Astragalus polysaccharide protects experimental colitis through an aryl hydrocarbon receptor-dependent autophagy mechanism.

BACKGROUND AND PURPOSE: Disruption of intestinal barriers plays a vital role in the pathogenesis of colitis. The aryl hydrocarbon receptor (AhR) is a recognition sensor that mediates intestinal immune homeostasis and minimizes intestinal inflammation. Astragalus polysaccharide (APS) exerts pharmacological actions in colitis; however, the mechanism has not been elucidated. We investigated whether APS protects through AhR-dependent autophagy. EXPERIMENTAL APPROACH: The symptoms of dextran sulfate sodium (DSS)-induced colitis in mice involving intestinal barrier function and inflammatory injury were evaluated after APS administration. Intestinal-specific Becn1 conditional knockout (Becn1 cKO) mice were constructed and compared with wild-type mice. Autophagy and the effects of APS were investigated after the deactivation of AhRs. The relationship between APS-induced AhRs and autophagic Becn1 was investigated using a dual-luciferase reporter system and chromatin immunoprecipitation (ChIP)-quantitative polymerase chain reaction assay. Caco-2 cells were used to investigate inflammatory responses and AhR-dependent autophagy. KEY RESULTS: APS improved intestinal barrier function in inflammatory injury in colitis mice. APS triggered autophagic flow; however, knockout of Becn1 in the gut increased susceptibility to colitis, leading to diminished epithelial barrier function and severe intestinal inflammation, impairing the protective effects of APS. Mechanistically, APS-triggered autophagy depends on AhR expression. Activated AhR binds to the promoter Becn1 to operate transcription of genes involved in anti-inflammation and intestinal barrier repair, while deactivation of AhR correlated with intestinal inflammation and the therapeutic function of APS. CONCLUSIONS AND IMPLICATIONS: APS protects colitis mice by targeting autophagy, especially as the AhR stimulates the repair of damaged intestinal barrier functions.

Ferroptosis Mediates Pulmonary Fibrosis: Implications for the Effect of Astragalus and Panax notoginseng Decoction.

Objective: To investigate the mechanism through which Astragalus and Panax notoginseng decoction (APD) facilitates the treatment of ferroptosis-mediated pulmonary fibrosis. Materials and Methods: First, the electromedical measurement systems were used to measure respiratory function in mice; the lungs were then collected for histological staining. Potential pharmacologic targets were predicted via network pharmacology. Finally, tests including immunohistochemistry, reverse transcription-quantitative polymerase chain reaction, and western blotting were used to evaluate the relative expression levels of collagen, transforming growth factor ß, α-smooth muscle actin, hydroxyproline, and ferroptosis-related genes (GPX4, SLC7A11, ACSL4, and PTGS2) and candidates involved in the mediation of pathways associated with ferroptosis (Hif-1α and EGFR). Results: APD prevented the occurrence of restrictive ventilation dysfunction induced by ferroptosis. Extracellular matrix and collagen fiber deposition were significantly reduced when the APD group compared with the model group; furthermore, ferroptosis was attenuated, expression of PTGS2 and ACSL4 increased, and expression of GPX4 and SLC7A11 decreased. In the APD group, the candidates related to the mediation of ferroptosis (Hif-1α and EGFR) decreased compared with the model group. Discussion and Conclusions. APD may ameliorate restrictive ventilatory dysfunction through the inhibition of ferroptosis. This was achieved through the attenuation of collagen deposition and inflammatory recruitment in pulmonary fibrosis. The underlying mechanisms might involve Hif-1α and EGFR.

Astragaloside trigger autophagy: Implication a potential therapeutic strategy for pulmonary fibrosis.

Pulmonary fibrosis is an abnormal wound-healing response to repeated alveolar injury, characterized by continuous inflammation and abnormal collagen deposition. Its treatment is problematic. Astragaloside (AST) is an active component of Astragalus membranaceus with anti-inflammatory and anti-tumor properties. Although the underlying mechanisms are unknown, AST is also used to treat fibrotic diseases. This study aimed to investigate the mechanisms of action of AST in pulmonary fibrosis treatment. We found that AST significantly improved restrictive ventilatory impairment, compliance, total lung capacity, and functional residual capacity. In mice with pulmonary fibrosis, extracellular matrix deposition in the pulmonary parenchyma and intemperate inflammation were reversed. This therapeutic effect can be attributed to autophagy, activating the genes for autophagy flux and autophagic vacuoles. Impaired autophagy increased susceptibility to pulmonary fibrosis by exacerbating collagen deposition in vitro and in vivo. Using a combination of molecular docking and network pharmacology, the Ras/Raf/MEK/ERK signaling pathway was identified as a possible candidate for the pharmacologic target of AST. Functional dephosphorylation of MEK and ERK inhibited the Ras/Raf/MEK/ERK signaling pathway, which converges at the rapamycin switch to initiate autophagy. Inhibitors of Ras and MEK regulated autophagy. These findings suggest that AST might treat pulmonary fibrosis by modulating the Ras/Raf/MEK/ERK signaling pathway mediated by depression.

