Conventional type 1 dendritic cells are essential for the development of primary biliary cholangitis

BACKGROUND & AIMS

Primary biliary cholangitis (PBC) is a progressive-cholestatic autoimmune liver disease. Dendritic cells (DC) are professional antigen-presenting cells and their prominent presence around damaged bile ducts of PBC patients are documented. cDC1 is a rare subset of DC known for its cross-presentation abilities and interleukin 12 production. Our aim was to assess the role of cDC1 in the pathogenesis of PBC.

METHODS

We utilized an inducible murine model of PBC and took advantage of the DC reporter mice Zbtb46gfp and the Batf3-/- mice that specifically lack the cDC1 subset. cDC1 cells were sorted from blood of PBC patients and healthy individuals and subjected to Bulk-MARS-seq transcriptome analysis.

RESULTS

Histopathology assessment demonstrated peri-portal inflammation in wild type (WT) mice, whereas only minor abnormalities were observed in Batf3-/- mice. Flow cytometry analysis revealed a two-fold reduction in hepatic CD8/CD4 T cells ratio in Batf3-/- mice, suggesting reduced intrahepatic CD8 T cells expansion. Histological evidence of portal fibrosis was detected only in the WT but not in Batf3-/- mice. This finding was supported by decreased expression levels of pro-fibrotic genes in the livers of Batf3-/- mice. Transcriptome analysis of human cDC1, revealed 78 differentially expressed genes between PBC patients and controls. Genes related to antigen presentation, TNF and IFN signalling and mitochondrial dysfunction were significantly increased in cDC1 isolated from PBC patients.

CONCLUSION

Our data illustrated the contribution the cDC1 subset in the pathogenesis of PBC and provides a novel direction for immune based cell-specific targeted therapeutic approach in PBC.

The Yield of Routine Tissue Sampling in Pediatric Gastrointestinal Endoscopy

OBJECTIVES

Societies' guidelines suggest routine tissue sampling in all children undergoing esophagogastroduodenoscopy and ileocolonoscopy, even in the absence of visible endoscopy abnormalities. We aimed to determine the agreement between endoscopic and histopathological findings in pediatric endoscopy and to assess the yield of routine biopsies from all sites.

METHODS

Since January 2019, our endoscopy institute protocol has included routine biopsies sampling from the esophagus, stomach, duodenum, ileum, and colon in all diagnostic procedures. Agreement between tests was done using the kappa coefficient ( κ ). The study included all endoscopies performed during 2019.

RESULTS

In total, 541 diagnostic endoscopies were done during the study period with 434 (80%) esophagogastroduodenoscopy and 107 (20%) were ileocolonoscopy. Compared to histology, endoscopic findings performance were: esophagus-sensitivity 33%, specificity 98%; stomach-sensitivity 60%, specificity 89%; duodenum-sensitivity 50%, specificity 97%; duodenal bulb-sensitivity 47%, specificity 89%; terminal ileum-sensitivity 82%, specificity 100%; colon-sensitivity 84%, specificity 96%. Assessment of concordance between endoscopic and histopathologic findings reveals an overall low level of agreement in esophagogastroduodenoscopy ( κ of 0.39, 0.51, 0.53, and 0.24 for the esophagus, stomach, duodenal second part, and bulb, respectively), and good agreement in ileocolonoscopy ( κ of 0.88 and 0.81 for the ileum and colon, respectively).

CONCLUSIONS

Endoscopy findings are highly specific for histologic pathology, whereas the absence of findings correlates poorly with histologic findings. Ileocolonoscopy shows better agreement than esophagogastroduodenoscopy. Our data support routine tissue sampling in pediatric endoscopy.

Immune cell C/EBPβ deficiency is associated with hepatic mononuclear defects and spontaneous hepatitis but not steatohepatitis induced liver fibrosis

BACKGROUND

CCAAT/enhancer-binding protein β (C/EBPβ) is a transcription factor known to be involved in macrophage differentiation and function, steatohepatitis and liver fibrosis.

METHODS

Immune restricted C/EBPβ deficient and control mice were investigated in steady-state and in the CDA-HFD steatohepatitis model. Mice were assessed for weight change, liver biochemical profile, histology and hepatic phagocytes composition.

RESULTS

Flow cytometry analysis of hepatic nonparenchymal cells revealed reduced numbers of hepatic monocytes and Kupffer cells and an increase in hepatic MHC class II positive myeloid cells in immune cells restricted C/EBPβ deficient mice. Immune-restricted C/EBPβ deficiency resulted in decreased weight gain and appearance of mild spontaneous liver inflammation. Nevertheless, In the CDA-HFD steatohepatitis model, immune restricted C/EBPβ deficient and proficient mice exhibit similar grade of hepatic steatosis, liver enzymes levels and fibrosis stage.

CONCLUSIONS

Immune-restricted C/EBPβ deficiency leads to significant alteration in hepatic mononuclear phagocytes composition associated with spontaneous mild hepatitis. Steatohepatitis associated fibrosis is not dependent on C/EBPβ expression by immune cells.

Management of pouch related symptoms in patients who underwent ileal pouch anal anastomosis surgery for adenomatous polyposis

BACKGROUND

Adenomatous polyposis syndromes (APS) patients with ileal pouch anal anastomosis (IPAA) suffer frequent symptoms with scarce signs of inflammation, distinct from ulcerative colitis patients. While the management of pouchitis in ulcerative colitis patients is well established, data regarding response to treatment modalities targeting pouch-related disorders in APS patient population is scarce.

AIM

To assess clinical, endoscopic and histologic response to various treatment modalities employed in the therapy of pouch related disorders.

METHODS

APS patients who underwent IPAA between 1987-2019 were followed every 6-12 mo and pouch-related symptoms were recorded at every visit. Lower endoscopy was performed annually, recording features of the pouch, cuff and terminal ileum. A dedicated gastrointestinal pathologist reviewed biopsies for signs and severity of inflammation. At current study, files were retrospectively reviewed for initiation and response to various treatment modalities between 2015-2019. Therapies included dietary modifications, probiotics, loperamide, antibiotics, bismuth subsalicylate, mebeverine hydrochloride, 5-aminosalicylic acid compounds and topical rectal steroids. Symptoms and endoscopic and histologic signs of inflammation before and after treatment were assessed. Pouchitis disease activity index (PDAI) and its subscores was calculated. Change of variables before and after therapy was assessed using Wilcoxon signed rank test for continuous variables and using McNemar's test for categorical variables.

RESULTS

Thirty-three APS patients after IPAA were identified. Before treatment, 16 patients (48.4%) suffered from abdominal pain and 3 (9.1%) from bloody stools. Mean number of daily bowel movement was 10.3. Only 4 patients (12.1%) had a PDAI ≥ 7. Mean baseline PDAI was 2.5 ± 2.3. Overall, intervention was associated with symptomatic relief, mainly decreasing abdominal pain (from 48.4% to 27.2% of patients, P = 0.016). Daily bowel movements decreased from a mean of 10.3 to 9.3 (P = 0.003). Mean overall and clinical PDAI scores decreased from 2.58 to 1.94 (P = 0.016) and from 1.3 to 0.87 (P = 0.004), respectively. Analyzing each treatment modality separately, we observed that dietary modifications decreased abdominal pain (from 41.9% of patients to 19.35%, P = 0.016), daily bowel movements (from 10.5 to 9.3, P = 0.003), overall PDAI (from 2.46 to 2.03, P = 0.04) and clinical PDAI (1.33 to 0.86, P = 0.004). Probiotics effectively decreased daily bowel movements (from 10.2 to 8.8, P = 0.007), overall and clinical PDAI (from 2.9 to 2.1 and from 1.38 to 0.8, P = 0.032 and 0.01, respectively). While other therapies had minimal or no effects. No significant changes in endoscopic or histologic scores were seen with any therapy.

CONCLUSION

APS patients benefit from dietary modifications and probiotics that improve their pouch-related symptoms but respond minimally to anti-inflammatory and antibiotic treatments. These results suggest a functional rather than inflammatory disorder.

