RESUMEN
Immunotherapy approaches focusing on T cells have provided breakthroughs in treating solid tumors. However, there remains an opportunity to drive anticancer immune responses via other cell types, particularly myeloid cells. ATRC-101 was identified via a target-agnostic process evaluating antibodies produced by the plasmablast population of B cells in a patient with non-small cell lung cancer experiencing an antitumor immune response during treatment with checkpoint inhibitor therapy. Here, we describe the target, antitumor activity in preclinical models, and data supporting a mechanism of action of ATRC-101. Immunohistochemistry studies demonstrated tumor-selective binding of ATRC-101 to multiple nonautologous tumor tissues. In biochemical analyses, ATRC-101 appears to target an extracellular, tumor-specific ribonucleoprotein (RNP) complex. In syngeneic murine models, ATRC-101 demonstrated robust antitumor activity and evidence of immune memory following rechallenge of cured mice with fresh tumor cells. ATRC-101 increased the relative abundance of conventional dendritic cell (cDC) type 1 cells in the blood within 24 h of dosing, increased CD8+ T cells and natural killer cells in blood and tumor over time, decreased cDC type 2 cells in the blood, and decreased monocytic myeloid-derived suppressor cells in the tumor. Cellular stress, including that induced by chemotherapy, increased the amount of ATRC-101 target in tumor cells, and ATRC-101 combined with doxorubicin enhanced efficacy compared with either agent alone. Taken together, these data demonstrate that ATRC-101 drives tumor destruction in preclinical models by targeting a tumor-specific RNP complex leading to activation of innate and adaptive immune responses.
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Antineoplásicos , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Neoplasias , Inmunidad Adaptativa , Animales , Antineoplásicos/farmacología , Línea Celular Tumoral , Humanos , Inmunidad Innata , Ratones , Neoplasias/patologíaRESUMEN
BACKGROUND: Semen cryopreservation has become an essential tool for conservation efforts of the giant panda (Ailuropoda melanoleuca); however, it is severely detrimental to sperm quality. Evidence has shown that antioxidants have the potential to reverse cryopreservation-induced damage in sperm. The purpose of this study was to screen effective antioxidants that could retain sperm quality during cryopreservation and to determine the optimal dose. Seven antioxidant groups, including resveratrol (RSV = 50 µM, RSV = 100 µM, RSV = 150 µM), lycium barbarum polysaccharide (LBP = 2 mg/mL, LBP = 4 mg/mL), laminaria japonica polysaccharides (LJP = 1 mg/mL) or combination (LBP = 2 mg/mL, LJP = 1 mg/mL and RSV = 100 µM) were assessed. RESULTS: RSV, LBP, LJP, or a combination of RSV, LBP, and LJP added to the freezing medium significantly improved sperm progressive motility, plasma membrane integrity, acrosome integrity, and mitochondrial activity during the cryopreservation process. Furthermore, the activities of glutathione peroxidase and superoxide dismutase were also improved. The levels of reactive oxygen species and malondialdehyde in semen were notably reduced. Hyaluronidase activity and acrosin activity were significantly increased in LBP-treated sperm. However, sperm total motility and DNA integrity were not significantly different between the groups. CONCLUSIONS: RSV (50 µM) or LBP (2 mg/mL) are the best candidate antioxidants for inclusion in the freezing medium to improve the quality of giant panda spermatozoa during semen cryopreservation.
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Criopreservación , Medicamentos Herbarios Chinos , Preservación de Semen , Espermatozoides , Ursidae , Animales , Antioxidantes , Criopreservación/veterinaria , Masculino , Resveratrol/farmacología , Análisis de Semen/veterinaria , Preservación de Semen/veterinariaRESUMEN
A complete simulation of a machine vision system aimed at defect inspection on a reflective surface is proposed by ray tracing. The simulated scene is composed of the camera model, surface reflectance property, and light intensity distribution along with their corresponding object geometries. A virtual reflective plane geometry with scratches of various directions and pits of various sizes is built as the sample. Its realistic image is obtained by Monte Carlo ray tracing. Compared to the pinhole camera model, the camera model with a finite aperture emits more rays to deliver physical imaging. The bidirectional reflectance distribution function is applied to describe the surface reflectance property. The illustrated machine vision system captures a number of images while translating the light tubes. Then the image sequence obtained by experiment or simulation is fused to generate a well-contrasted synthetic image for defect detection. A flexible fusion method based on differential images is introduced to enhance the defect contrast on a uniform flawless background. To improve detection efficiency, defect contrast of synthetic images obtained by various fusion methods is evaluated. Influence of total image number, light tube width, and fusion interval is further discussed to optimize the inspection process. Experiments on car painted surfaces have shown that the simulated parameters can instruct the setup of the optical system and detect surface defects efficiently. The proposed simulation is capable of saving great effort in carrying out experimental trials and making improvements on reflective surface defect inspection.
