Systemic Sclerosis Serum Steers the Differentiation of Adipose-Derived Stem Cells Toward Profibrotic Myofibroblasts: Pathophysiologic Implications

Abstract

Systemic sclerosis (SSc; scleroderma) is characterized by life-threatening progressive multiorgan fibrosis orchestrated by profibrotic myofibroblasts originating from different sources. Because recent data demonstrated that the majority of myofibroblasts in a murine scleroderma model arise from adipocytic progenitors through the adipocyte-myofibroblast transition process, we sought to determine whether the SSc microenvironment may affect the differentiation potential of adipose-derived stem cells (ADSC). Normal human ADSC from three donors were treated with serum from SSc patients (n = 6), serum from healthy individuals (n = 6), or recombinant human transforming growth factor-β1 (TGFβ1) as positive control of myofibroblastic phenotype induction. ADSC were subjected to in vitro adipogenic differentiation for up to 21 days in the presence of different stimuli followed by lipid content quantification. In selected experiments, adipocytic and mesenchymal/myofibroblast marker gene and protein expression levels were assessed by Real-Time PCR, immunoblotting and immunofluorescence after administration of different stimuli for 72 and 96 h, respectively. Cell contractile phenotype was assayed by collagen gel contraction assay. Likewise stimulation with TGFβ1, SSc serum was able to significantly inhibit the adipocyte differentiation of ADSC as testified by a strong decrease in red-colored lipid droplets after 21 days of adipogenic induction. Treatment of ADSC either with SSc serum or TGFβ1 resulted in the acquisition of a myofibroblast-like phenotype characterized by a reduced expression of the adipocytic markers perilipin and adiponectin, a significant upregulation of the mesenchymal/myofibroblast markers α-SMA+ stress fibers, S100A4 and type I collagen, and an ability to effectively contract collagen gels. In SSc, the pathologic environment may favor the differentiation of ADSC into profibrotic and contractile myofibroblast-like cells. These findings strengthen the notion that the generation of myofibroblasts from ADSC may be relevant in SSc pathophysiology potentially representing a new target for the prevention/treatment of multiorgan fibrosis.

Adipose-Derived Stem Cells from Systemic Sclerosis Patients Maintain Pro-Angiogenic and Antifibrotic Paracrine Effects In Vitro

“…These results appear to contrast with recent studies of miRs in silico, which reported a pro-fibrotic ASC signature from SSC patients [23]. Sera from SSc patients have also been shown to favor differentiation of healthy ASC into profibrotic myofibroblast-like cells in vitro [43].…”

The Phenotype and Secretory Activity of Adipose-Derived Mesenchymal Stem Cells (ASCs) of Patients with Rheumatic Diseases

“…By contrast, ASCs represent a more homogeneous population of cells and early phase clinical trials reported beneficial effects of autologous ASC transplantation in the alleviation of cutaneous symptoms in SSc patients [23][24][25]. However, there is still controversy over the use of autologous or allogeneic ASCs in the clinic because there are studies suggesting functional alterations of these cells in SSc [26,27]. Therefore, with the view of the potential therapeutic application of autologous ASCs in mind, we have performed a basic characterization of these cells and compared the phenotype and secretory potential of RD patients' ASCs (RD/ASCs) with the corresponding features of ASC lines originating from healthy donors (HDs).…”

Systemic Sclerosis Serum Significantly Impairs the Multi-Step Lymphangiogenic Process: In Vitro Evidence

“…In perspective, we frankly acknowledge that our data represent the necessary groundwork for further investigation aimed at unveiling the likely multiple factors that, in SSc, may prevent a timely lymphangiogenic response to the ongoing destruction of the dermal microlymphatic network [9][10][11][12]. In this regard, it is noteworthy that several factors with proven anti-lymphangiogenic activity, such as transforming growth factor-β1, thrombospondin, and endostatin, are known to be increased and to have pathogenic implications in SSc [1,6,14,23,29,[44][45][46][47][48]. In such a context, a very recent study has demonstrated that levels of CXCL10 and CXCL11, two C-X-C chemokines exerting angiostatic effects through their receptor CXCR3-B [49], are strongly increased in the circulation of SSc patients from the earliest disease stages, and may represent good biomarkers of vascular damage progression [50].…”