Mycobacterium Vaccae Regulate γδT17 and γδTreg Cells in Mice Asthmatic Lung.

Background Dysregulation of the balance between different T cell populations is believed to be an important basis for asthma.Objective To observe the changes in γδT subtypes in transgenic asthmatic mice after aerosol inhalation of Mycobacterium vaccae, and to further investigate the mechanism of M. vaccae in asthmatic mice and its relationship with γδT cells.Methods TCR-ß-/- mice were exposed to atomized normal saline or M. vaccae for 5 days and the γδT cells from the lung tissues were isolated. Changes in γδT17 and γδTreg populations were detected. Asthma was induced in BALB/c mice using ovalbumin, which was then transplanted with control or M. vaccae-primed γδT cells. First we analyzed the content of γδT cells that secrete IL-17 (IL-17 γδT cells) and Foxp3+ γδT cells in lung tissues and then measured the content of IL-17 in the bronchoalveolar lavage fluid (BALF) by ELISA.Results Exposure to M. vaccae increased and decreased the relative proportions of Foxp3+ γδT cells and IL-17+ γδT cells, respectively, thereby decreasing airway reactivity and inflammation levels in asthmatic mice, and significantly decreasing IL-17 levels in BALF. Furthermore, mice treated with these primed T cells showed a decrease in IL-17+ γδT cells, and a concomitant increase in Foxp3+ γδT cells in their lung tissues. Furthermore, adoptive transfer of M. vaccae-primed γδT cells decreased GATA3 and NICD and increased T-bet in lung.Conclusions The M. vaccae-primed γδT cells alleviated the symptoms of asthma by reversing Th2 polarization in the lungs and inhibiting the Notch/GATA3 pathway.

γδT17/γδTreg cell subsets: a new paradigm for asthma treatment.

Bronchial asthma (abbreviated as asthma), is a heterogeneous disease characterized by chronic airway inflammation and airway hyperresponsiveness. The main characteristics of asthma include variable reversible airflow limitation and airway remodeling. The pathogenesis of asthma is still unclear. Th1/Th2 imbalance, Th1 deficiency and Th2 hyperfunction are classic pathophysiological mechanisms of asthma. Some studies have shown that the imbalance of the Th1/Th2 cellular immune model and Th17/Treg imbalance play a key role in the occurrence and development of asthma; however, these imbalances do not fully explain the disease. In recent years, studies have shown that γδT and γδT17 cells are involved in the pathogenesis of asthma. γδTreg has a potential immunosuppressive function, but its regulatory mechanisms have not been fully elucidated. In this paper, we reviewed the role of γδT17/γδTreg cells in bronchial asthma, including the mechanisms of their development and activation. Here we propose that γδT17/Treg cell subsets contribute to the occurrence and development of asthma, constituting a novel potential target for asthma treatment.

Protective effects of different anti­inflammatory drugs on tracheal stenosis following injury and potential mechanisms.

Tracheal stenosis following injury cannot be effectively treated. The current study compared the protective effects of different anti­inflammatory drugs on tracheal stenosis and investigated their possible mechanisms. Rabbit tracheal stenosis models following injury were constructed and confirmed using hematoxylin and eosin (H&E) staining. A total of 30 rabbits were divided into the control (CON), penicillin (PEN), erythromycin (ERY), budesonide (BUD) and PEN + ERY + BUD groups (n=6). Stenotic tracheal tissue, serum and bronchoalveolar lavage fluid (BALF) were collected 10 days after continuous treatment. Pathological changes in the tracheas were observed by H&E staining. Histone deacetylase 2 (HDAC2) expression in tracheal tissues was detected by immunofluorescence. Immunohistochemistry was performed to detect collagen I (Col­I) and collagen III (Col­III) levels in tracheal tissues. Transforming growth factor ß1 (TGF­ß1), vascular endothelial growth factor (VEGF) and interleukin 8 (IL­8) levels in serum and BALF samples were determined using ELISA kits. Western blotting detected HDAC2, IL­8, TGF­ß1 and VEGF levels in tracheal tissues. H&E staining demonstrated that tracheal epithelial hyperplasia and fibroblast proliferation in the ERY and PEN + ERY + BUD groups markedly improved compared with the CON group. Furthermore, in tracheal tissues, HDAC2 expression was significantly increased and IL­8, TGF­ß1, VEGF, Col­I and Col­III levels were significantly decreased in the ERY and PEN + ERY + BUD groups compared with the CON group. Additionally, the results for the PEN + ERY + BUD were more significant compared with the ERY group. In serum and BALF samples, IL­8, TGF­ß1 and VEGF levels in the ERY and PEN + ERY + BUD groups were significantly lower compared with the CON group, with the results of the PEN + ERY + BUD group being more significant compared with the ERY group. There were no significant differences between the PEN, BUD and CON groups. ERY inhibited tracheal granulation tissue proliferation and improved tracheal stenosis following injury and synergistic effects with PEN and BUD further enhanced these protective effects. The mechanism may involve HDAC2 upregulation and inhibition of local airway and systemic inflammatory responses.

