| 1 | Neuroreport 2007 Nov 18: 1841-4 |
|---|---|
| PMID | 18090323 |
| Title | Expression of phosphodiesterase 4 is altered in the brains of subjects with autism. |
| Abstract | The cyclic adenosine monophosphate-specific phosphodiesterase-4 (PDE4) gene family is the target of several potential therapeutic inhibitors and the PDE4B gene has been associated with schizophrenia and depression. Little, however, is known of any connection between this gene family and autism, with limited effective treatment being available for autism. We measured the expression of PDE4A and PDE4B by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting in Brodmann's area 40 (BA40, parietal cortex), BA9 (superior frontal cortex), and cerebellum from subjects with autism and matched controls. We observed a lower expression of PDE4A5, PDE4B1, PDE4B3, PDE4B4, and PDE4B2 in the cerebella of subjects with autism when compared with matched controls. In BA9, we observed the opposite: a higher expression of PDE4AX, PDE4A1, and PDE4B2 in subjects with autism. No changes were observed in BA40. Our results demonstrate altered expressions of the PDE4A and PDE4B proteins in the brains of subjects with autism and might provide new therapeutic avenues for the treatment of this debilitating disorder. |
| SCZ Keywords | schizophrenia |
| 2 | Psychiatr. Genet. 2008 Dec 18: 282-8 |
| PMID | 19018233 |
| Title | Phosphodiesterase-4A expression is reduced in cerebella of patients with bipolar disorder. |
| Abstract | The cAMP-specific phosphodiesterase-4 (PDE4) gene family has four members (PDE4 A, B, C, and D) and is the target of several potential therapeutic inhibitors. Recently, PDE4A5 has been shown to bind with disrupted in schizophrenia 1 (DISC1), which has been identified as a risk factor for schizophrenia, bipolar disorder, and major depression. We sought to examine whether PDE4A5 expression was altered in cerebella of patients with schizophrenia, bipolar disorder, and major depression. We measured protein levels of PDE4A isoforms in cerebella of patients with schizophrenia, bipolar disorder, and major depression versus matched controls using sodium dodecyl sulfate polyacrylamide gel electrophoresis and western blotting. We observed that specific isoforms of PDE4A were reduced in cerebella of patients with bipolar disorder, whereas there was no change in patients with schizophrenia or major depression. Our results are the first to show that PDE4A expression is altered in patients with bipolar disorder and provide potential new therapeutic avenues for treatment of this disorder. |
| SCZ Keywords | schizophrenia |
| 3 | Psychopharmacology (Berl.) 2008 Mar 197: 115-26 |
| PMID | 18060387 |
| Title | Behavioral and neurochemical characterization of mice deficient in the phosphodiesterase-4B (PDE4B) enzyme. |
| Abstract | Phosphodiesterases (PDEs) belonging to the PDE4 family control intracellular concentrations of cyclic adenosine monophosphate (cAMP) by catalyzing its hydrolysis. Four separate PDE4 genes (PDE4A, PDE4B, PDE4C, and PDE4D) have been identified. PDE4 has been reported to be involved in various central nervous system (CNS) functions including depression, memory, and schizophrenia, although the specific subtype mediating these effects remains unclear. To investigate the role of PDE4B in the CNS, PDE4B wild-type and knockout mice (C57BL/6N background) were assessed in a variety of well-characterized behavioral tasks, and their brains were assayed for monoamine content. Knockout mice showed a significant reduction in prepulse inhibition. Spontaneous locomotor activity was decreased (16%) in knockout mice. Furthermore, when challenged with amphetamine, both groups of mice responded similarly to a low dose of d-amphetamine (1.0 mg/kg), but knockout mice showed an enhanced response to a higher dose (1.78 mg/kg). Decreases in baseline levels of monoamines and their metabolites within the striatum of knockout mice were also observed. PDE4B knockout mice showed a modest decrease in immobility time in the forced swim test that approached significance. In several other tests, including the elevated plus maze, hot plate, passive avoidance, and Morris water maze, wild-type and knockout mice performed similarly. The present studies demonstrate decreased striatal DA and 5-HT activity in the PDE4B knockout mice associated with decreased prepulse inhibition, decreased baseline motor activity, and an exaggerated locomotor response to amphetamine. These data further support a role for PDE4B in psychiatric diseases and striatal function. |
| SCZ Keywords | schizophrenia |
| 4 | Synapse 2010 Jul 64: 550-5 |
| PMID | 20222156 |
| Title | Levels of phosphodiesterase 4A and 4B are altered by chronic treatment with psychotropic medications in rat frontal cortex. |
| Abstract | Our laboratory has recently demonstrated altered expression of phosphodiesterase (PDE) 4A and 4B in subjects with autism, bipolar disorder, and schizophrenia, suggesting disrupted cAMP signaling in these diagnostic groups. In the current study, we measured expression of PDEs in rat frontal cortex (FC) following chronic treatment with clozapine, fluoxetine, haloperidol, lithium, olanzapine, valproic acid (VPA), or sterile saline for 21 days. Western blotting experiments showed decreased expression of PDE4A subtypes in FC following treatment with clozapine, haloperidol, lithium, and VPA. PDE4B subtypes were similarly reduced in FC following treatment with clozapine, fluoxetine, and lithium. We also measured levels of nine PDE subtypes via qRT-PCR in FC and found significant upregulation of PDE1A and PDE8B following treatment with olanzapine, while treatment with lithium reduced expression of mRNA for PDE8B. Our results demonstrate altered expression of PDE4A and PDE4B in response to a variety of psychotropic medications suggesting potentially new therapeutic avenues for treatment of neuropsychiatric diseases. |
