ABSTRACT
Synaptic elements from neuromuscular junctions (NMJs) undergo massive morphological and functional changes upon nerve injury. While morphological changes of NMJ-associated glia in response to injury has been investigated, their functional properties remain elusive. Perisynaptic Schwann cells (PSCs), glial cells at the NMJ, are essential for NMJ maintenance and repair, and are involved in synaptic efficacy and plasticity. Importantly, these functions are regulated by PSCs ability to detect synaptic transmission through, notably, muscarinic (mAChRs) and purinergic receptors' activation. Using Ca2+ imaging and electrophysiological recordings of synaptic transmission at the mouse NMJ, we investigated PSC receptors activation following denervation and during reinnervation in adults and at denervated NMJs in an ALS mouse model (SOD1G37R ). We observed reduced PSCs mAChR-mediated Ca2+ responses at denervated and reinnervating NMJs. Importantly, PSC phenotypes during denervation and reinnervation were distinct than the one observed during NMJ maturation. At denervated NMJs, exogenous activation of mAChRs greatly diminished galectin-3 expression, a glial marker of phagocytosis. PSCs Ca2+ responses at reinnervating NMJs did not correlate with the number of innervating axons or process extensions. Interestingly, we observed an extended period of reduced PSC mAChRs activation after the injury (up to 60 days), suggesting a glial memory of injury. PSCs associated with denervated NMJs in an ALS model (SOD1G37R mice) did not show any muscarinic adaptation, a phenotype incompatible with NMJ repair. Understanding functional mechanisms that underlie this glial response to injury may contribute to favor complete NMJ and motor recovery.
Subject(s)
Amyotrophic Lateral Sclerosis , Amyotrophic Lateral Sclerosis/metabolism , Animals , Cholinergic Agents/metabolism , Mice , Neuroglia/physiology , Neuromuscular Junction/metabolism , Schwann Cells/metabolism , Superoxide Dismutase-1/metabolismABSTRACT
Signal transducers and activators of transcription 3 (STAT3) acts as a transcriptional signal transducer, converting cytokine stimulation into specific gene expression. In tumor cells, aberrant activation of the tyrosine kinase pathway leads to excessive and continuous activation of STAT3, which provides further signals for tumor cell growth and surrounding angiogenesis. In this process, the tumor-associated protein Annexin A2 interacts with STAT3 and promotes Tyr705 phosphorylation and STAT3 transcriptional activation. In this study, we found that (20S) ginsenoside Rh2 (G-Rh2), a natural compound inhibitor of Annexin A2, inhibited STAT3 activity in HepG2 cells. (20S) G-Rh2 interfered with the interaction between Annexin A2 and STAT3, and inhibited Tyr705 phosphorylation and subsequent transcriptional activity. The inhibitory activity of STAT3 leaded to the negative regulation of the four VEGFs, which significantly reduced the enhanced growth and migration ability of HUVECs in co-culture system. In addition, (20S)G-Rh2 failed to inhibit STAT3 activity in cells overexpressing (20S)G-Rh2 binding-deficient Annexin A2-K301A mutant, further proving Annexin A2-mediated inhibition of STAT3 by (20S)G-Rh2. These results indicate that (20S)G-Rh2 is a potent inhibitor of STAT3, predicting the potential activity of (20S)G-Rh2 in targeted therapy applications.
