1.Effects of VX765 on osteoarthritis and chondrocyte inflammation in rats.
Wanran HUANG ; Junxue TU ; Aiqing QIAO ; Chujun HE
Chinese Journal of Reparative and Reconstructive Surgery 2024;38(1):74-81
OBJECTIVE:
To investigate the effects and underlying mechanisms of VX765 on osteoarthritis (OA) and chondrocytes inflammation in rats.
METHODS:
Chondrocytes were isolated from the knee joints of 4-week-old Sprague Dawley (SD) rats. The third-generation cells were subjected to cell counting kit 8 (CCK-8) analysis to assess the impact of various concentrations (0, 1, 5, 10, 20, 50, 100 μmol/L) of VX765 on rat chondrocyte activity. An in vitro lipopolysaccharide (LPS) induced cell inflammation model was employed, dividing cells into control group, LPS group, VX765 concentration 1 group and VX765 concentration 2 group without obvious cytotoxicity. Western blot, real-time fluorescence quantitative PCR, and ELISA were conducted to measure the expression levels of inflammatory factors-transforming growth factor β 1 (TGF-β 1), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α). Additionally, Western blot and immunofluorescence staining were employed to assess the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1). Thirty-two SD rats were randomly assigned to sham surgery group (group A), OA group (group B), OA+VX765 (50 mg/kg) group (group C), and OA+VX765 (100 mg/kg) group (group D), with 8 rats in each group. Group A underwent a sham operation with a medial incision, while groups B to D underwent additional transverse incisions to the medial collateral ligament and anterior cruciate ligament, with removal of the medial meniscus. One week post-surgery, groups C and D were orally administered 50 mg/kg and 100 mg/kg VX765, respectively, while groups A and B received an equivalent volume of saline. Histopathological examination using HE and safranin-fast green staining was performed, and Mankin scoring was utilized for evaluation. Immunohistochemical staining technique was employed to analyze the expressions of matrix metalloproteinase 13 (MMP-13) and collagen type Ⅱ.
RESULTS:
The CCK-8 assay indicated a significant decrease in cell viability at VX765 concentrations exceeding 10 μmol/L ( P<0.05), so 4 μmol/L and 8 μmol/L VX765 without obvious cytotoxicity were selected for subsequent experiments. Following LPS induction, the expressions of TGF-β 1, IL-6, and TNF-α in cells significantly increased when compared with the control group ( P<0.05). However, intervention with 4 μmol/L and 8 μmol/L VX765 led to a significant decrease in expression compared to the LPS group ( P<0.05). Western blot and immunofluorescence staining demonstrated a significant upregulation of Nrf2 pathway-related molecules Nrf2 and HO-1 protein expressions by VX765 ( P<0.05), indicating Nrf2 pathway activation. Histopathological examination of rat knee joint tissues and immunohistochemical staining revealed that, compared to group B, treatment with VX765 in groups C and D improved joint structural damage in rat OA, alleviated inflammatory reactions, downregulated MMP-13 expression, and increased collagen type Ⅱ expression.
CONCLUSION
VX765 can improve rat OA and reduce chondrocyte inflammation, possibly through the activation of the Nrf2 pathway.
Rats
;
Animals
;
Chondrocytes/metabolism*
;
Matrix Metalloproteinase 13/metabolism*
;
Rats, Sprague-Dawley
;
Tumor Necrosis Factor-alpha/metabolism*
;
Collagen Type II/metabolism*
;
Interleukin-6
;
Lipopolysaccharides/pharmacology*
;
NF-E2-Related Factor 2/pharmacology*
;
Inflammation/drug therapy*
;
Osteoarthritis/metabolism*
;
Transforming Growth Factor beta1/metabolism*
;
Dipeptides
;
para-Aminobenzoates
3.Application of precision-cut lung slice technology to study the role of DDR2 in pulmonary fibrosis.
