A circular RNA map for human induced pluripotent stem cells of foetal origin

Background Adult skin fibroblasts represent the most common starting cell type used to generate human induced pluripotent stem cells (F-hiPSC) for clinical studies. Yet, a foetal source would offer unique advantages, primarily the absence of accumulated somatic mutations. Herein, we generated hiPSC from cord blood multipotent mesenchymal stromal cells (MSC-hiPSC) and compared them with F-hiPSC. Assessment of the full activation of the pluripotency gene regulatory network (PGRN) focused on circular RNA (circRNA), recently proposed to participate in the control of pluripotency. Methods Reprogramming was achieved by a footprint-free strategy. Self-renewal and pluripotency of cord blood MSC-hiPSC were investigated in vitro and in vivo, compared to parental MSC, to embryonic stem cells and to F-hiPSC. High-throughput array-based approaches and bioinformatics analyses were applied to address the PGRN. • View related content for this article Findings Cord blood MSC-hiPSC successfully acquired a complete pluripotent identity. Functional comparison with F-hiPSC showed no differences in terms of i) generation of mesenchymal-like derivatives, ii) their subsequent adipogenic, osteogenic and chondrogenic commitment, and iii) their hematopoietic support ability. At the transcriptional level, specific subsets of mRNA, miRNA and circRNA (n = 4,429) were evidenced, casting a further layer of complexity on the PGRN regulatory crosstalk. Interpretation A circRNA map of transcripts associated to naïve and primed pluripotency is provided for hiPSC of clinical-grade foetal origin, offering insights on still unreported regulatory circuits of the PGRN to consider for the optimization and development of efficient differentiation protocols for clinical translation

Low-affinity nerve growth factor receptor (cd271) heterogeneous expression in adult and fetal mesenchymal stromal cells

Human multipotent mesenchymal stromal cells (MSC) are isolated from a plethora of tissue sources for cell therapy purposes. In 2006, the International Society for Cellular Therapy (ISCT) published minimal guidelines to define MSC identity. Nevertheless, many independent studies demonstrated that cells meeting the ISCT criteria possessed heterogeneous phenotypes and functionalities, heavily influenced by culture conditions. In this study, human MSC derived from many adult (bone marrow and adipose tissue) or fetal (cord blood, Wharton\u27s jelly, umbilical cord perivascular compartment and amniotic fluid) tissues were investigated. Their immunophenotype was analyzed to define consistent source-specific markers by extensive flow cytometry analysis and real-time qRT-PCR. CD271(+) subpopulations were detected in adult MSC, whereas NG2 was significantly more expressed in fetal MSC but failed validation on independent samples coming from an external laboratory. The highest number of CD271(+) adult MSC were detected soon after isolation in serum-based culture conditions. Furthermore, heterogeneous percentages of CD271 expression were found in platelet lysate-based or serum-free culture conditions. Finally, CD271(+) adult MSC showed high clonogenic and osteogenic properties as compared to CD271(+) cells. To conclude, in this phenotype-function correlation study CD271(+) subpopulation confers heterogeneity on adult MSC, confirming the need of more specific markers to address MSC properties

Low-affinity nerve growth factor receptor (cd271) heterogeneous expression in adult and fetal mesenchymal stromal cells

Human multipotent mesenchymal stromal cells (MSC) are isolated from a plethora of tissue sources for cell therapy purposes. In 2006, the International Society for Cellular Therapy (ISCT) published minimal guidelines to define MSC identity. Nevertheless, many independent studies demonstrated that cells meeting the ISCT criteria possessed heterogeneous phenotypes and functionalities, heavily influenced by culture conditions. In this study, human MSC derived from many adult (bone marrow and adipose tissue) or fetal (cord blood, Wharton's jelly, umbilical cord perivascular compartment and amniotic fluid) tissues were investigated. Their immunophenotype was analyzed to define consistent source-specific markers by extensive flow cytometry analysis and real-time qRT-PCR. CD271(+) subpopulations were detected in adult MSC, whereas NG2 was significantly more expressed in fetal MSC but failed validation on independent samples coming from an external laboratory. The highest number of CD271(+) adult MSC were detected soon after isolation in serum-based culture conditions. Furthermore, heterogeneous percentages of CD271 expression were found in platelet lysate-based or serum-free culture conditions. Finally, CD271(+) adult MSC showed high clonogenic and osteogenic properties as compared to CD271(+) cells. To conclude, in this phenotype-function correlation study CD271(+) subpopulation confers heterogeneity on adult MSC, confirming the need of more specific markers to address MSC properties