AIM: To explore the effect of dihydroquercetin on visual function in mice with form deprivation myopia based on the NOD-like receptor thermoprotein domain-related protein 3(NLRP3)inflammasome pathway.METHODS: The C57BL/6 mice were randomly divided into control group and form deprivation myopia model group, and the form deprivation myopia model group was constructed by covering the right eye with a translucent eye patch. After successful modeling, the mice in the model group of form deprivation myopia were randomly divided into model group, low-, medium- and high-dose dihydroquercetin groups, and high-dose dihydroquercetin + NLRP3 agonist group. The diopter and axial length of mice in each group were detected. The kit was used to detect the levels of superoxide dismutase(SOD)and malondialdehyde(MDA)in retinal tissue. RT-qPCR was used to detect the mRNA expressions of NLRP3, apoptosis-associated spot-like protein(ASC), Caspase-1, IL-1β and IL-18 in retinal tissues. Western blot was used to detect the expression of NLRP3, ASC, cleaved Caspase-1, IL-1β and IL-18 proteins in retinal tissues. TUNEL staining was used to detect apoptosis in retinal tissue.RESULTS: Compared with the control group, the diopter of the mice in the model group decreased, and axial length increased, and the SOD decreased whereas MDA, NLRP3, ASC, Caspase-1, IL-1β, IL-18 increased, and the rate of apoptosis in retinal tissue increased(all P<0.05). Compared with the model group, the diopter of mice in the low-, medium- and high-dose dihydroquercetin groups increased, axial length shortened, the SOD increased, whereas MDA, NLRP3, ASC, Caspase-1, IL-1β, IL-18 decreased, and the rate of apoptosis in retinal tissue decreased(all P<0.05). Compared with the high-dose dihydroquercetin group, the high-dose dihydroquercetin+NLRP3 agonist group had reduced diopter, increased axial length, decreased SOD levels, elevated MDA, NLRP3, ASC, Caspase-1, IL-1β, and IL-18 levels, as well as increased apoptosis rate in retinal tissue(all P<0.05).CONCLUSION: Dihydroquercetin can improve visual function in mice with form deprivation myopia by inhibiting pyroptosis and oxidative stress responses, which may be related to the suppression of NLRP3 inflammasome. NLRP3 agonists can partially mitigate the effects of high-dose dihydroquercetin on form deprivation myopia in mice.

BACKGROUND:Pinoresinol diglucoside promotes bone formation and bone matrix synthesis and accelerates bone tissue repair.However,the mechanism of action and effects of this compound in osteoblasts need to be further explored. OBJECTIVE:To investigate the effect and mechanism of action of pinoresinol diglucoside on dexamethasone-treated osteoblasts based on the Wnt/β-catenin signaling pathway. METHODS:Different concentrations of dexamethasone groups and pinoresinol diglucoside groups were set to treat osteoblasts for 24 hours,and the optimal intervention concentrations were screened.Osteoblasts were treated with dexamethasone,pinoresinol diglucoside and inhibitor XAV-939.Then,control group,dexamethasone group,XVA-939 group,pinoresinol diglucoside group,pinoresinol diglucoside+XVA-939 group were set up.Cell counting kit-8 assay was used to detect cell activity.Alkaline phosphatase activity and caspase3/7 enzyme activity in cells were detected.Annexin V/PI staining and EdU assay were used to detect cell apoptosis and proliferation.Real-time qPCR and western blot were used to detect the mRNA and protein expression levels of Wnt3a,β-catenin,c-myc,osteocalcin,and type I collagen,respectively. RESULTS AND CONCLUSION:After dexamethasone and pinoresinol diglucoside intervened in osteoblasts for 24 hours,10 μmol/L dexamethasone was found to be the optimal intervention concentration for cell inhibition,and cell proliferation was most pronounced at a concentration of pinoresinol diglucoside of 100 μmol/L.Compared with the dexamethasone group,alkaline phosphatase activity was significantly enhanced(P<0.05)and caspase3/7 enzyme activity was significantly reduced(P<0.05)in the pinoresinol diglucoside group.Annexin V/PI staining and cell proliferation assay by EdU method showed that pinoresinol diglucoside inhibited apoptosis and promoted proliferation of osteoblasts after dexamethasone intervention.The mRNA and protein expression levels of Wnt3a,β-catenin,c-myc,osteocalcin,and type I collagen were significantly higher in the pinoresinol diglucoside group and pinoresinol diglucoside+XVA-939 group compared with the dexamethasone and XVA-939 groups(P<0.05).To conclude,pinoresinol diglucoside can inhibit osteoblast apoptosis after dexamethasone intervention,protect osteoblast activity and promote osteoblast proliferation by activating the Wnt/β-catenin signaling pathway,which may play a role in delaying steroid-induced osteonecrosis of the femoral head.