Xi-Hui HUANG ; Tao CHENG ; Ling MOU ; Xin BO ; Xin-Ru WEI
Acta Physiologica Sinica 2023;75(4):515-520
Pulmonary fibrosis is a severe lung interstitial disease characterized by the destruction of lung tissue structure, excessive activation and proliferation of fibroblasts, secretion and accumulation of a large amount of extracellular matrix (ECM), and impaired lung function. Due to the complexity of the disease, a suitable animal model to mimic human pulmonary fibrosis has not yet been established. Precision-cut lung slice (PCLS) has been a widely used in vitro method to study lung physiology and pathogenesis in recent years. This method is an in vitro culture technology at the level between organs and cells, because it can preserve the lung tissue structure and various types of airway cells in the lung tissue, simulate the in vivo lung environment, and conduct the observation of various interactions between cells and ECM. Therefore, PCLS can compensate for the limitations of other models such as cell culture. In order to explore the role of discoidin domain receptor 2 (DDR2) in pulmonary fibrosis, Ddr2flox/flox mice were successfully constructed. The Cre-LoxP system and PCLS technology were used to verify the deletion or knockdown of DDR2 in mouse PCLS. Transforming growth factor β1 (TGF-β1) can induce fibrosis of mouse PCLS in vitro, which can simulate the in vivo environment of pulmonary fibrosis. In the DDR2 knock down-PCLS in vitro model, the expression of various fibrosis-related factors induced by TGF-β1 was significantly reduced, suggesting that knocking down DDR2 can inhibit the formation of pulmonary fibrosis. The results provide a new perspective for the clinical study of DDR2 as a therapeutic target in pulmonary fibrosis.
Animals
;
Humans
;
Mice
;
Discoidin Domain Receptor 2/metabolism*
;
Fibroblasts/pathology*
;
Fibrosis
;
Lung/pathology*
;
Pulmonary Fibrosis/metabolism*
;
Transforming Growth Factor beta1/metabolism*
4.Aqueous extract of Epimedium sagittatum mitigates pulmonary fibrosis in mice.
Ru WANG ; Fei-Yue HOU ; Meng-Nan ZENG ; Bei-Bei ZHANG ; Qin-Qin ZHANG ; Shuang-Shuang XIE ; Wei-Sheng FENG ; Xiao-Ke ZHENG
China Journal of Chinese Materia Medica 2023;48(20):5612-5622
This study aims to investigate the intervention effect of the aqueous extract of Epimedium sagittatum Maxim on the mouse model of bleomycin(BLM)-induced pulmonary fibrosis, so as to provide data support for the clinical treatment of pulmonary fibrosis. Ninety male C57BL/6N mice were randomized into normal(n=10), model(BLM, n=20), pirfenidone(PFD, 270 mg·kg~(-1), n=15), and low-, medium-, and high-dose E. sagittatum extract(1.67 g·kg~(-1), n=15; 3.33 g·kg~(-1), n=15; 6.67 g·kg~(-1), n=15) groups. The model of pulmonary fibrosis was established by intratracheal instillation of BLM(5 mg·kg~(-1)) in the other five groups except the normal group, which was treated with an equal amount of normal saline. On the day following the modeling, each group was treated with the corresponding drug by gavage for 21 days. During this period, the survival rate of the mice was counted. After gavage, the lung index was calculated, and the morphology and collagen deposition of the lung tissue were observed by hematoxylin-eosin(HE) and Masson staining, respectively. The levels of reactive oxygen species(ROS) in lung cell suspensions were measured by flow cytometry. The levels of glutathione peroxidase(GSH-Px), total superoxide dismutase(T-SOD), and malondialdehyde(MDA) the in lung tissue were measured. Terminal-deoxynucleoitidyl transferase-mediated nick-end labeling(TUNEL) was employed to examine the apoptosis of lung tissue cells. The content of interleukin-6(IL-6), chemokine C-C motif ligand 2(CCL-2), matrix metalloproteinase-8(MMP-8), transforming growth factor-beta 1(TGF-β1), alpha-smooth muscle actin(α-SMA), E-cadherin, collagen Ⅰ, and fibronectin in the lung tissue was measured by enzyme-linked immunosorbent assay(ELISA). The expression levels of F4/80, Ly-6G, TGF-β1, and collagen Ⅰ in the lung tissue were determined by immunohistochemistry. The mRNA levels of CCL-2, IL-6, and MMP-7 in the lung tissue were determined by qRT-PCR. The content of hydroxyproline(HYP) in the lung tissue was determined by alkaline hydrolysation. The expression of α-SMA and E-cadherin was detected by immunofluorescence, and the protein levels of α-SMA, vimentin, E-cadherin in the lung tissue were determined by Western blot. The results showed the aqueous extract of E. sagittatum increased the survival rate, decreased the lung index, alleviated the pathological injury, collagen deposition, and oxidative stress in the lung tissue, and reduced the apoptotic cells. Furthermore, the aqueous extract of E. sagittatum down-regulated the protein levels of F4/80 and Ly-6G and the mRNA levels of CCL-2, IL-6, and MMP-7 in the lung tissue, reduced the content of IL-6, CCL-2, and MMP-8 in the alveolar lavage fluid. In addition, it lowered the levels of HYP, TGF-β1, α-SMA, collagen Ⅰ, fibronectin, and vimentin, and elevated the levels of E-cadherin in the lung tissue. The aqueous extract of E. sagittatum can inhibit collagen deposition, alleviate oxidative stress, and reduce inflammatory response by regulating the expression of the molecules associated with epithelial-mesenchymal transition, thus alleviating the symptoms of bleomycin-induced pulmonary fibrosis in mice.
