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991.
Influences of disulfide connectivity on structure and antimicrobial activity of tachyplesin I
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Juan Shi Lok‐Yan So Fangling Chen Jiazhen Liang Ho‐Yin Chow Kwok‐Yin Wong Shengbiao Wan Tao Jiang Rilei Yu 《Journal of peptide science》2018,24(6)
Tachyplesin I is a potent antimicrobial peptide with broad spectrum of antimicrobial activity. It has 2 disulfide bonds and can form 3 disulfide bond isomers. In this study, the structure and antimicrobial activity of 3 tachyplesin I isomers (tachyplesin I, 3C12C, 3C7C) were investigated using molecular dynamic simulations, circular dichroism structural study, as well as antimicrobial activity and hemolysis assay. Our results suggest that in comparison to the native peptide, the 2 isomers (3C12C, 3C7C) have substantial structural and activity variations. The native peptide is in the ribbon conformation, while 3C12C and 3C7C possess remarkably different secondary structures, which are referred as “globular” and “beads” isomers, respectively. The substantially decreased hemolysis effects for these 2 isomers is accompanied by significantly decreased anti‐gram‐positive bacterial activity. 相似文献
992.
Shouheng Jin 《Autophagy》2018,14(1):171-172
Macroautophagy/autophagy is a conserved lysosomal degradation system that breaks down intracellular material through the formation of double-membrane autophagosomes in eukaryotic cells. Cargo receptors have been shown to play essential roles in capturing and delivering specific substrates into phagophores, the precursors to autophagosomes, for degradation. However, the detailed mechanism underlying selective recognition of the substrates for autophagic degradation remains poorly understood. Recently, we have revealed that IFN (interferon)-induced BST2 recruits the E3 ubiquitin ligase MARCH8 to catalyze the K27-linked ubiquitination of MAVS for CALCOCO2-directed autophagic degradation, hence inhibiting DDX58-mediated type I interferon signaling through a negative feedback loop. 相似文献
993.
The ischemia-reperfusion (I/R) induced skin lesion has been identified as primary cause of pressure ulcer. Better understanding of the mechanism is required for new therapy development. Leucine rich repeat containing protein 19 (LRRC19) is a recently discovered transmembrane protein containing leucine-rich repeats and plays a role in immune response. To investigate the role of LRRC19 in pressure ulcers, mouse ulcer model was established with two cycles of I/R. The expression of LRRC19 was assessed during injury. siRNA mediated LRRC19 downregulation was applied to investigate the disease severity, immune cell infiltration and pro-inflammatory cytokines production. The primary skin fibroblasts were stimulated with IL-1β to dissect the molecular mechanism. LRRC19 was readily induced in I/R induced lesion site in a pattern mimicking the disease progress as measured by wound area. Knockdown of LRRC19 by siRNA significantly alleviated the disease severity and attenuated immune cell infiltration and pro-inflammatory cytokines production. In primary skin fibroblast model, siRNA knockdown of LRRC19 suppressed IL-1β mediated NFκB activation and its downstream cytokines production. LRRC19 was a novel factor for I/R-induced tissue damage by promoting NFκB dependent pro-inflammatory response. Our results supported that LRRC19 could be a potential therapeutic target for pressure ulcers. 相似文献
994.
Chengming Ding Jun He Jun Zhao Junhua Li Jie Chen Wenyan Liao Yi Zeng Jing Zhong Chaoying Wei Liming Zhang Mei Zhou Zeming Jia Yaoting Zhang Hui Li Yuzheng Zhou Xiaolong Xiao Dong Han Chong Li Zhu Zhu Zanxian Xia Jian Peng 《Cell proliferation》2018,51(5)
Objective
β‐catenin is one of the most critical oncogenes associated with many kinds of human cancers, especially in the human CRC. Innate immunity recognizes tumour derived damage‐associated molecular patterns (DAMPs) and primes the anti‐tumour adaptive responses. While the function of β‐catenin in CRC tumourigenesis is well established, its impact on innate immune evasion is largely unknown. The aim of this study is to characterize the role of β‐catenin in inhibiting RIG‐I‐like receptor (RLR)‐mediated IFN‐β signalling in colorectal cancer.Materials and Methods
Immunohistochemical staining and western blotting were conducted to study the expression of β‐catenin, IRF3 and phospho‐IRF3 (p‐IRF3) in CRC samples and cell lines. Plaque assay determining virus replication was performed to assess the regulation of β‐catenin on IFN‐β signalling. The inhibition of β‐catenin on RLR‐mediated IFN‐β signalling was further studied by real‐time analyses and reporter assays in the context of lentiviral‐mediated β‐catenin stably knocking down. Lastly, co‐immunoprecipitation and nuclear fractionation assay were conducted to monitor the interaction between β‐catenin and IRF3.Results
We found that high expression of β‐catenin positively correlated with the expression of IRF3 in CRC cells. Overexpression of β‐catenin increased the viral replication. Conversely knocking down of β‐catenin inhibited viral replication. Furthermore, our data demonstrated that β‐catenin could inhibit the expression of IFN‐β and interferon‐stimulated gene 56 (ISG56). Mechanistically, we found that β‐catenin interacted with IRF3 and blocked its nuclear translocation.Conclusion
Our study reveals an unprecedented role of β‐catenin in enabling innate immune evasion in CRC.995.
Jutamas Apisornopas Patamawadee Silalai Teerapich Kasemsuk Anan Athipornchai Uthaiwan Sirion Kanoknetr Suksen Pawinee Piyachaturawat Apichart Suksamrarn Rungnapha Saeeng 《Bioorganic & medicinal chemistry letters》2018,28(9):1558-1561
New iridoid glycoside derivatives from durantoside I, the latter from the dried flowers and leaves of Citharexylum spinosum, were synthesized by variously modifying a sugar moiety by silylation or acetylation and/or removal of cinnamate group at C-7 position and subsequent screening for comparative cytotoxicity against several cancer cell lines. Addition of alkylsilane to durantoside I and removal of cinnamate group were most effective in improving cytotoxicity. 相似文献
996.
