Immunization of recombinant NS3 protein (protease region) of dengue virus induces high levels of CTLA-4 and apoptosis in splenocytes of BALB/c mice.

DENV infection outcomes depend on the host's variable expression of immune receptors and mediators, leading to either resolution or exacerbation. While the NS3 protein is known to induce robust immune responses, the specific impact of its protease region epitopes remains unclear. This study investigated the effect of recombinant NS3 protease region proteins from all four DENV serotypes on splenocyte activation in BALB/c mice (n = 5/group). Mice were immunized with each protein, and their splenocytes were subsequently stimulated with homologous antigens. We measured the expression of costimulatory molecules (CD28, CD80, CD86, CD152) by flow cytometry, along with IL-2 production, CD25 expression, and examined the antigen-specific activation of CD4 + and CD8 + T cells. Additionally, the expression of IL-1, IL-10, and TGF-ß1 in splenocytes from immunized animals was assessed. Apoptosis was evaluated using Annexin V/PI staining and DNA fragmentation analysis. Stimulation of splenocytes from immunized mice triggered apoptosis (phosphatidylserine exposure and caspase 3/7 activation) and increased costimulatory molecule expression, particularly CD152. Low IL-2 production and low CD25 expression, as well as sustained expression of the IL-10 gene. These results suggest that these molecules might be involved in mechanisms by which the NS3 protein contributes to viral persistence and disease pathogenesis.

Morphological and biochemical effects of carnosic acid on human hepatocellular carcinoma HepG2 cells / Efectos Morfológicos y Bioquímicos del ácido Carnósico en Células de Carcinoma Hepatocelular Humano HepG2

Background/aim: Autophagic cell death and apoptosis of tumor cells has become one of the main objectives in cancer treatment, whereas tumor cell lines are mainly used in studies for providing important data for the evaluation of potential anti cancer substances. In this study, our objective was to evaluate morphological and biochemical changes including rate of apoptosis and Alpha Fetoprotein (AFP) levels at different concentrations of Carnosic Acid (CA) on Human Hepatocellular Carcinoma HepG2 Cells.Materials and methods: Human Hepatocellular Carcinoma (7th passage HepG2 cells) Cell lines were cultured on 11 µM D263M schott glass coverslips placed in 12-well plates and were treated with DMSO, 1, 2.5, 5 and 10 µM concentrations of CA for 24, 48 and 72 hours. Morphological and biochemical data were recorded daily including apoptosis rates demonstrated by Caspase 3, Annexin V expressions under inverted light and Immunofluorescence microscopy, then data were analyzed for statistical significance. AFP, albumin and total protein levels were analyzed spectrophotometricaly for biochemical evaluation.Results: Our results showed that CA significantly inhibited HepG2 cell proliferation in a dose and time dependant manner and significantly caused the formation of autophagic vacuoles starting from 5µM and reaching significance at 10 µM concentrations. Significant decrease was observed in AFP when 48 and 72 hours expressions were examined, with the lowest level reached at 72 hours in the 10 µM CA group. Additionally, increase in albumin levels reached significance only in the 48 h group whereas non-significant increases were also observed in 24 h and 72 h groups.Conclusion: Our current study demonstrates significant increase in apoptosis rates by Carnosic Acid mainly at 10µM concentrations, supporting its anticancer effect on HepG2 cells. These findings are also supported by changes in biochemical analyses of Albumin and AFP levels at 10 µM concentrations.

