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1.
Neurología (Barc., Ed. impr.) ; 39(4): 329-339, May. 2024. ilus, tab, graf
Artigo em Inglês | IBECS | ID: ibc-VR-491

RESUMO

Introduction: In the present study, anticonvulsant effects of aqueous extract (AE), hydro-alcoholic crude extract (HE), and its fractions (F-CHCl3, F-EtOAc, F-MeOH) of Paeonia daurica subsp. macrophylla (P. daurica ssp. macrophylla) root examined by using a pentylenetetrazol-induced model (PTZ) on mice. Methods: HE and its fractions as well as AE, in concentrations of (100, 200 and 400 mg/kg), valproate (Val) (100 and 200 mg/kg), and saline (negative control) (10 mg/kg) were injected intraperitoneally (i.p.) 30 min before PTZ (80 mg/kg, i.p.). The time taken before the onset of myoclonic convulsions (MC), MC duration, time taken before the onset of generalized tonic-clonic seizures (GTCS), the duration of GTCS, and the percentage of GTCS and mortality protection recorded. The plant's anticonvulsant mechanisms were assessed using flumazenil (5 mg/kg, i.p.) before AE (100, 200, and 400 mg/kg, i.p.) injection. GraphPad Prism software was used to compare the differences between various treatment groups with one-way analysis of variance (ANOVA) followed by Tukey–Krammer multiple comparison tests. Results: All the plant samples except F-EtOAc significantly delayed the onset and decreased the duration of PTZ-induced MCS and GTCS, and significantly reduced the GTCS and mortality rate. Pretreatment with flumazenil diminished the significant anticonvulsant effects of AE against PTZ-induced seizures. Conclusions: It can report that extract of P. daurica ssp. macrophylla might be a helpful guide for future studies in the treatment of epilepsy.(AU)


Introducción: Epilepsia es el término usado para un grupo de trastornos caracterizado por las convulsiones espontáneas recurrentes. Un estudio enfocado en los productos naturales de los recursos tradicionales ofrece ventajas significativas que se están utilizando de manera más amplia en modelos animales de epilepsia y candidatos a mayor desarrollo clínico y sus fracciones (F-CHCl3, F-EtOAc, F-MeOH) de Paeonia daurica subsp. macrophylla (P. daurica ssp. macrophylla) raíz examinada utilizando un modelo inducido por pentilentetrazol (PTZ) en ratones. Métodos: La maceración dinámica utilizada para extraer HE de la planta y técnica de cromatografía en columna de sílice utilizada para obtener F-CHCl3, F-EtOAc, así como fracciones de F-MeOH. La extracción de raíces secas se utilizó con agua destilada y se provocó AE. Las muestras de plantas (100, 200 y 400 mg/kg), valproato (Val) (100 y 200 mg/kg) y suero (control negativo) se inyectaron por vía intraperitoneal (ip) 30 min antes de PTZ (80 mg/kg, ip). El tiempo transcurrido antes del comienzo de convulsiones mioclónicas (MC), duración de las MC, tiempo transcurrido antes del comienzo de convulsiones tónico-clónicas generalizadas (GTCS), la duración de GTCS, así como el porcentaje de GTCS y protección contra la mortalidad registrada. Los mecanismos anticonvulsivos de planta fueron evaluados mediante el uso de flumazenil (5 mg/kg, ip) antes de AE (100, 200 y 400 mg/kg, ip) inyección. Se utilizaba el software GraphPad Prism® comparando las diferencias entre varios grupos de tratamiento con un análisis unilateral de variación (ANOVA) seguido por las pruebas de comparación múltiple de Tukey's Krammer. Resultados: Todas las muestras de plantas, excepto F-EtOAc, retrasaron de manera considerable el inicio, y disminuyeron la duración de PTZ inducidos por MCS y GTCS, y redujo significativamente el GTCS, así como la tasa de mortalidad...(AU)


Assuntos
Animais , Anticonvulsivantes , Convulsões , Epilepsia/tratamento farmacológico , Flumazenil/uso terapêutico , Receptores de GABA , Paeonia , Neurologia , Doenças do Sistema Nervoso , Modelos Animais
2.
Pestic Biochem Physiol ; 200: 105843, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38582603

