Quantitative analysis of neuronal mitochondrial movement reveals patterns resulting from neurotoxicity of rotenone and 6-hydroxydopamine.

Alterations in mitochondrial dynamics, including their intracellular trafficking, are common early manifestations of neuronal degeneration. However, current methodologies used to study mitochondrial trafficking events rely on parameters that are primarily altered in later stages of neurodegeneration. Our objective was to establish a reliable applied statistical analysis to detect early alterations in neuronal mitochondrial trafficking. We propose a novel quantitative analysis of mitochondria trajectories based on innovative movement descriptors, including straightness, efficiency, anisotropy, and kurtosis. We evaluated time- and dose-dependent alterations in trajectory descriptors using biological data from differentiated SH-SY5Y cells treated with the mitochondrial toxicants 6-hydroxydopamine and rotenone. MitoTracker Red CMXRos-labelled mitochondria movement was analyzed by total internal reflection fluorescence microscopy followed by computational modelling to describe the process. Based on the aforementioned trajectory descriptors, this innovative analysis of mitochondria trajectories provides insights into mitochondrial movement characteristics and can be a consistent and sensitive method to detect alterations in mitochondrial trafficking occurring in the earliest time points of neurodegeneration.

Reduced Endothelial Leptin Signaling Increases Vascular Adrenergic Reactivity in a Mouse Model of Congenital Generalized Lipodystrophy.

The adipokine leptin, which is best-known for its role in the control of metabolic function, is also a master regulator of cardiovascular function. While leptin has been approved for the treatment of metabolic disorders in patients with congenital generalized lipodystrophy (CGL), the effects of chronic leptin deficiency and the treatment on vascular contractility remain unknown. Herein, we investigated the effects of leptin deficiency and treatment (0.3 mg/day/7 days) on aortic contractility in male Berardinelli-Seip 2 gene deficient mice (gBscl2-/-, model of CGL) and their wild-type control (gBscl2+/+), as well as in mice with selective deficiency in endothelial leptin receptor (LepREC-/-). Lipodystrophy selectively increased vascular adrenergic contractility via NO-independent mechanisms and induced hypertrophic vascular remodeling. Leptin treatment and Nox1 inhibition blunted adrenergic hypercontractility in gBscl2-/- mice, however, leptin failed to rescue vascular media thickness. Selective deficiency in endothelial leptin receptor did not alter baseline adrenergic contractility but abolished leptin-mediated reduction in adrenergic contractility, supporting the contribution of endothelium-dependent mechanisms. These data reveal a new direct role for endothelial leptin receptors in the control of vascular contractility and homeostasis, and present leptin as a safe therapy for the treatment of vascular disease in CGL.

Treatments for priapism in boys and men with sickle cell disease.

BACKGROUND: Sickle cell disease comprises a group of genetic haemoglobin disorders. The predominant symptom associated with sickle cell disease is pain resulting from the occlusion of small blood vessels by abnormally 'sickle-shaped' red blood cells. There are other complications, including chronic organ damage and prolonged painful erection of the penis, known as priapism. Severity of sickle cell disease is variable, and treatment is usually symptomatic. Priapism affects up to half of all men with sickle cell disease, however, there is no consistency in treatment. We therefore need to know the best way of treating this complication in order to offer an effective interventional approach to all affected individuals. This is an update of a previously published review. OBJECTIVES: To assess the benefits and risks of different treatments for stuttering (repeated short episodes) and fulminant (lasting for six hours or more) priapism in sickle cell disease. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register, which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also searched trial registries. Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 09 September 2019. Date of most recent search of trial registries and of Embase: 01 October 2019. SELECTION CRITERIA: All randomised or quasi-randomised controlled trials comparing non-surgical or surgical treatment with placebo or no treatment, or with another intervention for stuttering or fulminant priapism. DATA COLLECTION AND ANALYSIS: The authors independently extracted data and assessed the risk of bias of the trials. MAIN RESULTS: Three trials with 102 participants were identified and met the criteria for inclusion in this review. These trials compared stilboestrol to placebo, sildenafil to placebo and a four-arm trial which compared ephedrine or etilefrine to placebo and ranged in duration from two weeks to six months. All of the trials were conducted in an outpatient setting in Jamaica, Nigeria and the UK. None of the trials measured our first primary outcome, detumescence. However, all three trials reported on the reduction in frequency of stuttering priapism, our second primary outcome; and from the evidence included in this review, we are uncertain whether stilboestrol, etilefrine or ephedrine reduce the frequency of stuttering priapism as the certainty of the evidence has been assessed as very low. Additionally, we conclude that sildenafil may make little or no difference (low-certainty evidence). Two trials reported on immediate side effects and we are uncertain whether etilefrine or ephedrine reduce the occurrence of these (very low-certainty of evidence) and also conclude that sildenafil may make little or no difference in side effects (low-quality evidence). Given that all of the trials were at risk of bias and all had low participant numbers, we considered the certainty of the evidence to be low to very low. AUTHORS' CONCLUSIONS: There is a lack of evidence for the benefits or risks of the different treatments for both stuttering and fulminant priapism in sickle cell disease. This systematic review has clearly identified the need for well-designed, adequately-powered, multicentre randomised controlled trials assessing the effectiveness of specific interventions for priapism in sickle cell disease.

