Abstract 346: Lipophilic Statins Attenuate Human Atrial Fibroblast Viability In Vitro

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Kiranjit K Sran ◽  
Yun Li ◽  
Saeid Ghavami ◽  
Melanie Ngo ◽  
Rakesh C Arora ◽  
...  

Cardiovascular diseases (CVD) leading to heart failure are associated with myocardial cell loss and cardiac fibrosis. Hydroxymethylglutaryl-Coenzyme-A Reductase (HMGR) inhibitors ("statins") are widely used to limit cardiovascular events in patients with hypercholesterolemia and CVD by altering their lipid profile. HMGR inhibition reduces cholesterol precursor L-mevalonate production, whose depletion induces autophagy, apoptosis, and endoplasmic reticulum stress in various cell types. However it is unclear if this is a class effect or a phenomenon specific to various compounds. We examined the in vitro effect of HMGR inhibition on human atrial fibroblast (hATF) viability with particular reference to hydrophilic vs lipophilic compounds. Hypothesis- Lipophilic statins induce cell death in primary hATF via mevalonate depletion; whereas hydrophilic statins do not have any effect on hATF viability. IRB approval was obtained for collection of hATF from consenting patients undergoing open heart surgery. Cells were treated with atorvastatin, simvastatin or pravastatin (0.1, 1.0 or 10 λM) for 24, 48, 72 or 96 hours. Expression of proteins involved in the regulation of apoptosis and autophagy was assessed using immunoblotting. Cell viability was assessed using MTT assay. Treatment of hATF with 0.1 - 10 λM atorvastatin or simvastatin (lipophilic statins) resulted in progressively reduced cell viability in time and dose-dependent manner. Viability could be rescued by coincubation with mevalonate. Expression of key apoptotic cascade proteins -Bcl2, Bax and cleaved Caspase3 showed a clear induction of apoptosis. Also, there was an increase in Atg5-12 expression at 24h indicating induction of early autophagic response. Pravastatin (hydrophilic statin) did not affect cell viability or autophagy and apoptosis. We conclude that statin-induced cell death is mediated by mevalonate depletion, which activates intrinsic apoptotic pathways in hATF. Lipophilic statins impair the viability of hATFs in vitro, whereas hydrophilic statins have no effect on cell growth and cell viability of hATFs. This may represent an additional pleiotropic effect of statins, and may represent a novel therapeutic option for the prevention and treatment of cardiac fibrosis.

2020 ◽  
Vol 22 (1) ◽  
pp. 202
Author(s):  
Josephin Glück ◽  
Julia Waizenegger ◽  
Albert Braeuning ◽  
Stefanie Hessel-Pras

Pyrrolizidine alkaloids (PAs) are a group of secondary metabolites produced in various plant species as a defense mechanism against herbivores. PAs consist of a necine base, which is esterified with one or two necine acids. Humans are exposed to PAs by consumption of contaminated food. PA intoxication in humans causes acute and chronic hepatotoxicity. It is considered that enzymatic PA toxification in hepatocytes is structure-dependent. In this study, we aimed to elucidate the induction of PA-induced cell death associated with apoptosis activation. Therefore, 22 structurally different PAs were analyzed concerning the disturbance of cell viability in the metabolically competent human hepatoma cell line HepaRG. The chosen PAs represent the main necine base structures and the different esterification types. Open-chained and cyclic heliotridine- and retronecine-type diesters induced strong cytotoxic effects, while treatment of HepaRG with monoesters did not affect cell viability. For more detailed investigation of apoptosis induction, comprising caspase activation and gene expression analysis, 14 PA representatives were selected. The proapoptotic effects were in line with the potency observed in cell viability studies. In vitro data point towards a strong structure–activity relationship whose effectiveness needs to be investigated in vivo and can then be the basis for a structure-associated risk assessment.


