Upregulation of the Coagulation Factor VII Gene during Glucose Deprivation Is Mediated by Activating Transcription Factor 4

Abstract

BackgroundConstitutive production of blood coagulation proteins by hepatocytes is necessary for hemostasis. Stressful conditions trigger adaptive cellular responses and delay processing of most proteins, potentially affecting plasma levels of proteins secreted exclusively by hepatocytes. We examined the effect of glucose deprivation on expression of coagulation proteins by the human hepatoma cell line, HepG2.Methodology/Principal FindingsExpression of coagulation factor VII, which is required for initiation of blood coagulation, was elevated by glucose deprivation, while expression of other coagulation proteins decreased. Realtime PCR and ELISA demonstrated that the relative percentage expression +/− SD of steady-state F7 mRNA and secreted factor VII antigen were significantly increased (from 100+/−15% to 188+/−27% and 100+/−8.8% to 176.3+/−17.3% respectively, p<0.001) at 24 hr of treatment. The integrated stress response was induced, as indicated by upregulation of transcription factor ATF4 and of additional stress-responsive genes. Small interfering RNAs directed against ATF4 potently reduced basal F7 expression, and prevented F7 upregulation by glucose deprivation. The response of the endogenous F7 gene was replicated in reporter gene assays, which further indicated that ATF4 effects were mediated via interaction with an amino acid response element in the F7 promoter.Conclusions/SignificanceOur data indicated that glucose deprivation enhanced F7 expression in a mechanism reliant on prior ATF4 upregulation primarily due to increased transcription from the ATF4 gene. Of five coagulation protein genes examined, only F7 was upregulated, suggesting that its functions may be important in a systemic response to glucose deprivation stress.

Reproducible generation of human liver organoids (HLOs) on a pillar plate platform via microarray 3D bioprinting

“…The expression level of F7 coagulation factor VII could be up-regulated when liver cells are under glucose deprivation stress. 41 Thus, the result may imply that HLOs in large Matrigel dome in the 24-well plate is under the diffusion limitation of nutrients. Furthermore, the secretion level of albumin from HLOs on the pillar plate was approximately 2-fold higher than that from the conventional Matrigel dome culture (Fig.…”

Erythroid-transdifferentiated myeloid cells promote portal vein tumor thrombus in hepatocellular carcinoma

“…The expression of the transcription factors for FX 22 , FVII 23 , FGB 24 , 25 and TGF-β 26 , 27 in the CD45 + EPCs from the TME and circulation was analyzed with RNA-seq. The results showed that the transcription factors for FGB and TGF-β, C/EBPβ were elevated in EDMCs from the TME (Figure 4 A), which was confirmed by western blotting (Figure 4 B).…”