基于转录组学探究脂质运载蛋白-2调控矽肺炎症的作用机制OA

[Background]Lung tissue fibrosis caused by exposure to free silica(SiO2)dust is the core patho-logical feature of silicosis.Lipocalin-2(LCN2),as a secreted glycoprotein,plays an important role in various inflammatory diseases,but its specific role in silicosis-induced inflammatory injury re-mains unclear. [Objective]To identify differentially expressed genes(DEGs)and enriched pathways in the lung tissues of rats with silicosis,and to explore the regulatory mechanism of LCN2 in silicosis inflam-mation. [Methods]Twenty specific pathogen-free male SD rats were randomly divided into a control group and a silicosis model group(n=10 per group).The silicosis model was established via a single intratracheal instillation of silicon dioxide(SiO2)suspension(50 mg),while the control group received an equal volume of normal saline.In vitro,NR8383 cells were divided into a control group and a SiO2 treatment group.Hematoxylin-eosin(HE)staining and Van Gieson(VG)staining were used to evaluate alveolar structure damage,inflammatory in-filtration,and collagen deposition in the lung tissues.Transcriptomic sequencing was applied to screen for DEGs and enriched signaling pathways.Western blot was used to detect the protein expression of interleukin-6(IL-6),E-cadherin(ECA),cluster of differentiation 36(CD36),liver X receptor(LXR),ATP-binding cassette transporter A1(ABCA1),and LCN2 in both rat lung tissues and NR8383 cells.Immuno-histochemistry was used to further assess LCN2 expression and localization.Additionally,NR8383 cells were treated with the LCN2 inhibitor ZINC00640089 and assigned to four groups:control,ZINC00640089-only,SiO2,and SiO2+ZINC00640089.Western blot was used to evaluate the expression of LCN2,IL-6,and interleukin-1β(IL-1β). [Results]HE and VG staining revealed disorganized lung tissue structure,damaged alveolar walls,nodule formation,and increased collagen deposition in the silicosis model group compared to the controls.Transcriptomic analysis identified 2 723 DEGs in the lung tissues of silicosis rats(312 down-regulated and 2 411 up-regulated)with LCN2 expression being significantly up-regulated.These DEGs were primarily en-riched in pathways related to the innate immune response,extracellular matrix(ECM)-receptor interaction,and inflammatory response.Immunohistochemical staining confirmed elevated LCN2 levels in the lung tissues of the model rats.Western blot demonstrated that the protein levels of IL-6,CD36,and LCN2 were significantly increased(P<0.05),whereas ABCA1 and ECA were significantly decreased in the silicosis group(P<0.05).Similarly,in SiO2-treated NR8383 cells,IL-6,CD36,and LCN2 expressions significantly increased(P<0.05),while ABCA1 and LXR significantly decreased(P<0.05).Compared with the SiO2 group,treatment with ZINC00640089 significantly reduced the expression levels of LCN2,IL-6,and IL-1β(P<0.05). [Conclusion]LCN2 is significantly upregulated in both the lung tissues of silicosis rats and SiO2-treated NR8383 cells.Inhibiting LCN2 ex-pression effectively reduces the SiO2-induced inflammatory response,indicating that LCN2 serves as a potential therapeutic target for sil-icosis.