Homocysteinylation of neuronal proteins contributes to folate deficiency-associated alterations of differentiation, vesicular transport, and plasticity in hippocampal neuronal cells.
Despite the key role in neuronal development of a deficit in the methyl donor folate, little is known on the underlying mechanisms. We therefore studied the consequences of folate deficiency on proliferation, differentiation, and plasticity of the rat H19-7 hippocampal cell line. Folate deficit reduced proliferation (17%) and sensitized cells to differentiation-associated apoptosis (+16%). Decreased production (-58%) of S-adenosylmethionine (the universal substrate for transmethylation reactions) and increased expression of histone deacetylases (HDAC4,6,7) would lead to epigenomic changes that may impair the differentiation process. Cell polarity, vesicular transport, and synaptic plasticity were dramatically affected, with poor neurite outgrowth (-57%). Cell treatment by an HDAC inhibitor (SAHA) led to a noticeable improvement of cell polarity and morphology, with longer processes. Increased homocysteine levels (+55%) consecutive to folate shortage produced homocysteinylation, evidenced by coimmunoprecipitations and mass spectrometry, and aggregation of motor proteins dynein and kinesin, along with functional alterations, as reflected by reduced interactions with partner proteins. Prominent homocysteinylation of key neuronal proteins and subsequent aggregation certainly constitute major adverse effects of folate deficiency, affecting normal development with possible long-lasting consequences.
Inserm U954, Faculté de Médecine, 9 Avenue de la Forêt de Haye, F-54500 Vandoeuvre-lès-Nancy, France.
Nassila
N
Akchiche
Carine
C
Bossenmeyer-Pourié
Racha
R
Kerek
Nicolas
N
Martin
Grégory
G
Pourié
Violette
V
Koziel
Déborah
D
Helle
Jean-Marc
JM
Alberto
Sandrine
S
Ortiou
Jean-Michel
JM
Camadro
Thibaut
T
Léger
Jean-Louis
JL
Guéant
Jean-Luc
JL
Daval
D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D005492:Folic Acid / Q000494:pharmacology*; D005494:Folic Acid Deficiency / Q000378:metabolism*; D056945:Hep G2 Cells; D006624:Hippocampus / Q000166:cytology*; D006710:Homocysteine / Q000494:pharmacology*; D006801:Humans; D007150:Immunohistochemistry; D009474:Neurons / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D011485:Protein Binding; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D014805:Vitamin B 12 / Q000494:pharmacology
D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12