Mice
;
Male
;
Animals
;
Pulmonary Fibrosis/metabolism*
;
Transforming Growth Factor beta1/metabolism*
;
Epimedium/metabolism*
;
Fibronectins/metabolism*
;
Matrix Metalloproteinase 7/therapeutic use*
;
Matrix Metalloproteinase 8/therapeutic use*
;
Vimentin/metabolism*
;
Interleukin-6/metabolism*
;
Mice, Inbred C57BL
;
Lung
;
Collagen/metabolism*
;
Bleomycin/toxicity*
;
RNA, Messenger/metabolism*
;
Cadherins/metabolism*
5.Effect and mechanism of Jiming Powder on myocardial fibrosis in mice with myocardial infarction.
Xin-Yi FAN ; Xiao-Qi WEI ; Yun-Yang ZHANG ; Hai-Yin PU ; Fang-He LI ; Kuo GAO ; Xue YU ; Shu-Zhen GUO
China Journal of Chinese Materia Medica 2023;48(21):5838-5850
Jiming Powder is a traditional ancient prescription with good therapeutic effect in the treatment of heart failure, but its mechanism lacks further exploration. In this study, a mouse model of coronary artery ligation was used to evaluate the effect and mechanism of Jiming Powder on myocardial fibrosis in mice with myocardial infarction. The study constructed a mouse model of heart failure after myocardial infarction using the method of left anterior descending coronary artery ligation. The efficacy of Jiming Powder was evaluated from multiple angles, including ultrasound imaging, hematoxylin-eosin(HE) staining, Masson staining, Sirius Red staining, and serum myocardial enzyme spectrum detection. Western blot analysis was performed to detect key proteins involved in ventricular remodeling, including transforming growth factor-β1(TGF-β1), α-smooth muscle actin(α-SMA), wingless-type MMTV integration site family member 3a(Wnt3a), β-catenin, matrix metallopeptidase 2(MMP2), matrix metallopeptidase 3(MMP3), TIMP metallopeptidase inhibitor 1(TIMP1), and TIMP metallopeptidase inhibitor 2(TIMP2). The results showed that compared with the model group, the high and low-dose Jiming Powder significantly reduced the left ventricular internal diameter in systole(LVID;s) and diastole(LVID;d), increased the left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS), effectively improved cardiac function in mice after myocardial infarction, and effectively reduced the levels of myocardial injury markers such as creatine kinase(CK), creatine kinase isoenzyme(CK-MB), and lactic dehydrogenase(LDH), thus protecting ischemic myocardium. HE staining showed that Jiming Powder could attenuate myocardial inflammatory cell infiltration after myocardial infarction. Masson and Sirius Red staining demonstrated that Jiming Powder effectively inhibited myocardial fibrosis, reduced the collagen Ⅰ/Ⅲ ratio in myocardial tissues, and improved collagen remodeling after myocardial infarction. Western blot results showed that Jiming Powder reduced the expression of TGF-β1, α-SMA, Wnt3a, and β-catenin, decreased the levels of MMP2, MMP3, and TIMP2, and increased the level of TIMP1, suggesting its role in inhibiting cardiac fibroblast transformation, reducing extracellular matrix metabolism in myocardial cells, and lowering collagen Ⅰ and α-SMA content, thus exerting an anti-myocardial fibrosis effect after myocardial infarction. This study revealed the role of Jiming Powder in improving ventricular remodeling and treating myocardial infarction, laying the foundation for further research on the pharmacological effect of Jiming Powder.