RESUMO

Isoxazoline is a novel structure with strong potential for controlling agricultural insect pests, but its high toxicity to honeybees limits its development in agriculture. Herein, a series of N-phenylamide isoxazoline derivatives with low honeybee toxicity were designed and synthesized using the intermediate derivatization method. Bioassay results showed that these compounds exhibited good insecticidal activity. Compounds 3b and 3f showed significant insecticidal effects against Plutella xylostella (P. xylostella) with median lethal concentrations (LC50) of 0.06 and 0.07 mg/L, respectively, comparable to that of fluralaner (LC50 = 0.02 mg/L) and exceeding that of commercial insecticide fluxametamide (LC50 = 0.52 mg/L). It is noteworthy that the acute honeybee toxicities of compounds 3b and 3f (LD50 = 1.43 and 1.63 µg/adult, respectively) were significantly reduced to 1/10 of that of fluralaner (LD50 = 0.14 µg/adult), and were adequate or lower than that of fluxametamide (LD50 = 1.14 µg/adult). Theoretical simulation using molecular docking indicates that compound 3b has similar binding modes with fluralaner and a similar optimal docking pose with fluxametamide when binding to the GABA receptor, which may contribute to its potent insecticidal activity and relatively low toxicity to honey bees. This study provides compounds 3b and 3f as potential new insecticide candidates and provides insights into the development of new isoxazoline insecticides exhibiting both high efficacy and environmental safety.


Assuntos
Inseticidas , Mariposas , Abelhas , Animais , Inseticidas/toxicidade , Inseticidas/química , Simulação de Acoplamento Molecular , Insetos , Receptores de GABA/metabolismo , Amidas/toxicidade , Mariposas/metabolismo
3.
Neurosci Lett ; 828: 137766, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38583505

RESUMO

INTRODUCTION: The neuroimmune system performs a wide range of functions in the brain and the central nervous system. The microglial translocator protein (TSPO) has an established role as a cell marker in identification of the neuroimmune system. Previously, human studies have shown TSPO differences in neuropsychiatric disorders. Seasonal variability has also been demonstrated in multiple systems of healthy individuals. Therefore, in this study, we attempt to understand whether seasonal changes affect brain TSPO levels using [11C]PBR28 positron emission tomography (PET) imaging. METHODS: 46 healthy subjects (mean age ± SD = 32.5 ± 10); sex (M/F) = 32/14)) underwent PET imaging with [11C]PBR28 in a retrospectively conducted analysis. All PET scans were performed on the HRRT scanner. Volume of distribution (VT) values were generated for cortical and subcortical regions and the cerebellum. Spring/summer months were defined as March to August while fall/winter months were defined as September to February and were compared through 2-tailed t-tests (SciPy library v.1.10.1 and Pinguoin library on Python v.3.8.8). Average daylight hours and temperature in New Haven, CT were obtained online (www.wunderground.com) and compared to VT with Spearman's correlations. RESULTS: There were no significant differences observed between the TSPO levels of spring/summer and fall/winter months in the brain (t = 0.52, p = 0.61). Additional analysis on all individual brain regions also indicated non-significance. Likewise, no significant correlations were found between TSPO levels in the whole brain and brain regions against daylight hours (ρ= 0.05, p = 0.74), temperature (ρ = 0.04, p = 0.81), or month (ρ = 0.08, p = 0.60). Controlling TSPO gene polymorphisms and other variables had no significant effect on the outcome. CONCLUSION: To the best of our knowledge, this is the first human study to investigate seasonal changes in TSPO expression. Our results can be interpreted as the lack of seasonal variability in the neuroimmune system, but important limitations include high interindividual variability, test-retest variability, specificity of the tracer, and a limited sample size. Limitations notwithstanding, our results conclude that TSPO levels in the brain are not impacted by light and temperature changes in different seasons.


