scholarly journals CircHIPK3 knockdown suppresses E2F3 expression to inhibit the viability and promote the apoptosis of lens epithelial cells in age-related cataract by sponging miR-499a-5p

Author(s):  
Qichao Han ◽  
Rong Zhang ◽  
Lan Ma ◽  
Li Shao ◽  
Meiyan Feng

IntroductionCircular RNA (circRNA) is considered to be a vital regulator of disease progression, including age-related cataract (ARC). However, the molecular mechanism of circHIPK3 in ARC progression has not been fully elucidated.Material and methodsThe expression levels of circHIPK3, miR-499a-5p and E2F transcription factor 3 (E2F3) were measured by quantitative real-time PCR. Cell counting kit 8 assay and flow cytometry were performed to detect cell viability and apoptosis, respectively. Western blot analysis was employed to test the protein levels of apoptosis-related markers and E2F3. Biotin-labeled RNA pull-down assay was used to select miRNAs that could be targeted by circHIPK3, and dual-luciferase reporter assay was performed to confirm the interaction between miR-499a-5p and circHIPK3 or E2F3.ResultsCircHIPK3 is a stable circRNA that is significantly under-expressed in the anterior lens capsule tissues of ARC patients. Knockdown of circHIPK3 suppressed SRA01/04 cell viability and accelerated apoptosis. Moreover, miR-499a-5p could be targeted by circHIPK3, and its inhibitor reversed the effect of circHIPK3 silencing on cell viability and apoptosis. Furthermore, E2F3 was a target of miR-499a-5p, and its overexpression reversed the effect of miR-499a-5p on the viability and apoptosis of SRA01/04 cells. In addition, circHIPK3 positively regulated E2F3 expression by sponging miR-499a-5p.ConclusionsCircHIPK3 knockdown inhibited viability and enhanced apoptosis of lens epithelial cells to promote ARC progression by regulating miR-499a-5p/E2F3 axis.

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Wei Zheng ◽  
Guanhua Hou ◽  
Yong Li

Abstract Background Circular RNA (circRNA) has been shown to be associated with osteoarthritis (OA) progression. Circ_0116061 has been found to be highly expressed in OA cartilage tissues, but its role and mechanism in OA progression remain unclear. Methods Expression levels of circ_0116061, microRNA (miR)-200b-5p, and Smad ubiquitin regulatory factor 2 (SMURF2) were detected using quantitative real-time PCR. The proliferation and apoptosis of cells were measured using cell counting kit 8 (CCK8) assay, colony formation assay, and flow cytometry. Furthermore, the protein levels of proliferation-related marker, apoptosis-related markers, inflammatory factors, and SMURF2 were tested using western blot (WB) analysis. In addition, the interaction between miR-200b-3p and circ_0116061 or SMURF2 was examined using dual-luciferase reporter assay and biotin-labeled RNA pull-down assay. Results Circ_0116061 and SMURF2 were highly expressed, and miR-200b-3p was lowly expressed in OA cartilage tissues. Knockdown of circ_0116061 could promote the proliferation and inhibit the apoptosis and inflammation of OA chondrocytes. MiR-200b-3p could be sponged by circ_0116061, and its inhibitor could reverse the regulation of circ_0116061 silencing on the biological functions of OA chondrocytes. SMURF2 was a target of miR-200b-3p, and its expression was positively regulated by circ_0116061. Silencing of SMURF2 also could enhance the proliferation and suppress the apoptosis and inflammation of OA chondrocytes. Furthermore, the regulation of circ_0116061 silencing on the biological functions of OA chondrocytes also could be reversed by SMURF2 overexpression. Conclusion Our data showed that circ_0116061 might regulate the miR-200b-3p/SMURF2 axis to promote the progression of OA.


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.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Ting Li ◽  
Yanhong Huang ◽  
Wenkai Zhou ◽  
Qichang Yan

Background. Oxidative stress is an important factor during age-related cataract formation. Apoptosis and autophagy induced by oxidative stress have been reported as key factors in age-related cataract. In our research, we investigated the role of let-7c-3p in the regulation of autophagy and apoptosis during the formation of age-related cataract. Material and Methods. Real-time PCR and western blot were employed to detect the expression of let-7c-3p in the tissues of age-related cataract. Human lens epithelial cells (LECs) were treated with H2O2 as an age-related cataract model. The extent of apoptosis was measured by flow cytometry and western blot. To detect autophagy, immunofluorescence was used to analyze the spot number of LC3, and western blot was used to detect the expression of LC3-II/I and ATG3. The molecular mechanisms of let-7c-3p regulating autophagy via ATG3 under oxidative stress were performed by a luciferase report gene assay and rescue experiment. Results. Downregulation of let-7c-3p was found in the age-related cataract group aged >65 years relative to the age-related cataract group aged ≤65 years. Consistently, the expression of let-7c-3p was also lower under oxidative stress. The activities of LEC apoptosis and autophagy induced by oxidative stress were inhibited by let-7c-3p. By the bioinformatics database and the luciferase reporter assay, ATG3 was found to be a direct target of let-7c-3p. Let-7c-3p reduced the ATG3-mediated autophagy level, which was induced by oxidative stress in LECs. Conclusion. Let-7c-3p inhibits autophagy by targeting ATG3 in LECs in age-related cataract.


