https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Basal protein phosphatase 2A activity restrains cytokine expression: role for MAPKs and tristetraprolin https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:28327 in vitro we show that inhibition of basal PP2A activity by okadaic acid (OA) releases restraint on MAPKs and thereby increases MAPK-mediated pro-asthmatic cytokines, including IL-6 and IL-8. Notably, PP2A inhibition also impacts on the anti-inflammatory protein – tristetraprolin (TTP), a destabilizing RNA binding protein regulated at multiple levels by p38 MAPK. Although PP2A inhibition increases TTP mRNA expression, resultant TTP protein builds up in the hyperphosphorylated inactive form. Thus, when PP2A activity is repressed, pro-inflammatory cytokines increase and anti-inflammatory proteins are rendered inactive. Importantly, these effects can be reversed by the PP2A activators FTY720 and AAL(s), or more specifically by overexpression of the PP2A catalytic subunit (PP2A-C). Moreover, PP2A plays an important role in cytokine expression in cells stimulated with TNFα; as inhibition of PP2A with OA or PP2A-C siRNA results in significant increases in cytokine production. Collectively, these data reveal the molecular mechanisms of PP2A regulation and highlight the potential of boosting the power of endogenous phosphatases as novel anti-inflammatory strategies to combat asthmatic inflammation.]]> Wed 11 Apr 2018 13:50:35 AEST ]]> New therapeutic targets for the prevention of infectious acute exacerbations of COPD: role of epithelial adhesion molecules and inflammatory pathways https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:41455 Wed 10 Aug 2022 12:11:24 AEST ]]> Activating protein phosphatase 2A (PP2A) enhances tristetraprolin (TTP) anti-inflammatory function in A549 lung epithelial cells https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:23093 Thu 28 Oct 2021 13:04:03 AEDT ]]> A novel immunomodulatory function of neutrophils on rhinovirus-activated monocytes in vitro https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25846 Thu 28 Oct 2021 12:37:11 AEDT ]]> Enhancing tristetraprolin activity reduces the severity of cigarette smoke-induced experimental chronic obstructive pulmonary disease https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45028 Zfp36 gene is an anti‐inflammatory protein that induces mRNA decay, especially of transcripts encoding inflammatory cytokines, including those implicated in COPD. Methods: Here, we identify a novel protective role for TTP in CS‐induced experimental COPD using Zfp36aa/aa mice, a genetically modified mouse strain in which endogenous TTP cannot be phosphorylated, rendering it constitutively active as an mRNA‐destabilising factor. TTP wild‐type (Zfp36+/+) and Zfp36aa/aa active C57BL/6J mice were exposed to CS for four days or eight weeks, and the impact on acute inflammatory responses or chronic features of COPD, respectively, was assessed. Results: After four days of CS exposure, Zfp36aa/aa mice had reduced numbers of airway neutrophils and lymphocytes and mRNA expression levels of cytokines compared to wild‐type controls. After eight weeks, Zfp36aa/aa mice had reduced pulmonary inflammation, airway remodelling and emphysema‐like alveolar enlargement, and lung function was improved. We then used pharmacological treatments in vivo (protein phosphatase 2A activator, AAL(S), and the proteasome inhibitor, bortezomib) to promote the activation and stabilisation of TTP and show that hallmark features of CS‐induced experimental COPD were ameliorated. Conclusion: Collectively, our study provides the first evidence for the therapeutic potential of inducing TTP as a treatment for COPD.]]> Thu 27 Oct 2022 09:28:02 AEDT ]]> Protein phosphatase 2A (PP2A): a key phosphatase in the progression of chronic obstructive pulmonary disease (COPD) to lung cancer https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:41709 Thu 25 Aug 2022 10:06:29 AEST ]]> The phosphorylated form of FTY720 activates PP2A, represses inflammation and is devoid of S1P agonism in A549 lung epithelial cells https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26728 Thu 24 Mar 2022 11:33:42 AEDT ]]> Role of dynamin in elongated cell migration in a 3D matrix https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:27080 Sat 24 Mar 2018 07:40:44 AEDT ]]> Activiating protein phosphatase 2A (PP2A) enhances tristetraprolin (TTP) anti-inflammatory function in A549 lung epithelial cells https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:21995 Fri 25 May 2018 17:44:00 AEST ]]> TLR2 ligation induces corticosteroid insensitivity in A549 lung epithelial cells: anti-inflammatory impact of PP2A activators https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25080 Fri 01 Apr 2022 09:27:01 AEDT ]]> Theophylline represses IL-8 secretion from airway smooth muscle cells independently of phosphodiesterase inhibition: novel role as a protein phosphatase 2A activator https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25564 ex vivo and in vivo models of respiratory disease. Thus, our study is the first to link theophylline with PP2A activation as a novel mechanism to control respiratory inflammation.]]> Fri 01 Apr 2022 09:21:01 AEDT ]]>