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1.
Immunity ; 52(4): 650-667.e10, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32294406

RESUMO

Appropriate balance of T helper 17 (Th17) and regulatory T (Treg) cells maintains immune tolerance and host defense. Disruption of Th17-Treg cell balance is implicated in a number of immune-mediated diseases, many of which display dysregulation of the insulin-like growth factor (IGF) system. Here, we show that, among effector T cell subsets, Th17 and Treg cells selectively expressed multiple components of the IGF system. Signaling through IGF receptor (IGF1R) activated the protein kinase B-mammalian target of rapamycin (AKT-mTOR) pathway, increased aerobic glycolysis, favored Th17 cell differentiation over that of Treg cells, and promoted a heightened pro-inflammatory gene expression signature. Group 3 innate lymphoid cells (ILC3s), but not ILC1s or ILC2s, were similarly responsive to IGF signaling. Mice with deficiency of IGF1R targeted to T cells failed to fully develop disease in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis. Thus, the IGF system represents a previously unappreciated pathway by which type 3 immunity is modulated and immune-mediated pathogenesis controlled.


Assuntos
Autoimunidade , Encefalomielite Autoimune Experimental/imunologia , Proteínas Proto-Oncogênicas c-akt/imunologia , Receptor IGF Tipo 1/imunologia , Linfócitos T Reguladores/imunologia , Serina-Treonina Quinases TOR/imunologia , Células Th17/imunologia , Animais , Comunicação Celular , Diferenciação Celular , Linhagem da Célula/genética , Linhagem da Célula/imunologia , Encefalomielite Autoimune Experimental/induzido quimicamente , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/patologia , Feminino , Regulação da Expressão Gênica , Tolerância Imunológica , Imunidade Inata , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Glicoproteína Mielina-Oligodendrócito/administração & dosagem , Fragmentos de Peptídeos/administração & dosagem , Proteínas Proto-Oncogênicas c-akt/genética , Receptor IGF Tipo 1/genética , Transdução de Sinais , Linfócitos T Reguladores/patologia , Serina-Treonina Quinases TOR/genética , Células Th17/patologia
2.
PLoS Pathog ; 19(6): e1011088, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37352334

RESUMO

Macrophages employ an array of pattern recognition receptors to detect and eliminate intracellular pathogens that access the cytosol. The cytosolic carbohydrate sensors Galectin-3, -8, and -9 (Gal-3, Gal-8, and Gal-9) recognize damaged pathogen-containing phagosomes, and Gal-3 and Gal-8 are reported to restrict bacterial growth via autophagy in cultured cells. However, the contribution of these galectins to host resistance during bacterial infection in vivo remains unclear. We found that Gal-9 binds directly to Mycobacterium tuberculosis (Mtb) and Salmonella enterica serovar Typhimurium (Stm) and localizes to Mtb in macrophages. To determine the combined contribution of membrane damage-sensing galectins to immunity, we generated Gal-3, -8, and -9 triple knockout (TKO) mice. Mtb infection of primary macrophages from TKO mice resulted in defective autophagic flux but normal bacterial replication. Surprisingly, these mice had no discernable defect in resistance to acute infection with Mtb, Stm or Listeria monocytogenes, and had only modest impairments in bacterial growth restriction and CD4 T cell activation during chronic Mtb infection. Collectively, these findings indicate that while Gal-3, -8, and -9 respond to an array of intracellular pathogens, together these membrane damage-sensing galectins play a limited role in host resistance to bacterial infection.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Camundongos , Animais , Galectina 3/genética , Tuberculose/metabolismo , Galectinas/genética , Galectinas/metabolismo , Macrófagos , Salmonella typhimurium , Camundongos Knockout
3.
Eur J Neurosci ; 60(1): 3643-3658, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38698531

