Cellular and subcellular localization of PDE10A, a striatum-enriched phosphodiesterase

doi:10.1016/j.neuroscience.2005.12.042

Neuroscience

Volume 139, Issue 2, 2006, Pages 597-607

https://doi.org/10.1016/j.neuroscience.2005.12.042 Get rights and content

Abstract

PDE10A is a recently identified phosphodiesterase that is highly expressed by the GABAergic medium spiny projection neurons of the mammalian striatum. Inhibition of PDE10A results in striatal activation and behavioral suppression, suggesting that PDE10A inhibitors represent a novel class of antipsychotic agents. In the present studies we further elucidate the localization of this enzyme in striatum of rat and cynomolgus monkey. We find by confocal microscopy that PDE10A-like immunoreactivity is excluded from each class of striatal interneuron. Thus, the enzyme is restricted to the medium spiny neurons. Subcellular fractionation indicates that PDE10A is primarily membrane bound. The protein is present in the synaptosomal fraction but is separated from the postsynaptic density upon solubilization with 0.4% Triton X-100. Immuno-electron microscopy of striatum confirms that PDE10A is most often associated with membranes in dendrites and spines. Immuno-gold particles are observed on the edge of the postsynaptic density but not within this structure. Our studies indicate that PDE10A is associated with post-synaptic membranes of the medium spiny neurons, suggesting that the specialized compartmentation of PDE10A enables the regulation of intracellular signaling from glutamatergic and dopaminergic inputs to these neurons.

Section snippets

Animals

Male Sprague–Dawley rats (Charles River Laboratories, Kingston, NY, USA) weighing 300–400g were housed in groups of five to 10 at ambient temperature of 25–27°C, under a 12-h light/dark cycle. Food and water was available ad libitum. For preparation of samples for subcellular fractionation, rats were killed by decapitation. For preparation of samples for immunoelectron microscopy, rats were killed by overdose with 100 mg of pentobarbital prior to perfusion fixation. Cynomolgus monkeys (Charles

PDE10A is expressed only in striatal medium spiny projection neurons

The medium spiny projection neurons that express PDE10A are the major neuronal type in striatum. However, there are several classes of striatal interneurons that play a major role in organizing the activity of the medium spiny neurons (Kawaguchi et al., 1995). Thus, it is of interest to determine whether PDE10A is also expressed in any of the interneuron subtypes. This was investigated using immunofluorescent double staining to compare the disposition of PDE10A protein with that of a marker for

Discussion

PDE10A is highly enriched in the mammalian striatum (Coskran et al 2005, Seeger et al 2003; Coskran et al., in preparation; and present study) and specifically in the GABAergic medium spiny projection neurons that are the major neuronal cell type in this brain region. The medium spiny neurons are the principal input site for the basal ganglia circuit (Wilson, 1998). These neurons receive a massive excitatory input from cortical and thalamic glutamatergic neurons and are also the principal

Conclusion

In summary, the present study indicates that PDE10A is localized exclusively in the medium spiny projection neurons of the mammalian striatum. In these neurons, the enzyme is associated with dendrites and spines but is not tightly associated with the signaling complex of the PSD. Other studies (Siuciak et al 2005, Siuciak et al 2006) suggest that PDE10A plays a role in regulating the excitability of the medium spiny neurons. The findings presented here begin to elucidate the signaling

References (32)

