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Journal of Neurovirology Apr 2018Most studies of HIV latency focus on the peripheral population of resting memory T cells, but the brain also contains a distinct reservoir of HIV-infected cells in...
Most studies of HIV latency focus on the peripheral population of resting memory T cells, but the brain also contains a distinct reservoir of HIV-infected cells in microglia, perivascular macrophages, and astrocytes. Studying HIV in the brain has been challenging, since live cells are difficult to recover from autopsy samples and primate models of SIV infection utilize viruses that are more myeloid-tropic than HIV due to the expression of Vpx. Development of a realistic small animal model would greatly advance studies of this important reservoir and permit definitive studies of HIV latency. When radiation or busulfan-conditioned, immune-deficient NSG mice are transplanted with human hematopoietic stem cells, human cells from the bone marrow enter the brain and differentiate to express microglia-specific markers. After infection with replication competent HIV, virus was detected in these bone marrow-derived human microglia. Studies of HIV latency in this model would be greatly enhanced by the development of compounds that can selectively reverse HIV latency in microglial cells. Our studies have identified members of the CoREST repression complex as key regulators of HIV latency in microglia in both rat and human microglial cell lines. The monoamine oxidase (MAO) and potential CoREST inhibitor, phenelzine, which is brain penetrant, was able to stimulate HIV production in human microglial cell lines and human glial cells recovered from the brains of HIV-infected humanized mice. The humanized mice we have developed therefore show great promise as a model system for the development of strategies aimed at defining and reducing the CNS reservoir.
Topics: AIDS Dementia Complex; Animals; Anti-HIV Agents; Bone Marrow Cells; Brain; Busulfan; Cell Differentiation; Co-Repressor Proteins; Disease Models, Animal; Gene Expression Regulation; HIV-1; Hematopoietic Stem Cell Transplantation; Hematopoietic Stem Cells; Humans; Mice; Mice, Transgenic; Microglia; Monoamine Oxidase Inhibitors; Nerve Tissue Proteins; Phenelzine; Rats; Repressor Proteins; Transplantation, Heterologous; Virus Latency; Whole-Body Irradiation
PubMed: 29256041
DOI: 10.1007/s13365-017-0604-2 -
Psychological Medicine Sep 2018Guidelines about post-traumatic stress disorder (PTSD) recommend broad categories of drugs, but uncertainty remains about what pharmacological treatment to select among... (Comparative Study)
Comparative Study Meta-Analysis
BACKGROUND
Guidelines about post-traumatic stress disorder (PTSD) recommend broad categories of drugs, but uncertainty remains about what pharmacological treatment to select among all available compounds.
METHODS
Cochrane Central Register of Controlled Trials register, MEDLINE, PsycINFO, National PTSD Center Pilots database, PubMed, trial registries, and databases of pharmaceutical companies were searched until February 2016 for double-blind randomised trials comparing any pharmacological intervention or placebo as oral therapy in adults with PTSD. Initially, we performed standard pairwise meta-analyses using a random effects model. We then carried out a network meta-analysis. The main outcome measures were mean change on a standardised scale and all-cause dropout rate. Acute treatment was defined as 8-week follow up.
RESULTS
Desipramine, fluoxetine, paroxetine, phenelzine, risperidone, sertraline, and venlafaxine were more effective than placebo; phenelzine was better than many other active treatments and was the only drug, which was significantly better than placebo in terms of dropouts (odds ratio 7.50, 95% CI 1.72-32.80). Mirtazapine yielded a relatively high rank for efficacy, but the respective value for acceptability was not among the best treatments. Divalproex had overall the worst ranking.
CONCLUSIONS
The efficacy and acceptability hierarchies generated by our study were robust against many sources of bias. The differences between drugs and placebo were small, with the only exception of phenelzine. Considering the small amount of available data, these results are probably not robust enough to suggest phenelzine as a drug of choice. However, findings from this review reinforce the idea that phenelzine should be prioritised in future trials in PTSD.
