Inflammation In Lung Epithelial Cells Research Articles

Role of Mitophagy in Cigarette Smoke-induced Lung Epithelial Cell Injury In Vitro.

Mitochondria mediate airway inflammatory responses to cigarette smoke (CS). Removal of damaged or defective mitochondrial (mitophagy) may prevent the detrimental impact of CS extract (CSE) on airway and lung epithelial cells. We studied the effect of a mitophagy activator (Urolithin A, UA) and a mitophagy inhibitor (Liensinine diperchlorate, Ld) on CSE-exposed alveolar (A549) and airway (BEAS-2B) epithelial cell proliferation, intracellular and mitochondrial ROS, inflammatory response, mitochondrial membrane potential (Δψm), mitochondrial morphology, mitochondrial complex activities, and protein levels of mitochondrial fission (DRP1, MFF) and mitophagy (SQSTM1/p62, LC3B). In both cell types, CSE exposure led to increased intracellular and mitochondrial oxidative stress, decreased Δψm and resulted in structural disruption of the mitochondrial network. CSE increased the expression of DRP1, MFF and SQSTM1/p62 while decreasing LC3B-II/I protein expression ratio. CSE also increased inflammatory (IL-1β, IL-6, IL-18, CXCL1, CXCL8) and necroptosis factors (RIPK1, RIPK3, MLKL) mRNA expression. Pre-treatment with UA attenuated CSE-induced oxidative stress, inflammatory and necroptosis gene expression and restored mitochondrial structure and function. UA also prevented CSE-evoked increases in DRP1, MFF and SQSTM1/p62 protein expression and increased LC3B-II/I ratio. Conversely, pre-treatment with Ld aggravated CSE-induced cellular and mitochondrial responses. In conclusion, mitophagy mediates CSE-induced damage and inflammation of lung epithelial cells and may represent a therapeutic target in CS-driven diseases.

Human umbilical cord mesenchymal stromal cell small extracellular vesicle transfer of microRNA-223-3p to lung epithelial cells attenuates inflammation in acute lung injury in mice.

Acute lung injury (ALI), manifested as strong pulmonary inflammation and alveolar epithelial damage, is a life-threatening disease with high morbidity and mortality. Small extracellular vesicles (sEVs), secreted by multiple types of cells, are critical cellular communication mediators and can inhibit inflammation by transferring bioactive molecules, such as microRNAs (miRNAs). Thus, we hypothesized that sEVs derived from mesenchymal stromal cells (MSC sEVs) could transfer miRNAs to attenuate inflammation of lung epithelial cells during ALI. C57BL/6 male mice were intratracheally administered LPS (10mg/kg). Six hours later, the mice were randomly administered with MSC sEVs (40µg per mouse in 150µl of saline), which were collected by ultracentrifugation. Control group received saline administration. After 48h, the mice were sacrificed to evaluate pulmonary microvascular permeability and inflammatory responses. In vitro, A549 cells and primary human small airway epithelial cells (SAECs) were stimulated with LPS with or without MSC sEVs treatment. In vitro, MSC sEVs could also inhibit the inflammation induced by LPS in A549 cells and SAECs (reducing TNF-α, IL-1β, IL-6 and MCP-1). Moreover, MSC sEV treatment improved the survival rate, alleviated pulmonary microvascular permeability, and inhibited proinflammatory responses (reducing TNF-α, IL-1β, IL-6 and JE-1) in ALI mice. Notably, miR-223-3p was found to be served as a critical mediator in MSC sEV-induced regulatory effects through inhibition of poly (adenosine diphosphate-ribose) polymerase-1 (PARP-1) in lung epithelial cells. Overall, these findings suggest that MSC sEVs may offer a novel promising strategy for ALI.

Cholinergic α7 nAChR signaling suppresses SARS-CoV-2 infection and inflammation in lung epithelial cells.

Cholinergic α7 nAChR signaling suppresses SARS-CoV-2 infection and inflammation in lung epithelial cells.

Inhibition of PERK Kinase, an Orchestrator of the Unfolded Protein Response (UPR), Significantly Reduces Apoptosis and Inflammation of Lung Epithelial Cells Triggered by SARS-CoV-2 ORF3a Protein.

