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1.
iScience ; 27(9): 110687, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39252958

RESUMO

Chemical synaptic transmission is modulated to accommodate different activity levels, thus enabling homeostatic scaling in pre- and postsynaptic compartments. In nematodes, cholinergic neurons use neuropeptide signaling to modulate synaptic vesicle content. To explore if this mechanism is conserved in vertebrates, we studied the involvement of neuropeptides in cholinergic transmission at the neuromuscular junction of larval zebrafish. Optogenetic stimulation by photoactivated adenylyl cyclase evoked locomotion. We generated mutants lacking the neuropeptide-processing enzyme carboxypeptidase E (cpe), and the most abundant neuropeptide precursor in motor neurons, tachykinin (tac1). Both mutants showed exaggerated locomotion after photostimulation. Recording excitatory postsynaptic currents demonstrated overall larger amplitudes in the wild type. Exaggerated locomotion in the mutants thus reflected upscaling of postsynaptic excitability. Both mutant muscles expressed more nicotinic acetylcholine receptors (nAChRs) on their surface; thus, neuropeptide signaling regulates synaptic transmitter output in zebrafish motor neurons, and muscle cells homeostatically regulate nAChR surface expression, compensating reduced presynaptic input.

2.
Genetics ; 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39110015

RESUMO

To understand the function of cells such as neurons within an organism, it can be instrumental to inhibit cellular function, or to remove the cell (type) from the organism, and thus to observe the consequences on organismic and/or circuit function and animal behavior. A range of approaches and tools were developed and used over the past few decades that act either constitutively or acutely and reversibly, in systemic or local fashion. These approaches make use of either drugs or genetically encoded tools. Also, there are acutely acting inhibitory tools that require an exogenous trigger like light. Here, we give an overview of such methods developed and used in the nematode Caenorhabditis elegans.

3.
J Neurosci ; 44(31)2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-38951038

RESUMO

At chemical synapses, voltage-gated Ca2+ channels (VGCCs) translate electrical signals into a trigger for synaptic vesicle (SV) fusion. VGCCs and the Ca2+ microdomains they elicit must be located precisely to primed SVs to evoke rapid transmitter release. Localization is mediated by Rab3-interacting molecule (RIM) and RIM-binding proteins, which interact and bind to the C terminus of the CaV2 VGCC α-subunit. We studied this machinery at the mixed cholinergic/GABAergic neuromuscular junction of Caenorhabditis elegans hermaphrodites. rimb-1 mutants had mild synaptic defects, through loosening the anchoring of UNC-2/CaV2 and delaying the onset of SV fusion. UNC-10/RIM deletion much more severely affected transmission. Although postsynaptic depolarization was reduced, rimb-1 mutants had increased cholinergic (but reduced GABAergic) transmission, to compensate for the delayed release. This did not occur when the excitation-inhibition (E-I) balance was altered by removing GABA transmission. Further analyses of GABA defective mutants and GABAA or GABAB receptor deletions, as well as cholinergic rescue of RIMB-1, emphasized that GABA neurons may be more affected than cholinergic neurons. Thus, RIMB-1 function differentially affects excitation-inhibition balance in the different motor neurons, and RIMB-1 thus may differentially regulate transmission within circuits. Untethering the UNC-2/CaV2 channel by removing its C-terminal PDZ ligand exacerbated the rimb-1 defects, and similar phenotypes resulted from acute degradation of the CaV2 ß-subunit CCB-1. Therefore, untethering of the CaV2 complex is as severe as its elimination, yet it does not abolish transmission, likely due to compensation by CaV1. Thus, robustness and flexibility of synaptic transmission emerge from VGCC regulation.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Junção Neuromuscular , Transmissão Sináptica , Animais , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/fisiologia , Canais de Cálcio/metabolismo , Canais de Cálcio/fisiologia , Proteínas de Transporte , Proteínas de Membrana , Mutação , Rede Nervosa/fisiologia , Rede Nervosa/metabolismo , Junção Neuromuscular/metabolismo , Junção Neuromuscular/fisiologia , Sinapses/metabolismo , Sinapses/fisiologia , Transmissão Sináptica/fisiologia , Vesículas Sinápticas/metabolismo
4.
Radiother Oncol ; 194: 110179, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38403025