Mice
;
Animals
;
Transforming Growth Factor beta1/metabolism*
;
Matrix Metalloproteinase 2/metabolism*
;
beta Catenin/metabolism*
;
Matrix Metalloproteinase 3/therapeutic use*
;
Powders
;
Ventricular Remodeling
;
Stroke Volume
;
Ventricular Function, Left
;
Myocardial Infarction/drug therapy*
;
Myocardium/pathology*
;
Heart Failure/metabolism*
;
Collagen/metabolism*
;
Creatine Kinase
;
Fibrosis
6.A Chinese Herb Prescription "Fang-gan Decoction" Protects Against Damage to Lung and Colon Epithelial Cells Caused by the SARS-CoV-2 Spike Protein by Regulating the TGF-β/Smad2/3 and NF-κB Pathways.
Chao HUANG ; Hao-Sheng LIU ; Bing-Jun LIANG ; Sheng-Rong LIAO ; Wei-Zeng SHEN
Chinese Medical Sciences Journal 2023;38(3):206-217
Objective To explore the effects and mechanisms of a traditional Chinese medicine (TCM) prescription, "Fang-gan Decoction" (FGD), in protecting against SARS-CoV-2 spike protein-induced lung and intestinal injuries in vitro and in vivo.Methods Female BALB/c mice and three cell lines pretreated with FGD were stimulated with recombinant SARS-CoV-2 spike protein (spike protein). Hematoxylin-eosin (HE) staining and pathologic scoring of tissues, cell permeability and viability, and angiotensin-converting enzyme 2 (ACE2) expression in the lung and colon were detected. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the levels of inflammatory factors in serum and cell supernatant. The expression of NF-κB p65, p-NF-κB p65, p-IκBα, p-Smad2/3, TGF-β1, Caspase3, and Bcl-2 was evaluated by Western blotting.Results FGD protected against the damage to the lung and colon caused by the spike protein in vivo and in vitro according to the pathologic score and cell permeability and viability (P<0.05). FGD up-regulated ACE2 expression, which was reduced by the spike protein in the lung and colon, significantly improved the deregulation of inflammatory markers caused by the spike protein, and regulated the activity of TGF-β/Smads and NF-κB signaling.Conclusion Traditional Chinese medicine has a protective effect on lung and intestinal tissue injury stimulated by the spike protein through possible regulatory functions of the NF-κB and TGF-β1/Smad pathways with tissue type specificity.
Mice
;
Animals
;
Female
;
Humans
;
NF-kappa B/metabolism*
;
Spike Glycoprotein, Coronavirus/pharmacology*
;
Transforming Growth Factor beta1/metabolism*
;
Angiotensin-Converting Enzyme 2/pharmacology*
;
COVID-19
;
SARS-CoV-2/metabolism*
;
Lung
;
Antineoplastic Agents
;
Transforming Growth Factor beta/pharmacology*
;
Epithelial Cells/metabolism*
;
Colon
7.Expression of interleukin-37, vascular endothelial growth factor A, and transforming growth factor-β1 and their correlation with T cells in children with primary immune thrombocytopenia.
Lin-Lin TONG ; Li-Hua WANG ; Fang FANG ; Bin XU ; Su-Hua ZHENG
Chinese Journal of Contemporary Pediatrics 2023;25(11):1131-1136
OBJECTIVES:
To investigate the expression of interleukin-37 (IL-37), vascular endothelial growth factor A (VEGFA), and transforming growth factor-β1 (TGF-β1) in children with primary immune thrombocytopenia (ITP) and their correlation with T cells.
METHODS:
A retrospective analysis was conducted on 45 children with ITP (ITP group) who were admitted to Handan Central Hospital from January 2020 to April 2022, and 30 healthy children who underwent physical examination during the same period were included as the healthy control group. The mRNA expression levels of IL-37, VEGFA, and TGF-β1 and the levels of regulatory T cells (Treg) and helper T cells 17 (Th17) were measured before and after treatment, and the correlation between the mRNA expression levels of IL-37, VEGFA, and TGF-β1 and the levels of Treg, Th17, and Treg/Th17 ratio were analyzed.
