Dual Functioned Hexapeptide-Coated Lipid-Core Nanomicelles Suppress Toll-Like Receptor-Mediated Inflammatory Responses through Endotoxin Scavenging and Endosomal pH Modulation.

Excessive activation of Toll-like receptor (TLR) signaling pathways and the circulating endotoxin are key players in the pathogenesis of many acute and chronic inflammatory diseases. Regulation of TLR-mediated inflammatory responses by bioactive nanodevices represents a promising strategy for treating these diseases. In searching for novel, clinically applicable nanodevices with potent TLR inhibitory activities, three types of hexapeptide-modified nano-hybrids with different cores of phospholipid nanomicelles, liposomes, and poly(lactic-co-glycolic acid) nanoparticles are constructed. Interestingly, only the peptide-modified lipid-core nanomicelles (M-P12) display potent TLR inhibitory activities. Further mechanistic studies disclose that lipid-core nanomicelles have a generic property to bind to and scavenge lipophilic TLR ligands including lipopolysaccharide to block the ligand-receptor interaction and down-regulate the TLR signaling extracellularly. In addition, the peptide modification enables M-P12 a unique capability to modulate endosomal acidification upon being endocytosed into macrophages, which subsequently regulates the endosomal TLR signal transduction. In an acute lung injury mouse model, intratracheal administration of M-P12 can effectively target lung macrophages and reduce lung inflammation and injuries. This work defines a dual mechanism of action of the peptide-modified lipid-core nanomicelles in regulating TLR signaling, and provides new strategies for the development of therapeutic nanodevices for treating inflammatory diseases.

Perfusion of brain and viscera using modified retrograde cerebral perfusion for aortic arch surgery.

Anterograde or retrograde cerebral perfusion can protect the brain from ischemic injury during hypothermic circulatory arrest (HCA), but neither type of perfusion provides blood flow to the abdominal viscera. Here, we report a modified retrograde cerebral perfusion (RCP) technique in which we tethered both superior and inferior venae cavae with bands around the cannula and clamped the distal ends of the drainage tubes of both venae cavae. Modified RCP may provide greater blood flow to the brain and lower body than conventional RCP during HCA in hemiarch surgery.

Nano-Enabled Reposition of Proton Pump Inhibitors for TLR Inhibition: Toward A New Targeted Nanotherapy for Acute Lung Injury.

Toll-like receptor (TLR) activation in macrophages plays a critical role in the pathogenesis of acute lung injury (ALI). While TLR inhibition is a promising strategy to control the overwhelming inflammation in ALI, there still lacks effective TLR inhibitors for clinical uses to date. A unique class of peptide-coated gold nanoparticles (GNPs) is previously discovered, which effectively inhibited TLR signaling and protected mice from lipopolysaccharide (LPS)-induced ALI. To fast translate such a discovery into potential clinical applicable nanotherapeutics, herein an elegant strategy of "nano-enabled drug repurposing" with "nano-targeting" is introduced to empower the existing drugs for new uses. Combining transcriptome sequencing with Connectivity Map analysis, it is identified that the proton pump inhibitors (PPIs) share similar mechanisms of action to the discovered GNP-based TLR inhibitor. It is confirmed that PPIs (including omeprazole) do inhibit endosomal TLR signaling and inflammatory responses in macrophages and human peripheral blood mononuclear cells, and exhibits anti-inflammatory activity in an LPS-induced ALI mouse model. The omeprazole is then formulated into a nanoform with liposomes to enhance its macrophage targeting ability and the therapeutic efficacy in vivo. This research provides a new translational strategy of nano-enabled drug repurposing to translate bioactive nanoparticles into clinically used drugs and targeted nano-therapeutics for ALI.

Administration route governs the therapeutic efficacy, biodistribution and macrophage targeting of anti-inflammatory nanoparticles in the lung.

BACKGROUND: Uncontrolled inflammation is a central problem for many respiratory diseases. The development of potent, targeted anti-inflammatory therapies to reduce lung inflammation and re-establish the homeostasis in the respiratory tract is still a challenge. Previously, we developed a unique anti-inflammatory nanodrug, P12 (made of hexapeptides and gold nanoparticles), which can attenuate Toll-like receptor-mediated inflammatory responses in macrophages. However, the effect of the administration route on its therapeutic efficacy and tissue distribution remained to be defined. RESULTS: In this study, we systematically compared the effects of three different administration routes [the intratracheal (i.t.), intravenous (i.v.) and intraperitoneal (i.p.)] on the therapeutic activity, biodistribution and pulmonary cell targeting features of P12. Using the LPS-induced ALI mouse model, we found that the local administration route via i.t. instillation was superior in reducing lung inflammation than the other two routes even treated with a lower concentration of P12. Further studies on nanoparticle biodistribution showed that the i.t. administration led to more accumulation of P12 in the lungs but less in the liver and other organs; however, the i.v. and i.p. administration resulted in more nanoparticle accumulation in the liver and lymph nodes, respectively, but less in the lungs. Such a lung favorable distribution was also determined by the unique surface chemistry of P12. Furthermore, the inflammatory condition in the lung could decrease the accumulation of nanoparticles in the lung and liver, while increasing their distribution in the spleen and heart. Interestingly, the i.t. administration route helped the nanoparticles specifically target the lung macrophages, whereas the other two administration routes did not. CONCLUSION: The i.t. administration is better for treating ALI using nanodevices as it enhances the bioavailability and efficacy of the nanodrugs in the target cells of the lung and reduces the potential systematic side effects.