RESUMO

BACKGROUND AND PURPOSE: Motion management is essential to reduce normal tissue exposure and maintain adequate tumor dose in lung stereotactic body radiation therapy (SBRT). Lung SBRT using an articulated robotic arm allows dynamic tracking during radiation dose delivery. Two stereoscopic X-ray tracking modes are available - fiducial-based and fiducial-free tracking. Although X-ray detection of implanted fiducials is robust, the implantation procedure is invasive and inapplicable to some patients and tumor locations. Fiducial-free tracking relies on tumor contrast, which challenges the existing tracking algorithms for small (e.g., <15 mm) and/or tumors obscured by overlapping anatomies. To markedly improve the performance of fiducial-free tracking, we proposed a deep learning-based template matching algorithm - Deep Match. METHOD: Deep Match consists of four self-definable stages - training-free feature extractor, similarity measurements for location proposal, local refinements, and uncertainty level prediction for constructing a more trustworthy and versatile pipeline. Deep Match was validated on a 10 (38 fractions; 2661 images) patient cohort whose lung tumor was trackable on one X-ray view, while the second view did not offer sufficient conspicuity for tumor tracking using existing methods. The patient cohort was stratified into subgroups based on tumor sizes (<10 mm, 10-15 mm, and >15 mm) and tumor locations (with/without thoracic anatomy overlapping). RESULTS: On X-ray views that conventional methods failed to track the lung tumor, Deep Match achieved robust performance as evidenced by >80 % 3 mm-Hit (detection within 3 mm superior/inferior margin from ground truth) for 70 % of patients and <3 mm superior/inferior distance (SID) ∼1 mm standard deviation for all the patients. CONCLUSION: Deep Match is a zero-shot learning network that explores the intrinsic neural network benefits without training on patient data. With Deep Match, fiducial-free tracking can be extended to more patients with small tumors and with tumors obscured by overlapping anatomy.


Assuntos
Aprendizado Profundo , Neoplasias Pulmonares , Radiocirurgia , Humanos , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/diagnóstico por imagem , Radiocirurgia/métodos , Algoritmos , Movimento , Respiração , Radioterapia Guiada por Imagem/métodos , Marcadores Fiduciais
5.
Curr Biol ; 33(16): 3423-3435.e5, 2023 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-37527662

RESUMO

Sensation of light is essential for all organisms. The eye-less nematode Caenorhabditis elegans detects UV and blue light to evoke escape behavior. The photosensor LITE-1 absorbs UV photons with an unusually high extinction coefficient, involving essential tryptophans. Here, we modeled the structure and dynamics of LITE-1 using AlphaFold2-multimer and molecular dynamics (MD) simulations and performed mutational and behavioral assays in C. elegans to characterize its function. LITE-1 resembles olfactory and gustatory receptors from insects, recently shown to be tetrameric ion channels. We identified residues required for channel gating, light absorption, and mechanisms of photo-oxidation, involving a likely binding site for the peroxiredoxin PRDX-2. Furthermore, we identified the binding pocket for a putative chromophore. Several residues lining this pocket have previously been established as essential for LITE-1 function. A newly identified critical cysteine pointing into the pocket represents a likely chromophore attachment site. We derived a model for how photon absorption, via a network of tryptophans and other aromatic amino acids, induces an excited state that is transferred to the chromophore. This evokes conformational changes in the protein, possibly leading to a state receptive to oxidation of cysteines and, jointly, to channel gating. Electrophysiological data support the idea that LITE-1 is a photon and H2O2-coincidence detector. Other proteins with similarity to LITE-1, specifically C. elegans GUR-3, likely use a similar mechanism for photon detection. Thus, a common protein fold and assembly, used for chemoreception in insects, possibly by binding of a particular compound, may have evolved into a light-activated ion channel.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Peróxido de Hidrogênio , Canais Iônicos/metabolismo , Peroxirredoxinas/metabolismo , Receptores de Superfície Celular/metabolismo
6.
Nat Commun ; 14(1): 1939, 2023 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-37024493

RESUMO

Excitable cells can be stimulated or inhibited by optogenetics. Since optogenetic actuation regimes are often static, neurons and circuits can quickly adapt, allowing perturbation, but not true control. Hence, we established an optogenetic voltage-clamp (OVC). The voltage-indicator QuasAr2 provides information for fast, closed-loop optical feedback to the bidirectional optogenetic actuator BiPOLES. Voltage-dependent fluorescence is held within tight margins, thus clamping the cell to distinct potentials. We established the OVC in muscles and neurons of Caenorhabditis elegans, and transferred it to rat hippocampal neurons in slice culture. Fluorescence signals were calibrated to electrically measured potentials, and wavelengths to currents, enabling to determine optical I/V-relationships. The OVC reports on homeostatically altered cellular physiology in mutants and on Ca2+-channel properties, and can dynamically clamp spiking in C. elegans. Combining non-invasive imaging with control capabilities of electrophysiology, the OVC facilitates high-throughput, contact-less electrophysiology in individual cells and paves the way for true optogenetic control in behaving animals.


