Involvement of dopamine receptors in binge methamphetamine-induced activation of endoplasmic reticulum and mitochondrial stress pathways

PLoS One. 2011;6(12):e28946. doi: 10.1371/journal.pone.0028946. Epub 2011 Dec 13.

Abstract

Single large doses of methamphetamine (METH) cause endoplasmic reticulum (ER) stress and mitochondrial dysfunctions in rodent striata. The dopamine D(1) receptor appears to be involved in these METH-mediated stresses. The purpose of this study was to investigate if dopamine D(1) and D(2) receptors are involved in ER and mitochondrial stresses caused by single-day METH binges in the rat striatum. Male Sprague-Dawley rats received 4 injections of 10 mg/kg of METH alone or in combination with a putative D(1) or D(2) receptor antagonist, SCH23390 or raclopride, respectively, given 30 min prior to each METH injection. Rats were euthanized at various timepoints afterwards. Striatal tissues were used in quantitative RT-PCR and western blot analyses. We found that binge METH injections caused increased expression of the pro-survival genes, BiP/GRP-78 and P58(IPK), in a SCH23390-sensitive manner. METH also caused up-regulation of ER-stress genes, Atf2, Atf3, Atf4, CHOP/Gadd153 and Gadd34. The expression of heat shock proteins (HSPs) was increased after METH injections. SCH23390 completely blocked induction in all analyzed ER stress-related proteins that included ATF3, ATF4, CHOP/Gadd153, HSPs and caspase-12. The dopamine D(2)-like antagonist, raclopride, exerted small to moderate inhibitory influence on some METH-induced changes in ER stress proteins. Importantly, METH caused decreases in the mitochondrial anti-apoptotic protein, Bcl-2, but increases in the pro-apoptotic proteins, Bax, Bad and cytochrome c, in a SCH23390-sensitive fashion. In contrast, raclopride provided only small inhibition of METH-induced changes in mitochondrial proteins. These findings indicate that METH-induced activation of striatal ER and mitochondrial stress pathways might be more related to activation of SCH23390-sensitive receptors.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Benzazepines / pharmacology
  • Biomarkers / metabolism
  • Endoplasmic Reticulum Chaperone BiP
  • Endoplasmic Reticulum Stress / drug effects*
  • Endoplasmic Reticulum Stress / genetics
  • Fever / metabolism
  • Fever / pathology
  • HSP40 Heat-Shock Proteins / metabolism
  • HSP70 Heat-Shock Proteins / metabolism
  • Heat-Shock Proteins / metabolism
  • Male
  • Methamphetamine / administration & dosage
  • Methamphetamine / pharmacology*
  • Mitochondria / drug effects
  • Mitochondria / genetics
  • Mitochondria / metabolism*
  • Neostriatum / drug effects
  • Neostriatum / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Raclopride / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Dopamine D1 / metabolism*
  • Receptors, Dopamine D2 / metabolism*
  • Stress, Physiological / drug effects*
  • Stress, Physiological / genetics
  • Time Factors
  • Up-Regulation / drug effects

Substances

  • Benzazepines
  • Biomarkers
  • Endoplasmic Reticulum Chaperone BiP
  • HSP40 Heat-Shock Proteins
  • HSP70 Heat-Shock Proteins
  • Heat-Shock Proteins
  • RNA, Messenger
  • Receptors, Dopamine D1
  • Receptors, Dopamine D2
  • SCH 23390
  • Raclopride
  • Methamphetamine