Sortase A (SrtA) is a membrane-associated cysteine transpeptidase required for bacterial virulence regulation and anchors surface proteins to cell wall, thereby assisting biofilm formation. SrtA is targeted in antivirulence treatments against Gram-positive bacterial infections. However, the development of potent small-molecule SrtA inhibitors is constrained owing to the limited understanding of the mode of action of inhibitors in the SrtA binding pocket. Herein, we designed and synthesized a novel class of covalent SrtA inhibitors based on the binding mode detailed in the X-ray crystal structure of the ML346/Streptococcus pyogenes SrtA complex. ML346 analog Y40 exhibited 2-fold increased inhibitory activity on Staphylococcus aureus SrtA and showed superior inhibitory effects on biofilm formation in vitro. Y40 protected Galleria mellonella larvae fromS. aureusinfections in vivo while minimally attenuating staphylococcal growth in vitro. Our study indicates that the covalent SrtA inhibitor Y40 is an antivirulence agent that is effective againstS. aureusinfections.

International Journal of Molecular Sciences

Hsp70 Negatively Regulates Autophagy via Governing AMPK Activation, and Dual Hsp70-Autophagy Inhibition Induces Synergetic Cell Death in NSCLC Cells

Article

作者: Aksenov, Nikolai D. ; Margulis, Boris A. ; Sverchinsky, Dmitry V. ; Gladova, Yana A. ; Guzhova, Irina V. ; Alhasan, Bashar

Proteostasis mechanisms, such as proteotoxic-stress response and autophagy, are increasingly recognized for their roles in influencing various cancer hallmarks such as tumorigenesis, drug resistance, and recurrence. However, the precise mechanisms underlying their coordination remain not fully elucidated. The aim of this study is to investigate the molecular interplay between Hsp70 and autophagy in lung adenocarcinoma cells and elucidate its impact on the outcomes of anticancer therapies in vitro. For this purpose, we utilized the human lung adenocarcinoma A549 cell line and genetically modified it by knockdown of Hsp70 or HSF1, and the H1299 cell line with knockdown or overexpression of Hsp70. In addition, several treatments were employed, including treatment with Hsp70 inhibitors (VER-155008 and JG-98), HSF1 activator ML-346, or autophagy modulators (SAR405 and Rapamycin). Using immunoblotting, we found that Hsp70 negatively regulates autophagy by directly influencing AMPK activation, uncovering a novel regulatory mechanism of autophagy by Hsp70. Genetic or chemical Hsp70 overexpression was associated with the suppression of AMPK and autophagy. Conversely, the inhibition of Hsp70, genetically or chemically, resulted in the upregulation of AMPK-mediated autophagy. We further investigated whether Hsp70 suppression-mediated autophagy exhibits pro-survival- or pro-death-inducing effects via MTT test, colony formation, CellTiter-Glo 3D-Spheroid viability assay, and Annexin/PI apoptosis assay. Our results show that combined inhibition of Hsp70 and autophagy, along with cisplatin treatment, synergistically reduces tumor cell metabolic activity, growth, and viability in 2D and 3D tumor cell models. These cytotoxic effects were exerted by substantially potentiating apoptosis, while activating autophagy via rapamycin slightly rescued tumor cells from apoptosis. Therefore, our findings demonstrate that the combined inhibition of Hsp70 and autophagy represents a novel and promising therapeutic approach that may disrupt the capacity of refractory tumor cells to withstand conventional therapies in NSCLC.