COMMD10 is critical for Kupffer cell survival and controls Ly6Chi monocyte differentiation and inflammation in the injured liver

Liver-resident macrophages Kupffer cells (KCs) and infiltrating Ly6C^hi monocytes both contribute to liver tissue regeneration in various pathologies but also to disease progression upon disruption of orderly consecutive regeneration cascades. Little is known about molecular pathways that regulate their differentiation, maintenance, or inflammatory behavior during injury. Here, we show that copper metabolism MURR1 domain (COMMD)10-deficient KCs adopt liver-specific identity. Strikingly, COMMD10 deficiency in KCs and in other tissue-resident macrophages impedes their homeostatic survival, leading to their continuous replacement by Ly6C^hi monocytes. While COMMD10 deficiency in KCs mildly worsens acetaminophen-induced liver injury (AILI), its deficiency in Ly6C^hi monocytes results in exacerbated and sustained hepatic damage. Monocytes display unleashed inflammasome activation and a reduced type I interferon response and acquire "neutrophil-like" and lipid-associated macrophage differentiation fates. Collectively, COMMD10 appears indispensable for KC and other tissue-resident macrophage survival and is an important regulator of Ly6C^hi monocyte fate decisions and reparative behavior in the diseased liver.

Interleukin 23 Produced by Hepatic Monocyte-Derived Macrophages Is Essential for the Development of Murine Primary Biliary Cholangitis

Background and Aims

Primary Biliary Cholangitis (PBC) is an organ-specific autoimmune liver disease. Mononuclear phagocytes (MNPs), comprise of monocyte, dendritic cells and monocyte-derived macrophages, constitute major arm of the innate immune system known to be involved in the pathogenesis of autoimmune disorders. MNPs were shown to accumulate around intra-hepatic bile ducts in livers of PBC patients. Interleukin 23 (IL-23) is a pro-inflammatory cytokine. IL-23-positive cells were detected in livers of patients with advanced stage PBC and IL-23 serum levels found to be in correlation with PBC disease severity. Our overall goal was to assess the importance of IL-23 derived from MNPs in PBC pathogenesis.

Methods

We utilized an inducible murine model of PBC and took advantage of transgenic mice targeting expression of IL-23 by specific MNP populations. Analysis included liver histology assessment, flow cytometry of hepatic immune cells and hepatic cytokine profile evaluation. Specific MNPs sub-populations were sorted and assessed for IL-23 expression levels.

Results

Flow cytometry analysis of non-parenchymal liver cells in autoimmune cholangitis revealed massive infiltration of the liver by MNPs and neutrophils and a decrease in Kupffer cells numbers. In addition, a 4-fold increase in the incidence of hepatic IL-17A producing CD4⁺ T cells was found to be associated with an increase in hepatic IL23-p19 and IL17A expression levels. Disease severity was significantly ameliorated in both CD11c^creP19^flox/flox and CX₃CR1^creP19 ^flox/flox mice as assessed by reduced portal inflammation and decreased hepatic expression of various inflammatory cytokines. Amelioration of disease severity was associated with reduction in IL-17A producing CD4⁺ T cells percentages and decreased hepatic IL23-p19 and IL17A expression levels. qRT-PCR analysis of sorted hepatic MNPs demonstrated high expression levels of IL-23 mRNA specifically by CX₃CR1^hiCD11c⁺ monocyte-derived macrophages.

Conclusion

Our results indicate a major role for IL-23 produced by hepatic monocyte-derived macrophages in the pathogenesis of PBC. These results may pave the road for the development of new immune-based and cell specific therapeutic modalities for PBC patients not responding to current therapies.

Integrase-derived peptides together with CD24-targeted lentiviral particles inhibit the growth of CD24 expressing cancer cells

The integration of viral DNA into the host genome is mediated by viral integrase, resulting in the accumulation of double-strand breaks. Integrase-derived peptides (INS and INR) increase the number of integration events, leading to escalated genomic instability that induces apoptosis. CD24 is a surface protein expressed mostly in cancer cells and is very rarely found in normal cells. Here, we propose a novel targeted cancer therapeutic platform based on the lentiviral integrase, stimulated by integrase-derived peptides, that are specifically delivered to cancerous cells via CD24 antigen-antibody targeting. INS and INR were synthesized and humanized and anti-CD24 antibodies were fused to the lentivirus envelope. The activity, permeability, stability, solubility, and toxicity of these components were analyzed. Cell death was measured by fluorescent microscopy and enzymatic assays and potency were tested in vitro and in vivo. Lentivirus particles, containing non-functional DNA led to massive cell death (40–70%). Raltegravir, an antiretroviral drug, inhibited the induction of apoptosis. In vivo, single and repeated administrations of INS/INR were well tolerated without any adverse effects. Tumor development in nude mice was significantly inhibited (by 50%) as compared to the vehicle arm. In summary, a novel and generic therapeutic platform for selective cancer cell eradication with excellent efficacy and safety are presented.

Resection Versus Observation of Small Asymptomatic Nonfunctioning Pancreatic Neuroendocrine Tumors

BACKGROUND

Management of asymptomatic, nonfunctioning small pancreatic neuroendocrine tumors (PNETs) is controversial because of their overall good prognosis, and the morbidity and mortality associated with pancreatic surgery. Our aim was to compare the outcomes of resection with expectant management of patients with small asymptomatic PNETs.

METHODS

Retrospective review of patients with nonfunctioning asymptomatic PNETs < 2 cm that underwent resection or expectant management at the Tel-Aviv Medical Center between 2001 and 2018.

RESULTS

Forty-four patients with small asymptomatic, biopsy-proven low-grade PNETs with a KI67 proliferative index < 3% were observed for a mean of 52.48 months. Gallium⁶⁷DOTATOC-PET scan was completed in 32 patients and demonstrated uptake in the pancreatic tumor in 25 (78%). No patient developed systemic metastases. Two patients underwent resection due to tumor growth, and true tumor enlargement was evidenced in final pathology in one of them. Fifty-five patients underwent immediate resection. Significant complications (Clavien-Dindo grade ≥ 3) developed in 10 patients (18%), mostly due to pancreatic leak, and led to one mortality (1.8%). Pathological evaluation revealed lymphovascular invasion in 1 patient, lymph node metastases in none, and a Ki67 index ≥ 3% in 5. No case of tumor recurrence was diagnosed after mean follow-up of 52.8 months.

CONCLUSIONS

No patients with asymptomatic low-grade small PNETs treated by expectant management were diagnosed with regional or systemic metastases after a 52.8-month follow-up. Local tumor progression rate was 2.1%. Surgery has excellent long-term outcomes, but it harbors significant morbidity and mortality. Observation can be considered for selected patients with asymptomatic, small, low grade PNETs.

Increased Rate of Complete Pathologic Response After Neoadjuvant FOLFIRINOX for BRCA Mutation Carriers with Borderline Resectable Pancreatic Cancer

BACKGROUND

Neoadjuvant FOLFIRINOX is a standard-of-care treatment for BRPC patients. Patients with gBRCAm who have demonstrated improved response to platinum-based chemotherapy may have impaired homologous repair deficiency. This study aimed to describe the pathologic complete response rate and long-term survival for patients with germline BRCA1 or BRCA2 mutation (gBRCAm) and borderline resectable pancreatic cancer (BRPC) treated with neoadjuvant FOLFIRINOX.

METHODS

A dual-center retrospective analysis was performed. Patients who had BRPC treated with neoadjuvant FOLFIRINOX followed by curative resection were identified from clinical databases. Pathologic complete response was defined as no viable tumor cells present in the specimen. Common founder Jewish germline BRCA1 or BRCA2 mutation was determined for available patients.

RESULTS

The 61 BRPC patients in this study underwent resection after neoadjuvant FOLFIRINOX. Analysis of BRCA mutation was performed for 39 patients, and 9 patients were found to be BRCA2 germline mutation carriers. The pathologic complete response rate was 44.4% for the gBRCAm patients and 10% for the BRCA non-carriers (p = 0.009). The median disease-free survival was not reached for the gBRCAm patients and was 7 months for the BRCA non-carriers (p = 0.03). The median overall survival was not reached for the gBRCAm patients and was 32 months for the BRCA non-carriers (p = 0.2). After a mean follow-up period of 33.7 months, all eight patients with pathologic complete response were disease-free.

CONCLUSIONS

The study showed that gBRCAm patients with BRPC have an increased chance for pathologic complete response and prolonged survival after neoadjuvant FOLFIRINOX. The results support the benefit of exposing gBRCAm patients to platinum-based chemotherapy early in the course of the disease. Neoadjuvant FOLFIRINOX should be considered for BRCA carriers who have resectable pancreatic cancer.

