Verproside inhibits TNF-α-induced MUC5AC expression through suppression of the TNF-α/NF-κB pathway in human airway epithelial cells

Inflammation and cancer cell survival: TRAF2 as a key player

TNF receptor-associated factor 2 (TRAF2) plays a crucial role in both physiological and pathological processes. It takes part in the regulation of cell survival and death, tissue regeneration, development, endoplasmic reticulum stress response, autophagy, homeostasis of the epithelial barrier and regulation of adaptive and innate immunity. Initially identified for its interaction with TNF receptor 2 (TNFR2), TRAF2 contains a TRAF domain that enables homo- and hetero-oligomerization, allowing it to interact with multiple receptors and signaling molecules. While best known for mediating TNFR1 and TNFR2 signaling, TRAF2 also modulates other receptor pathways, including MAPK, NF-κB, and Wnt/β-catenin cascades. By regulating NF-κB-inducing kinase (NIK), TRAF2 is a key activator of the alternative NF-κB pathway, linking it to inflammatory diseases, immune dysfunction, and tumorigenesis. In the innate immune system, TRAF2 influences macrophage differentiation, activation, and survival and stimulates natural killer cell cytotoxicity. In the adaptive immune system, it represses effector B- and T-cell activity while sustaining regulatory T-cell function, thus promoting immune suppression. The lack of fine-tuning of TRAF2 activity leads to excessive NF-kB activation, driving chronic inflammation and autoimmunity. Although TRAF2 can act as a tumor suppressor, it is predominantly described as a tumor promoter, as its expression has been correlated with increased metastatic potential and poorer prognosis in several types of cancer. Targeting TRAF2 or TRAF2-dependent signaling pathways might represent a promising anti-cancer therapeutic strategy.

Reduction of Alcohol-Dependent Lung Pathological Features in Rats Treated with Fenofibrate

Alcohol use disorder (AUD) is a public health problem characterized by a marked increment in systemic inflammation. In the last few years, it has been described as the role of alcohol in neuroinflammation affecting some aspects of neuronal function. Interestingly, inflammation is reduced with fenofibrate treatment, a PPARα agonist used to treat dyslipidemia. On the other hand, alcohol has been associated with chronic inflammation and fibrosis in the lungs, affecting their normal function and increasing respiratory infections. However, a deep characterization of the role of alcohol in the worsening of chronic respiratory diseases has not been described completely. In this work, we present a novel study using rats treated with alcohol and fenofibrate to evaluate the relevant features of chronic respiratory disease: inflammation, mucus hypersecretion, and fibrosis. The analysis of extracted lungs showed an increment in the inflammatory infiltrates and pro-inflammatory cytokine levels associated with alcohol. Interestingly, the treatment with fenofibrate decreased the expression of these markers and the infiltrates observed in the lungs. The levels of mucin Muc5ac showed an increment in animals treated with alcohol. However, this increment was markedly reduced if animals were subsequently treated with fenofibrate. Finally, we documented an increment of collagen deposition around airways in the animals treated with alcohol compared with control animals. However, fenofibrate treatment reduced this deposition to a level similar to the control animals. These results showed the role of alcohol in the increment of pathological features in the lungs. Moreover, these features were attenuated due to the fibrate treatment, which allows us to glimpse this drug's promising role as lung anti-inflammatory therapy.

Tangeretin inhibits airway inflammatory responses by reducing early growth response 1 (EGR1) expression in mice exposed to cigarette smoke and lipopolysaccharide

Background

Tangeretin, a natural polymethoxyflavone compound, possesses potent anti-inflammatory activity that improves respiratory inflammation in chronic obstructive pulmonary disease (COPD). However, the molecular mechanisms underlying the anti-COPD effects of tangeretin remain unclear. In this study, we aimed to investigate the key molecular mechanisms by which tangeretin suppresses COPD-related inflammatory responses.

Methods

We conducted the investigation in phorbol-12-myristate-13-acetate (PMA)-stimulated human airway epithelial cells (in vitro) and cigarette smoke (CS)/lipopolysaccharide (LPS)-exposed mice (in vivo).

Results

Tangeretin decreased the release of inflammatory mediators, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and mucin 5AC (MUC5AC), by suppressing early growth response 1 (EGR1) expression in vitro. Tangeretin and EGR1 small interfering ribonucleic acid (siRNA) combination showed a synergistic reduction in MUC5AC and TNF-α secretion. Tangeretin administration significantly inhibited the levels of reactive oxygen species (ROS) production, elastase activity, TNF-α, IL-6, and monocyte chemoattractant protein-1 (MCP-1) secretion, and macrophage and neutrophil numbers in the bronchoalveolar lavage fluid of CS/LPS-exposed mice. Tangeretin also prevented CS/LPS-induced abnormal pathological changes and excessive MUC5AC and EGR1 expression in lung tissue.

Conclusion

Comprehensively, tangeretin inhibits the lung inflammatory response associated with COPD by reducing EGR1 expression in PMA-induced human epithelial cells and in a CS/LPS-stimulated mouse model. This study shows that tangeretin has anti-COPD properties and can be a promising alternative (or complementary) treatment for inflammatory lung disease.

Inhibition of transient receptor potential vanilloid 1 reduces shedding and transmission during Streptococcus pneumoniae co-infection with influenza

Transmission is the first step for a microorganism to establish colonization in the respiratory tract and subsequent development of infectious disease. Streptococcus pneumoniae is a leading pathogen that colonizes the mucosal surfaces of the human upper respiratory tract and causes subsequent transmission and invasive infections especially in co-infection with influenza A virus. Host factors contributing to respiratory contagion are poorly understood. Transient receptor potential vanilloid (TRPV) channels have various roles in response to microoorganism. Inhibition of TRPV exacerbates invasive infection by Streptococcus pneumoniae, but it is unclear how TRPV channels influence pneumococcal transmission. Here, we describe the effect of inhibition of TRPV1 on pneumococcal transmission. We adopted a TRPV1-deficient infant mouse model of pneumococcal transmission during co-infection with influenza A virus. We also analyzed the expression of nasal mucin or pro-inflammatory cytokines. TRPV1 deficiency attenuated pneumococcal transmission and shedding during co-infection with influenza A virus. TRPV1 deficiency suppressed the expression of nasal mucin. In addition, there were increases in the expression of tumor necrosis factor-α and type I interferon, followed by the suppressed replication of influenza A virus in TRPV1-deficient mice. Inhibition of TRPV1 was shown to attenuate pneumococcal transmission by reducing shedding through the suppression of nasal mucin during co-infection with influenza A virus. Inhibition of TRPV1 suppressed nasal mucin by modulation of pro-inflammatory responses and regulation of replication of influenza A virus. TRPV1 could be a new target in preventive strategy against pneumococcal transmission.

Veronica linariifolia subsp. dilatata ameliorates LPS-induced acute lung injury by attenuating endothelial cell barrier dysfunction via EGFR/Akt/ZO-1 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The dried aerial parts of Veronica linariifolia subsp. dilatata (Nakai & Kitag.) D.Y.Hong named Shui Man Jing (SMJ) is a traditional Chinese medicine with a long history of clinical use in the treatment of chronic bronchitis and coughing up blood, however, its role on acute lung injury (ALI) has not been revealed yet.

AIM OF THE STUDY

To assess the efficiency of SMJ on ALI and to investigate whether it inhibited endothelial barrier dysfunction by regulating the EGFR/Akt/ZO-1 pathway to alleviate ALI in vivo and in vitro based on the result of network pharmacology.

