Acta Pharmacologica Sinica最新文献

Negative-stranded segmented RNA viruses (NSVs) employ a cap-snatching mechanism for transcription, which makes cap-dependent endonuclease (CEN) an attractive target for drug development. Pathogenic arenaviruses pose a serious threat to humans, yet no approved treatments exist, underscoring the importance of discovering novel compounds targeting arenaviral CENs. Therefore, this study aimed to identify novel CEN inhibitors for arenaviruses and investigate their antiviral mechanisms. A high-throughput screening system based on enzymatic activity of CEN was established for discovering inhibitors of lymphocytic choriomeningitis virus (LCMV). Several hit compounds were screened from a vast natural product library, and then evaluated for both toxicity and inhibition through cellular and animal experiments. One candidate compound was finally identified, and its mechanism of action on CEN was elucidated through simulation analysis and biochemical studies. Moreover, its broad-spectrum effects were investigated among pathogenic arenaviruses as well as representative NSVs. Consequently, salvianolic acid A (SAA) from Salvia miltiorrhiza was identified as a promising compound that effectively inhibited LCMV infection and significantly reduced the viral load via intravenous administration. It was shown to bind to the active pocket of arenaviral CENs while chelating their metal ions through its acid carboxyl group, acting in a substrate-competitive manner. Additionally, SAA exhibited broad-spectrum inhibition of pathogenic arenaviruses as well as representative viruses from the order Bunyavirales. This study identified SAA as a novel CEN inhibitor, particularly for pathogenic arenaviruses, showcasing its promise for antiviral drug development.

Parkinson's disease (PD) involves α-synuclein (αSyn) oligomerization and aggregation, processes facilitated by glycosphingolipids. Defective glycosphingolipid transport and degradation-especially via the lipid-degrading enzyme glucocerebrosidase 1 (GCase, gene GBA1)-aggravate PD and increase dementia risk. Ambroxol is a mucolytic drug and has emerged as a promising add-on therapy for PD since it acts as a chaperone for misfolded GCase, thereby increases the likelihood that mutated and misfolded GCase eludes ER-associated degradation (ERAD) and is transported to its destination, the lysosome. In this study we investigated whether and how ambroxol provided therapeutic benefits for PD irrespective of the GBA1 mutation status. Pink1^-/-/SNCA^A53T double mutant PD mice were administered ambroxol either via the drinking water (120-150 mg·kg^-1·d^-1) or via food pellets (75-100 mg·kg^-1·d^-1) for approximately 6 months. During the treatments mice were observed in IntelliCages; and in motor, sensory and cognitive functions tests. After mice were euthanized, tissues were dissected for protein, lipidomic and metabolomic analyses. We showed that high-dose long-term ambroxol was well tolerated and led to mild behavioral and metabolic improvements but had adverse effects on brain sulfatides, lysosomal functions and mitochondrial cardiolipins. Notably, brain levels of glucosylceramides (GlcCer 16:0) were normalized, while sulfatides (SHexCer) further increased. Western blots revealed a modest reduction of αSyn and phosphorylated αSyn (P-Ser129). IntelliCage assessments showed increased exploratory activity with ambroxol, suggesting reduced bradykinesia, though sensory and motor functions remained unchanged. Lipidomic profiles of mitochondria showed accumulation of HexCer and triglycerides in PD mitochondria, regardless of treatment, while ambroxol led to an additional decline of cardiolipins including the most abundant tetralinoleoyl cardiolipins. In HT22 hippocampal neurons preloaded with αSyn pre-formed fibrils, ambroxol accumulated within lysosomes, increased lysosomal mass and sphingolipid content and promoted lysosomal enzyme release. Collectively, these results suggest that ambroxol confers transient behavioral benefits and modestly reduces αSyn pathology, albeit with potential drawbacks. In addition, its lysosomal accumulation may further disrupt sphingolipid metabolism and impair mitochondrial compensatory mechanisms. Ambroxol-induced lysosomal exocytosis may transiently relieve αSyn burden, but further interventions would be required to ensure αSyn clearance from the brain.

