Search bioRxiv⌕ Search

bioRxiv · 10.1101/2023.08.23.554560

Red cabbage juice-mediated gut microbiota modulation improves intestinal epithelial homeostasis and ameliorates colitis

Abstract

Gut microbiota plays a crucial role in inflammatory bowel disease (IBD) and has therapeutic benefits. Thus, targeting the gut microbiota is a promising therapeutic approach for IBD treatment. We recently found that red cabbage juice (RCJ) ameliorates dextran sulfate sodium (DSS)-induced colitis in mice. However, the underlying mechanisms remain unknown. The current study investigated the modulation of gut microbiota in response to treatment with RCJ to ameliorate the DSS colitis. The initial results demonstrated that mice treated with DSS + RCJ showed increased body weight and decreased diarrhea and blood in feces compared to the DSS alone group. RCJ ameliorated colitis by regulating the intestinal barrier function by reducing the number of apoptotic cells, improving colonic protective mucin, and increasing tight junction protein in RCJ + DSS groups compared to the DSS group. Short-gun metagenomic analysis revealed significant enrichment of short-chain fatty acid (SCFAs)-producing bacteria (Butyrivibrio, Ruminococcaceae, Acetatifactor muris, Rosburia Sp. CAG:303, Dorea Sp. 5-2) increased PPAR-(C) activation, leading to repression of the nuclear factor {kappa}B (NF{kappa}B) signaling pathway, thus decreasing the production of crucial inflammatory cytokines and chemokines in the RCJ + DSS groups compared to the DSS group. Pathway abundance analysis showed an increased abundance of the SCFA pathway, reduced histidine degradation (Bacteroides sartorii, and Bacteroides caecimuris), and LCFA production in the RCJ+DSS treated group, suggesting the promotion of good colonic health. Furthermore, increased T-reg (FOXP3+) cells in the colon were due to SCFAs produced by the gut microbiota, which was corroborated by an increase in IL-10, a vital anti-inflammatory cytokine. Thus, our study provides the first evidence that RCJ ameliorates colonic inflammation by modulating the gut microbiota.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Rachagani, S., Jean Wilson, E., Sirpu Natesh, N., Ghadermazi, P., Pothuraju, R., Shanmugam, M., R. Prajapati, D., Pandey, S., T. Kaifi, J., R. Dodam, J., Bryan, J., L. Lorson, C., A. Watrelot, A., M. Foster, J., J. Mansel, T., Joshua Chan, S. H., Batra, S. K., Subbiah, J.. 2023-08-24. Red cabbage juice-mediated gut microbiota modulation improves intestinal epithelial homeostasis and ameliorates colitis. https://doi.org/10.1101/2023.08.23.554560

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

NAE1-Dependent Protein Neddylation Preserves Endothelial Identity and Vascular Integrity

Background: Endothelial dysfunction is a central driver of cardiovascular and inflammatory diseases, yet the post-translational mechanisms that preserve endothelial homeostasis remain incompletely understood. Protein neddylation, the covalent conjugation of a ubiquitin-like modifier, regulates diverse cellular processes, yet its physiological role in the vascular endothelium remains unknown. This study investigated whether protein neddylation is required to preserve endothelial identity and vascular homeostasis. Methods: We generated tamoxifen-inducible endothelial-specific Nae1 knockout mice to inhibit neddylation and combined bulk RNA sequencing, single-cell and single-nucleus transcriptomics, quantitative proteomics, biochemical analyses, and gain- and loss-of-function approaches to define the role of endothelial neddylation in vascular homeostasis and inflammatory injury. Results: Endothelial-specific Nae1 deletion caused rapid mortality associated with vascular leakage, platelet accumulation, inflammation, and multi-organ injury. Multi-omics analyses demonstrated profound loss of endothelial identity, characterized by suppression of core endothelial programs and activation of inflammatory, procoagulant, and pyroptotic pathways. Single-cell analyses revealed progressive endothelial dysfunction culminating in depletion of the endothelial population and remodeling of the vascular niche. Mechanistically, endothelial neddylation deficiency activated gasdermin D (GSDMD)- and gasdermin E (GSDME)-dependent pyroptosis, whereas dual inhibition of GSDMD and GSDME markedly attenuated inflammatory transcriptomic remodeling, vascular injury, hepatocyte death, immune cell infiltration, and platelet accumulation. Translational analyses demonstrated reduced endothelial neddylation in experimental endotoxemia and decreased expression of neddylation pathway components in human atherosclerosis and COVID-19 datasets. Conversely, restoration of endothelial neddylation partially reversed inflammatory endothelial transcriptomic reprogramming in vivo. Conclusions: NAE1-dependent protein neddylation is an essential regulator of endothelial identity and vascular integrity. Loss of endothelial neddylation promotes gasdermin-dependent pyroptosis and thrombo-inflammatory vascular injury, whereas restoration of the neddylation pathway mitigates inflammatory endothelial dysfunction. These findings identify endothelial neddylation as a fundamental mechanism maintaining vascular homeostasis and a potential therapeutic target for cardiovascular and inflammatory diseases.