MATERIALS AND METHODS

An in vivo model of ALI was established using inhalation of atomized lipopolysaccharide (LPS), and the effects of SMJ on ALI were evaluated through histopathological examination and inflammatory cytokines, lung histology and edema, vascular and alveolar barrier disruption. Network pharmacology was applied to predict the mechanism of SMJ in the treatment of ALI. The crucial targets were validated by RT-PCR, Western Blotting, molecular docking, immunohistochemistry and immunofluorescence methods in vivo and in virto.

RESULTS

Administration of SMJ protected mice against LPS-induced ALI, including ameliorating the histological alterations in the lung tissues, and decreasing lung edema, protein content of bronchoalveolar lavage fluid, infiltration of inflammatory cell and secretion of cytokines. SMJ exerted protective effects in ALI by inhibiting endothelial barrier dysfunction in mice and bEnd.3 cell. SMJ relieved endothelial barrier dysfunction induced by LPS through upregulating the EGFR expression. SMJ also increased the phosphorylation of Akt, and ZO-1 expression both in vivo and in vitro.

CONCLUSION

SMJ attenuates vascular endothelial barrier dysfunction for LPS-induced ALI via EGFR/Akt/ZO-1 pathway, and is a promising novel therapeutic candidate for ALI.

Role of the cAMP-PKA-NF-κB pathway in Mucin1 over-expression in A549 cells during Respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is the most common pathogen associated with acute lower respiratory tract infections in infants and young children worldwide. RSV commonly presents as bronchiolitis in young children; however, it can sometimes progress to pneumonia, respiratory failure, apnoea and even death. Although mucin1 (MUC1), a type of transmembrane glycoprotein present on airway epithelial surfaces, plays a crucial anti-inflammatory role in airway infections; however, its roles in RSV-associated acute lower respiratory tract infections have rarely been explored. In this study, we first revealed very high MUC1 protein levels in the exacerbation phase in sputum samples from children with RSV bronchiolitis. Because MUC1 is the downstream target of tumour necrosis factor-alpha (TNF-α) in RSV-infected A549 cells, we observed the inhibition of NF-κB activity, main downstream signalling of TNF-α and remarkably reduced levels of MUC1 in RSV-infected and TNF-α treated A549 cells. Furthermore, the cyclic adenosine monophosphate (cAMP) analogue (dbcAMP) downregulated the protein levels of p-IκBα and MUC1 in TNF-α-treated A549 cells. By contrast, a protein kinase A inhibitor (KT5720) up-regulated the levels of those proteins. dbcAMP and KT5720 had the same effects on MUC1 protein levels in RSV-infected A549 cells. In conclusion, we found that the cAMP-PKA-NF-κB pathway may play a role in the regulation of MUC-1 over-expression during RSV infection.

Methyl lucidone inhibits airway inflammatory response by reducing TAK1 activity in human bronchial epithelial NCI-H292 cells

Background

Methyl lucidone (ML), a methyl derivative of lucidone, has anti-inflammatory properties. However, the molecular mechanisms that reduce the inflammatory effect of ML in human lung epithelial cells remain unkown. This study aimed to elucidate the molecular mechanisms underlying the anti-inflammatory effect of ML.

Methods

Four compounds (ML, methyl linderone, kanakugiol, and linderone) from Lindera erythrocarpa Makino were evaluated for their ability to reduce MUC5AC secretion levels in phorbol-12-myristate-13-acetate (PMA)-stimulated NCI-H292 cells using ELISA. The expression and secretion levels of inflammatory response-related proteins were analyzed using quantitative reverse transcription-PCR, ELISA, and western blotting. To determine whether ML directly regulates TGF-β-activated kinase 1 (TAK1), we performed an in vitro kinase assay.

Results

ML treatment effectively reduced the levels of inflammatory cytokines, including interleukin-1β and TNF-α, increased by stimulation. Furthermore, ML downregulated the pathway cascade of both IκB kinase (IKK)/NF-κB and p38 mitogen-activated protein (MAP) kinase/CREB by inhibiting the upstream kinase TAK1. An in vitro kinase analysis confirmed that ML treatment significantly reduced the kinase activity of TAK1.

Conclusion

ML pretreatment repressed the PMA-stimulated inflammation reaction by reducing the TAK1-mediated IKK/NF-κB and p38 MAP kinase/CREB signaling. These findings suggest that ML may improve respiratory health and can be used as a dietary supplement or functional food to prevent inflammatory lung diseases.

Efficacy of Veronica incana for Treating Osteoarthritis Induced by Monosodium Iodoacetate in Rats

The aim of this study is to investigate the efficacy and the underlying mechanism of Veronica incana in osteoarthritis (OA) induced by intraarticular injection of monosodium iodoacetate (MIA). The selected major four compounds (A-D) of V. incana were found from fractions 3 and 4. Its structure elucidation was determined by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) data analysis and nuclear magnetic resonance (NMR) data comparison with literature. MIA (50 μL with 80 mg/mL) for the animal experiment was injected into the right knee joint. The V. incana was administered orally every day to rats for 14 days from 7 days after MIA treatment. Finally, we confirmed the four compounds: (A) verproside; (B) catalposide; (C) 6-vanilloylcatapol; and (D) 6-isovanilloylcatapol. When we evaluated the effect of V. incana on the MIA injection-induced knee OA model, there were a noticeable initial decreased in hind paw weight-bearing distribution compared to the Normal group (P < .001), but V. incana supplementation resulted in a significant increase in the weight-bearing distribution to the treated knee (P < .001). Moreover, the V. incana treatment led to a decrease in the levels of liver function enzymes and tissue malondialdehyde (P < .05 and .01). The V. incana significantly suppressed the inflammatory factors through the nuclear factor-kappa B signaling pathway and downregulated the expression of matrix metalloproteinases, which are involved in the degradation of the extracellular matrix (P < .01 and .001). In addition, we confirmed the alleviation of cartilage degeneration through tissue stains. In conclusion, this study confirmed the major four compounds of V. incana and suggested that V. incana could serve as an anti-inflammatory candidate agent for patients with OA.

Verproside, the Most Active Ingredient in YPL-001 Isolated from Pseudolysimachion rotundum var. subintegrum, Decreases Inflammatory Response by Inhibiting PKCδ Activation in Human Lung Epithelial Cells

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease which causes breathing problems. YPL-001, consisting of six iridoids, has potent inhibitory efficacy against COPD. Although YPL-001 has completed clinical trial phase 2a as a natural drug for COPD treatment, the most effective iridoid in YPL-001 and its mechanism for reducing airway inflammation remain unclear. To find an iridoid most effectively reducing airway inflammation, we examined the inhibitory effects of the six iridoids in YPL-001 on TNF or PMA-stimulated inflammation (IL-6, IL-8, or MUC5AC) in NCI-H292 cells. Here, we show that verproside among the six iridoids most strongly suppresses inflammation. Both TNF/NF-κB-induced MUC5AC expression and PMA/PKCδ/EGR-1-induced IL-6/-8 expression are successfully reduced by verproside. Verproside also shows anti-inflammatory effects on a broad range of airway stimulants in NCI-H292 cells. The inhibitory effect of verproside on the phosphorylation of PKC enzymes is specific to PKCδ. Finally, in vivo assay using the COPD-mouse model shows that verproside effectively reduces lung inflammation by suppressing PKCδ activation and mucus overproduction. Altogether, we propose YPL-001 and verproside as candidate drugs for treating inflammatory lung diseases that act by inhibiting PKCδ activation and its downstream pathways.