SARS-CoV-2 ORF3a accessory protein was found to be involved in virus release, immunomodulation and exhibited a pro-apoptotic character. In order to unravel a potential ORF3a-induced apoptotic and inflammatory death mechanism, lung epithelial cells (A549) were transfected with in vitro synthesized ORF3a mRNA. The protein's dynamic involvement as "stress factor" for the endoplasmic reticulum, causing the activation of PERK kinase and other UPR-involved proteins and therefore the upregulation of their signaling pathway executioners (ATF6, XBP-1s, PERK, phospho eIF2a, ATF4, CHOP, GADD34), has been clearly demonstrated. Furthermore, the overexpression of BAX and BH3-only pro-apoptotic protein PUMA, the upregulation of Bcl-2 family genes (BAX, BAK, BID, BAD), the reduced expression of Bcl-2 in mRNA and protein levels, and lastly, the cleavage of PARP-1 and caspase family members (caspase-3,-8 and -9) indicate that ORF3a displays its apoptotic character through the mitochondrial pathway of apoptosis. Moreover, the upregulation of NFκB, phosphorylation of p65 and IκΒα and the elevated expression of pro-inflammatory cytokines (IL-1b, IL-6, IL-8 and IL-18) in transfected cells with ORF3a mRNA indicate that this protein causes the inflammatory response through NFκB activation and therefore triggers lung injury. An intriguing finding of our study is that upon treatment of the ORF3a-transfected cells with GSK2606414, a selective PERK inhibitor, both complications (apoptosis and inflammatory response) were neutralized, and cell survival was favored, whereas treatment of transfected cells with z-VAD (a pan-caspase inhibitor) despite inhibiting cell death, could not ameliorate the inflammatory response of transfected A549 cells. Given the above, we point out that PERK kinase is a "master tactician" and its activation constitutes the main stimulus for the emergence of ORF3a apoptotic and inflammatory nature and therefore could serve as potential target for developing novel therapeutic approaches against COVID-19.

Metabolomic, DNA Methylomic, and Transcriptomic Profiling of Suberoylanilide Hydroxamic Acid Effects on LPS-Exposed Lung Epithelial Cells.

Inflammation increases the risk of lung cancer and blocking inflammation could reduce the incidence of lung cancer. Herein, we demonstrate that histone deacetylase inhibitor suberoylanilide hydroxamic acid regulates metabolic rewiring and epigenetic reprogramming to attenuate lipopolysaccharide-driven inflammation in lung epithelial cells.

Sirtuin3 Alleviated Influenza A Virus-Induced Mitochondrial Oxidative Stress and Inflammation in Lung Epithelial Cells via Regulating Poly (ADP-Ribose) Polymerase 1 Activity

Introduction: Influenza A virus (IAV) infection causes severe lung inflammation and injury, particularly in children. Sirtuin3 (Sirt3) was confirmed to be effective in protecting the lung against injury. This study aims to explore the function and mechanism of Sirt3 on influenza development in children. Methods: The Sirt3 level in serum samples from IAV-infected children and lung epithelial cells were detected using RT-qPCR, ELISA, and Western blot assays. Cell viability and apoptosis were determined by MTT and flow cytometry assays. Virus titration was conducted by determining TCID₅₀. Cell inflammatory response was detected by a battery of inflammatory cytokines. The contents of ROS and ATP, mitochondrial membrane potential level, and oxygen-consumption rate were examined to reflect on oxidative stress and mitochondrial dysfunction. The activity of poly (ADP-ribose) polymerase 1 (PARP-1) was measured by colorimetry. Results: Sirt3 was downregulated in IAV-infected children’s serum samples and BEAS-2B cells. Overexpression of Sirt3 alleviated IAV replication and IAV-induced inflammatory injury, oxidative stress, and mitochondrial dysfunction in lung epithelial cells. Moreover, upregulation of Sirt3 deacetylated SOD2 and PARP-1 and inhibited the PARP-1 activity. Notably, the Sirt3 inhibitor (3-TYP) and PARP-1 activity agonist (nicotinamide) reversed the effects of Sirt3 overexpression on IAV replication and IAV-induced injury. Conclusion: Overexpression of Sirt3 attenuated IAV-evoked inflammatory injury and mitochondrial oxidative stress through the inhibition of PARP-1 activity in lung epithelial cells.

Poldip2/Nox4 Mediates Lipopolysaccharide-Induced Oxidative Stress and Inflammation in Human Lung Epithelial Cells.

