scholarly journals DPP4 inhibition by sitagliptin attenuates LPS-induced lung injury in mice

2018 ◽  
Vol 315 (5) ◽  
pp. L834-L845 ◽  
Author(s):  
Takeshi Kawasaki ◽  
Weiguo Chen ◽  
Yu Maw Htwe ◽  
Koichiro Tatsumi ◽  
Steven M. Dudek
Keyword(s):  
Epithelial Cells ◽  
Lung Injury ◽  
Human Lung ◽  
Cell Number ◽  
Lung Epithelial Cells ◽  
Dpp4 Inhibitors ◽  
Anti Inflammatory ◽  
Dpp4 Inhibition

Acute respiratory distress syndrome (ARDS) is a severe clinical condition marked by acute respiratory failure and dysregulated inflammation. Pulmonary vascular endothelial cells (PVECs) function as an important pro-inflammatory source in ARDS, suggesting that modulation of inflammatory events at the endothelial level may have a therapeutic benefit. Dipeptidyl peptidase-4 (DPP4) inhibitors, widely used for the treatment of diabetes mellitus, have been reported to have possible anti-inflammatory effects. However, the potential anti-inflammatory effects of DPP4 inhibition on PVEC function and ARDS pathophysiology are unknown. Therefore, we evaluated the effects of sitagliptin, a DPP4 inhibitor in wide clinical use, on LPS-induced lung injury in mice and in human lung ECs in vitro. In vivo, sitagliptin reduced serum DPP4 activity, bronchoalveolar lavage protein concentration, cell number, and proinflammatory cytokine levels after LPS and alleviated histological findings of lung injury. LPS decreased the expression levels of CD26/DPP4 on pulmonary epithelial cells and PVECs isolated from mouse lungs, and the effect was partially reversed by sitagliptin. In vitro, human lung microvascular ECs (HLMVECs) expressed higher levels of CD26/DPP4 than human pulmonary arterial ECs. LPS induced the release of TNFα, IL-6, and IL-8 by HLMVECs that were inhibited by sitagliptin. LPS promoted the proliferation of HLMVECs, and sitagliptin suppressed this response. However, sitagliptin failed to reverse LPS-induced permeability in cultured ECs or lung epithelial cells in vitro. In summary, sitagliptin attenuates LPS-induced lung injury in mice and exerts anti-inflammatory effects on HLMVECs. These novel observations indicate DPP4 inhibitors may have potential as therapeutic drugs for ARDS.

scholarly journals A High Content Screen for Mucin-1-Reducing Compounds Identifies Fostamatinib as a Candidate for Rapid Repurposing for Acute Lung Injury during the COVID-19 pandemic

2020 ◽  
Author(s):  
Maria Alimova ◽  
Eriene-Heidi Sidhom ◽  
Abhigyan Satyam ◽  
Moran Dvela-Levitt ◽  
Michelle Melanson ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Drug Repurposing ◽  
Lung Epithelial Cells ◽  
Drug Candidate ◽  
Mucin 1 ◽  
Standing Up

SummaryDrug repurposing is the only method capable of delivering treatments on the shortened time-scale required for patients afflicted with lung disease arising from SARS-CoV-2 infection. Mucin-1 (MUC1), a membrane-bound molecule expressed on the apical surfaces of most mucosal epithelial cells, is a biochemical marker whose elevated levels predict the development of acute lung injury (ALI) and respiratory distress syndrome (ARDS), and correlate with poor clinical outcomes. In response to the pandemic spread of SARS-CoV-2, we took advantage of a high content screen of 3,713 compounds at different stages of clinical development to identify FDA-approved compounds that reduce MUC1 protein abundance. Our screen identified Fostamatinib (R788), an inhibitor of spleen tyrosine kinase (SYK) approved for the treatment of chronic immune thrombocytopenia, as a repurposing candidate for the treatment of ALI. In vivo, Fostamatinib reduced MUC1 abundance in lung epithelial cells in a mouse model of ALI. In vitro, SYK inhibition by Fostamatinib promoted MUC1 removal from the cell surface. Our work reveals Fostamatinib as a repurposing drug candidate for ALI and provides the rationale for rapidly standing up clinical trials to test Fostamatinib efficacy in patients with COVID-19 lung injury.

scholarly journals A Novel Protective Mechanism for Melatonin Against Acute Lung Injury: Preserving Mitochondrial Dynamic Equilibrium of Lung Epithelial Cells Through SIRT3-Dependent Deacetylation of SOD2

