Lung as a target for COVID-19: Mechanistic insights and probable candidate molecules for cure.

Novel coronavirus (SARS nCoV2), belonging to the family coronaviridae, remains a dreadful pathogen affecting the respiratory tract and lungs. COVID-19 declared a global pandemic by WHO, has become a serious cause of concern for clinicians and researchers, who need to understand the significant biology and pathogenicity of this virus to design better treatment modalities. Existing antiretroviral drugs remain partially ineffective in critical subjects with associated co-morbidities. This review provides an insight into the molecular mechanisms by which SARS-CoV2 targets the lungs leading to ARDS in severe cases. This also addresses the possible drug targets and certain anti-inflammatory natural compounds that can be looked upon as promising adjuvant therapeutics for COVID-19.

Abnormal expression profile of plasma exosomal microRNAs in exclusive electronic cigarette adult users.

Background: Exposure to electronic cigarette (e-cigarette) aerosol has been linked to several health concerns, including DNA damage, elevated oxidative stress, the release of inflammatory cytokine, and dysfunctions in epithelial barriers. However, little is known about the effect of exclusive e-cigarette use on expression profiles of exosomal miRNAs, which play critical regulatory roles in many inflammatory responses and disease processes including cancer. We aim to compare the exosomal microRNA expression profile between exclusive e-cigarette users and normal controls without any tobacco product use (non-users). Methods: Using plasma samples from 15 exclusive e-cigarette users and 15 non-users in the Population Assessment of Tobacco and Health (PATH) Wave 1 study (2013-2014), we examined exosomal microRNAs expression levels through Illumina NextSeq 500/550 sequencing. The differential analyses between exclusive e-cigarette users and non-users were examined using the generalized linear model approach in the DESeq2 package in R/Bioconductor after adjusting the significant confounding effect from race. Gene enrichment analyses were conducted on target genes regulated by significant microRNAs in the differential analyses. Further, molecular-based techniques using the micro RNA mimics and inhibitors were applied for the validation of the expressions of the micro RNAs in vitro. Results: We identified four microRNAs that have significantly higher expression levels in exclusive e-cigarette users than non-users including hsa-miR-100-5p, hsa-miR-125a-5p, hsa-miR-125b-5p, and hsa-miR-99a-5p. GO enrichment analysis on the target genes regulated by the four microRNAs showed that dysregulation of the four microRNAs in exclusive e-cigarette users involved in multiple cell processes such as protein kinase binding and miRNA metabolic process. KEGG pathway enrichment analysis found the four upregulated miRNAs in exclusive e-cigarette users involved in many cancer pathways such as the non-small cell lung cancer, small cell lung cancer, pancreatic cancer, p53 signaling pathway, Hippo signaling pathway, HIF-1 signaling pathway, and MAPK signaling pathway. Overexpression of miRNA hsa-miR-125b-5p was shown to promote DNA damage in bronchial epithelia cells. Conclusions: Four plasma exosomal microRNAs involved in cancer development had higher expression levels in exclusive e-cigarette users than non-users, which might indicate a potentially elevated risk of cancer among exclusive e-cigarette users.

Corrigendum to "The role of synthetic coolants, WS-3 and WS-23, in modulating E-cigarette-induced reactive oxygen species (ROS) in lung epithelial cells" [Toxicol. Rep. 9 (2022) 1700-1709].

[This corrects the article DOI: 10.1016/j.toxrep.2022.08.007.].

Impact of aging on immune function in the pathogenesis of pulmonary diseases: potential for therapeutic targets.

