Faculty Collaboration Database

Tetrahydrobiopterin in Cell Function and Death Mechanisms. Antioxid Redox Signal 2022 Jul;37(1-3):171-183

Date

11/23/2021

Pubmed ID

34806400

Pubmed Central ID

PMC9293684

DOI

10.1089/ars.2021.0136

Scopus ID

2-s2.0-85132339483 (requires institutional sign-in at Scopus site)   24 Citations

Abstract

Significance: Tetrahydrobiopterin (BH4) is most well known as a required cofactor for enzymes regulating cellular redox homeostasis, aromatic amino acid metabolism, and neurotransmitter synthesis. Less well known are the effects dependent on the cofactor's availability, factors governing its synthesis and recycling, redox implications of the cofactor itself, and protein-protein interactions that underlie cell death. This review provides an understanding of the recent advances implicating BH4 in the mechanisms of cell death and suggestions of possible therapeutic interventions. Recent Advances: The levels of BH4 often reflect the sum of synthetic and recycling enzyme activities. Enhanced expression of GTP cyclohydrolase, the rate-limiting enzyme in biosynthesis, increases BH4, leading to improved cell function and survival. Pharmacologically increasing BH4 levels has similar beneficial effects, leading to enhanced production of neurotransmitters and nitric oxide or reducing oxidant levels. The GTP cyclohydrolase-BH4 pairing has been implicated in a type of cell death, ferroptosis. At the cellular level, BH4 counteracts anticancer therapies directed to enhance ferroptosis via glutathione peroxidase 4 (GPX4) activity inhibition. Critical Issues: Because of the multitude of intertwined mechanisms, a clear relationship between BH4 and cell death is not well understood yet. The possibility that the cofactor directly influences cell viability has not been excluded in previous studies when modulating BH4-producing enzymes. Future Directions: The importance of cellular BH4 variations and BH4 biosynthetic enzymes to cell function and viability makes it essential to better characterize temporal changes, cofactor activity, and the influence on redox status, which in turn would help develop novel therapies. Antioxid. Redox Signal. 37, 171-183.

Author List

Vasquez-Vivar J, Shi Z, Tan S

Author

Jeannette M. Vasquez-Vivar PhD Professor in the Biophysics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

GTP Cyclohydrolase
Nitric Oxide
Oxidation-Reduction