Assuntos
Caenorhabditis elegans , Músculos , Animais , Ratos , Caenorhabditis elegans/fisiologia , Potenciais de Ação/fisiologia , Neurônios/fisiologia , Optogenética/métodos
7.
Front Cell Neurosci ; 17: 1120651, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37066081

RESUMO

pH-sensitive fluorescent proteins are widely used to study synaptic vesicle (SV) fusion and recycling. When targeted to the lumen of SVs, fluorescence of these proteins is quenched by the acidic pH. Following SV fusion, they are exposed to extracellular neutral pH, resulting in a fluorescence increase. SV fusion, recycling and acidification can thus be tracked by tagging integral SV proteins with pH-sensitive proteins. Neurotransmission is generally activated by electrical stimulation, which is not feasible in small, intact animals. Previous in vivo approaches depended on distinct (sensory) stimuli, thus limiting the addressable neuron types. To overcome these limitations, we established an all-optical approach to stimulate and visualize SV fusion and recycling. We combined distinct pH-sensitive fluorescent proteins (inserted into the SV protein synaptogyrin) and light-gated channelrhodopsins (ChRs) for optical stimulation, overcoming optical crosstalk and thus enabling an all-optical approach. We generated two different variants of the pH-sensitive optogenetic reporter of vesicle recycling (pOpsicle) and tested them in cholinergic neurons of intact Caenorhabditis elegans nematodes. First, we combined the red fluorescent protein pHuji with the blue-light gated ChR2(H134R), and second, the green fluorescent pHluorin combined with the novel red-shifted ChR ChrimsonSA. In both cases, fluorescence increases were observed after optical stimulation. Increase and subsequent decline of fluorescence was affected by mutations of proteins involved in SV fusion and endocytosis. These results establish pOpsicle as a non-invasive, all-optical approach to investigate different steps of the SV cycle.

8.
Nat Commun ; 13(1): 7827, 2022 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-36535932

RESUMO

Acutely silencing specific neurons informs about their functional roles in circuits and behavior. Existing optogenetic silencers include ion pumps, channels, metabotropic receptors, and tools that damage the neurotransmitter release machinery. While the former hyperpolarize the cell, alter ionic gradients or cellular biochemistry, the latter allow only slow recovery, requiring de novo synthesis. Thus, tools combining fast activation and reversibility are needed. Here, we use light-evoked homo-oligomerization of cryptochrome CRY2 to silence synaptic transmission, by clustering synaptic vesicles (SVs). We benchmark this tool, optoSynC, in Caenorhabditis elegans, zebrafish, and murine hippocampal neurons. optoSynC clusters SVs, observable by electron microscopy. Locomotion silencing occurs with tauon ~7.2 s and recovers with tauoff ~6.5 min after light-off. optoSynC can inhibit exocytosis for several hours, at very low light intensities, does not affect ion currents, biochemistry or synaptic proteins, and may further allow manipulating different SV pools and the transfer of SVs between them.


Assuntos
Optogenética , Vesículas Sinápticas , Animais , Camundongos , Vesículas Sinápticas/metabolismo , Peixe-Zebra , Transmissão Sináptica/fisiologia , Caenorhabditis elegans/genética , Análise por Conglomerados
9.
Adv Radiat Oncol ; 7(5): 100941, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35847550

RESUMO

Background: Enzalutamide is an antiandrogen used to treat both metastatic and nonmetastatic prostate cancer. Here we present results from a phase 2 trial designed to determine the safety, tolerability, and efficacy of adding enzalutamide to standard androgen deprivation therapy with radiation therapy in high-risk localized or regional, nonmetastatic patients with prostate cancer. Methods and Materials: Enrollment criteria included at least 2 of the following: stage cT3a/b, prostate specific antigen (PSA) ≥20 ng/mL, Gleason grade 8 to 10, ≥33% core involvement on biopsy, or pelvic lymph node involvement on computed tomography or magnetic resonance imaging. Patients with metastatic disease were excluded. All patients received 24 months of leuprolide and enzalutamide, and 5 weeks of intensity modulated radiation therapy followed by a brachytherapy boost. Adverse events (AE), PSA, testosterone, and basic laboratory tests were then followed for up to 36 months. Primary outcomes were safety and tolerability and PSA complete response rate (PSA-CR, defined as PSA ≤0.3). Secondary outcomes included time to biochemical recurrence (BCR; nadir + 2 ng/mL). Results: Sixteen patients were enrolled; 2 were ineligible and 3 withdrew before starting treatment. Median age at enrollment was 69.0 years (interquartile range [IQR] 11.5). Median treatment duration was 24.0 months (IQR 11.9). Median follow-up time was 35.5 months (IQR 11.2), and 9 of 11 (81.8%) patients completed the 36 months of follow-up. One of 11 (9%) patients had grade 4 AE (seizure), and no grade 5 AE were reported. Four of 11 (36.4%) patients had grade 3 AE, such as erectile dysfunction and hot flashes. All patients achieved PSA-CR, and median time to PSA-CR was 4.2 months (IQR 1.4). At 24 months follow-up, 0 of 11 (0%) patients had a biochemical recurrence. At 36 months, 1 of 9 (11.1%) patient had a biochemical recurrence. Of note, this patient did not complete the full 24 months of enzalutamide and leuprolide due to AEs. Conclusions: Enzalutamide in combination with standard androgen deprivation therapy and radiation therapy was well-tolerated and effective warranting further study in a randomized controlled trial.