Biological Characteristics and Molecular Mechanism of Procymidone Resistance in Stemphylium eturmiunum From Garlic.

Garlic leaf blight caused by Stemphylium eturmiunum was first reported in Jiangsu Province in China. The dicarboximide fungicide (DCF) procymidone is reported to possess broad-spectrum action in inhibiting filamentous fungi and is widely used to control leaf disease of various plants. Of 41 Stemphylium eturmiunum isolates collected in this study from commercial garlic farms in Pizhou and Dafeng counties of Jiangsu Province, eight isolates were resistant to procymidone. The following three phenotypes were categorized according to in vitro responses to DCFs: sensitive, low resistance to iprodione and procymidone, and high resistance to all iprodione and procymidone. The fitness of all resistant isolates was decreased in accordance with data on mycelial growth, conidiation, and virulence. After treatment with 10 µg/ml of procymidone for 4 h, mycelial intracellular glycerol concentrations of resistant isolates were significantly lower than those of sensitive isolates. Positive cross-resistance was observed between dicarboximides and phenylpyrroles, but there was no cross-resistance between dicarboximides and fluazinam or difenoconazole in the two resistant phenotypes. Nucleotide sequence alignment of two-component histidine kinase genes from sensitive and resistant isolates indicated that amino acid mutations were located at the histidine kinase, adenylyl cyclase, methyl-accepting chemotaxis protein and at the phosphatase domain of the N-terminal region and the response regulator domain of the C-terminal region. To our knowledge, this is the first report of DCF resistance in Stemphylium eturmiunum, and these findings will help establish a rational strategy to manage DCF-resistant populations of Stemphylium eturmiunum in the field.

Manipulation of macrophage polarization by peptide-coated gold nanoparticles and its protective effects on acute lung injury.

BACKGROUND: Macrophage polarization and reprogramming in the lung play a critical role in the initiation, development and progression of acute lung injury (ALI). Regulating the activation and differentiation of pulmonary macrophages may provide a potential therapeutic strategy to treat ALI. We previously developed a novel class of anti-inflammatory nanoparticles (P12) that can potently inhibit Toll-like receptor (TLR) signaling in macrophages. These bioactive nanodevices were made of gold nanoparticles (GNPs) coated with hexapeptides to not only ensure their physiological stability but also enable GNPs with TLR inhibitory activity. RESULTS: In this study, using a lipopolysaccharide (LPS) induced ALI mouse model, we showed that P12 was able to alleviate lung inflammation and damage through reducing the infiltration of inflammatory cells and increasing the anti-inflammatory cytokine (IL-10) in the lung. These results prompted us to investigate possible macrophage polarization by P12. We first confirmed that P12 primarily targeted macrophages in the lung to exert anti-inflammatory activity. We then showed that P12 could drive the polarization of mouse bone marrow-derived macrophages (BMDMs) toward anti-inflammatory M2 phenotype. Interestingly, in the ALI mouse model, P12 was able to increase the alveolar M2 macrophages and reduce both the alveolar and interstitial M1 macrophages in the bronchoalveolar lavage fluid (BALF) and lung tissues. CONCLUSION: This study demonstrated that peptide-coated GNPs could induce M2 macrophage polarization in vitro and in vivo to effectively regulate lung inflammation, protect lung from injuries and promote inflammation resolution. The ability of regulating macrophage polarization together with TLR inhibition made such a bioactive nanodevice a new generation of potent therapeutics to treat ALI.

Involvement of the two L-lactate dehydrogenase in development and pathogenicity in Fusarium graminearum.

Lactate dehydrogenase (LDH) widely exists in organisms, which catalyzes the interconversion of pyruvate into lactate with concomitant interconversion of NADH and NAD+. In this study, two L-type lactate dehydrogenase genes FgLDHL1 and FgLDHL2 were characterized in an ascomycete fungus Fusarium graminearum, a causal agent of wheat head blight. Both the single-gene deletion mutants of FgLDHL1 or FgLDHL2 exhibited phenotypic defects in vegetative growth, sporulation, spore germination, L-lactate biosynthesis and activity. Additionally, the two L-lactate dehydrogenases were involved in the utilization of carbon sources and maintenance of redox homeostasis during spore germination. Pathogenicity assays showed that ΔFgLDHL1 exhibits reduced virulence on wheat spikelets and on corn stigmas, suggesting that it was indirectly correlated with a reduced level of deoxynivalenol accumulation. These results indicate that FgLDHL1 and FgLDHL2 play multiple roles in the developmental processes and pathogenesis in F. graminearum, and help understand the functional diversity of D-/L-lactate dehydrogenase in phytopathogenic fungi.

O-Benzoyl-naltrexone.

In the title compound, C27H27NO5 (systematic name: 17-cyclopropylmethyl-14-hydroxy-6-oxo-4,5-epoxymorphin-an-6-yl benzoate), which is the benzoate ester of the opioid receptor antagonist naltrexone, the dihedral angle between the two phenyl rings is 77.1 (1)°. In the crystal, a weak aromatic C-H⋯Ocarbox-yl hydrogen bond involving the benzoate groups of adjacent mol-ecules gives rise to a chain extending along the a-axis direction. The known absolute configuration for the mol-ecule was inferred from a previous naltrexone structure.