Effects of homocysteine on expression of TNFSF4 gene and interleukin-10 in monocytes cultured in vitro

Dandan HUANG; Shuren WANG

ABSTRACT

BACKGROUND:

Inflammatory response is one of potential cellular mechanisms by which hyperhomocysteinemia accelerates atherosclerosis. There are still many details need to be illuminated. TNFSF4 gene and interleukin (IL)-10 are two inflammatory factors related to atherosclerosis. But their correlation with hyperhomocysteinemia is seldom reported.

OBJECTIVE:

To investigate the effects of homocysteine (Hcy) on expression of TNFSF4 gene and IL-10 in the monocytes cultured in vitro. DESIGN, TIME AND

SETTING:

A randomized control experiment in vitro was conducted from July to December in 2007 in the Pathophysiology Laboratory of West China School of Preclinical and Forensic Medical Sciences of Sichuan University. MATERIALS THP-1 monocytes were offered by the Pathophysiology Laboratory of West China School of Preclinical and Forensic Medical Sciences of Sichuan University); Hcy, dexamethasone (Dex) and vitamin D3 (Vit D3) were all purchased from Sigma.

METHODS:

Cultured THP-1 monocytes were induced to macrophages by 0.1 ?mol/L phorbol myristate acetate, and the differentiated THP-1 macrophages were incubated with 200 ?mol/L Hcy for 24, 48 and 72 hours respectively. Then cell supernatant and lysate were collected as condition medium. Any other differentiated THP-1 macrophages were incubated with a combination of Dex and Vit D3 for 6 days, and then the condition mediums were added to incubate together for 24 hours. Cells were divided into blank control group, 200 ?mol/L Hcy group, Dex+Vit D3 group, 24-hour Hcy+Dex+Vit D3 group, 48-hour Hcy+Dex+Vit D3 group, and 72-hour Hcy+ Dex+Vit D3 group. MAIN OUTCOME

MEASURES:

The expression level of TNFSF4 mRNA was determined by reverse transcription polymerase chain reaction. The expression level of IL-10 protein was determined by ELISA.

RESULTS:

Compared with blank control group, no significant difference of TNFSF4 mRNA expression was found in the 24-hour Hcy group, while the expression level was significantly higher in 48-hour and 72-hour Hcy groups. Compared with Dex+Vit D3 group, the IL-10 expression of all Hcy+Dex+Vit D3 groups was significantly lower than that in the Dex+Vit D3 group.

CONCLUSION:

Hcy may increase TNFSF4 mRNA expression and decrease IL-10 expression in THP-1 macrophages.