Dataset on exposure conditions to Fe2O3 and SiO2 colloidal suspension and airborne particulate matter (PM) suspensions: crude NIST1648a and with reduced content of organic matter, LAp120.

Particulate matter (PM) present in the air pollution increases morbidity and mortality due to several reasons. The dataset presents a comparative analysis of nebulization process of Fe2O3 and SiO2 nanoparticles or crude PM (NIST1648a) and that with reduced content of organic matter (LAp120). Nebulization tests were carried out to determine concentrations of nanoparticle and PM suspensions, in order to create an atmosphere with a concentration of PM particles about 1000 µg/m3 of air in the exposure chambers. It is important to properly recreate environmental conditions during further research on animals. The absorbance spectrum of the suspensions of the tested materials was measured in the range of 300-700 nm. The changes in the absorbance of these suspensions depending on the concentration after their passage through the nebulizers were examined. Based on the absorbance, it was determined to what extent the suspensions are passed out and dispersed by the nebulizers. The operating mode of the nebulizers and the concentration of suspensions were determined in order to establish the optimal exposure conditions and the microclimate of the chambers for further studies with mice. The dataset can help in optimization of nebulization process for all researchers exploring the further issue of the influence of the air pollution on the broadly understood animal functions, behavioral parameters and biochemical aspects.

Investigating the potential effects of α-synuclein aggregation on susceptibility to chronic stress in a mouse Parkinson's disease model.

BACKGROUND: Parkinson's disease (PD) is a motor disorder characterized by the degeneration of dopaminergic neurons, putatively due to the accumulation of α-synuclein (α-syn) in Lewy bodies (LBs) in Substantia Nigra. PD is also associated with the formation of LBs in brain areas responsible for emotional and cognitive regulation such as the amygdala and prefrontal cortex, and concurrent depression prevalence in PD patients. The exact link between dopaminergic cell loss, α-syn aggregation, depression, and stress, a major depression risk factor, is unclear. Therefore, we aimed to explore the interplay between sensitivity to chronic stress and α-syn aggregation. METHODS: Bilateral injections of α-syn preformed fibrils (PFFs) into the striatum of C57Bl/6 J mice were used to induce α-syn aggregation. Three months after injections, animals were exposed to chronic social defeat stress. RESULTS: α-syn aggregation did not affect stress susceptibility but independently caused increased locomotor activity in the open field test, reduced anxiety in the light-dark box test, and increased active time in the tail suspension test. Ex vivo analysis revealed modest dopaminergic neuron loss in the substantia nigra and reduced dopaminergic innervation in the dorsal striatum in PFFs injected groups. α-Syn aggregates were prominent in the amygdala, prefrontal cortex, and substantia nigra, with minimal α-syn aggregation in the raphe nuclei and locus coeruleus. CONCLUSIONS: Progressive bilateral α-syn aggregation might lead to compensatory activity increase and alterations in emotionally regulated behavior, without affecting stress susceptibility. Understanding how α-syn aggregation and degeneration in specific brain structures contribute to depression and anxiety in PD patients requires further investigation.

Elevated Expression of HSP72 in the Prefrontal Cortex and Hippocampus of Rats Subjected to Chronic Mild Stress and Treated with Imipramine.

The HSP70 and HSP90 family members belong to molecular chaperones that exhibit protective functions during the cellular response to stressful agents. We investigated whether the exposure of rats to chronic mild stress (CMS), a validated model of depression, affects the expression of HSP70 and HSP90 in the prefrontal cortex (PFC), hippocampus (HIP) and thalamus (Thal). Male Wistar rats were exposed to CMS for 3 or 8 weeks. The antidepressant imipramine (IMI, 10 mg/kg, i.p., daily) was introduced in the last five weeks of the long-term CMS procedure. Depressive-like behavior was verified by the sucrose consumption test. The expression of mRNA and protein was quantified by real-time PCR and Western blot, respectively. In the 8-week CMS model, stress alone elevated HSP72 and HSP90B mRNA expression in the HIP. HSP72 mRNA was increased in the PFC and HIP of rats not responding to IMI treatment vs. IMI responders. The CMS exposure increased HSP72 protein expression in the cytosolic fraction of the PFC and HIP, and this effect was diminished by IMI treatment. Our results suggest that elevated levels of HSP72 may serve as an important indicator of neuronal stress reactions accompanying depression pathology and could be a potential target for antidepressant strategy.

