Objective To observe the effect of m⁶A methylation regulation on Notch1 pathway on the homing of BMSCs in asthma, and the intervention study of traditional Chinese medicine compound Yanghe Pingchuan Granules. Methods Rat bone mesenchymal stem cells(BMSC)and bronchial epithelial cells were cocultured. The extracted cells were divided into: bronchial epithelial cell group, asthma bronchial epithelial cell+mesenchymal stem cell co-culture group (co-culture group), co-culture cell+normal serum group, coculture cell+serum containing optimal drug group, siRNA FTO+normal serum group, siRNA FTO-NC+normal serum group, and siRNA FTO+serum containing optimal drug group. The vitality and cell cycle changes of co-cultured cells were detected. The level and markers of homing BMSC were detected by immunofluorescence staining. The expression of Notch1 pathway related genes were detected by qRT-PCR. The expression of Notch1 pathway related proteins were detected by Western blot. Results Compared with bronchial epithelial cell group, the co-cultured cell group showed an increase in the homing level of BMSCs and the expression of C-X-C motif chemokine receptor 4 (CXCR4), stromal cell-derived factor 1 (SDF-1), Notch1, transcription factor recombination signal binding protein-J (RBP-J), and hairy enhancer of split 1 (Hes1) proteins. Compared with the co-cultured cell group and co-cultured cell+normal serum group, the co-cultured cell+serum containing optimal drug group showed an increase in the homing level of BMSCs and the expressions of CXCR4 and SDF-1, while the protein and mRNA levels of Notch1 and Hes1 decreased. Compared with the siRNA FTO-NC+normal serum group, the siRNA FTO+normal serum group showed an increase in the levels of Notch1, activated Notch1, RBP-J, Hes1 protein, and cell viability, while the level of homing BMSC decreased. Compared with siRNA FTO+normal serum group, the levels of Notch1, RBP-J mRNA, activated Notch1, and Hes1 protein decreased, while the level of homing BMSCs increased in siRNA FTO+serum containing optimal drug group. The levels of Notch1, RBP-J, and Hes1 mRNA were reduced in the co-cultured cells+serum containing optimal drug group. Compared with siRNA FTO+serum containing optimal drug group, the expressions of Notch1, activated Notch1, RBP-J, Hes1 protein and cell viability decreased, while the level of homing BMSCs increased in the co-cultured cells+serum containing optimal drug group. Conclusion Yanghe Pingchuan Granules may promote the homing of BMSCs in asthma and alleviate asthma inflammation by upregulating the expression of FTO and inhibiting the expression of downstream genes in the Notch1 signaling pathway.
Animals ; Receptor, Notch1/genetics* ; Mesenchymal Stem Cells/cytology* ; Asthma/genetics* ; Drugs, Chinese Herbal/pharmacology* ; Signal Transduction/drug effects* ; Rats ; Coculture Techniques ; Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics* ; Epithelial Cells/metabolism* ; Rats, Sprague-Dawley ; Cells, Cultured ; Male

Objective This study aims to investigate the expression, phenotypic changes, and mechanisms of action of guanylate-binding protein 2 (GBP2) in the process of silica-induced pulmonary fibrosis. Methods The expression and localization of GBP2 in silicotic lung tissue were detected by immunohistochemical staining and immunofluorescence. An in vitro cell model was constructed, and methods such as Western blot and real-time quantitative reverse transcription polymerasechain reaction were utilized to investigate the function of GBP2 in different cell lines following silica stimulation. The mechanism of action of GBP2 in various cell lines was elucidated using Western blot analysis. Results GBP2 was highly expressed in the lung tissue of patients with silicosis. Immunohistochemical staining and immunofluorescence have revealed that GBP2 was localized in macrophages and epithelial cells. In vitro cell experiments demonstrated that silicon dioxide stimulated THP-1 cells to activate the c-Jun pathway through GBP2, promoting the secretion of inflammatory factors and facilitating the occurrence of M2 macrophage polarization. In epithelial cells, GBP2 promoted the occurrence of epithelial to mesenchymal transition (EMT) by upregulating Krueppel-like factor 8 (KLF8). Conclusion GBP2 not only activates c-Jun in macrophages to promote the production of inflammatory factors and the occurrence of M2 macrophage polarization, but also activates the transcription factor KLF8 in epithelial cells to induce EMT, collectively promoting the progression of silicosis.