Assuntos
Encéfalo , Receptores de GABA , Humanos , Estações do Ano , Estudos Retrospectivos , Receptores de GABA/metabolismo , Encéfalo/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Proteínas de Transporte/metabolismo
4.
J Integr Neurosci ; 23(3): 51, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38538228

RESUMO

BACKGROUND: The flavonoid chrysin produces rapid and long-lasting anxiolytic- and antidepressant-like effects in rats. However, it is not known whether low and high doses of chrysin produce differential anti-immobility effects through the Gamma-Aminobutyric Acid sub-type A (GABAA) receptor. The goal of this work was therefore to compare low and high doses of chrysin for their effects on depression-like behavior in a longitudinal study. Moreover, chrysin was compared with the serotonergic fluoxetine and Gamma-Aminobutyric Acid (GABA)ergic allopregnanolone, and its involvement with the GABAA receptor after chronic treatment was also investigated. METHODS: Male Wistar rats were assigned to five groups (n = 8 each): vehicle, 1 mg/kg chrysin, 5 mg/kg chrysin, 1 mg/kg fluoxetine, and 1 mg/kg allopregnanolone. In the first experiment, treatments were injected daily and the effects on locomotor activity and the forced swim test were evaluated at 0, 1, 14, and 28 days of treatment, and 48 h after the final treatment. In the second experiment, similar groups were treated for 28 days with injection of 1 mg/kg picrotoxin to investigate the role of the GABAA receptor. Depending on the experimental design, one- and two-way analysis of variance (ANOVA) tests were used for statistical analysis, with p < 0.05 set as the criteria for significance. RESULTS: In both experiments, the treatments did not alter locomotor activity. However, low and high doses of chrysin, allopregnanolone, and fluoxetine gradually produced antidepressant-like effects in the forced swim test, and maintained this effect for 48 h post-treatment, except with low dose chrysin. Picrotoxin blocked the antidepressant-like effects produced by low dose chrysin, but did not affect those produced by high dose chrysin, allopregnanolone, or fluoxetine. CONCLUSIONS: The differential antidepressant-like effects caused by low and high doses of chrysin are time-dependent. Low dose chrysin produces a rapid antidepressant-like effect, whereas high dose chrysin produces a delayed but sustained the effect, even 48 h after withdrawal. The effect with high dose chrysin was similar to that observed with allopregnanolone and fluoxetine. The mechanism for the antidepressant-like effect of low chrysin appears to be GABAergic, whereas the effect of high dose chrysin may involve other neurotransmission and neuromodulation systems related to the serotonergic system.


Assuntos
Fluoxetina , Receptores de GABA-A , Ratos , Masculino , Animais , Fluoxetina/farmacologia , Pregnanolona , Ratos Wistar , Receptores de GABA , Picrotoxina , Estudos Longitudinais , Antidepressivos/farmacologia , Flavonoides/farmacologia , Ácido gama-Aminobutírico
5.
Radiology ; 310(3): e230397, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38441089

RESUMO

Background Translocator protein (TSPO) PET has been used to visualize microglial activation in neuroinflammation and is a potential imaging tool for detecting autoimmune encephalitis (AIE). Purpose To compare the detection rate between TSPO radioligand fluorine 18 (18F) DPA-714 PET and conventional MRI and assess the relationship between 18F-DPA-714 uptake and clinical features in participants with AIE. Materials and Methods Healthy volunteers and patients with AIE were enrolled in this prospective study between December 2021 and April 2023. All participants underwent hybrid brain 18F-DPA-714 PET/MRI and antibody testing. Modified Rankin scale scoring and AIE-related symptoms were assessed in participants with AIE. Positive findings were defined as intensity of 18F-DPA-714 uptake above a threshold of the mean standardized uptake value ratio (SUVR) plus 2 SD inside the corresponding brain regions of healthy controls. The McNemar test was used to compare the positive detection rate between the two imaging modalities; the independent samples t test was used to compare continuous variables; and correlation with Bonferroni correction was used to assess the relationship between 18F-DPA-714 uptake and clinical features. Results A total of 25 participants with AIE (mean age, 39.24 years ± 19.03 [SD]) and 10 healthy controls (mean age, 28.70 years ± 5.14) were included. The positive detection rate of AIE was 72% (18 of 25) using 18F-DPA-714 PET compared to 44% (11 of 25) using conventional MRI, but the difference was not statistically significant (P = .065). Participants experiencing seizures exhibited significantly higher mean SUVR in the entire cortical region than those without seizures (1.23 ± 0.21 vs 1.15 ± 0.18; P = .003). Of the 13 participants with AIE who underwent follow-up PET/MRI, 11 (85%) demonstrated reduced uptake of 18F-DPA-714 accompanied by relief of symptoms after immunosuppressive treatment. Conclusion 18F-DPA-714 PET has potential value in supplementing MRI for AIE detection. Clinical trial registration no. NCT05293405 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Zaharchuk in this issue.