Iridoid Derivatives as Anticancer Agents: An Updated Review from 1970-2022

The rise of cancer cases has coincided with the urgent need for the development of potent chemical entities and/or modification of existing commodities to improve their efficacy. Increasing evidence suggests that cancer remains one of the leading causes of death globally, with colon cancer cases alone likely to rise exponentially by 2030. The exponential rise in cancer prevalence is largely attributable to the growing change toward a sedentary lifestyle and modern diets, which include genetically modified foods. At present, the prominent treatments for cancer are chemotherapy, surgery, and radiation. Despite slowing cancer progression, these treatments are known to have devastating side effects that may deteriorate the health of the patient, thus, have a low risk-benefit ratio. In addition, many cancer drugs have low bioavailability, thereby limiting their therapeutic effects in cancer patients. Moreover, the drastic rise in the resistance of neoplastic cells to chemotherapeutic agents is rendering the use of some drugs ineffective, thereby signaling the need for more anticancer chemical entities. As a result, the use of natural derivatives as anticancer agents is gaining considerable attention. Iridoids have the potential to form conjugates with other anticancer, antidiabetic, antileishmanial, and antimalarial drugs, which synergistically have the potential to increase their effects. Published studies have identified the role of iridoids, which, if fully explored, may result in cheaper and less toxic alternative/adjuvant cancer drugs. The subject of this article is natural and synthetic iridoid derivatives and their potential therapeutic roles as anticancer agents.

YPL-001 Shows Various Beneficial Effects against Cigarette Smoke Extract-Induced Emphysema Formation: Anti-Inflammatory, Anti-Oxidative, and Anti-Apoptotic Effects

Inflammation, oxidative stress, and apoptosis are thought to be important causes of chronic obstructive pulmonary disease (COPD). We investigated the effect of YPL-001 (under phase 2a study, ClinicalTrials.gov identifier NCT02272634), a drug derived from Pseudolysimachion rotundum var. subintegrum, on cigarette smoke extract (CSE)-induced inflammation, the anti-oxidative pathway, and apoptosis in human lung epithelial cells and on CSE-induced emphysema in mice. YPL-001 suppressed CSE-induced expression of IL8 mRNA and protein. This was due to the reduction in NF-κB transcriptional activity by YPL-001, which resulted from the blockade of acetylation of the NF-κB subunit p65 (Lys310). Histone deacetylases (HDACs) prevent gene transcription by condensing the DNA structure and affecting NF-κB nuclear binding. YPL-001 alone increased HDAC2 activity and enhanced CSE-induced activation of HDAC2. YPL-001-induced suppression of NF-κB transcriptional activity might be caused by increased HDAC2 activity. YPL-001 increased nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression via both degradation of its inhibitory protein, Kelch-like ECH-associated protein 1, and an increase in de novo protein synthesis. YPL-001 increased the DNA binding activity of Nrf2. Consequently, YPL-001 upregulated the expression of Nrf2-targeted anti-oxidant genes such as NAD(P)H quinone dehydrogenase 1 and heme oxygenase 1. Moreover, YPL-001 significantly suppressed CSE-induced apoptotic cell death. In vivo study showed that CSE-induced emphysematous changes, neutrophilic inflammation, protein leakage into bronchoalveolar space, and lung cell apoptosis in mice were suppressed by YPL-001 treatment. Taken together, these results suggest that YPL-001 is a good therapeutic candidate for the treatment of COPD by blocking inflammation and apoptosis and activating the anti-oxidative pathway.

Pathological Mechanism and Targeted Drugs of COPD

Chronic obstructive pulmonary disease (COPD) includes chronic bronchitis, emphysema, and small airway obstruction. Incompletely reversible airflow limitation, inflammation, excessive mucus secretion and bronchial mucosal epithelial lesions are the main pathological basis of the disease. The prevalence of COPD is increasingly worldwide, which has caused the burden on individuals and society. This paper summarizes the pathogenesis of COPD and clarifies the effect and mechanism of the latest targeted drugs for COPD. Besides, we focus on NOD-like receptor thermal protein domain associated protein 3 inflammasome (NLRP3 inflammasome). NLRP3 can promote production of interleukin-1β (IL-1β) and interleukin-18 (IL-18). NLRP3 is an important factor in the migratory aggregation of macrophages and neutrophils and the generation of oxidative stress. Inhibition of NLRP3 inflammasome indirectly blocks the inflammatory effects of IL-1β and IL-18, which may be regarded as an ideal target for COPD treatment.

Tiao-bu-fei-shen formula promotes downregulation of the caveolin 1-p38 mapk signaling pathway in COPD - Associated tracheobronchomalacia cell model

ETHNOPHARMACOLOGICAL RELEVANCE

The Tiao-bu-fei-shen (TBFS) formula, extensively used in Traditional Chinese Medicine (TCM), can enhance therapeutic efficacy and reduce the frequency of acute exacerbations of lung-kidney Qi deficiency in patients with chronic obstructive pulmonary disease (COPD). According to both TCM theory and long-term observation of practice, TBFS has become an effective treatment for COPD-associated tracheobronchomalacia (TBM).

AIM OF THE STUDY

To investigate the mechanism of the TBFS formula in treating COPD-associated TBM based on caveolin 1-p38 MAPK signaling and apoptosis.

MATERIALS AND METHODS

A rat COPD model was prepared by exposure to smoking combined with tracheal lipopolysaccharide injection. The trachea or bronchus chondrocytes from COPD rats were isolated, cultured, and treated with 10 ng/mL IL-1β for 24 h to develop a model of COPD-associated TBM. Normal rats were administered TBFS to prepare drug-containing serum, and CCK8 assays were used to screen the optimal drug-containing serum concentration and SB203580 dose. TBFS drug-containing serum and SB203580 were processed separately for the control, model, drug-containing serum, blocker, and drug-containing serum combined with blocker groups. Flow cytometry and CCK8 assays were used to detect apoptosis and proliferative activity. Toluidine blue staining and immunohistochemistry were used to analyze the chondrocyte proteoglycan and type II collagen content. Western blotting was used to detect the expression of caveolin 1, p-p38 MAPK, TNF-α, IL-1β, MMP-13, Bax, and Bcl-2 proteins. Quantitative PCR was used to detect the expression of caveolin 1, p38 MAPK, IL-1β, MMP-13, Bax, Bcl-2, and miR-140-5p.

RESULTS

The isolation and identification of bronchial chondrocytes from COPD rats revealed that 10 ng/mL IL-1β can produce a stable COPD-associated TBM model. Screened via the CCK8 method, fourth-generation bronchial chondrocytes were determined as the optimal cells, and 5 μM SB203580 and 5% low-dose drug-containing serum were the optimal intervention doses. The experimental chondrocytes of each group were treated separately for 48 h. Toluidine blue staining and immunohistochemical analysis revealed that TBFS drug-containing serum, SB203580, and TBFS drug-containing serum combined with SB203580 can effectively increase the proteoglycan and type II collagen content after chondrocyte degradation. Flow cytometry of cells treated with SB203580 and TBFS drug-containing serum combined with SB203580 revealed significantly reduced cell apoptosis and enhanced cell proliferation activity. Western blot and qPCR analyses revealed that the TBFS drug-containing serum, SB203580, and TBFS drug-containing serum combined with SB203580 effectively inhibit the expression of caveolin 1, p-p38 MAPK, MMP-13, IL-1β, TNF-α, and Bax proteins while promoting Bcl -2 protein expression. Treatment with TBFS drug-containing serum and SB203580 effectively inhibited the expression of MMP-13, p38 MAPK, caveolin 1, and Bax genes, and promoted the expression of Bcl-2 and miR-140-5p genes.

CONCLUSIONS

A concentration of 10 ng/mL of IL-1β can generate a stable COPD-associated TBM cell model. TBFS can improve the proteoglycan and type II collagen content, increase cell activity, and reduce the amount of chondrocyte apoptosis. The role of TBFS may be related to mechanisms of inhibiting the expression of the key signaling molecules caveolin 1 and p-p38 MAPK in the caveolin 1-p38 MAPK signaling pathway, thereby reducing the expression of the downstream effector products MMP-13, IL-1β, and TNF-α, while inhibiting the expression of the apoptotic gene Bax and improving the expression of Bcl-2 and miR-140-5p genes.

