Acta Pharmacologica Sinica最新文献

Cholestatic liver disease is characterized by highly accumulated bile acids and cholangiocyte proliferation, resulting in the development of fibrosis, cirrhosis, and ultimately liver failure necessitating liver transplantation. Calcium (Ca²⁺) signaling is commonly dysregulated in cholestasis and serves as an important regulator mediating cell proliferation. However, the role of Ca²⁺-mediated cholangiocyte proliferation and treatment strategies in bile duct ligation (BDL)-induced liver injury remains poorly understood. By integrating transcriptomic analysis with molecular biology techniques, we explored the mechanisms of liver injury across BDL animal models, primary cholangiocytes, and human intrahepatic biliary epithelial cholangiocytes. Here, we found that a natural ingredient, senkyunolide A (SenA), effectively alleviated cholestasis-induced Ca²⁺ release from ER by inhibiting RYR channel, thereby preventing FIP200-mediated ER autophagy in response to Ca²⁺ transients on the cytosolic ER surface. Increased cytosolic Ca²⁺ further triggered ER stress, cholangiocyte cycle progression, and ductular reaction (DR). Importantly, SenA reversed the above process through its binding to chloride Channel CLIC Like 1 (CLCC1) for ubiquitination, thereby inhibiting CLCC1 activity and ER Ca²⁺ release. si-CLCC1-loaded liposomes targeting cholangiocytes enhanced the anti-DR effects of SenA. Collectively, by controlling ER release of Ca²⁺ in cholangiocytes, SenA presents potential for the development of therapeutic strategies aimed at addressing cholestatic fibrosis. SenA inhibited Ca²⁺-mediated cholangiocyte proliferation by binding to and promoting the ubiquitination of CLCC1, thereby alleviating cholestatic liver fibrosis.

Rheumatoid arthritis with depressive symptoms is frequently encountered in clinic. In this study, we investigated the molecular mechanisms responsible for comorbid depression with rheumatoid arthritis in collagen-induced arthritis (CIA) model mice. We showed that depression-like behaviors were developed at 5 weeks after establishing CIA model. Furthermore, we found that in the hippocampus of CIA mice, G-protein coupled receptor kinase 2 (GRK2) was significantly upregulated, while the expression of its target, corticotropin releasing hormone receptor 1 (CRHR1) was notably decreased, as was the downstream cAMP/PKA/CREB/BDNF signaling. We demonstrated that GRK2 could directly interact with CRHR1, suppressing CRHR1-dependent signaling. Knockdown of hippocampal GRK2 or pharmacological inhibition with CP-25 (35 mg·kg^-1·d^-1, i.g. for 21 days) could alleviate the depression-like behaviors in CIA mice, whereas GRK2 overexpression induced depression-like behaviors in naive mice. Our study identifies hippocampal GRK2 as a regulator of depression-like behaviors associated with rheumatoid arthritis in CIA model mice, suggesting both a therapeutic target and potential treatment strategy.

Agomelatine, an atypical antidepressant, offers combined effects of sleep regulation, antidepressant action, and anxiolysis, making it particularly suitable for patients with insomnia and mood disorders. In this study, we investigated the mechanisms underlying the anxiolytic effects of agomelatine in mice. Mice were subjected to chronic restraint stress (CRS) for 14 consecutive days. The mice were treated with agomelatine (10 mg·kg^-1·d^-1, i.p.) for 30 days. Afterward, anxiety-related behavioral tests (OFT, EPM, TST, and FST) or c-Fos immunohistochemical analysis were conducted. The results from c-Fos immunofluorescence combined with in vivo two-photon (2P) calcium imaging demonstrated that the neuronal activity of pyramidal neurons in the ventral CA3 (vCA3) region of the hippocampus was critical for both the expression of anxiety-like behaviors and the anxiolytic effects of agomelatine. Transcriptome sequencing analysis revealed that agomelatine specifically downregulated 5-HTR4 expression and its downstream signaling pathway in the vCA3, but not in the dorsal CA3 (dCA3). Using CRISPR-SpCas9 technology to knock out 5-HTR4 in the vCA3 resulted in increased anxiety-like behaviors in mice, highlighting the essential role of 5-HTR4 in the anxiolytic effects of agomelatine. Together, these results suggest that agomelatine's anxiolytic effects are closely associated with the suppression of 5-HTR4 expression in the vCA3, along with modulation of neuronal activity and GPCR signaling. This study not only uncovers the molecular mechanisms underlying agomelatine's anxiolytic mechanism but also identifies 5-HTR4 as a potential target for anxiety disorders.

