), less tumor proximal to major vessel (6.1 vs. 29.2%; p = 0.018), shorter surgical time (113.2 ± 37.9 vs. 146.0 ± 50.5 min; p = 0.007), and shorter postoperative hospital stays (4.4 ± 1.1 vs. 5.4 ± 1.3 days; p = 0.002) compared with MILH group. In those of patients with tumor located at segment 5-6, no significant differences were observed in surgical time, blood loss, complications, and mortality. Single-incision laparoscopic partial hepatectomy was only associated with wider surgical margins (11.8 ± 7.0 vs. 5.3 ± 5.2 mm; p = 0.003). In the HCC subgroup, SILH had similar 1-, 3-, and 5-year overall survival and 1-, 3-, and 5-year recurrence-free survival rates compared with patients who had undergone MILH. CONCLUSIONS: The study demonstrates the safety and feasibility of single-incision laparoscopic liver resection for left lateral sectionectomy and partial hepatectomy for segment 5-6. In selected patients within the group and by experienced surgical team, the SILH technique results in comparable short-term surgical outcomes and long-term oncological outcomes.

Long-term and short-term surgical outcomes of laparoscopic versus open liver resection for hepatocellular carcinoma: might laparoscopic approach be better in early HCC?

BACKGROUND: This retrospective study compared the short- and long-term outcomes of laparoscopic liver resection (LLR) and open liver resection (OLR) and identified patients who might gain more benefits from LLR. METHODS: The demographic and perioperative data, short-term surgical outcomes, and long-term oncological results of all 313 patients who received elective liver resection for hepatocellular carcinoma (HCC) between January 2010 and June 2017 were analyzed. The patients were then divided into stage-specific subgroups according to the TNM staging system for comparison. RESULTS: LLR was performed in 153 patients and OLR in 160 patients. LLR is associated with less blood loss (p < 0.001), shorter surgical time (p = 0.001), shorter length of hospital stay (p < 0.001), and lower morbidity rate (p = 0.034). The 5-year overall survival (OS) rates in the LLR group were higher than those in the OLR group (78.1 vs. 57.6%; p = 0.002). Stage-specific subgroup analysis revealed similar 5-year OS in the two groups (stage I: 82.8 vs. 82.6%, p = 0.845; stage II: 80.3 vs. 69.2%, p = 0.638; stage III: 55.6 vs. 34.8%, p = 0.681), as did the 5-year recurrence-free survival. Moreover, the short-term outcomes were better in the LLR group in terms of surgical time, blood loss, and length of hospital stay, and these benefits attenuated with advancing tumor stage. CONCLUSIONS: LLR for HCC is a safe and feasible procedure that does not compromise long-term oncological outcomes. In early tumor stages, LLR might be better in terms of short-term surgical outcomes.

Risk Factors Analysis of Postoperative Pleural Effusion after Liver Resection.

BACKGROUND: Pulmonary complications remain relatively high in morbidities that arise after liver surgery and are associated with increased length of hospital stay and higher cost. Identification of possible risk factors in this retrospective analysis may help reduce operative morbidity and achieve better outcomes. METHODS: In all, 363 consecutive patients underwent elective hepatectomies between July 2008 and November 2013 and these were identified and analyzed retrospectively. Patient demographics and perioperative variables were collected. The main outcome was an analysis of risk factors associated with postoperative pleural effusion (PPE). RESULTS: Of 363 patients receiving hepatectomies, 80 patients (22.0%) developed pulmonary complications. The predominant pulmonary complication in this series is pleural effusion (76 patients, 95%). Univariate analysis found that older age, higher body mass index (BMI), chronic obstructive lung disease, asthma, heart disease, hepatitis C infection, heavy smoking, American Society of Anesthesiology class III and IV, hepatectomy site, combined surgeries, perioperative blood transfusion, and cirrhosis of liver were associated with PPE. Only older age, higher BMI, asthma, heavy smoker, combined gastrointestinal surgeries, and perioperative blood transfusion were identified as independent risk factors in multivariate analysis. CONCLUSION: This study identifies 6 risk factors for PPE. Identification and management of some of these factors could possibly reduce morbidity and improve short-term surgical outcomes.

iTAR: a web server for identifying target genes of transcription factors using ChIP-seq or ChIP-chip data.