RESUMEN
There is significant debate regarding whether B cells and their antibodies contribute to effective anti-cancer immune responses. Here we show that patients with metastatic but non-progressing melanoma, lung adenocarcinoma, or renal cell carcinoma exhibited increased levels of blood plasmablasts. We used a cell-barcoding technology to sequence their plasmablast antibody repertoires, revealing clonal families of affinity matured B cells that exhibit progressive class switching and persistence over time. Anti-CTLA4 and other treatments were associated with further increases in somatic hypermutation and clonal family size. Recombinant antibodies from clonal families bound non-autologous tumor tissue and cell lines, and families possessing immunoglobulin paratope sequence motifs shared across patients exhibited increased rates of binding. We identified antibodies that caused regression of, and durable immunity toward, heterologous syngeneic tumors in mice. Our findings demonstrate convergent functional anti-tumor antibody responses targeting public tumor antigens, and provide an approach to identify antibodies with diagnostic or therapeutic utility.
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Antígenos de Neoplasias/inmunología , Linfocitos B/inmunología , Neoplasias/inmunología , Adenocarcinoma del Pulmón/inmunología , Adenocarcinoma del Pulmón/secundario , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos , Sitios de Unión de Anticuerpos/inmunología , Carcinoma de Células Renales/inmunología , Carcinoma de Células Renales/secundario , Progresión de la Enfermedad , Femenino , Humanos , Neoplasias Renales/inmunología , Neoplasias Renales/patología , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/patología , Masculino , Melanoma/inmunología , Melanoma/secundario , Persona de Mediana Edad , Metástasis de la Neoplasia , Células Plasmáticas/inmunología , Células Precursoras de Linfocitos B , Neoplasias Cutáneas/inmunología , Neoplasias Cutáneas/patologíaRESUMEN
BACKGROUND: Dyskinesias are a disabling motor complication that arises with prolonged l-dopa treatment. Studies using D1 receptor drugs and genetically modified mice suggest that medium spiny neurons expressing D1 receptors play a primary role in l-dopa-induced dyskinesias. However, the specific role of these neurons in dyskinesias is not fully understood. METHODS: We used optogenetics, which allows for precise modulation of select neurons in vivo, to investigate whether striatal D1-expressing medium spiny neuron activity regulates abnormal involuntary movements or dyskinesia in parkinsonian mice. D1-cre mice unilaterally lesioned with 6-hydroxydopamine received striatal injections of cre-dependent channelrhodopsin2 virus or control virus. After stable virus expression, the effect of optical stimulation on dyskinesia was tested in l-dopa-naïve and l-dopa-primed mice. RESULTS: Single-pulse and burst-optical stimulation of D1-expressing medium spiny neurons induced dyskinesias in l-dopa-naïve channelrhodopsin2 mice. In stably dyskinetic mice, l-dopa injection induced dyskinesia to a similar or somewhat greater extent than optical stimulation. Combined l-dopa administration and stimulation resulted in an additive increase in dyskinesias, indicating that other mechanisms also contribute. Molecular studies indicate that changes in extracellular signal-regulated kinase phosphorylation in D1-expressing medium spiny neurons are involved. Optical stimulation did not ameliorate parkinsonism in l-dopa-naïve mice. However, it improved parkinsonism in l-dopa-primed mice to a similar extent as l-dopa administration. None of the stimulation paradigms enhanced dyskinesia or modified parkinsonism in l-dopa-naïve or l-dopa-primed control virus mice. CONCLUSION: The data provide direct evidence that striatal D1-expressing medium spiny neuron stimulation is sufficient to induce dyskinesias and contributes to the regulation of motor control. © 2017 International Parkinson and Movement Disorder Society.