Topics: Adult; Humans; Middle Aged; Network Meta-Analysis; Neurotransmitter Agents; Outcome Assessment, Health Care; Patient Acceptance of Health Care; Registries; Stress Disorders, Post-Traumatic
PubMed: 29254516
DOI: 10.1017/S003329171700349X -
Brain Research Oct 2017During typical late-postnatal CNS development, net reductions in dendritic spine densities are associated with activity-dependent learning. Prior results showed agonist...
Chronic CB1 cannabinoid receptor antagonism persistently increases dendritic spine densities in brain regions important to zebra finch vocal learning and production in an antidepressant-sensitive manner.
During typical late-postnatal CNS development, net reductions in dendritic spine densities are associated with activity-dependent learning. Prior results showed agonist exposure in young animals increased spine densities in a subset of song regions while adult exposures did not, suggesting endocannabinoid signaling regulates dendritic spine dynamics important to vocal development. Here we addressed this question using the CB1 receptor-selective antagonist SR141716A (SR) to disrupt endocannabinoid signaling both during and after vocal learning. We hypothesized antagonist exposure during vocal development, but not adulthood, would alter spine densities. Following 25days of exposure and a 25day maturation period, 3D reconstructions of Golgi-Cox stained neurons were used to measure spine densities. We found antagonist treatments during both age periods increased densities within Area X (basal ganglia) and following adult treatments within HVC (premotor cortical-like). Results suggest both inappropriate cannabinoid receptor stimulation and inhibition are capable of similar disregulatory effects during establishment of circuits important to vocal learning, with antagonism extending these effects through adulthood. Given clinical evidence of depressant effects of SR, we tested the ability of the antidepressant monoamine oxidase inhibitor (MAOI) phenelzine to mitigate SR-induced spine density increases. This was confirmed implicating interaction between monoamine and endocannabinoid systems. Finally, we evaluated acute effects of these drugs to alter ability of novel song exposure to increase spine densities in auditory NCM and other regions, finding when combined, SR and phenelzine increased densities within Area X. These results contribute to understanding relevance of dendritic spine dynamics in neuronal development, drug abuse, and depression.
Topics: Animals; Antidepressive Agents; Brain; Cannabinoid Receptor Antagonists; Cannabinoids; Dendritic Spines; Endocannabinoids; Finches; Learning; Male; Monoamine Oxidase Inhibitors; Neurogenesis; Receptor, Cannabinoid, CB1; Vocalization, Animal
PubMed: 28743448
DOI: 10.1016/j.brainres.2017.07.015 -
Journal of Neurochemistry Oct 2017Brain-derived neurotrophic factor (BDNF) promotes maturation of cholinergic neurons. However, how activity-dependent BDNF expression affects specific cholinergic gene...
Brain-derived neurotrophic factor (BDNF) promotes maturation of cholinergic neurons. However, how activity-dependent BDNF expression affects specific cholinergic gene expression remains unclear. This study addressed this question by determining mRNA levels of 22 acetylcholine receptor subunits, the choline transporter (CHT), and the choline acetyltransferase (ChAT) in mice deficient in activity-dependent BDNF via promoter IV (KIV) and control wild-type mice. Quantitative RT-PCR revealed significant reductions in nicotinic acetylcholine receptor alpha 5 (CHRNA5) in the frontal cortex and hippocampus and M5 muscarinic acetylcholine receptor (CHRM5) in the hippocampus, but significant increases in M2 muscarinic acetylcholine receptor (CHRM2) in the frontal cortex of KIV mice compared to wild-type mice. Three-week treatments with fluoxetine, phenelzine, duloxetine, imipramine, or an enriched environment treatment (EET) did not affect the altered expression of these genes except that EET increased CHRNA5 levels only in KIV frontal cortex. EET also increased levels of CHRNA7, CHT, and ChAT, again only in the KIV frontal cortex. The imipramine treatment was most prominent among the four antidepressants; it up-regulated hippocampal CHRM2 and frontal cortex CHRM5 in both genotypes, and frontal cortex CHRNA7 only in KIV mice. To the best of our knowledge, this is the first evidence that BDNF deficiency disturbs expression of CHRNA5, CHRM2, and CHRM5. Our results suggest that promoter IV-BDNF deficiency - which occurs under chronic stress - causes cholinergic dysfunctions via these receptors. EET is effective on CHRNA5, while its compensatory induction of other cholinergic genes or drugs targeting CHRNA5, CHRM2, and CHRM5 may become an alternative strategy to reverse these BDNF-linked cholinergic dysfunctions.
