scholarly journals Intense cardiac-targeted small extracellular vesicles-mediated delivery of RAGE siRNA attenuates inflammation in rat myocarditis model

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
H Kim ◽  
D Mun ◽  
J Kang ◽  
N Yun ◽  
B Joung
Keyword(s):  
Heart Disease ◽  
Western Blot ◽  
Extracellular Vesicles ◽  
Inflammatory Responses ◽  
Tnf Alpha ◽  
Major Barrier ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
In Vivo Inflammation ◽  
293 Cells

Abstract Background Despite advances in the field and new therapeutics being developed, heart disease remains the leading cause of mortality worldwide. Small extracellular vesicles (sEV) are 30–150 nm in diameter and ferry RNA and proteins to cells. sEV are a natural carrier of many signaling molecules and play an important role in heart disease. However, the high probability of off-target effects associated with these carriers is a major barrier to translation into clinical application. Purpose Our aim was to evaluate whether sEVs engineered to express potent cardiac targeting peptides (CTPs) could deliver siRNA to the heart and exert a therapeutic effect. Methods We use vectors encoding LAMP2B (sEV) or CTP-LAMP2B (PsEV) into HEK 293 cells expressing. sEVs were purified from culture media of HEK 293 cells by serial centrifugation followed by tangential flow filtration (TFF) system. sEV and PsEV were loaded with siRNAs by Exo-Fect™ exosome transfection reagent, and were treated into H9C2 rat cardiomyocyte. TNF-alpha were then added to the cells to induce inflammation. And sEVs were intravenously injected into myocarditis rat. Inflammation factors of in vitro and in vivo inflammation model were identified by western blot. Echocardiographic examination was also performed in rat. Results The successful development of PsEVs was analyzed by Western blot and TEM. We observed a 4 fold increase from that of the previously developed sEVs in H9C2 cells and a 200% increase in cardiac-specific delivery without toxicity in rat model. AGE is involved in proinflammatory/pro-apoptotic processes. To block RAGE, we loaded RAGE siRNA (siRAGE) in sEV that had high expression of PsEV. Characteristics of sEVs were maintained despite siRNA load.In inflammatory cell models and rat disease models, PsEV-treated groups significantly reduced molecular levels associated with inflammatory responses such as RAGE, IL-6, TNF-alpha, COX2, HMGB1, and p-p65 / p65. Conclusions Our results suggest that PsEV can potentially serve as a treatment delivery vehicle for heart disease. Scheme Funding Acknowledgement Type of funding source: None

Structural and Functional Interactions of KCl Cotransport Proteins KCC1 and KCC3 in Sickle and Normal Erythrocyte Membranes

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2474-2474
Author(s):  
Mary Risinger ◽  
Jesse Rinehart ◽  
Scott Crable ◽  
Anna Ottlinger ◽  
Richard Winkelmann ◽  
...  
Keyword(s):  
Western Blot ◽  
Specific Antibody ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Erythrocyte Membranes ◽  
Western Blots ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells ◽  
In Cells