INTRODUCTION: Several immunological alterations that occur during pulmonary diseases often mimic alterations observed in the aged lung. From the molecular perspective, pulmonary diseases and aging partake in familiar mechanisms associated with significant dysregulation of the immune systems. Here, we summarized the findings of how aging alters immunity to respiratory conditions to identify age-impacted pathways and mechanisms that contribute to the development of pulmonary diseases. AREAS COVERED: The current review examines the impact of age-related molecular alterations in the aged immune system during various lung diseases, such as COPD, IPF, Asthma, and alongside many others that could possibly improve on current therapeutic interventions. Moreover, our increased understanding of this phenomenon may play a primary role in shaping immunomodulatory strategies to boost outcomes in the elderly. Here, the authors present new insights into the context of lung-related diseases and describe the alterations in the functioning of immune cells during various pulmonary conditions altered with age. EXPERT OPINION: The expert opinion provided the concepts on how aging alters immunity during pulmonary conditions, and suggests the associated mechanisms during the development of lung diseases. As a result, it becomes important to comprehend the complex mechanism of aging in the immune lung system.

Classification, Perception, and Toxicity of Emerging Flavored Oral Nicotine Pouches.

INTRODUCTION: Oral Nicotine Pouches (ONPs) are the new form of nicotine pouches that have become a type of emerging smokeless tobacco product sold by various tobacco companies. These smokeless tobacco products are marketed for usage all over as snus containing tobacco-derived nicotine (natural) or as tobacco-free nicotine (synthetic) as substitutes for other tobacco products. Based on perception and socio-behavioral aspects, ONPs have become popular tobacco products among adolescents/young adults, and over 50% of young adult users of ONP use flavored ONPs, such as menthol/mint, tobacco, dessert/candy, and fruity, which are the most popular flavors. Various new ONP flavors are currently popular locally as well as in the online market. Tobacco, menthol, and fruit-flavored ONPs could motivate cigarette smokers to change to ONPs. METHODS: We expanded our knowledge on natural/synthetic ONP flavor wheels to available data on ONPs, describing, in detail, their flavors and brands (US and Europe) in both natural and synthetic ONP categories. We classified over 152 snus and 228 synthetic ONPs into the following flavor categories: "Tobacco", "Menthol/Mint", "Fruity", "Candy/Deserts", "Drink", "Aroma", "Spices", and "Mixed Flavors". RESULTS: Based on total numbers, we found the most popular ONP flavors, sold as tobacco and menthol, to be among natural ONPs; among synthetic ONPs, fruity and menthol are the most prominent flavors, with varying concentrations of nicotine and other flavoring chemicals, including coolant WS-23. We also showed possible molecular targets and toxicities, due to exposure to ONPs, activating several signaling cascades such as AKT and NF-kappaB, which might possibly lead to apoptosis and epithelial mesenchymal transition (EMT). CONCLUSIONS: Considering the marketing of ONP products with various flavor profiles and with most of these products containing tobacco/menthol/fruit flavor, it is likely to have regulation and a marketing disclaimer on some of these products. Further, it would be logical to determine how the market reacts in terms of compliance and non-compliance with flavor restrictions by the regulatory agencies.

Alterations in mRNA Expression Levels of Tight Junction Proteins in the Blood Cells of Smokers with or without COPD.

AIM: This study aimed to assess the role of Tight junction proteins (TJPs) and claudins in smokers with and without COPD compared to healthy individuals. BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a complex chronic respiratory disease, including various inflammatory mediators. The prime etiological element in the development of COPD is cigarette smoking. The lung airway epithelium comprises beneficial immunological barriers to draw in insults, such as environmental particulates, cigarette smoke, etc. Tight junctions (TJ) connected by transmembrane proteins determine epithelial permeability. Cigarette smoke is indicated to defect TJ integrity. The possible involvement of the airway epithelium in the pathogenesis of COPD has recently become apparent; however, its detailed mechanisms remain elusive. The integrity of airway epithelium is crucial for airway homeostasis; defective airway barrier activity contributes to COPD. OBJECTIVE: In the present study, the objective was to investigate mRNA expression levels of TJP's like TJP-1, TJP-2, TJP-3, Tight junction-associated proteins-1, claudin-1, claudin-3, claudin-4, claudin-7, claudin-10, claudin-15, claudin-19, and claudin-25 from blood samples of smokers with COPD and compared them with smokers without COPD and healthy individuals. METHODS: The mRNA expressions were evaluated by the quantitative PCR method. RESULTS: The gene expressions of these TJPs were significantly down-regulated, specifically in COPD patients with a history of smoking (Smokers with COPD). Besides, FEV% was also established for these patients. Similarly, smokers with COPD showed a significant increase in the expression levels of transcription factors, like ZEB-1, ZEB-2, PDGFA, and HDGF, compared to COPD patients without a history of smoking (smokers without COPD) and the healthy subjects. CONCLUSION: In conclusion, cigarette smoke disrupts TJ of the human airway epithelium, and the transcriptional factors counteract this smoke-induced COPD. Thus, TJPs may serve as protective elements for airway epithelial homeostasis during COPD.