Pheochromocytoma With Adrenergic Biochemical Phenotype Shows Decreased GLP-1 Secretion and Impaired Glucose Tolerance.

CONTEXT: Impaired glucose homeostasis is a common finding in pheochromocytoma (PHEO), especially with adrenergic phenotype. The possible contribution of incretin dysfunction to dysglycemia in PHEO patients has not been studied. OBJECTIVE: To compare changes in pancreatic endocrine function and gut hormones' production during a liquid meal test before and 1 year after adrenalectomy. METHODS: In a prospective study, we included 18 patients with PHEO (13 females) with adrenergic biochemical phenotype. A liquid meal test with predefined isocaloric enteral nutrition was performed to evaluate dynamic changes in pancreatic hormones and incretins. RESULTS: During the meal test, insulin levels were significantly lower before adrenalectomy only in the early phase of insulin secretion, but changes in area under the curve (AUC) did not reach statistical significance (AUC = 0.07). Plasma glucagon (AUC < 0.01) and pancreatic polypeptide levels (AUC < 0.01) were suppressed in comparison with the postoperative state. Impaired response to the meal was found preoperatively for glucagon-like peptide-1 (GLP-1; AUC P < 0.05), but not glucose-dependent insulinotropic polypepide (GIP; AUC P = 0.21). No significant changes in insulin resistance indices were found, except for the homeostatic model assessment-beta index, an indicator of the function of islet ß cells, which negatively correlated with plasma metanephrine (R = -0.66, P < 0.01). CONCLUSIONS: Our study shows suppression of pancreatic α and ß cell function and impaired GLP-1 secretion during a dynamic meal test in patients with PHEO, which is improved after its surgical treatment. These data demonstrate a novel and potentially significant interconnection between excessive catecholamine production and the secretion of glucoregulatory hormones.

Protective Effect of Neuropeptide Apelin-13 on 6-Hydroxydopamine-Induced Neurotoxicity in SH-SY5Y Dopaminergic Cells: Involvement of Its Antioxidant and Antiapoptotic Properties.

Parkinson's disease (PD) is a severe neurodegenerative disorder characterized by the loss of brain dopaminergic neurons. Beside pharmacologic and symptomatic treatment of PD the neuroprotective therapy has recently attracted more attention. Apelin, a novel neuropeptide, and its receptors have numerous reported roles in regulating brain functions. In addition, this peptide has potent neuroprotective effects in some neurodegenerative situations. In this study, the effects of apelin-13 were investigated in a cell model of PD. Human neuroblastoma SH-SY5Y cell damage was induced by 150 µM 6-hydroxydopamine (6-OHDA) and the cells viability was examined by MTT assay. Intracellular reactive oxygen species (ROS) and mitochondrial membrane potential were determined by fluorescence spectrophotometry method. Immunoblotting analysis was also employed to evaluate cytochrome c release and caspase-3 activity. Data showed that 6-OHDA could decrease cell viability and mitochondrial membrane potential and increase intracellular ROS, cytochrome c, and cleaved caspase-3 levels. Pretreatment of SH-SY5Y cells with apelin-13 (5 and 10 nM) significantly prevented the mentioned biochemical and molecular markers of 6-OHDA-induced neurotoxicity. Furthermore, the results showed that apelin receptor and PI3K signaling contributed to the observed protective effects of apelin. The results suggest that apelin-13 has protective effects against dopaminergic neural toxicity and its antioxidant and antiapoptotic properties are involved, at least in part, in such protection.