Humans ; Silicosis/genetics* ; Macrophages/cytology* ; Epithelial Cells/pathology* ; GTP-Binding Proteins/physiology* ; Epithelial-Mesenchymal Transition ; Disease Progression ; Cell Line ; Male

OBJECTIVES: Pyroptosis plays a critical role in tubulointerstitial lesions of diabetic kidney disease (DKD). Annexin A2 (ANXA2) is involved in cell proliferation, apoptosis, and adhesion and may be closely related to DKD, but its specific mechanism remains unclear. This study aims to investigate the role and molecular mechanism of ANXA2 in high glucose-induced pyroptosis of renal tubular epithelial cells, providing new targets for DKD prevention and treatment. METHODS: Human renal tubular epithelial HK-2 cells were divided into a normal glucose group (5.5 mmol/L), a high glucose group (30.0 mmol/L), and a osmotic control group (24.5 mmol/L mannitol+5.5 mmol/L glucose). ANXA2 expression was modulated by overexpression of plasmids and small interfering RNA (siRNA). Cell proliferation was measured by 5-ethynyl-2'-deoxyuridine (EdU) assay, apoptosis by flow cytometry, and ANXA2, p50, and p65 subcellular localization by immunofluorescence. Western blotting was employed to detect α-smooth muscle actin (α-SMA), fibronectin (FN), and collagen type IV (Col-IV). Real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting were used to analyze nuclear factor-κB (NF-κB) subunits p50/p65 and the pyroptosis pathway factors NLR family Pyrin domain containing 3 (NLRP3), caspase-1, inferleukin (IL)-1β, and IL-18. Protein interactions between ANXA2 and p50/p65 were examined by co-immunoprecipitation, while chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays were used to examine NF-κB binding to the ANXA2 promoter. RESULTS: High glucose upregulated ANXA2 expression and promoted its nuclear translocation (P<0.01). High glucose reduced cell proliferation, increased apoptosis, and elevated α-SMA, FN, and Col-IV expression (all P<0.05); ANXA2 overexpression aggravated these effects (all P<0.05), while ANXA2 knockdown reversed them (all P<0.05). High glucose activated NF-κB and increased NLRP3, caspase-1, L-1β, and IL-18 mRNA and protein expression (all P<0.05); ANXA2 overexpression further enhanced this, whereas knockdown suppressed NF-κB activation and downstream factors (all P<0.05). Co-immunoprecipitation confirmed ANXA2 directly binds the NF-κB subunit p65. ChIP assays revealed p65 binds specifically to ANXA2 promoter regions (ChIP-2, ChIP-4, and ChIP-6), and luciferase activity in corresponding mutant constructs (M2, M4, and M6) was significantly increased versus controls (all P<0.05), confirming positive transcriptional regulation of ANXA2 by p65. CONCLUSIONS ANXA2 and NF-κB form a positive feedback loop that sustains NLRP3 inflammasome activation, promotes pyroptosis pathway activation, and aggravates high glucose-induced renal tubular epithelial cell injury. Targeting ANXA2 or blocking its interaction with p65 may be a novel strategy to slow DKD progression.
