scholarly journals 24-Epibrassinolide, a Phytosterol from the Brassinosteroid Family, Protects Dopaminergic Cells against MPP+-Induced Oxidative Stress and Apoptosis

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Julie Carange ◽  
Fanny Longpré ◽  
Benoit Daoust ◽  
Maria-Grazia Martinoli

Oxidative stress and apoptosis are frequently cited to explain neuronal cell damage in various neurodegenerative disorders, such as Parkinson' s disease. Brassinosteroids (BRs) are phytosterols recognized to promote stress tolerance of vegetables via modulation of the antioxidative enzyme cascade. However, their antioxidative effects on mammalian neuronal cells have never been examined so far. We analyzed the ability of 24-epibrassinolide (24-Epi), a natural BR, to protect neuronal PC12 cells from 1-methyl-4-phenylpyridinium- (MPP+-) induced oxidative stress and consequent apoptosis in dopaminergic neurons. Our results demonstrate that 24-Epi reduces the levels of intracellular reactive oxygen species and modulates superoxide dismutase, catalase, and glutathione peroxidase activities. Finally, we determined that the antioxidative properties of 24-Epi lead to the inhibition of MPP+-induced apoptosis by reducing DNA fragmentation as well as the Bax/Bcl-2 protein ratio and cleaved caspase-3. This is the first time that the potent antioxidant and neuroprotective role of 24-Epi has been shown in a mammalian neuronal cell line.

Author(s):  
Aiqing Deng ◽  
Limin Ma ◽  
Xueli Zhou ◽  
Xin Wang ◽  
Shouyan Wang ◽  
...  

Autophagy has been implicated in neurodegenerative diseases. Forkhead box O3 (FoxO3) transcription factors promote autophagy in heart and inhibit oxidative damage. Here we investigate the role of FoxO3 transcription factors in regulating autophagy after oxidative stress injury in immortalized mouse hippocampal cell line (HT22). The present study confirms that hydrogen peroxide (H2O2) injury could induce autophagy and FoxO3 activation in HT22 cells. In addition, overexpression of FoxO3 enhanced H2O2-induced autophagy activation and suppressed neuronal cell damage, while knockdown of FoxO3 reduced H2O2-induced autophagy activation and exacerbated neuronal cell injury. Inhibition of autophagy by 3-Methyladenine (3-MA) resulted in reduced cell viability, increased production of reactive oxygen species (ROS), promoted nuclear condensation and decreased expression of antiapoptotic and autophagy-related proteins, indicating that autophagy may have protective effects on H2O2-induced injury in HT22 cells. Moreover, overexpression of FoxO3 prevented exacerbation of brain damage induced by 3-MA. Taken together, these results show that activation of FoxO3 could induce autophagy and inhibit H2O2-induced damage in HT22 cells. Our study demonstrates the critical role of FoxO3 in regulating autophagy in brain.


2020 ◽  
Vol 21 (12) ◽  
pp. 1216-1224
Author(s):  
Fatemeh Forouzanfar ◽  
Samira Asgharzade

Noise exposure (NE) has been recognized as one of the causes of sensorineural hearing loss (SNHL), which can bring about irreversible damage to sensory hair cells in the cochlea, through the launch of oxidative stress pathways and inflammation. Accordingly, determining the molecular mechanism involved in regulating hair cell apoptosis via NE is essential to prevent hair cell damage. However, the role of microRNAs (miRNAs) in the degeneration of sensory cells of the cochlea during NE has not been so far uncovered. Thus, the main purpose of this study was to demonstrate the regulatory role of miRNAs in the oxidative stress pathway and inflammation induced by NE. In this respect, articles related to noise-induced hearing loss (NIHL), oxidative stress, inflammation, and miRNA from various databases of Directory of Open Access Journals (DOAJ), Google Scholar, PubMed; Library, Information Science & Technology Abstracts (LISTA), and Web of Science were searched and retrieved. The findings revealed that several studies had suggested that up-regulation of miR-1229-5p, miR-451a, 185-5p, 186 and down-regulation of miRNA-96/182/183 and miR-30b were involved in oxidative stress and inflammation which could be used as biomarkers for NIHL. There was also a close relationship between NIHL and miRNAs, but further research is required to prove a causal association between miRNA alterations and NE, and also to determine miRNAs as biomarkers indicating responses to NE.


2021 ◽  
Vol 22 (11) ◽  
pp. 5590
Author(s):  
Clément Veys ◽  
Abderrahim Benmoussa ◽  
Romain Contentin ◽  
Amandine Duchemin ◽  
Emilie Brotin ◽  
...  

Chondrosarcomas are malignant bone tumors. Their abundant cartilage-like extracellular matrix and their hypoxic microenvironment contribute to their resistance to chemotherapy and radiotherapy, and no effective therapy is currently available. MicroRNAs (miRNAs) may be an interesting alternative in the development of therapeutic options. Here, for the first time in chondrosarcoma cells, we carried out high-throughput functional screening using impedancemetry, and identified five miRNAs with potential antiproliferative or chemosensitive effects on SW1353 chondrosarcoma cells. The cytotoxic effects of miR-342-5p and miR-491-5p were confirmed on three chondrosarcoma cell lines, using functional validation under normoxia and hypoxia. Both miRNAs induced apoptosis and miR-342-5p also induced autophagy. Western blots and luciferase reporter assays identified for the first time Bcl-2 as a direct target of miR-342-5p, and also Bcl-xL as a direct target of both miR-342-5p and miR-491-5p in chondrosarcoma cells. MiR-491-5p also inhibited EGFR expression. Finally, only miR-342-5p induced cell death on a relevant 3D chondrosarcoma organoid model under hypoxia that mimics the in vivo microenvironment. Altogether, our results revealed the tumor suppressive activity of miR-342-5p, and to a lesser extent of miR-491-5p, on chondrosarcoma lines. Through this study, we also confirmed the potential of Bcl-2 family members as therapeutic targets in chondrosarcomas.


