Photosensitized mefloquine induces ROS-mediated DNA damage and apoptosis in keratinocytes under ambient UVB and sunlight exposure

Abstract

The present study illustrates the photosensitizing behavior of mefloquine (MQ) in human skin keratinocytes under ambient doses of UVB and sunlight exposure. Photochemically, MQ generated reactive oxygen species superoxide radical, hydroxyl radical, and singlet oxygen through type I and type II photodynamic reactions, respectively, which caused photooxidative damage to DNA and formed localized DNA lesions cyclobutane pyrimidine dimers. Photosensitized MQ reduced the viability of keratinocytes to 25 %. Significant level of intracellular reactive oxygen species (ROS) generation was estimated through fluorescence probe DCF-H2. Increased apoptotic cells were evident through AO/EB staining and phosphatidyl serine translocation in cell membrane. Single-stranded DNA damage was marked through single-cell gel electrophoresis. Mitochondrial membrane depolarization and lysosomal destabilization were evident. Upregulation of Bax and p21 and downregulation of Bcl-2 genes and corresponding protein levels supported apoptotic cell death of keratinocyte cells. Cyclobutane pyrimidine dimers (CPDs) were confirmed through immunofluorescence. In addition, hallmarks of apoptosis and G2/M phase cell cycle arrest were confirmed through flow cytometry analysis. Our findings suggest that MQ may damage DNA and produce DNA lesions which may induce differential biological responses in the skin on brief exposure to UVB and sunlight.

Fish Scale Collagen Peptides Protect against CoCl2/TNF‐α‐Induced Cytotoxicity and Inflammation via Inhibition of ROS, MAPK, and NF‐κB Pathways in HaCaT Cells

“…ROS alter the DNA by inducing mutations, deletions, gene amplification, and rearrangements [34]. These changes can trigger the dysregulation of proapoptotic or antiapoptotic pathways, leading to apoptotic cell death.…”

The pathophysiological role of mitochondrial oxidative stress in lung diseases

“…mtDNA variants within cells can affect both energy and non-energy pathways (complement, inflammatory, and apoptotic); these effects have shifted the paradigm regarding the role of mitochondria to one beyond merely energy production [ 27 – 29 ]. For example, mtDNA damage causes the loss of mitochondrial membrane potential (ΔΨm) and then influences ETC efficiency; these changes contribute to increased permeability in the outer mitochondrial membrane [ 30 , 31 ]. In addition, pro-apoptogenic agents are commonly released after mtDNA damage and drive disease formation, aging, and tumorigenesis.…”

9-phenyl acridine photosensitizes A375 cells to UVA radiation

“…Photosensitization by anthrone with UVA also induced arrest at both S and G 2 /M phases of cell cycle with concomitant decrease in G 1 phase in HaCaT cells [ 72 ]. Ketoprofen and mefloquine with UVB light too, led to the cell cycle arrest in G 2 /M phase in HaCaT cells [ 73 , 74 ]. The photosensitizer, quinine could also induce cell cycle arrest in G 2 phase on UVA exposure to decrease proliferation of A375 cells [ 51 ].…”