Acta Pharmaceutica Sinica B

Photodynamic enhancement of PROTAC prodrug activation in hypoxic tumors

Acta Pharmaceutica Sinica B. 2025, 15(9): 4945-4960.

Proteolysis-targeting chimeras (PROTACs) have emerged as a promising therapeutic strategy for targeted protein degradation. However, the clinical application of PROTACs may be hindered by off-target toxicity resulting from non-tissue-specific protein degradation and ingenious prodrug strategies may open new avenues to addressing this concern. Herein, we propose a light-induced positive feedback strategy to use photodynamic therapy (PDT) to improve the activation efficiency of PROTAC prodrugs, monitor PROTAC release, and combine PROTAC to induce tumor cell apoptosis. In the hypoxic tumor microenvironment, the azo bond in AZO-PRO selectively cleaves, triggering the release of the potent protein degrader PRO and the multifunctional photosensitizer. Once activated, the fluoresce signal of the photosensitizer dramatically recovers, allowing monitoring of prodrug activation. Additionally, upon irradicating the tumor site using near-infrared (NIR) laser, PDT exacerbates tumor hypoxia, further promoting AZO-PRO activation. Our work introduces a novel approach to efficiently track and activate PROTAC prodrugs, enhance their antitumor efficacy, and mitigate off-target systemic toxicity.

Chemical and genetic molecular glues to degrade CoREST corepressors

Acta Pharmaceutica Sinica B. 2025, 15(9): 4964-4966.

From synaptic gatekeepers to affective-cognitive modulators: The astrocyte D1 receptor-d-serine axis in the prefrontal cortex

Li-Pao Fang, Frank Kirchhoff

Acta Pharmaceutica Sinica B. 2025, 15(9): 4967-4969.

Deubiquitinase OTUD6A alleviates acetaminophen-induced liver injury by targeting EZH2 to reduce cell death in hepatocytes

Acta Pharmaceutica Sinica B. 2025, 15(9): 4772-4788.

Acetaminophen (APAP) is the primary cause of drug-induced acute liver failure. Ovarian tumor deubiquitinase 6A (OTUD6A), a recently discovered deubiquitinase of the OTU family, has been primarily studied in tumor contexts. However, its role in APAP-induced liver injury (AILI) remains unclear. Therefore, this study aimed to investigate the involvement of OTUD6A in the pathogenesis of AILI. Our findings demonstrated a substantial upregulation of OTUD6A in both the liver tissue and isolated hepatocytes of mice following APAP stimulation. OTUD6A knockout exacerbated APAP-induced inflammation, hepatocyte necrosis, and liver injury, whereas OTUD6A overexpression alleviated these pathologies. Mechanistically, OTUD6A directly interacted with the enhancer of zeste homolog 2 (EZH2) and selectively removed K48-linked polyubiquitin chains from EZH2, enhancing its stability. This resulted in increased protein levels of EZH2 and H3K27me3, as well as reduced endoplasmic reticulum (ER) stress and cell death in hepatocytes. Collectively, our research uncovers a novel role for OTUD6A in mitigating APAP-induced liver injury by promoting EZH2 stabilization.

KRAS mutant colon cancer-targeted induction of ferroptosis via photocatalytic activation of BiVO₄-embedded silica nano with cascadic downregulation of GPX4/xCT axis

Acta Pharmaceutica Sinica B. 2025, 15(9): 4932-4944.

Kirsten rat sarcoma virus (KRAS) is a common oncogene in human cancers. Approximately 40% of the patients diagnosed with colorectal cancer (CRC) have KRAS mutations that exhibit strong resistance to targeted molecular therapy and EGFR antibody treatment. In this study, we present photocatalytic silica nanoparticles (A6-FS/BiVO₄ DMSNs) for targeted therapy of KRAS mutant CRC with the induction of cascadic ferroptosis events. Dendritic mesoporous silica nanoparticles (DMSNs) were impregnated with photocatalytic BiVO₄, loaded with ferroptotic agents (benzoyl ferrocene: B and sorafenib: S), and encoded with CD44-targeting A6 peptides. For the targeting design, we observed CD44 overexpression in KRAS mutant CRC cells using CPTAC data analysis. Upon laser irradiation, A6-FS/BiVO₄ DMSNs generate electron-hole pairs (e⁻/h⁺), which produce hydroxyl radical (OH·) and superoxide anions (O₂·⁻). Laser irradiation simultaneously initiates the dissociation of iron (Fe²⁺) from benzoyl ferrocene and the release of sorafenib. This cascade induces ferroptosis in KRAS mutant CRC cells, especially under conditional inhibition of redox-regulating proteins (cystine/glutamate antiporter and glutathione peroxidase 4), and significantly inhibits tumor growth in a KRAS mutant CRC xenograft animal model.

PARylation promotes acute kidney injury via RACK1 dimerization-mediated HIF-1α degradation

Acta Pharmaceutica Sinica B. 2025, 15(9): 4673-4691.