Antecedentes / objetivos: La muerte celular autofágica y la apoptosis de células tumorales se ha convertido en uno de los principales objetivos en el tratamiento del cáncer, mientras que las líneas celulares tumorales se utilizan principalmente en estudios para proporcionar datos importantes para la evaluación de posibles sustancias anticancerígenas. En este estudio, nuestro objetivo fue evaluar los cambios morfológicos y bioquímicos, incluida la tasa de apoptosis y los niveles de alfa fetoproteína (AFP) a diferentes concentraciones de ácido carnósico (CA) en células de carcinoma hepatocelular humano HepG2.Materiales y métodos: Carcinoma hepatocelular humano (HepG2).Las líneas celulares se cultivaron en cubreobjetos de vidrio Schott D263M de 11 µM colocados en placas de 12 pocillos y se trataron con DMSO, concentraciones de CA 1, 2,5, 5 y 10 µM durante 24, 48 y 72 horas. Los datos morfológicos y bioquímicos se registraron diariamente, incluidas las tasas de apoptosis demostradas por Caspasa 3, las expresiones de Anexina V bajo luz invertida y microscopía de inmunofluorescencia, luego se analizaron los datos para determinar la significación estadística. Los niveles de AFP, albúmina y proteínas totales se analizaron espectrofotométricamente para evaluación bioquímica.Resultados: Nuestros resultados mostraron que CA inhibió significativamente la proliferación de células HepG2 de una manera dependiente de la dosis y el tiempo y causó significativamente la formación de vacuolas autofágicas comenzando desde 5 µM y alcanzando significancia a concentraciones de 10 µM. Se observó una disminución significativa en la AFP cuando se examinaron las expresiones de 48 y 72 horas, alcanzando el nivel más bajo a las 72 horas en el grupo de CA 10 µM. Además, el aumento en los niveles de albúmina alcanzó significación solo en el grupo de 48 h, mientras que también se observaron aumentos no significativos en los grupos de 24 hy 72 h.Conclusión: Nuestro estudio demuestra un aumento significativo en las tasas de apoptosis por el ácido carnósico principalmente a concentraciones de 10 µM, lo que respalda su efecto anticancerígeno en las células HepG2. Estos hallazgos también están respaldados por cambios en los análisis bioquímicos de los niveles de albúmina y AFP a concentraciones de 10 µM.

In Vitro Apoptotic Cell Death Assessment.

Chemical compounds induce cytotoxicity by various mechanisms, including interference in membrane integrity, metabolism, cellular component degradation or release, and cell division. Between the classic death pathways, namely, autophagy, apoptosis, and necrosis, apoptosis have been in the focus for the last several years as an important pathway for the toxicity of different types of xenobiotics. Because of that, having the tools to evaluate it is key for understanding and explaining the toxicodynamics of different classes of substances. Here, we describe a wide array of classic assays that can be easily implemented to evaluate apoptosis induction.

Anti-annexin V autoantibodies and vascular abnormalities in systemic sclerosis: a longitudinal study.

BACKGROUND: Annexins are a group of conserved proteins which exert several regulatory functions on various cellular activities. Increased frequency and levels of antibodies against annexin V have already been observed in several autoimmune diseases including systemic sclerosis (SSc), but their role as a vascular biomarker is unknown. The aim of this study was to determine the serum levels and the dynamical behavior of anti-annexin V antibodies over a 24 months follow-up in patients with SSc. METHODS: In this bicentric cross-sectional study, 70 patients with SSc were consecutively selected from March 2016 to April 2017. Demographic and clinical features, including the presence of active DUs, were collected. Serum anti-annexin V IgG and IgM antibodies were measured at baseline and after 6, 12 and 24 months of follow-up. Videocapillaroscopy was performed in all patients. RESULTS: Among the 70 SSc patients included anti-annexin V IgG was found in 11 patients (15.7%) (range of 15.88-39.48 U/mL) and anti-annexin V IgM in 10 patients (14.3%) (range of 14.16-22.69 U/mL) at baseline. During follow-up, the number of patients who were positive for anti-annexin V IgG and IgM remained stable over 24 months. Among the patients with positive anti-annexin V IgG at baseline the frequency of patients with necrosis or amputation of extremities, forced vital capacity less than 70% and pulmonary arterial hypertension (PAH) was significantly higher than in patients with negative anti-annexin V IgG antibodies. Patients with anti-annexin V IgG had also a higher Raynaud's Condition Score and a higher Health Assessment Questionnaire Disability Index (HAQ-DI) than patients without these antibodies at baseline. Patients with positive anti-annexin V IgM at baseline presented a higher frequency of PAH, compared to those with negative anti-annexin V IgM at baseline. CONCLUSIONS: Anti-annexin V antibodies are stable and do not change their positivity during a 24 month follow-up in SSc patients. Anti-annexin V IgG was associated with more severe interstitial lung involvement and digital microangiopathy, and patients with anti-annexin V IgG or IgM had a higher occurrence of PAH indicating an association of these biomarker with more severe disease.

