Effects of keratinocyte growth factor on skin epithelial differentiation of human amnion epithelial cells

In vitro differentiation of human amniotic epithelial stem cells into keratinocytes regulated by OPN3

Human amniotic epithelial stem cells (hAESCs) are regarded as potential alternatives to keratinocytes (KCs) used for skin wound healing. Light is an alternative approach for inducing stem cell differentiation. Opsins (OPNs), a family of light-sensitive, G protein-coupled receptors, play a multitude of light-dependent and light-independent functions in extraocular tissues. However, it remains unclear whether the light sensitivity and function of OPNs are involved in light-induced differentiation of hAESCs to KCs. Herein, we determine the role of OPNs in differentiation of hAESCs into KCs through cell and molecular biology approaches in vitro. It is shown that mRNA expression of OPN3 in the amniotic membrane and hAESCs was higher than the other four primary OPNs by RT-qPCR analysis. Changes in OPN3 gene expression had a significant impact on cell proliferation, stemness and differentiation capability of hAESCs. Furthermore, we found a significant upregulation of OPN3, KRT5 and KRT14 with hAESCs treated at 3 × 33 J/cm2 irradiation from blue-light LED. Taken together, these results suggest that OPN3 acts as a positive regulator of differentiation of hAESCs into KCs. This study provides a novel insight into photosensitive OPNs associated with photobiomodulation(PBM)-induced differentiation in stem cells.

Mulla J, Imam Rabbani S. Evaluation of solid-lipid nanoparticles formulation of methotrexate for anti-psoriatic activity

Background & Objectives

Methotrexate (MTX) is commonly used to manage psoriasis. The drug has erratic absorption characteristics and shows several complications. The present study uses different experimental models to evaluate the solid-lipid nanoparticles of MTX (SLN-MTX) for the anti-psoriatic effect.

Methods

A prepared SLN-MTX formulation was used and its permeability studies were conducted on Wistar rat abdominal skin. The organ-level distribution of the drug in the formulation was tested in mice and the in-vitro anti-psoriatic activity was determined in CL-177; XB-2 keratinocytes cell lines. The efficacy of SLN-MTX formulation was compared with standard MTX and marketed MTX preparations. The results are analyzed statistically using the student's t-test.

Results

The data suggested that MTX from the formulation was slowly released and completely (80.36%) permeated through the skin. The flux and permeation data were found to be maximum for SLN-MTX compared to marketed and standard preparations. MTX in the formulation was found to be distributed more in the liver (67.5%) and kidney (2.34%). Further, SLN-MTX formulation showed dose-dependent inhibition on the growth of keratinocytes, and the cytotoxic concentration (CTC50) was found to be the least (518 mcg/ml).

Interpretation & Conclusion

The findings suggested that MTX in solid-lipid nanoparticles could be a promising formulation for the management of psoriasis since the drug was slowly released, progressively inhibited the growth of keratinocytes, and distributed mostly in organs meant for elimination. More studies in this direction might establish the precise safety and efficacy of SLN-MTX formulation in psoriasis.

The differentiation effect of bone morphogenetic protein (BMP) on human amniotic epithelial stem cells to express ectodermal lineage markers

Stem cells are a promising tool for treatment of a variety of degenerative diseases. Human amniotic epithelial stem cells (hAECs) have desirable and unique characteristics that make them a proper candidate for cell therapy. In this study, we have investigated the effects of BMP-4 (bone morphogenetic protein-4) and its inhibition on differentiation of AECs into ectodermal lineages. Analysis of AEC-derived ectodermal lineages (neurons and keratinocytes) was performed by using flow cytometry technique for Map2 and β-tubulin (as neuron markers), Olig2 and MBP (as oligodendrocyte markers), and K14 and K10 (as keratinocyte markers). The results of this study illustrated that noggin (as BMP antagonist), BMP4, and both BMP4 and heparin (together or separately) increased neural and keratinocyte marker expression, respectively. The expression of markers MAP2, olig2, and K14 in hAECs has been significantly decreased 21 days after exposure to differentiation medium (without growth factors) compared with isolation day, which supports the hypothesis that AECs can be dedifferentiated into pluripotent cells. Moreover, activation and inhibition of BMP signaling have no effects on viability of hAECs. The results of this study showed that BMP signaling and its inhibition are the key factors for ectodermal lineage differentiation of amnion-derived stem cells.