Spontaneous head twitches in aged rats: behavioral and molecular study.

RATIONALE: We have discovered that rats at the age of 18 months begin to twitch their heads spontaneously (spontaneous head twitching, SHT). To date, no one has described this phenomenon. OBJECTIVES: The purpose of this study was to characterize SHT pharmacologically and to assess some possible mechanisms underlying SHT. METHODS: Wistar male rats were used in the study. Animals at the age of 18 months were qualified as HSHT (SHT ≥ 7/10 min observations) or LSHT (SHT < 7/10 min observations). Quantitative real-time PCR with TaqMan low-density array (TLDA) approach was adopted to assess the mRNA expression of selected genes in rat's hippocampus. RESULTS: HSHT rats did not differ from LSHT rats in terms of survival time, general health and behavior, water intake, and spontaneous locomotor activity. 2,5-dimethoxy-4-iodoamphetamine (DOI) at a dose of 2.5 mg/kg increased the SHT in HSHT and LSHT rats, while ketanserin dose-dependently abolished the SHT in the HSHT rats. The SHT was reduced or abolished by olanzapine, clozapine, risperidone, and pimavanserin. All these drugs have strong 5-HT2A receptor-inhibiting properties. Haloperidol and amisulpride, as antipsychotic drugs with a mostly dopaminergic mechanism of action, did not influence SHT. Similarly, escitalopram did not affect SHT. An in-depth gene expression analysis did not reveal significant differences between the HSHT and the LSHT rats. CONCLUSIONS: SHT appears in some aging rats (about 50%) and is permanent over time and specific to individuals. The 5-HT2A receptor strongly controls SHT. HSHT animals can be a useful animal model for studying 5-HT2A receptor ligands.

Gene Expression Changes Induced by Exposure of RAW 264.7 Macrophages to Particulate Matter of Air Pollution: The Role of Endotoxins.

Despite the variable chemical and physical characteristics of particulate air pollutants, inflammation and oxidative stress have been identified as common mechanisms for cell damage and negative health influences. These effects are produced by organic components, especially by endotoxins. This study analyzed the gene expression profile after exposure of RAW 264.7 cells to the standard particulate matter (PM) material, NIST1648a, and PM with a reduced organic matter content, LAp120, in comparison to the effects of lipopolysaccharide (LPS). The selected parameters of cell viability, cell cycle progression, and metabolic and inflammatory activity were also investigated. Both forms of PM negatively influenced the parameters of cell activity. These results were generally reflected in the gene expression profile. Only NIST1648a, excluding LAp120, contained endotoxins and showed small but statistically significant pro-inflammatory activity. However, the gene expression profiling revealed strong pro-inflammatory cell activation induced by NIST1648a that was close to the effects of LPS. Changes in gene expression triggered by LAp120 were relatively small. The observed differences in the effects of NIST1648a and LAp120 were related to the content of organic matter in which bacterial endotoxins play an important role. However, other organic compounds and their interactions with other PM components also appear to be of significant importance.

Genetic lesions of the noradrenergic system trigger induction of oxidative stress and inflammation in the ventral midbrain.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor deficits caused by the loss of dopaminergic neurons in the substantia nigra (SN) and ventral tegmental area (VTA). However, clinical data revealed that not only the dopaminergic system is affected in PD. Postmortem studies showed degeneration of noradrenergic cells in the locus coeruleus (LC) to an even greater extent than that observed in the SN/VTA. Pharmacological models support the concept that modification of noradrenergic transmission can influence the PD-like phenotype induced by neurotoxins. Nevertheless, there are no existing data on animal models regarding the distant impact of noradrenergic degeneration on intact SN/VTA neurons. The aim of this study was to create a transgenic mouse model with endogenously evoked progressive degeneration restricted to noradrenergic neurons and investigate its long-term impact on the dopaminergic system. To this end, we selectively ablated the transcription initiation factor-IA (TIF-IA) in neurons expressing dopamine ß-hydroxylase (DBH) by the Cre-loxP system. This mutation mimics a condition of nucleolar stress affecting neuronal survival. TIF-IADbhCre mice were characterized by selective, progressive degeneration of noradrenergic neurons, followed by phenotypic alterations associated with sympathetic system impairment. Our studies did not show any loss of tyrosine hydroxylase (TH)-positive cells in the SN/VTA of mutant mice; however, we observed increased indices of oxidative stress, enhanced markers of glial cell activation, inflammatory processes and isolated degenerating cells positive for FluoroJade C. These results were supported by gene expression profiling of VTA and SN from TIF-IADbhCre mice, revealing that 34 out of 246 significantly regulated genes in the SN/VTA were related to PD. Overall, our results shed new light on the possible negative influence of noradrenergic degeneration on dopaminergic neurons, reinforcing the neuroprotective role of noradrenaline.

