lncRNA HOTAIR mediates OGD/R‑induced cell injury and angiogenesis in a EZH2‑dependent manner

Exosomes are nano-sized vesicles produced and secreted by cells to mediate intercellular communication. The production and function of exosomes in kidney tissues and cells remain largely unclear. Hypoxia is a common pathophysiological condition in kidneys. This study was designed to characterize exosome production during hypoxia of rat renal proximal tubular cells (RPTCs), investigate the regulation by hypoxia-inducible factor-1 (HIF-1), and determine the effect of the exosomes on ATP-depletion-induced tubular cell injury. Hypoxia did not change the average sizes of exosomes secreted by RPTCs, but it significantly increased exosome production in a time-dependent manner. HIF-1 induction with dimethyloxalylglycine also promoted exosome secretion, whereas pharmacological and genetic suppression of HIF-1 abrogated the increase of exosome secretion under hypoxia. The exosomes from hypoxic RPTCs had inhibitory effects on apoptosis of RPTCs following ATP depletion. The protective effects were lost in the exosomes from HIF-1α knockdown cells. It is concluded that hypoxia stimulates exosome production and secretion in renal tubular cells. The exosomes from hypoxic cells are protective against renal tubular cell injury. HIF-1 mediates exosome production during hypoxia and contributes to the cytoprotective effect of the exosomes.

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Lithium preserves peritoneal membrane integrity by suppressing mesothelial cell αB-crystallin

Science Translational Medicine ◽

10.1126/scitranslmed.aaz9705 ◽

2021 ◽

Vol 13 (608) ◽

pp. eaaz9705

Author(s):

Rebecca Herzog ◽

Juan Manuel Sacnun ◽

Guadalupe González-Mateo ◽

Maria Bartosova ◽

Katarzyna Bialas ◽

...

Keyword(s):

Cell Injury ◽

Membrane Integrity ◽

Mesothelial Cell ◽

Mesothelial Cells ◽

Cell Protein ◽

Dependent Manner ◽

Peritoneal Membrane ◽

Peritoneal Fibrosis ◽

Mesenchymal Transition ◽

Αb Crystallin

Life-saving renal replacement therapy by peritoneal dialysis (PD) is limited in use and duration by progressive impairment of peritoneal membrane integrity and homeostasis. Preservation of peritoneal membrane integrity during chronic PD remains an urgent but long unmet medical need. PD therapy failure results from peritoneal fibrosis and angiogenesis caused by hypertonic PD fluid (PDF)–induced mesothelial cytotoxicity. However, the pathophysiological mechanisms involved are incompletely understood, limiting identification of therapeutic targets. We report that addition of lithium chloride (LiCl) to PDF is a translatable intervention to counteract PDF-induced mesothelial cell death, peritoneal membrane fibrosis, and angiogenesis. LiCl improved mesothelial cell survival in a dose-dependent manner. Combined transcriptomic and proteomic characterization of icodextrin-based PDF-induced mesothelial cell injury identified αB-crystallin as the mesothelial cell protein most consistently counter-regulated by LiCl. In vitro and in vivo overexpression of αB-crystallin triggered a fibrotic phenotype and PDF-like up-regulation of vascular endothelial growth factor (VEGF), CD31-positive cells, and TGF-β–independent activation of TGF-β–regulated targets. In contrast, αB-crystallin knockdown decreased VEGF expression and early mesothelial-to-mesenchymal transition. LiCl reduced VEGF release and counteracted fibrosis- and angiogenesis-associated processes. αB-crystallin in patient-derived mesothelial cells was specifically up-regulated in response to PDF and increased in peritoneal mesothelial cells from biopsies from pediatric patients undergoing PD, correlating with markers of angiogenesis and fibrosis. LiCl-supplemented PDF promoted morphological preservation of mesothelial cells and the submesothelial zone in a mouse model of chronic PD. Thus, repurposing LiCl as a cytoprotective PDF additive may offer a translatable therapeutic strategy to combat peritoneal membrane deterioration during PD therapy.

