Cytoprotection of Human Endothelial Cells from Oxidant Stress with CDDO Derivatives: Network Analysis of Genes Responsible for Cytoprotection

Abstract

Aim: To identify drugs that may reduce the impact of oxidant stress on cell viability. Methods: Human umbilical vein endothelial cells were treated with 200 nmol/l CDDO-Im (imidazole) and CDDO-Me (methyl) after exposure to menadione and compared to vehicle-treated cells. Cell viability and cytotoxicity were assessed, and gene expression profiling was performed. Results: CDDO-Im was significantly more cytoprotective and less cytotoxic (p < 0.001) than CDDO-Me. Although both provided cytoprotection by induction of gene transcription, CDDO-Im induced more genes. In addition to a higher induction of the key cytoprotective gene heme oxygenase-1 (38.9-fold increase for CDDO-Im and 26.5-fold increase for CDDO-Me), CDDO-Im also induced greater expression of heat shock proteins (5.5-fold increase compared to 2.8-fold for CDDO-Me). Conclusions: Both compounds showed good induction of heme oxygenase, which largely accounted for their cytoprotective effect. Differences were detected in cytotoxicity at higher doses, indicating that CDDO-Me was more cytotoxic than CDDO-Im. Significant differences were detected in the ability of CDDO-Im and CDDO-Me to affect differential gene transcription. CDDO-Im induced more genes than did CDDO-Me. The source of the differences in gene expression patterns between CDDO-Im and CDDO-Me was not determined but may be important in long-term use of this class of drugs.

CDDO-Me Redirects Activation of Breast Tumor Associated Macrophages

“…Since CDDO-Me redirection of TAM activation significantly impaired endothelial cell tube formation, this drug may be important therapeutically in eliciting both immune activation and in combatting angiogenesis. In accordance with recent findings [ 60 ], we failed to observe direct effects of CDDO-Me on EC viability. Furthermore, our studies suggest CDDO-Me effects on EC vascularization are likely mediated indirectly though changes in TAM polarization, rather than through direct effects on ECs, as we did not observe changes in EC tube formation in the absence of CDDO-Me TAM conditioned media.…”

Time Course Expression Analysis of 1[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole Induction of Cytoprotection in Human Endothelial Cells

“…Both CDDO-Im and CDDO-Me have been shown to elicit protective effects largely through the activation of the transcription factor nuclear factor erythroid 2–related factor 2 ( NRF2 ). 12–14 Our previous work with CDDO-Im and CDDO-Me supported published work that demonstrated the central role of NRF2 in homeostasis 11,15 and its role in HMOX1 induction; in addition, it identified potentially new genes that provide additional cytoprotection. A recent study evaluated the kinetics of HMOX1 induction by 4 different transcription factors ( HSF-1, AP-1, NRF2 , and NF-κB ) and showed that they differ in their mechanism of action and kinetics of inducing HMOX1 .…”

“…7–10 Comparing these 2 structurally different forms of CDDO, we previously determined that there is a similar degree of cytoprotection between the 2 compounds; however, significant differences in gene expression were seen between the 2 following a 6-hour treatment on human umbilical vein endothelial cells (HUVEC). 11 The derivative CDDO-Im was shown to induce more gene expression changes than CDDO-Me and resulted in significantly higher expression levels of key cytoprotective genes, including heme oxygenase 1 ( HMOX1 ). 11 …”

“…11 The derivative CDDO-Im was shown to induce more gene expression changes than CDDO-Me and resulted in significantly higher expression levels of key cytoprotective genes, including heme oxygenase 1 ( HMOX1 ). 11 …”

“…The purpose of this study was to determine whether alterations in gene expression induced by CDDO-Im over time, particularly at early time points, could uncover the proximal mechanism responsible for the cytoprotective effect. 11,15 In addition, analysis with Expression2Kinases (X2K) was used to identify transcription factors, kinases, and complexes that drive changes in global gene expression. 17 Expression2Kinases integrates chromatin immunoprecipitation (ChIP)-seq/chip and position weight matrix data, protein-protein interactions, and kinase-substrate phosphorylation reactions to better identify regulatory mechanisms upstream of genome-wide differences in gene expression.…”