Influence of conjugated linoleic acid (c9, t11-CLA and t10, c12-CLA) on mRNA expression of bone metabolism related markers of bone marrow cells

Abstract

Objective To observe the effect of conjugated linoleic acid (c9,t11-CLA and t10,c12-CLA) on the mRNA expression of peroxisome proliferator activated receptorγ2 (PPARγ2),receptor activator of NF-κB ligand ( RANKL),alkaline phosphatase ( ALP),osteoprotegerin ( OPG),receptor activator of NF-κB (RANK) and tartrate-resistant acid phosphatase (TRAP) of bone marrow cells,and study the effect of c9,t11-CLA and t10,c12-CLA on bone metabolism.Methods Bone marrow cells of Wistar rats were cultured in vitro and then the cells were cultured in DMEM with c9,t11-CLA or t10,c12-CLA at different concentrations (the final concentration was 0,12.5,25.0,50.0 μmol/L,respectively) for 24 h.Reverse transcription-polymerase chain reaction (RT-PCR) was performed to detect the mRNA expression of PPARγ2,RANKL,ALP,OPG,RANK and TRAP.Results Semi-quantitative RT-PCR analysis showed that c9,t11-CLA down-regulated the mRNA expression of RANK and TRAP in a dose-dependent manner,and statistically significant difference was found in interclass comparison (P ＜ 0.05,P ＜ 0.01 ),while it had no effect on the mRNA expression of RANKL,ALP,OPG and PPARγ2.The results also showed that t10,c12-CLA up-regulated the mRNA expression of RANKL and OPG in a dose-dependent manner and down-regnlated the mRNA expression of RANK,TRAP and PPARγ2 in a dose-dependent manner,statistically significant difference was found in interclass comparison ( P ＜ 0.05,P ＜ 0.01 ),while it had no effect on the mRNA expression of ALP.Conclusion Our findings suggest that c9,t11-CLA and t10,c12-CLA can suppress the expression of osteoclastogenesis genes and t10,c12-CLA can also promote the expression of osteogenic genes,which suggests a possible benecial effect on bone formation. Key words: Peroxisome proliferator activated receptoryγ; Conjugated linoleic acid; Osteoporosis