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1.
Eur J Neurosci ; 57(5): 739-761, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36656174

RESUMO

Increasing evidence suggests that astrocytes play an important role in the progression of Parkinson's disease (PD). Previous studies on our parkin knockout mouse demonstrated a higher accumulation of damaged mitochondria in astrocytes than in surrounding dopaminergic (DA) neurons, suggesting that Parkin plays a crucial role regarding their interaction during PD pathogenesis. In the current study, we examined primary mesencephalic astrocytes and neurons in a direct co-culture system and discovered that the parkin deletion causes an impaired differentiation of mesencephalic neurons. This effect required the parkin mutation in astrocytes as well as in neurons. In Valinomycin-treated parkin-deficient astrocytes, ubiquitination of Mitofusin 2 was abolished, whereas there was no significant degradation of the outer mitochondrial membrane protein Tom70. This result may explain the accumulation of damaged mitochondria in parkin-deficient astrocytes. We examined differential gene expression in the substantia nigra region of our parkin-KO mouse by RNA sequencing and identified an upregulation of the endoplasmic reticulum (ER) Ca2+ -binding protein reticulocalbin 1 (RCN1) expression, which was validated using qPCR. Immunostaining of the SN brain region revealed RCN1 expression mainly in astrocytes. Our subcellular fractionation of brain extract has shown that RCN1 is located in the ER and in mitochondria-associated membranes (MAM). Moreover, a loss of Parkin function reduced ATP-stimulated calcium-release in ER mesencephalic astrocytes that could be attenuated by siRNA-mediated RCN1 knockdown. Our results indicate that RCN1 plays an important role in ER-associated calcium dyshomeostasis caused by the loss of Parkin function in mesencephalic astrocytes, thereby highlighting the relevance of astrocyte function in PD pathomechanisms.


Assuntos
Cálcio , Retículo Endoplasmático , Doença de Parkinson , Ubiquitina-Proteína Ligases , Animais , Camundongos , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Neurônios Dopaminérgicos/metabolismo , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/patologia , Camundongos Knockout , Doença de Parkinson/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Regulação para Cima
2.
Hum Mol Genet ; 20(6): 1197-211, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21212098

RESUMO

We recently described mitochondrial pathology in neurons of transgenic mice with genes associated with Parkinson's disease (PD). Now we describe severe mitochondrial damage in glial cells of the mesencephalon in mice carrying a targeted deletion of parkin (PaKO) or overexpressing doubly mutated human alpha-synuclein (asyn). The number of mitochondria with altered morphology in glial cells is cell type-dependent, but always higher than in neurons. Interestingly, mitochondrial damage also occurs in mesencephalic glia of mice carrying mutated asyn controlled by the tyrosine hydroxylase promoter. Such mice do not show glial expression of the transgene, but show expression in neighboring neurons. However, we found strong overexpression of endogenous asyn in mesencephalic astrocytes from these mice. Cortical astrocytes neither display enhanced asyn expression nor mitochondrial damage. Cultivated mesencephalic astrocytes from newborn transgenic mice display various functional defects along with the morphological damage of mitochondria. First, the mitochondrial Ca(2+)-storage capacity is reduced in asyn transgenic mesencephalic astrocytes, but not in astrocytes from PaKO. Second, the expression of the mitochondrial protein PTEN-induced putative kinase is constitutively increased in asyn transgenic mice, while in PaKO it reacts to oxidative stress by overexpressing this protein along with other mitochondria-related proteins. Third, the neurotrophic effects exerted by control astrocytes, stimulating cortical neurons from healthy mice to develop longer processes and larger neuronal areas, are lacking in co-cultures with transgenic mesencephalic astrocytes. In summary, glial mitochondria from transgenic mice display morphological and functional alterations. Such transgenic astrocytes fail to influence neuronal differentiation, reflecting an important role that glia may play in PD pathogenesis.


Assuntos
Modelos Animais de Doenças , Camundongos , Mitocôndrias/metabolismo , Neuroglia/metabolismo , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Animais , Astrócitos/metabolismo , Astrócitos/patologia , Astrócitos/ultraestrutura , Cálcio/metabolismo , Células Cultivadas , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mitocôndrias/genética , Mitocôndrias/patologia , Mitocôndrias/ultraestrutura , Neuroglia/patologia , Neuroglia/ultraestrutura , Neurônios/metabolismo , Neurônios/patologia , Neurônios/ultraestrutura , Doença de Parkinson/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
3.
Cell Biol Int ; 37(7): 731-6, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23505055

