Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 May 9:10:1040.
doi: 10.3389/fimmu.2019.01040. eCollection 2019.

Proteomic Profiling Unravels a Key Role of Specific Macrophage Subtypes in Sporadic Inclusion Body Myositis

Andreas Roos  1   2 , Corinna Preusse  3 , Denisa Hathazi  2 , Hans-Hilmar Goebel  3 , Werner Stenzel  3   4
Affiliations

Proteomic Profiling Unravels a Key Role of Specific Macrophage Subtypes in Sporadic Inclusion Body Myositis

Andreas Roos et al. Front Immunol. .

Abstract

Unbiased proteomic profiling was performed toward the identification of biological parameters relevant in sIBM, thus giving hints about the pathophysiological processes and the existence of new reliable markers. For that purpose, skeletal muscle biopsies from 13 sIBM and 7 non-diseased control patients were analyzed with various methods, including liquid chromatography coupled to tandem mass spectrometry (four patients). Subsequent data analysis identified key molecules further studied in a larger cohort by qPCR, immunostaining, and immunofluorescence in situ. Proteomic signature of muscle biopsies derived from sIBM patients revealed the chaperone and cell surface marker CD74, the macrophage scavenger molecule CD163 and the transcription activator STAT1 to be among the highly and relevantly expressed proteins suggesting a significant contribution of immune cells among the myofibers expressing these markers. Moreover, in silico studies showed that 39% of upregulated proteins were involved in type I or mixed type I and type II interferon immunity. Indeed, further studies via immunohistochemistry clearly confirmed the prominent involvement of the key type I interferon signature-related molecules, ISG15 as well as IRF8 with MHC class II+ myofibers. Siglec1 colocalized with CD163+ macrophages and MHC class II molecules also co-localized with CD74 on macrophages. STAT1 co-localized with Siglec1+ macrophages in active myofibre myophagocytosis while STAT6 colocalized with endomysial macrophages. These combined results show involvement of CD74, CD163, and STAT1 as key molecules of macrophage activation being crucially involved in mixed and specific type I interferon, and interferon gamma associated-pathways in sIBM. On a more general note, these results also highlight the type of immune-interaction between macrophages and myofibers in the etiopathology of sIBM.

Keywords: CD163; CD74; SIGLEC1; STAT1; STAT6; muscle proteomics; type I interferon (IFN).

PubMed Disclaimer

Figures

Figure 1
Figure 1
Key proteomic findings and subsequent in silico analyses. (A) 3-D montages of representative tryptic peptides highlighting the increased abundance of the corresponding proteins, CD47, STAT1, and CD163. (B) Proteomaps-based analysis of cellular processes addressed by up- and down-regulated proteins in sIBM-patient-derived muscle (left figures) as well as of proteins predominating the respective cellular processes by taking their relative abundance/fold of regulation into consideration (right figures). (C) Venn diagram-based categorization of proteins increased in sIBM-patient-derived muscle and modulated by the three different interferon types (detailed list of increased proteins controlled by interferons is provided in Table 2). (D) Cytoscape-based visualization of functional networks of upregulated proteins controlled by interferons. (E) STRING-based analysis of functional protein networks of CD74 (left figure), STAT1 (figure in the middle) and CD163 (right figure) toward the identification of further interferon-modulated and macrophage-expressed proteins with pathophysiological significance in sIBM.
Figure 2
Figure 2
Immunohistochemical reactions of potential key players in the skeletal muscle biopsies from sIBM patients. Proteomics-based identified key players showed a positive staining in sIBM patients' skeletal muscle biopsies, where CD74 (A), as well as CD163 (B) highlighted macrophages. STAT1 (C) was expressed in macrophages in active myophagocytosis, while it was not present at the sarcolemma of myofibers.
Figure 3
Figure 3
Double immunflorescent staining reveal functional interactions in sIBM patients' muscle tissue. Co-staining of various proteins revealed that CD74 co-labels with CD68+ macrophages (A), and MHC class II (B), but not with the macrophage migration inhibitory factor MIF (C). In addition, CD163+ macrophages partially co-express Siglec1 (D).
Figure 4
Figure 4
different subforms of macrophages, as well as type I interferon pathways are found in sIBM. We could demonstrate Siglec1+ macrophages, which express STAT1 (A), or STAT6 (B), hinting at involvement of different macrophage subtypes in sIBM muscle inflammation. The activation of STAT1 and STAT6 could also be demonstrated by significantly elevated gene expression levels (E), p < 0.01. MHC class II+ macrophages also clearly co-stained with key proteins of the type I interferon pathway like IRF8 (C) and ISG15 (D).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Benveniste O, Stenzel W, Hilton-Jones D, Sandri M, Boyer O, Van Engelen BGM. Amyloid deposits and inflammatory infiltrates in sporadic inclusion body myositis: the inflammatory egg comes before the degenerative chicken. Acta Neuropathol. (2015) 611–24. 10.1007/s00401-015-1384-5 - DOI - PMC - PubMed
    1. De Bleecker JL, Lundberg IE, De Visser M. 193rd ENMC international workshop pathology diagnosis of idiopathic inflammatory myopathies 30 November - 2 December 2012, Naarden, The Netherlands. Neuromusc Dis. (2013) 23:945–51. 10.1016/j.nmd.2013.07.007 - DOI - PubMed
    1. Brady S, Squier W, Hilton-Jones D. Clinical assessment determines the diagnosis of inclusion body myositis independently of pathological features. J Neurol Neurosurg Psychiatry. (2013) 84:1240–6. 10.1136/jnnp-2013-305690 - DOI - PubMed
    1. Dimachkie MM. Idiopathic inflammatory myopathies. J Neuroimmunol. (2011) 231:32–42. 10.1016/j.jneuroim.2010.10.013 - DOI - PubMed
    1. Benveniste O, Guiguet M, Freebody J, Dubourg O, Squier W, Maisonobe T, et al. . Long-term observational study of sporadic inclusion body myositis. Brain. (2011) 134:3176–84. 10.1093/brain/awr213 - DOI - PubMed

Publication types