Expression of histone deacetylase 2 in tracheal stenosis models and its relationship with tracheal granulation tissue proliferation.

The current treatments for benign tracheal stenosis are inefficient. The present study examined the expression of histone deacetylase 2 (HDAC2) in different tracheal stenosis models and explored its association with the proliferation of tracheal granulation tissue and its ability to constitute a potential therapy for tracheal stenosis. Animal tracheal stenosis models were established, as indicated by hematoxylin and eosin (H&E) staining. A total of 24 New Zealand White rabbits were randomly divided into control, erythromycin, budesonide and vorinostat groups. Stenotic tracheal tissues were collected on day 11 after drug administration for 10 days. The degree of tracheal stenosis in each group was calculated, and pathological alterations were observed using H&E staining. The mRNA expression of HDAC2, interleukin-8 (IL-8), transforming growth factor-ß1 (TGF-ß1) and vascular endothelial growth factor (VEGF) was examined via reverse transcription-quantitative PCR. The protein expression of HDAC2 was examined via immunofluorescence, while the expression of type I and type III collagen was assessed using immunohistochemistry. The results of the present study demonstrated that tracheal epithelial hyperplasia in the erythromycin group was improved, the degree of hyperplasia being the lowest among all groups, and tracheal stenosis was reduced compared with the control group. In the vorinostat group, tracheal epithelial tissue hyperplasia was aggravated and stenosis was increased. The HDAC2 mRNA and protein levels were increased and decreased in the erythromycin and vorinostat groups, respectively. In contrast, the IL-8 mRNA expression levels were decreased and increased in the erythromycin and vorinostat groups, respectively. TGF-ß1, VEGF, type I and type III collagen expression was decreased in the erythromycin group, while TGF-ß1, VEGF and type III collagen expression was increased in the vorinostat group. Compared with the control, the budesonide group did not exhibit any alterations in all of the indicators examined, including TGF-ß1, VEGF, IL-8, HDAC2 and collagen. Erythromycin treatment upregulated the expression of HDAC2, inhibited the inflammatory responses and reduced the proliferation of tracheal granulation tissue. In contrast, vorinostat treatment downregulated HDAC2 expression, promoted the inflammatory responses and increased the proliferation of tracheal granulation tissue. These results suggest that regulating HDAC2 may be used as a potential treatment for benign tracheal stenosis.

Nintedanib ameliorates tracheal stenosis by activating HDAC2 and suppressing IL-8 and VEGF in rabbit.

Acquired tracheal stenosis is a common disease occurring after endotracheal intubation or tracheotomy. Currently, surgery is the main option to treat the stenosis. This study investigated therapeutic effect and possible mechanism of nintedanib on tracheal stenosis. The rabbit models of tracheal stenosis were established and were administered with nintedanib and budesonide. The damage and repair of the tracheal tissue were determined using hematoxylin and eosin (HE) staining. The expression of histone deacetylase 2 (HDAC2), interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF) was detected by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western Blot and immunofluorescence assay. The expression of collagens I and III was assayed immunohistochemically. Remarkable tracheal stenosis was observed after the trachea was brushed in the rabbit model. Compared with control, the stenosis was improved after nintedanib treatment. The mRNA of HDAC2 was increased and that of IL-8 and VEGF was decreased significantly in the tracheal tissue following nintedanib treatment. Western blot analysis showed that HDAC2 increased to the level similar to that of control while VEGF remained unchanged following nintedanib treatment. Budesonide treatment also resulted in increased HDAC2 expression and decreased IL-8 and VEGF expression. Immunofluorescence assays also showed an increased HDAC2 expression following nintedanib treatment. Collagens I and III decreased significantly after nintedanib treatment in the tracheal tissues of models. Therefore, it is concluded that nintedanib alleviates the acquired tracheal stenosis by activating HDAC2 expression and suppressing IL-8 and VEGF expression, and may offer new option to medical treatment for the disease.