Topics: Animals; Antidepressive Agents; Brain-Derived Neurotrophic Factor; Environment; Female; Frontal Lobe; Gene Expression; Hippocampus; Male; Mice; Mice, 129 Strain; Mice, Inbred C57BL; Promoter Regions, Genetic; Receptor, Muscarinic M2; Receptor, Muscarinic M5; Receptors, Nicotinic
PubMed: 28722769
DOI: 10.1111/jnc.14129 -
Acta Pharmaceutica (Zagreb, Croatia) Jun 2017γ-Ethyl-γ-phenyl-butyrolactone (EFBL) is a structural combination of the anticonvulsant γ-hydroxy-γ-ethyl-γ-phenylbutyramide (HEPB) and the hypnotic...
γ-Ethyl-γ-phenyl-butyrolactone (EFBL) is a structural combination of the anticonvulsant γ-hydroxy-γ-ethyl-γ-phenylbutyramide (HEPB) and the hypnotic γ-butyrolactone (GBL), which inherits both properties. To clarify its mechanism of action, the effects of EFBL, GBL and HEPB on dopamine (DA) and noradrenaline (NA) brain levels were investigated. Influences of chlorpromazine, phenelzine and aminooxyacetic acid were also studied. EFBL increased DA in a dose-dependent manner, remaining enhanced by 80 % over a period of 24 h and augmented NA by 54 % one hour after treatment. HEPB increased DA and NA approximately 2-fold after the first hour. GBL raised DA and NA after three and 24 h, resp. EFBL reversed chlorpromazine effects but potentiated those of phenelzine on DA. Amino-oxyacetic modified neither DA nor NA brain levels, not even in the presence of EFBL. The anticonvulsant and hypnotic properties of EFBL are attributed to its effect on presynaptic dopaminergic receptors and its lasting effect on ethyl and phenyl radicals that hinder its degradation. The results support the role of DA and NA in regulating seizure activity in the brain and indicate that EFBL offers a potential treatment for refractory epilepsy without complementary drugs and Parkinson's disease, without the drawbacks of oral therapies.
Topics: 4-Butyrolactone; Animals; Anticonvulsants; Brain; Brain Chemistry; Catecholamines; Dopamine; Male; Mice; Norepinephrine
PubMed: 28590911
DOI: 10.1515/acph-2017-0014 -
The Primary Care Companion For CNS... Dec 2016
Topics: Brain; Cerebrovascular Disorders; Diagnosis, Differential; Female; Humans; Middle Aged; Monoamine Oxidase Inhibitors; Phenelzine; Tranylcypromine
PubMed: 27922229
DOI: 10.4088/PCC.16l01945 -
Journal of Neurotrauma Apr 2017Lipid peroxidation (LP) is a key contributor to the pathophysiology of traumatic brain injury (TBI). Traditional antioxidant therapies are intended to scavenge the free...
Phenelzine Protects Brain Mitochondrial Function In Vitro and In Vivo following Traumatic Brain Injury by Scavenging the Reactive Carbonyls 4-Hydroxynonenal and Acrolein Leading to Cortical Histological Neuroprotection.