RESULTS:
Compared with the healthy control group, the ITP group had a significantly higher mRNA expression level of IL-37 and a significantly higher level of Th17 before and after treatment, as well as significantly lower mRNA expression levels of VEGFA and TGF-β1 and significantly lower levels of Treg and Treg/Th17 ratio (P<0.05). After treatment, the ITP group had significant reductions in the mRNA expression level of IL-37 and the level of Th17 and significant increases in the mRNA expression levels of VEGFA and TGF-β1 and the levels of Treg and Treg/Th17 ratio (P<0.05). Correlation analysis showed that in the ITP group, the mRNA expression levels of IL-37 and TGF-β1 were negatively correlated with the levels of Treg and Treg/Th17 ratio (P<0.05) and were positively correlated with the level of Th17 (P<0.05) before and after treatment; the mRNA expression level of VEGFA was positively correlated with the levels of Treg and Treg/Th17 ratio (P<0.05) and was negatively correlated with the Th17 level (P<0.05) before and after treatment.
CONCLUSIONS
Abnormal expression levels of IL-37, VEGFA, and TGF-β1 may be observed in children with ITP, which is significantly associated with the imbalance of Treg/Th17 ratio. It is speculated that the cytokines such as IL-37, VEGFA, and TGF-β1 may be involved in the development and progression of ITP or may become important potential targets for the treatment of children with ITP. Citation:Chinese Journal of Contemporary Pediatrics, 2023, 25(11): 1131-1136.
Child
;
Humans
;
Interleukins
;
Purpura, Thrombocytopenic, Idiopathic
;
Retrospective Studies
;
RNA, Messenger/metabolism*
;
T-Lymphocytes, Regulatory
;
Th17 Cells/metabolism*
;
Transforming Growth Factor beta1/genetics*
;
Vascular Endothelial Growth Factor A/genetics*
8.Mechanism of transforming growth factor- β1 induce renal fibrosis based on transcriptome sequencing analysis.
Huanan LI ; Peifen LI ; Shanyi LI ; Xueying ZHANG ; Xinru DONG ; Ming YANG ; Weigan SHEN
Journal of Zhejiang University. Medical sciences 2023;52(5):594-604
OBJECTIVES:
To explore the mechanism of transforming growth factor-β1 (TGF-β1) induce renal fibrosis.
METHODS:
Renal fibroblast NRK-49F cells treated with and without TGF-β1 were subjected to RNA-seq analysis. DESeq2 was used for analysis. Differentially expressed genes were screened with the criteria of false discovery rate<0.05 and l o g 2 F C >1. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed for differentially expressed genes. Genes encoding transcription factors were further screened for differential expression genes. Then, the expression of these genes during renal fibrosis was verified using unilateral ureteral obstruction (UUO)-induced mouse renal fibrosis model and a public gene expression dataset (GSE104954).
RESULTS:
After TGF-β1 treatment for 6, 12 and 24 h, 552, 1209 and 1028 differentially expressed genes were identified, respectively. GO analysis indicated that these genes were significantly enriched in development, cell death, and cell migration. KEGG pathway analysis showed that in the early stage of TGF-β1 induction (TGF-β1 treatment for 6 h), the changes in Hippo, TGF-β and Wnt signaling pathways were observed, while in the late stage of TGF-β1 induction (TGF-β1 treatment for 24 h), the changes of extracellular matrix-receptor interaction, focal adhesion and adherens junction were mainly enriched. Among the 291 up-regulated differentially expressed genes treated with TGF-β1 for 6 h, 13 genes (Snai1, Irf8, Bhlhe40, Junb, Arid5a, Vdr, Lef1, Ahr, Foxo1, Myc, Tcf7, Foxc2, Glis1) encoded transcription factors. Validation in a cell model showed that TGF-β1 induced expression of 9 transcription factors (encoded by Snai1, Irf8, Bhlhe40, Junb, Arid5a, Vdr, Lef1, Myc, Tcf7), while the expression levels of the other 4 genes did not significantly change after TGF-β1 treatment. Validation results in UUO-induced mouse renal fibrosis model showed that Snai1, Irf8, Bhlhe40, Junb, Arid5a, Myc and Tcf7 were up-regulated after UUO, Vdr was down-regulated and there was no significant change in Lef1. Validation based on the GSE104954 dataset showed that IRF8 was significantly overexpressed in the renal tubulointerstitium of patients with diabetic nephropathy or IgA nephropathy, MYC was highly expressed in diabetic nephropathy, and the expressions of the other 7 genes were not significantly different compared with the control group.