Anti-fibrosis activity of quercetin attenuates rabbit tracheal stenosis via the TGF-ß/AKT/mTOR signaling pathway.

AIMS: This study aimed to explore the possible mechanism of trauma-induced laryngotracheal stenosis and potential protective and therapeutic efficacy of quercetin on trauma-induced laryngotracheal stenosis. MAIN METHODS: The expression and activity of fibrotic factors [interleukin (IL)-6, IL-8, autophagy related 5 (ATG5), collagen (COL)-1, tumor growth factor (TGF)-ß COL-3, microtubule-associated proteins 1A/1B light chain 3A (LC3), and vascular endothelial growth factor (VEGF)] and fibrotic signaling mediators [mammalian target of rapamycin (mTOR) and phosphorylated AKT (pAKT)] were detected by real-time quantitative PCR (qRT-PCR), ELISA, Western blot, and immunohistochemical staining, respectively, in the lipopolysaccharide (LPS)-induced WI-38 (a human embryonic lung fibroblast cell line) cellular fibrotic model and a trauma-induced rabbit tracheal stenosis model, with and without quercetin treatment. KEY FINDINGS: Pre-treatment with quercetin significantly reversed the LPS-induced upregulation of pro-fibrotic factors (IL-6, IL-8, COL-1, COL-3, LC3) and fibrotic signaling mediators (mTOR and AKT), and it induced the downregulation of ATG5 in the WI-38 cells. Furthermore, the anti-fibrotic activity of quercetin was confirmed in the trauma-induced rabbit tracheal stenosis model. Thus, the nasogastric administration of quercetin attenuated the tracheal stenosis of the rabbit tracheal stenosis model, in addition to effectively reversing an increase in pro-fibrotic factors (VEGF, IL-6, TGF-ß, COL-1, and COL-3) and fibrotic signaling mediators (mTOR and AKT), as well as downregulating ATG5 of the rabbit tracheal stenosis model. SIGNIFICANCE: Quercetin exhibits anti-fibrotic activity by inhibiting pro-fibrotic factors and AKT/mTOR signaling pathway, in addition to activating autophagy activity. This study provided experimental evidence supporting the application of quercetin in tracheal stenosis, clinically.

Role of Erythromycin-Regulated Histone Deacetylase-2 in Benign Tracheal Stenosis.

Objective: This study aims to explore the role of erythromycin-regulated histone deacetylase-2 in benign tracheal stenosis. Methods: The rabbit model of tracheal stenosis was established. The rabbits were randomly divided into 8 groups. Histone deacetylase-2 (HDAC2) expression was detected by immunofluorescence. The expression of type I collagen and type III collagen was detected by immunohistochemical method. The expression of TGF-ß1, VEGF and IL-8 in serum and alveolar lavage fluid was detected by ELISA. The expression of HDAC2, TGF-ß1, VEGF and IL-8 in serum and alveolar lavage fluid was detected by ELISA. The expression of HDAC2, TGF. Results: In Erythromycin (ERY) group, ERY + Budesonide group, ERY + Vorinostat group and ERY + Budesonide + Vorinostat group, the degree of bronchial stenosis was alleviated, and the mucosal epithelium was still slightly proliferated. The effect of ERY combined with other drugs was more obvious. The HDAC2 protein expression increased significantly in ERY group, ERY + Budesonide group and ERY + Budesonide + Vorinostat group and decreased significantly in Vorinostat group, the expression of collagen I and III decreased significantly in ERY group, ERY + Budesonide group and ERY + Budesonide + Vorinostat group (P < 0.05). The TGF-ß1, VEGF and IL-8 in serum and alveolar lavage fluid was detected by ELISA. The expression of HDAC2, TGF-P < 0.05). The TGF. Conclusions: Erythromycin inhibited inflammation and excessive proliferation of granulation tissue after tracheobronchial mucosal injury by up-regulating the expression of HDAC2, it promoted wound healing and alleviated tracheobronchial stenosis. When combined with budesonide, penicillin and other glucocorticoids and antibiotics, it had a good synergistic effect. However, vorinostat could attenuate erythromycin's effect by down-regulating the expression of HDAC2. It may have good clinical application prospects in the treatment of tracheal stenosis.