Influence of 6-Hydroxydopamine Toxicity on α-Synuclein Phosphorylation, Resting Vesicle Expression, and Vesicular Dopamine Release.

Post mortem studies on familial and sporadic Parkinson's disease patient striatal tissue have shown that nearly 90% of α-synuclein deposited in Lewy-bodies is phosphorylated at serine-129 (pSyn-129) as opposed to only 4% in normal human brain. We aimed to find the influence of endogenous neurotoxin 6-hydroxydopamine (6-OHDA) on α-synuclein phosphorylation, resting vesicles, and vesicular dopamine release. The relative distribution of pSyn-129+ cells in apoptotic and non-apoptotic populations at different 6-OHDA concentrations was assessed along with changes in oxidant-antioxidant system, mitochondrial membrane-potential, and intracellular-Ca2+ . Exposing SH-SY5Y cells to different concentrations of 6-OHDA for 48 h showed cell-death and apoptosis. Immunocytochemical analysis indicated an increase in pSyn-129 with increasing 6-OHDA concentration, and ELISA-estimation showed a significant increase in the pSyn-129 to α-synuclein ratio. FACS analysis also showed a significant increase in pSyn-129; and at sub-lethal 6-OHDA concentrations, pSyn-129+ cells were primarily distributed in the non-apoptotic population, suggesting that phosphorylation of α-synuclein precedes apoptosis. At higher 6-OHDA concentrations, the pSyn-129+ cell count significantly increased in the apoptotic population and decreased in the non-apoptotic population. Cytosolic co-localization of α-synuclein and ubiquitin was noticed at higher doses of 6-OHDA. FACS analysis showed decrease in vesicular monoamine transporter-2 (VMAT2) expression in 6-OHDA-treated cells, confirmed by reduction in functional dopamine-release on KCl and ATP stimulation. Significant decrease in VMAT2 expression and vesicular dopamine-release were observed with the lower 6-OHDA concentration, together with mild occurrence of apoptosis and significant increase in phosphorylated α-synuclein. This suggests that at sub-lethal 6-OHDA concentrations, the decrease in resting vesicles (VMAT2) and vesicular dopamine release are not attributable to apoptotic cell death and occur concomitantly with the phosphorylation of α-synuclein. J. Cell. Biochem. 117: 2719-2736, 2016. © 2016 Wiley Periodicals, Inc.

Allicin Protects PC12 Cells Against 6-OHDA-Induced Oxidative Stress and Mitochondrial Dysfunction via Regulating Mitochondrial Dynamics.