For several decades, the glutamate delta-1 receptor (GluD1) has remained an enigmatic entity among ionotropic glutamate receptors (iGluRs), primarily due to its lack of classical ion channel activity. Recent advancements have redefined GluD1 as a multifunctional synaptic organizer, essential for the development, plasticity, and behavioral regulation of both excitatory and inhibitory circuits. In this review, we synthesize recent progress at the structural, molecular, and circuit levels to reconceptualize GluD1 as a pivotal signaling scaffold that functions through non-ionotropic mechanisms. We emphasize the modular architecture of GluD1, encompassing the amino-terminal domain, ligand-binding domain, transmembrane region, and C-terminal domain to elucidate how each component uniquely contributes to synaptic function. Evidence from genetic models and structural biology underscores GluD1's involvement in transsynaptic adhesion, ligand-dependent conformational signaling, and intracellular pathway modulation. Additionally, we discuss its emerging clinical significance, with GRID1 mutations associated with neurodevelopmental and psychiatric disorders, and recent findings implicating GluD1 dysfunction in chronic pain. Finally, we explore domain-specific therapeutic strategies, including peptide mimetics, synthetic organizers, and non-ionotropic modulators, positioning GluD1 as a promising target for circuit-level intervention in brain disorders.

Peptide-drug conjugate (PDC) represents a special therapeutic strategy to enhance drug delivery by targeting tumor cell receptors while minimizing off-target effects. Comparing the antibody-drug conjugate (ADC), the targeting peptide constitutes the pivotal component of PDC, especially with easy optimization of peptides to promote their in vivo stability, and with the agonist stimulated GPCR internalization to facilitate drug distribution into tumor cell plasma. Herein, we have optimized a highly stable peptide molecule LanTC targeting somatostatin receptor 2 (SSTR2), through amino acid substitution and disulfide bond modification from an FDA proved peptide drug Lanreotide. The LanTC based PDC was constructed through conjugation of the cytotoxic drug emtansine (DM1). The LanTC-DM1 PDC exhibited high stability and high agonist affinity to SSTR2. Subsequent in vitro and in vivo pharmacological data revealed that LanTC-DM1 PDC exhibited antitumor activity in small cell lung cancers (SCLC) which was known to have over-expressing SSTR2. The LanTC-DM1 PDC with specific targeting and antitumor activity provides a solid basis not only for advancing SSTR2-targeted PDCs as a promising therapy for SCLC, but also for other PDC developments targeting GPCRs in plasma membrane of tumor cells.

Cancer metastasis and drug resistance are intricately linked processes that drive cancer progression and poor prognosis. One of the hallmarks of cancer is metabolic reprogramming, which evolves at various stages of tumor metastasis and drug resistance progression. This reprogramming involves the dysregulation of metabolic enzymes, which not only regulate the metabolic status in cancer cells, but also play multifunctional roles through influencing downstream signaling networks, acting as protein kinases, post-translational modifications and multiple biological processes, thereby exacerbating cancer malignancy. This review focuses on the metabolic enzyme-associated protein-protein interactions (mPPIs) during tumor metastasis and therapeutic resistance, and discusses the roles of key enzymes in glycolysis, the serine synthesis pathway, the pentose phosphate pathway, the glucuronate pathway and the sorbitol pathway. Understanding the distinct multifunctionality of these metabolic enzymes is crucial for gaining valuable insights into cancer pathogenesis and identifying potential therapeutic vulnerability to combat metastatic progression and overcome therapy resistance.

Ubiquitin-specific protease 14 (USP14) is a crucial modulator of proteasomal function and cellular proteostasis, which plays an important role in the development and progression of various cancers including colorectal cancer (CRC). In this study we screened 670 covalent compounds using the in vitro Ub-AMC hydrolysis assay, and identified AKOS, initially a Chikungunya virus inhibitor, as a novel small-molecule inhibitor of USP14. We showed that AKOS inhibiting USP14 deubiquitinase activity with an IC₅₀ value of 0.98 μM. AKOS directly bound to USP14, covalently modifying the active-site cysteine residue (Cys¹¹⁴), thereby effectively inhibiting its deubiquitinase activity. We demonstrated that inhibition of USP14 by AKOS might destabilize MEF2D, a critical substrate, resulting in downregulation of the expression and translation of ECM-related transcription factors such as ITGB4. AKOS exhibited potent anti-cancer effects: the USP14 inhibitor significantly inhibited the proliferation and metastasis of CRC cells in vitro with IC₅₀ values of 9.88 and 16.57 μM, respectively, in SW620 cells and HCT116 cells. Intratumoral injection of AKOS (15, 30 mg/kg, every 5 days) effectively suppressed the tumor growth in HCT116 xenograft mouse models in vivo. Collectively, we demonstrate that AKOS is a promising chemical probe for targeting USP14 in CRC, offering a novel strategy for disrupting the malignant progression of CRC.

