Hyperosmotic stress induces 2-cell-like cells through ROS and ATR signaling
Ontology highlight
ABSTRACT:
SUBMITTER: Dr. Antoine Canat
PROVIDER: S-SCDT-10_15252-EMBR_202256194 | biostudies-other |
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Mouse embryonic stem cells (ESCs) display pluripotency features characteristic of the inner cell mass of the blastocyst. ESC cultures are highly heterogeneous and include a rare population of cells, which recapitulate characteristics of the 2-cell embryo, referred to as 2-cell-like cells (2CLCs). Whether and how ESC and 2CLC respond to environmental cues has not been fully elucidated. Here, we investigate the impact of mechanical stress on the reprogramming of ESC to 2CLC. We show that hyperosmotic stress induces 2CLC and that this induction can occur even after a recovery time from hyperosmotic stress, suggesting a memory response. Hyperosmotic stress in ESCs leads to accumulation of reactive-oxygen species (ROS) as well as ATR checkpoint activation. Importantly, preventing either elevated ROS levels or ATR activation impairs hyperosmotic-mediated 2CLC induction. We further show that ROS generation and the ATR checkpoint act within the same molecular pathway in response to hyperosmotic stress to induce 2CLCs. Altogether, these results shed light on the response of ESC to mechanical stress and on our understanding of 2CLC reprogramming.
2023-08-15 | GSE231475 | GEO
Project description:Osmotic changes occur in many tissues and profoundly influence cell function. Herein, we investigated the effect of hyperosmotic stress on retinal pigmented epithelial (RPE) cells using a microarray approach. Upon 4-h exposure to 100 mM NaCl or 200 mM sucrose, 79 genes were downregulated and 72 upregulated. Three gene ontology categories were significantly modulated: cell proliferation, transcription from RNA polymerase II promoter and response to abiotic stimulus. Fluorescent-activated cell sorting analysis further demonstrated that owing to hyperosmotic stimulation for 24 h, cell count and cell proliferation, as well as the percentage of cells in G0/G1 and S phases were significantly decreased, whereas the percentage of cells in G2/M phases increased, and apoptosis and necrosis remained unaffected. Accordingly, hyperosmotic conditions induced a decrease of cyclin B1 and D1 expression, and an activation of the p38 mitogen-activated protein kinase. In conclusion, our results demonstrate that hypertonic conditions profoundly affect RPE cell gene transcription regulating cell proliferation by downregulation cyclin D1 and cyclin B1 protein expression.
| S-EPMC3702301 | biostudies-literature
Project description:The aggregation of alpha-synuclein (?-syn) is a pathological feature of a number of neurodegenerative conditions, including Parkinson's disease. Genetic mutations, abnormal protein synthesis, environmental stress, and aging have all been implicated as causative factors in this process. The importance of water in the polymerisation of monomers, however, has largely been overlooked. In the present study, we highlight the role of hyperosmotic stress in inducing human ?-syn to aggregate in cells in vitro, through rapid treatment of the cells with three different osmolytes: sugar, salt and alcohol. This effect is cell-dependent and not due to direct protein-osmolyte interaction, and is specific for ?-syn when compared to other neurodegeneration-related proteins, such as Tau or Huntingtin. This new property of ?-syn not only highlights a unique aspect of its behaviour which may have some relevance for disease states, but may also be useful as a screening test for compounds to inhibit the aggregation of ?-syn in vitro.
| S-EPMC6381101 | biostudies-literature
Project description:Epithelial-mesenchymal transition (EMT) of tubular epithelial cells is a hallmark of renal tubulointerstitial fibrosis and is associated with chronic renal injury as well as acute renal injury. As one of the incidences and risk factors for acute renal injury, increasing the osmolality in the proximal tubular fluid by administration of intravenous mannitol has been reported, but the detailed mechanisms remain unclear. Hyperosmotic conditions caused by mannitol in the tubular tissue may generate not only osmotic but also mechanical stresses, which are known to be able to induce EMT in epithelial cells, thereby contributing to renal injury. Herein, we investigate the effect of hyperosmolarity on EMT in tubular epithelial cells. Normal rat kidney (NRK)-52E cells were exposed to mannitol-induced hyperosmotic stress. Consequently, the hyperosmotic stress led to a reduced expression of the epithelial marker E-cadherin and an enhanced expression of the mesenchymal marker, α-smooth muscle actin (α-SMA), which indicates an initiation of EMT in NKR-52E cells. The hyperosmotic condition also induced time-dependent disassembly and rearrangements of focal adhesions (FAs) concomitant with changes in actin cytoskeleton. Moreover, prevention of FAs rearrangements by cotreatment with Y-27632, a Rho-associated protein kinase inhibitor, could abolish the effects of hyperosmotic mannitol treatment, thus attenuating the expression of α-SMA to the level in nontreated cells. These results suggest that hyperosmotic stress may induce EMT through FAs rearrangement in proximal tubular epithelial cells.
