Diversity of dermal fibroblasts as major determinant of variability in cell reprogramming

Abstract

Induced pluripotent stem cells (iPSCs) are adult somatic cells genetically reprogrammed to an embryonic stem cell‐like state. Notwithstanding their autologous origin and their potential to differentiate towards cells of all three germ layers, iPSC reprogramming is still affected by low efficiency. As dermal fibroblast is the most used human cell for reprogramming, we hypothesize that the variability in reprogramming is, at least partially, because of the skin fibroblasts used. Human dermal fibroblasts harvested from five different anatomical sites (neck, breast, arm, abdomen and thigh) were cultured and their morphology, proliferation, apoptotic rate, ability to migrate, expression of mesenchymal or epithelial markers, differentiation potential and production of growth factors were evaluated in vitro. Additionally, gene expression analysis was performed by real‐time PCR including genes typically expressed by mesenchymal cells. Finally, fibroblasts isolated from different anatomic sites were reprogrammed to iPSCs by integration‐free method. Intriguingly, while the morphology of fibroblasts derived from different anatomic sites differed only slightly, other features, known to affect cell reprogramming, varied greatly and in accordance with anatomic site of origin. Accordingly, difference also emerged in fibroblasts readiness to respond to reprogramming and ability to form colonies. Therefore, as fibroblasts derived from different anatomic sites preserve positional memory, it is of great importance to accurately evaluate and select dermal fibroblast population prior to induce reprogramming.

Decellularized Human Dermal Matrix as a Biological Scaffold for Cardiac Repair and Regeneration

“…In fact, using d-HuSk as an auto-graft would imply transplanting a fully compatible scaffold capable of averting the immunological response and the risk of rejection that affect the heterologous and xenogeneic transplant or implant. Noticeably yet, it has been recently demonstrated that adult fibroblasts isolated from the abdominal skin can be reprogrammed with higher efficiency (Sacco et al, 2019) and that skin fibroblasts can be directly reprogrammed to cardiac mature cells (Cao et al, 2016). Therefore, the preparation of d-HuSk scaffolds holds the potential to eventually evolve into the development of a more complex therapeutic strategy aimed at constructing, with one single intervention of skin harvesting, a fully autologous engineered myocardium using cardiac direct reprogramming of fibroblast to restore the cellular compartment and the decellularized dermal ECM to replace the extracellular compartment.…”

Origin and functional heterogeneity of fibroblasts

“…In the context of induced pluripotency, fibroblasts, neutrophils, and keratinocytes demonstrate cell type‐specific molecular reprograming, suggesting that fibroblasts from early embryos express a specific molecular identity . In addition, the anatomic site of dermal fibroblasts distinctly impact their capacity for iPSC reprogramming . Dermal fibroblasts from various anatomical sites express positional memory, supporting the anatomical heterogeneity of fibroblasts .…”

“…21 In addition, the anatomic site of dermal fibroblasts distinctly impact their capacity for iPSC reprogramming.22 Dermal fibroblasts from various anatomical sites express positional memory, supporting the anatomical heterogeneity of fibroblasts. 22 The anatomical site and age of human dermal fibroblasts also demonstrate functional differences in their ability to promote epidermal differentiation and wound healing response.23 These findings suggest resident fibroblasts, at least in the skin, undergo differentiation guided by their anatomic position embryologically. Comparative analyses of transcriptomes from dermal fibroblasts, evaluated from ex vivo cultures derived from various anatomical sites, support a developmental heterogeneity.24,25 Skin fibroblasts present | 3521 LEBLEU and nEILSOn with distinct gene expression profiles that vary by location in the body plan,25 and such topographic differences among fibroblasts are consistent with a differentiation encoded by axial Hox genes.6,24,25 Subsequent RNA analyses corroborate topographic differentiation of fibroblasts from the vocal fold, trachea, lung, abdomen, scalp, upper gingiva, and soft palate.…”

Characterization of the continuous skin fibroblastoid cell line, WE‐skin11f, from walleye (Sander vitreus)

“…The many fewer cell lines from the integument at other anatomical sites can be described as constituting the fish skin invitrome. The fin and skin invitromes might be expected to have cells lines with different properties because for human skin cultures from different anatomical sites, cells have different characteristics (Hausmann et al, 2019), especially for dermal fibroblasts (DF) (Sacco et al, 2019). For skin cell biology, other in vitro approaches would be primary fish skin cell cultures (Rakers, Klinger, Kruse, & Gebert, 2011), but cell lines have the potential to be more convenient and ethical, as they are for human skin research (Caley et al, 2018).…”