BACKGROUND: Parkinson disease (PD) is a common adult-onset neurodegenerative disorder, and PD related neuronal injury is associated with oxidative stress and mitochondrial dysfunction. Allicin, the main biologically active compound derived from garlic, has been shown to exert various anti-oxidative and anti-apoptotic activities in in vitro and in vivo studies. METHODS: The present study aimed to investigate the potential protective role of allicin in an in vitro PD model induced by 6-hydroxydopamine (6-OHDA) in PC12 cells. The protective effects were measured by cell viability, decreased lactate dehydrogenase (LDH) release and flow cytometry, and the anti-oxidative activity was determined by reactive oxygen species (ROS) generation, lipid peroxidation and the endogenous antioxidant enzyme activities. Mitochondrial function in PC12 cells was detected by mitochondrial membrane potential (MMP) collapse, cytochrome c release, mitochondrial ATP synthesis, and the mitochondrial Ca(2+) buffering capacity. To investigate the potential mechanism, we also measured the expression of mitochondrial biogenesis factors, mitochondrial morphological dynamic changes, as well as detected mitochondrial dynamic proteins by western blot. RESULTS: We found that allicin treatment significant increased cell viability, and decreased LDH release and apoptotic cell death after 6-OHDA exposure. Allicin also inhibited ROS generation, reduced lipid peroxidation and preserved the endogenous antioxidant enzyme activities. These protective effects were associated with suppressed mitochondrial dysfunction, as evidenced by decreased MMP collapse and cytochrome c release, preserved mitochondrial ATP synthesis, and the promotion of mitochondrial Ca(2+) buffering capacity. In addition, allicin significantly enhanced mitochondrial biogenesis and prevented fragmentation of mitochondrial network after 6-OHDA treatment. The results of western blot analysis showed that the 6-OHDA induced decrease in the expression of optic atrophy type 1 (Opa-1), increase in mitochondrial fission 1 (Fis-1) and dynamin-related protein 1 (Drp-1) were all partially revised by allicin. CONCLUSION: In summary, our data strongly suggested that allicin treatment can exert protective effects against PD related neuronal injury through inhibiting oxidative stress and mitochondrial dysfunction with dynamic changes.

Dual protection of hydroxytyrosol, an olive oil polyphenol, against oxidative damage in PC12 cells.

Hydroxytyrosol (3,4-dihydroxyphenylethanol, HT), a major polyphenol in olive oils, has received increasing attention due to its multiple pharmacological activities. However, it is not well understood how HT works on the neuronal system. We report herein that HT efficiently scavenges free radicals in vitro and displays cytoprotection against oxidative stress-induced damage in PC12 cells. HT completely protects the cells from hydrogen peroxide-induced death and rescues the cells from 6-hydroxydopamine-induced damage. Mechanistic studies reveal that Nrf2 is a prerequisite for the neuroprotection of HT as knocking down Nrf2 eliminated this action. HT, via activation of the Keap1-Nrf2 pathway, elevates a panel of cytoprotective enzymes, including glutamate-cysteine ligase, HO-1, NQO1 and thioredoxin reductase. Our study reveals that HT provides dual neuroprotection and cellular antioxidant defense as both a free radical scavenger and Nrf2 activator, suggesting the potential pharmaceutical usage of HT for the treatment of neurodegenerative disorders.

DJ-1 protects against dopamine toxicity: implications for Parkinson's disease and aging.

Parkinson's disease (PD) is a common age-related neurodegenerative disorder. Dopamine neurotoxicity, mediated through oxidative stress, is implicated in disease pathogenesis. The vesicular monoamine transporter-2 (VMAT2) transfers dopamine into synaptic vesicles preparing it for exocytotic release and preventing its cytoplasmic oxidation. DJ-1 mutations cause early-onset familial PD. Here, we show that DJ-1 protects dopaminergic neurons and controls the vesicular sequestration of dopamine by upregulating VMAT2. Overexpression of DJ-1 protected cells against dopamine toxicity, reduced oxidative stress, and increased VMAT2 expression and function. Reduced DJ-1 levels resulted in opposite effects. Dopamine vesicular sequestration and its release upon depolarization were dependent on DJ-1 levels. Transcriptional regulation of VMAT2 expression by DJ-1 was confirmed by chromatin immunoprecipitation assay. The results were corroborated in vivo using 6-hydroxydopamine hemiparkinsonian mouse model and transgenic DJ-1 knockout mice. Our experimental data point to a novel potential protective function of DJ-1, which could be used as a therapeutic tool.

Neuroprotective effects of erucin against 6-hydroxydopamine-induced oxidative damage in a dopaminergic-like neuroblastoma cell line.