Antioxidants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 522 ◽  
Author(s):  
Wang ◽  
Xiao ◽  
Huang ◽  
Liu

In this study, cell death induced by the oxidant tert-butylhydroperoxide (tBH) was observed in U2OS cells; this phenotype was rescued by Syntaxin 17 (STX17) knockout (KO) but the mechanism is unknown. STX17 plays dual roles in autophagosome–lysosome fusion and mitochondrial fission. However, the contribution of the two functions of STX17 to apoptosis has not been extensively studied. Here, we sought to dissect the dual roles of STX17 in oxidative-stress-induced apoptosis by taking advantage of STX17 knockout cells and an autophagosome–lysosome fusion defective mutant of STX17. We generated STX17 knockout U2OS cells using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system and the STX17 knockout cells were reconstituted with wild-type STX17 and its autophagosome–lysosome fusion defective mutant. Autophagy was assessed by autophagic flux assay, Monomer red fluorescent protein (mRFP)–GFP–LC3 assay and protease protection assay. Golgi, endoplasmic reticulum (ER)/ER–Golgi intermediate compartment (ERGIC) and mitochondrial dynamics were examined by staining the different indicator proteins. Apoptosis was evaluated by caspase cleavage assay. The general reactive oxygen species (ROS) were detected by flow cytometry. In STX17 complete knockout cells, sealed autophagosomes were efficiently formed but their fusion with lysosomes was less defective. The fusion defect was rescued by wild-type STX17 but not the autophagosome–lysosome fusion defective mutant. No obvious defects in Golgi, ERGIC or ER dynamics were observed. Mitochondria were significantly elongated, supporting a role of STX17 in mitochondria fission and the elongation caused by STX17 KO was reversed by the autophagosome–lysosome fusion defective mutant. The clearance of protein aggregation was compromised, correlating with the autophagy defect but not with mitochondrial dynamics. This study revealed a mixed role of STX17 in autophagy, mitochondrial dynamics and oxidative stress response. STX17 knockout cells were highly resistant to oxidative stress, largely due to the function of STX17 in mitochondrial fission rather than autophagy.


2011 ◽  
Vol 7 (6) ◽  
pp. 904-913 ◽  
Author(s):  
Maqusood Ahamed ◽  
Mohd Javed Akhtar ◽  
Mohan Raja ◽  
Iqbal Ahmad ◽  
Mohammad Kaleem Javed Siddiqui ◽  
...  

2020 ◽  
Author(s):  
Jianfeng Li ◽  
Shaoyu Hu ◽  
Song Hao ◽  
Shengjia Huang ◽  
Yi Qin ◽  
...  

Abstract Background The role of gene and pathway in recurrence of Ewing sarcoma (ES) was not clear. Thus, we investigated the biological role and underlying mechanism of gene and pathway in recurrence of ES. Methods Data sets of patients with ES were collected from the GEO database. We used dataset GSE63155 and GSE63156 to construct co-expression networks by weighted gene co-expression network analysis (WGCNA). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed by Database for Annotation, Visualization and Integrated Discovery (DAVID). Results We can find that genes with significant interactions in the genes of the recurrence group include SRSF11, TRIM39, SOCS3,NUPL2,COPS5. They work primarily through the oxidative stress pathway. Conclusion Through our research, for the first time found that ES by SRSF11 TRIM39, SOCS3, NUPL2, COPS5 interaction, activation of phosphorylation of bone and oxidative stress is affecting tumor recurrence.


Toxins ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 43 ◽  
Author(s):  
Junhua Yang ◽  
Wenbo Guo ◽  
Jianhua Wang ◽  
Xianli Yang ◽  
Zhiqi Zhang ◽  
...  

T-2 toxin, as a highly toxic mycotoxin to humans and animals, induces oxidative stress and apoptosis in various cells and tissues. Apoptosis and mitochondrial fusion/fission are two tightly interconnected processes that are crucial for maintaining physiological homeostasis. However, the role of mitochondrial fusion/fission in apoptosis of T-2 toxin remains unknown. Hence, we aimed to explore the putative role of mitochondrial fusion/fission on T-2 toxin induced apoptosis in normal human liver (HL-7702) cells. T-2 toxin treatment (0, 0.1, 1.0, or 10 μg/L) for 24 h caused decreased cell viability and ATP concentration and increased production of (ROS), as seen by a loss of mitochondrial membrane potential (∆Ψm) and increase in mitochondrial fragmentation. Subsequently, the mitochondrial dynamic imbalance was activated, evidenced by a dose-dependent decrease and increase in the protein expression of mitochondrial fusion (OPA1, Mfn1, and Mfn2) and fission (Drp1 and Fis1), respectively. Furthermore, the T-2 toxin promoted the release of cytochrome c from mitochondria to cytoplasm and induced cell apoptosis triggered by upregulation of Bax and Bax/Bcl-2 ratios, and further activated the caspase pathways. Taken together, these results indicate that altered mitochondrial dynamics induced by oxidative stress with T-2 toxin exposure likely contribute to mitochondrial injury and HL-7702 cell apoptosis.


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