Abstract:
Background and aims Stroke is the leading cause of adult-onset disability. Although clinical factors infuence stroke outcome, there is a signifcant variability among individuals that may be attributed to genetics and epigenetics, including DNA methylation (DNAm). We aimed to study the association between DNAm and stroke prognosis.
Methods and results To that aim, we conducted a two-phase study (discovery-replication and meta-analysis) in Caucasian patients with ischemic stroke from two independent centers (BasicMar [discovery, N=316] and St. Pau [replication, N=92]). Functional outcome was assessed using the modifed Rankin Scale (mRS) at three months after stroke, being poor outcome defned as mRS>2. DNAm was determined using the 450K and EPIC BeadChips in whole-blood samples collected within the frst 24 h. We searched for diferentially methylated positions (DMPs) in 370,344 CpGs, and candidates below p-value< 10–5 were subsequently tested in the replication cohort. We then meta-analyzed DMP results from both cohorts and used them to identify diferentially methylated regions (DMRs). After doing the epigenome-wide association study, we found 29 DMPs at p-value< 10–5 and one of them was replicated: cg24391982, annotated to thrombospondin-2 (THBS2) gene (p-valuediscovery=1.54·10–6; p-value replication=9.17·10–4; p-valuemeta-analysis=6.39·10–9). Besides, four DMRs were identifed in patients with poor outcome annotated to zinc fnger protein 57 homolog (ZFP57), Arachidonate 12-Lipoxygenase 12S Type (ALOX12), ABI Family Member 3 (ABI3) and Allantoicase (ALLC) genes (p-value<1·10–9 in all cases).
Discussion Patients with poor outcome showed a DMP at THBS2 and four DMRs annotated to ZFP57, ALOX12, ABI3 and ALLC genes. This suggests an association between stroke outcome and DNAm, which may help identify new stroke recovery mechanisms.
Methods and results To that aim, we conducted a two-phase study (discovery-replication and meta-analysis) in Caucasian patients with ischemic stroke from two independent centers (BasicMar [discovery, N=316] and St. Pau [replication, N=92]). Functional outcome was assessed using the modifed Rankin Scale (mRS) at three months after stroke, being poor outcome defned as mRS>2. DNAm was determined using the 450K and EPIC BeadChips in whole-blood samples collected within the frst 24 h. We searched for diferentially methylated positions (DMPs) in 370,344 CpGs, and candidates below p-value< 10–5 were subsequently tested in the replication cohort. We then meta-analyzed DMP results from both cohorts and used them to identify diferentially methylated regions (DMRs). After doing the epigenome-wide association study, we found 29 DMPs at p-value< 10–5 and one of them was replicated: cg24391982, annotated to thrombospondin-2 (THBS2) gene (p-valuediscovery=1.54·10–6; p-value replication=9.17·10–4; p-valuemeta-analysis=6.39·10–9). Besides, four DMRs were identifed in patients with poor outcome annotated to zinc fnger protein 57 homolog (ZFP57), Arachidonate 12-Lipoxygenase 12S Type (ALOX12), ABI Family Member 3 (ABI3) and Allantoicase (ALLC) genes (p-value<1·10–9 in all cases).
Discussion Patients with poor outcome showed a DMP at THBS2 and four DMRs annotated to ZFP57, ALOX12, ABI3 and ALLC genes. This suggests an association between stroke outcome and DNAm, which may help identify new stroke recovery mechanisms.
Funding: This work was supported by grants from the Spanish Ministry of Science and Innovation, Instituto de Salud Carlos III with the grants “Registro BASICMAR” Funding for Research in Health (PI051737), Fondos de Investigación Sanitaria ISC III (PI12/01238), (PI15/00451), (PI18/00022), (PI21/00593); Sara Borrell program, funded by Instituto de Salud Carlos III (CD22/00001, J.J.-B.); and Fondos FEDER/EDRF Spanish stroke research network INVICTUS+(RD16/0019/0002) and Grant “RICORS-ICTUS” (RD21/0006/0021) funded by Instituto de Salud Carlos III (ISCIII), and by the European Union NextGenerationEU, Mecanismo para la Recuperación y la Resiliencia (MRR). Additional support provided by the Fundació la Marató TV3 with the grant “GOD’s project. Genestroke Consor‑ tium” (76/C/2011) and Recercaixa’13 (JJ086116). Fundings were received from National Institute of Health, SiGN study, The NINDS Stroke Genetics Network Study (U01NS069208) and CaNVAS (1R01NS114045-01).