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Cuerpo Estriado/citología , Cuerpo Estriado/metabolismo , Discinesias/etiología , Neuronas/fisiología , Trastornos Parkinsonianos/patología , Receptores de Dopamina D1/metabolismo , Animales , Antiparkinsonianos/efectos adversos , Channelrhodopsins , Cocaína/análogos & derivados , Cocaína/farmacocinética , Cuerpo Estriado/diagnóstico por imagen , Modelos Animales de Enfermedad , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Femenino , Regulación de la Expresión Génica/genética , Regulación de la Expresión Génica/efectos de la radiación , Levodopa/efectos adversos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Oxidopamina/toxicidad , Trastornos Parkinsonianos/inducido químicamente , Trastornos Parkinsonianos/tratamiento farmacológico , Receptores de Dopamina D1/genética , Simpaticolíticos/toxicidadRESUMEN
L-dopa-induced dyskinesias (LIDs) are a serious complication of L-dopa therapy for Parkinson's disease. Emerging evidence indicates that the nicotinic cholinergic system plays a role in LIDs, although the pathways and mechanisms are poorly understood. Here we used optogenetics to investigate the role of striatal cholinergic interneurons in LIDs. Mice expressing cre-recombinase under the control of the choline acetyltransferase promoter (ChAT-Cre) were lesioned by unilateral injection of 6-hydroxydopamine. AAV5-ChR2-eYFP or AAV5-control-eYFP was injected into the dorsolateral striatum, and optical fibers implanted. After stable virus expression, mice were treated with L-dopa. They were then subjected to various stimulation protocols for 2h and LIDs rated. Continuous stimulation with a short duration optical pulse (1-5ms) enhanced LIDs. This effect was blocked by the general muscarinic acetylcholine receptor (mAChR) antagonist atropine indicating it was mAChR-mediated. By contrast, continuous stimulation with a longer duration optical pulse (20ms to 1s) reduced LIDs to a similar extent as nicotine treatment (~50%). The general nicotinic acetylcholine receptor (nAChR) antagonist mecamylamine blocked the decline in LIDs with longer optical pulses showing it was nAChR-mediated. None of the stimulation regimens altered LIDs in control-eYFP mice. Lesion-induced motor impairment was not affected by optical stimulation indicating that cholinergic transmission selectively regulates LIDs. Longer pulse stimulation increased the number of c-Fos expressing ChAT neurons, suggesting that changes in this immediate early gene may be involved. These results demonstrate that striatal cholinergic interneurons play a critical role in LIDs and support the idea that nicotine treatment reduces LIDs via nAChR desensitization.
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Cuerpo Estriado/efectos de los fármacos , Discinesia Inducida por Medicamentos/metabolismo , Interneuronas/efectos de los fármacos , Levodopa/farmacología , Neostriado/efectos de los fármacos , Nicotina/farmacología , Animales , Colina O-Acetiltransferasa/metabolismo , Cuerpo Estriado/metabolismo , Interneuronas/metabolismo , Ratones , Neostriado/metabolismo , Agonistas Nicotínicos/farmacología , Optogenética/métodosRESUMEN
Novel scroll peapods are fabricated simply by utilizing the spontaneous scrolling mechanism of graphene onto fullerene string. The basic interaction between the graphene and the fullerene string is investigated, and the mechanism of the formation of the scroll peapod is explained in particular. The formation of the scroll peapod and its formation time are influenced by the combined effects of fullerene number, diameter and graphene size. It is also worth noting that narrow graphene nanoribbon wrapped onto a C720 bean can form a particular helical peapod. Higher temperature slows the scrolling dynamics, and even hinders the formation of the scroll peapod. This study provides a scientific basis for producing scroll peapods simply, and eventually their applications in various areas.
RESUMEN
Molecular dynamics simulations demonstrate that the cut defect can induce and guide the self-assembly of an isolated graphene nanoring (GNR) to form multi-layered funnel morphology. The vdW force is the driving force; the tangent component drives the self-assembly of GNR and the normal component adjusts and maintains the vertical distance between graphene layers, which is two times of the vdW radius. Moreover, the offset π-π stacking aids the adjacent layers to achieve the lowest energy of AB stacking. With different diameters of the annular GNRs, the final configurations experience multilayered cone, funnel and tube-shaped structures. It also illustrates the influence of temperature in the funnel-forming process. The wide gap with two edges beyond the cutoff distance of vdW force can utilize fullerenes to help and induce the assembly of the GNR. Cutting defect fissure would be a new way to induce the self-assembly of isolated graphene to design and fabricate new carbon nanostructures without impurities.
