scholarly journals TAT-Mediated Delivery of a DNA Repair Enzyme to Skin Cells Rapidly Initiates Repair of UV-Induced DNA Damage

2011 ◽  
Vol 131 (3) ◽  
pp. 753-761 ◽  
Author(s):  
Jodi L. Johnson ◽  
Brian C. Lowell ◽  
Olga P. Ryabinina ◽  
R. Stephen Lloyd ◽  
Amanda K. McCullough
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Repair Enzyme ◽  
Skin Cells

Long-term efficacy of a new medical device containing Fernblock® and DNA repair enzyme complex in the treatment and prevention of cancerization field in patients with actinic keratosis.

2019 ◽  
Vol 2 (02) ◽  
pp. 80-89
Author(s):  
Blanca De Unamuno Bustos ◽  
Natalia Chaparr´´o Aguilera ◽  
Inmaculada Azorín García ◽  
Anaid Calle Andrino ◽  
Margarita Llavador Ros ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Medical Device ◽  
Actinic Keratosis ◽  
Statistical Significance ◽  
Dna Lesions ◽  
Enzyme Complex ◽  
Repair Enzyme ◽  
P53 Expression ◽  
Cancerization Field

Actinic keratosis (AKs) are part of the cancerization field, a region adjacent to AKs containing subclinical and histologically abnormal epidermal tissue due to Ultraviolet (UV)-induced DNA damage. The photoproducts as consequence of DNA damage induced by UV are mainly cyclobutane pyrimidine dimers (CPDs). Fernblock® demonstrated in previous studies significant reduction of the number of CPDs induced by UV radiation. Photolyases are a specific group of enzymes that remove the major UV-induced DNA lesions by a mechanism called photo-reactivation. A monocentric, prospective, controlled, and double blind interventional study was performed to evaluate the effect of a new medical device (NMD) containing a DNA-repair enzyme complex (photolyases, endonucleases and glycosilases), a combination of UV-filters, and Fernblock® in the treatment of the cancerization field in 30 AK patients after photodynamic therapy. Patients were randomized into two groups: patients receiving a standard sunscreen (SS) andpatients receiving the NMD. Clinical, dermoscopic, reflectance confocal microscopy (RCM) and histological evaluations were performed. An increase of AKs was noted in all groups after three months of PDT without significant differences between them (p=0.476). A significant increase in the number of AKs was observed in SS group after six (p=0.026) and twelve months of PDT (p=0.038); however, this increase did not reach statistical significance in the NMD group. Regarding RCM evaluation, honeycomb pattern assessment after twelve months of PDT showed significant differences in the extension and grade of the atypia in the NMD group compared to SS group (p=0.030 and p=0.026, respectively). Concerning histopathological evaluation, keratinocyte atypia grade improved from baseline to six months after PDT in all the groups, with no statistically significant differences between the groups. Twelve months after PDT, p53 expression was significantly lower in the NMD group compared to SS group (p=0.028). The product was well-tolerated, with no serious adverse events reported. Our results provide evidence of the utility of this NMD in the improvement of the cancerization field and in the prevention of the development of new AKs.  

scholarly journals Large-scale heterochromatin remodeling linked to overreplication-associated DNA damage

2016 ◽  
Vol 114 (2) ◽  
pp. 406-411 ◽  
Author(s):  
Wei Feng ◽  
Christopher J. Hale ◽  
Ryan S. Over ◽  
Shawn J. Cokus ◽  
Steven E. Jacobsen ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Large Scale ◽  
Double Strand Breaks ◽  
Repair Enzyme ◽  
Strand Breaks ◽  
Histone 3 ◽  
Challenging Environment ◽  
Chromatin Density ◽  
Being Moved