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Differential regulation by cytokines of constitutive and stimulated secretion of von Willebrand factor from endothelial cells

Blood ◽

10.1182/blood.v75.3.688.688 ◽

1990 ◽

Vol 75 (3) ◽

pp. 688-695 ◽

Cited By ~ 61

Author(s):

EM Paleolog ◽

DC Crossman ◽

JH McVey ◽

JD Pearson

Keyword(s):

Endothelial Cells ◽

Von Willebrand Factor ◽

Messenger Rna ◽

Cell Injury ◽

Interleukin 1 ◽

Tnf Alpha ◽

Detectable Effect ◽

Dependent Manner ◽

Von Willebrand ◽

Willebrand Factor

Abstract We examined the effect of cytokines on basal and agonist-stimulated release of von Willebrand factor (vWf) by human endothelial cells. Treatment of endothelial cells for up to 48 hours with human recombinant or purified interleukin 1 (IL-1) or human recombinant tumor necrosis factor-alpha (TNF-alpha) did not significantly affect constitutive secretion of vWf or intracellular levels of vWf, although basal prostacyclin (PGI2) production was markedly enhanced. In contrast, both IL-1 and TNF-alpha modulated vWf release in response to thrombin or phorbol ester. Pretreatment of endothelial cells for 2 hours with either cytokine enhanced by up to threefold the stimulatory effect of a subsequent 60-minute exposure to thrombin. Addition of cycloheximide (5 micrograms/mL) during the preincubation abolished this enhancement. Moreover, if the cytokine pretreatment time was extended to 24 hours, agonist-stimulated vWf release was significantly suppressed. Cytokine treatment for 2 or 24 hours had no detectable effect on levels of vWf messenger RNA. The effects of cytokines were not the result of contamination with bacterial lipopolysaccharide and were not attributable to endothelial cell injury. These results show that cytokines have little or no direct effect on vWf release from endothelial cells but can significantly modulate its acute release in response to other stimuli in a complex time- and dose-dependent manner.

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Silica directly increases permeability of alveolar epithelial cells

Journal of Applied Physiology ◽

10.1152/jappl.1990.68.4.1354 ◽

1990 ◽

Vol 68 (4) ◽

pp. 1354-1359 ◽

Cited By ~ 11

Author(s):

R. K. Merchant ◽

M. W. Peterson ◽

G. W. Hunninghake

Keyword(s):

Epithelial Cells ◽

Cell Injury ◽

Alveolar Epithelial Cell ◽

Alveolar Epithelium ◽

Alveolar Epithelial Cells ◽

Dependent Manner ◽

Alveolar Epithelial ◽

Lactate Dehydrogenase Release ◽

Capillary Membrane

Alveolar epithelial cell injury and increased alveolar-capillary membrane permeability are important features of acute silicosis. To determine whether silica particles contribute directly to this increased permeability, we measured paracellular permeability of rat alveolar epithelium after exposure to silica, in vitro, using markers of the extracellular space. Silica (Minusil) markedly increased permeability in a dose- and time-dependent manner. This was not the result of cytolytic injury, because lactate dehydrogenase release from monolayers exposed to silica was not increased. Pretreatment of the silica with serum, charged dextrans, or aluminum sulfate blocked the increase in permeability. Scanning electron microscopy demonstrated adherence of the silica to the surface of the alveolar epithelial cells. Thus silica can directly increase permeability of alveolar epithelium.

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T-2 Toxin Exposure Induces Apoptosis in TM3 Cells by Inhibiting Mammalian Target of Rapamycin/Serine/Threonine Protein Kinase(mTORC2/AKT) to Promote Ca2+Production

International Journal of Molecular Sciences ◽

10.3390/ijms19113360 ◽

2018 ◽

Vol 19 (11) ◽

pp. 3360 ◽

Cited By ~ 4

Author(s):

Ji Wang ◽

Chenglin Yang ◽

Zhihang Yuan ◽

Jine Yi ◽

Jing Wu

Keyword(s):

