scholarly journals The role of HIF‐1α in the TGF‐β2‐mediated epithelial‐to‐mesenchymal transition of human lens epithelial cells

2018 ◽  
Vol 119 (8) ◽  
pp. 6814-6827 ◽  
Author(s):  
Rooban B. Nahomi ◽  
Ram H. Nagaraj
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.


2013 ◽  
Vol 47 (8) ◽  
pp. 635-642 ◽  
Author(s):  
J. Bai ◽  
L. Dong ◽  
Z. Song ◽  
H. Ge ◽  
X. Cai ◽  
...  

2012 ◽  
Vol 449 (1) ◽  
pp. 241-251 ◽  
Author(s):  
Seok-Jo Kim ◽  
Tae-Wook Chung ◽  
Hee-Jung Choi ◽  
Choong-Hwan Kwak ◽  
Kwon-Ho Song ◽  
...  

TGF-β (transforming growth factor-β)-induced EMT (epithelial–mesenchymal transition) induces the proliferation and migration of the HLE (human lens epithelial) cells. Ganglioside GM3, simple sialic-acid-containing glycosphingolipids on mammalian cell membranes, regulates various pathological phenomena such as insulin resistance and tumour progression. However, the relationship between ganglioside GM3 and TGF-β-induced EMT in the HLE B-3 cells is poorly understood. In the present study we demonstrated that ganglioside GM3 was involved in TGF-β1-induced EMT in HLE B-3 cells. Our results indicated that the expression of ganglioside GM3 and GM3 synthase mRNA were significantly increased in TGF-β1-induced HLE B-3 cells. Reporter gene analysis also demonstrated that transcriptional activation of the GM3 synthase gene was regulated by Sp1 (specificity protein 1) in HLE B-3 cells upon TGF-β1 stimulation. Interestingly, the inhibition of ganglioside GM3 expression by d-PDMP [d-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol] and GM3 synthase shRNA (short hairpin RNA) resulted significantly in the suppression of cell migration and EMT-related signalling in HLE B-3 cells stimulated by TGF-β. Furthermore, exogenous treatment of ganglioside GM3 rescued the expression of EMT molecules and cell migration suppressed by the depletion of ganglioside GM3 in TGF-β1-induced HLE B-3 cells. We also found that ganglioside GM3 interacted with TGFβRs (TGF-β receptors) in TGF-β1-induced HLE B-3 cells. Taken together, these results suggest that ganglioside GM3 induced by TGF-β1 regulates EMT by potential interaction with TGFβRs.


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