Eupatilin downregulates phorbol 12-myristate 13-acetate-induced MUC5AC expression via inhibition of p38/ERK/JNK MAPKs signal pathway in human airway epithelial cells

Characteristics of mucin hypersecretion in different inflammatory patterns based on endotypes of chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is usually accompanied by mucin hypersecretion that can lead to mucus accumulation and impair nasal mucociliary clearance, thus exacerbating airway inflammation. Abnormal mucin hypersecretion is regulated by different T helper (Th) cytokines, which are associated with different endotype-driven inflammatory responses. Therefore, it is of great significance to understand how these factors regulate mucin hypersecretion to provide precise treatment strategies for different endotypes of CRS. BODY: Thus far, the most common endotypes of CRS are classified as type 1, type 2, or type 3 immune responses based on innate and adaptive cell-mediated effector immunity, and the representative Th cytokines in these immune responses, such as IFN-γ, TNF-α, IL-4, IL-5, IL-13, IL-10, IL-17, and IL-22, play an important regulatory role in mucin secretion. We reviewed all the related literature in the PubMed database to determine the expression of these Th cytokines in CRS and the role they play in the regulation of mucin secretion.

CONCLUSION

We believe that the main Th cytokines involved in specific endotypes of CRS play a key role in regulating abnormal mucin secretion, which contributes to better understanding of the pathogenesis of CRS and provides therapeutic targets for airway inflammatory diseases associated with mucin hypersecretion.

Cigarette smoke extract-mediated FABP4 upregulation suppresses viability and induces apoptosis, inflammation and oxidative stress of bronchial epithelial cells by activating p38 MAPK/MK2 signaling pathway

Background

Long-term inhalation of cigarette smoke is considered to be one of the main causes of bronchial epithelioid cell damage, but its underlying mechanism has to be further clarified.

Methods

Gene expression at mRNA level and protein levels were detected by qRT-PCR and western blot analysis respectively. CCK-8, TUNEL assays, ELISA, western blot analysis and commercial kits were utilized to test cell viability, apoptosis inflammatory response and oxidative stress. The correlation between fatty acid binding protein 4 (FABP4) and the p38 mitogen-activated protein kinase (MAPK)/MAPK activated kinase 2 (MK2) signaling pathway was verified by western blot analysis and rescue assays.

Results

Cigarette smoke extract (CSE) exposure decreased viability, induced apoptosis and inflammatory response in 16HBE cells. Moreover, the expression of FABP4 in CSE-treated 16HBE cells was up-regulated in a time and dose-dependent manner. Ablation of FABP4 in 16HBE cells significantly protected against CSE-mediated cell viability decline and apoptosis. Further, FABP4 knockdown suppressed inflammatory response by down-regulating the elevated levels of cellular inflammatory factors including TNF-α, IL-1β, IL-6, Cyclooxygenase-2 (Cox-2) and inducible nitric oxide synthase (iNOS) in CSE-treated 16HBE cells. The oxidative stress induced by CSE in 16HBE cells was also inhibited by FABP4 silence as evidence by reduced ROS and MDA level but increased SOD activity caused by FABP4 silence. Finally, all the above effects of FABP4 silence on CSE-treated 16HBE cells were reversed by asiatic acid, an agonist of p38 mitogen-activated protein kinase (MAPK).

Conclusions

The up-regulation of FABP4 expression mediated by CSE exerted pro-inflammatory, pro-oxidative stress and pro-apoptotic effects on bronchial epithelial cells by activating the p38 MAPK/MK2 signaling pathway. Our findings help to further understand the underlying mechanism of cigarette smoke-induced bronchial inflammation.

Daphnodorin C isolated from the stems of Daphne kiusiana Miquel attenuates airway inflammation in a mouse model of chronic obstructive pulmonary disease

BACKGROUND

Since long-term or high-dose use of COPD medication causes adverse effects in patients with COPD, more effective and safer ways to manage COPD symptoms are required. Daphne kiusiana Miquel is a medicinal plant, but its anti-COPD efficacy was little studied.

PURPOSE

We investigated the anti-COPD activity and molecular mechanism of action of active compounds isolated from D. kiusiana to find drug candidates for COPD.

METHODS

We isolated seven compounds (1-7) in an ethyl acetate (EtOAc) fraction from D. kiusiana, and determined that seven compounds effectively control the inflammatory responsiveness in both PMA-stimulated lung epithelial cells (in vitro) and/or in COPD model mice using cigarette smoke- and lipopolysaccharides-exposed animals in vivo.