| S-EPMC8691603 | biostudies-literature
Project description:PURPOSE:The activation of ROS-NLRP3-IL-1? signaling axis induced by hyperosmotic stress (HS) has been recognized as a key priming stage of epithelial inflammation in dry eye pathogenesis. The current study aims to investigate whether calcitriol, the active metabolite of vitamin D3, could protect cells against HS-induced inflammation through modulating this critical step. METHODS:Human corneal epithelial cells (iHCECs) were cultured in hyperosmotic medium (450 mOsM) with various concentrations of calcitriol. Small interfering RNA (siRNA) was used to knock down the expression of vitamin D receptor (VDR) in iHCECs. NLRP3 activation and IL-1? generation were detected by RT-qPCR or ELISA, respectively. Oxidative stress markers including ROS and 8-OHdG were examined by fluorometric analysis. The nuclear translocation of NRF2 was assessed by western blotting. RESULTS:Calcitriol could protect cells against HS-induced injury through inhibiting ROS-NLRP3-IL-1? signaling axis. Calcitriol remarkably suppressed the expression of NLRP3 inflammasome related genes and the production of IL-1? in cells that were exposed to HS. It could also significantly attenuate HS-induced oxidative stress, shown as the reduced intracellular ROS generation and 8-OHdG staining cells after calcitriol treatment. Calcitriol induced the translocation of NRF2 to the nucleus, and thereby triggered the expression of several antioxidant enzymes. CONCLUSION:The current study indicated that calcitriol could inhibit the priming stage of HS-induced cellular inflammation, highlighting its potential capacity to prevent and mitigate dry eye related corneal inflammation at an earlier stage.
| S-EPMC6313824 | biostudies-other
Project description:Breast cancer (BC) is the leading cause of cancer-related deaths among women worldwide. Ginsenosides exhibit anticancer activity against various cancer cells. However, the effects of ginsenoside Rh1 on BC and the underlying mechanisms remain unknown. Here, we investigated the anticancer effects of Rh1 on human BC MCF-7 and HCC1428 cells and the underlying signaling pathways. The anticancer effects of Rh1 in vitro were evaluated using sulforhodamine B (SRB), 3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), clonogenic assay, propidium iodide (PI)/Hoechst staining, Western blotting, flow cytometry, and immunofluorescence analysis. The in vivo effects of Rh1 were determined using a xenograft model via hematoxylin and eosin and the immunohistochemistry staining of tumor tissues. We found that Rh1 exerted cytotoxicity in the cells by increasing cell apoptosis, autophagy, and cell cycle arrest. These effects were further enhanced by a phosphatidylinositol 3-kinase (PI3K) inhibitor but were rescued by the inhibition of reactive oxygen species (ROS). Moreover, enhanced ROS generation by Rh1 inhibited the activation of the PI3K/Akt pathway. Consistently, Rh1 treatment significantly reduced tumor growth in vivo and increased the ROS production and protein expression of LC3B and cleaved caspase-3 but decreased the phosphorylation of Akt and retinoblastoma (Rb) in tumor tissues. Taken together, Rh1 exerted a potential anticancer effect on BC cells by inducing cell cycle arrest, apoptosis, and autophagy via inhibition of the ROS-mediated PI3K/Akt pathway.
| S-EPMC8071122 | biostudies-literature
Project description:Aquaporins (AQPs) are important mediators of water permeability and are closely associated with tumor cell proliferation, migration, angiogenesis and chemoresistance. Moreover, the chemosensitivity of tumor cells to cisplatin (CDDP) is potentially affected by osmotic pressure. The present study was undertaken to determine whether hyperosmosis regulates ovarian cancer cell sensitivity to CDDP in vitro and to explore whether this is associated with AQP expression. The hyperosmotic stress was induced by D-sorbitol. 3AO ovarian cancer cells were treated with different concentrations of hypertonic medium and/or CDDP for various times, followed by measuring the inhibition rate of cell proliferation using an MTT assay. In addition, AQP expression in response to osmotic pressure and/or CDDP was measured by reverse transcription-quantitative polymerase chain reaction and western blotting. Cell proliferation in response to hypertonic stress was also measured when AQP5 was knocked down by small interfering (si)RNA. 3AO cell proliferation was inhibited by hyperosmotic stress, while the expression of AQP5, but not that of AQP1, AQP3 or AQP9, was increased in a dose- and time-dependent manner in hypertonic sorbitol-containing medium. When AQP5 was silenced by siRNA, cells were susceptible to hypertonic stress. MTT analyses showed that the inhibition of cell proliferation by a low dose of CDDP increased significantly with exposure to a hyperosmotic stimulus, and this effect was reduced when a high dose of CDDP was used. AQP5 expression was induced by a low dose of CDDP, but was reduced by a high dose of CDDP. However, hyperosmosis enhanced AQP5 mRNA expression at every dose of CDDP tested, compared with isotonic medium. With prolonged treatment time, AQP5 expression was reduced by CDDP in hypertonic and isotonic culture medium. Thus, the effects of hyperosmosis on cell sensitivity to CDDP were associated with AQP5 expression. These results suggest that AQP5 expression in ovarian cancer cells is induced by hypertonic medium, and that the sensitivity of ovarian cancer cells to CDDP can be regulated by hyperosmosis associated with AQP5 expression.
