Lijuan Zhang1, Xiaowen Chi2, Wen Luo1, Shihuan Yu1, Jiawen Zhang1, Yuening Guo1, Qiu Ren3, Wei Zhang4. 1. Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, 150001, China. 2. Pediatrics, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, 150036, China. 3. Department of Respiratory, Heilongjiang Province Hospital, Harbin, Heilongjiang, 150001, China. 4. Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, 150001, China. Electronic address: weizh52121@163.com.
Abstract
BACKGROUND AND PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a life-threatening progressive disease characterized by aberrant fibroblast activation. This study aims to explore the role of the circ0044226 on fibroblast-to-myofibroblast transition (FMT). METHODS: Bleomycin and TGF-β1 were respectively used to induce the IPF mice model and human lung fibroblasts to myofibroblast differentiation. The mRNA and protein levels were examined by qRT-PCR and western blot. Localization of α-SMA was evaluated by immunofluorescence staining. Cell viability and proliferation were evaluated by CCK8 and EDU test. Dual-luciferase reporter assay was used to analyze the interaction between miR-7 and circ0044226 or sp1. Fluorescence in situ hybridization (FISH) assay was used for the identification of sub-location of circ0044226 and miR-7 in cells. The IPF model mice received intratracheal injection of AAV-sh-NC and AAV-sh- circ0044226, and lung fibrosis was detected by HE staining, Masson staining and immunohistochemistry assay. RESULTS: The circ0044226 was upregulated while miR-7 was downregulated in IPF mice model and FMT-derived myofibroblasts. miR-7 was a target of circ0044226 and sp1 was a target of miR-7. circ0044226 was distributed mostly in the cytoplasm and functioned as a miR-7 sponge to positively regulate the expression of sp1. Intervention of circ0044226 could ameliorate FMT and suppress fibroblast viability and proliferation by functioning as an endogenous miR-7 sponge. CONCLUSION: Circ0044226 knockdown alleviates fibroblast proliferation and FMT by functioning as a competing endogenous RNA, which may represent a promising therapy for pulmonary fibrosis.
BACKGROUND AND PURPOSE:Idiopathic pulmonary fibrosis (IPF) is a life-threatening progressive disease characterized by aberrant fibroblast activation. This study aims to explore the role of the circ0044226 on fibroblast-to-myofibroblast transition (FMT). METHODS:Bleomycin and TGF-β1 were respectively used to induce the IPFmice model and human lung fibroblasts to myofibroblast differentiation. The mRNA and protein levels were examined by qRT-PCR and western blot. Localization of α-SMA was evaluated by immunofluorescence staining. Cell viability and proliferation were evaluated by CCK8 and EDU test. Dual-luciferase reporter assay was used to analyze the interaction between miR-7 and circ0044226 or sp1. Fluorescence in situ hybridization (FISH) assay was used for the identification of sub-location of circ0044226 and miR-7 in cells. The IPF model mice received intratracheal injection of AAV-sh-NC and AAV-sh- circ0044226, and lung fibrosis was detected by HE staining, Masson staining and immunohistochemistry assay. RESULTS: The circ0044226 was upregulated while miR-7 was downregulated in IPFmice model and FMT-derived myofibroblasts. miR-7 was a target of circ0044226 and sp1 was a target of miR-7. circ0044226 was distributed mostly in the cytoplasm and functioned as a miR-7 sponge to positively regulate the expression of sp1. Intervention of circ0044226 could ameliorate FMT and suppress fibroblast viability and proliferation by functioning as an endogenous miR-7 sponge. CONCLUSION: Circ0044226 knockdown alleviates fibroblast proliferation and FMT by functioning as a competing endogenous RNA, which may represent a promising therapy for pulmonary fibrosis.