Metabolic Response of RAW 264.7 Macrophages to Exposure to Crude Particulate Matter and a Reduced Content of Organic Matter.

Exposure to air pollution from various airborne particulate matter (PM) is regarded as a potential health risk. Airborne PM penetrates the lungs, where it is taken up by macrophages, what results in macrophage activation and can potentially lead to negative consequences for the organism. In the present study, we assessed the effects of direct exposure of RAW 264.7 macrophages to crude PM (NIST1648a) and to a reduced content of organic matter (LAp120) for up to 72 h on selected parameters of metabolic activity. These included cell viability and apoptosis, metabolic activity and cell number, ROS synthesis, nitric oxide (NO) release, and oxidative burst. The results indicated that both NIST1648a and LAp120 negatively influenced the parameters of cell viability and metabolic activity due to increased ROS synthesis. The negative effect of PM was concentration-dependent; i.e., it was the most pronounced for the highest concentration applied. The impact of PM also depended on the time of exposure, so at respective time points, PM induced different effects. There were also differences in the impact of NIST1648a and LAp120 on almost all parameters tested. The negative effect of LAp120 was more pronounced, what appeared to be associated with an increased content of metals.

Anticonvulsant effect of pterostilbene and its influence on the anxiety- and depression-like behavior in the pentetrazol-kindled mice: behavioral, biochemical, and molecular studies.

RATIONALE: Pterostilbene is the 3,5-dimethoxy derivative of resveratrol with numerous beneficial effects including neuroprotective properties. Experimental studies revealed its anticonvulsant action in the acute seizure tests. OBJECTIVES: The purpose of the present study was to evaluate the effect of pterostilbene in the pentetrazol (PTZ)-induced kindling model of epilepsy in mice as well as to assess some possible mechanisms of its anticonvulsant action in this model. METHODS: Mice were repeatedly treated with pterostilbene (50-200 mg/kg) and its effect on the development of seizure activity in the PTZ kindling was estimated. Influence of pterostilbene on the locomotor activity and anxiety- and depression-like behavior in the PTZ-kindled mice was also assessed. To understand the possible mechanisms of anticonvulsant activity of pterostilbene, γ-aminobutyric acid (GABA) and glutamate concentrations in the prefrontal cortex and hippocampus of the PTZ-kindled mice were measured using LC-MS/MS method. Moreover, mRNA expression of BDNF, TNF-α, IL-1ß, IL-6, GABRA1A, and GRIN2B was determined by RT-qPCR technique. RESULTS: We found that pterostilbene at a dose of 200 mg/kg considerably reduced seizure activity but did not influence the locomotor activity and depression- and anxiety-like behavior in the PTZ-kindled mice. In the prefrontal cortex and hippocampus, pterostilbene reversed the kindling-induced decrease of GABA concentration. Neither in the prefrontal cortex nor hippocampus pterostilbene affected mRNA expression of IL-1ß, IL-6, GABRA1A, and GRIN2B augmented by PTZ kindling. Pterostilbene at a dose of 100 mg/kg significantly decreased BDNF and TNF-α mRNA expression in the hippocampus of the PTZ-kindled mice. CONCLUSIONS: Although further studies are necessary to understand the mechanism of anticonvulsant properties of pterostilbene, our findings suggest that it might be considered a candidate for a new antiseizure drug.