M. Conti et al.
Cyclic AMP-specific PDE4 phosphodiesterases as critical components of cyclic AMP signaling
J Biol Chem
(2003)
K. Fujishige et al.
Cloning and characterization of a novel human phosphodiesterase that hydrolyzes both cAMP and cGMP (PDE10A)
J Biol Chem
(1999)
P. Greengard et al.
Beyond the dopamine receptorthe DARPP-32/protein phosphatase-1 cascade
Neuron
(1999)
M.D. Houslay et al.
Tailoring cAMP-signalling responses through isoform multiplicity
Trends Biochem Sci
(1997)
Y. Kawaguchi
Neostriatal cell subtypes and their functional roles
Neurosci Res
(1997)
Y. Kawaguchi et al.
Striatal interneuroneschemical, physiological and morphological characterization
Trends Neurosci
(1995)
J. Kotera et al.
Subcellular localization of cyclic nucleotide phosphodiesterase type 10A
J Biol Chem
(2004)
K. Loughney et al.
Isolation and characterization of PDE10A, a novel human 3′, 5′-cyclic nucleotide phosphodiesterase
Gene
(1999)
K. Nakai et al.
PSORTa program for detecting sorting signals in proteins and predicting their subcellular localization
Trends Biochem Sci
(1999)
D.R. Repaske et al.
A cyclic GMP-stimulated cyclic nucleotide phosphodiesterase gene is highly expressed in the limbic system of the rat brain
Neuroscience
(1993)

C.J. Schmidt et al.

The neurochemical and behavioral effects of papaverine in vivo suggest PDE10 inhibition is “antipsychotic.”

Schizophr Res

(2003)

T.F. Seeger et al.

Immunohistochemical localization of PDE10A in the rat brain

Brain Res

(2003)

S.H. Soderling et al.

Regulation of cAMP and cGMP signalingnew phosphodiesterases and new functions

Curr Opin Cell Biol

(2000)

B. Wiedenmann et al.

Identification and localization of synaptophysin, an integral membrane glycoprotein of Mr 38,000 characteristic of presynaptic vesicles

Cell

(1985)

C.D. Blackstone et al.

Biochemical characterization and localization of a non-N-methyl-D-aspartate glutamate receptor in rat brain

J Neurochem

(1992)

M. Conti

Phosphodiesterases and cyclic nucleotide signaling in endocrine cells

Mol Endocrinol

(2000)

