Acta Pharmacologica Sinica最新文献

Epigenetic modulating drugs are emerging as promising cancer treatments. We previously showed that a natural compound, nordihydroguaiaretic acid (NDGA), exerted anti-prostate cancer effects in vitro and in vivo. In this study, we elucidated the anticancer mechanisms of NDGA against prostate cancer. Using integrating bioinformatics analysis and proteomic research, we identified 12 differentially expressed proteins in NDGA-treated PC3 cells that were associated with EZH2, a histone methyltransferase and a catalytic component of polycomb repressive complex 2 (PRC2), which catalyzed the trimethylation of histone H3 at Lys27 (H3K27me3). We showed that NDGA (5, 10, 20 μmol/L) dose-dependently inhibited EZH2 expression in PC3 cells by increasing its degradation and inhibiting its transcription. We demonstrated that NDGA targeted neuropilin 1 (NRP1) in PC3 cells, inhibiting the EZH2/H3K27me3 and PI3K/AKT/mTOR pathways and the expression of E2F1. NDGA blocked E2F1 binding to the EZH2 promoter, decreasing EZH2 and H3K27me3 levels. On the other hand, NDGA inhibited CBP/p300, decreased H3K27ac levels, and synergized with the EZH2 inhibitor EPZ6438 against PC3 cells. In conclusion, NDGA is a potential epigenetic antineoplastic agent that downregulates EZH2 and H3K27me3 through the NRP1 and PI3K/AKT/mTOR pathways and exerts a synergistic antitumor effect with H3K27ac and EZH2 inhibitors, suggesting that it could be a valuable therapeutic option for prostate cancer.

Status epilepticus (SE) is a serious neurological condition defined as a continuous seizure lasting longer than 5 min or multiple seizures without full recovery of consciousness between them. Uncontrolled SE causes severe brain inflammation and damage, leading to life-long epilepsy and behavioral comorbidities. 12/15-Lipoxygenase (12/15-LOX), an enzyme that generates bioactive lipid metabolites from polyunsaturated fatty acids, plays pathogenic role in oxidative and inflammatory processes that can aggravate tissue injuries. However, its involvement in SE-triggered neuroinflammation and long-term sequelae remains elusive. Herein, we report that 12/15-LOX was significantly upregulated in microglia in response to inflammatory stimuli as well as in the hippocampus after pilocarpine-induced SE in mice. Selective inhibition of 12/15-LOX by compound ML351 robustly reduced lipopolysaccharide-provoked pro-inflammatory gene expression both in vitro and in vivo. Treatment with ML351 (50 mg/kg, i.p.) after SE was interrupted by diazepam markedly decreased pro-inflammatory cytokines and reactive gliosis and broadly prevented neuronal injuries within the hippocampus. Moreover, repeated administration of ML351 for merely five consecutive days after SE led to a long-term improvement in spatial working and reference memory along with a reduction in anxiety-like behavior as well as an increase in hippocampal neuronal survival. These results suggest that inhibition of 12/15-LOX hours after SE onset can alleviate neuroinflammation, protect hippocampal neurons, and prevent long-term neurobehavioral deficits. Therefore, targeting 12/15-LOX might provide an adjunctive strategy, together with the current antiseizure medications, to mitigate neurobehavioral comorbidities associated with prolonged seizures.

