Acta Pharmacologica Sinica最新文献

Amyloid-beta (Aβ) aggregation, phosphorylated tau accumulation and neuroinflammation are considered as three hallmarks of Alzheimer's disease (AD). Rhynchophylline (RN), the major alkaloid of a Chinese medicinal plant Uncaria rhynchophylla, has been shown to possess potent anti-AD effects. This study explored the effects of RN on Aβ pathology, tauopathy, and neuroinflammation using three AD mouse models, including TgCRND8, 3×Tg-AD, and 5×FAD, with RN treatment lasting for 4, 6, and 6 months, respectively, followed by behavioral tests and biological assays. In addition, BV2 cells were employed to further evaluate the biological effects of RN. RN treatment improved cognitive functions by reducing anxiety-like behaviors, enhancing recognition ability, and ameliorating learning impairments. It modulated Aβ processing through reducing the Aβ-producing enzyme activities and enhancing degradation enzyme activities, thereby diminishing Aβ accumulation. RN also decreased hyperphosphorylated tau proteins at Thr181, Thr205, Ser396, and Ser404 sites. Moreover, RN diminished neuroinflammation by reducing microglia and astrocyte activation and lowering the release of inflammatory cytokines. Furthermore, RN treatment could restore gut microbiota dysbiosis in 5×FAD mice. In BV2 cells, knockdown of p53, HDAC2, and Galectin-3 markedly enhanced the anti-inflammatory effects of RN. Overall, the anti-AD properties of RN were attributed to its regulation of multiple biological pathways, including regulation of the p53/PINK1 signaling pathway, inhibition of the HDAC2/AMPK signaling pathway, suppression of the Galectin-3/C/EBPβ/AEP signaling pathway, and modulation of gut microflora dysbiosis. This pioneering study unambiguously revealed the effects of RN on cognitive impairments, APP processing, tauopathy, and neuroinflammation in different transgenic mouse models with differing AD burdens, highlighting its potential as an anti-AD therapeutic agent and enhancing the scientific basis for its clinical use in treating AD.

Prenatal inflammation exposure (PIE) is associated with increased prevalence of cardiovascular diseases (CVDs) in offspring, including heart failure and hypertension. In this study, we investigated the molecular mechanisms underlying the prenatal programming of cardiac function. Pregnant mice were injected with poly (I:C) (20 mg/kg, i.p.) on day 10.5 of gestation. Mothers and pubs were fed with high-fat diet during lactation. Cardiac tissues of the offspring were collected for analysis. We found that prenatal poly (I:C) exposure significantly reduced fatty acid metabolism and impaired the homeostasis of energy metabolism in the heart tissues of offspring at the age of 4 weeks. RNA-sequencing analysis of the heart tissues revealed that prenatal poly (I:C) exposure resulted in decreased expression of the fatty acid oxidation-related enzymes and increased expression of glycolysis-related enzymes, enabling rewiring of energy metabolism. High-fat intake during lactation partially ameliorated cardiac fatty acid metabolism in the heart tissues and prevented cardiac dysfunction in offspring mice exposed to prenatal poly (I:C) at the age of 16 weeks. Collectively, abnormal cardiac fatty acid metabolism accounts for the prenatal poly (I:C) exposure-induced cardiac dysfunction, highlighting the potential of dietary interventions to prevent cardiac dysfunction for PIE offspring.