Cell Injury ◽

Mammalian Target Of Rapamycin ◽

Annexin V ◽

Target Of Rapamycin ◽

Dependent Manner ◽

Toxin Exposure ◽

Concentration Changes ◽

Vitro Model ◽

Induced Apoptosis

Although mTOR (the mammalian target of rapamycin) can regulate intracellular free Ca2+concentration in normal cultured podocytes, it remains elusive as to how mTORC2/AKT-mediated Ca2+participates in the process of T-2 toxin-induced apoptosis. The potential signaling responsible for intracellular Ca2+ concentration changes was investigated using immunoblot assays in an in vitro model of TM3 cell injury induced by T-2 toxin. Changes in Ca2+ were assessed using the Ca2+-sensitive fluorescent indictor dye Fura 2-AM. The cytotoxicity of TM3 cells was assessed with an MTT bioassay, and apoptosis was measured using Annexin V-FITC staining. Following T-2 toxin treatment, the growth of cells, phospho-mTORSer2481, phospho-mTORSer2448, and phospho-AktSer473 were significantly decreased in a time-dependent manner, whereas Ca2+ and apoptosis were increased. T-2 toxin-induced apoptosis was prevented by BAPTA-AM (a Ca2+chelator) and MHY1485 (an mTOR activator), and the application of mTOR activator MHY1485 also prevented the increase of intracellular free Ca2+concentration in TM3 cells. Our results strongly suggest that T-2 toxin exposure induces apoptosis in TM3 cells by inhibiting mTORC2/AKT to promote Ca2+ production.

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Adaptive cytoprotection in the small intestine: role of mucus

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1993.264.5.g921 ◽

1993 ◽

Vol 264 (5) ◽

pp. G921-G927 ◽

Cited By ~ 3

Author(s):

G. Cepinskas ◽

R. D. Specian ◽

P. R. Kvietys

Keyword(s):

Small Intestine ◽

Oleic Acid ◽

Epithelial Cell ◽

Cell Injury ◽

Sodium Taurocholate ◽

Dependent Manner ◽

Adaptive Cytoprotection ◽

Epithelial Integrity ◽

Epithelial Cell Injury

Gastric mucosal injury induced by strong irritants can be dramatically reduced by pretreating the mucosa with mild forms of the same irritant. This phenomenon has been termed "adaptive cytoprotection." The aim of the present study was to use in vivo and in vitro approaches to study adaptive cytoprotection in the small intestine using physiologically relevant concentrations of oleic acid. Anesthetized rats were instrumented for perfusion of the proximal jejunum with 10 or 40 mM oleic acid (in 20 mM sodium taurocholate). Mucosal epithelial integrity was continuously monitored by measuring the blood-to-lumen clearance of 51Cr-labeled EDTA. Perfusion of the lumen with 40 mM oleic acid produced a 10-fold increase in 51Cr-EDTA clearance, which was not affected by a previous perfusion with 10 mM oleic acid, i.e., no adaptive cytoprotection. In another series of experiments, oleic acid was placed in the lumen rather than perfused, and mucosal epithelial integrity was assessed histologically. Intraluminal placement of 10 mM oleic acid resulted in the generation of a mucus layer over the epithelium. Subsequent placement of 40 mM oleic acid did not produce significant epithelial cell injury, i.e., adaptive cytoprotection. In in vitro studies, mucin (1, 5, and 10 mg/ml) was layered over confluent monolayers of Caco-2 cells prior to addition of 2 mM oleic acid in 4 mM sodium taurocholate. The epithelial cell injury induced by oleic acid was inhibited by mucin in a dose-dependent manner. Further studies indicate that mucin does not prevent, but simply delays, the onset of cell injury.(ABSTRACT TRUNCATED AT 250 WORDS)

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Endoplasmic reticulum stress regulates cell injury in lipopolysaccharide-induced nerve cells

Journal of International Medical Research ◽

10.1177/0300060520949762 ◽

2020 ◽

Vol 48 (9) ◽

pp. 030006052094976

Author(s):

Min Li ◽

Ying Zhang ◽

Jixing Wang

Keyword(s):

