1.Mechanism of Xixintang in Protecting Blood-brain Barrier in Alzheimer's Disease Model Rats Based on AQP4 Polarization
Siyuan JIA ; Yongchang DIWU ; Yuan TIAN ; Jie GAO ; Meirong WU ; Dengkun WANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(9):1-10
ObjectiveThis paper aims to investigate the effects of Xixintang on aquaporin-4 (AQP4) polarity distribution, blood-brain barrier (BBB) function, and neuroinflammationin rats with Alzheimer's disease (AD), thereby revealing the potential mechanism through which this formula protects the BBB by regulating AQP4 polarization. The aim is to provide a scientific basis for clinical treatment. MethodsSixty Sprague-Dawley (SD) rats were randomly divided into a normal group, a model group, a probiotic group, a donepezil group, and an Xixintang group. The model was established by intraperitoneal injection of D-galactose (D-Gal) combined with bilateral intracerebroventricular injection of amyloid-β25-35 (Aβ25-35). The probiotic group (30.85 mg·kg-1), donepezil group (0.88 mg·kg-1), and Xixintang group (1.174 g·kg-1) received daily gavage administration, while the normal and model groups received intragastric administration with an equal volume of normal saline for one month. Cognitive ability was assessed by using the Morris water maze. BBB permeability was detected via Evans blue extravasation. The contents of interleukin-6 (IL-6), amyloid-β1-42 (Aβ1-42), and tumor necrosis factor-α (TNF-α) in the hippocampal tissues were measured by enzyme-linked immunosorbent assay (ELISA). The protein expressions of zonula occludens-1 (ZO-1), occludin, tissue inhibitor of metalloproteinase-1 (TIMP-1), matrix metalloproteinase-9 (MMP-9), and AQP4 in the hippocampal tissues were detected by western blot. The expression and co-localization levels of Aβ1-42, ionized calcium-binding adapter molecule 1 (IBA1), and AQP4/platelet endothelial cell adhesion molecule 31 (CD31) in the hippocampal region were examined by immunofluorescence. ResultsCompared with the normal group, the model group exhibited a significant decline in cognitive ability (P<0.01) and a marked increase in Evans blue extravasation in the brain (P<0.01). The expressions of ZO-1, occludin, and TIMP-1 were significantly decreased (P<0.01), while the expressions of AQP4 and MMP-9 were significantly increased (P<0.01). The co-localization level of AQP4/CD31 was significantly reduced (P<0.01), and the expressions of Aβ1-42, IL-6, TNF-α, and IBA1 were significantly elevated (P<0.01). Compared with the model group, the Xixintang group showed significant improvement in cognitive ability (P<0.01) and a significant reduction in Evans blue extravasation in the brain (P<0.01). The expressions of occludin, TIMP-1, and ZO-1 were significantly increased (P<0.05, P<0.01), while the expressions of AQP4 and MMP-9 were significantly decreased (P<0.05). The co-localization level of AQP4/CD31 was significantly enhanced (P<0.01), and the expressions of Aβ1-42, IL-6, TNF-α, and IBA1 were significantly reduced (P<0.05, P<0.01). ConclusionXixintang may improve cognitive function and alleviate AD pathology in AD model rats by regulating AQP4 polarity distribution, thereby breaking the vicious cycle of "Aβ deposition-neuroinflammation-BBB damage" and restoring the homeostasis of the microenvironment in the brain.