10.
MicroPubl Biol ; 20222022.
Artigo em Inglês | MEDLINE | ID: mdl-35903772

RESUMO

Manipulation of neuronal or muscular activity by optogenetics or other stimuli can be directly linked to the analysis of Caenorhabditis elegans ( C. elegans ) body length. Thus, WormRuler was developed as an open-source video analysis toolbox that offers video processing and data analysis in one application. Utilizing this novel tool, the super red-shifted channelrhodopsin variant, ChrimsonSA, was characterized in C. elegans . Expression and activation of ChrimsonSA in GABAergic motor neurons results in their depolarization and therefore elongation of body length, the extent of which providing information about the strength of neuronal transmission.

11.
Methods Mol Biol ; 2483: 61-76, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35286669

RESUMO

In the past 15 years, optogenetic methods became invaluable tools in neurobiological research but also in general cell biology. Most prominently, optogenetic methods utilize microbial rhodopsins to elicit neuronal de- or hyperpolarization. However, other optogenetic tools have emerged that allow influencing neuronal function by different approaches. In this chapter we describe the use of photoactivated adenylyl cyclases (PACs) as modulators of neuronal activity. Using Caenorhabditis elegans as a model organism, this chapter shows how to measure the effect of PAC photoactivation by behavioral assays in different tissues (neurons and muscles), as well as their significance to neurobiology. Further, this chapter describes in vitro cyclic nucleoside-3',5'-monophosphate measurements (cNMP) to characterize new PACs in C. elegans.


Assuntos
Adenilil Ciclases , Optogenética , Adenilil Ciclases/genética , Animais , Caenorhabditis elegans/genética , Neurônios , Optogenética/métodos , Rodopsinas Microbianas
12.
Methods Mol Biol ; 2468: 89-115, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35320562

RESUMO

Over the past 15 years, optogenetic methods have revolutionized neuroscientific and cell biological research, also in the nematode Caenorhabditis elegans. In this chapter, we give an update about current optogenetic tools and methods to address neuronal activity and inhibition, as well as second messenger signaling, based on microbial rhodopsins. We address channelrhodopsins and variants thereof, which conduct cations or anions, for depolarization and hyperpolarization of the membrane potential. Also, we cover ion pumping rhodopsins, like halorhodopsin, Mac, and Arch. A recent addition to rhodopsin-based optogenetics is voltage imaging tools that allow fluorescent readout of membrane voltage (directly, via fluorescence of the rhodopsin chromophore retinal, or indirectly, via electrochromic FRET). Last, we report on a new addition to the optogenetic toolbox, which is rhodopsin guanylyl cyclases, as well as mutated variants with specificity for cyclic AMP. These can be used to regulate intracellular levels of cGMP and cAMP, which are important second messengers in sensory and other neurons. We further show how they can be combined with cyclic nucleotide-gated channels in two-component optogenetics, for depolarization or hyperpolarization of membrane potential. For all tools, we present protocols for straightforward experimentation to address neuronal activation and inhibition, particularly at the neuromuscular junction, and for combined optogenetic actuation and Ca2+ imaging. We also provide protocols for usage of rhodopsin guanylyl and adenylyl cyclases. Finally, we list a number of points to consider when designing and conducting rhodopsin-based optogenetic experiments.


Assuntos
Rede Nervosa , Optogenética , Rodopsinas Microbianas , Transmissão Sináptica , Rede Nervosa/fisiologia , Neurônios/fisiologia , Optogenética/métodos , Rodopsinas Microbianas/genética
13.
Br J Pharmacol ; 179(11): 2519-2537, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-33733470