The Air We Breathe: Air Pollution as a Prevalent Proinflammatory Stimulus Contributing to Neurodegeneration.

Air pollution is regarded as an important risk factor for many diseases that affect a large proportion of the human population. To date, accumulating reports have noted that particulate matter (PM) is closely associated with the course of cardiopulmonary disorders. As the incidence of Alzheimer's disease (AD), Parkinson's disease (PD), and autoimmune disorders have risen and as the world's population is aging, there is an increasing interest in environmental health hazards, mainly air pollution, which has been slightly overlooked as one of many plausible detrimental stimuli contributing to neurodegenerative disease onset and progression. Epidemiological studies have indicated a noticeable association between exposure to PM and neurotoxicity, which has been gradually confirmed by in vivo and in vitro studies. After entering the body directly through the olfactory epithelium or indirectly by passing through the respiratory system into the circulatory system, air pollutants are subsequently able to reach the brain. Among the potential mechanisms underlying particle-induced detrimental effects in the periphery and the central nervous system (CNS), increased oxidative stress, inflammation, mitochondrial dysfunction, microglial activation, disturbance of protein homeostasis, and ultimately, neuronal death are often postulated and concomitantly coincide with the main pathomechanisms of neurodegenerative processes. Other complementary mechanisms by which PM could mediate neurotoxicity and contribute to neurodegeneration remain unconfirmed. Furthermore, the question of how strong and proven air pollutants are as substantial adverse factors for neurodegenerative disease etiologies remains unsolved. This review highlights research advances regarding the issue of PM with an emphasis on neurodegeneration markers, symptoms, and mechanisms by which air pollutants could mediate damage in the CNS. Poor air quality and insufficient knowledge regarding its toxicity justify conducting scientific investigations to understand the biological impact of PM in the context of various types of neurodegeneration.

Antidepressants Differentially Regulate Intracellular Signaling from α1-Adrenergic Receptor Subtypes In Vitro.

Currently utilized antidepressants have limited effectiveness and frequently incur undesired effects. Most antidepressants are thought to act via the inhibition of monoamine reuptake; however, direct binding to monoaminergic receptors has been proposed to contribute to both their clinical effectiveness and their side effects, or lack thereof. Among the target receptors of antidepressants, α1­adrenergic receptors (ARs) have been implicated in depression etiology, antidepressant action, and side effects. However, differences in the direct effects of antidepressants on signaling from the three subtypes of α1-ARs, namely, α1A-, α1B- and α1D­ARs, have been little explored. We utilized cell lines overexpressing α1A-, α1B- or α1D-ARs to investigate the effects of the antidepressants imipramine (IMI), desipramine (DMI), mianserin (MIA), reboxetine (REB), citalopram (CIT) and fluoxetine (FLU) on noradrenaline-induced second messenger generation by those receptors. We found similar orders of inhibition at α1A-AR (IMI < DMI < CIT < MIA < REB) and α1D­AR (IMI = DMI < CIT < MIA), while the α1B-AR subtype was the least engaged subtype and was inhibited with low potency by three drugs (MIA < IMI = DMI). In contrast to their direct antagonistic effects, prolonged incubation with IMI and DMI increased the maximal response of the α1B-AR subtype, and the CIT of both the α1A- and the α1B-ARs. Our data demonstrate a complex, subtype-specific modulation of α1-ARs by antidepressants of different groups.

Chronic restraint stress induces changes in the cerebral Galpha 12/13 and Rho-GTPase signaling network.