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Phosphodiesterase 9 (PDE9) degrades selectively the second messenger cGMP, which is an important molecule of dopamine signaling pathways in striatal projection neurons (SPNs). In this study, we assessed the effects of a selective PDE9 inhibitor (PDE9i) in the primate model of Parkinson's disease (PD). Six macaques with advanced parkinsonism were used in the study. PDE9i was administered as monotherapy and co-administration with l-DOPA at two predetermined doses (suboptimal and threshold s.c. doses of l-Dopa methyl ester plus benserazide) using a controlled blinded protocol to assess motor disability, l-DOPA -induced dyskinesias (LID), and other neurologic drug effects. While PDE9i was ineffective as monotherapy, 2.5 and 5 mg/kg (s.c.) of PDE9i significantly potentiated the antiparkinsonian effects of l-DOPA with a clear prolongation of the “on” state (p < 0.01) induced by either the suboptimal or threshold l-DOPA dose. Co-administration of PDE9i had no interaction with l-DOPA pharmacokinetics. PDE9i did not affect the intensity of LID. These results indicate that cGMP upregulation interacts with dopamine signaling to enhance the l-DOPA reversal of parkinsonian motor disability. Therefore, striatal PDE9 inhibition may be further explored as a strategy to improve motor responses to l-DOPA in PD.
Discovery of a highly specific <sup>18</sup>F-labeled PET ligand for phosphodiesterase 10A enabled by novel spirocyclic iodonium ylide radiofluorination
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As a member of cyclic nucleotide phosphodiesterase (PDE) enzyme family, PDE10A is in charge of the degradation of cyclic adenosine (cAMP) and guanosine monophosphates (cGMP). While PDE10A is primarily expressed in the medium spiny neurons of the striatum, it has been implicated in a variety of neurological disorders. Indeed, inhibition of PDE10A has proven to be of potential use for the treatment of central nervous system (CNS) pathologies caused by dysfunction of the basal ganglia–of which the striatum constitutes the largest component. A PDE10A-targeted positron emission tomography (PET) radioligand would enable a better assessment of the pathophysiologic role of PDE10A, as well as confirm the relationship between target occupancy and administrated dose of a given drug candidate, thus accelerating the development of effective PDE10A inhibitors. In this study, we designed and synthesized a novel ¹⁸F-aryl PDE10A PET radioligand, codenamed [¹⁸F]P10A-1910 ([¹⁸F]9), in high radiochemical yield and molar activity via spirocyclic iodonium ylide-mediated radiofluorination. [¹⁸F]9 possessed good in vitro binding affinity (IC₅₀ = 2.1 nmol/L) and selectivity towards PDE10A. Further, [¹⁸F]9 exhibited reasonable lipophilicity (logD = 3.50) and brain permeability (P_app > 10 × 10⁻⁶ cm/s in MDCK-MDR1 cells). PET imaging studies of [¹⁸F]9 revealed high striatal uptake and excellent in vivo specificity with reversible tracer kinetics. Preclinical studies in rodents revealed an improved plasma and brain stability of [¹⁸F]9 when compared to the current reference standard for PDE10A-targeted PET, [¹⁸F]MNI659. Further, dose–response experiments with a series of escalating doses of PDE10A inhibitor 1 in rhesus monkey brains confirmed the utility of [¹⁸F]9 for evaluating target occupancy in vivo in higher species. In conclusion, our results indicated that [¹⁸F]9 is a promising PDE10A PET radioligand for clinical translation.
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Medium spiny neurons (MSNs) constitute the vast majority of striatal neurons and the principal interface between dopamine reward signals and functionally diverse cortico-basal ganglia circuits. Information processing in these circuits is dependent on distinct MSN types: cell types that are traditionally defined according to their projection targets or dopamine receptor expression. Single-cell transcriptional studies have revealed greater MSN heterogeneity than predicted by traditional circuit models, but the transcriptional landscape in the primate striatum remains unknown. Here, we set out to establish molecular definitions for MSN subtypes in Rhesus monkeys and to explore the relationships between transcriptionally defined subtypes and anatomical subdivisions of the striatum. Our results suggest at least nine MSN subtypes, including dorsal striatum subtypes associated with striosome and matrix compartments, ventral striatum subtypes associated with the nucleus accumbens shell and olfactory tubercle, and an MSN-like cell type restricted to μ-opioid receptor rich islands in the ventral striatum. Although each subtype was demarcated by discontinuities in gene expression, continuous variation within subtypes defined gradients corresponding to anatomical locations and, potentially, functional specializations. These results lay the foundation for achieving cell-type-specific transgenesis in the primate striatum and provide a blueprint for investigating circuit-specific information processing.
Antiparkinsonian-like effects of CPL500036, a novel selective inhibitor of phosphodiesterase 10A, in the unilateral rat model of Parkinson's disease
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Phosphodiesterase 10A (PDE10A), the enzyme which catalyzes hydrolysis of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), is located almost exclusively in striatal γ-amino-butyric acid (GABA)ergic medium spiny neurons (MSNs). Since dopaminergic deficiency in Parkinson's disease (PD) leads to functional imbalance of striatal direct and indirect output pathways formed by MSNs, PDE10A seems to be of special interest as a potential therapeutic target in PD.