RESUMEN
BACKGROUND: ABT-126 is a novel, safe, and well-tolerated α7 nicotinic receptor agonist in a Phase 2 Alzheimer's disease study. We tested the antidyskinetic effect of ABT-126 in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated squirrel monkeys with moderate and more severe nigrostriatal damage. METHODS: Monkeys (n = 21, set 1) were lesioned with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine 1-2×. When parkinsonian, they were gavaged with levodopa (10 mg/kg)/carbidopa (2.5 mg/kg) twice daily and dyskinesias rated. They were then given nicotine in drinking water (n = 5), or treated with vehicle (n = 6) or ABT-126 (n = 10) twice daily orally 30 min before levodopa. Set 1 was then re-lesioned 1 to 2 times for a total of 3 to 4 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine injections. The antidyskinetic effect of ABT-126, nicotine, and the ß2* nicotinic receptor agonist ABT-894 was re-assessed. Another group of monkeys (n = 23, set 2) were lesioned with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine only 1× to 2×. They were treated with levodopa/carbidopa, administered the α7 agonist ABT-107 (n = 6), ABT-894 (n = 6), nicotine (n = 5), or vehicle (n = 6) and dyskinesias evaluated. All monkeys were euthanized and the dopamine transporter measured. RESULTS: With moderate nigrostriatal damage (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine 1×-2×), ABT-126 dose-dependently decreased dyskinesias (â¼60%), with similar results seen with ABT-894 (â¼60%) or nicotine (â¼60%). With more severe damage (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine 3-4×), ABT-126 and nicotine reduced dyskinesias, but ABT-894 did not. The dopamine transporter was 41% and 8.9% of control, with moderate and severe nigrostriatal damage, respectively. No drug modified parkinsonism. CONCLUSION: The novel α7 nicotinic receptor drug ABT-126 reduced dyskinesias in monkeys with both moderate and severe nigrostriatal damage. ABT-126 may be useful to reduce dyskinesias in both early- and later-stage Parkinson's disease.
Asunto(s)
Antiparkinsonianos/efectos adversos , Discinesia Inducida por Medicamentos/tratamiento farmacológico , Levodopa/efectos adversos , Agonistas Nicotínicos/uso terapéutico , Trastornos Parkinsonianos/tratamiento farmacológico , Sustancia Negra/patología , Receptor Nicotínico de Acetilcolina alfa 7/agonistas , 1-Metil-4-fenil-1,2,3,6-Tetrahidropiridina , Animales , Antiparkinsonianos/uso terapéutico , Discinesia Inducida por Medicamentos/patología , Femenino , Levodopa/uso terapéutico , Masculino , Agonistas Nicotínicos/farmacología , Trastornos Parkinsonianos/patología , SaimiriRESUMEN
Previous studies in Parkinsonian rats and monkeys have shown that ß2-selective nicotinic acetylcholine receptor (nAChR) agonists reduce l-Dopa-induced dyskinesias (LIDs), a serious complication of l-Dopa therapy for Parkinson's disease. Since rodent studies also suggested an involvement of α7 nAChRs in LIDs, we tested the effect of the potent, selective α7 agonist ABT-107 [5-(6-[(3R)-1-azabicyclo[2.2.2]oct-3-yloxy] pyridazin-3-yl)-1H-indole]. MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)-lesioned monkeys were gavaged with l-Dopa/carbidopa (10 and 2.5 mg/kg, respectively) twice daily, which resulted in stable LIDs. A dose-response study (0.03-1.0 mg/kg) showed that oral ABT-107 decreased LIDs by 40-60%. LIDs returned to control levels only after a 6-week ABT-107 washout, suggesting that long-term molecular changes were involved. Subsequent readministration of ABT-107 decreased LIDs by 50-60%, indicating that tolerance did not develop. ABT-107 had no effect on Parkinsonism or cognitive performance. We next tested ABT-107 together with the ß2 agonist ABT-894 [(3-(5,6-dichloro-pyridin-3-yl)-1(S),5 (S)-3,6-diazabicyclo[3.2.0]heptane], previously shown to reduce LIDs in Parkinsonian monkeys. In one study, the monkeys were first given oral ABT-894 (0.01 mg/kg), which maximally decreased LIDs by 50-60%; they were then also treated with 0.1 mg/kg ABT-107, a dose that maximally reduced LIDs. The effect of combined treatment on LIDs was similar to that with either drug alone. Comparable results were observed in a group of monkeys first treated with ABT-107 and then also given ABT-894. Thus, α7 and ß2 nAChR-selective drugs may function via a final common mechanism to reduce LIDs. The present results suggest that drugs targeting either α7 or ß2 nAChRs may be useful as antidyskinetic agents in Parkinson's disease.
