LncRNA HSALR1 Is Involved In Regulating TGF-β1 Non-Classical Signaling Pathways In A Cell-Specific Manner

[Background]Lung remodeling is the main pathological feature of many chronic respiratory diseases.Lung tissue remodeling is the result of a variety of cell fate changes,and TGF-β cytokines have receptors in a variety of respiratory system related cells,it can regulate the fate of cells through classical signal transduction pathways and non-classical signal transduction pathways,so as to participate in the process of lung tissue remodeling.Our research group previously screened out a LncRNA strongly related to TGFβ and highly expressed in COPD,namely HSALR1.Our results suggest that HSALR1 promotes the proliferation of human bronchial fibroblasts dependent on the AKT pathway in the TGF-β1 nonclassical signal transduction pathway.In addition,HSALR1 binds directly to HSP90AB1,which regulates the stability of numerous kinases.Therefore,we still want to further understand whether TGF-β1-regulated HSALR1 is also involved in regulating its non-classical signal transduction pathways in other respiratory system-related cells,thereby affecting cell biological function.[Objective]The objective of this study was to investigate the role of LncRNA HSALR1 in regulating the activation of TGF-β1 non-classical signal transduction pathway in different cells.[Methods]1.The transcription level of HSALR1 in various respiratory system related cells after TGF-β1 stimulation was detected by RT-qPCR.2.WB was used to detect the phosphorylation levels of non-classical signal transduction pathway proteins(AKT,JNK,ERK1/2,P38)in various respiratory system related cells after TGF-β1 stimulation.3.HSALR1 was overexpressed and knocked down in cell models,and WB was used to detect whether HSALR1 was involved in the activation of TGF-β1 non-classical signal transduction pathway proteins(AKT,JNK,ERK1/2,P38).4.Explore the mechanism of HSALR1’s involvement in AKT activation in HBF cells with high expression of HSALR1:(1)Based on the previous findings that HSALR1 directly binds to HSP90AB1,the regulatory effect of HSALR1 on HSP90AB1 was explored by transfection and addition of CHX protein synthesis inhibitors.(2)The effects of HSALR1 on the binding activity of HSP90AB1 and p-AKT were investigated by co-ip and WB methods.5.Explore which cells have the binding of HSALR1 and HSP90AB1 by RIP experiment.[Results]1.The expression of HSALR1 is cell-specific,and HSALR1 is highly expressed in a variety of cancer epithelial cells.2.TGF-β1 regulates the function of different cells by activating different types of non-classical signal transduction pathways.3.High expression of HSALR1 can enhance the phosphorylation activity of TGF-β1 non-classical signal transduction pathway protein:(1)HSALR1 is involved in the activation of JNK,ERK1/2 and P38 pathway proteins in the cell model in which TGF-β1 can up-regulate HSALR1.(2)Overexpression of HSALR1 promoted the activation of ERK1/2 and P38 in cell models in which TGF-β1 did not upregulate HSALR1.4.In HBF cells with high HSALR1 expression,HSALR1 is involved in the activation of AKT pathway by stabilizing HSP90AB1 activity:(1)HSALR1 acted by enhancing the stability of HSP90AB1,but did not promote the increase of HSP90AB1 expression.(2)HSALR1 can enhance the binding of HSP90AB1 to p-AKT.5.The binding of HSALR1 and HSP90AB1 was cell-specific,and the binding of HSALR1 and HSP90AB1 was not found in all the cells in which TGF-β1 promoted the up-regulation of HSALR1 expression.[Experimental Conclusion]At the transcriptional level,TGF-β1 regulates cell-specific expression of HSALR1,and HSALR1 transcription is enhanced in a variety of carcinoma epithelial cells.At the post-transcriptional level,HSALR1 is involved in the regulation of different TGF-β1 non-classical signal transduction pathways by regulating the binding activity of HSP90AB1 to kinases.