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miR-484: A Possible Indicator of Drug-Induced Pulmonary Fibrosis
Takashi Konaka1, Masashi Kawami2, Ayano Yamamoto1
1Graduate School of Biomedical and Health Sciences, Hiroshima University.
Background:
Drug-induced lung injury leads to serious lung diseases, such as pulmonary fibrosis. We demonstrated in an alveolar epithelial cell line A549/ABCA3 that certain microRNAs were associated with bleomycin induced epithelial-mesenchymal transition (EMT) which is closely related to pulmonary fibrosis. In this study, we focused on the role of miR-484 in drug-induced EMT using A549/ABCA3 cells and a mouse lung injury model.
Methods:
The expression of EMT-related genes and miR-484 was detected by real-time polymerase chain reaction. miR-484-targeted proteins were analyzed by Western blot. Pulmonary fibrosis mouse model was prepared by the intratracheal administration of BLM. As miR-484 is known to target SMAD2 and zinc finger E-box binding homeobox 1 (ZEB1), which are the well-known EMT-related transcription factors, we assessed the effects of a miR-484 inhibitor or mimic on the mRNA/protein expression of both the factors.
Results:
We found that bleomycin significantly suppressed the intracellular expression and extracellular release of miR-484 in A549/ABCA3 cells. Moreover, the miR-484 mimic and inhibitor showed no drastic effects on the expression of the EMT-related transcription factors. In addition, the miR-484 mimic had no effect on the bleomycin-induced altered mRNA expression of the α-smooth muscle actin, a representative EMT marker. This suggested that miR-484 did not directly contribute to bleomycin-induced EMT in A549/ABCA3 cells. In contrast, the significant decrease in miR-484 expression in the lung tissue or plasma of bleomycin-administered mice suggested that miR-484 expression was closely correlated with bleomycin-induced lung injury.
Conclusions:
These findings indicate that miR-484 could be a novel diagnostic indicator for drug-induced pulmonary fibrosis.
Insights
MicroRNA-484 (miR-484) expression decreases in bleomycin-induced lung injury. Despite this, miR-484 does not directly drive epithelial-mesenchymal transition (EMT), suggesting it may serve as a diagnostic marker for drug-induced pulmonary fibrosis.
Area of Science:
- Cell Biology
- Molecular Biology
- Pulmonary Medicine
Background:
- Drug-induced lung injury can cause serious conditions like pulmonary fibrosis.
- Epithelial-mesenchymal transition (EMT) is closely linked to pulmonary fibrosis.
- MicroRNAs (miRNAs) play a role in bleomycin-induced EMT.
Purpose of the Study:
- To investigate the role of miR-484 in drug-induced EMT.
- To determine if miR-484 is a potential biomarker for drug-induced lung injury.
Main Methods:
- Real-time PCR and Western blot were used to detect EMT-related genes and miR-484.
- A mouse model of pulmonary fibrosis was established using bleomycin.
- The effects of miR-484 mimic/inhibitor on EMT factors (SMAD2, ZEB1) were assessed.
Main Results:
- Bleomycin suppressed intracellular and extracellular miR-484 expression in A549/ABCA3 cells.
- miR-484 mimic/inhibitor did not significantly alter EMT transcription factors or EMT markers.
- Decreased miR-484 in mouse lung tissue and plasma correlated with bleomycin-induced lung injury.
Conclusions:
- miR-484 does not appear to directly mediate bleomycin-induced EMT in alveolar epithelial cells.
- Reduced miR-484 levels in lung tissue and plasma are associated with bleomycin-induced lung injury.
- miR-484 shows potential as a novel diagnostic indicator for drug-induced pulmonary fibrosis.
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