Suppression or abnormalities of skeletal muscle function caused by disuse, aging and certain diseases are associated with increased oxidative stress and inflammatory response. Avenanthramides (Avns), the polyphenol compounds only found in oats, exhibit anti-inflammatory effects by inhibiting NFκB activation in select cell lines. However, the molecular mechanism by which Avns reduces inflammation in skeletal muscle cell is still unclear. PURPOSE: The purpose of this study was to investigate (1) whether Avns suppress inflammatory responses in skeletal muscle cells; and (2) the molecular mechanism by which Avns can inhibit NFκB activation. METHODS: C2C12 mouse skeletal muscle cell lines were treated with 200μM tert-Butyl hydroperoxide (tBHP) for 6h with or without three different forms of Avns (AvnA, AvnB and AvnC). Interactions between Avns and IκB kinase (IKKβ) were tested by protein-ligand docking and protein kinase assay. NFκB-mediated inflammatory pathways were evaluated. RESULTS: The docking score correlated with IKKβ in vitro activity suggesting Avns are synergistic bioinhibitors for IKKβ pathway. Avns reduced the kinase activity in response to tBHP treatment. TNF-α and IL-1β mRNA levels were increased by 6.2- and 13-fold (P<0.01), respectively, with tBHP compared to control, but these levels were reduced by approximately 2-fold with Avns (P<0.01). IκB protein degradation and NFκB luciferase assay, used as a marker of NFκB activation, showed that Avns suppressed tBHP-induced NFκB activation (all P<0.01). Cyclooxygenase-2 (COX-2) protein expression was increased with tBHP, along with a 3.1-fold increase in COX-2 luciferase activity (P<0.01), but these markers were reduced by ~2-fold with Avns (P<0.01). Prostaglandin E2 (PGE2) level was increased 3.7-fold with tBHP treatment (P<0.01), but was decreased by 59, 54 and 62% (P<0.01), respectively, with AvnA,B,and C. CONCLUSIONS: Avns are potent inhibitors of NFκB-mediated inflammatory response due to the downregulation of IKKβ activity in C2C12 cells.
, a predominant nosocomial pathogen, represents a grave threat to public health due to its multiple antimicrobial resistance. Managing patients afflicted with severe infections caused by multiple drug-resistant
// Chunlin Zhuang 1, 2, * , Chunquan Sheng 1, * , Woo Shik Shin 3 , Yuelin Wu 1 , Jin Li 1 , Jianzhong Yao 1 , Guoqiang Dong 1 , Wen Zhang 2 , Yuk Yin Sham 3 , Zhenyuan Miao 1 , Wannian Zhang 1 1 Department of Medicinal Chemistry, School of Pharmacy, Second Military Medical University, Shanghai, 200433, People's Republic of China 2 Research Center for Marine Drugs, School of Pharmacy, Second Military Medical University, Shanghai, 200433, People's Republic of China 3 Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, 55455, Minnesota * These authors contributed equally to this work Correspondence to: Zhenyuan Miao, e-mail: miaozhenyuan@hotmail.com Wannian Zhang, e-mail: zhangwnk@hotmail.com Yuk Yin Sham, e-mail: shamx002@umn.edu Keywords: p53-MDM2, NF-κB, antitumor activity, dual inhibitors, enantiomer, molecular dynamics, molecular recognition Received: June 30, 2014 Accepted: September 24, 2014 Published: October 07, 2014 ABSTRACT The p53 and nuclear factor κB (NF-κB) pathways play crucial roles in human cancer development. Simultaneous targeting of both pathways is an attractive therapeutic strategy against cancer. In this study, we report an antitumor molecule that bears a pyrrolo[3,4-c]pyrazole scaffold and functions as an enantiomeric inhibitor against both the p53-MDM2 interaction and the NF-κB activation. It is a first-in-class enantiomeric inhibitor with dual efficacy for cancer therapy. Synergistic effect was observed in vitro and in vivo . Docking and molecular dynamics simulation studies further provided insights into the nature of stereoselectivity.
Ischemic injury to white matter tracts is increasingly recognized to play a key role in age-related cognitive decline, vascular dementia, and Alzheimer's disease. Knowledge of the effects of ischemic axonal injury on cortical neurons is limited yet critical to identifying molecular pathways that link neurodegeneration and ischemia. Using a mouse model of subcortical white matter ischemic injury coupled with retrograde neuronal tracing, we employed magnetic affinity cell sorting with fluorescence-activated cell sorting to capture layer-specific cortical neurons and performed RNA-sequencing. With this approach, we identified a role for microtubule reorganization within stroke-injured neurons acting through the regulation of tau. We find that subcortical stroke-injured Layer 5 cortical neurons up-regulate the microtubule affinity-regulating kinase, Mark4, in response to axonal injury. Stroke-induced up-regulation of Mark4 is associated with selective remodeling of the apical dendrite after stroke and the phosphorylation of tau in vivo. In a cell-based tau biosensor assay, Mark4 promotes the aggregation of human tau in vitro. Increased expression of Mark4 after ischemic axonal injury in deep layer cortical neurons provides new evidence for synergism between axonal and neurodegenerative pathologies by priming of tau phosphorylation and aggregation.
Abstract Carbapenem-resistant Acinetobacter baumannii (CRAb) is an urgent bacterial threat to public health, with only a few treatment options and a >50% fatality rate. Although several resistance mechanisms are understood, the appearance of these mutations is generally considered stochastic. Recent reports have, however, begun to challenge this assumption. Here, we demonstrate that independent samples of Ab, exposed to different carbapenems with escalating concentrations, show concentration- and carbapenem-dependent trends in β-lactamase-isoform expression. This result, based on the isoforms identified through label-free-quantification LC-MS/MS measurements of cell-free, gel-separated β-lactamases, suggests that the appearance of antibiotic resistance may be somewhat non-stochastic. Specifically, several minor AmpC/ADC β-lactamase-isoforms were found to exhibit both dose- and carbapenem-dependent expression, suggesting the possibility of non-stochastic mutations. Additionally, these also have high sequence similarity to major expressed isoforms, indicating a potential path over which resistance occurred in independent samples. Antibiotic resistance maybe somewhat antibiotic-directed by a hitherto unknown mechanism and further investigation may lead to new strategies for mitigating antibiotic resistance. Teaser The emergence of antibiotic-resistant β-lactamase proteins from mutations may exhibit patterns based on specific antibiotics.
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