Project description:Intraperitoneal administration of ferric nitrilotriacetate initiates Fenton reaction in the renal proximal tubules in rodents that ultimately leads to a high incidence of renal cell carcinoma (RCC) after repeated treatment. We performed high-resolution microarray comparative genomic hybridization to identify characteristics in the genomic profiles of oxidative stress-induced RCCs and simultaneously developed malignant lymphomas in the mice. The results highlighted a substantial difference in the predisposition to chromosomal changes between animal species.
Project description:Oxidative DNA damage has been associated with cognitive decline. The Ogg1 and Mutyh DNA glycosylases cooperate to prevent mutations caused by 8-oxoG, a major premutagenic oxidative DNA base lesion. Here, we have examined behavior and cognitive function in mice deficient of these glycosylases. We found that Ogg1-/-Mutyh-/- mice were more active and less anxious and that their learning ability was impaired. In contrast, Mutyh-/- mice showed moderately improved memory compared to WT. There was no change in genomic 8-oxoG levels, suggesting that Ogg1 and Mutyh play minor roles in global repair in adult brain. Notably, transcriptome analysis of hippocampus revealed that differentially expressed genes in the mutant mice belong to pathways known to be involved in anxiety and cognitive function. Thus, beyond their involvement in DNA repair, Ogg1 and Mutyh modulate cognitive function and behavior, and related hippocampal gene expression, suggesting a novel role for 8-oxoG in regulating adaptive behavior.
Project description:Intraperitoneal administration of ferric nitrilotriacetate initiates Fenton reaction in the renal proximal tubules in rodents. Its repeated administration ultimately leads to the development of renal cell carcinoma (RCC). We performed high-resolution microarray comparative genomic hybridization to identify characteristics in the genomic profiles of oxidative stress-induced RCCs in the mice of A/J strain.
Project description:Intraperitoneal administration of ferric nitrilotriacetate (Fe-NTA) initiates Fenton reaction in the renal proximal tubules of rodents that ultimately leads to a high incidence of renal cell carcinoma (RCC) after repeated treatment. We performed high-resolution microarray comparative genomic hybridization to identify characteristics in the genomic profiles of oxidative stress-induced rat RCCs. The results revealed extensive large-scale genomic alterations with a preference for deletion.
Project description:Intraperitoneal administration of ferric nitrilotriacetate (Fe-NTA) initiates Fenton reaction in the renal proximal tubules of rodents that ultimately leads to a high incidence of renal cell carcinoma (RCC) after repeated treatment. We performed high-resolution microarray comparative genomic hybridization to identify characteristics in the genomic profiles of oxidative stress-induced rat RCCs. The results revealed extensive large-scale genomic alterations with a preference for deletion. Carcinogenesis protocol was performed using male F1 hybrid rats between Fischer344 and Brown-Norway strains. 13 primary tumors and 2 cell lines of Fe-NTA induced RCCs were profiled on Agilent 185K rat genome CGH microarrays. One RCC sample of a female Eker rat was also analyzed with the same Agilent 185K rat genome CGH microarray.
Project description:Oxidative stress is a major risk factor for Alzheimer’s disease (AD), which is characterized by brain atrophy, amyloid plaques, neurofibrillary tangles, and loss of neurons. 8-Oxoguanine, a major oxidatively generated nucleobase highly accumulated in the AD brain, is known to cause neurodegeneration. In mammalian cells, several enzymes play essential roles in minimizing the 8-oxoguanine accumulation in DNA. MUTYH with adenine DNA glycosylase activity excises adenine inserted opposite 8-oxoguanine in DNA. MUTYH is reported to actively contribute to the neurodegenerative process in Parkinson and Huntington diseases and some mouse models of neurodegenerative diseases by accelerating neuronal dysfunction and microgliosis under oxidative conditions; however, whether or not MUTYH is involved in AD pathogenesis remains unclear. In the present study, we examined the contribution of MUTYH to the AD pathogenesis. Using postmortem human brains, we showed that various types of MUTYH transcripts and proteins are expressed in most hippocampal neurons and glia in both non-AD and AD brains. We further introduced MUTYH deficiency into AppNL-G-F/NL-G-F knock-in AD model mice, which produce humanized toxic amyloid-β without the overexpression of APP protein, and investigated the effects of MUTYH deficiency on the behavior, pathology, gene expression, and neurogenesis. MUTYH deficiency improved memory impairment in AppNL-G-F/NL-G-F mice, accompanied by reduced microgliosis. Gene expression profiling strongly suggested that MUTYH is involved in the microglial response pathways under AD pathology and contributes to the phagocytic activity of disease-associated microglia. We also found that MUTYH deficiency ameliorates impaired neurogenesis in the hippocampus, thus improving memory impairment. In conclusion, we propose that MUTYH, which is expressed in the hippocampus of AD patients as well as non-AD subjects, actively contributes to memory impairment by inducing microgliosis with poor neurogenesis in the preclinical AD phase and that MUTYH is a novel therapeutic target for AD, as its deficiency is highly beneficial for ameliorating AD pathogenesis.