Idiopathic pulmonary fibrosis (IPF) is a progressive lethal disease. Profibrotic fibroblast polarization during wound healing is one of the main causes of IPF, and the molecular mechanisms involved have yet to be fully determined. LIM domain-only protein 7 (LMO7), which acts as an E3 ubiquitin ligase, is highly expressed in the lung, brain and heart and plays important roles in embryonic development, cancer progression, inflammatory bowel disease and Dreifuss muscular dystrophy (EDMD). In this study, we investigated the role of LMO7 in pulmonary fibrosis. Bleomycin (BLM)-induced lung fibrosis was established in mice. For AAV-mediated gene therapy, AAV-Lmo7 shRNA (AAV-Lmo7 shRNA) was intratracheally administered 6 days before BLM injection. Through transcriptome analysis, we found that the expression of LMO7 was significantly upregulated in the fibroblasts of IPF patients and BLM-induced mice. Knockdown of LMO7 impaired the profibrotic phenotype of fibroblasts in BLM-treated mice and in primary lung fibroblasts stimulated with TGF-β in vitro. We observed that LMO7 binds to SMAD7, mediating its degradation by polyubiquitination of lysine 70 and increasing the stability of TGF-β receptor 1 (TGFβR1). Finally, intratracheal administration of adeno-associated virus (AAV)-mediated Lmo7 shRNA significantly ameliorated the progression of BLM-induced lung fibrosis. Our results suggest that LMO7 is a promising target for blocking profibrotic fibroblast polarization for the treatment of fibrotic lung disease. A model for the role of LMO7 in TGF-β/SMAD signaling during pulmonary fibrosis. During pulmonary fibrosis, ubiquitin E3 ligase LMO7 is up-regulated, and binds with. SMAD7. LMO7 mediates the ubiquitination of SMAD7 on Lysine 70, leading to its degradation, and further enhances the stability of transforming growth factor-beta receptor 1 (TGFβR1).

Cullin 4B (CUL4B) is the scaffold protein in the CUL4B-RING E3 ubiquitin ligase (CRL4B) complex. Loss-of-function mutations in the human CUL4B gene result in syndromic X-linked intellectual disability (XLID). In addition to intellectual disability, patients with CUL4B mutations exhibit epilepsy. To date, the mechanism underlying epilepsy associated with CUL4B mutation has not been elucidated. Here, we show that male mice with Cul4b deleted in the nervous system are more susceptible to both pentylenetetrazole (PTZ)- and kainic acid (KA)-induced epilepsy and exhibit spontaneous epilepsy without any chemical inducers. We identify the CRL4B complex as an E3 ubiquitin ligase that targets GABA transporter 1 (GAT1). CUL4B deletion in male mice results in GAT1 accumulation and increased GABA reuptake, leading to impaired GABA-mediated inhibitory synaptic transmission. Treating CUL4B-deficient mice with the GAT1 inhibitor tiagabine effectively reverses the increased susceptibility to chemical-induced epilepsy and attenuates spontaneous epilepsy without the use of chemical inducers. We further confirm the role of CUL4B in the regulation of GAT1 levels and GABA uptake in neurons and astrocytes differentiated from induced pluripotent stem cells (iPSCs) derived from patients with CUL4B loss-of-function mutations. Our work reveals a novel mechanism underlying the pathogenesis of epilepsy and identifies a promising drug target for treating CUL4B mutation-associated epilepsy.

Multiple myeloma (MM) is a prevalent hematologic malignancy characterized by abnormal proliferation of cloned plasma cells. Given the aggressive nature and drug resistance of MM cells, identification of novel genes could provide valuable insights for treatment. In this study we performed machine learning in the RNA microarray data of purified myeloma plasma cell samples from five independent MM cohorts with 957 MM patients, and identified O-GlcNAcylation transferase (OGT) and cell division cycle 27 (CDC27) as the key prognostic genes for MM. We demonstrated a close link between OGT and CDC27 in MM cells by knockdown of OGT with siOGT, pharmacological inhibition of O-GlcNAcylation with OSMI-1 and pharmacological accumulation of O-GlcNAcylation with Thiamet G. Using mass spectrometry and immunoprecipitation, we identified the O-GlcNAcylated CDC27 protein as a key target protein that may be directly downregulated by OSMI-1 in MM.1S cells. We further revealed that O-GlcNAcylation maintained CDC27 protein stability by blocking the autophagy-lysosome pathway (ALP). Moreover, we demonstrated the enhanced antitumor efficacy of combined OSMI-1 and bortezomib (BTZ) treatment in MM cells both in vivo and in vitro. Thus, this study identifies a novel function of O-GlcNAcylation-related ALP in regulating CDC27 protein stability and a potential therapeutic strategy for treating MM.