RESUMO

The pedunculopontine tegmental nucleus of the brainstem (PPTg) has extensive interconnections and neuronal-behavioural correlates. It is implicated in movement control and sensorimotor integration. We investigated whether single neuron activity in freely moving rats is correlated with components of skilled forelimb movement, and whether individual neurons respond to both motor and sensory events. We found that individual PPTg neurons showed changes in firing rate at different times during the reach. This type of temporally specific modulation is like activity seen elsewhere in voluntary movement control circuits, such as the motor cortex, and suggests that PPTg neural activity is related to different specific events occurring during the reach. In particular, many neuronal modulations were time-locked to the end of the extension phase of the reach, when fine distal movements related to food grasping occur, indicating strong engagement of PPTg in this phase of skilled individual forelimb movements. In addition, some neurons showed brief periods of apparent oscillatory firing in the theta range at specific phases of the reach-to-grasp movement. When movement-related neurons were tested with tone stimuli, many also responded to this auditory input, allowing for sensorimotor integration at the cellular level. Together, these data extend the concept of the PPTg as an integrative structure in generation of complex movements, by showing that this function extends to the highly coordinated control of the forelimb during skilled reach to grasp movement, and that sensory and motor-related information converges on single neurons, allowing for direct integration at the cellular level.


Assuntos
Neurônios , Núcleo Tegmental Pedunculopontino , Ritmo Teta , Animais , Núcleo Tegmental Pedunculopontino/fisiologia , Neurônios/fisiologia , Ratos , Masculino , Ritmo Teta/fisiologia , Movimento/fisiologia , Membro Anterior/fisiologia , Ratos Long-Evans , Potenciais de Ação/fisiologia , Estimulação Acústica/métodos
4.
Eur J Neurosci ; 59(7): 1567-1584, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38314648

RESUMO

The spontaneously hypertensive rat (SHR) is a selectively bred animal strain that is frequently used to model attention-deficit hyperactivity disorder (ADHD) because of certain genetically determined behavioural characteristics. To test the hypothesis that the characteristically altered response to positive reinforcement in SHRs may be due to altered phasic dopamine response to reward, we measured phasic dopamine signals in the SHRs and Sprague Dawley (SD) rats using in vivo fast-scan cyclic voltammetry. The effects of the dopamine reuptake inhibitor, methylphenidate, on these signals were also studied. Phasic dopamine signals during the pairing of a sensory cue with electrical stimulation of midbrain dopamine neurons were significantly smaller in the SHRs than in the SD rats. Over repeated pairings, the dopamine response to the sensory cue increased, whereas the response to the electrical stimulation of dopamine neurons decreased, similarly in both strains. However, the final amplitude of the response to the sensory cue after pairing was significantly smaller in SHRs than in the SD rats. Methylphenidate increased responses to sensory cues to a significantly greater extent in the SHRs than in the SD rats, due largely to differences in the low dose effect. At a higher dose, methylphenidate increased responses to sensory cues and electrical stimulation similarly in SHRs and SD rats. The smaller dopamine responses may explain the reduced salience of reward-predicting cues previously reported in the SHR, whereas the action of methylphenidate on the cue response suggests a potential mechanism for the therapeutic effects of low-dose methylphenidate in ADHD.


Assuntos
Estimulantes do Sistema Nervoso Central , Metilfenidato , Ratos , Animais , Metilfenidato/farmacologia , Metilfenidato/uso terapêutico , Ratos Endogâmicos SHR , Dopamina , Ratos Endogâmicos WKY , Ratos Sprague-Dawley , Modelos Animais de Doenças , Estimulantes do Sistema Nervoso Central/farmacologia
5.
Small ; : e2402613, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38850186

RESUMO

Methanol is not only a promising liquid hydrogen carrier but also an important feedstock chemical for chemical synthesis. Catalyst design is vital for enabling the reactions to occur under ambient conditions. This study reports a new class of van der Waals heterojunction photocatalyst, which is synthesized by hot-injection method, whereby carbon dots (CDs) are grown in situ on ZnSe nanoplatelets (NPLs), i.e., metal chalcogenide quantum wells. The resultant organic-inorganic hybrid nanoparticles, CD-NPLs, are able to perform methanol dehydrogenation through CH splitting. The heterostructure has enabled light-induced charge transfer from the CDs into the NPLs occurring on a sub-nanosecond timescale, with charges remaining separated across the CD-NPLs heterostructure for longer than 500 ns. This resulted in significantly heightened H2 production rate of 107 µmole·g-1·h-1 and enhanced photocurrent density up to 34 µA cm-2 at 1 V bias potential. EPR and NMR analyses confirmed the occurrence of α-CH splitting and CC coupling. The novel CD-based organic-inorganic semiconductor heterojunction is poised to enable the discovery of a host of new nano-hybrid photocatalysts with full tunability in the band structure, charge transfer, and divergent surface chemistry for guiding photoredox pathways and accelerating reaction rates.

