scholarly journals Involvement of Histone Lysine Methylation in p21 Gene Expression in Rat KidneyIn Vivoand Rat Mesangial CellsIn Vitrounder Diabetic Conditions

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Xiangjun Li ◽  
Chaoyuan Li ◽  
Xiaoxia Li ◽  
Peihe Cui ◽  
Qifeng Li ◽  
...  

Diabetic nephropathy (DN), a common complication associated with type 1 and type 2 diabetes mellitus (DM), characterized by glomerular mesangial expansion, inflammation, accumulation of extracellular matrix (ECM) protein, and hypertrophy, is the major cause of end-stage renal disease (ESRD). Increasing evidence suggested that p21-dependent glomerular and mesangial cell (MC) hypertrophy play key roles in the pathogenesis of DN. Recently, posttranscriptional modifications (PTMs) have uncovered novel molecular mechanisms involved in DN. However, precise regulatory mechanism of histone lysine methylation (HKme) mediating p21 related hypertrophy associated with DN is not clear. We evaluated the roles of HKme and histone methyltransferase (HMT) SET7/9 in p21 gene expression in glomeruli of diabetic rats and in high glucose- (HG-) treated rat mesangial cells (RMCs). p21 gene expression was upregulated in diabetic rats glomeruli; chromatin immunoprecipitation (ChIP) assays showed decreased histone H3-lysine9-dimethylation (H3K9me2) accompanied with enhanced histone H3-lysine4-methylation (H3K4me1/3) and SET7/9 occupancies at the p21 promoter. HG-treated RMCs exhibited increased p21 mRNA, H3K4me level, SET7/9 recruitment, and inverse H3K9me, which were reversed by TGF-β1 antibody. These data uncovered key roles of H3Kme and SET7/9 responsible for p21 gene expressionin vivoandin vitrounder diabetic conditions and confirmed preventive effect of TGF-β1 antibody on DN.

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Liping Dou ◽  
Fei Yan ◽  
Jiuxia Pang ◽  
Dehua Zheng ◽  
Dandan Li ◽  
...  

Abstract The oncogenic fusion protein AML1-ETO retains the ability of AML1 to interact with the enhancer core DNA sequences, but blocks AML1-dependent transcription. Previous studies have shown that post-translational modification of AML1-ETO may play a role in its regulation. Here we report that AML1-ETO-positive patients, with high histone lysine methyltransferase Enhancer of zeste homolog 1 (EZH1) expression, show a worse overall survival than those with lower EZH1 expression. EZH1 knockdown impairs survival and proliferation of AML1-ETO-expressing cells in vitro and in vivo. We find that EZH1 WD domain binds to the AML1-ETO NHR1 domain and methylates AML1-ETO at lysine 43 (Lys43). This requires the EZH1 SET domain, which augments AML1-ETO-dependent repression of tumor suppressor genes. Loss of Lys43 methylation by point mutation or domain deletion impairs AML1-ETO-repressive activity. These findings highlight the role of EZH1 in non-histone lysine methylation, indicating that cooperation between AML1-ETO and EZH1 and AML1-ETO site-specific lysine methylation promote AML1-ETO transcriptional repression in leukemia.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Qiaoyan Guo ◽  
Xiaoxia Li ◽  
Hongbo Han ◽  
Chaoyuan Li ◽  
Shujun Liu ◽  
...  

Transforming growth factor beta1- (TGF-β1-) induced p21-dependent mesangial cell (MC) hypertrophy plays a key role in the pathogenesis of chronic renal diseases including diabetic nephropathy (DN). Increasing evidence demonstrated the role of posttranscriptional modifications (PTMs) in the event; however, the precise regulatory mechanism of histone lysine methylation remains largely unknown. Here, we examined the roles of both histone H3 lysine 4 and lysine 9 methylations (H3K4me/H3K9me) in TGF-β1 induced p21 gene expression in rat mesangial cells (RMCs). Our results indicated that TGF-β1 upregulated the expression of p21 gene in RMCs, which was positively correlated with the increased chromatin marks associated with active genes (H3K4me1/H3K4me2/H3K4me3) and negatively correlated with the decreased levels of repressive marks (H3K9me2/H3K9me3) at p21 gene promoter. TGF-β1 also elevated the recruitment of the H3K4 methyltransferase (HMT) SET7/9 to the p21 gene promoter. SET7/9 gene silencing with small interfering RNAs (siRNAs) significantly abolished the TGF-β1 induced p21 gene expression. Taken together, these results reveal the key role of histone H3Kme in TGF-β1 mediated p21 gene expression in RMC, partly through HMT SET7/9 occupancy, suggesting H3Kme and SET7/9 may be potential renoprotective agents in managing chronic renal diseases.