Anti-annexin V autoantibodies and vascular abnormalities in systemic sclerosis: a longitudinal study

Abstract Background: Annexins are a group of conserved proteins which exert several regulatory functions on various cellular activities. Increased frequency and levels of antibodies against annexin V have already been observed in several autoimmune diseases including systemic sclerosis (SSc), but their role as a vascular biomarker is unknown. The aim of this study was to determine the serum levels and the dynamical behavior of anti-annexin V antibodies over a 24 months follow-up in patients with SSc. Methods: In this bicentric cross-sectional study, 70 patients with SSc were consecutively selected from March 2016 to April 2017. Demographic and clinical features, including the presence of active DUs, were collected. Serum anti-annexin V IgG and IgM antibodies were measured at baseline and after 6, 12 and 24 months of follow-up. Videocapillaroscopy was performed in all patients. Results: Among the 70 SSc patients included anti-annexin V IgG was found in 11 patients (15.7%) (range of 15.88-39.48 U/mL) and anti-annexin V IgM in 10 patients (14.3%) (range of 14.16-22.69 U/mL) at baseline. During follow-up, the number of patients who were positive for anti-annexin V IgG and IgM remained stable over 24 months. Among the patients with positive anti-annexin V IgG at baseline the frequency of patients with necrosis or amputation of extremities, forced vital capacity less than 70% and pulmonary arterial hypertension (PAH) was significantly higher than in patients with negative anti-annexin V IgG antibodies. Patients with anti-annexin V IgG had also a higher Raynaud's Condition Score and a higher Health Assessment Questionnaire Disability Index (HAQ-DI) than patients without these antibodies at baseline. Patients with positive anti-annexin V IgM at baseline presented a higher frequency of PAH, compared to those with negative anti-annexin V IgM at baseline. Conclusions: Anti-annexin V antibodies are stable and do not change their positivity during a 24 month follow-up in SSc patients. Anti-annexin V IgG was associated with more severe interstitial lung involvement and digital microangiopathy, and patients with anti-annexin V IgG or IgM had a higher occurrence of PAH indicating an association of these biomarker with more severe disease.(AU)

Caracasine acid, an ent-3,4-seco-kaurene, promotes apoptosis and cell differentiation through NFkB signal pathway inhibition in leukemia cells.

Caracasine acid (CA) is an ent-3,4-seco-kaurene isolated from the plant Croton micans. Decreased cancer cell lines viability was reported upon CA treatment. The present study aimed to investigate the mechanism of CA induced cytotoxicity using two human cell lines, Jurkat E6.1 (human cell T lymphoma) and HL-60 (human acute promyelocytic leukemia). Significant increases of apoptotic cell death markers upon CA treatment were observed: annexin-V positiveness, potential mitochondrial disturbances, cell cycle changes, caspase activation, and CD95 expression. These effects were not detected in normal lymphocytes. CA induced the appearance of Bax, cleaved caspase 3, and cytochrome c release in Jurkat cells, and cleaved caspase 3 and phosphorylated p53 in HL60 cells. Likewise, downregulation of anti-apoptotic proteins such as Bcl-x (Jurkat), Bcl-2, and XIAP (HL60) was observed with CA treatment. Both pathways, intrinsic and extrinsic were activated when cell lines were treated with CA. NF-κB p65 inhibition was observed in Jurkat cells and cell differentiation in HL-60 cells. CA could be a potential leader compound for the development of new drugs for leukemia treatment in humans.

Oxysterols selectively promote short-term apoptosis in tumor cell lines.

