Artemisia gmelinii Attenuates Lung Inflammation by Suppressing the NF-κB/MAPK Pathway

Chinese herbal formula Regan Saibisitan alleviates airway inflammation of chronic bronchitis via inhibiting the JAK2/STAT3 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Regan Saibisitan (RGS) is a classic prescription used to treat cough, pneumonia, and other respiratory infections in Uygur medicine. It is a granule composed of 12 kinds of medicinal materials. However, the mechanism by which RGS regulates lung disease remains unclear.

AIM OF THE STUDY

Chronic bronchitis (CB) is characterized by persistent, non-specific inflammation in the trachea, bronchial mucosa, and surrounding tissues mainly resulting from infectious or non-infectious factors. This study aimed to explore the function of RGS in alleviating airway inflammation associated with chronic bronchitis, and to examine the mechanisms by which RGS exerts its effects via the JAK 2/STAT 3 signaling pathway.

MATERIALS AND METHODS

The CB mouse model was established by cigarette smoking (CS) and intranasal administration of lipopolysaccharide (LPS, 20 μg), histological changes of bronchial epithelium, collagen deposition, mucus secretion in lung tissue and inflammatory factors were assayed. Transcriptomics analysis was performed to detect the differentially regulated genes in lung tissue of CB mice treated with RGS. The effect of RGS on JAK 2/STAT 3 pathway was investigated in CB mice and NCI-H292 cells treated with PMA using western blotting, ELISA, and immunohistochemical analysis.

RESULTS

RGS treatment significantly improved the thickening of bronchial epithelium, decreased collagen deposition and secretion of mucus, and the levels of inflammatory factors in CB mice. Transcriptomics analysis showed that most of 402 differentially expressed genes in RGS-treated CB mice were related to inflammatory response. The results in CB mice and NCI-H292 cells showed that RGS reduced the phosphorylation level of JAK 2 and STAT 3. In addition, the use of JAK 2 inhibitor AG490 confirmed that JAK 2/STAT 3 pathway played a key role in the effects of RGS on CB.

CONCLUSIONS

RGS suppresses inflammation and improves chronic bronchitis in NCI-H292 cells and CB mice, at least in part, via inhibiting the JAK 2/STAT 3 pathway. This study demonstrated that RGS could be a potential drug in treating CB disease.

Design, Synthesis, and Evaluation of Selective PDE4 Inhibitors for the Therapy of Pulmonary Injury

Pulmonary inflammation is the main cause of lung injury. Phosphodiesterase 4 (PDE4) is a promising anti-inflammatory target for the treatment of respiratory diseases. Herein, we designed and synthesized 43 compounds in two novel series of benzimidazole derivatives as PDE4 inhibitors. Among them, compound A5 showed highly selective inhibition of PDE4, good safety, and liver microsomal stability in vitro. A5 administration remarkably attenuated inflammatory infiltration and pathologic injury of the lung in models of acute lung injury in mice and chronic obstructive pulmonary disease (COPD) in mice. In addition, A5 enhanced sputum secretion, relieved cough in mice, and inhibited phosphorylation of p38 MAP kinase, an important protein in the regulation of lung injury. Overall, A5, as an effective PDE4 inhibitor without acute toxicity and gastrointestinal reaction, may be a potent candidate for the treatment of pulmonary injury.

Neutrophil extracellular traps promote ΔNp63+ basal cell hyperplasia in chronic rhinosinusitis

BACKGROUND

Neutrophil extracellular traps (NETs) are observed in chronic rhinosinusitis (CRS), although their role remains unclear.

OBJECTIVES

This study aimed to investigate the influence of NETs on the CRS epithelium.

METHODS

Forty-five sinonasal biopsy specimens were immunofluorescence-stained to identify NETs and p63+ basal stem cells. Investigators treated human nasal epithelial cells with NETs and studied them with immunofluorescence staining, Western blotting, and quantitative real-time PCR. NET inhibitors were administered to a murine neutrophilic nasal polyp model.

RESULTS

NETs existed in tissues in patients with CRS with nasal polyps, especially in noneosinophilic nasal polyp tissues. p63+ basal cell expression had a positive correlation with the release of NETs. NETs induced the expansion of Ki-67+p63+ cells. We found that ΔNp63, an isoform of p63, was mainly expressed in the nasal epithelium and controlled by NETs. Treatment with deoxyribonuclease (DNase) I or Sivelestat (NET inhibitors) prevented the overexpression of ΔNp63+ epithelial stem cells and reduced polyp formation.

CONCLUSIONS

These results reveal that NETs are implicated in CRS pathogenesis via basal cell hyperplasia. This study suggests a novel possibility of treating CRS by targeting NETs.