Assuntos
Doenças Autoimunes do Sistema Nervoso , Encefalite , Doença de Hashimoto , Microglia , Pirazóis , Pirimidinas , Humanos , Adulto , Estudos Prospectivos , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Convulsões , Receptores de GABA
6.
Methods Mol Biol ; 2785: 177-193, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427195

RESUMO

This paper provides an overview of the role of neuroinflammation in Alzheimer's disease and other neurodegenerative diseases, highlighting the potential of anti-inflammatory treatments to slow or prevent decline. This research focuses on the use of positron emission tomography (PET) imaging to visualize and quantify molecular brain changes in patients, specifically microglial activation and reactive astrogliosis. We discuss the development and application of several PET radioligands, including first-generation ligands like PK11195 and Ro5-4864, as well as second- and third-generation ligands such as [11C]PBR28, [18F]DPA-714, [18F]GE-180, and [11C]ER176. These ligands target the 18-kDa translocator protein (TSPO), which is overexpressed in activated microglia and upregulated in astrocytes. We also address the limitations of these ligands, such as low brain uptake, poor penetration of the blood-brain barrier, short half-life, and variable kinetic behavior. Furthermore, we demonstrate the impact of genetic polymorphisms on ligand binding.


Assuntos
Doença de Alzheimer , Doenças Neuroinflamatórias , Humanos , Receptores de GABA/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Doença de Alzheimer/metabolismo , Ligantes , Microglia/metabolismo
7.
Pestic Biochem Physiol ; 199: 105776, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38458683

RESUMO

γ-Aminobutyric acid receptors (GABARs) are crucial targets for pest control chemicals, including meta-diamide and isoxazoline insecticides, which act as negative allosteric modulators of insect GABARs. Previous cell-based assays have indicated that amino acid residues in the transmembrane cavity between adjacent subunits of Drosophila RDL GABAR (i.e., Ile276, Leu280, and Gly335) are involved in mediating the action of meta-diamides. In this study, to confirm this result at the organismal level, we employed CRISPR/Cas9-mediated genome editing, generated six transgenic Drosophila strains carrying substitutions in these amino acid residues, and investigated their sensitivity to broflanilide and isocycloseram. Flies homozygous for the I276F mutation did not exhibit any change in sensitivity to the tested insecticides compared to the control flies. Conversely, I276C homozygosity was lethal, and heterozygous flies exhibited ∼2-fold lower sensitivity to broflanilide than the control flies. Flies homozygous for the L280C mutation survived into adulthood but exhibited infertility. Both heterozygous and homozygous L280C flies exhibited ∼3- and âˆ¼20-fold lower sensitivities to broflanilide and isocycloseram, respectively, than the control flies. The reduction in sensitivity to isocycloseram in L280C flies diminished to ∼3-fold when treated with piperonyl butoxide. Flies homozygous for the G335A mutation reached the adult stage. However, they were sterile, had small bodies, and exhibited reduced locomotion, indicating the critical role of Gly335 in RDL function. These flies exhibited markedly increased tolerance to topically applied broflanilide and isocycloseram, demonstrating that the conserved Gly335 is the target of the insecticidal actions of broflanilide and isocycloseram. Considering the significant fitness costs, the Gly335 mutation may not pose a serious risk for the development of resistance in field populations of insect pests. However, more careful studies using insect pests are needed to investigate whether our perspective applies to resistance development under field conditions.