Gurgem-7 toxicity assessment: Regulation of cell survival or death by traditional Mongolian prescription

Surgical treatments and chemotherapy are the most commonly used methods of colorectal cancer treatment (CRC), unfortunately, these therapies have many side effects. Moreover, despite advances in primary and adjuvant treatments, the survival time in CRC patients is still unsatisfactory. Treatment options for patients with CRC continue to advance and recent research has shown that colorectal cancer is sensitive to plant-derived substances. The use of natural compounds contained in herbal extracts for the treatment of colon cancer or as adjunctive therapy for CRC gives patients a wide range of treatment options. In this study, we evaluate the potential toxicity of the Mongolian preparation - Gurgem-7 composed of Crocus sativus, Veronica officinalis, Capsella bursa-pastoris, Arctostaphylos uva-ursi, Calendula officinalis, Gentiana lutea, and Terminalia chebula. Therefore, the aim of this study was to determine its biological activities, biochemical and molecular features in vitro and composition analysis by HPLC-ESI-QTOF-MS/MS platform. We identified 18 metabolites and 8 of them were quantified. Majority of the secondary metabolites belonged to the group of phenolic constituents with taxifolin, chlorogenic acids' family, hydroxysafflor yellow A and hydroxybenzoic acid as leading compounds. In turn, our in vitro results suggest that the preparation inhibits cell metabolic activity through oxidative stress, numerous DNA damage and cell cycle arrest. Simultaneously enzymatic and non-enzymatic cell protection mechanisms mediated by TP53/Keap1 and Nrf2/HO-1 pathways may be activated in a cell-specific manner in vitro. In conclusion, we provide preliminary molecular evidence of the toxic properties of Gurgem-7 preparation to Caco-2 and CT26. WT cells related to insufficient action of their repair and adaptive mechanisms to stress conditions.

PTX3/TWIST1 Feedback Loop Modulates Lipopolysaccharide-Induced Inflammation via PI3K/Akt Signaling Pathway

Chronic inflammation of nasal mucosal tissue is an obvious feature of allergic rhinitis. Pentraxin 3 (PTX3) is a member of the pentraxin family and plays important roles in inflammation. We aimed to investigate the roles and mechanisms of PTX3 in inflammatory factors and MUC5AC production in human nasal epithelia cells. Loss- and gain-of-function experiments were performed. We found that the silencing of PTX3 dramatically blocked the expression of interleukin (IL)-6, IL-8, IL-1β, and MUC5AC induced by lipopolysaccharide (LPS). Gain-of-function of PTX3 displayed the opposite results. Interestingly, the ablation of PTX3 blocked activation of the PI3K/Akt signaling pathway, whereas the administration of an agonist of PI3K, 740Y-P, partially reversed the inhibitory functions of PTX3 silencing on inflammation and MUC5AC production. Moreover, PTX3 was a positive regulator of TWIST1, which is one of the transcription factors of PTX3. We noticed that TWIST1 downregulation reduced the expression of PTX3. Furthermore, chromatin immunoprecipitation assay and dual-luciferase reporter assay demonstrated that TWIST1 could bind to the promoter of PTX3. Importantly, the depletion of TWIST1 attenuated the LPS-mediated expression and secretion of inflammatory cytokines, whereas these effects were partially abolished upon PTX3 overexpression. Taken together, our findings revealed that the PTX3/TWIST1 feedback loop modulates LPS-induced inflammation and MUC5AC production via the PI3K/Akt signaling pathway.

Black Ginseng Extract Suppresses Airway Inflammation Induced by Cigarette Smoke and Lipopolysaccharides In Vivo

Cigarette smoke (CS) is a risk factor that can induce airway enlargement, airway obstruction, and airway mucus hypersecretion. Although studies have shown that Korean black ginseng extract (BGE) has potent anti-inflammatory and antioxidant activities, the CS-induced inflammatory responses and molecular mechanisms are yet to be examined. The aim of this study was to examine the effect of BGE on the airway inflammatory response and its molecular mechanisms, using CS/lipopolysaccharides (LPS)-exposed animals and PMA-stimulated human airway epithelial NCI-H292 cells. The results show that BGE inhibited the recruitment of immune cells and the release of inflammatory mediators, such as tumor necrosis factor (TNF)-α and interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, elastase, and reactive oxygen species (ROS) in the airways of CS/LPS-exposed animals. BGE inhibited mucus secretion and the expression of Mucin 5AC (MUC5AC). Furthermore, BGE exhibited an anti-inflammatory effect by downregulating a signaling pathway mediated by transforming growth factor-β-activated kinase (TAK) 1, an important protein that accelerates inflammation by cigarette smoke (CS). Overall, the findings show that BGE inhibits lung inflammation and mucus secretion by decreasing the activation of TAK1 both in human epithelial cells and in CS/LPS-exposed animals, and could be a potential adjuvant in the treatment and prevention of airway inflammatory diseases caused by airway irritants such as CS.

In Vitro Multiplication and NMR Fingerprinting of Rare Veronica caucasica M. Bieb

Micropropagation of rare Veronica caucasica M. Bieb. was achieved by successful in vitro cultivation of mono-nodal segments on MS medium supplemented with 1.0 mg L^–1 6-benzylaminopurine (BA) and then transferring the regenerated plants on hormone free basal MS medium for root development. In vitro multiplicated plants were successively acclimated in a growth chamber and a greenhouse with 92% survival. The number of plastid pigments and the total phenolics content in in vitro cultivated and ex vitro adapted plants were unchanged, and no accumulation of reactive oxygen species (ROS) was detected by staining with 3-3′-diaminobenzidine (DAB) and 2′,7′-dichlorofluorescein diacetate (DCF-DA). Nuclear Magnetic Resonance (NMR) fingerprinting allowed for the identification of the major alterations in metabolome of V. caucasica plants during the process of ex situ conservation. Iridoid glucosides such as verproside, aucubin and catalpol were characteristic for in vitro cultivated plants, while in ex vitro acclimated plants phenolic acid–protocatechuic acid and caffeic acid appeared dominant. The successful initiation of in vitro and ex vitro cultures is an alternative biotechnological approach for the preservation of V. caucasica and would allow for further studies of the biosynthetic potential of the species and the selection of lines with a high content of pharmaceutically valuable molecules and nutraceuticals.

Muc5ac Production Inhibited by Decreased lncRNA H19 via PI3K/Akt/NF-kB in Asthma

Introduction

LncRNAs play important roles in multiple diseases including asthma, while there are a few reports on the role of lncRNA H19 about asthma. This study aimed to investigate the roles and mechanisms of lncRNA H19 in asthma.

Methods

We detected lncRNA H19 and Muc5ac mRNA by establishing a murine asthma model and an in vitro inflammation model. Regulatory roles of lncRNA H19 in asthma were explored by lncRNA H19 overexpression or knockdown in vitro. To study its mechanisms, we detect p-NF-κB and p-Akt expression, and treated 16-HBE cells with inhibitors of PI3K. To study regulatory effects of miR-675-3p on Muc5ac, miR-675-3p mimics and inhibitors were respectively transfected into 16-HBE cells.