Environmental toxicants such as MPTP and rotenone induce Parkinsonism in both humans and animals. Lactate-driven histone lactylation has recently been implicated in microglial activation and broader CNS pathology. However, its role in dopaminergic (DA) neurons and Parkinson's disease (PD)-related toxicant responses remains unclear. In this study, we investigated whether neurotoxicant-induced histone lactylation contributes to PD pathogenesis. SH-SY5Y cells were exposed to MPP⁺ (5 mM) or rotenone (5 μM) for 24 h. A mouse model of PD was established by injection of MPTP (25 mg/kg) for 5 days. We showed that PD-related neurotoxicants increased intracellular lactate levels, promoting histone lactylation in SH-SY5Y cells by suppressing PDH complex activity. By integrating RNA-seq and ChIP-seq analyses, we identified the DDIT4 gene as a lactylation target in response to MPP⁺ and rotenone. A pharmacological reduction in lactate production or inhibition of lactylation with sodium dichloroacetate (DCA) suppressed DDIT4 promoter lactylation and expression, reduced MPP⁺- and rotenone-induced cell death in SH-SY5Y cells in vitro and partially protected against MPTP-induced TH-positive DA neuron loss in the brains of MPTP-treated mice in vivo. We demonstrated that DDIT4 was upregulated in the AGTR1/SOX6-positive dopaminergic subpopulation that was highly susceptible to loss in PD patients. These results provide the first evidence that environmental toxicity-induced metabolic alterations drive histone lactylation of the DDIT4 promoter, directly linking a known PD stress effector gene to a lactate-epigenetic signal underlying DA neuron loss. This study reveals a lactate-epigenetic axis that contributes to environmental toxicant-induced Parkinsonism and identifies lactate metabolism and histone lactylation as promising targets for further preclinical investigation.

Somatostatin receptor 3 (SSTR3) exerts critical biological functions such as negatively regulating hormone release and cell proliferation, making it a promising therapeutic target for endocrine disorders and nonfunctioning pituitary tumors. However, the development of more effective and safer somatostatinergic therapies is limited due to a lack of molecular understanding of the ligand recognition and conformational dynamics of SSTR3. Here, we report the cryo-EM structure of the human SSTR3-Gi complex bound to octreotide at 2.90 Å resolution. Our structures reveal the molecular mechanisms of ligand recognition and receptor activation. Furthermore, mutagenesis analyses reveal that residue R203⁵·³⁵ of SSTR3 and F294⁷·³⁵ of SSTR2 play critical roles in mediating the subtype selectivity of octreotide. Using electron paramagnetic resonance spectroscopy, we have investigated the conformational dynamics of SSTR3. Our findings demonstrate that during ligand binding or G protein coupling, the labeled site on transmembrane helix 6 (TM6) of SSTR3 progressively becomes exposed to the extracellular environment and exhibits increased dynamical characteristics. Our work provides structural and dynamic insights that will facilitate the rational design of subtype-selective drugs targeting SSTRs and possessing improved therapeutic profiles.

Triptolide has demonstrated potent immunosuppressive properties in multiple autoimmune disorders, but its severe toxicity has greatly hampered clinical application. Here, we synthesized a triptolide derivative STP1, which exhibits remarkably reduced toxicity compared with triptolide. Immune dysfunction plays a critical role in systemic lupus erythematosus (SLE), an archetypical and refractory autoimmune disorder with limited therapeutic options and suboptimal outcomes. To elucidate the drugability and effect, we investigated the therapeutic potential, safety, regulatory mechanism and target of STP1 on SLE. Our data indicated that STP1 significantly ameliorates imiquimod-induced murine SLE by reducing anti-IgG, anti-dsDNA IgG, proteinuria, and renal pathological injury. Mechanistically, STP1 exerts markedly immunosuppressive roles by modulating the differentiation of B cell into plasma cells and T cell into Tfh cells. Further investigation showed that STP1 regulates B-cell receptor and T-cell receptor signaling by directly targeting Fyn kinase responsible for its immunosuppressive activity. For safety of STP1, our findings indicated that the STP1 did not show any toxicity in biochemical parameters and organ pathological analysis in subacute toxicity experiment. The findings suggested that STP1 is an attractive novel candidate for SLE and other autoimmune diseases for thorough evaluation. STP1, a structurally modified derivative of triptolide with improved safety, alleviates murine systemic lupus erythematosus by targeting and inhibiting Fyn, a Src kinase family member that regulates B- and T- cell responses.