BACKGROUND: Chromatin immunoprecipitation followed by massively parallel DNA sequencing (ChIP-seq) or microarray hybridization (ChIP-chip) has been widely used to determine the genomic occupation of transcription factors (TFs). We have previously developed a probabilistic method, called TIP (Target Identification from Profiles), to identify TF target genes using ChIP-seq/ChIP-chip data. To achieve high specificity, TIP applies a conservative method to estimate significance of target genes, with the trade-off being a relatively low sensitivity of target gene identification compared to other methods. Additionally, TIP's output does not render binding-peak locations or intensity, information highly useful for visualization and general experimental biological use, while the variability of ChIP-seq/ChIP-chip file formats has made input into TIP more difficult than desired. DESCRIPTION: To improve upon these facets, here we present are fined TIP with key extensions. First, it implements a Gaussian mixture model for p-value estimation, increasing target gene identification sensitivity and more accurately capturing the shape of TF binding profile distributions. Second, it enables the incorporation of TF binding-peak data by identifying their locations in significant target gene promoter regions and quantifies their strengths. Finally, for full ease of implementation we have incorporated it into a web server ( http://syslab3.nchu.edu.tw/iTAR/ ) that enables flexibility of input file format, can be used across multiple species and genome assembly versions, and is freely available for public use. The web server additionally performs GO enrichment analysis for the identified target genes to reveal the potential function of the corresponding TF. CONCLUSIONS: The iTAR web server provides a user-friendly interface and supports target gene identification in seven species, ranging from yeast to human. To facilitate investigating the quality of ChIP-seq/ChIP-chip data, the web server generates the chart of the characteristic binding profiles and the density plot of normalized regulatory scores. The iTAR web server is a useful tool in identifying TF target genes from ChIP-seq/ChIP-chip data and discovering biological insights.

Serum C-reactive protein level in COPD patients stratified according to GOLD 2011 grading classification.

BACKGROUND AND OBJECTIVE: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 grading classification has been used to evaluate the severity of patients with chronic obstructive pulmonary disease (COPD). However, little is known about the relationship between the systemic inflammation and this classification. We aimed to study the relationship between serum CRP and the components of the GOLD 2011 grading classification. METHODS: C-reactive protein (CRP) levels were measured in 391 clinically stable COPD patients and in 50 controls from June 2, 2015 to October 31, 2015 in the First Affiliated Hospital of Xiamen University. The association between CRP levels and the components of the GOLD 2011 grading classification were assessed. RESULTS: Correlation was found with the following variables: GOLD 2011 group (0.240), age (0.227), pack year (0.136), forced expiratory volume in one second % predicted (FEV1%; -0.267), forced vital capacity % predicted (-0.210), number of acute exacerbations in the past year (0.265), number of hospitalized exacerbations in the past year (0.165), British medical Research Council dyspnoea scale (0.121), COPD assessment test score (CAT, 0.233). Using multivariate analysis, FEV1% and CAT score manifested the strongest negative association with CRP levels. CONCLUSIONS: CRP levels differ in COPD patients among groups A-D based on GOLD 2011 grading classification. CRP levels are associated with several important clinical variables, of which FEV1% and CAT score manifested the strongest negative correlation.

Effect of Telmisartan on local cardiovascular oxidative stress in mouse under chronic intermittent hypoxia condition.

