Polyunsaturated fatty acids and renal fibrosis: pathophysiologic link and potential clinical implications

The role of polyunsaturated fatty acids in renal fibrosis. Several studies suggest a close relationship between polyunsaturated fatty acids (PUFA) and renal inflammation and fibrosis, which are crucial stages in chronic kidney disease (CKD). Beneficial effects of n-3 PUFA on the course of experimental and human nephropathies have been reported. PUFA can ameliorate chronic, progressive renal injury beyond the simple reduction of serum lipid levels. These pleiotropic effects of PUFA are due to their properties of interfering with the synthesis of a variety of inflammatory factors and events, through effects related both to the modulation of the balance of n-6 and n-3-derived eicosanoids and to direct action on the cellular production of the major cytokine mediators of inflammation and on endothelium function. The mechanisms by which PUFA can favorably interfere with some stages in renal fibrosis processes, such as mesangial cell activation and proliferation and extracellular matrix protein synthesis, include the regulation of some pro-inflammatory cytokine production, renin and nitric oxide (NO) systems and peroxisome proliferator-activated receptor gene expression. An optimal n-6/n-3 PUFA ratio dietary intake could offer new therapeutic strategies aimed at interrupting the irreversible process of renal fibrosis and ameliorating chronic renal injury. However, further experimental, epidemiological and clinical investigations are needed to confirm the role of PUFA in the renal fibrosis pathway and the natural history of chronic nephropathies.