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Unfolded Protein Response Regulates Pulmonary P53 Expression
Author(s) -
Akhter Mohammad Shohel,
Kubra Khadeja-Tul,
Uddin Mohammad Afaz,
Barabutis Nektarios
Publication year - 2020
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2020.34.s1.01803
Subject(s) - unfolded protein response , western blot , thapsigargin , chemistry , microbiology and biotechnology , andrology , pharmacology , immunology , biology , intracellular , medicine , apoptosis , biochemistry , gene
Lung endothelial barrier dysfunction leads to severe pathologies, including the lethal Acute Respiratory Distress Syndrome. P53 has been associated with anti‐inflammatory activities. The current study employs a variety of Unfolded Protein Response (UPR) activators and inhibitors to investigate the regulation of P53 by UPR in lung cells. The outcomes of our investigation reveal a positive regulation between UPR and P53. Since it has been shown that a mild induction of UPR opposes inflammation, we suggest that P53 is involved in those protective activities in the lung. METHODS Bovine Pulmonary Arterial Endothelial Cells (BPAEC) were maintained at 37°C in a humidified atmosphere of 5% CO 2 – 21% O 2 , and were cultured in DMEM medium supplemented with 10% FBS and 1X penicillin/streptomycin. Protein levels were measured by Western Blot analysis, and were quantified using Image J software. All antibodies were purchased from Cell Signaling (Danvers, MA), and the chemicals from VWR (Radnor, PA). BPAECs were purchased from Genlantis (San Diego, CA). RESULTS BPAEC exposed to the UPR inductors Brefeldin (2 μg/ml), Dithiothreitol (1mM), or Thapsigargin (1μM) for 4, 8 and 24 hours exerted increased expression of the UPR marker Binding Immunoglobulin Protein (BiP); as well as P53. On the other hand, treatment of those cells with the UPR suppressors N‐acetyl Cysteine (1mM), Kifunensine (5μM), or the ATP‐competitive IRE1α kinase inhibiting RNase attenuator (1μM) for the same periods (4, 8, 24 hours) exerted the opposite effects. Thus, those suppressors reduced both BiP and P53 abundance in the intracellular niche. CONCLUSIONS Our study suggests that UPR is directly associated with P53 expression, and that UPR induction induces P53. Since this protein supports the endothelium function, future studies may delineate the exact components of the UPR machinery in charge of that regulation, and reveal whether those effects are associated with lung endothelium integrity. Support or Funding Information This work was supported by 1) R&D, Research Competitiveness Subprogram of the Louisiana Board of Regents through the Board of Regents Support Fund (LEQSF(2019‐22)‐RD‐A‐26) II) NIGMS/NIH (5P20GM103424‐15, 3P20GM103424‐15S1).