OBJECTIVE: The objective of this study is to explore the protective effect of an angiotensin receptor blocker (ARB) on local cardiovascular angiotensin II (AngII) and oxidative stress markers such as malondialdehyde (MDA), NADPH oxydase p47(phox), and 8-hydroxy-2'-deoxyguanosine/8-hydroxyguanosine (8-OHdG/8-OHG) of mice that had chronic intermittent hypoxia (CIH). METHODS: Thirty-two healthy male C57B6J mice were randomly divided into four groups: CIH (12 weeks of CIH), ARB (CIH+Telmisartan), air control (room air delivery), and blank control (no treatment). AngII, p47(phox), and 8-OHdG/8-OHG were detected in mouse cardiocytes by immunohistochemistry. MDA was measured with the thiobarbituric acid method. MEASUREMENTS AND RESULTS: The highest AngII levels occur in the ARB treatment group (P < 0.05), followed by the CIH group (which was higher than the two control groups; P = 0.000). The levels of p47(phox) were statistically higher in the CIH group than in the other groups (P = 0.000) and lower in the ARB group (but still higher than in the two control groups, P = 0.000). The levels of 8-OHdG/8-OHG were the highest in the CIH group (P < 0.05), followed by the ARB group (which was higher than the two control groups, P = 0.000). The levels of MDA in the myocardial homogenate of mice were the highest in the CIH group (P = 0.000). CONCLUSIONS: Based on the above results, it can be concluded that Telmisartan may protect mouse cardiocytes from oxidative stress damage due to CIH.

Robotic versus laparoscopic hepatectomy: A single-center, propensity score- matched study.

BACKGROUND: Although the effectiveness of robotic hepatectomy (RH) has been evaluated in several studies, the superiority of RH over other approaches has not been definitely established. Therefore, in the present propensity score-matched cohort study, we compared RH and laparoscopic hepatectomy (LH) in terms of perioperative and oncologic outcomes. METHODS: This retrospective study included patients who underwent RH or LH for benign and malignant liver lesions at a single center in Taiwan at any time between 2014 and 2020. Confounding factors, specifically age, sex, body mass index, American Society of Anesthesiologists score, IWATE criteria, and Charlson comorbidity index, were adjusted through propensity score matching (PSM). RESULTS: A total of 329 patients were finally included in this study. Two homogeneous groups (RH and LH; n, 72 each) were formed using PSM. The RH group had a longer operative time (median: 231 vs.180 min, respectively; P = .001) and lower conversion (to open surgery) rate (9.7% vs.0.0%, respectively; P = .013) than did the LH group. However, the two groups did not differ in terms of other perioperative outcomes, specifically blood loss, hospital stay, intensive care unit admission, mortality, morbidity, or tumor margin status. CONCLUSIONS: The rate of conversion to open surgery is lower in RH than in LH. Although operative time is longer in RH than in LH, RH is feasible and safe for patients with benign or malignant liver lesion. Our study also demonstrated comparable oncological results in patients with hepatocellular carcinoma between LH and RH group.

Galectin-1-mediated MET/AXL signaling enhances sorafenib resistance in hepatocellular carcinoma by escaping ferroptosis.

Sorafenib, a small-molecule inhibitor targeting several tyrosine kinase pathways, is the standard treatment for advanced hepatocellular carcinoma (HCC). However, not all patients with HCC respond well to sorafenib, and 30% of patients develop resistance to sorafenib after short-term treatment. Galectin-1 modulates cell-cell and cell-matrix interactions and plays a crucial role in HCC progression. However, whether Galectin-1 regulates receptor tyrosine kinases by sensitizing HCC to sorafenib remains unclear. Herein, we established a sorafenib-resistant HCC cell line (Huh-7/SR) and determined that Galectin-1 expression was significantly higher in Huh-7/SR cells than in parent cells. Galectin-1 knockdown reduced sorafenib resistance in Huh-7/SR cells, whereas Galectin-1 overexpression in Huh-7 cells increased sorafenib resistance. Galectin-1 regulated ferroptosis by inhibiting excessive lipid peroxidation, protecting sorafenib-resistant HCC cells from sorafenib-mediated ferroptosis. Galectin-1 expression was positively correlated with poor prognostic outcomes for HCC patients. Galectin-1 overexpression promoted the phosphorylation of AXL receptor tyrosine kinase (AXL) and MET proto-oncogene, receptor tyrosine kinase (MET) signaling, which increased sorafenib resistance. MET and AXL were highly expressed in patients with HCC, and AXL expression was positively correlated with Galectin-1 expression. These findings indicate that Galectin-1 regulates sorafenib resistance in HCC cells through AXL and MET signaling. Consequently, Galectin-1 is a promising therapeutic target for reducing sorafenib resistance and sorafenib-mediated ferroptosis in patients with HCC.

Positively charged nanocomplex modulates dendritic cell differentiation to enhance Th1 immune response.