Results

Firstly, we established a murine asthma model and an in vitro inflammation model. We found that lncRNA H19 expression was decreased, while Muc5ac mRNA was increased in lung tissues of murine asthma model and in the in vitro inflammation model. lncRNA H19 overexpression increased Muc5ac mRNA expression and lncRNA H19 knockdown decreased Muc5ac mRNA expression in 16-HBE cells. Moreover, lncRNA H19 overexpression further increased Muc5ac expression in TNFα-induced in vitro inflammation model. lncRNA H19 knockdown decreased p-Akt and p-NF-κB expression. Inhibitors of PI3K abolished Muc5ac induced by lncRNA H19 overexpression. Although miR-675-3p was increased by lncRNA H19 overexpression, it had no regulatory effects on Muc5ac expression.

Discussion

These results demonstrated that lncRNA H19 positively regulates Muc5ac expression through PI3K/Akt /NF-κB pathway in the in vitro inflammation model. Therefore, this study indicated that decreased lncRNA H19 in asthma might play a protective role relieving mucus overproduction, and lncRNA H19 might be a potential target for asthma treatment.

Purple corn extract (PCE) alleviates cigarette smoke (CS)-induced DNA damage in rodent blood cells by activation of AMPK/Foxo3a/MnSOD pathway

Purple corn extract (PCE) is a nutraceutical, an activator of AMPK, and it has antioxidants and anticancer properties. Therefore, PCE could be a candidate for alleviating cigarette smoke (CS)-induced oxidative DNA damage. This study examined whether PCE can have a protective effect on blood cells in an animal model of cigarette smoke (CS)-induced DNA damage. PCE was orally administered to CS-inhaled Spraque-Dawley (SD) rats, followed by the target cells being examined for markers of DNA damage. The study also sought to elucidate the mechanism of PCE action in the PCE treated animals. SD rat inhalation of CS was for once a day for 30 min, repeated for 7 days. PCE was administered orally before CS inhalation. Pretreatment of the animals with oral PCE kept the numbers of white blood cells (WBC) as well as neutrophils (NE), lymphocytes (LY), monocytes (Mo), eosinophils (EO), abd jasophils (BA) from increasing as those were increased in the CS-inhaling SD rats. The amount of phosphorylated γ-H2AX, a DNA damage marker, was assayed in the circulating blood cells collected from the animals and western blot analysis with anti-Foxo3a, p-Foxo3a, p-AMPK, MnSOD antibodies were performed on those cells. PCE protected the circulating blood cells from CS inhalation-induced DNA damage by 44% as assayed by increases in γ-H2AX. PCE also increased the nuclear localization of Foxo3a by 52% over control cells. Mechanistically, PCE appears to efficiently protect various blood cell types from CS-induced DNA damage through removal of ROS via activation of the AMPK/Foxo3a/MnSOD pathway.

Transforming Growth Factor β Inhibits MUC5AC Expression by Smad3/HDAC2 Complex Formation and NF-κB Deacetylation at K310 in NCI-H292 Cells

Airway mucus secretion is an essential innate immune response for host protection. However, overproduction and hypersecretion of mucus, mainly composed of the gel- forming MUC5AC protein, are significant risk factors for patients with asthma and chronic obstructive pulmonary disease (COPD). The transforming growth factor β (TGFβ) signaling pathway negatively regulates MUC5AC expression; however, the underlying molecular mechanism is not fully understood. Here, we showed that TGFβ significantly reduces the expression of MUC5AC mRNA and its protein in NCI-H292 cells, a human mucoepidermoid carcinoma cell line. This reduced MUC5AC expression was restored by a TGFβ receptor inhibitor (SB431542), but not by the inhibition of NF-κB (BAY11-7082 or Triptolide) or PI3K (LY294002) activities. TGFβ-activated Smad3 dose-dependently bound to MUC5AC promoter. Notably, TGFβ-activated Smad3 recruited HDAC2 and facilitated nuclear translocation of HDAC2, thereby inducing the deacetylation of NF-κB at K310, which is essential for a reduction in NF-κB transcriptional activity. Both TGFβ-induced nuclear translocation of Smad3/HDAC2 and deacetylation of NF-κB at K310 were suppressed by a Smad3 inhibitor (SIS3). These results suggest that the TGFβ-activated Smad3/HDAC2 complex is an essential negative regulator for MUC5AC expression and an epigenetic regulator for NF-κB acetylation. Therefore, these results collectively suggest that modulation of the TGFβ1/Smad3/HDAC2/NF-κB pathway axis can be a promising way to improve lung function as a treatment strategy for asthma and COPD.

The Potential Role and Regulatory Mechanisms of MUC5AC in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is associated with high morbidity and mortality globally. Studies show that airway mucus hypersecretion strongly compromises lung function, leading to frequent hospitalization and mortality, highlighting an urgent need for effective COPD treatments. MUC5AC is known to contribute to severe muco-obstructive lung diseases, worsening COPD pathogenesis. Various pathways are implicated in the aberrant MUC5AC production and secretion MUC5AC. These include signaling pathways associated with mucus-secreting cell differentiation [nuclear factor-κB (NF-κB)and IL-13-STAT6- SAM pointed domain containing E26 transformation-specific transcription factor (SPDEF), as well as epithelial sodium channel (ENaC) and cystic fibrosis transmembrane conductance regulator (CFTR)], and signaling pathways related to mucus transport and excretion-ciliary beat frequency (CBF). Various inhibitors of mucus hypersecretion are in clinical use but have had limited benefits against COPD. Thus, novel therapies targeting airway mucus hypersecretion should be developed for effective management of muco-obstructive lung disease. Here, we systematically review the mechanisms and pathogenesis of airway mucus hypersecretion, with emphasis on multi-target and multi-link intervention strategies for the elucidation of novel inhibitors of airway mucus hypersecretion.

Recent Advances in the Development of Novel Drug Candidates for Regulating the Secretion of Pulmonary Mucus

Hypersecretion of pulmonary mucus is a major pathophysiological feature in allergic and inflammatory respiratory diseases including asthma and chronic obstructive pulmonary disease (COPD). Overproduction and/or oversecretion of mucus cause the airway obstruction and the colonization of pathogenic microbes. Developing a novel pharmacological agent to regulate the production and/or secretion of pulmonary mucus can be a useful strategy for the effective management of pathologic hypersecretion of mucus observed in COPD and asthma. Thus, in the present review, we tried to give an overview of the conventional pharmacotherapy for mucus-hypersecretory diseases and recent research results on searching for the novel candidate agents for controlling of pulmonary mucus hypersecretion, aiming to shed light on the potential efficacious pharmacotherapy of mucus-hypersecretory diseases.

Longifolioside A inhibits TLR4-mediated inflammatory responses by blocking PKCδ activation in LPS-stimulated THP-1 macrophages

Longifolioside A is an iridoid glucoside compound isolated from Pseudolysimachion rotundum var. subintegrum, which has been used in traditional herbal medicines to treat respiratory inflammatory diseases. Logifolioside A is a potent antioxidant; however, its underlying pharmacological mechanisms of action in inflammatory diseases are unknown. Here, we investigated the inhibitory effects of longifolioside A in lipopolysaccharide (LPS)-stimulated toll-like receptor 4 (TLR4) signal transduction systems using human THP-1 macrophages and HEK293 cells stably expressing human TLR4 protein (293/HA-hTLR4). Longifolioside A significantly reduced the release of inflammatory cytokines such as interleukin (IL)-6, -8, and tumor necrosis factor (TNF)-α in LPS-stimulated THP-1 macrophages. Furthermore, longifolioside A inhibited the expression of inflammatory mediator genes such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 that produce nitric oxide (NO) and prostaglandin E2 (PGE2), respectively. Longifolioside A suppressed the phosphorylation of PKCδ, IRAK4, IKKα/β, IκBα, and mitogen-activated protein (MAP) kinases (ERK 1/2 and JNK, but not p38), thereby inactivating the nuclear localization of NF-κB and AP-1, and thus decreasing the expression of inflammatory response genes. Notably, longifolioside A disrupted the interaction between human TLR4 and the TIR domain-containing adaptor protein (TIRAP), an early step during TLR4 activation, thereby reducing IL-8 secretion in 293/HA-hTLR4 cells. This inhibitory effect was comparable to that of TAK-242 (a TLR4 inhibitor, or resatorvid). Our results indicate that longifolioside A prevents inflammatory response by suppressing TLR4 activation required for NF-κB and AP-1 activation.

