Ltbp2 is a potential biomarker reflecting the fibrotic progression

SESSION TITLE: Diffuse Lung Disease Posters 5 SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/11/2023 12:00 pm - 12:45 pm PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a highly fatal lung disease of unknown cause with a median survival time of only 3-5 years. Current evidence manifests differentiation of lung fibroblasts into αSMA-positive myofibroblasts is important in the progress of IPF. However, few biomarkers reflecting the fibrotic process have been identified. In this study, we aim to explore whether LTBP2 is a new potential biomarker for predicting the progression and diagnosis of IPF, and which cell population may be the main cells for LTBP2 highly expressed to promote the progression of IPF disease. METHODS: The microarray data of GSE17978 and GSE53845 datasets were downloaded from the GEO database to analyze differentially expressed genes. Single-cell transcriptomic data of IPF patients and healthy donors were selected from GSE122960. IPF and healthy donor lung tissue samples were acquired from the First Affiliated Hospital of Zhengzhou University. This study was approved by Ethical Committee for Scientific Research and Clinical Trials of the First Affiliated Hospital of Zhengzhou University. The isolated lung tissue was placed in 10% formalin within half an hour and subsequently embedded in paraffin. Paraffin sections were used for HE and Masson staining to find fibroblast foci. Immunohistochemical techniques were used to detect the expression of LTBP2 in fibroblasts/myofibroblasts in the fibroblast foci of IPF lung tissues. Starving MRC-5 cells and CCC-HPF-1 cells in DMEM medium without fetal bovine serum for 12 hours, respectively, and then adding TGF-β1 at a concentration of 10 ng/ml. After 48 hours of stimulation, a fibrotic phenotype of fibroblasts was constructed. RESULTS: Utilizing GSE17978 and GSE53845 data, we found that the mRNA level of LTBP2 in IPF lung tissue was significantly higher than that in healthy lung tissue. In GSE122920 data, 14 major cell populations were clustered and identified based on screening out the expression of canonical cell markers. LTBP2 was strongly expressed in the fibroblast population. Additionally, LTBP2 was highly expressed in fibroblasts from IPF while fibroblasts from healthy donors rarely expressed LTBP2. Next, immunohistochemical analysis showed that LTBP2 was extensively positive in IPF lung tissue, and LTBP2 was strongly positive in fibroblasts/myofibroblasts in the fibroblast foci. Using serum-free DMEM containing 10 ng/ml of TGF-β1 to culture MRC-5 and CCC-HPF-1 cells respectively, the mRNA level of LTBP2 increased in a time-dependent manner, reaching the peak at 48 hours. CONCLUSIONS: In conclusion, we developed a validated and reproducible IRG-based prognostic signature that should be helpful for the personalized management of patients with IPF. CLINICAL IMPLICATIONS: Providing a new direction for targeted treatment of IPF. DISCLOSURES: No relevant relationships by Shanshan Chen No relevant relationships by Zemin Fang No relevant relationships by Liang Guo No relevant relationships by Chun Huang No relevant relationships by Hongxia Jia No relevant relationships by Hui Li No relevant relationships by Chunya Lu No relevant relationships by Lingxiao Qiu No relevant relationships by Wenjuan Wu No relevant relationships by Zhi Xu No relevant relationships by Xinye Zhang No relevant relationships by Guojun Zhang No relevant relationships by Huasi Zhao