Acta Pharmacologica Sinica最新文献

Current treatments for ischemic stroke aim to achieve rapid reperfusion with intravenous thrombolysis and/or endovascular thrombectomy, which have proven to attenuate disability. Despite the significant progress in reperfusion therapies, functional recovery remains inconsistent, primarily due to ongoing neuronal excitotoxicity and neuroinflammation. In this study we investigated the relationship between neuronal activity and neuroinflammation in an ischemic mouse model using chemogenetic techniques. MCAO cerebral ischemia model was established in mice; in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) was established in PC12 neurons. By measuring c-Fos expression, we showed that MCAO caused the activation of both excitatory and inhibitory neurons within the M1 primary motor cortex, which subsequently induced reactive activation of local microglia through the secretion of unique neuronal extracellular vesicles (EVs). Chemogenetic inhibition of abnormal neuronal activity in stroke-affected cortical neurons reversed microglia activation and reduced neuronal apoptosis. By analyzing the miRNAs in EVs from the ischemic M1 cortex, we found that miR-128-3p was significantly downregulated in ischemia-challenged neurons and their EVs, leading to neuronal injury and proinflammatory polarization of microglia. Intravenous injection of miR-128-3p mimics significantly improved neuronal survival, reduced neuroinflammation accompanied by better functional recovery after ischemic stroke. In summary, stroke-induced abnormal neuronal activity reduces miR-128-3p levels in ischemic neurons and EVs, leading to increased microglia activation and neuronal injury after a stroke. The study highlights that inhibiting abnormal neuronal activity or delivering miR-128-3p-enriched EVs as novel methods for stroke treatment.

SARS-CoV-2 can encode circular RNAs (circRNAs); however, the potential effects of exogenous SARS-CoV-2 circRNAs on cardiovascular sequelae remain unknown. Three circRNAs derived from the nucleocapsid (N) gene of SARS-CoV-2, namely, circSARS-CV2-Ns, were identified for functional studies. In particular, circSARS-CV2-N1368 was shown to enhance platelet adhesiveness to endothelial cells (ECs) and inhibit EC-dependent vascular relaxation. Moreover, exogenous expression of circSARS-CV2-N1368 suppressed EC proliferation and migration and decreased angiogenesis and cardiac organoid beating. Mechanistically, we elucidated that circSARS-CV2-N1368 sponged the microRNA miR-103a-3p, which could reverse circSARS-CV2-N1368-induced EC damage. Additionally, activating transcription factor 7 (ATF7) was identified as a target gene of miR-103a-3p, and Toll-like receptor 4 (TLR4) was verified as a downstream gene of ATF7 that mediates circARS-CV2-N1368-induced activation of nuclear factor kappa B (NF-κB) signaling and ROS production in ECs. Importantly, the reactive oxygen species (ROS) scavenger NAC mitigated the circSARS-CV2-N1368-promoted EC impairment. Our findings reveal that the TLR4/NF-κB/ROS signal pathway is critical for mediating circSARS-CV2-N1368-promoted oxidative damage in ECs, providing insights into the endothelial impairment caused by circSARS-CV2-Ns.

The acute phase of ischemic stroke is marked by a surge in matrix metalloproteinase-9 (MMP-9) activity. While integral to natural repair processes, MMP-9 exacerbates injury by breaking down the blood-brain barrier (BBB) and promoting edema and inflammation. MMP-9 is predominantly secreted by inflammatory cells such as neutrophils, macrophages and microglia soon after stroke onset. In this study we investigated the effects of MMP-9 inhibition via SB-3CT on astrocytic lipid metabolism, and its potential to enhance neuronal survival and recovery following ischemic stroke. Mice were subjected to transient middle cerebral artery occlusion (tMCAO) for 60 min, mice then were injected with SB-3CT (25 mg/kg, i.v.). On D3 post tMCAO, neurological outcomes were assessed, and whole brains were collected for analysis. Lipidomic analysis of brain tissue showed that SB-3CT treatment significantly restrained astrocytic cholesterol metabolism by modulating the sphingolipid and glycerophospholipid pathways. Specifically, SB-3CT reduced ceramide accumulation and promoted an increase in neuroprotective hexosylceramides, leading to enhanced neuronal survival and synaptic integrity. In addition, SB-3CT treatment reduced astrocytic and microglial reactivity, thereby mitigating neuroinflammation. In order to optimize the timing and dosage of MMP-9 inhibition to maximize the therapeutic efficacy, tMCAO mice were given three injections of SB-3CT on D0, D2 and D4 within 7 days after modeling. We found that prolonged MMP-9 inhibition alleviated astrogliosis, concurrently impaired neurological recovery and inhibited angiogenesis. These results demonstrate the critical role of lipid metabolism in MMP-9-mediated brain injury and the potential of SB-3CT as a therapeutic strategy for ischemic stroke by targeting astrocytic lipid metabolism.

