Dynamic Characteristics of Sequential Acute Exacerbations and Risk Windows in AECOPD Rats Induced by Cigarette-Smoke and Exposure to Klebsiella pneumoniae

Tong Sai granules improves AECOPD via regulation of MAPK-SIRT1-NF-κB pathway and cellular senescence alleviation

ETHNOPHARMACOLOGICAL RELEVANCE

Tong Sai granules (TSG) a traditional Chinese medicine, are used to treat acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Cellular senescence is considered the mechanism underlying AECOPD progression.

AIM OF THE STUDY

This study aimed to investigate the therapeutic mechanisms of TSG in an AECOPD rat model (established using cigarette smoke exposure and bacterial infection) and focused on the inhibition of cellular senescence in vivo and in vitro.

MATERIALS AND METHODS

Histological changes and levels of inflammatory cytokines, matrix metalloproteinases (MMPs), p53, and p21 were determined. A cellular senescence model was established by challenging airway epithelial cells with cigarette smoke extract (CSE) and lipopolysaccharide (LPS). Quantitative PCR, western blotting, and immunofluorescence were used to measure mRNA and protein levels. Additionally, UPLC-Q-Extractive-Orbitrap MS analysis, network analysis, and transcriptomics were used to analyze the potential compounds and molecular mechanisms of TSG.

RESULTS

The results showed that oral administration of TSG significantly reduced the severity of AECOPD in rats by ameliorating lung function decline and pathological injuries and increasing the levels of C-reactive protein and serum amyloid A, two well-known proinflammatory mediators of the acute phase response. Oral TSG administration also decreased the expression levels of proinflammatory cytokines (e.g., IL-6, IL-1β, and TNF-α), MMPs (e.g., MMP-2 and MMP-9), critical regulators of senescence such as p21 and p53, and the apoptotic marker γH2AX, all of which are factors in cellular senescence in lung tissue. TSG4 was isolated from TSGs using macroporous resin and found to significantly suppress cellular senescence in CSE/LPS-induced bronchial epithelial cells. Furthermore, 26 of 56 compounds identified in TSG4 were used to predict 882 potential targets. Additionally, 317 differentially expressed genes (DEGs) were detected in CSE/LPS-treated bronchial epithelial cells. Network analysis of the 882 targets and 317 DEGs revealed that TSG4 regulated multiple pathways, among which the mitogen-activated protein kinase-sirtuin 1-nuclear factor kappa B (MAPK-SIRT1-NF-κB) pathway is important in terms of antisenescent mechanisms. Moreover, in CSE/LPS-induced bronchial epithelial cells, p-p38, p-ERK1/2, p-JNK, and p-p65 levels were increased and SIRT1 levels were decreased after TSG4 treatment. Additionally, oral TSG administration decreased p-p38 and p-p65 levels and increased SIRT1 levels in the lung tissues of AECOPD model rats.

CONCLUSION

Collectively, these results indicate that TSGs ameliorate AECOPD by regulating the MAPK-SIRT1-NF-κB signaling pathway and subsequently suppressing cellular senescence.

Xiaoqinglong Decoction Protects the Lungs of AECOPD Mice through the AMPK/mTOR Signaling Pathway

Method

Male C57BL/6J mice were used to establish AECOPD model by cigarette smoke and bacterial exposure. Mice were randomly divided into normal control (NC), AECOPD, XQLD, Compound C (Com C), Com C + XQLD, and Clarithromycin (CLA) groups. After treatment, the pulmonary function was evaluated by whole-body plethysmograph. The lung histopathology was observed by HE staining. The serum levels of IL-6, TNF-α, and COX-2 were detected by ELISA assay. The apoptotic index was measured by TUNEL assay, and the protein expressions of Bax, Bcl-2, Caspase-3, GRP78, and CHOP in the lung tissues were measured by western blot assay.

Results

XQLD treatment can improve pulmonary function (PF), ameliorate lung injury, and suppress inflammation and apoptosis of lung tissues. In addition, XQLD also markedly attenuated endoplasmic reticulum stress (ERS) and activated AMPK/mTOR pathway in the lung tissues of mice with AECOPD. However, the AMPK inhibitor Compound C decreased the protective effect of XQLD in AECOPD mice.

Conclusion

These findings suggested that XQLD has protective effect against inflammation and apoptosis in AECOPD mice by attenuating ER stress via AMPK/mTOR pathway.