The effects of dietary supplementation of algae and synthetic astaxanthin on body astaxanthin, survival, growth, and low dissolved oxygen stress resistance of kuruma prawn, Marsupenaeus japonicus Bate

Natural carotenoids from astaxanthin containing alga Haematococcus pluvialis (H) and a non-astaxanthin carotenoid-containing alga Spirulina pacifica (S), and a synthetic astaxanthin Carophyll Pink (A) were supplemented in formulated diets at two concentrations, 50 (I) and 100 (II) mg kg⁻¹, resulting in seven pigmented diets HI, SI, AI, HII, SII, AII, and HS (H-50 mg kg⁻¹+S-50 mg kg⁻¹). Formulated diet without carotenoid supplementation served as a control (C). The different diets were fed to juvenile kuruma prawn Marsupenaeus japonicus for 9 weeks. Dietary carotenoid effects on survival, growth, and pigmentation were compared by the treatment individually or collectively. A low dissolved oxygen stress test was conducted 2 weeks later and prawns' survival time and oxygen consumption rate were also compared among treatments. After 9 weeks' rearing, C-fed prawn had significantly lower survival rate than the pigmented diets-fed prawns. No difference in weight gain was found among all prawns. C-fed prawn had 66.4% less flesh astaxanthin (FA) and 75.5% less shell astaxanthin (SA) than the pigmented diets-fed prawns. I-fed (AI, HI, and SI) prawns had 31.1% less FA and 29.6% less SA than II-fed (AII, HII, SII, and HS) prawns. No significant differences were found in the comparisons by other categories. The use of these three sources of carotenoids for pigmentation in crustacean was discussed along carotenoid conversion, deposition, digestibility, and absorption. When subjected to low dissolved oxygen stress, C-fed prawn had higher oxygen consumption rate (OCR) and shorter survival time (ST) than the prawns fed the pigmented diets. No differences in OCR or ST were found in the comparisons by other categories.     

Refining siRNA in vivo transfection: silencing SPHK1 reveals its key role in C5a-induced inflammation in vivo

The transfection of siRNA in vivo is essential for the study of gene functions, target validation, and for gene therapy. However, the successful delivery of siRNA in whole organisms is still very difficult to achieve. A high-pressure delivery technique, called the "hydrodynamics" method, has been used for siRNA transfection in mice. However, it is a method based on a high-speed and high-volume of i.v. injection, which makes it very difficult to implement in vivo, due to vascular breakage. Here, we systematically investigated ways to optimize the siRNA delivery, in order to avoid strong side effects, while achieving a high-efficiency siRNA-gene knockdown. We show here that the amount of siRNA delivered is crucial, as using too little or too much siRNA minimizes the knockdown effect. We demonstrate that by carefully identifying an optimal-minimal volume, and an optimal amount of siRNA, we achieve a high knockdown effect, with a 100% survival rate. We have previously shown that SphK1 plays a key role in anaphylatoxin (C5a) signaling in neutrophils and macrophages. Our approach, optimizing the dosage of siRNA, allowed us to successfully silence our target gene-product (SphK1) in vivo, and enabled us to validate SphK1 as a key player in our in vivo model of C5a-induced acute peritonitis and systemic inflammation including multi-organ damage, demonstrating that this improved siRNA-silencing method not only allowed us to identify SphK1 as a key therapeutic target, but brings us a step closer to the usage of siRNA for therapeutic intervention.     

Stieglitz rearrangement of N,N-dichloro-β,β-disubstituted taurines under mild aqueous conditions

New topical anti-infectives comprised of N,N-dichloro-β,β-disubstituted taurines [Tetrahedron Lett. 2008, 49, 2193; Biorg. Med. Chem. Lett. 2009, 19, 196] have been examined for structure–stability relationships (SSR) based upon various alkyl, heteroalkyl and cycloalkyl β-substitutions. These substitutions affect order-of-magnitude changes in the aqueous stability of these N,N-dichloroamines which can undergo Stieglitz rearrangement of alkyl groups under extremely mild conditions (H₂O, pH 4–7, 0–20 mM acetate or phosphate buffer, 20–40 °C). This process produces β-ketosulfonic acids which function as substrates for chlorination by the N-chlorotaurines which leads to their further degradation.     