6.
Proc Natl Acad Sci U S A ; 118(12)2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33723065

RESUMO

The ocean is a reservoir for CFC-11, a major ozone-depleting chemical. Anthropogenic production of CFC-11 dramatically decreased in the 1990s under the Montreal Protocol, which stipulated a global phase out of production by 2010. However, studies raise questions about current overall emission levels and indicate unexpected increases of CFC-11 emissions of about 10 Gg ⋅ yr-1 after 2013 (based upon measured atmospheric concentrations and an assumed atmospheric lifetime). These findings heighten the need to understand processes that could affect the CFC-11 lifetime, including ocean fluxes. We evaluate how ocean uptake and release through 2300 affects CFC-11 lifetimes, emission estimates, and the long-term return of CFC-11 from the ocean reservoir. We show that ocean uptake yields a shorter total lifetime and larger inferred emission of atmospheric CFC-11 from 1930 to 2075 compared to estimates using only atmospheric processes. Ocean flux changes over time result in small but not completely negligible effects on the calculated unexpected emissions change (decreasing it by 0.4 ± 0.3 Gg ⋅ yr-1). Moreover, it is expected that the ocean will eventually become a source of CFC-11, increasing its total lifetime thereafter. Ocean outgassing should produce detectable increases in global atmospheric CFC-11 abundances by the mid-2100s, with emission of around 0.5 Gg ⋅ yr-1; this should not be confused with illicit production at that time. An illustrative model projection suggests that climate change is expected to make the ocean a weaker reservoir for CFC-11, advancing the detectable change in the global atmospheric mixing ratio by about 5 yr.


Assuntos
Atmosfera , Clorofluorcarbonetos/efeitos adversos , Poluentes Ambientais/efeitos adversos , Oceanos e Mares , Ozônio , Mudança Climática , Monitoramento Ambiental , Modelos Teóricos
7.
Cancer ; 129(16): 2491-2498, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37282609

RESUMO

BACKGROUND: Chromosome 1 abnormalities in multiple myeloma (MM) are increasingly recognized as high risk-defining features. The authors report the prognostic value of del(1p13.3) by fluorescence in situ hybridization (FISH) at enrollment in subjects treated on total therapy clinical trials 2-6. METHODS: FISH probes were generated from specific BAC DNA clones for the AHCYL1 gene locus (1p13.3) and the CKS1B locus (1q21). RESULTS: A total of 1133 patients were included in this analysis. Although del(1p13.3) was detected in 220 (19.4%) patients, 1q21gain or 1q21amp were observed in 300 (26.5%) and 150 (13.2%) patients, respectively. Concomitant del(1p13.3) with 1q21 gain or amp was observed in 65 (5.7%) and 29 (2.5%) patients, respectively. There was enrichment of high-risk features such as International Staging System (ISS) stage 3 disease and gene expression profiling (GEP)70 high risk (HR) in the group with del(1p13.3). Presence of del(1p13.3) confers inferior progression-free survival (PFS) and overall survival (OS). On multivariate analysis, the presence of ISS stage 3 disease, GEP70 HR, 1q21gain, and 1q21amp were independent predictors of PFS or OS. CONCLUSIONS: The PFS and OS of patients with combined abnormalities of del (1p13.3)/1q21gain or amp was significantly worse compared to del(1p13.3) alone and 1q21gain or 1q21 amp alone, which identifies a subset of patients with poor clinical outcomes.


