Human Skin Culture as an Ex Vivo Model for Assessing the Fibrotic Effects of Insulin-Like Growth Factor Binding Proteins

Abstract

Systemic sclerosis (SSc) is a connective tissue disease of unknown etiology. A hallmark of SSc is fibrosis of the skin and internal organs. We recently demonstrated increased expression of IGFBP-3 and IGFBP-5 in primary cultures of fibroblasts from the skin of patients with SSc. In vitro, IGFBP-3 and IGFBP-5 induced a fibrotic phenotype and IGFBP-5 triggered dermal fibrosis in mice. To assess the ability of IGFBPs to trigger fibrosis, we used an ex vivo human skin organ culture model. Our findings demonstrate that IGFBP-3 and IGFBP-5, but not IGFBP-4, increase dermal and collagen bundle thickness in human skin explants, resulting in substantial dermal fibrosis and thickening. These fibrotic effects were sustained for at least two weeks. Our findings demonstrate that human skin ex vivo is an appropriate model to assess the effects of fibrosis-inducing factors such as IGFBPs, and for evaluating the efficacy of inhibitors/therapies to halt the progression of fibrosis and potentially reverse it.

A Peptide Derived from Endostatin Ameliorates Organ Fibrosis

“…S1A). Because the skin is affected by fibrosis in SSc, we evaluated the efficacy of endostatin as a potential therapeutic agent for fibrosis using our ex vivo human skin model (19). In untreated human skin, rE did not significantly alter dermal thickness (fig.…”

“…All tissues were obtained according to the guidelines of the University of Pittsburgh and under a protocol approved by the Institutional Review Board of the University of Pittsburgh, as described (19). The following were injected intradermally in a total volume of 100 μl of 1× PBS: rE alone (1 to 10 μg/ml), endostatin peptides alone (10 μg/ml), rE or endostatin peptides (1 to 20 μg/ml) in combination with TGF-β (10 ng/ml), or TGF-β alone (10 ng/ml).…”

The Mighty Fibroblast and Its Utility in Scleroderma Research

“…The response of fibroblasts can also be assessed in skin maintained in organ culture, which more closely mimics the in vivo environment than 2D or 3D culture systems (34, 58, 59). When maintained in primary human fibroblast culture media, human skin can respond to fibrotic triggers, such as TGFβ1 and IGFBP-5, as measured via increase in dermal thickness and collagen content (34, 58).…”

“…When maintained in primary human fibroblast culture media, human skin can respond to fibrotic triggers, such as TGFβ1 and IGFBP-5, as measured via increase in dermal thickness and collagen content (34, 58). This model not only facilitates the identification of pro-fibrotic factors, but also the testing of potential therapies that can reduce fibrosis, as was successfully reported for the endostatin-derived peptide E4 (34).…”

Sacha Inchi Oil (Plukenetia volubilis L.), effect on adherence of Staphylococus aureus to human skin explant and keratinocytes in vitro

“…The explants were then incubated for 24 h at 32 1C prior to being processed. Skin explants are closer to what happens in real life than isolated keratinocytes as they contain all cell types resident in the skin (dermis and epidermis) exerting their physiological effects on the tissue and adjacent cells (Yasuoka et al, 2008). Table 1 Lipid profile of Sacha Inchi Oil.…”