Efficient Generation of Chemically Induced Mesenchymal Stem Cells from Human Dermal Fibroblasts

Pei-Lun Lai,Shang-Chih Yang,Ching-Fang Chang,Yi-Hsuan Lee,Yu-Chuan Liu,Hsiao-Chun Huang,Frank Leigh Lu,Jean Lu,Shang-Fu Chen,Kuo-Hsuan Hung,Hsiang-Yi Chang,Hsuan Lin

doi:10.1038/srep44534

Abstract

Human mesenchymal stromal/stem cells (MSCs) are multipotent and currently undergoing hundreds of clinical trials for disease treatments. To date, no studies have generated induced MSCs from skin fibroblasts with chemicals or growth factors. Here, we established the first chemical method to convert primary human dermal fibroblasts into multipotent, induced MSC-like cells (iMSCs). The conversion method uses a defined cocktail of small molecules and growth factors, and it can achieve efficient conversion with an average rate of 38% in 6 days. The iMSCs have much higher clonogenicity than fibroblasts, and they can be maintained and expanded in regular MSC medium for at least 8 passages and further differentiated into osteoblasts, adipocytes, and chondrocytes. Moreover, the iMSCs can suppress LPS-mediated acute lung injury as effectively as bone marrow-derived mesenchymal stem cells. This finding may greatly benefit stem cell biology, cell therapy, and regenerative medicine.

Highlights

Mesenchymal stromal/stem cells (MSCs) were first isolated from bone marrow and able to differentiate into multiple lineages, including bone, fat, cartilage, and fibroblasts[1,2]
According to the Guidelines of the Mesenchymal and Tissue Stem Cell Committee of the International Society for Cellular Therapy (ISCT), mesenchymal stromal/stem cells (MSCs) should fulfill three criteria, including (1) being plastic-adherent when maintained in standard culture conditions, (2) expressing CD105, CD73 and CD90 surface markers, and not expressing CD45, CD34, CD14/CD11b, CD79a/CD19 and HLA-DR surface molecules, and (3) able to differentiate into osteoblasts, adipocytes, and chondrocytes in vitro[5]
SSEA-4 and PODXL were used as markers to isolate the potentially induced MSC-like cells with superior multipotency and expansion ability than the parental fibroblasts[9,10,11]

Summary

Introduction

Mesenchymal stromal/stem cells (MSCs) were first isolated from bone marrow and able to differentiate into multiple lineages, including bone, fat, cartilage, and fibroblasts[1,2]. In addition to their multipotency, MSCs are known for their immunoregulatory functions[3] and the ability to secrete multiple cytokines to promote tissue healing[4]. The chemical cocktail directly converts human fibroblasts to iMSCs with a monolayer culture in 6 days, and the conversion rate was approximately 38% These iMSCs fulfill all criteria of MSCs defined by the ISCT5, and they behave like primary BMMSCs in terms of their multipotency, clonogenicity, molecular signatures, surface marker expression profile, and antisepsis function in mice. Because the conversion method does not involve any processes that may lead to insertional mutagenesis, and MSCs have a low risk of tumorigenesis, the iMSCs described here have lower safety concerns for disease treatments

Methods

Results

Conclusion