2.Effect of Xixintang on Colonic Mucosal Barrier and TLR4 /NF-κB p65 Signaling Pathway in AD Model Rats Induced by D-galactose Combined with Aβ25-35
Yuan TIAN ; Yongchang DIWU ; Siyuan JIA ; Jie GAO ; Meirong WU ; Dengkun WANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):1-11
ObjectiveThis study aims to investigate whether Xixintang could ameliorate cognitive dysfunction in an Alzheimer's disease (AD) rat model induced by D-galactose and β-amyloid (Aβ25-35), by means of repairing the colonic mucosal barrier, regulating the Toll-like receptor 4 (TLR4)/nuclear factor-κB p65 (NF-κB p65) signaling pathway, and intervening in the pathological process mediated by the gut-brain axis. MethodsSixty specific pathogen-free (SPF) male Sprague-Dawley (SD) rats were randomly divided to five groups (n=12): A control group, a model group, a donepezil group, an Xixintang group, and a probiotic group. Except for those in the control group, rats in all other groups received daily intraperitoneal injections of D-galactose for six consecutive weeks. Subsequently, aggregated Aβ25-35 was injected stereotactically into the bilateral ventricles to establish the AD model. During the intervention periods, the rats in all groups were administered their respective drugs and normal saline by gavage. The Morris water maze test was used to assess the capacity for spatial learning and memory. Hematoxylin-eosin (HE) staining was employed to observe the histopathological changes in the colon tissues. Immunofluorescence was used to detect Aβ1-41 deposition in the hippocampal region and Mucin 2 (MUC2) expression in the colonic mucosa. Western blot was performed to measure the protein expression levels of FFAR2,TLR4, NF-κB p65, occludin (OCLN), zonula occludens-1 (ZO-1), and MUC2 in the colonic tissues. Enzyme-linked immunosorbent assay (ELISA) was used to determine the contents of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), serum amyloid A (SAA), and Aβ1-42 in the hippocampal region from the colonic tissues. The lipopolysaccharide (LPS) concentrations in colon tissues of rats were measured by using a dynamic chromogenic limulus assay. ResultsCompared with those in the control group, the rats in the model group exhibited a significantly prolonged escape latency and a markedly shorter duration in the target quadrant (P<0.01). The integrity of the colonic mucosal structure was compromised, with disordered gland arrangement and a reduced number of goblet cells. The Aβ1-42 deposition in the hippocampal region was significantly increased (P<0.01). The protein expression levels of TLR4 and NF-κB p65 in colonic tissues were significantly upregulated (P<0.01), while those of occludin and ZO-1 were downregulated (P<0.01). The contents of inflammatory factors such as IL-6, TNF-α, and SAA were significantly elevated (P<0.01), and the LPS level in the serum was markedly increased (P<0.01). In comparison to those in the model group, the rats in the Xixintang group showed a significantly shortened escape latency and a prolonged duration in the target quadrant (P<0.01). The colonic mucosal structure was ameliorated, with neat gland arrangement and an increased number of goblet cells. The Aβ1-42 deposition in the hippocampal region was reduced (P<0.01). The protein expressions of TLR4 and NF-κB p65 in the colon tissues were decreased (P<0.05,P<0.01), while the protein levels of occludin and ZO-1 were increased (P<0.01). The contents of IL-6, TNF-α, and serum amyloid A (SAA) were decreased (P<0.01), and the LPS level was reduced (P<0.01). ConclusionXixintang can significantly ameliorate cognitive dysfunction of AD model rats, by means of restoring the colonic mucosal barrier structure, reducing cerebral Aβ deposition, and suppressing peripheral and central inflammatory response. Its mechanism of action may be closely associated with the suppression of the TLR4/NF-κB signaling pathway activation, reduction of endotoxin levels, and regulation of the gut-brain axis.