Metastasis in breast cancer frequently spreads to the bones, significantly impacting patient outcomes and escalating mortality rates. The ataxia-telangiectasia mutated (ATM) kinase plays a pivotal role in regulating the DNA damage response (DDR) and has been linked to the invasion and spread of breast cancer. In this study we investigated the regulatory mechanisms of ATM in bone metastasis of breast cancer. The bone metastases models were constructed in female nude mice: The MDA-MB-231 tumor model was generated by implanting luciferase-tagged MDA-MB-231 cells into the left hind tibia and intra-caudal artery. For the SK-BR-3 tumor model, luciferase-tagged SK-BR-3 cells were injected through the intra-caudal artery. By conducting bioinformatics analyses and in vitro and in vivo experiments, we found that ATM expression was markedly elevated in bone metastasis samples compared to liver, lung or skin metastases. We demonstrated that ATM boosted the migrative and invasive abilities and pre-osteoclast differentiation of MDA-MB-231 and SK-BR-3 cell lines via expression of CCL2, an osteoclast-related cytokine. The regulation of ATM on CCL2 was found to be NFκB dependent. In vivo experiments confirmed that ATM knockout (ATM KO) or treatment with small-molecule ATM inhibitor KU55933 markedly inhibited osteoclastogenesis of SK-BR-3 cells and the progression of breast cancer bone metastasis. Our results underscore the pivotal role of ATM in regulating NFκB-CCL2 expression and promoting the progression of breast cancer bone metastasis.

Myocardial remodeling is critical pathological processes in various cardiovascular diseases, where redox imbalance and mitochondrial bioenergetic perturbations emerge as key determinants. Prohibitin 2 (PHB2), which resides in the mitochondrial inner membrane, serves as a critical regulator of mitochondrial homeostasis. In this study we investigated the protective role of PHB2 in transverse aortic constriction (TAC)-induced cardiac remodeling with a particular focus on its ability to safeguard the heart by improving mitochondrial function and alleviating oxidative stress. We revealed that PHB2 expression was significantly decreased in the heart of TAC mice and in Ang II (1 μM)-treated cardiomyocytes. Cardiac-specific PHB2 overexpression mitigated TAC-induced cardiac remodeling, improving cardiac function and attenuating hypertrophy. Additionally, PHB2 overexpression effectively suppressed oxidative stress in the hearts of TAC mice, while improving mitochondrial morphology and the integrity of inner membrane structure. Furthermore, PHB2 overexpression restored mitochondrial function in Ang II-treated cardiomyocytes evidenced by elevated ATP levels and enhanced oxidative phosphorylation capacity. IP-MS analysis revealed that PHB2 directly interacted with Transporter of Outer Mitochondrial Membrane 40 (TOMM40) to regulate mitochondrial function. Importantly, silencing TOMM40 abolished the protective effects of PHB2. We demonstrated that PHB2 preserves TOMM40 protein levels predominantly through inhibition of ubiquitin-dependent proteasomal degradation. Collectively, we discover a new function of PHB2 in safeguarding mitochondrial morphofunctional homeostasis in response to pathological stress through facilitating TOMM40 stabilization, suggesting PHB2 as a promising therapeutic target for potential interventions in heart diseases. Schematic illustration of PHB2's potential protective mechanism against cardiac hypertrophy. PHB2 protects against pressure overload-induced cardiac hypertrophy through preserving TOMM40 protein to maintain mitochondrial energetic homeostasis.

