title: Methyl donor deficiency in H9c2 cardiomyoblasts induces ER stress as an important part of the proteome response.
abstract: Deficiency of methyl donors (MDs, folate, vitamin B12, and choline) causes increased plasma level of Hcy, a risk factor for cardiovascular diseases. Previously, we showed that maternal MD deprivation altered the cardiac proteome of rat pups. To better understand its impact on cardiac cells, we exposed rat H9c2 cardiomyoblasts to selectively a synthetic folate- or MD-deficient (FD or MDD) medium. We found that a 4-day exposure to the FD medium, unlike the MDD one, did not cause an abnormal extracellular release of Hcy relatively to similar exposure to the control complete (C) medium. Comparative analyses of the proteomes of FD, MDD, and C cells identified 7 and 6 proteins up- or downregulated by either deficiency, respectively. Most proteins were found interrelated in a single network dealing with "post-translational modification, protein folding and cell death/survival" (FD cells) or "DNA replication/recombination/repair and cell morphology/compromise" (MDD cells). Both deficiencies altered the protein and mRNA levels of the chaperones α-crystallin B, protein disulfide-isomerase A4, and prohibitin. This was concurrent with rapid induction of several key genes of the ER stress response, notably gadd153/chop, and increased expression of the E3 ubiquitin ligases, Hrd1, and MAFbx. In conclusion, the effects of folate and MD deficiencies on the cardiomyoblast proteome display some dissimilarities possibly related to different cellular production of Hcy. In both cases activation of the ER stress could occur in response to accumulation of ubiquitinated misfolded proteins.
authors.affiliation: Unité Nutrition Humaine, Unité Mixte de Recherche 1019 Institut National de la Recherche Agronomique (INRA), Université d'Auvergne, Clermont Université, 63122 Saint-Genès Champanelle, France. Electronic address: m_emilie13@hotmail.com.
authors.forename: Emilie
authors.initials: E
authors.lastname: Martinez
authors.affiliation: Unité Nutrition Humaine, Unité Mixte de Recherche 1019 Institut National de la Recherche Agronomique (INRA), Université d'Auvergne, Clermont Université, 63122 Saint-Genès Champanelle, France. Electronic address: christiane.deval@clermont.inra.fr.
authors.forename: Christiane
authors.initials: C
authors.lastname: Deval
authors.affiliation: Unité Nutrition Humaine, Unité Mixte de Recherche 1019 Institut National de la Recherche Agronomique (INRA), Université d'Auvergne, Clermont Université, 63122 Saint-Genès Champanelle, France. Electronic address: celine.jousse@clermont.inra.fr.
authors.forename: Céline
authors.initials: C
authors.lastname: Jousse
authors.affiliation: Unité Nutrition Humaine, Unité Mixte de Recherche 1019 Institut National de la Recherche Agronomique (INRA), Université d'Auvergne, Clermont Université, 63122 Saint-Genès Champanelle, France. Electronic address: andre.mazur@clermont.inra.fr.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Mazur
authors.affiliation: Unité Nutrition Humaine, Unité Mixte de Recherche 1019 Institut National de la Recherche Agronomique (INRA), Université d'Auvergne, Clermont Université, 63122 Saint-Genès Champanelle, France. Electronic address: patrick.brachet@clermont.inra.fr.
authors.forename: Patrick
authors.initials: P
authors.lastname: Brachet
authors.affiliation: Unité Nutrition Humaine, Unité Mixte de Recherche 1019 Institut National de la Recherche Agronomique (INRA), Université d'Auvergne, Clermont Université, 63122 Saint-Genès Champanelle, France. Electronic address: blandine.comte@clermont.inra.fr.
authors.forename: Blandine
authors.initials: B
authors.lastname: Comte
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D002460:Cell Line; D048429:Cell Size; D002470:Cell Survival; D003720:Densitometry; D015180:Electrophoresis, Gel, Two-Dimensional; D059865:Endoplasmic Reticulum Stress; D005492:Folic Acid / Q000378:metabolism; D063990:Gene Ontology; D053263:Gene Regulatory Networks; D042541:Intracellular Space / Q000378:metabolism; D008745:Methylation; D032383:Myocytes, Cardiac / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D013997:Time Factors; D025801:Ubiquitin / Q000378:metabolism; D014805:Vitamin B 12 / Q000378:metabolism
chemical_list: D015415:Biomarkers; D020543:Proteome; D012333:RNA, Messenger; D025801:Ubiquitin; D005492:Folic Acid; D046988:Proteasome Endopeptidase Complex; D014805:Vitamin B 12
keywords: Cardiomyoblasts; ER stress; Homocysteine; Methyl donor deficiency; Proteomics