Surveillance of Stem Cell Fate and Function: A System for Assessing Cell Survival and Collagen Expression In Situ

Abstract

Cell-based therapy is an emerging paradigm in skeletal regenerative medicine. However, the primary means by which transplanted cells contribute to bone repair and regeneration remain controversial. To gain an insight into the mechanisms of how both transplanted and endogenous cells mediate skeletal healing, we used a transgenic mouse strain expressing both the topaz variant of green fluorescent protein under the control of the collagen, type I, alpha 1 promoter/enhancer sequence (Col1a1 GFP ) and membrane-bound tomato red fluorescent protein constitutively in all cell types (R26 mTmG ). A comparison of healing in parietal versus frontal calvarial defects in these mice revealed that frontal osteoblasts express Col1a1 to a greater degree than parietal osteoblasts. Furthermore, the scaffold-based application of adipose-derived stromal cells (ASCs), bone marrow-derived mesenchymal stem cells (BM-MSCs), and osteoblasts derived from these mice to critical-sized calvarial defects allowed for investigation of cell survival and function following transplantation. We found that ASCs led to significantly faster rates of bone healing in comparison to BM-MSCs and osteoblasts. ASCs displayed both increased survival and increased Col1a1 expression compared to BMMSCs and osteoblasts following calvarial defect transplantation, which may explain their superior regenerative capacity in the context of bone healing. Using this novel reporter system, we were able to elucidate how cell-based therapies impact bone healing and identify ASCs as an attractive candidate for cell-based skeletal regenerative therapy. These insights potentially influence stem cell selection in translational clinical trials evaluating cell-based therapeutics for osseous repair and regeneration.

An NIR‐II Fluorescence/Dual Bioluminescence Multiplexed Imaging for In Vivo Visualizing the Location, Survival, and Differentiation of Transplanted Stem Cells

“…These results agreed with previous in vitro studies that the BMP‐2 can promote the osteogenic differentiation of transplanted hMSCs (Figures D and ). In addition, it has been found that promoter Col1A1 drove the active expression of type I collagen gene at the early stage of osteoblast differentiation and promoted the extracellular matrix formation and the new bone generation, which was also consistent with the result of our Col1A1–GLuc‐based BLI imaging (Figure ). These results evidenced that the multiplexed imaging method works well in in vivo application.…”

Suction assisted liposuction does not impair the regenerative potential of adipose derived stem cells

“…For example, pullulan-collagen hydrogel scaffolds seeded with ASCs have been demonstrated to increase vascularity and improve wound healing [ 5 , 6 ]. With regard to skeletal regenerative potential, implantation of an ASC-seeded hydroxyapatite-coated poly (lactic-co-glycolic acid) scaffold into a critical-sized calvarial defect resulted in significant healing of the defect within 8 weeks [ 7 , 8 ]. Finally, the adipogenic and angiogenic capabilities of ASCs have been utilized in the technique of cell-assisted lipotransfer (CAL), in which fat grafts are enriched with their native ASCs to improve retention and variability [ 9 – 12 ].…”

Vergleich des Regenerativen Zytokinprofils von Adipose Derived Stromal Cells (ASCs) Gewonnen Mittels Abdominoplastik, Suction Assisted Liposuction (SAL) und Ultrasound Assisted Liposuction (UAL)

“…Diese heterogene Zellpopulation besteht aus Fibroblasten, Immunzellen, Prä-Adipozyten, Perizyten, Epithelzellen und, am wichtigsten für die regenerativen Eigenschaften, ASCs [7,20]. Die SVF kann entweder direkt zur Zelltherapie eingesetzt [21] oder weiter aufbereitet werden, um in diesem Prozess mittels Zellkultivierung oder Durchflusszytometrie reine ASCs zu gewinnen [22][23][24][25][26]. Ihre therapeutische Wirkung entfalten ASCs durch die Sekretion einer Vielzahl von pro-regenerativen Faktoren, wie pro-angiogenetische und immunmodulierende Zytokine (VEGF, MCP1, etc.…”