Search Results (79)

Background: Aralia echinocaulis has therapeutic effects on rheumatoid arthritis (RA), with total polysaccharide and glycoside (TPGs) as main active components. RA pathogenesis involves gut microbiota dysbiosis and immune–metabolic crosstalk, but the role of microbiota-derived succinate in RA remains unclear. Objective: This study explored the role of succinate-GPR91 signaling in intestinal dendritic cells (DCs) in the context of RA and the therapeutic mechanism of A. echinocaulis TPGs. Methods: Collagen-induced arthritis (CIA) mice were treated with TPGs or exogenous succinate. Paw edema, inflammation, gut succinate levels, the Th17/regulatory T (Treg) balance, and DC activation via succinate-GPR91 were detected, and GPR91-targeting siRNA and CD4+ T-cell coculture assays for verification. Results: TPGs alleviated symptoms in CIA mice and restored the Th17/Treg balance by reducing intestinal succinate levels. Succinate activated DCs via GPR91 to promote Th17 differentiation, while TPGs suppressed DC maturation and Th17-driven inflammation, supporting the involvement of a gut-centric immunometabolic axis in RA. Conclusions: TPGs ameliorate RA by targeting the succinate-GPR91-Th17 pathway, identifying succinate as a novel RA target and TPGs as a potential microbiota-modulating agent. Full article

Kynurenic acid (KynA), a tryptophan metabolite that regulates immune homeostasis via G protein-coupled receptor 35 (GPR35), has an undefined role in post-myocardial infarction (MI) immune responses. To clarify this role, we established a murine MI model and administered KynA intraperitoneally to evaluate cardiac function and ventricular remodeling. Macrophage infiltration was assessed, and macrophages were depleted via clodronate liposomes to confirm their contribution to KynA-mediated cardioprotection. In bone marrow-derived macrophages (BMDMs), GPR35-targeted siRNA verified the receptor-dependent action of KynA. KynA improved cardiac function, reduced infarct scarring and fibrosis, and suppressed pro-inflammatory macrophage infiltration in MI mice, with these cardioprotective effects abrogated by macrophage depletion. Mechanistically, KynA inhibited voltage-dependent anion channel 1 oligomerization, prevented mitochondrial DNA leakage, and downregulated the cGAS/STING/TBK1/IκBα/P65 pathway in macrophages, while exogenous mitochondrial DNA counteracted this inhibition. Collectively, the KynA/GPR35 axis exerts cardioprotective effects against MI by attenuating macrophage pro-inflammatory responses, highlighting its potential as a novel therapeutic target. Full article

Glioblastoma multiforme (GBM) is characterized by aggressive growth, extensive vascularization, high metabolic malleability, and a striking capacity for therapy resistance. Current treatments involve surgical resection and concomitant radiation therapy and chemotherapy, prolonging survival times marginally due to the therapy resistance that is built up by the tumor cells. A growing body of research has identified exosomes as critical enablers of therapy resistance. These nanoscale vesicles enable GBM cells to disseminate oncogenic proteins, nucleic acids, and lipids that collectively promote angiogenesis, maintain autophagy under metabolic pressure, and suppress apoptosis. As interest grows in targeting tumor communication networks, exosome-based therapeutic strategies have emerged as promising avenues for improving therapeutic outcomes in GBM. This review integrates current insights into two complementary therapeutic strategies: inhibiting exosome biogenesis and secretion, and engineering exosomes as precision vehicles for the delivery of anti-tumor molecular cargo. Key molecular regulators of exosome formation—including the endosomal sorting complex required for transport (ESCRT) machinery, tumor susceptibility gene 101 (TSG101) protein, ceramide-driven pathways, and Rab GTPases—govern the sorting and release of factors that enhance GBM survival. Targeting these pathways through pharmacological or genetic means has shown promise in suppressing angiogenic signaling, disrupting autophagic flux via modulation of autophagy-related gene (ATG) proteins, and sensitizing tumor cells to apoptosis by destabilizing mitochondria and associated survival networks. In parallel, advances in exosome engineering—encompassing siRNA loading, miRNA enrichment, and small-molecule drug packaging—offer new routes for delivering therapeutic agents across the blood–brain barrier with high cellular specificity. Engineered exosomes carrying anti-angiogenic, autophagy-inhibiting, or pro-apoptotic molecules can reprogram the tumor microenvironment and activate both the intrinsic mitochondrial and extrinsic ligand-mediated apoptotic pathways. Collectively, current evidence underscores the potential of strategically modulating endogenous exosome biogenesis and harnessing exogenous engineered therapeutic exosomes to interrupt the angiogenic and autophagic circuits that underpin therapy resistance, ultimately leading to the induction of apoptotic cell death in GBM. Full article