pathology↗

An image segmentation pipeline optimized for human microglia uncovers sources of morphological diversity in Alzheimer's disease

Alzheimers disease (AD) is a neurodegenerative disorder characterized by cognitive decline and the accumulation of beta-amyloid plaques and neurofibrillary tangles. Microglia, the resident immune cells in the brain, play a crucial role in AD pathology, particularly in relation to amyloid plaques. However, the exact role of plaque-associated microglia and their morphological changes in AD progression remains under debate. In this study, we aimed to establish an automated image segmentation and analysis pipeline optimized for the detection of human microglia, and we assessed its utility by systematically investigating topological relationships between microglia morphology and amyloid plaques. We accessed post-mortem brain tissue samples from persons with AD and utilized immunofluorescence staining to label microglia (IBA1) and amyloid plaques (A{beta}1-42). The acquired images were processed using CellProfiler, an open-source image analysis software, to automatically segment microglia and measure their morphological features. Specifically, since activated (stage III) microglia have a condensed morphology with retracted processes, we prioritized a morphological parameter called "compactness" in our analyses to capture shape changes in microglial found in proximity to amyloid plaques. Our results revealed that microglia unassociated with plaques (Mip-) were more abundant than microglia associated with plaques (Mip+) in the Dorsolateral Prefrontal Cortex (DLPFC) of both men and women with AD. Furthermore, we observed that Mip+ exhibited a significantly more ramified shape and had a higher expression of the IBA1 microglial marker gene compared to Mip. There were no significant differences in microglia morphology between men and women. Our study highlights the utility of automated image analysis in characterizing detailed microglia morphology at the single-cell level and its relationship with AD pathology.

pathology↗

Loss of TIM4-Dependent Efferocytosis in Kupffer CellsPromotes Liver Fibrosis in Nonalcoholic Steatohepatitis

Background and aimsHepatocyte apoptosis is a key feature of non-alcoholic steatohepatitis (NASH), but the fate of apoptotic hepatocytes in NASH is poorly understood. Herein we explore the hypothesis that impaired TIM4-mediated clearance of dead hepatocytes by liver macrophages (efferocytosis) is impaired in NASH and drives the progression to liver fibrosis. MethodsKupffer cell (KC)-TIM4 expression and efferocytosis were assayed in normal and NASH liver from humans and diet-induced NASH mice. The engulfment of human and mouse apoptotic hepatocytes by primary human and mouse liver KCs was assayed ex vivo. Causation was assessed in NASH mice using anti-TIM4 antibodies, KC-TIM4-knockout, or inducible KC-TIM4 expression, with analyses focused on efferocytosis of apoptotic hepatocytes by liver macrophages and liver fibrosis. ResultsIn human and mouse NASH liver, apoptotic hepatocytes accumulated and was associated with the loss of the KC efferocytosis receptor TIM4. Anti-TIM4 inhibited the engulfment of apoptotic hepatocytes by primary human and mouse liver KCs ex vivo, and anti-TIM4 administration to early NASH mice worsened liver macrophage efferocytosis and accelerated the progression to fibrotic NASH. A similar result was obtained by genetically deleting TIM4 in KCs in NASH mice. Most importantly, genetic restoration of macrophage TIM4 in NASH mice enhanced the clearance of apoptotic hepatocytes by liver macrophages and decreased liver fibrosis. ConclusionsThe loss of macrophage TIM4 that occurs during NASH progression impairs the clearance of apoptotic hepatocytes by liver macrophages, which subsequently promotes the progression to fibrotic NASH. This pathogenic sequence of events can be prevented by restoring macrophage TIM4, suggesting that future therapeutic approaches designed to boost TIM4 expression in liver macrophages could represent a novel strategy to prevent fibrotic NASH progression. Lay summaryNonalcoholic steatohepatitis (NASH) is emerging as the leading cause of liver disease, but the processes leading to liver fibrosis in NASH, which determines clinical outcome, are incompletely understood. Our study provides evidence impaired clearance of dead liver cells by liver macrophages in NASH, which is due to loss of a macrophage receptor called TIM4, contributes to liver fibrosis. Knowledge of this process may suggest new ways to bolster the clearance of dead liver cells in NASH and thereby prevent the progression to liver fibrosis and subsequent liver disease.

pathology↗