3.Effect of Xixintang on Colonic Mucosal Barrier and TLR4 /NF-κB p65 Signaling Pathway in AD Model Rats Induced by D-galactose Combined with Aβ25-35
Yuan TIAN ; Yongchang DIWU ; Siyuan JIA ; Jie GAO ; Meirong WU ; Dengkun WANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):1-11
ObjectiveThis study aims to investigate whether Xixintang could ameliorate cognitive dysfunction in an Alzheimer's disease (AD) rat model induced by D-galactose and β-amyloid (Aβ25-35), by means of repairing the colonic mucosal barrier, regulating the Toll-like receptor 4 (TLR4)/nuclear factor-κB p65 (NF-κB p65) signaling pathway, and intervening in the pathological process mediated by the gut-brain axis. MethodsSixty specific pathogen-free (SPF) male Sprague-Dawley (SD) rats were randomly divided to five groups (n=12): A control group, a model group, a donepezil group, an Xixintang group, and a probiotic group. Except for those in the control group, rats in all other groups received daily intraperitoneal injections of D-galactose for six consecutive weeks. Subsequently, aggregated Aβ25-35 was injected stereotactically into the bilateral ventricles to establish the AD model. During the intervention periods, the rats in all groups were administered their respective drugs and normal saline by gavage. The Morris water maze test was used to assess the capacity for spatial learning and memory. Hematoxylin-eosin (HE) staining was employed to observe the histopathological changes in the colon tissues. Immunofluorescence was used to detect Aβ1-41 deposition in the hippocampal region and Mucin 2 (MUC2) expression in the colonic mucosa. Western blot was performed to measure the protein expression levels of FFAR2,TLR4, NF-κB p65, occludin (OCLN), zonula occludens-1 (ZO-1), and MUC2 in the colonic tissues. Enzyme-linked immunosorbent assay (ELISA) was used to determine the contents of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), serum amyloid A (SAA), and Aβ1-42 in the hippocampal region from the colonic tissues. The lipopolysaccharide (LPS) concentrations in colon tissues of rats were measured by using a dynamic chromogenic limulus assay. ResultsCompared with those in the control group, the rats in the model group exhibited a significantly prolonged escape latency and a markedly shorter duration in the target quadrant (P<0.01). The integrity of the colonic mucosal structure was compromised, with disordered gland arrangement and a reduced number of goblet cells. The Aβ1-42 deposition in the hippocampal region was significantly increased (P<0.01). The protein expression levels of TLR4 and NF-κB p65 in colonic tissues were significantly upregulated (P<0.01), while those of occludin and ZO-1 were downregulated (P<0.01). The contents of inflammatory factors such as IL-6, TNF-α, and SAA were significantly elevated (P<0.01), and the LPS level in the serum was markedly increased (P<0.01). In comparison to those in the model group, the rats in the Xixintang group showed a significantly shortened escape latency and a prolonged duration in the target quadrant (P<0.01). The colonic mucosal structure was ameliorated, with neat gland arrangement and an increased number of goblet cells. The Aβ1-42 deposition in the hippocampal region was reduced (P<0.01). The protein expressions of TLR4 and NF-κB p65 in the colon tissues were decreased (P<0.05,P<0.01), while the protein levels of occludin and ZO-1 were increased (P<0.01). The contents of IL-6, TNF-α, and serum amyloid A (SAA) were decreased (P<0.01), and the LPS level was reduced (P<0.01). ConclusionXixintang can significantly ameliorate cognitive dysfunction of AD model rats, by means of restoring the colonic mucosal barrier structure, reducing cerebral Aβ deposition, and suppressing peripheral and central inflammatory response. Its mechanism of action may be closely associated with the suppression of the TLR4/NF-κB signaling pathway activation, reduction of endotoxin levels, and regulation of the gut-brain axis.
4.Role of exosomal miR-320c in gingerol-mediated defense against Staphylococcus aureus infection
Zhencai XING ; Mengxue XU ; Xiang KONG ; Jinghan SUN ; Zhen MA ; Yu GAO ; Siyuan DU ; Hong ZHENG ; Yakun LIU
Acta Universitatis Medicinalis Anhui 2026;61(5):795-802
ObjectiveTo investigate the inhibitory effect of gingerol, an active component of ginger, on Staphylococcus aureus (S. aureus) infection, and to preliminarily explore its mechanism related to extracellular vesicles (EVs). MethodsS.aureus infection models were established in human umbilical vein endothelial cell (HUVECs), Vero E6 cells, and C57BL/6 mice. Experimental groups included control, infection, and gingerol-treated groups. Bacterial load and VE-cadherin protein expression were detected using immunofluorescence and Western blot. EVs were isolated by size exclusion chromatography and characterized by transmission electron microscopy and nanoparticle tracking analysis. miRNA sequencing was performed on EVs. ResultsGingerol treatment significantly reduced the bacterial load in both in vitro and in vivo infection models and upregulated VE-cadherin expression. miRNA sequencing of EVs revealed that S. aureus infection upregulated the expression of hsa-miR-320c, while gingerol treatment reversed this abnormal expression. Bioinformatic analysis further predicted that the target genes of hsa-miR-320c were significantly enriched in cell junction-related pathways. ConclusionGingerol exhibits clear antibacterial and host-protective effects, by regulating hsa-miR-320c in EVs to maintain endothelial barrier integrity.