RESUMO

RA175/SynCAM1/Cadm1 (Cadm1), a member of the immunoglobulin superfamily, is a synaptic cell adhesion molecule that has a PDZ-binding motif at the C-terminal region. It promotes the formation of presynaptic terminals and induces functional synapses in the central nervous system. Cadm1-deficient (knockout [KO]) mice show behavioral abnormalities, including excessive aggression and anxiety, but do not show any symptoms of neuromuscular disorder, although neuromuscular junctions (NMJs) have structures similar to synapses. We have examined the expression of members of the Cadm family in the mouse muscle tissues. Cadm4 and Cadm1 were major components of the Cadm family, and Cadm3 was faintly detected, but Cadm2 was not detected by RT-PCR. Cadm4 as well as Cadm1 colocalized with alpha-bungarotoxin at the NMJs and interacted with the multiple PDZ domain protein Mupp1. Cadm4 was expressed in Cadm1-KO mice and might compensate for Cadm1 loss through interactions with Mupp1.


Assuntos
Moléculas de Adesão Celular/metabolismo , Imunoglobulinas/metabolismo , Junção Neuromuscular/metabolismo , Animais , Bungarotoxinas/metabolismo , Proteínas de Transporte/metabolismo , Molécula 1 de Adesão Celular , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/genética , Imunoglobulinas/química , Imunoglobulinas/genética , Imuno-Histoquímica , Proteínas de Membrana , Camundongos , Camundongos Knockout , Músculo Esquelético/metabolismo , Domínios PDZ , Ligação Proteica , Proteínas Recombinantes de Fusão/análise , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
4.
Pflugers Arch ; 463(1): 187-99, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21735059

RESUMO

The histaminergic neurons of the posterior hypothalamus (tuberomamillary nucleus-TMN) control wakefulness, and their silencing through activation of GABA(A) receptors (GABA(A)R) induces sleep and is thought to mediate sedation under propofol anaesthesia. We have previously shown that the ß1 subunit preferring fragrant dioxane derivatives (FDD) are highly potent modulators of GABA(A)R in TMN neurons. In recombinant receptors containing the ß3N265M subunit, FDD action is abolished and GABA potency is reduced. Using rat, wild-type and ß3N265M mice, FDD and propofol, we explored the relative contributions of ß1- and ß3-containing GABA(A)R to synaptic transmission from the GABAergic sleep-on ventrolateral preoptic area neurons to TMN. In ß3N265M mice, GABA potency remained unchanged in TMN neurons, but it was decreased in cultured posterior hypothalamic neurons with impaired modulation of GABA(A)R by propofol. Spontaneous and evoked GABAergic synaptic currents (IPSC) showed ß1-type pharmacology, with the same effects achieved by 3 µM propofol and 10 µM PI24513. Propofol and the FDD PI24513 suppressed neuronal firing in the majority of neurons at 5 and 100 µM, and in all cells at 10 and 250 µM, respectively. FDD given systemically in mice induced sedation but not anaesthesia. Propofol-induced currents were abolished (1-6 µM) or significantly reduced (12 µM) in ß3N265M mice, whereas gating and modulation of GABA(A)R by PI24513 as well as modulation by propofol were unchanged. In conclusion, ß1-containing (FDD-sensitive) GABA(A)R represent the major receptor pool in TMN neurons responding to GABA, while ß3-containing (FDD-insensitive) receptors are gated by low micromolar doses of propofol. Thus, sleep and anaesthesia depend on different GABA(A)R types.


Assuntos
Anestesia , Subunidades Proteicas/fisiologia , Receptores de GABA-A/fisiologia , Sono/fisiologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Fenômenos Eletrofisiológicos/efeitos dos fármacos , Fenômenos Eletrofisiológicos/fisiologia , Agonistas de Receptores de GABA-A/farmacologia , Expressão Gênica/genética , Histamina/metabolismo , Região Hipotalâmica Lateral/citologia , Região Hipotalâmica Lateral/metabolismo , Potenciais Pós-Sinápticos Inibidores/efeitos dos fármacos , Potenciais Pós-Sinápticos Inibidores/fisiologia , Ativação do Canal Iônico/efeitos dos fármacos , Ativação do Canal Iônico/fisiologia , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Mutação Puntual/fisiologia , Propofol/farmacologia , Ratos , Ratos Wistar , Receptores de GABA-A/genética , Ácido gama-Aminobutírico/farmacologia
5.
Photodiagnosis Photodyn Ther ; 39: 103004, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35811052

