Transfection Protocol:
There are two transfection protocols for transfecting endothelial cells, one protocol uses the Targefect-HUVEC (Targefect F-2) reagent along with the VIrofect enhancer and is used for transfecting cells in presence of serum. These protocls are applicable
The second protocol uses the Targefect -HUVEC (Targefect F-2) reagent along with the Peptide enahncer and requires that cell be transfected in the absence fo serum.
Both protocols work well and there is lab to lab variation as to which one is preferred so we really suggest tryign both procols. For transfecting HUVECs, BAECs and microvascular endothelial cells using the Vriofect enhancer, we have noticed that endothelial cells should be grown in media containing at least 10% serum.
General considerations::
Use early passage endothelial cells, avoid using collagen coated dishes as these may lower transfection efficiency. Culture media we recommend is Media 199 with 20% serum or EBM (Cambrex) 10% FCS (Gibco) & supplements (Cambrex). When using any low serum media we strongly recommned increasing serum concentraiton to 10% when using the Virofect enhancer.
Cell seeding: Set up cells so that they are approx 70% confluent at the time of experiment
Preparation of the complexes and transfection procedure:
Since reagents sometimes freeze during shipping, we recommend gently mixing the Targefect-F2 solution once upon receipt. The Targefect-F-2 reagent should be stored at 4 oC. Do not vortex the Targefect-HUVEC reagent. The Peptide Enhancer can be stored at 4 oC. The Virofect Enhancer should be stored at -20oC or -70oC.
See figure in Figures section.1| Add DMEM first. Add DNA, mix well by flicking the tube about 12 times to create a vortexing action.
2| Add Targefect next, mix well again by flicking the tube. Incubate the tubes at 37oC for 25 minutes to form the transfection complexes.
Condition A above is for transfecting cells in the presence of serum according to our fast protocol.-250 µl of transfection complex is added to 1 ml of complete media (with serum) per well of a six-well dish. The dish is swirled to enable mixing of the transfection complex with the cell culture medium and the cells are incubated at 37 oC overnight and assayed for gene expression 36-48 hrs post transfection. Add 0.5 ml of transfection complex to 2 ml of complete media with serum for one 60 mm dish. For transfecting cells in a 6-well dish add 0.25 ml of transfection complex to 1 ml of complete media, for a 12-well dish add 0.125 ml transfection complex to 0.5 ml of complete media. Swirl the dish to gently mix transfection complexes with the cell culture media. Incubate overnight. Assay at 24-48 hrs after transfection.
Conditions B and C are for transfecting HUVECs or HMVECs in the absence of serum
1| Aspirate cell culture media completely and add transfection complexes to the cells. The amount of transfection complexes recommended for different size dishes are shown in Table 2 below. In general the amount of transfection complex added should be just sufficient to cover the cells well for a 3 hour incubation period so that the cells dont dry up.
See figure in Figures section.2| Incubate cells with transfection complexes at 37 oC for 3 hours. Aspirate complexes and add complete media with at least 10% serum. If you are culturing HUVECs in serum-free media, we recommend adding 10% serum to media being added immediately after aspiration of transfection complexes as this helps cells recover faster. You can change media after a few hours or the next day. Replace the media with fresh complete media the next morning and assay at 36-48 hours post-transfection.
Additional Protocols for transfecting different types of endothelial cells taken form our customer citations:
Transfection of pulmonary microvascular endothelial cell monolayers (PMEM) using Targefect F-2 (Targefect-HUVEC) and Virofect)
This transfection protocol below and the pictures of tansfected lung microvascular endothelial cells has been taken form a publication from the Arnold Johnson (Gertzberg et al, 2007) lab cited below.
Pulmonary Microvessel Endothelial Cell Culture:
Bovine lung microvessel endothelial cells (BLMVEC) were obtained at passage 4 (Vec Technologies, Rensselaer, NY; Ref. 6). The preparations were identified by Vec Technologies as pure populations by: 1) the characteristic "cobblestone" appearance as assessed by phase contrast microscopy, 2) the presence of factor VIII-related antigen, 3) the uptake of acylated low-density lipoproteins, and 4) the absence of smooth muscle actin. For all studies, BLMVEC were cultured from 4 to 12 passages in medium containing DMEM (Gibco BRL, Grand Island, NY) supplemented with 20% fetal bovine serum (FBS; Hyclone, Logan, UT), 15 µg/ml endothelial cell growth supplement (Upstate Biotechnology, Lake Placid, NY), and 1% nonessential amino acids (Gibco BRL). The BLMVEC were maintained in 5% CO2 + humidified air at 37°C. A confluent pulmonary microvessel endothelial cell monolayer (PMEM) was reached within 2–3 population doublings, which took 3–4 days.
Transfection. Transfection complex was formed by adding Targefect F2 (a nonlipid cationic polymer; Targeting Systems, Santee, CA), Virofect (an adenovirus-derived formulation to enhance transfection efficiency; Targeting Systems), and the enhanced yellow fluorescent protein (EYFP-beta-actin) plasmids to serum-free DMEM. The transfection efficiency was similar among the groups such as in the wild-type EYFP-beta-actin (78.0% ± 0.02%) and the mutant Y198F isoform (79.9% ± 0.06%). The volume of reagents was formulated to achieve a final ratio of 1 µg of DNA to (2 µl of Targefect F2 + 5 µl/ml Virofect) to provide treatment concentrations of 0.25–0.35 µg of DNA/ml of media. The complexes were incubated in 5% CO2 + humidified air at 37°C for 25 min and then added to subconfluent PMEM. After 2 h, the complex and media were removed and replaced with normal growth medium, and the cells were incubated for 24 h until confluent.
Assay of Endothelial Permeability
Transfection of PMEM. The BLMVEC (0.7 x 105 in 0.5 ml of DMEM) were plated on collagen-coated Transwell-COL permeable supports (12 mm diameter, 0.4 µm pore size; Corning, Corning, NY) and incubated for 24 h (37°C, 5% CO2). The cells were transfected as described above adding 500 µl of the transfection complex to the top (i.e., luminal) well and 1.5 ml of serum-free DMEM to the bottom well (i.e., abluminal) to eliminate any hydrostatic pressure differential
Citation for transfection protocol of lung microvascular endothelial cells with targefect F-2 and Vriofect
Nancy Gertzberg,1,2 Tina Gurnani,3 Paul Neumann,1,2 Anne-Kay Forbes,4 Natacha Jean-Louis,4 and Arnold Johnson1,2 (2007) Tumor necrosis factor-{alpha} causes barrier dysfunction mediated by tyrosine198 and tyrosine218 in beta-actin Am J Physiol Lung Cell Mol Physiol 293: L1219-L1229, 2007;
Transfection of BAECs, Pulmonary aortic endothelial cells: we recommend using the Targefect F-2 plus Virofect protocol described above