RESUMO
Mycoplasma pneumoniae is the most common pathogen of respiratory tract infection in children and adults. Clinical observation shows that M. pneumoniae infection can cause massive mucus secretion in the respiratory tract, which makes the breathing of patients difficult. Studies have shown that M. pneumoniae infection can cause massive secretion of mucin 5AC (MUC5AC). Adhesin P1 plays an important role in the pathogenesis of M. pneumoniae infection by mediating the adhesion of pathogens to host cells, and the C-terminal residues of P1 (P1-C) are immunogenic. This study investigated the molecular mechanism of Wnt/β-catenin signaling pathway inhibitor Dickkopf-1 (DKK1) in the secretion of MUC5AC in mouse airway epithelial cells (MAECs) induced by P1-C. Scanning electron microscope and hematoxylin-eosin staining were used to observe the effect of P1-C on mucus secretion of MAECs. Protein chip was used to detect the secretion of cytokines and analyse the enrichment of related signaling pathways induced by P1-C in MAECs. Periodic acid schiff stain (PAS) staining, Tunel staining and Masson staining were used to detect the damage of the lungs of mouse exposed to P1-C. Immunohistochemistry was used to detect the secretion of MUC5AC expression, and Western blotting was used to reveal the molecular mechanism of DKK1-regulated secretion of MUC5AC induced by P1-C protein in MACES. The results showed that P1-C induced the massive secretion of mucus and inflammatory factors in MAECs. During P1-C infection, DKK1 down-regulated janus kinase 2 (JAK2), phosphorylation signaling and transcription activator 1 (p-STAT1) and phosphorylation signaling and activator of transcription 3 (p-STAT3) expression. Overexpression of DKK1 significantly up-regulated the expression of MUC5AC repressor transcription factor fork-head box protein A2 (FOXA2). At the same time, the expression of MUC5AC induced by P1-C was inhibited significantly. It is speculated that DKK1 can effectively reduce the secretion of MUC5AC in MAECs induced by P1-C by inhibiting the JAK/STAT1-STAT3 signaling pathway and up-regulating the expression of FOXA2.
Assuntos
Animais , Camundongos , Células Epiteliais , Pulmão , Mucina-5AC/metabolismo , Mycoplasma pneumoniae/metabolismo , Transdução de SinaisRESUMO
Objective: To explore the effect of endoplasmic reticulum stress (ERS) on neutrophil elastase (NE) induced mucin 5AC (MUC5AC) production in human airway epithelial cells. Methods: HBE16 airway epithelial cells were cultured and pretreated with reactive oxygen species (ROS) inhibitor N-acetylcysteine (NAC) or ERS inhibitor 4-phenylbutyrate (4-PBA), or transfected with small interfering RNA (siRNA) against inositolrequiring kinase 1α (IRE-1α) or X-box binding protein 1 (XBP-1), respectively before incubation with NE. NE group and blank control group were also set up. ROS production was assayed by detection kit; expression of glucose-regulated protein 78 (GRP78), phosphorylated protein kinase R-like endoplasmic reticulum kinase (pPERK), activating transcription factor 6 (ATF6), phosphorylated IRE-1α (pIRE-1α), and XBP-1 protein was detected by Western blotting; spliced XBP-1 (XBP-1s) mRNA was measured by real-time PCR; levels of MUC5AC protein in culture supernatant and cytoplasm were assayed by ELISA and immunofluorescence. Results: There was an obvious increase of ROS production with strong elevation of GRP78, ATF6, pPERK, and pIRE-1α protein in NE group cells after 24 h, compared with blank control group (P<0.05). The protein and mRNA of XBP-1s, and MUC5AC production also increased obviously (P<0.05). NAC and 4-PBA reduced ERS-related protein expression and MUC5AC production and secretion (P<0.05). Further studies showed that MUC5AC secretion was also blunted by IRE-1α siRNA or XBP-1 siRNA, accompanied with decreased expression of XBP-1s mRNA and protein (P<0.05). Conclusion: NE induces ERS by producing ROS, and increases MUC5AC protein production and secretion; IRE-1α/XBP-1 play a certain role in this process.
RESUMO
Objective: To observe the effect of Pinelliae Rhizoma Praeparatum Cum Alumine polysaccharides(PRPCAP)on airway mucus secretion in rats with allergic asthma, in order to study the material basis of the "macromolecule" component of the polysaccharides as the original medicinal materials. Method: The 60 SPF-grade Wistar rats were induced by intraperitoneal injection of chicken ovalbumin (OVA) and aluminum-magnesium adjuvant, except for the normal control group. The OVA solution was aerosolized to establish a rat model of allergic asthma. After successful modeling, the rats were randomly divided into 5 groups, namely allergic asthma model group, positive drug group (montalurast sodium,5 mg·kg-1), high-dose PRPCAP group (400 mg·kg-1), middle-dose PRPCAP group (200 mg·kg-1) and low-dose PRPCAP group (100 mg·kg-1). The contents of interleukin-4 (IL-4) and interferon-γ (IFN-γ) in serum and bronchoalveolar lavage fluid (BALF) supernatant were determined by enzyme-linked immunosorbent assay (ELISA), and the count of eosinophils (EOS) was detected by BALF sediment. The histopathological changes were observed by hematoxylin-eosin (HE) staining in lung tissue. The mRNA expression of mucin 5AC (MUC5AC) was detected by Real-time fluorescent quantitative polymerase chain reaction (Real-time PCR). Result: Compared with the normal control group, serum IL-4 level in the allergic asthma model group was significantly increased (Pγ level was significantly decreased (PPPPPγ in serum (PPPPConclusion: The "macromolecule" component of polysaccharides in the Pinelliae Rhizoma Praeparatum Cum Alumine may be the material basis for the efficacy of eliminating dampness and eliminating phlegm.
RESUMO
Objective:To investigate the effects of CCR3 on Muc5ac in the airway of asthmatic mice.Methods: Fifty clean BALB/c mice were randomly divided into control group,asthmatic group,dexamethasone treatment group,SB328437 treatment group, vehicle-control group.Total cells and differential inflammatory cells were counted in BALF, the levels of IL-4 and TNF-αwere determined by ELISA,lung tissue HE staining the expressions of Mucin5ac(Muc5ac) and CCR3 in lung tissue were detected by immu-neohistochemical staining and RT-PCR.Results:The total cells,eosinophil,monocytes and lymphocyte cells in BALF,the levels of IL-4,TNF-αin BALF ,the goblet cell of airway wall,the expression of Muc5ac and CCR3 positive staining IOD in the airway and the expression of Muc5ac and CCR3 mRNA lung tissue obviously decreased in SB328437 treatment group and DEX treatment group which compared with asthmatic mice model group ( P<0.05 ) .Conclusion: SB328437 can inhibit the expression of CCR3 in pulmonary tissue,furtherly inhibit the expression and secretion of Muc5ac and control the airway inflammation.