We previously demonstrated that the activation of FGFR signaling in GIST may be a mechanism of GIST resistance to imatinib mesylate (IM). We show here that IM-resistant GIST cells lacking secondary KIT mutations overexpress claudin-1 on both transcriptional and translational levels. In contrast, a knockdown of CLDN1 or inhibition of its activity by PDS-0330 effectively restored GIST’s sensitivity to IM both in vitro and in vivo. This was evidenced by the increased expression of apoptotic markers (e.g., cleaved PARP and caspase-3) and the decreased proliferation rate of IM-resistant GIST T-1R cells treated with a combination of IM and PDS-0330 (or siRNA CLDN1). In concordance with these findings, a significant synergy was observed between IM and PDS-0330 in GIST T-1R cells. Importantly, decreased tumor size and weight were observed in IM-resistant GIST xenografts treated with a combination of IM and PDS-0330. Furthermore, the combined treatment of IM-resistant tumors induced an increase in intratumoral apoptosis and other changes, as defined by the histopathologic response rate. Based on the co-immunoprecipitation and immunofluorescence microscopy data, we also demonstrated the strong interaction pattern between CLDN1 and FGFR2. Of note, the inhibition or knockdown of CLDN1 effectively decreased the phosphorylation of FGFR2 and FRS-2, a well-known FGFR adaptor protein, thereby illustrating CLDN1’s ability to regulate FGFR-signaling and thereby promote FGFR-mediated survival in KIT-inhibited GIST. Consequently, CLDN1 inhibition in GIST effectively disrupted the FGFR-mediated pathway and re-sensitized tumor cells to IM. In concordance with these data, molecular profiling of CLDN1-inhibited GIST T-1R cells illustrated a significant decrease in the majority of FGFR transcripts, including FGFR2, 3, and 4. Additionally, several FGFR ligands (e.g., FGF14, -19, and -23) were also down-regulated in PDS-0330-treated GIST. Notably, exogenous FGF-2 increased CLDN1 expression in a time-dependent manner. In contrast, pan-FGFR inhibitors effectively reduced CLDN1 levels in IM-resistant GIST T-1R cells, thereby illustrating a cross-talk between CLDN1- and FGFR-mediated pathways in IM-resistant GIST. Based on subcellular fractionation and immunofluorescence microscopy data, we also observed partial relocalization of CLDN1 into the cytoplasm in IM-resistant GIST. Notably, PDS-0330 effectively abrogated this relocalization, suggesting that changes in CLDN1 subcellular distribution might also impact GIST resistance to IM. Lastly, based on our small cohort clinical study (n = 24), we observed the increased expression of CLDN1 in most “high-risk” primary GIST known to be associated with poor prognosis and aggressive behavior, thereby illustrating the prognostic value of increased CLDN1 expression in GIST and providing a further rationale to evaluate the effectiveness of CLDN1 inhibition for GIST therapy. Full article

Exogenous RNA application, also known as spray-induced gene silencing (SIGS), is a new approach in plant biotechnology that utilizes RNA interference (RNAi) to modify plant traits. This technique involves applying RNA solutions of double-stranded RNA (dsRNA), hairpin RNA (hpRNA), small interfering RNA (siRNA), or microRNA (miRNA) directly onto plant surfaces. This triggers RNAi-mediated silencing of specific genes within the plant or invading pathogens. While extensively studied for enhancing resistance to pathogens, the application of exogenous RNA to regulate plant endogenous genes remains less explored, creating a rich area for further research. This review summarizes and analyzes the studies reporting on the exogenously induced silencing of plant endogenes and transgenes using various RNA types. We also discuss the RNA production and delivery approaches, analyze the uptake and transport of exogenous RNAs, and the mechanism of action. The analysis revealed that SIGS/exoRNAi affects the expression of plant genes, which may contribute to crop improvement and plant gene functional studies. Full article

