Human embryonic stem cell-derived melanocytes exhibit limited immunogenicity

Therapeutic approaches of cell therapy based on stem cells and terminally differentiated cells: Potential and effectiveness

Cell-based therapy, as a promising regenerative medicine approach, has been a promising and effective strategy to treat or even cure various kinds of diseases and conditions. Generally, two types of cells are used in cell therapy, the first is the stem cell, and the other is a fully differentiated cell. Initially, all cells in the body are derived from stem cells. Based on the capacity, potency and differentiation potential of stem cells, there are four types: totipotent (produces all somatic cells plus perinatal tissues), pluripotent (produces all somatic cells), multipotent (produces many types of cells), and unipotent (produces a particular type of cells). All non-totipotent stem cells can be used for cell therapy, depending on their potency and/or disease state/conditions. Adult fully differentiated cell is another cell type for cell therapy that is isolated from adult tissues or obtained following the differentiation of stem cells. The cells can then be transplanted back into the patient to replace damaged or malfunctioning cells, promote tissue repair, or enhance the targeted organ's overall function. With increasing science and knowledge in biology and medicine, different types of techniques have been developed to obtain efficient cells to use for therapeutic approaches. In this study, the potential and opportunity of use of all cell types, both stem cells and fully differentiated cells, are reviewed.

Management of the refractory vitiligo patient: current therapeutic strategies and future options

Vitiligo is an autoimmune disease that leads to disfiguring depigmented lesions of skin and mucosa. Although effective treatments are available for vitiligo, there are still some patients with poor responses to conventional treatment. Refractory vitiligo lesions are mostly located on exposed sites such as acral sites and lips, leading to significant life stress. Understanding the causes of refractory vitiligo and developing targeted treatments are essential to enhance vitiligo outcomes. In this review, we summarized recent treatment approaches and some potential methods for refractory vitiligo. Janus kinase inhibitors have shown efficacy in refractory vitiligo. A variety of surgical interventions and fractional carbon dioxide laser have been widely applied to combination therapies. Furthermore, melanocyte regeneration and activation therapies are potentially effective strategies. Patients with refractory vitiligo should be referred to psychological monitoring and interventions to reduce the potential pathogenic effects of chronic stress. Finally, methods for depigmentation and camouflage may be beneficial in achieving uniform skin color and improved quality of life. Our ultimate focus is to provide alternative options for refractory vitiligo and to bring inspiration to future research.

Functional and long-lived melanocytes from human pluripotent stem cells with transient ectopic expression of JMJD3

BACKGROUND

Melanocytes are an essential part of the epidermis, and their regeneration has received much attention because propagation of human adult melanocytes in vitro is too slow for clinical use. Differentiation from human pluripotent stem cells to melanocytes has been reported, but the protocols to produce them require multiple and complex differentiation steps.

METHOD

We differentiated human embryonic stem cells (hESCs) that transiently express JMJD3 to pigmented cells. We investigated whether the pigmented cells have melanocytic characteristics and functions by qRT-PCR, immunocytochemical analysis and flow cytometry. We also investigated their biocompatibility by injecting the cells into immunodeficient mice for clinical use.

RESULT

We successfully differentiated and established a pure culture of melanocytes. The melanocytes maintained their growth rate for a long time, approximately 200 days, and were functional. They exhibited melanogenesis and transfer of melanin to peripheral keratinocytes. Moreover, melanocytes simulated the developmental processes from melanoblasts to melanocytes. The melanocytes had high engraftability and biocompatibility in the immunodeficient mice.

CONCLUSION

The robust generation of functional and long-lived melanocytes are key to developing clinical applications for the treatment of pigmentary skin disorders.

Surgical procedures and innovative approaches for vitiligo regenerative treatment and melanocytorrhagy

Surgical treatments for vitiligo are a safe and effective treatment modality for select patients with vitiligo. Many techniques of vitiligo surgery exist, each with unique advantages and disadvantages. We reviewed the various surgical therapies and innovative approaches for vitiligo regenerative treatment reported in the literature. Surgical therapies can be subdivided into tissue grafting methods and cellular grafting methods. Tissue grafting methods mainly include mini punch grafts, suction blister roof grafts, and hair follicle grafts. Cellular grafting methods include cultured and non-cultured treatments. The efficacy needs to be improved largely due to the poor proliferation and quality of the autologous melanocytes. Rho-associated protein kinase inhibitor enhances primary melanocyte culture proliferation from vitiligo patients to prevent apoptosis. Innovative approaches using stem cell methods could prove invaluable in developing a novel cell therapy for patients suffering from vitiligo. We succeeded in inducing melanin pigmentation in mice skin in vivo using our human induced pluripotent stem cell-derived melanocytes. In addition, we reviewed melanocytorrhagy, detachment and transepidermal loss of melanocytes, and melanocyte-related adhesion molecules. These adhesion molecules include epithelial cadherin, discoidin domain receptor tyrosine kinase 1, glycoprotein non-metastatic melanoma protein B, macrophage migration inhibiting factor, 17β-hydroxysteroid dehydrogenase 1, and E26 transformation-specific 1.