NADPH oxidase 4 (Nox4) is an important source of reactive oxygen species (ROS) production, and its expression is increased in lipopolysaccharide- (LPS-) stimulated lung epithelial cells. Polymerase δ-interacting protein 2 (Poldip2) has been proved to bind Nox4 and participates in oxidative stress and inflammation. However, the role of Poldip2/Nox4 in LPS-induced oxidative stress and inflammation in lung epithelial cells remains unclear. Cell viability was measured via MTT assays. The expression of Poldip2, Nox4, heme oxygenase-1 (HO-1), cyclooxygenase-2 (COX-2), AKT, and p-AKT was detected by Western blotting and/or immunofluorescence. Poldip2 and Nox4 interaction was analyzed via coimmunoprecipitation (Co-IP) assay. NADPH enzymatic activity and production of ROS, prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) were assessed simultaneously. The small interfering RNA (siRNA) or plasmid targeting Nox4 was used to downregulate or upregulate Nox4, and the lentiviral vector encoding Poldip2 was used to downregulate or upregulate Poldip2. The present study demonstrated that LPS stimulation significantly increased the protein levels of Poldip2 and Nox4 and proved that Poldip2 interacted with Nox4 proved by Co-IP. Importantly, Poldip2 acted as an upstream regulator of Nox4. The increased expression of Nox4 and COX-2; NADPH enzymatic activity; production of ROS, PGE2, TNF-α, and IL-1β; and decreased HO-1 expression were significantly suppressed by lentiviral Poldip2 shRNA downregulation but were increased by lentiviral upregulation of Poldip2. Furthermore, inhibiting of PI3K-AKT signaling notably attenuated LPS-induced Poldip2/Nox4 activation. Our study demonstrated that Poldip2 mediates LPS-induced oxidative stress and inflammation via interaction with Nox4 and was regulated by the PI3K-AKT signaling. Targeting Poldip2 could be a beneficial therapeutic strategy for the treatment of ALI.

Ubiquitin specific peptidase 25 alleviates acute lung injury and suppresses the inflammatory response in lung epithelial cells.

As COVID-19 spreads over the world, the treatment of acute lung injury (ALI) has attracted much attention. Considering ubiquitin-specific protease (USP) 25 has been relevant to inflammation, this article focused on its role in ALI and its regulatory mechanism. Lipopolysaccharide (LPS) was applied to separately stimulate mice and human lung epithelial cells to establish in vivo and in vitro ALI models. To discover the effects of USP25 overexpression on mouse, lung pathology, inflammatory factor levels, edema, number of inflammatory cells, and downstream protein levels were evaluated. USP25 overexpression in mice could alleviate LPS-induced lung tissue lesions and edema, and reduce inflammatory factors and inflammatory cells. It also inhibited the levels of downstream TRAF6, MAPK pathway-related proteins, and Fos Proto-Oncogene (FOS) in vivo. Furthermore, BEAS-2B cells were transfected with TNF receptor-associated factor 6 (TRAF6) plasmids to study the role of TRAF6 in the regulatory mechanism of USP25. TRAF6 overexpression was found to reverse the functions of USP25 overexpression on cells. In conclusion, USP25 reduced ALI and inhibited inflammation in lung epithelial cells via regulating TRAF6/MAPK/FOS signaling.

Vitamin D3 decreases TNF-α-induced inflammation in lung epithelial cells through a reduction in mitochondrial fission and mitophagy.