The role of synthetic coolants, WS-3 and WS-23, in modulating E-cigarette-induced reactive oxygen species (ROS) in lung epithelial cells.

There has been a substantial rise in e-cigarette (e-cig) use or vaping in the past decade, prompting growing concerns about their adverse health effects. Recently, e-cig manufacturers have been using synthetic cooling agents, like WS-23 and WS-3, to provide a cooling sensation without the "menthol taste". Studies have shown that aerosols/vapes generated by e-cigs can contain significant levels of reactive oxygen species (ROS). However, studies investigating the role of synthetic coolants in modulating ROS levels generated by e-cigs are lacking. This study seeks to understand how synthetic coolants, e-cig additives that have become increasingly prevalent in e-liquids sold in the United States (US), impact acellular ROS production from e-liquid aerosols as well as cellular ROS levels from pulmonary epithelial cells exposed to these e-liquids. To further explain, our study aims to understand whether the addition of WS-3 and WS-23 to e-liquid base and e-liquid base with nicotine significantly modifies generated acellular ROS levels within aerosolized e-liquids, as well as cellular ROS within BEAS-2B cells treated with these same e-liquids. Aerosols were generated from e-liquids with and without synthetic coolants through a single-puff aerosol generator; subsequently, acellular ROS was semi-quantified in H2O2 equivalents via fluorescence spectroscopy. Our acellular ROS data suggest that adding WS-3 to e-liquid base (PG:VG), regardless of nicotine content, has a minimal impact on modifying e-cig generated acellular ROS levels. Additionally, we also measured cellular ROS in lung epithelial cells using both e-liquids containing and not containing synthetic coolants via the CellROX Green fluorescent sensor. Similar comparable results were found in BEAS2B cells though ROS was increased by WS-3 and WS-23 treated in e-cig nicotine groups. Altogether, our data suggest that neither the addition of WS-23 nor WS-3 to e-liquid base solution, with and without nicotine, significantly modifies e-cig generated acellular ROS levels within aerosolized e-liquids and cellular ROS levels within treated BEAS-2B cells. Together, our data provide insight into whether synthetic coolants added to e-liquids could impact vaping-induced oxidative stress in the lungs.

Flavor Classification/Categorization and Differential Toxicity of Oral Nicotine Pouches (ONPs) in Oral Gingival Epithelial Cells and Bronchial Epithelial Cells.

