NOTCH4 is a new player in the development of pulmonary fibrosis
image: contr – untransduced fibroblasts; pCIG – control vector transduced fibroblasts; N4ICD – N4ICD-transduced fibroblasts. (a) Expression efficiency of N4ICD transduction was evaluated by RT-PCR analysis with primers for N4ICD. *** p < 0.001. (b) Morphological changes in N4ICD-transduced cells compared to control ones. (c) RT-PCR results for SNAI1, SNAI2, ACTA2, and COL1A1 in control, pCIG- and N4ICD-transduced cells. *** p < 0.001; ** p < 0.01. (d) and (e). Immunofluorescence labeling analysis of control, pCIG- and N4ICD-transduced cells. Nuclei were stained with DAPI (blue). (d) Immunofluorescence staining with SNAI1 antibodies (green). (e) Immunofluorescence staining with ACTA2 antibodies (red). DAPI, 4′,6-diamidino-2-phenylindole; mRNA, messenger RNA; N4ICD, NOTCH4 intracellular domain; RT-PCR, real-time polymerase chain reaction.
Credit: Nadezhda Bakalenko
Background and objectives
Idiopathic pulmonary fibrosis is a chronic, progressive, incurable lung disease, leading to irreversible lung tissue remodeling. The Notch signaling pathway, essential for lung development, has gained attention for its role in pulmonary fibrosis. While Notch1 and Notch3 have been extensively studied, the involvement of other Notch receptors, especially Notch4, remains less explored. This study aimed to evaluate the impact of Notch4 on lung fibroblast activation and its potential interaction with the transforming growth factor-beta 1 (TGFβ1) signaling.
Methods
Primary human lung fibroblasts were transduced with lentivirus containing the intracellular domain of NOTCH4 (N4ICD). Changes in gene expression in transduced cells were assessed using real-time polymerase chain reaction, immunofluorescence staining, and Western blotting. Transcriptomic analysis was also performed on N4ICD-transduced lung fibroblasts.
Results
N4ICD overexpression significantly upregulated key fibrotic markers such as ACTA2 and COL1A1. It also induced the TGFβ1 pathway, as evidenced by SMAD2 phosphorylation and elevated TGFβ1 mRNA level. Transcriptomic analysis revealed that N4ICD-induced cells exhibited characteristics of highly invasive myofibroblasts.
Conclusions
This study establishes Notch4 as a novel contributor to pulmonary fibrosis, by demonstrating its ability to induce myofibroblast differentiation and interact with the TGFβ1 pathway.
Full text
https://www.xiahepublishing.com/1555-3884/GE-2024-00006
The study was recently published in the Gene Expression.
Gene Expression (GE) is an open-access journal. It was launched in 1991 by Chicago Medical School Press, and transferred to Cognizant Communication Corporation in 1994. From August 2022, GE is published by Xia & He Publishing Inc.
GE publishes peer-reviewed and high-quality original articles, reviews, editorials, commentaries, and opinions on its primary research topics including cell biology, molecular biology, genes, and genetics, especially on the cellular and molecular mechanisms of human diseases.
GE has been indexed in Medline (1991-2021), Scopus, Biological Abstracts, Biosis Previews, ProQuest, etc.
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