title: Quantum dot-based molecular beacon to monitor intracellular microRNAs.
abstract: Fluorescence monitoring of endogenous microRNA (miRNA or miR) activity related to neuronal development using nano-sized materials provides crucial information on miRNA expression patterns in a noninvasive manner. In this study, we report a new method to monitor intracellular miRNA124a using quantum dot-based molecular beacon (R9-QD-miR124a beacon). The R9-QD-miR124a beacon was constructed using QDs and two probes, miR124a-targeting oligomer and arginine rich cell-penetrating peptide (R9 peptide). The miR124a-targeting oligomer contains a miR124a binging sequence and a black hole quencher 1 (BHQ1). In the absence of target miR124a, the R9-QD-miR124a beacon forms a partial duplex beacon and remained in quenched state because the BHQ1 quenches the fluorescence signal of the R9-QD-miR124a beacon. The binding of miR124a to the miR124a binding sequence of the miR124a-targeting oligomer triggered the separation of the BHQ1 quencher and subsequent signal-on of a red fluorescence signal. Moreover, enhanced cellular uptake was achieved by conjugation with the R9 peptide, which resulted in increased fluorescent signal of the R9-QD-miR124a beacons in P19 cells during neurogenesis due to the endogenous expression of miR124a.
authors.affiliation: Institute for Bio-Medical Convergence, College of Medicine, Kwandong Catholic University, Gangneung-si, Gangwon-do 270-701, Korea. jonghwanlee104@gmail.com.|Catholic Kwandong University International St. Mary's Hospital, Incheon Metropolitan City 404-834, Korea. jonghwanlee104@gmail.com.
authors.forename: Jonghwan
authors.initials: J
authors.lastname: Lee
authors.affiliation: Institute for Bio-Medical Convergence, College of Medicine, Kwandong Catholic University, Gangneung-si, Gangwon-do 270-701, Korea. mboy2@korea.com.|Catholic Kwandong University International St. Mary's Hospital, Incheon Metropolitan City 404-834, Korea. mboy2@korea.com.
authors.forename: Sung Ung
authors.initials: SU
authors.lastname: Moon
authors.affiliation: Institute for Bio-Medical Convergence, College of Medicine, Kwandong Catholic University, Gangneung-si, Gangwon-do 270-701, Korea. inyasio0731@naver.com.|Catholic Kwandong University International St. Mary's Hospital, Incheon Metropolitan City 404-834, Korea. inyasio0731@naver.com.
authors.forename: Yong Seung
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Aljeraisy DNA Research Chair, Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia. bahali@ksu.edu.sa.|Department of Nucleic Acids Research, Genetic Engineering and Biotechnology Research Institute, City for Scientific Research and Technological Applications, Alexandria 21934, Egypt. bahali@ksu.edu.sa.
authors.forename: Bahy A
authors.initials: BA
authors.lastname: Ali
authors.affiliation: Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia. kedhairy@ksu.edu.sa.
authors.forename: Abdulaziz A
authors.initials: AA
authors.lastname: Al-Khedhairy
authors.affiliation: Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia. daoudali_p@yahoo.com.
authors.forename: Daoud
authors.initials: D
authors.lastname: Ali
authors.affiliation: Aljeraisy DNA Research Chair, Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia. javedbiochem@gmail.com.
authors.forename: Javed
authors.initials: J
authors.lastname: Ahmed
authors.affiliation: Aljeraisy DNA Research Chair, Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia. alsalem1985@hotmail.com.
authors.forename: Abdullah M
authors.initials: AM
authors.lastname: Al Salem
authors.affiliation: Institute for Bio-Medical Convergence, College of Medicine, Kwandong Catholic University, Gangneung-si, Gangwon-do 270-701, Korea. kimsoonhag@empal.com.|Catholic Kwandong University International St. Mary's Hospital, Incheon Metropolitan City 404-834, Korea. kimsoonhag@empal.com.
authors.forename: Soonhag
authors.initials: S
authors.lastname: Kim
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D005456:Fluorescent Dyes; D042541:Intracellular Space / Q000737:chemistry*; D051379:Mice; D035683:MicroRNAs / Q000032:analysis* / Q000737:chemistry*; D057054:Molecular Imaging / Q000379:methods*; D055495:Neurogenesis / Q000502:physiology; D010455:Peptides / Q000737:chemistry; D045663:Quantum Dots / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D035683:MicroRNAs; D010455:Peptides
keywords: microRNA; molecular beacon; neurogenesis; quantum dot