Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Human saliva, plasma and breast milk exosomes contain RNA: uptake by macrophages | Lăsser et al. Journal of Translational Medicine 2011 9 9 http content 9 1 9 TRANSLATIONAL MEDICINE RESEARCH Open Access Human saliva plasma and breast milk exosomes contain RNA uptake by macrophages 1 111 2 1 Cecilia Lasser Vesta Seyed Alikhani Karin Ekstrom Maria Eldh Patricia Torregrosa Paredes Apostolos Bossios Margareta Sjostrand1 Susanne Gabrielsson2 Jan Lotvall1 Hadi Valadi3 Abstract Background Exosomes are 30-100 nm membrane vesicles of endocytic origin produced by numerous cells. They can mediate diverse biological functions including antigen presentation. Exosomes have recently been shown to contain functional RNA which can be delivered to other cells. Exosomes may thus mediate biological functions either by surface-to-surface interactions with cells or by the delivery of functional RNA to cells. Our aim was therefore to determine the presence of RNA in exosomes from human saliva plasma and breast milk and whether these exosomes can be taken up by macrophages. Method Exosomes were purified from human saliva plasma and breast milk using ultracentrifugation and filtration steps. Exosomes were detected by electron microscopy and examined by flow cytometry. Flow cytometry was performed by capturing the exosomes on anti-MHC class II coated beads and further stain with anti-CD9 anti-CD63 or anti-CD81. Breast milk exosomes were further analysed for the presence of Hsc70 CD81 and calnexin by Western blot. Total RNA was detected with a Bioanalyzer and mRNA was identified by the synthesis of cDNA using an oligo dT primer and analysed with a Bioanalyzer. The uptake of PKH67-labelled saliva and breast milk exosomes by macrophages was examined by measuring fluorescence using flow cytometry and fluorescence microscopy. Results RNA was detected in exosomes from all three body fluids. A portion of the detected RNA in plasma exosomes was characterised as mRNA. Our result extends the characterisation of exosomes in healthy humans and confirms
