Journal Club – 2023.01.27

Ursolic acid downregulates thymic stromal lymphopoietin through the blockade of intracellular calcium/caspase‐1/NF‐κB signaling cascade in HMC‐1 cells

PHIL-DONG MOON1,2*, NA-RA HAN1*, JIN SOO LEE1, HYUNG-MIN KIM1 and HYUN-JA JEONG3

1department of Pharmacology, college of Korean Medicine, 2center for converging Humanities, Kyung Hee University, Seoul 02447; 3department of Food Science and Technology and Research Institute for Basic Science, Hoseo University, Asan, chungnam 31499, Republic of Korea

Received december 14, 2018; Accepted March 20, 2019 dOI: 10.3892/ijmm.2019.4144

Thymic stromal lymphopoietin (TSLP) plays an important role in allergic disorders, including atopic dermatitis and asthma. Ursolic acid (UA) has various pharmacological properties, such as antioxidant, anti‐inflammatory and anti- cancer. However, the effect of UA on TSLP regulation has not been fully elucidated. The aim of the present study was to analyze how UA regulates the production of TSLP in the human mast cell line HMc-1. Enzyme-linked immunosorbent assay, quantitative polymerase chain reaction analysis, western blotting, caspase-1 assay and fluorescent measurements of intracellular calcium levels were conducted to analyze the regulatory effects of UA. The results revealed that UA inhib- ited TSLP production and mRNA expression. In addition, UA reduced the activation of nuclear factor-κB and degradation of IκBα. caspase-1 activity was increased by exposure to phorbol myristate acetate plus calcium ionophore, whereas it was reduced by UA. Finally, UA treatment prevented an increase in intracellular calcium levels. These results indicated that UA may be a useful agent for the treatment and/or prevention of atopic and inflammatory diseases, and its effects are likely mediated by TSLP downregulation.

Berbamine Reduces Chloroquine-Induced Itch in Mice through Inhibition of MrgprX1

Kunhi Ryu Yunkyung Heo Yechan Lee Hyejin Jeon Wan Namkung 

Abstract

Chloroquine (CQ) is an antimalaria drug that has been widely used for decades. However, CQ-induced pruritus remains one of the major obstacles in CQ treatment for uncomplicated malaria. Recent studies have revealed that MrgprX1 plays an essential role in CQ-induced itch. To date, a few MrgprX1 antagonists have been discovered, but they are clinically unavailable or lack selectivity. Here, a cell-based high-throughput screening was performed to identify novel antagonists of MrgprX1, and the screening of 2543 compounds revealed two novel MrgprX1 inhibitors, berbamine and closantel. Notably, berbamine potently inhibited CQ-mediated MrgprX1 activation (IC50 = 1.6 μM) but did not alter the activity of other pruritogenic GPCRs. In addition, berbamine suppressed the CQ-mediated phosphorylation of ERK1/2. Interestingly, CQ-induced pruritus was significantly reduced by berbamine in a dose-dependent manner, but berbamine had no effect on histamine-induced, protease-activated receptors 2-activating peptide-induced, and deoxycholic acid-induced itch in mice. These results suggest that berbamine is a novel, potent, and selective antagonist of MrgprX1 and may be a potential drug candidate for the development of therapeutic agents to treat CQ-induced pruritus.

Keywords: Chloroquine; MrgprA3; MrgprX1; antagonist; berbamine; itch.

Presenter: Hye In Kim

Scratch-AID, a deep learning basedsystem for automatic detection of mousescratching behavior with high accuracy

Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States; 2
Graduate Group in Biostatistics, University of California Davis, Davis, United States; 3 Howard Hughes Medical Institute,
Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, United States; 4 Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, United States; 5 Department of Molecular and Cellular Biology, University of California Davis, Davis,
United States; 6 Department of Mathematics, University of California Davis, Davis, United States

Abstract

Mice are the most commonly used model animals for itch research and for development of anti-itch drugs. Most laboratories manually quantify mouse scratching behavior to assess itch intensity. This process is labor-intensive and limits large-scale genetic or drug screenings. In this study, we developed a new system, Scratch-AID (Automatic Itch Detection), which could automatically identify and quantify mouse scratching behavior with high accuracy. Our system included a custom-designed videotaping box to ensure high-quality and replicable mouse behavior recording and a convolutional recurrent neural network trained with frame-labeled mouse scratching behavior videos, induced by nape injection of chloroquine. The best trained network achieved 97.6% recall and 96.9% precision on previously unseen test videos. Remarkably, Scratch-AID could reliably identify scratching behavior in other major mouse itch models, including the acute cheek model, the histaminergic model, and a chronic itch model. Moreover, our system detected significant differences in scratching behavior between control and mice treated with an anti-itch drug. Taken together, we have established a novel deep learning-based system that could replace manual quantification for mouse scratching behavior in different itch models and for drug screening.

Presenter: Gi Baek Lee

Scroll to Top