This study investigated the recovery of renal proximal tubule cellular (RPTC) functions following oxidant-induced sublethal injury. tert-Butylhydroperoxide (TBHP) treatment resulted in 24% cell death and loss 4 h following the exposure. The remaining sublethally injured RPTC proliferated, and monolayer DNA content returned to control values on day 4 following TBHP exposure. Basal oxygen consump...

Although homologous recombination and DNA repair phenomena in bacteria were initially extensively studied without regard to any relationship between the two, it is now appreciated that DNA repair and homologous recombination are related through DNA replication. In Escherichia coli, two-strand DNA damage, generated mostly during replication on a template DNA containing one-strand damage, is repa...

UV-induced DNA damage gives rise to mutations and skin cancer. We have previously reported that treatment of skin cells in vitro with thymidine dinucleotide (pTT) activates p53 and increases the ability of cells to repair subsequent UV-induced DNA damage by enhancing endogenous DNA repair capacity. Here we show that topical pTT pretreatment enhances the rate of DNA photoproduct removal, decreas...

BACKGROUND To investigate whether different conditions of DNA structure and radiation treatment could modify heterogeneity of response. Additionally to study variance as a potential parameter of heterogeneity for radiosensitivity testing. METHODS Two-hundred leukocytes per sample of healthy donors were split into four groups. I: Intact chromatin structure; II: Nucleoids of histone-depleted DN...

Eukaryotic genomes are packaged into chromatin, which is the physiological substrate for all DNA transactions, including DNA damage and repair. Chromatin organization imposes major constraints on DNA damage repair and thus undergoes critical rearrangements during the repair process. These rearrangements have been integrated into the "access-repair-restore" (ARR) model, which provides a molecula...

Recent evidence has linked mitochondrial DNA (mtDNA) damage to several disease processes,including cancer and aging. An important source of such damage is reactive oxygen species. These molecules can be generated endogenously via the electron transport system or may arise from a host of exogenous sources. It has been reported that extracts from cells of individuals with xeroderma pigmentosum gr...

Although there has been a renewed interest in the field of cancer metabolism in the last decade, the link between metabolism and DNA damage/DNA repair in cancer has yet to be appreciably explored. In this review, we examine the evidence connecting DNA damage and repair mechanisms with cell metabolism through three principal links. (1) Regulation of methyl- and acetyl-group donors through differ...

PURPOSE Mitochondrial DNA (mtDNA) damage may be associated with age-related diseases, such as age-related macular degeneration (AMD). The present study was designed to test whether the frequency of mtDNA damage, heteroplasmic mtDNA mutations, and repair capacity correlate with progression of AMD. METHODS Macular and peripheral RPE cells were isolated and cultured from human donor eyes with an...

Oxidative stress is thought to play a role in the pathogenesis of age-related macular degeneration (AMD). We determined the extent of oxidative DNA damage and the kinetics of its removal as well as the genotypes of the Ser326Cys polymorphism of the hOGG1 gene in lymphocytes of 30 wet AMD patients and 30 controls. Oxidative DNA damage induced by hydrogen peroxide and its repair were evaluated by...

Alternative excision repair (AER) is a category of excision repair initiated by a single nick, made by an endonuclease, near the site of DNA damage, and followed by excision of the damaged DNA, repair synthesis, and ligation. The ultraviolet (UV) damage endonuclease in fungi and bacteria introduces a nick immediately 5' to various types of UV damage and initiates its excision repair that is ind...