Rudraprasad Dhanwini, Sushma Mudigunda V, Rengan Aravind Kumar, Naik Milind N, Joseph Joveeta
Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L.V. Prasad Eye Institute, Hyderabad, Telangana, India; Manipal Academy of Higher Education, Karnataka, India.
Department of Biomedical Engineering, Indian Institute of Technology Hyderabad, Telangana, India.
Microbes Infect. 2022 Nov-Dec;24(8):105014. doi: 10.1016/j.micinf.2022.105014. Epub 2022 May 21.
Endophthalmitis is a vision-threatening complication of intraocular surgery or penetrating injury of which Staphylococcus aureus is an important etiological agent. Extracellular vesicles (EVs) hold a tremendous possibility for developing diagnostic and therapeutic biomarkers due to their role in the pathogenesis of various infections. The aim of this study was to characterise the protein cargo of EVs, isolated from a murine (C57BL/6) model of S. aureus endophthalmitis by LC-MS/MS. Contralateral eye injected with sterile media served as control and both eyes were enucleated after 24 h, followed by extraction of EVs by ultracentrifugation. EVs were characterized by DLS and western blotting with tetraspanin markers, CD9 and CD81 and quantified by ExoCet quantification kit. Proteomic analysis identified 1964 proteins (FDR ≤ 0.01) in EVs from infected mice eyes, of which 40 proteins varied significantly in their amounts in comparison to EVs obtained from control eyeballs (P-value ≤ 0.05). The results of this study provide insight into the global EV proteome of S. aureus endophthalmitis with their functional correlation and differential protein amounts between infected and control set. Annexin A5, cathepsin D and C5a play a pivotal role in disease pathogenesis and could possibly play a role as a prognostic marker in endophthalmitis.
眼内炎是眼内手术或穿透性损伤的一种威胁视力的并发症，其中金黄色葡萄球菌是重要的病原体。细胞外囊泡（EVs）由于其在各种感染发病机制中的作用，在开发诊断和治疗生物标志物方面具有巨大潜力。本研究的目的是通过液相色谱-串联质谱法（LC-MS/MS）对从金黄色葡萄球菌性眼内炎小鼠（C57BL/6）模型中分离出的EVs的蛋白质成分进行表征。向对侧眼注射无菌培养基作为对照，24小时后摘除双眼，然后通过超速离心提取EVs。通过动态光散射（DLS）和用四跨膜蛋白标志物CD9和CD81进行蛋白质印迹法对EVs进行表征，并通过ExoCet定量试剂盒进行定量。蛋白质组学分析在感染小鼠眼睛的EVs中鉴定出1964种蛋白质（错误发现率≤0.01），其中与从对照眼球获得的EVs相比，有40种蛋白质的含量有显著差异（P值≤0.05）。本研究结果深入了解了金黄色葡萄球菌性眼内炎的整体EV蛋白质组，以及它们在感染组和对照组之间的功能相关性和蛋白质含量差异。膜联蛋白A5、组织蛋白酶D和C5a在疾病发病机制中起关键作用，可能在眼内炎中作为预后标志物发挥作用。
