THE JOURNAL OF BIOLOGICAL CHEMISTRY VOL. 290, NO. 12, p. 8011, March 20, 2015 Published in the U.S.A.
LETTER
Detecting Collagen VI in Bethlem Myopathy
The study of col6 in muscle was performed with a monoclonal antibody (VI-26) raised against an uncharacterized triple helical epitope (1). It is noteworthy that col6 was not detected with this antibody in muscle and skin biopsies of a UCMD patient, but it was instead revealed by 3C4 antibody (see Fig. 2, patient P3, in Ref. 4). These observations highlight the importance of using different and well characterized col6 antibodies, including those raised against single col6 chains, especially in the absence of a correlation with biochemical data. In addition, alkaline treatment on frozen sections to retrieve antigen is unusual and may affect the detection of extracellular matrix proteins (5).
MARCH 20, 2015 • VOLUME 290 • NUMBER 12
Patrizia Sabatelli ‡1, Francesca Gualandi§, Paolo Bonaldo¶, and Luciano Merlini 㥋 ‡ Institute of molecular Genetics-CNR, SC Laboratory of Musculoskeletal Cell Biology, IOR, 40136 Bologna, Italy, §Department of Medical Sciences, University of Ferrara, Ferrara, Italy, ¶Department of Molecular Medicine, University of Padova, Padova, Italy, and 㛳SC Laboratory of Musculoskeletal Cell Biology, IOR, Bologna, Italy 1. Zamurs, L. K., Idoate, M. A., Hanssen, E., Gomez-Iban˜ez, A., Pastor, P., and Lamande´, S. R. (2015) Aberrant mitochondria in a Bethlem myopathy patient with a homozygous amino acid substitution that destabilizes the collagen VI ␣2(VI) chain. J. Biol. Chem. 290, 4272– 4281 2. Merlini, L., Martoni, E., Grumati, P., Sabatelli, P., Squarzoni, S., Urciuolo, A., Ferlini, A., Gualandi, F., and Bonaldo, P. (2008) Autosomal recessive myosclerosis myopathy is a collagen VI disorder. Neurology 71, 1245–1253 3. Zhang, R. Z., Zou, Y., Pan, T. C., Markova, D., Fertala, A., Hu, Y., Squarzoni, S., Reed, U. C., Marie, S. K., Bo¨nnemann, C. G., and Chu, M. L. (2010) Recessive COL6A2 C-globular missense mutations in Ullrich congenital muscular dystrophy. Role of the C2a splice variant. J. Biol. Chem. 285, 10005–10015 4. Jimenez-Mallebrera, C., Maioli, M. A., Kim, J., Brown, S. C., Feng, L., Lampe, A. K., Bushby, K., Hicks, D., Flanigan, K. M., Bonnemann, C., Sewry, C. A., and Muntoni, F. (2006) A comparative analysis of collagen VI production in muscle, skin and fibroblasts from 14 Ullrich congenital muscular dystrophy patients with dominant and recessive COL6A mutations. Neuromuscular Disorders: NMD 16, 571–582 5. Tsuchiya, T., Balestrini, J. L., Mendez, J., Calle, E. A., Zhao, L., and Niklason, L. E. (2014) Influence of pH on extracellular matrix preservation during lung decellularization. Tissue Eng. Part C Methods 20, 1028 –1036
DOI 10.1074/jbc.L115.639088 1
E-mail: [email protected]
JOURNAL OF BIOLOGICAL CHEMISTRY
8011
Downloaded from http://www.jbc.org/ at FLORIDA ATLANTIC UNIV on May 23, 2015
Zamurs et al. (1) investigated the functional consequences of a homozygous COL6A2 p.D871N mutation in muscle biopsy and fibroblast cultures of a recessive Bethlem myopathy patient. The authors reported the absence of collagen VI (col6) in muscle biopsy, a pattern considered distinctive for Ullrich congenital muscular dystrophy (UCMD). This finding appears inconsistent with the data provided for the patient’s skin fibroblasts, which clearly show that col6 was secreted in the extracellular matrix (1). Moreover, other authors showed that recessive mutations in the ␣2(VI) C2 domain, with consequences similar to those reported for this patient, cause a partial col6 deficiency in muscle biopsies (2, 3).
Indeed, if ever a lack of col6 is ascertained in Bethlem myopathy muscle, it will indicate that other factors are responsible for the different clinical outcomes, questioning the criteria of diagnosis, prognosis, and potential therapeutic approaches. Given the relevance of this issue, we recommend caution in data interpretation.