CONCLUSIONS
TGF-β1 induces differentially expressed genes in renal fibroblasts, among which Irf8 and Myc were identified as potential targets of chronic kidney disease and renal fibrosis.
Mice
;
Animals
;
Humans
;
Transforming Growth Factor beta1/metabolism*
;
Diabetic Nephropathies/pathology*
;
Transcriptome
;
Signal Transduction
;
Kidney
;
Ureteral Obstruction/pathology*
;
Fibrosis
;
Interferon Regulatory Factors
;
Transforming Growth Factor beta/metabolism*
;
DNA-Binding Proteins/metabolism*
;
Transcription Factors/metabolism*
9.Research progress on the correlation between transforming growth factor- β level and symptoms of depression.
Yanran LI ; Huiying WANG ; Jiansong ZHOU ; Changhong WANG
Journal of Zhejiang University. Medical sciences 2023;52(5):646-652
Transforming growth factor (TGF)-β is a group of cytokines with anti-inflammatory effects in the TGF family, which participates in the development of stress and depression-related mechanisms, and plays roles in the regulation of inflammatory response in depression and the recovery of various cytokine imbalances. The core symptoms of depression is associated with TGF-β level, and the psychological symptoms of depression are related to TGF-β gene polymorphism. Various antidepressants may up-regulate TGF-β level through the complex interaction between neurotransmitters and inflammatory factors, inhibiting inflammatory response and regulating cytokine imbalance to improve depressive symptoms. Studies have shown that recombinant TGF-β1 protein has beneficial effects in mouse depression models, indicating TGF-β1 might be a potential therapeutic target for depression and nasal sprays having the advantage of being fast acting delivery method. This article reviews the research progress on dynamic changes of TGF-β level before and after depression treatment and the application of TGF-β level as an indicator for the improvement of depressive symptoms. We provide ideas for the development of new antidepressants and for the evaluation of the treatment efficacy in depression.
Animals
;
Mice
;
Transforming Growth Factor beta/metabolism*
;
Transforming Growth Factor beta1
;
Depression
;
Cytokines
;
Antidepressive Agents/therapeutic use*
;
Transforming Growth Factors
10.Role of PI3K/Akt/mTOR pathway-mediated macrophage autophagy in affecting the phenotype transformation of lung fibroblasts induced by silica dust exposure.
Yue DU ; Fangcai HUANG ; Lan GUAN ; Ming ZENG
Journal of Central South University(Medical Sciences) 2023;48(8):1152-1162
OBJECTIVES:
The phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway is one of the main signaling pathways related to autophagy. Autophagy plays a key role in the formation of silicosis fibrosis. The phenotypic transformation of lung fibroblasts into myofibroblasts is a hallmark of the transition from the inflammatory phase to the fibrotic phase in silicosis. This study aims to investigate whether the PI3K/Akt/mTOR pathway affects the phenotypic transformation of silicosis-induced lung fibroblasts into myofibroblasts via mediating macrophage autophagy.