Induction of autophagy via the TLR4/NF-κB signaling pathway by astragaloside â £ contributes to the amelioration of inflammation in RAW264.7 cells.

Cigarette smoking-related lung injury is one of the most common and fatal etiologies of many respiratory diseases, for which no effective interventions are available. Astragaloside Ⅳ (ASⅣ) is an active component extracted from Astragalus membranaceus. It is prescribed as a treatment for upper respiratory tract infections. Here, we report the potential anti-inflammatory effects and mechanisms of ASⅣ on cigarette smoking extract- (CSE)-exposed RAW264.7 cells. Murine macrophages were exposed to CSE, followed by administration of ASⅣ at 25-100 µg/mL for 24 h. ASⅣ significantly rescued CSE-induced cell death by inhibition of release pro-inflammatory cytokines. We measured autophagy as an intracellular scavenger by analyzing autophagic flux using tandem mRFP-GFP-LC3 fluorescence microscopy. Following administration with ASⅣ in CSE-exposed RAW264.7 cells, there was a notable increase in autophagosomes and a range of autophagic vacuoles were generated, as seen with transmission electron microscopy. Loss of autophagy following transfection siRNA aggravated inflammatory injury and release of inflammatory cytokines. Mechanistically, ASⅣ-triggered autophagy is mediated by the TLR4/NF-κB signaling pathway to reduce inflammation. Taken together, our findings suggest that ASⅣ acts stimulates autophagy, and that ASⅣ induces autophagy by inhibiting the TLR4/NF-κB signaling pathway, contributing to alleviation of inflammation.

Gastrodia remodels intestinal microflora to suppress inflammation in mice with early atherosclerosis.

Atherosclsis is a critical actuator causing cardiac-cerebral vascular disease with a complicated pathogeneon, refered to the disorders of intestinal flora and persistent inflammation. Gastrodin (4-(hydroxymethyl) phenyl-ß-D- Glucopyranoside) is the most abundant glucoside extracted from the Gastrodiaelata, which is a traditional Chinese herbal medicine for cardiac-cerebral vascular disease, yet its mechanisms remain little known. In the present study, the gastrodia extract and gastrodin attenuate the lipid deposition and foam cells on the inner membrane of the inner membrane of the thoracic aorta in the early atherosclerosis mice. Blood lipid detection tips that TC and LDL-C were reduced in peripheral blood after treatment with the gastrodia extract and gastrodin. Furthermore, unordered gut microbes are remodeled in terms of bacterial diversity and abundance at family and genus level. Also, the intestinal mucosa damage and permeability were reversed, accompaniedwith the reducing of inflammatory cytokines. Our findings revealed that the functions of gastrodia extract and gastrodin in cardiac-cerebral vascular disease involved to rescued gut microbes and anti-inflammation may be the mechanismof remission lipid accumulation.

Antifibrotic action of Yifei Sanjie formula enhanced autophagy via PI3K-AKT-mTOR signaling pathway in mouse model of pulmonary fibrosis.

Pulmonary fibrosis (PF) is a crippling disease characterized by progressive dyspnea and associated with a high mortality rate, but its origin is unknown and there is no effective treatment. Yifei Sanjie formula (YFSJF) is a Chinese medicine that is widely used for treatment of respiratory systems disease. However, the molecular basis for the function of YFSJF has not been determined. Here we investigate the contribution of YFSJF in BLM-induced PF mice. Administration with YFSJF significantly alleviated the degree of BLM-induced collagen I and III deposition and the inflammatory injuring in the lungs and suppressed hydroxyproline release in PF animals. The active components of YFSJF are comprised with flavonoid, amino acids, saponins, oligosaccharide, organic acid, vitamin, esters, purine nucleosides. Additionally, there was a significant increase in autophagosomes, after treatment with YFSJF in PF animals. Interestingly, autophagy dysfunction by the blocker chloroquine (CQ) resulted in collagen deposition and inducing the expression of fibrosis-related genes. In addition, YFSJF-induced autophagy is mediated by the PI3K-AKT-mTOR pathway, and knockdown of PI3K by siRNA up-regulated the expression of autophagy-related genes and down-regulated the expression of collagen in human lung fibroblasts (HLF). Our findings provide a detailed understanding that YFSJF-antifibrotic effects are mainly mediated by triggering autophagy, and suppressing phosphorylation of the PI3K-AKT-mTOR pathway is required for YFSJF-curative effect.

