The impact and mechanism of pulmonary and renal replenishing method intervention on cell autophagy in COPD-related pulmonary vascular remodeling via TLR4/NF-κB pathway
LI Xiao-dan
LIU Wei
GAO Wei-wei
ZHANG Tian-yi
GUAN Peng
YANG Shui-miao
Abstract：Objective To investigate the effects and mechanisms of the pulmonary and renal replenishing method(PRRM)intervention on cell autophagy in chronic obstructive pulmonary disease(COPD)-related pulmonary vascular remodeling,focusing on the Toll-like receptor 4(TLR4)/nuclear factor-κB(NF-κB)pathway.Methods A COPD model was established in SD rats through a combination of cigarette smoke exposure and repeated bacterial infections.Rats were randomly divided into three groups:Model group,PRRM group(3.7 g/kg),and PRRM+Lipopolysaccharide(LPS)(TLR4 activator,15 mg/kg)group.Another 12 rats were maintained with normal breathing and received tracheal instillation of an equivalent volume of saline as the control group.After intervention with PRRM and LPS,lung function indicators[tidal volume(TV),peak expiratory flow(PEF),forced expiratory volume in 0.3 seconds(FEV0 3)/forced vital capacity(FVC)]were measured.Histopathological examination using Hematoxylin and Eosin(HE)staining as-sessed lung tissue morphology and pulmonary vascular remodeling,including wall thickness(WT)percentage of vessel di-ameter(VD)(WT/VD％)and lumen area(LA)percentage of total vessel area(TA)(LA/TA％).Immunofluores-cence staining measured the expression of the pulmonary vascular endothelial marker CD34.Enzyme-linked immunosor-bent assay(ELISA)measured levels of pro-inflammatory factors,tumor necrosis factor-α(TNF-α),and interleukin(IL)-17 in bronchoalveolar lavage fluid(BALF)and serum.Immunoblotting was employed to evaluate the expression of autophagy-related proteins and proteins in the TLR4/NF-κB signaling pathway in lung tissues.Results Compared to the control group,rats in the Model group exhibited significant pathological damage and symptoms of pulmonary vascular remodeling,decreased TV,PEF,FEV0 3/FVC,LA/TA,and reduced Beclin-1 protein expression,as well as a de-creased LC3 Ⅱ/LC3 Ⅰ ratio(P＜0.05).Furthermore,WT/VD％,CD34 positive expression,levels of TNF-α and IL-17 in BALF and serum,and the expression of TLR4 protein and p-NF-κB p65/NF-κB p65 in lung tissue were significantly elevated(P＜0.05).In comparison to the Model group,rats in the PRRM group showed alleviated lung tis-sue damage and pulmonary vascular remodeling,increased TV,PEF,FEV0 3/FVC,LA/TA,and elevated Beclin-1 pro-tein expression with an increased LC3 Ⅱ/LC3 Ⅰ ratio(P＜0.05).Moreover,WT/VD％,CD34 positive expression,lev-els of TNF-α and IL-17 in BALF and serum,and the expression of TLR4 protein and p-NF-κB p65/NF-κB p65 in lung tissue were significantly reduced(P＜0.05).Comparing the PRRM group to the PRRM+LPS group,rats in the PRRM+LPS group showed aggravated lung tissue damage and pulmonary vascular remodeling,decreased TV,PEF,FEV0 3/FVC,LA/TA,and decreased Beclin-1 protein expression with a reduced LC3 Ⅱ/LC3 Ⅰ ratio(P＜0.05).Ad-ditionally,WT/VD％,CD34 positive expression,levels of TNF-α and IL-17 in BALF and serum,and the expression of TLR4 protein and p-NF-κB p65/NF-κB p65 in lung tissue were significantly increased(P＜0.05).Conclusion PRRM can inhibit inflammation and enhance autophagy in the COPD rat model by suppressing the TLR4/NF-κB signa-ling pathway,thereby alleviating pathological damage and pulmonary vascular remodeling and improving lung function.
Keywords：Toll-like receptor 4/nuclear transcription factor-κBmethod of regulating and tonifying the lungs and kidneysautophagychronic obstructive pulmonary diseasepulmonary vascular remodeling
Publication Date：2024-05-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 553-559 )