Collier, C. A. | Search bioRxiv

bioRxiv2025

Immune-Competent 3D Bioengineered Colons for Functional Interrogation of Neuroinflammation-Induced Colonic Dysmotility

Functional gastrointestinal disorders (FGIDs) affect [~]40% of the global population and are frequently characterized by colonic dysmotility. Symptomatic manifestations of colonic dysmotility significantly reduce quality of life in inflammatory bowel disease (IBD), diabetes, and Gulf War Illness (GWI). Current in vitro models lack the integration of functional physiology with immune and neuronal complexity required to establish causal links between neuroinflammation and dysmotility. Here, an immune-competent bioengineered colon assembloid is introduced that integrates multiple cell types of the external colonic wall, along with functional readouts of motility. Within bioengineered colon assembloids, various inflammatory insults resulted in enteric neuroinflammation, cascading to changes in colonic motility. Key mechanisms of dysmotility following inflammatory insult within the bioengineered colon assembloids included impaired neuronal regeneration, and aberrant smooth muscle remodeling. The bioengineered colon assembloid model mimicked diverse aspects of enteric neuroinflammation. Ultimately, the platform offers a physiologically relevant avenue to interrogate neuroimmune crosstalk and dissect mechanisms of colonic dysmotility, paving the way to new therapeutic strategies to improve colonic motility.

bioengineering↗

bioRxiv2024

Oncogenic KRAS Mutations Confer a Unique Mechanotransduction Response to Peristalsis in Colorectal Cancer Cells

Colorectal cancer (CRC) tumors start as precancerous polyps on the inner lining of the colon or rectum, where they are exposed to the mechanics of colonic peristalsis. Our previous work leveraged a custom-built peristalsis bioreactor to demonstrate that colonic peristalsis led to cancer stem cell enrichment in colorectal cancer cells. However, this malignant mechanotransductive response was confined to select CRC lines that harbored an oncogenic mutation in the KRAS gene. In this work, therefore, we explored the involvement of activating KRAS mutations on peristalsis-associated mechanotransduction in CRC. Peristalsis enriched the cancer stem cell marker LGR5 in KRAS mutant (G13D, etc.) lines, in a Wnt-independent manner. Conversely, LGR5 enrichment in wild type KRAS lines exposed to peristalsis were minimal. LGR5 enrichment downstream of peristalsis translated to increased tumorigenicity in vivo in KRAS mutant vs. wild type lines. Differences in mechanotransduction response was additionally apparent via unbiased gene set enrichment analysis, where many unique pathways were enriched in wild type vs. mutant lines, in response to peristalsis. Interestingly, peristalsis also triggered {beta}-catenin nuclear localization independent of Wnt, particularly in KRAS mutant lines. The central involvement of KRAS in the mechanotransductive responses was validated via gain and loss of function strategies. {beta}-catenin activation and LGR5 enrichment downstream of peristalsis converged to the activation of the MEK/ERK kinase cascade, that remains active in cells that harbor oncogenic KRAS mutations. Taken together, our results demonstrated that oncogenic KRAS mutations conferred a unique peristalsis-associated mechanotransduction response to colorectal cancer cells, resulting in cancer stem cell enrichment and increased tumorigenicity. These mechanosensory connections can be leveraged in improving the sensitivity of emerging therapies that target oncogenic KRAS.

bioengineering↗