Histologic Disease Persists beyond Mucosal Healing and Could Predict Reactivation in Ulcerative Colitis.

Mucosal healing (MH) is the main target in ulcerative colitis (UC) treatment. Even if MH lowers the risk of disease reactivation, some patients still relapse. Histologic activity (HA) beyond MH could explain these cases. This study aims to assess how many patients with MH have HA and which lesions are associated with relapse. We retrospectively enrolled UC patients showing MH, expressed as a Mayo Endoscopic Subscore (MES) of 0 and 1 upon colonoscopy. We reviewed the histological reports of biopsies evaluating the presence of typical lesions of UC and assessed the number of clinical relapses after 12 months. Among 100 enrolled patients, 2 showed no histological lesions. According to univariate analysis, patients with a higher number of histological lesions at the baseline had a higher risk of relapse (OR 1.25, p = 0.012), as well as patients with basal plasmacytosis (OR 4.33, p = 0.005), lamina propria eosinophils (OR 2.99, p = 0.047), and surface irregularity (OR 4.70, p = 0.010). However, in the multivariate analysis, only basal plasmacytosis (OR 2.98, p = 0.050) and surface irregularity (OR 4.50, p = 0.024) were confirmed as risk factors for disease reactivation. HA persists in a significant percentage of patients with MH. Despite the presence of MH, patients with basal plasmacytosis and surface irregularity have a higher risk of relapse.

Epidemiology of inflammatory bowel disease in the Republic of San Marino: The "EPIMICI - San Marino" study.

BACKGROUND: The burden of Crohn's disease (CD) and ulcerative colitis (UC) has never been estimated in the Republic of San Marino, the third smallest nation of the world. AIMS: To assess the occurrence and clinical features of CD and UC in San Marino during the last 35 years. METHODS: We retrospectively evaluated the prevalence, incidence, and main clinical aspects of CD and UC from 1980 to 2014, crossing data from various sources. RESULTS: Prevalence rates (per 100,000) on December 31, were 241 for CD (263 in males and 220 in females) and 311 for UC (370 in males and 255 in females). The specific incidence of UC steadily increased from 4.6 (95% CI: 1.5-10.6) in 1980-1984 to 12.4 (95% CI: 7.6-19.1) in 2010-2014; CD incidence showed a higher proportional increase, from 1.8 (95% CI: 0.2-6.6) in 1980-1984 to 17.9 (95% CI: 12.0-25.7) in 2010-2014. The main clinical features of CD and UC (activity and location at diagnosis, extra-intestinal manifestations, disease progression overtime, therapies, and hospitalizations) were analyzed. CONCLUSIONS: This study provides the first epidemiological report on CD and UC in San Marino, showing specific traits and overall higher prevalence and incidence rates than previously reported in neighbor Areas.

Multiparametric Evaluation Predicts Different Mid-Term Outcomes in Crohn's Disease.

AIM: To evaluate if a single and/or combined (clinical, endoscopic and radiological) assessment could predict clinical outcomes in Crohn's disease (CD). METHODS: We prospectively evaluated 57 CD cases who underwent both a colonoscopy and a CT-enterography (CTE). Harvey-Bradshaw Index (HBi), SES-CD (and/or Rutgeerts score) and the radiological disease activity were defined to stratify patients according to clinical, endoscopic and radiological disease activity respectively. Hospitalizations, surgery, therapeutic changes and deaths were evaluated up to 36 months (time 1) for 53 patients. RESULTS: CTE and endoscopy agreed in stratifying disease activity in 47% of cases (k = -0.05; p = 0.694), CTE and HBi in 35% (k = 0.09; p = 0.08), endoscopy and HBi in 39% (k = 0.13; p = 0.03). Taken together, CTE, endoscopy and HBi agreed only in 18% of cases (k = 0.01; p = 0.41). Among the 11 cases with mucosal healing, only 3 (27%) showed transmural healing. Patients with endoscopic activity needed significantly more changes of therapy compared to patients with endoscopic remission (p = 0.02). Patients with higher transmural or clinical activity at baseline required significantly more hospitalizations (p < 0.01). Hospitalization rate decreases with an increase in the number of parameters indicating remissions at baseline (p = 0.04). CONCLUSIONS: Clinical, endoscopic and radiological assessments offer complementary information and could predict different mid-term outcomes in CD.

Nodular lymphoid hyperplasia: A marker of low-grade inflammation in irritable bowel syndrome?