RESUMO

BACKGROUND: Photodynamic therapy (PDT) is clinically approved to treat neoplastic skin diseases such as precursors of cutaneous squamous cell carcinoma (cSCC). In PDT, 5-aminolevulinic acid (5-ALA) drives the selective formation of the endogenous photosensitizer protoporphyrin IX (PpIX). Although 5-ALA PDT is clinically highly effective, resistance might occur due to decreased accumulation of PpIX in certain tumors. Such resistance may be caused by any fundamental step of PpIX accumulation: 5-ALA uptake, PpIX synthesis and PpIX efflux. METHODS: We investigated PpIX accumulation and photodynamically induced cell death in PDT refractory SCC-13, PDT susceptible A431, and normal human epidermal keratinocytes (NHEK). Expression of genes associated with cellular PpIX kinetics was investigated on mRNA and protein level. PpIX accumulation and cell death upon illumination were pharmacologically manipulated using drugs targeting 5-ALA uptake, PpIX synthesis or efflux. RESULTS: The experiments indicate that taurine transporter (SLC6A6) is the major pathway for 5-ALA uptake in cSCC cells, while being less important in NHEK. Downregulation of PpIX synthesis enzymes in SCC-13 was counteracted by methotrexate (MTX) treatment, which restored PpIX formation and cell death. PpIX efflux inhibitors targeting ABC transporters led to significantly increased PpIX accumulation in SCC-13, thereby fully overcoming resistance. CONCLUSIONS: The results indicate a conserved threshold for PpIX accumulation with respect to PDT-resistance. Cells showed increased viability after PDT at PpIX concentrations below 1.5 nM. Selective uptake of 5-ALA via taurine transporter SLC6A6 in cutaneous tumor cells is novel but unrelated to resistance. MTX can partially abrogate resistance by PpIX synthesis enzyme induction, while efflux mechanisms via ABC transporters seem the main driving force and promising drug targets.


Assuntos
Carcinoma de Células Escamosas , Fotoquimioterapia , Neoplasias Cutâneas , Transportadores de Cassetes de Ligação de ATP , Ácido Aminolevulínico/farmacologia , Ácido Aminolevulínico/uso terapêutico , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Humanos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Protoporfirinas/metabolismo , Neoplasias Cutâneas/tratamento farmacológico
6.
Clin Pharmacol Drug Dev ; 11(4): 535-550, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34633154

RESUMO

The nanoemulsion-based 10% aminolevulinic acid (ALA) hydrochloride gel BF-200 ALA optimizes epidermal penetration of its active ingredient and is approved for topical photodynamic therapy (PDT) for the treatment of actinic keratosis in the United States and Europe. To characterize systemic absorption from dermal application during PDT, ALA and its key active metabolite protoporphyrin IX (PpIX) were analyzed in 2 maximal usage pharmacokinetic trials (MUsT) in patients severely affected with actinic keratosis. The primary objective of both MUsTs was to assess baseline-adjusted plasma concentration-time curves for ALA and PpIX after a single PDT treatment applying either 2 g (1 tube) of BF-200 ALA on the face (MUsT-1) or applying 6 g (3 tubes) of BF-200 ALA on the face/scalp or body periphery (MUsT-2), to 20 or 60 cm2 , respectively. All PDTs were performed using red light at around 635 nm wavelength. Safety and tolerability were documented along with pharmacokinetics. In both MUsTs, ALA plasma concentrations were transiently increased to a maximum concentration at about 2.5 to 3.3 times above endogenous baseline with time to maximum concentration at ≈3 hours after dosing. Plasma levels subsequently returned to baseline within 10 hours after dosing. Overall baseline-adjusted mean area under the baseline-adjusted plasma concentration-time curve from time zero to the last sampling time point at which the concentration was at or above the lower limit of quantification ranged from 142.8 to 146.2, indicating that a similar, minor fraction of topical ALA is systemically absorbed under both dosing regimens. Systemic PpIX exposure after administration of either dose of BF-200 ALA was equally minimal. Application site skin reactions were treatment area size-related, albeit transient and consistent with the known safety profile of BF-200 ALA.


Assuntos
Ceratose Actínica , Fotoquimioterapia , Ácido Aminolevulínico/efeitos adversos , Ácido Aminolevulínico/análogos & derivados , Humanos , Ceratose Actínica/tratamento farmacológico , Fotoquimioterapia/efeitos adversos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/efeitos adversos , Fármacos Fotossensibilizantes/farmacocinética
7.
J Neurosci ; 30(35): 11805-14, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20810900

RESUMO

Parkinson's disease (PD) is a common neurodegenerative disease that involves the deterioration of dopaminergic neurons in the substantia nigra pars compacta. Although the etiology of PD remains poorly understood, recent genetic, postmortem, and experimental evidence shows that abnormal protein accumulation and subsequent aggregate formation are prominent features of both sporadic and familial PD. While proteasome dysfunction is observed in PD, diverse mutations in the parkin gene are linked to early-onset autosomal-recessive forms of familial PD. We demonstrate that parkin, an E3 ubiquitin ligase, activates the 26S proteasome in an E3 ligase activity-independent manner. Furthermore, an N-terminal ubiquitin-like domain within parkin is critical for the activation of the 26S proteasome through enhancing the interaction between 19S proteasomal subunits, whereas the PD-linked R42P mutant abolishes this action. The current findings point to a novel role for parkin for 26S proteasome assembly and suggest that parkin mutations contribute to the proteasomal dysfunction in PD.


