ERK1/2 Mediates Cytoskeleton and Focal Adhesion Impairment in Proximal Epithelial Cells after Renal Ischemia

Sáenz-Morales, David; Conde, Elisa; Escribese, María M.; García-Martos, Maria; Alegre, Laura; Blanco-Sánchez, Ignacio; García‐Bermejo, Maria Laura

doi:10.1159/000218175

Cited by 27 publications

(18 citation statements)

References 33 publications

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“…miR-199a-3p targets the MET proto-oncogene and ERK-2, thereby inhibiting proliferation and apoptosis (31), and targets hypoxia-inducible factor-1α, thereby reducing apoptosis of cardiac myocytes after hypoxic injury (32). miR-199a-3p may therefore limit kidney injury resulting from hypoxia and may control inflammation and ERK-MAPK signaling, which has been shown to mediate tubular injury after IRI (33). miR-214 is also up-regulated following IRI, and targets PTEN, a negative regulator of the AKT-signaling pathway, thereby promoting cell proliferation and survival (34).…”

Section: Discussionmentioning

confidence: 99%

Identification of a microRNA signature of renal ischemia reperfusion injury

Godwin

Ge²,

Stephan³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

347

345

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Renal ischemia reperfusion injury (IRI) is associated with significant morbidity and mortality. Given the importance of microRNAs (miRNAs) in regulating gene expression, we examined expression profiles of miRNAs following renal IRI. Global miRNA expression profiling on samples prepared from the kidneys of C57BL/6 mice that underwent unilateral warm ischemia revealed nine miRNAs (miR-21, miR-20a, miR-146a, miR-199a-3p, miR-214, miR-192, miR-187, miR-805, and miR-194) that are differentially expressed following IRI when compared with sham controls. These miRNAs were also differently expressed following IRI in immunodeficient RAG-2/ common γ-chain double-knockout mice, suggesting that the changes in expression observed are not significantly influenced by lymphocyte infiltration and therefore define a lymphocyte-independent signature of renal IRI. In vitro studies revealed that miR-21 is expressed in proliferating tubular epithelial cells (TEC) and up-regulated by both cell-intrinsic and -extrinsic mechanisms resulting from ischemia and TGF-β signaling, respectively. In vitro, knockdown of miR-21 in TEC resulted in increased cell death, whereas overexpression prevented cell death. However, overexpression of miR-21 alone was not sufficient to prevent TEC death following ischemia. Our findings therefore define a molecular fingerprint of renal injury and suggest miR-21 may play a role in protecting TEC from death.kidney | miR-21 | tubular epithelial cells | programmed cell death protein 4 I schemic injury followed by reperfusion results in the clinical syndrome of acute kidney injury, a common clinical problem (1-4). The initial nonimmune hypoxic injury and subsequent reperfusion leads to activation of innate and adaptive immune responses, resulting in tissue damage (5). Following injury, a repair process involving cellular proliferation must take place to regain renal function (6). Ischemia reperfusion injury (IRI) is also inevitable in kidney transplantation and contributes to delayed graft function and long-term changes in kidney transplants that affect outcome (7-9). Although IRI is clearly a major clinical problem in native kidneys and in the setting of renal transplantation, the pathogenesis of renal IRI is not fully understood.MicroRNAs (miRNAs) are a class of small, noncoding RNAs ≈21-22 nucleotides in length that regulate gene expression and many disease processes (10, 11). A role for miRNAs in kidney disease is rapidly emerging (12). Numerous hallmarks of IRI (9), such as apoptosis (13), fibrosis (14), epithelial-mesenchymal transition (15), and TLR signaling (16), are regulated by miRNAs in other settings. Recent work has also revealed a role for miRNAs in the regulation of cardiac (13) and hepatic IRI (17).We hypothesized that miRNA expression patterns may serve as a biomarker of kidney injury. To test this hypothesis we reasoned that it would be necessary to examine miRNA expression patterns in an unbiased manner and examine whether differences in miRNA expression patterns were the result of lymphocyte in...

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Section: Discussionmentioning

confidence: 99%

Identification of a microRNA signature of renal ischemia reperfusion injury

Godwin

Ge²,

Stephan³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

347

345

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“…The OGD/R protocol was performed as previously described [25,26,27,28] with a slight modification. Confluent HK-2 cells were made quiescent by serum deprivation for 24 hours and then cultured for the indicated periods of time in DMEM containing no glucose (M&C GENE, Beijing, China) in a hermetic incubator (Hitech biotechnology, Guangzhou, China) with an anaerobic environment (85%N 2 , 10%H 2 , 5%CO 2 ).…”

Section: Methodsmentioning

confidence: 99%

Nitro-Oleic Acid Attenuates OGD/R-Triggered Apoptosis in Renal Tubular Cells via Inhibition of Bax Mitochondrial Translocation in a PPAR-γ-Dependent Manner

