1
|
Bianca Maria Platania C, Drago F, Bucolo C. The P2X7 receptor as a new pharmacological target for retinal diseases. Biochem Pharmacol 2022; 198:114942. [DOI: 10.1016/j.bcp.2022.114942] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 01/28/2022] [Accepted: 01/31/2022] [Indexed: 11/02/2022]
|
2
|
Zuo J, Tong Y, Yang Y, Wang Y, Yue D. Claudin-18 expression under hyperoxia in neonatal lungs of bronchopulmonary dysplasia model rats. Front Pediatr 2022; 10:916716. [PMID: 36299696 PMCID: PMC9589239 DOI: 10.3389/fped.2022.916716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 09/21/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Bronchopulmonary dysplasia (BPD) is characterized by impaired alveolar and microvascular development. Claudin-18 is the only known lung-specific tight junction protein affecting the development and transdifferentiation of alveolar epithelium. OBJECTIVE We aimed to explore the changes in the expression of claudin-18, podoplanin, SFTPC, and the canonical WNT pathway, in a rat model of hyperoxia-induced BPD, and to verify the regulatory relationship between claudin-18 and the canonical WNT pathway by cell experiments. METHODS A neonatal rat and cell model of BPD was established by exposing to hyperoxia (85%). Hematoxylin and eosin (HE) staining was used to confirm the establishment of the BPD model. The mRNA levels were assessed using quantitative real-time polymerase chain reaction(qRT-PCR). Protein expression levels were determined using western blotting, immunohistochemical staining, and immunofluorescence. RESULTS As confirmed by HE staining, the neonatal rat model of BPD was successfully established. Compared to that in the control group, claudin-18 and claudin-4 expression decreased in the hyperoxia group. Expression of β-catenin in the WNT signaling pathway decreased, whereas that of p-GSK-3β increased. Expression of the AEC II marker SFTPC initially decreased and then increased, whereas that of the AEC I marker podoplanin increased on day 14 (P < 0.05). Similarly, claudin-18, claudin-4, SFTPC and β-catenin were decreased but podoplanin was increased when AEC line RLE-6TN exposed to 85% hyperoxia. And the expression of SFTPC was increased, the podoplanin was decreased, and the WNT pathway was upregulated when claudin-18 was overexpressed. CONCLUSIONS Claudin-18 downregulation during hyperoxia might affect lung development and maturation, thereby resulting in hyperoxia-induced BPD. Additionally, claudin-18 is associated with the canonical WNT pathway and AECs transdifferentiation.
Collapse
Affiliation(s)
- Jingye Zuo
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yajie Tong
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yuting Yang
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yirui Wang
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Dongmei Yue
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| |
Collapse
|
3
|
Zuo JY, Tong YJ, Yue DM. [A review on the effect of Claudin-18 on bronchopulmonary dysplasia in preterm infants]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2021; 23:542-547. [PMID: 34020748 PMCID: PMC8140329 DOI: 10.7499/j.issn.1008-8830.2101025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 02/19/2021] [Indexed: 06/12/2023]
Abstract
Bronchopulmonary dysplasia (BPD) has the main manifestations of pulmonary edema in the early stage and characteristic alveolar obstruction and microvascular dysplasia in the late stage, which may be caused by structural and functional destruction of the lung epithelial barrier. The Claudin family is the main component of tight junction and plays an important role in regulating the permeability of paracellular ions and solutes. Claudin-18 is the only known tight junction protein solely expressed in the lung. The lack of Claudin-18 can lead to barrier dysfunction and impaired alveolar development, and the knockout of Claudin-18 can cause characteristic histopathological changes of BPD. This article elaborates on the important role of Claudin-18 in the development and progression of BPD from the aspects of lung epithelial permeability, alveolar development, and progenitor cell homeostasis, so as to provide new ideas for the pathogenesis and clinical treatment of BPD.
