Developing defined substrates for stem cell culture and differentiation

Over the past few decades, a variety of different reagents for stem cell maintenance and differentiation have been commercialized. These reagents share a common goal in facilitating the manufacture of products suitable for cell therapy while reducing the amount of non-defined components. Lessons from developmental biology have identified signalling molecules that can guide the differentiation process in vitro, but less attention has been paid to the extracellular matrix used. With the introduction of more biologically relevant and defined matrices, that better mimic specific cell niches, researchers now have powerful resources to fine-tune their in vitro differentiation systems, which may allow the manufacture of therapeutically relevant cell types. In this review article, we revisit the basics of the extracellular matrix, and explore the important role of the cell –matrix interaction. We focus on laminin proteins because they help to maintain pluripotency and drive cell fate specification. This article is part of the theme issue ‘Designer human tissue: coming to a lab near you’

Genome-wide expression changes induced by bisphenol A, F and S in human stem cell derived hepatocyte-like cells

Acknowledgments BLV and DCH were funded by an award from the Chief Scientist Office (TCS 16/37). This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 681002 (EU-ToxRisk) and from TransQST (no. 116030).Peer reviewedPublisher PD

Quantification of ethyl glucuronide, ethyl sulfate, nicotine, and its metabolites in human fetal liver and placenta

This research was supported by the Medical Research Council (UK) grant MR/L010011/1 and the Intramural Research Program at the National Institute on Drug Abuse of the National Institutes of Health. Paired fetal liver and placenta samples were graciously provided by the Joint Medical Research Council/Wellcome Trust (grant number 099175/Z/12/Z) Human Developmental Biology Resource (www.hdbr.org). The online version of this article (doi:10.1007/s11419-017-0389-2) contains supplementary material, which is available to authorized users.Peer reviewedPostprin

Liver cell therapy: is this the end of the beginning?

The prevalence of liver diseases is increasing globally. Orthotopic liver transplantation is widely used to treat liver disease upon organ failure. The complexity of this procedure and finite numbers of healthy organ donors have prompted research into alternative therapeutic options to treat liver disease. This includes the transplantation of liver cells to promote regeneration. While successful, the routine supply of good quality human liver cells is limited. Therefore, renewable and scalable sources of these cells are sought. Liver progenitor and pluripotent stem cells offer potential cell sources that could be used clinically. This review discusses recent approaches in liver cell transplantation and requirements to improve the process, with the ultimate goal being efficient organ regeneration. We also discuss the potential off-target effects of cell-based therapies, and the advantages and drawbacks of current pre-clinical animal models used to study organ senescence, repopulation and regeneration

Nonalcoholic fatty liver disease is associated with decreased hepatocyte mitochondrial respiration, but not mitochondrial number

AbstractNonalcoholic fatty liver disease (NAFLD) is currently the most prevalent form of liver disease worldwide. This term covers a spectrum of pathologies, from benign hepatic steatosis to non-alcoholic steatohepatitis (NASH). As the disease progresses, NASH can develop into cirrhosis and hepatocellular carcinoma. However, the underlying mechanisms and the factors which predispose an individual to disease progression remain poorly understood. Whilst NAFLD appears to be associated with mitochondrial dysfunction, it is unclear whether this is due to respiratory impairment, changes in mitochondrial mass, or mitochondrial fragmentation. Using a human pluripotent stem cell-based model of NAFLD we show that exposure to lactate, pyruvate and octanoic acid results in the development of macrovesicular steatosis. We do not observe changes in mitochondrial mass or fragmentation but do find decreases in maximal respiration and reserve capacity, suggesting impairment in the electron transport chain (ETC). Taken together, these findings indicate that the development of macrovesicular steatosis in NAFLD may be linked to the impairment of the ETC in mitochondria.</jats:p

A human pluripotent stem cell model for the analysis of metabolic dysfunction in hepatic steatosis

Nonalcoholic fatty liver disease (NAFLD) is currently the most prevalent form of liver disease worldwide. This term encompasses a spectrum of pathologies, from benign hepatic steatosis to non-alcoholic steatohepatitis, which have, to date, been challenging to model in the laboratory setting. Here, we present a human pluripotent stem cell- (hPSC)-derived model of hepatic steatosis, which overcomes inherent challenges of current models, and provides insights into the metabolic rewiring associated with steatosis. Following induction of macrovesicular steatosis in hepatocyte-like cells using lactate, pyruvate and octanoate (LPO), respirometry and transcriptomic analyses revealed compromised electron transport chain activity. C isotopic tracing studies revealed enhanced TCA cycle anaplerosis, with concomitant development of a compensatory purine nucleotide cycle shunt leading to excess generation of fumarate. This model of hepatic steatosis is reproducible, scalable, and overcomes the challenges of studying mitochondrial metabolism in currently available models