AIM: To evaluate the prevalence of nodular lymphoid hyperplasia (NLH) in adult patients undergoing colonoscopy and its association with known diseases. METHODS: We selected all cases showing NLH at colonoscopy in a three-year timeframe, and stratified them into symptomatic patients with irritable bowel syndrome (IBS)-type symptoms or suspected inflammatory bowel disease (IBD), and asymptomatic individuals undergoing endoscopy for colorectal cancer screening. Data collection included medical history and final diagnosis. As controls, we considered all colonoscopies performed for the aforementioned indications during the same period. RESULTS: One thousand and one hundred fifty colonoscopies were selected. NLH was rare in asymptomatic individuals (only 3%), while it was significantly more prevalent in symptomatic cases (32%). Among organic conditions associated with NLH, the most frequent was IBD, followed by infections and diverticular disease. Interestingly, 31% of IBS patients presented diffuse colonic NLH. NLH cases shared some distinctive clinical features among IBS patients: they were younger, more often female, and had a higher frequency of abdominal pain, bloating, diarrhoea, unspecific inflammation, self-reported lactose intolerance and metal contact dermatitis. CONCLUSION: About 1/3 of patients with IBS-type symptoms or suspected IBD presented diffuse colonic NLH, which could be a marker of low-grade inflammation in a conspicuous subset of IBS patients.

Circulating hematopoietic stem cells and putative intestinal stem cells in coeliac disease.

BACKGROUND: The intestinal stem cells (ISC) modulation and the role of circulating hematopoietic stem cells (HSC) in coeliac disease (CD) are poorly understood. Our aim was to investigate the longitudinal modifications in peripheral blood HSC traffic and putative ISC density induced by gluten-free diet (GFD) in CD. METHODS: Thirty-one CD patients and 7 controls were enrolled. Circulating CD133(+) and CD34(+) HSC were measured by flow cytometry, at enrolment and after 7 days and 1, 3, 6, 12, and 24 months of GFD. Endoscopy was performed at diagnosis and repeated at 6, 12, and 24 months following GFD. We used the Marsh-Oberhuber score to evaluate the histological severity of duodenal damage; immunohistochemistry was employed to measure the intraepithelial lymphoid infiltrate (IEL, CD3(+) lymphoid cells) and the putative ISC compartment (CD133(+) and Lgr5(+) epithelial cells). RESULTS: At enrolment, circulating HSCs were significantly increased in CD patients and they further augmented during the first week of GFD, but progressively decreased afterwards. CD patients presented with villous atrophy, abundant IEL and rare ISC residing at the crypt base. Upon GFD, IEL progressively decreased, while ISC density increased, peaking at 12 months. After 24 months of GFD, all patients were asymptomatic and their duodenal mucosa was macroscopically and histologically normal. CONCLUSIONS: In active CD patients, the ISC niche is depleted and there is an increased traffic of circulating HSC versus non-coeliac subjects. GFD induces a precocious mobilization of circulating HSC, which is followed by the expansion of the local ISC compartment, leading to mucosal healing and clinical remission.

The multikinase inhibitor Sorafenib enhances glycolysis and synergizes with glycolysis blockade for cancer cell killing.

Although the only effective drug against primary hepatocarcinoma, the multikinase inhibitor Sorafenib (SFB) usually fails to eradicate liver cancer. Since SFB targets mitochondria, cell metabolic reprogramming may underlie intrinsic tumor resistance. To characterize cancer cell metabolic response to SFB, we measured oxygen consumption, generation of reactive oxygen species (ROS) and ATP content in rat LCSC (Liver Cancer Stem Cells) -2 cells exposed to the drug. Genome wide analysis of gene expression was performed by Affymetrix technology. SFB cytotoxicity was evaluated by multiple assays in the presence or absence of metabolic inhibitors, or in cells genetically depleted of mitochondria. We found that low concentrations (2.5-5 µM) of SFB had a relatively modest effect on LCSC-2 or 293 T cell growth, but damaged mitochondria and increased intracellular ROS. Gene expression profiling of SFB-treated cells was consistent with a shift toward aerobic glycolysis and, accordingly, SFB cytotoxicity was dramatically increased by glucose withdrawal or the glycolytic inhibitor 2-DG. Under metabolic stress, activation of the AMP dependent Protein Kinase (AMPK), but not ROS blockade, protected cells from death. We conclude that mitochondrial damage and ROS drive cell killing by SFB, while glycolytic cell reprogramming may represent a resistance strategy potentially targetable by combination therapies.