Lipid peroxidation (LP) is a key contributor to the pathophysiology of traumatic brain injury (TBI). Traditional antioxidant therapies are intended to scavenge the free radicals responsible for either initiation or propagation of LP. A more recently explored approach involves scavenging the terminal LP breakdown products that are highly reactive and neurotoxic carbonyl compounds, 4-hydroxynonenal (4-HNE) and acrolein (ACR), to prevent their covalent modification and rendering of cellular proteins nonfunctional leading to loss of ionic homeostasis, mitochondrial failure, and subsequent neuronal death. Phenelzine (PZ) is a U.S. Food and Drug Administration-approved monoamine oxidase (MAO) inhibitor (MAO-I) used for treatment of refractory depression that possesses a hydrazine functional group recently discovered by other investigators to scavenge reactive carbonyls. We hypothesized that PZ will protect mitochondrial function and reduce markers of oxidative damage by scavenging LP-derived aldehydes. In a first set of in vitro studies, we found that exogenous application of 4-HNE or ACR significantly reduced respiratory function and increased markers of oxidative damage (p < 0.05) in isolated noninjured rat brain cortical mitochondria, whereas PZ pre-treatment significantly prevented mitochondrial dysfunction and oxidative modification of mitochondrial proteins in a concentration-related manner (p < 0.05). This effect was not shared by a structurally similar MAO-I, pargyline, which lacks the hydrazine group, confirming that the mitochondrial protective effects of PZ were related to its carbonyl scavenging and not to MAO inhibition. In subsequent in vivo studies, we documented that PZ treatment begun at 15 min after controlled cortical impact TBI significantly attenuated 72-h post-injury mitochondrial respiratory dysfunction. The cortical mitochondrial respiratory protection occurred together with a significant increase in cortical tissue sparing.
Topics: Acrolein; Aldehydes; Animals; Brain Injuries, Traumatic; Cerebral Cortex; Disease Models, Animal; Male; Mitochondria; Monoamine Oxidase Inhibitors; Neuroprotective Agents; Phenelzine; Rats; Rats, Sprague-Dawley
PubMed: 27750484
DOI: 10.1089/neu.2016.4624 -
Journal of Neuroinflammation Jun 2016Chronic neuropathic pain is a common symptom of multiple sclerosis (MS). MOG35-55-induced experimental autoimmune encephalomyelitis (EAE) has been used as an animal...
BACKGROUND
Chronic neuropathic pain is a common symptom of multiple sclerosis (MS). MOG35-55-induced experimental autoimmune encephalomyelitis (EAE) has been used as an animal model to investigate the mechanisms of pain in MS. Previous studies have implicated sensitization of spinal nociceptive networks in the pathogenesis of pain in EAE. However, the involvement of supraspinal sites of nociceptive integration, such as the primary somatosensory cortex (S1), has not been defined. We therefore examined functional, structural, and immunological alterations in S1 during the early stages of EAE, when pain behaviors first appear. We also assessed the effects of the antidepressant phenelzine (PLZ) on S1 alterations and nociceptive (mechanical) sensitivity in early EAE. PLZ has been shown to restore central nervous system (CNS) tissue concentrations of GABA and the monoamines (5-HT, NA) in EAE. We hypothesized that PLZ treatment would also normalize nociceptive sensitivity in EAE by restoring the balance of excitation and inhibition (E-I) in the CNS.
METHODS
We used in vivo flavoprotein autofluorescence imaging (FAI) to assess neural ensemble responses in S1 to vibrotactile stimulation of the limbs in early EAE. We also used immunohistochemistry (IHC), and Golgi-Cox staining, to examine synaptic changes and neuroinflammation in S1. Mechanical sensitivity was assessed at the clinical onset of EAE with Von Frey hairs.
RESULTS
Mice with early EAE exhibited significantly intensified and expanded FAI responses in S1 compared to controls. IHC revealed increased vesicular glutamate transporter (VGLUT1) expression and disrupted parvalbumin+ (PV+) interneuron connectivity in S1 of EAE mice. Furthermore, peri-neuronal nets (PNNs) were significantly reduced in S1. Morphological analysis of excitatory neurons in S1 revealed increased dendritic spine densities. Iba-1+ cortical microglia were significantly elevated early in the disease. Chronic PLZ treatment was found to normalize mechanical thresholds in EAE. PLZ also normalized S1 FAI responses, neuronal morphologies, and cortical microglia numbers and attenuated VGLUT1 reactivity-but did not significantly attenuate the loss of PNNs.
