NRF2 activation protects against valproic acid-induced disruption of neurogenesis in P19 cells

Ted B Piorczynski; Madison W Larsen; Sariah J Lee; Jason M Hansen

doi:10.1016/j.diff.2021.12.002

NRF2 activation protects against valproic acid-induced disruption of neurogenesis in P19 cells

Differentiation. 2022 Jan-Feb:123:18-29. doi: 10.1016/j.diff.2021.12.002. Epub 2021 Dec 7.

Authors

Ted B Piorczynski¹, Madison W Larsen¹, Sariah J Lee¹, Jason M Hansen²

Affiliations

¹ Department of Cell Biology and Physiology, Brigham Young University, Provo, UT, 84602, USA.
² Department of Cell Biology and Physiology, Brigham Young University, Provo, UT, 84602, USA. Electronic address: jason_hansen@byu.edu.

PMID: 34902770
DOI: 10.1016/j.diff.2021.12.002

Abstract

Valproic acid (VPA) is a commonly prescribed antiepileptic drug that causes fetal valproate syndrome (FVS) in developing embryos exposed to it. Symptoms of FVS include neural tube defects (NTDs), musculoskeletal abnormalities, and neurodevelopmental difficulties. One proposed mechanism of VPA-induced developmental toxicity is via oxidative stress, defined as the disruption of redox-sensitive cell signaling. We propose that redox imbalances caused by VPA exposure result in improper cellular differentiation that may contribute to FVS. In undifferentiated P19 mouse embryonal carcinoma cells treated with VPA, glutathione disulfide (GSSG) concentrations were higher and the glutathione (GSH)/GSSG redox potential (E_h) was more oxidizing compared to vehicle-treated control cells, both of which are indications of potential intracellular oxidative stress. Interestingly, VPA had no effect on GSH or GSSG levels in differentiated P19 neurons. Undifferentiated cells pretreated with 3H-1,2-dithiole-3-thione (D3T), an inducer of the nuclear factor erythroid 2-related factor 2 (NRF2) antioxidant response that combats cellular redox disruption, were protected from VPA-induced alterations to the GSH/GSSG system. To assess differential periods of susceptibility, P19 cells were exposed to VPA at various time points during their neuronal differentiation. Cells exposed to VPA early in the differentiation process did not undergo normal neurogenesis as measured by POU domain, class 5, transcription factor 1 (OCT4) and tubulin beta-3 chain (βIII-tubulin), markers of cell stemness and neuronal differentiation, respectively. Neurogenesis was improved with D3T pretreatments prior to VPA exposure. Furthermore, differentiating P19 cells treated with VPA exhibited increased protein oxidation that was diminished with D3T pretreatment. These findings demonstrate that VPA inhibits neurogenesis and propose NRF2-mediated redox homeostasis as a means to promote normal neuronal differentiation, thereby potentially decreasing the prevalence of FVS outcomes.

Keywords: Fetal valproate syndrome; Glutathione; NRF2; P19; Valproic acid.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Abnormalities, Drug-Induced
Animals
Glutathione / metabolism
Glutathione Disulfide
Mice
NF-E2-Related Factor 2* / genetics
NF-E2-Related Factor 2* / metabolism
Neurogenesis
Tubulin
Valproic Acid* / adverse effects
Valproic Acid* / toxicity

Substances

NF-E2-Related Factor 2
Tubulin
Valproic Acid
Glutathione
Glutathione Disulfide

Supplementary concepts

Valproic acid antenatal infection