Project description:Here we reported the Jmjd2a and Jmjd2c are co-targeted at the essential genes of mouse activating B220+ B cells. B cell activation programs transcription networks that subsequently induce plasma cell differentiation, but how histone demethylases participating in this process remains elusive. We found that histone demethylases Jmjd2a and Jmjd2c are expressed in Tfh-mediated signals stimulated mouse spelenic B220+ B cells. we then perform ChIP-seq by using anti-Jmjd2a and anti-Jmjd2c antibodies to identified the genes regulated by Jmjd2a and Jmjd2c and required for correct activation. Overall design: Examination the genes which are regulated by two different histone demeltylases, Jmjd2a and Jmjd2c in Tfh-mediated signals stimulated B220+ B cells by ChIP-seq.
Project description:Chromatin-associated proteins are essential for the specification and maintenance of cell identity. They exert these functions through modulating and maintaining transcriptional patterns. To elucidate the functions of the Jmjd2 family of H3K9/H3K36 histone demethylases, we generated conditional Jmjd2a/Kdm4a, Jmjd2b/Kdm4b and Jmjd2c/Kdm4c/Gasc1 single, double and triple knockout mouse embryonic stem cells (ESCs). We report that while individual Jmjd2 family members are dispensable for ESC maintenance and embryogenesis, combined deficiency for specifically Jmjd2a and Jmjd2c leads to early embryonic lethality and impaired ESC self-renewal, with spontaneous differentiation towards primitive endoderm under permissive culture conditions. We further show that Jmjd2a and Jmjd2c both localize to H3K4me3-positive promoters, where they have widespread and redundant roles in preventing accumulation of H3K9me3 and H3K36me3. Jmjd2 catalytic activity is required for ESC maintenance, and increased H3K9me3 levels in knockout ESCs compromise the expression of several Jmjd2a/c targets, including genes that are important for ESC self-renewal. Thus, continual removal of H3K9 promoter methylation by Jmjd2 demethylases represents a novel mechanism ensuring transcriptional competence and stability of the pluripotent cell identity.
Project description:Base on the privious studie from our lab, we found the histone demethylases, Jmjd2a and Jmjd2c are upregulated in stimulated primary B cells, depletion of Jmjd2a and Jmjd2c in stimulated B cells resulted in failed activation of B cells. Owimg to the essential functions of Jmjd2a and Jmjd2c, We here applied loss of function approach, such as siRNA, to study the how Jmjd2a and Jmjd2c regulate plasma cell differentiation. Overall design: Splenic B220+ B cells from total splenocytes were isolated, and treated with Tfh-derived signals. The cells were transfected with sicontrol, siJmjd2a or siJmjd2c to deplete Jmjd2a or Jmjd2c. Collected the cells and lysed the cells directly by adding TRIZOL at day 0, day 1, and day 3 after stimulation.
Project description:We have characterized the role of the Jmjd2/Kdm4 proteins in embryonic stem cell (ESC) biology, histone methylation and gene regulation. The Jmjd2 proteins are H3K9/H3K36 histone demethylases and three Jmjd2 family members are expressed in ESCs: Jmjd2a/Kdm4a, Jmjd2b/Kdm4b and Jmjd2c/Kdm4c/Gasc1. We find that specifically Jmjd2a and Jmjd2c exert redundant functions, which are essential for ESC self-renewal and early embryonic development. ChIP-seq studies show that Jmjd2a and Jmjd2c both localize to H3K4me3 marked regions, where they have general and widespread roles preventing the accumulation of especially H3K9me3, but also H3K36me3. Jmjd2 catalytic activity is required for ESC maintenance, and increased H3K9me3 levels in knockout ESCs compromise the expression of several Jmjd2a/c targets, including genes that are important for ESC self-renewal. Thus, continual removal of H3K9 promoter methylation by Jmjd2 demethylases represents a novel mechanism ensuring transcriptional competence and stability of the pluripotent cell identity. Overall design: We generated conditional Jmjd2a;Jmjd2c (2ac) double knockout ESCs (Jmjd2a(f/f);Jmjd2c(f/f);Rosa26::CreERT2) and Jmjd2a:Jmjd2b;Jmjd2c (2abc) triple knockout ESCs (Jmjd2a(f/f);Jmjd2b(f/f);Jmjd2c(f/f);Rosa26::CreERT2). 3 independently established ESC lines of 2ac and 2abc ESCs, respectively, were grown in the absence or presence of OHT leading to activation of the Cre recombinase and subsequent loss of Jmjd2 expression. Upon recovery from the OHT treatment, RNA was extracted for gene expression analyses. ESCs were cultured in 2i serum-free medium.