Assuntos
Mieloma Múltiplo , Humanos , Mieloma Múltiplo/terapia , Hibridização in Situ Fluorescente , Cromossomos Humanos Par 1/genética , Aberrações Cromossômicas , Prognóstico , Deleção Cromossômica
8.
Nature ; 548(7666): 214-218, 2017 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-28783727

RESUMO

The origins of the Bronze Age Minoan and Mycenaean cultures have puzzled archaeologists for more than a century. We have assembled genome-wide data from 19 ancient individuals, including Minoans from Crete, Mycenaeans from mainland Greece, and their eastern neighbours from southwestern Anatolia. Here we show that Minoans and Mycenaeans were genetically similar, having at least three-quarters of their ancestry from the first Neolithic farmers of western Anatolia and the Aegean, and most of the remainder from ancient populations related to those of the Caucasus and Iran. However, the Mycenaeans differed from Minoans in deriving additional ancestry from an ultimate source related to the hunter-gatherers of eastern Europe and Siberia, introduced via a proximal source related to the inhabitants of either the Eurasian steppe or Armenia. Modern Greeks resemble the Mycenaeans, but with some additional dilution of the Early Neolithic ancestry. Our results support the idea of continuity but not isolation in the history of populations of the Aegean, before and after the time of its earliest civilizations.


Assuntos
Etnicidade/genética , Filogenia , Cromossomos Humanos X/genética , Etnicidade/história , Feminino , Grécia , História Antiga , Migração Humana/história , Humanos , Masculino , Polimorfismo de Nucleotídeo Único/genética , Análise de Componente Principal
9.
J Phycol ; 59(4): 751-774, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37243501

RESUMO

Phylogenetic analyses of rbcL gene sequences and of concatenated rbcL, psbA, and nuclear SSU rRNA gene sequences resolved the generitype of Lithothamnion, L. muelleri, in a clade with three other southern Australian species, L. kraftii sp. nov., L. saundersii sp. nov., and L. woelkerlingii sp. nov. Cold water boreal species currently classified in Lithothamnion and whose type specimens have been sequenced are transferred to Boreolithothamnion gen. nov., with B. glaciale comb. nov. as the generitype. The other species are B. giganteum comb. nov., B. phymatodeum comb. nov., and B. sonderi comb. nov., whose type specimens are newly sequenced, and B. lemoineae comb. nov., B. soriferum comb. nov., and B. tophiforme comb. nov., whose type specimens were already sequenced. Based on rbcL sequences from the type specimens of Lithothamnion crispatum, L. indicum, and L. superpositum, each is recognized as a distinct species and transferred to the recently described Roseolithon as R. crispatum comb. nov., R. indicum comb. nov., and R. superpositum com. nov., respectively. To correctly assign species to these three genera based only on morpho-anatomy, specimens must have multiporate conceptacles and some epithallial cells with flared walls. The discussion provides examples demonstrating that only with phylogenetic analyses of DNA sequences can the evolution of morpho-anatomical characters of non-geniculate corallines be understood and applied at the correct taxonomic rank. Finally, phylogenetic analyses of DNA sequences support recognition of the Hapalidiales as a distinct order characterized by having multiporate tetra/bisporangial conceptacles, and not as a suborder of Corallinales whose tetra/bisporangial conceptacles are uniporate.


Assuntos
Rodófitas , Filogenia , Análise de Sequência de DNA , Austrália , RNA Ribossômico 16S/genética
10.
J Phycol ; 59(6): 1179-1201, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37770245

RESUMO

Porolithon is one of the most ecologically important genera of tropical and subtropical crustose (non-geniculate) coralline algae growing abundantly along the shallow margins of coral reefs and functioning to cement reef frameworks. Thalli of branched, fruticose Porolithon specimens from the Indo-Pacific Ocean traditionally have been called P. gardineri, while massive, columnar forms have been called P. craspedium. Sequence comparisons of the rbcL gene both from type specimens of P. gardineri and P. craspedium and from field-collected specimens demonstrate that neither species is present in east Australia and instead resolve into four unique genetic lineages. Porolithon howensis sp. nov. forms columnar protuberances and loosely attached margins and occurs predominantly at Lord Howe Island; P. lobulatum sp. nov. has fruticose to clavate forms and free margins that are lobed and occurs in the Coral Sea and on the Great Barrier Reef (GBR); P. parvulum sp. nov. has short (<2 cm), unbranched protuberances and attached margins and is restricted to the central and southern GBR; and P. pinnaculum sp. nov. has a mountain-like, columnar morphology and occurs on oceanic Coral Sea reefs. A rbcL gene sequence of the isotype of P. castellum demonstrates it is a different species from other columnar species. In addition to the diagnostic rbcL and psbA marker sequences, the four new species may be distinguished by a combination of features including thallus growth form, margin shape (attached or unattached), and medullary system (coaxial or plumose). Porolithon species, because of their ecological importance and sensitivity to ocean acidification, need urgent documentation of their taxonomic diversity.