Accurately quantifying protein-DNA interactions (PDIs) is critical for understanding biological processes and facilitating drug design. However, the inherent flexibility of nucleic acids limits the availability of experimentally determined structures of PDI complexes, posing a significant challenge for training reliable scoring functions (SFs). To address this, we developed PDIScore, a novel deep learning-based SF for PDI prediction. PDIScore utilizes a comprehensive graph representation to capture nucleotide flexibility, employs a scalable GraphGPS architecture with BigBird linear global attention to handle large interaction interfaces, and leverages Mixture Density Networks (MDNs) to model residue-nucleotide distance distributions. PDIScore was trained on a self-collected dataset of ~7000 protein-nucleic acid complex structures and validated on three rigorous test sets for evaluating its screening, docking, and ranking capabilities. The results illustrated that PDIScore significantly outperformed existing methods: it achieved the best screening power on the screening set (e.g., EF_1% = 14.13, AUROC = 0.82 using AlphaFold3 structures), the highest docking success rate on the docking set (48.94% top1), and superior ranking capability on the ranking set (PCC = 0.50). Case studies demonstrated PDIScore's ability to elucidate biological mechanisms (e.g., adenovirus transcription, SOCS1 regulation) and its interpretability at the nucleotide level for identifying key interaction sites. PDIScore represents a robust, generalizable tool with significant potential for advancing PDI-related research and therapeutic design.

T cell immune responses are triggered by antigenic peptides presented through major histocompatibility complex class Is (pMHC-Is), which play an important role in the genesis, development, and therapy of tumors. The capacity of a specific pMHC-I to elicit T cell responses is deeply influenced by its expression level (quantity) and its immunogenicity (quality). Tumor cells can evade T cell immunity by down-regulating the quantity of pMHC-Is or selectively eliminating highly immunogenic antigenic peptides. Augmenting the quantity or quality of pMHC-Is is essential for tumor immunotherapy. However, the complexity of pMHC-I regulation and tumor heterogeneity pose challenges to clinical strategies. Consequently, developing approaches grounded in comprehensive analyses of pMHC-I regulatory mechanisms remains a focal point in the research of T cell immunity. In this review, we discuss how tumors modulate their surface pMHC-Is through genetic, epigenetic, and proteomic mechanisms and summarize potential therapeutic strategies targeting these mechanisms, which may provide a valuable reference for the development of novel tumor immunotherapies based on pMHC-I modulation. Tumor cells can achieve immune escape by interfering with the quantity and quality of pMHC-Is, and corresponding immunotherapy can also be achieved by the regulation of pMHC-Is.

Prodrugs usually convert into active compounds within cells via endogenous or external stimuli to improve the diagnostic accuracy and therapeutic efficacy, but this singular release profile often fails to meet the multifunctional needs of cancer therapeutics. In this study we proposed a strategy of "nanostructural conversion at nano-bio interface" and constructed a small-molecule nanoprodrug (APO-S-Cy7-TCF) for multifunctional anti-tumor phototheranostics. Upon exposure to redox biomolecules (ROS/GSH) in tumor microenvironment, the pristine nanostructure of APO-S-Cy7-TCF disassembled, releasing Cy7-TCF-OH and APO that interacted with heat shock proteins to initiate apoptosis. Cy7-TCF-OH could then re-assemble into smaller nanosaucers with enhanced photothermal properties and self-augmented ROS-generating capacity, enabling synergistic phototherapy for tumor ablation. In particular, Cy7-TCF-OH nanosaucers were long retained in residual tumors and could further interact with albumin to form smaller Cy7-TCF-OH@albumin nanocomposites that time-dependently activated near-infrared fluorescence for prognostic assessment. Using these biomolecule-derived elements to program supramolecular sequential structural conversions at nano-bio interface, our study establishes a new way for small-molecule-based multifunctional phototheranostic platform.