BACKGROUND: Evidence indicates that Gα12, Gα13, and its downstream effectors, RhoA and Rac1, regulate neuronal morphology affected by stress. This study was aimed at investigating whether repeated stress influences the expression of proteins related to the Gα12/13 intracellular signaling pathway in selected brain regions sensitive to the effects of stress. Furthermore, the therapeutic impact of ß(1)adrenergic receptors (ß1AR) blockade was assessed. METHODS: Restraint stress (RS) model in mice (2 h/14 days) was used to assess prolonged stress effects on the mRNA expression of Gα12, Gα13, RhoA, Rac1 in the prefrontal cortex (PFC), hippocampus (HIP) and amygdala (AMY). In a separate study, applying RS model in rats (3-4 h/1 day or 14 days), we evaluated stress effects on the expression of Gα12, Gα11, Gαq, RhoA, RhoB, RhoC, Rac1/2/3 in the HIP. Betaxolol (BET), a selective ß1AR antagonist, was introduced (5 mg/kg/p.o./8-14 days) in the rat RS model to assess the role of ß1AR in stress effects. RT-qPCR and Western Blot were used for mRNA and protein assessments, respectively. RESULTS: Chronic RS decreased mRNA expression of Gα12 and increased mRNA for Rac1 in the PFC of mice. In the mice AMY, decreased mRNA expression of Gα12, Gα13 and RhoA was observed. Fourteen days of RS exposure increased RhoA protein level in the rats' HIP in the manner dependent on ß1AR activity. CONCLUSIONS: Together, these results suggest that repeated RS affects the expression of genes and proteins known to be engaged in neural plasticity, providing potential targets for further studies aimed at unraveling the molecular mechanisms of stress-related neuropsychiatric diseases.

Psychosocial Crowding Stress-Induced Changes in Synaptic Transmission and Glutamate Receptor Expression in the Rat Frontal Cortex.

This study demonstrates how exposure to psychosocial crowding stress (CS) for 3, 7, and 14 days affects glutamate synapse functioning and signal transduction in the frontal cortex (FC) of rats. CS effects on synaptic activity were evaluated in FC slices of the primary motor cortex (M1) by measuring field potential (FP) amplitude, paired-pulse ratio (PPR), and long-term potentiation (LTP). Protein expression of GluA1, GluN2B mGluR1a/5, VGLUT1, and VGLUT2 was assessed in FC by western blot. The body's response to CS was evaluated by measuring body weight and the plasma level of plasma corticosterone (CORT), adrenocorticotropic hormone (ACTH), and interleukin 1 beta (IL1B). CS 3 14d increased FP and attenuated LTP in M1, while PPR was augmented in CS 14d. The expression of GluA1, GluN2B, and mGluR1a/5 was up-regulated in CS 3d and downregulated in CS 14d. VGLUTs expression tended to increase in CS 7d. The failure to blunt the effects of chronic CS on FP and LTP in M1 suggests the impairment of habituation mechanisms by psychosocial stressors. PPR augmented by chronic CS with increased VGLUTs level in the CS 7d indicates that prolonged CS exposure changed presynaptic signaling within the FC. The CS bidirectional profile of changes in glutamate receptors' expression seems to be a common mechanism evoked by stress in the FC.

Pharmacological Blockade of Spinal CXCL3/CXCR2 Signaling by NVP CXCR2 20, a Selective CXCR2 Antagonist, Reduces Neuropathic Pain Following Peripheral Nerve Injury.

Recently, the role of CXCR2 in nociception has been noted. Our studies provide new evidence that the intrathecal administration of its CINC ligands (Cytokine-Induced Neutrophil Chemoattractant; CXCL1-3) induces pain-like behavior in naïve mice, and the effect occurring shortly after administration is associated with the neural location of CXCR2, as confirmed by immunofluorescence. RT-qPCR analysis showed, for the first time, raised levels of spinal CXCR2 after chronic constriction injury (CCI) of the sciatic nerve in rats. Originally, on day 2, we detected escalated levels of the spinal mRNA of all CINCs associated with enhancement of the protein level of CXCL3 lasting until day 7. Intrathecal administration of CXCL3 neutralizing antibody diminished neuropathic pain on day 7 after CCI. Interestingly, CXCL3 is produced in lipopolysaccharide-stimulated microglial, but not astroglial, primary cell cultures. We present the first evidence that chronic intrathecal administrations of the selective CXCR2 antagonist, NVP CXCR2 20, attenuate neuropathic pain symptoms and CXCL3 expression after CCI. Moreover, in naïve mice, this antagonist prevented CXCL3-induced hypersensitivity. However, NVP CXCR2 20 did not diminish glial activation, thus not enhancing morphine/buprenorphine analgesia. These results provide novel insight into the crucial role of CXCR2 in neuropathy based on CXCL3 modulation, which may become a potential therapeutic target in pain treatment.

