Functional Melanocytes Are Readily Reprogrammable from Multilineage-Differentiating Stress-Enduring (Muse) Cells, Distinct Stem Cells in Human Fibroblasts

Abstract

The induction of melanocytes from easily accessible stem cells has attracted attention for the treatment of melanocyte dysfunctions. We found that multilineage-differentiating stress-enduring (Muse) cells, a distinct stem cell type among human dermal fibroblasts, can be readily reprogrammed into functional melanocytes, whereas the remainder of the fibroblasts do not contribute to melanocyte differentiation. Muse cells can be isolated as cells positive for stage-specific embryonic antigen-3, a marker for undifferentiated human embryonic stem cells, and differentiate into cells representative of all three germ layers from a single cell, while also being nontumorigenic. The use of certain combinations of factors induces Muse cells to express melanocyte markers such as tyrosinase and microphthalmia-associated transcription factor and to show positivity for the 3,4-dihydroxy-L-phenylalanine reaction. When Muse cell-derived melanocytes were incorporated into three-dimensional (3D) cultured skin models, they localized themselves in the basal layer of the epidermis and produced melanin in the same manner as authentic melanocytes. They also maintained their melanin production even after the 3D cultured skin was transplanted to immunodeficient mice. This technique may be applicable to the efficient production of melanocytes from accessible human fibroblasts by using Muse cells, thereby contributing to autologous transplantation for melanocyte dysfunctions, such as vitiligo.

Therapeutic Potential of Adipose-Derived SSEA-3-Positive Muse Cells for Treating Diabetic Skin Ulcers

“…Previous reports have investigated Muse cells derived from human adipose tissue (previously termed “adipose Muse” [10], “Muse‐AT” [9], or, in our study, Muse ASCs), which were shown to also be positive for CD105 and to differentiate into cells representative of the three germ layers from a single cell [10]. In addition, Muse cells could be efficiently isolated as cells single positive for SSEA‐3 in human dermal fibroblasts, because nearly all dermal fibroblasts were positive for CD105 [6, 12]. Although fluorescence activated cell sorting (FACS) or stress conditions were used in previous studies [6, 9, 12, 18, 19], we used autoMACS, with double collection of the positive fraction after preliminary optimization experiments.…”

“…Magnetic‐activated cell sorting (MACS) (autoMACS; Miltenyi Biotec, Bergisch Gladbach, Germany, http://www.miltenyibiotec.com) was used to collect SSEA‐3 + Muse cells. Although Muse cells are reported to be double positive for SSEA‐3 and CD105, previous studies collected Muse cells using single SSEA‐3 labeling because nearly 100% of mesenchymal cells, including ASCs, will be CD105 + [6, 10, 12]. We, therefore, collected Muse cells using the anti‐SSEA‐3 antibody conjugated with phycoerythrin (PE) (dilution 1:3, Miltenyi Biotec) and anti‐PE microbeads (dilution 1:2, Miltenyi Biotec) were used for MACS separation of the Muse cells.…”

The secretome of MUSE cells contains factors that may play a role in regulation of stemness, apoptosis and immunomodulation

“…7,9 For example, when fibroblasts were separated into Muse and non-Muse cells and were subjected to melanocyte induction, Muse cells were converted to melanin-producing functional melanocytes but non-Muse cells responded partially to the induction and failed to become melanocytes. 10 This suggested that Muse cells are able to cross oligolineage boundary between mesodermal to ectodermal because they are pluripotent but non-Muse cells could not because they do not have pluripotent-like property. Other than differentiation ability, they are reported to exert tissue repair effect by replenishment of lost cell types by spontaneous differentiation after homing into damaged site; they spontaneously differentiated into dermal and epidermal cells to repair skin ulcer of diabetes mellitus model.…”

Trehalose preincubation increases mesenchymal (CD271⁺) stem cells post-cryopreservation viability

“…[5][6][7] Mesenchymal stem cell is a heterogeneous population recently discovered to contain not only multipotent stem cell but also non-tumorigenic pluripotent stem cell subpopulation known as the multi-lineage differentiating stress enduring (MUSE) cells. 8,9 The ability to preserve functional properties of such unique subpopulation will greatly contribute to the development of regenerative medicine.…”