Uric acid induces liver fibrosis through activation of inflammatory mediators and proliferating hepatic stellate cell in mice

INTRODUCTION: Uric acid is associated with cardiometabolic risk factor and severity of liver damage. The mechanism of uric acid inducing liver damage is still elusive. This study elucidates the development of liver fibrosis under hyperuricemia.

METHODS AND MATERIALS: Hyperuricemia model was performed in male Swiss Webster mice. Intraperitoneally injection of uric acid (125mg/kg body weight) was done for 7 and 14 days (UA7 and UA14 groups). Meanwhile, the UAL groups were injected with uric acid and followed by the administration of allopurinol (UAL7 and UAL14 groups). On the due date, mice were sacrificed, and liver was harvested. Uric acid, SGOT, SGPT, and albumin level were measured from the serum. The mRNA expression of TLR4, MCP1, CD68, and collagen1 were assessed through RT-PCR. Liver fibrosis was quantified through Sirius red staining, while the number of hepatic stellates cells (HSCs) and TLR4 were assessed through IHC staining.

RESULTS: Uric acid induction for 7 and 14 days stimulated an increase of both SGOT and SGPT serum levels. Followed by enhanced inflammatory mediators: Toll-like receptor-4 (TLR- 4), Monocyte Chemoattractant Protein-1 (MCP-1) and Cluster of Differentiation 68 (CD68) mRNA expression in the liver (p<0.05). The histological findings showed that the UA7 and UA14 groups had higher liver fibrosis scores (p<0.05), collagen I mRNA expression (p<0.05), and the number of HSCs (p<0.05) compared to Control group. Administration of allopurinol showed amelioration of uric acid and liver enzymes levels which followed by inflammatory mediators, liver fibrosis and collagen1, and hepatic stellate cells significantly.

CONCLUSION: Therefore, uric acid augmented the liver fibrosis by increasing the number of hepatic stellate cells.