- Email: [email protected]
Su2002 Nonmyeloablative Stem Cell Therapy for Perianal Fistulizing Crohn's Disease: A Systematic Review of Safety and Efficacy
Su2003
The Role of the Histone Methyltransferase EZH2 in the Mouse Intestinal Epithelium Reina Aoki, Klaus H. Kaestner
Ultrahigh Speed Optical Coherence Tomography With Micromotor Imaging Probe Enables Three-Dimensional Visualization of Mucosal Surface Patterns in the Gastrointestinal Tract Osman O. Ahsen, Hsiang-Chieh Lee, Kaicheng Liang, Michael G. Giacomelli, Tsung-Han Tsai, Zhao Wang, Marisa Figueiredo, Qin Huang, Benjamin Potsaid, James G. Fujimoto, Hiroshi Mashimo
Background and Aims: Dynamic epigenetic changes are necessary during development and differentiation of mammalian tissues. Because the intestinal epithelium turns over rapidly, it requires the execution of transcriptional changes from stem to differentiated cells. While multiple transcription factors are known to contribute to intestinal differentiation, the role of epigenetic modifiers in this process remains unknown. As histone modifications are labile, it is possible that histone modifiers are involved in the transcriptional regulation of the intestinal epithelium. Our aim was to investigate whether the histone methyltransferase Ezh2 is required for intestinal epithelial cell differentiation. Methods: We determined the expression pattern of Ezh2 in the mouse intestine using immunofluorescence staining. To assess the function of Ezh2 in intestinal epithelial differentiation, we inhibited Ezh2 activity in intestinal organoid using an Ezh2-specific inhibitor. Results: Ezh2 immunofluorescence indicated that Ezh2 is expressed highly in crypt base columnar stem cells and proliferative cells in transit amplifying cells, but expression gradually decreases as cells differentiate as the migrate up the villus. Inhibition of Ezh2 activity b in crypt organoid culture showed an increase in the number of crypt buds as compared to the control crypt organoids. Inhibition of Ezh2 activity also resulted in higher expression of ZO-1, suggesting accelerated establishment of epithelial cell polarity. Our data indicate that Ezh2 may play a role in balancing cell maturation and crypt expansion in the intestinal epithelium.
ABSTRACT BODY: BACKGROUND/AIMS: Three-dimensional endomicroscopy using optical coherence tomography (3D-OCT) provides volumetric images of tissue microstructure without requiring extrinsic contrast agents. Commercially available OCT systems have limited frame rates and typically use proximal rotation and pullback mechanisms to scan the imaging beam across the tissue. These two factors limit the ability to generate high quality en face images of aberrant mucosal surface patterns, which correlate with the presence and grade of dysplasias. In this study, we present a prototype ultrahigh speed 3D-OCT system with an advanced imaging probe using distal micromotor scanning. This system enables en face 3D-OCT images that visualize the mucosal surface patterns in a variety of GI structures in vivo. METHODS: The study was performed at the VA Boston Healthcare System (VABHS) under a study protocol approved by the VABHS, Harvard Medical School and M.I.T. We used a prototype 3D-OCT system that has an imaging speed (axial scan rate) of 600 kHz, which is ~10 times faster than commercially available 3D-OCT imaging systems. Scanning of the imaging beam is performed using a micromotor at the distal end of the OCT probe. The probe was passed through the accessory channel of an Olympus double channel endoscope (GIF-2TH180) to allow coregistration of images with biopsies. RESULTS: The combined advantages of ultrahigh speed and distal scanning of the new 3D-OCT system and probe enables visualization of mucosal surface patterns with unprecedented clarity. Fig. 1(A) demonstrates a volumetric reconstruction of a 3D-OCT dataset acquired in the gastric body of a patient. While cross sectional images give information on the layered architecture of the tissue, gastric folds and pit pattern can be visualized in the en face direction. Fig. 1(C) shows the squamocolumnar junction (SCJ) of a patient with Barrett's esophagus (BE), where the squamous epithelium (SE) appears as a smooth layer, whereas the area with BE has a well-defined pit pattern architecture. Fig. 1(D) shows a region of the esophagus a BE patient immediately after radiofrequency ablation (RFA), where residual BE that is missed by the RFA application can be observed. CONCLUSIONS: This study demonstrates that ultrahigh speed 3D-OCT system with a distal scanning micromotor probe can generate cross-sectional and en face images from the same dataset, yielding a more comprehensive evaluation of tissue architecture. Moreover, imaging can be performed even after biopsies or ablations, and can survey margins of endoscopic resections which is not possible with confocal endomicroscopy using exogenous contrast agents. Therefore, this novel imaging system has the potential to greatly improve the clinical utility of 3D-OCT. ACKNOWLEDGEMENT: NIH 5R01-CA075289-16, R44-CA101067-06, AFOSR FA9550-12-1-0499, and FA9550-10-10551.