T cell augments the antitumor activity of tumor-targeting <Emphasis Type="Italic">Salmonella</Emphasis>

Systemic administration of Salmonella to tumor-bearing mice leads to preferential accumulation within tumor sites and retardation of tumor growth. However, the detailed mechanism of Salmonella-induced antitumor immune response via host T cell remains uncertain. Herein, we used wild-type, CD4⁺ T-cell-deficient, and CD8⁺ T-cell-deficient mice to study the role of T cell in the antitumor immune responses induced by Salmonella enterica serovar Choleraesuis (Salmonella Choleraesuis). When systemically administered into mice bearing tumors, Salmonella Choleraesuis significantly inhibited tumor growth by 50%. In contrast, in T-cell-deficient mice, there was only 34–42% inhibition of tumor growth. We found that treatment with Salmonella Choleraesuis significantly upregulates interferon-γ in wild-type and CD8⁺ T-cell-deficient mice, but not in CD4⁺ T-cell-deficient mice. Furthermore, immunohistochemical staining of the tumors revealed more infiltration of macrophages and neutrophils in wild-type mice after Salmonella Choleraesuis treatment compared with those in T-cell-deficient mice. The antitumor therapeutic effect mediated by Salmonella Choleraesuis is associated with an inflammatory immune response at the tumor site and a tumor T helper 1-type immune response. In conclusion, these results suggest that tumor-targeted therapy using Salmonella Choleraesuis, which exerts tumoricidal effects and stimulates T cell activities, represents a potential strategy for the treatment of tumor.     

Galectin-1 binds to influenza virus and ameliorates influenza virus pathogenesis

Innate immune response is important for viral clearance during influenza virus infection. Galectin-1, which belongs to S-type lectins, contains a conserved carbohydrate recognition domain that recognizes galactose-containing oligosaccharides. Since the envelope proteins of influenza virus are highly glycosylated, we studied the role of galectin-1 in influenza virus infection in vitro and in mice. We found that galectin-1 was upregulated in the lungs of mice during influenza virus infection. There was a positive correlation between galectin-1 levels and viral loads during the acute phase of viral infection. Cells treated with recombinant human galectin-1 generated lower viral yields after influenza virus infection. Galectin-1 could directly bind to the envelope glycoproteins of influenza A/WSN/33 virus and inhibit its hemagglutination activity and infectivity. It also bound to different subtypes of influenza A virus with micromolar dissociation constant (K(d)) values and protected cells against influenza virus-induced cell death. We used nanoparticle, surface plasmon resonance analysis and transmission electron microscopy to further demonstrate the direct binding of galectin-1 to influenza virus. More importantly, we show for the first time that intranasal treatment of galectin-1 could enhance survival of mice against lethal challenge with influenza virus by reducing viral load, inflammation, and apoptosis in the lung. Furthermore, galectin-1 knockout mice were more susceptible to influenza virus infection than wild-type mice. Collectively, our results indicate that galectin-1 has anti-influenza virus activity by binding to viral surface and inhibiting its infectivity. Thus, galectin-1 may be further explored as a novel therapeutic agent for influenza.     

Adenovirus-Mediated Prothymosin α Gene Transfer Inhibits the Development of Atherosclerosis in Apoe-Deficient Mice

Prothymosin α (ProT) is involved in regulating expression of the oxidative stress-protective genes and it also exerts immunomodulatory activities. In this study, we investigated the therapeutic effects of ProT gene transfer on atherosclerosis in endothelial cells and in ApoE-deficient mice. Adenoviruses encoding mouse ProT (AdProT) were used for the management of atherosclerosis. In vitro, the effects of ProT on antioxidant gene expressions and the protection effect against oxidant-mediated injury in endothelial cells were examined. In vivo, AdProT were administered intraventricularly into the heart of ApoE^-/- mice. Histopathological and immunohistochemical assessments of the aortic tissues were performed. Expressions of HO-1 and antioxidant genes in the aortic tissues were also determined. Our results demonstrated that ProT gene transfer increased antioxidant gene expressions, eNOS expression and NO release, as well as reduced the reactive oxygen species production in endothelial cells. Intraventricular administration of AdProT reduced the lesion formation, increased expressions of HO-1 and SOD genes, and reduced infiltrating macrophages in the aorta of ApoE^-/- mice. This study suggests that ProT gene transfer may have the therapeutic potential for the management of atherosclerosis via inducing antioxidant gene expressions, eNOS expression and NO release, reducing ROS production and macrophage infiltration in endothelium.