CONCLUSIONS
These findings implicate a pro-excitatory shift in the E-I balance of the somatosensory CNS, arising early in the pathogenesis EAE and leading to large-scale functional and structural plasticity in S1. They also suggest a novel antinociceptive effect of PLZ treatment.
Topics: Animals; Antidepressive Agents; Calcium-Binding Proteins; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Freund's Adjuvant; Hyperalgesia; Mice; Mice, Inbred C57BL; Microfilament Proteins; Myelin-Oligodendrocyte Glycoprotein; Neuralgia; Neurons; Pain Measurement; Pain Threshold; Parvalbumins; Peptide Fragments; Phenelzine; Plant Lectins; Receptors, N-Acetylglucosamine; Somatosensory Cortex; Synapses
PubMed: 27282914
DOI: 10.1186/s12974-016-0609-4 -
Journal of Pharmacology &... 2016An infrequent manifestation of monoamine oxidase inhibitor (MAOI) toxicity is "ping-pong gaze" (PPG). We describe the case of a 26-year-old female who was found...
An infrequent manifestation of monoamine oxidase inhibitor (MAOI) toxicity is "ping-pong gaze" (PPG). We describe the case of a 26-year-old female who was found unresponsive after taking 40 tablets of phenelzine. On presentation to the hospital, her eyes were moving in characteristic "ping pong" fashion. After 6 hours her gaze terminated. The following day her neurologic exam was benign and she had no long-term sequelae. While the etiology of PPG is unknown, it is most often seen with irreversible structural brain damage. However, a detailed literature review revealed that previous cases of MAOI toxicity where the patient survived have all had complete neurologic recovery.
PubMed: 27127395
DOI: 10.4103/0976-500X.179360 -
Journal of Neurochemistry Jul 2016Currently there are no effective therapies available for the excruciating neuropathic pain that develops after spinal cord injuries (SCI). As such, a great deal of...
Currently there are no effective therapies available for the excruciating neuropathic pain that develops after spinal cord injuries (SCI). As such, a great deal of effort is being put into the investigation of novel therapeutic targets that can alleviate this pain. One such target is acrolein, a highly reactive aldehyde produced as a byproduct of oxidative stress and inflammation that is capable of activating the transient receptor potential ankyrin 1 (TRPA1) cation channel, known to be involved in the transmission and propagation of chronic neuropathic pain. One anti-acrolein agent, hydralazine, has already been shown to reduce neuropathic pain behaviors and offer neuroprotection after SCI. This study investigates another acrolein scavenger, phenelzine, for its possible role of alleviating sensory hypersensitivity through acrolein suppression. The results show that phenelzine is indeed capable of attenuating neuropathic pain behaviors in acute, delayed, and chronic administration schedules after injury in a rat model of SCI. In addition, upon the comparison of hydralazine to phenelzine, both acrolein scavengers displayed a dose-dependent response in the reduction of acrolein in vivo. Finally, phenelzine proved capable of providing locomotor function recovery and neuroprotection of spinal cord tissue when administered immediately after injury for 2 weeks. These results indicate that phenelzine may be an effective treatment for neuropathic pain after SCI and likely a viable alternative to hydralazine. We have shown that phenelzine can attenuate neuropathic pain behavior in acute, delayed, and chronic administration in post-SCI rats. This was accompanied by a dose-dependent reduction in an acrolein metabolite in urine and an acrolein adduct in spinal cord tissue, and the suppression of TRPA1 over-expression in central and peripheral locations post-trauma. Acrolein scavenging might be a novel therapeutic strategy to reduce post-SCI neuropathic pain.
Topics: Animals; Behavior, Animal; Contusions; Disease Models, Animal; Hydralazine; Hyperalgesia; Male; Neuralgia; Phenelzine; Rats, Sprague-Dawley; Recovery of Function; Spinal Cord Injuries
PubMed: 27060873
DOI: 10.1111/jnc.13639