Abdominal aortic aneurysm (AAA) is a chronic, inflammatory and degenerative vascular disease. Previous studies have demonstrated that stimulator of interferon genes (STING) is involved in multiple inflammatory diseases. However, the role of STING in AAA formation and its possible mechanisms have yet to be investigated. Here, we investigated the role of STING in the development of AAA using two murine AAA models induced by porcine pancreatic elastase (PPE)/β-aminopropionitrile (BAPN) or angiotensin II (Ang II). The STING signaling pathway was significantly activated in AAA tissues from both mice and patients. Sting mutation slowed AAA formation, as confirmed by reduced AAA incidence, maximal abdominal aortic diameter, elastin disruption, collagen deposition, and inhibited immune cell infiltration in AAA mice. RNA-sequencing analysis revealed that compared with the control, Sting mutation inhibited inflammatory and immune responses in AAA tissues. Similar effects were observed after pharmacological inhibition of STING in Ang II infused ApoE^-/- mice. Besides, STING signaling pathway was also activated in TNFα treated MOVAS. Sting knockdown suppressed inflammatory response and oxidative stress in vitro. Finally, colchicine protected against AAA formation in mice partially through inhibition of the STING signaling pathway. Our study demonstrated that Sting mutation and pharmacological inhibition could limit AAA progression possibly through inhibition of inflammation and oxidative stress. Colchicine could slow AAA formation in a partially STING-dependent manner in AAA mice. These findings suggest that STING might be a potential pharmacological target for the treatment of AAA.

Abnormal proliferation of vascular smooth muscle cells (VSMCs) plays a critical role in vascular remodeling associated with various cardiovascular disorders. G9a, also known as euchromatic histone methyltransferase 2 (EHMT2), is a lysine methyltransferase that influences histone modifications, particularly H3K9me1 and H3K9me2. In this study we investigated the role of G9a in promoting VSMC proliferation and vascular intimal hyperplasia and the underlying mechanisms. To induce VSMC proliferation, primary aortic VSMCs were treated with platelet-derived growth factor-BB (PDGF-BB) and 10% fetal bovine serum (FBS) in vitro. An in vivo model of carotid intimal hyperplasia was established in mice by ligating the left common carotid artery just below the bifurcation. We showed that the expression levels of G9a were significantly elevated in both in vitro and in vivo models of VSMC proliferation. In the primary aortic VSMCs, co-treatment with G9a inhibitor UNC0642 (1 μM) effectively reduced cell viability, cyclin D1 expression, and EdU incorporation induced by PDGF-BB or 10% FBS. In mouse carotid intimal hyperplasia model, administration of UNC0642 (50 mg·kg^-1·d^-1, i.p.) for 14 days significantly decreased the intimal area and cyclin D1 levels, whereas intravenous administration of G9a adenovirus worsened neointimal hyperplasia. RNA-seq analysis identified CCAAT/enhancer binding protein delta (CEBPδ) as the downstream target gene that was upregulated following G9a modulation. ChIP assays revealed that G9a mediated VSMC proliferation primarily by regulating H3K9me1 at the promoter of CEBPδ. Knockdown of CEBPδ counteracted the pro-proliferative effects of G9a. In conclusion, G9a serves as a positive regulator of VSMC proliferation and presents a potential therapeutic target for cardiovascular diseases concomitant with vascular remodeling.