RESULTS

We show that the ethyl acetate (EtOAc) fraction from D. kiusiana. suppresses inflammatory response in both PMA-stimulated human lung epithelial cells (in vitro) and COPD model mice (in vivo). The EtOAc fraction effectively suppresses various inflammatory responses, such as mucus secretion, ROS production, bronchial recruitment of inflammatory cells, and release of proinflammatory cytokines. Additionally, we isolated three compounds with anti-inflammatory efficacy from the EtOAc fraction, out of which daphnodorin C was the most effective. Finally, we demonstrated that daphnodorin C negatively regulates inflammatory gene expression by suppressing NF-κB and specific MAPK signaling pathways (JNK and p38) in vitro and in vivo.

CONCLUSIONS

These results suggest that daphnodorin C could be a promising therapeutic alternative for managing COPD symptoms.

sRAGE Inhibits the Mucus Hypersecretion in a Mouse Model with Neutrophilic Asthma

Background: Neutrophilic asthma (NA) may result in irreversible airflow limitations. Soluble advanced glycosylation receptor (sRAGE) has been shown to be associated with neutrophilic airway inflammation. However, the association between sRAGE and mucus hypersecretion in NA remains unknown. This study aims to assess the function of sRAGE on mucus hypersecretion.Methods: A NA mouse model was established and treated with adeno-associated virus 9 (AAV9)-sRAGE and inhibitors. Collagen deposition and goblet cell hyperplasia in the lungs were evaluated by periodic acid-Schiff (PAS) and Masson staining. sRAGE and mucin levels in bronchoalveolar lavage fluid were measured by ELISA. Pathway molecule expression levels were determined by RT-qPCR and western blotting.Results: The results showed that the NA mouse model exhibited airway mucus hypersecretion. Mice can be effectively transfected by AAV9-sRAGE via tail-vein injection and intranasal drip. AAV9-sRAGE increased the sRAGE levels but it inhibited the collagen deposition, the PAS score, as well as the expression of MUC5AC and MUC5B. Inhibitors of high-mobility group protein 1 (HMGB1), receptor for advanced glycation end product (RAGE) and phosphatidylinositol 3-kinase (PI3K) suppressed the MUC5AC levels in NA mice as well as in cultured HMGB1-induced human bronchial epithelial cells. Furthermore, the phospho- extracellular signal-regulated kinase (ERK) protein in NA was increased while the sRAGE intervention inhibited this elevation.Conclusions: These results suggest that sRAGE may be a potential target for the treatment of mucus hypersecretion in NA.

Eupatilin Inhibits the Proliferation and Migration of Prostate Cancer Cells through Modulation of PTEN and NF-κB Signaling

BACKGROUND

Despite advances in the treatment of prostate cancer, side effects and the risks of developing drug resistance require new therapeutic agents. Eupatilin is a secondary metabolite of Artemisia asiatica and has shown potential anti-tumor activity in some cancers, but its potential in prostate cancer treatment has not yet been evaluated.

OBJECTIVE

The aim of the study was to investigate the effectiveness of eupatilin on prostate cancer cell proliferation and migration.

METHODS

Human prostate cancer PC3 and LNCaP cells were exposed to eupatilin and its efficacy on cell survival was determined by the MTT test. Apoptosis and cell cycle phases were evaluated by an image-based cytometer. Cell migration and invasion were evaluated by wound healing and matrigel migration assays; the expression of mRNA and protein was assessed by RT-qPCR and Western blot, respectively.

RESULTS

Eupatilin time- and dose-dependently reduced the viability of prostate cancer cells. Exposure of PC3 cells to 12.5μM-50μM eupatilin resulted in apoptosis by upregulating the expression of caspase 3, Bax and cytochrome c. Annexin V assessment also confirmed that eupatilin causes apoptosis. The treatment significantly upregulated the mRNA expression of p53, p21, and p27, causing cell cycle arrest in the G1 phase. Administration of eupatilin inhibited migration and invasion of the cells by downregulating the expression of Twist, Slug and MMP-2, -7. In addition, the agent increased protein expression of tumor suppressor PTEN, while transcription factor NF-κB expression was reduced.

CONCLUSION

Eupatilin strongly prevents the proliferation of prostate cancer cells, and suppresses migration and invasion. Due to its therapeutic potential, the clinical use of eupatilin in prostate cancer should also be supported by in vivo studies.