Background/Purpose: The oncoprotein survivin coded by the BIRC5 gene was described as an important marker in rheumatoid arthritis (RA). Survivin participates in cell division being a member of the chromosomal passenger complex, while its role in gene transcription remains unknown. The purpose of this study was to identify survivin-specific transcription pattern in CD4⁺ T-cells.

Methods: CD4+ T cells of RA patients and healthy females were isolated from the perpheral blood, activated and treated with a survivin inhibitor YM155. Chromatin was immunoprecipitated using polyclonal antibodies to survivin and to histone H3 trimethylation H3K27me3, H3K4me3 and acetylation H3K27ac marks. DNA libraries were prepared for all ChIP material using ThruPLEX (Rubicon) and high throughput sequencing was performed using Hiseq2000 (Illumina) and aligned to the human reference genome (Ensembl GRCh38) using the STAR aligner. Transcriptional analysis was done by RNAseq (Illumina) and conventional qPCR.

Results: Genome-wide analysis of survivin binding to chromatin in activated primary CD4+ T cells was enriched (p< 10-5) and annotated to RNA polymerase II-specific DNA binding transcription factor activity (GO:0000981) with known roles in developmental processes (GO:0032502), and cell communication (GO:0010646, GO:0098742). A search in the ENDCODE ChIP database identified colocalization of survivin with the enhancer of zeste homolog 2 (FDR< 10-33) and Suz12 (FDR< 0.001%), the subunits of the Polycomb-repressive complex 2 responsible for the trimethylation of H3K27. The analysis of histone H3 bound chromatin in CD4 cells revealed colocalisation of H3K27ac, H3K27me3 and H3K4me3 marks to 3784 common peaks. A surplus of the activation marks H3K4me3 and H3K27ac was found in 74%, while 25.6% genes had a surplus of the repressive mark H3K27me3, which was in agreement with the activated cell phenotype. Alignment of survivin peaks with histone H3 marks revealed a co-localization of survinin-ChIP with H3K27me3 (82.7%) mark rather than H3K4me3 (66%) (p=0.042). Depletion of survivin in cultured CD4 cells resulted in a significant general increase in deposition of the repressive H3K27me3 mark on chromatin (FC 1.98; p< 10-24) and shifted a balance from H3K27ac and H3K4me3 marks. Only 4% of the H3K4me3 surplus peaks kept it after survivin depletion. mRNA analysis of CD4 cells showed that survivin depletion changed the transcription of the genes controlled by H3K27me3 and EZH2. Among those we found the the genes of HOX-B cluster and their partners MEIS, PKNOX and PBX1 controlling the development of anatomical structures including joints.

Conclusion: This genome-wide study suggest that survivin has important transcription regulating function. It preserves optimal levels of the repressive histone H3K27me3 mark with a potential impact on the function of HOX genes and limb pathology in RA patients.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/survivin-controls-the-transcriptional-activity-by-changing-the-pattern-of-histone-h3-marks-on-chromatin/