The regulation of epigenetics on bone marrow mesenchymal stem cells (BMSCs) has been a research hot spot in medical area. This paper mainly summarizes the progress of the regulation of DNA methylation, histone acetylation, small interfering RNA (siRNA) induced gene silence and microRNA (miRNA) on BMSCs. Our analysis shows that the regulation of epigenetics on BMSCs plays a significant role in the repair of bone tissue, nervous tissue and cardiac muscle.
ObjectiveTo explore the effects and molecular mechanisms of histone methylase G9a inhibitor BIX-01294 on apoptosis in esophageal squamous cell carcinoma (ESCC).MethodsMTT assay and Colony-forming Units were adopted to determine the effects of BIX-01294 on the growth and proliferation of ESCC cell lines EC109 and KYSE150. Flow cytometry was used to analyze the apoptosis status of ESCC cells after the treatment of BIX-01294. The effects of BIX-01294 treatment on the expressions of G9a catalytic product H3K9me2, DNA double-strand break (DSB) markers, and apoptosis-related proteins were detected by Western blotting.ResultsBIX-01294 inhibited the growth of EC109 and KYSE150 cells in a dose-dependent manner (P<0.05), and BIX-01294 with the inhibitory concentration 50% (IC50) significantly inhibited the formation of colony (P<0.05). After 24 hours treatment of BIX-01294 (IC50), the apoptosis rate of EC109 cells increased from 11.5%±2.1% to 42.5%±5.4%, and KYSE150 cells from 7.5%±0.9% to 49.2%±5.2% (P<0.05). The expression level of the G9a catalytic product, H3K9me2, significantly decreased (P<0.05); while the expression of the DSB marker γH2AX was dramatically enhanced (P<0.05). We also found that the mitochondrial apoptosis pathway was activated and the expression levels of cleaved caspase3 and cleaved PARP were significantly elevated (P<0.05).ConclusionBIX-01294, the inhibitor of methyltransferase G9a, prompted apoptosis in ESCC cells by inducing DSB damage and activating mitochondrial apoptosis pathway.
This study aims to construct the recombinant lentivirus vector containing specific small interfering RNA (siRNA) targeting rat CREB binding protein(CBP)gene and to identify its function of inhibiting the expressions of acetylated histone in primarily cultured hippocampal neurons. Firstly, we constructed four kinds of recombinant lentivirus siCBP. And then we used them to infect the primarily cultured hippocampal neurons, and performed real-time PCR, western blot respectively to detect the expressions of CBP. Afterwards, the most effective lentivirus siCBP was used to infect the primarily cultured hippocampal neurons, and then the HAT activity and protein expressions of acetylated histone Ac-H3, Ac-H4 of the neurons were examined. By using PCR, endonuclease cutting and gene sequencing, we confirmed that the target genes were correctly cloned in lentivirus vector. Besides, CBP mRNA and protein expressions in neurons were found to be with varying degrees of decreases after infections of the four kinds of lentivirus siCBP. Furthermore, the representative and most effective lentivirus GR806 could effectively inhibit the HAT activity and the protein expressions of Ac-H3, Ac-H4 in neurons. It provides the experimental basis for the subsequent application of siCBP to clarify the effects and corresponding molecular mechanism of the CBP-dependent histone acetylation on learning and memory function in hippocampus.
Objective To investigate the expression of the histone deacetylases 1( HDAC1) and the level of whole histone acetylation and methylation in lung T cells of asthmatic rats, and investigate their role in the pathogenesis of asthma.Methods Sixteen wistar rats were randomly divided into a control group and an asthma group( n =8 in each group) . The rats was sensitized with ovalbumin( OVA) and challenged with aerosol OVA to establish asthma model. The asthmatic ratmodel was confirmed by measurement of pulmonary function, histochemical staining, HE staining, and the levels of interleukin-4 ( IL-4 ) , interferon-gamma ( IFN-γ) and immunoglobulin E( IgE) in serum and bronchoalveolar lavage fluid ( BALF) . T cells were isolated fromrat lungs and the purity was identified. The expression of the HDAC1, the level of whole histone H3 and H4 acetylation, and whole H3K9 dimethylation were analyzed by Western blot in lung T cells. Results Compared with the control group, the protein expression of HDAC1 was significantly lower( 0. 465±0. 087 vs 0. 790 ±0. 076, P lt;0. 05) in lung T cells of the asthma group. No significant differences werefound in regard to the level of whole histone H3 and H4 acetylation and whole H3K9 dimethylation betweenthe two groups. Conclusions HDAC1 in lung T cells may be involved in the pathogenesis of asthma.Histone modification by HDAC1 may be a specific eventwith gene transcription which may not be associated with asthma.