Collapse
Affiliation(s)
- Jing-Ye Zuo
- Department of Neonatology, Shengjing Hospital, China Medical University, Shenyang 110004, China
| | - Ya-Jie Tong
- Department of Neonatology, Shengjing Hospital, China Medical University, Shenyang 110004, China
| | - Dong-Mei Yue
- Department of Neonatology, Shengjing Hospital, China Medical University, Shenyang 110004, China
| |
Collapse
|
4
|
Incense smoke-induced oxidative stress disrupts tight junctions and bronchial epithelial barrier integrity and induces airway hyperresponsiveness in mouse lungs. Sci Rep 2021; 11:7222. [PMID: 33790367 PMCID: PMC8012366 DOI: 10.1038/s41598-021-86745-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/19/2021] [Indexed: 12/01/2022] Open
Abstract
Recent clinical studies have suggested that inhalation of incense smoke (IS) may result in impaired lung function and asthma. However, there is little experimental evidence to link IS with airway hyperresponsiveness (AHR) and bronchial epithelial barrier function. Using mouse and cell culture models, we evaluated the effects of IS exposure on AHR, expression of multiple epithelial tight junction (TJ)- and adherens junction-associated mRNAs and proteins in the lungs, and the barrier function of bronchial epithelial cells assessed by transepithelial electronic resistance (TEER). Exposure of BALB/c mice to IS increased AHR and inflammatory macrophage recruitment to BALF; reduced claudin-1, -2, -3, -7, -10b, -12, -15, and -18, occludin, zonula occludens-1 [ZO-1], and E-cadherin mRNA expression; and caused discontinuity of claudin-2 and ZO-1 protein immunostaining in lung tissue. IS extract dose-dependently decreased TEER and increased reactive oxygen species production in bronchial epithelial cell cultures. Treatment with N-acetyl-l-cysteine, but not glucocorticosteroids or long-acting β2-agonists, prevented the detrimental effects of IS. IS exposure can be problematic for respiratory health, as evidenced by AHR, increased recruitment of inflammatory macrophages and disruption of TJ proteins in the lung, and damage to epithelial barrier function. However, antioxidants may be useful for the treatment of IS-induced airway dysfunction.
Collapse
|
5
|
Conte G, Nguyen NT, Alves M, de Diego-Garcia L, Kenny A, Nicke A, Henshall DC, Jimenez-Mateos EM, Engel T. P2X7 Receptor-Dependent microRNA Expression Profile in the Brain Following Status Epilepticus in Mice. Front Mol Neurosci 2020; 13:127. [PMID: 32982684 PMCID: PMC7485385 DOI: 10.3389/fnmol.2020.00127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/26/2020] [Indexed: 12/17/2022] Open
Abstract
The ionotropic ATP-gated P2X7 receptor is an important contributor to inflammatory signaling cascades via the release of Interleukin-1β, as well as having roles in cell death, neuronal plasticity and the release of neurotransmitters. Accordingly, there is interest in targeting the P2X7 receptor for the treatment of epilepsy. However, the signaling pathways downstream of P2X7 receptor activation remain incompletely understood. Notably, recent studies showed that P2X7 receptor expression is controlled, in part, by microRNAs (miRNAs). Here, we explored P2X7 receptor-dependent microRNA expression by comparing microRNA expression profiles of wild-type (wt) and P2X7 receptor knockout mice before and after status epilepticus. Genome-wide microRNA profiling was performed using hippocampi from wt and P2X7 receptor knockout mice following status epilepticus induced by intra-amygdala kainic acid. This revealed that the genetic deletion of the P2X7 receptor results in distinct patterns of microRNA expression. Specifically, we found that in vehicle-injected control mice, the lack of the P2X7 receptor resulted in the up-regulation of 50 microRNAs and down-regulation of 35 microRNAs. Post-status epilepticus, P2X7 receptor deficiency led to the up-regulation of 44 microRNAs while 13 microRNAs were down-regulated. Moreover, there was only limited overlap among identified P2X7 receptor-dependent microRNAs between control conditions and post-status epilepticus, suggesting that the P2X7 receptor regulates the expression of different microRNAs during normal physiology and pathology. Bioinformatic analysis revealed that genes targeted by P2X7 receptor-dependent microRNAs were particularly overrepresented in pathways involved in intracellular signaling, inflammation, and cell death; processes that have been repeatedly associated with P2X7 receptor activation. Moreover, whereas genes involved in signaling pathways and inflammation were common among up- and down-regulated P2X7 receptor-dependent microRNAs during physiological and pathological conditions, genes associated with cell death seemed to be restricted to up-regulated microRNAs during both physiological conditions and post-status epilepticus. Taken together, our results demonstrate that the P2X7 receptor impacts on the expression profile of microRNAs in the brain, thereby possibly contributing to both the maintenance of normal cellular homeostasis and pathological processes.