Assuntos
Benzamidas , Proteínas de Drosophila , Fluorocarbonos , Inseticidas , Animais , Receptores de GABA/genética , Receptores de GABA/metabolismo , Drosophila/genética , Drosophila/metabolismo , Inseticidas/farmacologia , Inseticidas/química , Glicina/farmacologia , Mutagênese , Resistência a Inseticidas/genética , Receptores de GABA-A/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo
8.
Cells ; 13(4)2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38391931

RESUMO

Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central nervous system (CNS). Most GABAergic neurons synthesize GABA from glutamate and release it in the synaptic cleft in the CNS. However, astrocytes can also synthesize and release GABA, activating GABA receptors in the neighboring neurons in physiological and pathological conditions. As the primary homeostatic glial cells in the brain, astrocytes play a crucial role in regulating GABA homeostasis and synaptic neurotransmission. Accumulating evidence demonstrates that astrocytic GABA dysregulation is implicated in psychiatric disorders, including alcohol use disorder (AUD) and major depressive disorder (MDD), the most prevalent co-occurring psychiatric disorders. Several current medications and emerging pharmacological agents targeting GABA levels are in clinical trials for treating AUD and MDD. This review offers a concise summary of the role of astrocytic GABA regulation in AUD and MDD. We also provide an overview of the current understanding and areas of debate regarding the mechanisms by which astrocytes regulate GABA in the CNS and their potential significance in the molecular basis of AUD and MDD, paving the way toward future research directions and potential therapeutic target areas within this field.


Assuntos
Transtorno Depressivo Maior , Humanos , Astrócitos/fisiologia , Ácido gama-Aminobutírico , Receptores de GABA , Neurônios GABAérgicos
9.
FEBS Lett ; 598(4): 477-484, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38302739

RESUMO

Niemann-Pick type C disease (NPCD) is a rare neurodegenerative disorder most commonly caused by mutations in the lysosomal protein Niemann-Pick C1 (NPC1), which is implicated in cholesterol export. Mitochondrial insufficiency forms a significant feature of the pathology of this disease, yet studies attempting to address this are rare. The working hypothesis is that mitochondria become overloaded with cholesterol which renders them dysfunctional. We examined two potential protein targets-translocator protein (TSPO) and steroidogenic acute regulatory protein D1 (StARD1)-which are implicated in cholesterol transport to mitochondria, in addition to glucocerbrosidase 2 (GBA2), the target of miglustat, which is currently the only approved treatment for NPCD. However, inhibiting these proteins did not correct the mitochondrial defect in NPC1-deficient cells.


Assuntos
Doenças Mitocondriais , Doença de Niemann-Pick Tipo C , Fosfoproteínas , Humanos , Glucosilceramidase/genética , Glucosilceramidase/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Doença de Niemann-Pick Tipo C/tratamento farmacológico , Doença de Niemann-Pick Tipo C/genética , Doença de Niemann-Pick Tipo C/metabolismo , Colesterol/metabolismo , Proteína C1 de Niemann-Pick/metabolismo , Receptores de GABA/metabolismo
10.
Brain ; 147(4): 1321-1330, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38412555

RESUMO

The pathophysiological underpinnings of critically disrupted brain connectomes resulting in coma are poorly understood. Inflammation is potentially an important but still undervalued factor. Here, we present a first-in-human prospective study using the 18-kDa translocator protein (TSPO) radioligand 18F-DPA714 for PET imaging to allow in vivo neuroimmune activation quantification in patients with coma (n = 17) following either anoxia or traumatic brain injuries in comparison with age- and sex-matched controls. Our findings yielded novel evidence of an early inflammatory component predominantly located within key cortical and subcortical brain structures that are putatively implicated in consciousness emergence and maintenance after severe brain injury (i.e. mesocircuit and frontoparietal networks). We observed that traumatic and anoxic patients with coma have distinct neuroimmune activation profiles, both in terms of intensity and spatial distribution. Finally, we demonstrated that both the total amount and specific distribution of PET-measurable neuroinflammation within the brain mesocircuit were associated with the patient's recovery potential. We suggest that our results can be developed for use both as a new neuroprognostication tool and as a promising biometric to guide future clinical trials targeting glial activity very early after severe brain injury.