Current treatments of inflammatory bowel disease (IBD) largely depend on anti-inflammatory and immunosuppressive strategies with unacceptable efficacy and adverse events. Resolution or repair agents to treat IBD are not available but potential targets like formyl peptide receptor 2 (FPR2/ALX) may fill the gap. In this study we evaluated the therapeutic effects of two small molecule FPR2/ALX modulators (agonist Quin-C1 and antagonist Quin-C7) against IBD. We first analyzed the cryo-electron microscopy structure of the Quin-C1-FPR2 in complex with heterotrimeric G_i to reveal the structural basis for ligand recognition and FPR2 activation. We then established dextran sulfate sodium (DSS)-induced colitis model in both normal and myeloid depletion mice. We showed that oral administration of Quin-C1 for 7 days ameliorated DSS-induced colitis evidenced by alleviated disease activity indexes, reduced colonic histopathological scores, and corrected cytokine disorders. Meanwhile, we found that oral administration of FPR2/ALX antagonist Quin-C7 exerted therapeutic actions similar to those of Quin-C1. In terms of symptomatic improvements, the ED₅₀ values of Quin-C1 and Quin-C7 were 1.3660 mg/kg and 2.2110 mg/kg, respectively. The underlying mechanisms involved ERK- or ERK/JNK-mediated myeloid cell regulation that limited the development of colitis and inflammation. This is the first demonstration of anti-colitis property caused by synthetic small molecule FPR2/ALX modulators, implying that FPR2/ALX modulation rather than agonism alone ameliorates IBD.

Patients with hepatocellular carcinoma (HCC) at advanced stages face limited treatment options, highlighting the urgent need for more effective early detection methods and advanced therapeutic modalities. Emerging evidence shows that multiple CYP450 proteins are involved in the pathogenesis of HCC. CYP1A2, CYP2E1 and CYP3A5 have been shown to modulate important signaling pathways, hereby inhibiting the proliferation and invasion of HCC cells. In this study we investigated the role of cytochrome P-450 2A6 (CYP2A6) in HCC progression, focusing on its potential as a diagnostic biomarker and therapeutic target. By analyzing TCGA and GEO databases, we found that the expression levels of CYP2A6 were significantly decreased in HCC compared to normal tissues. Overexpression of CYP2A6 resulted in reduced proliferation, migration, invasion, adhesion, tube-forming in PLC/PRF/5 and HepG2 cells in vitro, as well as tumorigenicity and metastasis in nude mice. Notably, the anti-HCC effects of CYP2A6 were independent of its metabolic functions. We demonstrated that CYP2A6 could bind to proto-oncogene tyrosine-protein kinase SRC (SRC) and inhibit the SRC/Wnt/β-Catenin pathway. Overexpression of SRC abrogated the inhibitory effects of upregulating CYP2A6 on the migration and invasion of PLC/PRF/5 cells. These results together suggest the potential of CYP2A6 as a biomarker and therapeutic target for HCC. Its modulation of the SRC/Wnt/β-Catenin pathway provides a new insight for HCC treatment.

Parkinson's disease (PD) is a neurodegenerative disease, and emerging evidence has shown that iron deposition, ferroptosis and epigenetic modifications are implicated in the pathogenesis of PD. However, the interplay among these factors in PD has not been fully understood. In this review, we provide an overview of the current research progress on iron metabolism, ferroptosis and epigenetic alterations associated with PD. Furthermore, we present new frontiers concerning various epigenetic modifications related to iron metabolism and ferroptosis that might contribute to the pathology of PD. Notably, epigenetic modifications of iron metabolism and ferroptosis as both diagnostic and therapeutic targets in PD have been discussed. This opens new avenues for the regulation of iron homeostasis and ferroptosis in PD from epigenetic perspectives, and provides evidence for their potential implications in the diagnosis and treatment of PD.