5.Effect of trans-nasal humidified rapid insufflation ventilatory exchange on early postoperative atelectasis in patients undergoing prolonged gastrointestinal endoscopic procedures
Xinyi WANG ; Xin LIU ; Zi WANG ; Siyuan SONG ; Mingzhu MENG ; Ju GAO
Chinese Journal of Anesthesiology 2025;45(10):1269-1274
Objective:To evaluate the effect of trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) on the early postoperative atelectasis in patients undergoing prolonged non-intubated intravenous anesthesia for gastrointestinal endoscopic procedures.Methods:In this randomized double-blind controlled trial, 150 patients of either sex, aged 18-80 yr, with American Society of Anesthesiologists Physical Status classification Ⅰ or Ⅱ and body mass index of 18-30 kg/m 2, scheduled for endoscopic mucosal resection of multiple colorectal polyps at Northern Jiangsu People′s Hospital Affiliated to Yangzhou University from February 18 to June 15, 2024, were divided into 2 groups ( n=75 each) using simple random allocation: THRIVE group (group T) and conventional oxygen therapy group (group C). In group T, the oxygen flow rate was 10 L/min before anesthesia induction and increased to 50 L/min after induction until the end of operation, and the inhaled oxygen concentration was 100%. Group C used conventional mask oxygen inhalation, with an oxygen flow rate of 10 L/min during anesthesia induction and maintenance. Lung ultrasonography was performed immediately before anesthesia induction and after the end of surgery, and the modified lung ultrasound score and diaphragm mobility during quiet breathing were recorded to assess the occurrence of atelectasis and diaphragmatic dysfunction. The lowest intraoperative SpO 2 value, adverse events during surgery and in the postanesthesia care unit (PACU), duration of PACU stay, adverse events within 7 days after operation, hospitalization duration, and satisfaction scores of both patients and endoscopists were recorded. Results:Compared with group C, the postoperative modified lung ultrasound score and incidence of atelectasis and diaphragmatic dysfunction were significantly decreased, the lowest intraoperative SpO 2 value was increased, the incidence of hypoxemia was decreased, the duration of PACU stay was shortened, and endoscopists′ satisfaction scores were increased ( P<0.05), and no statistically significant changes were observed in diaphragm mobility, incidence of other intraoperative adverse events, incidence of adverse events during PACU stay and within 7 days after operation, or patients′ satisfaction scores in group T ( P>0.05). Conclusions:THRIVE can reduce the risk of early postoperative atelectasis and intraoperative hypoxemia, thereby promoting postoperative recovery of patients undergoing gastrointestinal endoscopy under long-term non-intubated anesthesia.