Assuntos
Recifes de Corais , Rodófitas , Concentração de Íons de Hidrogênio , Filogenia , Água do Mar
11.
J Phycol ; 59(1): 221-235, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36336979

RESUMO

Partial rbcL sequences from type specimens of three of the earliest described Corallina species showed that C. arbuscula (type locality: Unalaska Island, Alaska, USA) and C. pilulifera (type locality: Okhotsk Sea, Russia) are synonymous, with C. pilulifera as the taxonomically accepted name and that C. vancouveriensis (type locality: Botanical Beach, Vancouver Island, Canada) is a distinct species. To identify molecular species limits and clarify descriptions and distributions of C. pilulifera and C. vancouveriensis, we sequenced and analyzed portions of one mitochondrial and two plastid genes from historical and recent collections. The single-gene phylogenetic reconstructions support the recognition of both species as distinct, as well as two additional species, C. hakodatensis sp. nov. and C. parva sp. nov., which are sister to, and often morphologically indistinguishable from C. pilulifera and C. vancouveriensis, respectively. DNA sequence data currently illustrate that C. pilulifera is found in the cold northern Pacific waters from the Okhotsk Sea of Russia to Hokkaido, Japan, eastward across the Aleutian Islands to Knoll Head, Alaska, and as far south as Nanaimo, British Columbia. Corallina vancouveriensis is distributed as far west as Attu Island in the Aleutian Islands to Sitka, Alaska, and southeasterly at numerous sites from British Columbia to the north of Point Conception, California, USA. The cryptic species C. hakodatensis and C. parva occur sympatrically with their sister species but with narrower ranges. The complex phylogenetic relationships shown by the single gene trees recommend Corallina as a model genus to explore coralline algal biogeography, evolution, and patterns of speciation.


Assuntos
Rodófitas , Filogenia , Análise de Sequência de DNA , Colúmbia Britânica , Japão
12.
J Strength Cond Res ; 37(10): e546-e554, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37639655

RESUMO

ABSTRACT: Wizenberg, AM, Gonzalez-Rojas, D, Rivera, PM, Proppe, CE, Laurel, KP, Stout, JR, Fukuda, DH, Billaut, F, Keller, JL, and Hill, EC. Acute effects of continuous and intermittent blood flow restriction on sprint interval performance and muscle oxygen responses. J Strength Cond Res 37(10): e546-e554, 2023-This investigation aimed to examine the acute effects of continuous and intermittent blood flow restriction (CBFR and IBFR, respectively) during sprint interval training (SIT) on muscle oxygenation, sprint performance, and ratings of perceived exertion (RPE). Fifteen men (22.6 ± 2.4 years; 176 ± 6.3 cm; 80.0 ± 12.6 kg) completed in random order a SIT session with CBFR, IBFR (applied during rest), and no blood flow restriction (NoBFR). Each SIT session consisted of two 30-second all-out sprint tests separated by 2 minutes. Peak power (PP), total work (TW), sprint decrement score (S dec ), RPE, and muscle oxygenation were measured during each sprint. A p value ≤0.05 was considered statistically significant. PP decreased to a greater extent from sprint 1 to sprint 2 during CBFR (25.5 ± 11.9%) and IBFR (23.4 ± 9.3%) compared with NoBFR (13.4 ± 8.6%). TW was reduced similarly (17,835.6 ± 966.2 to 12,687.2 ± 675.2 J) from sprint 1 to sprint 2 for all 3 conditions, but TW was lower (collapsed across time) for CBFR (14,320.7 ± 769.1 J) than IBFR (15,548.0 ± 840.5 J) and NoBFR (15,915.4 ± 771.5 J). There were no differences in S dec (84.3 ± 1.7%, 86.1 ± 1.5%, and 87.2 ± 1.1% for CBFR, IBFR, and NoBFR, respectively) or RPE, which increased from sprint 1 (8.5 ± 0.3) to sprint 2 (9.7 ± 0.1). Collective muscle oxygenation responses increased across time and were similar among conditions, whereas increases in deoxy[heme] and total[heme] were greatest for CBFR. Applying BFR during SIT induced greater decrements in PP, and CBFR resulted in greater decrements in work across repeated sprints. The larger increases in deoxy[heme] and total[heme] for CBFR suggested it may induce greater metabolite accumulation than IBFR and NoBFR when combined with SIT.