Collapse
Affiliation(s)
- Giorgia Conte
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Ngoc T Nguyen
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland.,FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Mariana Alves
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Laura de Diego-Garcia
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Aidan Kenny
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - David C Henshall
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland.,FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Eva M Jimenez-Mateos
- Discipline of Physiology, School of Medicine, Trinity College Ireland, The University of Dublin, Dublin, Ireland
| | - Tobias Engel
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland.,FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| |
Collapse
|
6
|
Lin WC, Gowdy KM, Madenspacher JH, Zemans RL, Yamamoto K, Lyons-Cohen M, Nakano H, Janardhan K, Williams CJ, Cook DN, Mizgerd JP, Fessler MB. Epithelial membrane protein 2 governs transepithelial migration of neutrophils into the airspace. J Clin Invest 2020; 130:157-170. [PMID: 31550239 DOI: 10.1172/jci127144] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 09/18/2019] [Indexed: 02/06/2023] Open
Abstract
Whether respiratory epithelial cells regulate the final transit of extravasated neutrophils into the inflamed airspace or are a passive barrier is poorly understood. Alveolar epithelial type 1 (AT1) cells, best known for solute transport and gas exchange, have few established immune roles. Epithelial membrane protein 2 (EMP2), a tetraspan protein that promotes recruitment of integrins to lipid rafts, is highly expressed in AT1 cells but has no known function in lung biology. Here, we show that Emp2-/- mice exhibit reduced neutrophil influx into the airspace after a wide range of inhaled exposures. During bacterial pneumonia, Emp2-/- mice had attenuated neutrophilic lung injury and improved survival. Bone marrow chimeras, intravital neutrophil labeling, and in vitro assays suggested that defective transepithelial migration of neutrophils into the alveolar lumen occurs in Emp2-/- lungs. Emp2-/- AT1 cells had dysregulated surface display of multiple adhesion molecules, associated with reduced raft abundance. Epithelial raft abundance was dependent upon putative cholesterol-binding motifs in EMP2, whereas EMP2 supported adhesion molecule display and neutrophil transmigration through suppression of caveolins. Taken together, we propose that EMP2-dependent membrane organization ensures proper display on AT1 cells of a suite of proteins required to instruct paracellular neutrophil traffic into the alveolus.
Collapse
Affiliation(s)
- Wan-Chi Lin
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Kymberly M Gowdy
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Jennifer H Madenspacher
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Rachel L Zemans
- Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Kazuko Yamamoto
- Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts, USA.,Second Department of Internal Medicine, Nagasaki University Hospital, Nagasaki, Japan.,Department of Clinical Research Center, National Hospital Organization Nagasaki Medical Center, Omura, Japan
| | - Miranda Lyons-Cohen
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Hideki Nakano
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Kyathanahalli Janardhan
- Cellular & Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.,Integrated Laboratory Systems Inc., Research Triangle Park, North Carolina, USA
| | - Carmen J Williams
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Donald N Cook
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Joseph P Mizgerd
- Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Michael B Fessler
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| |
Collapse
|
7
|
Blood-retinal barrier protection against high glucose damage: The role of P2X7 receptor. Biochem Pharmacol 2019; 168:249-258. [PMID: 31302133 DOI: 10.1016/j.bcp.2019.07.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/09/2019] [Indexed: 12/13/2022]
Abstract
Blood retinal barrier (BRB) breakdown is a hallmark of diabetic retinopathy, whose occurrence in early or later phases of the disease has not yet been completely clarified. Recent evidence suggests that hyperglycemia induces activation of the P2X7 receptor (P2X7R) leading to pericyte cell death. We herein investigated the role of P2X7R on retinal endothelial cells viability and expression of tight- and adherens-junctions following high glucose (HG) exposure. We found that HG elicited P2X7R activation and expression and release of the pro-inflammatory cytokine IL-1β in human retinal endothelial cells (HRECs). Furthermore, HG exposure caused a decrease in HRECs viability and a damage of the BRB. JNJ47965567, a P2X7R antagonist, protected HRECs from HG-induced damage (LDH release) and preserved the BRB, as shown by transendothelial electrical resistance and cell junction morphology (ZO-1, claudin-5 and VE-cadherin). Moreover, JNJ47965567 treatment significantly decreased IL-1β expression and release, elicited by HG. These data indicate that P2X7R plays an important role to regulate BRB integrity, in particular the block of this receptor was useful to counteract the damage elicited by HG in HRECs, and warranting further clinical evaluation of P2X7R antagonists for the treatment of diabetic macular edema.