2004 ◽  
Vol 16 (2) ◽  
pp. 87 ◽  
Author(s):  
Le Ann Blomberg ◽  
Kurt A. Zuelke

Functional genomics provides a powerful means for delving into the molecular mechanisms involved in pre-implantation development of porcine embryos. High rates of embryonic mortality (30%), following either natural mating or artificial insemination, emphasise the need to improve the efficiency of reproduction in the pig. The poor success rate of live offspring from in vitro-manipulated pig embryos also hampers efforts to generate transgenic animals for biotechnology applications. Previous analysis of differential gene expression has demonstrated stage-specific gene expression for in vivo-derived embryos and altered gene expression for in vitro-derived embryos. However, the methods used to date examine relatively few genes simultaneously and, thus, provide an incomplete glimpse of the physiological role of these genes during embryogenesis. The present review will focus on two aspects of applying functional genomics research strategies for analysing the expression of genes during elongation of pig embryos between gestational day (D) 11 and D12. First, we compare and contrast current methodologies that are being used for gene discovery and expression analysis during pig embryo development. Second, we establish a paradigm for applying serial analysis of gene expression as a functional genomics tool to obtain preliminary information essential for discovering the physiological mechanisms by which distinct embryonic phenotypes are derived.


Blood ◽  
1996 ◽  
Vol 88 (1) ◽  
pp. 114-123 ◽  
Author(s):  
S Matikainen ◽  
T Ronni ◽  
M Hurme ◽  
R Pine ◽  
I Julkunen

All-trans-retinoic acid (ATRA) is the drug of choice in the treatment of acute promyelocytic leukemia (APL). ATRA induces both in vitro and in vivo differentiation of APL cells into mature granulocytes. However, the molecular mechanisms involved in ATRA-dependent growth inhibition and cellular differentiation are not presently understood. The NB4 cell line, which is derived from the bone marrow of a patient with APL during relapse, can be used as a model system to study the growth and differentiation of APL cells. Because interferon (IFN) regulatory factors (IRF-1 and IRF-2) and other IFN-inducible gene products regulate cell growth, we analyzed the effects of ATRA on the expression of these genes. We show that ATRA directly activates IRF-1 gene expression, followed by activation of IRF-2 and 2′–5′ oligoadenylate synthetase (OAS) gene expression with slower kinetics. In addition to NB4 cells, ATRA also activated IRF-1 gene expression in HL-60, U937, and THP-1 cells, which all respond to ATRA by growth inhibition. A more than additive increase in IRF-1 gene expression was seen with ATRA and IFN-gamma in NB4 cells. ATRA did not activate nuclear factor kappa B or signal transducer and activator of transcription (STAT) activation pathways, suggesting that an alternate mechanism is involved in IRF-1 gene activation. The ATRA-induced expression of IRF-1, an activator of transcription and repressor of transformation, may be one of the molecular mechanisms of ATRA-induced growth inhibition, and the basis for the synergistic actions of ATRA and IFNs in myeloid leukemia cells.


2020 ◽  
Vol 477 (19) ◽  
pp. 3833-3838
Author(s):  
Jie Gao ◽  
Bin Wang ◽  
Huijuan Yu ◽  
Gao Wu ◽  
Cuihong Wan ◽  
...  

Post-translational modifications play important roles in mediating protein functions in a wide variety of cellular events in vivo. HEMK2–TRMT112 heterodimer has been reported to be responsible for both histone lysine methylation and eukaryotic release factor 1 (eRF1) glutamine methylation. However, how HEMK2–TRMT112 complex recognizes and catalyzes eRF1 glutamine methylation is largely unknown. Here, we present two structures of HEMK2–TRMT112, with one bound to SAM and the other bound with SAH and methylglutamine (Qme). Structural analyses of the post-catalytic complex, complemented by mass spectrometry experiments, indicate that the HEMK2 utilizes a specific pocket to accommodate the substrate glutamine and catalyzes the subsequent methylation. Therefore, our work not only throws light on the protein glutamine methylation mechanism, but also reveals the dual activity of HEMK2 by catalyzing the methylation of both Lys and Gln residues.


2014 ◽  
Vol 14 (1) ◽  
pp. 25
Author(s):  
Masayo Morishita ◽  
Damiaan Mevius ◽  
Eric di Luccio

2021 ◽  
Author(s):  
Jordi Hintzen ◽  
Yan Luo ◽  
Miriam Porzberg ◽  
Paul White ◽  
Jie Jian ◽  
...  

Histone lysine methylation and acetylation are important posttranslational modifications that regulate gene expression in humans. Due to the interplay of these two modifications, new chemical methods to study lysine posttranslational...