Most existing vaccines use activators that polarize the immune response to T-helper (Th) 2 response for antibody production. Our positively charged chitosan (Cs)-based nanocomplex (CNC) drives the Th1 response through unknown mechanisms. As receptors for the positively charged CNC are not determined, the physico-chemical properties are hypothesized to correlate with its immunomodulatory effects. To clarify the effects of surface charge and size on the immune response, smaller CNC and negatively charged CNC encapsulating ovalbumin are tested on dendritic cell (DC) 2.4 â€‹cells. The negatively charged CNC loses activity, but the smaller CNC does not. To further evaluate the material effects, we replace Cs by poly-amino acids. Compared with the negatively charged nanocomplex, the positively charged one preserves its activity. Using immature bone marrow-derived DCs (BMDC) enriched from BALB/c mice as a model to analyze DC differentiation, treatments with positively charged nanocomplexes evidently increase the proportions of Langerin+ dermal DC, CD11blo interstitial DC, and CD8a+ conventional DC. Additionally, vaccination with two doses containing positively charged nanocomplexes are safe and increase ovalbumin-specific IgG and recall T-cell responses in mice. Overall, a positive charge seems to contribute to the immunological effect of nanocomplexes on elevating the Th1 response by modulating DC differentiation.

Comparison of surgical outcomes for laparoscopic liver resection of large hepatocellular carcinomas: A retrospective observation from single-center experience.

BACKGROUND/PURPOSE: Although laparoscopic liver resection (LLR) is a common surgical procedure for hepatocellular carcinoma (HCC), its suitability for large HCCs (≥5 cm) remains controversial. This study compared surgical outcomes of open hepatectomy with LLR for large HCCs. METHODS: A total of 313 patients with HCC who underwent hepatectomy between January 2010 and June 2017 were analyzed retrospectively. Demographic data, short-term outcomes, and long-term survivals were analyzed. RESULTS: Among patients with large HCCs (n = 122), the open group (n = 85) had larger tumor sizes (10.91 ± 4.72 vs. 7.45 ± 2.95 cm; p < 0.001) and more advanced stages (stages 3/4: 71.8% vs. 45.9%; p = 0.029) than the LLR group (n = 37), while LLR group achieved less blood loss (623.24 ± 841.75 mL vs. 1091.76 ± 1004.72 mL, p = 0.014) and shorter LOS (9.00 ± 5.13 d vs. 12.82 ± 8.51 d, p = 0.013). There were no significant differences in complication and mortality rates between groups. The 5-year overall and recurrence-free survival rates between the two groups were not significantly different (p = 0.408 and 0.644 respectively). The surgical outcomes showed equal benefit of the two operation types. CONCLUSION: With sufficient surgeon experience and appropriate patient selection, LLR is a feasible treatment choice for large HCCs.

N49 phospholipase A2, a unique subgroup of snake venom group II phospholipase A2.

A novel phospholipase A2 (PLA2) with Asn at its site 49 was purified from the snake venom of Protobothrops mucrosquamatus by using SP-Sephadex C25, Superdex 75, Heparin-Sepharose (FF) and HPLC reverse-phage C18 chromatography and designated as TM-N49. It showed a molecular mass of 13.875 kDa on MALDI-TOF. TM-N49 does not possess enzymatic, hemolytic and hemorrhagic activities. It fails to induce platelet aggregation by itself, and does not inhibit the platelet aggregation induced by ADP. However, it exhibits potent myotoxic activity causing inflammatory cell infiltration, severe myoedema, myonecrosis and myolysis in the gastrocnemius muscles of BALB/c mice. Phylogenetic analysis found that that TM-N49 combined with two phospholipase A2s from Trimeresurus stejnegeri, TsR6 and CTs-R6 cluster into one group. Structural and functional analysis indicated that these phospholipase A2s are distinct from the other subgroups (D49 PLA2, S49 PLA2 and K49 PLA2) and represent a unique subgroup of snake venom group II PLA2, named N49 PLA2 subgroup.

[Adsorptive Remediation of Cr(â ¥) Contaminated Groundwater with Chemically Synthesized Schwertmannite].