Oxysterols are 27-carbon oxidation products of cholesterol metabolism. Oxysterols possess several biological actions, including the promotion of cell death. Here, we examined the ability of several oxysterols to induce short-term death in cancerous (human breast cancer and mouse skin melanoma cells) and non-cancerous (human endothelial cells and lung fibroblasts) cell lines. We determined cell viability, Ki67 expression, cell cycle regulation, and apoptosis after 24-h incubations with oxysterols. We found that different oxysterols had different effects on the studied parameters. Moreover, the effects depended on cell type and oxysterol concentration. Three cytotoxic oxysterols (7-ketocholesterol, cholestane-3ß-5α-6ß-triol, and 5α-cholestane-3ß,6ß-diol) inhibited the S phase and stimulated the G0/G1 or G2/M phases. These oxysterols promoted apoptosis, determined with Annexin V and propidium iodide assays. These results showed that different oxysterols have cytotoxic effects depending on the cell line. The findings suggest a potential pharmacological utility of cytotoxic oxysterols.

Prevalencia de anticuerpos antifosfolípidos y anti anexina V en pacientes dializados de Bahía Blanca / Prevalence of antiphospholipid antibodies and anti anexin V in dialysis patients in Bahía Blanca / Prevalência de anticorpos antifosfolípides e anti anexina V em pacientes em diálise em Bahía Blanca

En los pacientes hemodializados son frecuentes las oclusiones de los accesos vasculares por una diálisis insuficiente y en un bajo porcentaje por un estado hipercoagulable desencadenado por anticuerpos dirigidos contra determinados componentes fosfolipídicos. El objetivo del trabajo fue evaluar la prevalencia de estos autoanticuerpos (APL) y del marcador anti anexina V en 79 pacientes en plan de hemodiálisis y en 66 donantes de sangre de la ciudad de Bahía Blanca. Para la detección del anticoagulante lúpico (AL) se realizaron estudios coagulométricos básicos, pruebas de detección, corrección con mezclas con plasma normal y ensayos confirmatorios con lisados plaquetarios. En paralelo, se efectuaron ensayos inmunológicos séricos: anticuerpos anticardiolipinas (ACL) IgM/IgG, anticuerpos anti β2 Glicoproteina I (aβ2GPI) IgM/IgG y anticuerpos anti anexina V IgM/IgG. Para estimar las diferencias se realizó el test de Fisher con una significancia del 5%. No se detectó anticoagulante AL en ninguna de las dos poblaciones. La prevalencia de los ACL IgG fue mayor en los dializados que en los dadores (31,6% vs. 12,1%, p: 0,0056); la correspondiente a las antiβ2 GPI fue similar (2,5% en dializados vs. 7,6% en dadores, p: 0,2458), mientras que la correspondiente a la anti anexina V IgG resultó mayor en dializados (16,4% vs. 4,5%, p: 0,0316). Los resultados obtenidos sugieren la importancia de monitorear la presencia de anticuerpos antifosfolípidos y anti anexina V previo al ingreso de un plan de diálisis para prevenir eventos trombóticos.

In hemodialysis patients, occlusions of vascular access are frequent due to insufficient dialysis and in a low percentage, due to a hypercoagulable state triggered by antibodies directed against certain phospholipid components. The objective of this work was to evaluate the prevalence of these autoantibodies (APL) and the anti-annexin V marker in 79 patients undergoing hemodialysis and in 66 blood donors in the city of Bahía Blanca. For the detection of lupus anticoagulant (LA), basic coagulometric studies, detection tests, correction with mixtures with normal plasma and confirmatory tests with platelet lysates were performed. In parallel, serum immunological assays were performed: IgM/IgG anticardiolipin antibodies (ACL), IgM/IgG anti-β2 glycoprotein I (aβ2GPI) antibodies and IgM/IgG anti-annexin V antibodies. To estimate the differences, a Fisher test with a significance of 5% was performed. Lupus anticoagulant (LA) was not detected in any of the two populations. The prevalence of IgG ACL was higher in the dialysate than in the donors (31.6% vs. 12.1%, p: 0.0056); the corresponding antiβ2GPI was similar (2.5% dialysate vs. 7.6% donors, p: 0.2458), while the corresponding anti-Annexin V IgG was higher in dialysate (16.4% vs. 4.5%, p: 0.0316). The results obtained suggest the importance of monitoring the presence of antiphospholipid and anti-annexin V antibodies prior to entry to a dialysis plan to prevent thrombotic events.