Project description:We have characterized the role of the Jmjd2/Kdm4 proteins in embryonic stem cell (ESC) biology, histone methylation and gene regulation. The Jmjd2 proteins are H3K9/H3K36 histone demethylases and three Jmjd2 family members are expressed in ESCs: Jmjd2a/Kdm4a, Jmjd2b/Kdm4b and Jmjd2c/Kdm4c/Gasc1. We find that specifically Jmjd2a and Jmjd2c exert redundant functions, which are essential for ESC self-renewal and early embryonic development. ChIP-seq studies show that Jmjd2a and Jmjd2c both localize to H3K4me3 marked regions, where they have general and widespread roles preventing the accumulation of especially H3K9me3, but also H3K36me3. Jmjd2 catalytic activity is required for ESC maintenance, and increased H3K9me3 levels in knockout ESCs compromise the expression of several Jmjd2a/c targets, including genes that are important for ESC self-renewal. Thus, continual removal of H3K9 promoter methylation by Jmjd2 demethylases represents a novel mechanism ensuring transcriptional competence and stability of the pluripotent cell identity. Overall design: For the identification of Jmjd2a binding patterns, ChIP experiments were performed using conditional Jmjd2a knockout ESCs (Jmjd2a(f/f);Rosa26::CreERT2). The OHT-treated sample (devoid of Jmjd2a) serves as a negative control. H3K9me3, H3K36me3, H3K4me3 and H3 distributions were mapped for conditional Jmjd2a/c double (Jmjd2a(f/f);Jmjd2c(f/f);Rosa26::CreERT2/CreERT2) and Jmjd2a/b/c triple (Jmjd2a(f/f);Jmjd2b(f/f);Jmjd2c(f/f);Rosa26::CreERT2/CreERT2) knockout ESCs grown in the absence or presence of OHT to induce loss of Jmjd2 expression. ESCs were cultured in 2i serum-free medium.
Project description:We have mapped transcriptional changes after depletion of the histone demethylases JMJD2C/GASC1/KDM4C and JMJD2A/KDM4A alone or in combination in the esophageal squamous carcinoma cell line, KYSE150. The KYSE150 cell line contains an amplification of the JMJD2C locus. RNA was extracted from KYSE150 cells transfected with shRNAs targeting JMJD2C and/or JMJD2A. The experiment was performed in triplicates and expression levels analyzed using Affymetrix microarrays.
Project description:The development of cardiovascular pathologies is partly attributed to epigenetic causes, including histone methylation, which appears to be an important marker in hearts that develop cardiac hypertrophy. Previous studies showed that the histone demethylase JMJD2A can regulate the hypertrophic process in murine cardiomyocytes. However, the influence of JMJD2A on cardiac hypertrophy in a human cardiomyocyte model is still poorly understood. In the present study, cardiomyocytes derived from human induced pluripotent stem cells (iPSCs) were used. Hypertrophy was induced by angiotensin II and endothelin-1 (ET-1), and transfections were performed to overexpress JMJD2A and for small interfering RNA (siRNA)-induced silencing of JMJD2A. Gene expression analyses were determined using RT-PCR and Western blot. The expression levels of B-type natriuretic peptide (BNP), natriuretic peptide A (ANP), and beta myosin heavy chain (?-MHC) were increased by nearly 2-10-fold with ET-1 compared with the control. However, a higher level of JMJD2A and UTX was detected, whereas the level of JMJD2C was lower. When cardiomyocytes were transiently transfected with JMJD2A, an increase close to 150% in BNP was observed, and this increase was greater after treatment with ET-1. To verify the specificity of JMJD2A activity, a knockdown was performed by means of siRNA-JMJD2A, which led to a significant reduction in BNP. The involvement of JMJD2A suggests that histone-specific modifications are associated with genes encoding proteins that are actively transcribed during the hypertrophy process. Since BNP is closely related to JMJD2A expression, we suggest that there could be a direct influence of JMJD2A on the expression of BNP. These results may be studied further to reduce cardiac hypertrophy via the regulation of epigenetic modifiers.
