DNA repair in bacterial cultures and plasmid DNA exposed to infrared laser for treatment of pain

Canuto, K S; Sergio, L P S; Marciano, R S; Guimarães, Oscar Roberto; Polignano, Giovanni Augusto Castanheira; Geller, Mauro; Paoli, Flávia de; Fonseca, A S

doi:10.1088/1612-2011/10/6/065606

Cited by 18 publications

(28 citation statements)

References 49 publications

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“…Due to these properties, T 4 endonuclease V protects patients with xeroderma pigmentosum against skin cancer ( 32 ). Plasmid DNA exposed to low-intensity red and infrared lasers did not show any alterations in electrophoretic profile in agarose gels, suggesting absence of detectable single- or double-strand DNA breaks, as previous studies have demonstrated ( 19 , 20 ). In addition, the plasmids did not show any alteration in their electrophoretic profile after incubation with T 4 endonuclease V, suggesting that red and infrared laser lights did not induce DNA lesions targeted by this enzyme, at least under the laser irradiation conditions used in this study.…”

Section: Methodssupporting

confidence: 81%

“…Previous studies demonstrated a biostimulatory effect in prokaryote ( 10 ) and eukaryote ( 30 ) cells. Recently, we observed this effect in cell cultures proficient in DNA repair mechanisms, but not in an E. coli strain deficient in repair of oxidative DNA lesions ( 20 ). No studies have demonstrated biostimulation that was dependent on laser beam power.…”

Section: Methodsmentioning

confidence: 94%

“…The nature of laser-induced side effects is still in dispute, although there are data about DNA damage after laser exposure in eukaryotic ( 1315 ) and prokaryotic cells ( 16 , 17 ). Moreover, previous studies have demonstrated that red and near-infrared lasers decrease survival of E. coli cells deficient in base excision repair, a pathway involved in repair of oxidative DNA lesions, and induce the filamentation phenotype more frequently than in wild type E. coli cells ( 18 - 20 ). While the controversies about laser-induced DNA lesions by free radicals have not been resolved, it is interesting to evaluate whether other DNA repair pathways are involved in cellular responses to low-intensity lasers.…”

Section: Introductionmentioning

confidence: 99%

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Nucleotide excision repair pathway assessment in DNA exposed to low-intensity red and infrared lasers

Fonseca

Campos²,

Magalhães³

et al. 2015

Braz J Med Biol Res

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Low-intensity lasers are used for prevention and management of oral mucositis induced by anticancer therapy, but the effectiveness of treatment depends on the genetic characteristics of affected cells. This study evaluated the survival and induction of filamentation of Escherichia coli cells deficient in the nucleotide excision repair pathway, and the action of T4endonuclease V on plasmid DNA exposed to low-intensity red and near-infrared laser light. Cultures of wild-type (strain AB1157) E. coli and strain AB1886 (deficient in uvrA protein) were exposed to red (660 nm) and infrared (808 nm) lasers at various fluences, powers and emission modes to study bacterial survival and filamentation. Also, plasmid DNA was exposed to laser light to study DNA lesions produced in vitro by T4endonuclease V. Low-intensity lasers:i) had no effect on survival of wild-type E. coli but decreased the survival of uvrA protein-deficient cells,ii) induced bacterial filamentation, iii) did not alter the electrophoretic profile of plasmids in agarose gels, andiv) did not alter the electrophoretic profile of plasmids incubated with T4 endonuclease V. These results increase our understanding of the effects of laser light on cells with various genetic characteristics, such as xeroderma pigmentosum cells deficient in nucleotide excision pathway activity in patients with mucositis treated by low-intensity lasers.

