ADVANCEMENTS IN UNDERSTANDING THE MOLECULAR MECHANISMS REGULATING URIC ACID METABOLISM IN THE INTESTINE

Abstract

This review provides contemporary insights into the direct and indirect pathogenetic connections between purine compound metabolism and biochemical processes within the cells of the gastrointestinal system. A thorough analysis of recent publications from 2000 to 2024, sourced from databases including Scopus, PubMed, eLIIBRARY, and Google Scholar, was conducted. Uric acid serves as the end product of purine-containing compound catabolism. Its concentration is intricately regulated through the collaboration of the kidneys and gastrointestinal organs, namely the small intestine and liver. Gout, a chronic condition, emerges from the interplay between molecular genetic factors and external influences. Elevated levels of urates in the blood serum (hyperuricemia) and the deposition of sodium urate crystals in organs and tissues set off a cascade of inflammatory and fibrotic processes within mucosal, smooth muscle, parenchymal, and endothelial cells, including those within the gastrointestinal tract. Normally, a person excretes about 1.5 g of uric acid per day. Under physiological conditions, two-thirds of uric acid is excreted from the body by the kidneys, one-third through the intestines, and a small part is excreted with bile. The hypothesis that links the pathogenesis of hyperuricemia with “renal overload” suggests that the disease may develop as a result of impaired renal excretion with insufficient elimination of uric acid through the intestines. Part of uric acid transport systems actively works in hepatocytes and enterocytes, which determines its formation and clearance. Uric acid transporter proteins are divided into two categories: urate reabsorption transporters and urate excretion transporters, their expression is regulated by transcription factors, hormones and metabolites of intestinal microflora. The influence of intestinal microbiota on uric acid metabolism is related to its participation in purine metabolism, decomposition and elimination of uric acid with metabolites of intestinal flora and inhibition of gouty inflammation and is evaluated as a new therapeutic potential in gout and hyperuricemia, which allows to avoid kidney damage and urolithiasis.