8 research outputs found

    Cyclic ADP ribose isomers: Production, chemical structures, and immune signaling

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    Cyclic adenosine diphosphate (ADP)–ribose (cADPR) isomers are signaling molecules produced by bacterial and plant Toll/interleukin-1 receptor (TIR) domains via nicotinamide adenine dinucleotide (oxidized form) (NAD+) hydrolysis. We show that v-cADPR (2′cADPR) and v2-cADPR (3′cADPR) isomers are cyclized by O-glycosidic bond formation between the ribose moieties in ADPR. Structures of 2′cADPR-producing TIR domains reveal conformational changes that lead to an active assembly that resembles those of Toll-like receptor adaptor TIR domains. Mutagenesis reveals a conserved tryptophan that is essential for cyclization. We show that 3′cADPR is an activator of ThsA effector proteins from the bacterial antiphage defense system termed Thoeris and a suppressor of plant immunity when produced by the effector HopAM1. Collectively, our results reveal the molecular basis of cADPR isomer production and establish 3′cADPR in bacteria as an antiviral and plant immunity–suppressing signaling molecule

    pH and thermo-responsive poly(N-isopropylacrylamide) copolymer grafted to poly(ethylene glycol)

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    pH and thermo-responsive graft copolymers are reported where thermo-responsive poly(N-isopropylacrylamide) [poly(NIPAAm), poly A], poly(N-isopropylacrylamide-co-2-(diethylamino) ethyl methacrylate) [poly(NIPAAm-co-DEA), poly B], and poly(N-isopropylacrylamide-co-methacrylic acid) [poly(NIPAAm-co-MAA), poly C] have been installed to benzaldehyde grafted polyethylene glycol (PEG) back bone following introducing a pH responsive benzoic-imine bond. All the prepared graft copolymers for PEG-g-poly(NIPAAm) [P-N1], PEG-g-poly(NIPAAm-co-DEA) [P-N2], and PEG-g-poly(NIPAAm-co-MAA) [P-N3] were characterized by H-1-NMR to assure the successful synthesis of the expected polymers. Molecular weight of all synthesized polymers was evaluated following gel permeation chromatography. The lower critical solution temperature of graft copolymers varied significantly when grafted to benzaldehyde containing PEG and after further functionalization of copolymer based poly(NIPAAm). The contact angle experiment showed the changes in hydrophilic/hydrophobic behavior when the polymers were exposed to different pH and temperature. Particle size measurement investigation by dynamic light scattering was performed to rectify thermo and pH responsiveness of all prepared polymers. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 201

    Therapeutic Effects of Ten Commonly Used Chinese Herbs and Their Bioactive Compounds on Cancers

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    Effective cancer therapy is one of the biggest global challenges. Conventional cancer therapies have been at the forefront of combating cancers, but more evidence showed considerable side effects, limiting their use. There are various new therapies in development, but combined approaches for treating cancer are much expected. Natural herbs had been traditionally in use for cancer therapy in most parts of the world. In this review, we have examined ten commonly used Chinese herbs that have, for centuries, shown effectiveness in treating cancers. They demonstrated the abilities to promote the apoptosis of cancer cells, inhibit their metastasis, activate the patient’s anticancer immunity, and synergistically increase the efficacy of conventional chemotherapy and radiation therapy when used in combination. Clinical experiences had proved that these herbs and their bioactive compounds were effective against a plethora of cancers through a variety of mechanisms, effectively improving patients’ quality of life without significant side effects. These advantages indicate that there are huge potentials in the development of Chinese herbs into cancer medicine as part of a promising, holistic cancer treatment modality

    Significance of LL-37 on Immunomodulation and Disease Outcome

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    LL-37, also called cathelicidin, is an important part of the human immune system, which can resist various pathogens. A plethora of experiments have demonstrated that it has the multifunctional effects of immune regulation, in addition to antimicrobial activity. Recently, there have been increasing interest in its immune function. It was found that LL-37 can have two distinct functions in different tissues and different microenvironments. Thus, it is necessary to investigate LL-37 immune functions from the two sides of the same coin. On the one side, LL-37 promotes inflammation and immune response and exerts its anti-infective and antitumor effects; on the other side, it has the ability to inhibit inflammation and promote carcinogenesis. This review presents a brief summary of its expression, structure, and immunomodulatory effects as well as brief discussions on the role of this small peptide as a key factor in the development and treatment of various inflammation-related diseases and cancers

    Thioamide derivative of the potent antitubercular 2-(decylsulfonyl) acetamide is less active against mycobacterium tuberculosis, but a more potent antistaphylococcal agent

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    Due to the prevalence of thioamides in antibacterial compounds, we chose to convert the amide in the antitubercular compound 2-(decylsulfonyl)acetamide to a thioamide using Lawesson's reagent to study its activity against a range of microorganisms. This derivative (8) had significantly diminished activity against tuberculosis but slightly better activity than the parent compound against the Gram positive species Staphylococcus aureus. This activity against a second major pathogen is remarkable considering the structural simplicity of these compounds

    Cyclic ADP ribose isomers : production, chemical structures, and immune signaling

    No full text
    Cyclic adenosine diphosphate (ADP)–ribose (cADPR) isomers are signaling molecules produced by bacterial and plant Toll/interleukin-1 receptor (TIR) domains via nicotinamide adenine dinucleotide (oxidized form) (NAD+) hydrolysis. We show that v-cADPR (2′cADPR) and v2-cADPR (3′cADPR) isomers are cyclized by O-glycosidic bond formation between the ribose moieties in ADPR. Structures of 2′cADPR-producing TIR domains reveal conformational changes that lead to an active assembly that resembles those of Toll-like receptor adaptor TIR domains. Mutagenesis reveals a conserved tryptophan that is essential for cyclization. We show that 3′cADPR is an activator of ThsA effector proteins from the bacterial antiphage defense system termed Thoeris and a suppressor of plant immunity when produced by the effector HopAM1. Collectively, our results reveal the molecular basis of cADPR isomer production and establish 3′cADPR in bacteria as an antiviral and plant immunity–suppressing signaling molecule

    Carbohydrate-based nanocarriers and their application to target macrophages and deliver antimicrobial agents

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