Glutamate excitotoxicity is intricately linked to the pathogenesis of neurodegenerative diseases, exerting a profound influence on cognitive functions such as learning and memory in mammals. Glutamate, while crucial for these processes, can lead to neuronal damage and death when present in excessive amounts. Our previous review delved into the cascade of excitotoxic injury events and the underlying mechanisms of excitotoxicity. Building on that foundation, this update summarizes the latest research on the role of excitotoxicity in neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis, as well as new cutting-edge techniques applied in the study of excitotoxicity. We also explore the mechanisms of action of various excitotoxicity inhibitors and their clinical development status. This comprehensive analysis aims to enhance our understanding of the nexus between excitotoxicity and neurodegenerative diseases, offering valuable insights for therapeutic strategies in these conditions.

The special AT-rich sequence binding protein 1 (SATB1) has been linked to neurodevelopmental disorders (NDDs) including developmental delay, intellectual disabilities (ID) and autism spectrum disorder (ASD). But the underlying biological mechanisms are still not fully understood. In this study we generated a rat model with a truncated Satb1 protein. We showed that Satb1 mutant caused growth retardation, microcephaly, altered ultrasonic vocalization and delayed neurobehavioral development in mutant pups as well as social and cognitive behavior deficits in adult mutants, mimicking the typical clinical characteristics of SATB1-associated NDDs. Injection of a GABAergic enhancer clonazepam (0.04 mg/kg, i.p.) effectively alleviated the abnormal social and cognitive behaviors in Satb1 mutant rats. Finally, RNA sequencing analysis further revealed a potential role of Satb1 in a cortical transcriptional regulatory network associated with NDDs including ID and ASD. Our results confirm the crucial roles of SATB1 in the pathogenesis of NDDs and provide insights into treatment strategies for SATB1-associated NDDs.

Triple-negative breast cancer (TNBC) is highly prone to lung metastasis, primarily driven by epithelial-mesenchymal transition (EMT) and vasculogenic mimicry (VM). Therefore, inhibiting EMT and VM represents a promising therapeutic strategy for TNBC. The immunosuppressive tumor microenvironment contributes substantially to poor treatment outcomes, with M2-type macrophages secreting excessive levels of TGF-β that promote both EMT and VM. In this study, we proposed a combination therapy strategy involving shikonin (SHK) and JQ1 delivered via a mesoporous polydopamine-based Pickering emulsion (termed MPDA@PE). This formulation significantly suppressed tumor growth and lung metastasis by inducing apoptosis in TNBC and inhibiting TGF-β-induced EMT and VM. Furthermore, MPDA@PE can be incorporated into a thermosensitive hydrogel for application in the prevention of TNBC recurrence and lung metastasis following surgical resection. These findings highlight a potential therapeutic approach for effective TNBC treatment. The combined administration of SHK and JQ1 inhibits both EMT and VM. This approach disrupts the nutrient supply in tumor tissues by blocking VM and suppresses tumor metastasis through EMT inhibition. Consequently, it demonstrates therapeutic efficacy against TNBC recurrence post-surgery and effectively limits lung metastasis.

Hyperuricemia and gout are increasingly prevalent among global health concerns, necessitating the development of more effective and safer urate level-lowering therapies. As uricase-based therapeutics represent a critical approach for managing refractory gout, challenges related to their activity, stability and immunogenicity need to be addressed. However, the structure-function relationships of uricase remain ambiguous. In this study, we performed structure-guided engineering on Arthrobacter globiformis Uricase (AgUricase), a typical bacterial enzyme characterized by its notable activity and thermostability, to elucidate the structural determinants that govern these critical properties. Through rational structure-based sequence design, we targeted the binding pocket of uric acid, the regions exhibiting structural divergence from the corresponding mammalian uricase, and the predicted channel for substrate entry. We generated fourteen recombinant AgUricase mutants via rational site-directed mutagenesis. Through further tests, we found that a series of AgUricase mutations T67A, K157A, E162G, F163A, L182F, L220P, L222V and F253A obviously reduced the enzymatic activity and/or thermostability. To probe the structural mechanism underlying these functional alterations, we performed molecular dynamics (MD) simulations on both the mutants and the WT enzyme. Notably, the L254N and P259K AgUricase mutants exhibited higher catalytic activity than the WT, although a minor decrease in thermostability was observed. These results demonstrate the crucial role of residues near the substrate access channel in modulating enzymatic function. This study provides new insights into uricase structure-function relationships, which could be fundamentally used for the design of improved uricase-based therapeutics for patients with hyperuricemia and gout.