AIMTo assay the transcriptional activation effect of TR3 and it's deletion mutation in yeast two hybrid system.

METHODSThe total length of TR3 and TR3/delta1-690 gene was amplified by PCR method and cloned into pGBKT7 vector. Bait vector of pGBKT7-TR3 and pGBKT7-TR3/delta1-690 was transformed into AH109 competence yeast. Then self activation of the recombination vector was tested by assay the activity of beta-galactosidae.

RESULTSThe pGBKT7-TR3 and pGBKT7-TR3/AM 690 vector was successfully constructed. The filter paper containing beta-galactosidae didn't changed to blue showed that the reporter gene wasn't activationed.

CONCLUSIONTR3 and TR3/delta1-690 hadn't the activity of transcriptional activation.

Nuclear Receptor Subfamily 4, Group A, Member 1 ; genetics ; physiology ; Sequence Deletion ; Transcriptional Activation ; genetics ; Two-Hybrid System Techniques

BACKGROUND AND OBJECTIVE: Acute liver failure (ALF) is a type of disease with high mortality and rapid progression with no specific treatment methods currently available. Glucocorticoids exert beneficial clinical effects on therapy for ALF. However, the mechanism of this effect remains unclear and when to use glucocorticoids in patients with ALF is difficult to determine. The purpose of this study was to investigate the specific immunological mechanism of dexamethasone (Dex) on treatment of ALF induced by lipopolysaccharide (LPS)/D-galactosamine (D-GaIN) in mice. METHODS: Male C57BL/6 mice were given LPS and D-GaIN by intraperitoneal injection to establish an animal model of ALF. Dex was administrated to these mice and its therapeutic effect was observed. Hematoxylin and eosin (H&E) staining was used to determine liver pathology. Multicolor flow cytometry, cytometric bead array (CBA) method, and next-generation sequencing were performed to detect changes of messenger RNA (mRNA) in immune cells, cytokines, and Kupffer cells, respectively. RESULTS: A mouse model of ALF can be constructed successfully using LPS/D-GaIN, which causes a cytokine storm in early disease progression. Innate immune cells change markedly with progression of liver failure. Earlier use of Dex, at 0 h rather than 1 h, could significantly improve the progression of ALF induced by LPS/D-GaIN in mice. Numbers of innate immune cells, especially Kupffer cells and neutrophils, increased significantly in the Dex-treated group. In vivo experiments indicated that the therapeutic effect of Dex is exerted mainly via the glucocorticoid receptor (Gr). Sequencing of Kupffer cells revealed that Dex could increase mRNA transcription level of nuclear receptor subfamily 4 group A member 1 (Nr4a1), and that this effect disappeared after Gr inhibition. CONCLUSIONS In LPS/D-GaIN-induced ALF mice, early administration of Dex improved ALF by increasing the numbers of innate immune cells, especially Kupffer cells and neutrophils. Gr-dependent Nr4a1 upregulation in Kupffer cells may be an important ALF effect regulated by Dex in this process.
Animals ; Dexamethasone/therapeutic use* ; Disease Models, Animal ; Kupffer Cells/physiology* ; Liver Failure, Acute/pathology* ; Male ; Mice ; Mice, Inbred C57BL ; Nuclear Receptor Subfamily 4, Group A, Member 1/physiology* ; Receptors, Glucocorticoid/physiology*