Polygonatum kingianum Coll. et Hemsl. (Huang Jing), a traditional Chinese medicinal herb, has long been used as a functional food and immune-enhancing remedy. Its polysaccharide component (PKP) is believed to drive immunomodulatory effects, though the molecular mechanisms behind its adjuvant potential remain unclear. PKP was isolated using water extraction, ethanol precipitation, enzymatic digestion, and purification. The immunostimulatory activity was assessed in vitro using RAW264.7 macrophages and primary macrophages from TLR4+/+ and TLR4-/- mice. Cytokine secretion (TNF-α, IL-6), nitric oxide production, and gene/protein expression were evaluated through RT-PCR, Western blotting, and immunofluorescence to analyze the activation of the TLR4/NF-κB/MAPK pathway. In vivo, the adjuvant activity of PKP was tested in BALB/c mice immunized with ovalbumin (OVA), measuring antigen-specific immune responses. The results revealed that PKP robustly activated macrophages in a TLR4-dependent manner, significantly enhancing TNF-α (3.8-fold) and IL-6 (2.5-fold) secretion, and upregulating MyD88, TRIF, p65-NF-κB, and MAPK phosphorylation. TLR4-/- macrophages showed abolished responses, confirming TLR4 as the critical receptor. PKP also enhanced antigen-specific IgG titers and Th1/Th2 cytokine production (IFN-γ, IL-4) in OVA-immunized mice, demonstrating its adjuvant efficacy. Notably, while PKP exhibited activity at higher in-vitro concentrations than LPS, its low toxicity and plant origin constitute key advantages over bacterial endotoxins; accordingly, PKP should be framed not as a more potent LPS alternative, but as a safer adjuvant candidate for vaccine development. In conclusion, PKP activates macrophages through the TLR4/MyD88/TRIF/NF-κB/MAPK axis and functions as a potent vaccine adjuvant, providing mechanistic validation for its traditional use and positioning it as a promising low-toxicity candidate for improving vaccine-mediated immunity.
Resveratrol (RES), a natural polyphenolic compound, has garnered significant attention for its therapeutic potential in various pathological conditions. This review explores how RES modulates mitophagy-the selective autophagic degradation of mitochondria essential for maintaining cellular homeostasis. RES promotes the initiation and execution of mitophagy by enhancing PINK1/Parkin-mediated mitochondrial clearance, reducing reactive oxygen species production, and mitigating apoptosis, thereby preserving mitochondrial integrity. Additionally, RES regulates mitophagy through the activation of key molecular targets such as AMP-activated protein kinase (AMPK), the mechanistic target of rapamycin (mTOR), deacetylases (SIRT1 and SIRT3), and mitochondrial quality control (MQC) pathways, demonstrating substantial therapeutic effects in multiple disease models. We provide a detailed account of the biosynthetic pathways, pharmacokinetics, and metabolic characteristics of RES, focusing on its role in mitophagy modulation and implications for medical applications. Potential adverse effects associated with its clinical use are also discussed. Despite its promising therapeutic properties, the clinical application of RES is limited by issues of bioavailability and pharmacokinetic profiles. Future research should concentrate on enhancing RES bioavailability and developing derivatives that precisely modulate mitophagy, thereby unlocking new avenues for disease therapy.
