METHODS: We screened the in-house built fluorescent library compounds that specifically bind human iPS cells. After tertiary screening, the selected probe was analyzed for its ability to detect reprogramming cells in the time-dependent manner using high-content imaging analysis. The probe was compared with conventional dyes in different reprogramming methods, cell types, and cell culture conditions. Cell sorting was performed with the fluorescent probe to analyze the early reprogramming cells for their pluripotent characteristics and genome-wide gene expression signatures by RNA-seq. Finally, the candidate reprogramming factor identified was investigated for its ability to modulate reprogramming efficiency.
RESULTS: We identified a novel BODIPY-derived fluorescent probe, BDL-E5, which detects live human iPS cells at the early reprogramming stage. BDL-E5 can recognize authentic reprogramming cells around 7 days before iPS colonies are formed and stained positive with conventional pluripotent markers. Cell sorting of reprogrammed cells with BDL-E5 allowed generation of an increased number and higher quality of iPS cells. RNA sequencing analysis of BDL-E5-positive versus negative cells revealed early reprogramming patterns of gene expression, which notably included CREB1. Reprogramming efficiency was significantly increased by overexpression of CREB1 and decreased by knockdown of CREB1.
CONCLUSION: Collectively, BDL-E5 offers a valuable tool for delineating the early reprogramming pathway and clinically applicable commercial production of human iPS cells.
MATERIALS AND METHODS: The cows with mastitis were divided into two groups. In antibiotic control group, the cows were given tetraneomycin ointment. In conditioned-DPBS of AMSCs treatment group, amniotic membrane was collected for AMSCs after delivery. With expression of surface antigen and potential of tri-linage differentiation, AMSCs were injected into mammary glands. Then, milk was sampled every three days to monitor the effect of both treatments. The quality of milk was measured with pH, titratable acidity, free calcium ions and somatic cell count.
RESULTS: Our results demonstrated the Bovine AMSCs expressed CD44, low levels of CD4 and no CD105. Bovine AMSCs demonstrated the differentiation capability in the tri-cell lineages. Mastitis treatment with conditioned-DPBS from AMSCs (experimental group) and conventional antibiotics (control group) showed insignificant difference in pH value and titratable acidity. The level of ionic calcium concentration in the conditioned-DPBS group decreased from 3rd day to 12th day, while the level in the antibiotic group decreased from 0 day to 12th day. The somatic cell number was similar in both groups, which meet the standard of Taiwan milk collection.
CONCLUSION: In conclusion, conditioned-DPBS from bovine AMSCs has the therapeutic potential to treat bovine mastitis and may replace antibiotics therapy in the future.
RESULTS: We show that loss of Hmgn1 or Hmgn2 in pluripotent embryonal carcinoma cells leads to increased levels of spontaneous neuronal differentiation. This is accompanied by the loss of pluripotency markers Nanog and Ssea1, and increased expression of the pro-neural transcription factors Neurog1 and Ascl1. Neural stem cells derived from these Hmgn-knockout lines also show increased spontaneous neuronal differentiation and Neurog1 expression. The loss of HMGN2 leads to a global reduction in H3K9 acetylation, and disrupts the profile of H3K4me3, H3K9ac, H3K27ac and H3K122ac at the Nanog and Oct4 loci. At endodermal/mesodermal genes, Hmgn2-knockout cells show a switch from a bivalent to a repressive chromatin configuration. However, at neuronal lineage genes whose expression is increased, no epigenetic changes are observed and their bivalent states are retained following the loss of HMGN2.
CONCLUSIONS: We conclude that HMGN1 and HMGN2 maintain the identity of pluripotent embryonal carcinoma cells by optimising the pluripotency transcription factor network and protecting the cells from precocious differentiation. Our evidence suggests that HMGN2 regulates active and bivalent genes by promoting an epigenetic landscape of active histone modifications at promoters and enhancers.