Oxidative stress (OS) contributes to the cascade leading to the dysfunction or death of dopaminergic neurons during Parkinson's disease (PD). A strategy to prevent the OS of dopaminergic neurons may be the use of phytochemicals as inducers of endogenous antioxidants and phase 2 enzymes. In this study, we demonstrated that treatment of the dopaminergic-like neuroblastoma SH-SY5Y cell line with isothiocyanate erucin (ER), a compound of cruciferous vegetables, resulted in significant increases of both total glutathione (GSH) levels and total antioxidant capacity at the cytosolic level. The increase of GSH levels was associated with an increase in the resistance of SH-SY5Y cells to neuronal death, in terms of apoptosis, induced by 6-hydroxydopamine (6-OHDA). The pretreatment of SH-SY5Y cells with ER was also shown to prevent the redox status impairment, in terms of intracellular ROS and O(2) (•-) formation, and loss of mitochondrial membrane potential, early events that are initiators of the apoptotic process, induced by 6-OHDA. Last, the antiapoptotic and antioxidant effects of ER were abolished by buthionine sulfoximine, supporting the main role of GSH in the neuroprotective effects recorded by ER. These results suggest that ER may prevent the oxidative damage induced by 6-OHDA.

Antidepressants that inhibit neuronal norepinephrine reuptake are not associated with increased spontaneous reporting of cardiomyopathy.

A recent literature review linked norepinephrinergic stimulation to alterations in cyclic adenosine monophosphate (cAMP)-mediated signaling in cardiac myocytes and suggested that this might contribute to the pathological mechanisms that lead to chamber enlargement and hypocontractility, which are seen in dilated cardiomyopathy. This accompanies a large body of literature linking cardiac sympathetic outflow activation in early heart failure with progressive myocyte deterioration. As the mode of action of a number of antidepressants involves the inhibition of neuronal norepinephrine reuptake to varying degrees, this study was conducted to assess whether such agents might be associated with disproportionate reporting of cardiomyopathy. Limited data exist specifically examining the association between the antidepressant use and the cardiomyopathy. Using a data mining algorithm (DMA), we quantitatively investigated the association between antidepressant agents that predominantly exert their effects through inhibiting neuronal norepinephrine reuptake (rather than serotonin) and cardiomyopathy. We retrospectively applied a Bayesian DMA, the Bayesian Confidence Propagation Neural Network, to the cumulative reports in the Food and Drug Administration Adverse Event Reporting System (through the fourth quarter of 2006) and World Health Organization Vigibase (through the second quarter of 2007) databases. A threshold of the posterior interval 95% lower limit > 0 was used to define a signal of disproportionate reporting with individual or groups of antidepressants and cardiomyopathy-related terms. The analysis suggested that there is no direct relationship between antidepressants with greater norepinephrine reuptake inhibitor activity (affinity for norepinephrine reuptake transporter or selectivity for norepinephrine versus serotonin) and reporting of cardiomyopathy. In contrast, an inverse correlation might exist with a higher number of cases identified with tricyclic antidepressants showing lower norepinephrine reuptake inhibition and the serotonin/norepinephrine reuptake inhibitors as well as with serotonin/ norepinephrine/slight dopamine reuptake inhibitor.

The role of beta-adrenoceptor signaling in skeletal muscle: therapeutic implications for muscle wasting disorders.

PURPOSE OF REVIEW: The beta-adrenergic signaling pathway represents a novel therapeutic target for skeletal muscle wasting disorders due to its roles in regulating protein synthesis and degradation. beta-Adrenoceptor agonists (beta-agonists) have therapeutic potential for attenuating muscle wasting associated with sarcopenia (age-related muscle wasting), cancer cachexia, sepsis, disuse, burns, HIV-AIDS, chronic kidney or heart failure, and neuromuscular diseases such as the muscular dystrophies. This review describes the role of beta-adrenergic signaling in the mechanisms controlling muscle wasting due to its effects on protein synthesis, protein degradation, and muscle fiber phenotype. RECENT FINDINGS: Stimulation of the beta-adrenergic signaling pathway with beta-agonists has therapeutic potential for muscle wasting since administration can elicit an anabolic response in skeletal muscle. As a consequence of their potent muscle anabolic actions, the effects of beta-agonist administration have been examined in several animal models and human conditions of muscle wasting in the hope of discovering a new therapeutic. The repartitioning characteristics of beta-agonists (increasing muscle mass and decreasing fat mass) have also made them attractive anabolic agents for use in livestock and by some athletes. However, potentially deleterious cardiovascular side-effects of beta-agonists have been identified and these will need to be obviated in order for the therapeutic potential of beta-agonists to be realized. SUMMARY: Multiple studies have identified anticachectic effects of beta-agonists and their therapeutic potential for pathologic states when muscle protein hypercatabolism is indicated. Future studies examining beta-agonist administration for muscle wasting conditions need to separate beneficial effects on skeletal muscle from potentially deleterious effects on the heart and cardiovascular system.