Letters to the Editor: Detecting Collagen VI in Bethlem Myopathy Patrizia Sabatelli, Francesca Gualandi, Paolo Bonaldo and Luciano Merlini J. Biol. Chem. 2015, 290:8011. doi: 10.1074/jbc.L115.639088
Find articles, minireviews, Reflections and Classics on similar topics on the JBC Affinity Sites. Alerts: • When this article is cited • When a correction for this article is posted Click here to choose from all of JBC's e-mail alerts This article cites 5 references, 2 of which can be accessed free at http://www.jbc.org/content/290/12/8011.full.html#ref-list-1
Downloaded from http://www.jbc.org/ at FLORIDA ATLANTIC UNIV on May 23, 2015
Access the most updated version of this article at http://www.jbc.org/content/290/12/8011
LETTER
Detecting Collagen VI in Bethlem Myopathy
The study of col6 in muscle was performed with a monoclonal antibody (VI-26) raised against an uncharacterized triple helical epitope (1). It is noteworthy that col6 was not detected with this antibody in muscle and skin biopsies of a UCMD patient, but it was instead revealed by 3C4 antibody (see Fig. 2, patient P3, in Ref. 4). These observations highlight the importance of using different and well characterized col6 antibodies, including those raised against single col6 chains, especially in the absence of a correlation with biochemical data. In addition, alkaline treatment on frozen sections to retrieve antigen is unusual and may affect the detection of extracellular matrix proteins (5).
MARCH 20, 2015 • VOLUME 290 • NUMBER 12
Patrizia Sabatelli ‡1, Francesca Gualandi§, Paolo Bonaldo¶, and Luciano Merlini 㥋 ‡ Institute of molecular Genetics-CNR, SC Laboratory of Musculoskeletal Cell Biology, IOR, 40136 Bologna, Italy, §Department of Medical Sciences, University of Ferrara, Ferrara, Italy, ¶Department of Molecular Medicine, University of Padova, Padova, Italy, and 㛳SC Laboratory of Musculoskeletal Cell Biology, IOR, Bologna, Italy 1. Zamurs, L. K., Idoate, M. A., Hanssen, E., Gomez-Iban˜ez, A., Pastor, P., and Lamande´, S. R. (2015) Aberrant mitochondria in a Bethlem myopathy patient with a homozygous amino acid substitution that destabilizes the collagen VI ␣2(VI) chain. J. Biol. Chem. 290, 4272– 4281 2. Merlini, L., Martoni, E., Grumati, P., Sabatelli, P., Squarzoni, S., Urciuolo, A., Ferlini, A., Gualandi, F., and Bonaldo, P. (2008) Autosomal recessive myosclerosis myopathy is a collagen VI disorder. Neurology 71, 1245–1253 3. Zhang, R. Z., Zou, Y., Pan, T. C., Markova, D., Fertala, A., Hu, Y., Squarzoni, S., Reed, U. C., Marie, S. K., Bo¨nnemann, C. G., and Chu, M. L. (2010) Recessive COL6A2 C-globular missense mutations in Ullrich congenital muscular dystrophy. Role of the C2a splice variant. J. Biol. Chem. 285, 10005–10015 4. Jimenez-Mallebrera, C., Maioli, M. A., Kim, J., Brown, S. C., Feng, L., Lampe, A. K., Bushby, K., Hicks, D., Flanigan, K. M., Bonnemann, C., Sewry, C. A., and Muntoni, F. (2006) A comparative analysis of collagen VI production in muscle, skin and fibroblasts from 14 Ullrich congenital muscular dystrophy patients with dominant and recessive COL6A mutations. Neuromuscular Disorders: NMD 16, 571–582 5. Tsuchiya, T., Balestrini, J. L., Mendez, J., Calle, E. A., Zhao, L., and Niklason, L. E. (2014) Influence of pH on extracellular matrix preservation during lung decellularization. Tissue Eng. Part C Methods 20, 1028 –1036
DOI 10.1074/jbc.L115.639088 1
E-mail: [email protected]
JOURNAL OF BIOLOGICAL CHEMISTRY
8011
Downloaded from http://www.jbc.org/ at FLORIDA ATLANTIC UNIV on May 23, 2015
Zamurs et al. (1) investigated the functional consequences of a homozygous COL6A2 p.D871N mutation in muscle biopsy and fibroblast cultures of a recessive Bethlem myopathy patient. The authors reported the absence of collagen VI (col6) in muscle biopsy, a pattern considered distinctive for Ullrich congenital muscular dystrophy (UCMD). This finding appears inconsistent with the data provided for the patient’s skin fibroblasts, which clearly show that col6 was secreted in the extracellular matrix (1). Moreover, other authors showed that recessive mutations in the ␣2(VI) C2 domain, with consequences similar to those reported for this patient, cause a partial col6 deficiency in muscle biopsies (2, 3).
Indeed, if ever a lack of col6 is ascertained in Bethlem myopathy muscle, it will indicate that other factors are responsible for the different clinical outcomes, questioning the criteria of diagnosis, prognosis, and potential therapeutic approaches. Given the relevance of this issue, we recommend caution in data interpretation.
Letters to the Editor: Detecting Collagen VI in Bethlem Myopathy Patrizia Sabatelli, Francesca Gualandi, Paolo Bonaldo and Luciano Merlini J. Biol. Chem. 2015, 290:8011. doi: 10.1074/jbc.L115.639088
Find articles, minireviews, Reflections and Classics on similar topics on the JBC Affinity Sites. Alerts: • When this article is cited • When a correction for this article is posted Click here to choose from all of JBC's e-mail alerts This article cites 5 references, 2 of which can be accessed free at http://www.jbc.org/content/290/12/8011.full.html#ref-list-1
Downloaded from http://www.jbc.org/ at FLORIDA ATLANTIC UNIV on May 23, 2015
Access the most updated version of this article at http://www.jbc.org/content/290/12/8011