Assuntos
Treinamento Intervalado de Alta Intensidade , Músculos , Humanos , Masculino , Heme , Oxigênio , Descanso , Adulto Jovem
13.
Can Assoc Radiol J ; 74(3): 514-525, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36710521

RESUMO

The Canadian Association of Radiologists (CAR) Incidental Findings Working Group consists of both academic subspeciality and general radiologists tasked with either adapting American College of Radiology (ACR) guidelines to meet the needs of Canadian radiologists or authoring new guidelines where appropriate. In this case, entirely new guidelines to deal with incidental musculoskeletal findings that may be encountered on thoracoabdominal computed tomography or magnetic resonance imaging were drafted, focussing on which findings should prompt recommendations for further workup. These recommendations discuss how to deal with incidental marrow changes, focal bone lesions, abnormalities of the pubic symphysis and sacroiliac joints, fatty soft tissue masses, manifestations of renal osteodystrophy and finally discuss opportunistic osteoporosis evaluation.


Assuntos
Achados Incidentais , Imageamento por Ressonância Magnética , Humanos , Canadá , Tomografia Computadorizada por Raios X , Radiologistas
14.
J Neurosci ; 41(37): 7831-7847, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34348999

RESUMO

The principal neurons of the striatum, the spiny projection neurons (SPNs), make inhibitory synaptic connections with each other via collaterals of their main axon, forming a local lateral inhibition network. Serotonin, acting via the 5-HT1B receptor, modulates neurotransmitter release from SPN terminals in striatal output nuclei, but the role of 5-HT1B receptors in lateral inhibition among SPNs in the striatum is unknown. Here, we report the effects of 5-HT1B receptor activation on lateral inhibition in the mouse striatum. Whole-cell recordings were made from SPNs in acute brain slices of either sex, while optogenetically activating presynaptic SPNs or fast-spiking interneurons (FSIs). Activation of 5-HT1B receptors significantly reduced the amplitude of IPSCs evoked by optical stimulation of both direct and indirect pathway SPNs. This reduction was blocked by application of a 5-HT1B receptor antagonist. Activation of 5-HT1B receptors did not reduce the amplitude of IPSCs evoked from FSIs. These results suggest a new role for serotonin as a modulator of lateral inhibition among striatal SPNs. The 5-HT1B receptor may, therefore, be a suitable target for future behavioral experiments investigating the currently unknown role of lateral inhibition in the function of the striatum.SIGNIFICANCE STATEMENT We show that stimulation of serotonin receptors reduces the efficacy of lateral inhibition between spiny projection neurons (SPNs), one of the biggest GABAergic sources in the striatum, by activation of the serotonin 5-HT1B receptor. The striatum receives serotonergic input from the dorsal raphe nuclei and is important in behavioral brain functions like learning and action selection. Our findings suggest a new role for serotonin in modulating the dynamics of neural interactions in the striatum, which extends current knowledge of the mechanisms of the behavioral effects of serotonin.


Assuntos
Corpo Estriado/efeitos dos fármacos , Inibição Neural/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Receptor 5-HT1B de Serotonina/metabolismo , Agonistas do Receptor 5-HT1 de Serotonina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Corpo Estriado/metabolismo , Interneurônios/efeitos dos fármacos , Interneurônios/metabolismo , Camundongos , Neurônios/metabolismo , Técnicas de Patch-Clamp , Serotonina/metabolismo , Transmissão Sináptica/efeitos dos fármacos , Ácido gama-Aminobutírico/metabolismo
15.
J Neurophysiol ; 127(3): 607-622, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35080448