Tomoyuki Ohe Ryutaro Umezawa Yumina Kitagawara Daisuke Yasuda Kyoko Takahashi Shigeo Nakamura Akiko Abe Shuichi Sekine Kousei Ito Kentaro Okunushi Hanae Morio Tomomi Furihata Naohiko Anzai Tadahiko Mashino 《Bioorganic & medicinal chemistry letters》2018,28(23-24):3708-3711
We synthesized six novel BBR derivatives that were designed to avoid metabolic activation via ipso-substitution and evaluated for their degree of toxicity and hURAT1 inhibition. It was found that all of the derivatives demonstrate lower cytotoxicity in mouse hepatocytes and lower levels of metabolic activation than BBR, while maintaining their inhibitory activity toward the uric acid transporter. We propose that these derivatives could serve as effective uricosuric agents that have much better safety profiles than BBR. 相似文献
997.
Yaping Huang Geng Sun Pengfei Wang Rui Shi Yanchun Zhang Xiaoan Wen Hongbin Sun Caiping Chen 《Bioorganic & medicinal chemistry letters》2018,28(17):2957-2960
In this study, Complex I inhibitor R419 was firstly revealed to have significant anticancer activity against HepG2 cells (IC50?=?5.2?±?0.9?μM). Based on this finding, a series of R419 derivatives were synthesized and biologically evaluated. As results, 9 derivatives were found to have obvious anticancer activity. Among them, H20 exhibited the most potent activity (IC50?=?2.8?±?0.4?μM). Mechanism study revealed that H20 caused severe depletion of cellular ATP, dose-dependently activated AMPK, decreased Bcl-2/Bax ratio and induced necrotic cell death. Most importantly, H20 displayed definite inhibitory activity against Complex I. 相似文献
998.
Teppei Ikeya David Ban Donghan Lee Yutaka Ito Koichi Kato Christian Griesinger 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(2):287-306
Background
To understand the mechanisms related to the ‘dynamical ordering’ of macromolecules and biological systems, it is crucial to monitor, in detail, molecular interactions and their dynamics across multiple timescales. Solution nuclear magnetic resonance (NMR) spectroscopy is an ideal tool that can investigate biophysical events at the atomic level, in near-physiological buffer solutions, or even inside cells.Scope of review
In the past several decades, progress in solution NMR has significantly contributed to the elucidation of three-dimensional structures, the understanding of conformational motions, and the underlying thermodynamic and kinetic properties of biomacromolecules. This review discusses recent methodological development of NMR, their applications and some of the remaining challenges.Major conclusions
Although a major drawback of NMR is its difficulty in studying the dynamical ordering of larger biomolecular systems, current technologies have achieved considerable success in the structural analysis of substantially large proteins and biomolecular complexes over 1 MDa and have characterised a wide range of timescales across which biomolecular motion exists. While NMR is well suited to obtain local structure information in detail, it contributes valuable and unique information within hybrid approaches that combine complementary methodologies, including solution scattering and microscopic techniques.General significance
For living systems, the dynamic assembly and disassembly of macromolecular complexes is of utmost importance for cellular homeostasis and, if dysregulated, implied in human disease. It is thus instructive for the advancement of the study of the dynamical ordering to discuss the potential possibilities of solution NMR spectroscopy and its applications. This article is part of a Special Issue entitled “Biophysical Exploration of Dynamical Ordering of Biomolecular Systems” edited by Dr. Koichi Kato. 相似文献999.
Lin Wang Ziru Yu Shuyue Ren Junke Song Jinhua Wang Guanhua Du 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(10):2281-2292
Background
Metabolic reprogramming and hypoxia contribute to the resistance of conventional chemotherapeutic drugs in kinds of cancers. In this study, we investigated the effect of dihydrotanshinone I (DHTS) on reversing dysregulated metabolism of glucose and fatty acid in colon cancer and elucidated its mechanism of action.Methods
Cell viability was determined by MTT assay. Oxidative phosphorylation, glycolysis, and mitochondrial fuel oxidation were assessed by Mito stress test, glycolysis stress test, and mito fuel flex test, respectively. Anti-cancer activity of DHTS in vivo was evaluated in Colon cancer xenograft. Hexokinase activity and free fatty acid (FFA) content were assessed using respective Commercial kits. Gene expression patterns were determined by performing DNA microarray analysis and real-time PCR. Protein expression was assessed using immunoblotting and immunohistochemistry.Results
DHTS showed similar cytotoxicity against colon cancer cells under hypoxia and normoxia. DHTS decreased the efficiency of glucose and FA as mitochondrial fuels in HCT116 cells, which efficiently reversed by VO-OHpic trihydrate. DHTS reduced hexokinase activity and free fatty acid (FFA) content in tumor tissue of xenograft model of colon cancer. Gene expression patterns in metabolic pathways were dramatically differential between model and treatment group. Increases in PTEN and a substantial decrease in the expression of SIRT3, HIF1α, p-AKT, HKII, p-MTOR, RHEB, and p-ACC were detected.Conclusions
DHTS reversed metabolic reprogramming in colon cancer through PTEN/AKT/HIF1α-mediated signal pathway.General significance
The study is the first to report the reverse of metabolic reprogramming by DHTS in colon cancer. Meantime, SIRT3/PTEN/AKT/HIF1α mediated signal pathway plays a critical role during this process. 相似文献1000.