Hydrogen sulfide potently promotes neuronal differentiation of adipose tissue-derived stem cells involving nitric oxide-mediated signaling cascade with the aid of cAMP-elevating agents

Abstract

Neuronal differentiation of adipose tissue-derived stem cells (ASCs) is potently promoted by valproic acid (VPA) through a gaseous signaling molecule, nitric oxide (NO). Here, we investigated the involvement of hydrogen sulfide (H₂S), another gaseous signaling molecule, in neuronal differentiation of ASCs. VPA-promoted neuronal differentiation of ASCs was accompanied by increased intracellular H₂S and sulfane sulfur with increased mRNA expression of enzymes synthesizing sulfane sulfur including cystathionine β-synthase (CBS), of which inhibition reduced the differentiation efficiency. H₂S donors, GYY4137 (GYY) or NaHS, potently promoted neuronal differentiation of ASCs when cAMP-elevating agents, dibutyryl cyclic adenosine monophosphate and isobutyl methyl-xanthine, were added as neuronal induction medium (NIM). Neuronal differentiation of ASCs promoted by NaHS or GYY was accompanied by Ca²⁺ entry and increased mRNA expression of voltage-gated Ca²⁺ channels. NaHS or GYY also increased mRNA expression of enzymes of the NO-citrulline cycle including inducible NO synthase (iNOS). It was concluded from these results that H₂S potently promoted differentiation of ASCs into neuronal cells expressing functional voltage-gated Ca²⁺ channels with the aid of cAMP-elevating agents, involving NO-mediated signaling cascade. These effects of H₂S were also considered as a partial mechanism for the VPA-promoted neuronal differentiation of ASCs.

Keywords: Adipose tissue-derived stem cells; Calcium channels; Hydrogen sulfide; Neuronal differentiation; Nitric oxide signaling; cAMP.