Schwertmannite is usually naturally found in acidic mining wastewater and frequently used in the adsorption of heavy metal anions from water and wastewater. Schwertmannite was synthesized through a facile chemical method and utilized to remove Cr(Ⅵ) from contaminated groundwater. The kinetics, thermodynamics and isotherms, as well as the effects of environmental factors on the Schwertmannite adsorption processes were investigated. The experimental results showed that the synthesized Schwertmannite had a strong adsorption capability of Cr(Ⅵ) from aqueous solution. At the pre-set initial concentrations of Cr(Ⅵ), the Schwertmannite adsorption of Cr(Ⅵ) achieved equilibrium within 24 h, and the Lagergren's second-order model fitted the adsorption process better compared to Lagergren's first-order model and intraparticle diffusion model. Langmiur equation fitted the adsorption isotherms better than Freundlich equation. The Cr(Ⅵ) adsorption on Schwertmannite mainly involved ion exchange reaction between Cr(Ⅵ) and anions such as OH- and SO42- and surface complexation reactions. The ΔHθ and ΔGθ were 6.368 kJ·mol-1 and -1.215 kJ·mol-1, respectively, therefore the adsorption of Cr(Ⅵ) was a spontaneous and endothermic process. The removal of Cr(Ⅵ) from aqueous solution increased with increasing Schwertmannite dosage at pH=4.5. Acidic pH in the range of 4.5-6 favored Cr(Ⅵ) removal with Schwertmannite compared to that under basic conditions. Under the conditions of 5 mg·L-1of initial Cr(Ⅵ) concentration, 0.5 g·L-1 of Schwertmannite dosage, pH=6, maximum Cr(Ⅵ) removal of 93.1% was achieved and the adsorption capacity of Cr(Ⅵ) with Schwertmannite reached up to 40.4 mg·g-1. Batch tests showed that the presence of HCO3- and SO42- inhibited the adsorption of Cr(Ⅵ) while Cl- had no significant impact. Cations and natural organic matter had a pH-dependent impact on Cr(Ⅵ) removal:at pH=8 natural organic matter and cations would significantly inhibit the Cr(Ⅵ) sorption, while the impact could be neglected at weak acidic conditions (pH=6).

Galectin-3 Inhibits Galectin-8/Parkin-Mediated Ubiquitination of Group A Streptococcus.

Group A streptococcus (GAS) is an important human pathogen that causes a wide variety of cutaneous and systemic infections. Although originally thought to be an extracellular bacterium, numerous studies have demonstrated that GAS can trigger internalization into nonimmune cells to escape from immune surveillance or antibiotic-mediated killing. Epithelial cells possess a defense mechanism involving autophagy-mediated targeting and killing of GAS within lysosome-fused autophagosomes. In endothelial cells, in contrast, we previously showed that autophagy is not sufficient for GAS killing. In the present study, we showed higher galectin-3 (Gal-3) expression and lower Gal-8 expression in endothelial cells than in epithelial cells. The recruitment of Gal-3 to GAS is higher and the recruitment of Gal-8 to GAS is lower in endothelial cells than in epithelial cells. We further showed that Gal-3 promotes GAS replication and diminishes the recruitment of Gal-8 and ubiquitin, the latter of which is a critical protein for autophagy sequestration. After knockdown of Gal-3 in endothelial cells, the colocalization of Gal-8, parkin, and ubiquitin-decorated GAS is significantly increased, as is the interaction of Gal-8 and parkin, an E3 ligase. Furthermore, inhibition of Gal-8 in epithelial cells attenuates recruitment of parkin; both Gal-8 and parkin contribute to ubiquitin recruitment and GAS elimination. Animal studies confirmed that Gal-3-knockout mice develop less-severe skin damage and that GAS replication can be detected only in the air pouch and not in organs and endothelial cells. These results demonstrate that Gal-3 inhibits ubiquitin recruitment by blocking Gal-8 and parkin recruitment, resulting in GAS replication in endothelial cells.IMPORTANCE In epithelial cells, GAS can be efficiently killed within the lysosome-fused autophaosome compartment. However, we previously showed that, in spite of LC-3 recruitment, the autophagic machinery is not sufficient for GAS killing in endothelial cells. In this report, we provide the first evidence that Gal-3, highly expressed in endothelial cells, blocks the tagging of ubiquitin to GAS by inhibiting recruitment of Gal-8 and parkin, leading to an enhancement of GAS replication. We also provide the first demonstration that Gal-8 can interact with parkin, the critical E3 ligase, for resistance to intracellular bacteria by facilitating the decoration of bacteria with ubiquitin chains. Our findings reveal that differential levels of Gal-3 and Gal-8 expression and recruitment to GAS between epithelial cells and endothelial cells may contribute to the different outcomes of GAS elimination or survival and growth of GAS in these two types of cells.