| SCZ Keywords | schizophrenia |
| 5 | Am. J. Med. Genet. B Neuropsychiatr. Genet. 2011 Dec 156B: 850-8 |
| PMID | 21898905 |
| Title | Positive association of phencyclidine-responsive genes, PDE4A and PLAT, with schizophrenia. |
| Abstract | As schizophrenia-like symptoms are produced by administration of phencyclidine (PCP), a noncompetitive antagonist of N-methyl-D-aspartate (NMDA) receptors, PCP-responsive genes could be involved in the pathophysiology of schizophrenia. We injected PCP to Wistar rats and isolated five different parts of the brain in 1 and 4?hr after the injection. We analyzed the gene expression induced by the PCP treatment of these tissues using the AGILENT rat cDNA microarray system. We observed changes in expression level in 90 genes and 21 ESTs after the treatment. Out of the 10 genes showing >2-fold expressional change evaluated by qRT-PCR, we selected 7 genes as subjects for the locus-wide association study to identify susceptibility genes for schizophrenia in the Japanese population. In haplotype analysis, significant associations were detected in combinations of two SNPs of BTG2 (P?=?1.4?×?10(-6) ), PDE4A (P?=?1.4?×?10(-6) ), and PLAT (P?=?1?×?10(-3) ), after false discovery rate (FDR) correction. Additionally, we not only successfully replicated the haplotype associations in PDE4A (P?=?6.8?×?10(-12) ) and PLAT (P?=?0.015), but also detected single-point associations of one SNP in PDE4A (P?=?0.0068) and two SNPs in PLAT (P?=?0.0260 and 0.0104) in another larger sample set consisting of 2,224 cases and 2,250 controls. These results indicate that PDE4A and PLAT may be susceptibility genes for schizophrenia in the Japanese population. |
| SCZ Keywords | schizophrenia |
| 6 | Psychopharmacology (Berl.) 2012 Feb 219: 1065-79 |
| PMID | 21833500 |
| Title | Phosphodiesterase 4 inhibition enhances the dopamine D1 receptor/PKA/DARPP-32 signaling cascade in frontal cortex. |
| Abstract | Alteration of dopamine neurotransmission in the prefrontal cortex, especially hypofunction of dopamine D1 receptors, contributes to psychotic symptoms and cognitive deficit in schizophrenia. D1 receptors signal through the cAMP/PKA second messenger cascade, which is modulated by phosphodiesterase (PDE) enzymes that hydrolyze and inactivate cyclic nucleotides. Though several PDEs are expressed in cortical neurons, the PDE4 enzyme family (PDE4A-D) has been implicated in the control of cognitive function. The best studied isoform, PDE4B, interacts with a schizophrenia susceptibility factor, disrupted in schizophrenia 1 (DISC1). We explore the control of mouse frontal cortex dopamine D1 receptor signaling and associated behavior by PDE4. Inhibition of PDE4 by rolipram induced activation of cAMP/PKA signaling in cortical slices and in vivo, leading to the phosphorylation of DARPP-32 and other postsynaptic and presynaptic PKA-substrates. Rolipram also enhanced DARPP-32 phosphorylation invoked by D1 receptor activation. Immunohistochemical studies demonstrated PDE4A, PDE4B, and PDE4D expression in DARPP-32-positive neurons in layer VI of frontal cortex, most likely in D1 receptor-positive, glutamatergic corticothalamic pyramidal neurons. Furthermore, the ability of rolipram treatment to improve the performance of mice in a sensorimotor gating test was DARPP-32-dependent. PDE4, which is co-expressed with DARPP-32 in D1 receptor-positive cortical pyramidal neurons in layer VI, modulates the level of D1 receptor signaling and DARPP-32 phosphorylation in the frontal cortex, likely influencing cognitive function. These biochemical and behavioral actions of PDE4 inhibitors may contribute to the hypothesized antipsychotic actions of this class of compounds. |
| SCZ Keywords | schizophrenia |
| 7 | Cereb. Cortex 2013 Jul 23: 1643-54 |
| PMID | 22693343 |
| Title | Constellation of HCN channels and cAMP regulating proteins in dendritic spines of the primate prefrontal cortex: potential substrate for working memory deficits in schizophrenia. |
| Abstract | schizophrenia associates with impaired prefrontal cortical (PFC) function and alterations in cyclic AMP (cAMP) signaling pathways. These include genetic insults to disrupted-in-schizophrenia (DISC1) and phosphodiesterases (PDE4s) regulating cAMP hydrolysis, and increased dopamine D1 receptor (D1R) expression that elevates cAMP. We used immunoelectron microscopy to localize DISC1, PDE4A, PDE4B, and D1R in monkey PFC and to view spatial interactions with hyperpolarization-activated cyclic nucleotide-gated (HCN) channels that gate network inputs when opened by cAMP. Physiological interactions between PDE4s and HCN channels were tested in recordings of PFC neurons in monkeys performing a spatial working memory task. The study reveals a constellation of cAMP-related proteins (DISC1, PDE4A, and D1R) and HCN channels next to excitatory synapses and the spine neck in thin spines of superficial PFC, where working memory microcircuits interconnect and spine loss is most evident in schizophrenia. In contrast, channels in dendrites were distant from synapses and cAMP-related proteins, and were associated with endosomal trafficking. The data suggest that a cAMP signalplex is selectively positioned in the spines to gate PFC pyramidal cell microcircuits. Single-unit recordings confirmed physiological interactions between cAMP and HCN channels, consistent with gating actions. These data may explain why PFC networks are especially vulnerable to genetic insults that dysregulate cAMP signaling. |
| SCZ Keywords | schizophrenia |