The aim of the present study was to examine the influence of 7-{5,8-dimethyl-[1,2,4]triazolo[1,5-a]pyrazin-2-yl}-2-phenylimidazo[1,2-a]pyrimidine (CPL500036), a novel selective inhibitor of PDE10A, on sensorimotor deficits and therapeutic effects of L-3,4-dihydroxyphenylalanine (L-DOPA) in hemiparkinsonian rats.
Animals were unilaterally lesioned with 6-hydroxydopamine, and their sensorimotor deficits were examined in the stepping, cylinder, vibrissae and catalepsy tests. CPL500036 (0.1 and 0.3 mg/kg) was administered either acutely or chronically (2 weeks), alone or in combination with L-DOPA/benserazide (6 mg/kg/6 mg/kg).
Acute treatment with CPL500036 reversed the lesion-induced impairments of contralateral forelimb use in the stepping and cylinder tests but did not influence deficits in the vibrissae test and the lesion-induced catalepsy. Moreover, CPL500036 did not diminish the therapeutic effects produced by acute and chronic treatment with L-DOPA in these tests.
The present study suggests a potential use of CPL500036 as a co-treatment to L-DOPA in PD therapy.
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Phosphodiesterases (PDEs) play an important function in transduction of cellular signals by modulating the activation of G-proteins by hydrolyzing cAMP and cGMP. PDE10A has emerged as an inhibitory target for development of effective therapeutics against various disorders such as schizophrenia, psychosis, Huntington disease, and other disorders related to the central nervous system. We utilized various computational methods such as molecular docking, molecular dynamic simulations, and MM-PBSA to find a more potent and selective PDE10A inhibitor compared to papaverine, which is a known standard inhibitor of PDE10A. Molecular docking of papaverine and twenty-eight in house synthesized 3-Methylenisoindolin-1-one based molecules provided two potential lead molecules (molecule #3 and molecule #28), which could be developed as potent PDE10A inhibitors. However, molecule #28 was excluded from further studies due to its cross reactivity with other PDE isoforms. Molecular dynamics and MM-PBSA techniques were used to further analyze the molecular docking results. Molecule #3 binds to the conserved substrate recognizing residue (Gln726) and also fits into the selectivity pocket by anchoring to the hydrophobic residue Tyr693. This study provides a promising candidate molecule that could be developed as a more potent and selective inhibitor of PDE10A.
Medicinal chemistry strategies for the development of phosphodiesterase 10A (PDE10A) inhibitors - An update of recent progress
2021, European Journal of Medicinal Chemistry
Phosphodiesterase 10A is a member of Phosphodiesterase (PDE)-superfamily of the enzyme which is responsible for hydrolysis of cAMP and cGMP to their inactive forms 5′-AMP and 5′-GMP, respectively. PDE10A is highly expressed in the brain, particularly in the putamen and caudate nucleus. PDE10A plays an important role in the regulation of localization, duration, and amplitude of the cyclic nucleotide signalling within the subcellular domain of these regions, and thereby modulation of PDE10A enzyme can give rise to a new therapeutic approach in the treatment of schizophrenia and other neurodegenerative disorders. Limitation of the conventional therapy of schizophrenia forced the pharmaceutical industry to move their efforts to develop a novel treatment approach with reduced side effects. In the past decade, considerable developments have been made in pursuit of PDE10A centric antipsychotic agents by several pharmaceutical industries due to the distribution of PDE10A in the brain and the ability of PDE10A inhibitors to mimic the effect of D2 antagonists and D1 agonists. However, no selective PDE10A inhibitor is currently available in the market for the treatment of schizophrenia. The present compilation concisely describes the role of PDE10A inhibitors in the therapy of neurodegenerative disorders mainly in psychosis, the structure of PDE10A enzyme, key interaction of different PDE10A inhibitors with human PDE10A enzyme and recent medicinal chemistry developments in designing of safe and effective PDE10A inhibitors for the treatment of schizophrenia. The present compilation also provides useful information and future direction to bring further improvements in the discovery of PDE10A inhibitors.

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NeuroanatomyCellular and subcellular localization of PDE10A, a striatum-enriched phosphodiesterase

Abstract

Section snippets

Animals

PDE10A is expressed only in striatal medium spiny projection neurons

Discussion

Conclusion

J Biol Chem

J Biol Chem

Neuron

Trends Biochem Sci

Neurosci Res

Trends Neurosci

J Biol Chem

Gene

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Neuroscience

Schizophr Res

Brain Res

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Cell

Biochemical characterization and localization of a non-N-methyl-D-aspartate glutamate receptor in rat brain

J Neurochem

Phosphodiesterases and cyclic nucleotide signaling in endocrine cells

Mol Endocrinol

Neuroanatomy
Cellular and subcellular localization of PDE10A, a striatum-enriched phosphodiesterase