Late-stage Use of Low-dose Corticosteroids Aid Recovery of Severe H1N1 Viral Pneumonia

The role of corticosteroids in the management of severely ill patients with inlfuenza A (H1N1) viral infection is unclear and controversial. Two critically ill cases with influenza A (H1N1) infections complicated with organizing pneumonia (OP) in 2011 successfully treated with low dose corticosteroids were reported here. After initial clinical improvement, the condition of both patients aggravated 20-23 days after the onset of illness. Chest X-ray and computed tomographies (CT) showed an increment of lung infiltrates. Cultures of blood, pleural lfuid and transbronchial aspirate were negative for bacteria and fungi. Organizing pneumonia was diagnosed clinically and both patients were successfully treated with low-dose corticosteroids. Low-dose corticosteroids initiated during convalescence may be beneficial for severe swine-origin influenza A H1N1 pandemic 2009 virus (S-OIV) infections.

Melittin analog p5RHH enhances recombinant adeno-associated virus transduction efficiency

Objective Melittin and its derivatives have been characterized to establish effective gene delivery systems.Their capability of facilitating endosomal release enhances the nanoparticles-based gene delivery.Nevertheless,little investigation has been conducted to explore its potential application in the context of viral vectors.Methods Various melittin-derived peptides were inserted into the loop VIII of the capsid proteins of recombinant adeno-associated virus vectors.These vectors carrying either gfp or fluc genes were subjected to qPCR assays and transduction assays of HEK293T cells to investigate the efficiency of vector production and gene delivery.In addition,the ability of a specific p5RHH-rAAV vector to deliver genes was examined through in vitro transduction of different cultured cells and in vivo tail vein administration to C57BL/6 mice.Finally,the intricate details of the vector-mediated transduction mechanisms were revealed by specific pharmacological inhibitors of every stage of the rAAV2 intracellular life cycle.Results A total of 76 melittin-related peptides were compiled from existing literature.Among them,cMA2,Melt13,p5RHH and aAR3 were found to significantly enhance the gene delivery efficiency of rAAV2 vectors.The p5RHH-rAAV2 vectors efficiently transduced not only rAAV-potent cell lines but also cell lines previously considered resistant to rAAV.Mechanistically,bafilomycin A1,a vacuolar endosome acidification inhibitor,completely inhibited the transgene expression mediated by the p5RHH-rAAV2 vectors.Most importantly,p5RHH-rAAV8 vectors also demonstrated increased hepatic transduction in vivo in C57BL/6 mice.Conclusion The incorporation of melittin analogues into the rAAV capsids results in a significant improvement in rAAV-mediated transgene expression.While further modifications remain an area of interest,our studies have substantially broadened the pharmacological prospects of melittin in the context of viral vector-mediated gene delivery.

The use of melittin to enhance transgene expression mediated by recombinant adeno-associated virus serotype 2 vectors both in vitro and in vivo

Objective: Melittin, a cell-penetrating peptide, improves the efficiency of many non-viral gene delivery vectors, yet its application in viral vectors has not been well studied. The non-pathogenic recombinant adeno-associated virus(rAAV) vector is an ideal in vivo gene delivery vector. However, its full potential will only be achieved after improvement of its transduction efficiency. To improve the transduction efficiency of rAAV2 vectors, we attempted to develop a melittin-based r AAV2 vector delivery strategy.Methods: The melittin peptide was inserted into the rAAV2 capsid either in the loop Ⅷ of all viral proteins(VPs) or at the N terminus of VP2. Various r AAV2-gfp or-fluc vectors were subjected to quantitative real-time polymerase chain reaction and Western blot assays to determine their titers and integrity of capsid proteins, respectively. Alternatively, the vectors based on wild-type capsid were pre-incubated with melittin, followed by transduction of cultured cells or tail vein administration of the mixture to C57BL/6 and BALB/c nude mice. In vivo bioluminescence imaging was performed to evaluate the transgene expression.Results: rAAV2 vectors with melittin peptide inserted in the loop Ⅷ of VPs had low transduction efficiency, probably due to dramatically reduced ability to bind to the target cells. Fusing the melittin peptide at the N-terminus of VP2 produced vectors without the VP2 subunit. Interestingly, among the commonly used rAAV vectors, pre-incubation of r AAV2 and rAAV6 vectors with melittin significantly enhanced their transduction efficiency in HEK293 and Huh7 cells in vitro. Melittin also had the ability to increase the rAAV2-mediated transgene expression in mouse liver in vivo. Mechanistically, melittin did not change the vector-receptor interaction. Moreover, cell counting kit-8 assays of cultured cells and serum transaminase levels indicated melittin had little cytotoxicity.Conclusion: Pre-incubation with melittin, but not insertion of melittin into the rAAV2 capsid, significantly enhanced rAAV2-mediated transgene expression. Although further in vivo evaluations are required, this research not only expands the pharmacological potential of melittin, but also provides a new strategy to improve gene therapy mediated by rAAV vectors.

Evodiamine inhibits high-fat diet-induced colitis-associated cancer in mice through regulating the gut microbiota

Objective:High-fat diet is one of the main risk factors that disrupt the balance of gut microbiota,which eventually will induce colorectal cancer(CRC).Evodiamine(EVO)is a wildly used multifunctional traditional Chinese medicine extract.In this study,we investigated the role of gut microbiota in high-fat dietpropelled CRC and the potential of EVO for CRC chemoprevention.Methods:Gut microbiota,serum D-lactic acid and endotoxin from 38 patients with colon cancer and 18 healthy subjects were detected by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay(ELISA).In addition,body mass index,phospho-signal transducer and activator of transcription 3(p-STAT3)expression in cancer tissues and paracancerous tissues were detected by immunohistochemistry.A mouse intestinal inflammatory tumor model was established by azomethane/sodium dextran sulfate,followed by treatment with EVO and 5-aminosalicylic acid(ASA).Gut microbiota and inflammatory factors were detected by quantitative polymerase chain reaction,while serum D-lactic acid and endotoxin were detected by ELISA.Furthermore,cell proliferation,cell apoptosis,and interleukin(IL)-6/STAT3/P65 pathway were evaluated by 5-ethynyl-20-deoxyuridine,terminal-deoxynucleotidyl transferase-mediated nick-end labeling,and Western blot assays.Results:In patients with colon cancer,the numbers of Enterococcus faecalis and Escherichia coli were increased,while those of Bifidobacterium,Campylobacter and Lactobacillus were decreased.Serum endotoxin and D-lactic acid levels and p-STAT3 levels were significantly increased.In the mouse model,both EVO and ASA inhibited tumor formation,decreased the proliferation of tumor cells,and induced apoptosis of tumor cells.Compared with the control group,the numbers of E.faecalis and E.coli were decreased,while Bifidobacterium,Campylobacter and Lactobacillus numbers were increased.In the EVO group,serum endotoxin and D-lactic acid levels and inflammatory factors were significantly decreased.Further,the IL6/STAT3/P65 signaling pathway was inhibited in the EVO group.Conclusion:EVO may inhibit the occurrence of colon cancer by regulating gut microbiota and inhibiting intestinal inflammation.The potential mechanism involves inhibition of the IL6/STAT3/P65 signaling pathway,revealing its potential therapeutic significance in clinical applications.