Mitochondrial Oxidative Stress-Induced Epigenetic Modif ications in Pancreatic Epithelial Cells

2014 ◽  
Vol 33 (2) ◽  
pp. 116-129 ◽  
Author(s):  
Pradyumna Kumar Mishra ◽  
Gorantla Venkata Raghuram ◽  
Deepika Jain ◽  
Subodh Kumar Jain ◽  
Naveen Kumar Khare ◽  
...  

Emerging studies have linked prooxidative carbamate compound exposures with various human pathologies including pancreatic cancer. In these studies, our aim was to examine mitochondrial oxidative stress-mediated aberrant chromatin responses in human pancreatic ductal epithelial cells. Posttranslational histone modifications, promoter DNA methylation, and micro-RNA (miRNA) expression patterns were evaluated following induction of mitochondrial oxidative stress by N-succinimidyl N-methylcarbamate exposure. In treated cells, perturbation in mitochondrial machinery led to hypermethylation of p16 and smad4 gene promoters and downregulation of respective gene products. Posttranslational histone modifications that include hypoacetylation of acetylated histone (AcH) 3 and AcH4, hypermethylation of monomethylated histone 3 at lysine 9 and trimethylated histone 4 at lysine 20 ubiquitinated histone (uH) 2A/uH2B, and increased phosphorylation of H2AX and H3 were observed in the treated cells. Altered expression of miRNAs denoted possible location of corresponding genes at oxidatively damaged fragile sites. Collectively, our results provide a direct role of mitochondrial oxidative stress-mediated epigenetic imbalance to perturbed genomic integrity in oxygen radical-induced pancreatic injury. Further, identification and characterization of molecular switches that affect these epigenomic signatures and targets thereof will be imperative to understand the complex role of redox-regulatory network in pancreatic milieu.

2011 ◽  
Vol 301 (4) ◽  
pp. F793-F801 ◽  
Author(s):  
Abolfazl Zarjou ◽  
Shanzhong Yang ◽  
Edward Abraham ◽  
Anupam Agarwal ◽  
Gang Liu

Renal fibrosis is a final stage of many forms of kidney disease and leads to impairment of kidney function. The molecular pathogenesis of renal fibrosis is currently not well-understood. microRNAs (miRNAs) are important players in initiation and progression of many pathologic processes including diabetes, cancer, and cardiovascular disease. However, the role of miRNAs in kidney injury and repair is not well-characterized. In the present study, we found a unique miRNA signature associated with unilateral ureteral obstruction (UUO)-induced renal fibrosis. We found altered expression in UUO kidneys of miRNAs that have been shown to be responsive to stimulation by transforming growth factor (TGF)-β1 or TNF-α. Among these miRNAs, miR-21 demonstrated the greatest increase in UUO kidneys. The enhanced expression of miR-21 was located mainly in distal tubular epithelial cells. miR-21 expression was upregulated in response to treatment with TGF-β1 or TNF-α in human renal tubular epithelial cells in vitro. Furthermore, we found that blocking miR-21 in vivo attenuated UUO-induced renal fibrosis, presumably through diminishing the expression of profibrotic proteins and reducing infiltration of inflammatory macrophages in UUO kidneys. Our data suggest that targeting specific miRNAs could be a novel therapeutic approach to treat renal fibrosis.


2017 ◽  
Vol Volume 13 ◽  
pp. 1633-1645 ◽  
Author(s):  
Xiaosong Bu ◽  
De Wu ◽  
Xiaomei Lu ◽  
Li Yang ◽  
Xiaoyan Xu ◽  
...  

2006 ◽  
Vol 64 (10) ◽  
pp. 31-39 ◽  
Author(s):  
José L. Quiles ◽  
Gustavo Barja ◽  
Maurizio Battino ◽  
José Mataix ◽  
Vincenzo Solfrizzi

2019 ◽  
Vol 33 (11) ◽  
pp. 12060-12072 ◽  
Author(s):  
Gema Marín‐Royo ◽  
Cristina Rodríguez ◽  
Aliaume Le Pape ◽  
Raquel Jurado‐Lopez ◽  
María Luaces ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Jiaojie Zhou ◽  
Ke Yao ◽  
Yidong Zhang ◽  
Guangdi Chen ◽  
Kairan Lai ◽  
...  