2020 ◽  
Author(s):  
Yan Wang ◽  
Quande Lin ◽  
Chunge Song ◽  
Ruojin Ma ◽  
Xiaojie Li

Abstract Background The pathogenesis of multiple myeloma (MM) is not completely known. Herein, we explored the function and the working mechanism of circular RNA circ_0007841 in MM progression. Methods Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect the expression of circ_0007841, microRNA-338-3p (miR-338-3p) and bromodomain containing 4 (BRD4). The proliferation and metastasis of MM cells were examined by cell counting kit-8 (CCK8) assay and transwell assays. Flow cytometry was conducted to assess the cell cycle and the apoptosis of MM cells. The targets of circ_0007841 and miR-338-3p were predicted by circinteractome and targetscan softwares, and these predictions were confirmed by dual-luciferase reporter assay and RNA-pull down assay. The protein levels of BRD4, phosphorylated-phosphatidylinositol 3-kinase (p-PI3K), PI3K, p-AKT serine/threonine kinase (p-AKT) and AKT were measured by Western blot assay. Exosomes were extracted using Exosome isolation kit. Results Circ_0007841 was highly expressed in bone marrow (BM)-derived plasma cells of MM patients and MM cells than that in healthy volunteers and normal plasma cells nPCs. Circ_0007841 promoted the proliferation, cell cycle and metastasis and impeded the apoptosis of MM cells. MiR-338-3p was a direct target of circ_0007841 in MM cells. Circ_0007841 accelerated the progression of MM through targeting miR-338-3p. BRD4 could directly bind to miR-338-3p in MM cells. MiR-338-3p exerted an anti-tumor role through targeting BRD4. Circ_0007841 promoted the activation of PI3K/AKT signaling via miR-338-3p/BRD4 axis. Exosomes generated from mesenchymal stromal cells (MSCs) elevated the malignant behaviors of MM cells via circ_0007841. Conclusion Circ_0007841 acted as an oncogene to promote the proliferation, cell cycle and motility and restrain the apoptosis of MM cells through sequestering miR-338-3p to up-regulate the expression of BRD4.


2021 ◽  
Vol 12 ◽  
Author(s):  
Juan Tan ◽  
Weinan Pan ◽  
Huilin Chen ◽  
Yafang Du ◽  
Peiyong Jiang ◽  
...  

Circular RNA (circRNA) is an important factor for regulating the progression of many cardiovascular diseases, including acute myocardial infarction (AMI). However, the role of circ_0124644 in AMI progression remains unclear. Hypoxia was used to induce cardiomyocytes injury. The expression of circ_0124644, microRNA (miR)-590-3p, and SRY-box transcription factor 4 (SOX4) mRNA was measured by qRT-PCR. Cell counting kit 8 (CCK8) assay and flow cytometry were utilized to detect cell viability, cell cycle progression, and apoptosis. The protein levels of apoptosis markers and SOX4 were determined by western blot (WB) analysis, and the levels of oxidative stress markers were assessed using commercial Assay Kits. Dual-luciferase reporter assay, RIP assay, and RNA pull-down assay were employed to confirm the interaction between miR-590-3p and circ_0124644 or SOX4. Circ_0124644 was upregulated in AMI patients and hypoxia-induced cardiomyocytes. Hypoxia could inhibit cardiomyocytes viability, cell cycle process, and promote apoptosis and oxidative stress, while silencing circ_0124644 could alleviate hypoxia-induced cardiomyocytes injury. In terms of mechanism, circ_0124644 could target miR-590-3p. MiR-590-3p overexpression could relieve hypoxia-induced cardiomyocytes injury. Also, the suppressive effect of circ_0124644 knockdown on hypoxia-induced cardiomyocytes injury could be reversed by miR-590-3p inhibitor. Moreover, SOX4 was found to be a target of miR-590-3p, and its overexpression also could reverse the regulation of miR-590-3p on hypoxia-induced cardiomyocytes injury. Circ_0124644 silencing could alleviate hypoxia-induced cardiomyocytes injury by regulating the miR-590-3p/SOX4 axis, suggesting that it might be a target for alleviating AMI.