Umbilical Cord Tissue Derived Mesenchymal Stem Cells can Differentiate into Skin Cells

Autologous skin grafts are used to treat severe burn wounds, however, the availability of adequate donor sites makes this option less practical. Recently, stem cells have been used successfully in tissue engineering and in regenerative medicine. The current study aims to differentiate umbilical cord tissue derived mesenchymal stem cells (CT-MSCs) into skin cells (fibroblasts and keratinocytes) for use to treat severe burn wounds. After isolation, MSCs were characterized and their growth characteristics were determined. The cells were induced to differentiate into fibroblasts and keratinocytes using respective induction medium. Results indicated that CT-MSCs were spindle shaped, plastic adherent and positive for CD29, CD44, CD73, CD90 markers. CT-MSCs also showed high proliferative potential as indicated by cumulative population doubling, doubling time and plating efficiency. The MSCs were successfully differentiated into fibroblast and keratinocytes as indicated by morphological changes and expression of lineage specific genes. We propose that these differentiated skin cells which are derived from CT-MSCs can thus be used for the development of bioengineered skin; however, further studies are required to evaluate the utility of these substitutes.

Using human epithelial amnion cells in human de-epidermized dermis for skin regeneration

BACKGROUND

Human amniotic epithelial cells (hAECs) is a desirable reserve of stem cells. Human de-epidermized dermis (DED) retains basic tissue structure and parts of the basement membrane (BM) components at the acelluIar dermal surface, and provides a potential tool for skin regeneration.

OBJECTIVE

To evaluate the potential role of hAECs in skin regeneration, we used DED to perform organotypic culture of hAECs to develop organotypic skin.

METHODS

HAECs were isolated and cultured. Biological characteristics of hAECs were determined by immunocytochemistry and flow cytometry. To prepare DED, the epidermis was removed and then repeated freeze-thaw cycles. HAECs and fibroblast were seeded onto DED to perform the submerged culture for 3 days and then to be maintained at the air-liquid interface for 14 days to form organotypic culture. To identify whether the obtained DED retain the BM structure and components, the histological characteristics of DED and the BM were detected by immunohistochemistry. To evaluate whether the organotypic skin has similar histological characteristics with normal human skin, the marks of epidermal proliferation and differentiation and basement membrane component were detected by immunohistochemistry. Moreover, cell ultrastructure, cell-cell contact and ultrastructure of BM were examined under the transmission electron microscopy.

RESULTS

HAECs has stem-cell characteristics with strong pluripotent Oct-4 and embryonic marker SSEA-4 expression. DED has effectively cleansed the cell components and continuous distributions of laminin and collagen IV. The histological appearance of tissue-engineered skin in vitro has 4 to 9 continuous layers of stratified epithelium and is similar to normal human skin in morphology. Immunohistochemical studies revealed that proliferation and differentiation markers such as Ki67, CK19, CK14, CK10, filaggrin but not CK18 expressed similar pattern characteristics to normal human epidermis. In addition, Periodic acid-Schiff stain showed that a uniform red staining strip located at the epidermal-dermal junction. BM component proteins (type IV collagen and laminin) and cell adhesion protein (desmoglein) were detected by immunohistochemistry in organotypic skin. Ultrastructurally, desmosomes, hemidesmosomes and BM zone (BMZ) were observed in organotypic skin.

CONCLUSIONS

Our studies indicate that the hAECs is a promising stem cell source for tissue-engineered skin, and DED with hAECs is a potential application prospects in regenerative medicine.

In Vitro Differentiation Potential of Human Placenta Derived Cells into Skin Cells

Skin autografting is the most viable and aesthetic technique for treatment of extensive burns; however, this practice has potential limitations. Harvesting cells from neonatal sources (such as placental tissue) is a simple, inexpensive, and noninvasive procedure. In the current study authors sought to evaluate in vitro potential of human placenta derived stem cells to develop into skin-like cells. After extensive washing, amniotic membrane and umbilical cord tissue were separated to harvest amniotic epithelial cells (AECs) and umbilical cord mesenchymal stem cells (UC-MSCs), respectively. Both types of cells were characterized for the expression of embryonic lineage markers and their growth characteristics were determined. AECs and UC-MSCs were induced to differentiate into keratinocytes-like and dermal fibroblasts-like cells, respectively. After induction, morphological changes were detected by microscopy. The differentiation potential was further assessed using immunostaining and RT-PCR analyses. AECs were positive for cytokeratins and E-Cadherin while UC-MSCs were positive for fibroblast specific makers. AECs differentiated into keratinocytes-like cells showed positive expression of keratinocyte specific cytokeratins, involucrin, and loricrin. UC-MSCs differentiated into dermal fibroblast-like cells indicated expression of collagen type 3, desmin, FGF-7, fibroblast activation protein alpha, procollagen-1, and vimentin. In conclusion, placenta is a potential source of cells to develop into skin-like cells.