Objective To investigate the effects of histone modification on the expression of chemokines in alveolar epithelial typeⅡ cells ( AECⅡ) in a rat model of chronic obstructive pulmonary disease ( COPD) . Methods 20 SD rats were randomly assigned to a normal control group and a COPD group. The rat model of COPD was established by cigarette smoking. Lung histological changes were observed by HE staining. AECⅡ cells were isolated and identified by alkaline phosphatase staining and electron microscopic. The mRNA expressions of monocyte chemoattractant protein ( MCP) -1, IL-8, and macrophage inflammatory protein ( MIP) -2αwere detected by real-time quantitative PCR. The expression of histone deacetylase ( HDAC) 2 was measured by western blot. Chromatin immunoprecipitation ( ChIP) was used todetect H3 and H4 acetylation, and H4K9 methylation in the promoter region of chemokine gene. Results Compared with the control group, the mRNA expressions of MCP-1, IL-8, and MIP-2αin the COPD group increased 4. 48,3. 14, and 2. 83 times, respectively. The expression of HDAC2 protein in the COPD group wassignificantly lower than in the control group ( 0. 25 ±0. 15 vs. 0. 66 ±0. 15, P lt; 0. 05) . The expression of HDAC2 had a negative correlation with the gene expressions of IL-8, MCP-1, and MIP-2α( r = - 0. 960,- 0. 914, - 0. 928, respectively, all P lt;0. 05) . The levels of H3 and H4 acetylation were higher, and H4K9 methylation level was lower in the promoter region of chemokine gene in the COPD group compared with the control group ( all P lt; 0. 05) . Conclusions MCP-1, IL-8, and MIP-2α participate and promote the lung inflammatory response in COPD. HDAC2-mediated histone modification may play an important role in COPD inflammation.
ObjectiveTo investigate the protective effects and mechanism of selective histone deacetylases 6 (HDAC6) inhibitor 23BB in myoglobin-induced proximal tubular cell lines (HK-2).MethodsHK-2 cells were divided into 5 groups, including control group, myoglobin (200 μmol/L) group, myoglobin (200 μmol/L)+23BB (1.25 nmol/L) group, myoglobin (200 μmol/L)+4-phenylbutyric acid (2 mmol/L) group, and myoglobin (200 μmol/L)+23BB (1.25 nmol/L)+tunicamycin (25 ng/mL) group. Cells were collected at 24 hours after treatment. The endoplasmic reticulum (ER) stress-related gene mRNA level and marker protein expression were evaluated by RT-PCR and Western blotting, including glucose regulated protein 78 (GRP78), C/EBP homology protein (CHOP), inositol-requiring enzyme 1 (IRE1), PKR-like ER kinase (PERK), and activating transcription factor 6.ResultsIn in vitro study, ER stress-related mRNA of GRP78, IRE1α, PERK, and CHOP and marker protein expression of GRP78 and CHOP were found to increase in response to myoglobin treatment. Either administration of 23BB or 4-PBA could alleviate myoglobin-induced these changes.ConclusionThe protective effect of HDAC6 inhibitor 23BB is through the inhibition of myoglobin-induced ER stress in HK-2 cells.
Objective To review the relationship between histone modifications and gastrointestinal cancer. Methods Literatures on histone modifications and the relationship between histone modifications and gastrointestinal cancer were collected and reviewed. Results Histone modifications played an important role in the establishment of gene silencing during tumorgenesis. DNA methylation and histone modifications might interact with each other and form a complex network to establish and maintain gene silencing. Restoring gene function silenced by epigenetic changes in cancer had the potential of ‘normalizing’ cancer cells, which was named epigenetic therapy. Epigenetic therapy was very promising in prevention and treatment of gastrointestinal cancer, but many unsolved issues remain which need to be addressed in future studies. Conclusion Histone modifications are associated with the pathogenesis of gastrointestinal cancer. Restoring gene function silenced by epigenetic changes may have a great role in the prevention and treatment of gastrointestinal cancer.