Abstract:

ABSTRACT Objective: To investigate the effect and mechanisms of fatty acid binding protein 3 on the fat metabolism of podocyte. Methodology: We transfect the lentivirus vector to heat-sensitive mouse podocytes（HSMPs） to construct the cell line which express FABP3 stabile and excessively. Two siRNAs were desianed and synthesized. One of them that was capable of silencing FABP3 more effectively in HSMPs were chosen to do the next interference study. They were divided into ten cell groups: (1) normal control group; (2) NC-siRNA group; (3) FABP3-siRNA group; (4) NC group; (5) excessive express FABP3 group;(6)normal control+palmic acid(PA) group(7)NC-siRNA+PA group;(8)FABP3-siRNA+PA group;(9)NC+PA group;(10)excessive express FABP3+PA group. Triglycerides(TG) and free fatty acid contents in podocytes were determined by colorimetric method. The mRNA expression of peroxisome proliferator activated receptors α(PPARα) and ACOX3 of each group was determined by using Real-Time PCR. The proteins of PPARα and ACOX3 were examined by using Western blot. Results: Compared with normal control group, the levels of TG and free fatty acid were up-regulated in group5(FABP3 group), while down-regulated in group3(FABP3-siRNA group) (P<0.05).Compared with normal control group, mRNA and protein expressions of PPARα were down-regulated in FABP3 group(P<0.05), while mRNA and protein expressions of ACOX3 were up-regulated in FABP3 group(P<0.05) with or without PA. Compared with normal control group, mRNA and protein expressions of PPARα were up-regulated in FABP3-siRNA group(P<0.05), while mRNA and protein expressions of ACOX3 were down-regulated in FABP3-siRNA group with or without PA(P<0.05). Compared with FABP3 group, mRNA and protein expressions of PPARα were up-regulated in FABP3-siRNA group(P<0.05), while mRNA and protein expressions of ACOX3 were down-regulated in FABP3-siRNA group(P<0.05). There was more conspicuous statistical difference between FABP3+PA group and FABP3-siRNA+PA group in the expression of mRNA and proteins of PPARα and ACOX3(P<0.01). Conclusion: The excessive expression of FABP3 may induce fatty metabolic disturbance in podocytes. Inhibiting the expression of FABP3 may improve the fatty metabolic disturbance in podocytes. These results prompted that inhibiting the expression of FABP3 may ameliorate the metabolic disorder induced podocyte injury, such as diabetes mellitus, obesity and dyslipidemia.

Key words:  Fatty acid binding protein 3, peroxisome proliferator activated receptors α, Acyl-Coenzyme A oxidase 3, podocyte