Baseline Characteristics Sa1303 INTESTINAL FAILURE: A RARE BUT SIGNIFICANT OUTCOME OF RESTORATIVE PROCTOCOLECTOMY Siddhartha Oke, Jonathan Segal, Susan Clark, Ailsa Hart, Simon M. Gabe AGA Abstracts Restorative proctocolectomy with ileal pouch-anal anastomosis (RPC-IPAA) removes the entire colon & rectum, while preserving the anal sphincter, maintaining intestinal continuity1-4. RPC-IPAA is offered to patients with ulcerative colitis (UC) refractory to treatment or associated with dysplasia, and some patients with familial adenomatous polyposis (FAP). Complications are well described, but intestinal failure (IF) requiring parenteral support (PS) is an uncommon complication of this surgery that carries with it significant morbidity & mortality. We report of the complication of IF as a complication of RPC-IPAA. Methods Adult patients with RPC-IPAA as an underlying cause of IF who were treated at our institution, were identified between 1/1/1998 & 1/1/2016. Information on complications, small intestinal length & pathophysiological causes of IF were recorded7. Date & cause of death were also recorded. Comparison was made with other patients who had received PS for IF at the same unit during the same time period. Patients were excluded if RPC-IPAA was not a direct cause of IF, or if the cause of the IF was due to malignancy. Results Of 807 in the IF database, 35 were identified with a RPC-IPAA and met the inclusion criteria. There were 13 male patients in the pouch group with IF. The pouch was formed for UC in 26, FAP in 6, & other reasons in 3. The pathophysiological classification of IF was short bowel in 49% (n=17), mechanical obstruction in 29% (n=10), intestinal fistulae in 14% (n=5), intestinal dysmotility in 6% (n=2) & small bowel mucosal disease in 3% (n=1). Survival was 96 % at 1 year and 75% at, 5 years. This compared to 76% & 48% respectively in the non-pouch group (p=0.02). IF was a potentially avoidable complication in three patients (9%) with a pouch. Two developed IF due to short bowel after index pouch formation (residual small bowel length of 50-100cm). One patient underwent a pouch originally for ulcerative colitis but developed IF due to small bowel Crohn's disease with no prior small bowel imaging prior to pouch formation was documented. Sa1305 NHE3 EXPRESSION IS NEGATIVELY REGULATED BY MIR-326 AND MIR330-5P IN INTESTINAL EPITHELIAL CELLS Arivarasu Natarajan Anbazhagan, Shubha Priyamvada, Anoop Kumar, Waddah A. Alrefai, Seema Saksena, Ravinder K. Gill, Pradeep K. Dudeja Background: Na+/H+ exchanger-3 (NHE3) is the major apical membrane transporter involved in intestinal Na+ absorption. Dysregulation of NHE3 expression and/or function has been implicated in pathophysiology of diarrhea associated with inflammatory disorders of the gut. Therefore, it is critical to understand the mechanism involved in the regulation of NHE3 expression. In this regard, microRNAs (miRNAs) are highly conserved small RNAs that can regulate gene expression at the post transcriptional level. Very little is known about the microRNA regulation of NHE3. Therefore, current studies were undertaken to examine the potential miRNA candidates that can regulate the expression of NHE3 in intestinal epithelial cells. In silico analysis, using different algorithms predicted several miRNAs that target NHE3. MicroRNAs with highest context and target score, miR-326 and miR-330-5p, were selected for the current study. Methods: NHE3 3′UTR (160 bp) was cloned in pmirGLO vector upstream of luciferase. SK-CO15 cells were used as a model of intestinal epithelial cells that robustly express NHE3. The levels of microRNA and NHE3 mRNA expression were determined by RT-PCR. The effect of NHE3 3′UTR was evaluated by a dual luciferase reporter assay. NHE3 protein levels in response to transient transfection of miRNA mimics were assessed by western blotting. Results: Transfection with pmirGLO dual luciferase vector containing 3′UTR of NHE3 resulted in a significant decrease in relative luciferase activity (25 ± 1.8 %, P<0.0002) as compared to the empty vector. This data indicate that binding of certain miRNAs/RNA binding proteins to the 3′UTR of NHE3 is responsible for the repression of the reporter luciferase activity. Co-transfection of NHE3 3′ UTR with miR326 and -miR-330-5p mimic resulted in a significant decrease in relative luciferase activity by 53.1 ± 8.1 % (P<0.009) and 52.7 ± 9.7 % (p<0.009) respectively. Transfection of miR326 and 330-5p mimics into SK-CO15 cells significantly decreased the NHE3 protein expression by 44.4 ± 5.3 % (P<0.008) and 36.1 ± 12.8 %, (P<0.02), respectively, with no change in NHE3 mRNA levels. Conclusion: Our findings demonstrate a novel mechanism for post transcriptional regulation of NHE3 by miR-326 and -330-5p by translational repression without affecting the NHE3 mRNA levels. We speculate that miR-326 and -330-5p dependent pathways may be involved in modulating NHE3 expression under physiological conditions and/or in disease states such as Inflammatory Bowel Diseases (IBD). Sa1304 INTESTINAL-FAILURE ASSOCIATED LIVER DISEASE: INCIDENCE AND PREDICTORS Blake A. Jones, Suraj Sharma, Carol E. Semrad, Elizabeth Wall Sa1306 Background: The incidence and prognosis of