TY - JOUR

T1 - The Biochemical Pathways of Nicotinamide-Derived Pyridones

AU - Hayat, Faisal

AU - Sonavane, Manoj

AU - Makarov, Mikhail V.

AU - Trammell, Samuel A.J.

AU - McPherson, Pamela

AU - Gassman, Natalie R.

AU - Migaud, Marie E.

PY - 2021

Y1 - 2021

N2 - As catabolites of nicotinamide possess physiological relevance, pyridones are often included in metabolomics measurements and associated with pathological outcomes in acute kidney injury (AKI). Pyridones are oxidation products of nicotinamide, its methylated form, and its ribosylated form. While they are viewed as markers of over-oxidation, they are often wrongly reported or mislabeled. To address this, we provide a comprehensive characterization of these catabolites of vitamin B3, justify their nomenclature, and differentiate between the biochemical pathways that lead to their generation. Furthermore, we identify an enzymatic and a chemical process that accounts for the formation of the ribosylated form of these pyridones, known to be cytotoxic. Finally, we demonstrate that the ribosylated form of one of the pyridones, the 4-pyridone-3-carboxamide riboside (4PYR), causes HepG3 cells to die by autophagy; a process that occurs at concentrations that are comparable to physiological concentrations of this species in the plasma in AKI patients.

AB - As catabolites of nicotinamide possess physiological relevance, pyridones are often included in metabolomics measurements and associated with pathological outcomes in acute kidney injury (AKI). Pyridones are oxidation products of nicotinamide, its methylated form, and its ribosylated form. While they are viewed as markers of over-oxidation, they are often wrongly reported or mislabeled. To address this, we provide a comprehensive characterization of these catabolites of vitamin B3, justify their nomenclature, and differentiate between the biochemical pathways that lead to their generation. Furthermore, we identify an enzymatic and a chemical process that accounts for the formation of the ribosylated form of these pyridones, known to be cytotoxic. Finally, we demonstrate that the ribosylated form of one of the pyridones, the 4-pyridone-3-carboxamide riboside (4PYR), causes HepG3 cells to die by autophagy; a process that occurs at concentrations that are comparable to physiological concentrations of this species in the plasma in AKI patients.

KW - NAD

KW - Nicotinamide

KW - Pyridones

KW - Redox cofactor

U2 - 10.3390/ijms22031145

DO - 10.3390/ijms22031145

M3 - Journal article

C2 - 33498933

AN - SCOPUS:85099770166

VL - 22

JO - International Journal of Molecular Sciences (CD-ROM)

JF - International Journal of Molecular Sciences (CD-ROM)

SN - 1424-6783

IS - 3

M1 - 1145

ER -