Toll like receptor 2 knock-out attenuates carbon tetrachloride (CCl4)-induced liver fibrosis by downregulating MAPK and NF-κB signaling pathways

Innate immune signaling associated with Toll-like receptors (TLRs) is a key pathway involved in the progression of liver fibrosis. In this study, we reported that TLR2 is required for hepatic fibrogenesis induced by carbon tetrachloride (CCl₄). After CCl₄ treatment, TLR2^−/− mice had reduced liver enzyme levels, diminished collagen deposition, decreased inflammatory infiltration and impaired activation of hepatic stellate cells (HSCs) than wild type (WT) mice. Furthermore, after CCl₄ treatment, TLR2^−/− mice demonstrated downregulated expression of profibrotic and proinflammatory genes and impaired mitogen-activated protein kinases (MAPK) and nuclear factor kappa B (NF-κB) activation than WT mice. Collectively, our data indicate that TLR2 deficiency protects against CCl₄-induced liver fibrosis.     

Salvianolic acid B protects cardiomyocytes from angiotensin II-induced hypertrophy via inhibition of PARP-1

Salvianolic acid B (SalB), one of the major bioactive components in Salviamiltiorrhiza, has plenty of cardioprotective effects. The present study was designed to investigate the effect of SalB on angiotensin II (AngII)-induced hypertrophy in neonatal rat cardiomyocytes, and to find out whether or not this effect is attributed to inhibition of poly (ADP-ribose) polymerase-1 (PARP-1), which plays a key role in cardiac hypertrophy. Our results showed that SalB prevented the cardiomyocytes from AngII-induced hypertrophy, associated with attenuation of the mRNA expressions of atrial natriuretic factor and brain natriuretic peptide, and reduction in the cell surface area. SalB inhibited the activity of PARP-1. The inhibitory effect was comparable to that of the PARP-1 inhibitor 3-Aminobenzamide (3-AB). In addition, SalB reversed the depletion of cellular NAD⁺ induced by AngII. Moreover, overexpression of PARP-1 attenuated the anti-hypertrophic effect of SalB. These observations suggested that SalB prevented the cardiomyocytes from AngII-induced hypertrophy, at least partially through inhibition of PARP-1. Moreover, SalB attenuated the generation of oxidative stress via suppression of NADPH oxidase 2 and 4, which might probably contribute to the inhibition of PARP-1. These present findings may shed new light on the understanding of the cardioprotective effect of SalB.     

Algicidal effects of yellow clay and the thiazolidinedione derivative TD49 on the fish-killing dinoflagellate Cochlodinium polykrikoides in microcosm experiments

In order to evaluate the potential to control the fish-killing dinoflagellate Cochlodinium polykrikoides, we compared the algicidal effects of the thiazolidinedione derivative TD49 with those of yellow clay in 10-L microcosms. The responses of higher trophic level marine organisms and microbial loop communities to the algicide were also evaluated. In the yellow clay treatments, the concentration of C. polykrikoides was slightly reduced at day 1 of the experiment but remained higher than that of the control, suggesting that the reduction ratio of C. polykrikoides was <20 %. In the 0.8-μM TD49 treatment, the abundance of C. polykrikoides declined by 98 % 1 day following the addition of the algicide. The algicide did not affect nontarget algae including Chaetoceros spp., Skeletonema spp., Cylindrotheca spp., and other species. In all microcosms, bacterial abundance increased abruptly after day 1, then declined over the next 2 days as a result of predation by heterotrophic nanoflagellates and the small protozoan Uronema sp. Predation by the large protozoan species Euplotes sp. on Uronema sp. gradually increased with increasing incubation time in the TD49 treatment. Zooplankton were particularly affected by the environmental changes that occurred in the microcosms following collapse of the C. polykrikoides populations. Striped beak perch were not affected by the yellow clay treatments and concentrations of TD49?C. polykrikoides, whereas the algicide TD49 is effective in controlling the harmful alga. The results imply that the algicide has positive effects on natural microbial communities and is not toxic to nonharmful algae and higher trophic level marine organisms.     