2022 ◽  
Author(s):  
Li Ning ◽  
Xiong Rui ◽  
Li Guorui ◽  
Fu Tinglv ◽  
Li Donghang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Acute Lung Injury ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Dynamic Equilibrium ◽  
Lung Epithelial Cells ◽  
Mitochondrial Dynamic ◽  
Lung Epithelial

Abstract Mitochondrial dynamic equilibrium of lung epithelial cells is disturbed during sepsis, which contributes to abnormal mitochondrial function and acute lung injury (ALI). Melatonin is one primary hormone secreted by the pineal gland, displaying favorable antioxidative actions in sepsis and cardiopulmonary disease. However, the potential roles and molecular basis of melatonin in lipopolysaccharide (LPS)-treated lung epithelial cells have not been explored and reported. Herein, we investigated whether melatonin could protect against sepsis-induced ALI and lipopolysaccharide (LPS)-treated lung epithelial cells through mitochondrial dynamic equilibrium as well as its possible molecular targets. Wild type and Sirt3 knockout mice were instilled with LPS intratracheally for 12 hours to construct an in vivo ALI model. And A549 lung epithelial cells were used to explore the possible roles of melatonin in vitro by incubating with small interfering RNA (siRNA) against Sirt3. To figure out the involvement of melatonin receptor, si Mtnr1b and luzindole were used in cells and mice. Melatonin pretreatment significantly inhibited pathological injury, inflammatory response, oxidative stress and apoptosis in LPS-treated lung tissues and LPS-treated lung epithelial cells. Meanwhile, melatonin also shifted the dynamic course of mitochondria from fission into fusion in LPS-treated lung epithelial cells in vivo and in vitro. However, SIRT3 inhibition abolished the protective roles of melatonin in ALI. Mechanistically, we found that melatonin increased the activity and expression of SIRT3, which further promoted the deacetylation of SOD2 at K122 and K68. More importantly, melatonin exerted pulmonary protection by activating MTNR1B but not MTNR1A in ALI. Collectively, melatonin could preserve mitochondrial dynamic equilibrium of lung epithelial cells through the deacetylation of SOD2 in a SIRT3-dependent manner, which eventually alleviated LPS-elicited injury, inflammation, oxidative stress, apoptosis. Thus, melatonin may serve as a promising candidate against ALI in the future.

Ionizing radiation enhances matrix metalloproteinase-2 production in human lung epithelial cells

2001 ◽  
Vol 280 (1) ◽  
pp. L30-L38 ◽  
Author(s):  
Jun Araya ◽  
Muneharu Maruyama ◽  
Kazuhiko Sassa ◽  
Tadashi Fujita ◽  
Ryuji Hayashi ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Ionizing Radiation ◽  
Basement Membrane ◽  
Lung Injury ◽  
Human Lung ◽  
A549 Cells ◽  
Lung Epithelial Cells ◽  
Lung Epithelial ◽  
Radiation Induced ◽  
Human Lung Epithelial Cells

Radiation pneumonitis is a major complication of radiation therapy. However, the detailed cellular mechanisms have not been clearly defined. Based on the recognition that basement membrane disruption occurs in acute lung injury and that matrix metalloproteinase (MMP)-2 can degrade type IV collagen, one of the major components of the basement membrane, we hypothesized that ionizing radiation would modulate MMP-2 production in human lung epithelial cells. To evaluate this, the modulation of MMP-2 with irradiation was investigated in normal human bronchial epithelial cells as well as in A549 cells. We measured the activity of MMP-2 in the conditioned medium with zymography and the MMP-2 mRNA level with RT-PCR. Both of these cells constitutively expressed 72-kDa gelatinolytic activity, corresponding to MMP-2, and exposure to radiation increased this activity. Consistent with the data of zymography, ionizing radiation increased the level of MMP-2 mRNA. This radiation-induced increase in MMP-2 expression was mediated via p53 because the p53 antisense oligonucleotide abolished the increase in MMP-2 activity as well as the accumulation of p53 after irradiation in A549 cells. These results indicate that MMP-2 expression by human lung epithelial cells is involved in radiation-induced lung injury.