Abstract The KCl cotransporter (KCC) mediates volume reduction in normal reticulocytes and exaggerated KCC activity in sickle red blood cells (SS RBC) (Joiner et al, Blood109:1728, 2007) contributes to pathological dehydration that potentiates sickling. Three separate genes (KCC1, KCC3, KCC4) are expressed in RBC (Crable et al, Exp. Hem.33:624, 2005). KCC1 and KCC3 proteins have been shown to interact in ex vivo expression systems (Simard et al, JBC282(25):18083, 2007), and co-expression of an N-terminal truncation of KCC1 reduces KCC activity mediated by full-length KCC1 or KCC3 (Casula et al. JBC276:41870, 2001), suggesting functional interaction. We show here via western blot analysis that SS RBC membranes contain more KCC1 protein (relative to KCC3) than AA RBC, independent of the reticulocytosis of sickle blood. Immunoprecipitation of solubilized SS RBC membranes with KCC3-specific antibody yielded a band at 125 kD on SDS PAGE which contained KCC1, as identified by western blotting with KCC1-specific antibody and by TOF mass spectroscopy. The effect of co-expression of KCC1 and KCC3 on KCC activity was assessed by measuring NEM-stimulated, Cl-dependent, (ouabain + bumetanide)-insensitive Rb uptake in HEK 293 cells. The Flip-In T-rex HEK 293 cell line (Invitrogen) containing a tetracycline-response promoter was transfected with a pcDNA5a plasmid containing KCC3a cDNA. Recombination of the plasmid with the integrated tet-promoter construct inserts the KCC3a gene under control of a tetracycline-responsive promoter. These cells were subsequently transduced with a retroviral vector (SF-91. Hildinger et at, Gene Ther. 5:1575, 1998) containing KCC1 cDNA linked to a GFP cassette. Control cells contained SF-91 vector lacking KCC1. Cells were selected for GFP expression and grown in the absence (un-induced, no KCC3a expression) or presence of tetracycline (induced, KCC3a expression). From this binary matrix, four types of cells were obtained: Cells with no additional KCC expression, representing endogenous KCC activity; cells with only KCC1 or KCC3a expression; cells with both KCC1 and KCC3a expression. Western blots indicated similar KCC1 expression in cells with KCC1 only and [KCC1 + KCC3] and similar KCC3 expression in cells with KCC3 only and [KCC1 + KCC3]. Thus, the expression of neither isoform was affected by the presence of the other. KCC activity in cells overexpressing KCC1 only was similar to endogenous activity in HEK 293 cells; i.e., transport activity of KCC1 alone was minimal. Cells overexpressing KCC3 only had a 5-fold increase in KCC activity over endogenous levels. When KCC1 was co-expressed with KCC3 in [KCC1 + KCC3] cells, an additional 50% increase in KCC activity was observed (p < 0.05 by paired t-test, N=4), despite similar levels of KCC3 expression by western blot analysis. This synergistic effect was dependent on the cytoplasmic N-terminus of KCC1, as it was not seen when the first 39 amino acids of KCC1 were removed. Interestingly, removal of the entire cytoplasmic N-terminal domain (117 aa) produced an inhibitory effect when co-expressed with KCC3a in HEK cells, as previously reported in Xenopus oocytes (Casula et al.). These data indicate that KCC1 and KCC3 interact structurally and functionally in RBC membranes, and provide another potential mechanism for regulation of KCC activity via multimeric associations between KCC isoforms. Thus, KCC activity could be modulated not only by transcriptional mechanisms and post-translational modification (phosphorylation), but also by altering the ratios of KCC isoforms or the kinetics of their association. We speculate that higher levels of KCC1 protein relative to KCC3 in SS RBC membranes could account for higher KCC activity in these cells relative to AA RBC.

scholarly journals Peroxiredoxin 6 (Prdx6) Is Associated with Changes in Autophagy in Myeloid and Non-Myeloid Cells

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1407-1407
Author(s):  
Michael Ellison ◽  
Gail Thurman ◽  
Daniel R. Ambruso
Keyword(s):  
Western Blot ◽  
Active Site ◽  
Oxidase Activity ◽  
Myeloid Cells ◽  
Pla2 Activity ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
Opsonized Zymosan ◽  
293 Cells ◽  
Starvation Conditions

