TY  - EJOU
AU  - Qiu, Huiping 
AU  - Huang, Shaofang 
AU  - Xiong, Xin 
AU  - Zhang, Li 

TI  - Taraxasterol Ameliorates Pulmonary Fibrosis by Regulating PPP2R1B Expression
T2  - BIOCELL

PY  - 2025
VL  - 49
IS  - 12
SN  - 1667-5746

AB  -  <b>Background:</b> Pulmonary fibrosis is an irreversible lung disorder that currently has a limited number of effective therapeutic strategies. Taraxasterol (TAR), a bioactive triterpenoid isolated from plants used in traditional Chinese medicine (TCM), possesses anti-inflammatory and antioxidant activities. However, its precise role in pulmonary fibrosis remains incompletely defined. This study aimed to elucidate whether TAR alleviates pulmonary fibrosis by modulating Protein Phosphatase 2 Scaffold Subunit Abeta (PPP2R1B) expression. <b>Methods:</b> A bleomycin-induced murine model of pulmonary fibrosis and a transforming growth factor-β1 (TGF-β1) stimulated mouse lung fibroblast cell line (MLg) were established. To evaluate the effects of TAR on PPP2R1B expression and markers associated with fibrosis, histopathological staining, quantitative real-time PCR, Western blotting, and immunofluorescence were utilized. Additionally, si-PPP2R1B was used to validate its role in TAR-mediated anti-fibrotic effects. <b>Results:</b> 5 μg/mL TAR significantly suppressed 5 ng/mL TGF-β1-induced fibroblast activation, migration, and collagen deposition by downregulating PPP2R1B expression (<i>p</i> &lt; 0.05). <i>In vivo</i> experiments demonstrated that 10 mg/kg TAR treatment improved alveolar structural integrity, reduced collagen accumulation, and suppressed the secretion of inflammatory cytokines (including TGF-β1, CTGF, TNF-α, and IL-1β) (<i>p</i> &lt; 0.05). The concurrent improvement in these key histological and biochemical markers of pulmonary fibrosis indicates that TAR holds strong therapeutic potential for enhancing lung function. Furthermore, si-PPP2R1B confirmed the pivotal role of PPP2R1B in TAR anti-fibrotic action (<i>p</i> &lt; 0.05). <b>Conclusion:</b> TAR ameliorates pulmonary fibrosis by downregulating PPP2R1B expression, which consequently attenuates TGF-β1-stimulated fibroblast activation, migration, and collagen deposition <i>in vitro</i>, and reduces collagen accumulation and inflammatory cytokine release in bleomycin-induced murine model of pulmonary fibrosis <i>in vivo</i>.
KW  - Taraxasterol (TAR); PPP2R1B; pulmonary fibrosis; transforming growth factor-β1 (TGF-β1)

DO  - 10.32604/biocell.2025.070402