Biology subjects

Elfick, A.

Publications and source records attributed to Elfick, A..

4 recordsLinked to original sources

bioRxiv2026

Development and characterisation of an optimised in vitro differentiation protocol for deriving hepatocyte-like cells from mouse embryonic stem cells

IntroductionReliable generation of hepatocyte-like cells (HLCs) from pluripotent stem cells remains limited by heterogeneity and incomplete maturation of the cells. Derivation of induced pluripotent- and embryonic stem cells into hepatocytes typically relies on complex, and costly reagent-intensive protocols, with inconsistent reporting of differentiation efficiencies and functional maturation criteria. Variability in protocol designs highlights the need for optimisation, particularly in mouse embryonic stem cells (mESCs) systems that can be more comparable with mouse models for underpinning translational and toxicological studies. Here, we developed and evaluated two cytokine-based strategies: an advanced hepatic-inducing cocktail (A-HIC) and a simplified hepatic-inducing cocktail (HIC), both designed to reduce complexity while increasing functional maturation. MethodsHepatic differentiation and maturation were assessed by morphology, immunofluorescence, flow cytometry, and qRT-PCR. Functional competence was evaluated via urea production, glutathione synthesis, indocyanine green handling, cytochrome P450 inducibility, and impedance-based cell layer integrity monitoring. ResultsMorphological, molecular and phenotypic analyses confirmed that both protocols supported hepatic lineage progression, generating heterogeneous populations of hepatoblast-like and more mature HLCs. Gene expression confirmed the loss of pluripotency, transient endoderm induction, and subsequent hepatic specification. Functionally, cells exhibited glycogen storage, inducible urea production, glutathione depletion, and active ICG uptake and clearance, with stable monolayer formation by day 21. A-HIC-derived HLCs demonstrated enhanced maturation, with higher ASGR1 expression and stronger Cyp1a1 induction. DiscussionThese findings suggest that both protocols generate functional HLCs; however, A-HIC yields a higher proportion of functionally mature cells with reduced variability. This approach enables a simple, cost-effective, and time-efficient generation of HLCs, supported by improved functional characterisation with potential applicability to more complex pluripotent systems, including human iPSC-based models for disease modelling and toxicology.

cell biology↗

bioRxiv2023

PUFFFIN: A novel, ultra-bright, customisable, singleplasmid system for labelling cell neighbourhoods

Cell communication orchestrates development, homeostasis, and disease. Understanding these processes depends on effective methods to study how cells influence their neighbours. Here, we present Positive Ultra-bright Fluorescent Fusion For Identifying Neighbours (PUFFFIN), a novel cell neighbour-labelling system based upon secretion and uptake of a positively supercharged fluorescent protein s36GFP. To achieve sensitive labelling, we amplified the fluorescent signal by fusing s36GFP to the ultra-bright protein mNeonGreen. Secretor cells transfer s36GFP-mNeonGreen to neighbours while retaining a nuclear mCherry, making it straightforward to unambiguously identify, isolate, and profile neighbours of secretor cells. Transfer of the s36GFP-mNeonGreen fusion occurs within minutes, enabling even relatively transient interactions to be captured or tracked over time with live-imaging or flow cytometry. To enhance flexibility of use, we incorporated HaloTag technology to facilitate colour-of-choice labelling. To further increase the range of applications, we engineered a customisable single-plasmid construct composed of interchangeable components with option to incorporate any additional transgene. This allows users to manipulate the properties of a cell, while at the same time applying a fluorescent label to the surrounding cells. PUFFFIN offers a simple, sensitive, customisable approach to profile non-cell-autonomous responses to natural or induced changes in cell identity or behaviour in mammalian cells. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/556381v1_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@1ea5bcaorg.highwire.dtl.DTLVardef@1303810org.highwire.dtl.DTLVardef@b0d863org.highwire.dtl.DTLVardef@4e7b1f_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2021

Using ultraviolet absorption spectroscopy to study nanoswitches based on non-canonical DNA structures

Non-canonical forms of DNA are attracting increasing interest for applications in nanotechnology. It is frequently convenient to characterize DNA molecules using a label-free approach such as ultraviolet absorption spectroscopy. In this paper we present the results of our investigation into the use of this technique to probe the folding of quadruplex and triplex nanoswitches. We confirmed that four G-quartets were necessary for folding at sub-mM concentrations of potassium and found that the wrong choice of sequence for the linker between G-tracts could dramatically disrupt folding, presumably due to the presence of kinetic traps in the folding landscape. In the case of the triplex nanoswitch we examined, we found that the UV spectrum showed a small change in absorbance when a triplex was formed. We anticipate that our results will be of interest to researchers seeking to design DNA nanoswitches based on quadruplexes and triplexes. HighlightsO_LIUltraviolet absorption spectroscopy can probe non-canonical DNA structures. C_LIO_LIAbsorbance at 295nm tends to increase as G-quadruplexes form. C_LIO_LIFour G-quartets are needed to form a quadruplex with less than 1mM potassium. C_LIO_LIFormation of DNA triplexes can also yield a small change in UV spectra. C_LIO_LIUV absorption is a cheap label-free method for studying DNA nanoswitches. C_LI

bioengineering↗

bioRxiv2017

Systematic identification of novel regulatory interactions controlling biofilm formation in the bacterium Escherichia coli

Here, we investigated novel interactions of three global regulators of the network that controls biofilm formation in the model bacterium Escherichia coli using computational network analysis, an in vivo reporter assay and physiological validation experiments. We were able to map critical nodes that govern planktonic to biofilm transition and identify 8 new regulatory interactions for CRP, IHF or Fis responsible for the control of the promoters of rpoS, rpoE, flhD, fliA, csgD and yeaJ. Additionally, an in vivo promoter reporter assay and motility analysis revealed a key role for IHF as a repressor of cell motility through the control of FliA sigma factor expression. This investigation of first stage and mature biofilm formation indicates that biofilm structure is strongly affected by IHF and Fis, while CRP seems to provide a fine-tuning mechanism. Taken together, the analysis presented here shows the utility of combining computational and experimental approaches to generate a deeper understanding of the biofilm formation process in bacteria.

microbiology↗