LOXL2 Inhibition Paves the Way for Macrophage-Mediated Collagen Degradation in Liver Fibrosis

Liver fibrosis is characterized by the excessive accumulation of extracellular matrix (ECM) proteins and enzymes, especially fibrillary collagens, and represents a major cause of morbidity and mortality worldwide. Lysyl oxidases (LOXs) drive covalent crosslinking of collagen fibers, thereby promoting stabilization and accumulation of liver fibrosis while limiting its resolution. Here we show in a carbon tetrachloride (CCl₄)-induced liver fibrosis murine model that treatment with a novel anti-lysyl oxidase like 2 (LOXL2) neutralizing antibody, which targets extracellular LOXL2, significantly improves fibrosis resolution. LOXL2 inhibition following the onset of fibrosis accelerated and augmented collagen degradation. This was accompanied by increased localization of reparative monocyte-derived macrophages (MoMFs) in the proximity of fibrotic fibers and their representation in the liver. These cells secreted collagenolytic matrix metalloproteinases (MMPs) and, in particular, the membrane-bound MT1-MMP (MMP-14) collagenase. Inducible and selective ablation of infiltrating MoMFs negated the increased "on-fiber" accumulation of MMP-14-expressing MoMFs and the accelerated collagenolytic activity observed in the anti-LOXL2-treated mice. Many studies of liver fibrosis focus on preventing the progression of the fibrotic process. In contrast, the therapeutic mechanism of LOXL2 inhibition presented herein aims at reversing existing fibrosis and facilitating endogenous liver regeneration by paving the way for collagenolytic macrophages.

Micro-RNA Expression Patterns Predict Metastatic Spread in Solid Pseudopapillary Neoplasms of the Pancreas

Solid pseudopapillary neoplasm (SPN) of pancreas is a rare pancreatic neoplasm with a low metastatic potential. Up to 10% of patients with localized disease at presentation will develop systemic metastases, usually in the peritoneum or the liver. Due to the rarity of SPNs and the overall excellent prognosis, reliable prognostic factors to predict malignant biological behavior remain undetermined. Therefore, we aimed to define clinical, histological, and microRNA patterns that are associated with metastatic disease. We conducted a retrospective single center study on all patients operated for SPN of pancreas between 1995 and 2018. Clinical and pathological data were collected, and expression patterns of 2,578 human microRNAs were analyzed using microRNA array (Affimetrix 4.1) in normal pancreases (NPs), localized tumors (LTs), and metastatic tumors (MTs). The diagnosis of SPN was confirmed in 35 patients who included 28 females and 3 males, with a mean age of 33.8 ± 13.9 years. The only clinical factor associated with metastases was tumor size (mean tumor size 5.20 ± 3.78 in LT vs. 8.13± 1.03 in MT, p < 0.012). Microscopic features of malignancy were not associated with metastases, nor were immunohistochemical stains, including the proliferative index KI67. Higher expressions of miR-184, miR-10a, and miR-887, and lower expressions of miR-375, miR-217, and miR-200c were observed in metastatic tissues on microarray, and validated by real-time polymerase chain reaction. Hierarchal clustering demonstrated that the microRNA expression pattern of MTs was significantly different from that of LTs. The only clinical factor associated with metastases of SPN of pancreas was tumor size. Histological features and immunohistological staining were not predictive of metastases. A panel of six microRNAs was differentially expressed in MTs, and these findings could potentially be used to predict tumor behavior. Validation of these results is needed in larger series.

Resorting the function of the colorectal cancer gatekeeper adenomatous polyposis coli

As a large number of cancers are caused by nonsense mutations in key genes, read-through of these mutations to restore full-length protein expression is a potential therapeutic strategy. Mutations in the adenomatous polyposis coli (APC) gene initiate the majority of both sporadic and hereditary colorectal cancers (CRC) and around 30% of these mutations are nonsense mutations. Our goal was to test the feasibility and effectiveness of APC nonsense mutation read-through as a potential chemo-preventive therapy in Familial Adenomatous Polyposis (FAP), an inherited CRC syndrome patients. Ten FAP patients harboring APC nonsense mutations were treated with the read-through inducing antibiotic erythromycin for 4 months. Endoscopic assessment of the adenomas was performed at baseline, after 4 and after 12 months. Adenoma burden was documented in terms of adenoma number, maximal polyp size and cumulative polyp size per procedure. Tissue samples were collected and subjected to molecular and genetic analyses. Our results show that in the majority of patients the treatment led to a decrease in cumulative adenoma burden, median reduction in cumulative adenoma size and median reduction in adenoma number. Molecular and genetic analyses of the adenomas revealed that the treatment led to a reduced number of somatic APC mutations, reduced cellular proliferation and restoration of APC tumor-suppressing activity. Together, our findings show that induced read-through of APC nonsense mutations leads to promising clinical results and should be further investigated to establish its therapeutic potential in FAP and sporadic CRCs harboring nonsense APC mutations.

The chick embryo chorioallantoic membrane assay: In ovo model for personalized assessment and evaluation of the most effective therapeutic approach in cancer therapy

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Background: "Personalized medicine,” is the tailoring of medical treatment to a single person aiming to maximize efficacy and minimize toxicity. Currently there is no good prediction for response to therapy. The Chick Chorioallantoic Membrane (CAM) is naturally immuno-deficient and rich in vascularity therefore an ideal system, allowing generate 3D cancerous “organoids” in a very efficient, reproducible and cost-effective manner and translates basic research to the clinic. Aims: Generate a “personalized” HTP system for a quick, reliable and effective evaluation of different therapeutic options using 3D tumors in a "humanized egg" instead of mouse PDX model. Methods: Fertilized eggs were incubated until day 3 (37°C, 75-90% humidity). Then, 2ml of albumin was pulled out to separate the CAM from the eggshell and a small window in the eggshell has been made. To destroy the chicken immune system development, the eggs were irradiated at day 5 and human immune cells were then inoculated onto the CAM. On day 7, single cells suspension or tissues, derived from cancer patients, were transplanted onto the CAM and visible tumors were performed ("CAM-PDX"). Drugs, mAbs and chemotherapy, were applied via the yolk sac. Tumor growth was measured, weighted and monitored by caliper and IVIS fluorescent imaging platform. IHC was performed and confirmed the response of the particular specimens to the tested regiment. Results: Histology and IHC analysis confirmed that the established tumors retained their characteristics. Positive Ki-67 staining confirmed that cancer cells proliferate while the treated tumors showed reduced staining. Anti-CD24 mAb, FOLFOX, cetuximab, Foflorinox and Gemcitabine, given as single agent or combinations, successfully inhibited CR and pancreatic tumors (by 70-75%). Detection of active caspase 3 confirmed those results. Biopsies from human specimens, were successfully established and expanded by serial passages allows generation of bio-bank. The stimulated human PBMCs demonstrated enhanced proliferation in vitro and in ovo, even after 5 days in the egg. Irradiated eggs showed no functional immune system even after 2 weeks of development. Conclusions: The CAM is an ideal, effective, economical and powerful avatar-based precision medicine approach to predict the best protocol for cancer therapy.

Activated Eosinophils Exert Antitumorigenic Activities in Colorectal Cancer

Immunotherapies targeting T lymphocytes are revolutionizing cancer therapy but only benefit a subset of patients, especially in colorectal cancer. Thus, additional insight into the tumor microenvironment (TME) is required. Eosinophils are bone marrow-derived cells that have been largely studied in the context of allergic diseases and parasite infections. Although tumor-associated eosinophilia has been described in various solid tumors including colorectal cancer, knowledge is still missing regarding eosinophil activities and even the basic question of whether the TME promotes eosinophil recruitment without additional manipulation (e.g., immunotherapy) is unclear. Herein, we report that eosinophils are recruited into developing tumors during induction of inflammation-induced colorectal cancer and in mice with the Apc^{min /+} genotype, which develop spontaneous intestinal adenomas. Using adoptive transfer and cytokine neutralization experiments, we demonstrate that the TME supported prolonged eosinophil survival independent of IL5, an eosinophil survival cytokine. Tumor-infiltrating eosinophils consisted of degranulating eosinophils and were essential for tumor rejection independently of CD8⁺ T cells. Transcriptome and proteomic analysis revealed an IFNγ-linked signature for intratumoral eosinophils that was different from that of macrophages. Our data establish antitumorigenic roles for eosinophils in colorectal cancer. These findings may facilitate the development of pharmacologic treatments that could unleash antitumor responses by eosinophils, especially in colorectal cancer patients displaying eosinophilia.