The transcription and replication of the genome of influenza A virus (IAV) take place in the nucleus of infected cells, which is catalyzed by the viral ribonucleoprotein (vRNP) complex. The nuclear import of the vRNP complex and its component proteins is essential for the efficient replication of IAV and is therefore prone to be targeted by host restriction factors. Herein, we found that host cellular protein keratin 6A (KRT6A) is a negative regulator of IAV replication because siRNA-mediated knockdown of KRT6A expression increased the growth titers of IAV, whereas exogenous overexpression of KRT6A reduced viral yields. The nuclear import of incoming vRNP complexes and newly synthesized nucleoprotein (NP) was significantly impaired when KRT6A was overexpressed. Further studies showed that KRT6A interacts with the four vRNP complex proteins—polymerase basic protein 1 (PB1), polymerase basic protein 2 (PB2), polymerase acidic protein (PA), and NP. Notably, the interaction between KRT6A and vRNP complex proteins had no effect on the nuclear import of PB2 or the PB1-PA heterodimer but impaired the interaction between NP and the nuclear import adaptor importin α3, thereby inhibiting the nuclear import of incoming vRNP complexes and newly synthesized NP. Moreover, KRT6A was further shown to suppress the assembly of the vRNP complex and consequently reduce viral polymerase activity. Together, our data uncover a novel role of KRT6A in counteracting the nuclear import and functions of the vRNP complex, thereby restricting the replication of IAV. Full article

Background: the treatment of squamous cell carcinomas of the oral cavity (OSCCs) is limited by the lack of reliable diagnostic/prognostic, and predictive markers, as well as by intrinsic tumor cell heterogeneity. 5-azacytidine (5-AZA) offers opportunities for cancer cell reprogramming to develop new target-specific treatments. The protein annexin A1 (ANXA1) is downregulated in head and neck squamous cell carcinoma (HNSCC), correlated with pathological differentiation grade. Objectives: this work aimed to further investigate the role of ANXA1 in OSCC progression based on 5-AZA activity. Methods: we used CAL27 and CAL33 cell lines, which differ in drug sensitivity and differentiation status. Results: CAL27 showed a higher expression of the stemness markers compared to CAL33 cells, but this positivity was lost after treatment with 5-AZA. This drug also decreased CAL27 cell motility, promoting a less aggressive phenotype. Moreover, 5-AZA increased ANXA1 expression only in CAL27. After siRNA-mediated downmodulation, we witnessed a significant rise in cell motility and the inversion of E-/N-cadherin expression, which was reverted again by 5-AZA. To investigate the role of exogenous ANXA1 derived from the tumor microenvironment, we treated CAL27 with Ac2-26, an ANXA1 mimetic peptide. Interestingly, we found that this peptide alone showed impacts similar to 5-AZA in reversing the aggressive phenotype. All these effects were not evidenced in CAL33 cells. Finally, to prove the loop of the exogenous protein, we detected increased expression of its receptors, formyl peptide receptors (FPRs), and their activation, leading to oncosuppressor effects. Conclusions: we propose that ANXA1 mediates the effects of 5-AZA only in poorly differentiated stemlike CAL27 cell lines. This suggests the relevance of ANXA1 as a diagnostic/prognostic biomarker in OSCCs, paving the way for personalized therapies to overcome treatment difficulties. Full article

Extracellular vesicles (EVs) contain bioactive lipids that play a key role in pathophysiology. We hypothesized that EVs released from salt-loaded hypertensive diabetic db/db mice have increased bioactive lipid content that inhibits intracellular calcium mobilization and increases the activity of renal epithelial sodium channels (ENaC). An enrichment of sphingomyelins (SMs) was found in small urinary EVs (uEVs) isolated from salt-loaded hypertensive diabetic db/db mice (n = 4) compared to non-salt loaded db/db mice with diabetes alone (n = 4). Both groups of mice were included in the same cohort to control for variability. Cultured mouse cortical collecting duct (mpkCCD) cells loaded with a calcium reporter dye and challenged with small uEVs from hypertensive diabetic db/db mice showed a decrease in calcium mobilization when compared to cells treated with small uEVs from diabetic db/db mice. The amiloride-sensitive transepithelial current was increased in mpkCCD cells treated with small uEVs with abundant sphingomyelin content from hypertensive diabetic db/db mice in a dose- and time-dependent manner. Similar results were observed in mpkCCD cells and Xenopus 2F3 cells treated with exogenous sphingomyelin in a time-dependent manner. Single-channel patch clamp studies showed a decrease in ENaC activity in cells transiently transfected with sphingomyelin synthase 1/2 specific siRNA compared to non-targeting siRNA. These data suggest EVs with high sphingomyelin content positively regulate renal ENaC activity in a mechanism involving an inhibition of calcium mobilization. Full article