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Imke Kirste ◽  
Tilanthi M Jayawardena ◽  
J. A Payne ◽  
Victor J Dzau ◽  
Maria Mirotsou

Rationale: Regeneration of damaged cardiac tissue after injury presents a daunting challenge in cardiovascular medicine. Recent developments in reprogramming of somatic cells directly to cells of other lineages have raised the possibility of using this approach for cardiac regenerative therapy. Our group recently demonstrated successful miRNA mediated cardiac reprogramming in vitro and in vivo using a combination of miRNAs 1, 133, 206 and 499. Although, the molecular mechanisms underlying miRNA mediated fibroblast reprogramming to cardiomyocytes are yet unknown, accumulating evidence suggest that reprogramming acts through distinct phases and that histone modifications play an important role in these processes. Objective: Identify key genes involved in initiating miRNA mediated reprogramming via histone modifications. Methods and Results: For this, we analyzed the expression levels of 81 different genes involved in chromatin modification 4 days after miRNA transfection using PCR arrays. This analysis revealed that 6 of the 81 tested genes showed differential gene expression (≤-1.5-fold and p <0.02). JAK inhibitor-1 treatment, known for increasing reprogramming efficiency, further enhanced gene expression changes in 5 of these 6 genes. Setdb2, an H3K9 methyltransferase, was one of the most down-regulated targets 4 days after miRNA transfection (-1.4 fold, p<0.001). This effect was enhanced further when miRNAs were combined with the JAK inhibitor-1 (-2.6 fold, p<0.001). Silencing of Setdb2 using siRNAs further accentuated miRNA cardiac reprogramming as measured by cardiac transcription factor expression at 3 days and 6 days post treatment. Similar trends were observed by FACS analysis detecting increased percentage of αMHC-positive cells in siRNA treated fibroblasts compared to control treated only with the miRNA combination. Interestingly, our data showed that Setdb2 silencing alone was sufficient to initiate cardiac reprogramming, suggesting that Setdb2 might play a crucial role in defining cardiac cell fate. Conclusion: In conclusion our results indicate that Setdb2 down-regulation plays an important role in the direct reprogramming of fibroblasts to cardiomyocyte-like cells.


2007 ◽  
Vol 178 (6) ◽  
pp. 925-936 ◽  
Author(s):  
Roberta Benetti ◽  
Susana Gonzalo ◽  
Isabel Jaco ◽  
Gunnar Schotta ◽  
Peter Klatt ◽  
...  

Mammalian telomeres have heterochromatic features, including trimethylated histone H3 at lysine 9 (H3K9me3) and trimethylated histone H4 at lysine 20 (H4K20me3). In addition, subtelomeric DNA is hypermethylated. The enzymatic activities responsible for these modifications at telomeres are beginning to be characterized. In particular, H4K20me3 at telomeres could be catalyzed by the novel Suv4-20h1 and Suv4-20h2 histone methyltransferases (HMTases). In this study, we demonstrate that the Suv4-20h enzymes are responsible for this histone modification at telomeres. Cells deficient for Suv4-20h2 or for both Suv4-20h1 and Suv4-20h2 show decreased levels of H4K20me3 at telomeres and subtelomeres in the absence of changes in H3K9me3. These epigenetic alterations are accompanied by telomere elongation, indicating a role for Suv4-20h HMTases in telomere length control. Finally, cells lacking either the Suv4-20h or Suv39h HMTases show increased frequencies of telomere recombination in the absence of changes in subtelomeric DNA methylation. These results demonstrate the importance of chromatin architecture in the maintenance of telomere length homeostasis and reveal a novel role for histone lysine methylation in controlling telomere recombination.


2016 ◽  
Vol 310 (10) ◽  
pp. L940-L954 ◽  
Author(s):  
Irina G. Luzina ◽  
Virginia Lockatell ◽  
Sang W. Hyun ◽  
Pavel Kopach ◽  
Phillip H. Kang ◽  
...  

Idiopathic pulmonary fibrosis (IPF) poses challenges to understanding its underlying cellular and molecular mechanisms and the development of better therapies. Previous studies suggest a pathophysiological role for neuraminidase 1 (NEU1), an enzyme that removes terminal sialic acid from glycoproteins. We observed increased NEU1 expression in epithelial and endothelial cells, as well as fibroblasts, in the lungs of patients with IPF compared with healthy control lungs. Recombinant adenovirus-mediated gene delivery of NEU1 to cultured primary human cells elicited profound changes in cellular phenotypes. Small airway epithelial cell migration was impaired in wounding assays, whereas, in pulmonary microvascular endothelial cells, NEU1 overexpression strongly impacted global gene expression, increased T cell adhesion to endothelial monolayers, and disrupted endothelial capillary-like tube formation. NEU1 overexpression in fibroblasts provoked increased levels of collagen types I and III, substantial changes in global gene expression, and accelerated degradation of matrix metalloproteinase-14. Intratracheal instillation of NEU1 encoding, but not control adenovirus, induced lymphocyte accumulation in bronchoalveolar lavage samples and lung tissues and elevations of pulmonary transforming growth factor-β and collagen. The lymphocytes were predominantly T cells, with CD8+ cells exceeding CD4+ cells by nearly twofold. These combined data indicate that elevated NEU1 expression alters functional activities of distinct lung cell types in vitro and recapitulates lymphocytic infiltration and collagen accumulation in vivo, consistent with mechanisms implicated in lung fibrosis.


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