Abstract
BackgroundMyostatin is a muscle derived factor that functions as a negative regulator of skeletal muscle growth. Induction of myostatin expression was observed in rodent models of muscle wasting and in cachectic patients with cancer or pulmonary disease. Therefore, there is an increasing interest to use serum myostatin as a biomarker.MethodsWe established an immunoradiometric sandwich assay (IRMA), which uses a commercially available chicken polyclonal, affinity purified antibody directed against human myostatin prodomain. We determined the serum concentrations of myostatin prodomain in 249 healthy individuals as well as 169 patients with heart failure, 53 patients with cancer and 44 patients with chronic pulmonary disease.ResultsThe IRMA had a detection limit of 0.7ng/ml, an intraassay imprecision of ≤14.1% and an interassay imprecision of ≤ 18.9%. The specificity of our assay was demonstrated by size exclusion chromatography, detection of myostatin by Western-blotting and a SMAD-dependent transcriptional-reporter assay in the signal-rich serum fractions, as well as lack of interference by unspecific substances like albumin, hemoglobin or lipids. Myostatin prodomain was stable at room temperature and resistant to freeze-thaw cycles. Apparently healthy individuals over the age of 55 had a median myostatin prodomain serum concentration of 3.9ng/ml (25th-75th percentiles, 2-7ng/ml) and we could not detect increased levels in patients with stable chronic heart failure or cancer related weight loss. In contrast, we found strongly elevated concentrations of myostatin prodomain (median 26.9ng/ml, 25th-75th percentiles, 7-100ng/ml) in the serum of underweight patients with chronic pulmonary disease.ConclusionsWe established a highly specific IRMA for the quantification of myostatin prodomain concentration in human serum. Our assay could be useful to study myostatin as a biomarker for example in patients with chronic pulmonary disease, as we detected highly elevated myostatin prodomain serum levels in underweight individuals of this group.
Highlights
Myostatin is a protein of the TGF-β family secreted mainly by skeletal muscle fibres and by adipocytes and cardiac myocytes [1,2]
In the “latent complex”, which consists of two molecules of each myostatin prodomain and ligand and is about 80kDa in size, the prodomain inhibits the activity of the myostatin ligand [1,2]
The specificity of our assay was proven by several approaches: First, size exclusion chromatography and assessment of myostatin prodomain abundance in 75 subfractions from human serum with high prodomain concentration revealed a single detection peak between 66kDa and 100kDa in size, which was not detected in serum with very low prodomain abundance
Summary
Myostatin is a protein of the TGF-β family secreted mainly by skeletal muscle fibres and by adipocytes and cardiac myocytes [1,2]. We determined the serum concentrations of myostatin prodomain in 249 healthy individuals as well as 169 patients with heart failure, 53 patients with cancer and 44 patients with chronic pulmonary disease. Healthy individuals over the age of 55 had a median myostatin prodomain serum concentration of 3.9ng/ml (25th-75th percentiles, 2-7ng/ml) and we could not detect increased levels in patients with stable chronic heart failure or cancer related weight loss. We found strongly elevated concentrations of myostatin prodomain (median 26.9ng/ml, 25th-75th percentiles, 7-100ng/ml) in the serum of underweight patients with chronic pulmonary disease. Our assay could be useful to study myostatin as a biomarker for example in patients with chronic pulmonary disease, as we detected highly elevated myostatin prodomain serum levels in underweight individuals of this group
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
