RESUMO
Recent evidence has suggested that human skin fibroblasts may represent a novel source of therapeutic stem cells. In this study, we report a 3-stage method to induce the differentiation of skin fibroblasts into insulin-producing cells (IPCs). In stage 1, we establish the isolation, expansion and characterization of mesenchymal stem cells from human labia minora dermis-derived fibroblasts (hLMDFs) (stage 1: MSC expansion). hLMDFs express the typical mesenchymal stem cell marker proteins and can differentiate into adipocytes, osteoblasts, chondrocytes or muscle cells. In stage 2, DMEM/F12 serum-free medium with ITS mix (insulin, transferrin, and selenite) is used to induce differentiation of hLMDFs into endoderm-like cells, as determined by the expression of the endoderm markers Sox17, Foxa2, and PDX1 (stage 2: mesenchymal-endoderm transition). In stage 3, cells in the mesenchymal-endoderm transition stage are treated with nicotinamide in order to further differentiate into self-assembled, 3-dimensional islet cell-like clusters that express multiple genes related to pancreatic beta-cell development and function (stage 3: IPC). We also found that the transplantation of IPCs can normalize blood glucose levels and rescue glucose homeostasis in streptozotocin-induced diabetic mice. These results indicate that hLMDFs have the capacity to differentiate into functionally competent IPCs and represent a potential cell-based treatment for diabetes mellitus.
Assuntos
Animais , Feminino , Humanos , Camundongos , Biomarcadores/metabolismo , Técnicas de Cultura de Células , Diferenciação Celular , Proliferação de Células/efeitos dos fármacos , Separação Celular , Células Cultivadas , Derme/citologia , Diabetes Mellitus Experimental/cirurgia , Fibroblastos/citologia , Genitália Feminina/citologia , Glucose/metabolismo , Fator 3-beta Nuclear de Hepatócito/metabolismo , Proteínas de Homeodomínio/metabolismo , Insulina/farmacologia , Células Secretoras de Insulina/citologia , Transplante das Ilhotas Pancreáticas , Células-Tronco Mesenquimais/citologia , Camundongos Nus , Niacinamida/farmacologia , Recuperação de Função Fisiológica , Fatores de Transcrição SOXF/metabolismo , Selenito de Sódio/farmacologia , Transativadores/metabolismo , Transferrina/farmacologiaRESUMO
We report the case of a 3-yr-old boy with Down-Turner mosaicism and review the previous reports of Down-Turner syndrome with documented karyotyping and clinical features. The patient showed clinical features of Down syndrome without significant stigma of Turner syndrome. Cytogenetic analysis of peripheral blood preparations by using G-banding revealed mosaicism with 2 cell lines (45,X[29]/47,XY,+21[4]). FISH analysis revealed that 87.5% of the cells had monosomy X karyotype and 12.5% of the cells had XY karyotype; trisomy 21 was only detected in the Y-positive cells. We suggest that additional cells should be analyzed and molecular genetic studies should be conducted to rule out double aneuploidy when karyotypes with sex chromosome aneuploidies and mosaicism are encountered, as in our case of Down syndrome mosaic with sex chromosome aneuploidy.
