ABSTRACT
OBJECTIVE: Atomoxetine and fluoxetine are psychopharmacologic agents associated with loss of appetite and weight. Adenosine monophosphate-activated protein kinase (AMPK) is the cellular energy sensor that regulate metabolism and energy, being activated by fasting and inhibited by feeding in the hypothalamus. METHODS: Human brain cell lines (SH-SY5Y and U-87 MG cells) were used to study the outcome of atomoxetine and fluoxetine treatment in the activity of AMPK-acetyl-CoA carboxylase (ACC)- carnitine palmitoyl transferase 1 (CPT1) pathway and upstream regulation by calcium/calmodulin-dependent kinase kinase ß (CaMKKß) using immunoblotting and CPT1 enzymatic activity measures. RESULTS: Phosphorylation of AMPK and ACC increased significantly after atomoxetine and fluoxetine treatment in the first 30-60 minutes of treatment in the two cell lines. Activation of AMPK and inhibition of ACC was associated with an increase by 5-fold of mitochondrial CPT1 activity. Although the neuronal isoform CPT1C could be detected by immunoblotting, activity was not changed by the drug treatments. In addition, the increase in phospho-AMPK and phospho-ACC expression induced by atomoxetine was abolished by treatment with STO-609, a CaMKKß inhibitor, indicating that AMPK-ACC-CPT1 pathway is activated through CaMKKß phosphorylation. CONCLUSION: These findings indicate that at the cellular level atomoxetine and fluoxetine treatments may activate AMPK-ACC-CPT1 pathways through CaMKKß in human SH-SY5Y and U-87 MG cells.
ABSTRACT
ABSTRACT: Chronic pain reduces life quality and is an important clinical problem associated with emotional and cognitive dysfunction. Epigenetic regulation of DNA methylation is involved in the induction of abnormal behaviors and pathological gene expression. We examined whether acupuncture can restore epigenetic changes caused by chronic pain, and identified the underlying mechanisms in neuropathic pain mice. Acupuncture treatment for 6 months (3 days/week) improved mechanical/cold allodynia and the emotional/cognitive dysfunction caused by left partial sciatic nerve ligation (PSNL)-induced neuropathic pain. The effects of acupuncture were associated with global DNA methylation recovery in the prefrontal cortex (PFC). Analysis of DNA methylation patterns in PFC indicated that 1364 overlapping genes among 4442 and 4416 methylated genes in the PSNL vs sham and PSNL vs acupuncture points groups, respectively, were highly associated with the DNA methylation process. Acupuncture restored the reduced expression of 5-methylcytosine, methyl-cytosine-phospho-guanine binding protein 2, and DNA methyltransferase family enzymes induced by PSNL in PFC. Methylation levels of Nr4a1 and Chkb associated with mitochondrial dysfunction were decreased in PFC of the PSNL mice, and increased by acupuncture. By contrast, high expression of Nr4a1 and Chkb mRNA in PSNL mice decreased after acupuncture. We also found that acupuncture inhibited the expression of Ras pathway-related genes such as Rasgrp1 and Rassf1. Finally, the expression of Nr4a1, Rasgrp1, Rassf1, and Chkb mRNA increased in the neuronal cells treated with Mecp2 small interfering RNA. These results suggest that acupuncture can relieve chronic pain-induced comorbid conditions by altering DNA methylation of Nr4a1, Rasgrp1, Rassf1, and Chkb in the PFC.
Subject(s)
Acupuncture Therapy , Chronic Pain , Neuralgia , Animals , Chronic Pain/genetics , Chronic Pain/therapy , DNA Methylation/genetics , Epigenesis, Genetic , Guanine Nucleotide Exchange Factors , Mice , Neuralgia/genetics , Neuralgia/therapy , Prefrontal CortexABSTRACT
Resistance switching phenomena in an amorphous Ni-Ti-O film were investigated. Very clear bipolar resistive switching characteristics were observed with good reproducibility. Stable retention and on/off pulse switching operation was demonstrated. An analysis of x-ray photoelectron spectroscopy of the Ni-Ti-O film provided a clue that the observed unusual bipolar resistance switching in the film is due to a microscopic change in the Ni-O and Ti-O binding states at the Ni-Ti-O film/electrode interface.