Assuntos
Lesões Encefálicas , Coma Pós-Traumatismo da Cabeça , Humanos , Coma/complicações , Coma Pós-Traumatismo da Cabeça/complicações , Estudos Prospectivos , Imageamento por Ressonância Magnética/métodos , Encéfalo/metabolismo , Lesões Encefálicas/complicações , Hipóxia/complicações , Receptores de GABA/metabolismo
11.
Alzheimers Dement ; 20(4): 2397-2407, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38298155

RESUMO

INTRODUCTION: Evidence suggests microglial activation precedes regional tau and neurodegeneration in Alzheimer's disease (AD). We characterized microglia with translocator protein (TSPO) positron emission tomography (PET) within an AD progression model where global amyloid beta (Aß) precedes local tau and neurodegeneration, resulting in cognitive impairment. METHODS: Florbetaben, PBR28, and MK-6240 PET, T1 magnetic resonance imaging, and cognitive measures were performed in 19 cognitively unimpaired older adults and 22 patients with mild cognitive impairment or mild AD to examine associations among microglia activation, Aß, tau, and cognition, adjusting for neurodegeneration. Mediation analyses evaluated the possible role of microglial activation along the AD progression model. RESULTS: Higher PBR28 uptake was associated with higher Aß, higher tau, and lower MMSE score, independent of neurodegeneration. PBR28 mediated associations between tau in early and middle Braak stages, between tau and neurodegeneration, and between neurodegeneration and cognition. DISCUSSION: Microglia are associated with AD pathology and cognition and may mediate relationships between subsequent steps in AD progression.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Idoso , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Microglia/metabolismo , Proteínas tau/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Disfunção Cognitiva/metabolismo , Progressão da Doença , Receptores de GABA/metabolismo
12.
Nucl Med Biol ; 128-129: 108878, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38324923

RESUMO

OBJECTIVE: Diabetic patients often experience chronic inflammation and fibrosis in their cardiac tissues, highlighting the pressing need for the development of sensitive diagnostic methods for longitudinal assessment of diabetic cardiomyopathy. This study aims to evaluate the significance of an inflammatory marker known as translocator protein (TSPO) in a positron emission tomography (PET) protocol for longitudinally monitoring cardiac dysfunction in a diabetic animal model. Additionally, we compared the commonly used radiotracer, 18F-fluoro-2-deoxy-d-glucose (18F-FDG). METHODS: Fourteen 7-week-old female Sprague-Dawley rats were used in this study. Longitudinal PET experiments were conducted using 18F-N-2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide (18F-FEPPA) (n = 3), the TSPO radiotracer, and 18F-FDG (n = 3), both before and after the onset of diabetes. Histological and immunohistochemical staining assays were also conducted in both the control (n = 4) and diabetes (n = 4) groups. RESULTS: Results indicated a significant increase in cardiac tissue uptake of 18F-FEPPA after the onset of diabetes (P < 0.05), aligning with elevated TSPO levels observed in diabetic animals according to histological data. Conversely, the uptake of 18F-FDG in cardiac tissue significantly decreased after the onset of diabetes (P < 0.05). CONCLUSION: These findings suggest that 18F-FEPPA can function as a sensitive probe for detecting chronic inflammation and fibrosis in the cardiac tissues of diabetic animals.


Assuntos
Diabetes Mellitus Tipo 1 , Cardiomiopatias Diabéticas , Humanos , Ratos , Feminino , Animais , Fluordesoxiglucose F18 , Compostos Radiofarmacêuticos , Ratos Sprague-Dawley , Tomografia por Emissão de Pósitrons , Inflamação , Fibrose , Receptores de GABA/metabolismo
13.
Ann Nucl Med ; 38(4): 264-271, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38285284