Su2002 Nonmyeloablative Stem Cell Therapy for Perianal Fistulizing Crohn's Disease: A Systematic Review of Safety and Efficacy Maneesh Dave, Kathan Mehta, William A. Faubion Background & Aims: Perianal fistula is common in Crohn's disease (CD) patients and results in a more disabling course of disease requiring biologics and in 10-20% a permanent ostomy. Recently, a number of studies have utilized autologous or allogeneic stem cells as a nonmyeloablative stem cell therapy (SCT) for perianal fistulizing Crohn's disease (PCD). However, the data on safety and efficacy is limited given the small sample size of the original studies. We performed a systematic review of the literature following Cochrane guidelines to determine the safety and efficacy of SCT for PCD. Methods: A systematic search of bibliographic databases (PubMed, EMBASE & GI meeting abstracts) from inception through November 2013 was performed by two independent reviewers. Studies were selected based on use of SCT for treatment in patients with and without PCD. Total adverse events (TAE) were pooled across studies and were further categorized as serious (SAE) and non-serious (NSAE). Efficacy was defined as fistula healing or closure as per the criteria used by investigators of their study. Risk of bias was assessed for all included studies using the Cochrane risk of bias assessment tool. Results: Of the 5107 abstracts reviewed, 12 promising articles were reviewed in detail. 6 manuscripts with a total of 288 subjects met the study inclusion criteria. 47 patients with PCD and 150 patients without PCD underwent SCT and 91 patients with perianal fistulae (with or without underlying CD) received fibrin glue therapy. In PCD patients receiving SCT, 8.9% (4/47) experienced SAE and 22.5% (9/40) experienced NSAE. There was no death or malignancy in the SCT group (table 1). In PCD patients who underwent SCT between 37.5% to 75% (n=47) had healing of at least one fistula compared to 14.3% in PCD patients who had fibrin glue injection alone. In non-PCD patients with fistula who received SCT the fistula closure rate varied between 32.3% to 71% (n=150). Three studies used MRI for assessment of fistula closure in PCD. The mean follow up time after SCT ranged from 3 to 22 months. 4 studies utilized autologous adipose stem cells, 1 study used autologous bone marrow stem cells and 1 study used allogeneic adipose stem cells for SCT. Absence of controls in four of six studies precluded a meta-analysis. There was high risk of attrition and selection bias in the included studies. Conclusions: This systematic review suggests that SCT is safe and efficacious for treatment of perianal CD but is limited by relatively small number of patients and high risk of bias. This review highlights the significant drawbacks of current studies including need for; a control group, standardized definitions of AE's, inadequate reporting of AE's, and longer duration of follow up. SCT is a promising new treatment modality for PCD that needs further safety and efficacy data in larger clinical trials. Adverse events from nonmyeloablative stem cell therapy for perianal fistulizing Crohn's disease.
Figure 1: (A) Volumetric reconstruction of a 3D-OCT dataset acquired in the gastric body of a patient showing cross sectional as well as en face visualization of the gastric folds and pit patterns. (B) Zoomed view of the en face image shown in (A). (C) Squamocolumnar junction (SCJ) of a patient with Barrett's esophagus (BE) showing a region with smooth squamous epithelium and the BE region with well-defined pit patterns. (D) A region of a patient with BE immediately after radiofrequency ablation (RFA), where the encircled area shows BE glands that are likely missed by the RFA. Scale bars: 500um. Su2004 Volumetric Laser Endomicroscopy in Barrett's Esophagus: A Study on Histological Correlation Anne-Fré Swager, David F. Boerwinkel, Daniel M. de Bruin, Guillermo J. Tearney, Cadman L. Leggett, Bas L. Weusten, Dirk J. Faber, Ton G. van Leeuwen, Sybren L. Meijer, Wouter L. Curvers, Jacques J. Bergman Background: Volumetric laser endomicroscopy (VLE) is a novel balloon based optical coherence tomography (OCT) imaging technique. It provides a 6-cm long circumferential volumetric scan of the esophageal wall layers to a depth of 3 mm with a resolution that is comparable to low-power microscopy. VLE has the potential for detection and delineation of early neoplastic lesions in Barrett's esophagus (BE). In order to investigate this, it is important that structures identified on VLE can be correlated with histology and -vice versa- that of areas containing early neoplasia on histology the corresponding VLE features can be studied. Most previous OCT studies lack such a direct correlation between histology and OCT images. Aim: To investigate the optimal approach for one-to-one correlation of VLE images with
S-519
AGA Abstracts
AGA Abstracts
Su2001