6.Network correlation between interoceptive sensitivity and sleep quality in colorectal cancer patients with colostomy: the bridging role of trust
Weijing CHEN ; Huanling GAO ; Lihong LIU ; Siyuan ZHANG ; Caicai CUI ; Xujing LYU
Chinese Journal of Modern Nursing 2025;31(35):4809-4815
Objective:To explore the complex network correlation between interoceptive sensitivity and sleep quality in colorectal cancer patients with colostomy, clarify core symptoms and bridging symptoms, so as to provide theoretical support for developing targeted intervention measures.Methods:Convenience sampling method was used to select 287 colorectal cancer patients with colostomy at Shanxi Province Fenyang Hospital and Lyuliang First People's Hospital between October 2023 and November 2024 as study subjects. Patients were assessed using the General Information Questionnaire, Multidimensional Assessment of Interoceptive Awareness Version 2-Chinese, and Pittsburgh Sleep Quality Index. Network analysis was employed to investigate the network correlation between interoceptive sensitivity and sleep quality, as well as the characteristics of core nodes. A total of 287 questionnaires were distributed, and 281 effective questionnaires were collected, with an effective response rate of 97.91% (281/287) .Results:Network analysis revealed that the strongest connection weights linking interoceptive sensitivity to sleep quality were observed between trust and daytime dysfunction (connection weight: -0.20), followed by trust and sleep duration (connection weight: -0.10). The strength, betweenness, and closeness of trust centrality indicators were 1.24, 2.34, and 1.73, respectively. Trust emerged as the core node within the interoceptive sensitivity cluster. The strength, betweenness, and closeness of daytime dysfunction indicators were 1.15, 1.92 and 1.67. Daytime dysfunction emerged as the core node within the sleep quality cluster. Trust served as a bridging role in the complex network correlation between interoceptive sensitivity and sleep quality.Conclusions:There is a strong correlation between trust and daytime dysfunction and sleep duration among colorectal cancer patients with colostomy. Trust is a key factor in the network correlation between interoceptive sensitivity and sleep quality. Clinical healthcare providers can develop targeted interventions based on trust to improve the interoceptive sensitivity and sleep quality of colorectal cancer patients with colostomy.
7.Network analysis of factors related to non suicidal self injury among middle school students in Guizhou Province
ZHAO Wenxin, TIAN Meng, CHEN Siyuan, WU Jinyi, GAO Ying, DENG Xiwen, ZHANG Wanzhu
Chinese Journal of School Health 2025;46(1):92-95
Objective:
To explore the relationship between related factors of non-suicidal self-injury behavior (NSSI) among middle school students in Guizhou Province, so as to provide the evidence for preventing high risk behaviors in adolescents.
Methods:
A stratified cluster random sampling method was used to select 1 034 junior and senior middle school students from Zunyi City, Qiannan Prefecture and Tongren City in Guizhou Province from April to October in 2023. Questionnaire survey was conducted to collect information including Adolescent Self injury Scale and Family Assessment Device. The R 4.4.1 software was employed for network analysis visualization, centrality indicators, and result stability assessment.
Results:
The detection rate of NSSI behavior among middle school students in Guizhou province was 29.6%, with a detection rate of 25.5% for boys and 33.1% for girls, showing a statistically significant difference ( χ 2=7.07, P <0.05). There were statistically significant differences in scores of emotional communication, egoism, family rules, positive communication, problem solving, expression of positive emotions and management of negative emotions self-efficacy, and bullying victimization in various dimensions between middle school students with and without NSSI ( Z =-13.66 to -7.05, P <0.01). NSSI among middle school students was positively correlated with social/relational bullying, depression and anxiety, and there were relatively close connections in the network ( r =0.35, 0.43, 0.42, P <0.01). Centrality indicators showed that the highest in strength and closeness centrality were stress ( Z =1.29, 1.58), the highest in betweenness centrality was for emotional communication ( Z =1.91), and the highest in expected influence index was for physical bullying ( Z =1.44)( P < 0.05).
Conclusions
Stress, emotional communication and physical bullying have significant impacts in the network of factors related to NSSI. Social/relational bullying, depression and anxiety have strong direct correlations with NSSI behavior among middle school students.
8.Jasurolignoside from Ilex pubescens exerts a therapeutic effect on acute lung injury in vitro and in vivo by binding to TLR4.
