Pro-apoptotic effects of micro-ribonucleic acid-365 on retinal neurons by targeting insulin-like growth factor-1 in diabetic rats: An in vivo and in vitro study

J Diabetes Investig. 2018 Sep;9(5):1041-1051. doi: 10.1111/jdi.12815. Epub 2018 May 14.

Abstract

Aims/objective: The present study aimed to explore the effects of micro-ribonucleic acid-365 (miR-365) on apoptosis of retinal neurons by targeting insulin-like growth factor-1 (IGF-1) in diabetes mellitus rats.

Materials and methods: High glucose-induced retinal neurons were assigned into the blank (with no plasmid transfection), negative control (with plasmid transfection), anti-miR-365 (transfected miR-365 antagomir), transfected IGF-1 short hairpin RNA plasmid (sh-IGF-1) and transfected miR-365 antagomir and IGF-1 shRNA plasmid (anti-miR-365 + sh-IGF-1) groups. Proliferation and apoptosis of retinal neurons were detected by 5-ethynyl-2'-deoxyuridine assay and Hoechst 33342 staining, respectively. Expressions of miR-365, IGF-1, Bcl-2-associated X protein (Bax) and Bcl-2 were determined by reverse transcription quantitative polymerase chain reaction and western blotting. A control group contained 10 healthy rats. Terminal deoxynucleotidyl transferase dUTP nick-end labeling staining was used to evaluate apoptosis of retinal neurons in rats.

Results: In the anti-miR-365 group, the apoptosis rate and Bax expression were reduced in comparison with the negative control and blank groups, whereas the sh-IGF-1 and anti-miR-365 + sh-IGF-1 groups presented an opposite trend. Compared with the normal group, expressions of miR-365 and Bax were increased, and expressions of IGF-1 and Bcl-2 were decreased, with more apoptotic cells in diabetes mellitus rat models. The sh-IGF-1 group had lower Bax expression, and higher expressions of IGF-1 and Bcl-2 with fewer apoptotic cells. Additionally, Bax expression was upregulated, expressions of IGF-1 and Bcl-2 were downregulated, and apoptotic cells were higher in the anti-miR-365 + sh-IGF-1 groups than the anti-miR-365 group.

Conclusion: The results of the present study suggest that suppressed miR-365 increases the IGF-1 expression, leading to anti-apoptotic effects on retinal neurons in diabetic rats.

Keywords: Diabetes mellitus; Insulin-like growth factor-1; Micro-ribonucleic acid-365.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis / physiology*
  • Cells, Cultured
  • Diabetes Mellitus, Experimental / genetics
  • Diabetes Mellitus, Experimental / metabolism
  • Diabetes Mellitus, Experimental / therapy*
  • Dose-Response Relationship, Drug
  • Gene Targeting / methods*
  • Insulin-Like Growth Factor I / antagonists & inhibitors*
  • Insulin-Like Growth Factor I / biosynthesis
  • Insulin-Like Growth Factor I / genetics
  • Male
  • MicroRNAs / antagonists & inhibitors*
  • MicroRNAs / biosynthesis
  • MicroRNAs / genetics
  • RNA, Small Interfering / administration & dosage
  • Rats
  • Rats, Sprague-Dawley
  • Retinal Neurons / drug effects
  • Retinal Neurons / physiology*

Substances

  • MIRN365 microRNA, rat
  • MicroRNAs
  • RNA, Small Interfering
  • insulin-like growth factor-1, rat
  • Insulin-Like Growth Factor I