MicroRNAs: new insights into the pathogenesis of endodontic periapical disease.

By Chan LT, Zhong S, Naqvi AR, Self-Fordham J, Nares S, Bair E, Khan AA.

Date: 01/2013
Journal: JOE

Purpose:

  • To examine the differential expression of miRNAs in diseased periapical tissues as compared to healthy controls.

Materials/Methods:

  • N= 381 miRNAs.
  • Exclusion criteria: Patients who were immune compromised or currently taking antibiotics or other medications known to influence the immune response were excluded from the study.
  • Inclusion criteria: Age ≥ 12 years and American Society of Anesthesiologists class I or II.
  • Positive/negative control: Two different types of tissues were used as controls, normal periodontal ligament (PDL) and pulp tissues. These were collected from extracted noncarious third molars or premolars.
  • Control & Design: Diseased tissue was collected during apicoectomy on previously treated teeth w/non-healing lesion. Tissue samples stored in RNAsafer stabilizer. 13 samples (8 diseased) used for miRNA microarray, and 19 samples (8 diseased) used for qRT-PCR.   9 miRNAs that demonstrated significant differential expression in the microarray were selected for further validation w/qRT-PCR.
  • Criteria of evaluation: miRNA expression, age/gender correlation, presence of disease

Results:

  • No significant differences for gender
  • Microarray results: 24/381 miRNAs significantly down-regulated in diseased tissues vs health pulp tissue (9 selected for qt-PCR)
  • 21 samples down-regulated 2-5 times the norm
  • Qt-PCR results: 7/9 miRNAsdownregulated in disease tissue
  • miR-181 most affected family of miRNAs

Clinical Significance:

This study offers potential candidates for further investigation of miRNAs in endodontic disease. These findings could facilitate the development of potential biomarkers and possible therapeutic targets for the treatment of endodontic disease.