Potent histamine-releasing activity of atrahagin, a novel snake venom metalloproteinase.

Poisonous snakebite wound is a popular disease worldwide. However, the pathogenesis remains unclear. In the present study, a novel metalloproteinase atrahagin in Chinese cobra (Naja atra) snake venom was purified, using heparin-sepharose followed by Superdex 75 gel filtration chromatography. Apart from its alpha-fibrinogenase activity, atrahagin potently activated human colon, lung and tonsil mast cells with the net histamine release being 25.9+/-4.4, 17.0+/-1.9, 13.2+/-3.6%, respectively. Time course studies revealed that the peak histamine release induced by atrahagin occurred at 12, 12 and 8 min following incubation of the enzyme with colon, lung and tonsil mast cells, respectively. The response of mast cells to atrahagin was abolished by preincubation of the cells with metabolic inhibitors or pertussis toxin, and by removal of Ca2+ and Mg2+ from the challenge buffer. In conclusion, activation of human mast cells by atrahagin indicated that the enzyme might contribute to the pathogenesis of snakebite wound.

Purification, characterization and cytokine release function of a novel Arg-49 phospholipase A(2) from the venom of Protobothrops mucrosquamatus.

Group IIA phospholipase A(2) (PLA(2)) are major components in Viperidae/Crotalidae venom. In the present study, a novel PLA(2) named promutoxin with Arg at the site 49 has been purified from the venom of Protobothrops mucrosquamatus by chromatography. It consists of 122 amino acid residues with a molecular mass of 13,656 Da assessed by MALDI-TOF. It has the structural features of snake venom group IIA PLA(2)s, but has no PLA(2) enzymatic activity. Promutoxin shows higher amino acid sequence identity to the K49 PLA(2)s (72-95%) than to D49 PLA(2)s (52-58%). Promutoxin exhibits potent myotoxicity in the animal model with as little as 1 microg of promutoxin causing myonecrosis and myoedema in the gastrocnemius muscle of mice. Promutoxin is also able to stimulate the release of IL-12, TNFalpha, IL-6 and IL-1beta from human monocytes, and induce IL-2, TNFalpha and IL-6 release from T cells, indicating that this snake venom group IIA PLA(2) is actively involved in the inflammatory process in man caused by snake venom poisoning.

Characterization and molecular cloning of dabocetin, a potent antiplatelet C-type lectin-like protein from Daboia russellii siamensis venom.

A novel C-type lectin-like protein, dabocetin, was purified from Daboia russellii siamensis venom. On SDS-polyacrylamide gel electrophoresis, it showed a single band with an apparent molecular weight of 28 kDa and two distinct bands with the apparent molecular weights of 15.0 kDa and 14.5 kDa under non-reducing and reducing conditions, respectively. cDNA clones containing the coding sequences for dabocetin alpha and beta subunits were isolated and sequenced. The deduced protein sequences of both subunits were confirmed by N-terminal amino acid sequencing and trypsin-digested peptide mass fingerprinting. Dabocetin did not induce platelet aggregation in platelet-rich plasma. It also had little effect on the platelet aggregation induced by ADP, TMVA or stejnulxin. Whereas, dabocetin inhibited ristocetin-induced platelet agglutination in platelet-rich plasma in a dose-dependent manner with an IC50 value of 0.35 microM. Flow cytometry analysis showed that dabocetin significantly inhibited mAb SZ2 binding to platelet membrane glycoprotein Ib alpha, indicating that platelet membrane glycoprotein Ib is involved in the inhibitory effect of dabocetin on ristocetin-induced platelet agglutination.