Previous work has shown an association between vitamin D3 deficiency and an increased risk for acquiring various inflammatory diseases. Vitamin D3 can reduce morbidity and mortality in these patients via different mechanisms. Lung inflammation is an important event in the initiation and development of respiratory disorders. However, the anti-inflammatory effects of vitamin D3 and the underlying mechanisms remained to be determined. The purpose of this study was to examine the effects and mechanisms of action of vitamin D3 (Vit. D) on the expression of intercellular adhesion molecule-1 (ICAM-1) in vitro and in vivo with or without tumor necrosis factor α (TNF-α) treatment. Pretreatment with Vit. D reduced the expression of ICAM-1 and leukocyte adhesion in TNF-α-treated A549 cells. TNF-α increased the accumulation of mitochondrial reactive oxygen species (mtROS), while Vit. D reduced this effect. Pretreatment with Vit. D attenuated TNF-α-induced mitochondrial fission, as shown by the increased expression of mitochondrial fission factor (Mff), phosphorylated dynamin-related protein 1 (p-DRP1), and mitophagy-related proteins (BCL2/adenovirus E1B 19 kDa protein-interacting protein 3, Bnip3) in A549 cells. Inhibition of DRP1 or Mff significantly decreased ICAM-1 expression. In addition, we found that Vit. D decreased TNF-α-induced ICAM-1 expression, mitochondrial fission, and mitophagy via the AKT and NF-κB pathways. Moreover, ICAM-1 expression, mitochondrial fission, and mitophagy were increased in the lung tissues of TNF-α-treated mice, while Vit. D supplementation reduced these effects. In this study, we elucidated the mechanisms by which Vit. D reduces the expression of adhesion molecules in models of airway inflammation. Vit. D might be served as a novel therapeutic agent for the targeting of epithelial activation in lung inflammation.Graphical abstract Graphical Headlights: • The expression of DRP1 and Mff, mitochondrial fission-related proteins, was increased in TNF-α-treated A549 cells.• The expression of Bnip3 and LC3B, mitophagy-related proteins, was increased in TNF-α-treated A549 cells.• Vit. D pretreatment decreased TNF-α-induced inflammation through the reduction of mitochondrial fission and mitophagy in A549 cells.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10565-021-09629-6.

Cannabis compounds exhibit anti-inflammatory activity in vitro in COVID-19-related inflammation in lung epithelial cells and pro-inflammatory activity in macrophages

Cannabis sativa is widely used for medical purposes and has anti-inflammatory activity. This study intended to examine the anti-inflammatory activity of cannabis on immune response markers associated with coronavirus disease 2019 (COVID-19) inflammation. An extract fraction from C. sativa Arbel strain (FCBD) substantially reduced (dose dependently) interleukin (IL)-6 and -8 levels in an alveolar epithelial (A549) cell line. FCBD contained cannabidiol (CBD), cannabigerol (CBG) and tetrahydrocannabivarin (THCV), and multiple terpenes. Treatments with FCBD and a FCBD formulation using phytocannabinoid standards (FCBD:std) reduced IL-6, IL-8, C–C Motif Chemokine Ligands (CCLs) 2 and 7, and angiotensin I converting enzyme 2 (ACE2) expression in the A549 cell line. Treatment with FCBD induced macrophage (differentiated KG1 cell line) polarization and phagocytosis in vitro, and increased CD36 and type II receptor for the Fc region of IgG (FcγRII) expression. FCBD treatment also substantially increased IL-6 and IL-8 expression in macrophages. FCBD:std, while maintaining anti-inflammatory activity in alveolar epithelial cells, led to reduced phagocytosis and pro-inflammatory IL secretion in macrophages in comparison to FCBD. The phytocannabinoid formulation may show superior activity versus the cannabis-derived fraction for reduction of lung inflammation, yet there is a need of caution proposing cannabis as treatment for COVID-19.

STIM1 mediates IAV-induced inflammation of lung epithelial cells by regulating NLRP3 and inflammasome activation via targeting miR-223

AimsInfluenza A virus (IAV) infection accelerates the inflammatory injury of lung epithelial cells that contributes to pulmonary lesion. Recently, stromal interaction molecule 1 (STIM1) was found to mediate cellular immune response and participated in lung tumorigenesis. Our study aimed to illustrate the function and mechanism of STIM1 in IAV-induced inflammation injury and oxidative stress of lung epithelial cells. Main methodsWe evaluated the levels of STIM1 in IAV-infected patients' serum and BEAS-2B cells using RT-qPCR, Elisa and western blotting methods. MTT and Elisa were performed to measure cell viability and cytokine contents. Besides, ROS intensity, SOD contents and cell apoptosis were detected based on DCFH-DA probe, colorimetry and cell death kits. A luciferase assay and Pearson's correlation analysis evaluated the associations between target genes. Key findingsSTIM1 was dramatically up-regulated in IAV-infected patients' serum and BEAS-2B cells. Silencing STIM1 in vitro inhibited oxidative stress and inflammatory responses induced by IAV, and reversed cell viability and suppressed apoptosis. Moreover, miR-223 and NLRP3 were negatively and positively correlated with STIM1. STIM1 was found to regulate NLRP3 expression by binding the AACUGAC motif in miR-223. STIM1/miR-223/NLRP3 axis modulated IAV-induced inflammation injury of lung epithelial cells. SignificanceOur evidence indicated that silencing STIM1 alleviated IAV-induced inflammation injury of lung epithelial cells by inactivating NLRP3 and inflammasome via promoting miR-223 expression. These findings may contribute to understand the mechanism of IAV-induced lung injury and help for therapy of IAV infection.

