abstract
Background: Nicotinamide adenine dinucleotide (NAD) metabolism is involved in redox and non-redox reactions that regulate several processes including differentiation of cells of different origins. Here, the role of NAD metabolism in neuronal differentiation, which remains elusive so far, was investigated.Material and methods: A protein-protein interaction network between neurotrophin signaling and NAD metabolic pathways was built. Expression of NAD biosynthetic enzymes in SH-SY5Y cells during retinoic acid (RA)/brain derived neurotrophic factor (BDNF) differentiation, was evaluated. The effects of NAD biosynthetic enzymes QPRT and NAPRT inhibition in neurite outgrowth, cell viability, NAD availability and histone deacetylase (HDAC) activity, were analyzed in RA- and BDNF-differentiated cells.Results: Bioinformatics analysis revealed the interaction between NAD biosynthetic enzyme NMNAT1 and NTRK2, a receptor activated by RA/BDNF sequential treatment. Differences were found in the expression of NAD biosynthetic enzymes during neuronal differentiation, namely, increased QPRT gene expression along the course of RA/BDNF treatment and NAPRT protein expression after a 5-day treatment with RA. QPRT inhibition in BDNF-differentiated SH-SY5Y cells resulted in less neuritic length per cell, decreased expression of the neuronal marker beta-III Tubulin and also decreased NAD+ levels and HDAC activity. NAPRT inhibition had no effect in neuritic length per cell, NAD+ levels and HDAC activity. Of note, NAD supplementation along with RA, but not with BDNF, resulted in considerable cell death.Conclusions: Taken together, our results show the involvement of NAD metabolism in neuronal differentiation, specifically, the importance of QPRT-mediated NAD biosynthesis in BDNF-associated SH-SY5Y differentiation and suggest additional roles for NAPRT beyond NAD production in RA-differentiated cells.
keywords
NICOTINIC-ACID PHOSPHORIBOSYLTRANSFERASE; RETINOIC ACID; SIRT1-MEDIATED DEACETYLATION; SH-SY5Y CELLS; IN-VITRO; NAMPT; NEURITOGENESIS; TRANSCRIPTION; CONTRIBUTES; INHIBITION
subject category
Biochemistry & Molecular Biology; Neurosciences & Neurology
authors
Neves, D; Goodfellow, BJ; Vieira, SI; Silva, RM
our authors
Brian James Goodfellow
Assistant Professor
Diogo André Teixeira Neves
PhD StudentProjects
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
acknowledgements
This work was supported by FCT (Fundacao para a Ciencia e Tecnologia), FEDER (Programa Operacional Factores de Competitividade - COMPETE) and by QREN, through the grant SFRH/BD/129409/2017 to DN, and the projects GoBack (PTDC/CVT-CVT/32261/2017), UIDB/04501/2020 (POCI-01-0145-FEDER-007628) to iBiMED, UIDB/04279/2020 to CIIS and UIDB/50011/2020 & UIDP/50011/2020 to CICECO. Image acquisition was performed in the LiM facility of iBiMED, a node of PPBI (Portuguese Platform of BioImaging): POCI-01-0145-FEDER-022122. FCT/MCTES and UCP support CEEC institutional funding of RMS (CEECINST/00137/2018/CP1520/CT0012).