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博文

目前显示的是 十一月, 2018的博文

First characterization of an anti-lipopolysaccharide factor (ALF) from hydrothermal vent shrimp: Insights into the immune function of deep-sea crustacean ALF

Author:Han-jie Gu, Qing-lei Sun, Shuai Jiang, Jian Zhang,  Li Sun     《Developmental & Comparative Immunology》 ABSTRACTS Anti-lipopolysaccharide factor (ALF) is a type of  antimicrobial peptides   (AMPs) with a vital role in antimicrobial defense. Although a large amount of ALFs have been identified from neritic and fresh water crustacean species, no functional investigation of ALFs from deep-sea animals have been documented. In the present study, we characterized the immune function of an ALF molecule (named RspALF1) from the shrimp  Rimicaris   sp. residing in the deep-sea hydrothermal vent in Desmos, Manus Basin. RspALF1 shares 51.5%–62.4% overall sequence identities with known shrimp ALFs and contains the conserved LPS  binding domain   (LBD). Both  recombinant   RspALF1 (rRspALF1) and the LBD-derived  peptide   (ALF1P1) bound to the cell wall components of  Gram-negative   and  G...

Deubiquitinating enzyme USP9X regulates cellular clock function by modulating the ubiquitination and degradation of a core circadian protein BMAL1

Author:Yang Zhang, Chunyan Duan, Jing Yang, Suping Chen,  Qing Liu, Liang Zhou, Zhengyun Huang, Ying Xu, Guoqiang Xu     《Biochemical Journal》 ABSTRACTS Living organisms on the earth maintain a roughly 24 h circadian rhythm, which is regulated by circadian clock genes as well as their protein products. Post-translational modifications of core clock proteins could affect the circadian behavior. Although ubiquitination of core clock proteins was studied extensively, the reverse process, deubiquitination, has only begun to unfold and the role of this regulation on circadian function is not completely understood. Here, we use affinity purification and mass spectrometry analysis to identify probable ubiquitin carboxyl-terminal hydrolase FAF-X (USP9X) as an interacting protein of the core clock protein aryl hydrocarbon receptor nuclear translocator-like protein 1 (ARNTL or BMAL1). Through biochemical experiments, we discover that USP9X reduces BMAL1 ubiquitina...

The targeted antioxidant MitoQ causes mitochondrial swelling and depolarization in kidney tissue

Author:Esther M. Gottwald, Michael Duss, Milica Bugarski,  Dominik Haenni, Claus D. Schuh, Ehud M. Landau, Andrew M. Hall     《Physiological Reports》 ABSTRACTS Kidney proximal tubules (PTs) contain a high density of mitochondria, which are required to generate ATP to power solute transport. Mitochondrial dysfunction is implicated in the pathogenesis of numerous kidney diseases. Damaged mitochondria are thought to produce excess reactive oxygen species (ROS), which can lead to oxidative stress and activation of cell death pathways. MitoQ is a mitochondrial targeted antioxidant that has shown promise in preclinical models of renal diseases. However, recent studies in nonkidney cells have suggested that MitoQ might also have adverse effects. Here, using a live imaging approach, and both in  vitro and ex  vivo models, we show that MitoQ induces rapid swelling and depolarization of mitochondria in PT cells, but these effects were not observed with S...

Mutational analysis of the extracellular disulphide bridges of the atypical chemokine receptor ACKR3/CXCR7 uncovers multiple binding and activation modes for its chemokine and endogenous non-chemokine agonists

Author:Martyna Szpakowska, Max Meyrath, Nathan Reynders,  Manuel Counson, Julien Hanson, Jan Steyaert, Andy Chevigné     《Biochemical Pharmacology》 ABSTRACTS The atypical chemokine receptor ACKR3/CXCR7 plays crucial roles in numerous physiological processes but also in viral infection and cancer. ACKR3 shows strong propensity for activation and, unlike classical chemokine receptors, can respond to chemokines from both the CXC and CC families as well as to the endogenous peptides BAM22 and adrenomedullin. Moreover, despite belonging to the G protein coupled receptor family, its function appears to be mainly dependent on β-arrestin. ACKR3 has also been shown to continuously cycle between the plasma membrane and the endosomal compartments, suggesting a possible role as a scavenging receptor. So far, the molecular basis accounting for these atypical binding and signalling properties remains elusive. Noteworthy, ACKR3 extracellular domains bear three  di...