Abstract Introduction: Prdx6, a member of a new family of peroxidases, is found in neutrophil cytosol associated with p67phox. This protein reduces H2O2 with a conserved cysteine (C47) and also expresses PLA2 activity. In human neutrophils, Prdx6 translocates to plasma membrane after activation and enhances Nox2 activity in a cell-free system of oxidase activity. In transgenic K562 cells and PLB-985 cells, suppression of Prdx6 by siRNA or shRNA decreases Nox2 activity. In these studies, we investigated the association of Prdx6with autophagy in PLB-985 and HEK-293 cells. Methods: PLB-985 and HEK-293 cells were cultured under standard conditions and were transfected with a plasmid producing stable expression of an shRNA targeting Prdx6. PLB-985 cells were matured with the addition of 1.3% DM50 for 4 days. DNA for wild type (WT) Prdx6 and mutants for the Prdx6 active site (C47S) and PLA2active sites (H26A, S32A, S140A) were cloned into pcDNA3.1 which also had silent mutations making all corresponding mRNAs resistant to shRNA targeting. Prdx6 knockdown and vector control cells had stable re-expression of the various proteins when cultured with appropriate antibiotics. Superoxide anion (O2-) was determined by SOD inhibitable chemilluminescence with Digenes (National Diagnosistics). Proteins from lysates of various cell lines were separated by 10-12% SDS-PAGE and blotted onto nitrocellulose. Specific proteins were detected standard antibodies and a chemilluminescent technique with quantitation completed using Image J platform. Autophagy in PLB-985 cells with or without suppression of Prdx6 was completed by expression of LC3-II by Western blot after stimulation with serum opsonized zymsoan (5mg/mL). In HEK-293 cells, autophagy was determined by quantification of LC3-II (western blot) under based conditions with the addition of 10µM Chloraquine or starvation conditions with minimal media. Results: Stable suppression of Prdx6 by shRNA was achieved in both PLB-985 cells (down to 30%) and HEK cells (25%). Re-expression of WT and Prdx6 mutant proteins re-established normal levels. O2-production in response to lµM FMLP was decreased by 44% in KD PLB-985 cells compared to control and re-establishment of oxidase activity depended on PLA2, not Prdx activity. In PLB-985 cells, LC3-II levels increased (seven fold) over the first 30 minutes after exposure to opsonized zymosan, decreasing to baseline at 60 minutes. Prdx6 suppressed PLB-985 cells showed no change in LC3-II after opsonized zymosan. In HEK-293 cells lacking an active oxidase, suppression of Prdx6 resulted in increased autophagy under basal and starvation conditions. Furthermore, in HEK-293 cells, reintroduction of empty vector or Prdx6 mutated at the Prdx active site (C47S) did not suppress autophagy under basal conditions. However, re-introduction of WT and mutant Prdx6 at the PLA2 active site (D140A) did suppress autophagy demonstrating that this effect was associated with Prdx activity. Similar results were obtained under starvation conditions. Conclusions: In neutrophil like cells Prdx6 enhanced Nox2 activity through its PLA2 activity and suppression of Prdx6 decreased autophagy as measured by LC3-II accumulation after exposure to a phagocytic stimulus. In non-myeloid HEK-293 cells, suppression of Prdx6 was associated with increased autophagy under basal and starvation conditions, and this effect was dependent on Prdx activity. Prdx6, then, plays a critical role in neutrophil functions such as Nox2 activity and autophagy. Prdx6 may also be involved in autophagy in non-myeloid cells, and the mechanism for its involvement in autophagy may relate to different activities expressed by this protein. Disclosures No relevant conflicts of interest to declare.

scholarly journals Characteristics and requirements of basal autophagy in HEK 293 cells

Autophagy ◽  
2013 ◽  
Vol 9 (9) ◽  
pp. 1407-1417 ◽  
Author(s):  
Patience Musiwaro ◽  
Matthew Smith ◽  
Maria Manifava ◽  
Simon A. Walker ◽  
Nicholas T. Ktistakis
Keyword(s):  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells

Halothane Inhibition of Recombinant Cardiac L-type Ca2+ Channels Expressed in HEK-293 Cells

2005 ◽  
Vol 103 (6) ◽  
pp. 1156-1166 ◽  
Author(s):  
Kevin J. Gingrich ◽  
Son Tran ◽  
Igor M. Nikonorov ◽  
Thomas J. Blanck
Keyword(s):  
Charge Transfer ◽  
Calcium Channels ◽  
Dependent Manner ◽  
Current Time ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells ◽  
Dependent Inactivation ◽  
Voltage Dependent