Asunto(s)
Discinesia Inducida por Medicamentos/tratamiento farmacológico , Indoles/uso terapéutico , Intoxicación por MPTP/tratamiento farmacológico , Agonistas Nicotínicos/uso terapéutico , Quinuclidinas/uso terapéutico , Receptor Nicotínico de Acetilcolina alfa 7/agonistas , Animales , Antiparkinsonianos/efectos adversos , Femenino , Indoles/farmacología , Levodopa/efectos adversos , Masculino , Agonistas Nicotínicos/farmacología , Quinuclidinas/farmacología , SaimiriRESUMEN
Levodopa-induced dyskinesias (LIDs) are a serious complication of levodopa therapy for Parkinson's disease for which there is little treatment. Accumulating evidence shows that nicotinic acetylcholine receptor (nAChR) drugs decrease LIDs in parkinsonian animals. Here, we examined the effect of two ß2 nAChR agonists, ABT-089 and ABT-894, that previously were approved for phase 2 clinical trials for other indications. Two sets of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned monkeys were administered levodopa/carbidopa (10 mg/kg and 2.5 mg/kg, respectively) twice daily 5 days a week until they were stably dyskinetic. Each set had a vehicle-treated group, an nAChR agonist-treated group, and a nicotine-treated group as a positive control. Set A monkeys had previously received other nAChR drugs (nAChR drug-primed), whereas Set B monkeys were initially nAChR drug-naive. Both sets were administered the partial agonist ABT-089 (range, 0.01-1.0 mg/kg) orally 5 days a week twice daily 30 minutes before levodopa with each dose given for 1 to 5 weeks. ABT-089 decreased LIDs by 30% to 50% compared with vehicle-treated monkeys. Nicotine reduced LIDs by 70% in a parallel group. After 4 weeks of washout, the effect of the full agonist ABT-894 (range, 0.0001-0.10 mg/kg) was assessed on LIDs in Set A and Set B. ABT-894 reduced LIDs by 70%, similar to nicotine. Both drugs acted equally well at α4ß2* and α6ß2* nAChRs; however, ABT-089 was 30 to 60 times less potent than ABT-894. Tolerance did not develop for the time periods tested (range, 3-4 months). The nAChR drugs did not worsen parkinsonism or cognitive ability. Emesis, a common problem with nAChR drugs, was not observed. ABT-894 and ABT-089 appear to be good candidate nAChR drugs for the management of LIDs in Parkinson's disease.
Asunto(s)
Antiparkinsonianos/efectos adversos , Discinesia Inducida por Medicamentos/tratamiento farmacológico , Levodopa/efectos adversos , Intoxicación por MPTP/tratamiento farmacológico , Agonistas Nicotínicos/uso terapéutico , Piridinas/uso terapéutico , Pirrolidinas/uso terapéutico , Animales , Antiparkinsonianos/uso terapéutico , Femenino , Levodopa/uso terapéutico , Masculino , Saimiri , Resultado del TratamientoRESUMEN
The issue of poor sexual performance of some male giant pandas seriously impairs the growth and the genetic diversity of the captive population, yet there is still no clear understanding of the cause of the loss of this ability and its underlying mechanism. In this study, we analyzed the gut microbiota and its function in 72 fecal samples obtained from 20 captive male giant pandas, with an equal allocation between individuals capable and incapable of natural mating. Additionally, we investigated fecal hormone levels and behavioral differences between the two groups. A correlation analysis was then conducted among these factors to explore the influencing factors of their natural mating ability. The results showed significant differences in the composition of gut microbiota between the two groups of male pandas. The capable group had significantly higher abundance of Clostridium sensu stricto 1 (p adjusted = .0021, GLMM), which was positively correlated with fatty acid degradation and two-component system functions (Spearman, p adjusted < .05). Additionally, the capable group showed higher gene abundance in gut microbiota function including purine and pyrimidine metabolism and galactose metabolism, as well as pathways related to biological processes such as ribosome and homologous recombination (DEseq2, p adjusted < .05). We found no significant differences in fecal cortisol and testosterone levels between the two groups, and no difference was found in their behavior either. Our study provides a theoretical and practical basis for further studying the behavioral degradation mechanisms of giant pandas and other endangered mammal species.