RESUMO

BACKGROUND AND PURPOSE: The cyclic nucleotides cAMP and cGMP are ubiquitous second messengers regulating numerous biological processes. Malfunctional cNMP signalling is linked to diseases and thus is an important target in pharmaceutical research. The existing optogenetic toolbox in Caenorhabditis elegans is restricted to soluble adenylyl cyclases, the membrane-bound Blastocladiella emersonii CyclOp and hyperpolarizing rhodopsins; yet missing are membrane-bound photoactivatable adenylyl cyclases and hyperpolarizers based on K+ currents. EXPERIMENTAL APPROACH: For the characterization of photoactivatable nucleotidyl cyclases, we expressed the proteins alone or in combination with cyclic nucleotide-gated channels in muscle cells and cholinergic motor neurons. To investigate the extent of optogenetic cNMP production and the ability of the systems to depolarize or hyperpolarize cells, we performed behavioural analyses, measured cNMP content in vitro, and compared in vivo expression levels. KEY RESULTS: We implemented Catenaria CyclOp as a new tool for cGMP production, allowing fine-control of cGMP levels. We established photoactivatable membrane-bound adenylyl cyclases, based on mutated versions ("A-2x") of Blastocladiella and Catenaria ("Be," "Ca") CyclOp, as N-terminal YFP fusions, enabling more efficient and specific cAMP signalling compared to soluble bPAC, despite lower overall cAMP production. For hyperpolarization of excitable cells by two-component optogenetics, we introduced the cAMP-gated K+ -channel SthK from Spirochaeta thermophila and combined it with bPAC, BeCyclOp(A-2x), or YFP-BeCyclOp(A-2x). As an alternative, we implemented the B. emersonii cGMP-gated K+ -channel BeCNG1 together with BeCyclOp. CONCLUSION AND IMPLICATIONS: We established a comprehensive suite of optogenetic tools for cNMP manipulation, applicable in many cell types, including sensory neurons, and for potent hyperpolarization. LINKED ARTICLES: This article is part of a themed issue on cGMP Signalling in Cell Growth and Survival. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.11/issuetoc.


Assuntos
Nucleotídeos Cíclicos , Optogenética , Adenilil Ciclases/genética , Adenilil Ciclases/metabolismo , Animais , Caenorhabditis elegans/metabolismo , GMP Cíclico/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos/genética , Canais de Cátion Regulados por Nucleotídeos Cíclicos/metabolismo , Minociclina , Nucleotídeos Cíclicos/metabolismo
14.
Nat Commun ; 12(1): 4527, 2021 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-34312384

RESUMO

Optogenetic manipulation of neuronal activity through excitatory and inhibitory opsins has become an indispensable experimental strategy in neuroscience research. For many applications bidirectional control of neuronal activity allowing both excitation and inhibition of the same neurons in a single experiment is desired. This requires low spectral overlap between the excitatory and inhibitory opsin, matched photocurrent amplitudes and a fixed expression ratio. Moreover, independent activation of two distinct neuronal populations with different optogenetic actuators is still challenging due to blue-light sensitivity of all opsins. Here we report BiPOLES, an optogenetic tool for potent neuronal excitation and inhibition with light of two different wavelengths. BiPOLES enables sensitive, reliable dual-color neuronal spiking and silencing with single- or two-photon excitation, optical tuning of the membrane voltage, and independent optogenetic control of two neuronal populations using a second, blue-light sensitive opsin. The utility of BiPOLES is demonstrated in worms, flies, mice and ferrets.


Assuntos
Membrana Celular/fisiologia , Opsinas/metabolismo , Optogenética/métodos , Células Piramidais/fisiologia , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Células Cultivadas , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Feminino , Furões/genética , Furões/metabolismo , Células HEK293 , Hipocampo/citologia , Humanos , Masculino , Potenciais da Membrana/fisiologia , Camundongos Transgênicos , Opsinas/genética , Técnicas de Patch-Clamp/métodos , Células Piramidais/citologia , Células Piramidais/metabolismo , Ratos Wistar , Reprodutibilidade dos Testes
15.
J Neurosci ; 41(19): 4187-4201, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33820857

