DNA methylation and histone post-translational modification stability in post-mortem brain tissue
Abstract Background Epigenetic (including DNA and histone) modifications occur in a variety of neurological disorders. If epigenetic features of brain autopsy material are to be studied, it is critical to understand the post-mortem stability of the modifications. Methods Pig and mouse brain tissue w...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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BMC
2019-01-01
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| Series: | Clinical Epigenetics |
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| Online Access: | http://link.springer.com/article/10.1186/s13148-018-0596-7 |
| _version_ | 1819208404896317440 |
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| author | Jessica S. Jarmasz Hannah Stirton James R. Davie Marc R. Del Bigio |
| author_facet | Jessica S. Jarmasz Hannah Stirton James R. Davie Marc R. Del Bigio |
| author_sort | Jessica S. Jarmasz |
| collection | DOAJ |
| description | Abstract Background Epigenetic (including DNA and histone) modifications occur in a variety of neurological disorders. If epigenetic features of brain autopsy material are to be studied, it is critical to understand the post-mortem stability of the modifications. Methods Pig and mouse brain tissue were formalin-fixed and paraffin-embedded, or frozen after post-mortem delays of 0, 24, 48, and 72 h. Epigenetic modifications frequently reported in the literature were studied by DNA agarose gel electrophoresis, DNA methylation enzyme-linked immunosorbent assays, Western blotting, and immunohistochemistry. We constructed a tissue microarray of human neocortex samples with devitalization or death to fixation times ranging from < 60 min to 5 days. Results In pig and mouse brain tissue, we found that DNA cytosine modifications (5mC, 5hmC, 5fC, and 5caC) were stable for ≥ 72 h post-mortem. Histone methylation was generally stable for ≥ 48 h (H3K9me2/K9me3, H3K27me2, H3K36me3) or ≥ 72 h post-mortem (H3K4me3, H3K27me3). Histone acetylation was generally less stable. The levels of H3K9ac, H3K27ac, H4K5ac, H4K12ac, and H4K16ac declined as early as ≤ 24 h post-mortem, while the levels of H3K14ac did not change at ≥ 48 h. Immunohistochemistry showed that histone acetylation loss occurred primarily in the nuclei of large neurons, while immunoreactivity in glial cell nuclei was relatively unchanged. In the human brain tissue array, immunoreactivity for DNA cytosine modifications and histone methylation was stable, while subtle changes were apparent in histone acetylation at 4 to 5 days post-mortem. Conclusion We conclude that global epigenetic studies on human post-mortem brain tissue are feasible, but great caution is needed for selection of post-mortem delay matched controls if histone acetylation is of interest. |
| first_indexed | 2024-12-23T05:38:51Z |
| format | Article |
| id | doaj.art-b8418571732642d4b96d900880d1f962 |
| institution | Directory Open Access Journal |
| issn | 1868-7075 1868-7083 |
| language | English |
| last_indexed | 2024-12-23T05:38:51Z |
| publishDate | 2019-01-01 |
| publisher | BMC |
| record_format | Article |
| series | Clinical Epigenetics |
| spelling | doaj.art-b8418571732642d4b96d900880d1f9622022-12-21T17:58:15ZengBMCClinical Epigenetics1868-70751868-70832019-01-0111112310.1186/s13148-018-0596-7DNA methylation and histone post-translational modification stability in post-mortem brain tissueJessica S. Jarmasz0Hannah Stirton1James R. Davie2Marc R. Del Bigio3Department of Human Anatomy and Cell Science, University of ManitobaMax Rady College of Medicine, University of ManitobaDepartment of Biochemistry and Medical Genetics, University of ManitobaDepartment of Pathology, University of ManitobaAbstract Background Epigenetic (including DNA and histone) modifications occur in a variety of neurological disorders. If epigenetic features of brain autopsy material are to be studied, it is critical to understand the post-mortem stability of the modifications. Methods Pig and mouse brain tissue were formalin-fixed and paraffin-embedded, or frozen after post-mortem delays of 0, 24, 48, and 72 h. Epigenetic modifications frequently reported in the literature were studied by DNA agarose gel electrophoresis, DNA methylation enzyme-linked immunosorbent assays, Western blotting, and immunohistochemistry. We constructed a tissue microarray of human neocortex samples with devitalization or death to fixation times ranging from < 60 min to 5 days. Results In pig and mouse brain tissue, we found that DNA cytosine modifications (5mC, 5hmC, 5fC, and 5caC) were stable for ≥ 72 h post-mortem. Histone methylation was generally stable for ≥ 48 h (H3K9me2/K9me3, H3K27me2, H3K36me3) or ≥ 72 h post-mortem (H3K4me3, H3K27me3). Histone acetylation was generally less stable. The levels of H3K9ac, H3K27ac, H4K5ac, H4K12ac, and H4K16ac declined as early as ≤ 24 h post-mortem, while the levels of H3K14ac did not change at ≥ 48 h. Immunohistochemistry showed that histone acetylation loss occurred primarily in the nuclei of large neurons, while immunoreactivity in glial cell nuclei was relatively unchanged. In the human brain tissue array, immunoreactivity for DNA cytosine modifications and histone methylation was stable, while subtle changes were apparent in histone acetylation at 4 to 5 days post-mortem. Conclusion We conclude that global epigenetic studies on human post-mortem brain tissue are feasible, but great caution is needed for selection of post-mortem delay matched controls if histone acetylation is of interest.http://link.springer.com/article/10.1186/s13148-018-0596-7CortexHuman brainPig brainMouse brainAutopsyPost-mortem delay |
| spellingShingle | Jessica S. Jarmasz Hannah Stirton James R. Davie Marc R. Del Bigio DNA methylation and histone post-translational modification stability in post-mortem brain tissue Clinical Epigenetics Cortex Human brain Pig brain Mouse brain Autopsy Post-mortem delay |
| title | DNA methylation and histone post-translational modification stability in post-mortem brain tissue |
| title_full | DNA methylation and histone post-translational modification stability in post-mortem brain tissue |
| title_fullStr | DNA methylation and histone post-translational modification stability in post-mortem brain tissue |
| title_full_unstemmed | DNA methylation and histone post-translational modification stability in post-mortem brain tissue |
| title_short | DNA methylation and histone post-translational modification stability in post-mortem brain tissue |
| title_sort | dna methylation and histone post translational modification stability in post mortem brain tissue |
| topic | Cortex Human brain Pig brain Mouse brain Autopsy Post-mortem delay |
| url | http://link.springer.com/article/10.1186/s13148-018-0596-7 |
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