[Could anaesthesia, analgesia and sympathetic modulation affect neoplasic recurrence after surgery? A systematic review centred over the modulation of natural killer cells activity]. / L'anesthésie, l'analgésie et la modulation sympathique augmentent-elles l'incidence des récidives néoplasiques après chirurgie? Une revue de la littérature centrée sur la modulation de l'activité des lymphocytes natural killer.

OBJECTIVE: The Natural Killer cells (NK) are an important part of non-specific cellular-mediated and antitumoral immunity. The goal of this review is to recapitulate data published over NK activity during the perioperative period and the influence of anaesthesia, analgesia and modulation of sympathetic system. DATA SOURCES: Pubmed/Medline database. STUDY SELECTION AND DATA EXTRACTION: Keywords-based selection, without limit of date: fundamental studies, randomized controlled trials and non-randomized comparative studies. DATA SYNTHESIS: In human as in animal studies, an important correlation exists between NK activity and prognosis linked to the development of metastasis. The great depression of this cytotoxicity during the perioperative period could be able to compromise host defenses. The influence of anaesthetics and analgesics is important. The effects of the opioids, the agonists and the antagonists of the sympathetic nervous system, the prostaglandins, the NSAIDs, the ketamine, the hypnotics and the locoregional anaesthesia are systematically reviewed. The limits of experimental model presented are covered. CONCLUSION: The effects of anaesthetic/analgesic drugs and techniques, the consequences of sympathomodulation on NK activity are numerous and sometimes opposite. It is important for the anaesthesiologist to keep in mind that the long term consequences of his techniques on the patients' outcome must be clarified.

Reversible neurochemical changes mediated by delayed intrastriatal glial cell line-derived neurotrophic factor gene delivery in a partial Parkinson's disease rat model.

BACKGROUND: Efficient protection of dopaminergic neurons against a subsequent 6-hydroxydopamine lesion by glial cell line-derived neurotrophic factor (GDNF) gene delivery has been demonstrated. By contrast, the neurorestorative effects of GDNF administered several weeks after the toxin have been less characterized. In particular, whether these were permanent or dependent on the continuous presence of GDNF remains elusive. METHODS: A tetracycline-inducible adeno-associated virus (AAV)-1 vector expressing human GDNF cDNA was administered unilaterally in the rat striatum 5 weeks after 6-hydroxydopamine. Rats were treated with doxycycline (dox) or untreated from the day of vector injection until sacrifice (4 or 14 weeks). A sub-group was dox-treated for 7 weeks then untreated until 14 weeks. The motor behavior was assessed by amphetamine-induced rotations and spontaneous forelimb asymmetry. The amounts of tyrosine hydroxylase (TH), serine-40-phosphorylated TH (S40-TH) and aromatic amino acid decarboxylase (AADC) proteins were compared by western blotting and the dopamine levels quantified by high-performance liquid chromatography. RESULTS: Dox-dependent behavioral improvements were demonstrated 4 weeks post-vector injection. At later time points, spontaneous partial recovery was observed in all rats, but no further improvement was found in dox-treated animals. TH levels were significantly increased in dox-treated rats at all time points. By contrast, striatal dopamine and S40-TH were increased at 4 weeks, but not 14 weeks, and AADC remained unchanged. Dox withdrawal after 7 weeks, resulted in TH levels comparable to the controls at 14 weeks. CONCLUSIONS: Delayed GDNF gene delivery only transiently improved dopaminergic function. Over the long term, TH was more abundant, but not functional, and the increase was lost when GDNF gene expression was switched off.

