# Gut Dysbiosis and Cardiac Remodeling in IBD

> **NIH NIH R01** · UNIVERSITY OF TEXAS MED BR GALVESTON · 2020 · $653,505

## Abstract

PROJECT SUMMARY/ABSTRACT
Inflammatory bowel disease (IBD) is a debilitating and difficult to manage chronic inflammation in the digestive
tract, causing gastrointestinal symptoms such as diarrhea. It is associated with lifelong morbidity, greater medical
attention, and diminished quality of life. About 3 million Americans suffer from IBD and its huge financial burden.
Extraintestinal manifestations (EIM) of IBD are common, especially in children, and even overshadow the
intestinal symptoms. Accumulating evidence suggests that IBD is associated with an increased incidence of
cardiovascular events. However, the molecular mechanisms by which IBD predisposes patients to
cardiovascular diseases (CVD) remain elusive. In addition to chronic inflammation, a signature of IBD is
dysbiosis of the gut microbiota marked by a significant reduction of obligate anaerobes and a sharp increase in
facultative anaerobes. While inflammation could be well controlled by drug therapy or surgery, gut microbial
dysbiosis persists and may play a key role in IBD-associated CVD. We confirmed this phenomenon in murine
models of colitis, which recapitulate some common EIM of human IBD. Our preliminary findings suggest that
dysbiotic gut microbiota contributes to cardiac dysfunction by up-regulating miR-155 and down-regulating brain-
derived neurotrophic factor (BDNF), both identified as crucial players in cardiac system. We hypothesize that
colitis-induced microbiota dysbiosis triggers molecular remodeling in the adult heart through epigenetic
mechanisms. We will test the hypothesis by pursuing three specific aims. Aim 1 will establish dysbiosis as a key
player in colitis-induced heart dysfunction by transplanting dysbiotic fecal microbiota from patients with IBD and
mice with colitis to bacteria-depleted mice. We will also determine whether the disease signal can be ablated by
transplantation of normal fecal microbiota and/or probiotics. Aim 2 will focus on characterizing exosomal miR-
155 as a key player in IBD-induced molecular remodeling. We foresee that exosomal miR-155 derived
specifically from the intestinal epithelial cells (IEC) functions as a major mediator of the crosstalk between gut
microbiota and the heart. Using novel IEC-specific miR-155-knockout (Mir155ΔIEC) and Mir155ΔIEC/IL10-/- mice,
we aim to show that exosomal miR-155 of gut origin epigenetically down-regulates cardiac BDNF in the presence
of chronic colitis. We will also determine if miR-155 inhibitors mitigate IBD-induced heart diseases. In Aim 3,
epigenetic mechanisms of BDNF reduction in cardiomyocytes will be elucidated using in vivo, in vitro, and
proteomics approaches. We will characterize the functional and phenotypic roles of BDNF in the adult heart
using a novel tamoxifen-inducible, cardiac-specific BDNF knockout mouse model. We will also explore the
preventive and therapeutic potential of BDNF for IBD-associated CVD. Our results should help establish a novel
paradigm that colitis induces cardia...

## Key facts

- **NIH application ID:** 10072717
- **Project number:** 1R01HL152683-01A1
- **Recipient organization:** UNIVERSITY OF TEXAS MED BR GALVESTON
- **Principal Investigator:** Ken Fujise
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $653,505
- **Award type:** 1
- **Project period:** 2020-09-01 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10072717

## Citation

> US National Institutes of Health, RePORTER application 10072717, Gut Dysbiosis and Cardiac Remodeling in IBD (1R01HL152683-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10072717. Licensed CC0.

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