Acute gut mucosal injury occurs commonly in various critical surgical disorders such as trauma, thermal injury, shock, sepsis, and massive surgical operations. Since the exact mechanisms underlying mucosal injury and repair are still obscure, effective therapies to preserve the epithelial integrity in patients with critical surgical illnesss are limited, contributing to mucosal hemorrhage, delayed healing, epithelial barrier dysfunction, and the translocation of luminal toxic substances and bacteria to the blood stream. During previous funding period, we have demonstrated that activation of Wnt signaling stimulates mucosal healing after acute injury and also identified a novel mechanism through which the RNA-binding proteins HuR and AUF1 regulate expression of c-Myc and JunD in critical surgical conditions. Recently, the essential contribution of posttranscriptional events, particularly altere mRNA turnover and translation through microRNAs (miRNAs), in the control of gene expression program in the mucosal tissues is becoming increasingly recognized, but little is known about their importance in the control of mucosal injury/repair in critical surgical conditions. Based on our significant progress during the previous funding period and exciting preliminary studies, experiments proposed in this competitive renewal application are to test the HYPOTHESIS that miRNA-222 (miR-222) and miR-503 play an important role in the regulation of mucosal healing after acute injury in critical surgical conditions by altering the stability and/or translation of arget mRNAs.
Three specific aims are proposed to test the hypothesis. 1) To define the exact roles of miR-222 and miR-503 in mucosal healing after acute injury in critical surgical conditions. 2) To determine if miR-222 and miR-503 regulate mucosal healing by altering the stability and translation of their target mRNAs. 3) To characterize the exact mechanism by which miR-222 and miR-503 regulate expression of key molecules of Wnt signals under surgical stress. Completion of these specific aims will make a significant conceptual advance by linking the miRNA- mediated posttranscriptional regulation with mucosal healing in patients with critical surgical illness and will create a fundamental base for development of novel therapies to preserve the epithelial integrity. Moreover, the identification of the mRNA targets that mediate the actions of miRNAs in mucosal healing will also reveal previously unrecognized components of cellular stress responses that may serve as targets for more traditional drug development.

Public Health Relevance

Acute gut mucosal injury occurs commonly during various critical surgical disorders such as trauma, thermal injury, shock, sepsis, and massive surgical operations. Since the exact mechanisms underlying mucosal injury and repair are still obscure, effective therapies to preserve the epithelial integrity in patients with critical surgical illnesss are limited, contributing to acute mucosal hemorrhage, delayed healing, impaired barrier function, and bacterial translocation. Completion of this project will identify the molecular mechanism underlying mucosal injury and repair in critical surgical conditions and provide a fundamental base for development of new therapies to protect the gut mucosa and enhance healing in patients with critical surgical illnesses.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK061972-14
Application #
9274248
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Hamilton, Frank A
Project Start
2002-07-01
Project End
2019-05-31
Budget Start
2017-06-01
Budget End
2018-05-31
Support Year
14
Fiscal Year
2017
Total Cost
Indirect Cost
Name
University of Maryland Baltimore
Department
Surgery
Type
Schools of Medicine
DUNS #
188435911
City
Baltimore
State
MD
Country
United States
Zip Code
21201
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Chung, Hee Kyoung; Wang, Shelley R; Xiao, Lan et al. (2018) ?4 Coordinates Small Intestinal Epithelium Homeostasis by Regulating Stability of HuR. Mol Cell Biol 38:
Xiao, Lan; Wu, Jing; Wang, Jun-Yao et al. (2018) Long Noncoding RNA uc.173 Promotes Renewal of the Intestinal Mucosa by Inducing Degradation of MicroRNA 195. Gastroenterology 154:599-611
Wang, Jun-Yao; Cui, Yu-Hong; Xiao, Lan et al. (2018) Regulation of Intestinal Epithelial Barrier Function by Long Noncoding RNA uc.173 through Interaction with MicroRNA 29b. Mol Cell Biol 38:
Lai, Keane K Y; Kweon, Soo-Mi; Chi, Feng et al. (2017) Stearoyl-CoA Desaturase Promotes Liver Fibrosis and Tumor Development in Mice via a Wnt Positive-Signaling Loop by Stabilization of Low-Density Lipoprotein-Receptor-Related Proteins 5 and 6. Gastroenterology 152:1477-1491
Wang, Peng-Yuan; Wang, Shelley R; Xiao, Lan et al. (2017) c-Jun enhances intestinal epithelial restitution after wounding by increasing phospholipase C-?1 transcription. Am J Physiol Cell Physiol 312:C367-C375
Wang, Jun-Yao; Xiao, Lan; Wang, Jian-Ying (2017) Posttranscriptional regulation of intestinal epithelial integrity by noncoding RNAs. Wiley Interdiscip Rev RNA 8:
Zhang, Yuan; Zhang, Yun; Xiao, Lan et al. (2017) Cooperative Repression of Insulin-Like Growth Factor Type 2 Receptor Translation by MicroRNA 195 and RNA-Binding Protein CUGBP1. Mol Cell Biol 37:
Liu, Lan; Zhuang, Ran; Xiao, Lan et al. (2017) HuR Enhances Early Restitution of the Intestinal Epithelium by Increasing Cdc42 Translation. Mol Cell Biol 37:
Xu, Yan; Chen, Jie; Xiao, Lan et al. (2016) Transcriptional regulation of importin-?1 by JunD modulates subcellular localization of RNA-binding protein HuR in intestinal epithelial cells. Am J Physiol Cell Physiol 311:C874-C883

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