One of the challenges in Good Manufacturing Practice (GMP)-compliant human induced pluripotent stem cell (hiPSC) production is the validation of quality control (QC) tests specific for hiPSCs, which are required for GMP batch release. This study presents a comprehensive description of the validation process for hiPSC-specific GMP-compliant QC assays; more specifically, the validation of assays to assess the potential presence of residual episomal vectors (REVs), the expression of markers of the undifferentiated state and the directed differentiation potential of hiPSCs. Critical aspects and specific acceptance criteria were formulated in a validation plan prior to assay validation. Assay specificity, sensitivity and reproducibility were tested, and the equipment used for each assay was subjected to performance qualification. A minimum input of 20 000 cells (120 ng of genomic DNA) was defined for accurate determination of the presence of REVs. Furthermore, since vector loss in hiPSC lines is a passage-dependent process, we advocate screening for REVs between passages eight and 10, as testing at earlier passages might lead to unnecessary rejection of hiPSC lines. The cutoff value for assessment of markers of the undifferentiated state was set to the expression of at least three individual markers on at least 75% of the cells. When multi-color flow cytometry panels are used, a fluorescence minus one control is advised to ensure the control for fluorescent spread. For the assay to assess the directed differentiation potential, the detection limit was set to two of three positive lineage-specific markers for each of the three individual germ layers. All of our assays proved to be reproducible and specific. Our data demonstrate that our implemented analytical procedures are suitable as QC assays for the batch release of GMP-compliant hiPSCs.
Copyright © 2024 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.

Stem/progenitor cells, because of their self-renewal and multiple cell type differentiation abilities, have good potential in regenerative medicine. We previously reported a lung epithelial cell population that expressed the stem cell marker SSEA-1 was abundant in neonatal but scarce in adult mice. In the current study, neonatal and adult mouse-derived pulmonary SSEA-1+ cells were isolated for further characterization. The results showed that neonatal-derived pulmonary SSEA-1+ cells highly expressed lung development-associated genes and had enhanced organoid generation ability compared with the adult cells. Neonatal pulmonary SSEA-1+ cells generated airway-like and alveolar-like organoids, suggesting multilineage cell differentiation ability. Organoid generation of neonatal but not adult pulmonary SSEA-1+ cells was enhanced by fibroblast growth factor 7 (FGF 7). Furthermore, neonatal pulmonary SSEA-1+ cells colonized and developed in decellularized and injured lungs. These results suggest the potential of lung-derived neonatal-stage SSEA-1+ cells with enhanced stem/progenitor activity and shed light on future lung engineering applications.© 2022 The Author(s).

Alzheimer's disease (AD) is the most common form of dementia. Mutations in the gene PSEN1 encoding Presenilin1 are known to cause familial forms of AD with early age of onset. The most common mutation in the PSEN1 gene is the E280A mutation. iPSCs are an optimal choice for modeling AD, as they can be differentiated in vitro into neural cells. Here, we report the generation of two isogenic iPSC lines with either a homozygous or a heterozygous E280A mutation in the PSEN1 gene. The mutation was introduced into an iPSC line from a healthy individual using the CRISPR-Cas9 technology. Resource table.
Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.

Alzheimer's disease (AD) is the most common form of dementia, affecting millions of people worldwide. Mutations in the genes PSEN1, PSEN2 or APP are known to cause familial forms of AD with an early age of onset. In this study, specific pathogenic mutations in the APP gene were introduced into an iPSC line from a healthy individual by the use of CRISPR-Cas9. The study resulted in the generation of two new cell lines, one carrying the V717I APP mutation and one with the KM670/671NL APP mutation.
Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Alzheimer's disease (AD) is the most frequent neurodegenerative disease amongst the elderly. The SNPs rs429358 and rs7412 in the APOE gene are the most common risk factor for sporadic AD, and there are three different alleles commonly referred to as APOE-ε2, APOE-ε3 and APOE-ε4. Induced pluripotent stem cells (iPSCs) hold great promise to model AD as such cells can be differentiated in vitro to the required cell type. Here we report the use of CRISPR/Cas9 technology employed on iPSCs from a healthy individual with an APOE-ε3/ε4 genotype to obtain isogenic APOE-ε2/ε2, APOE-ε3/ε3, APOE-ε4/ε4 lines as well as an APOE-knock-out line.
Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.