Oral nicotine pouches (ONPs) are a modern form of smokeless tobacco products sold by several brands in the U.S., which comprise a significant portion of non-combustible nicotine-containing product (NCNP) sales to date. ONPs are available in various flavors and may contain either tobacco-derived nicotine (TDN) or tobacco-free nicotine (TFN). The growth in popularity of these products has raised concerns that flavored ONPs may cause adverse oral health effects and promote systemic toxic effects due to nicotine and other ONP by-products being absorbed into the circulatory system through oral mucosa. We hypothesized that flavored ONPs are unsafe and likely to cause oral and pulmonary inflammation in oral and respiratory epithelial cells. Before analyzing the effects of ONPs, we first classified ONPs sold in the U.S. based on their flavor and the flavor category to which they belonged using a wheel diagram. Human gingival epithelial cells (HGEP) were treated with flavored ONP extracts of tobacco (original, smooth), menthol (wintergreen and cool cider), and fruit flavor (americana and citrus), each from the TDN and TFN groups. The levels of ONP-induced inflammatory cytokine release (TNF-α, IL-6, and IL-8) by ELISA, cellular reactive oxygen species (ROS) production by CellRox Green, and cytotoxicity by lactate dehydrogenase (LDH) release assay in HGEP cells were assessed. Flavored ONP extracts elicited differential toxicities in a dose- and extract-dependent manner in HGEP cells 24 h post-treatment. Both fruit TDN and TFN extracts resulted in the greatest cytotoxicity. Tobacco- and fruit-flavored, but not menthol-flavored, ONPs resulted in increased ROS production 4 h post-treatment. Flavored ONPs led to differential cytokine release (TNF-α, IL-6, and IL-8) which varied by flavor (menthol, tobacco, or fruit) and nicotine (TDN vs. TFN) 24 h post-treatment. Menthol-flavored ONPs led to the most significant TNF-α release; fruit TFN resulted in the most significant IL-6 release; and fruit TDN and tobacco TFN led to the highest release of IL-8. Subsequently, human bronchial epithelial cells (16-HBE and BEAS-2B) were also treated with flavored ONP extracts, and similar assays were evaluated. Here, the lowest concentration treatments displayed increased cytotoxicity. The most striking response was observed among cells treated with spearmint and tobacco flavored ONPs. Our data suggest that flavored ONPs are unsafe and likely to cause systemic and local toxicological responses during chronic usage.

Curcumin intervention during progressive fibrosis controls inflammatory cytokines and the fibrinolytic system in pulmonary fibrosis.

Persistent injuries and chronic inflammation paired with dysregulated healing process in the lungs leads to scarring and stiffening of the tissue leading to a condition called pulmonary fibrosis. There is no efficacious therapy against the condition because of the poorly understood pathophysiology of the disease. Curcumin is well known anti-inflammatory natural compound and is shown to have beneficial effects in many diseases. It is also reported to show antifibrotic activities in pulmonary fibrosis. There are evidences that fibrinolytic system plays a crucial role in the development of pulmonary fibrosis. We aimed to see whether curcumin could regulate inflammation and fibrinolysis in murine model of pulmonary fibrosis. We prepared BLM induced pulmonary fibrosis model by administering BLM at a dose of 2 mg/ kg bodyweight. Curcumin (75 mg/kg body wt) was instilled intraperitoneally on different time points. The effect of curcumin on inflammatory cytokines and fibrinolytic system was studied using molecular biology techniques like RT-PCR, western blot and immunohistochemistry/immunofluorescence. We observed that BLM brought changes in the expressions of components in the fibrinolytic system, i.e. BLM favoured fibrin deposition by increasing the expression of PAI-1 (plasminogen activator inhibitor) and decreasing the expression of uPA (Urokinase plasminogen activator) and uPAR (Urokinase plasminogen activator receptor). We also demonstrate that curcumin could restore the normal expression of fibrinolytic components, uPA, uPAR and PAI-1. Curcumin could also minimize the expression of key enzymes in tissue remodeling in pulmonary fibrosis, MMP-2 and MMP-9, which were elevated in the BLM treated group. Our data suggest that curcumin exerts an anti-inflammatory and antifibrotic effect in lungs. We highlight curcumin as a feasible adjuvant therapy option against pulmonary fibrosis.

Comparative protein profiling reveals the inhibitory role of curcumin on IL-17A mediated minichromosome maintenance (MCM) proteins as novel putative markers for acute lung injury in vivo.