A multicentre case control study on complicated coeliac disease: two different patterns of natural history, two different prognoses.

BACKGROUND: Coeliac disease is a common enteropathy characterized by an increased mortality mainly due to its complications. The natural history of complicated coeliac disease is characterised by two different types of course: patients with a new diagnosis of coeliac disease that do not improve despite a strict gluten-free diet (type A cases) and previously diagnosed coeliac patients that initially improved on a gluten-free diet but then relapsed despite a strict diet (type B cases). Our aim was to study the prognosis and survival of A and B cases. METHODS: Clinical and laboratory data from coeliac patients who later developed complications (A and B cases) and sex- and age-matched coeliac patients who normally responded to a gluten-free diet (controls) were collected among 11 Italian centres. RESULTS: 87 cases and 136 controls were enrolled. Complications tended to occur rapidly after the diagnosis of coeliac disease and cumulative survival dropped in the first months after diagnosis of complicated coeliac disease. Thirty-seven cases died (30/59 in group A, 7/28 in group B). Type B cases presented an increased survival rate compared to A cases. CONCLUSIONS: Complicated coeliac disease is an extremely serious condition with a high mortality and a short survival. Survival depends on the type of natural history.

Intestinal stem cells and celiac disease.

Stem cells (SCs) are the key to tissue genesis and regeneration. Given their central role in homeostasis, dysfunctions of the SC compartment play a pivotal role in the development of cancers, degenerative disorders, chronic inflammatory pathologies and organ failure. The gastrointestinal tract is constantly exposed to harsh mechanical and chemical conditions and most of the epithelial cells are replaced every 3 to 5 d. According to the so-called Unitarian hypothesis, this renewal is driven by a common intestinal stem cell (ISC) residing within the crypt base at the origin of the crypt-to-villus hierarchical migratory pattern. Celiac disease (CD) can be defined as a chronic immune-mediated disease that is triggered and maintained by dietary proteins (gluten) in genetically predisposed individuals. Many advances have been achieved over the last years in understanding of the pathogenic interactions among genetic, immunological and environmental factors in CD, with a particular emphasis on intestinal barrier and gut microbiota. Conversely, little is known about ISC modulation and deregulation in active celiac disease and upon a gluten-free diet. Nonetheless, bone marrow-derived SC transplantation has become an option for celiac patients with complicated or refractory disease. This manuscript summarizes the "state of the art" regarding CD and ISCs, their niche and potential role in the development and treatment of the disease.

Therapeutic application of stem cells in gastroenterology: an up-date.

Adult stem cells represent the self-renewing progenitors of numerous body tissues, and they are currently classified according to their origin and differentiation ability. In recent years, the research on stem cells has expanded enormously and holds therapeutic promises for many patients suffering from currently disabling diseases. This paper focuses on the possible use of stem cells in the two main clinical settings in gastroenterology, i.e., hepatic and intestinal diseases, which have a strong impact on public health worldwide. Despite encouraging results obtained in both regenerative medicine and immune-mediated conditions, further studies are needed to fully understand the biology of stem cells and carefully assess their putative oncogenic properties. Moreover, the research on stem cells arouses fervent ethical, social and political debate. The Italian Society of Gastroenterology sponsored a workshop on stem cells held in Verona during the XVI Congress of the Federation of Italian Societies of Digestive Diseases (March 6-9, 2010). Here, we report on the issues discussed, including liver and intestinal diseases that may benefit from stem cell therapy, the biology of hepatic and intestinal tissue repair, and stem cell usage in clinical trials.

Identification of Endothelin-1 and NR4A2 as CD133-regulated genes in colon cancer cells.

Several in vitro assays have been proposed to identify cancer stem cells (CSCs), including immunophenotyping, sphere assay and side population (SP) assay. CD133 antigen has been proposed as a CSC marker in colon cancer (CC). However, no functional data are available to date and conflicting results have been reported regarding its role as true CSC marker. Here we set out to identify a molecular signature associated with potential CSC. CD133(+) cells isolated from the CaCo-2 CC cell line were analysed by microarray molecular profiling compared to CD133(-) counterparts. Various differentially expressed genes were identified and the most relevant transcripts found to be over-expressed in CD133(+) cells were evaluated by quantitative RT-PCR in the CD133(+) fractions isolated from several CC cell lines. In the attempt to find a correlation between putative CSCs, isolated by means of CD133 immunophenotyping and the SP approach, we demonstrated a significant enrichment of CD133(+) cells within the SP fraction of CC cells, and comparison of the gene expression profiles revealed that Endothelin-1 (END-1) and nuclear receptor subfamily 4, group A, member 2 (NR4A2) transcripts are highly expressed in both CD133(+) and SP fractions of CC cells. Moreover, depletion of CD133 by siRNA induced a significant attenuation of END-1 and NR4A2 expression levels in CaCo-2 cells, while expression of all three molecules decreased during sodium butyrate-induced differentiation. In conclusion, we have identified a molecular signature associated with potential CSCs and showed for the first time the existence of a functional relationship between CD133, END-1 and NR4A2 expression in colon cancer cells.