Endoplasmic Reticulum ◽

Cell Viability ◽

Er Stress ◽

Cell Apoptosis ◽

Caspase 3 ◽

Cell Injury ◽

Cell Counting ◽

Tunel Staining ◽

Dependent Manner ◽

Stress Markers

Objective Sepsis-associated encephalopathy (SAE) is a common complication of sepsis, and excessive endoplasmic reticulum (ER) stress is closely correlated with the cell injury caused by sepsis. This study aimed to analyze the possible role of ER stress in SAE cell models. Methods PC12 and MES23.5 cells were treated with increasing concentrations of lipopolysaccharides (LPS). The Cell Counting Kit-8 assay was used to detect cell viability and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to assess cell apoptosis. In addition, the protein expression levels of ER stress markers [GRP78, CHOP, inositol-requiring enzyme 1 (IRE1), and PKR-like ER kinase (PERK)] and apoptosis-related proteins (Bax, Bcl-2, caspase-3, and cleaved caspase-3) were analyzed using western blotting. Results LPS treatment activated ER stress markers in both the PC12 and MES23.5 cells. The overexpression of GRP78 significantly reduced cell viability and enhanced cell apoptosis in a time-dependent manner. An ER stress inhibitor, 4-PBA, significantly enhanced cell viability and inhibited the cell apoptosis induced by LPS. Therefore, an enhanced unfolded protein response (UPR) and UPR suppression may regulate cell apoptosis. Conclusions UPR was shown to be involved in regulating LPS-induced neuron injury. UPR could be a potential therapeutic target in SAE.

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Apigetrin inhibits cytotoxicity and dysregulation of ACE2, IL1α and TGFβ expression induced by recombinant spike protein of SARS-CoV-2

World Journal of Advanced Research and Reviews ◽

10.30574/wjarr.2021.9.2.0035 ◽

2021 ◽

Vol 9 (2) ◽

pp. 144-154

Author(s):

Grace Luo ◽

Wei Zhu

Keyword(s):

Cell Proliferation ◽

Cytotoxic Effect ◽

Molecular Mechanisms ◽

Cell Injury ◽

Cytokine Production ◽

Human Cells ◽

Spike Protein ◽

Dependent Manner ◽

Pathological Effect ◽

Health Crisis

SARS-CoV-2 virus is a novel coronavirus that was first identified in Wuhan, China in December 2019 and has caused an ongoing global health crisis. It has been a worldwide focus in research to understand viral pathogenesis and discover effective therapies. SARS-CoV-2 belongs to the same genus as the viruses responsible for Severe Acute Respiratory Syndrome (SARS) and the Middle East Respiratory Syndrome (MERS). Spike protein (SP) on SARS-CoV-2 plays a key role in the pathogenesis of SARS-CoV-2. The virus enters human cells via the binding of SP to the angiotensin-converting enzyme 2 (ACE2) on human cells. The binding of SP inhibits ACE2 function by reducing formation of angiotensin-(1-7), a compound that has inhibitory effects on inflammation. In addition, SARS-CoV-2 induces excessive proinflammatory cytokine production through various other signaling pathways such as the NFκB and NLRP3 inflammasome pathways. Previous evidence showed that apigenin (APG), a plant phenolic compound, can bind to SP. However, whether or not apigetrin (APT), the glucoside conjugate of APG, can protect human cells against cell injury caused by SARS-CoV-2 is still unknown. Studies have shown that SARS-CoV-2 induced dysregulation of host cell ACE2 expression is one of the major pathophysiological factors of COVID-19 infection. Our current study demonstrated that recombinant SP significantly reduced ACE2 level in human neuronal cells in a dose dependent manner using ELISA assay. Interestingly, APT reversed the SP induced ACE2 downregulation in these cells. In this study, the effect of SP on cell proliferation and immune regulation was also investigated. Using MTT and LDH assays, I discovered that SP had a cytotoxic effect on these cells and significantly inhibited cell proliferation. This cytotoxic effect was mitigated by adding APT treatment. Furthermore, APT reduced SP induced cytokine production such as IL1α and TGFβ . In sum, my study demonstrated that APT inhibited SARS-CoV-2 SP induced dysregulation of human cells and reduced its cytotoxic effects on cells. APT significantly upregulated ACE2 expression and inhibited the production of cytokines IL1α and TGFβ in the cells treated with SP. My study indicated that APT has potential to be a novel therapy for COVID-19 infection. More experiments to further elucidate molecular mechanisms of how APT modulates pathological effect of SP with different in vitro models including other human cell lines and in vivo animal models are currently being performed.