Neutrophil extracellular traps in pediatric inflammatory bowel disease

Neutrophil extracellular traps (NETs) are fibers composed of chromatin and neutrophil proteins released by activated neutrophils. NETs trap and kill microbes, activate dendritic and T cells, and are implicated in autoimmune and vascular diseases. The pathogenesis of inflammatory bowel disease (IBD) is multifactorial and characterized by chronic active mucosal inflammation with controversial contribution of neutrophils. Our aim is to describe the involvement of NETs in pediatric IBD. We retrospectively examined biopsies from the small bowel and colon of children at diagnosis of Crohn's disease (CD) or ulcerative colitis (UC). The biopsies were labeled for neutrophil elastase, myeloperoxidase, DNA, chromatin and histones in order to identify NETs. Samples of two children with normal colonoscopy served as controls. Twelve patients (5 boys) were included, 6 with CD and 6 with UC. Their average age was 12.2 years (range 5-16). NETs were found in all samples from patients and not in the samples from the two controls. This is the first demonstration of the presence of NETs in biopsies taken from the small bowel and colon of pediatric patients with IBD. More studies are needed in order to identify the role of NETs in CD/UC pathogenesis.

The Critical Role of Chemokine (C-C Motif) Receptor 2-Positive Monocytes in Autoimmune Cholangitis

The therapy of primary biliary cholangitis (PBC) has lagged behind other autoimmune diseases despite significant improvements in our understanding of both immunological and molecular events that lead to loss of tolerance to the E2 component of pyruvate dehydrogenase, the immunodominant autoepitope of PBC. It is well known that Ly6C^hi monocytes are innate immune cells infiltrating inflammatory sites that are dependent on the expression of C–C motif chemokine receptor 2 (CCR2) for emigration from bone marrow. Importantly, humans with PBC have a circulating monocyte pro-inflammatory phenotype with macrophage accumulation in portal tracts. We have taken advantage of an inducible chemical xenobiotic model of PBC and recapitulated the massive infiltration of monocytes to portal areas. To determine the clinical significance, we immunized both CCR2-deficient mice and controls with 2OA-BSA and noted that CCR2 deficiency is protective for the development of autoimmune cholangitis. Importantly, because of the therapeutic potential, we focused on inhibiting monocyte infiltration through the use of cenicriviroc (CVC), a dual chemokine receptor CCR2/CCR5 antagonist shown to be safe in human trials. Importantly, treatment with CVC resulted in amelioration of all aspects of disease severity including serum total bile acids, histological severity score, and fibrosis stage. In conclusion, our results indicate a major role for Ly6C^hi monocytes and for CCR2 in PBC pathogenesis and suggest that inhibition of this axis by CVC should be explored in humans through the use of clinical trials.

Ly6Chi Monocytes and Their Macrophage Descendants Regulate Neutrophil Function and Clearance in Acetaminophen-Induced Liver Injury

Monocyte-derived macrophages (MoMF) play a pivotal role in the resolution of acetaminophen-induced liver injury (AILI). Timely termination of neutrophil activity and their clearance are essential for liver regeneration following injury. Here, we show that infiltrating Ly6C^hi monocytes, their macrophage descendants, and neutrophils spatially and temporally overlap in the centrilobular necrotic areas during the necroinflammatory and resolution phases of AILI. At the necroinflammatory phase, inducible ablation of circulating Ly6C^hi monocytes resulted in reduced numbers and fractions of reactive oxygen species (ROS)-producing neutrophils. In alignment with this, neutrophils sorted from monocyte-deficient livers exhibited reduced expression of NADPH oxidase 2. Moreover, human CD14⁺ monocytes stimulated with lipopolysaccharide or hepatocyte apoptotic bodies directly induced ROS production by cocultured neutrophils. RNA-seq-based transcriptome profiling of neutrophils from Ly6C^hi monocyte-deficient versus normal livers revealed 449 genes that were differentially expressed with at least twofold change (p ≤ 0.05). In the absence of Ly6C^hi monocytes, neutrophils displayed gene expression alterations associated with decreased innate immune activity and increased cell survival. At the early resolution phase, Ly6C^hi monocytes differentiated into ephemeral Ly6C^lo MoMF and their absence resulted in significant accumulation of late apoptotic neutrophils. Further gene expression analysis revealed the induced expression of a specific repertoire of bridging molecules and receptors involved with apoptotic cell clearance during the transition from Ly6C^hi monocytes to MoMF. Collectively, our findings establish a phase-dependent task division between liver-infiltrating Ly6C^hi monocytes and their MoMF descendants with the former regulating innate immune functions and cell survival of neutrophils and the later neutrophil clearance.

Solid pseudopapillary neoplasm of the pancreas: Management and long-term outcome

BACKGROUND

Solid pseudopapillary neoplasm (SPN) of pancreas is a rare pancreatic neoplasm with a low metastatic potential. Our aim was to study the clinical-pathological characteristics, and long-term outcome of this tumor.

MATERIALS

Rretrospective single center study of patients operated for SPN of pancreas. Clinical and pathological data were collected.

RESULTS

From 1995 to 2016, 1320 patients underwent pancreatic resection. SPN was confirmed in 32 cases (2.46%), including 29 (90.6%) female and three (9.4%) male, with a mean age of 28.4 ± 12.2 years. SPN was the most common pathology among female patients under age of 40 (72.4%). Abdominal pain was the most frequent presenting symptom (48%), whereas none of the patients presented with jaundice. Mean tumor diameter was 5.9 cm (range, 0.9-14 cm). All patients underwent margin-negative surgical resection. Two patients demonstrated gross malignant features, including liver metastases at presentation (n = 1), and adjacent organ and vascular invasion (n = 1). Microscopic malignant features were present in thirteen patients (40.6%). Recurrence occurred in the retroperitoneal lymph nodes (n = 1, 7 years post resection) and in the liver (n = 2, 1 and 5 years post resection). Mean follow-up was 49.2 months (range, 1-228 months). Five and 10-year disease-free survival was 96.5% and 89.6% respectively.

CONCLUSIONS

SPNs are low-grade tumors with a good prognosis. Margin-negative surgical resection is curative in most patients. However, almost 15% of patients demonstrate malignant features including invasion of adjacent organs or metastatic disease. Patients with malignant disease are still expected to have long survival, and aggressive surgical approach is advocated.

Gene expression alterations in ulcerative colitis patients after restorative proctocolectomy extend to the small bowel proximal to the pouch

OBJECTIVES

To evaluate molecular profiles in the small bowel (SB) mucosa proximal to the pouch in ulcerative colitis (UC) patients after pouch surgery.

DESIGN

Patients were prospectively recruited and stratified according to disease behaviour: normal pouch (NP), chronic pouchitis (CP), and Crohn's-like disease of the pouch (CLDP). Biopsies obtained from the pouch and the normal-appearing proximal SB (40 cm proximal to the anal verge) were compared to ileal biopsies from normal controls (NC). A histopathological score based on the degree of polymorphonuclear and mononuclear infiltrates was used to assess inflammation in the pouch and the proximal SB. Gene expression analysis was performed using microarrays, and validated by real-time PCR. Gene ontology and clustering were evaluated by bioinformatics.

RESULTS

Thirty-six subjects were recruited (age 18-71 years, 16 males). Histopathology scores demonstrated minimal differences in the normal-appearing proximal SB of all groups. Nonetheless, significant (fold change ≥2, corrected p [FDR] ≤ 0.05) molecular alterations in the proximal SB were detected in all groups (NP n=9; CP n=80; and CLDP n=230) compared with NC. The magnitude of DUOX2 alteration in the proximal SB was highest. An increase of 6.0, 9.8 and 21.7 folds in DUOX2 expression in NP, CP, CLDP, respectively was observed. This was followed by alterations in MMP1, SLC6A14 and PGC. Gene alterations in the proximal SB overlapped with alterations within the pouch (76% and 97% overlap in CP and CLDP, respectively). Gene ontology analysis in the proximal SB and pouch were comparable.

CONCLUSIONS

Significant gene expression alterations exist in an apparently unaffected proximal SB. Alterations in the pouch and the proximal SB were comparable, suggesting that inflammation may not be limited to the pouch, but that it extends to the proximal SB.