Overexpression of D2/D3 receptors increases efficacy of ropinirole in chronically 6-OHDA-lesioned Parkinsonian rats.

Ropinirole, which is a non-ergot dopamine agonist derivative, exerts therapeutic benefits in Parkinson's disease (PD). Based on recent studies implicating dopamine receptors 2 and 3 (D2R and D3R) as possible targets of ropinirole, we over-expressed these dopamine receptor genes in the dopamine-denervated striatum of rodents to reveal whether their over-expression modulated ropinirole activity. Adult Sprague-Dawley rats initially received unilateral 6-hydroxydopamine lesion of the medial forebrain bundle. At 1 month after surgery, successfully lesioned animals (3 or less forelimb akinesia score, and 8 or more apomorphine-induced rotations/min over 1 h) were randomly assigned to intrastriatal injection (ipsilateral to the lesion) of blank lentiviral vector, D2R, D3R or both genes. At about 5 months post-lesion, ropinirole (0.2 mg/kg, i.p.) was administered daily for 9 consecutive days. The subtherapeutic dose of ropinirole improved the use of previously akinetic forelimb and produced robust circling behavior in lesioned animals with striatal over-expression of both D2R and D3R compared to lesioned animals that received blank vector. In contrast, the subtherapeutic dose of ropinirole generated only modest motor effects in lesioned animals with sole over-expression of D2R or D3R. Western immunoblot and autoradiographic assays showed enhanced D2R and D3R protein levels coupled with normalized D2R and D3R binding in the ventral striatum of lesioned animals with lentiviral over-expression of both D2R and D3R relative to vehicle-treated lesioned animals. Immunohistochemical analyses showed that D2R and D3R GFP fluorescent cells colocalized with enkephalin and substance P immunoreactive medium spiny neurons. These data support the use of the subtherapeutic dose of ropinirole in a chronic model of PD.

Coordinated and spatial upregulation of arc in striatonigral neurons correlates with L-dopa-induced behavioral sensitization in dyskinetic rats.

Although oral administration of L-Dopa remains the best therapy for Parkinson disease, its long-term administration causes the appearance of abnormal involuntary movements such as dyskinesia. Although persistent striatal induction of some genes has already been associated with such pathologic profiles in hemiparkinsonian rats, molecular and cellular mechanisms underlying such long-term adaptations remain to be elucidated. In this study, using a rat model of L-Dopa-induced dyskinesia, we report that activity regulated cytoskeletal (Arc)-associated protein is strongly upregulated in the lesioned striatum and that the extent of its induction further varies according to the occurrence or absence of locomotor sensitization. Moreover, Arc is preferentially induced, along with FosB, nur77, and homer-1a, in striatonigral neurons, which express mRNA encoding the precursor of dynorphin. Given the likely importance of Arc in the regulation of cytoskeleton during synaptic plasticity, its upregulation supports the hypothesis that a relationship exists between cytoskeletal modifications and the longlasting action of chronically administrated L-Dopa.

Pharmacological validation of a mouse model of l-DOPA-induced dyskinesia.

