The Role of E3 Ubiquitin Ligases and Deubiquitinases in Inflammatory Bowel Disease: Friend or Foe?

Inflammatory bowel disease (IBD), which include Crohn's disease (CD) and ulcerative colitis (UC), exhibits a complex multifactorial pathogenesis involving genetic susceptibility, imbalance of gut microbiota, mucosal immune disorder and environmental factors. Recent studies reported associations between ubiquitination and deubiquitination and the occurrence and development of inflammatory bowel disease. Ubiquitination modification, one of the most important types of post-translational modifications, is a multi-step enzymatic process involved in the regulation of various physiological processes of cells, including cell cycle progression, cell differentiation, apoptosis, and innate and adaptive immune responses. Alterations in ubiquitination and deubiquitination can lead to various diseases, including IBD. Here, we review the role of E3 ubiquitin ligases and deubiquitinases (DUBs) and their mediated ubiquitination and deubiquitination modifications in the pathogenesis of IBD. We highlight the importance of this type of posttranslational modification in the development of inflammation, and provide guidance for the future development of targeted therapeutics in IBD.

Digestive Inflammation: Role of Proteolytic Dysregulation.

Dysregulation of the proteolytic balance is often associated with diseases. Serine proteases and matrix metalloproteases are involved in a multitude of biological processes and notably in the inflammatory response. Within the framework of digestive inflammation, several studies have stressed the role of serine proteases and matrix metalloproteases (MMPs) as key actors in its pathogenesis and pointed to the unbalance between these proteases and their respective inhibitors. Substantial efforts have been made in developing new inhibitors, some of which have reached clinical trial phases, notwithstanding that unwanted side effects remain a major issue. However, studies on the proteolytic imbalance and inhibitors conception are directed toward host serine/MMPs proteases revealing a hitherto overlooked factor, the potential contribution of their bacterial counterpart. In this review, we highlight the role of proteolytic imbalance in human digestive inflammation focusing on serine proteases and MMPs and their respective inhibitors considering both host and bacterial origin.

Regulation of inflammation by the antioxidant haem oxygenase 1.

Haem oxygenase 1 (HO-1), an inducible enzyme responsible for the breakdown of haem, is primarily considered an antioxidant, and has long been overlooked by immunologists. However, research over the past two decades in particular has demonstrated that HO-1 also exhibits numerous anti-inflammatory properties. These emerging immunomodulatory functions have made HO-1 an appealing target for treatment of diseases characterized by high levels of chronic inflammation. In this Review, we present an introduction to HO-1 for immunologists, including an overview of its roles in iron metabolism and antioxidant defence, and the factors which regulate its expression. We discuss the impact of HO-1 induction in specific immune cell populations and provide new insights into the immunomodulation that accompanies haem catabolism, including its relationship to immunometabolism. Furthermore, we highlight the therapeutic potential of HO-1 induction to treat chronic inflammatory and autoimmune diseases, and the issues faced when trying to translate such therapies to the clinic. Finally, we examine a number of alternative, safer strategies that are under investigation to harness the therapeutic potential of HO-1, including the use of phytochemicals, novel HO-1 inducers and carbon monoxide-based therapies.

Intestinal Inflammation Modulates the Expression of ACE2 and TMPRSS2 and Potentially Overlaps With the Pathogenesis of SARS-CoV-2-related Disease.

BACKGROUND AND AIMS: The presence of gastrointestinal symptoms and high levels of viral RNA in the stool suggest active severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication within enterocytes. METHODS: Here, in multiple, large cohorts of patients with inflammatory bowel disease (IBD), we have studied the intersections between Coronavirus Disease 2019 (COVID-19), intestinal inflammation, and IBD treatment. RESULTS: A striking expression of ACE2 on the small bowel enterocyte brush border supports intestinal infectivity by SARS-CoV-2. Commonly used IBD medications, both biologic and nonbiologic, do not significantly impact ACE2 and TMPRSS2 receptor expression in the uninflamed intestines. In addition, we have defined molecular responses to COVID-19 infection that are also enriched in IBD, pointing to shared molecular networks between COVID-19 and IBD. CONCLUSIONS: These data generate a novel appreciation of the confluence of COVID-19- and IBD-associated inflammation and provide mechanistic insights supporting further investigation of specific IBD drugs in the treatment of COVID-19. Preprint doi: https://doi.org/10.1101/2020.05.21.109124.