The Pro-inflammatory cytokine, Interleukin 17A (IL-17A) plays a vital role in the pathogenesis of inflammatory-induced acute lung injury (ALI). But, the mechanisms of this pro-inflammatory cytokine in response to activation after replication stress are not yet known. Control on DNA replication (DR) is vital for maintaining genome stability. Minichromosome maintenance (MCM) proteins play essential roles in various cancers, but their involvement during ALI is not yet been discussed. The present study was carried out to assess the participation of IL-17A during replication stress and to evaluate the contribution of curcumin on this. Mass spectrometry-based proteomic approach has been used on mice lung tissues treated with IL-17A, as a prime mediator to cause injury and curcumin a natural polyphenol as an intervention. Several trends were identified from the proteomic subset which revealed that IL-17A induces expressions of proteins like MCM2, MCM3, and MCM6 along with other proteins involved in DR. Interestingly, curcumin was found in suppressing the expression levels of these proteins. This was also confirmed via validating LC-MS/MS data using appropriate molecular techniques. Pathway and gene ontology analysis were performed with DAVID GO databases. Apart from this, the present study also reports the unique contribution of curcumin in suppressing the mRNA levels of other MCMs like MCM4, MCM5, and MCM7 as well as of ORC1 and ORC2. Hence, the present study revolves around linking the replication stress by pro-inflammatory effects, highlighting the implications for ALI and therapies. This study, therefore, enhances our capacity to therapeutically target DR-specific proteins.

The unique molecular targets associated antioxidant and antifibrotic activity of curcumin in in vitro model of acute lung injury: A proteomic approach.

Bleomycin (BLM) injury is associated with the severity of acute lung injury (ALI) leading to fibrosis, a high-morbidity, and high-mortality respiratory disease of unknown etiology. BLM-induced ALI is marked by the activation of a potent fibrogenic cytokine transcription growth factor beta-1 (TGFß-1), which is considered a critical cytokine in the progression of alveolar injury. Previously, our work demonstrated that a diet-derived compound curcumin (diferuloylmethane), represents its antioxidative and antifibrotic application in TGF-ß1-mediated BLM-induced alveolar basal epithelial cells. However, curcumin-specific protein targets, as well as its mechanism using mass spectrometry-based proteomic approach, remain elusive. To elucidate the underlying mechanism, a quantitative proteomics approach and bioinformatics analysis were employed to identify the protein targets of curcumin in BLM or TGF-ß1-treated cells. With subsequent in vitro experiments, curcumin-related pathways and cellular processes were predicted and validated. The current study discusses two separate proteomics experiments using BLM and TGF-ß1-treated cells with the proteomics approach, various unique target proteins were identified, and proteomic analysis revealed that curcumin reversed the expressions of unique proteins like DNA topoisomerase 2-alpha (TOP2A), kinesin-like protein (KIF11), centromere protein F (CENPF), and so on BLM or TGF-ß1 injury. For the first time, the current study reveals that curcumin restores TGF-ß1 induced peroxisomes like PEX-13, PEX-14, PEX-19, and ACOX1. This was verified by subsequent in vitro assays. This study generated molecular evidence to deepen our understanding of the therapeutic role of curcumin at the proteomic level and may be useful to identify molecular targets for future drug discovery.

Therapeutic properties of Punica granatum L (pomegranate) and its applications in lung-based diseases: A detailed review.

Respiratory diseases are the prime cause of death and disability worldwide. The majority of lung-based diseases are resistant to treatment. Hence, research on unique drugs/compounds with a more efficient and minimum side effect for treating lung diseases is urgent. Punica granatum L (pomegranate) fruit has been used in the prevention and treatment of various respiratory disorders in recent times. In vivo and in vitro studies have demonstrated that pomegranate fruit, as well as its juice, extract, peel powder, and oil, exert anti-proliferative, anti-oxidant, anti-microbial, anti-inflammatory, anti-cancer, and anti-tumorigenic properties by attenuating various respiratory conditions such as asthma, lung fibrosis, lung cancer, chronic obstructive pulmonary disease (COPD), and alveolar inflammation via modulating various signaling pathways. The current review summarizes the potential properties and medical benefits of pomegranate against different lung-based diseases, also highlighting its possible role in the lung fibrinolytic system. The available data suggest that pomegranate is effective in controlling the disease progressions and could be a potential therapeutic target benefiting human health status. Furthermore, this review also outlines the preclinical and clinical studies highlighting the role of pomegranate in lung diseases further evoking future studies to investigate the effect of intake of this anti-oxidant fruit in larger and well-defined human clinical trials. PRACTICAL APPLICATIONS: This review outlines the putative pharmacologic benefits of P. granatum L (pomegranate) in treating various chronic lung-based diseases such as lung cancer, COPD, ARDS, asthma, lung fibrosis, and cystic fibrosis. This review also highlights the possible inhibitory role of P. granatum L (pomegranate) in the lung fibrinolytic system triggering the fibrinolytic markers. This review summarizes the preclinical and clinical studies using in vitro, in vivo, and human models highlighting the potential role of P. granatum L (pomegranate) in lung diseases. This review evokes future research to investigate the effect of intake of pomegranate fruit in well-defined human clinical trials.