Poly(ADP-ribosyl)ation (PARylation) is a specific form of post-translational modification (PTM) predominantly triggered by the activation of poly-ADP-ribose polymerase 1 (PARP1). However, the role and mechanism of PARylation in the advancement of acute kidney injury (AKI) remain undetermined. Here, we demonstrated the significant upregulation of PARP1 and its associated PARylation in murine models of AKI, consistent with renal biopsy findings in patients with AKI. This elevation in PARP1 expression might be attributed to trimethylation of histone H3 lysine 4 (H3K4me3). Furthermore, a reduction in PARylation levels mitigated renal dysfunction in the AKI mouse models. Mechanistically, liquid chromatography-mass spectrometry indicated that PARylation mainly occurred in receptor for activated C kinase 1 (RACK1), thereby facilitating its subsequent phosphorylation. Moreover, the phosphorylation of RACK1 enhanced its dimerization and accelerated the ubiquitination-mediated hypoxia inducible factor-1α (HIF-1α) degradation, thereby exacerbating kidney injury. Additionally, we identified a PARP1 proteolysis-targeting chimera (PROTAC), A19, as a PARP1 degrader that demonstrated superior protective effects against renal injury compared with PJ34, a previously identified PARP1 inhibitor. Collectively, both genetic and drug-based inhibition of PARylation mitigated kidney injury, indicating that the PARylated RACK1/HIF-1α axis could be a promising therapeutic target for AKI treatment.

Author correction to “Microbial metabolite 3-indolepropionic acid alleviated PD pathologies by decreasing enteric glia cell gliosis via suppressing IL-13Rα1 related signaling pathways” [Acta Pharm Sin B 15 (2025) 2024-2038]

Meiyu Shang, Jingwen Ning, Caixia Zang, Jingwei Ma, Yang Yang, Zhirong Wan, Jing Zhao, Yueqi Jiang, Qiuzhu Chen, Yirong Dong, Jinrong Wang, Fangfang Li, Xiuqi Bao, Dan Zhang

Acta Pharmaceutica Sinica B. 2025, 15(9): 4972-4972.

Intercellular communication interference through energy metabolism-related exosome secretion inhibition for liver fibrosis treatment

Acta Pharmaceutica Sinica B. 2025, 15(9): 4900-4916.

As activated hepatic stellate cells (aHSCs) play a central role in fibrogenesis, they have become key target cells for anti-fibrotic treatment. Nevertheless, the therapeutic efficiency is constrained by the exosomes they secrete, which are linked to energy metabolism and continuously stimulate the activation of neighboring quiescent hepatic stellate cells (qHSCs). Herein, an intercellular communication interference strategy is designed utilizing paeoniflorin (PF) loaded and hyaluronic acid (HA) coated copper-doped ZIF-8 (PF@HA-Cu/ZIF-8, PF@HCZ) to reduce energy-related exosome secretion from aHSCs, thus preserving neighboring qHSCs in a quiescent state. Simultaneously, the released copper and zinc ions disrupt key enzymes involved in glycolysis to reduce bioenergy synthesis in aHSCs, thereby promoting the reversion of aHSCs to a quiescent state and further decreasing exosome secretion. Therefore, PF@HCZ can effectively sustain both aHSCs and qHSCs in a metabolically dormant state to ultimately alleviate liver fibrosis. The study provides an enlightening strategy for interrupting exosome-mediated intercellular communication and remodeling the energy metabolic status of HSCs with boosted antifibrogenic activity.

USP20 as a super-enhancer-regulated gene drives T-ALL progression via HIF1A deubiquitination

Acta Pharmaceutica Sinica B. 2025, 15(9): 4751-4771.

T-cell acute lymphoblastic leukemia (T-ALL) is a highly aggressive hematologic malignancy with a poor prognosis, despite advancements in treatment. Many patients struggle with relapse or refractory disease. Investigating the role of the super-enhancer (SE) regulated gene ubiquitin-specific protease 20 (USP20) in T-ALL could enhance targeted therapies and improve clinical outcomes. Analysis of histone H3 lysine 27 acetylation (H3K27ac) chromatin immunoprecipitation sequencing (ChIP-seq) data from six T-ALL cell lines and seven pediatric samples identified USP20 as an SE-regulated driver gene. Utilizing the Cancer Cell Line Encyclopedia (CCLE) and BloodSpot databases, it was found that USP20 is specifically highly expressed in T-ALL. Knocking down USP20 with short hairpin RNA (shRNA) increased apoptosis and inhibited proliferation in T-ALL cells. In vivo studies showed that USP20 knockdown reduced tumor growth and improved survival. The USP20 inhibitor GSK2643943A demonstrated similar anti-tumor effects. Mass spectrometry, RNA-Seq, and immunoprecipitation revealed that USP20 interacted with hypoxia-inducible factor 1 subunit alpha (HIF1A) and stabilized it by deubiquitination. Cleavage under targets and tagmentation (CUT&Tag) results indicated that USP20 co-localized with HIF1A, jointly modulating target genes in T-ALL. This study identifies USP20 as a therapeutic target in T-ALL and suggests GSK2643943A as a potential treatment strategy.

Targeting PARylated RACK1/HIF-1α axis: A novel mechanism in acute kidney injury and therapeutic promise

Acta Pharmaceutica Sinica B. 2025, 15(9): 4970-4971.