Tyrosine Kinase 2 Signalling Drives Pathogenic T cells in Colitis.

BACKGROUND AND AIMS: Tyrosine kinase 2 [TYK2] is required for the signalling of key cytokines in the pathogenesis of inflammatory bowel disease [IBD]. We assessed the efficacy of a novel selective TYK2 inhibitor [TYK2i] in experimental colitis, using pharmacological and genetic tools. METHODS: At onset of T cell transfer colitis, RAG1-/- mice received vehicle or TYK2i daily by oral gavage. T cells lacking TYK2 kinase activity [TYK2KE] were used to confirm selectivity of the inhibitor. To this end, RAG1-/- or RAG1-/-TYK2KE animals were transferred with either wild type [WT] or TYK2KE-CD45RBhigh colitogenic T cells. Loss of body weight, endoscopic disease, the disease activity index [DAI], and histopathology scores were recorded. Tissues were analysed ex vivo for lymphocyte populations by flow cytometry. The impact of TYK2 inhibition on human DC-T cell interactions were studied using autologous Revaxis specific T cell assays. RESULTS: TYK2i [70 mg/kg] prevented weight loss and limited endoscopic activity during T cell transfer colitis. TYK2i [70 mg/kg] decreased DAI. Whereas transfer of WT T cells into RAG-/-TYK2KE hosts induced colitis, TYK2KE T cells transferred into RAG1-/-TYK2KErecipients failed to do so. Ex vivo analysis showed a decrease in colon tissue Th1 cells and an increase in Th17 cells upon transfer of TYK2KE-CD45RBhigh cells. In human antigen-triggered T cells, TYK2i displayed reduced Th1 differentiation, similar to murine Th1 cells. CONCLUSIONS: Oral administration of TYK2i, as well as transfer of T cells lacking TYK2 activity, reduced human Th1 differentiation and ameliorated the course of murine T cell transfer colitis. We conclude that TYK2 is a promising drug target for the treatment of IBD.

ACE2 contributes to the maintenance of mouse epithelial barrier function.

BACKGROUND: The whole world was hit hard by the coronavirus disease-19 (COVID-19). Given that angiotensin I converting enzyme 2 (ACE2) is the viral entry molecule, understanding ACE2 has become a major focus of current COVID-19 research. ACE2 is highly expressed in the gut, but its role has not been fully understood and thus COVID-19 treatments intending to downregulate ACE2 level may cause untoward side effects. Gaining insight into the functions of ACE2 in gut homeostasis therefore merits closer examination, and is beneficial to find potential therapeutic alternatives for COVID-19. METHODS: We took advantage of Ace2 knockout out mice and isolated intestinal organoids to examine the role of ACE2 in intestinal stemness. Inflammatory bowel disease (IBD) mouse model was established by 4% dextran sodium sulfate. LGR5 and KI67 levels were quantitated to reflect the virtue of intestinal stem cells (ISCs). FITC-dextran 4 (FD-4) assay was used to assess intestinal barrier function. RESULTS: Western blotting identified the expression of ACE2 in colon, which was consistent with the results of immunofluorescence and RT-PCR. Moreover, Ace2-/- organoids showed decreased LRG5 and KI67 levels, and elevated calcium concentration. Furthermore, the permeability of ace2-/- organoids was markedly increased compared with ace2+/+ organoids. Collectively, ace2-/- mice were more susceptible than ace2+/+ mice to IBD, including earlier bloody stool, undermined intestinal architecture and more pronounced weight loss. CONCLUSIONS: Our data reveal that ACE2 contributes to the proliferation of intestinal stem cells and hence orchestrates the mucosal homeostasis.

Serum Cholinesterases, a Novel Marker of Clinical Activity in Inflammatory Bowel Disease: A Retrospective Case-Control Study.

