10-b

Pulmonary fibrosis is a progressive interstitial lung disease characterized by excessive extracellular matrix (ECM) deposition, resulting in impaired respiratory function. Due to the limited efficacy of current antifibrotic therapies, there is an urgent need to develop novel agents or optimize existing drugs. In this study, a series of pirfenidone (PFD) derivatives were rationally designed and synthesized with targeted modifications at the third position of the core scaffold to enhance antifibrotic efficacy. A total of 30 derivatives (100 μM) were screened using a TGF-β-induced differentiation model, leading to the identification of hit compounds with superior activity compared to PFD (500 μM). Selected candidates were further validated both in vitro (LL29 and DHLF cells) and in the bleomycin (BLMN)-induced pulmonary fibrosis mouse model. In vitro, compounds 6a and 10b (50 and 100 μM) demonstrated robust suppression of fibrotic markers, as confirmed by RT-qPCR and immunofluorescence, indicating a dose-dependent antifibrotic effect. In vivo, BLMN administration significantly increased the lung index and fibrotic marker expression. In contrast, compounds 6a and 10b significantly downregulated the expression of fibrotic markers (including FN1, α-SMA, and collagen1α1). Histopathological analysis revealed that compound 10b effectively mitigated BLMN-induced alveolar wall thickening and collagen deposition, and significantly restored lung function in a dose-dependent manner, outperforming the PFD group. Mechanistic studies further indicated that 10b exerts its effects through modulation of the SMAD3/SMAD7 signaling pathway. Additionally, compound 10b exhibited a pharmacokinetic profile comparable to PFD. Collectively, these findings support compound 10b as a promising antifibrotic candidate with strong potential for clinical translation.

Acetaminophen (N-acetyl-p-aminophenol, APAP), is the most frequent cause of drug-induced liver injury. Reducing APAP-induced oxidative stress is an effective strategy to improve acute liver injury. Glycogen synthase kinase-3β (GSK3β), is sensitive to redox homeostasis and is involved in oxidative stress-related injuries. However, whether GSK3β influences APAP-induced acute liver injury by modulating oxidative stress remains incompletely elucidated. To address this issue, we developed a novel GSK3β inhibitor 10b and conducted a series of studies to elucidate the role and specific mechanism of GSK3β in APAP-induced liver injury. The GSK3β inhibitor 10b suppressed the reduction of inhibitory phosphorylation levels of GSK3β, stabilized the protein level of PGC1α, protected mitochondrial function in hepatocytes, alleviated oxidative stress, and improved acute liver injury induced by APAP. Importantly, GSK3β siRNA clearly reversed the protection of 10b on APAP-stimulated AML12 cells. In conclusion, the GSK3β inhibitor 10b attenuate APAP-induced liver injury by regulating PGC1α-mediated oxidative stress.