2019 ◽  
Vol 18 (10) ◽  
pp. 1386-1393 ◽  
Author(s):  
Tereza C.C. Silva ◽  
Giselle P. de Faria Lopes ◽  
Noélio de J. Menezes-Filho ◽  
Diêgo M. de Oliveira ◽  
Ezequiel Pereira ◽  
...  

Background: A glioblastoma is a primary CNS tumor that is more aggressive and lethal than other brain tumors. Its location, rapid proliferation, invasive growth, angiogenesis and immunosuppression are the main factors that limit its treatment, making it a major challenge to neuro-oncology. Objective: This study investigated the in vitro effects of the alkaloid dihydrochelerythrine (DHC), which is extracted from Zanthoxylum stelligerum, on the viability, proliferation, cell death and β-catenin, NFκB, STAT3/pSTAT3 and interleukins roles. Method: In vitro experimental models of human (U251 and GL-15) and murine (C6) glioblastoma cells were cultured in the presence of DHC at increasing concentrations for MTT assay and exclusion trypan blue dye to determine EC50. Afterward, C6 and U251 cells were treated with 100 µM DHC or DMSO 0.1% for cell cycle, annexin and expression of β-catenin/NFκB/STAT3/pSTAT3 by flow cytometry or immunofluorescence. Interleukin quantification was made by Cytometric Bead Array. Results: A significant decrease was observed in C6 and U251 cell viability in a time and dose-dependent manner. GL-15 cell viability decreased only when treated with 200 µM DHC. This maximum concentration affected neither astrocytes nor microglia viability. A cytostatic effect of DHC was observed in C6 and U251 cells after 48 h of 100 µM DHC treatment. After 72 h of DHC treatment, C6 presented 80% of annexin-V+ cells compared to 10% of annexin-V+ U251 cells. C6 cells demonstrated significant high levels of NFκ B and β-catenin cytoplasmic fraction. Additionally, DHC treatment resulted in higher significant levels of IL-6 than did other interleukins and STAT3 up-regulation in U251 cells. Conclusion: These results demonstrate that DHC acts as a chemosensitizing agent selective for glioma cells not affecting non-tumor cells. Considering tumor heterogeneity, DHC demonstrated an anti-cancer potential to activate different cell death pathways. DHC demonstrated could be used for chemotherapy and immunotherapy applications in glioblastomas in the future.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Alison L Müller ◽  
Darren H Freed

There are many cell types that can contribute to cardiac fibrosis including atrial fibroblasts (AFs) and bone marrow-derived progenitor cells (MPCs). We have previously shown that MPCs display a myofibroblast phenotype in vitro which is linked to altered microRNA(miR)-301a expression, a miR affiliated with maintaining proliferation in numerous cell types. We have also shown that miR-301a influences a dichotomous phenotype in primary human MPCs isolated from patients undergoing open heart surgery. As both MPCs and AFs display a dichotomous phenotype where each cell type displays a phenotype that pathologically contributes to fibrosis, we transfected both MPCs and AFs with miR-301a. AFs were also isolated from patients undergoing open heart surgery. We observed decreases in levels of both mRNA and protein of collagen I, non-muscle myosin IIA, and EDA-fibronectin. These proteins are expressed in myofibroblasts, the cell type predominantly responsible for causing cardiac fibrosis. In addition, transfection of miR301a caused both cell types to increase proliferation, which was analyzed using MTT proliferation assays. These results indicate that miR-301a could be influencing a non-fibrotic phenotype, which could prove useful in cell therapy trials where progenitor cells are injected into scar tissue in order to help heal patients who have suffered from a myocardial infarction. Over-expressing miR-301a in cells used could prevent them from differentiating into pro-fibrotic phenotypes and encourage their proliferation, thereby potentiating their efficacy.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Zabirnyk ◽  
M Bogdanova ◽  
M Ferrer ◽  
M Perez ◽  
M Kaljusto ◽  
...  