BACKGROUND: Circular RNAs (circRNAs) are the emerging informative RNAs, involved in cardiovascular diseases including atherosclerosis (AS). Endothelial injury is the initial qualitative change of AS. Thus, the objective of this study was to confirm the dysregulation and mechanism of circ_0000231 in cell model of AS at early stage in human umbilical vein endothelial cells (HUVECs) induced by oxidized low-density lipoprotein (ox-LDL). METHODS: The expression of circ_0000231, miR-590-5p and programmed cell death 4 (PDCD4) was detected using real-time quantitative PCR and western blot. Cell injury was measured with MTT, flow cytometry, caspase-3 activity assay and enzyme-linked immunosorbent assay (ELISA). The interaction among circ_0000231, miR-590-5p and PDCD4 was validated by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) and pull-down assays. RESULTS: Stress ox-LDL decreased cell viability, and increased apoptosis rate and caspase-3 activity in HUVECs in a dose- and time-dependent manner in concomitant with promotions of interleukin-6, interleukin-1β, tumor necrosis factor-α, LC3-II/I and Beclin-1 levels. Besides, circ_0000231 and PDCD4 expressions were upregulated, and miR-590-5p was downregulated in ox-LDL-stimulated HUVECs. Functionally, knockdown of circ_0000231 and overexpression of miR-590-5p could suppress ox-LDL-elicited above effects on apoptosis, autophagy and inflammatory response, accompanied with PDCD4 downregulation. Physically, miR-590-5p could directly interact with circ_0000231 and PDCD4. CONCLUSION: Downregulation of circ_0000231 suppresses HUVECs from ox-LDL-induced injury partially through regulating miR-590-5p/PDCD4 axis via competing endogenous RNA mechanism, showing a novel potential target for the pathology and treatment of endothelial injury in AS.
BackgroundLocal inflammation induced by microglial activation plays a significant role in the pathological process of cerebral ischemia. Angelica keiskei, a traditional botanical drug, can be used as a diuretic, laxative or galactagogue. Xanthoangelol (XA), an active chalcone compound from the aerial part of Angelica keiskei, has anti-inflammatory effects in the peripheral tissues. However, its effect against neuroinflammation is yet unclear.ObjectiveTo investigate whether XA could mitigate ischemic stroke damage through attenuating neuroinflammation due to microglia activation.MethodsMiddle cerebral artery occlusion/reperfusion (MCAO/R) induced cerebral ischemia and oxygen-glucose deprivation/reperfusion (OGD/R) or lipopolysaccharide (LPS)-stimulated BV2 microglia cells were utilized to evaluate XA's protection against ischemic injury and neuroinflammation. The severity of brain injury was assessed using 2, 3, 5-triphenyltetrazolium chloride (TTC) staining and neurological assessment. The expressions of inflammatory cytokines were quantified by enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR). Reactive oxygen species (ROS) were assessed using dichlorodihydrofluorescein diacetate (DCF-DA) staining. NF-κB p65 nuclear translocation was confirmed by immunofluorescence (IF) staining. The expressions of proteins were quantified by Western blotting.ResultsXA was efficacious in reducing infarct size and improving neurological function in MCAO/R mice. In ischemic brain tissue, XA reduced microglial activation and proinflammatory cytokine expression. In lipopolysaccharide (LPS) and OGD/R-induced cell models, XA suppressed the production of ROS and decreased the secretion of inflammatory cytokines. Additionally, XA suppressed the nuclear translocation and phosphorylation of NF-κB p65 and blocked the activation of NLR family pyrin domain containing 3 (NLRP3) inflammasome. The protection of XA against MCAO/R-induced damages was not attenuated in TLR4−/− and MD2−/− mice. Mito-TEMPO treatment reversed XA's anti-inflammatory properties in OGD/R-induced BV2 cells.ConclusionXA attenuates ischemic stroke injury by suppressing microglial inflammatory responses. This efficacy is tied to its antioxidant activity and is independent of Toll-like receptor 4 (TLR4) or myeloid differentiation protein 2 (MD2).
An 83-year-old Chinese man presented with a huge left chest wall hematoma and hemorrhagic shock 4 months after permanent pacemaker implantation. Computed Tomography of Angiogram of the left subclavian artery revealed a pseudoaneurysm. He underwent radiologically guided stenting followed by hematoma clearance. It is rare to have delayed formation of pseudoaneurysm at 4 months post pacemaker implantation. Radiologically guided stenting is the preferred treatment, followed by hematoma clearance. It is strongly advised against blind surgery for wound debridement or bleeding detection. Familiarizing with axillary vein anatomy, improving axillary vein cannulation skills, and detecting early complications of artery injury are key strategies in preventing pseudoaneurysm formation post pacemaker implantation.