Curcumin Targets p53-Fibrinolytic System in TGF-ß1 Mediated Alveolar Epithelial Mesenchymal Transition in Alveolar Epithelial Cells.

AIMS: We aim to investigate curcumin interaction with p53-fibrinolytic system, smad dependent and independent pathways underlying their prime role during lung injury and fibrosis. BACKGROUND: Curcumin, an active component of Curcuma longa plant, substantially modulates respiratory conditions. TGF-ß1 plays a central role in lung remodeling by balancing extracellular matrix (ECM) production and degradation, which is a hallmark for alveolar EMT. However, the crosstalk of curcumin is not known yet with TGF- ß1 mediated p53-Fibrinolytic system regulating alveolar EMT leading to IPF. In the present study, the potential molecular mechanism of curcumin in TGF-ß1 mediated p53-fibrinolytic system in basal alveolar epithelial cells was explored. OBJECTIVES: To understand the potential molecular mechanism of curcumin in TGF-ß1 mediated p53-fibrinolytic system in basal alveolar epithelial cells. METHODS: Basal alveolar epithelial cells were treated with TGF- ß1 to induce alveolar EMT and after 24 hrs curcumin was administered to study its anti-fibrotic effects. Molecular techniques like immunoblot, RT-PCR and immunofluorescence were performed to assess the anti-fibrotic role of curcumin on EMT markers, IL-17A, p53-smad interaction to investigate the anti-fibrotic role of curcumin. RESULTS: The results indicated that TGF-ß1-induced EMT in A549 cells exhibited altered expression of the IL-17A, p53-fibrinolytic markers and EMT markers at the mRNA and protein level. Intervention with curcumin attenuated alveolar EMT and inactivated TGF-ß1 induced Smad/non Smad signaling pathways via blocking p53-fibrinolytic system. CONCLUSION: This study provides the first evidence of the dynamic response of curcumin on TGF- ß1 mediated p53-fibrinolytic system during alveolar injury in vitro.

CRISPR/Cas9 Genome Editing Tool: A Promising Tool for Therapeutic Applications on Respiratory Diseases.

Respiratory diseases are one of the prime topics of concern in the current era due to improper diagnostics tools. Gene-editing therapy, like Clustered regularly interspaced palindromic repeats- associated nuclease 9 (CRISPR/Cas9), is gaining popularity in pulmonary research, opening up doors to invaluable insights on underlying mechanisms. CRISPR/Cas9 can be considered as a potential gene-editing tool with a scientific community that is helping in the advancement of knowledge in respiratory health and therapy. As an appealing therapeutic tool, we hereby explore the advanced research on the application of CRISPR/Cas9 tools in chronic respiratory diseases such as lung cancer, Acute respiratory distress syndrome (ARDS) and cystic fibrosis (CF). We also address the urgent need to establish this gene-editing tool in various other lung diseases such as asthma, Chronic obstructive pulmonary disease (COPD) and Idiopathic pulmonary fibrosis (IPF). The present review introduces CRISPR/Cas9 as a worthy application in targeting epithelial-mesenchymal transition and fibrinolytic system via editing specific genes. Thereby, based on the efficiency of CRISPR/Cas9, it can be considered as a promising therapeutic tool in respiratory health research.