Abstract Background Calcific aortic valve disease is the 2nd most frequent cause of open heart surgery. The valve interstitial cells (VIC) are crucial for calcification. SNF472 (a derivative of phytic acid) is a calcification inhibitor currently in clinical development for the treatment of cardiovascular calcification (Phase 2 CaLIPSO trial, EudraCT 2016–002834–59). SNF472 has been shown to inhibit vascular calcification in several preclinical models. Purpose 1. Establish a new model of calcification in cultured human VIC; 2. Investigate whether SNF472 would inhibit calcification in this model, and 3. Study if SNF472 might inhibit ongoing calcification processes. Methods Healthy and calcified aortic valves were obtained from heart transplant recipients and patients undergoing aortic valve replacement due to calcific valve disease, respectively. VIC were isolated and seeded in basic growth medium, osteogenic differentiation medium (Osteodiff) alone, and with addition of different concentrations of SNF472. The following series of studies were performed: 1. VIC from healthy and calcified valves were cultured for three weeks with Osteodiff; 2. VIC from calcified valves were cultured for 3 weeks in Osteodiff media with 0, 1, 3, 10, 30, or 100 μM SNF472; 3. VIC from calcified valves were cultured for 3 weeks in Osteodiff media in total, but after 1 or 2 weeks 30 or 100 μM SNF472 was added to the cultures (n=8). Calcification was visualized by Alzarin Red staining and quantified by spectrophotometry. Statistics analysis was performed nonparametric One-Way ANOVA (Friedman and Kruskal–Wallis tests) with Dunn's post-test. Results Calcification was found to be 30% stronger in cultures of VIC from calcified valves as compared to cultured VIC from healthy valves (p=0.03). SNF472 successfully inhibited VIC calcification in a dose-dependent manner. SNF472 concentrations of 1, and 3 μM inhibited calcification by 7% (not significant) and 66% (p=0.08) respectively. Concentrations of 10, 30, and 100 μM completely inhibited calcification. 30 and 100 μM of SNF472 added after 1 week reduced ongoing calcification by 84% (p<0.01) and 100% (p<0.01) respectively. When given after 2 weeks of ongoing calcification non-significant inhibition was still observed (21 and 30%, respectively). Conclusions VIC from calcified valves have a more pro-calcification phenotype than VIC from healthy valves. SNF472 is able to inhibit the development VIC calcification in vitro. By early intervention SNF472 is also able to stop the progression of ongoing calcification. SNF472 shows to be a promising therapy to treat heart valve calcification. Acknowledgement/Funding EC FP7 (GA 609020), Balearic Islands Government grant (ES01/TCAI/41_2017), FEDER 2014-2020, Laboratoris Sanifit, Palma, Spain; University of Oslo


2011 ◽  
Vol 22 (8) ◽  
pp. 1398-1408 ◽  
Author(s):  
Choon-Ho Park ◽  
Bo-Hwa Choi ◽  
Min-Woo Jeong ◽  
Sangjune Kim ◽  
Wanil Kim ◽  
...  

Vaccinia-related kinase 1 (VRK1) is a novel serine/threonine kinase that plays an important role in cell proliferation. However, little is known about the upstream regulators of VRK1 activity. Here we provide evidence for a role of protein kinase Cδ (PKCδ) in the regulation of murine VRK1. We show that PKCδ interacts with VRK1, phosphorylates the Ser-355 residue in the putative regulatory region, and negatively regulates its kinase activity in vitro. Intriguingly, PKCδ-induced cell death was facilitated by phosphorylation of VRK1 when cells were exposed to a DNA-damaging agent. In addition, p53 played a critical role in the regulation of DNA damage–induced cell death accompanied by PKCδ-mediated modulation of VRK1. In p53-deficient cells, PKCδ-mediated phosphorylation of VRK1 had no effect on cell viability. However, cells overexpressing p53 exhibited significant reduction of cell viability when cotransfected with both VRK1 and PKCδ. Taken together, these results indicate that PKCδ regulates phosphorylation and down-regulation of VRK1, thereby contributing to cell cycle arrest and apoptotic cell death in a p53-dependent manner.