RESUMO

Release of neuropeptides from dense core vesicles (DCVs) is essential for neuromodulation. Compared with the release of small neurotransmitters, much less is known about the mechanisms and proteins contributing to neuropeptide release. By optogenetics, behavioral analysis, electrophysiology, electron microscopy, and live imaging, we show that synapsin SNN-1 is required for cAMP-dependent neuropeptide release in Caenorhabditis elegans hermaphrodite cholinergic motor neurons. In synapsin mutants, behaviors induced by the photoactivated adenylyl cyclase bPAC, which we previously showed to depend on ACh and neuropeptides (Steuer Costa et al., 2017), are altered as in animals with reduced cAMP. Synapsin mutants have slight alterations in synaptic vesicle (SV) distribution; however, a defect in SV mobilization was apparent after channelrhodopsin-based photostimulation. DCVs were largely affected in snn-1 mutants: DCVs were ∼30% reduced in synaptic terminals, and their contents not released following bPAC stimulation. Imaging axonal DCV trafficking, also in genome-engineered mutants in the serine-9 protein kinase A phosphorylation site, showed that synapsin captures DCVs at synapses, making them available for release. SNN-1 colocalized with immobile, captured DCVs. In synapsin deletion mutants, DCVs were more mobile and less likely to be caught at release sites, and in nonphosphorylatable SNN-1B(S9A) mutants, DCVs traffic less and accumulate, likely by enhanced SNN-1 dependent tethering. Our work establishes synapsin as a key mediator of neuropeptide release.SIGNIFICANCE STATEMENT Little is known about mechanisms that regulate how neuropeptide-containing dense core vesicles (DCVs) traffic along the axon, how neuropeptide release is orchestrated, and where it occurs. We found that one of the longest known synaptic proteins, required for the regulation of synaptic vesicles and their storage in nerve terminals, synapsin, is also essential for neuropeptide release. By electrophysiology, imaging, and electron microscopy in Caenorhabditis elegans, we show that synapsin regulates this process by tethering the DCVs to the cytoskeleton in axonal regions where neuropeptides are to be released. Without synapsin, DCVs cannot be captured at the release sites and, consequently, cannot fuse with the membrane, and neuropeptides are not released. We suggest that synapsin fulfills this role also in vertebrates, including humans.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/fisiologia , AMP Cíclico/metabolismo , Neuropeptídeos/metabolismo , Sinapsinas/genética , Sinapsinas/fisiologia , Vesículas Sinápticas/fisiologia , Animais , Animais Geneticamente Modificados , Comportamento Animal , Caenorhabditis elegans , Fenômenos Eletrofisiológicos , Mutação , Optogenética , Estimulação Luminosa , Terminações Pré-Sinápticas , Transmissão Sináptica/genética , Vesículas Sinápticas/genética
16.
Int J Radiat Oncol Biol Phys ; 110(2): 429-437, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33385496

RESUMO

PURPOSE: To perform a propensity-score matched analysis comparing stereotactic body radiation therapy (SBRT) boost and high-dose-rate (HDR) boost for localized prostate cancer. METHODS AND MATERIALS: A single-institution retrospective chart review was conducted of men treated with pelvic external beam radiation therapy (EBRT) and SBRT boost (21 Gy and 19 Gy in 2 fractions) to the prostate for prostate cancer. A cohort treated at the same institution with HDR brachytherapy boost (19 Gy in 2 fractions) was compared. Propensity-score (PS) matching and multivariable Cox regression were used for analysis. Outcomes were biochemical recurrence freedom (BCRF) and metastasis freedom (MF). RESULTS: One hundred thirty-one men were treated with SBRT boost and 101 with HDR boost with median follow-up of 73.4 and 186.0 months, respectively. In addition, 68.8% of men had high-risk and 26.0% had unfavorable-intermediate disease, and 94.3% received androgen deprivation therapy. Five- and 10-year unadjusted BCRF was 88.8% and 85.3% for SBRT and 91.8% and 74.6% for HDR boost (log-rank P = .3), and 5- and 10-year unadjusted MF was 91.7% and 84.3% for SBRT and 95.8% and 82.0% for HDR (log-rank P = .8). After adjusting for covariates, there was no statistically significant difference in BCRF (hazard ratio [HR] 0.81; 95% confidence interval [CI], 0.37-1.79; P = .6) or MF (HR 1.07; 95% CI, 0.44-2.57; P = .9) between SBRT and HDR boost. Similarly, after PS matching, there was no statistically significant difference between SBRT and HDR (BCRF: HR 0.66, 0.27-1.62, P = .4; MF: HR 0.84, 0.31-2.26, P = .7). Grade 3+ genitourinary and gastrointestinal toxicity in the SBRT cohort were 4.6% and 1.5%, and 3.0% and 0.0% in the HDR cohorts (P = .4, Fisher exact test). CONCLUSIONS: SBRT boost plus pelvic EBRT for prostate cancer resulted in similar BCRF and MF to HDR boost in this single institution, PS matched retrospective analysis. Toxicity was modest. Prospective evaluation of SBRT boost for the treatment of unfavorable-intermediate and high-risk prostate cancer is warranted.


Assuntos
Braquiterapia/métodos , Neoplasias da Próstata/radioterapia , Radiocirurgia , Radioterapia de Intensidade Modulada , Idoso , Antagonistas de Androgênios/uso terapêutico , Anilidas/uso terapêutico , Braquiterapia/efeitos adversos , Estudos de Coortes , Terapia Combinada/métodos , Intervalos de Confiança , Fracionamento da Dose de Radiação , Humanos , Leuprolida/uso terapêutico , Masculino , Pessoa de Meia-Idade , Nitrilas/uso terapêutico , Pontuação de Propensão , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Radiocirurgia/efeitos adversos , Radioterapia de Intensidade Modulada/efeitos adversos , Análise de Regressão , Estudos Retrospectivos , Compostos de Tosil/uso terapêutico
17.
JAMA Netw Open ; 3(9): e209750, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32997124