Em pacientes hemodialisados são frequentes as oclusões dos acessos vasculares devido a uma diálise insuficiente e, um percentual baixo, a um estado de hipercoagulabilidade desencadeado por anticorpos dirigidos contra determinados componentes dos fosfolípidos. O objetivo do trabalho foi avaliar a prevalência desses autoanticorpos (APL) e do marcador anti Anexina V em 79 pacientes em plano de hemodiálise e em 66 doadores de sangue da cidade de Bahía Blanca. Para a detecção do anticoagulante lúpico (AL) foram realizados estudos coagulométricos básicos, testes de detecção, correção com misturas com plasma normal e ensaios de confirmação com lisados de plaquetas. Em paralelo se realizaram ensaios imunológicos séricos: anticorpos anticardiolipinas (ACL) a IgM/IgG, anticorpos anti β 2 GlicoproteinaI (aβ 2GPI) IgM/IgG e anticorpos anti Anexina V IgM/IgG. Para estimar as diferenças foi realizado o teste de Fisher com uma significância de 5%. Não foi detectado anticoagulante AL em qualquer uma das duas populações. A prevalência de ACL IgG foi maior nos dialisados que nos doadores (31,6% vs. 12,1%, p: 0,0056); a correspondente às anti β 2GPI foi semelhante (2,5% em dialisados vs. 7,6% em doadores, p: 0,2458), enquanto que o correspondente à anti Anexina V IgG foi maior em dialisados (16,4% vs. 4.5 %, p: 0,0316). Os resultados obtidos sugerem a importância de monitorar a presença de anticorpos antifosfolipídios e anti Anexina V antes de entrar em um plano de diálise para prevenção de eventos trombóticos.

Proteoliposomes with the ability to transport Ca(2+) into the vesicles and hydrolyze phosphosubstrates on their surface.

We describe the production of stable DPPC and DPPC:DPPS-proteoliposomes harboring annexin V (AnxA5) and tissue-nonspecific alkaline phosphatase (TNAP) and their use to investigate whether the presence of AnxA5 impacts the kinetic parameters for hydrolysis of TNAP substrates at physiological pH. The best catalytic efficiency was achieved in DPPS 10%-proteoliposomes (molar ratio), conditions that also increased the specificity of TNAP hydrolysis of PPi. Melting behavior of liposomes and proteoliposomes was analyzed via differential scanning calorimetry. The presence of 10% DPPS in DPPC-liposomes causes a broadening of the transition peaks, with AnxA5 and TNAP promoting a decrease in ΔH values. AnxA5 was able to mediate Ca(2+)-influx into the DPPC and DPPC:DPPS 10%-vesicles at physiological Ca(2+) concentrations (∼2 mM). This process was not affected by the presence of TNAP in the proteoliposomes. However, AnxA5 significantly affects the hydrolysis of TNAP substrates. Studies with GUVs confirmed the functional reconstitution of AnxA5 in the mimetic systems. These proteoliposomes are useful as mimetics of mineralizing cell-derived matrix vesicles, known to be responsible for the initiation of endochondral ossification, as they successfully transport Ca(2+) and possess the ability to hydrolyze phosphosubstrates in the lipid-water interface.

Proteomic analysis identifies differentially expressed proteins after red propolis treatment in Hep-2 cells.