Collapse
|
8
|
P2X7 Receptor Indirectly Regulates the JAM-A Protein Content via Modulation of GSK-3β. Int J Mol Sci 2019; 20:ijms20092298. [PMID: 31075901 PMCID: PMC6539570 DOI: 10.3390/ijms20092298] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 04/30/2019] [Accepted: 05/08/2019] [Indexed: 12/20/2022] Open
Abstract
The alveolar epithelial cells represent an important part of the alveolar barrier, which is maintained by tight junction proteins, particularly JAM-A, occludin, and claudin-18, which regulate paracellular permeability. In this study, we report on a strong increase in epithelial JAM-A expression in P2X7 receptor knockout mice when compared to the wildtype. Precision-cut lung slices of wildtype and knockout lungs and immortal epithelial lung E10 cells were treated with bleomycin, the P2X7 receptor inhibitor oxATP, and the agonist BzATP, respectively, to evaluate early changes in JAM-A expression. Biochemical and immunohistochemical data showed evidence for P2X7 receptor-dependent JAM-A expression in vitro. Inhibition of the P2X7 receptor using oxATP increased JAM-A, whereas activation of the receptor decreased the JAM-A protein level. In order to examine the role of GSK-3β in the expression of JAM-A in alveolar epithelial cells, we used lithium chloride for GSK-3β inhibiting experiments, which showed a modulating effect on bleomycin-induced alterations in JAM-A levels. Our data suggest that an increased constitutive JAM-A protein level in P2X7 receptor knockout mice may have a protective effect against bleomycin-induced lung injury. Bleomycin-treated precision-cut lung slices from P2X7 receptor knockout mice responded with a lower increase in mRNA expression of JAM-A than bleomycin-treated precision-cut lung slices from wildtype mice.
Collapse
|
9
|
Hasan D, Satalin J, van der Zee P, Kollisch-Singule M, Blankman P, Shono A, Somhorst P, den Uil C, Meeder H, Kotani T, Nieman GF. Excessive Extracellular ATP Desensitizes P2Y2 and P2X4 ATP Receptors Provoking Surfactant Impairment Ending in Ventilation-Induced Lung Injury. Int J Mol Sci 2018; 19:ijms19041185. [PMID: 29652806 PMCID: PMC5979391 DOI: 10.3390/ijms19041185] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/08/2018] [Accepted: 04/10/2018] [Indexed: 12/16/2022] Open
Abstract
Stretching the alveolar epithelial type I (AT I) cells controls the intercellular signaling for the exocytosis of surfactant by the AT II cells through the extracellular release of adenosine triphosphate (ATP) (purinergic signaling). Extracellular ATP is cleared by extracellular ATPases, maintaining its homeostasis and enabling the lung to adapt the exocytosis of surfactant to the demand. Vigorous deformation of the AT I cells by high mechanical power ventilation causes a massive release of extracellular ATP beyond the clearance capacity of the extracellular ATPases. When extracellular ATP reaches levels >100 μM, the ATP receptors of the AT II cells become desensitized and surfactant impairment is initiated. The resulting alteration in viscoelastic properties and in alveolar opening and collapse time-constants leads to alveolar collapse and the redistribution of inspired air from the alveoli to the alveolar ducts, which become pathologically dilated. The collapsed alveoli connected to these dilated alveolar ducts are subject to a massive strain, exacerbating the ATP release. After reaching concentrations >300 μM extracellular ATP acts as a danger-associated molecular pattern, causing capillary leakage, alveolar space edema, and further deactivation of surfactant by serum proteins. Decreasing the tidal volume to 6 mL/kg or less at this stage cannot prevent further lung injury.
