scholarly journals Intra- and extracellular reactive oxygen species generated by blue light

2006 ◽  
Vol 77A (3) ◽  
pp. 470-477 ◽  
Author(s):  
Y. Omata ◽  
J.B. Lewis ◽  
S. Rotenberg ◽  
P.E. Lockwood ◽  
R.L.W. Messer ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Blue Light ◽  
Reactive Oxygen ◽  
Oxygen Species

Blue light generates reactive oxygen species (ROS) differentially in tumor vs. normal epithelial cells

2005 ◽  
Vol 21 (7) ◽  
pp. 683-688 ◽  
Author(s):  
Daniel B. Lockwood ◽  
John C. Wataha ◽  
Jill B. Lewis ◽  
Wan Y. Tseng ◽  
Regina L.W. Messer ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Epithelial Cells ◽  
Blue Light ◽  
Reactive Oxygen ◽  
Oxygen Species

scholarly journals Blue-Light Inhibition of Listeria monocytogenes Growth Is Mediated by Reactive Oxygen Species and Is Influenced by σBand the Blue-Light Sensor Lmo0799

2016 ◽  
Vol 82 (13) ◽  
pp. 4017-4027 ◽  
Author(s):  
Beth O'Donoghue ◽  
Kerrie NicAogáin ◽  
Claire Bennett ◽  
Alan Conneely ◽  
Teresa Tiensuu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Listeria Monocytogenes ◽  
Stress Response ◽  
Blue Light ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Content Type ◽  
General Stress Response ◽  
General Stress ◽  
Light Sensor

ABSTRACTListeria monocytogenessenses blue light via the flavin mononucleotide-containing sensory protein Lmo0799, leading to activation of the general stress response sigma factor SigB (σB). In this study, we investigated the physiological response of this foodborne pathogen to blue light. We show that blue light (460 to 470 nm) doses of 1.5 to 2 mW cm−2cause inhibition of growth on agar-based and liquid culture media. The inhibitory effects are dependent on cell density, with reduced effects evident when high cell numbers are present. The addition of 20 mM dimethylthiourea, a scavenger of reactive oxygen species, or catalase to the medium reverses the inhibitory effects of blue light, suggesting that growth inhibition is mediated by the formation of reactive oxygen species. A mutant strain lacking σB(ΔsigB) was found to be less inhibited by blue light than the wild type, likely indicating the energetic cost of deploying the general stress response. When a lethal dose of light (8 mW cm−2) was applied to cells, the ΔsigBmutant displayed a marked increase in sensitivity to light compared to the wild type. To investigate the role of the blue-light sensor Lmo0799, mutants were constructed that either had a deletion of the gene (Δlmo0799) or alteration in a conserved cysteine residue at position 56, which is predicted to play a pivotal role in the photocycle of the protein (lmo0799C56A). Both mutants displayed phenotypes similar to the ΔsigBmutant in the presence of blue light, providing genetic evidence that residue 56 is critical for light sensing inL. monocytogenes. Taken together, these results demonstrate thatL. monocytogenesis inhibited by blue light in a manner that depends on reactive oxygen species, and they demonstrate clear light-dependent phenotypes associated with σBand the blue-light sensor Lmo0799.IMPORTANCEListeria monocytogenesis a bacterial foodborne pathogen that can cause life-threatening infections in humans. It is known to be able to sense and respond to visible light. In this study, we examine the effects of blue light on the growth and survival of this pathogen. We show that growth can be inhibited at comparatively low doses of blue light, and that at higher doses,L. monocytogenescells are killed. We present evidence suggesting that blue light inhibits this organism by causing the production of reactive oxygen species, such as hydrogen peroxide. We help clarify the mechanism of light sensing by constructing a “blind” version of the blue-light sensor protein. Finally, we show that activation of the general stress response by light has a negative effect on growth, probably because cellular resources are diverted into protective mechanisms rather than growth.

scholarly journals Blue Light Induces Impaired Autophagy through Nucleotide-Binding Oligomerization Domain 2 Activation on the Mouse Ocular Surface

2021 ◽  
Vol 22 (4) ◽  
pp. 2015
Author(s):  
Ying Li ◽  
Rujun Jin ◽  
Lan Li ◽  
Ji Suk Choi ◽  
Jonghwa Kim ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Blue Light ◽  
Ocular Surface ◽  
Light Exposure ◽  
Reactive Oxygen ◽  
Nucleotide Binding ◽  
Oxygen Species ◽  
Knock Out ◽  
Corneal Epithelial ◽  
Oligomerization Domain

In this study, we investigated the effects of blue light exposure on nucleotide-binding oligomerization domain 2 (NOD2) expression on the mouse ocular surface and evaluated the role of NOD2 activation in light-induced cell death. Mice were divided into wild-type (WT), NOD2-knock out (KO), WT + blue light (WT + BL), and NOD2-KO + blue light (NOD2-KO + BL) groups, and the mice in the WT+BL and NOD2-KO + BL groups were exposed to blue light for 10 days. After 10 days of blue light exposure, increased reactive oxygen species and malondialdehyde were observed in the WT + BL and NOD2-KO + BL groups, and the WT + BL group showed a higher expression of NOD2 and autophagy related 16 like 1. Although both WT+BL and NOD2-KO + BL groups showed an increase in the expression of light chain 3-II, NOD2-KO + BL mice had a significantly lower p62 expression than WT + BL mice. In addition, NOD2-KO+BL mice had significantly lower corneal epithelial damage and apoptosis than WT + BL mice. In conclusion, blue light exposure can induce impaired autophagy by activation of NOD2 on the ocular surface. In addition, the reactive oxygen species (ROS)–NOD2–autophagy related 16 like 1 (ATG16L) signaling pathway may be involved in the blue-light-induced autophagy responses, resulting in corneal epithelial apoptosis.

Intracellular reactive oxygen species in monocytes generated by photosensitive chromophores activated with blue light

2008 ◽  
Vol 24 (8) ◽  
pp. 1070-1076 ◽  
Author(s):  
Serge Bouillaguet ◽  
Brandi Owen ◽  
John C. Wataha ◽  
Marino A. Campo ◽  
Norbert Lange ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Blue Light ◽  
Reactive Oxygen ◽  
Intracellular Reactive Oxygen Species ◽  
Oxygen Species
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