Pre-pregnancy obesity (PPO) seriously threatens the health of both mother and offspring. Pre-pregnancy weight management is particularly important for the prevention of metabolic diseases in offspring. Semaglutide is one of the most effective glucagon-like peptide-1 agonizts for the management of obesity and metabolic diseases, but little is known about its effect on the long-term health of offspring. In this study we investigated the effects of semaglutide administered before pregnancy on the offspring health from PPO mice. PPO mice model was established by feeding with high-fat diet for 16 weeks, and then injected with semaglutide (30 nmol/kg^-1·d^-1, sc.) for 22 days before pregnancy. After the treatment, the mice were mated with normal males or underwent in vitro fertilization (IVF) for offspring reproduction. We showed that the semaglutide treatment not only improved the lipid and glucose metabolic disorders and fertility of PPO mice, but also significantly reversed the overweight, impaired energy balance, adipose inflammatory state, lipid and glucose metabolic disorders and insulin resistance of their IVF offspring. By conducting RNA-seq analysis, SOD activity and malondialdehyde assays in ovaries, as well as ROS staining in oocytes, we revealed that the semaglutide treatment reduced the elevated oxidative stress in ovaries and high ROS levels in oocytes from PPO mice, possibly through activating the PI3K/AKT pathway and improving the state of SOD. Interestingly, incubation of oocytes from semaglutide-treated dams with H₂O₂ (100 μM) in vitro during IVF blocked the protective effects of semaglultide against the metabolic disorders in the offspring. In conclusion, semaglutide treatment before pregnancy effectively alleviates obesity-related metabolic disorders in offspring. The regulation of ROS in oocytes plays a crucial role in the protective effects of semaglutide.

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. NAFLD encompasses a spectrum of liver damage starting with liver steatosis and lipid disorders presented as the hallmark. Cannabinoid-2 receptor (CB2R) is the receptor of endocannabinoids mainly expressed in immune cells. Our preliminary study revealed the preventative role of CB2R in liver injury related to lipid metabolism. In this study, we aimed to explore the role of CB2R in NAFLD and the underlying mechanism related to microbial community. High-fat diet-induced NAFLD model was established in mice. We found that hepatic CB2R expression was significantly reduced in NAFLD mice and CB2R^-/- mice fed with normal chow. Interestingly, cohousing with or transplanted with microbiota from WT mice, or treatment with an antibiotic cocktail ameliorated the NAFLD phenotype of CB2R^-/- mice. The gut dysbiosis in CB2R^-/- mice including increased Actinobacteriota and decreased Bacteroidota was similar to that of NAFLD patients and NAFLD mice. Microbial functional analysis and metabolomics profiling revealed obviously disturbed tryptophan metabolism in NAFLD patients and NAFLD mice, which were also seen in CB2R^-/- mice. Correlation network showed that the disordered tryptophan metabolites such as indolelactic acid (ILA) and xanthurenic acid in CB2R^-/- mice were mediated by gut dysbiosis and related to NAFLD severity indicators. In vitro and in vivo validation experiments showed that the enriched tryptophan metabolites ILA aggravated NAFLD phenotypes. These results demonstrate the involvement of CB2R in NAFLD, which is related to gut microbiota-mediated tryptophan metabolites. Our findings highlight CB2R and the associated microbes and tryptophan metabolites as promising targets for the treatment of NAFLD.

Research shows that chronic pain may induce depression-like behaviors through impairing adult hippocampal neurogenesis (AHN) in the ventral dentate gyrus (DG), whereas restoration of AHN may effectively alleviate depression. The C-X-C motif chemokine receptor 2 (CXCR2) is a chemokine receptor involved in various neural activities of the hippocampus including AHN. In this study we investigated the role of CXCR2 of neural stem cells (NSCs) in the ventral DG in regulating both AHN and depression-like behaviors of mice with chronic neuropathic pain. Chronic neuropathic pain was induced in mice by the spared nerve injury (SNI) surgery; mechanical allodynia and depression-like behaviors were monitored, then mouse DG was collected for analysis. We observed that chronic neuropathic pain significantly decreased the number of immature neurons in the ventral DG by inhibiting the neuronal differentiation of NSCs; specific overexpression of CXCR2 in NSCs by injecting the adeno-associated virus (AAV) into the DG restored adult neurogenesis accompanied by alleviated depression-like behaviors in SNI mice. In contrast, the knockdown of CXCR2 in hippocampal NSCs of naive mice was sufficient to inhibit adult neurogenesis, inducing depression-like behaviors. Moreover, we found that the Wnt3a/β-catenin pathway was downregulated in the ventral DG of SNI mice, which was restored after CXCR2 overexpression or infusing a CXCR2 agonist CXCL1 into the ventral DG. We conclude that CXCR2 expressed in hippocampal NSCs is crucial for regulating adult neurogenesis and chronic pain-induced depression-like behavior, thus representing a new target for the treatment of chronic pain comorbid depression.