Subject(s)
Annexin A2/antagonists & inhibitors , Carcinoma, Hepatocellular/drug therapy , Gene Expression Regulation, Neoplastic/drug effects , Ginsenosides/pharmacology , Liver Neoplasms/drug therapy , STAT3 Transcription Factor/antagonists & inhibitors , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Annexin A2/genetics , Annexin A2/metabolism , Apoptosis , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Cell Cycle , Cell Movement , Cell Proliferation , Humans , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism , Tumor Cells, Cultured , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolismABSTRACT
(20S) ginsenoside Rh2 (G-Rh2), a major bioactive metabolite of ginseng, effectively inhibits the survival and proliferation of human liver cancer cells. However, its molecular targets and working mechanism remain largely unknown. Excitingly, we screened out heat shock protein 90 alpha (HSP90A), a key regulatory protein associated with liver cancer, as a potential target of (20S) G-Rh2 by phage display analysis and mass spectrometry. The molecular docking and thermal shift analyses demonstrated that (20S) G-Rh2 directly bound to HSP90A, and this binding was confirmed to inhibit the interaction between HSP90A and its co-chaperone, cell division cycle control protein 37 (Cdc37). It is well-known that the HSP90A-Cdc37 system aids in the folding and maturation of cyclin-dependent kinases (CDKs). As expected, CDK4 and CDK6, the two G0-G1 phase promoting kinases as well as CDK2, a key G1-S phase transition promoting kinase, were significantly downregulated with (20S) G-Rh2 treatment, and these downregulations were mediated by the proteasome pathway. In the same condition, the cell cycle was arrested at the G0-G1 phase and cell growth was inhibited significantly by (20S) G-Rh2 treatment. Taken together, this study for the first time reveals that (20S) G-Rh2 exerts its anti-tumor effect by targeting HSP90A and consequently disturbing the HSP90A-Cdc37 chaperone system. HSP90A is frequently overexpressed in human hepatoma cells and the higher expression is closely correlated to the poor prognosis of liver cancer patients. Thus, (20S) G-Rh2 might become a promising alternative drug for liver cancer therapy.
Subject(s)
Biomarkers, Tumor/metabolism , Carcinoma, Hepatocellular/drug therapy , Cell Cycle Proteins/metabolism , Chaperonins/metabolism , Gene Expression Regulation, Neoplastic/drug effects , Ginsenosides/pharmacology , HSP90 Heat-Shock Proteins/metabolism , Liver Neoplasms/drug therapy , Apoptosis , Biomarkers, Tumor/genetics , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Cell Cycle , Cell Cycle Proteins/genetics , Cell Proliferation , Chaperonins/genetics , HSP90 Heat-Shock Proteins/genetics , Humans , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Tumor Cells, CulturedABSTRACT
Objective: In this study, we investigated the effect and mechanism of action of eugenol on oxidized low-density lipoprotein (ox-LDL)-induced abnormal proliferation and migration of human vascular smooth muscle cells (HVSMCs). Methods: HVSMCs were treated with 100 ug/mL ox-LDL for 24 hours to establish a cell model. After 1-hour pretreatment, eugenol at concentrations of 5, 25, and 50 uM was added. Cell viability was assessed using an MTT assay, PCNA expression was detected using Western blot, cell cycle distribution was analyzed using flow cytometry, and cell migration ability was evaluated using wound healing and Transwell migration assays. To investigate the mechanisms, Ang II receptors were inhibited by 1000 nM valsartan, MFG-E8 was knocked down by shRNA, MCP-1 was inhibited by siRNA, and MFG-E8 was overexpressed using plasmids. Results: The findings from this study elucidated the stimulatory impact of ox-LDL on the proliferation and functionality of HVSMCs. Different concentrations of eugenol effectively mitigated the enhanced activity of HVSMCs induced by ox-LDL, with 50 uM eugenol exhibiting the most pronounced inhibitory effect. Flow cytometry and Western blot results showed ox-LDL reduced G1 phase cells and increased PCNA expression, while 50 uM eugenol inhibited ox-LDL-induced HVSMC proliferation. In wound healing and Transwell migration experiments, the ox-LDL group showed larger cell scratch filling and migration than the control group, both of which were inhibited by 50 uM eugenol. Inhibiting the Ang II/MFG-E8/MCP-1 signaling cascade mimicked eugenol's effects, while MFG-E8 overexpression reversed eugenol's inhibitory effect. Conclusion: Eugenol can inhibit the proliferation and migration of ox-LDL-induced HVSMCs by inhibiting Ang II/MFG-E8/MCP-1 signaling cascade, making it a potential therapeutic drug for atherosclerosis.
ABSTRACT
Myocarditis can cause ventricular wall thickening due to myocardial edema. If the condition improves, the ventricular wall thickening should gradually decrease; a persistent thickening of the patient's ventricular wall indicates the coexistence of hypertrophic cardiomyopathy (HCM) and myocarditis. A 30-year-old man was referred to our hospital with continuous chest pain accompanied by profuse sweating. He suffered from fever for two days (the maximum body temperature: 38 °C) and the conditions improved following the use of antipyretics as self-administered medication before admission. Electrocardiogram exhibited ST-segment elevation in leads I and avL, and ST-T wave changes in leads II, III, avF, and V1-V6. Marked elevation of cardiac troponin I was found on laboratory testing. Respiratory tract infection testing showed negative results. A TORCH screen revealed positive herpes simplex virus (HSV), rubella virus (RV), and cytomegalovirus (CMV) IgG but all with negative IgM titer. Ultrasonic echocardiography showed thickness of the interventricular septum (17 mm) and diffuse left ventricular (LV) hypokinesia, without LV outflow tract obstruction. After consultation with the cardiology team, a diagnosis of myocarditis with HCM was made. Patients with myocarditis should be alerted to the possibility of HCM when there is persistent ventricular wall thickening.