Background Volatile anesthetics depress cardiac contractility, which involves inhibition of cardiac L-type calcium channels. To explore the role of voltage-dependent inactivation, the authors analyzed halothane effects on recombinant cardiac L-type calcium channels (alpha1Cbeta2a and alpha1Cbeta2aalpha2/delta1), which differ by the alpha2/delta1 subunit and consequently voltage-dependent inactivation. Methods HEK-293 cells were transiently cotransfected with complementary DNAs encoding alpha1C tagged with green fluorescent protein and beta2a, with and without alpha2/delta1. Halothane effects on macroscopic barium currents were recorded using patch clamp methodology from cells expressing alpha1Cbeta2a and alpha1Cbeta2aalpha2/delta1 as identified by fluorescence microscopy. Results Halothane inhibited peak current (I(peak)) and enhanced apparent inactivation (reported by end pulse current amplitude of 300-ms depolarizations [I300]) in a concentration-dependent manner in both channel types. alpha2/delta1 coexpression shifted relations leftward as reported by the 50% inhibitory concentration of I(peak) and I300/I(peak)for alpha1Cbeta2a (1.8 and 14.5 mm, respectively) and alpha1Cbeta2aalpha2/delta1 (0.74 and 1.36 mm, respectively). Halothane reduced transmembrane charge transfer primarily through I(peak) depression and not by enhancement of macroscopic inactivation for both channels. Conclusions The results indicate that phenotypic features arising from alpha2/delta1 coexpression play a key role in halothane inhibition of cardiac L-type calcium channels. These features included marked effects on I(peak) inhibition, which is the principal determinant of charge transfer reductions. I(peak) depression arises primarily from transitions to nonactivatable states at resting membrane potentials. The findings point to the importance of halothane interactions with states present at resting membrane potential and discount the role of inactivation apparent in current time courses in determining transmembrane charge transfer.

Micropatterned surfaces of PDMS as growth templates for HEK 293 cells

2007 ◽  
Vol 9 (4) ◽  
pp. 475-485 ◽  
Author(s):  
R. M. Johann ◽  
Ch. Baiotto ◽  
Ph. Renaud
Keyword(s):  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells

Calcium Induces Expression of Cytoplasmic Gelsolin in SH-SY5Y and HEK-293 Cells

2010 ◽  
Vol 35 (7) ◽  
pp. 1075-1082 ◽  
Author(s):  
Lina Ji ◽  
Abha Chauhan ◽  
Ved Chauhan
Keyword(s):  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells ◽  
Cytoplasmic Gelsolin

Characteristics of rat downregulated in adenoma (rDRA) expressed in HEK 293 cells

2007 ◽  
Vol 454 (3) ◽  
pp. 441-450 ◽  
Author(s):  
Christian Barmeyer ◽  
Jeff Huaqing Ye ◽  
Shafik Sidani ◽  
John Geibel ◽  
Henry J. Binder ◽  
...  
Keyword(s):  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells

Abstract 5316: hERG 1b as a Potential Target for Inherited and Acquired Long QT Syndrome

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Gail A Robertson ◽  
Harinath Sale ◽  
David Tester ◽  
Thomas J O’Hara ◽  
Pallavi Phartiyal ◽  
...  
Keyword(s):  
Action Potential ◽  
Long Qt Syndrome ◽  
Time Course ◽  
Drug Sensitivity ◽  
Long Qt ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
Acquired Long Qt Syndrome ◽  
293 Cells ◽  
Qt Syndrome

