8.A.131.1.15
Haptoglobin, HP(T), or zonulin (a modulator of tight junctions; see TC# 1.H.1) of 406 aas and 0 TMSs. As a result of hemolysis, hemoglobin is found to accumulate in the kidney and is secreted in the urine. Haptoglobin captures and combines with free plasma hemoglobin to allow hepatic recycling of heme iron and to prevent kidney damage. Haptoglobin also acts as an antioxidant, has antibacterial activity, and plays a role in modulating many aspects of the acute phase response. Hemoglobin/haptoglobin complexes are rapidly cleared by the macrophage CD163 scavenger receptor expressed on the surface of liver Kupfer cells through an endocytic lysosomal degradation pathway. The uncleaved form of allele alpha-2 (2-2), known as zonulin, plays a role in intestinal permeability (Fasano 2011), allowing intercellular tight junction disassembly, and controlling the equilibrium between tolerance and immunity to non-self antigens (Zengil and Laloğlu 2023). Zonulin and occludin levels in bipolar disorder (BD) increase independently of the disease stage. Consideration of the role of IP in the pathogenesis of BD may be helpful in determining the appropriate treatment modality (Zengil and Laloğlu 2023).