Ontology highlight
ABSTRACT:
PROVIDER: PRJNA774373 | ENA |
REPOSITORIES: ENA
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Project description:Age-related macular degeneration (AMD), the leading cause of blindness among the elderly, is without effective treatment for early, dry disease. Retinal pigment epithelial (RPE) cell degeneration is a cardinal feature of dry AMD. Given the reliance of photoreceptors on the RPE for maintaining health and vision, rejuvenating dysfunctional RPE is a logical treatment strategy. Here, the interplay between two cytoprotective pathways, Pink1 mediated mitophagy and the Nrf2 stress-response, was studied in human AMD tissue samples, RPE cells, and relevant mouse models. Pink1 immunolabeling was decreased in the RPE of early AMD eyes. The RPE from Pink1-/- mice and Pink1 deficient cultured human RPE cells displayed impaired mitophagy, decreased aerobic respiration, and increased mitochondrial reactive oxygen species (ROS) generation, and coincidently, developed morphological, molecular, and functional features of epithelial-mesenchymal transition (EMT). This change was triggered by novel retrograde mitochondrial to nuclear signaling that was initiated by mitochondrial ROS, which activated Nrf2 to induce TXNRD1, PI3K/AKT, and canonical EMT transcription factors Zeb1 and Snail. Nrf2 signaling was pivotal since its deficiency prevented EMT and increased cell death. A dendrimer containing N-acetyl cysteine that is tropic for the RPE and contains the mitochondrial targeting ligand Triphenyl phosphinium abrogates EMT in human RPE cells in vitro and in Pink1-/- mice. This study describes a novel interdependency of mitophagy and the Nrf2 antioxidant response in determining cell fate and introduces an RPE and mitochondrial specific ROS reducing dendrimer that can rescue RPE cells in EMT, a change recognized in early AMD.
2022-01-01 | GSE186751 | GEO
Project description:Enhancing mitophagy, a naturally-occurring cellular process for elimination of damaged mitochondria, holds great promise for the intervention of many human diseases. Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules that induce ubiquitination and subsequent proteasome-mediated degradation of a target protein through simultaneously binding to the target protein and an E3 ubiquitin ligase. However, the narrow cavity of the proteasome prevents the degradation of mitochondria. Here we show that the E3 ubiquitin ligase MAP3K1, when recruited to the outer mitochondria membrane (OMM) protein TSPO by our PROTAC-designed molecules (termed “mitophagy-enhancing chimeras”, or MECs), induced extensive K63 ubiquitination of TSPO and other OMM proteins, reminiscent of the PINK1-activated Parkin, without triggering proteasome-mediated degradation of TSPO. Aided by NBR1 and Nur77, this increased K63 ubiquitination of OMM proteins triggered mitophagy exclusively for damaged mitochondria, leading to improved mitochondria function and diminished cellular ROS. With the capability to enhance mitophagy at low nanomolar concentrations, MECs effectively inhibited NLRP3 inflammasome activation, abrogated acetaminophen-induced acute liver injury and mitigated high-fat diet-induced obesity in mice. Our work provided a proof-of-concept for developing unconventionally-acting PROTACs to achieve degradation of damaged mitochondria and possibly other organelles.
2024-02-08 | GSE255354 | GEO
Project description:PTEN-induced kinase 1 (PINK1) is a very short-lived protein that is required for the removal of damaged mitochondria through Parkin translocation and mitophagy. Because the short half-life of PINK1 limits its ability to be trafficked into neurites, local translation is required for this mitophagy pathway to be active far from the soma. The Pink1 transcript is associated with and cotransported with neuronal mitochondria. In concert with translation, the mitochondrial outer membrane protein Synaptojanin 2 Binding Protein (SYNJ2BP) and Synaptojanin 2 (SYNJ2) are required for tethering Pink1 mRNA to mitochondria via an RNA-binding domain in SYNJ2. This neuron-specific adaptation for local translation of PINK1 provides distal mitochondria with a continuous supply of PINK1 for activation of mitophagy.
