title: Aerobic expression of Vitreoscilla hemoglobin improves the growth performance of CHO-K1 cells.
abstract: Inefficient carbon metabolism is a relevant issue during the culture of mammalian cells for the production of biopharmaceuticals. Therefore, cell engineering strategies to improve the metabolic and growth performance of cell lines are needed. The expression of Vitreoscilla stercoraria hemoglobin (VHb) has been shown to significantly reduce overflow metabolism and improve the aerobic growth of bacteria. However, the effects of VHb on mammalian cells have been rarely studied. Here, the impact of VHb on growth and lactate accumulation during CHO-K1 cell culture was investigated. For this purpose, CHO-K1 cells were transfected with plasmids carrying the vgb or gfp gene to express VHb or green fluorescence protein (GFP), respectively. VHb expression increased the specific growth rate and biomass yields on glucose and glutamine by 60 %, and reduced the amount of lactate produced per cell by 40 %, compared to the GFP-expression controls. Immunofluorescence microscopy showed that VHb is distributed in the cytoplasm and organelles, which support the hypothesis that VHb could serve as an oxygen carrier, enhancing aerobic respiration. These results are useful for the development of better producing cell lines for industrial applications.
authors.affiliation: Posgrado en Ciencias Naturales e Ingeniería, Universidad Autónoma Metropolitana-Cuajimalpa, Ciudad de México, México.
authors.forename: Mariana
authors.initials: M
authors.lastname: Juárez
authors.affiliation: Departamento de Ciencias Naturales, Universidad Autónoma Metropolitana-Cuajimalpa, Ciudad de México, México.
authors.forename: Claudia H
authors.initials: CH
authors.lastname: González-De la Rosa
authors.affiliation: Departamento de Ciencias Naturales, Universidad Autónoma Metropolitana-Cuajimalpa, Ciudad de México, México.
authors.forename: Elisa
authors.initials: E
authors.lastname: Memún
authors.affiliation: Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Ciudad de México, México.
authors.forename: Juan-Carlos
authors.initials: JC
authors.lastname: Sigala
authors.affiliation: Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Ciudad de México, México.
authors.forename: Alvaro R
authors.initials: AR
authors.lastname: Lara
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D018533:Biomass; D016466:CHO Cells; D060846:Cell Engineering; D003412:Cricetulus; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D019344:Lactic Acid / Q000378:metabolism; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D054793:Truncated Hemoglobins / Q000096:biosynthesis* / Q000235:genetics; D020589:Vitreoscilla / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D054793:Truncated Hemoglobins; C082613:hemoglobin protein, Vitreoscilla; D049452:Green Fluorescent Proteins; D019344:Lactic Acid
keywords: CHO cells; Energy metabolism; Lactate; Transient expression; Vitreoscilla hemoglobin