Humans ; Pyroptosis/drug effects* ; Annexin A2/physiology* ; Epithelial Cells/cytology* ; Kidney Tubules/cytology* ; Glucose/pharmacology* ; Diabetic Nephropathies/metabolism* ; NF-kappa B/metabolism* ; Cell Line ; Cell Proliferation ; Transcription Factor RelA/metabolism* ; Feedback, Physiological

Objective:The mucosa of Chronic rhinosinusitis with nasal polyps（CRSwNP） is accompanied by tissue remodeling. Epithelial-mesenchymal transition（EMT） plays an important role in tissue remodeling, but the mechanism of EMT is not yet clear. The purpose of this study is to further clarify the pathogenesis of CRSwNP and provide another idea and theoretical basis for the treatment of CRSwNP. Methods:①The expression of NLRP3 and EMT-related protein（E-cadherin, Vimentin） in the nasal mucosa of the CRSwNP group and the normal control group were detected by immunohistochemistry（IHC）. ②Primary human nasal epithelial cells（HNECs） were cultured in vitro, and HNE-intervened cells with different concentrations（0, 10, 25, 50, 100 ng/mL） were used. After stimulation for 24 h, mRNA and protein expressions of E-cadherin, Vimentin, NLRP3 were detected by qRT-PCR and western blotting. ③Cells were collected at 0, 24, 36, 48 and 72 hours later after incubation with HNE with the optimal concentration, and the mRNA and protein expressions of E-cadherin, Vimentin and NLRP3 were detected by qRT-PCR and western blotting. ④Primary human nasal epithelial cells were pretreated with NLRP3 inhibitor MCC950, then stimulated with HNE, and EMT-related proteins（E-cadherin, Vimentin） and NLRP3 expression were detected by qRT-PCR and western blotting. Results:①The expression levels of NLRP3 and Vimentin in nasal polyps of CRSwNP patients were higher than those of control group, and the expression of E-cadherin was lower（P<0.05）. The mRNA and protein expression levels of NLRP3 and Vimentin increased when HNE stimulated primary human nasal epithelial cells, while the expression of E-cadherin decreased. ②The effect was most significant when the HNE stimulated nasal mucosal epithelial cells were exposed to 50 ng/mL（P<0.05）. The primary human nasal epithelial cells were stimulated with 50 ng/ml HNE, and the effect was most significant when the duration of HNE exposure was 36 h（P<0.05）. ③Primary human nasal epithelial cells were pretreated with MCC950 and then stimulated with HNE. The mRNA and protein expression levels of E-cadherin in the NLRP3 inhibitor pretreated group were increased, while the mRNA and protein expression levels of Vimentin and NLRP3 were decreased（P<0.05）. Conclusion:ln CRSwNP, HNE promotes EMT in human nasal mucosal epithelial cells by activating NLRP3.
Humans ; Nasal Polyps/metabolism* ; Epithelial-Mesenchymal Transition ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Sinusitis/metabolism* ; Cadherins/metabolism* ; Vimentin/metabolism* ; Chronic Disease ; Nasal Mucosa/cytology* ; Rhinitis/metabolism* ; Epithelial Cells/metabolism* ; Cells, Cultured ; Rhinosinusitis

OBJECTIVES: To investigate the mechanism mediating the regulatory effect of miR-155-5p on proliferation of human submandibular gland epithelial cells (HSGECs) in primary Sjogren's syndrome (pSS). METHODS: Dual luciferase reporter assay was used to verify the targeting relationship between miR-155-5p and the PI3K/AKT pathway. In a HSGEC model of pSS induced by simulation with TRAIL and INF-γ, the effects of miR-155-inhibitor-NC or miR-155 inhibitor on cell viability, cell cycle, apoptosis and proliferation were evaluated using CKK8 assay, flow cytometry and colony formation assay. ELISA and RT-PCR were used to detect the expressions of inflammatory cytokines and miR-155-5p mRNA in the cells; Western blotting was performed to detect the expressions of proteins in the PI3K/AKT signaling pathway. RESULTS: Dual luciferase assay showed that miR-155-5p targets the PI3K/AKT pathway via PIK3R1 mRNA. The HSGEC model of pSS showed significantly decreased cell viability, cell clone formation ability and expressions IL-10 and IL-4 and increased cell apoptosis, cell percentage in G2 phase, expressions of TNF‑α, IL-6, miR-155-5p and PIK3R1 mRNA, p-PI3K/PI3K ratio, p-Akt/AKT ratio, and PIK3R1 protein expression. Treatment of the cell models with miR-155 inhibitor significantly increased the cell viability, G1 phase cell percentage, colony formation ability, and expressions of IL-10 and IL-4 levels, and obviously reduced cell apoptosis rate, G2 phase cell percentage, expressions of TNF-α, IL-6, miR-155-5p and PIK3R1 mRNA, p-PI3K/PI3K ratio, p-AKT/AKT ratio, and PIK3R1 protein expression. CONCLUSIONS In HSGEC model of pSS, inhibition of miR-155-5p can promote cell proliferation and reduced cell apoptosis by targeting PI3K1 mRNA to negatively regulate the overexpression of PI3K/AKT signaling pathway.