Assuntos
Doença de Parkinson/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina-Proteína Ligases/fisiologia , Animais , Animais Geneticamente Modificados , Drosophila/genética , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/genética , Proteínas de Drosophila/fisiologia , Ativação Enzimática/genética , Genes Recessivos , Células HeLa , Humanos , Camundongos , Camundongos Knockout , Mutação , Doença de Parkinson/enzimologia , Doença de Parkinson/genética , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/genética
8.
J Biol Chem ; 285(31): 23985-93, 2010 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-20511229

RESUMO

Nineteen GABA(A) receptor (GABA(A)R) subunits are known in mammals with only a restricted number of functionally identified native combinations. The physiological role of beta1-subunit-containing GABA(A)Rs is unknown. Here we report the discovery of a new structural class of GABA(A)R positive modulators with unique beta1-subunit selectivity: fragrant dioxane derivatives (FDD). At heterologously expressed alpha1betaxgamma2L (x-for 1,2,3) GABA(A)R FDD were 6 times more potent at beta1- versus beta2- and beta3-containing receptors. Serine at position 265 was essential for the high sensitivity of the beta1-subunit to FDD and the beta1N286W mutation nearly abolished modulation; vice versa the mutation beta3N265S shifted FDD sensitivity toward the beta1-type. In posterior hypothalamic neurons controlling wakefulness GABA-mediated whole-cell responses and GABAergic synaptic currents were highly sensitive to FDD, in contrast to beta1-negative cerebellar Purkinje neurons. Immunostaining for the beta1-subunit and the potency of FDD to modulate GABA responses in cultured hypothalamic neurons was drastically diminished by beta1-siRNA treatment. In conclusion, with the help of FDDs we reveal a functional expression of beta1-containing GABA(A)Rs in the hypothalamus, offering a new tool for studies on the functional diversity of native GABA(A)Rs.


Assuntos
Dioxanos/química , Receptores de GABA-A/química , Animais , Eletrofisiologia/métodos , Hipotálamo/metabolismo , Masculino , Camundongos , Neuroquímica/métodos , Neurônios/metabolismo , Oócitos/metabolismo , Estrutura Terciária de Proteína , Células de Purkinje/metabolismo , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Wistar , Xenopus laevis
9.
Exp Dermatol ; 19(8): e80-8, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19849712

RESUMO

Cathepsin S (CATS) is a cysteine protease, well known for its role in MHC class II-mediated antigen presentation and extracellular matrix degradation. Disturbance of the expression or metabolism of this protease is a concomitant feature of several diseases. Given this importance we studied the localization and regulation of CATS expression in normal and pathological human/mouse skin. In normal human skin CATS-immunostaining is mainly present in the dermis and is localized in macrophages, Langerhans, T- and endothelial cells, but absent in keratinocytes. In all analyzed pathological skin biopsies, i.e. atopic dermatitis, actinic keratosis and psoriasis, CATS staining is strongly increased in the dermis. But only in psoriasis, CATS-immunostaining is also detectable in keratinocytes. We show that cocultivation with T-cells as well as treatment with cytokines can trigger expression and secretion of CATS, which is involved in MHC II processing in keratinocytes. Our data provide first evidence that CATS expression (i) is selectively induced in psoriatic keratinocytes, (ii) is triggered by T-cells and (iii) might be involved in keratinocytic MHC class II expression, the processing of the MHC class II-associated invariant chain and remodeling of the extracellular matrix. This paper expands our knowledge on the important role of keratinocytes in dermatological disease.


Assuntos
Catepsinas/metabolismo , Queratinócitos/metabolismo , Psoríase/metabolismo , Regulação para Cima/fisiologia , Animais , Biópsia , Comunicação Celular , Linhagem Celular , Técnicas de Cocultura , Citocinas/farmacologia , Dermatite Atópica/induzido quimicamente , Dermatite Atópica/metabolismo , Dermatite Atópica/patologia , Modelos Animais de Doenças , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/patologia , Complexo Principal de Histocompatibilidade , Camundongos , Oxazolona/efeitos adversos , Psoríase/patologia , Linfócitos T/patologia
10.
Mol Cell Neurosci ; 40(4): 421-32, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19167501

RESUMO

Parkinson's disease (PD) is characterized by the deterioration of dopaminergic neurons in the pars compacta of substantia nigra and the formation of intraneuronal protein inclusions. The etiology of PD is not known, but the recent identification of several mutation genes in familial PD has provided a rich understanding of the molecular mechanisms of PD pathology. Mutations in PTEN-induced putative kinase 1 (PINK1) and parkin are linked to early-onset autosomal recessive forms of familial PD. Here we show molecular and functional interactions between parkin and PINK1. Parkin selectively binds to PINK1 and upregulates PINK1 levels. In addition, PINK1 reduces the solubility of parkin, which induces the formation of microtubule-dependent cytoplasmic aggresomes. Our findings reveal that parkin and PINK1 affect each other's stability, solubility and tendency to form aggresomes, and have important implications regarding the formation of Lewy bodies.