The deposition of β-amyloid (Aβ) in the brain is a crucial factor in the pathogenesis of Alzheimer's disease (AD). Insulin-degrading enzyme (IDE) plays a critical role in the balance between Aβ production and degradation. However, the regulatory mechanisms of IDE are not yet fully understood. Therefore, uncovering additional IDE regulatory mechanisms will help elucidate the pathogenesis of AD and identify key therapeutic targets for this disease. This study revealed that global Krüppel-like factor 9-mutant (Klf9^-/-) mice exhibited impaired cognitive function. Additionally, we found that Klf9 expression in hippocampal tissue was reduced in APPswe/PS1dE9 (APP/PS1) mice. This study also showed that Klf9 stimulates IDE expression and promotes the Aβ degradation process by directly binding to IDE and activating its transcription. Silencing IDE blocked the Klf9-induced Aβ degradation process. We stereotactically injected an adeno-associated virus to selectively overexpress IDE (AAV-IDE) in the hippocampal neurons of Klf9^-/- mice and found that the overexpression of IDE in hippocampal neurons ameliorated cognitive deficits and reduced the Aβ content in Klf9^-/- mice. Additionally, we also stereotactically injected AAV-Klf9 into the hippocampal neurons of APP/PS1 mice and found that overexpression of Klf9 in hippocampal neurons ameliorated cognitive deficits and reduced Aβ levels in APP/PS1 mice. These findings suggest that downregulation of Klf9 may be a key factor in AD progression, as it reduces Aβ clearance by decreasing IDE expression. Overexpression or activation of Klf9 may be a potential strategy for preventing the pathogenesis of AD.

Current anti-epileptic drugs remain to be unsatisfactory, new therapeutic approaches are needed. Circular RNA is a promising class of therapeutic RNAs. Recent studies have shown the role of circRNA in the pathologic process of epilepsy. In this study, we identified the circRNA in epileptic patients in remission that inhibited the epileptic course. By comparing the profiles of differentially expressed circRNAs in peripheral serum between patients in remission and those not in remission, we found that the level of hsa_circ_0000288 (circ288) was markedly elevated in the epileptic patients in remission. We established a kainic acid-induced status epilepticus model in mice. Overexpression of Circ288 by injecting adeno-associated virus (AAV)-circ288-overexpression vector into hippocampi significantly ameliorated epilepsy-induced neuronal injury, promoted hippocampus neurogenesis, and inhibited abnormal migration of newborn neurons into the dentate hilus. Moreover, circ288 overexpression significantly decreased the epileptiform discharges and the spontaneous seizures in the chronic phase of epileptogenesis and alleviated mood disorders (anxiety, depression), and cognitive deficits in epileptic mice. We revealed that circ288 directly bound to an RNA-binding protein caprin1 and inhibited its degradation. The protective action of circ288 was reversed by the knockdown of caprin1 in an in vitro epileptic model and lost in the neuron-specific caprin1 knockout mice (CaMK2α-Cre:Caprin1^f/f). Overexpression of circ288 or caprin1 raised the mRNA level of NMDA receptor 3B, a negative modulator of NMDA receptors, suggesting the involvement of the carpin1-NMDA receptor 3B pathway in the role of circ288. Given the disadvantages of circ288 overexpression by a virus, we constructed exosomes-encapsulated circ288 (EXO-circ288) and demonstrated that tail vein injection of EXO-circ288 exerted robust protective effects. This study provides a new avenue for developing anti-epileptic therapeutic RNAs.