In vivoassessment of the permeability of the blood-brain barrier and blood-retinal barrier to fluorescent indoline derivatives in zebrafish

Abstract

BackgroundSuccessful delivery of compounds to the brain and retina is a challenge in the development of therapeutic drugs and imaging agents. This challenge arises because internalization of compounds into the brain and retina is restricted by the blood–brain barrier (BBB) and blood-retinal barrier (BRB), respectively. Simple and reliable in vivo assays are necessary to identify compounds that can easily cross the BBB and BRB.MethodsWe developed six fluorescent indoline derivatives (IDs) and examined their ability to cross the BBB and BRB in zebrafish by in vivo fluorescence imaging. These fluorescent IDs were administered to live zebrafish by immersing the zebrafish larvae at 7-8 days post fertilization in medium containing the ID, or by intracardiac injection. We also examined the effect of multidrug resistance proteins (MRPs) on the permeability of the BBB and BRB to the ID using MK571, a selective inhibitor of MRPs.ResultsThe permeability of these barriers to fluorescent IDs administered by simple immersion was comparable to when administered by intracardiac injection. Thus, this finding supports the validity of drug administration by simple immersion for the assessment of BBB and BRB permeability to fluorescent IDs. Using this zebrafish model, we demonstrated that the length of the methylene chain in these fluorescent IDs significantly affected their ability to cross the BBB and BRB via MRPs.ConclusionsWe demonstrated that in vivo assessment of the permeability of the BBB and BRB to fluorescent IDs could be simply and reliably performed using zebrafish. The structure of fluorescent IDs can be flexibly modified and, thus, the permeability of the BBB and BRB to a large number of IDs can be assessed using this zebrafish-based assay. The large amount of data acquired might be useful for in silico analysis to elucidate the precise mechanisms underlying the interactions between chemical structure and the efflux transporters at the BBB and BRB. In turn, understanding these mechanisms may lead to the efficient design of compounds targeting the brain and retina.

Pharmacological study of the light/dark preference test in zebrafish (Danio rerio): Waterborne administration

“…Finally, the immersion method can be used for chronic administration of the drug, whereas it is not advisable to repeat injections in small animals, such as zebrafish (Stewart et al, 2011a). Additionally, the validity of drug administration by simple immersion was checked for the assessment of blood-brain barrier and blood-retinal barrier permeability to fluorescent indoline derivatives (Watanabe et al, 2012).…”

Molecular Determinants of blood–brain Barrier Permeation

“…[29, 43, 44] Additionally, the zebrafish ( Danio rerio ) has also been used successfully as surrogate model for the BBB permeability studies of compounds. [45, 46]…”

Drug Screening to Treat Early-Onset Eye Diseases

“…First, there are studies that have attempted to determine the bioavailability of the drugs in the whole embryo. Zebrafish have functional BRB 112,113 and blood-brain barrier 112Y114 that are analogous to the other mammals and begin to function at around 3 dpf, whereas the BAB has not been characterized in fish yet. Specifically, drugs with LogP value greater than 1 have been proposed to be used in general screen 111 because they were readily absorbed by fish embryos and showed specific response in a screen of drugs that cause bradycardia.…”