Fibroblasts Derived From Human Adipose Stem Cells Produce More Effective Extracellular Matrix and Migrate Faster Compared to Primary Dermal Fibroblasts.

BACKGROUND: The efficacy of adipose-derived stem cells (ASCs) to improve wound healing has been extensively investigated. Unfortunately, no consistent reports have described significant improvements in healing time or outcomes in large-scale clinical trials utilizing human ASCs. Primarily, these studies examined undifferentiated ASCs as opposed to specific cells differentiated from ASCs. OBJECTIVES: The authors sought to examine the properties of fibroblasts differentiated from human ASCs (dFib cells) compared with those of primary dermal fibroblasts. METHODS: ASCs were isolated from healthy female patients, differentiated into dFib cells, and compared with intra-patient primary dermal fibroblasts for morphology, extracellular matrix (ECM) marker expression, and cell migration employing qPCR, western blot, and scratch test assays. RESULTS: De novo differentiated fibroblasts produce higher levels of the healthy ECM markers Elastin, Fibronectin, and Collagen 1 compared with primary fibroblasts. In contrast, dFib cells have reduced expression of the scar tissue markers αSMA, Collagen 3, and MMP-1. Further, dFib cells close scratch defects more quickly than primary dermal fibroblasts (32 ± 12.85 hours vs 64 ± 13.85 hours, P < 0.01) in a scratch test assay. CONCLUSIONS: These data suggest that fibroblasts newly differentiated from human ASCs migrate well and produce a robust ECM, the combination of which may contribute to improved wound healing, and thus should be further investigated.

Tshz1 Regulates Pancreatic ß-Cell Maturation.

The homeodomain transcription factor Pdx1 controls pancreas organogenesis, specification of endocrine pancreas progenitors, and the postnatal growth and function of pancreatic ß-cells. Pdx1 expression in human-derived stem cells is used as a marker for induced pancreatic precursor cells. Unfortunately, the differentiation efficiency of human pancreatic progenitors into functional ß-cells is poor. In order to gain insight into the genes that Pdx1 regulates during differentiation, we performed Pdx1 chromatin immunoprecipitation followed by high-throughput sequencing of embryonic day (e) 13.5 and 15.5 mouse pancreata. From this, we identified the transcription factor Teashirt zinc finger 1 (Tshz1) as a direct Pdx1 target. Tshz1 is expressed in developing and adult insulin- and glucagon-positive cells. Endocrine cells are properly specified in Tshz1-null embryos, but critical regulators of ß-cell (Pdx1 and Nkx6.1) and α-cell (MafB and Arx) formation and function are downregulated. Adult Tshz1(+/-) mice display glucose intolerance due to defects in glucose-stimulated insulin secretion associated with reduced Pdx1 and Clec16a expression in Tshz1(+/-) islets. Lastly, we demonstrate that TSHZ1 levels are reduced in human islets of donors with type 2 diabetes. Thus, we position Tshz1 in the transcriptional network of maturing ß-cells and suggest that its dysregulation could contribute to the islet phenotype of human type 2 diabetes.