Humans ; MicroRNAs/genetics* ; Cell Proliferation ; Signal Transduction ; Proto-Oncogene Proteins c-akt/metabolism* ; Sjogren's Syndrome/pathology* ; Epithelial Cells/cytology* ; Submandibular Gland/cytology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Apoptosis ; Class Ia Phosphatidylinositol 3-Kinase ; Cells, Cultured

OBJECTIVES: To investigate the therapeutic mechanism of nodakenin for Crohn's disease (CD)-like colitis in mice. METHODS: Using a colonic organoid model with lipopolysaccharide (LPS)- and ATP-induced pyroptosis, we investigated the effects of nodakenin on pyroptosis, intestinal barrier function and inflammatory response by detecting key pyroptosis-regulating factors and assessing changes in permeability and pro-inflammatory factors. In a mouse model of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced CD-like colitis, the therapeutic effect of nodakenin was evaluated by measuring changes in body weight, DAI score, colonic histopathologies, inflammation score, intestinal barrier function and intestinal epithelial cell pyroptosis. The mechanism of nodakenin protection against pyroptosis of intestinal epithelial cells was explored using network pharmacology analysis and in vivo and in vitro experiments. RESULTS: In LPS- and ATP-induced colonic organoids, treatment with nodakenin significantly inhibited the expressions of NLRP3, GSDMD-N, cleaved caspase-1 and caspase-11, improved intestinal FITC-dextran (FD4, 4000) permeability, and decreased the levels of IL-1β and IL-18. In the mouse model of TNBS-induced colitis, nodakenin treatment significantly alleviated weight loss, reduced DAI score, inflammatory cell infiltration and inflammation score, and decreased serum FD4 and I-FABP levels and bacteria translocation to the mesenteric lymph nodes, spleen and liver. The mice with nodakenin treatment had also lowered expressions of NLRP3, GSDMD-N, cleaved caspase-1 and caspase-11 in the intestinal mucosa. Network pharmacology analysis suggested that the inhibitory effect of nodakenin on colitis was associated with the PI3K/Akt pathway. In both the colonic organoid model and mouse models of colitis, nodakenin effectively inhibited the activation of the PI3K/Akt pathway, and the application of IGF-1, a PI3K/Akt pathway activator, strongly attenuated the protective effect of nodakenin against intestinal epithelial cell pyroptosis and intestinal barrier dysfunction. CONCLUSIONS Nodakenin protects intestinal barrier function and alleviates CD-like colitis in mice at least partly by inhibiting PI3K/Akt signaling to reduce intestinal epithelial cell pyroptosis.
