An intravital window to image the colon in real time

Abstract

Intravital microscopy is a powerful technique to observe dynamic processes with single-cell resolution in live animals. No intravital window has been developed for imaging the colon due to its anatomic location and motility, although the colon is a key organ where the majority of microbiota reside and common diseases such as inflammatory bowel disease, functional gastrointestinal disorders, and colon cancer occur. Here we describe an intravital murine colonic window with a stabilizing ferromagnetic scaffold for chronic imaging, minimizing motion artifacts while maximizing long-term survival by preventing colonic obstruction. Using this setup, we image fluorescently-labeled stem cells, bacteria, and immune cells in live animal colons. Furthermore, we image nerve activity via calcium imaging in real time to demonstrate that electrical sacral nerve stimulation can activate colonic enteric neurons. The simple implantable apparatus enables visualization of live processes in the colon, which will open the window to a broad range of studies.

Functional circuits and signal processing in the enteric nervous system

“…On the other hand, the measurement of these intestinal movements and their correlation with nerve activity may provide an informative readout. Advances in intravital abdominal imaging techniques [ 193 – 195 ] also open up further possibilities for the addressing longstanding questions on the coordination of intestinal secretion and motility. With these developments, we are well positioned in our pursuit of a more comprehensive understanding of integrated gut physiology and we anticipate interesting times ahead.…”

New technologies for developing phage-based tools to manipulate the human microbiome

“…These models are highly beneficial for studying phage kinetics as they allow unbiased and comprehensive studies of the interactions between phages and the whole mammalian body [75]. In addition, a new technique has recently been developed that allows real-time observation of cellular processes in the colon of live animals using high-resolution, chronic fluorescent imaging of the organs, tissues, and more for weeks with no pain, discomfort, or intestinal obstruction [76]. This technique can be helpful to study the phage-based modulation in diseases more relevant to the colon, such as CRC.…”

Renal subcapsular delivery of PGE2 promotes kidney repair by activating endogenous Sox9+ stem cells

“…Advances in imaging-based monitoring methods have allowed the tracking of stem cells and the evaluation of their therapeutic effects (Huang et al, 2015;Liu et al, 2020;Zhang and Li, 2020). Intravital two-photon microscopy (TPM) with an abdominal imaging window (AIW) allows monitoring of the spatiotemporal dynamics of endogenous stem cells in the processes of tissue repair at the single-cell level in living animals longitudinally for weeks using a lineage tracing animal model (Hato et al, 2017;Rakhilin et al, 2019;Zhang and Li, 2020). In this study, Sox9 + cell tracking provided new insights into the dynamic cellular processes involved in kidney regeneration with high resolution under treatment with the COL-PGE 2 matrix.…”