The Secretory Profiles of Cultured Human Articular Chondrocytes and Mesenchymal Stem Cells: Implications for Autologous Cell Transplantation Strategies

Abstract

This study was undertaken to compare the phenotype of human articular chondrocytes (ACs) and bone marrow-derived mesenchymal stem cells (MSCs) after cell expansion by studying the spectrum of proteins secreted by cells into the culture medium. ACs and MSCs were expanded in monolayer cultures for some weeks, as done in standard cell transplantation procedures. Initially, the expression of cartilage signature genes was compared by real-time PCR. Metabolic labeling of proteins (SILAC) in combination with mass spectrometry (LC/MS-MS) was applied to investigate differences in released proteins. In addition, multiplex assays were carried out to quantify the amounts of several matrix metalloproteases (MMPs) and their natural inhibitors (TIMPs). Expanded chondrocytes showed a slightly higher expression of cartilage-specific genes than MSCs, whereas the overall spectra of released proteins were very similar for the two cell types. In qualitative terms MSCs seemed to secrete similar number of extracellular matrix proteins (43% vs. 45% of total proteins found) and catabolic agents (9% vs. 10%), and higher number of anabolic agents (12 % vs. 7%) compared to ACs. Some matrix-regulatory agents such as serpins, BMP-1, and galectins were detected only in MSC supernatants. Quantitative analyses of MMPs and TIMPs revealed significantly higher levels of MMP-1, MMP-2, MMP-3, and MMP-7 in the medium of ACs. Our data show that after the expansion phase, both ACs and MSCs express a dedifferentiated phenotype, resembling each other. ACs hold a phenotype closer to native cartilage at the gene expression level, whereas MSCs show a more anabolic profile by looking at the released proteins pattern. Our data together with the inherent capability of MSCs to maintain their differentiation potential for longer cultivation periods would favor the use of these cells for cartilage reconstruction.

Paracrine Effect of Mesenchymal Stem Cells Derived from Human Adipose Tissue in Bone Regeneration

“…Recent preclinical studies have reported that secretomes from MSC have the potential for treating some intractable diseases as acute myocardial infarction [16], fulminant hepatic failure [43], renal failure [44], [45], ischemic stroke [46], experimental autoimmune encephalomyelitis [47] and hypoxic brain injury [48] and for the repair of soft tissues [49]. Also, has been reported that MSC-CM has a very high potential for bone regeneration, mediated by the cooperative effects of cytokines such as IGF-1, TGF-ß1 [50], [51], VEGF, angiogenin [50], HGF (Hepatocyte growth factor) [51], BMP-1 [52], IL-6, IL-3, MCP-1 (Monocyte Chemoattractant Protein-1) and MCP-3 (Monocyte Chemoattractant Protein-3) [41]. These cytokines regulate several events of osteogenesis, angiogenesis, cell migration, proliferation, and osteoblast differentiation [50].…”

Adipose-derived stromal cells for osteoarticular repair: trophic function versus stem cell activity

“…Similar to the established trophic role of BMSC (Refs 72, 73), cultured ASC were shown to secrete a wide range of proteins (Ref. 74) into conditioned media that predominantly exert anti-apoptotic (Refs 75, 76, 77), immunomodulatory (Refs 78, 79, 80) and angiogenic (Refs 77, 81, 82) effects on co-cultured cell types.…”

Fibroblast Growth Factor-1 Is a Mesenchymal Stromal Cell-Secreted Factor Stimulating Proliferation of Osteoarthritic Chondrocytes in Co-Culture

“…Only a few studies explored the secretome of undifferentiated MSCs [30]. It has been shown in a proteomic study that undifferentiated MSCs secrete a number of matrix components and matrix regulators in 2D cultures [31]; however, the expression of the regulation of these proteins by cellular interactions between MSCs and other cell types is not yet investigated. The current study is one of the first to explore the response and changes in the gene expression of MSCs in co-culture with other cell types.…”

“…Combined with the fact that FGF-1 concentration increased dramatically in the CM of co-culture pellets when compared with mono-cultures, we also concluded that not only expression but also secretion of FGF-1 is increased by the cross-talk between MSCs and hPCs. From literature, it can be deduced that both cells secrete a wide range of growth factors, cytokines, and extracellular matrix components into their surrounding environment [31]. Some of these molecules may form a feedback loop that stimulates the expression of FGF-1.…”