Shan HAN ; Chi Teng VONG ; Jia HE ; Qinqin WANG ; Qiumei FAN ; Siyuan LI ; Jilang LI ; Min LIAO ; Shilin YANG ; Renyikun YUAN ; Hongwei GAO
Chinese Journal of Natural Medicines (English Ed.) 2025;23(9):1058-1068
Acute lung injury (ALI) is a severe disease caused by viral infection that triggers an uncontrolled inflammatory response. This study investigated the capacity of jasurolignoside (JO), a natural compound, to bind to Toll-like receptor 4 (TLR4) and treat ALI. The anti-inflammatory properties of JO were evaluated in vitro through Western blotting, enzyme-linked immunosorbent assay (ELISA), immunofluorescence staining, and co-immunoprecipitation. The investigation utilized a lipopolysaccharide (LPS)-induced ALI animal model to examine the therapeutic efficacy and mechanism of JO in vivo. JO attenuated inflammatory symptoms in infected cells and tissues by modulating the NOD-like receptor family pyrin domain containing protein 3 (NLRP3) inflammasome and the nuclear factor κB (NF-κB)/mitogen-activated protein kinase (MAPK) pathway. Molecular docking simulations revealed JO binding to TLR4 active sites, confirmed by cellular thermal shift assay. Surface plasmon resonance (SPR) demonstrated direct interaction between JO and TLR4 with a Kd value of 35.1 μmol·L-1. Moreover, JO inhibited tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and IL-6 secretion and reduced leukocyte, neutrophil, lymphocyte, and macrophage infiltration in ALI-affected mice. JO also enhanced lung function and reduced ALI-related mortality. Immunohistochemical staining demonstrated JO's ability to suppress TLR4 expression in ALI-affected mouse lung tissue. This study establishes that JO can bind to TLR4 and effectively treat ALI, indicating its potential as a therapeutic agent for clinical applications.
Toll-Like Receptor 4/chemistry*
;
Animals
;
Acute Lung Injury/chemically induced*
;
Mice
;
Humans
;
Ilex/chemistry*
;
Molecular Docking Simulation
;
Male
;
NF-kappa B/immunology*
;
Mice, Inbred C57BL
;
NLR Family, Pyrin Domain-Containing 3 Protein/immunology*
;
Tumor Necrosis Factor-alpha/genetics*
;
Interleukin-1beta/genetics*
;
RAW 264.7 Cells
;
Disease Models, Animal
9.Network correlation between interoceptive sensitivity and sleep quality in colorectal cancer patients with colostomy: the bridging role of trust
Weijing CHEN ; Huanling GAO ; Lihong LIU ; Siyuan ZHANG ; Caicai CUI ; Xujing LYU
Chinese Journal of Modern Nursing 2025;31(35):4809-4815
Objective:To explore the complex network correlation between interoceptive sensitivity and sleep quality in colorectal cancer patients with colostomy, clarify core symptoms and bridging symptoms, so as to provide theoretical support for developing targeted intervention measures.Methods:Convenience sampling method was used to select 287 colorectal cancer patients with colostomy at Shanxi Province Fenyang Hospital and Lyuliang First People's Hospital between October 2023 and November 2024 as study subjects. Patients were assessed using the General Information Questionnaire, Multidimensional Assessment of Interoceptive Awareness Version 2-Chinese, and Pittsburgh Sleep Quality Index. Network analysis was employed to investigate the network correlation between interoceptive sensitivity and sleep quality, as well as the characteristics of core nodes. A total of 287 questionnaires were distributed, and 281 effective questionnaires were collected, with an effective response rate of 97.91% (281/287) .Results:Network analysis revealed that the strongest connection weights linking interoceptive sensitivity to sleep quality were observed between trust and daytime dysfunction (connection weight: -0.20), followed by trust and sleep duration (connection weight: -0.10). The strength, betweenness, and closeness of trust centrality indicators were 1.24, 2.34, and 1.73, respectively. Trust emerged as the core node within the interoceptive sensitivity cluster. The strength, betweenness, and closeness of daytime dysfunction indicators were 1.15, 1.92 and 1.67. Daytime dysfunction emerged as the core node within the sleep quality cluster. Trust served as a bridging role in the complex network correlation between interoceptive sensitivity and sleep quality.Conclusions:There is a strong correlation between trust and daytime dysfunction and sleep duration among colorectal cancer patients with colostomy. Trust is a key factor in the network correlation between interoceptive sensitivity and sleep quality. Clinical healthcare providers can develop targeted interventions based on trust to improve the interoceptive sensitivity and sleep quality of colorectal cancer patients with colostomy.
