Nintedanib inhibits keloid fibroblast functions by blocking the phosphorylation of multiple kinases and enhancing receptor internalization

Abstract

Keloid is a benign skin tumor characterized by its cell hyperproliferative activity, invasion into normal skin, uncontrolled growth, overproduction and deposition of extracellular matrices and high recurrence rate after various therapies. Nintedanib is a receptor tyrosine kinase inhibitor targeting VEGF, PDGF, FGF, and TGF-β receptors with proved efficacy in anti-angiogenesis and in treating various types of cancers. In this study, we investigated the effects of nintedanib on keloid fibroblasts in both in vitro and ex vivo models. Keloid fibroblasts were prepared from 54 keloid scar samples in active stages collected from 49 patients. We found that nintedanib (1−4 μM) dose-dependently suppressed cell proliferation, induced G 0 /G 1 cell cycle arrest, and inhibited migration and invasion of keloid fibroblasts. The drug also significantly inhibited the gene and protein expression of collagen I (COL-1) and III (COL-3) , fibronectin (FN) , and connective growth factor (CTGF) , as well as the gene expression of other pathological factors, such as alpha smooth muscle actin (α-SMA) , plasminogen activator inhibitor-1 (PAI-1) , FK506-binding protein 10 (FKBP10) , and heat shock protein 47 (HSP47) in keloid fibroblasts. Furthermore, nintedanib treatment significantly suppressed the phosphorylation of p38, JNK, ERK, STAT3, and Smad, enhanced endocytosis of various growth factor receptors. Using an ex vivo tissue explant model, we showed that nintedanib significantly suppressed cell proliferation, migration, and collagen production. The drug also significantly disrupted microvessel structure ex vivo. In summary, our results demonstrate that nintedanib is likely to become a potential targeted drug for keloid systemic therapy.

Exosomes from human adipose-derived mesenchymal stem cells inhibit production of extracellular matrix in keloid fibroblasts via downregulating transforming growth factor-β2 and Notch-1 expression

“…Similar to the procedure used in the explant culture method for KF isolation, the epidermis was removed from keloid tissues, which were minced into 3 mm × 3 mm × 2 mm fragments [ 17 ]. The fragments were then equally treated and seeded onto three culture dishes (Corning, 430,167) with DMEM containing 10% FBS.…”

Long-term explant culture: an improved method for consistently harvesting homogeneous populations of keloid fibroblasts

“…As previously described by Zhou et al [ 7 ], 1 × 10 6 P4 KFs from each sample were fixed in 70% pre-cooled ethanol at 4°C overnight. Subsequent steps were carried out according to the instructions provided in the Cell Cycle Kit (7sea Biotech, Shanghai, China).…”

“…Currently, the primary KFs are isolated mainly through enzyme digestion and explant culture [ 7–10 ]. To isolate KFs by enzyme digestion, the specimens are dissected into pieces and digested with collagenase (with or without trypsin) in a constant-temperature shaker at 37°C for several hours.…”

Molecular Changes Underlying Hypertrophic Scarring Following Burns Involve Specific Deregulations at All Wound Healing Stages (Inflammation, Proliferation and Maturation)

“…Due to the morphological similarity of keloids and tumors, cutaneous leiomyomas may sometimes be misdiagnosed as keloids and vice versa [ 177 ]. Of note, inhibitor of receptor kinase nintedanib, which is used in cancer therapy, is also effective in the treatment of therapy-refractive keloids [ 178 ].…”