Project description:Recurrent prostate cancer remains a major clinical challenge. The lysine specific demethylase-1 (LSD1/KDM1A), together with the JmjC domain-containing JMJD2A and JMJD2C proteins, have emerged as critical regulators of histone lysine methylation. The LSD1-JMJD2 complex functions as a transcriptional co-regulator of hormone activated androgen and estrogen receptors at specific gene promoters. LSD1 also regulates DNA methylation and p53 function. LSD1 is overexpressed in numerous cancers including prostate cancer through an unknown mechanism. We investigated expression of the LSD1 and JMJD2A in malignant human prostate specimens. We correlated LSD1 and JMJD2A expression with known mediators of prostate cancer progression: VEGF-A and cyclin A1. We show that elevated expression of LSD1, but not JMJD2A, correlates with prostate cancer recurrence and with increased VEGF-A expression. We show that functional depletion of LSD1 expression using siRNA in prostate cancer cells decreases VEGF-A and blocks androgen induced VEGF-A, PSA and Tmprss2 expression. We demonstrate that pharmacological inhibition of LSD1 reduces proliferation of both androgen dependent (LnCaP) and independent cell lines (LnCaP: C42, PC3). We show a direct mechanistic link between LSD1 over-expression and increased activity of pro-angiogenic pathways. New therapies targeting LSD1 activity should be useful in the treatment of hormone dependent and independent prostate cancer.
Project description:Occupational and/or environmental exposure to nickel has been implicated in various types of cancer, and in vitro exposure to nickel compounds results in the accumulation of Ni(II) ions in cells. One group of major targets of Ni(II) ions inside the cell consists of Fe(II)- and ?KG-dependent dioxygenases. Using JMJD2A and JMJD2C as examples, we show that the JMJD2 family of histone demethylases, which are products of putative oncogenes as well as Fe(II)- and ?KG-dependent dioxygenases, are highly sensitive to inhibition by Ni(II) ions. In this work, X-ray absorption spectroscopy (XAS) has been used to investigate the Fe(II) active site of truncated JMJD2A and JMJD2C (1-350 amino acids) in the presence and absence of ?KG and/or substrate to obtain mechanistic details of the early steps in catalysis that precede O2 binding in histone demethylation by the JMJD2 family of histone demethylases. Zinc K-edge XAS has been performed on the resting JMJD2A (with iron in the active site) to confirm the presence of the expected structural zinc site. XAS of the Ni(II)-substituted enzymes has also been performed to investigate the inhibition of these enzymes by Ni(II) ions. Our XAS results indicate that the five-coordinate Fe(II) center in the resting enzyme is retained in the binary and ternary complexes. In contrast, the Ni(II) center is six-coordinate in the resting enzyme and binary and ternary complexes. XAS results indicate that both Fe(II) and Ni(II) bind ?KG in the binary and ternary complexes. The electron density buildup that is observed at the Fe(II) center in the presence of ?KG and substrate is not observed at the Ni(II) center. Thus, both electronic and steric factors are responsible for Ni-induced inhibition of the JMJD2 family of histone demethylases. Ni-induced inhibition of these enzymes may explain the alteration of the epigenetic mechanism of gene expression that is responsible for Ni-induced carcinogenesis.
Project description:The transcriptional changes that occur in response to oxidative stress help direct the decision to maintain cell viability or enter a cell death pathway. Cyclin C-Cdk8 is a conserved kinase that associates with the RNA polymerase II Mediator complex that stimulates or represses transcription depending on the locus. In response to oxidative stress, cyclin C, but not Cdk8, displays partial translocation into the cytoplasm. These findings open the possibility that cyclin C relocalization is a regulatory mechanism governing oxidative stress-induced transcriptional changes. In the present study, the cyclin C-dependent transcriptome was determined and compared to transcriptional changes occurring in oxidatively stressed Mus musculus embryonic fibroblasts. We observed a similar number (∼2000) of genes up or downregulated in oxidatively stressed cells. Induced genes include cellular repair/survival factors while repressed loci were generally involved in proliferation or differentiation. Depleting cyclin C in unstressed cells produced an approximately equal number of genes (∼2400) that were repressed by, or whose transcription required, cyclin C. Consistent with the possibility that cyclin C nuclear release contributes to transcriptional remodeling in response to oxidative stress, we found that 37% cyclin C-dependent genes were downregulated following stress. Moreover, 20% of cyclin C- repressed genes were induced in response to stress. These findings are consistent with a model that cyclin C relocalization to the cytoplasm, and corresponding inactivation of Cdk8, represents a regulatory mechanism to repress and stimulate transcription of stress-responsive genes.