2022-01-14 | GSE193443 | GEO
Project description:Malignant carcinomas that recur following therapy are typically de-differentiated and multi-drug resistant (MDR). De-differentiated cancer cells acquire MDR by upregulating reactive oxygen species (ROS)-scavenging enzymes and drug efflux pumps, but how these genes are upregulated in response to de-differentiation is not known. Here, we examine this question by using global transcriptional profiling to identify ROS-induced genes that are already upregulated in de-differentiated cells, even in the absence of oxidative damage. Using this approach, we found that the Nrf2 transcription factor, which is the master regulator of cellular response to oxidative stress, is pre-activated in de-differentiated cells. In de-differentiated cells, Nrf2 is not activated by oxidation but rather through a non-canonical mechanism involving its phosphorylation by the ER membrane kinase PERK. In contrast, differentiated cells require oxidative damage to activate Nrf2. Constitutive PERK-Nrf2 signaling protects de-differentiated cells from chemotherapy by reducing ROS levels and increasing drug efflux. These findings are validated in therapy-resistant basal breast cancer cell lines and animal models, where inhibition of the PERK-Nrf2 signaling axis reversed the MDR of de-differentiated cancer cells. Additionally, analysis of patient tumor datasets showed that a PERK pathway signature correlates strongly with chemotherapy resistance, tumor grade, and overall survival. Collectively, these results indicate that de-differentiated cells upregulate MDR genes via PERK-Nrf2 signaling, and suggest that targeting this pathway could sensitize drug-resistant cells to chemotherapy. Differentiated human breast epithelial cells (HMLE-shGFP) or de-differentiated cells (HMLE-Twist) were treated in culture with 40uM menadione for 2 hours or 1uM PERK inhibitor for 48 hours and compared to control DMSO-treated cells.
2014-10-01 | E-GEOD-59780 | biostudies-arrayexpress
Project description:Background: Epithelial-mesenchymal transition (EMT) has been implicated in metastasis, drug resistance, survival under stress and also conferring stem cell-like traits to cancer cells. We have aimed at exploring the crosstalk between ROS and an EMT induced by TGFb in breast cancer cells. Methods: We observed that cells exposed to TGFb displayed a decrease of ROS levels. Furthermore, we identified an activation of the Nrf2 transcription factor, master regulator of the antioxidant response in TGFb-induced mesenchymal cells. In order to know the effect of Nrf2 ablation in epithelial and mesenchymal cells, RNAi-mediated ablation for Nrf2 was performed. Results: RNAi-mediated ablation of Nrf2 led to mesenchymal cancer cell death due to ferroptosis, an iron- and oxidative stress-dependent cell death. Moreover, analysis revealed that several glutathione pathway genes were specifically regulated by Nrf2, suggesting a role of glutathione-related pathways in mesenchymal cell survival. Conclusion: In this study we report the criticial role of the Nrf2-mediated glutathione metabolism in the protection of metastatic breast cancer cells from ferroptosis. Therapeutic targeting of antioxidant pathways may thus be beneficial for patients with metastatic disease.
2022-10-15 | GSE187478 | GEO
Project description:Background: Epithelial-mesenchymal transition (EMT) has been implicated in metastasis, drug resistance, survival under stress and also conferring stem cell-like traits to cancer cells. We have aimed at exploring the crosstalk between ROS and an EMT induced by TGFb in breast cancer cells. Methods: We observed that cells exposed to TGFb displayed a decrease of ROS levels. To identify the antioxidant pathways activated during EMT, we investigated the effect of long-term oxidative stress, for example by H2O2 (80 µM and 150 µM), on MTflECad epithelial cells derived from the MMTV-Neu mouse model. Results: We show that long-term treated MTflEcad epithelical cells with H2O2 display both higher migratory capability and tumorigenicity. Furthermore, we identified an activation of the Nrf2 transcription factor, master regulator of the antioxidant response, in H2O2-resistant cells, as well as in TGFb-induced mesenchymal cells. Conclusion: In this study we report the criticial role of the Nrf2-mediated glutathione metabolism in the protection of metastatic breast cancer cells from ferroptosis. Therapeutic targeting of antioxidant pathways may thus be beneficial for patients with metastatic disease.
2022-10-15 | GSE187476 | GEO
Project description:Background: Epithelial-mesenchymal transition (EMT) has been implicated in metastasis, drug resistance, survival under stress and also conferring stem cell-like traits to cancer cells. We have aimed at exploring the crosstalk between ROS and an EMT induced by TGFb in breast cancer cells. Methods: We observed that cells exposed to TGFb displayed a decrease of ROS levels. To identify the antioxidant pathways activated during EMT, we investigated the effect of long-term oxidative stress, for example by H2O2 (40 µM and 60 µM), on Py2T epithelial cells derived from the MMTV-PyMT mouse model. Results: We show that long-term treated Py2T epithelical cells with H2O2 display both higher migratory capability and tumorigenicity. Furthermore, we identified an activation of the Nrf2 transcription factor, master regulator of the antioxidant response, in H2O2-resistant cells, as well as in TGFb-induced mesenchymal cells. Conclusion: In this study we report the criticial role of the Nrf2-mediated glutathione metabolism in the protection of metastatic breast cancer cells from ferroptosis. Therapeutic targeting of antioxidant pathways may thus be beneficial for patients with metastatic disease.