Gene profiling of bone marrow- and adipose tissue-derived stromal cells: a key role of Kruppel-like factor 4 in cell fate regulation.

BACKGROUND AIMS: Bone marrow- and adipose tissue-derived mesenchymal stromal cells (MSC) represent promising sources for regenerative medicine. However, the precise molecular mechanisms underlying MSC stemness maintenance versus differentiation are not fully understood. The aim of this study was to compare the genome-wide expression profiles of bone marrow-and adipose tissue-derived MSC, in order to identify a common molecular stemness core. METHODS: Molecular profiling was carried out using Affymetrix microarray and relevant genes were further validated by Q-PCR. RESULTS: We identified an overlapping dataset of 190 transcripts commonly regulated in both cell populations, which included several genes involved in stemness regulation (i.e. self-renewal potential and the ability to generate differentiated cells), various signaling pathways and transcription factors. In particular, we identified a central role of the Kruppel-like factor 4 (KLF4) DNA-binding protein in regulating MSC transcriptional activity. CONCLUSIONS: Our results provide new insights toward understanding the molecular basis of MSC stemness maintenance and underline the ability of KLF4 to maintain cells in an undifferentiated state.

CD133+ stem cell mobilization after partial hepatectomy depends on resection extent and underlying disease.

BACKGROUND: Bone marrow stem cells (BMSC) can participate to liver regeneration. However, conflicting results have been reported on this topic in patients undergoing liver resection. AIMS: To assess the impact of liver resection extent and presence of underlying liver disease in modulating BMSC mobilization. METHODS: We enrolled 29 patients undergoing liver resection of different extents, 5 surgical controls and 10 blood donors. Circulating CD133+ BMSC were measured by flow cytometry at different time-points after surgery. The hepatic commitment of mobilized BMSC was investigated by polymerase chain reaction. Liver specimens were collected during surgery for histopathological analysis. Hepatocyte growth factor and granulocyte-colony stimulating factor serum levels were measured by enzyme-linked immunosorbent assay. RESULTS: BMSC mobilization was found in patients undergoing major liver resection, especially in the presence of underlying disease. Ductular reactions were noted in patients with chronic hepatopathy and the hepatic progenitor-like cells expressed CD133, NCAM, cytokeratin-19, and alpha-fetoprotein. Hepatocyte growth factor and granulocyte-colony stimulating factor levels increased following liver resection and the contemporaneous presence of liver disease was associated with their highest raise. CONCLUSIONS: Liver repair is mainly an endogenous process. BMSC become important in case of extensive resection, especially in the presence of underlying hepatopathy and hepatic progenitor-like cells activation. Hepatocyte growth factor and granulocyte-colony stimulating factor seem to be involved in the dynamics underlying hepatic regeneration and BMSC recruitment.

Therapeutic implications of mesenchymal stem cells in liver injury.

Mesenchymal stem cells (MSCs), represent an attractive tool for the establishment of a successful stem-cell-based therapy of liver diseases. A number of different mechanisms contribute to the therapeutic effects exerted by MSCs, since these cells can differentiate into functional hepatic cells and can also produce a series of growth factors and cytokines able to suppress inflammatory responses, reduce hepatocyte apoptosis, regress liver fibrosis, and enhance hepatocyte functionality. To date, the infusion of MSCs or MSC-conditioned medium has shown encouraging results in the treatment of fulminant hepatic failure and in end-stage liver disease in experimental settings. However, some issues under debate hamper the use of MSCs in clinical trials. This paper summarizes the biological relevance of MSCs and the potential benefits and risks that can result from translating the MSC research to the treatment of liver diseases.

Stem cell-based therapies for liver diseases: state of the art and new perspectives.