BACKGROUND: The aim of our study was to investigate whether serum cholinesterase (ChE) levels were associated with inflammatory bowel disease (IBD). MATERIALS AND METHODS: We conducted a retrospective case-control study to clarify the relationship between serum ChE levels and IBD that included 142 patients with ulcerative colitis (UC), 60 patients with Crohn's disease (CD), and 264 healthy controls (HCs). We used ROC curves to evaluate the diagnostic value of serum ChE levels for IBD. RESULTS: Substantially lower serum ChE levels were detected in patients with UC than in HCs (6376 U/L versus 8418 U/L, P < 0.001) and in patients with CD than in HCs (5181 U/L versus 8418 U/L, P < 0.001). Additionally, patients with CD displayed significantly lower serum ChE levels than patients with UC (5181 U/L versus 6376 U/L, P < 0.01). We also found that there was a negative association between serum ChE levels and the Crohn's Disease Activity Index (CDAI) score of patients with CD (P = 0.011) and the Simple Clinical Colitis Activity Index (SCCAI) score of patients with UC (P = 0.018). The area under the curve (AUC) for serum ChE for the diagnosis of IBD was 0.826, and the AUCs of serum ChE for the diagnosis of CD and UC were 0.890 and 0.800, respectively. CONCLUSIONS: Serum ChE levels have important clinical significance in the diagnosis and assessment of clinical activity in patients with IBD, and the cholinergic anti-inflammatory pathway may provide new ideas for targeted treatment of IBD.

Dual role of sirtuin 1 in inflammatory bowel disease.

Silent information regulator-1 (SIRT-1), is a member of the class III group of histone deacetylases and is collectively called sirtuins. There have been preclinical and clinical studies indicating the downregulation and decreased activity of sirtuin 1 in various inflammatory bowel disease models. Furthermore, the downregulation of sirtuin 1 is responsible for the sustained production of proinflammatory cytokines and the generation of oxidative stress in colitis. Hyperacetylation of NF-κB and HSF-1 (heat shock factor-1) in the absence of sirtuin1 is responsible for the induction of colitis. Accordingly, exogenous administration of sirtuin1 activators has been shown to attenuate the colitis in various inflammatory bowel disease models. On the other hand, the knockdown of sirtuin 1 gene or pharmacologic inhibition of sirtuin 1 has also been shown to be protective in the colitis. The deletion of the sirtuin1 gene may be helpful in the improvement of the disease condition of colitis through the maintenance of gastrointestinal immune homeostasis. The current review highlights the dual role of sirtuin 1 in the different experimental models of IBD along with possible mechanisms.

Detecting Basal Myeloperoxidase Activity in Living Systems with a Near-Infrared Emissive "Turn-On" Probe.

Detecting myeloperoxidase (MPO) activity in living organisms is important because MPO contributes to the pathogenesis of many diseases such as rheumatoid arthritis and other inflammatory diseases, artherosclerosis, neurodegenerative disease, and some cancers. However, rapid and effective methods for the detection of basal MPO activity in living systems have not yet been reported. Herein, we report a near-infrared (NIR) emissive "turn-on" probe FD-301 that can specifically bind to MPO and accurately measure MPO activity in living cells and in vivo via a rapid response to initial hypochlorous acid (HOCl), produced by MPO. Notably, FD-301 could detect the basal level of MPO activity in human promyelocytic leukemia cells (HL-60) and could discriminate between MPO high-expression and low-expression cells. Furthermore, FD-301 was successfully applied to in vivo imaging of MPO in MPO-dependent diseases, such as arthritis and inflammatory bowel disease.

PTPN2 Regulates Interactions Between Macrophages and Intestinal Epithelial Cells to Promote Intestinal Barrier Function.

BACKGROUND & AIMS: The mechanisms by which macrophages regulate intestinal epithelial cell (IEC) barrier properties are poorly understood. Protein tyrosine phosphatase non-receptor type 2 (PTPN2) protects the IEC barrier from inflammation-induced disruption and regulates macrophage functions. We investigated whether PTPN2 controls interactions between IECs and macrophages to maintain intestinal barrier function. METHODS: Human IEC (Caco-2BBe/HT-29.cl19a cells) and mouse enteroid monolayers were cocultured with human macrophages (THP-1, U937, primary monocyte-derived macrophages from patients with inflammatory bowel disease [IBD]) or mouse macrophages, respectively. We assessed barrier function (transepithelial electrical resistance [TEER] and permeability to 4-kDa fluorescently labeled dextran or 70-kDa rhodamine B-dextran) and macrophage polarization. We analyzed intestinal tissues from mice with myeloid cell-specific deletion of PTPN2 (Ptpn2-LysMCre mice) and mice without disruption of Ptpn2 (controls); some mice were given injections of a neutralizing antibody against interleukin (IL) 6. Proteins were knocked down in macrophages and/or IECs with small hairpin RNAs. RESULTS: Knockdown of PTPN2 in either macrophages and/or IECs increased the permeability of IEC monolayers, had a synergistic effect when knocked down from both cell types, and increased the development of inflammatory macrophages in macrophage-IEC cocultures. Colon lamina propria from Ptpn2-LysMCre mice had significant increases in inflammatory macrophages; these mice had increased in vivo and ex vivo colon permeability to 4-kDa fluorescently labeled dextran and reduced ex vivo colon TEER. Nanostring analysis showed significant increases in the expression of IL6 in colon macrophages from Ptpn2-LysMCre mice. An IL6-blocking antibody reversed the effects of PTPN2-deficient macrophages, reducing the permeability of IEC monolayers in culture and in Ptpn2-LysMCre mice. Macrophages from patients with IBD carrying a single-nucleotide polymorphism associated with the disease (PTPN2 rs1893217) had the same features of PTPN2-deficient macrophages from mice, including reduced TEER and increased permeability in cocultures with human IEC or mouse enteroid monolayers, which were restored by anti-IL6. CONCLUSIONS: PTPN2 is required for interactions between macrophages and IECs; loss of PTPN2 from either cell type results in intestinal barrier defects, and loss from both cell types has a synergistic effect. We provide a mechanism by which the PTPN2 gene variants compromise intestinal epithelial barrier function and increase the risk of inflammatory disorders such as IBD.