Vitamin D inhibits development of liver fibrosis in an animal model but cannot ameliorate established cirrhosis

1,25(OH)2D3, the active form of vitamin D, has an antiproliferative and antifibrotic effect on hepatic stellate cells. Our aim was to investigate the potential of 1,25(OH)2D3 to inhibit the development of liver fibrosis and to ameliorate established fibrosis in vivo. The antifibrotic effect of 1,25(OH)2D3 was investigated in a thioacetamide (TAA) model (as a preventive treatment and as a remedial treatment) and in a bile duct ligation model. In the preventive model, rats received simultaneously intraperitoneum injection of TAA and/or 1,25(OH)2D3 for 10 wk. In the remedial model, rats were treated with TAA for 10 wk and then received 1,25(OH)2D3 or saline for 8 wk. Fibrotic score was determined by Masson staining. Collagen I, α-smooth muscle actin (α-SMA), tissue inhibitor of metalloproteinase-1 (TIMP1), platelet-derived growth factor (PDGF), and transforming growth factor-β (TGF-β) expression were measured by Western blot analysis and real-time PCR. Hypercalemia was detected by chemistry measurements. Preventive treatment of 1,25(OH)2D3 significantly suppressed liver fibrosis both macroscopically and microscopically and significantly lowered the fibrotic score of the TAA + 1,25(OH)2D3 group compared with the TAA group. 1,25(OH)2D3 significantly inhibited expression of PDGF and TGF-β by ∼50% and suppressed the expression of collagen Iα1, TIMP1, and α-SMA by approximately three-, two-, and threefold, respectively. In contrast, 1,25(OH)2D3 was inefficient in amelioration of established liver fibrosis. Administration of 1,25(OH)2D3 to bile duct ligation rats led to a high mortality rate probably caused by hypercalcemia. We conclude that 1,25(OH)2D3 may be considered as a potential preventive treatment in an in vivo model but failed to ameliorate established cirrhosis.

Human intestinal epithelial cells respond to β-glucans via Dectin-1 and Syk

Intestinal epithelial cells (IECs) are the first to encounter luminal antigens and may be involved in intestinal immune responses. Fungi are important components of the intestinal microflora. The potential role of fungi, and in particular their cell wall component β-glucan, in modulating human intestinal epithelial responses is still unclear. Here we examined whether human IECs are capable of recognizing and responding to β-glucans, and the potential mechanisms of their activation. We show that human IECs freshly isolated from surgical specimens, and the human IEC lines HT-29 and SW480, express the β-glucan receptor Dectin-1. The β-glucan-consisting glycans curdlan and zymosan stimulated IL-8 and CCL2 secretion by IEC lines. This was significantly inhibited by a Dectin-1 blockade using its soluble antagonist laminarin. Spleen tyrosine kinase (Syk), a signaling mediator of Dectin-1 activation, is expressed in human IECs. β-glucans and Candida albicans induced Syk phosphorylation, and Syk inhibition significantly decreased β-glucan-induced chemokine secretion from IECs. Thus, IECs may respond to β-glucans by the secretion of pro-inflammatory chemokines in a Dectin-1- and Syk-dependent pathway, via receptors and a signaling pathway described to date only for myeloid cells. These findings highlight the importance of fungi-IEC interactions in intestinal inflammation.

MicroRNA expression signatures in intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMN) represent a spectrum of tumors that range from low-grade (LG) dysplastic tumors to invasive cancer. Identification of IPMN at high risk for malignant transformation is important for the prevention and early treatment of pancreatic cancer. The roles of microRNA expression in the development of IPMN have not been extensively evaluated.

METHODS

Expression patterns of 846 human microRNAs (miRNAs) was analyzed using microRNA microarray in 55 tissues, including LG IPMN (n = 10), moderate-grade (MG) IPMN (n = 5), high-grade (HG) IPMN (n = 5), invasive cancer with IPMN (IPMC; n = 10), pancreatic ductal adenocarcinoma without IPMN (PDA; n = 5), LG IPMN extracted from specimens that contain IPMC (LG_Ca; n = 10), and normal pancreatic tissues (n = 10).

RESULTS

Fourteen miRNAs were differentially expressed in all IPMN tissues compared with normal pancreatic tissue. Expression level of 3 miRNAs was proportional to dysplasia level. Hierarchical clustering demonstrated grouping of 2 IPMN subgroups: LG and MG IPMN verses HG IPMN and IPMC. Expression of 15 miRNAs was significantly different between these groups. LG_Ca tissues clustered with the HG IPMC group, and 12 miRNAs were differentially expressed in LG_Ca, HG lesions, and IPMC compared with LG lesions. The expression patterns of selected miRNAs were validated using quantitative reverse-transcription real-time polymerase chain reaction. Hierarchical clustering demonstrated microRNA expression profile in IPMC was significantly different from PDA, suggesting that different pathways are involved in these cancer types.

CONCLUSION

This study demonstrates that miRNAs are involved in the development and progression of IPMN. We identified potential targets for diagnosis, prognostication, and treatment of IPMN.

Vitamin D inhibits proliferation and profibrotic marker expression in hepatic stellate cells and decreases thioacetamide-induced liver fibrosis in rats

BACKGROUND AND AIM

Hepatic stellate cells (HSCs) are key participants in liver fibrosis development. 1,25(OH)(2)D(3), the active form of vitamin D, has antiproliferative properties and antifibrotic potential, as well as a role in extracellular matrix and matrix metalloproteinase (MMP) regulation in renal and lung fibrosis. Little is known about the role of 1,25(OH)(2)D(3) in liver and its involvement in liver fibrosis. Therefore, we investigated the antiproliferative and antifibrotic effects of 1,25(OH)(2)D(3) in primary cultured HSCs and in a rat model of liver fibrosis induced by thioacetamide (TAA).

METHODS

Primary HSCs were isolated from rats' livers and treated with 1,25(OH)(2)D(3). Proliferation was examined by bromodeoxyuridine. Vitamin D receptor (VDR) expression and several fibrotic markers were detected by western blot analysis and real-time PCR. Collagen Iα1 and MMP-9 promoter activity were measured by luciferase assay. MMP-9 enzymatic activity was investigated by zymography. VDR silencing was performed by sh-RNA. An in vivo study was performed on TAA-induced liver fibrosis model in rats treated with or without 1,25(OH)(2)D(3). The fibrotic score and collagen deposition were determined by Masson and by Sirius red staining.

RESULTS

While VDR was highly expressed in quiescent HSCs, its expression decreased up to 40% during activation. Addition of 1,25(OH)(2)D(3) to activated HSCs stimulated VDR expression. 1,25(OH)(2)D(3) suppressed HSC proliferation and cyclin D1 expression by ~50% and tissue inhibitor of metalloproteinase 1 (TIMP-1) by 60% and led to a 40% downregulation of collagen Iα1 expression. Moreover, 1,25(OH)(2)D(3) increased MMP-9 activity by 30%. Silencing VDR by sh-RNA demonstrated that suppression of cyclin D1 and collagen Iα1 protein expression was VDR dependent. Treatment with 1,25(OH)(2)D(3) significantly reduced extracellular matrix deposition and lowered the fibrotic score in TAA-induced liver fibrosis.

CONCLUSION

1,25(OH)(2)D(3) has antiproliferative and antifibrotic effects on liver fibrosis in in vitro and in vivo models and may be considered as having potential therapeutic value.

Intraductal papillary mucinous neoplasm of the pancreas: associated cancers, family history, genetic predisposition?

BACKGROUND

High rates of extrapancreatic malignancies (EPM) have been observed in patients with intraductal papillary mucinous neoplasm (IPMN). IPMN in patients with familial pancreatic cancer have also been reported. Our purpose was to evaluate the association of IPMN with EPM, malignancies in family members, and germline BRCA1 and BRCA2 mutations.

METHODS

Using retrospective analysis on prospectively collected data from 82 patients with IPMN and direct contact for familial cancer history, data were compared with those of 150 patients with pancreatic ductal adenocarcinoma (PDAC). The common germline mutations in the BRCA1 and BRCA2 genes were evaluated on available IPMN patients.

RESULTS

EPM rates were greater in IPMN than PDAC patients (P = .002). Malignancies in first-degree relatives, specifically pancreatic cancer, were more common among IPMN than PDAC patients (P = .028). IPMN patients with EPM had high rates of relatives with colorectal cancer (31%). Two of the 51 genetically tested patients (4%) were BRCA2 mutation carriers, and both had first-degree relatives with pancreatic cancer. One patient fulfilled the Amsterdam criteria for hereditary nonpolyposis colon cancer; however, the neoplasm was microsatellite stable.

CONCLUSION

Our results demonstrated high rates of EPM among IPMN patients. There was an increased rate of cancer in families of IPMN patients, specifically pancreatic cancer. A high rate of colorectal cancer in families of IPMN patients who have EPM was also observed. These findings suggest a genetic component in the pathogenesis of IPMN. Possible genetic changes include BRCA2 mutations, which are found in 25% of IPMN patients with a family history of pancreatic cancer.