Use of Natural Products in Asthma Treatment

Asthma, a disease classified as a chronic inflammatory disorder induced by airway inflammation, is triggered by a genetic predisposition or antigen sensitization. Drugs currently used as therapies present disadvantages such as high cost and side effects, which compromise the treatment compliance. Alternatively, traditional medicine has reported the use of natural products as alternative or complementary treatment. The aim of this review was to summarize the knowledge reported in the literature about the use of natural products for asthma treatment. The search strategy included scientific studies published between January 2006 and December 2017, using the keywords "asthma," "treatment," and "natural products." The inclusion criteria were as follows: (i) studies that aimed at elucidating the antiasthmatic activity of natural-based compounds or extracts using laboratory experiments (in vitro and/or in vivo); and (ii) studies that suggested the use of natural products in asthma treatment by elucidation of its chemical composition. Studies that (i) did not report experimental data and (ii) manuscripts in languages other than English were excluded. Based on the findings from the literature search, aspects related to asthma physiopathology, epidemiology, and conventional treatment were discussed. Then, several studies reporting the effectiveness of natural products in the asthma treatment were presented, highlighting plants as the main source. Moreover, natural products from animals and microorganisms were also discussed and their high potential in the antiasthmatic therapy was emphasized. This review highlighted the importance of natural products as an alternative and/or complementary treatment source for asthma treatment, since they present reduced side effects and comparable effectiveness as the drugs currently used on treatment protocols.

Bioactivities of Natural Catalpol Derivatives

Catalpol, a famous molecule of iridoids, possesses extensive pharmacological activities. Our studies found that compounds with low-polarity substituents at the 6-O position of catalpol exhibited higher NF-κB inhibitory potency than catalpol. However, catalpol derivatives are not much focused. Here this review provides extensive coverage of naturally occurring catalpol derivatives discovered from 1888 until 2018. It covers their distribution, chemotaxonomic significance, chemical structures, and bioactivities from more than 200 peer-reviewed articles, and highlights the structure-activity relationship of catalpol derivatives.

Picroside II Isolated from Pseudolysimachion rotundum var. subintegrum Inhibits Glucocorticoid Refractory Serum Amyloid A (SAA) Expression and SAA-induced IL-33 Secretion

Chronic obstructive pulmonary disease (COPD) is a major inflammatory lung disease characterized by irreversible and progressive airflow obstruction. Although corticosteroids are often used to reduce inflammation, steroid therapies are insufficient in patients with refractory COPD. Both serum amyloid A (SAA) and IL-33 have been implicated in the pathology of steroid-resistant lung inflammation. Picroside II isolated from Pseudolysimachion rotundum var. subintegrum(Plantaginaceae) is a major bioactive component of YPL-001, which has completed phase-2a clinical trials in chronic obstructive pulmonary disease patients. In this study, we investigated whether picroside II is effective in treating steroid refractory lung inflammation via the inhibition of the SAA-IL-33 axis. Picroside II inhibited LPS-induced SAA1 expression in human monocytes, which are resistant to steroids. SAA induced the secretion of IL-33 without involving cell necrosis. Picroside II, but not dexamethasone effectively inhibited SAA-induced IL-33 expression and secretion. The inhibitory effect by picroside II was mediated by suppressing the mitogen-activated protein kinase (MAPK) p38, ERK1/2, and nuclear factor-κB pathways. Our results suggest that picroside II negatively modulates the SAA-IL-33 axis that has been implicated in steroid-resistant lung inflammation. These findings provide valuable information for the development of picroside II as an alternative therapeutic agent against steroid refractory lung inflammation in COPD.

Natural inhibitors on airway mucin: Molecular insight into the therapeutic potential targeting MUC5AC expression and production

Airway mucin overproduction is the hallmark risk factor of asthma, which is associated with the reduction of lung function. An aberrant mucin expression is responsible for airway obstruction due to its high viscous characteristics. Among the mucins discovered, MUC5AC is the prime mucin of airway epithelia. Nowadays, mucins induced asthma and chronic obstructive pulmonary disease (COPD) are a great concern all over the world. This review focuses on the effects of natural compounds that can be beneficial to explore new drugs to halt MUC5AC secretion and production in airway epithelial, and also their underlying molecular mechanisms based on recent studies. Several researchers are seeking natural sources to identify a new potent MUC5AC inhibitory agent for clinical applications, because of countable limitations of existing synthetic drugs. Currently, flavonoids, glycoside and steroids like natural compounds have acquired great attention due to their anti-inflammatory and mucoregulatory effects. Most importantly, many natural compounds have shown their potential effects as the modulator of mucin expression, secretion, and production. Therefore, targeting airway MUC5AC expression and production represents an auspicious area of research for the development of drugs against various respiratory diseases.

S-Allyl cysteine reduces eosinophilic airway inflammation and mucus overproduction on ovalbumin-induced allergic asthma model

S-Allyl cysteine (SAC) is an active component in garlic and has various pharmacological effects, such as anti-inflammatory, anti-oxidant, and anti-cancer activities. In this study, we explored the suppressive effects of SAC on allergic airway inflammation induced in an ovalbumin (OVA)-induced asthma mouse model. To induce asthma, BALB/c mice were sensitized to OVA on days 0 and 14 by intraperitoneal injection and exposed to OVA from days 21 to 23 using a nebulizer. SAC was administered to mice by oral gavage at a dose of 10 or 20 mg/kg from days 18 to 23. SAC significantly reduced airway hyperresponsiveness, inflammatory cell counts, and Th2 type cytokines in bronchoalveolar lavage fluid induced by OVA exposure, which was accompanied by reduced serum OVA-specific immunoglobulin E. In histological analysis of the lung tissue, administration of SAC reduced inflammatory cell accumulation into lung tissue and mucus production in airway goblet cells induced by OVA exposure. Additionally, SAC significantly decreased MUC5AC expression and nuclear factor-κB phosphorylation induced by OVA exposure. In summary, SAC effectively suppressed allergic airway inflammation and mucus production in OVA-challenged asthmatic mice. Therefore, SAC shows potential for use in treating allergic asthma.

Lignans Isolated From Flower Buds of Magnolia fargesii Attenuate Airway Inflammation Induced by Cigarette Smoke in vitro and in vivo

The flower buds of Magnolia fargesii, known traditionally as Xinyi, exert anti-inflammatory effects against inflammatory lung diseases such as COPD. Lignans isolated from Xinyi are an important group of plant-derived anti-inflammatory compounds. However, the mechanisms of action underlying their protective effects against COPD are not yet fully understood. Here, we showed that seven lignans (lignans 1–7) obtained from a CHCl₃ fraction of Xinyi effectively suppress the inflammatory response in CSC-stimulated airway epithelial cells (in vitro) and in a mouse model of COPD established by exposure to CS and LPS. The CHCl₃ fraction was found to inhibit CSC-induced IL-6 expression in human airway epithelial cells and to suppress the infiltration of inflammatory cells (neutrophils and macrophages) and secretion of inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the mouse model. Similarly, each of the seven lignans isolated from the CHCl₃ fraction also suppressed the infiltration of inflammatory cells (neutrophils and macrophages) and secretion of inflammatory mediators such as reactive oxygen species (ROS), TNF-α, and IL-6 in vivo. Notably, all lignan compounds significantly suppressed both extracellular signal-related kinase (ERK) and Akt phosphorylation levels in CSC-stimulated human lung mucoepidermoid carcinoma (NCI-H292) cells. Of these, lignan 1 (dimethylpinoresinol) inhibited the expression of CSC-induced inflammatory cytokines (IL-1β, -6, and -8) in vitro in a dose-dependent manner by suppressing the activation of epidermal growth factor receptor (EGFR) and its downstream effectors, including ERK and Akt, in NCI-H292 cells. Our results show that the lignans isolated from Xinyi may prevent airway inflammatory diseases through the suppression of EGFR and its downstream effectors.