Invited commentary

Invited commentary

Oxidatively Damaged Mitochondrial DNA Induces Inflammation in Lung Epithelial Cells

Pulmonary epithelial cells are key effectors and targets in the pathogenesis of inflammatory lung diseases such as asthma, and chronic obstructive pulmonary disease, among others. Oxidative stress has been implicated at the earliest step in development of lung inflammation, but the molecular mechanisms of how oxidative injury to epithelial cells develops inflammatory response remain unclear. While investigating the mechanisms responsible for activating inflammation in response to prolonged, low-level oxidative stress, we identified a role for an active and selective cellular extrusion of damaged mitochondrial DNA, that did not affect cellular viability. Selective release of damaged mitochondrial DNA, first into the cytoplasm where it binds to intracellular DNA sensor and subsequently into the extracellular space, triggers autocrine and paracrine modes of the inflammatory response. In vivo, intratracheal administration of the isolated mtDNA induces production of pro-inflammatory mediators in lungs of naive mice without tissue injury. Extrusion of mtDNA also occurs in vivo into the bronchoalveolar lavage fluid of mice subjected to cigarette smoke injury. We proposed that inflammation triggered by mtDNA-specific damage contribute to development of inflammatory lung diseases.

14,15-Epoxyeicosatrienoic acid suppresses cigarette smoke condensate-induced inflammation in lung epithelial cells by inhibiting autophagy.

Epoxyeicosatrienoic acids (EETs) are metabolic products of free arachidonic acid, which are produced through cytochrome P-450 (CYP) epoxygenases. EETs have anti-inflammatory, antiapoptotic, and antioxidative activities. However, the effect of EETs on cigarette smoke-induced lung inflammation is not clear. Autophagy is believed to be involved in the pathogenesis of chronic obstructive pulmonary disease. In addition, nuclear erythroid-related factor 2 (Nrf2), a transcription factor that regulates many antioxidant genes, is thought to regulate antioxidant defenses in several lung diseases. In addition, interaction between EETs, autophagy, and Nrf2 has been reported. The aim of this study was to explore the effect of 14,15-EET on cigarette smoke condensate (CSC)-induced inflammation in a human bronchial epithelial cell line (Beas-2B), and to determine whether the underlying mechanisms involved in the regulation of Nrf2 through inhibition of autophagy. Autophagy and expression of autophagy signaling pathway proteins (LC3B, p62, PI3K, Akt, p-Akt, and p-mTOR) and anti-inflammatory proteins (Nrf2 and HO-1) were assessed via Western blot analysis. Autophagosomes and autolysosomes were detected by adenoviral mRFP-GFP-LC3 transfection. Inflammatory factors (IL-6, IL-8, and MCP-1) were detected by ELISA. Lentiviral vectors carrying p62 short hairpin RNA were used to interfere with p62 expression to evaluate the effect of p62 on Nrf2 expression. Nrf2 expression was determined through immunocytochemistry. 14,15-EET treatment resulted in a significant reduction in IL-6, IL-8, and MCP-1 secretion, and increased accumulation of Nrf2 and expression of HO-1. In addition, 14,15-EET inhibited CSC-induced autophagy in Beas-2B cells. The mechanism of the anti-inflammatory effect of 14,15-EET involved inhibition of autophagy and an increase in p62 levels, followed by translocation of Nrf2 into the nucleus, which then upregulated expression of the antioxidant enzyme HO-1. 14,15-EET protects against CSC-induced lung inflammation by promoting accumulation of Nrf2 via inhibition of autophagy.