Animals ; Pyroptosis/drug effects* ; Mice ; Trinitrobenzenesulfonic Acid ; Colitis/drug therapy* ; Epithelial Cells/drug effects* ; Intestinal Mucosa/cytology* ; Disease Models, Animal ; Coumarins/pharmacology* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Crohn Disease/drug therapy*

OBJECTIVES: To reprogram human placental fibroblasts (HPFs) into chemically induced epithelioid-like cells (ciEP-Ls) using a combination of small-molecule compounds. METHODS: HPFs cultured under normoxic conditions were identified using immunofluorescence assay, PCR and chromosomal karyotyping. Under hypoxic conditions (37 ℃, 5% O₂), HPFs were cultured in a medium containing small-molecule compounds C6TSEDRVAJZ (CHIR99021, 616452, TTNPB, SAG, EPZ5676, DZNep, Ruxolitinib, VTP50469, Afuresertib, JNK-IN-8, and EZM0414), and the cell morphology was observed daily. The expression levels of epithelial cell markers in the induced cells were detected by immunofluorescence, Western blotting and PCR. Chromosomal karyotyping of the induced cells was performed and the induction efficiency was calculated. RESULTS: Before induction, HPFs showed positive expressions of fibroblast surface markers CD34 and vimentin and were negative for epithelial surface markers. PCR results showed high expressions of fibroblast-specific genes S100A4 and COL1A1 in HPFs with a normal human diploid karyotype. After one day of induction, the HPFs underwent morphological changes from a multinodular spindle shape to a round or polygonal shape, which was morphologically characteristic of ciEP-Ls. On day 4 of induction, the cells exhibited high expressions of the epithelial cell markers E-cadherin and Lin28A. RT-qPCR results also showed that the cells expressed the epithelial markers Smad3, GLi3, PAX8, WT1, KRT19, and KRT18 with significantly down-regulated expressions of all the fibroblast surface markers and a normal human diploid karyotype. The reprogramming efficiency of HPFs into ciEP-Ls ranged from (64.53±2.8)% to (68.10±3.6)%. CONCLUSIONS The small-molecule compound combination C6TSEDRVAJZ is capable of inducing HPFs into ciEP-Ls under hypoxic conditions with a high induction efficiency.
Humans ; Fibroblasts/drug effects* ; Pregnancy ; Female ; Cell Differentiation/drug effects* ; Pyrimidines/pharmacology* ; Placenta/cytology* ; Cells, Cultured ; Pyridines/pharmacology* ; Pyrazoles/pharmacology* ; Epithelial Cells/cytology*

OBJECTIVES: To evaluate the protective effect of Bufei Yishen Formula (BYF) against cigarette smoke extract (CSE)-induced injuries in human bronchial epithelial BEAS-2B cells and explore the underlying mechanism. METHODS: BEAS-2B cells exposed to CSE were treated with normal rat serum, BYF-medicated rat serum at low or high doses, pyrrolidine dithiocarbamate (PDTC, a NF-κB inhibitor), PDTC combined with high-dose BYF-medicated serum, or S-carbomethyloysteine (S-CMC, as the positive control). CCK-8 assay was used to determine the optimal concentration and treatment time of CSE, BYF-medicated serum and S-CMC. The treated cells were examined for inflammatory factor levels in the supernatant and cellular expressions of MUC5AC and MUC5B using ELISA, cell ultrastructural changes with transmission electron microscopy, and cell apoptosis rate using flow cytometry. The expression levels of TLR4/NF‑κB pathway-associated mRNAs and proteins were determined by qRT-PCR and Western blotting. RESULTS: CSE exposure significantly increased secretions of IL-1β, IL-6 and TNF-α, mRNA and protein expressions of MUC5AC and MUC5B, and early and total apoptosis rates in BEAS-2B cells, where the presence of apoptotic bodies was detected. CSE also significantly enhanced the mRNA and protein expressions of TLR4, I-κB, and NF-κB and reduced mRNA and protein expressions of AQP5. Treatments of the CSE-exposed cells with BYF-medicated serum, PDTC and S-CMC all significantly lowered inflammatory factor levels, MUC5AC and MUC5B expressions, and early and total cell apoptosis rates, and partly reversed the changes in cellular ultrastructure and mRNA and protein expressions of the TLR4/NF-κB pathway, and the effects were the most conspicuous following the combined treatment with high-dose BYF-medicated serum and PDTC. CONCLUSIONS BYF can inhibit cell apoptosis, inflammation and mucus hypersecretion in CSE-induced BEAS-2B cells by inhibiting the TLR4/NF-κB signaling pathway.