Intestinal Failure Associated Liver Disease (IFALD) in adult patients on parenteral nutrition (PN) is not well established. Prior case series show discordant results, and the definition of ‘liver injury' is not standardized. In prior studies outcomes vary from transaminitis to liver failure under this definition. We aim to establish the incidence and predictors of IFALD in a well-characterized cohort of patients on long-term PN. Methods: Patients receiving home PN at the University of Chicago Medical Center between January 1, 2003 and December 31, 2014 were reviewed. Adult patients with a diagnosis of intestinal failure on PN for more than 12 months were included. Patients with primary liver conditions, such as viral hepatitis, were excluded. Data collected included: age, sex, BMI, PN indication, length of small bowel, liver tests, and PN prescription. Outcome measures included: transaminitis (AST or ALT >2XULN), cholestasis (ALP or bilirubin >2XULN), cirrhosis (based on ultrasound, clinical or biopsy findings) and all-cause mortality. Mixed-effects Poisson regression was used to identify significant predictors of cirrhosis. Results: Sixty-five patients met the inclusion criteria and were seen for a combined 551 clinic visits over the follow-up period. Median follow-up was 2.7 years (IQR 1.7-7.9 years). In a majority of patients intestinal failure was due to short bowel. Specifically intestinal failure was due to: IBD (46.2%), ischemia (12.3%), frozen bowel (3.1%) and other (38.5%). Median age at first visit was 54.6 years (IQR 48.0-65.4 years); 63% of patients were female. Median BMI at initiation of PN was 20.6 (IQR 17.0-25.8). The PN prescription had a median 1105 kCals (IQR 605-1440) and 20g of lipid (IQR 5-35). Transaminitis was found at 10.9% of clinic visits, and 35.4% of patients had at least one episode. Cholestasis was found at 21.8% of clinic visits, and 46.1% of patients had at least one episode. More than half (52%) of all patients had at least one episode of transaminitis or cholestasis. Cirrhosis was diagnosed in 5 (7.7%) patients. One patient (1.5%) died due to liver failure. Parenteral nutrition caloric content, BMI, indication (IBD vs. non-IBD) and small bowel length were found to be significant predictors of cirrhosis after controlling for age and sex. Conclusion: Transaminitis and cholestasis are common findings in adulte patients with intestinal failure on long term PN. However, development of cirrhosis and death is uncommon. INTESTINAL SEROTONIN TRANSPORTER UNTRANSLATED REGIONS INFLUENCE MRNA ABUNDANCE AND PROTEIN EXPRESSION Christopher R. Manzella, Megha Singhal, Max T. Ackerman, Haya Rashdan, Seema Saksena, Waddah A. Alrefai, Pradeep K. Dudeja, Ravinder K. Gill The serotonin transporter (SERT, SLC6A4) is a Na+ and Cl- dependent transporter that regulates the availability of serotonin (5-HT) in various tissues including brain, platelets, and intestine. Decreases in SERT expression have been implicated in pathophysiological conditions including anxiety, obesity, and GI disorders such as IBD, IBS, and diarrhea. A novel transcription start site and alternative promoter in the SERT gene has been demonstrated in human intestine leading to an intestine specific mRNA transcript variant (iSERT) and a variant similar to the neuronal SERT transcript (nSERT). While these two transcripts produce an identical SERT protein, the 5' untranslated regions (UTRs) differ due to alternative splicing of noncoding exons 1A, 1B, 1C, and 2 with 1C located immediately upstream of exon 1B. The SERT 3'UTR is identical for the transcript variants. However, the impact of the 5' or 3' UTRs in influencing SERT expression in intestinal epithelial cells (IECs) is unknown. Current studies tested the hypothesis that the UTRs of SERT influence its expression in IECs by controlling mRNA or protein levels. Methods: The nSERT 5'UTR composed of exon 1A spliced to exon 2 (1A-2) and the iSERT 5'UTR composed of exons 1C-1B spliced to exon 2 (1C-1B-2) were cloned into a reporter plasmid upstream of luciferase. The 3'UTR was cloned into the pmirGLO reporter. Luciferase mRNA and activity were measured 3648h post-transfection of the UTR constructs in Caco-2 cells. Results: Compared to a reporter construct without a 5'UTR, luciferase mRNA was increased ~2-fold (p < 0.05) for the nSERT 5'UTR and increased ~3-fold (p < 0.05) for the iSERT 5'UTR. This was reflected in increased protein abundance as measured by luciferase activity which increased ~4-fold (p < 0.05) for the nSERT 5'UTR and ~2-fold (p < 0.05) for the iSERT 5'UTR. These data indicate that the nSERT 5'UTR exerts comparatively higher translation efficiency (luciferase activity divided by the relative luciferase mRNA level) as compared to the iSERT 5'UTR. Inspection of exons 1C, 1B, and 2 reveals multiple upstream AUGs that may negatively influence the translation efficiency of iSERT. Compared to the empty pmirGLO, the SERT 3'UTR decreased luciferase activity by ~90% (p < 0.01). In silico analysis of the SERT 3'UTR reveals many conserved potential miRNA binding sites that may be responsible for this decrease. Conclusion: We have shown that intestinal SERT 5'UTR variants differentially regulate mRNA abundance S-271 AGA Abstracts