TOXICITY AND MITOCHONDRIAL DELIVERY OF FLAVONOL-BASED CO-RELEASING MOLECULES

Class

Article

Graduation Year

2017

College

College of Agriculture and Applied Sciences

Department

Animal, Dairy, and Veterinary Sciences Department

Faculty Mentor

Abby Benninghoff

Presentation Type

Oral Presentation

Abstract

Our research group previously developed a new class of photo-sensitive, flavonol-based carbon monoxide releasing molecules (CORMs) that are structurally tunable, exhibit low toxicity and exhibit both oxygen-dependent and independent CO release activity. This next-generation photo-sensitive CORM, called Flav-1, could be therapeutically useful if CO release can be targeted to mitochondria. We hypothesized that modification of the Flav-1 structure by addition of triphenylphosphonium (TPP) tail moieties of varying lengths (2 and 8 carbons) would facilitate targeting of this CORM, and thus CO release, to the mitochondria. Cytotoxicity of TPP-modified Flav-1 was assessed in human umbilical vein endothelial cells (HUVEC) using standard cell viability assays. Localization of TPP-modified Flav-1, which fluoresces when exposed to visible light, was determined using confocal microscopy; HUVECs were co-stained with Hoechst, CellMask Deep Red plasma membrane stain and MitoTracker Red for visualization of the nucleus, plasma membrane, and mitochondria, respectively. Modification of Flav-1 with either C2 or C8 TPP moieties did not increase cytotoxicity compared to the parent Flav-1 compound, though the C8 modification appeared slightly more cytotoxic than C2, perhaps reflecting greater bioavailability to the cell. Confocal microscopy of HUVEC cells treated with 100 uM Flav-1:C8 for 4 hr revealed co-localization of the CORM to the mitochondria. Exposure to laser light at 405 nm, 488 nm or both wavelengths together quenched the fluorescence of Flav-1:C2, indicating light-induced CO-release in A549 cells. Ongoing work aims to evaluate the impact of CO release from photo-triggered TPP-modified Flav-1 on the generation of reactive oxygen species via uncoupling mitochondrial respiration and subsequent effects on CO-triggered cell signaling pathways.

Location

Room 154

Start Date

4-13-2017 12:00 PM

End Date

4-13-2017 1:15 PM

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Apr 13th, 12:00 PM Apr 13th, 1:15 PM

TOXICITY AND MITOCHONDRIAL DELIVERY OF FLAVONOL-BASED CO-RELEASING MOLECULES

Room 154

Our research group previously developed a new class of photo-sensitive, flavonol-based carbon monoxide releasing molecules (CORMs) that are structurally tunable, exhibit low toxicity and exhibit both oxygen-dependent and independent CO release activity. This next-generation photo-sensitive CORM, called Flav-1, could be therapeutically useful if CO release can be targeted to mitochondria. We hypothesized that modification of the Flav-1 structure by addition of triphenylphosphonium (TPP) tail moieties of varying lengths (2 and 8 carbons) would facilitate targeting of this CORM, and thus CO release, to the mitochondria. Cytotoxicity of TPP-modified Flav-1 was assessed in human umbilical vein endothelial cells (HUVEC) using standard cell viability assays. Localization of TPP-modified Flav-1, which fluoresces when exposed to visible light, was determined using confocal microscopy; HUVECs were co-stained with Hoechst, CellMask Deep Red plasma membrane stain and MitoTracker Red for visualization of the nucleus, plasma membrane, and mitochondria, respectively. Modification of Flav-1 with either C2 or C8 TPP moieties did not increase cytotoxicity compared to the parent Flav-1 compound, though the C8 modification appeared slightly more cytotoxic than C2, perhaps reflecting greater bioavailability to the cell. Confocal microscopy of HUVEC cells treated with 100 uM Flav-1:C8 for 4 hr revealed co-localization of the CORM to the mitochondria. Exposure to laser light at 405 nm, 488 nm or both wavelengths together quenched the fluorescence of Flav-1:C2, indicating light-induced CO-release in A549 cells. Ongoing work aims to evaluate the impact of CO release from photo-triggered TPP-modified Flav-1 on the generation of reactive oxygen species via uncoupling mitochondrial respiration and subsequent effects on CO-triggered cell signaling pathways.