METHODS:
The human monocytic leukemia cell line THP-1 cells were differentiated into macrophages by treating with 100 ng/mL of phorbol ester for 24 h. Macrophages were exposed to different concentrations (0, 25, 50, 100, 200, 400 μg/mL) and different times (0, 6, 12, 24, 48 h) of SiO2 dust suspension. The survival rate of macrophages was measured by cell counting kit-8 (CCK-8) method. Enzyme linked immunosorbent assay (ELISA) was used to measure the contents of transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α) in the cell supernatant. The co-culture system of macrophages and HFL-1 cells was established by transwell. A blank control group, a SiO2 group, a LY294002 group, a SC79 group, a LY294002+SiO2 group, and a SC79+SiO2 group were set up in this experiment. Macrophages in the LY294002+SiO2 group were pretreated with LY294002 (PI3K inhibitor) for 18 hours, and macrophages in the SC79+SiO2 group were pretreated with SC79 (Akt activator) for 24 hours, and then exposed to SiO2 (100 μg/mL) dust suspension for 12 hours. The expression of microtubule-associated protein 1 light chain 3 (LC3) protein in macrophages was detected by the immunofluorescence method. The protein expressions of PI3K, Akt, mTOR, Beclin-1, LC3 in macrophages, and collagen III (Col III), α-smooth muscle actin (α-SMA), fibronectin (FN), matrix metalloproteinase-1 (MMP-1), tissue metalloproteinase inhibitor-1 (TIMP-1) in HFL-1 cells were measured by Western blotting.
RESULTS:
After the macrophages were exposed to SiO2 dust suspension of different concentrations for 12 h, the survival rates of macrophages were gradually decreased with the increase of SiO2 concentration. Compared with the 0 μg/mL group, the survival rates of macrophages in the 100, 200, and 400 μg/mL groups were significantly decreased, and the concentrations of TGF-β1 and TNF-α in the cell supernatant were obviously increased (all P<0.05). When 100 μg/mL SiO2 dust suspension was applied to macrophages, the survival rates of macrophages were decreased with the prolonged exposure time. Compared with the 0 h group, the survival rates of macrophages were significantly decreased (all P<0.05), the concentrations of TGF-β1 and TNF-α in the cell supernatant were significantly increased, and the protein expression levels of Beclin-1 and LC3II were increased markedly in the 6, 12, 24, and 48 h groups (all P<0.05). Immunofluorescence results demonstrated that after exposure to SiO2 (100 μg/mL) dust for 12 h, LC3 exhibited punctate aggregation and significantly higher fluorescence intensity compared to the blank control group (P<0.05). Compared with the blank control group, the protein expressions of Col III, FN, α-SMA, MMP-1, and TIMP-1 in HFL-1 cells were up-regulated in the SiO2 group (all P<0.05). Compared with the SiO2 group, the protein expressions of PI3K, Akt, and mTOR were down-regulated and the protein expressions of LC3II and Beclin-1 were up-regulated in macrophages (all P<0.05), the contents of TNF-α and TGF-β1 in the cell supernatant were decreased (both P<0.01), and the protein expressions of Col III, FN, α-SMA, MMP-1, and TIMP-1 in HFL-1 cells were down-regulated (all P<0.05) in the LY294002+SiO2 group. Compared with the SiO2 group, the protein expressions of PI3K, Akt, and mTOR were up-regulated and the protein expressions of LC3II and Beclin-1 were down-regulated in macrophages (all P<0.05), the contents of TNF-α and TGF-β1 in the cell supernatant were increased (both P<0.01), and the protein expressions of Col III, FN, α-SMA, MMP-1, and TIMP-1 in HFL-1 cells were up-regulated (all P<0.05) in the SC79+SiO2 group.
CONCLUSIONS
Silica dust exposure inhibits the PI3K/Akt/mTOR pathway, increases autophagy and concentration of inflammatory factors in macrophages, and promotes the phenotype transformation of HFL-1 cells into myofibroblasts. The regulation of the PI3K/Akt/mTOR pathway can affect the autophagy induction and the concentration of inflammatory factors of macrophages by silica dust exposure, and then affect the phenotype transformation of HFL-1 cells into myofibroblasts induced by silica dust exposure.
Humans
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Transforming Growth Factor beta1/metabolism*
;
Silicon Dioxide/metabolism*
;
Phosphatidylinositol 3-Kinases/metabolism*
;
Matrix Metalloproteinase 1/metabolism*
;
Tissue Inhibitor of Metalloproteinase-1
;
Sirolimus
;
Beclin-1/metabolism*
;
Tumor Necrosis Factor-alpha/metabolism*
;
Dust
;
TOR Serine-Threonine Kinases/metabolism*
;
Lung/metabolism*
;
Fibroblasts/metabolism*
;
Silicosis/metabolism*
;
Macrophages/metabolism*
;
Autophagy

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