Millions of patients worldwide suffer from end-stage liver pathologies, whose only curative therapy is liver transplantation (OLT). Given the donor organ shortage, alternatives to OLT have been evaluated, including cell therapies. Hepatocyte transplantation has been attempted to cure metabolic liver disorders and end-stage liver diseases. The evaluation of its efficacy is complicated by the shortage of human hepatocytes and their difficult expansion and cryopreservation. Recent advances in cell biology have led to the concept of "regenerative medicine", based on the therapeutic potential of stem cells (SCs). Different types of SCs are theoretically eligible for liver cell replacement. These include embryonic and fetal SCs, induced pluripotent cells, annex SCs, endogenous liver SCs, and extrahepatic adult SCs. Aim of this paper is to critically analyze the possible sources of SCs suitable for liver repopulation and the results of the clinical trials that have been published until now.

Molecular mechanisms underlying human adipose tissue-derived stromal cells differentiation into a hepatocyte-like phenotype.

BACKGROUND: Adipose tissue-derived stromal cells (ATSCs) hold great promises in regenerative medicine. In the last decade, several studies have reported the plasticity of ATSCs toward a hepatocyte-like phenotype. Nonetheless, the molecular mechanisms underlying the conversion from a mesenchymal to an epithelial phenotype remain poorly understood. AIM: In this study, we compared the full genome expression profiles of ATSCs cultured for 4 weeks under pro-hepatogenic conditions to undifferentiated ATSCs, in order to depict the molecular events involved in ATSC hepatic transdifferentiation. METHODS: Analysis was performed using the Affymetrix human focus arrays. Sets of differentially expressed genes were functionally categorized in order to understand which pathways drive the hepatic conversion and interesting targets were validated by Q-PCR. RESULTS: ATSC-derived hepatocyte-like cells activate several genes associated with specific liver functions, including protein metabolism, innate immune response regulation, and biodegradation of toxic compounds. Furthermore, microarray analysis highlighted downregulation of transcripts associated with the mesenchymal lineage, while epithelial-related genes were overexpressed. CONCLUSION: Our data suggest that the in vitro system used in this study drove ATSCs toward a hepatic conversion through a subtle regulation of molecular pathways controlling lineage commitment that promote mesenchymal-epithelial transition.

Stem cells, a two-edged sword: risks and potentials of regenerative medicine.

The recent advancements in stem cell (SC) biology have led to the concept of regenerative medicine, which is based on the potential of SC for therapies aimed to facilitate the repair of degenerating or injured tissues. Nonetheless, prior to large scale clinical applications, critical aspects need to be further addressed, including the long-term safety, tolerability, and efficacy of SC-based treatments. Most problematic among the risks of SC-based therapies, in addition to the possible rejection or loss of function of the infused cells, is their potential neoplastic transformation. Indeed, SCs may be used to cure devastating diseases, but their specific properties of self-renewal and clonogenicity may render them prone to generate cancers. In this respect, 'Stemness' might be seen as a two-edged sword, its bright side being represented by normal SCs, its dark side by cancer SCs. A better understanding of SC biology will help fulfill the promise of regenerative medicine aimed at curing human pathologies and fighting cancer from its roots.

Stem cell-based therapy in gastroenterology and hepatology.

Protagonists of a new scientific era, stem cells are promising tools on which regenerative medicine relies for the treatment of human pathologies. Stem cells can be obtained from various sources, including embryos, fetal tissues, umbilical cord blood, and also terminally differentiated organs. Once forced to expand and differentiate into functional progenies, stem cells may become suitable for cell replacement and tissue engineering. The manipulation and/or stimulation of adult stem cells seems to be particularly promising, as it could improve the endogenous regenerative potential without risks of rejection and overcome the ethical and political issues related to embryonic stem cell research. Stem cells are already leaving the bench and reaching the bedside, despite an incomplete knowledge of the genetic control program driving their fate and plasticity. In gastroenterology and hepatology, the first attempts to translate stem cell basic research into novel therapeutic strategies have been made for the treatment of several disorders, such as inflammatory bowel diseases, diabetes mellitus, celiachy and acute or chronic hepatopaties. Nonetheless, critical aspects need to be further addressed, including the long-term safety, tolerability and efficacy of cell-based treatments, as well as their carcinogenic potential. Aim of this review is to summarize the state-of-the-arts on gastrointestinal and hepatic stem cells and on stem cell-based therapies in gastroenterology and hepatology, highlighting both the benefits and the potential risks of these new tools for the treatment and prevention of human diseases.