CpG array analysis of histone H3 lysine 4 trimethylation by chromatin immunoprecipitation linked to microarrays analysis in peripheral blood mononuclear cells of IgA nephropathy patients.
OBJECTIVE
The purpose of the present study was to investigate the aberrance of histone H3 lysine 4 trimethylation (H3K4me3) in patients with IgA Nephropathy (IgAN).


METHODS
In this study, H3K4me3 variations in peripheral blood mononuclear cells (PBMCs) from 15 IgAN patients and 15 healthy subjects were analyzed using chromatin immunoprecipitation linked to microarrays analysis (ChIP-chip). ChIP real-time PCR was used to validate the microarray results. Expression analysis by quantitative real-time PCR (qRT-PCR) revealed correlations between mRNA and H3K4me3 levels. DNA methylation status was analyzed by quantitative methylation-specific PCR.


RESULTS
We found that 321 probes displayed significant H3K4me3 differences in IgAN patients compared with healthy controls. Among these probes, 154 probes displayed increased H3K4me3 and 167 probes demonstrated decreased H3K4me3. For further validation, we selected 4 key relevant genes (FCRL4, GALK2, PTPRN2 and IL1RAPL1) to study. The results of ChIP real-time PCR coincided well with the microarray data. Quantitative RT-PCR revealed the correlations between the mRNA expression and the methylation levels of H3K4me3. Different degrees of DNA methylation alterations appeared on the selected positive genes.


CONCLUSIONS
Our studies indicated that there were significant alterations in H3K4me3 in IgAN patients. These findings may help to explain the disturbed immunity and abnormal glycosylation involved in IgAN patients.
Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Chongqing Medical University, Chongqing, China.
Suwen
S
Qi
Weiguo
W
Sui
Ming
M
Yang
Jiejing
J
Chen
Yong
Y
Dai
D000328:Adult; D016022:Case-Control Studies; D047369:Chromatin Immunoprecipitation; D005260:Female; D005922:Glomerulonephritis, IGA / Q000235:genetics* / Q000378:metabolism*; D006657:Histones / Q000378:metabolism*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism*; D008297:Male; D008745:Methylation; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction; D055815:Young Adult
D006657:Histones; D008239:Lysine