Induction of Cyclobutane Pyrimidine Dimer Photolyase in Cultured Fish Cells by UVA and Blue Light

Abstract

The cyclobutane pyrimidine dimer (CPD) photolyase in fish cells is known to be regulated by environmental factors, such as light, hydrogen peroxide and growth inhibition. The induction of CPD photolyase by light in cultured goldfish cells was dependent on the wavelength of the light, and UVA and blue light had high inductive activity. The spectrum for CPD photolyase activity was different from that for the induction. Treatment with blue or yellow light for a short time, which did not induce any CPD photolyase, induced high CPD photolyase activity in the presence of the photosensitizers, TPPS (monosulfonated meso-tetraphenyl porphine) and ALPS (aluminum phthalocyanine tetrasulfonate), respectively. These results suggest that the induction of CPD photolyase might be triggered by active oxygen produced by light and cellular photosensitizers. We also found that immediately after treatment with UVA, blue light or a photosensitizer in combination with light, cellular attachment to the substratum was enhanced, as was the CPD photolyase activity. Pretreatment with a flavonoid, quercetin, inhibited both photoinduction of CPD photolyase and enhancement of cellular attachment. Vitamin E inhibited only photoinduction of CPD photolyase activity.Treatment with H7, a strong inhibitor for protein kinase C, after light treatment inhibited photoinduction of CPD photolyase activity, but an analogue of H7, Ha1004, which is a weak inhibitor of protein kinase C, did not have such an effect.

Accumulation and removal of UVBR-induced DNA damage in marine tropical plankton subjected to mixed and simulated non-mixed conditions

“…if the photochemical law of reciprocity would hold, the mean UVBR, UVAR and PAR doses in the wind mixed surface layer (WML) would be sufficient to predict effects on plankton organisms. However, there are indications that this is not always the case, especially for repair processes (Zagarese et al 1998); not only the rate of photorepair, but also the induction of the repair system is light dependent (Mitani et al 1996). This means that under fluctuating irradiance conditions, as experienced by plankton in the WML, repair rates may not always be optimal.…”

The phrA gene of Rhodobacter sphaeroides encodes a photolyase and is regulated by singlet oxygen and peroxide in a σ E-dependent manner

“…However, we have reported before that blue light stimulates phrA expression . In the fungus Trichoderma harzianum (Berrocal-Tito et al, 1999) and in the goldfish Carassius auratus (Mitani et al, 1996;Mitani & Shima, 1995;Yasuhira et al, 1991) blue light as well as H 2 O 2 induces the transcription of the photolyase gene. Kihara et al (2004) showed that near-UV light (300-400 nm) and sunlight enhance the expression of the photolyase in the fungus Bipolaris oryzae.…”

Dose and dose-rate dependency in the mortality response of Calanus finmarchicus embryos exposed to ultraviolet radiation

“…Illumination was provided by two 30 W Vita-Lite ® (Duro-Test Canada) fluorescent tubes placed 1.5 m from the eggs. The spectral output of these lamps includes some longwave ultraviolet-A (320 to 400 nm = UV-A); photorepair mechanisms should have been active under this light regime (Mitchell et al 1993, Mitani et al 1996. The PAR (400 to 700 nm) output of these lamps, at the position where the eggs were incubated, was 0.03 W m -2 .…”