Dextran Sodium Sulfate-Induced Impairment of Protein Trafficking and Alterations in Membrane Composition in Intestinal Caco-2 Cell Line.

A key morphological feature of inflammatory bowel disease (IBD) is the loss of the barrier function of intestinal epithelial cells. The present study investigates endoplasmic reticulum (ER) stress in addition to alterations in protein and membrane trafficking in a dextran sulfate sodium (DSS)-induced IBD-like phenotype of intestinal Caco-2 cells in culture. DSS treatment significantly reduced the transepithelial electric resistance (TEER) and increased the epithelial permeability of Caco-2 cells, without affecting their viability. This was associated with an alteration in the expression levels of inflammatory factors in addition to an increase in the expression of the ER stress protein markers, namely immunoglobulin-binding protein (BiP), C/EBP homologous protein (CHOP), activation transcription factor 4 (ATF4), and X-box binding protein (XBP1). The DSS-induced ER-stress resulted in impaired intracellular trafficking and polarized sorting of sucrase-isomaltase (SI) and dipeptidyl peptidase-4 (DPPIV), which are normally sorted to the apical membrane via association with lipid rafts. The observed impaired sorting was caused by reduced cholesterol levels and subsequent distortion of the lipid rafts. The data presented confirm perturbation of ER homeostasis in DSS-treated Caco-2 cells, accompanied by impairment of membrane and protein trafficking resulting in altered membrane integrity, cellular polarity, and hence disrupted barrier function.

Janus Kinase inhibitors in the New Treatment Paradigms of Inflammatory Bowel Disease.

This review provides guidance in the decision-making process regarding when to choose a janus kinase [JAK] inhibitor as medical treatment strategy. The focus will be on ulcerative colitis, because the only yet available JAK inhibitor, tofacitinib, has approval for use in ulcerative colitis. The guidance path will include consideration of disease activity, previous treatment, comorbidities, family planning, patient preferences, pharmacology as well as concurrent chronic inflammatory diseases or extraintestinal manifestations. The suggested guidance path illustrates our daily difficulties in the decision-making process regarding best choice for the individual patient. However if predictive biomarkers are lacking, the named criteria can be applied to any other strategy and hence provide support in daily practice.

Targeting Mitogen-Activated Protein Kinases by Natural Products: A Novel Therapeutic Approach for Inflammatory Bowel Diseases.

An increase in the prevalence of Inflammatory Bowel Diseases (IBD) as a multifactorial intestinal chronic inflammation as well as the absence of a certain cure, has created an innovative era in the management of IBD by molecule/pathway-based anti-inflammatory approaches. There are credible documentations that demonstrate Mitogen-Activated Protein Kinases (MAPK) acts as IBD regulator. Upon the activation of MAPK signalling pathway, the transcription and expression of various encoding inflammatory molecules implicated in IBD are altered, thereby exacerbating the inflammation development. The current pharmacological management of IBD, including drug and biological therapies are expensive, possess temporary relief and some adverse effects. In this context, a variety of dietary fruits or medicinal herbs have received worldwide attention versus the development of IBD. Infact, natural ingredients, such as Flavaglines, Fisetin, Myricitrin, Cardamonin, Curcumin, Octacosanol and Mangiferin possess protective and therapeutic effects against IBD via modulation of different segments of MAPK signaling pathway. This review paper calls attention to the role of MAPK signaling triggered by natural products in the prevention and treatment of IBD.