The Role of the Histone Methyltransferase EZH2 in the Mouse Intestinal Epithelium Reina Aoki, Klaus H. Kaestner
Ultrahigh Speed Optical Coherence Tomography With Micromotor Imaging Probe Enables Three-Dimensional Visualization of Mucosal Surface Patterns in the Gastrointestinal Tract Osman O. Ahsen, Hsiang-Chieh Lee, Kaicheng Liang, Michael G. Giacomelli, Tsung-Han Tsai, Zhao Wang, Marisa Figueiredo, Qin Huang, Benjamin Potsaid, James G. Fujimoto, Hiroshi Mashimo
Background and Aims: Dynamic epigenetic changes are necessary during development and differentiation of mammalian tissues. Because the intestinal epithelium turns over rapidly, it requires the execution of transcriptional changes from stem to differentiated cells. While multiple transcription factors are known to contribute to intestinal differentiation, the role of epigenetic modifiers in this process remains unknown. As histone modifications are labile, it is possible that histone modifiers are involved in the transcriptional regulation of the intestinal epithelium. Our aim was to investigate whether the histone methyltransferase Ezh2 is required for intestinal epithelial cell differentiation. Methods: We determined the expression pattern of Ezh2 in the mouse intestine using immunofluorescence staining. To assess the function of Ezh2 in intestinal epithelial differentiation, we inhibited Ezh2 activity in intestinal organoid using an Ezh2-specific inhibitor. Results: Ezh2 immunofluorescence indicated that Ezh2 is expressed highly in crypt base columnar stem cells and proliferative cells in transit amplifying cells, but expression gradually decreases as cells differentiate as the migrate up the villus. Inhibition of Ezh2 activity b in crypt organoid culture showed an increase in the number of crypt buds as compared to the control crypt organoids. Inhibition of Ezh2 activity also resulted in higher expression of ZO-1, suggesting accelerated establishment of epithelial cell polarity. Our data indicate that Ezh2 may play a role in balancing cell maturation and crypt expansion in the intestinal epithelium.
ABSTRACT BODY: BACKGROUND/AIMS: Three-dimensional endomicroscopy using optical coherence tomography (3D-OCT) provides volumetric images of tissue microstructure without requiring extrinsic contrast agents. Commercially available OCT systems have limited frame rates and typically use proximal rotation and pullback mechanisms to scan the imaging beam across the tissue. These two factors limit the ability to generate high quality en face images of aberrant mucosal surface patterns, which correlate with the presence and grade of dysplasias. In this study, we present a prototype ultrahigh speed 3D-OCT system with an advanced imaging probe using distal micromotor scanning. This system enables en face 3D-OCT images that visualize the mucosal surface patterns in a variety of GI structures in vivo. METHODS: The study was performed at the VA Boston Healthcare System (VABHS) under a study protocol approved by the VABHS, Harvard Medical School and M.I.T. We used a prototype 3D-OCT system that has an imaging speed (axial scan rate) of 600 kHz, which is ~10 times faster than commercially available 3D-OCT imaging systems. Scanning of the imaging beam is performed using a micromotor at the distal end of the OCT probe. The probe was passed through the accessory channel of an Olympus double channel endoscope (GIF-2TH180) to allow coregistration of images with biopsies. RESULTS: The combined advantages of ultrahigh speed and distal scanning of the new 3D-OCT system and probe enables visualization of mucosal surface patterns with unprecedented clarity. Fig. 1(A) demonstrates a volumetric reconstruction of a 3D-OCT dataset acquired in the gastric body of a patient. While cross sectional images give information on the layered architecture of the tissue, gastric folds and pit pattern can be visualized in the en face direction. Fig. 1(C) shows the squamocolumnar junction (SCJ) of a patient with Barrett's esophagus (BE), where the squamous epithelium (SE) appears as a smooth layer, whereas the area with BE has a well-defined pit pattern architecture. Fig. 1(D) shows a region of the esophagus a BE patient immediately after radiofrequency ablation (RFA), where residual BE that is missed by the RFA application can be observed. CONCLUSIONS: This study demonstrates that ultrahigh speed 3D-OCT system with a distal scanning micromotor probe can generate cross-sectional and en face images from the same dataset, yielding a more comprehensive evaluation of tissue architecture. Moreover, imaging can be performed even after biopsies or ablations, and can survey margins of endoscopic resections which is not possible with confocal endomicroscopy using exogenous contrast agents. Therefore, this novel imaging system has the potential to greatly improve the clinical utility of 3D-OCT. ACKNOWLEDGEMENT: NIH 5R01-CA075289-16, R44-CA101067-06, AFOSR FA9550-12-1-0499, and FA9550-10-10551.