Assuntos
Neurônios/metabolismo , Proteínas Quinases/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Linhagem Celular , Chlorocebus aethiops , Humanos , Corpos de Inclusão/metabolismo , Camundongos , Camundongos Knockout , Neurônios/citologia , Doença de Parkinson/metabolismo , Ligação Proteica , Proteínas Quinases/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Ubiquitina-Proteína Ligases/genética
11.
J Neurochem ; 110(6): 1931-41, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19627446

RESUMO

Activated microglia release inflammatory mediators that display either beneficial or harmful effects on neuronal survival and signaling. In the present study we demonstrate that exposure to lipopolysaccharide leads to an increase in the lysosomal cysteine proteases, cathepsin B, K, S, and X, in culture supernatants of the microglia cell line BV-2. In addition, we observed an up-regulation of cathepsins in the cytoplasmic fraction in response to stimulation with lipopolysaccharide. Conditioned medium from these cells was toxic to the neuroblastoma cell line Neuro2a. Experiments with membrane-permeable and membrane-impermeable cysteine protease inhibitors suggested that blocking extracellular cathepsins had no effect on microglia-mediated neuron death in this medium transfer model. However, intracellular cathepsins seem to trigger the release of neurotoxic factors. In lipopolysaccharide-stimulated BV-2 cells, inhibition of intracellular cathepsins significantly diminished microglial activation characterized by reduced expression of different proinflammatory cytokines, thereby reducing the neurotoxic effects of the medium. This hitherto unknown intracellular effect of cysteine proteases in activated microglia might connect chronic neuroinflammation with neurodegeneration.


Assuntos
Cisteína Endopeptidases/metabolismo , Citoplasma/enzimologia , Lisossomos/enzimologia , Microglia/química , Regulação para Cima/fisiologia , Análise de Variância , Animais , Catepsinas/genética , Catepsinas/metabolismo , Linhagem Celular Transformada , Linhagem Celular Tumoral , Meios de Cultivo Condicionados/farmacologia , Cisteína Endopeptidases/genética , Citoplasma/efeitos dos fármacos , Dipeptídeos/farmacologia , Inibidores Enzimáticos/farmacologia , Leucina/análogos & derivados , Leucina/farmacologia , Lipopolissacarídeos/farmacologia , Lisossomos/efeitos dos fármacos , Camundongos , Microglia/efeitos dos fármacos , Neuroblastoma/patologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Regulação para Cima/efeitos dos fármacos
12.
Naunyn Schmiedebergs Arch Pharmacol ; 379(1): 73-86, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18704368

RESUMO

Rotigotine (Neupro) is a non-ergoline dopamine agonist developed for the once daily treatment of Parkinson's disease (PD) using a transdermal delivery system (patch) which provides patients with the drug continuously over 24 h. To fully understand the pharmacological actions of rotigotine, the present study determined its extended receptor profile. In standard binding assays, rotigotine demonstrated the highest affinity for dopamine receptors, particularly the dopamine D3 receptor (Ki=0.71 nM) with its affinities to other dopamine receptors being (Ki in nM): D4.2 (3.9), D4.7 (5.9), D5 (5.4), D2 (13.5), D4.4 (15), and D1 (83). Significant affinities were also demonstrated at alpha-adrenergic (alpha2B, Ki=27 nM) and serotonin receptors (5-HT1A Ki=30 nM). In newly developed reporter-gene assays for determination of functional activity, rotigotine behaved as a full agonist at dopamine receptors (rank order: D3>D2L>D1=D5>D4.4) with potencies 2,600 and 53 times higher than dopamine at dopamine D3 and D2L receptors, respectively. At alpha-adrenergic sites, rotigotine acted as an antagonist on alpha2B receptors. At serotonergic sites, rotigotine had a weak but significant agonistic activity at 5-HT1A receptors and a minor or nonexistent activity at other serotonin receptors. Thus, in respect to PD, rotigotine can be characterized as a specific dopamine receptor agonist with a preference for the D3 receptor over D2 and D1 receptors. In addition, it exhibits interaction with D4 and D5 receptors, the role of which in relation to PD is not clear yet. Among non-dopaminergic sites, rotigotine shows relevant affinity to only 5-HT1A and alpha2B receptors. Further studies are necessary to investigate the contribution of the different receptor subtypes to the efficacy of rotigotine in Parkinson's disease and possible other indications such as restless legs syndrome.


