Dexamethasone-conjugated polyethylenimine as an efficient gene carrier with an anti-apoptotic effect to cardiomyocytes

• Published in: The journal of gene medicine 2009-06, Vol.11 (6), p.515-522
• Main Authors: Kim, Hyunjung, Kim, Hyun Ah, Bae, Yun Mi, Choi, Joon Sig, Lee, Minhyung
• Format: Article
• Language: English
• Subjects: Animals; Anti-Inflammatory Agents - administration & dosage; Apoptosis; Caspase 3 - metabolism; Cells, Cultured; dexamethasone; Dexamethasone - administration & dosage; Enzyme-Linked Immunosorbent Assay; gene carrier; Gene therapy; Gene Transfer Techniques; heme oxygenase-1; hydrogen peroxide; Myocytes, Cardiac - metabolism; Polyethyleneimine - chemistry; Polyethyleneimine - toxicity; polyethylenimine; Rats; Transfection
• ISSN: 1099-498X; 1521-2254; 1521-2254
• DOI: 10.1002/jgm.1320

Background Dexamethasone is a potent glucocorticoid with anti‐inflammatory effects. Dexamethasone can protect ischemic cardiomyocytes from apoptosis. To apply the anti‐apoptotic effect of dexamethasone to ischemic disease gene therapy, dexamethasone‐conjugated polyethylenimine (PEI‐Dexa) was synthesized and evaluated as an anti‐apoptotic gene carrier. Methods PEI‐Dexa was synthesized with low molecular weight polyethylenimine (PEI2K, 2 kDa). The transfection efficiency and cytotoxicity of PEI‐Dexa were evaluated by luciferase assay and the MTT assay. To evaluate the anti‐apoptotic effect, PEI‐Dexa/DNA complex was transfected into cells and the cells were treated with H2O2. Cell viability and apoptosis level were measured by the MTT assay and caspase‐3 assay, respectively. Results A transfection assay into H9C2 rat cardiomyocytes showed that PEI‐Dexa had the highest transfection efficiency at an 8 : 1 weight ratio (PEI‐Dexa/DNA). At this ratio, PEI‐Dexa had higher transfection efficiency than high molecular polyethylenimine (PEI25K, 25 kDa) and PEI2K. In addition, the cytotoxicity of PEI‐Dexa was lower than that of PEI25K. To evaluate the anti‐apoptotic effect, PEI‐Dexa/pSV‐Luc or PEI2K/pSV‐Luc was transfected into H9C2 cells and the cells were treated with H2O2. PEI‐Dexa was found to reduce caspase‐3 activity and increase cell viability compared to PEI2K. Heme oxygenase‐1 (HO‐1) can protect ischemic cardiomyocytes from apoptosis. Therefore, pSV‐HO‐1 was cloned and transfected into H9C2 cells using PEI‐Dexa. The cells transfected with PEI‐Dexa/pSV‐HO‐1 complex had lower caspase‐3 activity and higher viability than the cells transfected with PEI‐Dexa/pSV‐Luc complex after the H2O2 treatment. Conclusions PEI‐Dexa is an efficient gene carrier with an anti‐apoptotic effect and may be useful for anti‐apoptotic gene therapy in combination with pSV‐HO‐1. Copyright © 2009 John Wiley & Sons, Ltd.