Review paper
Epigenetics of inflammatory bowel disease (Gut 2000;47:302?306)
www.ncbi.nlm.nih.gov/pmc/articles/PMC1728011/pdf/v047p00302.pdf
Abstract about above review paper
What is Epigenetics (from wikipedia)?
In biology, and specifically genetics, epigenetics is the study of heritable changes in gene activity that are not caused by changes in the DNA sequence; it also can be used to describe the study of stable, long-term alterations in the transcriptional potential of a cell that are not necessarily heritable. Unlike simple genetics based on changes to the DNA sequence (the genotype), the changes in gene expression or cellular phenotype of epigenetics have other causes, thus use of the term epi- (Greek: επ?- over, outside of, around) -genetics
Author of that paper says below are clinical or expremental data
suggest that epigenetic factors may be of aetipatho-genic relevance to IBD.
Parent-of-origin effect in IBD transmission
Clinical evidence for a parent of origin effect was recently shown in the anlysis of 135 families in which both a parent and an offspring had IBD
In the majority of families, the transmission of susceptibility to disease occured from mother to child, and
the difference between maternal versus paternal transmission was highly significant
(Of 135 families, 93 involved maternal transmission, while 42 involved paternal)
...
maternal effect suggests serveral possibilities, mitochondrial transmission, X linked effects, genomic imprinting
None can be excluded at present
Given the relatively late onset of IBD as well remission and relapses of this disease, a defect in mitochondrial genome is not likely to be the main cause of the maternal effect
X linked factors are of interest as an association of IBD with Tuner's syndrome has been identified.
The third possibility is genomic imprinting.
...
it has been shown that aberrant imprinting can lead to a wide variety of clinical disorders ranging from tumours to pronounced growth abnormality
...
Parent-of-origin effect in genetic anticipation
Genetic anticipation is a biological phenomenon that exhibits an earlier age of disease onset and increase serverity in affected offspring in comparsion with there affected parent
..
Discordance of monozygotic twins for IBD
Although IBD twin significantly higher concordance rate among monozygotic twin for both UC and CD compared with dizygotic twins, concordance of monozygotic twins for IBD was relatively low.
In a combined Swedish and British sample, concordance of monozygotic twins reached only 13% for UC and 30% for CD.
...
To some extent the epigenetic status of a gene represents an "interface" between the DNA sequence and the intra- and extra- cellular environment.
Monozygotic twins, although carrying identical DNA sequences may be very differenct from an epigenetic point of view
Epigenetics and genetic association studies in IBD
... just read link ...
Epigenetics and IBD treatment
Glucocorticoids(cortisol => steroid hormone, glucocorticoids, released when stressed, low blood pressure) can increase transcription
of anti-inflammatory genes which results from the uncoiling
of DNA wound around histone and this is achieved by
acetylation of the histone residues. Glucocorticoids may
also lead to deacetylation of histones of genes of
proinflammatory cytokines, resulting in tighter coiling of
DNA and reduced access of transcription factors to their
binding sites, thereby suppressing gene expression.
......
My current personal view to Crohn's disease is (although I'm not professional nor
doctor, just patient)
First epigenetic factor(environment, hormone .. chemical)
Second impared immunity (either adaptive or innate)
Finally unable to clear inter-cellular bacteria (like map...)
Epigenetics of inflammatory bowel disease (Gut 2000;47:302?306)
www.ncbi.nlm.nih.gov/pmc/articles/PMC1728011/pdf/v047p00302.pdf
Abstract about above review paper
What is Epigenetics (from wikipedia)?
In biology, and specifically genetics, epigenetics is the study of heritable changes in gene activity that are not caused by changes in the DNA sequence; it also can be used to describe the study of stable, long-term alterations in the transcriptional potential of a cell that are not necessarily heritable. Unlike simple genetics based on changes to the DNA sequence (the genotype), the changes in gene expression or cellular phenotype of epigenetics have other causes, thus use of the term epi- (Greek: επ?- over, outside of, around) -genetics
Author of that paper says below are clinical or expremental data
suggest that epigenetic factors may be of aetipatho-genic relevance to IBD.
Parent-of-origin effect in IBD transmission
Clinical evidence for a parent of origin effect was recently shown in the anlysis of 135 families in which both a parent and an offspring had IBD
In the majority of families, the transmission of susceptibility to disease occured from mother to child, and
the difference between maternal versus paternal transmission was highly significant
(Of 135 families, 93 involved maternal transmission, while 42 involved paternal)
...
maternal effect suggests serveral possibilities, mitochondrial transmission, X linked effects, genomic imprinting
None can be excluded at present
Given the relatively late onset of IBD as well remission and relapses of this disease, a defect in mitochondrial genome is not likely to be the main cause of the maternal effect
X linked factors are of interest as an association of IBD with Tuner's syndrome has been identified.
The third possibility is genomic imprinting.
...
it has been shown that aberrant imprinting can lead to a wide variety of clinical disorders ranging from tumours to pronounced growth abnormality
...
Parent-of-origin effect in genetic anticipation
Genetic anticipation is a biological phenomenon that exhibits an earlier age of disease onset and increase serverity in affected offspring in comparsion with there affected parent
..
Discordance of monozygotic twins for IBD
Although IBD twin significantly higher concordance rate among monozygotic twin for both UC and CD compared with dizygotic twins, concordance of monozygotic twins for IBD was relatively low.
In a combined Swedish and British sample, concordance of monozygotic twins reached only 13% for UC and 30% for CD.
...
To some extent the epigenetic status of a gene represents an "interface" between the DNA sequence and the intra- and extra- cellular environment.
Monozygotic twins, although carrying identical DNA sequences may be very differenct from an epigenetic point of view
Epigenetics and genetic association studies in IBD
... just read link ...
Epigenetics and IBD treatment
Glucocorticoids(cortisol => steroid hormone, glucocorticoids, released when stressed, low blood pressure) can increase transcription
of anti-inflammatory genes which results from the uncoiling
of DNA wound around histone and this is achieved by
acetylation of the histone residues. Glucocorticoids may
also lead to deacetylation of histones of genes of
proinflammatory cytokines, resulting in tighter coiling of
DNA and reduced access of transcription factors to their
binding sites, thereby suppressing gene expression.
......
My current personal view to Crohn's disease is (although I'm not professional nor
doctor, just patient)
First epigenetic factor(environment, hormone .. chemical)
Second impared immunity (either adaptive or innate)
Finally unable to clear inter-cellular bacteria (like map...)
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