2018 ◽  
Vol 96 (5) ◽  
pp. 702-706 ◽  
Author(s):  
Tanes I. Lima ◽  
Leonardo R. Silveira

The main goal of this study was to develop a straightforward and rapid microplate assay for measuring propidium iodide (PI) in C2C12 cells. The PI method has proven to be an efficient quantitative assay for analyzing cell viability through PI fluorescence analysis. Importantly, the protocol takes less than 30 min and the results are reproducible. C2C12 cells were exposed to an increasing concentration of palmitate for a period of 24 h to induce cell death, and the PI fluorescence increased in a concentration-dependent manner. Evaluation of mitochondrial function and the production of reactive oxygen species confirmed the deleterious effects of palmitate. Also, the microplate PI assay demonstrated high sensitivity, as indicated by the detection of modest fluctuations in cell viability in response to catalase overexpression in palmitate-treated cells. The microplate PI assay, therefore, offers an accurate method for use in in-vitro studies.


1997 ◽  
Vol 77 (05) ◽  
pp. 0920-0925 ◽  
Author(s):  
Bernd Pötzsch ◽  
Katharina Madlener ◽  
Christoph Seelig ◽  
Christian F Riess ◽  
Andreas Greinacher ◽  
...  

SummaryThe use of recombinant ® hirudin as an anticoagulant in performing extracorporeal circulation systems including cardiopulmonary bypass (CPB) devices requires a specific and easy to handle monitoring system. The usefulness of the celite-induced activated clotting time (ACT) and the activated partial thromboplastin time (APTT) for r-hirudin monitoring has been tested on ex vivo blood samples obtained from eight patients treated with r-hirudin during open heart surgery. The very poor relationship between the prolongation of the ACT and APTT values and the concentration of r-hirudin as measured using a chromogenic factor Ila assay indicates that both assays are not suitable to monitor r-hirudin anticoagulation. As an alternative approach a whole blood clotting assay based on the prothrombin-activating snake venom ecarin has been tested. In vitro experiments using r-hirudin- spiked whole blood samples showed a linear relationship between the concentration of hirudin added and the prolongation of the clotting times up to a concentration of r-hirudin of 4.0 µg/ml. Interassay coefficients (CV) of variation between 2.1% and 5.4% demonstrate the accuracy of the ecarin clotting time (ECT) assay. Differences in the interindividual responsiveness to r-hirudin were analyzed on r-hirudin- spiked blood samples obtained from 50 healthy blood donors. CV- values between 1.8% and 6% measured at r-hirudin concentrations between 0.5 and 4 µg/ml indicate remarkably slight differences in r-hirudin responsiveness. ECT assay results of the ex vivo blood samples linearily correlate (r = 0.79) to the concentration of r-hirudin. Moreover, assay results were not influenced by treatment with aprotinin or heparin. These findings together with the short measuring time with less than 120 seconds warrant the whole blood ECT to be a suitable assay for monitoring of r-hirudin anticoagulation in cardiac surgery.


2019 ◽  
Vol 19 (2) ◽  
pp. 112-119 ◽  
Author(s):  
Mariana B. de Oliveira ◽  
Luiz F.G. Sanson ◽  
Angela I.P. Eugenio ◽  
Rebecca S.S. Barbosa-Dantas ◽  
Gisele W.B. Colleoni

Introduction:Multiple myeloma (MM) cells accumulate in the bone marrow and produce enormous quantities of immunoglobulins, causing endoplasmatic reticulum stress and activation of protein handling machinery, such as heat shock protein response, autophagy and unfolded protein response (UPR).Methods:We evaluated cell lines viability after treatment with bortezomib (B) in combination with HSP70 (VER-15508) and autophagy (SBI-0206965) or UPR (STF- 083010) inhibitors.Results:For RPMI-8226, after 72 hours of treatment with B+VER+STF or B+VER+SBI, we observed 15% of viable cells, but treatment with B alone was better (90% of cell death). For U266, treatment with B+VER+STF or with B+VER+SBI for 72 hours resulted in 20% of cell viability and both treatments were better than treatment with B alone (40% of cell death). After both triplet combinations, RPMI-8226 and U266 presented the overexpression of XBP-1 UPR protein, suggesting that it is acting as a compensatory mechanism, in an attempt of the cell to handle the otherwise lethal large amount of immunoglobulin overload.Conclusion:Our in vitro results provide additional evidence that combinations of protein homeostasis inhibitors might be explored as treatment options for MM.