A Disintegrin and A Metalloproteinase-9 (ADAM9): A Novel Proteinase Culprit with Multifarious Contributions to COPD

INTRODUCTION

Proteinases with a disintegrin and a metalloproteinase domain (ADAMs) have not been well studied in COPD. We investigated whether ADAM9 is linked to COPD in humans and mice.

METHODS

ADAM9 blood and lung levels were measured in COPD patients versus controls, and air- versus cigarette smoke (CS)-exposed wild-type (WT) mice. WT and Adam9-/- mice were exposed to air or CS for 1-6 months, and COPD-like lung pathologies were measured.

RESULTS

ADAM9 staining was increased in lung epithelial cells and macrophages in smokers and even more so in COPD patients and correlated directly with pack-year smoking history and inversely with airflow obstruction and/or FEV1 % predicted. Bronchial epithelial cell ADAM9 mRNA levels were higher in COPD patients than controls and correlated directly with pack-year smoking history. Plasma, BALF and sputum ADAM9 levels were similar in COPD patients and controls. CS exposure increased Adam9 levels in WT murine lungs. Adam9-/- mice were protected from emphysema development, small airway fibrosis, and airway mucus metaplasia. CS-exposed Adam9-/- mice had reduced lung macrophage counts, alveolar septal cell apoptosis, lung elastin degradation, and shedding of VEGFR2 and EGFR in BALF samples. Recombinant ADAM9 sheds EGF and VEGF receptors from epithelial cells to reduce activation of the Akt pro-survival pathway and increase cellular apoptosis.

CONCLUSIONS

ADAM9 levels are increased in COPD lungs and linked to key clinical variables. Adam9 promotes emphysema development, and large and small airway disease in mice. Inhibition of ADAM9 could be a therapeutic approach for multiple COPD phenotypes.

Fisetin inhibits TNF-α/NF-κB-induced IL-8 expression by targeting PKCδ in human airway epithelial cells

Fisetin (3,7,3',4'-tetrahydroxyflavone), a natural flavonoid, is a therapeutic agent for respiratory inflammatory diseases such as chronic obstructive pulmonary disease (COPD). However, detailed molecular mechanisms regarding the target protein of fisetin remain unknown. Fisetin significantly reduces tumour necrosis factor alpha (TNF-α)-induced interleukin (IL)-8 levels by inhibiting both nuclear factor kappa B (NF-κB) transcriptional activity and the phosphorylation of its upstream effectors. We show that fisetin prevents interactions between protein kinase C (PKC)δ and TNF receptor-associated factor 2 (TRAF2), thereby inhibiting the inhibitor of kappa B kinase (IKK)/NF-κB downstream signalling cascade. Furthermore, we found that fisetin directly binds to PKCδ in vitro. Our findings provide evidence that fisetin inhibits the TNF-α-activated IKK/NF-κB cascade by targeting PKCδ, thereby mediating inflammatory diseases such as COPD. These data suggest that fisetin is a good therapeutic drug for the treatment of inflammatory lung diseases, such as COPD, by inhibiting the TNF-α/NF-κB signalling pathway.

Piscroside C inhibits TNF-α/NF-κB pathway by the suppression of PKCδ activity for TNF-RSC formation in human airway epithelial cells

BACKGROUND

Piscroside C, isolated from Pseudolysimachion rotundum var. subintegrum, is a novel iridoid glycoside with therapeutic efficacy in a mouse model of chronic obstructive pulmonary disease (COPD). Piscroside C has been reported as a constituent of YPL-001 (under Phase 2a study, ClinicalTrials.gov identifier NCT02272634).

PURPOSE

To investigate the mechanisms behind piscroside C therapeutic effects on COPD in human airway epithelial NCI-H292 cells.

METHODS

We tested if piscroside C effectively suppresses MUC5AC gene expression and TNF-RSC/IKK/NF-κB cascades in TNF-α-stimulated NCI-H292 cells by employing, reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, luciferase reporter assays, chromatin immunoprecipitation assays and immunoprecipitation.

RESULTS

Piscroside C markedly suppressed the expression of TNF-α-induced MUC5AC mucus protein by inhibiting the transcriptional activity of NF-κB in NCI-H292 cells. Indeed, piscroside C negatively regulated the function of TNF receptor 1 signaling complex (TNF-RSC, an upstream regulator of the NF-κB pathway) without affecting its extracellular interaction with the TNF-α ligand. This inhibitory effect by piscroside C is mediated by the inactivation of protein kinase C (PKC), an essential regulator of TNF-RSC. PKC inactivation by piscroside C results in decreased PKCδ binding to a TRAF2 subunit of TNF-RSC and subsequent reduced IKK phosphorylation, resulting in NF-κB inactivation.

CONCLUSION

We propose that piscroside C is a promising therapeutic constituent of YPL-001 through its inhibition of PKCδ activity in the TNF-RSC/IKK/NF-κB/MUC5AC signaling cascade.

Neutrophil extracellular traps promote lipopolysaccharide-induced airway inflammation and mucus hypersecretion in mice

Bacterial lipopolysaccharide (LPS) contributes to airway inflammation and mucus hypersecretion in chronic airway inflammatory diseases, such as chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF). Neutrophil extracellular traps (NETs) are extracellular meshworks composed of DNA fibers and antimicrobial proteins. Although NET formation has been detected in COPD and CF patients, how NETs contribute to these diseases is poorly understood. This study was performed to clarify the effects and mechanisms of action of NETs in airway inflammation and mucus hypersecretion. We created a murine model of LPS-induced airway inflammation and mucus hypersecretion, and found that LPS-induced NET formation was degraded by aerosolized DNase I treatment in mice. Degradation of NETs by aerosolized DNase I reduced LPS-induced airway inflammation and mucus hypersecretion in mice, this reduction correlated with suppression of TLR4/NF-κB signaling pathway. More importantly, NETs promoted LPS-induced production of IL-1β, IL-6 and TNF-α in macrophages. These results suggest NET degradation using aerosolized DNase I is a potential new therapeutic strategy for treating COPD and CF.

Active Fragment of Veronica ciliata Fisch. Attenuates t-BHP-Induced Oxidative Stress Injury in HepG2 Cells through Antioxidant and Antiapoptosis Activities

Excessive amounts of reactive oxygen species (ROS) in the body are a key factor in the development of hepatopathies such as hepatitis. The aim of this study was to assess the antioxidation effect in vitro and hepatoprotective activity of the active fragment of Veronica ciliata Fisch. (VCAF). Antioxidant assays (DPPH, superoxide, and hydroxyl radicals scavenging) were conducted, and hepatoprotective effects through the application of tert-butyl hydroperoxide- (t-BHP-) induced oxidative stress injury in HepG2 cells were evaluated. VCAF had high phenolic and flavonoid contents and strong antioxidant activity. From the perspective of hepatoprotection, VCAF exhibited a significant protective effect on t-BHP-induced HepG2 cell injury, as indicated by reductions in cytotoxicity and the levels of ROS, 8-hydroxydeoxyguanosine (8-OHdG), and protein carbonyls. Further study demonstrated that VCAF attenuated the apoptosis of t-BHP-treated HepG2 cells by suppressing the activation of caspase-3 and caspase-8. Moreover, it significantly decreased the levels of ALT and AST, increased the activities of acetyl cholinesterase (AChE), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT), and increased total antioxidative capability (T-AOC). Collectively, we concluded that VCAF may be a considerable candidate for protecting against liver injury owing to its excellent antioxidant and antiapoptosis properties.