Objective To analyze the clinical effects of left ventricular lead reimplantation on prognosis of heart failure patients with non-response to cardiac resynchronization therapy(CRT). Methods A total of 15 heart failure patients with non-response to CRT underwent left ventricular(LV) lead reimplantation during generator replacement for pacemaker battery depletion from January 2016 to December 2018 in Zhejiang Provincial People’s Hospital. LV lead position, QRS duration, LV end-diastolic diameter(LVEDd) and LV end-systolic diameter(LVESd)diameter, LV ejection fraction(LVEF), NYHA class, 6-min walk distance before and after LV lead reimplantation were compared. All patients were followed up and adverse events were recorded. Results LV lead was reimplanted successfully in 14 patients(93.3%). The reimplantation sites were anterolateral vein in 5 cases, anterior vein in 5 cases,posterolateral vein in 3 cases, and middle cardiac vein in 1 case. Pacing sites were all located at the basal and middle segments(100.0%). The response rate was 57.1% in 14 patients with successful reimplantation. LVEDd, LVESd, LVEF,6-min walk distance and NYHA class were improved after procedure compared to those before procedure(all P<0.05).During follow-up period, 6 patients died due to cardiogenic shock. Of them, 4 cases were non-response after lead reimplantation and one was the patient with lead reimplantation failure. Conclusion LV lead reimplantation may improve clinical efficacy in half of patients with non-response to first CRT.
Microglia exert diverse functions by responding in diverse ways to different stimuli, yet little is known about the plasticity of various phenotypes that microglia display. We used interferon (IFN)-γ, interleukin (IL)-4 and IL-10 to induce different phenotypes in mouse primary microglia. RNA sequencing was used to identify genes differentially expressed in response to stimulation, and the different stimulated populations were compared in terms of morphology, proliferative capacity, phagocytic ability and neurotoxicity. IFN-γ induced an "immunodefensive" phenotype characterizing both induction of filopodia and upregulation of inducible nitric oxide synthase (iNOS) and tumor necrosis factor α. Microglia with this phenotype mediated an acute inflammatory response accompanied by excellent proliferative capacity and neurotoxicity, and remained susceptible to remodeling for up to 48 h after initial stimulation. IL-4 induced an enduring "neuroimmunoregulatory" phenotype involving induction of lamellipodium and persistent upregulation of arginase (Arg)-1 and YM-1 expression. Microglia with this phenotype remained susceptible to remodeling for up to 24 h after initial stimulation. IL-10 induced an "immunosuppressive" phenotype involving induction of ameba-like morphology and upregulation of transforming growth factor β and IL-10 as well as inhibition of inflammation. This phenotype was accompanied by inhibition of self-proliferation, while its morphology, molecular properties and function were the least susceptible to remodeling. IFN-γ, IL-4, or IL-10 appear to induce substantially different phenotypes in microglia. The immunodefensive microglia induced by IFN-γ showed remarkable plasticity, which may help repair CNS inflammation damage under pathological condition. Chronic activation with IL-10 decreases microglial plasticity, which may help protect the brain form the immune response. Our research justifies and guides further studies into the molecular pathways that operate in each phenotype to help multitasking microglia regulate homeostasis in the brain.
Tetrastigma hemsleyanum Diels et Gilg is a valuable Chinese medicinal herb with a long history of clinical application. Our previous study isolated and characterized a purified polysaccharide from the aerial part of Tetrastigma hemsleyanum (SYQP) and found it having antipyretic and antitumor effects in mice. A preliminary mechanistic study suggests these effects may be related to the binding of toll-like receptor (TLR4). The objective of this study is to further explore the detailed stimulating characteristics of SYQP on TLR4 signaling pathway and its in vivo immune regulating effect. We use HEK-BLUE hTLR4, mouse and human macrophage cell lines, as research tools. In vitro results show SYQP activated HEK-BLUE hTLR4 instead of HEK-BLUE Null cells. The secretion and the mRNA expression of cytokines related to TLR4 signaling significantly increased after SYQP treatment in both PMA-induced THP-1 and RAW264.7 macrophage cell lines. The TLR4 antagonist TAK-242 can almost completely abolish this activation. Furthermore, molecules such as IRAK1, NF-κB, MAPKs, and IRF3 in both the MyD88 and TRIF branches were all activated without pathway selection. In vivo results show SYQP enhanced antigen-specific spleen lymphocyte proliferation and serum IgG levels in OVA-immunized C57BL/6 mice. Orally administered 200 mg/kg SYQP induced obvious tumor regression, spleen weight increase, and the upregulation of the mRNA expression of TLR4-related cytokines in Lewis lung carcinoma–bearing mice. These results indicate SYQP can act as both a human and mouse TLR4 agonist and enhance immune responses in mice ( p < 0.05). This study provides a basis for the development and utilization of SYQP as a new type of TLR4 agonist in the future.