RESUMO

Importance: The association of guideline-based decision support with the quality of care in patients with non-small cell lung cancer (NSCLC) is not known. Objective: To evaluate the association of exposure to the National Comprehensive Cancer Center (NCCN) guidelines with guideline-concordant care and patients' decisional conflict. Design, Setting, and Participants: A nonrandomized clinical trial, conducted at a tertiary care academic institution, enrolled patients from February 23, 2015, to September 28, 2017. Data analysis was conducted from July 19, 2019, to April 22, 2020. A cohort of 76 patients with NSCLC seen at diagnosis or disease progression and a retrospective cohort of 157 patients treated before the trial were included. Adherence to 6 NCCN recommendations were evaluated: (1) smoking cessation counseling, (2) adjuvant chemotherapy for patients with stage IB to IIB NSCLC after surgery, (3) pathologic mediastinal staging in patients with stage III NSCLC before surgery, (4) pathologic mediastinal staging in patients with stage III NSCLC before nonsurgical treatment, (5) definitive chemoradiotherapy for patients with stage III NSCLC not having surgery, and (6) molecular testing for epidermal growth factor receptor and anaplastic lymphoma kinase alterations for patients with stage IV NSCLC. Subgroup analysis was conducted to compare the rates of guideline concordance between the prospective and retrospective cohorts. Secondary end points included decisional conflict and satisfaction. Interventions: An online tool customizing the NCCN guidelines to patients' clinical and pathologic features was used during consultation, facilitated by a trained coordinator. Main Outcomes and Measures: Concordance of practice with 6 NCCN treatment recommendations on NSCLC and patients' decisional conflict. Results: Of the 76 patients with NSCLC, 44 were men (57.9%), median age at diagnosis was 68 years (interquartile range [IQR], 41-87 years), and 59 patients (77.6%) had adenocarcinoma. In the retrospective cohort, 91 of 157 patients (58.0%) were men, median age at diagnosis was 66 years (IQR, 61-65 years), and 105 patients (66.9%) had adenocarcinoma. After the intervention, patients received more smoking cessation counseling (4 of 5 [80.0%] vs 1 of 24 [4.2%], P < .001) and less adjuvant chemotherapy (0 of 7 vs 7 of 11 [63.6%]; P = .012). There was no significant change in mutation testing of non-squamous cell stage IV disease (20 of 20 [100%] vs 48 of 57 [84.2%]; P = .10). There was no significant change in pathologic mediastinal staging or initial chemoradiotherapy for patients with stage III disease. After consultation with the tool, decisional conflict scores improved by a median of 20 points (IQR, 3-34; P < .001). Conclusions and Relevance: The findings of this study suggest that exposure to the NCCN guidelines is associated with increased guideline-concordant care for 2 of 6 preselected recommendations and improvement in decisional conflict. Trial Registration: ClinicalTrials.gov Identifier: NCT03982459.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Sistemas de Apoio a Decisões Clínicas , Neoplasias Pulmonares , Qualidade de Vida , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/psicologia , Adenocarcinoma de Pulmão/terapia , Idoso , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/psicologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Assistência Integral à Saúde/métodos , Assistência Integral à Saúde/normas , Técnicas de Apoio para a Decisão , Feminino , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/psicologia , Neoplasias Pulmonares/terapia , Masculino , Estadiamento de Neoplasias/métodos , Satisfação do Paciente , Guias de Prática Clínica como Assunto , Prognóstico , Qualidade da Assistência à Saúde/normas , Avaliação de Sintomas/métodos
18.
Sci Rep ; 10(1): 9929, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32555288

RESUMO

Sleep and wakefulness are fundamental behavioral states of which the underlying molecular principles are becoming slowly elucidated. Transitions between these states require the coordination of multiple neurochemical and modulatory systems. In Caenorhabditis elegans sleep occurs during a larval transition stage called lethargus and is induced by somnogenic neuropeptides. Here, we identify two opposing neuropeptide/receptor signaling pathways: NLP-22 promotes behavioral quiescence, whereas NLP-2 promotes movement during lethargus, by signaling through gonadotropin-releasing hormone (GnRH) related receptors. Both NLP-2 and NLP-22 belong to the RPamide neuropeptide family and share sequence similarities with neuropeptides of the bilaterian GnRH, adipokinetic hormone (AKH) and corazonin family. RPamide neuropeptides dose-dependently activate the GnRH/AKH-like receptors GNRR-3 and GNRR-6 in a cellular receptor activation assay. In addition, nlp-22-induced locomotion quiescence requires the receptor gnrr-6. By contrast, wakefulness induced by nlp-2 overexpression is diminished by deletion of either gnrr-3 or gnrr-6. nlp-2 is expressed in a pair of olfactory AWA neurons and cycles with larval periodicity, as reported for nlp-22, which is expressed in RIA. Our data suggest that the somnogenic NLP-22 neuropeptide signals through GNRR-6, and that both GNRR-3 and GNRR-6 are required for the wake-promoting action of NLP-2 neuropeptides.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiologia , Hormônio Liberador de Gonadotropina/metabolismo , Neuropeptídeos/farmacologia , Receptores LHRH/metabolismo , Sono/fisiologia , Vigília/fisiologia , Animais , Caenorhabditis elegans/efeitos dos fármacos , Proteínas de Caenorhabditis elegans/genética , Hormônio Liberador de Gonadotropina/genética , Receptores LHRH/genética , Sono/efeitos dos fármacos , Vigília/efeitos dos fármacos
19.
Proc Natl Acad Sci U S A ; 117(11): 6178-6188, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32123108