项与 ML-346 相关的新闻（医药）

2024-01-21

·精准药物

【JMC】上海药物研究所杨财广团队在SortaseA抑制剂领域再获进展

英文原题：Structure-Guided Design, Synthesis, and Antivirulence Assessment of Covalent Staphylococcus aureus Sortase A Inhibitors通讯作者：杨财广，张涛（中国科学院上海药物研究所）作者：Chuan Yue (岳川) #, Ziqi Yuan (袁子琪) #, Guobin Xu, Xiang-Na Guan, Bingyan Wei, Hequan Yao, Cai-Guang Yang (杨财广),* and Tao Zhang (张涛)*金黄色葡萄球菌（Staphylococcus aureus, S. aureus）是能够引起皮肤和软组织感染以及多种侵入性感染疾病的主要人类病原体。甲氧西林耐药的金黄色葡萄球菌（Methicillin-resistant S. aureus, MRSA）等多药耐药菌的出现，已成为公众健康的严重威胁。为了应对抗生素的耐药危机，抗细菌致病力（antivirulence）策略受到关注。Sortase A（SrtA）是一种半胱氨酸转肽酶，主要分布在革兰氏阳性菌中。它特异性地识别与细菌致病力密切相关的表面蛋白并将其锚定在细胞壁上，对病原细菌黏附、侵染宿主细胞、生物膜形成和免疫逃逸等发挥重要作用。敲除srta基因可显著降低金黄色葡萄球菌感染宿主的毒力。转肽酶SrtA在生物学意义上是具有潜力的抗菌靶标，然而SrtA抑制剂抗MRSA感染的验证性研究仍然是基础研究的探索方向之一。杨财广团队围绕SrtA抑制剂开展抗细菌致病力研究取得持续性进展，取得了不同类型的SrtA抑制剂，包括非共价抑制剂和共价抑制剂（如图1）。在非共价抑制剂方面，通过虚拟筛选和合成优化获得化合物6e，开发小分子抑制SrtA活性的SDS-PAGE实验，确定了6e对SrtA具有中等抑制活性，且可以在不影响金黄色葡萄球菌正常生长的前提下，抑制细菌的致病力，延长Newman感染小鼠的生存期。此外，筛选含2400个临床以及临床候选药物小分子库，发现苗头化合物TD对SrtA具有抑制活性，通过药物化学结构优化进一步改善该类化合物的理化性质和活性得到化合物TD32。该化合物与SrtA可逆结合，抑制细菌生物膜形成，延长金黄色葡萄球菌感染小鼠的生存期。在共价抑制剂方面，发现含有醌类骨架的天然产物及其衍生物可以与金黄色葡萄球菌SrtA的C184形成共价键，抑制SrtA的活性，降低细菌的毒力。随后，进一步对临床候选药物库进行筛选，发现热激蛋白Hsp70抑制剂ML346可以非可逆地与SrtA结合，ML346与酿脓链球菌SrtA的复合物晶体结构清晰地揭示了小分子抑制剂与SrtA的作用机制，该部分工作为SrtA抑制剂的结构优化提供分子基础和优化方向。图1. 杨财广团队前期SrtA小分子抑制剂工作进展近期，杨财广团队围绕苗头化合物ML346展开药物化学构效关系研究。ML346与酿脓链球菌SrtA的复合物晶体结构表明，ML346的尾端甲氧基部分并没有占满SrtA的口袋，可以通过尾端的优化改造，进一步提高化合物抑制SrtA蛋白的活性。在此工作中，将ML346划分为弹头区域、核心区和尾端区域，并围绕这三个区域展开结构优化，最终获得化合物Y40（图2）。Y40与SrtA非可逆地结合，抑制细菌的毒力。虽然Y40的酶学活性与ML346相当，但其抑制细菌生物膜形成的能力更加显著。此外，Y40可以改善大蜡螟因金黄色葡萄球菌感染导致的黑化作用，并提高Newman和USA300感染的大蜡螟幼虫的生存率。该工作为SrtA共价抑制剂的合理设计和持续优化奠定了基础。图2. ML346类似物Y40抑制SrtA功能降低细菌毒力上海药物所与南京中医药大学联合培养硕士研究生岳川、上海药物所硕士研究生袁子琪为论文的共同第一作者，上海药物所杨财广研究员、张涛副研究员为共同通讯作者。该研究获得国家自然科学基金和中科院青年创新促进会的资助。Chuan Yue#, Ziqi Yuan#, Guobin Xu, Xiang-Na Guan, Bingyan Wei, Hequan Yao, Cai-Guang Yang,* and Tao Zhang*，Structure-Guided Design, Synthesis, and Antivirulence Assessment of Covalent Staphylococcus aureus Sortase A Inhibitors，J. Med. Chem., 2024, ASAPhttps://doi.org/10.1021/acs.jmedchem.3c01615声明：发表/转载本文仅仅是出于传播信息的需要，并不意味着代表本公众号观点或证实其内容的真实性。据此内容作出的任何判断，后果自负。若有侵权，告知必删！长按关注本公众号粉丝群/投稿/授权/广告等请联系公众号助手觉得本文好看，请点这里↓

临床研究微生物疗法

100 项与 ML-346 相关的药物交易

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