Increasing evidence indicates that the gut microbiota can be altered to ameliorate or prevent disease states, and engineering the gut microbiota to therapeutically modulate host metabolism is an emerging goal of microbiome research. In the intestine, bacterial urease converts host-derived urea to ammonia and carbon dioxide, contributing to hyperammonemia-associated neurotoxicity and encephalopathy in patients with liver disease. Here, we engineered murine gut microbiota to reduce urease activity. Animals were depleted of their preexisting gut microbiota and then inoculated with altered Schaedler flora (ASF), a defined consortium of 8 bacteria with minimal urease gene content. This protocol resulted in establishment of a persistent new community that promoted a long-term reduction in fecal urease activity and ammonia production. Moreover, in a murine model of hepatic injury, ASF transplantation was associated with decreased morbidity and mortality. These results provide proof of concept that inoculation of a prepared host with a defined gut microbiota can lead to durable metabolic changes with therapeutic utility.
Ting-Chin David Shen, Lindsey Albenberg, Kyle Bittinger, Christel Chehoud, Ying-Yu Chen, Colleen A. Judge, Lillian Chau, Josephine Ni, Michael Sheng, Andrew Lin, Benjamin J. Wilkins, Elizabeth L. Buza, James D. Lewis, Yevgeny Daikhin, Ilana Nissim, Marc Yudkoff, Frederic D. Bushman, Gary D. Wu
Tissue homeostasis requires balanced self-renewal and differentiation of stem/progenitor cells, especially in tissues that are constantly replenished like the esophagus. Disruption of this balance is associated with pathological conditions, including eosinophilic esophagitis (EoE), in which basal progenitor cells become hyperplastic upon proinflammatory stimulation. However, how basal cells respond to the inflammatory environment at the molecular level remains undetermined. We previously reported that the bone morphogenetic protein (BMP) signaling pathway is critical for epithelial morphogenesis in the embryonic esophagus. Here, we address how this pathway regulates tissue homeostasis and EoE development in the adult esophagus. BMP signaling was specifically activated in differentiated squamous epithelium, but not in basal progenitor cells, which express the BMP antagonist follistatin. Previous reports indicate that increased BMP activity promotes Barrett’s intestinal differentiation; however, in mice, basal progenitor cell–specific expression of constitutively active BMP promoted squamous differentiation. Moreover, BMP activation increased intracellular ROS levels, initiating an NRF2-mediated oxidative response during basal progenitor cell differentiation. In both a mouse EoE model and human biopsies, reduced squamous differentiation was associated with high levels of follistatin and disrupted BMP/NRF2 pathways. We therefore propose a model in which normal squamous differentiation of basal progenitor cells is mediated by BMP-driven NRF2 activation and basal cell hyperplasia is promoted by disruption of BMP signaling in EoE.
Ming Jiang, Wei-Yao Ku, Zhongren Zhou, Evan S. Dellon, Gary W. Falk, Hiroshi Nakagawa, Mei-Lun Wang, Kuancan Liu, Jun Wang, David A. Katzka, Xiaopeng Lan, Jeffrey H. Peters, Jianwen Que
Epithelial restitution is an essential process that is required to repair barrier function at mucosal surfaces following injury. Prolonged breaches in epithelial barrier function result in inflammation and further damage; therefore, a better understanding of the epithelial restitution process has potential for improving the development of therapeutics. In this work, we demonstrate that endogenous annexin A1 (ANXA1) is released as a component of extracellular vesicles (EVs) derived from intestinal epithelial cells, and these ANXA1-containing EVs activate wound repair circuits. Compared with healthy controls, patients with active inflammatory bowel disease had elevated levels of secreted ANXA1-containing EVs in sera, indicating that ANXA1-containing EVs are systemically distributed in response to the inflammatory process and could potentially serve as a biomarker of intestinal mucosal inflammation. Local intestinal delivery of an exogenous ANXA1 mimetic peptide (Ac2-26) encapsulated within targeted polymeric nanoparticles (Ac2-26 Col IV NPs) accelerated healing of murine colonic wounds after biopsy-induced injury. Moreover, one-time systemic administration of Ac2-26 Col IV NPs accelerated recovery following experimentally induced colitis. Together, our results suggest that local delivery of proresolving peptides encapsulated within nanoparticles may represent a potential therapeutic strategy for clinical situations characterized by chronic mucosal injury, such as is seen in patients with IBD.