Subject(s)
Cardiomyopathy, Hypertrophic , Myocarditis , Adult , Cardiomyopathy, Hypertrophic/diagnosis , Echocardiography , Heart Ventricles , Humans , Male , Myocarditis/diagnosis , MyocardiumABSTRACT
(1) Background: Epithelial-mesenchymal transition (EMT) is an essential step for cancer metastasis; targeting EMT is an important path for cancer treatment and drug development. NF-κB, an important transcription factor, has been shown to be responsible for cancer metastasis by enhancing the EMT process. Our previous studies showed that (20S)Ginsenoside Rh2 (G-Rh2) inhibits NF-κB activity by targeting Anxa2, but it is still not known whether this targeted inhibition of NF-κB can inhibit the EMT process. (2) Methods: In vivo (20S)G-Rh2-Anxa2 interaction was assessed by cellular thermal shift assay. Protein interaction was determined by immuno-precipitation analysis. NF-κB activity was determined by dual luciferase reporter assay. Gene expression was determined by RT-PCR and immuno-blot. EMT was evaluated by wound healing and Transwell assay and EMT regulating gene expression. (3) Results: Anxa2 interacted with the NF-κB p50 subunit, promoted NF-κB activation, then accelerated mesenchymal-like gene expression and enhanced cell motility; all these cellular processes were inhibited by (20S)G-Rh2. In contrast, these (20S)G-Rh2 effect were completely eliminated by overexpression of Anxa2-K301A, an (20S)G-Rh2-binding-deficient mutant of Anxa2. (4) Conclusion: (20S)G-Rh2 inhibited NF-κB activation and related EMT by targeting Anxa2 in MDA-MB-231 cells.
Subject(s)
Annexin A2/metabolism , Antineoplastic Agents/pharmacology , Epithelial-Mesenchymal Transition/drug effects , Ginsenosides/pharmacology , NF-kappa B/metabolism , Cell Line, Tumor , Cell Movement/drug effects , Dose-Response Relationship, Drug , Humans , Neoplasm InvasivenessABSTRACT
BACKGROUND: The underlying changes of peripheral blood inflammatory cells (PBICs) in COVID-19 patients are little known. Moreover, the risk factors for the underlying changes of PBICs and their predicting role in severe COVID-19 patients remain uncertain. MATERIAL AND METHODS: This retrospective study including two cohorts: the main cohort enrolling 45 patients of severe type serving as study group, and the secondary cohort enrolling 12 patients of no-severe type serving as control group. The PBICs analysis was based on blood routine and lymphocyte subsets. The inflammatory cell levels were compared among patients according to clinical classifications, disease-associated phases, as well as one-month outcomes. RESULTS: Compared with patients of non-severe type, the patients of severe type suffered from significantly decreased counts of lymphocytes, eosinophils, basophils, but increased counts of neutrophils. These PBICs alterations got improved in recovery phase, but persisted or got worse in aggravated phase. Compared with patients in discharged group, the patients in un-discharged/died group suffered from decreased counts of total T lymphocytes, CD4 + T lymphocytes, CD8 + T lymphocytes, as well as NK cells at 2 weeks after treatment. Clinical classification-critically severe was the independently risk factor for lymphopenia (OR = 7.701, 95%CI:1.265-46.893, P = 0.027), eosinopenia (OR = 5.595, 95%CI:1.008-31.054, P = 0.049), and worse one-month outcome (OR = 8.984; 95%CI:1.021-79.061, P = 0.048). CONCLUSION: Lymphopenia and eosinopenia may serve as predictors of disease severity and disease progression in COVID-19 patients, and enhancing the cellular immunity may contribute to COVID-19 treatment. Thus, PBICs might become a sentinel of COVID-19, and it deserves attention during COVID-19 treatment.