RESUMO

GNAO1 encodes Gαo, a heterotrimeric G protein α subunit in the Gi/o family. In this report, we used a Gnao1 mouse model "G203R" previously described as a "gain-of-function" Gnao1 mutant with movement abnormalities and enhanced seizure susceptibility. Here, we report an unexpected second mutation resulting in a loss-of-function Gαo protein, and describe alterations in central synaptic transmission. Whole cell patch clamp recordings from Purkinje cells (PCs) in acute cerebellar slices from Gnao1 mutant mice showed significantly lower frequencies of spontaneous and miniature inhibitory postsynaptic currents (sIPSCs and mIPSCs) compared with WT mice. There was no significant change in sEPSCs or mEPSCs. Whereas mIPSC frequency was reduced, mIPSC amplitudes were not affected, suggesting a presynaptic mechanism of action. A modest decrease in the number of molecular layer interneurons was insufficient to explain the magnitude of IPSC suppression. Paradoxically, Gi/o inhibitors (pertussis toxin) enhanced the mutant-suppressed mIPSC frequency and eliminated the difference between WT and Gnao1 mice. Although GABAB receptor regulates mIPSCs, neither agonists nor antagonists of this receptor altered function in the mutant mouse PCs. This study is an electrophysiological investigation of the role of Gi/o protein in cerebellar synaptic transmission using an animal model with a loss-of-function Gi/o protein.NEW & NOTEWORTHY This report reveals the electrophysiological mechanisms of a movement disorder animal model with monoallelic Gnao1 loss. This study illustrates the role of Gαo protein in regulating GABA release in mouse cerebellum. This study could also facilitate the discovery of new drugs or drug repurposing for GNAO1-associated disorders. Moreover, since GNAO1 shares pathways with other genes related to movement disorders, developing drugs for the treatment of GNAO1-associated movement disorders could further the pharmacological intervention for other monogenic movement disorders.


Assuntos
Transtornos dos Movimentos , Células de Purkinje , Animais , Cerebelo/fisiologia , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Camundongos , Células de Purkinje/fisiologia , Transmissão Sináptica/fisiologia , Ácido gama-Aminobutírico/metabolismo
16.
Development ; 146(13)2019 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-31189664

RESUMO

Astrocytes display diverse morphologies in different regions of the central nervous system. Whether astrocyte diversity is attributable to developmental processes and bears functional consequences, especially in humans, is unknown. RNA-seq of human pluripotent stem cell-derived regional astrocytes revealed distinct transcript profiles, suggesting differential functional properties. This was confirmed by differential calcium signaling as well as effects on neurite growth and blood-brain barrier formation. Distinct transcriptional profiles and functional properties of human astrocytes generated from regionally specified neural progenitors under the same conditions strongly implicate the developmental impact on astrocyte diversity. These findings provide a rationale for renewed examination of regional astrocytes and their role in the pathogenesis of psychiatric and neurological disorders.


Assuntos
Astrócitos/fisiologia , Diferenciação Celular/genética , Neurogênese/genética , Células-Tronco Pluripotentes/fisiologia , Transcriptoma , Sequência de Bases , Biomarcadores/análise , Biomarcadores/metabolismo , Células Cultivadas , Córtex Cerebral/citologia , Córtex Cerebral/metabolismo , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Células-Tronco Pluripotentes Induzidas/fisiologia , Células-Tronco Neurais/fisiologia , Especificidade de Órgãos/genética , Prosencéfalo/citologia , Prosencéfalo/metabolismo , Análise de Sequência de RNA
17.
Plant Biotechnol J ; 20(2): 374-389, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34614273

RESUMO

Vegetative storage proteins (VSPs) are known to serve as nitrogen reserves in many dicot plants but remain undiscovered in grasses, most widely grown group of crops globally. We identified and characterized a VSP in maize and demonstrated that its overexpression improved drought tolerance. Nitrogen supplementation selectively induced a mesophyll lipoxygenase (ZmLOX6), which was targeted to chloroplasts by a novel N-terminal transit peptide of 62 amino acids. When ectopically expressed under the control of various tissue-specific promoters, it accumulated to a fivefold higher level upon expression in the mesophyll cells than the wild-type plants. Constitutive expression or targeted expression specifically to the bundle sheath cells increased its accumulation by less than twofold. The overexpressed ZmLOX6 was remobilized from the leaves like other major proteins during grain development. Evaluated in the field over locations and years, transgenic hybrids overexpressing ZmLOX6 in the mesophyll cells significantly outyielded nontransgenic sibs under managed drought stress imposed at flowering. Additional storage of nitrogen as a VSP in maize leaves ameliorated the effect of drought on grain yield.