Hormone‐induced mitochondrial fission is utilized by brown adipocytes as an amplification pathway for energy expenditure

Adrenergic stimulation of brown adipocytes (BA) induces mitochondrial uncoupling, thereby increasing energy expenditure by shifting nutrient oxidation towards thermogenesis. Here we describe that mitochondrial dynamics is a physiological regulator of adrenergically‐induced changes in energy expenditure. The sympathetic neurotransmitter Norepinephrine (NE) induced complete and rapid mitochondrial fragmentation in BA, characterized by Drp1 phosphorylation and Opa1 cleavage. Mechanistically, NE‐mediated Drp1 phosphorylation was dependent on Protein Kinase‐A (PKA) activity, whereas Opa1 cleavage required mitochondrial depolarization mediated by FFAs released as a result of lipolysis. This change in mitochondrial architecture was observed both in primary cultures and brown adipose tissue from cold‐exposed mice. Mitochondrial uncoupling induced by NE in brown adipocytes was reduced by inhibition of mitochondrial fission through transient Drp1 DN overexpression. Furthermore, forced mitochondrial fragmentation in BA through Mfn2 knock down increased the capacity of exogenous FFAs to increase energy expenditure. These results suggest that, in addition to its ability to stimulate lipolysis, NE induces energy expenditure in BA by promoting mitochondrial fragmentation. Together these data reveal that adrenergically‐induced changes to mitochondrial dynamics are required for BA thermogenic activation and for the control of energy expenditure.     

Light limitation and litter of an invasive clonal plant,Wedelia trilobata,inhibit its seedling recruitment

Background and Aims

Invasive clonal plants have two reproduction patterns, namely sexual and vegetative propagation. However, seedling recruitment of invasive clonal plants can decline as the invasion process proceeds. For example, although the invasive clonal Wedelia trilobata (Asteraceae) produces numerous seeds, few seedlings emerge under its dense population canopy in the field. In this study it is hypothesized that light limitation and the presence of a thick layer of its own litter may be the primary factors causing the failure of seedling recruitment for this invasive weed in the field.

Methods

A field survey was conducted to determine the allocation of resources to sexual reproduction and seedling recruitment in W. trilobata. Seed germination was also determined in the field. Effects of light and W. trilobata leaf extracts on seed germination and seedling growth were tested in the laboratory.

Key Results

Wedelia trilobata blooms profusely and produces copious viable seeds in the field. However, seedlings of W. trilobata were not detected under mother ramets and few emerged seedlings were found in the bare ground near to populations. In laboratory experiments, low light significantly inhibited seed germination. Leaf extracts also decreased seed germination and inhibited seedling growth, and significant interactions were found between low light and leaf extracts on seed germination. However, seeds were found to germinate in an invaded field after removal of the W. trilobata plant canopy.

Conclusions

The results indicate that lack of light and the presence of its own litter might be two major factors responsible for the low numbers of W. trilobata seedlings found in the field. New populations will establish from seeds once the limiting factors are eliminated, and seeds can be the agents of long-distance dispersal; therefore, prevention of seed production remains an important component in controlling the spread of this invasive clonal plant.     

Phase II clinical trial of ex vivo-expanded cytokine-induced killer cells therapy in advanced pancreatic cancer

Second-line chemotherapy in patients with gemcitabine-refractory advanced pancreatic cancer has shown disappointing survival outcomes due to rapid disease progression and performance deterioration. The aim of this phase II trial was to evaluate the efficacy and safety of adoptive immunotherapy using ex vivo-expanded, cytokine-induced killer (CIK) cells in gemcitabine-refractory advanced pancreatic cancer. Patients with advanced pancreatic cancer who showed disease progression during gemcitabine-based chemotherapy were enrolled in this study. For generation of CIK cells, peripheral blood samples were collected from each patient and cultured with anti-CD3 monoclonal antibody and IL-2. Patients received CIK cells intravenously 10 times, every week for 5 weeks and then every other week for 10 weeks. Twenty patients were enrolled between November 2009 and September 2010. The disease control rate was 25 % (4/16 patients). The median progression-free survival (PFS) was 11.0 weeks (95 % CI 8.8–13.2), and the median overall survival (OS) was 26.6 weeks (95 % CI 8.6–44.6). Grade 3 toxicities included general weakness in two patients and thrombocytopenia in one patient. Grade 4 hematologic or non-hematologic toxicity was not observed. Patients showed improvement in pancreatic pain, gastrointestinal distress, jaundice, body image alterations, altered bowel habits, health satisfaction, and sexuality when assessing quality of life (QoL). Adoptive immunotherapy using CIK cells showed comparable PFS and OS to survival data of previous trials that assessed conventional chemotherapies while maintaining tolerability and showing encouraging results in terms of patient QoL in gemcitabine-refractory advanced pancreatic cancer (clinicalTrials.gov number NCT00965718).     