Previously, we have shown that loss of the histone 3 lysine 27 (H3K27) monomethyltransferases ARABIDOPSIS TRITHORAX-RELATED 5 (ATXR5) and ATXR6 (ATXR6) results in the overreplication of heterochromatin. Here we show that the overreplication results in DNA damage and extensive chromocenter remodeling into unique structures we have named “overreplication-associated centers” (RACs). RACs have a highly ordered structure with an outer layer of condensed heterochromatin, an inner layer enriched in the histone variant H2AX, and a low-density core containing foci of phosphorylated H2AX (a marker of double-strand breaks) and the DNA-repair enzyme RAD51. atxr5,6 mutants are strongly affected by mutations in DNA repair, such as ATM and ATR. Because of its dense packaging and repetitive DNA sequence, heterochromatin is a challenging environment in which to repair DNA damage. Previous work in animals has shown that heterochromatic breaks are translocated out of the heterochromatic domain for repair. Our results show that atxr5,6 mutants use a variation on this strategy for repairing heterochromatic DNA damage. Rather than being moved to adjacent euchromatic regions, as in animals, heterochromatin undergoes large-scale remodeling to create a compartment with low chromatin density.

scholarly journals Paulownia tomentosa (Princess Tree) Extract Reduces DNA Damage and Induces DNA Repair Processes in Skin Cells

10.5772/60005 ◽  
2015 ◽  
Author(s):  
Simarna Kaur ◽  
Heng Kuan Wong ◽  
Michael D. Southall ◽  
Khalid Mahmood
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Paulownia Tomentosa ◽  
Skin Cells ◽  
Repair Processes

scholarly journals Emerging Roles of the Nucleolus in Regulating the DNA Damage Response: The Noncanonical DNA Repair Enzyme APE1/Ref-1 as a Paradigmatical Example

2014 ◽  
Vol 20 (4) ◽  
pp. 621-639 ◽  
Author(s):  
Giulia Antoniali ◽  
Lisa Lirussi ◽  
Mattia Poletto ◽  
Gianluca Tell
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Dna Damage Response ◽  
Repair Enzyme ◽  
Damage Response

Oxidative DNA damage and DNA repair enzyme expression are inversely related in murine models of fatty liver disease

2004 ◽  
Vol 287 (5) ◽  
pp. G1070-G1077 ◽  
Author(s):  
Daqing Gao ◽  
Chiming Wei ◽  
Lei Chen ◽  
Jiawen Huang ◽  
Shiqi Yang ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Liver Disease ◽  
Fatty Liver ◽  
Mouse Models ◽  
Fatty Liver Disease ◽  
Oxidative Dna Damage ◽  
Oxidant Stress ◽  
Repair Enzyme ◽  
Hepatocyte Death

Mitochondrial generation of reactive oxygen species (ROS) is increased in mice with fatty livers induced by genetic obesity, chronic consumption of ethanol, or methionine/choline-deficient diets. Both nuclear and mitochondrial (mt) DNA are targets for ROS-induced damage and accumulate hydroxylated bases, such as 8-hydroxy-2′-deoxyguanosine (8-oxoG) and base substitution of adenine with 8-oxoG (A*8-oxoG), that introduce mutations that promote cancer as well as cell death. The mammalian homolog of the bacterial DNA mismatch repair enzyme MutY (MYH) removes A*8-oxoG from nuclear and mtDNA, reduces 8-oxoG accumulation, and restores genomic stability after ROS exposure. Cumulative damage to mtDNA occurs as fatty liver disease progresses. Therefore, differences in hepatic MYH activity may influence the severity of fatty liver disease. To evaluate this hypothesis, we compared mtH2O2 production, MYH expression, oxidative DNA damage, and hepatocyte death in healthy mice and different mouse models of fatty liver disease. The results show that diverse causes of steatohepatitis increase mtROS production, limit repair of mtDNA, and oxidatively damage DNA. However, there are important differences in the DNA repair response to oxidant stress among mouse models of fatty liver disease. Independent of the degree of mtROS generation, models with the least MYH exhibit the greatest accumulation of 8-oxoG and the most hepatocyte death. These findings raise the intriguing possibility that inherited or acquired differences in DNA repair enzyme activity may underlie some of the interindividual differences in fatty liver disease outcomes.

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