Assuntos
Secas , Zea mays , Cloroplastos , Grão Comestível/genética , Nitrogênio/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Zea mays/genética
18.
Am J Ind Med ; 65(1): 51-58, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34727383

RESUMO

BACKGROUND: Opioid use in the treatment of musculoskeletal injuries is a complex decision where benefits must be balanced with risk. Previous research has shown an association between higher opioid doses and adverse health effects. The study's objective was to investigate whether opioid prescriptions are associated with increased costs and deaths through an injury mechanism or as a direct result of the opioid prescription. METHODS: Data for 144,553 deidentified Ohio Bureau of Workers' Compensation claims from 2010 to 2014 with shoulder, knee, and low back injuries were obtained and followed until 2016. Each claim had associated prescription information. Injury claims were further classified using the allowed diagnoses by single or multiple body areas affected and injury severity ("simple" or "complex"). The outcome variables were medical and indemnity costs, lost days, MaxMED (maximum claim-prescribed daily morphine equivalent dose), and death status. Association between maximum opioid dose with deaths was determined by logistic regression analysis. RESULTS: Several outcome variables, including claim medical and indemnity costs, and the likelihood of claimant death, showed significant associations with the MaxMED. In the analysis of claim deaths, these associations held for all claim types (except complex), even after adjusting for age, gender, surgery, and lost time. CONCLUSION: The association between increasing opioid doses and deaths for low-severity diagnoses was disturbing given the lack of demonstrated efficacy of opioids for treatment of minor injuries. A focus on provider education, increased utilization of non-opioids, and early intervention for minor soft-tissue injuries could reduce claims costs, disability, and future deaths.


Assuntos
Doenças Musculoesqueléticas , Doenças Profissionais , Analgésicos Opioides , Humanos , Prescrições , Indenização aos Trabalhadores
19.
Molecules ; 27(4)2022 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-35208986

RESUMO

The cholinergic interneurons of the striatum account for a small fraction of all striatal cell types but due to their extensive axonal arborization give the striatum the highest content of acetylcholine of almost any nucleus in the brain. The prevailing theory of striatal cholinergic interneuron signaling is that the numerous varicosities on the axon produce an extrasynaptic, volume-transmitted signal rather than mediating rapid point-to-point synaptic transmission. We review the evidence for this theory and use a mathematical model to integrate the measurements reported in the literature, from which we estimate the temporospatial distribution of acetylcholine after release from a synaptic vesicle and from multiple vesicles during tonic firing and pauses. Our calculations, together with recent data from genetically encoded sensors, indicate that the temporospatial distribution of acetylcholine is both short-range and short-lived, and dominated by diffusion. These considerations suggest that acetylcholine signaling by cholinergic interneurons is consistent with point-to-point transmission within a steep concentration gradient, marked by transient peaks of acetylcholine concentration adjacent to release sites, with potential for faithful transmission of spike timing, both bursts and pauses, to the postsynaptic cell. Release from multiple sites at greater distance contributes to the ambient concentration without interference with the short-range signaling. We indicate several missing pieces of evidence that are needed for a better understanding of the nature of synaptic transmission by the cholinergic interneurons of the striatum.


Assuntos
Acetilcolina/metabolismo , Corpo Estriado/metabolismo , Interneurônios/metabolismo , Transmissão Sináptica , Animais , Humanos
20.
Can Assoc Radiol J ; 73(2): 312-319, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34154391

RESUMO

The Canadian Association of Radiologists Incidental Findings Working Group consists of both academic subspecialty and general radiologists and is tasked with adapting and expanding upon the American College of Radiology incidental findings white papers to more closely apply to Canadian practice patterns, particularly more comprehensively dealing with the role of ultrasound and pursuing more cost-effective approaches to the workup of incidental findings without compromising patient care. Presented here are the 2021 Canadian guidelines for the management of pancreatic incidental findings. Topics covered include anatomic variants, fatty atrophy, pancreatic calcifications, ductal ectasia, and management of incidental pancreatic cysts.

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