The influence of TNF-a on the expression profile of key enzymes of steroidogenesis in H295R cells

Introduction
Tumor necrosis factor-α (TNF-α) plays an extremely important role in the regulation of hypothalamicpituitary- adrenal axis. It is believed that chronic inflammation is the main cause of cancerogenesis and TNF-α plays a significant role in both of these processes. Unfortunately, the function of TNF-α in human adrenal steroidogenesis has not been explained enough.

Aim
To evaluate the changes in transcriptional activity of STAR, CYP11A1, CYP11B1, and CYP11B2 in H295R cell line exposed to TNF-α.

Material and methods
NCI-H295R, human adrenocortical cell line was exposed to human recombinant TNF-α at the concentrations ranging from 0.001 to 10 nM for 3, 12, 24, and 48 h. Cells not exposed to TNF-α were the control of this experiment. RTqPCR assay was used to determine the changes in the expression of genes encoding STAR, CYP11A1, CYP11B1, and CYP11B2.

Results
The highest differences between stimulated and non-stimulated cells were observed in the expression of STAR (FC = +2.2; 0.01 nM of TNF-α; 48 h); CYP11A1 (FC = +3.5; 0.1 nM of TNF-α; 24 h); CYP11B1 (FC = +7.0; 10 nM of TNF-α; 48 h); CYP11B2 (FC = +2.5; 10 nM of TNF-α; 48 h). Statistically significant differences (p < 0.05) in the expression were found only for CYP11A1. The interaction effect between genes was also noticed (p < 0.05).

Conclusions
The research showed the impact of TNF-α on the expression of the key genes encoding enzymes involved in adrenal steroidogenesis. Different expression patterns of was observed, depending on time and TNF-α concentration increased synthesis of this pro-inflammatory cytokine may intensify adrenal steroidogenesis.