(P16-019-23) Effect of ALA/LA Fatty Acid Oxidation on Renal Tubulointerstitial Fibrosis of HK-2 Cells Induced by High Glucose

Objectives: Fatty Acid Oxidation (FAO) is the preferred energy source for highly metabolic cells, such as tubular epithelial cells. Mitochondria metabolism regulated by FAO has a key role in epithelial-to-mesenchymal transition (EMT) and kidney fibrosis development. But very little is known about the effect and metabolism of essential fatty acid (alpha-linolenic acid, ALA/linoleic acid, LA) on it. So, we use HK-2 cell to expose the mechanism of ALA/LA on DKD fibrosis and find out its proper concentration and ratio.

Methods: Two key fatty acid enzymes, carnitine palmitate transferase1α (CPT-1α), acyl CoA oxidase 1 (ACOX1), TGF-β1, peroxidase proliferator activator Receptor-α (PPAR-α)  and PPAR co-activator factor-1 α (PGC-1α) signaling pathway were determined at the mRNA and the protein expression levels via Realtime-PCR and Western Blot, respectively. The expressions of tubulointerstitial fibrosis-associated proteins Collagen-1 (Col-1) and fibronectin (FN) were determined by immunofluorescence. The contents of ATP, ADP and AMP were determined by liquid chromatography.

Results: After intervention, the levels of ACOX1and CPT-1αmRNA and protein expression in 50μM and 100μM, ratio of 1:4 ALA/LA intervention groups. Compared to the high glucose model group, the expression of PGC-1α mRNA and protein was increased in 100μM, ratio of 1:4 ALA/LA intervention group. While with the intervention of 100μM, ratio of 1:4 ALA/LA, the level of TGF-β1 mRNA and protein was decreased. The results of immunofluorescence showed that the expression of FN was lower than the high glucose model group (P < 0.05). we also measured the concentration of ATP, AMP and ADP in HK-2 cells after intervention of free fatty acid. It showed that total concentration of ATP, AMP and ADP was significantly enhanced after 48 h incubation with 100 μM ratio of 1:4 ALA/LA (P < 0.05).

Conclusions: Results showed that concentration of 50μM and 100μM, ratio of 1:4 ALA/LA improved recovery of key synthetase of FAO from the injury of HK-2 induced by high glucose and inhabited fibrosis, by down-regulating mRNA and protein expression of COX1 and Furthermore, 100μM 1:4 ALA/LA improved FAO and mitochondria metabolism synthesis via TGF-β1/PPAR-α/PCG-1α signal pathway.

Funding Sources: Financial assistance for this study was provided by the National Natural Science Foundation of China (No. 81903318 and No. 81372986 ).