RESUMEN
Abnormal involuntary movements or dyskinesias are a serious complication of long-term l-DOPA treatment of Parkinson's disease, for which there are few treatment options. Accumulating preclinical data show that nicotine decreases l-DOPA-induced dyskinesias (LIDs), suggesting that it may be a useful antidyskinetic therapy for Parkinson's disease. Here, we investigated whether nicotinic acetylcholine receptor (nAChR) agonists reduced LIDs in nonhuman primates. We first tested the nonselective nAChR agonist 1, 6,7,8,9-tetrahydro-6,10-methano-6H-pyrazino[2,3-h][3]benzazepine (varenicline), which offers the advantage that it is approved by the U.S. Food and Drug Administration for use in humans. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned monkeys (n = 23) were first administered l-DOPA/carbidopa (10/2.5 mg/kg) twice daily 5 days/week until stably dyskinetic. Oral varenicline (0.03-0.10 mg/kg) decreased LIDs â¼50% compared with vehicle-treated monkeys, whereas nicotine treatment (300 µg/ml in drinking water) reduced LIDs by 70% in a parallel group of animals. We next tested the selective α4ß2*/α6ß2* nAChR agonist TC-8831 [3-cyclopropylcarbonyl-3,6-diazabicyclo[3.1.1]heptane] on LIDs in the same set of monkeys after a 10-week washout. We also tested TC-8831 in another set of MPTP-lesioned monkeys (n = 16) that were nAChR drug-naïve. Oral TC-8831 (0.03-0.3 mg/kg) reduced LIDs in both sets by 30-50%. After a washout period, repeat TC-8831 dosing led to a greater decline in LIDs (60%) in both sets of monkeys that was similar to the effect of nicotine. Tolerance to any nAChR drug did not develop over the course of the study (3-4 months). NAChR drug treatment did not worsen parkinsonism or cognitive ability. These data suggest that nAChR agonists may be useful for the management of dyskinesias in l-DOPA-treated Parkinson's disease patients.
Asunto(s)
Modelos Animales de Enfermedad , Discinesia Inducida por Medicamentos/tratamiento farmacológico , Levodopa/toxicidad , Agonistas Nicotínicos/uso terapéutico , Enfermedad de Parkinson/tratamiento farmacológico , Animales , Discinesia Inducida por Medicamentos/fisiopatología , Femenino , Masculino , Nicotina/uso terapéutico , Enfermedad de Parkinson/fisiopatología , Receptores Nicotínicos/fisiología , SaimiriRESUMEN
Although 3,4-dihydroxyphenylalanine (levodopa) is the gold-standard treatment for Parkinson's disease, it can lead to disabling dyskinesias. Previous work demonstrated that nicotine reduces levodopa-induced dyskinesias (LIDs) in several parkinsonian animal models. The goal of this study was to determine whether the duration of nicotine administration affects its ability to reduce LIDs in levodopa-primed and levodopa-naíve monkeys and also to test whether tolerance develops to the beneficial effects of nicotine. Monkeys were injected with MPTP (1.9-2.0 mg/kg subcutaneously) over 3 to 5 months until parkinsonism developed. Nicotine (300 µg/mL) was administered in drinking water (over 4-6 months) to levodopa-primed or levodopa-naíve monkeys, with levodopa/carbidopa (10/2.5 mg/kg) gavaged twice daily. One set of MPTP-lesioned monkeys (n = 23) was first gavaged with levodopa and subsequently received nicotine 4 weeks later, when dyskinesias plateaued, or 8 weeks later, when dyskinesias were established. A 60% to 70% decrease in LIDs was observed after several weeks of nicotine treatment in both groups. A second set of monkeys (n = 26) received nicotine 8 or 2 weeks before levodopa. In the 8-week nicotine pretreatment group, there was an immediate reduction in LIDs, which plateaued at 60% to 70%. In the 2-week nicotine pretreatment group, there were initial small decreases in LIDs, which plateaued at 60% to 70% several weeks later. Thus, nicotine pretreatment and nicotine post-treatment were similarly efficacious in reducing LIDs. The beneficial effect of nicotine persisted throughout the study (17-23 weeks). Nicotine did not worsen parkinsonism. These data suggest that nicotine treatment has potential as a successful antidyskinetic therapy for patients with Parkinson's disease.
Asunto(s)
Antidiscinéticos , Antiparkinsonianos , Discinesia Inducida por Medicamentos/tratamiento farmacológico , Levodopa , Nicotina/uso terapéutico , Agonistas Nicotínicos/uso terapéutico , Enfermedad de Parkinson Secundaria/tratamiento farmacológico , Animales , Cotinina/sangre , Interpretación Estadística de Datos , Femenino , Intoxicación por MPTP/tratamiento farmacológico , Masculino , Enfermedad de Parkinson Secundaria/inducido químicamente , SaimiriRESUMEN
Mutations in a broad variety of genes can provoke the severe childhood disorder trichothiodystrophy (TTD) that is classified as a DNA repair disease or a transcription syndrome of RNA polymerase II. In an attempt to identify the common underlying pathomechanism of TTD we performed a knockout/knockdown of the two unrelated TTD factors TTDN1 and RNF113A and investigated the consequences on ribosomal biogenesis and performance. Interestingly, interference with these TTD factors created a nearly uniform impact on RNA polymerase I transcription with downregulation of UBF, disturbed rRNA processing and reduction of the backbone of the small ribosomal subunit rRNA 18S. This was accompanied by a reduced quality of decoding in protein translation and the accumulation of misfolded and carbonylated proteins, indicating a loss of protein homeostasis (proteostasis). As the loss of proteostasis by the ribosome has been identified in the other forms of TTD, here we postulate that ribosomal dysfunction is a common underlying pathomechanism of TTD.