RESUMO

PURPOSE: N-benzyl-N-methyl-2-[7, 8-dihydro-7-(2-[18F] fluoroethyl) -8-oxo-2-phenyl-9H-purin-9-yl] acetamide ([18F] FEDAC) is a novel positron emission tomography (PET) tracer that targets the translocator protein (TSPO; 18 kDa) in the mitochondrial outer membrane, which is known to be upregulated in various diseases such as malignant tumors, neurodegenerative diseases, and neuroinflammation. This study presents the first attempt to use [18F]FEDAC PET/CT and evaluate its biodistribution as well as the systemic radiation exposure to the radiotracer in humans. MATERIALS AND METHODS: Seventeen whole-body [18F]FEDAC PET/CT (injected dose, 209.1 ± 6.2 MBq) scans with a dynamic scan of the upper abdomen were performed in seven participants. Volumes of interest were assigned to each organ, and a time-activity curve was created to evaluate the biodistribution of the radiotracer. The effective dose was calculated using IDAC-Dose 2.1. RESULTS: Immediately after the intravenous injection, the radiotracer accumulated significantly in the liver and was subsequently excreted into the gastrointestinal tract through the biliary tract. It also showed high levels of accumulation in the kidneys, but showed minimal migration to the urinary bladder. Thus, the liver was the principal organ that eliminated [18F] FEDAC. Accumulation in the normal brain tissue was minimal. The effective dose estimated from biodistribution in humans was 19.47 ± 1.08 µSv/MBq, and was 3.60 mSV for 185 MBq dose. CONCLUSION: [18F]FEDAC PET/CT provided adequate image quality at an acceptable effective dose with no adverse effects. Therefore, [18F]FEDAC may be useful in human TSPO-PET imaging.


Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Compostos Radiofarmacêuticos , Humanos , Distribuição Tecidual , Tomografia por Emissão de Pósitrons/métodos , Proteínas de Transporte/metabolismo , Radiometria , Receptores de GABA/metabolismo
14.
Mol Med Rep ; 29(2)2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38186312

RESUMO

The 18 kDa translocator protein (TSPO) is an essential outer mitochondrial membrane protein that is responsible for mitochondrial transport, maintenance of mitochondrial homeostasis and normal physiological cell function. The role of TSPO in the pathogenesis of ocular diseases is a growing area of interest. More notably, TSPO exerts positive effects in regulating various pathophysiological processes, such as the inflammatory response, oxidative stress, steroid synthesis and modulation of microglial function, in combination with a variety of specific ligands such as 1­(2­chlorophenyl­N­methylpropyl)­3­isoquinolinecarboxamide, 4'­chlorodiazepam and XBD173. In the present review, the expression of TSPO in ocular tissues and the functional role of TSPO and its ligands in diverse ocular diseases was discussed.


Assuntos
Oftalmopatias , Proteínas de Membrana , Receptores de GABA , Transporte Biológico , Homeostase , Ligantes , Humanos
15.
BMC Pediatr ; 24(1): 67, 2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38245687

RESUMO

BACKGROUND: Neonatal sepsis, a perilous medical situation, is typified by the malfunction of organs and serves as the primary reason for neonatal mortality. Nevertheless, the mechanisms underlying newborn sepsis remain ambiguous. Programmed cell death (PCD) has a connection with numerous infectious illnesses and holds a significant function in newborn sepsis, potentially serving as a marker for diagnosing the condition. METHODS: From the GEO public repository, we selected two groups, which we referred to as the training and validation sets, for our analysis of neonatal sepsis. We obtained PCD-related genes from 12 different patterns, including databases and published literature. We first obtained differential expressed genes (DEGs) for neonatal sepsis and controls. Three advanced machine learning techniques, namely LASSO, SVM-RFE, and RF, were employed to identify potential genes connected to PCD. To further validate the results, PPI networks were constructed, artificial neural networks and consensus clustering were used. Subsequently, a neonatal sepsis diagnostic prediction model was developed and evaluated. We conducted an analysis of immune cell infiltration to examine immune cell dysregulation in neonatal sepsis, and we established a ceRNA network based on the identified marker genes. RESULTS: Within the context of neonatal sepsis, a total of 49 genes exhibited an intersection between the differentially expressed genes (DEGs) and those associated with programmed cell death (PCD). Utilizing three distinct machine learning techniques, six genes were identified as common to both DEGs and PCD-associated genes. A diagnostic model was subsequently constructed by integrating differential expression profiles, and subsequently validated by conducting artificial neural networks and consensus clustering. Receiver operating characteristic (ROC) curves were employed to assess the diagnostic merit of the model, which yielded promising results. The immune infiltration analysis revealed notable disparities in patients diagnosed with neonatal sepsis. Furthermore, based on the identified marker genes, the ceRNA network revealed an intricate regulatory interplay. CONCLUSION: In our investigation, we methodically identified six marker genes (AP3B2, STAT3, TSPO, S100A9, GNS, and CX3CR1). An effective diagnostic prediction model emerged from an exhaustive analysis within the training group (AUC 0.930, 95%CI 0.887-0.965) and the validation group (AUC 0.977, 95%CI 0.935-1.000).