| S-EPMC4665691 | biostudies-literature
Project description:Cadmium is a toxic heavy metal which is environmentally and occupationally relevant. The mechanisms underlying cadmium-induced autophagy are not yet completely understood. The present study shows that cadmium induces autophagy, as demonstrated by the increase of LC3-II formation and the GFP-LC3 puncta cells. The induction of autophagosomes was directly visualized by electron microscopy in cadmium-exposed skin epidermal cells. Blockage of LKB1 or AMPK by siRNA transfection suppressed cadmium-induced autophagy. Cadmium-induced autophagy was inhibited in dominant-negative AMPK-transfected cells, whereas it was accelerated in cells transfected with the constitutively active form of AMPK. mTOR signaling, a negative regulator of autophagy, was downregulated in cadmium-exposed cells. In addition, cadmium generated reactive oxygen species (ROS) at relatively low levels, and caused poly(ADP-ribose) polymerase-1 (PARP) activation and ATP depletion. Inhibition of PARP by pharmacological inhibitors or its siRNA transfection suppressed ATP reduction and autophagy in cadmium-exposed cells. Furthermore, cadmium-induced autophagy signaling was attenuated by either exogenous addition of catalase and superoxide dismutase, or by overexpression of these enzymes. Consequently, these results suggest that cadmium-mediated ROS generation causes PARP activation and energy depletion, and eventually induces autophagy through the activation of LKB1-AMPK signaling and the down-regulation of mTOR in skin epidermal cells.
| S-EPMC3439510 | biostudies-literature
Project description:Over recent decades, many studies have reported that hypocrellin A (HA) can eliminate cancer cells with proper irradiation in several cancer cell lines. However, the precise molecular mechanism underlying its anticancer effect has not been fully defined. HA-mediated cytotoxicity and apoptosis in human lung adenocarcinoma A549 cells were evaluated after photodynamic therapy (PDT). A temporal quantitative proteomics approach by isobaric tag for relative and absolute quantitation (iTRAQ) 2D liquid chromatography with tandem mass spectrometric (LC-MS/MS) was introduced to help clarify molecular cytotoxic mechanisms and identify candidate targets of HA-induced apoptotic cell death. Specific caspase inhibitors were used to further elucidate the molecular pathway underlying apoptosis in PDT-treated A549 cells. Finally, down-stream apoptosis-related protein was evaluated. Apoptosis induced by HA was associated with cell shrinkage, externalization of cell membrane phosphatidylserine, DNA fragmentation, and mitochondrial disruption, which were preceded by increased intracellular reactive oxygen species (ROS) generations. Further studies showed that PDT treatment with 0.08 µmol/L HA resulted in mitochondrial disruption, pronounced release of cytochrome c, and activation of caspase-3, -9, and -7. Together, HA may be a possible therapeutic agent directed toward mitochondria and a promising photodynamic anticancer candidate for further evaluation.
| S-EPMC6437636 | biostudies-literature
Project description:Galiellalactone (GL) is a fungal metabolite that presents antitumor activities on prostate cancer in vitro and in vivo. In this study we show that GL induced cell cycle arrest in G2/M phase, caspase-dependent apoptosis and also affected the microtubule organization and migration ability in DU145 cells. GL did not induce double strand DNA break but activated the ATR and ATM-mediated DNA damage response (DDR) inducing CHK1, H2AX phosphorylation (fH2AX) and CDC25C downregulation. Inhibition of the ATM/ATR activation with caffeine reverted GL-induced G2/M cell cycle arrest, apoptosis and DNA damage measured by fH2AX. In contrast, UCN-01, a CHK1 inhibitor, prevented GL-induced cell cycle arrest but enhanced apoptosis in DU145 cells. Furthermore, we found that GL did not increase the levels of intracellular ROS, but the antioxidant N-acetylcysteine (NAC) completely prevented the effects of GL on fH2AX, G2/M cell cycle arrest and apoptosis. In contrast to NAC, other antioxidants such as ambroxol and EGCG did not interfere with the activity of GL on cell cycle. GL significantly suppressed DU145 xenograft growth in vivo and induced the expression of fH2AX in the tumors. These findings identify for the first time that GL activates DDR in prostate cancer.
| S-EPMC4826221 | biostudies-literature