Kobe Pharmaceutical University

The Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway is a central regulator of cellular defense mechanisms against oxidative stress. The pharmacological activation of this pathway has emerged as a promising strategy for the treatment of diseases such as neurodegeneration and inflammation. In this study, we performed a high-throughput luciferase reporter assay to screen the original compound library comprising small molecules synthesized at Kobe Pharmaceutical University. Initial screening identified KU-0016, KU-0017, and KU-0171 as moderate activators of the Nrf2 pathway. Furthermore, structural comparison revealed a common α,β-unsaturated imide motif, which led to the synthesis of KU-0017-based analogs for structure-activity relationship analysis. Among them, KU-0479 exhibited potent Nrf2 activation and low cytotoxicity. Further assays demonstrated that KU-0479 increased the intracellular glutathione (GSH) levels and protected cells from hydrogen peroxide-induced oxidative damage in a GSH-dependent manner. Moreover, LC-MS analysis confirmed the formation of mono-GSH adducts, and covalent docking simulations suggested covalent binding at the Cys151 residue of Keap1. These findings highlight KU-0479 as a synthetically accessible covalent Nrf2 activator with favorable redox-modulating properties and therapeutic potential.

Hepatitis B virus (HBV) infection is a major global health burden worldwide despite the availability of an effective vaccine and effective anti-HBV drugs. The currently approved anti-HBV drugs-i.e., nucleos(t)ide analogues and pegylated interferon α-can effectively suppress HBV replication, but rarely achieve a functional cure. Accordingly, new anti-HBV agents targeting different aspects of the HBV life cycle are needed. In this study, we screened for anti-HBV agents using the recombinant HBV expressing NanoLuc (NL) reporter gene (HBV/NL) and our original synthetic heterocyclic compound library. As a result, we identified a synthetic bile acid derivative, SO-145, as a potential novel anti-HBV agent, and investigated its effects in several cellular models of HBV. Treatment of HepG2-NTCP-C4 cells with SO-145 suppressed their NL activity following infection with HBV/NL. SO-145 suppressed HBV replication in PXB-cells infected with HBV genotype D, but did not show any inhibitory effect on HBV replication in Hep38.7-Tet cells. These results suggest that SO-145 specifically inhibits the early phase of the HBV life cycle. In other experiments, SO-145 was also shown to inhibit hepatitis D virus infection. Immunofluorescence analysis using fluorescent-labeled preS1 peptide revealed that SO-145 does not inhibit the preS1 attachment to the NTCP, but does markedly inhibit the HBV/preS1 internalization. Moreover, SO-145 does not inhibit the bile acid uptake facilitated by NTCP. Further mechanistic analysis suggested that SO-145 interferes with the NTCP oligomerization. Taken together, these results suggest that SO-145 inhibits HBV entry into hepatocytes by interfering with the NTCP oligomerization.

The aim of this study was to clarify the association between serum total cholesterol and fatal subarachnoid hemorrhage in Japanese men and women.

The study involved a pooled analysis of individual data from 12 well-qualified cohort studies conducted in Japan. The participants were classified according to their serum total cholesterol levels: ＜4.14 mmol/L (＜160 mg/dL), 4.14-4.64 mmol/L (160-180 mg/dL), 4.65-5.16 mmol/L (180-199 mg/dL), 5.17-5.68 mmol/L (200-219 mg/dL), 5.69-6.20 mmol/L (220-239 mg/dL), and ≥ 6.21 mmol/L (≥ 240 mg/dL). The outcome of the analysis was death from subarachnoid hemorrhage.

A total of 120,973 participants (70,947 women and 50,026 men) aged 18-96 years at baseline underwent follow-up for a median of 12.7 years, and 261 participants died from subarachnoid hemorrhage during this period. In women, both low (＜5.69 mmol/L [＜220 mg/dL]) and high (≥ 6.21 mmol/L [≥ 240 mg/dL]) serum total cholesterol levels were significantly associated with a higher risk of fatal subarachnoid hemorrhage compared with the reference group (5.69-6.20 mmol/L [220-239 mg/dL]). These associations remained significant after adjustment for confounding factors. In contrast, no associations were observed in men.

Both low and high serum total cholesterol levels were associated with a higher risk of fatal subarachnoid hemorrhage in 70,947 female participants from 12 cohort studies throughout Japan.