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Section: Methodssupporting

confidence: 81%

Section: Methodsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nucleotide excision repair pathway assessment in DNA exposed to low-intensity red and infrared lasers

Fonseca

Campos²,

Magalhães³

et al. 2015

Braz J Med Biol Res

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“…Induction of filamentation phenotype is reported in E. coli cells irradiated with the low-level lasers, as in those with mutations in genes related to DNA repair pathways for oxidative damages. 15,16,20 However, the filamentation assay performed in these studies did not allow for evaluating what happened with cells which do not present this phenotype. To attempt this need, area and perimeter were measured in mutant E. coli cells in SOS functions (AB2463 and AB2494) and compared to E. coli wild type cells (AB1157).…”

Section: Discussionmentioning

confidence: 99%

Low-Power Red and Infrared Laser Effects on Cells Deficient in DNA Repair

2019

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Introduction: Low-level lasers are successfully used to prevent and treat diseases in soft oral and bone tissues, particularly diseases in oral cavity caused by chemotherapy and radiotherapy in oncology. However, controversy exists as to whether these lasers induce molecular side effects, mainly on DNA. The aim of this work was to assess the effects of low-power lasers on mutant Escherichia coli cells in DNA repair. Methods: Escherichia coli wild type cultures as well as those lacking recombination DNA repair (recA- ) and la SOS responses (lexA- ) irradiated with lasers at different energy densities, powers, and emission modes for cell viability and morphology assessment were used in this study. Results: Laser irradiation: (i) did not affect cell viability of non-mutant and lexA- cells but decreased viability in recA- cultures; (ii) altered morphology of wild type and lexA, depending on the energy density, power, emission mode, and wavelength. Conclusion: Results show that low-level lasers have lethal effects on both recombination DNA repair and SOS response bacterial cells but do not induce morphological modifications in these cells.

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“…Biological effects caused by free radicals from laser light are controversial and possible adverse effects on cells and data about DNA damage after laser exposure have been reported in eukaryotic [10][11][12][13][14] and prokaryotic cells [15][16][17][18][19][20][21][22][23] , at different powers, wavelengths and fluences. In addition, as regard to DNA, a variety of studies have suggested that exposure to red and near infrared low-intensity lasers could induce adaptation or DNA damage at a sub-lethal level.…”

Section: Introductionmentioning

confidence: 99%

DNA fragmentation and nuclear phenotype in tendons exposed to low-intensity infrared laser

et al. 2015

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Clinical protocols are recommended in device guidelines outlined for treating many diseases on empirical basis. However, effects of low-intensity infrared lasers at fluences used in clinical protocols on DNA are controversial. Excitation of endogenous chromophores in tissues and free radicals generation could be described as a consequence of laser used. DNA lesions induced by free radicals cause changes in DNA structure, chromatin organization, ploidy degrees and cell death. In this work, we investigated whether low-intensity infrared laser therapy could alter the fibroblasts nuclei characteristics and induce DNA fragmentation. Tendons of Wistar rats were exposed to low-intensity infrared laser (830 nm), at different fluences (1, 5 and 10 J/cm 2 ), in continuous wave (power output of 10mW, power density of 79.6 mW/cm 2 ). Different frequencies were analyzed for the higher fluence (10 J/cm 2 ), at pulsed emission mode (2.5, 250 and 2500 Hz), with the laser source at surface of skin. Geometric, densitometric and textural parameters obtained for Feulgen-stained nuclei by image analysis were used to define nuclear phenotypes. Significant differences were observed on the nuclear phenotype of tendons after exposure to laser, as well as, high cell death percentages was observed for all fluences and frequencies analyzed here, exception 1 J/cm 2 fluence. Our results indicate that low-intensity infrared laser can alter geometric, densitometric and textural parameters in tendon fibroblasts nuclei. Laser can also induce DNA fragmentation, chromatin lost and consequently cell death, using fluences, frequencies and emission modes took out from clinical protocols.

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DNA repair in bacterial cultures and plasmid DNA exposed to infrared laser for treatment of pain

Cited by 18 publications

References 49 publications

Nucleotide excision repair pathway assessment in DNA exposed to low-intensity red and infrared lasers

Nucleotide excision repair pathway assessment in DNA exposed to low-intensity red and infrared lasers

Low-Power Red and Infrared Laser Effects on Cells Deficient in DNA Repair

DNA fragmentation and nuclear phenotype in tendons exposed to low-intensity infrared laser

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