Pseudomonas toxin pyocyanin triggers autophagy: Implications for pathoadaptive mutations.

Pseudomonas aeruginosa can establish life-long chronic infection in patients with cystic fibrosis by generating genetic loss-of-function mutations, which enhance fitness of the bacterium in the airways. However, the precise role of the pathoadaptive mutations in persistence in chronic airways infection remains largely unknown. Here we demonstrate that pyocyanin, a well-described P. aeruginosa virulence factor that plays an important role in the initial infection, promotes autophagy in bronchial epithelial cells. Disruption of phzM, which is required for pyocyanin biosynthesis, leads to a significant reduction in autophagy in Beas-2B cells and lung tissues. Pyocyanin-induced autophagy is mediated by the EIF2AK4/GCN2-EIF2S1/eIF2α-ATF4 pathway. Interestingly, rats infected with the phzMΔ mutant strain have high mortality rate and numbers of colony-forming units, compared to those infected with wild-type (WT) P. aeruginosa PA14 strain, during chronic P. aeruginosa infection. In addition, the phzMΔ mutant strain induces more extensive alveolar wall thickening than the WT strain in the pulmonary airways of rats. As autophagy plays an essential role in suppressing bacterial burden, our findings provide a detailed understanding of why reduction of pyocyanin production in P. aeruginosa in chronic airways infections has been associated with better host adaptation and worse outcomes in cystic fibrosis.

Anti-inflammatory effect of Yu-Ping-Feng-San via TGF-ß1 signaling suppression in rat model of COPD.

OBJECTIVES: Yu-Ping-Feng-San (YPFS) is a classical traditional Chinese medicine that is widely used for treatment of the diseases in respiratory systems, including chronic obstructive pulmonary disease (COPD) recognized as chronic inflammatory disease. However, the molecular mechanism remains unclear. Here we detected the factors involved in transforming growth factor beta 1 (TGF-ß1)/Smad2 signaling pathway and inflammatory cytokines, to clarify whether YPFS could attenuate inflammatory response dependent on TGF-ß1/Smad2 signaling in COPD rats or cigarette smoke extract (CSE)-treated human bronchial epithelial (Beas-2B) cells. MATERIALS AND METHODS: The COPD rat model was established by exposure to cigarette smoke and intratracheal instillation of lipopolysaccharide, YPFS was administered to the animals. The efficacy of YPFS was evaluated by comparing the severity of pulmonary pathological damage, pro-inflammation cytokines, collagen related genes and the activation of TGF-ß1/Smad2 signaling pathway. Furthermore, CSE-treated cells were employed to confirm whether the effect of YPFS was dependent on the TGF-ß1/Smad2 signaling via knockdown Smad2 (Si-RNA), or pretreatment with the inhibitor of TGF-ß1. RESULTS: Administration of YPFS effectively alleviated injury of lung, suppressed releasing of pro-inflammatory cytokines and collagen deposition in COPD animals (P<0.05), whereas exogenous TGF-ß1 promoted releasing of IL-1ß, IL-6, TNFα (P<0.05). Administration YPFS reduced inflammatory response significantly, also down-regulated TGF-ß1/Smad2 signaling in vivo and in vitro. Unexpectedly, knockdown Smad2 or inhibition of TGF-ß1 abolished anti-inflammatory effect of YPFS in CSE-treated cells. CONCLUSION: YPFS accomplished anti-inflammatory effects mainly by suppressing phosphorylation of Smad2, TGF-ß1/Smad2 signaling pathway was required for YPFS-mediated anti-inflammation in COPD rats or CSE-treated Beas-2B cells.

Y55 and D78 are crucial amino acid residues of a new IgE epitope on trichosanthin.

Trichosanthin (TCS) possesses many biological and pharmaceutical activities, but its strong immunogenicity limits its clinical application. To reduce the immunogenicity of TCS, we modified the reported method for the prediction of antigenic site and identified two crucial amino acid residues (Y55 and D78) for a new epitope. We mutated these two residues into glycine and serine, respectively, and obtained three mutants, Y55G, D78S, and Y55G/D78S. These mutants induced less amount of Ig and IgG antibodies in C57BL/6J mice than wild-type TCS (wTCS) (p<0.01) and almost lost the ability to induce IgE antibody production. The mutants stimulated fewer TCS-specific B cells in C57BL/6J mice than wTCS (p<0.01). Compared with wTCS, Y55G, D78S, and Y55G/D78S lost 26.9%, 17.9%, and 98.7% specific binding ability to anti-TCS monoclonal antibody TCS4E9, respectively. These mutants still retained RNA N-glycosidase activity. In conclusion, Y55 and D78 are two crucial amino acid residues of a new IgE epitope on TCS, and their mutation reduces the immunogenicity of TCS, but still retained the enzymatic activity.