Cardiac I Kr is a critical repolarizing current in the heart and a target for inherited and acquired long QT syndrome. Biochemical studies show that native I Kr channels are heteromers composed of both hERG 1a and 1b subunits, yet our current understanding of I Kr functional properties derives primarily from studies of homo-oligomers of the original hERG 1a isolate. The hERG 1a and 1b subunits are identical except at the amino (NH2) terminus, which in hERG 1b is much shorter and has a unique primary sequence. We compared the biophysical properties of currents produced by hERG 1a and 1a/1b channels expressed in HEK-293 cells at near-physiological temperatures. We found that heteromeric hERG 1a/1b currents are much larger than hERG 1a currents and conduct 80% more charge during an action potential. This surprising difference corresponds to a two-fold increase in the apparent rates of activation and recovery from inactivation, which reduces rectification and facilitates current rebound during repolarization. Kinetic modeling shows these gating differences account quantitatively for the differences in current amplitude between the two channel types. Depending on the action potential model used, loss of 1b predicts an increase in action potential duration of 27 ms (7%) or 41 ms (17%), respectively. Drug sensitivity was also different. Compared to homomeric 1a channels, heteromeric 1a/1b channels were inhibited by E-4031 with a slower time course and a corresponding four-fold positive shift in the IC 50 . Differences in current kinetics and drug sensitivity were modeled by “NH2 mode” gating with conformational states bound by the amino terminus in hERG 1a homomers but not 1a/1b heteromers. The importance of hERG 1b in vivo is supported by the identification of a 1b-specific A8V missense mutation in 1/269 unrelated genotype-negative LQTS patients and absent in 400 control alleles. Mutant 1bA8V expressed alone or with hERG 1a in HEK-293 cells nearly eliminated 1b protein. Thus, mutations specifically disrupting hERG 1b function are expected to reduce cardiac I Kr , prolong QT interval and enhance drug sensitivity, thus representing a potential mechanism underlying inherited or acquired LQTS.

COOH-terminal association of human smooth muscle calcium channel Cav1.2b with Src kinase protein binding domains: effect of nitrotyrosylation

2007 ◽  
Vol 293 (6) ◽  
pp. C1983-C1990 ◽  
Author(s):  
Minho Kang ◽  
Gracious R. Ross ◽  
Hamid I. Akbarali
Keyword(s):  
Smooth Muscle ◽  
Calcium Channel ◽  
Tyrosine Phosphorylation ◽  
Src Kinase ◽  
Sh2 Domain ◽  
Calcium Currents ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
Binding Domains ◽  
293 Cells

The carboxyl terminus of the calcium channel plays an important role in the regulation of calcium entry, signal transduction, and gene expression. Potential protein-protein interaction sites within the COOH terminus of the L-type calcium channel include those for the SH3 and SH2 binding domains of c-Src kinase that regulates calcium currents in smooth muscle. In this study, we examined the binding sites involved in Src kinase-mediated phosphorylation of the human voltage-gated calcium channel (Cav) 1.2b (hCav1.2b) and the effect of nitrotyrosylation. Cotransfection of human embryonic kidney (HEK)-293 cells with hCav1.2b and c-Src resulted in tyrosine phosphorylation of the calcium channel, which was prevented by nitration of tyrosine residues by peroxynitrite. Whole cell calcium currents were reduced by 58 + 5% by the Src kinase inhibitor PP2 and 64 + 6% by peroxynitrite. Nitrotyrosylation prevented Src-mediated regulation of the currents. Glutathione S-transferase fusion protein of the distal COOH terminus of hCav1.2b (1809-2138) bound to SH2 domain of Src following tyrosine phosphorylation, while binding to SH3 required the presence of the proline-rich motif. Site-directed mutation of Y2134 prevented SH2 binding and resulted in reduced phosphorylation of hCav1.2b. Within the distal COOH terminus, single, double, or triple mutations of Y1837, Y1861, and Y2134 were constructed and expressed in HEK-293 cells. The inhibitory effects of PP2 and peroxynitrite on calcium currents were significantly reduced in the double mutant Y1837-2134F. These data demonstrate that the COOH terminus of hCav1.2b contains sites for the SH2 and SH3 binding of Src kinase. Nitrotyrosylation of these sites prevents Src kinase regulation and may be importantly involved in calcium influx regulation during inflammation.

Sign in / Sign up

Export Citation Format

Share Document