Bioresponsive supramolecular hydrogels for hemostasis, infection control and accelerated dermal wound healing.

Injectable, drug-releasing hydrogel scaffolds with multifunctional properties including hemostasis and anti-bacterial activity are essential for successful wound healing; however, designing ideal materials is still challenging. Herein, we demonstrate the fabrication of a biodegradable, temperature-pH dual responsive supramolecular hydrogel (SHG) scaffold based on sodium alginate/poly(N-vinyl caprolactam) (AG/PVCL) through free radical polymerization and the subsequent chemical and ionic cross-linking. A natural therapeutic molecule, tannic acid (TA)-incorporated SHG (AG/PVCL-TA), was also fabricated and its hemostatic and wound healing efficiency were studied. In the AG/PVCL-TA system, TA acts as a therapeutic molecule and also substitutes as an effective gelation binder. Notably, the polyphenol-arm structure and diverse bonding abilities of TA can hold polymer chains through multiple bonding and co-ordinate cross-linking, which were vital in the formation of the mechanically robust AG/PVCL-TA. The SHG formation was successfully balanced by varying the composition of SA, VCL, TA and cross-linkers. The AG/PVCL-TA scaffold was capable of releasing a therapeutic dose of TA in a sustained manner under physiological temperature-pH conditions. AG/PVCL-TA displayed excellent free radical scavenging, anti-inflammatory, anti-bacterial, and cell proliferation activity towards the 3T3 fibroblast cell line. The wound healing performance of AG/PVCL-TA was further confirmed in skin excision wound models, which demonstrated the potential application of AG/PVCL-TA for skin regeneration and rapid wound healing.

Curcumin attenuates IL-17A mediated pulmonary SMAD dependent and non-dependent mechanism during acute lung injury in vivo.

Acute lung injury (ALI) is a pathologic condition responsible for incurable human chronic respiratory diseases. Recent studies have shown the involvement of the glycoprotein, IL17A secreted by IL-17 producing cells in chronic inflammation. The current investigation was carried out to study the IL-17A mediated activation of SMAD and non- SMAD signaling in alveolar epithelial cells and to assess the putative modulatory role of curcumin. C57BL/6 mice were exposed to IL-17A and curcumin was administered as an intervention to modulate the IL-17A-induced alveolar damage. Techniques like Immunofluorescence and real-time PCR were used. We found elevated expression of IL-17A and IL-17A-associated signaling pathways to be activated in mice lung tissues. Curcumin intervention in vivo promoted the resolution of IL-17A-induced ALI and attenuated pulmonary damage. Increase phosphorylation of non- SMAD proteins like P-EGFR, P-STAT-1, STAT-3, P-JAK-1/2, P-JNK, and also SMAD proteins like P- SMAD 2/3 and TGF-ß1 was encountered upon IL-17A exposure, while curcumin intervention reversed the protein expression levels. Curcumin was found to block mRNA expressions of non- SMAD genes EGFR, JNK-1, JAK1, JAK2, STAT-1, STAT-3, MAPK14, also of TGF-ß1 and SMAD genes like SMAD 2, SMAD 3. However, mRNA expressions of SMAD 6 and SMAD 7 were increased upon curcumin intervention. Our study indicates that IL-17A participates in the development of ALI in both SMAD dependent and independent manner and the IL-17A signaling components were effectively controlled by curcumin, suggesting probable anti-inflammatory use of curcumin during ALI.

Effect of curcumin on IL-17A mediated pulmonary AMPK kinase/cyclooxygenase-2 expressions via activation of NFκB in bleomycin-induced acute lung injury in vivo.

