Sweat Gland Organoids Originating from Reprogrammed Epidermal Keratinocytes Functionally Recapitulated Damaged Skin

Abstract

Restoration of sweat glands (SwGs) represents a great issue in patients with extensive skin defects. Recent methods combining organoid technology with cell fate reprogramming hold promise for developing new regenerative methods for SwG regeneration. Here, a practical strategy for engineering functional human SwGs in vitro and in vivo is provided. First, by forced expression of the ectodysplasin-A in human epidermal keratinocytes (HEKs) combined with specific SwG culture medium, HEKs are efficiently converted into SwG cells (iSwGCs). The iSwGCs show typical morphology, gene expression pattern, and functions resembling human primary SwG cells. Second, by culturing the iSwGCs in a special 3D culturing system, SwG organoids (iSwGOs) that exhibit structural and biological features characteristic of native SwGs are obtained. Finally, these iSwGOs are successfully transplanted into a mouse skin damage model and they develop into fully functioning SwGs in vivo. Regeneration of functional SwG organoids from reprogrammed HEKs highlights the great translational potential for personalized SwG regeneration in patients with large skin defects.

Small Molecules Facilitate Single Factor-Mediated Sweat Gland Cell Reprogramming

“…Accumulating evidences suggest that EDA plays an essential role in SG morphogenesis [19,27], and defective development of SG in hypohidrotic ectodermal dysplasia (HED) could be rescued by EDA administration [18]. Our previous work also demonstrated targeting ectodysplasin promotor by CRISPR/dCas9-effector effectively induced the reprogramming of human bone marrow-derived mesenchymal stem cells and epidermal cells into sweat gland cells [4,5]. Theses transfected cells not only expressed the related markers (CK5, CK10, CK18, CEA, CK7, CK14, and CK19) of sweat gland cells, but contributed to sweat gland reconstruction in vivo [4,5].…”

“…To overcome these challenges, cellular reprogramming offers an attractive novel strategy for the acquisition of high-quality SG cells in large scale for the functional repair and regeneration of damaged skin tissues. It has been reported that mesenchymal stem cells (MSCs) and epidermal keratinocytes could be converted into induced sweat gland cells (iSGCs) by the modulation of EDA expression [4][5][6]. The reprogrammed cells not only expressed SG cell markers CK5, CK10, CK18, CK19, CK14, CEA and AQP5, but also facilitated the restoration of SG in vivo.…”

Small molecules facilitate single factor-mediated sweat gland cell reprogramming

“…Accumulating evidence suggests that EDA plays an essential role in SG morphogenesis [ 28 , 29 ], and defective development of SG in hypohidrotic ectodermal dysplasia can be rescued by EDA administration [ 30 ]. Our previous work has also demonstrated that CRISPR/dCas9-effector targeting of the ectodysplasin promoter effectively induces the reprogramming of human bone marrow-derived mesenchymal stem cells and epidermal cells to SG cells [ 4 , 5 ]. These transfected cells not only express SG related markers (CK5, CK10, CK18, CEA, CK7, CK14 and CK19) but also contribute to SG reconstruction in vivo [ 4 , 5 ].…”

“…Our previous work has also demonstrated that CRISPR/dCas9-effector targeting of the ectodysplasin promoter effectively induces the reprogramming of human bone marrow-derived mesenchymal stem cells and epidermal cells to SG cells [ 4 , 5 ]. These transfected cells not only express SG related markers (CK5, CK10, CK18, CEA, CK7, CK14 and CK19) but also contribute to SG reconstruction in vivo [ 4 , 5 ]. Therefore, EDA could reasonably be used to induce SG fate.…”

“…To overcome these challenges, cellular reprogramming offers an attractive novel strategy for the acquisition of high-quality SG cells on a large scale for the functional repair and regeneration of damaged skin tissues. Mesenchymal stromal cells and epidermal keratinocytes can be converted to induced SG cells (iSGCs) through the modulation of ectodermal dysplasia antigen (EDA) expression [ 4 , 5 ]. The reprogrammed cells not only express the SG cell markers cytokeratin (CK)5, CK10, CK18, CK19, CK14, CEA and aquaporin 5 (AQP5), but also facilitate the restoration of SGs in vivo.…”