[This corrects the article DOI: 10.1016/j.apsb.2024.09.010.].

Cuproptosis, a recently identified form of regulated cell death triggered by excess intracellular copper, has emerged as a promising cytotoxic strategy for cancer therapy. However, the therapeutic efficacy of copper ionophores such as elesclomol (ES) is often hindered by cellular copper homeostasis mechanisms that limit copper influx and cuproptosis induction. To address this challenge, we developed a nanoagent utilizing outer membrane vesicle (OMV) derived from Akkermansia muciniphila (Akk) for co-delivery of antioxidant 1 copper chaperone (Atox1)-targeting siRNA and ES (siAtox1/ES@OMV) to tumors. In vitro, we demonstrated that Atox1 knockdown via siRNA significantly disrupted copper export mechanisms, resulting in elevated intracellular copper levels. Simultaneously, ES facilitated efficient copper influx and mitochondrial transport, leading to Fe-S cluster depletion, increased proteotoxic stress, and robust cuproptosis. In vivo, siAtox1/ES@OMV achieved targeted tumor delivery and induced pronounced cuproptosis. Furthermore, leveraging the immunomodulatory properties of OMVs, siAtox1/ES@OMV promoted T-cell infiltration and the activation of tumor-reactive cytotoxic T cells, enhancing tumor immune responses. The combination of siAtox1/ES-induced cuproptosis and immunogenic cell death synergistically suppressed tumor growth in both subcutaneous breast cancer and orthotopic rectal cancer mouse models. This study highlights the potential of integrating copper homeostasis disruption with a copper ionophore using an immunomodulatory OMV-based vector, offering a promising combinatorial strategy for cancer therapy.

Cyclin-dependent kinase 9 (CDK9) is a member of the transcription CDK subfamily and plays a role in transcriptional regulation. Selective CDK9 degraders possess potent clinical advantages over reversible CDK9 inhibitors. Herein, we report the first ATG101-recruiting selective CDK9 degrader, AZ-9, based on the hydrophobic tag kinesin degradation technology. AZ-9 showed significant degradation effects and selectivity toward other homologous cell cycle CDKs in vitro and in vivo, which could also affect downstream related phenotypes. Mechanism research revealed that AZ-9 recruits ATG101 to initiate the autophagy-lysosome pathway, and forms autophagosomes through the recruitment of LC3, which then fuses with lysosomes to degrade CDK9 and the partner protein Cyclin T1. These dates validated the existence of non-proteasomal degradation pathway of hydrophobic driven protein degradation strategy for the first time, which might provide research ideas for chemical induction intervention on other types of pathogenic proteins.

Idiopathic pulmonary fibrosis (IPF), a chronic interstitial lung disease, is characterized by aberrant wound healing, excessive scarring and the formation of myofibroblastic foci. Although the role of alternative splicing (AS) in the pathogenesis of organ fibrosis has garnered increasing attention, its specific contribution to pulmonary fibrosis remains incompletely understood. In this study, we identified an up-regulation of serine/arginine-rich splicing factor 7 (SRSF7) in lung fibroblasts derived from IPF patients and a bleomycin (BLM)-induced mouse model, and further characterized its functional role in both human fetal lung fibroblasts and mice. We demonstrated that enhanced expression of Srsf7 in mice spontaneously induced alveolar collagen accumulation. Mechanistically, we investigated alternative splicing events and revealed that SRSF7 modulates the alternative splicing of pyruvate kinase (PKM), leading to metabolic dysregulation and fibroblast activation. In vivo studies showed that fibroblast-specific knockout of Srsf7 in conditional knockout mice conferred resistance to bleomycin-induced pulmonary fibrosis. Importantly, through drug screening, we identified lomitapide as a novel modulator of SRSF7, which effectively mitigated experimental pulmonary fibrosis. Collectively, our findings elucidate a molecular pathway by which SRSF7 drives fibroblast metabolic dysregulation and propose a potential therapeutic strategy for pulmonary fibrosis.