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miR-149 Alleviates Ox-LDL-Induced Endothelial Cell Injury by Promoting Autophagy through Akt/mTOR Pathway

Cardiology Research and Practice ◽

10.1155/2021/9963258 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Zhongsheng Zhu ◽

Jinyu Li ◽

Rui Tong ◽

Xiaorong Zhang ◽

Bo Yu

Keyword(s):

Endothelial Cell ◽

Cell Viability ◽

Cell Injury ◽

Low Density Lipoprotein ◽

Density Lipoprotein ◽

Mtor Pathway ◽

Micro Rna ◽

Endothelial Injury ◽

Dependent Manner ◽

Endothelial Cell Injury

Background. Atherosclerosis is a chronic process that takes place in the vascular wall and causes various cardiovascular diseases (CVDs). Micro-RNA-149 (miR-149) mediates many physiological and pathological processes, including atherosclerosis. However, it is unclear about the roles of miR-149 in endothelial injury. Here, we explored the protective effect and related mechanism of miR-149 in endothelial cells induced with oxidized low-density lipoprotein (ox-LDL). Methods. Human endothelial cell lines (HUVECs) were exposed to ox-LDL to induce endothelial injury. Cell viability was determined by the CCK-8 assay. Autophagy was detected by immunofluorescence. RT-qPCR and western blot were carried out to determine the mRNA and protein expressions of Akt and mTOR. Results. The miR-149 level in HUVECs was reduced by ox-LDL (100 μg/mL) incubation in a time-dependent manner. miR-149-mimic transfection markedly protected HUVECs from ox-LDL-induced injury, with increased cell viability and reduced caspase-3 activity. miR-149 mimics enhanced HUVEC autophagy, which was induced initially by ox-LDL. miR-149 mimics also markedly downregulated the expression of Akt, p-Akt, mTOR, and p-mTOR in ox-LDL-treated HUVECs. The miR-149-induced protection against HUVECs injury could be reversed by cotreatment with 3-methyladenine (3-MA, an autophagy inhibitor) or insulin (an activator of Akt/mTOR pathway). Conclusions. miR-149 prevents ox-LDL-induced endothelial cell injury by enhancing autophagy via increasing Akt and mTOR expressions.

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Hydrogen Sulfide Protects against Chemical Hypoxia-Induced Injury via Attenuation of ROS-Mediated Ca2+Overload and Mitochondrial Dysfunction in Human Bronchial Epithelial Cells

BioMed Research International ◽

10.1155/2018/2070971 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 7

Author(s):

Cai-Xia Liu ◽

Yu-Rong Tan ◽

Yang Xiang ◽

Chi Liu ◽

Xiao-Ai Liu ◽

...

Keyword(s):

Oxidative Stress ◽

Hydrogen Sulfide ◽

Cell Injury ◽

Fluorescence Probe ◽

Environmental Pollutants ◽

Cell Counting ◽

Dependent Manner ◽

Mitochondria Membrane Potential ◽

Chemical Hypoxia ◽

The Impact

Oxidative stress induced by hypoxia/ischemia resulted in the excessive reactive oxygen species (ROS) and the relative inadequate antioxidants. As the initial barrier to environmental pollutants and allergic stimuli, airway epithelial cell is vulnerable to oxidative stress. In recent years, the antioxidant effect of hydrogen sulfide (H2S) has attracted much attention. Therefore, in this study, we explored the impact of H2S on CoCl2-induced cell injury in 16HBE14o- cells. The effect of CoCl2on the cell viability was detected by Cell Counting Kit (CCK-8) and the level of ROS in 16HBE14o- cells in response to varying doses (100–1000μmol/L) of CoCl2(a common chemical mimic of hypoxia) was measured by using fluorescent probe DCFH-DA. It was shown that, in 16HBE14o- cells, CoCl2acutely increased the ROS content in a dose-dependent manner, and the increased ROS was inhibited by the NaHS (as a donor of H2S). Moreover, the calcium ion fluorescence probe Fura-2/AM and fluorescence dye Rh123 were used to investigate the intracellular calcium concentration ([Ca2+]i) and mitochondria membrane potential (MMP) in 16HBE14o- cells, respectively. In addition, we examined apoptosis of 16HBE14o- cells with Hoechst 33342. The results showed that the CoCl2effectively elevated the Ca2+influx, declined the MMP, and aggravated apoptosis, which were abrogated by NaHS. These results demonstrate that H2S could attenuate CoCl2-induced hypoxia injury via reducing ROS to perform an agonistic role for the Ca2+influx and MMP dissipation.

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