Asunto(s)
Síndromes de Tricotiodistrofia , Humanos , Niño , Síndromes de Tricotiodistrofia/genética , Síndromes de Tricotiodistrofia/metabolismo , Ribosomas/genética , Ribosomas/metabolismo , Mutación/genética , ARN Polimerasa I/metabolismo , Proteínas/metabolismo , Proteínas de Unión al ADN/metabolismoRESUMEN
Group A beta-hemolytic streptococcus (GABHS) infections are implicated in neuropsychiatric disorders associated with an increased expression of repetitive stereotyped movements. Anti-streptococcus IgG presumably cross-reacts with elements on basal ganglia cells, modifies their function, and triggers symptoms. IgM may play a unique role in precipitating behavioral disturbances since variations in cortico-striatal activity occur in temporal congruity with peak IgM titers during an orchestrated immune response. We discovered in Balb/c mice that single subcutaneous injections of mouse monoclonal IgM antibodies to streptococcus group A bacteria induce marked dose-dependent increases in repetitive stereotyped movements, including head bobbing, sniffing, and intense grooming. Effects were antibody- and antigen-specific: anti-streptococcus IgG stimulated ambulatory activity and vertical activity but not these stereotypies, while anti-KLH IgM reduced activity. We suggest that anti-streptococcus IgM and IgG play unique roles in provoking GABHS-related behavioral disturbances. Paralleling its stereotypy-inducing effects, anti-streptococcus IgM stimulated Fos-like immunoreactivity in regions linked to cortico-striatal projections involved in motor control, including subregions of the caudate, nucleus accumbens, and motor cortex. This is the first evidence that anti-streptococcus IgM antibodies induce in vivo functional changes in these structures. Moreover, there was a striking similarity in the distributions of anti-streptococcus IgM deposits and Fos-like immunoreactivity in these regions. Of further importance, Fcα/µ receptors, which bind IgM, were present- and co-localized with anti-streptococcus IgM in these structures. We suggest that anti-streptococcus IgM-induced alterations of cell activity reflect local actions of IgM that involve Fcα/µ receptors. These findings support the use of anti-streptococcus monoclonal antibody administration in Balb/c mice to model GABHS-related behavioral disturbances and identify underlying mechanisms.
Asunto(s)
Anticuerpos Antibacterianos/farmacología , Anticuerpos Monoclonales de Origen Murino/farmacología , Inmunoglobulina M/farmacología , Conducta Estereotipada/efectos de los fármacos , Trastorno de Movimiento Estereotipado/inmunología , Streptococcus pyogenes/inmunología , Animales , Ganglios Basales/efectos de los fármacos , Ganglios Basales/inmunología , Hemocianinas/inmunología , Inmunoglobulina G/farmacología , Inmunoglobulina M/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Modelos Animales , Corteza Motora/efectos de los fármacos , Corteza Motora/inmunología , Proteínas Proto-Oncogénicas c-fos/inmunología , Receptores Fc/inmunologíaRESUMEN
Manganese (Mn) exposure causes manganism, a neurological disorder similar to Parkinson's disease. However, the cellular mechanism by which Mn impairs the dopaminergic neurotransmitter system remains unclear. We previously demonstrated that caspase-3-dependent proteolytic activation of protein kinase C delta (PKCδ) plays a key role in Mn-induced apoptotic cell death in dopaminergic neurons. Recently, we showed that PKCδ negatively regulates tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine synthesis, by enhancing protein phosphatase-2A activity in dopaminergic neurons. Here, we report that Mn exposure can affect the enzymatic activity of TH, the rate-limiting enzyme in dopamine synthesis, by activating PKCδ-PP2A signaling pathway in a dopaminergic cell model. Low dose Mn (3-10µM) exposure to differentiated mesencephalic dopaminergic neuronal cells for 3h induced a significant increase in TH activity and phosphorylation of TH-Ser40. The PKCδ specific inhibitor rottlerin did not prevent Mn-induced TH activity or TH-Ser40 phosphorylation. On the contrary, chronic exposure to 0.1-1 µM Mn for 24h induced a dose-dependent decrease in TH activity. Interestingly, chronic Mn treatment significantly increased PKCδ kinase activity and protein phosphatase 2A (PP2A) enzyme activity. Treatment with the PKCδ inhibitor rottlerin almost completely prevented chronic Mn-induced reduction in TH activity, as well as increased PP2A activity. Neither acute nor chronic Mn exposures induced any cytotoxic cell death or altered TH protein levels. Collectively, these results demonstrate that low dose Mn exposure impairs TH activity in dopaminergic cells through activation of PKCδ and PP2A activity.