Assuntos
Antiparkinsonianos/farmacologia , Agonistas de Dopamina/farmacologia , Animais , Ligação Competitiva , Células CHO , Cricetinae , Cricetulus , Feminino , Humanos , Receptores Adrenérgicos/metabolismo , Receptores de Dopamina D3/metabolismo , Receptores de Dopamina D4/metabolismo , Receptores de Serotonina/metabolismo , Tetra-Hidronaftalenos/farmacologia , Tiofenos/farmacologia
13.
J Neurochem ; 106(3): 1287-97, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18537874

RESUMO

Tech is a RhoA guanine nucleotide exchange factor (GEF) that is highly enriched in hippocampal and cortical neurons. To help define its function, we have conducted studies aimed at identifying partner proteins that bind to its C-terminal PDZ ligand motif. Yeast two hybrid studies using the Tech C-terminal segment as bait identified MUPP1, a protein that contains 13 PDZ domains and has been localized to the post-synaptic compartment, as a candidate partner protein for Tech. Co-transfection of Tech and MUPP1 in human embryonic kidney 293 cells confirmed that these full-length proteins interact in a PDZ-dependent fashion. Furthermore, we confirmed that endogenous Tech co-precipitates with MUPP1, but not PSD-95, from hippocampal and cortical extracts prepared from rat brain. In addition, immunostaining of primary cortical cultures revealed co-localization of MUPP1 and Tech puncta in the vicinity of synapses. In assessing which PDZ domains of MUPP1 mediate binding to Tech, we found that Tech can bind to either PDZ domain 10 or 13 of MUPP1 as mutation of both these domains is needed to disrupt their interaction. Taken together, these findings demonstrate that Tech binds to MUPP1 and suggest that it regulates RhoA signaling pathways in the vicinity of synapses.


Assuntos
Proteínas de Transporte/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Domínios PDZ/fisiologia , Sinapses/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Animais , Proteínas de Transporte/genética , Linhagem Celular , Células Cultivadas , Fatores de Troca do Nucleotídeo Guanina/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Neurônios/fisiologia , Ratos , Sinapses/genética , Proteína rhoA de Ligação ao GTP/genética
14.
BMC Neurosci ; 9: 80, 2008 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-18700000

RESUMO

BACKGROUND: Ample evidence suggests a substantial contribution of cellular and molecular changes in the spinal cord to the induction and persistence of chronic neuropathic pain conditions. While for a long time, proteases were mainly considered as protein degrading enzymes, they are now receiving growing interest as signalling molecules in the pain pathology. In the present study we focused on two cathepsins, CATS and CATX, and studied their spatiotemporal expression and activity during the development and progression of neuropathic pain in the CNS of the rat 5th lumbar spinal nerve transection model (L5T). RESULTS: Immediately after the lesion, both cathepsins, CATS and CATX, were upregulated in the spinal cord. Moreover, we succeeded in measuring the activity of CATX, which was substantially increased after L5T. The differential expression of these proteins exhibited the same spatial distribution and temporal progression in the spinal cord, progressing up to the medulla oblongata in the late phase of chronic pain. The cellular distribution of CATS and CATX was, however, considerably different. CONCLUSION: The cellular distribution and the spatio-temporal development of the altered expression of CATS and CATX suggest that these proteins are important players in the spinal mechanisms involved in chronic pain induction and maintenance.


Assuntos
Catepsinas/biossíntese , Modelos Animais de Doenças , Regulação da Expressão Gênica/fisiologia , Neuralgia/enzimologia , Medula Espinal/enzimologia , Animais , Catepsina K , Catepsinas/genética , Masculino , Neuralgia/genética , Neuralgia/patologia , Medição da Dor/métodos , Ratos , Ratos Wistar , Medula Espinal/patologia
15.
Brain Res ; 1232: 7-20, 2008 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-18694734

RESUMO

Cathepsins have long been regarded enzymes that are primarily involved in general protein turnover within lysosomes. However, more recently, their differential cell and tissue distributions suggest that at least some of them participate in specific cellular processes. Cathepsin S (CATS) is mainly expressed in cells of mononuclear phagocytotic origin and plays a major role in the MHC-II-mediated antigen presentation. Although a central role for CATS in brain function has also been suggested, its localization and regulation in the central nervous system are still poorly understood. In the present study we investigated the regional and cellular expression of CATS in normal, aging and pathological mouse brain. Our studies show that CATS is expressed throughout the adult mouse brain, in particular in microglial cells. In aged mice, CATS protein expression increases in these cells. In addition, it became apparent that in old mice a larger number of neuronal cells stained positive for this protease. At the subcellular level, CATS immunostaining accumulated in granules, indicating a lysosomal localization. In a transgenic mouse model of amyotrophic lateral sclerosis expressing mutant superoxide dismutase 1 (SOD1), CATS transcript and protein levels were significantly upregulated in spinal cord and lower brain regions displaying neuronal degeneration. The majority of strongly immunopositive cells in these regions exhibited microglial morphology. These results suggest that CATS participates in inflammatory processes accompanying aging and pathologies of the CNS.