Inflammatory Bowel Disease in Children with Elevated Serum Gamma Glutamyltransferase Levels.

OBJECTIVE: To assess the characteristics of inflammatory bowel disease and disease prognosis among children with elevated gamma glutamyltransferase (GGT) and primary sclerosing cholangitis (PSC)-ulcerative colitis (UC). STUDY DESIGN: Our longitudinal, population-based cohort comprised all children and young adults diagnosed with UC in the Canadian province of Manitoba between 2011 and 2018. Diagnosis of PSC was confirmed based on a combination of cholestatic biochemical markers and cholangiographic features. The Fisher exact test with Bonferroni correction was used to examine the relationship between categorical variables. RESULTS: We enrolled 95 children with UC/Inflammatory bowel disease-unclassified with a median age at diagnosis of 14 years (IQR: 10.4-15.9 years) and 1399 person-years follow-up. Among them, 9 children developed PSC-UC, with an incidence rate of 6.43 new cases per 1000 person-years. In this cohort, 8 (72.7%) of 11 children with high baseline serum GGT levels developed PSC-UC in comparison with 1 (1.2%) of 84 children with normal serum GGT levels at baseline (P < .001). All children with high serum GGT levels at diagnosis had pancolitis in comparison with 63.9% of children with normal serum GGT levels (P = .01). Children with high serum GGT levels were more likely to be perinuclear neutrophil antibodies-positive than those with normal levels (90.9% vs 52.0%, P = .01). CONCLUSIONS: Our findings indicated that pediatric patients with UC and with even mild elevations of serum GGT levels, especially at baseline, might be predisposed to develop PSC.

Pyruvate kinase M2: A simple molecule with complex functions.

Pyruvate kinase M2 is a critical enzyme that regulates cell metabolism and growth under different physiological conditions. In its metabolic role, pyruvate kinase M2 catalyzes the last glycolytic step which converts phosphoenolpyruvate to pyruvate with the generation of ATP. Beyond this metabolic role in glycolysis, PKM2 regulates gene expression in the nucleus, phosphorylates several essential proteins that regulate major cell signaling pathways, and contribute to the redox homeostasis of cancer cells. The expression of PKM2 has been demonstrated to be significantly elevated in several types of cancer, and the overall inflammatory response. The unusual pattern of PKM2 expression inspired scientists to investigate the unrevealed functions of PKM2 and the therapeutic potential of targeting PKM2 in cancer and other disorders. Therefore, the purpose of this review is to discuss the mechanistic and therapeutic potential of targeting PKM2 with the focus on cancer metabolism, redox homeostasis, inflammation, and metabolic disorders. This review highlights and provides insight into the metabolic and non-metabolic functions of PKM2 and its relevant association with health and disease.

Epithelial Indoleamine 2,3-Dioxygenase 1 Modulates Aryl Hydrocarbon Receptor and Notch Signaling to Increase Differentiation of Secretory Cells and Alter Mucus-Associated Microbiota.