Giovanna Leoni, Philipp-Alexander Neumann, Nazila Kamaly, Miguel Quiros, Hikaru Nishio, Hefin R. Jones, Ronen Sumagin, Roland S. Hilgarth, Ashfaqul Alam, Gabrielle Fredman, Ioannis Argyris, Emile Rijcken, Dennis Kusters, Chris Reutelingsperger, Mauro Perretti, Charles A. Parkos, Omid C. Farokhzad, Andrew S. Neish, Asma Nusrat
Cystic fibrosis (CF) intestinal disease is associated with the pathological manifestation mucoviscidosis, which is the secretion of tenacious, viscid mucus that plugs ducts and glands of epithelial-lined organs. Goblet cells are the principal cell type involved in exocytosis of mucin granules; however, little is known about the exocytotic process of goblet cells in the CF intestine. Using intestinal organoids from a CF mouse model, we determined that CF goblet cells have altered exocytotic dynamics, which involved intrathecal granule swelling that was abruptly followed by incomplete release of partially decondensated mucus. Some CF goblet cells exhibited an ectopic granule location and distorted cellular morphology, a phenotype that is consistent with retrograde intracellular granule movement during exocytosis. Increasing the luminal concentration of bicarbonate, which mimics CF transmembrane conductance regulator–mediated anion secretion, increased spontaneous degranulation in WT goblet cells and improved exocytotic dynamics in CF goblet cells; however, there was still an apparent incoordination between granule decondensation and exocytosis in the CF goblet cells. Compared with those within WT goblet cells, mucin granules within CF goblet cells had an alkaline pH, which may adversely affect the polyionic composition of the mucins. Together, these findings indicate that goblet cell dysfunction is an epithelial-autonomous defect in the CF intestine that likely contributes to the pathology of mucoviscidosis and the intestinal manifestations of obstruction and inflammation.
Jinghua Liu, Nancy M. Walker, Akifumi Ootani, Ashlee M. Strubberg, Lane L. Clarke
The intracellular protein HMGB1 is released from cells and acts as a damage-associated molecular pattern molecule during many diseases, including inflammatory bowel disease (IBD); however, the intracellular function of HMGB1 during inflammation is poorly understood. Here, we demonstrated that cytosolic HMGB1 regulates apoptosis by protecting the autophagy proteins beclin 1 and ATG5 from calpain-mediated cleavage during inflammation. Colitis in mice with an intestinal epithelial cell–specific
Xiaorong Zhu, Jeannette S. Messer, Yunwei Wang, Fanfei Lin, Candace M. Cham, Jonathan Chang, Timothy R. Billiar, Michael T. Lotze, David L. Boone, Eugene B. Chang
Satiety and other core physiological functions are modulated by sensory signals arising from the surface of the gut. Luminal nutrients and bacteria stimulate epithelial biosensors called enteroendocrine cells. Despite being electrically excitable, enteroendocrine cells are generally thought to communicate indirectly with nerves through hormone secretion and not through direct cell-nerve contact. However, we recently uncovered in intestinal enteroendocrine cells a cytoplasmic process that we named neuropod. Here, we determined that neuropods provide a direct connection between enteroendocrine cells and neurons innervating the small intestine and colon. Using cell-specific transgenic mice to study neural circuits, we found that enteroendocrine cells have the necessary elements for neurotransmission, including expression of genes that encode pre-, post-, and transsynaptic proteins. This neuroepithelial circuit was reconstituted in vitro by coculturing single enteroendocrine cells with sensory neurons. We used a monosynaptic rabies virus to define the circuit’s functional connectivity in vivo and determined that delivery of this neurotropic virus into the colon lumen resulted in the infection of mucosal nerves through enteroendocrine cells. This neuroepithelial circuit can serve as both a sensory conduit for food and gut microbes to interact with the nervous system and a portal for viruses to enter the enteric and central nervous systems.
