RNA interference-mediated inhibition of wild-type Torsin A expression increases apoptosis caused by oxidative stress in cultured cells

Neurochem Res. 2010 Aug;35(8):1214-23. doi: 10.1007/s11064-010-0177-4. Epub 2010 May 9.

Abstract

To assess RNAi mediated inhibition of the expression of wt-DYT1 on H(2)O(2)-induced toxicity in NIH 3T3 cells and primary cortical neurons. To detect the function of wild-type Torsin A and the effect of SiRNA on the wt-DYT1 gene. The shRNA expression vector was constructed by ligating annealed complementary shRNA oligonucleotides into the down-stream of the human U6 promoter (PU6) of the RNAi-ready pSIREN-Shuttle vector. Then, the pSIREN-Shuttle-DYT1-shRNA cassette was ligated to Adeno-X Viral DNA to construct the recombinant adenoviral vector pAd-DYT1-shRNA. Cultured cerebral cortical neurons and NIH 3T3 cells were transfected with pAd-DYT1-shRNA and pSIREN-Shuttle-DYT1-shRNA. We evaluated NIH 3T3 cells and neurons in the presence of oxidative stress using a TUNEL assay under different conditions. The knockdown efficacy of the DYT1 was confirmed by real-time RT-PCR and Western Blot analysis. After exposure to H(2)O(2,) the quantity of NIH 3T3 cells transfected with pSIREN-Shuttle-DYT1-shRNA, which stained positively in the TUNEL assay, was significantly higher than the cells transfected with pSIREN-Shuttle-negative control-shRNA. (44.85 +/- 1.81% vs. 8.98 +/- 2.73%, t = 26.168). There were significantly more apoptotic neurons infected with pAd-DYT1-shRNA (45.63 +/- 7.53%) than neurons infected with pAd-X-negative control-shRNA (17.33 +/- 2.43%) (t = 9.816). The observed silencing of wild-type Torsin A expression by DYT1-shRNA was sequence-specific. RNAi-mediated inhibition of the expression of wild-type Torsin A increases apoptosis caused by oxidative stress. It is reasonable to consider that wild-type Torsin A has the capacity to protect cortical neurons against oxidative stress, and in the development of DYT1-delta GAG-dystonia the neuroprotective function of wild-type Torsin A may be compromised.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae / genetics
  • Animals
  • Apoptosis*
  • Cells, Cultured
  • Cerebral Cortex / cytology
  • Gene Knockdown Techniques
  • Genetic Vectors
  • Humans
  • Kinesins
  • Mice
  • Microtubule-Associated Proteins / metabolism
  • Molecular Chaperones / biosynthesis*
  • Molecular Chaperones / genetics
  • Neurons / cytology
  • Neurons / metabolism*
  • Oxidative Stress*
  • Plasmids
  • RNA Interference*
  • RNA, Small Interfering / genetics
  • Transfection

Substances

  • Dyt1 protein, mouse
  • Microtubule-Associated Proteins
  • Molecular Chaperones
  • RNA, Small Interfering
  • Kinesins