The influence of CaMKII and ERK phosphorylation on BDNF changes observed in mice selectively devoid of CREB in serotonergic or noradrenergic neurons.

BACKGROUND: The transcription factor CREB and the neurotrophin BDNF are important mood regulators due to their profound role in controlling the neuronal plasticity. Our previously published results from transgenic mice functionally lacking CREB in chosen neural populations have shown that BDNF upregulation evoked by chronic treatment with fluoxetine seems to be dependent on CREB residing exclusively in serotonergic neurons. To further elucidate this observation, we focused on the representative signaling cascades engaged in the regulation of BDNF production. METHODS: The study was carried out on mice lacking CREB in noradrenergic (Creb1DBHCre) or serotonergic (Creb1TPH2CreERT2) neurons in CREM deficient background. Animals received fluoxetine (10 mg/kg, ip) or desipramine (20 mg/kg, ip) for 21 days. The expression of following proteins and their phosphorylated forms was assessed by Western blot: CREB, BDNF, CaMKIIα, ERK1/2. RESULTS: We showed that consistent with previously observed BDNF upregulation, chronic treatment with fluoxetine causes an increase in the pool of active CaMKIIα in w/t males, while in Creb1TPH2CreERT2 mutants, this effect ceased along with the observed decrease in ERK1/2 phosphorylation. These effects were region- and sex-specific. We did not observe a similar pattern of changes regarding the levels of BDNF expression and the CaMKIIα, ERK1/2 kinases in Creb1DBHCre mice exposed to desipramine. However, sex-dependent changes in the regulation of CaMKIIα and ERK1/2 activity were also observed. CONCLUSIONS: Our study highlights the pivotal role of CREB in response to antidepressants, emphasizing different sex-dependent vulnerabilities to particular drugs and the important impact of CREM on the effects of CREB deletion.

Fear memory-induced alterations in the mRNA expression of G proteins in the mouse brain and the impact of immediate posttraining treatment with morphine.

Disturbances in fear-evoked signal transduction in the hippocampus (HP), the nuclei of the amygdala (AMY), and the prefrontal cortex (PFC) underlie anxiety-related disorders. However, the molecular mechanisms underlying these effects remain elusive. Heterotrimeric G proteins (GPs) are divided into the following four families based on the intracellular activity of their alpha subunit (Gα): Gα(s) proteins stimulate cyclic AMP (cAMP) generation, Gα(i/o) proteins inhibit the cAMP pathway, Gα(q/11) proteins increase the intracellular Ca++ concentration and the inositol trisphosphate level, and Gα(12/13) proteins activate monomeric GP-Rho. In the present study, we assessed the effects of a fear memory procedure on the mRNA expression of the Gα subunits of all four GP families in the HP, AMY and PFC. C57BL/6 J mice were subjected to a fear conditioning (FC) procedure followed by a contextual or cued fear memory test (CTX-R and CS-R, respectively). Morphine (MOR, 1 mg/kg/ip) was injected immediately after FC to prevent the fear consolidation process. Real-time quantitative PCR was used to measure the mRNA expression levels of Gα subunits at 1 h after FC, 24 h after FC, and 1 h after the CTX-R or CS-R. In the HP, the mRNA levels of Gα(s), Gα(12) and Gα(11) were higher at 1 h after training. Gα(s) levels were slightly lower when consolidation was stabilized and after the CS-R. The mRNA levels of Gα(12) were increased at 1 h after FC, returned to control levels at 24 h after FC and increased again with the CTX-R. The increase in the Gα(11) level persisted at 24 h after FC and after CTX-R. In the AMY, no specific changes were induced by FC. In the PFC, CTX-R was accompanied by a decrease in Gα(i/o) mRNA levels; however, only Gα(i2) downregulation was prevented by MOR treatment. Hence, the FC-evoked changes in Gα mRNA expression were observed mainly in the HP and connected primarily to contextual learning. These results suggest that the activation of signaling pathways by Gα(s) and Gα(12) is required to begin the fear memory consolidation process in the HP, while signal transduction via Gα(11) is implicated in the maintenance of fear consolidation. In the PFC, the downregulation of Gα(i2) appears to be related to the contextual learning of fear.