Reciprocal regulation of CXCR4 and CXCR7 in intestinal mucosal homeostasis and inflammatory bowel disease

IBDs are characterized by increased influx of immune cells to the mucosa of genetically susceptible persons. Cellular migration to injury sites is mediated by chemokines. CXCL12 is a ubiquitous, constitutive chemokine that participates in stem cell proliferation and migration and mediates T lymphocyte migration to inflamed tissues. We have recently reported that CXCL12 and its receptor, CXCR4, are expressed in normal and more prominently, inflamed human intestinal mucosa. However, the interactions and roles of CXCL12 and its receptors, CXCR4 and the recently discovered CXCR7, in intestinal inflammation have not been defined. In the present study, we further dissected the effects of CXCL12 on lymphocytes in intestinal homeostasis and inflammation and delineated the interplay between CXCL12 and its receptors CXCR4 and CXCR7. To that end, fresh mononuclear cells were isolated from mucosa and PB of healthy or IBD patients. Phenotypical and functional assays were conducted using flow cytometry, Transwell migration chambers, and ELISA. The data show that CXCL12-mediated migration of T cells is CXCR4- but not CXCR7-dependent. T cell activation reciprocally regulates CXCR7 and CXCR4 expression and migratory capacity. IBD PBTs expressed more CXCR7 than normal PBTs. Finally, T cells attracted by CXCL12 are mostly of a memory phenotype. In conclusion, the present study suggests that the interplay between CXCL12 and its receptors affects homeostasis and inflammation in the intestinal mucosa.

FOXP3 expression in duodenal mucosa in pediatric patients with celiac disease

OBJECTIVE

It was the aim of this study to evaluate the number of 2 lymphoid subpopulations, CD8(+) cells and FOXP3(+), in the duodenum mucosa from pediatric celiac patients.

METHODS

Tissue sections prepared from paraffin-embedded biopsies of the descending duodenum of 61 celiac patients with Marsh grade 1 (M1), M2 and M3 disease and biopsies from 21 age-matched non-celiac (NC) patients were immunohistostained with anti-CD8 or FOXP3 antibodies.

RESULTS

The histological Marsh grade correlated with the mean number of FOXP3(+) cells in the lamina propria (LP) mucosa (8.9 ± 1.1, 6.8 ± 2.4, 24.5 ± 2.6 and 31.1 ± 2.8 for NC, M1, M2 and M3 biopsies, respectively; p < 0.001). Using a cutoff point of 15 cells, 95% of NC and 88% of M1 biopsies had a mean of <15 FOXP3(+) cells compared with 14% for M2 and 13% for M3 biopsies. The number of FOXP3(+) cells in the epithelial mucosa also correlated with transglutaminase type 2 serum levels from the celiac patients. Unlike the FOXP3(+) cells, CD8(+) lymphocytes were present in both LP and surface epithelial mucosa and significantly different only in the LP mucosa of the M2 and M3 groups.

CONCLUSION

The number of FOXP3(+) cells is substantially increased in the mucosa of celiac patients at advanced stages. Characterization of the activity of these cells in celiac and in other inflammatory bowel diseases will enable us to understand the significance of these cells in celiac disease.

CCL2 (pM levels) as a therapeutic agent in Inflammatory Bowel Disease models in mice

BACKGROUND

Chemokines regulate the pathways that restrict homing of specific subsets of immune cells, and thereby fine tune the immune response at specific lymphoid and peripheral tissues. CCL2 is a chemokine that induces migration of monocytes, memory T cells, and dendritic cells. Previously, we demonstrated that pM levels of CCL2 dramatically inhibit migration of T cells. The aim was to test whether subphysiological doses of CCL2 can ameliorate murine colitis and inflammation-induced colorectal cancer.

METHODS

TNBS (2,4,6 trinitrobenzene sulfonic acid) colitis and dextran sodium sulfate (DSS) colitis were induced in Balb/c and C57BL/6 mice, respectively. Mice were treated daily with intraperitoneal CCL2 injections. Disease activity was assessed clinically, histologically, and by measuring inflammatory cytokine levels. In addition, an inflammatory cancer model was induced by azoxymethane-DSS (AOM-DSS) in Balb/c mice. Mice were treated daily with CCL2 for 11 weeks and then assessed for number of tumors in the colons.

RESULTS

Daily administration of CCL2 (60-120 ng) significantly decreased the development of TNBS- and DSS-induced colitis. In a DSS-AOM model, CCL2-treated mice developed significantly fewer tumors (P < 0.005) at 11 weeks. Chronic inflammation in the CCL2-treated mice was significantly less pronounced as compared to phosphate-buffered saline-treated mice.

CONCLUSIONS

Administration of pM levels of CCL2 significantly inhibits migration of T cells in amelioration of TNBS and DSS colitis and inhibits development of colorectal cancer in an AOM-DSS colitis model in mice. Thus, pM levels of CCL2 may be clinically beneficial as an antiinflammatory agent in IBD.

Clinical presentation can predict disease course in patients with intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND

Preoperative diagnosis of malignancy within intraductal papillary mucinous neoplasm of the pancreas (IPMN) solely by clinical or radiological findings is not always possible. We sought a correlation between preoperative clinico-radiological findings and outcome.

METHODS

A prospective database of pancreatic resections for IPMN (2002-2008) and a retrospective pathological revision of all pancreatic cancer specimens (1995-2001) were analyzed. The patients were grouped into asymptomatic with preoperative diagnosis of IPMN (group 1), symptomatic with a preoperative diagnosis of IPMN (group 2), and those with a preoperative diagnosis of pancreatic cancer whose specimen revealed a background of IPMN (group 3). The groups were compared for demographics, clinical presentation, pathological findings, and outcome.

RESULTS

Of the 62 patients with IPMN, 19 were in group 1, 23 in group 2, and 20 in group 3. Their median age (range) was 65.6 (46-80), 67 (50-84), and 73.4 (57-86) years, respectively. The clinical presentation for groups 2 and 3 included abdominal pain (56% vs. 32 %), weight loss (8% vs. 52%), obstructive jaundice (4% vs. 57%), pancreatitis (22% and 5%), and new onset of diabetes (14% and 44%). Invasive cancer was found in one patient in group 1 (5.2%), two patients in group 2 (8.7%), and all patients in group 3. IPMN was present in 23 of 217 (10.6%) of all resected pancreatic cancer specimens. Five year survival for patients with invasive disease was 47% and 92% for patients with noninvasive disease (mean follow-up 37.6 months).

CONCLUSIONS

Benign IPMN can usually be differentiated from adenocarcinoma preoperatively. The clinical presentation is highly indicative of disease course.

CXCL12 is a constitutive and inflammatory chemokine in the intestinal immune system

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by increased lymphocytic infiltrate to the lamina propria (LP) and upregulation of inflammatory chemokines and receptors. CXCL12 is a constitutive chemokine involved in lung, brain, and joint inflammation. We hypothesized that CXCL12 and its receptor, CXCR4, would have a constitutive and inflammatory role in the gut.

METHODS

Intestinal epithelial cells (IECs) and T lymphocytes were isolated from intestinal mucosa of IBD and control patients undergoing bowel resection. Autologous T cells were isolated from peripheral blood (PB). CXCL12 and CXCR4 expression by IECs was assessed by polymerase chain reaction and immunohistochemistry, lymphocyte phenotype by flow cytometry, and migration by Transwells.

RESULTS

IECs expressed CXCL12 and expression was increased and more diffuse in IBD compared to normal crypts (ulcerative colitis [UC] > Crohn's disease [CD], inflamed > noninflamed). CXCR4 was expressed by IECs, LP T cells (LPTs), and PB T cells (PBTs), and CXCR4+ cells were increased in IBD LP in situ. PBTs and LPTs from all patients had a high and comparable migration toward CXCL12 (P < 0.0001 and P < 0.05 vs. medium, respectively). Migration toward IBD-IEC-derived supernatant was significantly higher compared to normal. Antibodies against CXCR4 and CXCL12 blocked migration.

CONCLUSIONS

CXCL12 is expressed by normal IECs and upregulated and differentially distributed in IBD IECs. CXCR4 is expressed by IECs and LPTs, and CXCR4+ cells are significantly increased in IBD LP. CXCL12 is chemotactic for both PBTs and LPTs. Thus, CXCL12 and CXCR4 have a constitutive and inflammatory role in the intestinal mucosa and their selective therapeutic manipulation may be considered in IBD management.

Effects of 5-FU on DNA synthesis and cytotoxicity of human lymphocytes induced by IL-2, TGF-beta3 and PGE2

BACKGROUND

Low 5-fluorouracil (5-FU) concentrations cause a significant increase in DNA synthesis in mitogen-activated human lymphocytes.