BACKGROUND Myocardial infarction (MI) is the principal cause of mortality globally. Fraxetin (Fra) has anti-oxidative and anti-inflammatory properties. Nevertheless, the functional action of Fra in the progression of MI has never been elucidated. METHOD The in vivo model of MI was set up by ligating left anterior descending artery. The gene expression was tested by qRT-PCR and WB. The 2,3,5-triphenyltetrazolium chloride staining was applied to assess MI size. The cell viability was tested by MTT assay. Commercial kits were utilized to detect the activity of serum LDH and the levels of Fe2+, malondialdehyde (MDA), and glutathione (GSH). RESULTS Fra treatment could reduce the infraction size and restrain ferroptosis in rats with MI. Moreover, Fra reduced the activity of serum LDH, the accumulation of iron and the MDA level, and increased GSH and glutathione peroxidase 4 (GPX4) in rats with MI. Furthermore, Fra protected H9C2 myocardial cells against OGD/R-induced ferroptosis by up-regulating HO-1. Moreover, Fra activated phosphorylation of AKT and Nrf2 nuclear accumulation in MI in vivo and in vitro models. Notably, silencing Nrf2 enhanced the ferroptosis in H9C2 cells induced by OGD/R, while LY, an inhibitor of AKT phosphorylation, diminished the inhibition of Fra. CONCLUSION Fra attenuated MI-induced ferroptosis via AKT/Nrf2/HO-1 signaling, providing a potential therapeutic agent for MI.
Idiopathic pulmonary fibrosis (IPF), a chronic, progressive and irreversible disease, needs long-term treatment. Bicyclol was found to play a great role in pulmonary fibrosis, and the present study is to explore how bicyclol affects IPF with the involvement of microRNA-455-3p (miR-455-3p) and Bax. Bleomycin (BLM) was used to induce the IPF model in Sprague-Dawley rats to detect the expression of miR-455-3p, Bax, and B-cell lymphoma factor 2 (Bcl-2). Moreover, to further investigate the mechanisms of bicyclol, the BLM-induced fibrotic cell model was used after the lung epithelial cells HPAEpiC received miR-455-3p knockout treatment. The rats were then treated with vehicle and bicyclol, respectively. The apoptosis of fibrotic cells and Bax/Bcl-2 were identified. Inhibition function of bicyclol was optimal at a dose of 150 mg/kg. Bicyclol inhibited cell apoptosis and reduced Bax/Bcl-2 expression in rats. miR-455-3p could potentially bind to Bax gene. Bicyclol reduced the levels of methylenedioxyamphetamine, superoxide dismutase, and glutathione in rat lung tissue, inhibited the apoptosis of rats with IPF and upregulated miR-455-3p expression. In vitro studies showed that bicyclol significantly promoted miR-455-3p expression in HPAEpiC fibrosis. Bicyclol inhibited fibrosis-induced apoptosis of HPAEpiC in alveolar epithelial cells through promoting miR-455-3p, which inhibited Bax expression in IPF. Bicyclol may suppress the apoptosis of alveolar epithelial cells by upregulating miR-455-3p. This study laid a theoretical foundation for further understanding of IPF and searching for new molecular therapeutic targets.