Immunotherapy targeting tumor-associated macrophages (TAMs) has emerged as a promising approach for treating glioma, driven by advances in drug discovery and development, including colony-stimulating factor 1 receptor (CSF1R) inhibitors. We previously developed a CSF1R inhibitor, C19, for TAM-targeting immunotherapy, which can reprogram TAMs and remodel the tumor immunosuppressive microenvironment. However, the application of CSF1R inhibitors in brain cancer is limited due to inefficient delivery across the blood-brain barrier (BBB). To address this limitation, we designed a brain-targeted liposomal delivery system (T12-Lipo) modified with the transferrin receptor-binding peptide T12. T12-Lipo can specifically bind to transferrin receptors, which are overexpressed in both the BBB and TAMs, thus enhancing the delivery efficiency of C19 across the BBB and to TAMs. This system promoted TAM repolarization toward an anti-tumor M1-like phenotype and thereby facilitated T-cell-mediated tumor killing. T12-Lipo improved the BBB permeability of C19, exhibiting significant therapeutic efficacy against glioma growth. The brain-targeted liposomal formulation of the CSF1R inhibitor C19 represents a promising and effective approach for glioma immunotherapy. T12 peptide-modified liposomes loaded with CSF1R inhibitor C19 can penetrate the BBB, promote M1 phenotypic differentiation of macrophages, effectively activate T-cell immunity, alleviate the tumor immunosuppressive microenvironment, and improve the therapeutic efficacy against glioma.

Addiction is a chronic relapsing disorder characterized by compulsive seeking and consumption of drugs, with this abnormal "Go" behavior resulting in significant negative consequences. Research has shown that the dorsal medial striatum (DMS) is associated with the pathophysiological mechanisms of addiction; however, drugs targeting the DMS to achieve therapeutic effects for addiction remain unavailable. Intracellular cAMP signaling, regulated by G protein-coupled receptors (GPCRs), critically modulates the excitability, plasticity and neurotransmission of GABAergic medium spiny neurons (MSNs). In this study we investigated how inhibition of PDE4 modulated cAMP levels with a specific focus on how these changes influenced the dopamine D1 receptor MSNs (D1-MSNs) and D2 receptor MSNs (D2-MSNs) in the DMS, thereby influencing abnormal "Go" behavior. We established alcohol-induced conditioned place preference (CPP) model and two-bottle choice drinking model in mice. PDE4 inhibitor rolipram (0.5 μg) were bilaterally microinjected into the DMS of mice 2 h prior to the combination of alcohol. The activation of D1-MSNs and D2-MSNs in the DMS was assayed using c-Fos immunofluorescence staining. We showed that rolipram microinjection significantly increased cAMP levels in MSNs of the DMS and restored the activation balance between D1-MSNs and D2-MSNs. This rebalancing of MSN activity attenuated abnormal "Go" behaviors including high-drinking behavior. We further identified the ERK signaling downstream of cAMP in D2-MSNs of the DMS, together with the PDE4 subtype PDE4B, as key mediators of the inhibitory effects of PDE4 inhibitors on high-drinking behavior. These results highlight a new strategy emphasizing the pivotal role of PDE4 as a key regulator of cAMP signaling in MSNs, maintaining the dynamic balance between D1-MSNs and D2-MSNs, and further identify D2-MSNs specific PDE4B/cAMP/ERK modulation as a promising target for addiction treatment.

Inflammatory bowel disease (IBD) comprises Crohn's disease and ulcerative colitis, and that is a major risk factor for colitis-associated colorectal cancer (CAC), a distinct and aggressive malignancy driven by chronic intestinal inflammation. Artemisinins, a group of sesquiterpene lactones derived from Artemisia annua, have emerged as promising therapeutic candidates for IBD due to their potent anti-inflammatory and anticancer properties. In this review, we summarize the current evidence that artemisinins exert diverse pharmacological actions including modulation of immune responses, reduction of oxidative stress, preservation of epithelial barrier function, and suppression of oncogenic signaling relevant to IBD and CAC. We also introduce the recent progress in formulation strategies designed to enhance the bioavailability, tissue specificity, and therapeutic efficacy of artemisinin-based agents. By bridging traditional medical philosophy with modern pharmacological insights, artemisinins represent a versatile platform for preventing and treating inflammation-driven colorectal cancer. This review offers a comprehensive overview of their translational potential in addressing the IBD-CAC continuum.