Su2002 Nonmyeloablative Stem Cell Therapy for Perianal Fistulizing Crohn's Disease: A Systematic Review of Safety and Efficacy Maneesh Dave, Kathan Mehta, William A. Faubion Background & Aims: Perianal fistula is common in Crohn's disease (CD) patients and results in a more disabling course of disease requiring biologics and in 10-20% a permanent ostomy. Recently, a number of studies have utilized autologous or allogeneic stem cells as a nonmyeloablative stem cell therapy (SCT) for perianal fistulizing Crohn's disease (PCD). However, the data on safety and efficacy is limited given the small sample size of the original studies. We performed a systematic review of the literature following Cochrane guidelines to determine the safety and efficacy of SCT for PCD. Methods: A systematic search of bibliographic databases (PubMed, EMBASE & GI meeting abstracts) from inception through November 2013 was performed by two independent reviewers. Studies were selected based on use of SCT for treatment in patients with and without PCD. Total adverse events (TAE) were pooled across studies and were further categorized as serious (SAE) and non-serious (NSAE). Efficacy was defined as fistula healing or closure as per the criteria used by investigators of their study. Risk of bias was assessed for all included studies using the Cochrane risk of bias assessment tool. Results: Of the 5107 abstracts reviewed, 12 promising articles were reviewed in detail. 6 manuscripts with a total of 288 subjects met the study inclusion criteria. 47 patients with PCD and 150 patients without PCD underwent SCT and 91 patients with perianal fistulae (with or without underlying CD) received fibrin glue therapy. In PCD patients receiving SCT, 8.9% (4/47) experienced SAE and 22.5% (9/40) experienced NSAE. There was no death or malignancy in the SCT group (table 1). In PCD patients who underwent SCT between 37.5% to 75% (n=47) had healing of at least one fistula compared to 14.3% in PCD patients who had fibrin glue injection alone. In non-PCD patients with fistula who received SCT the fistula closure rate varied between 32.3% to 71% (n=150). Three studies used MRI for assessment of fistula closure in PCD. The mean follow up time after SCT ranged from 3 to 22 months. 4 studies utilized autologous adipose stem cells, 1 study used autologous bone marrow stem cells and 1 study used allogeneic adipose stem cells for SCT. Absence of controls in four of six studies precluded a meta-analysis. There was high risk of attrition and selection bias in the included studies. Conclusions: This systematic review suggests that SCT is safe and efficacious for treatment of perianal CD but is limited by relatively small number of patients and high risk of bias. This review highlights the significant drawbacks of current studies including need for; a control group, standardized definitions of AE's, inadequate reporting of AE's, and longer duration of follow up. SCT is a promising new treatment modality for PCD that needs further safety and efficacy data in larger clinical trials. Adverse events from nonmyeloablative stem cell therapy for perianal fistulizing Crohn's disease.
Figure 1: (A) Volumetric reconstruction of a 3D-OCT dataset acquired in the gastric body of a patient showing cross sectional as well as en face visualization of the gastric folds and pit patterns. (B) Zoomed view of the en face image shown in (A). (C) Squamocolumnar junction (SCJ) of a patient with Barrett's esophagus (BE) showing a region with smooth squamous epithelium and the BE region with well-defined pit patterns. (D) A region of a patient with BE immediately after radiofrequency ablation (RFA), where the encircled area shows BE glands that are likely missed by the RFA. Scale bars: 500um. Su2004 Volumetric Laser Endomicroscopy in Barrett's Esophagus: A Study on Histological Correlation Anne-Fré Swager, David F. Boerwinkel, Daniel M. de Bruin, Guillermo J. Tearney, Cadman L. Leggett, Bas L. Weusten, Dirk J. Faber, Ton G. van Leeuwen, Sybren L. Meijer, Wouter L. Curvers, Jacques J. Bergman Background: Volumetric laser endomicroscopy (VLE) is a novel balloon based optical coherence tomography (OCT) imaging technique. It provides a 6-cm long circumferential volumetric scan of the esophageal wall layers to a depth of 3 mm with a resolution that is comparable to low-power microscopy. VLE has the potential for detection and delineation of early neoplastic lesions in Barrett's esophagus (BE). In order to investigate this, it is important that structures identified on VLE can be correlated with histology and -vice versa- that of areas containing early neoplasia on histology the corresponding VLE features can be studied. Most previous OCT studies lack such a direct correlation between histology and OCT images. Aim: To investigate the optimal approach for one-to-one correlation of VLE images with
S-519
AGA Abstracts
AGA Abstracts
Su2001