Humans ; Epithelial Cells/cytology* ; Drugs, Chinese Herbal/pharmacology* ; NF-kappa B/metabolism* ; Bronchi/cytology* ; Smoke/adverse effects* ; Apoptosis/drug effects* ; Mucin 5AC/metabolism* ; Cell Line ; Toll-Like Receptor 4/metabolism* ; Mucin-5B/metabolism* ; Signal Transduction/drug effects* ; Nicotiana ; Rats ; Thiocarbamates/pharmacology* ; Animals

Mechanical ventilation (MV) is currently widely used in the treatment of respiratory failure and anesthesia surgery, and is a commonly used respiratory support method for critically ill patients; however, improper usage of MV can lead to ventilator-induced lung injury (VILI), which poses a significant threat to patient life. Alveolar epithelial cell (AEC) has the functions of mechanosensation and mechanotransduction. Physiological mechanical stretching is beneficial for maintaining the lineage homeostasis and normal physiological functions of AEC cells, while excessive mechanical stretching can cause damage to AEC cells. Damage to AEC cells is an important aspect in the occurrence and development of VILI. Understanding the effects of mechanical stretching on AEC cells is crucial for developing safe and effective MV strategies, preventing the occurrence of VILI, and improving the clinical prognosis of VILI patients. From the perspective of cell mechanics, this paper aims to briefly elucidate the mechanical properties of AEC cells, mechanosensation and mechanotransduction of mechanical stretching in AEC cells, and the injury and repair of AEC cells under mechanical stretch stimulation, and potential mechanisms with the goal of helping clinical doctors better understand the pathophysiological mechanism of VILI caused by MV, improve their understanding of VILI, provide safer and more effective strategies for the use of clinical MV, and provide theoretical basis for the prevention and treatment of VILI.
Humans ; Mechanotransduction, Cellular ; Ventilator-Induced Lung Injury ; Stress, Mechanical ; Alveolar Epithelial Cells ; Respiration, Artificial/adverse effects* ; Epithelial Cells ; Pulmonary Alveoli/cytology* ; Animals

OBJECTIVE: To elucidate the role and mechanism of microRNA-145-5p (miR-145-5p) in hypoxia-induced pyroptosis of human alveolar epithelial cells. METHODS: In vitro, human alveolar epithelial cell line BEAS-2B was cultured. Cells in the logarithmic growth phase were cultured to 80% confluence and then used for the experiment. (1) BEAS-2B cells were cultured under 1% O₂ hypoxic condition, with a normoxic control group. Western blotting was employed to detect the expressions of pyroptosis marker proteins [NOD-like receptor protein 3 (NLRP3), Gasdermin D N-terminal domain (GSDMD-N), and caspase-1] in cells cultured for 24 hours. Real-time fluorescent quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression of miR-145-5p in cells cultured for 6 hours and 12 hours. (2) Cells were transfected with 30 nmol/L miR-145-5p mimic to overexpress miR-145-5p expression under normoxic condition or 30 nmol/L miR-145-5p inhibitor to suppress miR-145-5p expression under hypoxic condition. Control group and negative control group were respectively set up. After 24 hours of cell culture, Western blotting was used to detect the expressions of pyroptosis marker proteins and nuclear factor-E2-related factor 2 (Nrf2) in cells. Flow cytometry was applied to detect the level of reactive oxygen species (ROS) in cells. The target genes of miR-145-5p were predicted