Stimulation of noradrenergic transmission by reboxetine is beneficial for a mouse model of progressive parkinsonism.

Parkinson's disease (PD) is the second most common neurodegenerative disorder and is characterized by motor deficits such as tremor, rigidity and bradykinesia. These symptoms are directly caused by the loss of dopaminergic neurons. However, a wealth of clinical evidence indicates that the dopaminergic system is not the only system affected in PD. Postmortem studies of brains from PD patients have revealed the degeneration of noradrenergic neurons in the locus coeruleus (LC) to the same or even greater extent than that observed in the dopaminergic neurons of substantia nigra (SN) and ventral tegmental area (VTA). Moreover, studies performed on rodent models suggest that enhancement of noradrenergic transmission may attenuate the PD-like phenotype induced by MPTP administration, a neurotoxin-based PD model. The aim of this study was to investigate whether chronic treatment with either of two compounds targeting the noradrenergic system (reboxetine or atipamezole) possess the ability to reduce the progression of a PD-like phenotype in a novel mouse model of progressive dopaminergic neurodegeneration induced by the genetic inhibition of rRNA synthesis in dopaminergic neurons, mimicking a PD-like phenotype. The results showed that reboxetine improved the parkinsonian phenotype associated with delayed progression of SN/VTA dopaminergic neurodegeneration and higher dopamine content in the striatum. Moreover, the alpha1-adrenergic agonist phenylephrine enhanced survival of TH+ neurons in primary cell cultures, supporting the putative neuroprotective effects of noradrenergic stimulation. Our results provide new insights regarding the possible influence of the noradrenergic system on dopaminergic neuron survival and strongly support the hypothesis regarding the neuroprotective role of noradrenaline.

Selective Depletion of CREB in Serotonergic Neurons Affects the Upregulation of Brain-Derived Neurotrophic Factor Evoked by Chronic Fluoxetine Treatment.

Neurotrophic factors are regarded as crucial regulatory components in neuronal plasticity and are postulated to play an important role in depression pathology. The abundant expression of brain-derived neurotrophic factor (BDNF) in various brain structures seems to be of particular interest in this context, as downregulation of BDNF is postulated to be correlated with depression and its upregulation is often observed after chronic treatment with common antidepressants. It is well-known that BDNF expression is regulated by cyclic AMP response element-binding protein (CREB). In our previous study using mice lacking CREB in serotonergic neurons (Creb1TPH2CreERT2 mice), we showed that selective CREB ablation in these particular neuronal populations is crucial for drug-resistant phenotypes in the tail suspension test observed after fluoxetine administration in Creb1TPH2CreERT2 mice. The aim of this study was to investigate the molecular changes in the expression of neurotrophins in Creb1TPH2CreERT2 mice after chronic fluoxetine treatment, restricted to the brain structures implicated in depression pathology with profound serotonergic innervation including the prefrontal cortex (PFC) and hippocampus. Here, we show for the first time that BDNF upregulation observed after fluoxetine in the hippocampus or PFC might be dependent on the transcription factor CREB residing, not within these particular structures targeted by serotonergic projections, but exclusively in serotonergic neurons. This observation may shed new light on the neurotrophic hypothesis of depression, where the effects of BDNF observed after antidepressants in the hippocampus and other brain structures were rather thought to be regulated by CREB residing within the same brain structures. Overall, these results provide further evidence for the pivotal role of CREB in serotonergic neurons in maintaining mechanisms of antidepressant drug action by regulation of BDNF levels.

The Protective Effect of Repeated 1MeTIQ Administration on the Lactacystin-Induced Impairment of Dopamine Release and Decline in TH Level in the Rat Brain.

