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Huang Y, Xie Y, Abel PW, Wei P, Plowman J, Toews ML, Strah H, Siddique A, Bailey KL, Tu Y. TGF-β1-induced miR-424 promotes pulmonary myofibroblast differentiation by targeting Slit2 protein expression. Biochem Pharmacol 2020; 180:114172. [PMID: 32712053 PMCID: PMC8742596 DOI: 10.1016/j.bcp.2020.114172] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 01/09/2023]
Abstract
Idiopathic pulmonary fibrosis (IPF) is a devastating interstitial lung disease with irreversible loss of lung tissue and function. Myofibroblasts in the lung are key cellular mediators of IPF progression. Transforming growth factor (TGF)-β1, a major profibrogenic cytokine, induces pulmonary myofibroblast differentiation, and emerging evidence has established the importance of microRNAs (miRs) in the development of IPF. The objective of this study was to define the pro-fibrotic roles and mechanisms of miRs in TGF-β1-induced pulmonary myofibroblast differentiation. Using RNA sequencing, we identified miR-424 as an important TGF-β1-induced miR in human lung fibroblasts (HLFs). Quantitative RT-PCR confirmed that miR-424 expression was increased by 2.6-fold in HLFs in response to TGF-β1 and was 1.7-fold higher in human fibrotic lung tissues as compared to non-fibrotic lung tissues. TGF-β1-induced upregulation of miR-424 was blocked by the Smad3 inhibitor SIS3, suggesting the involvement of this canonical TGF-β1 signaling pathway. Transfection of a miR-424 hairpin inhibitor into HLFs reduced TGF-β1-induced expression of classic myofibroblast differentiation markers including ɑ-smooth muscle actin (ɑ-SMA) and connective tissue growth factor (CTGF), whereas a miR-424 mimic significantly enhanced TGF-β1-induced myofibroblast differentiation. In addition, TGF-β1 induced Smad3 phosphorylation in HLFs, and this response was reduced by the miR-424 inhibitor. In silico analysis identified Slit2, a protein that inhibits TGF-β1 profibrogenic signaling, as a putative target of regulation by miR-424. Slit2 is less highly expressed in human fibrotic lung tissues than in non-fibrotic lung tissues, and knockdown of Slit2 by its siRNA enhanced TGF-β1-induced HLF differentiation. Overexpression of a miR-424 mimic down-regulated expression of Slit2 but not the Slit2 major receptor ROBO1 in HLFs. Luciferase reporter assays showed that the miR-424 mimic represses Slit2 3' untranslated region (3'-UTR) reporter activity, and mutations at the seeding regions in the 3'-UTR of Slit2 abolish this inhibition. Together, these data demonstrate a pro-fibrotic role of miR-424 in TGF-β1-induced HLF differentiation. It functions as a positive feed-back regulator of the TGF-β1 signaling pathway by reducing expression of the negative regulator Slit2. Thus, targeting miR-424 may provide a new therapeutic strategy to prevent myofibroblast differentiation and IPF progression.
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Affiliation(s)
- Yapei Huang
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Yan Xie
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Peter W Abel
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Peng Wei
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Jocelyn Plowman
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Myron L Toews
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Heather Strah
- Department of Internal Medicine, Pulmonary Critical Care, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Aleem Siddique
- Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Kristina L Bailey
- Department of Internal Medicine, Pulmonary Critical Care, University of Nebraska Medical Center, Omaha, NE 68198, USA; VA Nebraska-Western Iowa Health Care Center, Omaha, NE 68105, USA.
| | - Yaping Tu
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA.
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Feng H, Jin Z, Liu K, Peng Y, Jiang S, Wang C, Hu J, Shen X, Qiu W, Cheng X, Zhao R. Identification and validation of critical alternative splicing events and splicing factors in gastric cancer progression. J Cell Mol Med 2020; 24:12667-12680. [PMID: 32939931 PMCID: PMC7686978 DOI: 10.1111/jcmm.15835] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 08/12/2020] [Accepted: 08/17/2020] [Indexed: 12/13/2022] Open
Abstract
Gene expression and alternative splicing (AS) interact in complex ways to regulate biological process which is associated with cancer development. Here, by integrated analysis of gene expression and AS events, we aimed to identify the hub AS events and splicing factors relevant in gastric cancer development (GC). RNA‐seq data, clinical data and AS events of 348 GC samples were obtained from the TCGA and TCGASpliceSeq databases. Cox univariable and multivariable analyses, KEGG and GO pathway analyses were performed to identify hub AS events and splicing factor/spliceosome genes, which were further validated in 53 GCs. By bioinformatics methods, we found that gene AS event‐ and gene expression‐mediated GC progression shared the same mechanisms, such as PI3K/AKT pathway, but the involved genes were different. Though expression of 17 hub AS events were confirmed in 53 GC tissues, only 10 AS events in seven genes were identified as critical candidates related to GC progression, notably the AS events (Exon Skip) in CLSTN1 and SEC16A. Expression of these AS events in GC correlated with activation of the PI3K/AKT pathway. Genes with AS events associated with clinical parameters and prognosis were different from the genes whose mRNA levels were related to clinical parameters and prognosis. Besides, we further revealed that QKI and NOVA1 were the crucial splicing factors regulating expression of AS events in GC, but not spliceosome genes. Our integrated analysis revealed hub AS events in GC development, which might be the potential therapeutic targets for GC.
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Affiliation(s)
- Haoran Feng
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of General Surgery, Ruijin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhijian Jin
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Kun Liu
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of General Surgery, Ruijin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi Peng
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of General Surgery, Ruijin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Songyao Jiang
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of General Surgery, Ruijin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Changgang Wang
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of General Surgery, Ruijin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jiele Hu
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of General Surgery, Ruijin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoyun Shen
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of General Surgery, Ruijin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weihua Qiu
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xi Cheng
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ren Zhao
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of General Surgery, Ruijin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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