2020 ◽  
Author(s):  
Shanshan Hu ◽  
Dongmei Su ◽  
Lei Sun ◽  
Zhongying Wang ◽  
Lina Guan ◽  
...  

Abstract Background: Age-related cataract (ARC) is a serious visual impairment disease, and its pathogenesis is unclear. This article aims to investigate the role of ROCK1 in the apoptosis of lens epithelial cells (LECs) in age-related cataracts. Methods: We collect anterior capsule samples from normal people, patients with age-related cataracts, young mice and naturally aging cataract mice. The Oxidative stress-induced apoptosis model was constructed by cultivating HLE-B3 cells with H2O2. MTT, Hoechst 33342, and TUNEL assay were performed to explore proliferation and apoptosis. HE assay was used to observe cell morphology. The gene and protein expression were assessed by quantitative real-time PCR, western blot, immunofluorescence, and immunohistochemical staining.Result: The results from the clinic and mice experiments showed that the numbers of lens epithelial cells from cataract individuals were less than the control individuals. In vitro, the apoptotic cells were increased in lens epithelial cells under H2O2 treatment. The ROCK1 protein level increased in the lens epithelial cells from age-related cataract patients and the old mice, respectively. Meanwhile, the up-regulation of the ROCK1 gene was associated with H2O2-induced HLE-B3 cells apoptosis. MTT and apoptosis assay showed ROCK1 was necessary in mediating H2O2-induced lens epithelial cells apoptosis through ROCK1 over-expression and knockdown experiment, respectively. Further investigation showed that p53 protein levels had been increased during ROCK1-mediated apoptosis in response to H2O2. Besides, ROCK1 phosphorylated p53 at ser15 to up-regulate its protein level. Conclusions: This study established the novel association of ROCK1/p53 signaling with lens epithelial cells apoptosis and age-related cataract genesis.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhao-Na Li ◽  
Ming-Xu Ge ◽  
Zhong-Fang Yuan

Abstract Background MicroRNAs (miRNAs) are abnormally expressed in various ocular diseases, including age-related cataract. However, the role of miR-182-5p in the progression of age-related cataract remains unclear. Methods The expression of miR-182-5p in HLE-B3 cells was detected by qRT-PCR. HLE-B3 cells were transfected with miR-182-5p mimics. CCK-8, EdU, flow cytometry, 2′,7′-dichlorodihydrofluorescein diacetate, JC-1 kit, and western blot were used to assess the cell viability, proliferation, apoptosis, reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP), and protein expression, respectively, in vitro. The relationship between miR-182-5p and NOX4 was confirmed using the dual-luciferase reporter gene analysis. Results We found that miR-182-5p expression was significantly decreased by the H2O2 exposure. Overexpression of miR-182-5p promoted cell proliferation and inhibited ROS production and apoptosis in H2O2-induced HLE-B3 cells. Moreover, p-p-38, p-ERK, and p-JNK were up-regulated in H2O2-treated HLE-B3 cells, and overexpression of miR-182-5p reversed the effects of H2O2 on HLE-B3 cells. In addition, dual-luciferase reporter assay substantiated that NOX4 was a direct target and downregulated by miR-182-5p. Conclusions We concluded that miR-182-5p inhibited lens epithelial cells apoptosis through regulating NOX4 and p38 MAPK signaling, providing a novel biomarker for treatment of age-related cataract.


2020 ◽  
Author(s):  
Zhao-Na Li ◽  
Ming-Xu Ge ◽  
Zhong-Fang Yuan

Abstract Background: MicroRNAs (miRNAs) are abnormally expressed in various ocular diseases, including age-related cataract. However, the role of miR-182-5p in the progression of age-related cataract remains unclear.Methods: The expression of miR-182-5p in HLE-B3 cells was detected by qRT-PCR. HLE-B3 cells were transfected with miR-182-5p mimics. CCK-8, EdU, flow cytometry, 2',7'-dichlorodihydrofluorescein diacetate, JC-1 kit, and western blot were used to assess the cell viability, proliferation, apoptosis, reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP), and protein expression, respectively, in vitro. The relationship between miR-182-5p and NOX4 was confirmed using the dual-luciferase reporter gene analysis.Results: We found that miR-182-5p expression was significantly decreased by the H2O2 exposure. Overexpression of miR-182-5p promoted cell proliferation and inhibited ROS production and apoptosis in H2O2-induced HLE-B3 cells. Moreover, p-p-38, p-ERK, and p-JNK were up-regulated in H2O2-treated HLE-B3 cells, and overexpression of miR-182-5p reversed the effects of H2O2 on HLE-B3 cells. In addition, dual-luciferase reporter assay substantiated that NOX4 was a direct target and downregulated by miR-182-5p.Conclusions: We concluded that miR-182-5p inhibited lens epithelial cells apoptosis through regulating NOX4 and p38 MAPK signaling, providing a novel biomarker for treatment of age-related cataract.