Artemisia gmelinii Extract Attenuates Particulate Matter-Induced Neutrophilic Inflammation in a Mouse Model of Lung Injury

Particulate matter (PM) induces and augments oxidative stress and inflammation, leading to respiratory diseases. Although Artemisia gmelinii Weber ex Stechm has antioxidant and anti-inflammatory effects, there are no reports on whether Artemisia gmelinii extract (AGE) regulates lung inflammation in a PM-induced model. Thus, we investigated the protective effects of AGE using a PM-induced mouse lung inflammation model. AGE significantly decreased the expression of inflammatory chemokines, neutrophil extracellular trap formation, and the total number of inflammatory cells in the bronchoalveolar lavage fluid (BALF). Furthermore, AGE attenuated lung inflammation through the suppression of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)/mitogen-activated protein kinase (MAPK) signaling pathway, while promoting the nuclear factor erythroid-2-related factor 2 (NRF2)/heme oxygenase-1 (HO-1) signaling pathway in lung tissues. Concordant with these observations, AGE suppressed inflammatory cytokines, chemokines, reactive oxygen species, NETosis, myeloperoxidase, and neutrophil elastase by decreasing the mRNA expression of High mobility group box 1, Runt-related transcription factor 1, and Kruppel-like factor 6 in differentiated HL-60 cells. In summary, our data demonstrated that AGE suppresses PM-induced neutrophil infiltration, lung damage, and pulmonary inflammation by suppressing NF-κB/MAPK signaling pathways and enhancing the NRF2/HO-1 signaling pathway. These findings suggest that AGE administration is an effective approach for preventing and treating PM-induced respiratory inflammation.

1,5-Dicaffeoylquinic acid from Pseudognaphalium affine ameliorates dry eye disease via suppression of inflammation and protection of the ocular surface

PURPOSE

Pseudognaphalium affine (P. affine), a medicinal plant, has long been used to treat various diseases due to its astringent and vulnerary effects. These therapeutic benefits are largely attributed to high contents of phytochemicals, such as flavonoids and polyphenols, that have anti-inflammatory and tissue-protective activities. Herein, we investigated the potential of dicaffeoylquinic acids (diCQAs), polyphenols from P. affine, as a novel treatment for dry eye disease (DED).

METHODS

We isolated 1,5-, 3,4-, 3,5- and 4,5-diCQAs from the P. affine methanol extract, and tested the effects of diCQA isomers in cultures of human corneal epithelial cells (CECs) under desiccating hyperosmolar stress and in two mouse models for DED: desiccating environmental stress-induced DED and the NOD.B10-H2b mouse model of ocular Sjögren's syndrome.

RESULTS

Initial screening showed that, among the diCQAs, 1,5-diCQA significantly inhibited apoptosis and enhanced viability in cultures of CECs under hyperosmolar stress. Moreover, 1,5-diCQA protected CECs by promoting proliferation and downregulating inflammatory activation. Subsequent studies with two mouse models of DED revealed that topical 1,5-diCQA administration dose-dependently decreased corneal epithelial defects and increased tear production while repressing inflammatory cytokines and T cell infiltration on the ocular surface and in the lacrimal gland. 1,5-diCQA was more effective in alleviating DED, as compared with two commercially-available dry eye treatments, 0.05% cyclosporine and 0.1% sodium hyaluronate eye drops.

CONCLUSIONS

Together, our results demonstrate that 1,5-diCQA isolated from P. affine ameliorates DED through protection of corneal epithelial cells and suppression of inflammation, thus suggesting a novel DED therapeutic strategy based on natural compounds.

Neutrophil Extracellular Traps in Airway Diseases: Pathological Roles and Therapeutic Implications

Neutrophils are important effector cells of the innate immune response that fight pathogens by phagocytosis and degranulation. Neutrophil extracellular traps (NETs) are released into the extracellular space to defend against invading pathogens. Although NETs play a defensive role against pathogens, excessive NETs can contribute to the pathogenesis of airway diseases. NETs are known to be directly cytotoxic to the lung epithelium and endothelium, highly involved in acute lung injury, and implicated in disease severity and exacerbation. This review describes the role of NET formation in airway diseases, including chronic rhinosinusitis, and suggests that targeting NETs could be a therapeutic strategy for airway diseases.

Camellia sinensis L. Alleviates Pulmonary Inflammation Induced by Porcine Pancreas Elastase and Cigarette Smoke Extract

Cigarette smoke (CS) is the major factor in the development of chronic obstructive pulmonary disease (COPD), the third leading cause of death worldwide. Furthermore, although Camellia sinensis (CN) has been known as an anti-inflammatory material, the effect of CN has not yet been known on pulmonary inflammation in COPD. Thus, we investigated the protective effects of Camellia sinensis L. extract (CLE) against pulmonary inflammation in porcine pancreas elastase (PPE) and a cigarette smoke extract (CSE)-induced COPD mouse model. Oral administration of CLE suppressed the symptoms such as infiltration of immune cells, cytokines/chemokines secretion, mucus hypersecretion, and injuries of the lung parenchyma. Increased inflammatory responses in COPD are mediated by various immune cells such as airway epithelial cells, neutrophils, and alveolar macrophages. Thus, we investigated the effect and mechanisms of CLE in H292, HL-60, and MH-S cells. The CLE inhibited the expression of IL-6, IL-8, MUC5AC and MUC5B on CSE/LPS-stimulated H292 cells and also suppressed the formation of neutrophil extracellular traps and secretion of neutrophil elastase by inhibiting reactive oxygen species in PMA-induced HL-60 cells. In particular, the CLE suppressed the release of cytokines and chemokines caused by activating the nuclear factor kappa-light-chain-enhancer of activated B via the activation of nuclear factor erythroid-2-related factor 2 and the heme oxygenase-1 pathway in CSE/LPS-stimulated MH-S cells. Therefore, we suggest that the CLE administration be the effective approach for treating or preventing chronic pulmonary diseases such as COPD induced by CS.