Targeting the leptin receptor: To evaluate therapeutic efficacy and anti-tumor effects of Doxil, in vitro and in vivo in mice bearing C26 colon carcinoma tumor

Author:Shahrzad Amiri Darban, Sara Nikoofal-Sahlabadi,  Nafise Amiri, Nafiseh Kiamanesh, Amin Mehrabian, Bamdad Zendehbad, Zahra Gholizadeh, Mahmoud Reza Jaafari     《Colloids and Surfaces B: Biointerfaces》 ABSTRACTS Leptin is an appetite regulatory hormone that is secreted into the blood circulation by the adipose tissue and it functions via its over expressed receptors (Ob-R) in a wide variety of cancers. In the present study, the function of a leptin-derived peptide (LP16, 91–110 of Leptin) was investigated as a targeting ligand to decorate PEGylated liposomal doxorubicin (PLD, Doxil ? ) surface and the anti-tumor activity and therapeutic efficacy of Doxil in C26 (Colon Carcinoma) tumor model were also evaluated. As a result of this, Doxil with different LP16 peptide density (25, 50, 100 and 200 peptide on the surface of each liposome) was successfully prepared and characterized. In vitro results showed significant enhanced cytotoxicity and cellular b...

α-Conotoxin ImI-modified polymeric micelles as potential nanocarriers for targeted docetaxel delivery to α7-nAChR overexpressed non-small cell lung cancer

Author:Dong Mei, Libo Zhao, Binlong Chen, Xiaoyan Zhang,  Xiaoling Wang, Zhiying Yu, Xin Ni & Qiang Zhang     《Drug Delivery》 ABSTRACTS A micelle system modified with α-Conotoxin ImI (ImI), a potently antagonist for alpha7 nicotinic acetylcholine receptor (α7-nAChR) previously utilized for targeting breast cancer, was constructed. Its targeting efficiency and cytotoxicity against non-small cell lung cancer (NSCLC) highly expressing α7-nAChR was investigated. A549, a non-small cell lung cancer cell line, was selected as the cell model. The cellular uptake study showed that the optimal modification ratio of ImI on micelle surface was 5% and ImI-modification increased intracellular delivery efficiency to A549 cells via receptor-mediated endocytosis. Intracellular Ca 2+   transient assay demonstrated that ImI modification led to enhanced molecular interaction between nanocarriers and A549 cells. The  in vivo   near-infrared fluorescence im...

Versatile multicolor nanodiamond probes for intracellular imaging and targeted labeling

Author:Kerem Bray, Leonard Cheung, Khondker Rufaka Hossain, Igor Aharonovich, Stella M. Valenzuela, Olga Shimoni     《Journal of Materials Chemistry B》 ABSTRACTS We report on the sizable production of fluorescent nanodiamonds (FNDs) containing a near infrared (NIR) color center – namely the silicon vacancy (SiV) defect, and their first demonstration inside cells for bio-imaging. We further demonstrate a concept of multi-color bio-imaging using FNDs to investigate intercellular processes using two types of FNDs. Due to their specific spectral properties, SiV FNDs can be distinguished from common nitrogen-vacancy (NV) FNDs and show a distinct initial spreading throughout the cell interior. The reported results are the first demonstration of multi-color labeling with FNDs that are especially interesting for  in vivo   bio-imaging due to their stable fluorescence. SCREENSHOT RELATED PRODUCTS trans-activating transcriptional activator (TAT,...