Nie

Xue

et al. 2015

Cell Physiol Biochem

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Background: Nitroalkene derivatives of oleic acid (OA-NO₂) serve as high-affinity ligand for PPAR-γ, which regulates apoptosis, oxidation and inflammation and plays a central role in ischemia-reperfusion injury. In the present study, we elucidated the protective mechanisms of OA-NO₂ against renal ischemia-reperfusion injury. Methods: HK-2 cells were subjected to oxygen and glucose deprivation followed by re-oxygenation (OGD/R) to mimic renal ischemia-reperfusion injury. Cell apoptosis was analyzed by flow cytometry. Bax mitochondrial translocation, cytochrome c and apoptosis-inducing factor (AIF) cytosolic leakage and Akt/Gsk 3β phosphorylation were evaluated by Western blotting. Bax activation was visualized by immunocytochemistry. GW9662 and siRNA transfection were employed to examine the involvement of PPAR-γ. Results: OGD/R injury promoted mitochondrial translocation and activation of Bax, leakage of cytochrome c and AIF, subsequent caspase-3 activation, and eventually cell apoptosis. Pre-incubation with OA-NO₂ (1.25 µM, 45min) inhibited Bax activation and blocked apoptotic cascade, while the protective effects were negated by GW9662 or PPAR-γ siRNA. Moreover, OA-NO₂ restored Akt and Gsk 3β phosphorylation in a PPAR-γ-dependent way. Conclusion: These findings suggest that OA-NO₂ attenuates OGD/R-induced apoptosis by inhibiting Bax translocation and activation and the subsequent mitochondria-dependent apoptotic cascade in a PPAR-γ dependent manner.

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“…To further evaluate the effect of TRPV1 activation on tight junction function, TER and paracellular permeability assays were performed as described previously Sáenz-Morales et al, 2009). In SMG-C6 cells, the initial TER value was 516.2698.62 V .…”

Section: Activation Of Trpv1 Decreases Ter and Increases Paracellularmentioning

confidence: 99%

“…We used Trypan Blue and FITC-dextran as indicators, and calculated their flow rate as described previously (Sáenz-Morales et al, 2009;Rosenthal et al, 2010). Capsaicin significantly elicited a brief and transient approximately twofold increase in Trypan Blue flux during a 5-10 min period (Fig.…”

Section: Activation Of Trpv1 Decreases Ter and Increases Paracellularmentioning

confidence: 99%

“…The background value of the blank filter (90 V) was subtracted, and all measurements were performed on a minimum of three wells. Trypan Blue was used as a paracellular tracer for non-selective monolayer permeability as performed previously (Sáenz-Morales et al, 2009;Strober, 2001). In brief, a cell monolayer was incubated for 15 min at 37˚C with 0.04% Trypan Blue in the upper chamber.…”

Section: Preparation Of Cytoplasm and Membrane Fractionsmentioning

confidence: 99%

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Occludin is required for TRPV1-modulated paracellular permeability in the submandibular gland

Cong

Zhang

Yang

et al. 2013

Journal of Cell Science

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SummaryOccludin plays an important role in maintaining tight junction barrier function in many types of epithelia. We previously reported that activation of transient receptor potential vanilloid subtype 1 (TRPV1) in rabbit submandibular gland promoted salivary secretion, partly by an increase in paracellular permeability. We have now explored the role of occludin in TRPV1-modulated paracellular permeability in a rat submandibular gland cell line SMG-C6. Both TRPV1 and occludin were expressed in SMG-C6 cells, and capsaicin induced redistribution of occludin, but not claudin-3, claudin-4 or E-cadherin, from the cell membrane into the cytoplasm. Capsaicin also decreased transepithelial electrical resistance (TER) and increased the Trypan Blue and FITC-dextran flux. Capsazepine (CPZ), a TRPV1 antagonist, inhibited the capsaicin-induced occludin redistribution and TER decrease. Moreover, occludin knockdown by shRNA suppressed, whereas occludin re-expression restored, the TER response to capsaicin. Mechanistically, TRPV1 activation increased ERK1/2 and MLC2 phosphorylation. PD98059, an ERK1/2 kinase inhibitor, abolished the capsaicin-induced MLC2 phosphorylation, whereas ML-7, an MLC2 kinase inhibitor, did not affect ERK1/2 phosphorylation, suggesting that ERK1/2 is the upstream signaling molecule of MLC2. Capsaicin also induced F-actin reorganization, which was abolished by CPZ, PD98059 and ML-7, indicating that TRPV1 activation altered F-actin organization in an ERK1/2-and MLC2-dependent manner. Furthermore, either PD98059 or ML-7 could abolish the capsaicin-induced TER response and occludin redistribution, whereas knockdown of ERK1/2 further confirmed that the TRPV1-modulated paracellular permeability was ERK1/2 dependent. Taken together, these results identified a crucial role of occludin in submandibular epithelial cells, and more importantly, demonstrated that occludin was required to mediate TRPV1-modulated paracellular permeability.

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ERK1/2 Mediates Cytoskeleton and Focal Adhesion Impairment in Proximal Epithelial Cells after Renal Ischemia

Cited by 27 publications

References 33 publications

Identification of a microRNA signature of renal ischemia reperfusion injury

Identification of a microRNA signature of renal ischemia reperfusion injury

Nitro-Oleic Acid Attenuates OGD/R-Triggered Apoptosis in Renal Tubular Cells via Inhibition of Bax Mitochondrial Translocation in a PPAR-γ-Dependent Manner

Occludin is required for TRPV1-modulated paracellular permeability in the submandibular gland

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