Comparison of Four Protocols for In Vitro Differentiation of Human Embryonic Stem Cells into Trophoblast Lineages by BMP4 and Dual Inhibition of Activin/Nodal and FGF2 Signaling.

Human embryonic stem cells (hESCs) cultured in media containing bone morphogenic protein 4 (BMP4; B) differentiate into trophoblast-like cells. Supplementing media with inhibitors of activin/nodal signaling (A83-01) and of fibroblast growth factor 2 (PD173074) suppresses mesoderm and endoderm formation and improves specification of trophoblast-like lineages, but with variable effectiveness. We compared differentiation in four BMP4-containing media: mTeSR1-BMP4 only, mTeSR1-BAP, basal medium with BAP (basal-BAP), and a newly defined medium, E7-BAP. These media variably drive early differentiation towards trophoblast-like lineages with upregulation of early trophoblast markers CDX2 and KRT7 and downregulation of pluripotency markers (OCT4 and NANOG). As expected, based on differences between media in FGF2 and its inhibitors, downregulation of mesendoderm marker EOMES was variable between media. By day 7, only hESCs grown in E7-BAP or basal-BAP expressed HLA-G protein, indicating the presence of cells with extravillous trophoblast characteristics. Expression of HLA-G and other differentiation markers (hCG, KRT7, and GCM1) was highest in basal-BAP, suggesting a faster differentiation in this medium, but those cultures were more inhomogeneous and still expressed some endodermal and pluripotency markers. In E7-BAP, HLA-G expression increased later and was lower. There was also a low but maintained expression of some C19MC miRNAs, with more CpG hypomethylation of the ELF5 promoter, suggesting that E7-BAP cultures differentiate slower along the trophoblast lineage. We conclude that while all protocols drive differentiation into trophoblast lineages with varying efficiency, they have advantages and disadvantages that must be considered when selecting a protocol for specific experiments.

Molecular and clinical profiling in a large cohort of Asian Indians with glycogen storage disorders.

Glycogen storage disorders occur due to enzyme deficiencies in the glycogenolysis and gluconeogenesis pathway, encoded by 26 genes. GSD's present with overlapping phenotypes with variable severity. In this series, 57 individuals were molecularly confirmed for 7 GSD subtypes and their demographic data, clinical profiles and genotype-phenotype co-relations are studied. Genomic DNA from venous blood samples was isolated from clinically affected individuals. Targeted gene panel sequencing covering 23 genes and Sanger sequencing were employed. Various bioinformatic tools were used to predict pathogenicity for new variations. Close parental consanguinity was seen in 76%. Forty-nine pathogenic variations were detected of which 27 were novel. Variations were spread across GSDIa, Ib, III, VI, IXa, b and c. The largest subgroup was GSDIII in 28 individuals with 24 variations (12 novel) in AGL. The 1620+1G>C intronic variation was observed in 5 with GSDVI (PYGL). A total of eleven GSDIX are described with the first Indian report of type IXb. This is the largest study of GSDs from India. High levels of consanguinity in the local population and employment of targeted sequencing panels accounted for the range of GSDs reported here.