Abstract:
:Cell proliferation may be altered in many diseases, but it is uncertain exactly how to measure total numbers of divisions. Although it is impossible to count every division directly, potentially total numbers of stem cell divisions since birth may be inferred from numbers of somatic errors. The idea is that divisions are surreptitiously recorded by random errors that occur during replication. To test this "molecular clock" hypothesis, epigenetic errors encoded in certain methylation patterns were counted in glands from 30 uteri. Endometrial divisions can differ among women because of differences in estrogen exposures or numbers of menstrual cycles. Consistent with an association between mitotic age and methylation, there was an age-related increase in methylation with stable levels after menopause, and significantly less methylation was observed in lean or older multiparous women. Methylation patterns were diverse and more consistent with niche rather than immortal stem cell lineages. There was no evidence for decreased stem cell survival with aging. An ability to count lifetime numbers of stem cell divisions covertly recorded by random replication errors provides new opportunities to link cell proliferation with aging and cancer.
journal_name
Proc Natl Acad Sci U S Aauthors
Kim JY,Tavaré S,Shibata Ddoi
10.1073/pnas.0503976102keywords:
subject
Has Abstractpub_date
2005-12-06 00:00:00pages
17739-44issue
49eissn
0027-8424issn
1091-6490pii
0503976102journal_volume
102pub_type
杂志文章abstract::Evolution of an oxygenic atmosphere required primordial life to accommodate the toxicity associated with reactive oxygen species. We have characterized an archaeal antioxidant from the hyperthermophilic acidophile Sulfolobus solfataricus. The amino acid sequence of this approximately 22-kDa protein shares little seque...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0501497102
更新日期:2005-07-26 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.70.3.904
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doi:10.1073/pnas.1108464109
更新日期:2012-01-31 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.0308344101
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2010-01-26 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.92.10.4611
更新日期:1995-05-09 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1515373112
更新日期:2015-11-24 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.91.22.10675
更新日期:1994-10-25 00:00:00
abstract::Hydrogen bonds and their relative strengths in proteins are of importance for understanding protein structure and protein motions. The correct strength of such hydrogen bonds is experimentally known to vary greatly from approximately 5-6 kcal/mol for the isolated bond to approximately 0.5-1.5 kcal/mol for proteins in ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2003-10-28 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1991-10-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1996-04-30 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1986-06-01 00:00:00
abstract::Wood-degrading brown rot fungi are essential recyclers of plant biomass in forest ecosystems. Their efficient cellulolytic systems, which have potential biotechnological applications, apparently depend on a combination of two mechanisms: lignocellulose oxidation (LOX) by reactive oxygen species (ROS) and polysaccharid...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2016-09-27 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.222467299
更新日期:2002-11-26 00:00:00