Induction of cytochrome P450 1 genes and stress response genes in developing zebrafish exposed to ultraviolet radiation

Abstract

Ultraviolet (UV) radiation damages cell molecules, and has been suggested to upregulate mammalian cytochrome P4501 (CYP1) genes through an aryl hydrocarbon receptor (AHR) mediated mechanism. In this study, embryos and larvae of zebrafish (Danio rerio) were exposed to UV to determine the effects on expression of CYP1 and stress response genes in vivo in these fish. Zebrafish embryos were exposed for varying times to UV on two consecutive days, with exposure beginning at 24 and 48 hours post-fertilization (hpf). Embryos exposed for 2, 4 or 6 hours twice over two days to UVB (0.62 W/m 2 ; 8.9-26.7 kJ/m 2 ) plus UVA (2.05 W/m 2 ; 29.5-144.6 kJ/m 2 ) had moderately (2.4 ± 0.8-fold) but significantly upregulated levels of CYP1A. UVA alone had no effect on CYP1A expression. Proliferating cellular nuclear antigen (PCNA) and Cu-Zn superoxide dismutase (SOD1) transcript levels were induced (2.1 ± 0.2 and 2.3 ± 0.5 fold, respectively) in embryos exposed to two 6-hour pulses of 0.62 W/m 2 UVB (26.8 kJ/m 2 ). CYP1A was induced also in embryos exposed to higher intensity UVB (0.93 W/m 2 ) for two 3-hour or two 4-hour pulses (20.1 or 26.8 kJ/m 2 ). CYP1B1, SOD1 and PCNA expression was induced by the two 3-hour pulses of the higher intensity UVB, but not after two 4-hour pulses of the higher intensity UVB, possibly due to impaired condition of surviving embryos, reflected in a mortality of 34% at that UVB dose. A single 8-hour long exposure of zebrafish larvae (8 dpf) to UVB at 0.93 W/m 2 (26.8 kJ/m 2 ) significantly induced CYP1A and CYP1B1 expression, but other CYP1 genes (CYP1C1, CYP1C2 and CYP1D1) showed no increase. The results show that UVB can induce expression of CYP1 genes as well stress response genes in developing zebrafish, and that UVB intensity and duration influence the responses.

UVB-induced gene expression in the skin of Xiphophorus maculatus Jp 163 B

“…Although CYPs (cytochrome P450s) are well known for their role in aryl hydrocarbon metabolism in the liver, studies have shown that it also has an essential role in vitamin D signaling, which regulates hundreds of genes in many physiological functions including the immune response (Schartl et al, 2013). Furthermore, our finding also correlates with the previous study showing that CYP 1 genes appear to be up-expressed at moderate dose (20.1 kJ/m 2 ) but not at higher dose (26.8 kJ/m 2 ) in UVB exposure of developing zebrafish (Behrendt et al, 2010). From methionine and ATP, MAT1A catalyzes the formation of S-adenosylmethionine, which is the main methyl donor for a vast number of methylation processes (Chiang et al, 1996).…”

Identification and Transcriptional Profiling of Differentially Expressed Genes Associated With Response to Uva Radiation inDrosophila melanogaster(Diptera: Drosophilidae)

“…Several studies have reported on transcription factors related to UVA radiation stress in organisms. For example, transcription factor AP-2, NF-E2-related factor 2, HSP family, and P450 family are involved in the transcriptional response induced by UVA radiation (GretherÐBeck et al 1996, Behrendt et al 2010, Gruber et al 2010, Sang et al 2012. In our study, these eight potential TFBMs observed for the UVA-associated genes may play important roles in protecting insects against challenge with UVA radiation stress.…”

Effect of GSTM1 and GSTT1 Polymorphisms on Genetic Damage in Humans Populations Exposed to Radiation From Mobile Towers

“…Phase II drugmetabolizing enzymes play an important role in the biotransformation of endogenous compounds and free radicals to more easily excretable forms as well as in the metabolic inactivation of pharmacologically active compounds. The adverse effects of nonionizing radiation are partially reduced by molecular defense mechanisms including GSH and enzymes such as superoxide dismutase, catalase, and glutathione peroxidase, which are involved in quenching excessive levels of ROS and other free radicals (Behrendt et al 2010). GSTs are multi-gene families of enzymes involved in the metabolism of a wide range of electrophilic compounds of both exogenous and endogenous origin.…”