Estriol Inhibits Dermcidin Isoform-2 Induced Inflammatory Cytokine Expression Via Nitric Oxide Synthesis in Human Neutrophil

Abstract

Background: An increase in the level of cytokines like TNF-α and IL-6 causes the inflammatory surge in acute ischemic heart disease (AIHD).

Objective: A high-level dermcidin isoform-2 (DCN-2) occurrence in AIHD was subjected to determine a possible regulation of cytokines expression. The effect of estrogen to counteract the inflammatory response was determined.

Methods: Blood was collected from AIHD patients and normal volunteers with consent. Nitric oxide (NO) synthesis was done with methemoglobin method.TNF-α and IL-6 expression were determined by ELISA and Western blot.

Results: (DCN-2) incubation with 120nM to the normal neutrophil solution for 2h resulted in the increase of TNF-α from 3.82±1.53pg/ml to 20.7±6.9pg/ml and IL-6 from 3.27±1.52pg/ml to 47.07±3.4pg/ml. In AIHD patients, the cytokine level was18.3- 27.3pg/ml, with a median value 21.86pg/ml (TNF-α) and IL-6 level was 23.54- 52.73pg/ml, with a median value 42.16pg/ml. Treatment with 0.6nM estriol, a kind of female steroid hormone estrogen for 45min decreased the elevated cytokine level in 120nM DCN-2 treated normal neutrophils. DCN-2 induced TNF-α synthesis in neutrophils was further determined by Western blot technique with a thickened band intensity of TNF-α. Estriol (0.6nM) treatment also influenced the DCN-2 induced inhibition of nitric oxide (NO) synthesis from 0nmol NO/ml to 0.56nmol/ml. The subsequent reduction of TNF-α level correlates the increase of NO level.

Conclusion: In conclusion, the stress-induced DCN-2 production in AIHD propagates the inflammatory response. Steroid molecule like estriol plays a protective role by reducing DCN-2 responses in the NO synthesis.

Keywords: Acute ischemic heart disease; Dermcidin isoform-2; IL-6; Inflammation; TNF-α; leukocytes..