Diego V. Bohórquez, Rafiq A. Shahid, Alan Erdmann, Alex M. Kreger, Yu Wang, Nicole Calakos, Fan Wang, Rodger A. Liddle
Metaplasia can result when injury reactivates latent developmental signaling pathways that determine cell phenotype. Barrett’s esophagus is a squamous-to-columnar epithelial metaplasia caused by reflux esophagitis. Hedgehog (Hh) signaling is active in columnar-lined, embryonic esophagus and inactive in squamous-lined, adult esophagus. We showed previously that Hh signaling is reactivated in Barrett’s metaplasia and overexpression of Sonic hedgehog (SHH) in mouse esophageal squamous epithelium leads to a columnar phenotype. Here, our objective was to identify Hh target genes involved in Barrett’s pathogenesis. By microarray analysis, we found that the transcription factor
David H. Wang, Anjana Tiwari, Monica E. Kim, Nicholas J. Clemons, Nanda L. Regmi, William A. Hodges, David M. Berman, Elizabeth A. Montgomery, D. Neil Watkins, Xi Zhang, Qiuyang Zhang, Chunfa Jie, Stuart J. Spechler, Rhonda F. Souza
Interactions between the host and gut microbial community likely contribute to Crohn disease (CD) pathogenesis; however, direct evidence for these interactions at the onset of disease is lacking. Here, we characterized the global pattern of ileal gene expression and the ileal microbial community in 359 treatment-naive pediatric patients with CD, patients with ulcerative colitis (UC), and control individuals. We identified core gene expression profiles and microbial communities in the affected CD ilea that are preserved in the unaffected ilea of patients with colon-only CD but not present in those with UC or control individuals; therefore, this signature is specific to CD and independent of clinical inflammation. An abnormal increase of antimicrobial dual oxidase (
Yael Haberman, Timothy L. Tickle, Phillip J. Dexheimer, Mi-Ok Kim, Dora Tang, Rebekah Karns, Robert N. Baldassano, Joshua D. Noe, Joel Rosh, James Markowitz, Melvin B. Heyman, Anne M. Griffiths, Wallace V. Crandall, David R. Mack, Susan S. Baker, Curtis Huttenhower, David J. Keljo, Jeffrey S. Hyams, Subra Kugathasan, Thomas D. Walters, Bruce Aronow, Ramnik J. Xavier, Dirk Gevers, Lee A. Denson
Microvillus inclusion disease (MVID) is a severe form of congenital diarrhea that arises from inactivating mutations in the gene encoding myosin Vb (MYO5B). We have examined the association of mutations in
Byron C. Knowles, Joseph T. Roland, Moorthy Krishnan, Matthew J. Tyska, Lynne A. Lapierre, Paul S. Dickman, James R. Goldenring, Mitchell D. Shub
The protective role of hemeoxygenase-1 (HO-1) in various inflammatory conditions is mediated in part by its products, carbon monoxide (CO) and biliverdin. Here we investigated a therapeutic role for CO and CO-primed cells in acute pancreatitis (AP). In a mouse model of AP, treatment with CO-releasing molecule–2 (CORM-2) decreased mortality, pancreatic damage, and lung injury. CORM-2 decreased systemic inflammatory cytokines, suppressed systemic and pancreatic macrophage TNF-α secretion, and inhibited macrophage TLR4 receptor complex expression. In both human and mouse cells, CORM-2 inhibited endogenous and exogenous ligand-dependent TLR4 activation, which indicates that CORM-2 could be therapeutic for both early and late stages of AP, which involve sterile- and endotoxin-mediated inflammation, respectively. Mice engrafted with TLR4-deficient hematopoietic cells were protected against caerulein-induced AP. In the absence of leukocyte TLR4 expression, CORM-2 did not confer additional protection, which indicates that CORM-2–dependent effects are mediated via suppression of macrophage TLR4 activation. We determined that CO was directly responsible for the protective effects of CORM-2 in AP, as inactive forms of CORM-2 were ineffective. Importantly, adoptive transfer of CORM-2–primed cells reduced AP. Such a therapeutic approach would translate the beneficial effects of CO-based therapies, avoiding CO- or CORM-mediated toxicities in AP and a wide range of diseases.
Jing Xue, Aida Habtezion