title: Exploring tight junction alteration using double fluorescent probe combination of lanthanide complex with gold nanoclusters.
abstract: Tight junctions play a key role in restricting or regulating passage of liquids, ions and large solutes through various biological barriers by the paracellular route. Changes in paracellular permeation indicate alteration of the tight junction. However, it is very difficult to obtain the structural change information by measuring paracellular flux based on transepithelial electrical resistance or using fluorescein-labeled dextrans. Here we show that the BSA and GSH stabilized gold nanoclusters exhibit marginal cytotoxicity and pass through the MDCK monolayer exclusively through the paracellular pathway. We propose a double fluorescence probe strategy, the combination of a proven paracellular indicator (europium complex) with fluorescent gold nanoclusters. We calculate changes of structural parameters in tight junctions based on determination of the diffusion coefficients of the probes. Two different types of tight junction openers are used to validate our strategy. Results show that EDTA disrupts tight junction structures and induces large and smooth paracellular pore paths with an average radius of 17 nm, but vanadyl complexes induce paths with the radius of 6 nm. The work suggests that the double fluorescence probe strategy is a useful and convenient approach for in vitro investigation of tight junction structural alternations caused by pharmacological or pathological events.
authors: Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.|College of Sciences, Shenyang Agricultural University, Shenyang 110161, China.
authors: Xinyi
authors: X
authors: Wang
authors: Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.|Department of Pharmacognosy, School of Pharmaceutical Sciences, Hebei Medical University, Shijiazhuang 050017, China.
authors: Na
authors: N
authors: Wang
authors: Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors: Lan
authors: L
authors: Yuan
authors: Beijing National Laboratory for Molecular Sciences (BNLMS), The Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors: Na
authors: N
authors: Li
authors: Department of Molecular Biology, Hebei Key Lab of Laboratory Animal, Hebei Medical University, Shijiazhuang 050017, China.
authors: Junxia
authors: J
authors: Wang
authors: Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors: Xiaoda
authors: X
authors: Yang