Correction: Development of three-dimensional primary human myospheres as culture model of skeletal muscle cells for metabolic studies

Andrea Dalmao-Fernandez^*Aleksandra AizenshtadtHG BakkeStefan KraussAC RustanG Hege ThoresenEili Tranheim Kase

• University of Oslo, Oslo, Norway

Frontiers' correction template for authors A correction refers to a change to their article that the author wishes to publish after publication. The publication of this article is subject to Frontiers' editorial approval. Instructions: ● Please read through all the templates before choosing ● Pick the most relevant text template(s) from the following page and delete all others. ● Edit the text as necessary, ensuring that the original incorrect text is included for the record, please see the below. ● Please do not use any extra formatting when editing the templates, and only modify the red text unless absolutely necessary ● Submit to Frontiers following the instructions on this page. When the original text contained incorrect information, to preserve the scientific record, please include that text when editing the below templates. For example: There was a mistake in the Funding statement, an incorrect number was used. The correct number is "2015C03Bd051.". The publisher apologizes for this mistake. The original version of this article has been updated. In the published article, there was a mistake in the Funding statement. The funding statement for the Key Development Project of the Department of Science and Technology was displayed as "2015CBd051". The correct statement is "Key Development Project of Department of Science and Technology (2015C03Bd051).'' Correction: Development of three-dimensional primary human myospheres as culture model of skeletal muscle cells for metabolic studies Correction on: Dalmao-Fernandez A, Aizenshtadt A, Bakke HG, Krauss S, Rustan AC, Thoresen GH, Kase ET. Development of three-dimensional primary human myospheres as culture model of skeletal muscle cells for metabolic studies. Front Bioeng Biotechnol. 2023 Mar 23;11:1130693. doi: 10.3389/fbioe.2023.1130693. PMID: 37034250; PMCID: PMC10076718. Error in figure/table Wrong content There was a mistake in figure [1] as published. One of the gene names is misspelled: solute carrier family 26 member 4 (SLC26A4), the correct form is: solute carrier family 2 member 4 (SLC2A4). The corrected figure [1] appears below. "Evaluation of 3D morphological parameters and comparison of muscle cell differentiation markers in 2D and 3D models. Myospheres were formed in the ultra-low attachment treatment (ULA) 96-well plate system and differentiation was carried out between 0 and 21 days. After 10 days of differentiation, mRNA was isolated, and gene expression was analyzed by qPCR. (A) Phase-contrast photos of myospheres during 3, 5, 10 and 12 of differentiation. Area (B) and diameter (C) were analyzed by AnaSP for up to 21 days of differentiation. (D) mRNA expression of the muscle differentiation markers MYOD, MYOG, MYH2, MYH7, and SLC2A4 before (day 0) and after differentiation (day 10), normalized to housekeeping gene (RPLP0). Scale bar = 200 µm. Results are presented as mean ± SEM. *p < 0.05 **p < 0.01 ****p < 0.0001 by ordinary one-way ANOVA test." "The process of muscle differentiation is regulated through different phases which stimulate myoblasts into fusion and maturation to become myotubes (Schmidt et al., 2019; Isesele and Mazurak, 2021). The differentiation process is initiated by an increased expression of myogenic differentiation 1 (MYOD) which induces gene expression of myogenin (MYOG) and subsequent expression of differentiation markers such as the myosin-heavy chains 2 (MYH2) and 7 (MYH7), and maturation factors related to metabolic muscle function like the insulin-regulated facilitative glucose transporter, solute carrier family 2 member 4 (SLC2A4). Comparison of expression of MYOD, MYH2, MYH7, and SLC2A4 revealed higher mRNA expression levels in 3D than 2D myotube models (Figure 1C). This relevant finding demonstrated a higher efficiency of cell maturation during differentiation in 3D than in 2D myotube models. In both cell models, mRNA expression levels of MYOD, MYOG, MYH2, MYH7, and SLC2A4 tended to increase after 10 days of differentiation (Figure 1C)".