2020 ◽  
Vol 17 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Xuan Chen ◽  
Sumei Zhang ◽  
Peipei Shi ◽  
Yangli Su ◽  
Dong Zhang ◽  
...  

Objective: Ischemia-reperfusion (I/R) injury is a pathological feature of ischemic stroke. This study investigated the regulatory role of miR-485-5p in I/R injury. Methods: SH-SY5Y cells were induced with oxygen and glucose deprivation/reoxygenation (OGD/R) to mimic I/R injury in vitro. Cells were transfected with designated constructs (miR-485- 5p mimics, miR-485-5p inhibitor, lentiviral vectors overexpressing Rac1 or their corresponding controls). Cell viability was evaluated using the MTT assay. The concentrations of lactate dehydrogenase, malondialdehyde, and reactive oxygen species were detected to indicate the degree of oxidative stress. Flow cytometry and caspase-3 activity assay were used for apoptosis assessment. Dual-luciferase reporter assay was performed to confirm that Rac family small GTPase 1 (Rac1) was a downstream gene of miR-485-5p. Results: OGD/R resulted in decreased cell viability, elevated oxidative stress, increased apoptosis, and downregulated miR-485-5p expression in SH-SY5Y cells. MiR-485-5p upregulation alleviated I/R injury, evidenced by improved cell viability, decreased oxidative markers, and reduced apoptotic rate. OGD/R increased the levels of Rac1 and neurogenic locus notch homolog protein 2 (Notch2) signaling-related proteins in cells with normal miR-485-5p expression, whereas miR- 485-5p overexpression successfully suppressed OGD/R-induced upregulation of these proteins. Furthermore, the delivery of vectors overexpressing Rac1 in miR-485-5p mimics-transfected cells reversed the protective effect of miR-485-5p in cells with OGD/R-induced injury. Conclusion: This study showed that miR-485-5p protected cells following I/R injury via targeting Rac1/Notch2 signaling suggest that targeted upregulation of miR-485-5p might be a promising therapeutic option for the protection against I/R injury.


2018 ◽  
Vol 18 (2) ◽  
pp. 255-262 ◽  
Author(s):  
Aikebaier Maimaiti ◽  
Amier Aili ◽  
Hureshitanmu Kuerban ◽  
Xuejun Li

Aims: Gallic acid (GA) is generally distributed in a variety of plants and foods, and possesses cell growth-inhibiting activities in cancer cell lines. In the present study, the impact of GA on cell viability, apoptosis induction and possible molecular mechanisms in cultured A549 lung carcinoma cells was investigated. Methods: In vitro experiments showed that treating A549 cells with various concentrations of GA inhibited cell viability and induced apoptosis in a dose-dependent manner. In order to understand the mechanism by which GA inhibits cell viability, comparative proteomic analysis was applied. The changed proteins were identified by Western blot and siRNA methods. Results: Two-dimensional electrophoresis revealed changes that occurred to the cells when treated with or without GA. Four up-regulated protein spots were clearly identified as malate dehydrogenase (MDH), voltagedependent, anion-selective channel protein 1(VDAC1), calreticulin (CRT) and brain acid soluble protein 1(BASP1). VDAC1 in A549 cells was reconfirmed by western blot. Transfection with VDAC1 siRNA significantly increased cell viability after the treatment of GA. Further investigation showed that GA down regulated PI3K/Akt signaling pathways. These data strongly suggest that up-regulation of VDAC1 by GA may play an important role in GA-induced, inhibitory effects on A549 cell viability.


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