2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Shanshan Hu ◽  
Dongmei Su ◽  
Lei Sun ◽  
Zhongying Wang ◽  
Lina Guan ◽  
...  

Abstract Background Age-related cataract (ARC) is a serious visual impairment disease, and its pathogenesis is unclear. This article aims to investigate the role of ROCK1 in the apoptosis of lens epithelial cells (LECs) in age-related cataracts. Methods We collect anterior capsule samples from normal people, patients with age-related cataracts, young mice and naturally aging cataract mice. The oxidative stress-induced apoptosis model was constructed by cultivating HLE-B3 cells with H2O2. MTT, Hoechst 33342, and TUNEL assay were performed to explore proliferation and apoptosis. HE assay was used to observe cell morphology. The gene and protein expression were assessed by quantitative real-time PCR, western blot, immunofluorescence, and immunohistochemical staining. Result The results from the clinic and mice experiments showed that the numbers of lens epithelial cells from cataract individuals were less than the control individuals. In vitro, the apoptotic cells were increased in lens epithelial cells under H2O2 treatment. The ROCK1 protein level increased in the lens epithelial cells from age-related cataract patients and the old mice, respectively. Meanwhile, the up-regulation of the ROCK1 gene was associated with H2O2-induced HLE-B3 cells apoptosis. MTT and apoptosis assay showed ROCK1 was necessary in mediating H2O2-induced lens epithelial cells apoptosis through ROCK1 over-expression and knockdown experiment, respectively. Further investigation showed that p53 protein levels had been increased during ROCK1-mediated apoptosis in response to H2O2. Besides, ROCK1 phosphorylated p53 at ser15 to up-regulate its protein level. Conclusions This study established the novel association of ROCK1/p53 signaling with lens epithelial cells apoptosis and age-related cataract genesis.


2020 ◽  
Vol 15 (1) ◽  
pp. 848-859
Author(s):  
Wei Wei ◽  
Liefeng Ji ◽  
Wanli Duan ◽  
Jiang Zhu

AbstractCircular RNA sterile alpha motif domain containing 4A (circSAMD4A) was found to be differentially expressed in osteosarcoma and contributed to the tumorigenesis of osteosarcoma. However, the role of circSAMD4A in doxorubicin (DXR) resistance of osteosarcoma is yet to be elucidated. Levels of circSAMD4A, microRNA (miR)-218-5p and Krüppel-like factor 8 (KLF8) were detected using quantitative reverse transcription-polymerase chain reaction. Western blot was applied to detect the protein levels of KLF8, cyclin D1 and p21. Cell viability, cell cycle, migration and invasion were analyzed using Cell Counting Kit-8 assay, flow cytometry and transwell assay, respectively. The interaction between miR-218-5p and circSAMD4A or KLF8 was verified using dual-luciferase reporter assay or RNA immunoprecipitation assay. In vivo experiments were performed using murine xenograft models. CircSAMD4A and KLF8 were elevated in osteosarcoma, and knockdown of circSAMD4A or KLF8 sensitized osteosarcoma cells to DXR by mediating resistant cell viability, migration and invasion inhibition, and cell cycle arrest in vitro. miR-218-5p was decreased in osteosarcoma, and miR-218-5p inhibition enhanced DXR resistance. Besides, miR-218-5p was found to bind to circSAMD4A or KLF8, and subsequent rescue experiments indicated that miR-218-5p inhibition reversed the inhibitory effects of circSAMD4A silencing on DXR resistance, and silencing miR-218-5p enhanced DXR resistance by targeting KLF8 in osteosarcoma cells. Moreover, circSAMD4A could indirectly regulate KLF8 via miR-218-5p. Additionally, circSAMD4A knockdown enhanced the cytotoxicity of DXR in osteosarcoma in vivo via regulating miR-218-5p and KLF8. In all, circSAMD4A enhanced cell DXR resistance in osteosarcoma by regulating the miR-218-5p/KLF8 axis, suggesting a novel therapeutic target for therapy-resistant osteosarcoma.


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