Collapse
Affiliation(s)
- Djo Hasan
- Mobile Intensive Care Unit Zuid-West Nederland, 3062 NW Rotterdam, The Netherlands.
- Department of Surgery, Erasmus MC, Erasmus Universiteit Rotterdam, 3015 CE Rotterdam, The Netherlands.
| | - Joshua Satalin
- Department of Surgery, Upstate Medical University, Syracuse, NY 13210, USA.
| | - Philip van der Zee
- Adult Intensive Care Unit, Erasmus MC, Erasmus Universiteit Rotterdam, 3015 CE Rotterdam, The Netherlands.
| | | | - Paul Blankman
- Department of Anesthesiology, Universitair Medisch Centrum Utrecht, 3584 CX Utrecht, The Netherlands.
| | - Atsuko Shono
- Department of Anesthesiology, Shimane University, Izumo, Shimane Prefecture 693-0021, Japan.
| | - Peter Somhorst
- Adult Intensive Care Unit, Erasmus MC, Erasmus Universiteit Rotterdam, 3015 CE Rotterdam, The Netherlands.
| | - Corstiaan den Uil
- Adult Intensive Care Unit, Erasmus MC, Erasmus Universiteit Rotterdam, 3015 CE Rotterdam, The Netherlands.
- Department of Cardiology, Erasmus MC, Erasmus Universiteit Rotterdam, 3062 PA Rotterdam, The Netherlands.
| | - Han Meeder
- Mobile Intensive Care Unit Zuid-West Nederland, 3062 NW Rotterdam, The Netherlands.
- Adult Intensive Care Unit, Erasmus MC, Erasmus Universiteit Rotterdam, 3015 CE Rotterdam, The Netherlands.
| | - Toru Kotani
- Department of Anesthesiology and Critical Care Medicine, Showa University, School of Medicine, Tokyo 142-8666, Japan.
| | - Gary F Nieman
- Department of Surgery, Upstate Medical University, Syracuse, NY 13210, USA.
| |
Collapse
|
10
|
P2X7R: independent modulation of aquaporin 5 expression in CdCl 2-injured alveolar epithelial cells. Histochem Cell Biol 2018; 149:197-208. [PMID: 29397411 DOI: 10.1007/s00418-018-1637-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2018] [Indexed: 10/18/2022]
Abstract
The expression of aquaporin 5 in alveolar epithelial type I cells under conditions of cadmium-induced injury has not yet been discovered. We investigated the effect of the P2X7R agonist BzATP under this condition, since P2X7R is involved in altered regulation of aquaporin 5 in pulmonary fibrosis. CdCl2/TGF-β1 treatment of lung epithelial MLE-12 cells was leading to increasing P2X7R, and aquaporin 5 protein levels. The aquaporin 5 expression was P2X7R-independent in MLE-12 cells under cadmium, as was shown in blocking experiments with oxATP. Further, the expression of both proteins increased after 24 h CdCl2/TGF-β1 treatment of precision-cut lung slices, but decreased after 72 h. Using immunohistochemistry, the activation of the P2X7R with the agonist BzATP modulated the aquaporin 5 immunoreactivity in the alveolar epithelium of precision-cut lung slices from wild-type but not from P2X7R knockout mice. Similarly, aquaporin 5 protein was reduced in BzATP-treated immortal lung epithelial E10 cells. Surprisingly, untreated alveolar epithelial type II cells of P2X7R knockouts exhibited a pronounced apical immunoreactivity in addition to the remaining alveolar epithelial type I cells. BzATP exposure did not alter this distribution pattern, but increased the number of apoptotic alveolar epithelial type II cells in wild-type lung slices.
Collapse
|
11
|
In focus in HCB: from cell biology to tissue structure and function. Histochem Cell Biol 2016; 146:645-646. [PMID: 27796529 DOI: 10.1007/s00418-016-1511-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2016] [Indexed: 10/20/2022]
|