fig1

Figure 1. Schematic representation of copper metabolism in healthy individuals compared to Wilson disease. The regulation of copper levels involves absorption in the upper gastrointestinal tract and excretion by liver cells (hepatocytes) into bile as an insoluble complex. Key components include the mucosal cell and the hepatocyte. This diagram illustrates the processes of cellular uptake, intracellular transport, storage, metabolic processing within the liver, and cellular excretion. In Wilson disease, a mutation in the ATP7B gene leads to a defective copper transporter at the trans-Golgi network, hindering proper loading of apoceruloplasmin with copper, resulting in decreased serum copper levels. Additionally, impaired biliary excretion causes copper accumulation in hepatocytes, initially bound to metallothionein. Cu⁺: Cuprous form; Cu²⁺: cupric form; ATOX1: antioxidant copper chaperone; ATP7A: ATPase copper transporter alpha; ATP7B: ATPase copper transporter beta; CTR1: copper transporter 1.