IL-17 in the lung: the good, the bad, and the ugly

The IL-17 family of cytokines has emerged over the last two decades as a pleiotropic group of molecules that function in a wide variety of both beneficial and detrimental (pathological) processes, mainly in mucosal barrier tissue. The beneficial effects of IL-17 expression are especially important in the lung, where exposure to foreign agents is abundant. IL-17A plays an important role in protection from both extracellular bacteria and fungi, as well as viruses that infect cells of the mucosal tracts. IL-17 coregulated cytokines, such as IL-22, are involved in maintaining epithelial cell homeostasis and participate in epithelial cell repair/regeneration following inflammatory insults. Thus, the IL-17/IL-22 axis is important in both responding to, and recovering from, pathogens. However, aberrant expression or overexpression of IL-17 cytokines contributes to a number of pathological outcomes, including asthma, pneumonitis, and generation or exacerbation of pulmonary fibrosis. This review covers the good, bad, and ugly aspects of IL-17 in the lung.

NPS2143 Inhibits MUC5AC and Proinflammatory Mediators in Cigarette Smoke Extract (CSE)-Stimulated Human Airway Epithelial Cells

Mucus overproduction is a fundamental hallmark of COPD that is caused by exposure to cigarette smoke. MUC5AC is one of the main mucin genes expressed in the respiratory epithelium, and its transcriptional upregulation often correlates with increased mucus secretion. Calcium-sensing receptor (CaSR) antagonists have been reported to possess anti-inflammatory effects. The purpose of the present study was to investigate the protective role of NPS2143, a selective CaSR antagonist on cigarette smoke extract (CSE)-stimulated NCI-H292 mucoepidermoid human lung cells. Treatment of NPS2143 significantly inhibited the expression of MUC5AC in CSE-stimulated H292 cells. NPS2143 reduced the expression of MMP-9 in CSE-stimulated H292 cells. NPS2143 also decreased the release of proinflammatory cytokines such as IL-6 and TNF-α in CSE-stimulated H292 cells. Furthermore, NPS2143 attenuated the activation of MAPKs (JNK, p38, and ERK) and inhibited the nuclear translocation of NF-κB in CSE-stimulated H292 cells. These results indicate that NPS2143 had a therapeutic potential in COPD.

Multiple UDP-Glucuronosyltransferase and Sulfotransferase Enzymes are Responsible for the Metabolism of Verproside in Human Liver Preparations

Verproside, an active iridoid glycoside component of Veronica species, such as Pseudolysimachion rotundum var. subintegrum and Veronica anagallis-aquatica, possesses anti-asthma, anti-inflammatory, anti-nociceptive, antioxidant, and cytostatic activities. Verproside is metabolized into nine metabolites in human hepatocytes: verproside glucuronides (M1, M2) via glucuronidation, verproside sulfate (M3) via sulfation, picroside II (M4) and isovanilloylcatalpol (M5) via O-methylation, M4 glucuronide (M6) and M4 sulfate (M8) via further glucuronidation and sulfation of M4, and M5 glucuronide (M7) and M5 sulfate (M9) via further glucuronidation and sulfation of M5. Drug-metabolizing enzymes responsible for verproside metabolism, including sulfotransferase (SULT) and UDP-glucuronosyltransferase (UGT), were characterized. The formation of verproside glucuronides (M1, M2), isovanilloylcatalpol glucuronide (M7), and picroside II glucuronide (M6) was catalyzed by commonly expressed UGT1A1 and UGT1A9 and gastrointestinal-specific UGT1A7, UGT1A8, and UGT1A10, consistent with the higher intrinsic clearance values for the formation of M1, M2, M6, and M7 in human intestinal microsomes compared with those in liver microsomes. The formation of verproside sulfate (M3) and M5 sulfate (M9) from verproside and isovanilloylcatalpol (M5), respectively, was catalyzed by SULT1A1. Metabolism of picroside II (M4) into M4 sulfate (M8) was catalyzed by SULT1A1, SULT1E1, SULT1A2, SULT1A3, and SULT1C4. Based on these results, the pharmacokinetics of verproside may be affected by the co-administration of relevant UGT and SULT inhibitors or inducers.

Picroside II Attenuates Airway Inflammation by Downregulating the Transcription Factor GATA3 and Th2-Related Cytokines in a Mouse Model of HDM-Induced Allergic Asthma

Picroside II isolated from Pseudolysimachion rotundum var. subintegrum has been used as traditional medicine to treat inflammatory diseases. In this study, we assessed whether picroside II has inhibitory effects on airway inflammation in a mouse model of house dust mite (HDM)-induced asthma. In the HDM-induced asthmatic model, picroside II significantly reduced inflammatory cell counts in the bronchoalveolar lavage fluid (BALF), the levels of total immunoglobulin (Ig) E and HDM-specific IgE and IgG1 in serum, airway inflammation, and mucus hypersecretion in the lung tissues. ELISA analysis showed that picroside II down-regulated the levels of Th2-related cytokines (including IL-4, IL-5, and IL-13) and asthma-related mediators, but it up-regulated Th1-related cytokine, IFNγ in BALF. Picroside II also inhibited the expression of Th2 type cytokine genes and the transcription factor GATA3 in the lung tissues of HDM-induced mice. Finally, we demonstrated that picroside II significantly decreased the expression of GATA3 and Th2 cytokines in developing Th2 cells, consistent with in vivo results. Taken together, these results indicate that picroside II has protective effects on allergic asthma by reducing GATA3 expression and Th2 cytokine bias.

HSCCC Separation of the Two Iridoid Glycosides and Three Phenolic Compounds from Veronica ciliata and Their in Vitro Antioxidant and Anti-Hepatocarcinoma Activities

Five main compounds, including two iridoid glycosides (catalposide, verproside) and three phenolic compounds (luteolin, 4-hydroxy benzoic acid, 3,4-dihydroxy benzoic acid), were separated and prepared from the crude extract of Veronica ciliata by high-speed countercurrent chromatography. n-Hexane/n-butanol/water (1.5:5:5, v/v/v) was used for the separation of catalposide and verproside. n-Hexane/n-butanol/water (3:2:5, v/v/v) was used for the separation of luteolin, 4-hydroxy benzoic acid and 3,4-dihydroxy benzoic acid. The head-to-tail elution mode was used with a flow rate of 5.0 mL/min and a rotary speed of 800 rpm. Finally, a total of 1.28 mg luteolin, 6 mg 4-hydroxy benzoic acid, 2 mg 3,4-dihydroxy benzoic acid, 2 mg verproside and 10 mg catalposide with purities of 98%, 99.1%, 99.5%, 99.8% and 99%, respectively, were obtained from 200 mg of crude extract. In addition, their structure was identified using MS, ¹H-NMR and ¹³C-NMR. To the best of our knowledge, this is the first report of the separation and purification of iridoid glycosides and phenolic compounds from V. ciliata by high-speed countercurrent chromatography (HSCCC). Among these compounds, luteolin, 4-hydroxy benzoic acid and 3,4-dihydroxy benzoic acid were separated from V. ciliata Fisch. for the first time. The results of the antioxidant activity show that protocatechuic acid and luteolin have strong antioxidant activity compared to 2,6-di-tert-butyl-4-methylphenol (BHT) and vitamin C (Vc). Five compounds also exhibited strong anti-hepatocarcinoma activities.