Cryptoporus volvatus polysaccharides attenuate LPS-induced expression of pro-inflammatory factors via the TLR2 signaling pathway in human alveolar epithelial cells

Context: Cryptoporus volvatus (Peck) Hubb grows wild in China, and its fruiting bodies have been used traditionally to treat asthma and bronchitis.Objectives: This study evaluates the anti-inflammatory effect of Cryptoporus polysaccharides (CP) extracted from fruiting bodies of C. volvatus on lipopolysaccharide (LPS)-induced pro-inflammatory factors and the signaling pathways involved in human alveolar epithelial cells.Materials and methods: To evaluate the effects of CP on LPS-induced pro-inflammatory factors, A549 cells were pre-incubated with CP 1, 10, and 100 μg/ml for 1 h and then stimulated with LPS 10 μg/ml for 24 h. The expression of pro-inflammatory factors monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), Toll-like receptor 2 (TLR2), and phosphorylation of ERK1/2, p38, and NF-κB p65 were measured by q-PCR, ELISA, and western blotting.Results: CP decreased LPS-induced mRNA expression of MCP-1, TNF-α, and IL-1β (IC50 = 83.3, 85.2, and 91.6 μg/ml, respectively) and their correspondent protein expression (IC50 = 88.6, 76.4, and 81.6 μg/ml, respectively). Investigation of potential mechanisms indicated that CP 100 μg/ml reduced LPS-induced expression of TLR2 mRNA (66.9%, p < 0.01) and protein (63.2%, p < 0.01) that was a result of the decreased pro-inflammatory factors. LPS induction increased the expression of TLR2 and the phosphorylation of p38 and ERK1/2, NF-kB p65 concomitantly. CP 100 μg/ml inhibited the LPS-induced phosphorylation of the signaling proteins (p < 0.05).Conclusions: This suggests that CP pretreatment down-regulates LPS-mediated inflammation in lung epithelial cells. This study further confirmed that CP is a potential anti-inflammatory drug for the treatment of airway inflammatory diseases.

0987. FAS activation alters tight junction proteins in pulmonary alveolar epithelial cells

Active soluble Fas ligand (sFasL) accumulates in lung fluid of patients with acute respiratory distress syndrome (ARDS), and causes apoptosis and inflammation in lung epithelial cells [1]. Alveolar epithelial damage induced by Fas receptor activation results in protein-rich lung edema [2]. Dysfunction of the tight junction proteins may contribute to the formation of lung edema.

Monascin attenuates oxidative stress-mediated lung inflammation via peroxisome proliferator-activated receptor-gamma (PPAR-γ) and nuclear factor-erythroid 2 related factor 2 (Nrf-2) modulation.

We speculated that peroxisome proliferator-activated receptor (PPAR)-γ agonists may modulate the oxidative stress pathway to ameliorate the development of airway inflammation. The effect of Monascus-fermented metabolite monascin (MS) and rosiglitazone (Rosi) on oxidative stress-induced lung inflammation was evaluated. Luciferase assay and DNA binding activity assay were used to point out that MS may be a novel PPAR-γ agonist and nuclear factor-erythroid 2 related factor 2 (Nrf-2) activator. We used hydrogen peroxide (H2O2) to induce inflammation in lung epithelial cells. MS and Rosi prevented H2O2-induced ROS generation in A549 epithelial cells through PPAR-γ translocation, avoiding inflammatory mediator expression via inhibiting nuclear factor (NF)-κB translocation. The regulatory ability of MS was abolished by siRNA against PPAR-γ. MS also elevated antioxidant enzyme expression via Nrf-2 activation. Both PPAR-γ and Nrf-2 might have benefits against lung inflammation. MS regulated PPAR-γ and Nrf-2 to improve lung oxidative inflammation.

Pulmonary oxidative stress, inflammation and cancer: respirable particulate matter, fibrous dusts and ozone as major causes of lung carcinogenesis through reactive oxygen species mechanisms.

Reactive oxygen or nitrogen species (ROS, RNS) and oxidative stress in the respiratory system increase the production of mediators of pulmonary inflammation and initiate or promote mechanisms of carcinogenesis. The lungs are exposed daily to oxidants generated either endogenously or exogenously (air pollutants, cigarette smoke, etc.). Cells in aerobic organisms are protected against oxidative damage by enzymatic and non-enzymatic antioxidant systems. Recent epidemiologic investigations have shown associations between increased incidence of respiratory diseases and lung cancer from exposure to low levels of various forms of respirable fibers and particulate matter (PM), at occupational or urban air polluting environments. Lung cancer increases substantially for tobacco smokers due to the synergistic effects in the generation of ROS, leading to oxidative stress and inflammation with high DNA damage potential. Physical and chemical characteristics of particles (size, transition metal content, speciation, stable free radicals, etc.) play an important role in oxidative stress. In turn, oxidative stress initiates the synthesis of mediators of pulmonary inflammation in lung epithelial cells and initiation of carcinogenic mechanisms. Inhalable quartz, metal powders, mineral asbestos fibers, ozone, soot from gasoline and diesel engines, tobacco smoke and PM from ambient air pollution (PM10 and PM2.5) are involved in various oxidative stress mechanisms. Pulmonary cancer initiation and promotion has been linked to a series of biochemical pathways of oxidative stress, DNA oxidative damage, macrophage stimulation, telomere shortening, modulation of gene expression and activation of transcription factors with important role in carcinogenesis. In this review we are presenting the role of ROS and oxidative stress in the production of mediators of pulmonary inflammation and mechanisms of carcinogenesis.