Assuntos
Envelhecimento/metabolismo , Catepsinas/biossíntese , Doenças do Sistema Nervoso/metabolismo , Esclerose Lateral Amiotrófica/metabolismo , Animais , Western Blotting , Encéfalo/crescimento & desenvolvimento , Química Encefálica/fisiologia , Interpretação Estatística de Dados , Técnica Indireta de Fluorescência para Anticorpo , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Superóxido Dismutase/genética , Superóxido Dismutase-1 , Regulação para Cima
16.
Neurosci Lett ; 432(1): 30-4, 2008 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-18162314

RESUMO

Dopamine agonists used to manage Parkinsonian motor symptoms have been suggested to be neuroprotective. The study was designed to assess the neuroprotective potential of the D(3)/D(2)/D(1) dopamine receptor agonist rotigotine in the acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned (MPTP) mouse model of Parkinson's disease by measuring mesencephalic degenerating neurons using FluoroJade staining and the remaining dopaminergic nerve endings in the striatum using dopamine transporter binding. Continuous administration of rotigotine at a dose of 3mg/kg significantly attenuated MPTP-induced acute cell degeneration in the FluoroJade-staining paradigm. Rotigotine (0.3-3mg/kg) partially protected dopamine nerve endings from MPTP-induced degeneration in a dose-dependent manner. These data suggest that rotigotine, at the doses employed, significantly protected dopamine neurons from degeneration in an acute mouse model of MPTP intoxication.


Assuntos
Agonistas de Dopamina/farmacologia , Fármacos Neuroprotetores/farmacologia , Transtornos Parkinsonianos/tratamento farmacológico , Transtornos Parkinsonianos/prevenção & controle , Tetra-Hidronaftalenos/farmacologia , Tiofenos/farmacologia , Doença Aguda , Administração Cutânea , Animais , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Relação Dose-Resposta a Droga , Radioisótopos do Iodo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Degeneração Neural/tratamento farmacológico , Degeneração Neural/prevenção & controle , Ensaio Radioligante , Receptores Dopaminérgicos/metabolismo , Substância Negra/efeitos dos fármacos , Substância Negra/metabolismo
17.
Acta Histochem ; 120(8): 846-857, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30292321

RESUMO

The human dura mater encephali is a well innervated and vascularized membrane. Its vascular system plays a crucial role in disorders and pathological cases like dural hematoma, meningitis, and different headache types. To investigate these diseases mouse models are increasingly being used. However, the literature on the vascular system of the mouse dura mater is sparse and explicit studies concerned exclusively with its vasculature are lacking. Here we present a detailed light and scanning electron microscopic investigation of the supratentorial dura mater of the mouse species, with a focus on the largest part of it, the parietal dura mater. By utilizing different immunohistochemical and classical staining methods, a "cartography" of the vascular system was achieved. Additionally, the different blood vessel types with their mural cells were characterized. In contrast to humans, no arteries were found in the mouse parietal dura mater. Its supply is assured through frontolateral and occipital localized arteriolar branches. These arteriolar vessels exhibit in some specimens arteriolar anastomoses with one another. The venous blood is drained to the superior sagittal and transverse sinus through satellite venules accompanying the arterioles or through solitary venules. In all samples, large ruptured venules were identified in the frontolateral dural area. Scanning electron microscopy revealed that these vessels were ruptured on the dorsal side (skull bones-oriented side) of the dura. Our results contribute to the anatomical data on the mouse species and may set up a basis for fundamental investigation of disorders, for which the role of dural blood vessels is not yet clarified.


