Circulating protein biomarkers identified in two independent clinical trial cohorts of glucocorticoid-naive Duchenne muscular dystrophy patients

Abstract

Blood-accessible biomarkers offer promising insights into the pathogenesis of Duchenne muscular dystrophy (DMD) and other muscle diseases. Here, we quantified the relative abundance of 7,289 serum proteins using SomaScan proteomics in pre-treatment samples from 51 boys with DMD (aged 4 to <7) and 13 healthy controls from the VISION DMD (VBP15-004) trial. An independent validation cohort of untreated DMD boys (aged 4 to <8) from the FOR-DMD trial was also analyzed. Of the proteins screened, 26% and 15% were significantly elevated and decreased, respectively, in the serum of young DMD boys compared to controls (adjusted p-value < 0.05). A high correlation (Spearman r = 0.85) in fold changes was observed between the two datasets. Many proteins with altered levels overlapped with known markers of muscle injury, inflammation, regeneration, and extracellular matrix remodeling. Selected biomarkers were queried in two published muscle mRNA and a muscle snRNAseq dataset in DMD biopsies. Novel factors involved in muscle regeneration and ECM remodeling were identified. This larger-scale, multi-clinical trial-based cohort study in untreated DMD boys substantially expands the catalog of circulating biomarkers, highlighting early-stage pathological processes. These findings can help identify new therapeutic targets and develop clinically actionable biomarkers to assess disease progression and response to therapies.

Keywords: Biomarker discovery-validation; Duchenne muscular dystrophy; Proteomics, SomaScan; Serum-muscle omics integration.

Fig. 1

Volcano plots showing elevated and decreased proteins measured by SomaScan assay in serum samples of DMD boys (n = 51) relative to age matched healthy controls (n = 13). Cut off was ± 1.5-fold change with adjusted p values < 0.05.

Fig. 2

Log2 fold changes from 1,500 overlapping serum proteins measured by SomaScan in serum samples from two independent DMD cohorts: VBP15-004 and FOR-DMD.

Fig. 3

Box plots of exemplar muscle injury biomarkers identified in serum of DMD subjects. Levels are shown in both VBP and FORDM cohorts compared to controls. ACTN2: Alpha-actinin-2; ADSS1: Adenylosuccinate synthetase isozyme 1; KLHL41: Kelch-like protein 41; TRIM72: Tripartite motif-containing protein 72; ANKRD2: Ankyrin repeat domain-containing protein 2; MUSTN1: Musculoskeletal embryonic nuclear protein 1.

Fig. 4

Box plots of exemplar ECM protein biomarkers identified in serum of DMD subjects. Levels are shown in both VBP and FORDM cohorts compared to controls. CCDC80: Coiled-coil domain-containing protein 80; THBS4: Thrombospondin-4; COL28A1: Collagen alpha-1(XXVIII) chain; IBSP: Bone sialoprotein 2; SPP1: osteopontin; CDH17: Cadherin-17.

Fig. 5

Box plots of exemplar circulating growth factors identified in serum of DMD subjects. Levels are shown in both VBP and FORDM cohorts compared to controls.

Fig. 6

Box plots of exemplar circulating immune and pro-inflammatory associated markers identified in serum of DMD subjects. Levels are shown in both VBP and FORDM cohorts compared to controls.