by miR target gene prediction software miRWalk and verified by Western blotting. (3) Under hypoxic condition, cells were transfected with 6.94 ng/μL silent information regulator 5 (Sirt5) overexpression plasmid or pretreated with 12.5 mmol/L N-acetyl-L-cysteine (NAC) as an ROS inhibitor. The empty plasmid group and control group were set up. After 24 hours of cell culture, Western blotting was used to detect the expressions of Sirt5, Nrf2, and pyroptosis marker proteins in cells. Flow cytometry was used to detect the level of ROS in cells. RESULTS: (1) Compared with the normoxic control group, the expression levels of pyroptosis marker proteins in the 24-hour hypoxia group was significantly increased, indicating that hypoxia could induce pyroptosis in BEAS-2B cells. The expression level of miR-145-5p in cells gradually increased with the extension of hypoxia induction time, indicating that hypoxia could cause the increase of miR-145-5p expression level. (2) The expression levels of pyroptosis marker proteins in cells of miR-145-5p mimic group significantly increased under normoxic condition as compared with the control and negative control groups [NLRP3 protein (NLRP3/β-actin): 1.58±0.07 vs. 1.00±0.01, 0.98±0.07, GSDMD-N protein (GSDMD-N/β-actin): 1.71±0.03 vs. 1.01±0.01, 0.85±0.03, caspase-1 protein (caspase-1/β-actin): 2.33±0.04 vs. 1.01±0.01, 1.05±0.04, all P < 0.05], Nrf2 protein expression level was significantly decreased (Nrf2/β-actin: 0.79±0.03 vs. 1.00±0.01, 1.03±0.04, both P < 0.05), ROS level was significantly up-regulated (fluorescence intensity: 1.74±0.03 vs. 1.00±0.01, 0.92±0.03, both P < 0.05). Under hypoxia condition, compared with control group and negative control group, the expression levels of pyroptosis marker proteins in miR-145-5p inhibitor group were significantly decreased [NLRP3 protein (NLRP3/β-actin): 0.21±0.04 vs. 1.70±0.02, 1.63±0.04; GSDMD-N protein (GSDMD-N/β-actin): 1.32±0.02 vs. 2.51±0.02, 2.72±0.03; caspase-1 protein (caspase-1/β-actin): 0.56±0.01 vs. 2.77±0.02, 3.12±0.03; all P < 0.05], Nrf2 protein expression level was significantly increased (Nrf2/β-actin: 1.57±0.04 vs. 1.22±0.01, 1.28±0.04, both P < 0.05), ROS level was significantly down-regulated (fluorescence intensity: 0.64±0.05 vs. 1.87±0.04, 1.70±0.07, both P < 0.05). The results indicated that miR-145-5p could promote cell pyrodeath. The predictive result of miRWalk showed that the 3' untranslated region (3'UTR) of Sirt5 had complementary base binding sites with miR-145-5p. The expression level of Sirt5 protein in cells of miR-145-5p mimic group was significantly lower than that of control group and negative control group under normoxic condition (Sirt5/β-actin: 0.59±0.03 vs. 1.00±0.01, 1.01±0.03, both P < 0.05), which verified that Sirt5 was the target gene of miR-145-5p. (3) The occurrence of pyrodeath could be partially reversed by transfection with Sirt5 overexpression plasmid or adding ROS inhibitor NAC into cells, and Sirt5 overexpression could also up-regulate Nrf2 expression and eliminate intracellular ROS. CONCLUSION In human alveolar epithelial cells, miR-145-5p can down-regulate Nrf2 by targeting Sirt5, thereby increasing ROS expression and inducing pyrodeath.
Humans ; MicroRNAs ; Pyroptosis ; Cell Hypoxia ; Alveolar Epithelial Cells/cytology* ; Cell Line ; NLR Family, Pyrin Domain-Containing 3 Protein ; Caspase 1/metabolism* ; Epithelial Cells/metabolism* ; Gasdermins ; Phosphate-Binding Proteins