The increasing challenges posed by plant viral diseases demand innovative and sustainable management strategies to minimize agricultural losses. Exogenous double-stranded RNA (dsRNA)-mediated RNA interference (RNAi) represents a transformative approach to combat plant viral pathogens without the need for genetic transformation. This review explores the mechanisms underlying dsRNA-induced RNAi, highlighting its ability to silence specific viral genes through small interfering RNAs (siRNAs). Key advancements in dsRNA production, including cost-effective microbial synthesis and in vitro methods, are examined alongside delivery techniques such as spray-induced gene silencing (SIGS) and nanocarrier-based systems. Strategies for enhancing dsRNA stability, including the use of nanomaterials like layered double hydroxide nanosheets and carbon dots, are discussed to address environmental degradation challenges. Practical applications of this technology against various plant viruses and its potential to ensure food security are emphasized. The review also delves into regulatory considerations, risk assessments, and the challenges associated with off-target effects and pathogen resistance. By evaluating both opportunities and limitations, this review underscores the role of exogenous dsRNA as a sustainable solution for achieving viral disease resistance in plants. Full article

The establishment of neuronal polarity, involving axon specification and outgrowth, is critical to achieve the proper morphology of neurons, which is important for neuronal connectivity and cognitive functions. Extracellular factors, such as Wnts, modulate diverse aspects of neuronal morphology. In particular, non-canonical Wnt5a exhibits differential effects on neurite outgrowth depending upon the context. Thus, the role of Wnt5a in axon outgrowth and neuronal polarization is not completely understood. In this study, we demonstrate that Wnt5a, but not Wnt3a, promotes axon outgrowth in dissociated mouse embryonic cortical neurons and does so in coordination with the core PCP components, Prickle and Vangl. Unexpectedly, exogenous Wnt5a-induced axon outgrowth was dependent on endogenous, neuronal Wnts, as the chemical inhibition of Porcupine using the IWP2- and siRNA-mediated knockdown of either Porcupine or Wntless inhibited Wnt5a-induced elongation. Importantly, delayed treatment with IWP2 did not block Wnt5a-induced elongation, suggesting that endogenous Wnts and Wnt5a act during specific timeframes of neuronal polarization. Wnt5a in fibroblast-conditioned media can associate with small extracellular vesicles (sEVs), and we also show that these Wnt5a-containing sEVs are primarily responsible for inducing axon elongation. Full article

Castration is commonly used to reduce stink during boar production. In porcine adipose tissue, castration reduces androgen levels resulting in metabolic disorders and excessive fat deposition. However, the underlying detailed mechanism remains unclear. In this study, we constructed porcine preadipocyte models with and without androgen by adding testosterone exogenously. The fluorescence intensity of lipid droplet (LD) staining and the fatty acid synthetase (FASN) mRNA levels were lower in the testosterone-treated cells than in the untreated control cells. In contrast, the mRNA levels of adipose triglycerides lipase (ATGL) and androgen receptor (AR) were higher than in the testosterone-treated cells than in the control cells. Subsequently, transcriptomic sequencing of porcine preadipocytes incubated with and without testosterone showed that the mRNA expression levels of very long-chain fatty acid elongase 3 (ELOVL3), a key enzyme involved in fatty acids synthesis and metabolism, were high in control cells. The siRNA-mediated knockdown of ELOVL3 reduced LD accumulation and the mRNA levels of FASN and increased the mRNA levels of ATGL. Next, we conducted dual-luciferase reporter assays using wild-type and mutant ELOVL3 promoter reporters, which showed that the ELOVL3 promoter contained an androgen response element (ARE); furthermore, its transcription was negatively regulated by AR overexpression. In conclusion, our study reveals that testosterone inhibits fat deposition in porcine preadipocytes by suppressing ELOVL3 expression. Moreover, our study provides a theoretical basis for further studies on the mechanisms of fat deposition caused by castration. Full article

Hepatocellular carcinoma (HCC) is the most prevalent primary liver malignancy and is a major cause of cancer-related mortality in the world. This study aimed to characterize glutamine amino acid transporter expression profiles in HCC compared to those of normal liver cells. In vitro and in vivo models of HCC were studied using qPCR, whereas the prognostic significance of glutamine transporter expression levels within patient tumors was analyzed through RNAseq. Solute carrier (SLC) 1A5 and SLC38A2 were targeted through siRNA or gamma-p-nitroanilide (GPNA). HCC cells depended on exogenous glutamine for optimal survival and growth. Murine HCC cells showed superior glutamine uptake rate than normal hepatocytes (p < 0.0001). HCC manifested a global reprogramming of glutamine transporters compared to normal liver: SLC38A3 levels decreased, whereas SLC38A1, SLC7A6, and SLC1A5 levels increased. Also, decreased SLC6A14 and SLC38A3 levels or increased SLC38A1, SLC7A6, and SLC1A5 levels predicted worse survival outcomes (all p < 0.05). Knockdown of SLC1A5 and/or SLC38A2 expression in human Huh7 and Hep3B HCC cells, as well as GPNA-mediated inhibition, significantly decreased the uptake of glutamine; combined SLC1A5 and SLC38A2 targeting had the most considerable impact (all p < 0.05). This study revealed glutamine transporter reprogramming as a novel hallmark of HCC and that such expression profiles are clinically significant. Full article

