Myostatin and markers of bone metabolism in dermatomyositis

Abstract

Background In dermatomyostis (DM) patients, inflammation, reduced activity, and medication have a negative impact on the musculoskeletal system. Several endocrine factors are involved in muscle growth and bone turnover. Objective: We aimed to investigate factors regulating myogenesis and bone metabolism and to evaluate possible associations between these endocrine factors, muscle strength, and functional tests in DM patients. Methods We conducted a cross-sectional study in 20 dermatomyositis patients. Serum levels of myostatin (MSTN), follistatin (FSTN), dickkopf 1 (Dkk1), sclerostin (SOST), periostin (PSTN), the receptor activator nuclear factor kB ligand (RANKL):osteoprotegerin (OPG) ratio and fibroblast growth factor 23 (FGF23) were determined. Physical function was evaluated by hand-held strength measurement, chair rising test, timed up and go test and the 3-min walking test. Results Serum MSTN and FGF23 levels (2.5 [1.9; 3.2] vs. 1.9 [1.6; 2.3] and 2.17 [1.45; 3.26] vs. 1.28 [0.79; 1.96], respectively; p < 0.05) were significantly higher in DM patients than in controls. Dkk1 was significantly lower (11.4 [6.9; 20.0] vs. 31.8 [14.3; 50.6], p < 0.01). Muscle strength and physical function tests correlated with each other (e.g. hip flexion – timed up and go test: r = − 0.748, p < 0.01). Conclusion In DM patients, biochemical musculo-skeletal markers are altered and physical function shows deficits. All these tests reflect independent of each other different deficits in long-term DM patients which is important for the assessment of DM patients as well as planning of therapeutic interventions in clinical routine.

Myostatin in idiopathic inflammatory myopathies: Serum assessment and disease activity

“…Moreover, myostatin level was higher in inactive IIM patients compared to active ones, except for IMNM patients where it remained unchanged. Only a few studies have previously examined myostatin in IIM and they are often contradictory [13,14,[27][28][29][30]. Some results are concordant with our studies [13,14], whereas others are not [27][28][29][30],…”

Serum Myostatin and Follistatin Levels in Patients With Dermatomyositis and Polymyositis

“…There are only 2 studies analyzing serum levels of myostatin and follistatin in DM and PM, and these studies showed contradictory results. 22,33 Vernerova et al 22 evaluated serum levels of myostatin and follistatin in 94 IIM patients with short disease duration, 44 established rheumatoid arthritis (RA), 36 early RA patients without corticosteroids, and 134 healthy control subjects; the authors reported decreased serum myostatin levels and increased follistatin levels. The authors also evaluated muscle biopsies in 20 IIM patients and 28 healthy control subjects and found an increased follistatin gene expression in patients with IIM.…”

Myostatin regulates the production of fibroblast growth factor 23 (FGF23) in UMR106 osteoblast–like cells

“…In dermatomyositis, an inflammatory condition, the plasma myostatin concentration is elevated [ 23 ]. Importantly, the same study also found higher FGF23 levels in patients with dermatomyositis [ 23 ].…”

“…In dermatomyositis, an inflammatory condition, the plasma myostatin concentration is elevated [ 23 ]. Importantly, the same study also found higher FGF23 levels in patients with dermatomyositis [ 23 ]. Moreover, CKD, another disease associated with elevated FGF23 levels [ 26 ], is characterized by a higher myostatin plasma concentration [ 46 ] and enhanced myostatin expression in muscle of mice [ 48 ].…”

“…Some human diseases with enhanced myostatin plasma levels including dermatomyositis and CKD are characterized by enhanced FGF23 production [ 23 , 46 ]. This and the well-established muscle and bone cross-talk [ 25 ] prompted us to investigate whether myostatin directly impacts on FGF23 formation and to uncover the underlying mechanism.…”