Gadolinium-induced fibrosis is counter-regulated by CCN3 in human dermal fibroblasts: a model for potential treatment of nephrogenic systemic fibrosis

Abstract

We recently show that CCN3 is a counterregulatory molecule for the pro-fibrotic protein CCN2, and a potentially novel fibrosis therapy. The goal of this study was to assess the role of CCN3 in fibroproliferative/fibrotic responses in human dermal fibroblasts exposed to Omniscan, one of the gadolinium-based contrast agents associated with development of nephrogenic systemic fibrosis (NSF) a rare but life-threatening disease thought to be complication of NMR diagnostics in renal impaired patients. Human dermal fibroblasts were exposed to Omniscan; or to platelet-derived growth factor (PDGF) and transforming growth factor-β (TGF-β) as controls. Proliferation was assessed along with matrix metalloproteinase-1, tissue inhibitor of metalloproteinases-1 and type 1 procollagen in the absence and presence of CCN3. In parallel, CCN3 production was assessed in control and Omniscan-treated cells. The results showed that PDGF stimulated fibroblast proliferation, production of Timp-1 and MMP-1 whereas exogenous CCN3 inhibited, in a dose response manner, cell proliferation (approx. 50 % max.) and production of MMP-1 (approx 35 % max.) but had little effect on TIMP-1. TGF-β stimulated type 1 procollagen production but not proliferation, Timp-1 or MMP-1 compared to non-TGF-ß treated control cells, and CCN3 treatment blocked (approx. 80 % max.) this upregulation. Interestingly, untreated, control fibroblasts produced high constitutive levels of CCN3 and concentrations of Omniscan that induced fibroproliferative/ fibrogenic changes in dermal fibroblasts correspondingly suppressed CCN3 production. The use of PDGF and TGF-β as positive controls, and the study of differential responses, including that to Omniscan itself, provide the first evidence for a role of fibroblast-derived CCN3 as an endogenous regulator of pro-fibrotic changes, elucidating possible mechanism(s). In conclusion, these data support our hypothesis of a role for fibroblast-derived CCN3 as an endogenous regulator of pro-fibrotic changes in these cells, and suggest that CCN3 may be an important regulatory molecule in NSF and a target for treatment in this and other fibrotic diseases.

Treatment with the Matricellular Protein CCN3 Blocks and/or Reverses Fibrosis Development in Obesity with Diabetic Nephropathy

“…Gadolinium, frequently used as a contrast agent in magnetic resonance imaging and the suspected causal factor in this disease, when incubated with skin fibroblasts, induced proliferation mediated by PDGF. 37 Furthermore, high constitutive expression of CCN3 was down-regulated by PDGF, and treatment with rhCCN3 blocked the induction of cell proliferation and the stimulation of metalloproteinases. TGF-b, on the other hand, was found to stimulate collagen synthesis and was also blocked by CCN3.…”

Effects of CCN3 on fibroblast proliferation, apoptosis and extracellular matrix production

“…CCN2 and CCN3 are opposing factors in regulating collagen promoter activity and the secretion of this ECM protein. Riser et al demonstrated that CCN3, an endogenous regulator of pro-fibrotic changes, markedly downregulates collagen production and deposition (14). Collectively, these data suggest that CCN3 is a potentially important regulatory molecule in the TGF-β1/Smad signaling pathway and a target for treatment in scar formation.…”

Balanced regulation of the CCN family of matricellular proteins: a novel approach to the prevention and treatment of fibrosis and cancer

“…This supports the idea that CCN3 provides a potent anti‐fibrosis effect working on multiple pathways that include regulation of CCN2 and, perhaps in at least some fibrotic diseases, both CCN1 and CCN4. The more direct effect of CCN3 on protection of renal cells from injury in DN and the anti‐fibrotic effect occurring with PDGF in skin fibroblasts (Riser et al 2012) suggest that its therapeutic application may go even beyond its ability to balance the pro‐fibrotic action of CCN members.…”