Upregulation of proapoptotic microRNA mir-125a after massive small bowel resection in rats

Ann Surg. 2012 Apr;255(4):747-53. doi: 10.1097/SLA.0b013e31824b485a.

Abstract

Objective: Short bowel syndrome remains a condition of high morbidity and mortality, and current therapeutic options carry significant side effects. To identify new treatments we focused on postresection changes in microRNAs--short noncoding RNAs, which suppress target genes--and suggest a previously undiscovered role for microRNA-125a (mir-125a) in intestinal adaptation.

Methods: Rats underwent either 80% massive small bowel resection or transection and were harvested after 48 hours. Jejunum was harvested for microRNA microarrays, laser capture microdissection, and RNA and protein analysis. Mir-125a was overexpressed in intestinal epithelium-6 (crypt-derived) cells (IEC-6) and effects on proliferation and apoptosis determined using MTS and flow cytometry. Expression of potential targets of mir-125a in rat jejunum and IEC-6 cells was determined using quantitative real-time polymerase chain reaction (RNA) and Western blotting (protein).

Results: Resection upregulated mir-125a and mir-214 by 2.4-folds and 3.2-folds, respectively. Highest levels of expression were noted in the crypt fraction. Mir-125a overexpression induced apoptosis and resultant growth arrest in IEC-6 cells. The expression of the prosurvival Bcl-2 family member Mcl-1 was downregulated in both mir-125a-overexpressing IEC-6 cells and in jejunum of resected rats, confirming Mcl-1 as a previously undiscovered target of mir-125a.

Conclusions: Upregulation of mir-125a suppresses the prosurvival protein Mcl1, producing the increase in apoptosis known to accompany the proliferative changes characteristic of intestinal adaptation. Our data highlight a potential role for microRNAs as mediators of the adaptive process and may facilitate the development of new therapeutic options for short bowel syndrome.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / genetics*
  • Blotting, Western
  • Cell Line
  • Cell Proliferation
  • Flow Cytometry
  • Intestinal Mucosa / metabolism
  • Intestinal Mucosa / pathology
  • Intestine, Small / metabolism
  • Intestine, Small / pathology
  • Intestine, Small / surgery*
  • Laser Capture Microdissection
  • Male
  • MicroRNAs / metabolism*
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Oligonucleotide Array Sequence Analysis
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Real-Time Polymerase Chain Reaction
  • Short Bowel Syndrome / genetics*
  • Short Bowel Syndrome / metabolism
  • Short Bowel Syndrome / pathology
  • Up-Regulation

Substances

  • Mcl1 protein, rat
  • MicroRNAs
  • Mirn214 microRNA,rat
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Proto-Oncogene Proteins c-bcl-2

Associated data

  • GEO/GSE26542