10.miR-411-3p attenuates silica-induced pulmonary fibrosis in mice by suppressing alveolar type II epithelial-mesenchymal transition via targeting SMURF2 regulation
Siyi WANG ; Jiakun DU ; Siyuan SHAN ; Bingbing LI ; Xinyu WANG ; Zhongqiu WEI ; Hong XU ; Xuemin GAO
Journal of Environmental and Occupational Medicine 2025;42(12):1438-1445
Background Pneumoconiosis is the most serious occupational disease in China, among which silicosis accounts for more than 50%. microRNA (miRNA) plays an important role in the occurrence process of silicosis fibrosis, but the mechanism of it has not been fully clarified yet. Objective To explore the molecular mechanism by which miR-411-3p modulates the ubiquitination degradation of SMAD specific E3 ubiquitin protein ligase (SMURF) 2/Smad7, thereby suppressing epithelial-mesenchymal transition (EMT) in mouse alveolar type II epithelial cells and counteracting silica-induced pulmonary fibrosis. Methods Twenty-four 8-week-old SPF male C57BL/6J mice were randomly divided into four groups: Control group, silica group, silica +miR-411-3p agomir-NC group, and silica +miR-411-3p agomir group, with 6 mice in each group. Silicosis model was prepared by a one-time bronchial infusion of silicon dioxide (SiO2) (200 mg·mL-1, 50 μL). In vitro MLE-12 cells were divided into (1) control group and SiO2 group, (2) SiO2+negative control siRNA (siRNA-NC) group and SiO2+Smurf2 gene silencing (si-Smurf2) group, (3) SiO2+solvent (DMSO) group and SiO2+protease inhibitor (MG132) group, (4) mutant sequence plasmid (Mut)+miR-411-3p mimic control (miR-NC) group, Mut+miR-411-3p mimic group, wild sequence plasmid (Wt)+miR-NC group, and Wt+miR-411-3p mimic group, (5) SiO2+miR-NC group and SiO2+miR-411-3p mimic group. The pathological morphology and collagen deposition of lung tissue were observed after staining. Detection of miR-411-3p and proteins was conducted by real-time fluorescent quantitative PCR and Western blot. The binding of SMURF2 to Smad7 protein and Smad7 to ubiquitin (Ub) were detected by co-immunoprecipitation (Co-IP) method. Dual-luciferase reporter gene assay was adopted to verify the regulatory effect of miR-411-3p on Smurf2. Results In the SiO2-induced MLE-12 cells, compared to the control group, the SiO2-treated group showed significantly upregulated expressions of N-cadherin (N-Cad), collagen I (CoL I), SMURF2, transforming growth factor-β1 (TGF-β1), and phosphorylated Smad2/3 (p-Smad2/3). In contrast, the expressions of E-cadherin (E-Cad), Smad7, and miR-411-3p were significantly downregulated (P<0.05). The dual-luciferase reporter gene assay revealed a regulatory effect of miR-411-3p on Smurf2 (P<0.05). Meanwhile, in the MLE-12 cells induced by SiO2, the miR-411-3p mimic down-regulated the protein expressions of SMURF2, N-Cad, CoL I, TGF-β1, and p-Smad2/3, while up-regulated the protein expressions of E-Cad and Smad7 (P<0.05). The silenced Smurf2 gene inhibited the expressions of N-Cad, CoL I, and p-Smad2/3 proteins, while promoted the expressions of E-Cad and Smad7 proteins in the MLE-12 cells (P<0.05). The Co-IP results showed that the binding of SMURF2 to Smad7 was enhanced, and the ubiquitin binding ability of Smad7 was enhanced in the SiO2 group. In the lung tissue of mice, the results of pathological observation with hematoxylin-eosin (HE) and sirius red (VG) staining showed that compared with the agomir-NC, the lesion was relieved in the lung tissue of the miR-411-3p agomir group. Meanwhile, the expressions of SMURF2, N-Cad, CoL I, TGF-β1, and p-Smad2/3 were significantly down-regulated, while the expressions of E-Cad and Smad7 were significantly up-regulated (P<0.05). Conclusion MiR-411-3p alleviates the EMT of alveolar type II epithelial cells and antagonizes silicosis fibrosis progression in mice by inhibiting SMURF2-mediated ubiquitination and degradation of Smad7.


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