Iron is often accumulated in the liver during pathological conditions such as cirrhosis and cancer. Elevated expression of glucose transporters GLUT1 and GLUT3 is associated with reduced overall survival in patients with hepatocellular carcinoma. However, it is not known whether iron can regulate glucose transporters and contribute to tumor proliferation. In the present study, we found that treatment of human liver cell line HepG2 with ferric ammonium citrate (FAC) resulted in a significant upregulation of GLUT3 mRNA and protein in a dose-dependent manner. Similarly, iron accumulation in mice fed with high dietary iron as well as in mice injected intraperitoneally with iron dextran enhanced the GLUT3 expression drastically in the liver. We demonstrated that iron-induced hepatic GLUT3 upregulation is mediated by the LKB1/AMPK/CREB1 pathway, and this activation was reversed when treated with iron chelator deferiprone. In addition, inhibition of GLUT3 using siRNA prevented iron-mediated increase in the expression of cell cycle markers and cellular hyperproliferation. Furthermore, exogenous sodium beta-hydroxybutyrate treatment prevented iron-mediated hepatic GLUT3 activation both in vitro and in vivo. Together, these results underscore the importance of iron, AMPK, CREB1 and GLUT3 pathways in cell proliferation and highlight the therapeutic potential of sodium beta-hydroxybutyrate in hepatocellular carcinoma with high GLUT3 expression. Full article

The role if insulin-like growth factor binding protein-2 (IGFBP-2) in mediating chemoresistance in breast cancer cells has been demonstrated, but the mechanism of action is unclear. This study aimed to further investigate the role of IGFBP-2 in the DNA damage response induced by etoposide in MCF-7, T47D (ER+ve), and MDA-MB-231 (ER-ve) breast cancer cell lines. In the presence or absence of etoposide, IGFBP-2 was silenced using siRNA in the ER-positive cell lines, or exogenous IGFBP-2 was added to the ER-negative MDA-MB-231 cells. Cell number and death were assessed using trypan blue dye exclusion assay, changes in abundance of proteins were monitored using Western blotting of whole cell lysates, and localization and abundance were determined using immunofluorescence and cell fractionation. Results from ER-positive cell lines demonstrated that upon exposure to etoposide, loss of IGFBP-2 enhanced cell death, and this was associated with a reduction in P-DNA-PKcs and an increase in γH2AX. Conversely, with ER-negative cells, the addition of IGFBP-2 in the presence of etoposide resulted in cell survival, an increase in P-DNA-PKcs, and a reduction in γH2AX. In summary, IGFBP-2 is a survival factor for breast cancer cells that is associated with enhancement of the DNA repair mechanism. Full article

Extracellular vesicles (EVs) have been found to have the characteristics of their parent cells. Based on the characteristics of these EVs, various studies on disease treatment using mesenchymal stem cell (MSC)-derived EVs with regenerative activity have been actively conducted. The therapeutic nature of MSC-derived EVs has been shown in several studies, but in recent years, there have been many efforts to functionalize EVs to give them more potent therapeutic effects. Strategies for functionalizing EVs include endogenous and exogenous methods. In this study, human umbilical cord MSC (UCMSC)-derived EVs were selected for optimum OA treatments with expectation via bioinformatics analysis based on antibody array. And we created a novel nanovesicle system called the IGF-si-EV, which has the properties of both cartilage regeneration and long-term retention in the lesion site, attaching positively charged insulin-like growth factor-1 (IGF-1) to the surface of the UCMSC-derived Evs carrying siRNA, which inhibits MMP13. The downregulation of inflammation-related cytokine (MMP13, NF-kB, and IL-6) and the upregulation of cartilage-regeneration-related factors (Col2, Acan) were achieved with IGF-si-EV. Moreover, the ability of IGF-si-EV to remain in the lesion site for a long time has been proven through an ex vivo system. Collectively, the final constructed IGF-si-EV can be proposed as an effective OA treatment through its successful MMP13 inhibition, chondroprotective effect, and cartilage adhesion ability. We also believe that this EV-based nanoparticle-manufacturing technology can be applied as a platform technology for various diseases. Full article