Global Transcriptional Analyses of Fibromodulin Reprogrammed Cells - A New Multipotent Cell Source for Craniofacial Tissue Reconstruction

点击翻译按钮获取中文摘要

PROJECT SUMMARY / ABSTRACT Regeneration of damaged craniofacial tissue is extremely difficult and often unsatisfactory due to insufficient endogenous precursor cells as well as a corresponding finite regenerative capability. Furthermore, inherent tumorigenicity and/or tumor supporting properties render the currently available pluripotent and multipotent cells unsuitable for tissue regeneration, especially for craniofacial tissues. Thus, the production of safer and readily available cell sources for functional craniofacial tissue regeneration remains a major challenge for regenerative medicine, and particularly for craniofacial reconstruction. In response to this demand, we established a novel technology platform in which dermal fibroblasts acquire multipotency by continuous exposure to an extracellular matrix (ECM) proteoglycan, fibromodulin (FMOD), under serum-free conditions. Importantly, although both FMOD reprogrammed (FReP) cells and induced pluripotent stem cells (iPSCs) express similar pluripotent markers and hold the triploblastic differentiation potentials, their respective tumorigenic potencies are entirely different, which could relate back to the fundamentally disparate methodologies for reprogramming dermal fibroblasts into FReP cells or iPSCs. Unlike iPSCs generated through oncogene activation, FReP cells are reprogrammed through a simple ECM stimulation procedure that does not require genome integration or oncogene activation. It is worth noting that low tumorigenicity is a prerequisite for using a potential cell source in skeletal muscle regeneration (an essential component of craniofacial disorder and trauma reconstruction) since the highly vascularized microenvironment of the muscle compartment can be especially conducive to tumor formation. Indeed, intramuscular implantation is a common route for teratoma formation when testing for cellular pluripotency. Therefore, FReP cells appear to be a potentially safe and effective cell source that can be adequately obtained for functional tissue regeneration. However, compared with mesenchymal stem cells (MSCs) and iPSCs, FReP cells’ investigation is still in its infancy. A further comparison of the publicly accessible transcriptomic data between FReP cells and iPSCs will provide more understanding into FMOD reprogramming and the cell signal pathways that orchestrate the cell fate determination and tumorigenesis. In this study, we will perform an in-depth transcriptomic profile to confirm the non-tumorigenic nature or FReP cells is independent of the sex and age of their parental fibroblasts (AIM 1) and track the transcriptomic alteration of bioenergetic-related genes during FMOD reprogramming to gain insight into a novel strategy to advance this technology (AIM 2). Completing these AIMs will enrich our knowledge about cell fate determination and reprogramming, and tumorigenesis, thus building the fundamentals for future investigations in the R01 stage. Therefore, the current study will directly benefit the development of FReP cell-based therapies for the craniofacial or musculoskeletal reconstruction and regenerative medicine in general. As such, this proposal is tightly aligned with the mission of the current NIDCR R03 grant.