The GluN1/GluN3A receptor, a unique excitatory glycine receptor recently identified in the central nervous system, challenges traditional perspectives of N-methyl-D-aspartate (NMDA) receptor diversity and glycinergic signaling. Its role in emotional regulation positions it as a potential therapeutic target for neuropsychiatric disorders. However, pharmacological research on GluN1/GluN3A receptors remains at an early stage. Traditional high-throughput screening methods for ion channel drug discovery often lack efficiency, particularly when applied to large compound libraries. To address this concern, we designed a deep learning-based strategy that balances efficiency and accuracy for identifying GluN1/GluN3A inhibitors. First, a sequence-based scoring function was developed to rapidly screen a library containing 18 million compounds, reducing the pool to approximately 10⁵ candidates. Next, two complex-based scoring functions, IGModel and RTMScore, were employed to precisely score and rank the remaining candidates. Finally, an active molecule with an IC₅₀ of 2.87 ± 0.80 μM for the GluN1/GluN3A receptor was confirmed through whole-cell voltage-clamp electrophysiology. This study also presents a paradigm for integrating deep learning into rapid and precise high-throughput screening.

Gene therapy, epigenetic therapies, natural compounds targeted therapy, photodynamic therapy, nanoparticles, and precision medicines are becoming available to diagnose and treat cancer. Gracillin, a natural steroidal saponin extracted from herbs, has shown potent efficacy against a range of malignancies. In this study, we investigated the molecular anticancer mechanisms of gracillin. We showed that gracillin dose-dependently suppressed proliferation, migration, and invasion in breast cancer, liver cancer, and glioblastoma cells with IC₅₀ values around 1 μM, which were associated with MST-independent activation of Hippo signaling pathway and subsequent decreased YAP activity. We demonstrated that gracillin activated the Hippo signaling by inducing Merlin/LATS protein-protein interaction (PPI). A competitive inhibitory peptide (SP) derived from the binding interface of the PPI, disrupted the interaction, abolishing the anticancer activity of gracillin. In nude mice bearing MDA-MB-231, HCCLM3, or U87MG xenograft tumor, administration of gracillin (5, 10 mg·kg^-1·d^-1, i.g. for 21 days) dose-dependently suppressed the tumor growth, associated with the induced Merlin/LATS PPI, activated Hippo signaling, as well as decreased YAP activity in tumor tissues. Our data demonstrate that gracillin is an efficacious therapeutic agent for cancer treatment, induction of Merlin/LATS PPI might provide proof-of-concept in developing therapeutic agent for cancer treatment.

Although significant progress has been made in the development of antidepressants, a large subpopulation of individuals remains unresponsive to existing treatments. Ginsenoside Rg1 (Rg1), a natural compound with well-defined antidepressant effects and low-cost administrations, holds therapeutic promise but requires mechanistic elucidation for clinical translation. Based on our previous finding that Rg1 rescued astrocytic connexin43 (Cx43) downregulation in depression models, we investigated its brain-wide effects and molecular mechanisms in chronic unpredictable stress (CUS)-induced rats. Male rats subjected to CUS received Rg1 (40 mg· kg^-1 ·d^-1, i.g.) for 8 weeks. Multimodal neuroimaging (fMRI and PET/CT) revealed that Rg1 restored functional connectivity and ameliorated neuroinflammation in CUS rats, with the prelimbic area identified as a critical target region. Through integrated proteomic profiling, molecular docking, and surface plasmon resonance analyses, we pinpointed Cx43-mediated gap junction as the primary target underlying Rg1's therapeutic action. Mechanistically, we showed that Yes-associated protein (YAP), the primary effector of the Hippo pathway, was translocated into the nucleus to promote the expression of specific genes including those involved in inflammation. Notably, we demonstrated that Rg1 potentiated the Cx43-YAP interaction in the cytoplasm and restricted YAP nuclear translocation activity. The degradation of Cx43 and potentiation of YAP nuclear translocation might represent a novel mechanism for the pathogenesis of depression. Specific blockade of Cx43-based gap junctions, knockdown of Cx43 expression in primary cultured astrocytes, and conditional knockout of astrocytic Cx43 in mice promoted YAP nuclear translocation and retarded the antidepressant effects of Rg1. Accordingly, the Cx43-YAP connection may represent a potential therapeutic target for the antidepressant mechanism of Rg1.