Acute lung injury (ALI) remains to be the major cause of mortality. Bleomycin (BLM) injury activates the pro-inflammatory cytokine Interleukin L-17A which regulates the expression of COX-2 and inhibits P-AMPKα in BLM/IL-17A exposed mice upon activation of NFκB and other inflammatory molecules the actual mechanism behind which remains unclear. The current investigation was carried out to assess the role of IL-17A with COX-2 and P- AMPKα and to highlight the important contribution of adjunctive use of curcumin as a promising preventive strategy for the BLM-induced ALI. Immunofluorescence analysis reveals that the natural spice curcumin blocks the expressions of COX-2, NF-κB-p65, fibronectin (FBN), and expresses P-AMPKα in vivo. Curcumin could also suppress the expressions of NF-κB-p105 in BLM/IL-17A exposed mice. mRNA expressions showed reduced expressions of PDGFA, PDGFB, CTGF, IGF1, NFκB1, NFκB2, MMP-3, MMP-9, and MMP-14 on curcumin treatment. Our study implicates a critical role of AMPKα/COX- 2 in the emergence of pulmonary fibrosis via exerting the potential role of curcumin as an adjuvant anti-inflammatory therapeutic for treating lung injury.

Curcumin Suppresses Epithelial Growth Factor Receptor (EGFR) and Proliferative Protein (Ki 67) in Acute Lung Injury and Lung Fibrosis In vitro and In vivo.

BACKGROUND: Acute lung injury is one of the common conditions caused due to bleomycin therapy which leads to pulmonary fibrosis, which is one of the severe interstitial lung diseases most commonly affecting the elderly individuals. EGFR and Ki67 can be marked as beneficial markers for detecting pulmonary fibrosis based on which clinicians can guide the therapy. OBJECTIVE: The aim of the study was to evaluate the effect of curcumin as an intervention on two prognostic markers EGFR and Ki67 in bleomycin-induced basal alveolar epithelial cells and C57BL/6 mice. Protein expressions and pathological expressions of EGFR and Ki67 were evaluated to analyze the effect of curcumin via both in vitro and in vivo approaches. METHODS: The effect of curcumin was investigated both on cell lines (A549) and animal model (both normal and bleomycin-induced mice, n=6) via techniques like western blotting for protein expression. Techniques like immunofluorescence and immunohistochemistry were carried out and examined under confocal microscopy and phase contrast microscopy to analyze the expressions of the said biomarkers. Bleomycin was used as a causative agent to induce inflammation. RESULTS: The natural polyphenol curcumin could downregulate the expressions levels of Ki67 and EGFR both in vitro and in vivo. Immunofluorescence analysis of proliferative marker Ki67 showed a reduced expression on curcumin treatment in vitro. The pathological sections from treated lungs showed a significant decrease in EGFR and Ki67 levels when exposed to curcumin. CONCLUSION: We conclude that curcumin, a well-known natural bioactive compound holds strong antiproliferative effects on Ki67 and EGFR expressions.We observed that a clinical outcome in the diagnosis of pulmonary fibrosis remains to be unconvincing so far. Curcumin can be considered as a potential therapeutic.

Interleukin-17A: A Potential Therapeutic Target in Chronic Lung Diseases.

BACKGROUND: Interleukin-17A (IL-17A) is a pro-inflammatory cytokine that has gained a lot of attention because of its involvement in respiratory diseases. Interleukin-17 cytokine family includes six members, out of which, IL-17A participates towards the immune responses in allergy and inflammation. It also modulates the progression of respiratory disorders. OBJECTIVE: The present review is an insight into the involvement and contributions of the proinflammatory cytokine IL-17A in chronic respiratory diseases like Idiopathic Pulmonary Fibrosis (IPF), Chronic Obstructive Pulmonary Distress (COPD), asthma, pneumonia, obliterative bronchiolitis, lung cancer and many others. CONCLUSION: IL-17A is a major regulator of inflammatory responses. In all the mentioned diseases, IL- 17A plays a prime role in inducing the diseases, whereas the lack of this pro-inflammatory cytokine reduces the severity of respective respiratory diseases. Thereby, this review suggests IL-17A as an instrumental target in chronic respiratory diseases.