Oxidative stress plays an essential role in the development of age-related cataract. Thioredoxin binding protein-2 (TBP-2) is a negative regulator of thioredoxin (Trx), which deteriorates cellular antioxidant system. Our study focused on the autophagy-regulating effect of TBP-2 under oxidative stress in human lens epithelial cells (LECs). Human lens epithelial cells were used for cell culture and treatment. Lentiviral-based transfection system was used for overexpression of TBP-2. Cytotoxicity assay, western blot analysis, GFP/mCherry-fused LC3 plasmid, immunofluorescence, and transmission electronic microscopy were performed. The results showed that autophagic response of LECs with increased LC3-II, p62, and GFP/mCherry-LC3 puncta (P<0.01) was induced by oxidative stress. Overexpression of TBP-2 further strengthens this response and worsens the cell viability (P<0.01). Knockdown of TBP-2 attenuates the autophagic response and cell viability loss induced by oxidative stress. TBP-2 mainly regulates autophagy in the initiation stage, which is mTOR-independent and probably caused by the dephosphorylation of Akt under oxidative stress. These findings suggest a novel role of TBP-2 in human LECs under oxidative stress. Oxidative stress can cause cell injury and autophagy in LECs, and TBP-2 regulates this response. Hence, this study provides evidence regarding the role of TBP-2 in lens and the possible mechanism of cataract development.


2018 ◽  
Vol 50 (1) ◽  
pp. 246-260 ◽  
Author(s):  
Xin Liu ◽  
Chang Liu ◽  
Kun Shan ◽  
Shujie Zhang ◽  
Yi Lu ◽  
...  

Background/Aims: Age-related cataract (ARC) remains the leading cause of visual impairment among the elderly population. Long non-coding RNAs (lncRNAs) have emerged as potential regulators in many ocular diseases. However, the role of lncRNAs in nuclear ARC, a subtype of ARC, requires further elucidation. Methods: LncRNA sequencing was performed to identify differentially expressed lncRNAs between the capsules of transparent and nuclear ARC lenses. Expression validation was confirmed by qRT-PCR. MTT assay, Calcein-AM and propidium iodide double staining, Rhodamine 123 and Hoechst double staining, EdU and transwell assay were used to determine the role of H19 or miR-675 in the viability, apoptosis, proliferation and migration of primary cultured human lens epithelial cells (HLECs). Bioinformatics and luciferase reporter assays were used to identify the binding target of miR-675. Results: Sixty-three lncRNAs are differentially expressed between the capsules of transparent and nuclear ARC lenses. One top abundantly expressed lncRNA, H19, is significantly up-regulated in the nuclear ARC lens capsules and positively associated with nuclear ARC grade. H19 knockdown accelerates apoptosis development and reduces the proliferation and migration of HLECs upon oxidative stress. H19 is the precursor of miR-675, and a reduction of H19 inhibits miR-675 expression. miR-675 regulates CRYAA expression by targeting the binding site within the 3’UTR. Moreover, miR-675 increases the proliferation and migration while decreasing the apoptosis of HLECs upon oxidative stress. Conclusion: H19 regulates HLECs function through miR-675-mediated CRYAA expression. This finding would provide a novel insight into the pathogenesis of nuclear ARC.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Apor Veres-Székely ◽  
Mária Bernáth ◽  
Domonkos Pap ◽  
Réka Rokonay ◽  
Beáta Szebeni ◽  
...  

Coeliac disease (CD) is a chronic, immune-mediated small intestinal enteropathy, accompanied with gluten-triggered oxidative damage of duodenal mucosa. Previously, our research group reported an increased mucosal level of the antioxidant protein Parkinson’s disease 7 (PARK7) in children with CD. In the present study, we investigated the role of increased PARK7 level on the epithelial cell and mucosal integrity of the small intestine. The presence of PARK7 was investigated using immunofluorescent staining on duodenal mucosa of children with CD and on FHs74Int duodenal epithelial cells. To investigate the role of oxidative stress, FHs74Int cells were treated with H2O2 in the absence or presence of Comp23, a PARK7-binding compound. Intracellular accumulation of reactive oxygen species (ROS) was determined by DCFDA-based assay. Cell viability was measured by MTT, LDH, and Annexin V apoptosis assays. Disruption of cytoskeleton and cell adhesion was investigated by immunofluorescence staining and by real-time RT PCR. Effect of PARK7 on mucosal permeability was investigated ex vivo using intestinal sacs derived from control and Comp-23-pretreated mice. Comp23 treatment reduced the H2O2-induced intracellular accumulation of ROS, thus preserving the integrity of the cytoskeleton and also the viability of the FHs74Int cells. Accordingly, Comp23 treatment increased the expression of antioxidants (NRF2, TRX1, GCLC, HMOX1, NQO1), cell-cycle regulators (TP53, CDKN1A, PCNA, BCL2, BAX), and cell adhesion molecules (ZO1, CDH1, VCL, ITGB5) of H2O2-treated cells. Pretreatment with Comp23 considerably decreased the small intestinal permeability. In this study, we demonstrate that PARK7-binding Comp23 reduces the oxidative damage of duodenal epithelial cells, via increased expression of NRF2- and P53-regulated genes. Our results suggest that PARK7 plays a significant role in the maintenance of mucosal integrity in CD.


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