Biology subjects

Tran, T.

Publications and source records attributed to Tran, T..

93 records · Page 6Linked to original sources

bioRxiv2017

A simple bioreactor-based method to generate kidney organoids from pluripotent stem cells

Kidney organoids generated from human pluripotent stem cells have the potential to revolutionize how kidney development and injury are studied. Current protocols are technically complex and suffer from poor reproducibility and high reagent costs restricting scalability. To overcome these issues, we have established a simple, inexpensive and robust method to grow kidney organoids in bulk from human induced pluripotent stem cells. Our organoids develop tubular structures by day (d) 8 and show optimal tissue morphology at d14. A comparison with fetal human kidney suggests that d14 organoid renal structures most closely resemble capillary loop stage nephrons. We show that deletion of HNF1B, a transcription factor linked to congenital kidney defects, interferes with tubulogenesis, validating our experimental system for studying renal developmental biology. Taken together, our protocol provides a fast, efficient and cost-effective method for generating large quantities of human fetal kidney tissue, enabling the study of normal and aberrant human renal development.

developmental biology↗

bioRxiv2017

Identification of a Small Molecule Inhibitor of the Aminoglycoside 6’-N-Acetyltransferase Type Ib [AAC(6’)-Ib] Using Mixture-Based Combinatorial Libraries

The aminoglycoside 6'-N-acetyltransferase type Ib [AAC(6)-Ib] is the most widely distributed enzyme among AAC(6)-I-producing Gram-negative pathogens and confers resistance to clinically relevant aminoglycosides including amikacin. This enzyme is therefore ideal to target with enzymatic inhibitors that could overcome resistance to aminoglycosides. The search for inhibitors was carried out using mixture-based combinatorial libraries, the scaffold ranking approach, and the positional scanning strategy. A library with high inhibitory activity had pyrrolidine pentamine scaffold and was selected for further analysis. This library contained 738,192 compounds with functionalities derived from 26 different amino acids (R1, R2 and R3) and 42 different carboxylic acids (R4) in four R group functionalities. The most active compounds all contained S-phenyl (R1 and R3) and S-hydromethyl (R2) functionalities at three locations and differed at the R4 position. The compound containing 3-phenylbutyl at R4 (compound 206) was a robust enzymatic inhibitor in vitro, in combination with amikacin potentiated the inhibition of growth of three resistant bacteria in culture, and improved survival when used as treatment of Galleria mellonella infected with aac(6)-Ib-harboring Klebsiella pneumoniae and Acinetobacter baumannii strains.

microbiology↗

bioRxiv2017

Ionic Current Correlations Are Ubiquitous Across Phyla

Ionic currents, whether measured as conductance amplitude or as ion channel transcript levels, can vary many-fold within a population of identified neurons. This variability has been observed in multiple invertebrate neuronal types, but they do so in a coordinated manner such that their magnitudes are correlated. These conductance correlations are thought to reflect a tight homeostasis of cellular excitability that enhances the robustness and stability of neuronal activity over long stretches of time. Notably, although such ionic current correlations are well documented in invertebrates, they have not been reported in vertebrates. Here we demonstrate with two examples, identified mouse hippocampal granule cells and cholinergic basal forebrain neurons, that ionic current correlations is a ubiquitous phenomenon expressed by a number of species across phyla.

neuroscience↗