Rabbit Anti-Human PDLIM4 Polyclonal Antibody

Histone H3K27 demethylase JMJD3 plays a critical role in gene expression and T cell differentiation. However, the role and mechanisms of JMJD3 in T cell trafficking remain poorly understood. Here, we show that JMJD3 deficiency in CD4(+) T cells resulted in an accumulation of T cells in the thymus and reduction of T cell number in the secondary lymphoid organs. We identified PDLIM4 as a significantly downregulated target gene in JMJD3-deficient CM4(+) T cells by gene profiling and ChIP-Seq analyses. We further showed that PDLIM4 functioned as an adaptor protein to interact with sphingosine-1 phosphate receptor 1 (S1P1) and filamentous actin (F-actin), thus serving as a key regulator of T cell trafficking. Mechanistically, JMJD3 bound to the promoter and gene-body regions of the Pdlim4 gene and regulated its expression by interacting with zinc finger transcription factor KLF2. Our findings have identified Pdlim4 as a JMJD3 target gene that affects T cell trafficking by cooperating with S1P1 and have provided insights into the molecular mechanisms by which JMJD3 regulates genes involved in T cell trafficking.

The epigenetic impact of DNA methylation in chronic myelogenous leukemia (CML) is not completely understood. To elucidate its role we analyzed 120 patients with CML for methylation of promoter-associated CpG islands of 10 genes. Five genes were identified by DNA methylation screening in the K562 cell line and 3 genes in patients with myeloproliferative neoplasms. The CDKN2B gene was selected for its frequent methylation in myeloid malignancies and ABL1 as the target of BCR-ABL translocation. Thirty patients were imatinib-naive (mostly treated by interferon-alpha before the imatinib era), 30 were imatinib-responsive, 50 were imatinib-resistant, and 10 were imatinib-intolerant. We quantified DNA methylation by bisulfite pyrosequencing. The average number of methylated genes was 4.5 per patient in the chronic phase, increasing significantly to 6.2 in the accelerated and 6.4 in the blastic phase. Higher numbers of methylated genes were also observed in patients resistant or intolerant to imatinib. These patients also showed almost exclusive methylation of a putative transporter OSCP1. Abnormal methylation of a Src suppressor gene PDLIM4 was associated with shortened survival independently of CML stage and imatinib responsiveness. We conclude that aberrant DNA methylation is associated with CML progression and that DNA methylation could be a marker associated with imatinib resistance. Finally, DNA methylation of PDLIM4 may help identify a subset of CML patients that would benefit from treatment with Src/Abl inhibitors.