A mechanistic study on the effect of dexamethasone in moderating cell death in Chinese Hamster Ovary cell cultures

Abstract

Dexamethasone (DEX) was previously shown (Jing et al., Biotechnol Bioeng. 2010;107:488-496) to play a dual role in increasing sialylation of recombinant glycoproteins produced by Chinese Hamster Ovary (CHO) cells. DEX addition increased sialic acid levels of a recombinant fusion protein through increased expression of α2,3-sialyltransferase and β1,4-galactosyltransferase, but also decreased the sialidase-mediated, extracellular degradation of sialic acid through slowing cell death at the end of the culture period. This study examines the underlying mechanism for this cytoprotective action by studying the transcriptional response of the CHO cell genome upon DEX treatment using DNA microarrays and gene ontology term analysis. Many of those genes showing a significant transcriptional response were associated with the regulation of programmed cell death. The gene with the highest change in expression level, as validated by Quantitative PCR assays with TaqMan® probes and confirmed by Western Blot analysis, was the antiapoptotic gene Tsc22d3, also referred to as GILZ (glucocorticoid-induced leucine zipper). The pathway by which DEX suppressed cell death towards the end of the culture period was also confirmed by showing involvement of glucocorticoid receptors and GILZ through studies using the glucocorticoid antagonist mifepristone (RU-486). These findings advance the understanding of the mechanism by which DEX suppresses cell death in CHO cells and provide a rationale for the application of glucocorticoids in CHO cell culture processes.

Mechanisms of unprimed and dexamethasone‐primed nonviral gene delivery to human mesenchymal stem cells

“…Our results are consistent with reports that DEX treatment ameliorates transfection-induced hMSC viability decrease as measured by WST-1 cell proliferation assay (Kelly et al, 2016). Furthermore, DEX has also been shown to rescue cytotoxicity and apoptosis induced in transfected HC92 rat cardiomyocytes (Kim et al, 2009), and reduced death of chinese hamster ovary (CHO) cells producing recombinant protein by modulating apoptosis-related gene expression (Jing et al, 2012). In addition to increasing transgenic protein synthesis, attenuation of apoptosis by DEX-priming could also promote the observed increase in relative transgenic enzyme HAMANN ET AL.…”

Dynamic regulatory network controlling TH17 cell differentiation

“…This suggests a model where Tsc22d3 is part of a negative feedback loop for the induction of a Th17 cell subtype that coproduce IL-17 and IL-10 and limits their pro-inflammatory capacity. Tsc22d3 is induced in other cells in response to the steroid Dexamethasone 41 , which represses Th17 differentiation and ROR-γt expression 42 . Thus, Tsc22d3 may mediate this effect of steroids.…”

Overexpression of Serpinb1 in Chinese hamster ovary cells increases recombinant IgG productivity

“…The same group of researchers also reported 1.6-fold upregulation of Serpinh1 in low temperature and butyrate treated CHO cells that produced more IgG (Kantardjieff et al, 2010). Jing and colleagues observed that angiotensinogen (serpin peptidase inhibitor, clade A, member 8) was upregulated 2.15 fold in dexamethasone treated CHO cultures, and they associated the upregulation to the anti-apoptotic effects of dexamethasone (Jing et al, 2012). Most recently, Doolan et al concluded that Serpinf1 negatively correlated to growth rate in their transcriptomic studies on biomarker discovery for higher growth in CHO cells (Doolan et al, 2013).…”