Substance P induces the secretion of gelatinase A from human synovial fibroblasts

Sensory neurons from dorsal root ganglia regulate endothelial cell function in extracellular matrix remodelling

BACKGROUND

Recent physiological and experimental data highlight the role of the sensory nervous system in bone repair, but its precise role on angiogenesis in a bone regeneration context is still unknown. Our previous work demonstrated that sensory neurons (SNs) induce the osteoblastic differentiation of mesenchymal stem cells, but the influence of SNs on endothelial cells (ECs) was not studied.

METHODS

Here, in order to study in vitro the interplay between SNs and ECs, we used microfluidic devices as an indirect co-culture model. Gene expression analysis of angiogenic markers, as well as measurements of metalloproteinases protein levels and enzymatic activity, were performed.

RESULTS

We were able to demonstrate that two sensory neuropeptides, calcitonin gene-related peptide (CGRP) and substance P (SP), were involved in the transcriptional upregulation of angiogenic markers (vascular endothelial growth factor, angiopoietin 1, type 4 collagen, matrix metalloproteinase 2) in ECs. Co-cultures of ECs with SNs also increased the protein level and enzymatic activity of matrix metalloproteinases 2 and 9 (MMP2/MMP9) in ECs.

CONCLUSIONS

Our results suggest a role of sensory neurons, and more specifically of CGRP and SP, in the remodelling of endothelial cells extracellular matrix, thus supporting and enhancing the angiogenesis process. Video abstract.

Basic fibroblast growth factor accelerates matrix degradation via a neuro-endocrine pathway in human adult articular chondrocytes

Pain-related neuropeptides released from synovial fibroblasts, such as substance P, have been implicated in joint destruction. Substance P-induced inflammatory processes are mediated via signaling through a G-protein-coupled receptor, that is, neurokinin-1 tachykinin receptor (NK(1)-R). We determined the pathophysiological link between substance P and its receptor in human adult articular cartilage homeostasis. We further examined if catabolic growth factors such as basic fibroblast growth factor (bFGF or FGF-2) or IL-1beta accelerate matrix degradation via a neural pathway upregulation of substance P and NK(1)-R. We show here that substance P stimulates the production of cartilage-degrading enzymes, such as matrix metalloproteinase-13 (MMP-13), and suppresses proteoglycan deposition in human adult articular chondrocytes via NK(1)-R. Furthermore, we have demonstrated that substance P negates proteoglycan stimulation promoted by bone morphogenetic protein-7, suggesting the dual role of substance P as both a pro-catabolic and anti-anabolic mediator of cartilage homeostasis. We report that bFGF-mediated stimulation of substance P and its receptor NK(1)-R is, in part, through an IL-1beta-dependent pathway.

Evidence for tumor-host cooperation in regulating MMP-2 expression in human colon cancer

Matrix metalloproteinase 2 (MMP-2) facilitates tumor growth and metastasis in colon cancer. Although tumor cells may produce MMP-2, stromal cells, such as macrophages and fibroblasts, contribute significantly to MMP-2 synthesis in human tumors. We characterized four human colon cancer cell lines with differing biological behavior for MMP-2 expression. While the parent tumors from which the cell lines were derived all expressed MMP-2 mRNA, MMP-2 transcripts were detected in only one cell line, TF-17C, which is nontumorigenic in a nude mouse tumor model. TF-43C, which is tumorigenic and metastatic in the same tumor model, did not produce MMP-2, yet the tumors which arose from it after injection into nude mice did contain MMP-2 mRNA, suggesting a contribution from stromal cells. Co-culturing TF-43C with fibroblasts resulted in an increase in MMP-2 protein, whereas co-culturing with the nontumorigenic cell line TF-13Cm did not alter constitutive fibroblast MMP-2 secretion. Conditioned medium from TF-43C cells also stimulated fibroblast MMP-2 production. These data suggest that a soluble factor from TF-43C cells can stimulate fibroblast MMP-2 production and support the hypothesis that colon cancer cell interactions with stromal fibroblasts may be important determinants of tumor behavior in vivo.