MATERIALS AND METHODS

We explored 2.5 microM 5-FU-induced DNA synthesis by testing 5-FU activity in hypoxanthine-aminopterin-thymidine (HAT)-containing medium, and its effect on thymidylate synthase (TS) activity and CD25 expression in interleukin (IL)-2-activated human peripheral blood mononuclear cells (PBMCs) and the combined effects with prostaglandin E(2) (PGE(2)) and transforming growth factor (TGF)-beta3.

RESULTS

The co-stimulatory effect of 2.5 microM 5-FU on DNA synthesis was abrogated in HAT-cultured medium. 5-FU substantially reduced TS activity by 50% in IL-2-activated PBMCs. 5-FU combined with TGF-beta3 and PGE(2) did not alter their inhibitory effects on IL-2-activated natural killer cell cytotoxicity, but substantially affected increased DNA synthesis of cells cultured in IL-2 and co-cultured with 10 ng/ml TGF-beta3 and 10 microM PGE(2).

CONCLUSION

Low 5-FU concentrations increase DNA synthesis in lymphocytes and exert a co-stimulatory activity on TGF-beta3 and PGE(2) modulation of IL-2-activated lymphocytes.

Utilization of murine laparoscopy for continuous in-vivo assessment of the liver in multiple disease models

Background

Current strategies for follow up of murine models of liver disease are flawed by inability to continuously monitor disease progression in the tissue level, and necessitate sacrifice of animals for tissue sampling.

Aims

In this study we aimed at developing a safe repetitive tool for sampling livers in vivo, by utilization of a miniaturized endoscopy system for laparoscopic liver biopsies and for injection of tumor cells into livers.

Results

We report the development of a protocol for murine laparoscopy that allows repeated visualization of murine intra-abdominal organs. The system enables safe and repeated liver biopsies in mice and rats, yielding adequate tissue for histological staining and RNA extraction. In addition, injection of tumor cells into livers facilitates under-vision implantation of hepatic tumors in liver, followed by visualization of tumor growth.

Conclusions

Murine laparoscopy may be employed as a novel imaging modality for continuous assessment and manipulation of chronic liver disease models.

Galectin-3 expression in pouchitis in patients with ulcerative colitis who underwent ileal pouch-anal anastomosis (IPAA)

Galectin-3, an endogenous pleiotropic beta-galactoside-binding protein, which is expressed by various malignant and normal cells, regulates many biological and pathological processes, including inflammation. In the present study, we tested a possible correlation between the severity of pouchitis in patients with ulcerative colitis who underwent ileal pouch-anal anastomosis (IPAA) and the presence of galectin-3(+) macrophages in pouch mucosa. Paraffin-embedded pouch biopsies from patients with normal pouch function or chronic and recurrent acute pouchitis were immunohistostained with galectin-3, CD68, and smooth muscle actin (SMA) antibodies. Microscopic examination was performed in a blinded fashion. There was a significant decrease in the staining index of galectin-3 in the subepithelial macrophages in patients with chronic pouchitis (0.53, P=0.001; n=12) or recurrent acute pouchitis (0.43, P=0.008; n=10) when compared to patients with no clinical manifestations of pouchitis (0.63, n=12). No significant differences were noted in the lamina propria of small intestine biopsies from the same patients (from 0.63 to 0.68, P=0.24). Galectin-3 staining was restricted to CD68(+) macrophages and not present in myofibroblasts. Clinical manifestation of pouchitis is inversely correlated with galectin-3 expression in the pouches' subepithelial lamina propria macrophages.

Competitive inhibition of leptin signaling results in amelioration of liver fibrosis through modulation of stellate cell function

Leptin signaling is involved in T-cell polarization and is required for profibrotic function of hepatic stellate cells (HSCs). Leptin-deficient ob/ob mice do not develop liver fibrosis despite the presence of severe long-standing steatohepatitis. Here, we blocked leptin signaling with our recently generated mouse leptin antagonist (MLA), and examined the effects on chronic liver fibrosis in vivo using the chronic thioacetamide (TAA) fibrosis model, and in vitro using freshly-isolated primary HSCs. In the chronic TAA fibrosis model, leptin administration was associated with significantly enhanced liver disease and a 100% 5-week to 8-week mortality rate, while administration or coadministration of MLA markedly improved survival, attenuated liver fibrosis, and reduced interferon gamma (IFN-gamma) levels. No significant changes in weight, serum cholesterol, or triglycerides were noted. In vitro administration of rat leptin antagonist (RLA), either alone or with leptin, to rat primary HSCs reduced leptin-stimulated effects such as increased expression of alpha-smooth muscle actin (alpha-SMA), and activation of alpha1 procollagen promoter.

CONCLUSION

Inhibition of leptin-enhanced hepatic fibrosis may hold promise as a future antifibrotic therapeutic modality.

Effects of 5-fluorouracil on human mitogen-activated peripheral blood lymphocytes from healthy individuals

BACKGROUND

The effect of 5-fluorouracil (5-FU) on activated lymphocytes was explored.

MATERIALS AND METHODS

The in vitro effects of 5-FU on DNA synthesis in mitogen-activated lymphocytes from healthy volunteers were compared to those of the antimetabolites doxorubicin, cyclophosphamide and 6-mercaptopurine. These effects were assessed by alterations in the phenotypic profile and the percentage of cells in various phases of the cell cycle, as well as by the secretion of T helper (Th)1 and Th2 cytokines (ELISA).

RESULTS

Unlike 5-FU, the other antimetabolites failed to augment DNA synthesis in activated lymphocytes. The effect of 5-FU correlated with an increase in the percentage of cells in the S-phase and caused an increased in CD4+ cells, a decrease in CD56+ cells and a shift of the cytokine secretion pattern from Th2 to Th1.

CONCLUSION

5-FU exhibited a unique effect on DNA synthesis in activated lymphocytes which was accompanied by selective effects on various lymphocyte subpopulations.

Comprehensive pouch clinic concept for follow-up of patients after ileal pouch anal anastomosis: report of 3 years' experience in a tertiary referral center

BACKGROUND

We designed and evaluated a novel concept in enhancing postoperative care of patients following restorative proctocolectomy (RPC) for ulcerative colitis (UC) and determined the risk factors, incidence, and nature of RPC-associated complications in this population.

METHODS

The study cohort consisted of consecutive UC patients post-RPC attending a comprehensive pouch clinic run by a gastroenterologist and a colorectal surgeon in a tertiary care medical center (from January 2003 to December 2005). Data were collected on their medical history, physical examination, laboratory tests, pouch endoscopy and biopsies, and anonymous in-house patient satisfaction questionnaires mailed to the first 90 patients. Assessment was also done on data regarding risk factors, incidence, and nature of RPC-associated complications.

RESULTS

A total of 120 UC patients with a functioning pouch visited the clinic: mean age 37 years, range 13-75; 57 males; mean disease duration 11 years; mean follow-up 65 months. Of the 55 patients who responded to the questionnaire, 48 (87%) felt that the comprehensive clinic significantly improved the quality of their care. The major complications were pouchitis (52%), extraintestinal manifestations, pouch-related fistula, and mechanical dysfunction. The risk factors for the development of pouchitis were time since surgery, >1-stage surgery, and reason for surgery (acute exacerbation/intractable disease more than dysplasia/cancer); the latter was the only independent risk factor.

CONCLUSIONS

The pouch clinic concept significantly enhanced patient satisfaction. The most common RPC-associated complication was pouchitis. Risk factors for developing pouchitis were duration since operation, >1-stage operation, and indication for surgery.

A novel assessment of the quality of immunohistostaining overcomes the limitations of current methods

Quality assurance has become an integral part of surgical pathology. Despite the development of interdisciplinary quality systems, however, the means for objective analysis in surgical pathology are limited. Immunohistostaining is a multi-factorial procedure that depends on the quality of reagents and antibodies employed in the process and on technical methodology. In the present study, we aim to establish a straightforward procedure for objective quality evaluation of the components involved in immunohistostaining. The quality of two of these components, the primary antibody and the automated staining device, was assessed by employing each component from two different sources, one serving as the test substance and the second as the reference. Assessment was performed by at least two pathologists in a blinded fashion using pre-established quality criteria and scores. The quality analysis of two automated devices revealed a significant difference between the reference and tested devices (3.5+/-1.7 and 4.2+/-1.5, respectively, P>0.05), while the analysis of two selected antibodies did not reveal any statistical difference. The described method provided objective quality assessment of selected components affecting immunohistostaining by elaborating numeric values that enabled statistical analysis. This approach is applicable to any given component in various surgical pathology procedures.

