bioRxiv Science⌕ Search

Biology subjects

Barton, M. C.

Publications and source records attributed to Barton, M. C..

2 recordsLinked to original sources

A Linkable, Polycarbonate Gut Microbiome-Distal Tumor Chip Platform for Interrogating Cancer Promoting Mechanisms

Gut microbiome composition has been tied to diseases ranging from arthritis to cancer to depression. However, mechanisms of action are poorly understood, limiting development of relevant therapeutics. Organ-on-chip platforms, which model minimal functional units of tissues and can tightly control communication between them, are ideal platforms to study these relationships. Many gut microbiome models have been published to date but devices are typically fabricated using oxygen permeable PDMS, requiring interventions to support anaerobic bacteria. To address this challenge, a novel platform was developed where the chips were fabricated entirely from gas-impermeable polycarbonate without tapes or gaskets. These chips replicated polarized villus-like structures of the native tissue. Further, they enabled co-cultures of commensal anaerobic bacteria Blautia coccoides on the surface of gut epithelia for two days within a standard incubator. Another complication of PDMS devices is high ad-/absorption, limiting applications in high-resolution microscopy and biomolecule interaction studies. For future communication studies between gut microbiota and distal tumors, an additional polycarbonate chip design was developed to support hydrogel-embedded tissue culture. These chips enable high-resolution microscopy with all relevant processing done on-chip. Designed for facile linking, this platform will make a variety of mechanistic studies possible.

bioengineering↗

P53 is not necessary for DUX4 pathology

AbstractsFSHD is a genetically dominant myopathy caused by mutations that cause expression of the normally silent DUX4 gene. This transcription factor has been shown to interfere with myogenesis when misexpressed at very low levels in myoblasts, and to cause cell death when overexpressed at high levels. A previous report using adeno-associated virus to deliver high levels of DUX4 to mouse skeletal muscle demonstrated severe pathology that was suppressed on a p53 knockout background, implying that DUX4 acted through the p53 pathway. Here, we investigate the p53-dependence of DUX4 using both in vitro cellular and the transgenic iDUX4[2.7] mouse models. We find that inhibiting p53 has no effect on the cytoxicity of DUX4 in vitro. When crossed onto the p53 null background, we find no suppression of the male-specific lethality or skin phenotypes of the DUX4 transgene, and find that primary myoblasts from this mouse are still killed by DUX4 expression. These data challenge the notion that the p53 pathway is central to the pathogenicity of DUX4.\n\nSummary StatementDUX4 is thought to mediate cytopathology through p53. Here, DUX4 is shown to kill primary myoblasts and promote pathological phenotypes in the iDUX4[2.7] mouse model on the p53-null background, calling into question this notion.

genetics↗