Subject(s)
Betacoronavirus/pathogenicity , Coronavirus Infections/diagnosis , Eosinophils/pathology , Lymphocyte Subsets/pathology , Lymphopenia/diagnosis , Pneumonia, Viral/diagnosis , Aged , Biomarkers/blood , COVID-19 , Cell Count , Coronavirus Infections/blood , Coronavirus Infections/physiopathology , Coronavirus Infections/virology , Disease Progression , Eosinophils/virology , Female , Humans , Killer Cells, Natural/pathology , Killer Cells, Natural/virology , Lymphocyte Subsets/virology , Lymphopenia/blood , Lymphopenia/physiopathology , Lymphopenia/virology , Male , Middle Aged , Monocytes/pathology , Monocytes/virology , Neutrophils/pathology , Neutrophils/virology , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/physiopathology , Pneumonia, Viral/virology , Prognosis , Retrospective Studies , SARS-CoV-2 , Severity of Illness Index , Survival AnalysisABSTRACT
BACKGROUND: Ginsenoside compound K(C-K), a major metabolite of ginsenoside, exhibits anticancer activity in various cancer cells and animal models. A cell signaling study has shown that C-K inhibited nuclear factor-kappa B (NF-κB) pathway in human astroglial cells and liver cancer cells. However, the molecular targets of C-K and the initiating events were not elucidated. METHODS: Interaction between C-K and Annexin A2 was determined by molecular docking and thermal shift assay. HepG2 cells were treated with C-K, followed by a luciferase reporter assay for NF-кB, immunofluorescence imaging for the subcellular localization of Annexin A2 and NF-кB p50 subunit, coimmunoprecipitation of Annexin A2 and NF-кB p50 subunit, and both cell viability assay and plate clone formation assay to determine the cell viability. RESULTS: Both molecular docking and thermal shift assay positively confirmed the interaction between Annexin A2 and C-K. This interaction prevented the interaction between Annexin A2 and NF-кB p50 subunit and their nuclear colocalization, which attenuated the activation of NF-кB and the expression of its downstream genes, followed by the activation of caspase 9 and 3. In addition, the overexpression of Annexin A2-K320A, a C-K binding-deficient mutant of Annexin A2, rendered cells to resist C-K treatment, indicating that C-K exerts its cytotoxic activity mainly by targeting Annexin A2. CONCLUSION: This study for the first time revealed a cellular target of C-K and the molecular mechanism for its anticancer activity.
ABSTRACT
Annexin A2, a multifunctional tumor associated protein, promotes nuclear factor-kappa B (NF-κB) activation by interacting with NF-κB p50 subunit and facilitating its nuclear translocation. Here we demonstrated that two ginsenosides Rg5 (G-Rg5) and Rk1 (G-Rk1), with similar structure, directly bound to Annexin A2 by molecular docking and cellular thermal shift assay. Both Rg5 and Rk1 inhibited the interaction between Annexin A2 and NF-κB p50 subunit, their translocation to nuclear and NF-κB activation. Inhibition of NF-κB by these two ginsenosides decreased the expression of inhibitor of apoptosis proteins (IAPs), leading to caspase activation and apoptosis. Over expression of K302A Annexin A2, a mutant version of Annexin A2, which fails to interact with G-Rg5 and G-Rk1, effectively reduced the NF-κB inhibitory effect and apoptosis induced by G-Rg5 and G-Rk1. In addition, the knockdown of Annexin A2 largely enhanced NF-κB activation and apoptosis induced by the two molecules, indicating that the effects of G-Rg5 and G-Rk1 on NF-κB were mainly mediated by Annexin A2. Taken together, this study for the first time demonstrated that G-Rg5 and G-Rk1 inhibit tumor cell growth by targeting Annexin A2 and NF-κB pathway, and G-Rg5 and G-Rk1 might be promising natural compounds for targeted cancer therapy.
