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Fig. 1 | Journal of Neuroinflammation

Fig. 1

From: Plasma neurofilament light chain and amyloid-β are associated with the kynurenine pathway metabolites in preclinical Alzheimer’s disease

Fig. 1

The kynurenine pathway schematic. Within the KP, tryptophan is metabolised to kynurenine (KYN) via the enzymes indoleamine 2,3-deoxygenase or tryptophan deoxygenase and formamidase. KYN gets converted to kynurenic acid (KA) via the enzyme kynurenine aminotransferase. KYN is also metabolised to anthranilic acid (AA) by the enzyme kynureninase and to 3-hydroxykynurenine (3-HK) by the enzyme kynurenine-3-monooxygenase. AA and 3-HK are metabolised to 3-hydroxyanthranilic acid (3-HAA). 3-HAA further converts to aminocarboxymuconic semialdehyde that spontaneously either converts to the neurotoxin, quinolinic acid, a substrate for the redox agent, NAD+ or is assisted by enzyme 2-amino-3-carboxymuconatesemialdehyde decarboxylase to generate picolinic acid

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