Human acidic mammalian chitinase (AMCase); molecular cloning, protein expression, and production of monoclonal antibody

Event Abstract Back to Event Human acidic mammalian chitinase (AMCase); molecular cloning, protein expression, and production of monoclonal antibody Kanokwan Lowhalidanon1, Piyanat Meekrathok1, Sunisa Thongsom1, Wipa Suginta1 and Panida Khunkaewka1* 1 Suranaree University of Technology, Biochemistry-Electrochemistry Research Unit, Thailand Human acidic mammalian chitinase (AMCase), is a 50 kDa protein containing a 30 kDa N-terminal catalytic domain that can hydrolyze chitin. This enzyme belongs to family 18 glycosyl hydrolases. High abundant of this enzyme was found in gastrointestinal tract. In lung, interleukin-13 was proposed to play a key role as primary effector that induces secretion of AMCase by airway epithelial cells and macrophages. The secreted AMCase activates elevation of monocyte chemoattractant protein 1 (MCP-1) and eotaxin-1, which induce the recruitment of eosinophils, T cells, and macrophages to site of inflammation in lung epithelial cells. Nonetheless, the mechanisms underlying AMCase mediated cells recruitment and its surface receptor have not been identified. Present study, the gene encoding AMCase was isolated from the human cDNA, cloned into pQE-tri vector, and the recombinant protein was expressed in E. coli M15. The affinity-purified AMCase was further used as immunogen for monoclonal antibody (mAb) production by standard hybridroma technique. Two specific mAbs against AMCase were successfully raised and named as 4G1 and 6E5. Both monoclones belong to IgG1 isotype. Western blot analysis showed that the mAbs strongly reacted with a corresponding protein with molecular weight of about 50 kDa in human acute monocytic leukemia cell line, THP1, and peripheral blood mononuclear cells. In conclusion, the AMCase was cloned and expressed in E. Coli system. Two specific mAbs to AMCase were raised and specifically reacted to human AMCase. The generated mAbs will be used for further functional analysis of the AMCase in regulation of the immune system. Acknowledgements This work was supported by the National Research Council of Thailand and Suranaree University of Technology, Thailand. References Louise E. Donnelly and Peter J. Barnes. (2004). Acidic mammalian chitinase – a potential target for asthma therapy. TRENDS in Pharmacological Science Vol.25. Keywords: AMCase, Molecular cloning, protein expression, Monoclonal antibody, Asthma Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Immune-mediated disease pathogenesis Citation: Lowhalidanon K, Meekrathok P, Thongsom S, Suginta W and Khunkaewka P (2013). Human acidic mammalian chitinase (AMCase); molecular cloning, protein expression, and production of monoclonal antibody. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00189 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 11 Mar 2013; Published Online: 22 Aug 2013. * Correspondence: Dr. Panida Khunkaewka, Suranaree University of Technology, Biochemistry-Electrochemistry Research Unit, Nakhonratchasima, 30000, Thailand, kpanida@sut.ac.th Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Kanokwan Lowhalidanon Piyanat Meekrathok Sunisa Thongsom Wipa Suginta Panida Khunkaewka Google Kanokwan Lowhalidanon Piyanat Meekrathok Sunisa Thongsom Wipa Suginta Panida Khunkaewka Google Scholar Kanokwan Lowhalidanon Piyanat Meekrathok Sunisa Thongsom Wipa Suginta Panida Khunkaewka PubMed Kanokwan Lowhalidanon Piyanat Meekrathok Sunisa Thongsom Wipa Suginta Panida Khunkaewka Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.