Subject(s)
Annexin A2/metabolism , Antineoplastic Agents/pharmacology , Biological Products/pharmacology , Molecular Targeted Therapy , Active Transport, Cell Nucleus/drug effects , Annexin A2/chemistry , Annexin A2/deficiency , Annexin A2/genetics , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Apoptosis/drug effects , Biological Products/chemistry , Biological Products/metabolism , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Down-Regulation/drug effects , Drug Discovery , Gene Knockdown Techniques , Ginsenosides/chemistry , Hep G2 Cells , Humans , Molecular Docking Simulation , NF-kappa B p50 Subunit/metabolism , Protein ConformationABSTRACT
The 20S ginsenoside Rh2 (G-Rh2) effectively inhibits cancer cell growth and survival in both animal models and cell lines. However, its molecular targets and mechanism of action remain largely unknown. By screening for molecules that interact with (20S)G-Rh2 in a phage display assay, we have identified Annexin A2 as a potential target that mediates its anti-cancer activity. Isothermal titration calorimetry and a cellular thermal shift assay demonstrated that (20S)G-Rh2 directly bound to either recombinant or intracellular Annexin A2. This binding inhibited the interaction between Annexin A2 and the NF-кB p50 subunit, which attenuated the nuclear translocations of NF-кB p50 subunit and reduced the transactivation activity of NF-кB. Correspond to this result, (20S)G-Rh2 treatment significantly down-regulated the expression of IAPs (inhibitors of apoptosis), the well-established NF-кB targets that promote cell survival. Moreover, (20S)G-Rh2 synergized with Annexin A2 inactivation to promote apoptosis. Taken together, this study for the first time suggests a cellular target and a molecular pathway by which (20S)G-Rh2 inhibits cancer cell growth. As over-expression of Annexin A2 was evident in human hepatoma, (20S)G-Rh2 might be a promising natural compound for targeted liver cancer therapy.
Subject(s)
Annexin A2/metabolism , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Ginsenosides/pharmacology , Carcinoma, Hepatocellular/drug therapy , HEK293 Cells , Hep G2 Cells , Humans , Liver Neoplasms/drug therapy , NF-kappa B p50 Subunit/metabolismABSTRACT
Retinoblastoma (RB) is a childhood malignancy caused by inactivation of the RB gene, with neuron-specific enolase (NSE) levels considered as its diagnostic marker. MicroRNAs (miRNAs) have been proven to play a significant role in multiple physiological and pathological processes and several miRNAs were identified as tumor biomarkers in recent studies. In the present study, 65 plasma samples were collected from RB patients and 65 samples from healthy individuals to serve as controls. The miRNA levels were measured via quantitative reverse transcription-polymerase chain reaction and their association with RB was assessed by statistical data analysis and receiver operating characteristic curves. Plasma miRNA (miR)-320, miR-let-7e and miR-21 levels were downregulated in the patient samples, the areas under the curves (AUCs) were 0.548-0.660, whereas the AUCs of combined classifiers were ≥0.990. The plasma miRNA levels, particularly of miR-320, were found to be of value in RB diagnosis and may be considered as novel diagnostic biomarkers.
ABSTRACT
The purpose of our study was to investigate the expression levels of TREM-1 (triggering receptor expressed on myeloid cells-1) in U937 foam cells and determine whether TREM-1 regulates the production of tumor necrosis factor-alpha and interleukin-8 in these cells. Human U937 cells were incubated with phorbol 12-myristate 13-acetate and then oxidized human low-density lipoprotein to induce foam cell formation. Oil red O staining was used to identify the foam cells. The production of IL-8 and TNF-α by U937 foam cells was assayed by enzyme-linked immunosorbent assay. The expression of TREM-1 mRNA in U937 foam cells was detected by reverse transcription-polymerase chain reaction. Moreover, U937 foam cells were transfected by small interfering RNA using Lipofectamine 2000 to knockdown TREM-1. Western blot was performed to assay protein expression of TREM-1 and ELISA was used to examine the effect of TREM-1 knockdown on IL-8 and TNF-α production. PMA and ox-LDL induced U937 cells to form foam cells. The production of TNF-α and IL-8 was found to be significantly elevated in U937 foam cells, concomitant with a significant up-regulation of TREM-1 mRNA. TREM-1 siRNA was able to partially silence the expression of TREM-1 protein and remarkably inhibited TNF-α and IL-8 production in U937 foam cells, suggesting that TREM-1 is a positive regulator of TNF-α and IL-8 production in U937 foam cells. Our finding that TREM-1 controls the production of IL-8 and TNF-α in U937 foam cells defines a potentially critical role of TREM-1 in the pathogenesis of atherosclerosis and implicates TREM-1 as a potential therapeutic target for the disease.