Dyskinesia (abnormal involuntary movements) is a common complication of l-DOPA pharmacotherapy in Parkinson's disease, and is thought to depend on abnormal cell signaling in the basal ganglia. Dopamine (DA) denervated mice can exhibit behavioral and cellular signs of dyskinesia when they are treated with l-DOPA, but the clinical relevance of this animal model remains to be established. In this study, we have examined the pharmacological profile of l-DOPA-induced abnormal involuntary movements (AIMs) in the mouse. C57BL/6 mice sustained unilateral injections of 6-hydroxydopamine (6-OHDA) in the striatum. The animals were treated chronically with daily doses of l-DOPA that were sufficient to ameliorate akinetic features without inducing overt signs of dyskinesia upon their first administration. In parallel, other groups of mice were treated with antiparkinsonian agents that do not induce dyskinesia when administered de novo, that is, the D2/D3 agonist ropinirole, and the adenosine A2a antagonist KW-6002. During 3 weeks of treatment, l-DOPA-treated mice developed AIMs affecting the head, trunk and forelimb on the side contralateral to the lesion. These movements were not expressed by animals treated with ropinirole or KW-6002 at doses that improved forelimb akinesia. The severity of l-DOPA-induced rodent AIMs was significantly reduced by the acute administration of compounds that have been shown to alleviate l-DOPA-induced dyskinesia both in parkinsonian patients and in rat and monkey models of Parkinson's disease (amantadine, -47%; buspirone, -46%; riluzole, -33%). The present data indicate that the mouse AIMs are indeed a functional equivalent of l-DOPA-induced dyskinesia.

Role of postoperative use of adrenergic drugs in occurrence of atrial fibrillation after cardiac surgery.

BACKGROUND: Use of adrenergic (inotropic and vasopressor) drugs is common after cardiac surgery. HYPOTHESIS: The study was undertaken to evaluate the role of postoperative adrenergic drug use as a predictor of postoperative atrial fibrillation (AF) after cardiac surgery. METHODS: The study population consisted of 199 patients post cardiac surgery. Postoperative adrenergic drug use and the baseline and clinical variables were analyzed as possible predictors of postoperative AF. RESULTS: Of 199 patients, postoperative AF occurred in 59 patients (incidence 30%). The adrenergic drugs were used in 127 (64%) patients. Postoperative AF occurred in 49 of the 127 patients (39%) with and in 10 of the 72 patients (14%) without adrenergic drug use (p < 0.01). By univariate analyses, postoperative adrenergic drug use, age, left ventricular hypertrophy, left atrial size, valve surgery, aortic valve replacement, cross clamp time, bypass time, postoperative ventricular pacing, and hours in intensive care unit were predictors of development of postoperative AF. Atrial pacing was a predictor of freedom from developing AF. By multivariate logistic regression analysis, adrenergic drug use was an independent predictor of postoperative AF (odds ratio [OR] 3.35, 95% confidence interval [CI] 1.38-8.12, p = 0.016). Two other independent predictors were valve surgery (OR 2.88, 95% CI 1.31-6.35, p = 0.002) and age (OR 10.73, 95% CI 10.37-11.10, p = 0.0001). Adrenergic drug use, valve surgery, ventricular pacing, and age were predictors of time duration from surgery to the occurrence of AF. Drugs with predominantly beta1-adrenergic receptor affinity were associated with a higher incidence of postoperative AF (dopamine 44%, dobutamine 41% vs. phenylepherine 20%, p = 0.001). CONCLUSION: Use of adrenergic drugs is an independent predictor of postoperative AF after cardiac surgery.

Enhancement of graft survival and sensorimotor behavioral recovery in rats undergoing transplantation with dopaminergic cells exposed to glial cell line-derived neurotrophic factor.

OBJECT: The goal of this study was to investigate the ability of fetal dopaminergic neurons to improve complex sensorimotor behavior. METHODS: The authors obtained ventral mesencephalic tissue from 14-day-old rat fetuses. The cells were exposed to glial cell line-derived neurotrophic factor (GDNF) prior to transplantation into rats with unilateral 6-hydroxydopamine lesions of the dopaminergic nigrostriatal pathway. Animals that received 400,000 cells exposed to GDNF demonstrated significant improvement in contralateral forelimb function and showed improvement in rotational behavior faster than animals that received cells not exposed to GDNF. Increasing the number of implanted cells to 800,000 exposed to GDNF did not result in any additional improvement in functional recovery. CONCLUSIONS: As neural grafting procedures in the nervous system evolve and genetically engineered cells or stem cells replace fetal tissue, crucial questions about cell number and trophic regulation will need to be addressed. This study demonstrates that grafting of 400,000 cells exposed to GDNF before transplantation has a beneficial effect in the restoration of complex sensorimotor behavior.