Hepatic stellate cells (HSCs) are the primary fibrogenic cells in the liver, and their activation plays a crucial role in the development and progression of hepatic fibrosis. Here, we report that retinoid X receptor-alpha (RXRα), a unique member of the nuclear receptor superfamily, is a key modulator of HSC activation and liver fibrosis. RXRα exerts its effects by modulating calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ)-mediated activation of AMP-activated protein kinase-alpha (AMPKα). In addition, we demonstrate that K-80003, which binds RXRα by a unique mechanism, effectively suppresses HSC activation, proliferation, and migration, thereby inhibiting liver fibrosis in the CCl₄ and amylin liver NASH (AMLN) diet animal models. The effect is mediated by AMPKα activation, promoting mitophagy in HSCs. Mechanistically, K-80003 activates AMPKα by inducing RXRα to form condensates with CaMKKβ and AMPKα via a two-phase process. The formation of RXRα condensates is driven by its N-terminal intrinsic disorder region and requires phosphorylation by CaMKKβ. Our results reveal a crucial role of RXRα in liver fibrosis regulation through modulating mitochondrial activities in HSCs. Furthermore, they suggest that K-80003 and related RXRα modulators hold promise as therapeutic agents for fibrosis-related diseases.

Cancer multidrug resistance (MDR) impairs the therapeutic efficacy of various chemotherapeutics. Novel approaches, particularly the development of MDR reversal agents, are critically needed to address this challenge. This study demonstrates that tenacissoside I (TI), a compound isolated from Marsdenia tenacissima (Roxb.) Wight et Arn, traditionally used in clinical practice as an ethnic medicine for cancer treatment, exhibits significant MDR reversal effects in ABCB1-mediated MDR cancer cells. TI reversed the resistance of SW620/AD300 and KBV200 cells to doxorubicin (DOX) and paclitaxel (PAC) by downregulating ABCB1 expression and reducing ABCB1 drug transport function. Mechanistically, protein arginine methyltransferase 1 (PRMT1), whose expression correlates with poor prognosis and shows positive association with both ABCB1 and EGFR expressions in tumor tissues, was differentially expressed in TI-treated SW620/AD300 cells. SW620/AD300 and KBV200 cells exhibited elevated levels of EGFR asymmetric dimethylarginine (aDMA) and enhanced PRMT1-EGFR interaction compared to their parental cells. Moreover, TI-induced PRMT1 downregulation impaired PRMT1-mediated aDMA of EGFR, PRMT1-EGFR interaction, and EGFR downstream signaling in SW620/AD300 and KBV200 cells. These effects were significantly reversed by PRMT1 overexpression. Additionally, TI demonstrated resistance reversal to PAC in xenograft models without detectable toxicities. This study establishes TI's MDR reversal effect in ABCB1-mediated MDR human cancer cells through inhibition of PRMT1-mediated aDMA of EGFR, suggesting TI's potential as an MDR modulator for improving chemotherapy outcomes.
Humans ; Protein-Arginine N-Methyltransferases/antagonists & inhibitors* ; Drug Resistance, Neoplasm/drug effects* ; ErbB Receptors/genetics* ; Animals ; Cell Line, Tumor ; Drug Resistance, Multiple/drug effects* ; Methylation/drug effects* ; Saponins/administration & dosage* ; Mice ; Mice, Nude ; Mice, Inbred BALB C ; ATP Binding Cassette Transporter, Subfamily B/genetics* ; Doxorubicin/pharmacology* ; Paclitaxel/pharmacology* ; Female ; Repressor Proteins

The PIF7 gene is a member of the bHLH family, playing a pivotal role in plant germination. However, its roles in tea plants (Camellia sinensis) remain largely unexplored. In this study, we cloned the phytochrome-interacting factor gene CsPIF7 to elucidate its role in the germination of tea plants. Subcellular localization analysis demonstrated that CsPIF7 was localized in the nucleus. Yeast one-hybrid and dual-luciferase reporter assays demonstrated that CsPIF7 directly bound to a specific region (7-321 bp) of the CsEXP promoter, thereby repressing the expression of CsEXP. These findings suggest that CsPIF7 may modulate the germination of tea plants by inhibiting the expression of CsEXP. Quantitative real-time PCR results showed that both CsPIF7 and CsEXP exhibited high expression levels in tea buds, with different expression patterns in response to abscisic acid (ABA) treatment. Furthermore, both CsPIF7 and CsEXP were upregulated under cold stress at 4 ℃, indicating their involvement in the cold response of tea plants. Taken together, these results suggest that CsPIF7 regulates CsEXP expression in an ABA-dependent manner, thereby influencing the germination of tea plants. This study provides both theoretical and experimental insights into the molecular mechanisms governing the germination of tea plants, laying the groundwork for further exploring the role of PIF7 in plant development and stress responses.
Camellia sinensis/metabolism* ; Gene Expression Regulation, Plant ; Plant Proteins/metabolism* ; Abscisic Acid/pharmacology* ; Germination/genetics* ; Basic Helix-Loop-Helix Transcription Factors/metabolism* ; Promoter Regions, Genetic ; Cold Temperature