Simultaneous silencing of VEGF and KSP by siRNA cocktail inhibits proliferation and induces apoptosis of hepatocellular carcinoma Hep3B cells

Background

Vascular endothelial growth factor (VEGF) is involved in the growth of new blood vessels that feed tumors and kinesin spindle protein (KSP) plays a critical role in mitosis involving in cell proliferation. Simultaneous silencing of VEGF and KSP, an attractive and viable approach in cancer, leads on restricting cancer progression. The purpose of this study is to examine the therapeutic potential of dual gene targeted siRNA cocktail on human hepatocellular carcinoma Hep3B cells.

Results

The predesigned siRNAs could inhibit VEGF and KSP at mRNA level. siRNA cocktail showed a further downregulation on KSP mRNA and protein levels compared to KSP-siRNA or VEGF-siRNA, but not on VEGF expression. It also exhibited greater suppression on cell proliferation as well as cell migration or invasion capabilities and induction of apoptosis in Hep3B cells than single siRNA simultaneously. This could be explained by the significant downregulation of Cyclin D1, Bcl-2 and Survivin. However, no sigificant difference in the mRNA and protein levels of ANG2, involving inhibition of angiogenesis was found in HUVECs cultured with supernatant of Hep3B cells treated with siRNA cocktail, compared to that of VEGF-siRNA.

Conclusion

Silencing of VEGF and KSP plays a key role in inhibiting cell proliferation, migration, invasion and inducing apoptosis of Hep3B cells. Simultaneous silencing of VEGF and KSP using siRNA cocktail yields promising results for eradicating hepatocellular carcinoma cells, a new direction for liver cancer treatment.     

A novel thiazolidinedione derivative TD118 showing selective algicidal effects for red tide control

Thiazolidinedione (TD) derivatives have been found to have an algicidal effect on harmful algal bloom microalgae. In this study, 75 TD derivatives were synthesized and analyzed for algicidal activity. Among these synthetic TDs, 18 TD derivatives showed specific algicidal activity on two strains belonging to the classes Raphidophyceae (Chattonella marina and Heterosigma akashiwo) and Dinophyceae (Cochlodinium polykrikoides). Two strains belonging to Bacillariophyceae (Navicula pelliculosa and Phaeodactylum EPV), one strain belonging to Dinophyceae (Amphidinium sp.), and a Eustigmatophycean microalga (Nannochloropsis oculata) showed less sensitivity to the TD derivatives than the other two phyla. The most reactive TD derivative, compound 2 (TD118), was selected and tested for morphological and physiological changes. TD118 effectively damaged the cell membrane of C. marina, H. akashiwo and C. polykrikoides. The O₂ evolution and photosystem II efficiency (F _v /F _m ) of C. marina, H. akashiwo and C. polykrikoides were also severely reduced by TD118 treatment. Amphidinium sp., N. pelliculosa, Phaeodactylum EPV and N. oculata showed less reduction of O₂ evolution and the F _v /F _m by TD118. These results imply that the species-specific TD structure relationship may be due to structural and/or physiological differences among microalgal species.     

Rhizobium smilacinae sp. nov., an endophytic bacterium isolated from the leaf of Smilacina japonica

During a study of endophytic bacteria from traditional Chinese medicinal plants, a bacterial strain, designated PTYR-5^T, was isolated from the leaf of Smilacina japonica A. Gray collected from Taibai Mountain in Shaanxi Province, north-west China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain PTYR-5^T is a member of the genus Rhizobium, exhibiting the highest sequence similarities to R. cellulosilyticum LMG 23642^T (97.2 %), R. huautlense LMG 18254^T (97.2 %) and R. alkalisoli CCBAU 01393^T (97.1 %). The levels of 16S rRNA gene sequence similarity with respect to other Rhizobium species with validly published names were less than 97.0 %. Phylogenies of the housekeeping genes atpD, recA and glnII confirmed its distinct position, showing low similarity with respect to those of recognized Rhizobium species (no more than 94.1?, 90.0 and 88.0 ?    % similarity, respectively). The DNA–DNA relatedness values of strain PTYR-5^T with R. cellulosilyticum LMG 23642^T, R. huautlense LMG 18254^T and R. alkalisoli CCBAU 01393^T were 33.6, 21.4 and 29.5 %, respectively. Based on phenotypic, phylogenetic and genotypic data, strain PTYR-5^T is considered to represent a novel species of the genus Rhizobium, for which the name Rhizobium smilacinae sp. nov. is proposed. The type strain is PTYR-5^T (=CCTCC AB 2013016^T=KCTC 32300^T=LMG 27604^T).