BACKGROUND & AIMS: Inflammation, injury, and infection up-regulate expression of the tryptophan metabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1) in the intestinal epithelium. We studied the effects of cell-specific IDO1 expression in the epithelium at baseline and during intestinal inflammation in mice. METHODS: We generated transgenic mice that overexpress fluorescence-tagged IDO1 in the intestinal epithelium under control of the villin promoter (IDO1-TG). We generated intestinal epithelial spheroids from mice with full-length Ido1 (controls), disruption of Ido1 (knockout mice), and IDO1-TG and analyzed them for stem cell and differentiation markers by real-time polymerase chain reaction, immunoblotting, and immunofluorescence. Some mice were gavaged with enteropathogenic Escherichia coli (E2348/69) to induce infectious ileitis, and ileum contents were quantified by polymerase chain reaction. Separate sets of mice were given dextran sodium sulfate or 2,4,6-trinitrobenzenesulfonic acid to induce colitis; intestinal tissues were analyzed by histology. We utilized published data sets GSE75214 and GDS2642 of RNA expression data from ilea of healthy individuals undergoing screening colonoscopies (controls) and patients with Crohn's disease. RESULTS: Histologic analysis of small intestine tissues from IDO1-TG mice revealed increases in secretory cells. Enteroids derived from IDO1-TG intestine had increased markers of stem, goblet, Paneth, enteroendocrine, and tuft cells, compared with control enteroids, with a concomitant decrease in markers of absorptive cells. IDO1 interacted non-enzymatically with the aryl hydrocarbon receptor to inhibit activation of NOTCH1. Intestinal mucus layers from IDO1-TG mice were 2-fold thicker than mucus layers from control mice, with increased proportions of Akkermansia muciniphila and Mucispirillum schaedleri. Compared to controls, IDO1-TG mice demonstrated an 85% reduction in ileal bacteria (P = .03) when challenged with enteropathogenic E coli, and were protected from immune infiltration, crypt dropout, and ulcers following administration of dextran sodium sulfate or 2,4,6-trinitrobenzenesulfonic acid. In ilea of Crohn's disease patients, increased expression of IDO1 correlated with increased levels of MUC2, LYZ1, and aryl hydrocarbon receptor, but reduced levels of SLC2A5. CONCLUSIONS: In mice, expression of IDO1 in the intestinal epithelial promotes secretory cell differentiation and mucus production; levels of IDO1 are positively correlated with secretory cell markers in ilea of healthy individuals and Crohn's disease patients. We propose that IDO1 contributes to intestinal homeostasis.

Dihydroartemisinin Regulates the Th/Treg Balance by Inducing Activated CD4+ T cell Apoptosis via Heme Oxygenase-1 Induction in Mouse Models of Inflammatory Bowel Disease.

Dihydroartemisinin (DHA) is a derivative of the herb Artemisia annua L. that has prominent immunomodulatory activity; however, its underlying mechanism remains elusive. Inflammatory bowel disease (IBD) is an idiopathic inflammatory condition characterized as an autoimmune disorder that includes dysfunctions in the T helper (Th)/T regulatory cell (Treg) balance, which normally plays pivotal roles in immune homeostasis. The aim of this study was to explore the potential of DHA to ameliorate IBD by restoring the Th/Treg cell balance. To this end, we established mouse models of colitis induced by oxazolone (OXA) and 2,4,6-trinitro-benzene sulfonic acid (TNBS). We then treated mice with DHA at 4, 8, or 16 mg/kg/day. DHA treatment ameliorated colitis signs and reduced lymphocyte infiltration and tissue fibrosis. Moreover, DHA decreased the numbers of Th1 and Th17 cells and Th9 and Th22 cells in TNBS- or OXA-induced colitis, respectively, and increased Tregs in both models. DHA (0.8 mg/mL) also inhibited activated CD4+ T lymphocytes, which was accompanied by apoptosis induction. Moreover, it promoted heme oxygenase-1 (HO-1) production in vitro and in vivo, concomitant with CD4+ T cell apoptosis and restoration of the Th/Treg balance, and these effects were blocked by treatment with the HO-1 inhibitor Sn-protoporphyrin IX. Overall, these results suggest that DHA is a novel and valuable candidate for IBD therapy or Th/Treg immunoregulation.

Ectonucleotidases in Intestinal and Hepatic Inflammation.

Purinergic signaling modulates systemic and local inflammatory responses. Extracellular nucleotides, including eATP, promote inflammation, at least in part via the inflammasome upon engagement of P2 purinergic receptors. In contrast, adenosine generated during eATP phosphohydrolysis by ectonucleotidases, triggers immunosuppressive/anti-inflammatory pathways. Mounting evidence supports the role of ectonucleotidases, especially ENTPD1/CD39 and CD73, in the control of several inflammatory conditions, ranging from infectious disease, organ fibrosis to oncogenesis. Our experimental data generated over the years have indicated both CD39 and CD73 serve as pivotal regulators of intestinal and hepatic inflammation. In this context, immune cell responses are regulated by the balance between eATP and adenosine, potentially impacting disease outcomes as in gastrointestinal infection, inflammatory bowel disease, ischemia reperfusion injury of the bowel and liver, autoimmune or viral hepatitis and other inflammatory conditions, such as cancer. In this review, we report the most recent discoveries on the role of ENTPD1/CD39, CD73, and other ectonucleotidases in the regulation of intestinal and hepatic inflammation. We discuss the present knowledge, highlight the most intriguing and promising experimental data and comment on important aspects that still need to be addressed to develop purinergic-based therapies for these important illnesses.