METHODS: Normal wildtype C57Bl/6J(WT) and IL-10-/- adult murine primary fibroblasts isolated from 8- to 10-week old mice were treated with IL-10 (200 ng/mL) and CD-26 inhibitor K579 (5 ng/mL). Gene expression of CD-26, mir-29b, and alpha-SMA were analyzed by RT-PCR using Sybr Green assays. Preliminary data are presented as fold-changes. RESULTS: CD-26 expression was 4-fold greater in IL-10-/- fi- broblasts compared to WT, suggesting that endogenous levels of IL-10 regulate the fibrogenic potential of fibroblasts. Treat- ment of WT fibroblasts with IL-10 reduced their CD-26 expres- sion by 3.5-fold; however, IL-10 did not affect the IL-10-/- fibroblast expression of CD-26. Addition of either IL-10 or CD-26 inhibitor alone showed no effect on expression of miR- 29b in WT or IL-10-/- fibroblasts, but concurrent addition of both increased expression of miR-29b in WT and IL-10-/- fibroblasts. CONCLUSIONS: Our data suggest that IL-10 is upstream of CD- 26 expression in fibroblasts. Further, the synergistic effect of IL-10 and CD26 in regulating mir-29b expression suggests that there may be a fundamental relationship between these molecules that plays a central role in fibrosis. Increased YAP, a Key Component of the Hippo Pathway, Is Detected in Peak Proliferation During Intestinal Adaptation Mubina A Isani, MD, Kathy A Schall, MD, Christopher R Schlieve, MD, Kathryn L Fowler, Xiaogang Hou, PhD, Tracy C Grikscheit, MD, FACS Children’s Hospital of Los Angeles, Los Angeles, CA INTRODUCTION: Failure of intestinal adaptation (IA) in short bowel syndrome (SBS) can lead to morbidity and death. In a zebra- fish model of SBS, we identified that genes downstream in the Hippo pathway were 2- to 4-fold elevated at 2 weeks, when epithe- lial proliferation was most elevated, and therefore hypothesized that the transcriptional regulator YAP, a key to the Hippo pathway, might be important in successful IA in SBS. METHODS: SBS was generated in zebrafish by performing a prox- imal stoma and distal ligation. Sham fish had ventral laparotomy. After 2 weeks, fish were weighed, injected with BrdU, and prox- imal/distal samples were analyzed for IA. YAP+ and BrdU+ cells in our samples were evaluated by immunofluorescent antibody staining. RESULTS: Confirming this described model, animals with SBS lost weight, and proximal SBS intestine demonstrated IA with increased intestinal epithelium and BrdU positivity compared to sham control animals. Proximal SBS intestine demonstrated a marked increase in YAP detection (measured as YAP+ cells per vil- lus, 7.44 Æ 1.21, n ¼ 5) compared to proximal sham (2.14 Æ 0.78, n ¼ 3, p ¼ 0.02) or distal SBS intestine (1.08 Æ 0.18, n ¼ 2, p ¼ 0.03) (Figure). YAP+ cells did not colocalize with BrdU+ cells. CONCLUSIONS: Increased YAP expression is demonstrated in proximal intestine in peak proliferation during intestinal adapta- tion. Intestinal cells with increased YAP expression did not co- localize with BrdU + cells, suggesting that YAP+ cells are not the immediately proliferating cells and may be modulating the effect of IA. As YAP activity is key to the regulation of organ growth, further investigation may identify future SBS therapies. Intravenous Arginine and Citrulline Supplementation Increases Rate of Nitric Oxide Formation, Near-Infrared Spectroscopy Values and Decreases the Incidence of Necrotizing Enterocolitis in a Premature Piglet Model Patricio E Lau, MD, Stephanie M Cruz, MD, Jason L Robinson, PhD, Candace C Style, MD, Barbara Stoll, PhD, Ling Yu, PhD, Doug Burrin, PhD, Oluyinka O Olutoye, MD, PhD Texas Children’s Hospital, Baylor College of Medicine, Houston, TX INTRODUCTION: Bowel ischemia is a component of the patho- genesis of necrotizing enterocolitis (NEC). We hypothesized that supplementation with nitric oxide (NO) precursors will decrease the rate of NEC by increasing the rate of NO production and bowel perfusion as measured by abdominal near-infrared spectros- copy (A-NIRS). METHODS: Premature newborn piglets received parenteral nutri- tion for 48 hours, followed by 48 hours of enteral feeds. At 12 hours, piglets were randomized into citrulline, arginine, and saline continuous infusion groups. Six hours prior to initiation of feeds, arginine, citrulline and nitrate tracers were administered intrave- nously to quantify citrulline-arginine-NO kinetics. A-NIRS were Figure. Increased YAP detected in proximal SBS intestine compared to proximal sham and distal SBS intestine. Vol. 225, No. 4S1, October 2017 Scientific Forum Abstracts S151