The pathological origin of Alzheimer’s disease(AD)is still shrouded in mystery,despite intensive worldwide research efforts.The selective visualization ofβ-amyloid(Aβ),the most abundant proteinaceous deposit in AD,...The pathological origin of Alzheimer’s disease(AD)is still shrouded in mystery,despite intensive worldwide research efforts.The selective visualization ofβ-amyloid(Aβ),the most abundant proteinaceous deposit in AD,is pivotal to reveal AD pathology.To date,several small-molecule fluorophores for Aβspecies have been developed,with increasing binding affinities.In the current work,two organic small-molecule dioxaborine-derived fluorophores were rationally designed through tailoring the hydrophobicity with the aim to enhance the binding affinity for Aβ_(1-42) fibrils-while concurrently preventing poor aqueous solubility-via biannulate donor motifs in D-π-A dyes.An unprecedented sub-nanomolar affinity was found(K_(d)=0.62±0.33 nM)and applied to super-sensitive and red-emissive fluorescent staining of amyloid plaques in cortical brain tissue ex vivo.These fluorophores expand the dioxaborine-curcumin-based family of Aβ-sensitive fluorophores with a promising new imaging agent.展开更多
The nucleolus,the locus of ribosome biogenesis,was found to be the predominant intracellular target of a new fluorescent probe,V-P1.In solution,the probe demonstrated both a selectivity to RNA G-quadruplexes and a sen...The nucleolus,the locus of ribosome biogenesis,was found to be the predominant intracellular target of a new fluorescent probe,V-P1.In solution,the probe demonstrated both a selectivity to RNA G-quadruplexes and a sensitivity to the viscosity,while G-quadruplex binding did not disturb the viscosity sensing.In cells,confocal and fluorescence lifetime imaging,combined with digestion and competition experiments,lent support to the hypothesis of an RNA-based G-quadruplex as the intracellular target,postulated to be nucleolar ribosomal RNA(rRNA).The probe demonstrated a high sensitivity to viscosity in both the cytoplasm and the nuclear compartment and was used to precisely interrogate the viscosity changes resulting from diverse stimuli,such as temperature,monensin treatment,and etoposide-induced apoptosis.Owing to the putative rRNA G-quadruplex binding in vitro and in vivo,and further combined with a relatively low degree of toxicity,the dye enabled the interrogation of cytoplasm and intranuclear viscosity changes under diverse conditions and found applications in studying the influence and significance of cytoplasm and intranuclear viscosity as well as in gaining insight into the native secondary structure of rRNA in nucleoli.展开更多
基金This research was supported by the National Research Foundation of Korea(CRI project no.2018R1A3B1052702,NRF-2019M3E5D1A01068998,J.S.Kim)the Korea University Graduate School Junior Fellow Research Grant(J.An)+3 种基金the National Research Council of Science&Technology(NST)granted by the Ministry of Science,ICT&Future Planning(MSIP)(No.CRC-15-04-KIST)the Korea Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI)and Korea Dementia Research Center(KDRC)the Ministry of Health&Welfare and Ministry of Science and ICT,Republic of Korea(No.HI20C1234)P.V.acknowledges support from Interne Fondsen KU Leuven/Internal Funds KU Leuven(STG/19/029).
文摘The pathological origin of Alzheimer’s disease(AD)is still shrouded in mystery,despite intensive worldwide research efforts.The selective visualization ofβ-amyloid(Aβ),the most abundant proteinaceous deposit in AD,is pivotal to reveal AD pathology.To date,several small-molecule fluorophores for Aβspecies have been developed,with increasing binding affinities.In the current work,two organic small-molecule dioxaborine-derived fluorophores were rationally designed through tailoring the hydrophobicity with the aim to enhance the binding affinity for Aβ_(1-42) fibrils-while concurrently preventing poor aqueous solubility-via biannulate donor motifs in D-π-A dyes.An unprecedented sub-nanomolar affinity was found(K_(d)=0.62±0.33 nM)and applied to super-sensitive and red-emissive fluorescent staining of amyloid plaques in cortical brain tissue ex vivo.These fluorophores expand the dioxaborine-curcumin-based family of Aβ-sensitive fluorophores with a promising new imaging agent.
基金supported by CRI project(no.2018R1A3B1052702J.S.K.)from the National Research Foundation of Korea(NRF)+3 种基金by the China Scholarship Fund(CSC no.201907030009L.Y.)by the Interne Fondsen KU Leuven/Internal Funds KU Leuven(STG/19/029P.V.).
文摘The nucleolus,the locus of ribosome biogenesis,was found to be the predominant intracellular target of a new fluorescent probe,V-P1.In solution,the probe demonstrated both a selectivity to RNA G-quadruplexes and a sensitivity to the viscosity,while G-quadruplex binding did not disturb the viscosity sensing.In cells,confocal and fluorescence lifetime imaging,combined with digestion and competition experiments,lent support to the hypothesis of an RNA-based G-quadruplex as the intracellular target,postulated to be nucleolar ribosomal RNA(rRNA).The probe demonstrated a high sensitivity to viscosity in both the cytoplasm and the nuclear compartment and was used to precisely interrogate the viscosity changes resulting from diverse stimuli,such as temperature,monensin treatment,and etoposide-induced apoptosis.Owing to the putative rRNA G-quadruplex binding in vitro and in vivo,and further combined with a relatively low degree of toxicity,the dye enabled the interrogation of cytoplasm and intranuclear viscosity changes under diverse conditions and found applications in studying the influence and significance of cytoplasm and intranuclear viscosity as well as in gaining insight into the native secondary structure of rRNA in nucleoli.