Asunto(s)
Dopamina/fisiología , Manganeso/toxicidad , Neuronas/efectos de los fármacos , Neuronas/enzimología , Tirosina 3-Monooxigenasa/metabolismo , Animales , Línea Celular , Activación Enzimática/efectos de los fármacos , Activación Enzimática/fisiología , Fosforilación/efectos de los fármacos , Fosforilación/fisiología , Proteína Quinasa C-delta/metabolismo , Proteína Fosfatasa 2/metabolismoRESUMEN
Drawing on Self-Determination Theory, the current study analysed the relationship between teachers' perceived autonomy support and work engagement while it also explored the mediating effect of basic psychological need satisfaction and intrinsic motivation. The study investigated 520 elementary teachers in Beijing, and we found the following: (1) teachers in different groups reported diverse senses of perceived autonomy support, in that teachers with less teaching experience as well as those with a master's degree have a higher score regarding the perceptions of teacher autonomy; and (2) teacher autonomy can affect work engagement not only in terms of the satisfaction of basic psychological needs but also by the chain of satisfaction of basic psychological needs and intrinsic motivation. Teachers with more autonomy support will have higher basic psychological need satisfaction and stronger teaching motivation, which will further enhance their work engagement.
RESUMEN
Oxidative stress, neuroinflammation and apoptosis are some of the key etiological factors responsible for dopamin(DA)ergic degeneration during Parkinson's disease (PD), yet the downstream molecular mechanisms underlying neurodegeneration are largely unknown. Recently, a genome-wide association study revealed the FYN gene to be associated with PD, suggesting that Fyn kinase could be a pharmacological target for PD. In this study, we report that Fyn-mediated PKCδ tyrosine (Y311) phosphorylation is a key event preceding its proteolytic activation in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinsonism. MPP+/MPTP induced Fyn kinase activation in N27 DAergic neuronal cells and the mouse substantia nigra. PKCδ-Y311 phosphorylation by activated Fyn initiates the apoptotic caspase-signaling cascade during DAergic degeneration. Pharmacological attenuation of Fyn activity protected DAergic neurons from MPP+-induced degeneration in primary mesencephalic neuronal cultures. We further employed Fyn wild-type and Fyn knockout (KO) mice to confirm whether Fyn is a valid pharmacological target of DAergic neurodegeneration. Primary mesencephalic neurons from Fyn KO mice were greatly protected from MPP+-induced DAergic cell death, neurite loss and DA reuptake loss. Furthermore, Fyn KO mice were significantly protected from MPTP-induced PKCδ-Y311 phosphorylation, behavioral deficits and nigral DAergic degeneration. This study thus unveils a mechanism by which Fyn regulates PKCδ's pro-apoptotic function and DAergic degeneration. Pharmacological inhibitors directed at Fyn activation could prove to be a novel therapeutic target in the delay or halting of selective DAergic degeneration during PD.
RESUMEN
Extant giant pandas are divided into Sichuan and Qinling subspecies. The giant panda has many species-specific characteristics, including comparatively small organs for body size, small genitalia of male individuals, and low reproduction. Here, we report the most contiguous, high-quality chromosome-level genomes of two extant giant panda subspecies to date, with the first genome assembly of the Qinling subspecies. Compared with the previously assembled giant panda genomes based on short reads, our two assembled genomes increased contiguity over 200-fold at the contig level. Additional sequencing of 25 individuals dated the divergence of the Sichuan and Qinling subspecies into two distinct clusters from 10,000 to 12,000 years ago. Comparative genomic analyses identified the loss of regulatory elements in the dachshund family transcription factor 2 (DACH2) gene and specific changes in the synaptotagmin 6 (SYT6) gene, which may be responsible for the reduced fertility of the giant panda. Positive selection analysis between the two subspecies indicated that the reproduction-associated IQ motif containing D (IQCD) gene may at least partly explain the different reproduction rates of the two subspecies. Furthermore, several genes in the Hippo pathway exhibited signs of rapid evolution with giant panda-specific variants and divergent regulatory elements, which may contribute to the reduced inner organ sizes of the giant panda.