In vitro modulation of interleukin-2-mediated human peripheral mononuclear cell proliferation and antitumor cytotoxicity by 5-fluorouracil

BACKGROUND

Studies on cancer patients undergoing chemotherapy have shown inhibitory effects of anticancer drugs on certain immune activities.

MATERIALS AND METHODS

The in vitro effect of 5-(FU) fluorouracil was studied on both lymphocyte proliferation and natural killer (NK) cell antitumor cytotoxicity following incubation of peripheral mononuclear cells (PBMCs) from healthy donors with interleukin (IL)-2, phytohemagglutinin A (PHA) and pokeweed mitogen (PWM).

RESULTS

Activation of PBMCs with IL-2, PHA and PWM in the presence of 250 and 2500 microM of 5-FU caused a marked decrease in both the induction of activated natural killer (ANK) cell cytotoxic activity and DNA synthesis, while 2.5 microM increased DNA synthesis by 195%, 58% and 222% for IL-2, PHA and PWM, respectively, more than cells cultured without the drug. No effect of 5-FU was noted on mature ANK cells.

CONCLUSION

5-FU exhibits diverse effects on lymphocyte proliferation and on the generation of ANK antitumor cytotoxic activity.

Role of CYP2D6 polymorphism in predicting liver fibrosis progression rate in Caucasian patients with chronic hepatitis C

OBJECTIVE

Previous studies have demonstrated that CYP2D6 polymorphism is associated with liver cirrhosis. The aim of the present study was to find out whether CYP2D6*4, the poor metabolizer allele can predict fibrosis progression rate.

METHODS

Seventy-five Caucasian patients with chronic hepatitis C infection were recruited. They were divided into two groups, 'fast fibrosers' and 'slow fibrosers', according to Poynard's fibrosis progression curves. Sixty-two patients underwent liver biopsy. Twenty healthy neonates were included as control population. DNA was extracted from peripheral blood and CYP2D6*4 was tested by polymer chain reaction using fluorescent hybridization probes in a lightCycler instrument.

RESULTS

Forty-two patients were classified as 'fast fibrosers' and 33 patients as 'slow fibrosers'. The frequency of CYP2D6*4 allele in the 'fast fibrosers' (34.5%) was significantly higher compared with the 'slow fibrosers' (15%) (P-value=0.007). There was no significant difference between the frequency of CYP2D6*4 in the 'slow fibrosers' (15%) compared with the controls (12.5%). Carrier state of CYP2D6*4 was the only covariate that was significantly positively correlated with fast progression to cirrhosis (odds ratio=6.5, P=0.01).

CONCLUSION

This study indicates for the first time that CYP2D6 genotype might be a significant predictor of liver fibrosis progression rate in chronic hepatitis C patients.

Characteristics of familial juvenile polyps expressing cyclooxygenase-2

OBJECTIVES

Familial juvenile polyposis (FJP) is a dominant genetic disorder characterized by colorectal, gastric, and small bowel juvenile polyps, and high risk for gastrointestinal cancer. Patients are treated by repeated endoscopic polypectomies and elective surgery. We determined the characteristics of FJP polyps expressing cyclooxygenase-2 (COX-2).

METHODS

A total of 115 colorectal and 6 gastric polyps were available from 17 FJP patients. Comparison tissues were 18 sporadic juvenile colorectal polyps, 6 gastric hyperplastic polyps, 9 normal colons, and 3 colorectal cancers (CRCs). Histology sections were classified and stained for COX-2. The polyps' epithelium and stroma and comparison tissues were quantified for COX-2 by: area of staining (0-3) x intensity (0-3). Epithelial and stromal scores (0-9) and total scores (0-18) were evaluated in relationship to patient's age, polyp site, size, dysplasia, and stromal cellularity.

RESULTS

Colonic FJP polyps mean total COX-2 score was 10.3 +/- 6.0, and that of sporadic juvenile polyps 3.6 +/- 2.2 (p < 0.01), and in contrast to the latter, FJP COX-2 scores increased significantly (p < 0.01) with polyp size. Linear regression analysis showed significant associations of COX-2 in FJP polyps with dysplasia (p < 0.01), stromal cellularity (p < 0.01), size (> or =1.5 cm) (p= 0.02), and site (right colon) (p= 0.01), and not with age. COX-2 total scores of gastric FJP polyps and hyperplastic polyps were similar.

CONCLUSIONS

Expression of COX-2 in FJP polyps and its association with size and dysplasia suggest that, in these patients, chemoprevention with selective COX-2 inhibitors might be a useful adjunct therapy to colonoscopic polypectomy.

Cyclooxygenase-2 expression in the hereditary mixed polyposis syndrome

Hereditary mixed polyposis syndrome (HMPS), characterized by hyperplastic, juvenile, admixed, serrated adenomas and eventually colorectal cancer, is managed by repeated polypectomy and surgery. We determined if HMPS polyps express cyclooxygenase-2 (COX-2). Nineteen recent HMPS polyps, from five family members, were stained for COX-2. Polyps' epithelium and stroma and comparison tissues (normal colonic mucosa [9], sporadic juvenile polyps [18], colorectal cancers [3]) were quantified for COX-2 by: area of staining (0-3) x intensity (0-3). Epithelial, stromal, and total scores were evaluated in relationship to histology and dysplasia. HMPS polyps COX-2 mean epithelial (5.0+/-3.0), stromal (6.9+/-1.9), and total (11.8+/-4.6) scores were significantly higher (P < 0.01) than sporadic juvenile polyps (0.6+/-0.7, 3.1+/-2.2, and 3.6+/- 2.2 respectively), while colorectal cancer scored 9, 9, and 18. There was a positive association (P < 0.01) among histology, degree of dysplasia, and COX-2 expression. COX-2 expression in HMPS polyps and its association with dysplasia suggest that chemoprevention might be a useful adjunct therapy.

Extramammary Paget's disease of the perianal region

OBJECTIVE

Perianal Paget's disease (PPD) is a rare entity. The standard treatment for either in situ or invasive extra mammary Paget's disease (EMPD) is surgical excision. Local recurrence and morbidity from surgery, especially in the elderly, can, however, be high. The aim of this article is to review our experience with PPD and question the currently preferred treatment approaches in light of its histopathology and therapeutic outcome.

PATIENTS AND METHODS

A chart review of our patients with PPD from 1996 to 2002 was carried out to determine their outcome after treatment. Data from review of the literature are presented.

RESULTS

Five patients with in situ disease (four females, median age 68 years) were diagnosed as having PPD. A complete surgical excision was attempted in 4 patients and the fifth was treated by photodynamic therapy. At present, all patients are alive, two are free of disease, one has persistent disease and two have local recurrence.

CONCLUSION

Considering the significant rate of recurrence even after wide local excision, the extent of surgery needed and the good prognosis with long-term survival, we question whether nonsurgical modalities should be considered in place of surgery as primary treatment for noninvasive PPD, with radical surgery being reserved for failures or invasive disease.

An audit of familial juvenile polyposis at the Tel Aviv Medical Center: demographic, genetic and clinical features

Familial juvenile polyposis (JP) is an uncommon genetic disorder that, if untreated, can lead to gastrointestinal cancer. To evaluate familial JP prevalence, phenotypic manifestations, causative mutations, treatment and compliance for diagnosis and follow-up in our registry. Since 1993 our familial JP patients were registered, followed-up before and/or after surgery and their families encouraged to have mutation analysis, endoscopic screening and treatment. Ten pedigrees were identified, all Jewish, but only one was Ashkenazi, six were Sepharadi and three were Oriental; the only mutation found was BMPR1A in two of six pedigrees examined. Of 139 first-degree relatives at risk for JP, 62 (45%) had JP or cancer; 56 (40.3%) were available for follow-up and 35 entered the registry. Of these, 71% reported rectal bleeding, 40% had <20 colonic polyps, 31% had 20-100 polyps; 2 had >100 gastric polyps. Cancer occurred in 22.9% (6 colonic, 2 gastric) before familial JP diagnosis or during follow-up elsewhere or non-compliance for follow-up; however, 1 gastric cancer developed during our treatment. In 46% the initial clinical-pathological diagnosis was incorrect. Compliance for evaluation and follow-up of pedigree members and individual familial JP patients was inadequate in 20% and 26%, respectively. Familial JP does not occur in the Israeli Ashkenazi Jewish population at the expected proportion; it is often misdiagnosed and is inadequately recognized in Israeli non-Jews. Mutations were identified in only a minority of pedigrees despite comprehensive screening. The inadequate compliance for screening and follow-up needs to be addressed by educating the public, health care workers and health insurances.