Parkinson's disease (PD) is a neurodegenerative disorder of the central nervous system (CNS) caused by a progressive loss of nigrostriatal dopaminergic neurons. Dysfunction of the ubiquitin-proteasome system (UPS) plays an important role in the pathogenesis of PD. Intranigral administration of the UPS inhibitor lactacystin is used to obtain a valuable animal model for investigating putative neuroprotective treatments for PD. 1-Methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ) is an endogenous amine that displays neuroprotective properties. This compound acts as a reversible monoamine oxidase (MAO) inhibitor and a natural free radical scavenger. In the present experiment, we investigated the effect of acute and chronic treatment with 1MeTIQ on locomotor activity and the release of dopamine as well as its metabolites in the striatum of unilaterally lactacystin-lesioned and sham-operated rats using in vivo microdialysis. Additionally, changes in the level of tyrosine hydroxylase (TH) in the substantia nigra were measured. Unilateral lactacystin injection into the substantia nigra caused significant impairment of dopamine release (approx. 45%) and a marked decline in the TH level. These effects were completely antagonized by multiple treatments with 1MeTIQ. The results obtained from the in vivo microdialysis study as well as from the ex vivo experiments suggest that multiple administration of 1MeTIQ protects dopaminergic neurons against the lactacystin-induced decline in TH concentration in the substantia nigra and prevents disturbances of dopamine release in the striatum. We have demonstrated that 1MeTIQ is capable of maintaining the physiological functions of the striatal dopamine neurons damaged by unilateral lactacystin lesion.

Involvement of Macrophage Inflammatory Protein-1 Family Members in the Development of Diabetic Neuropathy and Their Contribution to Effectiveness of Morphine.

Current investigations underline the important roles of C-C motif ligands in the development of neuropathic pain; however, their participation in diabetic neuropathy is still undefined. Therefore, the goal of our study was to evaluate the participation of macrophage inflammatory protein-1 (MIP-1) family members (CCL3, CCL4, CCL9) in a streptozotocin (STZ)-induced mouse model of diabetic neuropathic pain. Single intrathecal administration of each MIP-1 member (10, 100, or 500 ng/5 µl) in naïve mice evoked hypersensitivity to mechanical (von Frey test) and thermal (cold plate test) stimuli. Concomitantly, protein analysis has shown that, 7 days following STZ injection, the levels of CCL3 and CCL9 (but not CCL4) are increased in the lumbar spinal cord. Performed additionally, immunofluorescence staining undoubtedly revealed that CCL3, CCL9, and their receptors (CCR1 and CCR5) are expressed predominantly by neurons. In vitro studies provided evidence that the observed expression of CCL3 and CCL9 may be partially of glial origin; however, this observation was only partially possible to confirm by immunohistochemical study. Single intrathecal administration of CCL3 or CCL9 neutralizing antibody (2 and 4 µg/5 µl) delayed neuropathic pain symptoms as measured at day 7 following STZ administration. Single intrathecal injection of a CCR1 antagonist (J113863; 15 and 20 µg/5 µl) also attenuated pain-related behavior as evaluated at day 7 after STZ. Both neutralizing antibodies, as well as the CCR1 antagonist, enhanced the effectiveness of morphine in STZ-induced diabetic neuropathy. These findings highlight the important roles of CCL3 and CCL9 in the pathology of diabetic neuropathic pain and suggest that they play pivotal roles in opioid analgesia.

Novel multi-target azinesulfonamides of cyclic amine derivatives as potential antipsychotics with pro-social and pro-cognitive effects.

Currently used antipsychotics are characterized by multireceptor mode of action. While antagonism of dopamine D2 receptors is responsible for the alleviation of "positive" symptoms of schizophrenia and the effects at other, particularly serotonergic receptors are necessary for their additional therapeutic effects, there is no consensus regarding an "ideal" target engagement. Here, a detailed SAR analysis in a series of 45 novel azinesulfonamides of cyclic amine derivatives, involving the aryl-piperazine/piperidine pharmacophore, central alicyclic amine and azinesulfonamide groups has led to the selection of (S)-4-((2-(2-(4-(benzo[b]thiophen-4-yl)piperazin-1-yl)ethyl)pyrrolidin-1-yl)sulfonyl)isoquinoline (62). The polypharmacology profile of 62, characterized by partial 5-HT1AR agonism, 5-HT2A/5-HT7/D2/D3R antagonism, and blockade of SERT, reduced the "positive"-like, and "negative"-like symptoms of psychoses. Compound 62 produced no catalepsy, demonstrated a low hyperprolactinemia liability and displayed pro-cognitive effects in the novel object recognition task and attentional set-shifting test. While association of in vitro features with the promising in vivo profile of 62 is still not fully established, its clinical efficacy should be verified in further stages of development.