Here we investigated alterations in the protein profile of Hep-2 treated with red propolis using two-dimensional electrophoresis associated to mass spectrometry and apoptotic rates of cells treated with and without red propolis extracts through TUNEL and Annexin-V assays. A total of 325 spots were manually excised from the two-dimensional gel electrophoresis and 177 proteins were identified using LC-MS-MS. Among all proteins identified that presented differential expression, most were down-regulated in presence of red propolis extract at a concentration of 120 µg/mL (IC50): GRP78, PRDX2, LDHB, VIM and TUBA1A. Only two up-regulated proteins were identified in this study in the non-cytotoxic (6 µg/mL) red propolis treated group: RPLP0 and RAD23B. TUNEL staining assay showed a markedly increase in the mid- to late-stage apoptosis of Hep-2 cells induced by red propolis at concentrations of 60 and 120 µg/mL when compared with non-treated cells. The increase of late apoptosis was confirmed by in situ Annexin-V analysis in which red propolis extract induced late apoptosis in a dose-dependent manner. The differences in tumor cell protein profiles warrant further investigations including isolation of major bioactive compounds of red propolis in different cell lines using proteomics and molecular tests to validate the protein expression here observed.

Measurement of annexin V uptake and lactadherin labeling for the quantification of apoptosis in adherent Tca8113 and ACC-2 cells

Phosphatidylserine (PS) exposure occurs during the cell death program and fluorescein-labeled lactadherin permits the detection of PS exposure earlier than annexin V in suspended cell lines. Adherent cell lines were studied for this apoptosis-associated phenomenon to determine if PS probing methods are reliable because specific membrane damage may occur during harvesting. Apoptosis was induced in the human tongue squamous carcinoma cell line (Tca8113) and the adenoid cystic carcinoma cell line (ACC-2) by arsenic trioxide. Cells were harvested with a modified procedure and labeled with lactadherin and/or annexin V. PS exposure was localized by confocal microscopy and apoptosis was quantified by flow cytometry. The detachment procedure without trypsinization did not induce cell damage. In competition binding experiments, phospholipid vesicles competed for more than 95 and 90 percent of lactadherin but only about 75 and 70 percent of annexin V binding to Tca8113 and ACC-2 cells. These data indicate that PS exposure occurs in three stages during the cell death program and that fluorescein-labeled lactadherin permitted the detection of early PS exposure. A similar pattern of PS exposure has been observed in two malignant cell lines with different adherence, suggesting that this pattern of PS exposure is common in adherent cells. Both lactadherin and annexin V could be used in adherent Tca8113 and ACC-2 cell lines when an appropriate harvesting procedure was used. Lactadherin is more sensitive than annexin V for the detection of PS exposure as the physical structure of PS in these blebs and condensed apoptotic cell surface may be more conducive to binding lactadherin than annexin V.

Evaluation of annexin V and Calcein-AM as markers of mononuclear cell apoptosis during human immunodeficiency virus infection

Evaluation of apoptosis by flow cytometry is generally accomplished by methods that use annexin V-FITC as vital dye, which access phosphatidylserine exposed on the external membrane at the beginning of this process. In addition, the concomitant use of propidium iodide makes possible to verify the characteristic nuclear alterations in the late stages of apoptosis, as a consequence of the increase in membrane permeability. On the other hand, the use of calcein-AM in association with ethidium homodimer (EthD-1) allows the evaluation of cell apoptosis through detection of esterase activity and cellular membrane physical and chemical alterations. The aim of this study was to compare the sensibility of calcein-AM and EthD-1 with annexin V-FITC and propidium iodide for early apoptosis evaluation in peripheral blood mononuclear cell culture, obtained from HIV-infected patients. Apoptosis and cellular viability were detected and quantified by flow cytometry after 24 and 48 hours incubation times. Our results showed that calcein-AM/EthD-1 was more sensitive for apoptotic cell quantification in both incubation times than annexin V-FITC/propidium iodide (mean of 46.95 percent ± 3.56, p < 0.0001, for 24 hours and mean of 37.67 percent ± 2.47, p < 0.0014 for 48 hours), besides allowing to clearly define viable, apoptotic and dead cell populations.