RESUMO

The nervous system evaluates environmental cues and adjusts motor output to ensure navigation toward a preferred environment. The nematode Caenorhabditis elegans navigates in the thermal environment and migrates toward its cultivation temperature by moving up or down thermal gradients depending not only on absolute temperature but on relative difference between current and previously experienced cultivation temperature. Although previous studies showed that such thermal context-dependent opposing migration is mediated by bias in frequency and direction of reorientation behavior, the complete neural pathways-from sensory to motor neurons-and their circuit logics underlying the opposing behavioral bias remain elusive. By conducting comprehensive cell ablation, high-resolution behavioral analyses, and computational modeling, we identified multiple neural pathways regulating behavioral components important for thermotaxis, and demonstrate that distinct sets of neurons are required for opposing bias of even single behavioral components. Furthermore, our imaging analyses show that the context-dependent operation is evident in sensory neurons, very early in the neural pathway, and manifested by bidirectional responses of a first-layer interneuron AIB under different thermal contexts. Our results suggest that the contextual differences are encoded among sensory neurons and a first-layer interneuron, processed among different downstream neurons, and lead to the flexible execution of context-dependent behavior.


Assuntos
Comportamento Animal/fisiologia , Caenorhabditis elegans/fisiologia , Interneurônios/fisiologia , Navegação Espacial/fisiologia , Termorreceptores/fisiologia , Animais , Técnicas de Observação do Comportamento , Locomoção/fisiologia , Vias Neurais/fisiologia , Temperatura , Sensação Térmica/fisiologia
20.
Int J Radiat Oncol Biol Phys ; 107(1): 48-61, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32001383

RESUMO

PURPOSE: To perform a systematic review and pooled meta-analysis of adrenal metastasis stereotactic body radiation therapy (SBRT) outcomes, treatment characteristics, and toxicity to define the efficacy and propose guidelines for intervention. METHODS AND MATERIALS: We performed a comprehensive literature search of the Embase and PubMed databases of studies reporting outcome or toxicity data for photon-based SBRT of adrenal metastases in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We then conducted a meta-analysis to estimate pooled overall response, local control (LC), and overall survival and analyzed these outcomes in the context of dosimetric parameters and toxicity using metaregression. RESULTS: Thirty-nine studies published between 2009 and 2019 reporting outcomes on 1006 patients were included. The median follow-up was 12 months, and the median biological equivalent dose (BED10, alpha/beta = 10) was 67 Gy. The pooled overall response was 54.6% (95% confidence interval [CI], 46.5%-62.5%). The pooled 1- and 2-year rates of LC were 82% (95% CI, 74%-88%) and 63% (95% CI, 50%-74%), respectively, and the pooled 1- and 2-year overall survival rates were 66% (95% CI, 57%-74%) and 42% (95% CI, 31%-53%), respectively. There was a strong positive association between SBRT dose and 1- and 2-year LC (P < .0001, P = .0002) and an association with 2-year OS (P = .03). Based on a metaregression of dose and LC, BED10 of 60 Gy, 80 Gy, and 100 Gy predicted 1-year LC of 70.5%, 84.8%, and 92.9% and 2-year LC of 47.8%, 70.1%, and 85.6%, respectively. The overall rate of grade 3 or higher toxicity was 1.8%. CONCLUSIONS: SBRT of adrenal metastases provides good 1-year LC with an excellent safety profile, and dose escalation may be associated with improved LC. Prospective studies are needed to validate these findings and determine whether there are subsets of patients for whom adrenal metastasis-directed SBRT may confer a survival advantage.


Assuntos
Neoplasias das Glândulas Suprarrenais/radioterapia , Neoplasias das Glândulas Suprarrenais/secundário , Radiocirurgia , Humanos , Medidas de Resultados Relatados pelo Paciente , Radiocirurgia/efeitos adversos , Segurança
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