Assuntos
Capilares/anatomia & histologia , Dura-Máter/patologia , Animais , Capilares/patologia , Dura-Máter/anatomia & histologia , Feminino , Imuno-Histoquímica , Camundongos , Microscopia Eletrônica de Varredura
18.
Eur J Cell Biol ; 96(1): 34-46, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27939274

RESUMO

Studies within the last decade have localized the functional expression of olfactory receptors (ORs) to cells outside of the olfactory epithelium. In human hepatocarcinoma and prostate cancer cells, the activation of ORs by odors modulates elementary physiological processes and leads to an inhibitory effect on proliferation. Cells of the respiratory tract are in direct contact with the surrounding air, in which a myriad of volatile molecules, especially odors, are present. Non-small-cell lung cancer (NSCLC) has a high prevalence, a high mortality rate and is difficult to treat. NSCLC cells are nearly resistant to common chemotherapeutic approaches, and surgical resection provides the only possible chance of a cure for most patients. New approaches for the treatment of NSCLC are the focus of many current studies. Thus, it is of interest to characterize the functional expression of ORs in cancer cells of the lung and to investigate the impact of ORs on pathophysiological processes. In the present study, we demonstrate that the expression of OR2J3 and cytosolic Ca2+ increase via the activation of the agonist helional in the NSCLC cell line A549. We further investigated the underlying pathway. Helional triggers phoshoinositol-3 kinase (PI3K), signaling the release of intracellular Ca2+ and phosphorylation of ERK. We observed that OR2J3 activation induces apoptosis and inhibits cell proliferation and migration in long-term stimulus experiments with helional. Our study provides the first evidence of the functional expression of an OR in NSCLC cells and its putative therapeutic impact.


Assuntos
Apoptose , Sinalização do Cálcio , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Proliferação de Células , Neoplasias Pulmonares/metabolismo , Sistema de Sinalização das MAP Quinases , Proteínas de Neoplasias/metabolismo , Receptores Odorantes/metabolismo , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/genética , Proteínas de Neoplasias/agonistas , Proteínas de Neoplasias/genética , Receptores Odorantes/agonistas , Receptores Odorantes/genética
19.
Brain Res ; 1096(1): 180-95, 2006 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-16737688

RESUMO

Transgenic mice expressing a mutated human Cu/Zn superoxide dismutase (SOD1) gene develop a motor neuron disease similar to familial amyotrophic lateral sclerosis (FALS). While the histopathology and the inflammatory reactions in the spinal cord of these mice are well described, their spatiotemporal extension into brain areas and the relationship between degenerative and inflammatory events remain obscure. In the present study, we investigated the time course and extent of degenerative changes and inflammatory reactions in the CNS during progression of the disease in a transgenic FALS model, the SOD1-G93A mouse with histological and immunohistochemical methods. Compared to non-transgenic littermates, the SOD1-G93A transgenics developed widespread degeneration in both motor and extra-motor regions up to telencephalic regions, including the cerebral cortex but sparing distinct regions like the striatum and hippocampus. We provide evidence that these degenerative processes are accompanied by intense inflammatory reactions in the brain, which spatiotemporally correlate with degeneration and comprise besides strong astro- and microgliotic reactions also an influx of peripheral immune cells such as T-lymphocytes and dendritic cells. Both degeneration and inflammatory reactions spread caudocranially, starting at 2 months in the spinal cord and reaching the telencephalon at 5 months of age. Since the corticospinal tract lacked any signs of degeneration, we conclude that the upper and the lower motor neurons degenerate independently of each other.


Assuntos
Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Sistema Nervoso Central/enzimologia , Superóxido Dismutase/genética , Esclerose Lateral Amiotrófica/psicologia , Animais , Comportamento Animal/fisiologia , Progressão da Doença , Feminino , Imuno-Histoquímica , Inflamação/patologia , Masculino , Camundongos , Camundongos Transgênicos , Atividade Motora/fisiologia , Mutação , Degeneração Neural/patologia , Superóxido Dismutase-1 , Tirosina 3-Mono-Oxigenase/metabolismo
20.
Front Physiol ; 7: 339, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27540365

RESUMO

Pathophysiological mechanisms in human airway smooth muscle cells (HASMCs) significantly contribute to the progression of chronic inflammatory airway diseases with limited therapeutic options, such as severe asthma and COPD. These abnormalities include the contractility and hyperproduction of inflammatory proteins. To develop therapeutic strategies, key pathological mechanisms, and putative clinical targets need to be identified. In the present study, we demonstrated that the human olfactory receptors (ORs) OR1D2 and OR2AG1 are expressed at the RNA and protein levels in HASMCs. Using fluorometric calcium imaging, specific agonists for OR2AG1 and OR1D2 were identified to trigger transient Ca(2+) increases in HASMCs via a cAMP-dependent signal transduction cascade. Furthermore, the activation of OR2AG1 via amyl butyrate inhibited the histamine-induced contraction of HASMCs, whereas the stimulation of OR1D2 with bourgeonal led to an increase in cell contractility. In addition, OR1D2 activation induced the secretion of IL-8 and GM-CSF. Both effects were inhibited by the specific OR1D2 antagonist undecanal. We herein provide the first evidence to show that ORs are functionally expressed in HASMCs and regulate pathophysiological processes. Therefore, ORs might be new therapeutic targets for these diseases, and blocking ORs could be an auspicious strategy for the treatment of early-stage chronic inflammatory lung diseases.

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