Ulinastatin Activated The ERK5/Mer Signaling Pathway To Promote Macrophage Efferocytosis And Ameliorate Lung Inflammation

2021 ◽  
Author(s):  
Jinju Li ◽  
Rongge Shao ◽  
Qiuwen Xie ◽  
XueKe Du
Keyword(s):  
Lung Injury ◽  
Signaling Pathway ◽  
Lung Inflammation ◽  
Raw264.7 Cells ◽  
Inflammatory Factors ◽  
Inflammatory Factor ◽  
Dependent Manner ◽  
Anti Inflammatory

Abstract Purpose:Ulinastatin (UTI) is an endogenous protease inhibitor with potent anti-inflammatory, antioxidant and organ protective effects. The inhibitor has been reported to ameliorate inflammatory lung injury but precise mechanisms remain unclear. Methods: An in vivo model of lung injury has been constructed by intratracheal infusion of lipopolysaccharide (LPS). The number of neutrophils and the phagocytosis of apoptotic neutrophils were observed by Diff- Quick method. Lung injury was observed by HE staining .BALF cells were counted by hemocytometer and concentrations of protein plus inflammatory factors were measured with a BCA test kit. During in vitro experiments, RAW264.7 cells were pretreated with UTI (1000 and 5000U/ mL), stained with CellTrackerTM Green B0DIPYTM and HL60 cells added with UV-induced apoptosis and PKH26 Red staining. The expression of ERK5\Mer related proteins was detected by western blot and immunofluorescence.Results: An in vivo model of lung injury has been constructed by intratracheal infusion of lipopolysaccharide (LPS). UTI treatment enhanced the phagocytotic effect of mouse alveolar macrophages on neutrophils, alleviated lung lesions, decreased the pro-inflammatory factor and total protein content of BALF and increased levels of anti-inflammatory factors. in vitro experiments ，UTI enhanced the phagocytosis of apoptotic bodies by RAW264.7 cells in a dose-dependent manner. Increased expression levels of ERK5 and Mer by UTI were shown by Western blotting and immunofluorescence.Conclusions: UTI mediated the activation of the ERK5/Mer signaling pathway, enhanced phagocytosis of neutrophils by macrophages and improved lung inflammation. The current study indicates potential new clinical approaches for accelerating the recovery from lung inflammation.

scholarly journals Downregulation of TNF-α/TNF-R1 Signals by AT-Lipoxin A4 May Be a Significant Mechanism of Attenuation in SAP-Associated Lung Injury

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Suhui Yu ◽  
Jianming Xie ◽  
Yukai Xiang ◽  
Shengjie Dai ◽  
Dinglai Yu ◽  
...  
Keyword(s):  
Lung Injury ◽  
Tumor Necrosis Factor Receptor ◽  
Microvascular Endothelial Cell ◽  
Death Domain ◽  
Lipoxin A4 ◽  
Proinflammatory Mediators ◽  
Anti Inflammatory ◽  
Significant Mechanism

Our previous studies verified the potent anti-inflammatory effects against severe acute pancreatitis (SAP) of AT-Lipoxin A4 and their analogues. However, the anti-inflammatory effects of AT-Lipoxin A4 on SAP-associated lung injury are not thoroughly known. We used western blot, polymerase chain reaction (PCR), and immunofluorescence to investigate the downregulation of TNF-α signals in cellular and animal models of SAP-associated lung injury following AT-Lipoxin A4 intervention. In vitro, we found that AT-Lipoxin A4 markedly suppressed protein expression in TNF-α signals in human pulmonary microvascular endothelial cell, such as tumor necrosis factor receptor-associated factor 2 (TRAF2), TNF-R1-associated death domain (TRADD), receptor-interacting protein (RIP), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. Moreover, AT-Lipoxin A4 inhibited downstream signals activated by TNF-α, including NF-κB/p65, JNK/MAPK, and ERK/MAPK. In vivo, AT-Lipoxin A4 significantly decreased pathological scores of the pancreas and lungs and the serum levels of IL-6 and TNF-α. Immunofluorescence, western blotting, and real-time PCR assay showed that AT-Lipoxin A4 significantly attenuated the expression of TNF-R1, TRADD, TRAF2, and RIP in the lungs of SAP rats. In addition, the activation of NF-κB was also downregulated by AT-Lipoxin A4 administration as compared with SAP rats. AT-Lipoxin A4 could inhibit the production of proinflammatory mediators and activation of TNF-α downstream signals such as NF-κB and MAPK. Downregulation of TNF-α signals by AT-Lipoxin A4 may be a significant mechanism in the attenuation of SAP-associated lung injury.

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