2022-10-15 | GSE187364 | GEO
Project description:This study aims to investigate the role and mechanism of DEK in asthmatic airway inflammation and in regulating PTEN-induced putative kinase 1 (PINK1)-Parkin mediated mitophagy, NLRP3 (NOD-like receptor family pyrin domain containing 3) inflammasome activation, and apoptosis. We found that recombinant DEK protein (rmDEK) promoted eosinophils recruitment, mitochondrial fragmentation, and outer membrane 20 (TOM20) and LC3 co-localization representing mitophagosomes in bronchoalveolar lavage fluid (BALF) in house dust mite (HDM) induced-asthma. rmDEK also reduced co-localization of mitochondrial fusion protein mitofusin1 (MFN1) and mitochondria, and the protein level of manganese superoxide dismutase (MnSOD), enhanced microtubule-associated protein1 light chain 3 (LC3) and voltage-dependent anion channels (VDAC) co-localization which also represent the mitophagosomes in airway epithelial cells, furthermore, increased dynamin-related protein 1 (DRP1) expression, PINK1-Parkin-mediated mitophagy, NLRP3 inflammasome activation, and apoptosis. In the DEK knockout mice, HDM induced asthmatic airway inflammation, MnSOD, PINK1-Parkin protein level, Parkin mediated mitophagy characterized by LC3 and Parkin co-localization in the airways, ROS generation, NLRP3 inflammation and apoptosis were fully reversed. Similar effects of rmDEK were also observed in the BEAS-2B cells, which were rescued by the autophagy inhibitor 3-MA. Moreover, DEK silencing diminished the Parkin, LC3, DRP1 translocation to mitochondria; as well as mitochondrial ROS; TOM20 and mitochondrial DNA mediated mitochondrial oxidative damage. ChIP-sequence analysis showed that DEK was enriched on the AAA domain-containing protein 3A (ATAD3A) promoter and could positively regulate ATAD3A expression. Additionally, ATAD3A was highly expressed in HDM-induced asthma models. Furthermore, ATAD3A interacted with DRP1, and knockdown of ATAD3A could down-regulate DRP1 and mitochondrial oxidative damage. Conclusively, DEK deficiency alleviates airway inflammation in asthma by down-regulating PINK1-Parkin mitophagy, NLRP3 inflammasome activation, and apoptosis. The mechanism may be through the DEK/ATAD3A/DRP1 signaling axis. Our findings may provide new potential therapeutic targets for asthma treatment.
2023-09-24 | GSE243532 | GEO
Project description:The maintenance of mitochondrial homeostasis requires PTEN-induced kinase 1 (PINK1)-dependent mitophagy, and mutations in PINK1 are associated with Parkinson's disease (PD). PINK1 is also downregulated in tumor cells with PTEN mutations. However, there is limited information concerning the role of PINK1 in tissue growth and tumorigenesis. Here, we show that loss of pink1 caused multiple growth defects independent of its pathological target, Parkin. Moreover, knocking-down pink1 in muscle cells induced hyperglycemia and limited systemic organismal growth by induction of Imaginal morphogenesis protein-Late 2 (ImpL2). Similarly, disrupting PTEN activity in multiple tissues impaired systemic growth by reducing pink1 expression, resembling wasting-like syndrome in cancer patients. Furthermore, re-expression of PINK1 fully rescued defects in carbohydrate metabolism and systemic growth induced by the tissue-specific pten mutations. Our data suggest a new function for PINK1 in regulating systemic growth in Drosophila, and shed light on its role in wasting in context of PTEN mutations.
2021-02-20 | GSE167076 | GEO
Project description:Malignant carcinomas that recur following therapy are typically de-differentiated and multi-drug resistant (MDR). De-differentiated cancer cells acquire MDR by upregulating reactive oxygen species (ROS)-scavenging enzymes and drug efflux pumps, but how these genes are upregulated in response to de-differentiation is not known. Here, we examine this question by using global transcriptional profiling to identify ROS-induced genes that are already upregulated in de-differentiated cells, even in the absence of oxidative damage. Using this approach, we found that the Nrf2 transcription factor, which is the master regulator of cellular response to oxidative stress, is pre-activated in de-differentiated cells. In de-differentiated cells, Nrf2 is not activated by oxidation but rather through a non-canonical mechanism involving its phosphorylation by the ER membrane kinase PERK. In contrast, differentiated cells require oxidative damage to activate Nrf2. Constitutive PERK-Nrf2 signaling protects de-differentiated cells from chemotherapy by reducing ROS levels and increasing drug efflux. These findings are validated in therapy-resistant basal breast cancer cell lines and animal models, where inhibition of the PERK-Nrf2 signaling axis reversed the MDR of de-differentiated cancer cells. Additionally, analysis of patient tumor datasets showed that a PERK pathway signature correlates strongly with chemotherapy resistance, tumor grade, and overall survival. Collectively, these results indicate that de-differentiated cells upregulate MDR genes via PERK-Nrf2 signaling, and suggest that targeting this pathway could sensitize drug-resistant cells to chemotherapy.
2014-10-01 | GSE59780 | GEO