Lipopolysaccharide-induced TNFα factor (LITAF) promotes inflammatory responses and activates apoptosis in zebrafish Danio rerio.

Abstract

Lipopolysaccharide-induced TNFα factor (LITAF) is an important transcription factor which activates the transcription of TNFα and regulates cell apoptosis and inflammatory response. In the present study, a LITAF gene homologue was identified in zebrafish (Danio rerio) and was shown to be well conserved in the protein sequence, genomic organization and synteny with human LITAF. DrLITAF was constitutively expressed in tissues, with the highest expression detected in the gills. Its expression could be modulated by LPS, poly(I:C), and infection with Edwardsiella tarda, Aeromonus hydrophila and septicemia viremia of carp virus (SVCV). DrLITAF, when overexpressed, was shown to be located on the cellular membrane and nuclear membrane of HEK293T and ZF4 cells and was associated with the endoplasmic reticulum. Stimulation with LPS resulted in rapid translocation of DrLITAF into the nucleus. In addition, DrLITAF was able to induce cell apoptosis and the expression of caspase 3. The results demonstrate that DrLITAF is involved in the immune defence against bacterial and viral infection and plays a role in regulating inflammation and apoptosis.