Related Experiment Video
Updated: Oct 22, 2025
Visualization of Neutrophil Extracellular Traps in Mesenteric Venules After Mesenteric Ischemia-Reperfusion Injury via Intravital Microscopy
Published on: September 27, 2024
Colonization with Altered Schaedler Flora Impacts Leukocyte Adhesion in Mesenteric Ischemia-Reperfusion Injury
Franziska Bayer1, Stefanie Ascher1,2, Klytaimnistra Kiouptsi1
1Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg-University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany.
Abstract:
The microbiota impacts mesenteric ischemia-reperfusion injury, aggravating the interaction of leukocytes with endothelial cells in mesenteric venules. The role of defined gut microbiomes in this life-threatening pathology is unknown. To investigate how a defined model microbiome affects the adhesion of leukocytes in mesenteric ischemia-reperfusion, we took advantage of gnotobiotic isolator technology and transferred altered Schaedler flora (ASF) from C3H/HeNTac to germ-free C57BL/6J mice. We were able to detect all eight bacterial taxa of ASF in fecal samples of colonized C57BL/6J mice by PCR. Applying qRT-PCR for quantification of species-specific 16S rDNA sequences of ASF bacteria, we found a major shift in the abundance of ASF 500, which was greater in C57BL/6J mice relative to the C3H/HeNTac founder breeding pair. Using high-speed epifluorescence intravital microscopy to visualize the venules of the small bowel mesentery, we found that gnotobiotic ASF-colonized mice showed reduced leukocyte adherence, both pre- and post-ischemia. Relative to germ-free mice, the counts of adhering leukocytes were increased pre-ischemia but did not significantly increase in ASF-colonized mice in the post-ischemic state. Collectively, our results suggest a protective role of the minimal microbial consortium ASF in mesenteric ischemia-reperfusion injury.
Insights
A minimal gut microbiome consortium, altered Schaedler flora (ASF), protects against mesenteric ischemia-reperfusion injury by reducing leukocyte adhesion in mice. This suggests a protective role for defined gut microbiomes in this condition.
Area of Science:
- Gastroenterology
- Immunology
- Microbiology
Background:
- The gut microbiota influences mesenteric ischemia-reperfusion injury.
- The specific role of defined gut microbiomes in this pathology remains unclear.
Purpose of the Study:
- To investigate the effect of a defined model microbiome, altered Schaedler flora (ASF), on leukocyte adhesion during mesenteric ischemia-reperfusion injury.
- To explore the protective potential of a minimal microbial consortium in this condition.
Main Methods:
- Utilized gnotobiotic isolator technology to colonize germ-free C57BL/6J mice with ASF.
- Employed PCR and qRT-PCR to confirm ASF colonization and quantify bacterial taxa abundance.
- Applied high-speed epifluorescence intravital microscopy to visualize leukocyte-endothelial cell interactions in mesenteric venules pre- and post-ischemia.
Main Results:
- ASF colonization was confirmed in C57BL/6J mice, with a notable shift in the abundance of ASF 500.
- Gnotobiotic ASF-colonized mice exhibited reduced leukocyte adherence in mesenteric venules compared to germ-free controls, both before and after ischemia.
- While leukocyte counts increased pre-ischemia in ASF-colonized mice, they did not significantly rise post-ischemia, unlike in germ-free mice.
Conclusions:
- The minimal microbial consortium, ASF, demonstrates a protective role in mitigating mesenteric ischemia-reperfusion injury.
- Defined gut microbiomes may offer a therapeutic strategy for managing this life-threatening condition.