Assuntos
Sepse Neonatal , Recém-Nascido , Humanos , Sepse Neonatal/diagnóstico , Sepse Neonatal/genética , Apoptose , Biologia Computacional , Bases de Dados Factuais , Aprendizado de Máquina , Receptores de GABA
16.
J Neuroinflammation ; 21(1): 30, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38263017

RESUMO

BACKGROUND AND OBJECTIVES: 18-kDa translocator protein position-emission-tomography (TSPO-PET) imaging emerged for in vivo assessment of neuroinflammation in Alzheimer's disease (AD) research. Sex and obesity effects on TSPO-PET binding have been reported for cognitively normal humans (CN), but such effects have not yet been systematically evaluated in patients with AD. Thus, we aimed to investigate the impact of sex and obesity on the relationship between ß-amyloid-accumulation and microglial activation in AD. METHODS: 49 patients with AD (29 females, all Aß-positive) and 15 Aß-negative CN (8 female) underwent TSPO-PET ([18F]GE-180) and ß-amyloid-PET ([18F]flutemetamol) imaging. In 24 patients with AD (14 females), tau-PET ([18F]PI-2620) was additionally available. The brain was parcellated into 218 cortical regions and standardized-uptake-value-ratios (SUVr, cerebellar reference) were calculated. Per region and tracer, the regional increase of PET SUVr (z-score) was calculated for AD against CN. The regression derived linear effect of regional Aß-PET on TSPO-PET was used to determine the Aß-plaque-dependent microglial response (slope) and the Aß-plaque-independent microglial response (intercept) at the individual patient level. All read-outs were compared between sexes and tested for a moderation effect of sex on associations with body mass index (BMI). RESULTS: In AD, females showed higher mean cortical TSPO-PET z-scores (0.91 ± 0.49; males 0.30 ± 0.75; p = 0.002), while Aß-PET z-scores were similar. The Aß-plaque-independent microglial response was stronger in females with AD (+ 0.37 ± 0.38; males with AD - 0.33 ± 0.87; p = 0.006), pronounced at the prodromal stage. On the contrary, the Aß-plaque-dependent microglial response was not different between sexes. The Aß-plaque-independent microglial response was significantly associated with tau-PET in females (Braak-II regions: r = 0.757, p = 0.003), but not in males. BMI and the Aß-plaque-independent microglial response were significantly associated in females (r = 0.44, p = 0.018) but not in males (BMI*sex interaction: F(3,52) = 3.077, p = 0.005). CONCLUSION: While microglia response to fibrillar Aß is similar between sexes, women with AD show a stronger Aß-plaque-independent microglia response. This sex difference in Aß-independent microglial activation may be associated with tau accumulation. BMI is positively associated with the Aß-plaque-independent microglia response in females with AD but not in males, indicating that sex and obesity need to be considered when studying neuroinflammation in AD.


Assuntos
Doença de Alzheimer , Microglia , Humanos , Feminino , Masculino , Índice de Massa Corporal , Doenças Neuroinflamatórias , Peptídeos beta-Amiloides , Obesidade , Receptores de GABA
17.
Neurology ; 102(1): e207901, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38165362

RESUMO

BACKGROUND AND OBJECTIVES: Corticobasal syndrome (CBS) with underlying 4-repeat tauopathy is a progressive neurodegenerative disease characterized by declining cognitive and motor functions. Biomarkers for assessing pathologic brain changes in CBS including tau-PET, 18 kDa translocator protein (TSPO)-PET, structural MRI, neurofilament light chain (NfL), or glial fibrillary acidic protein (GFAP) have recently been evaluated for differential diagnosis and disease staging, yet their association with disease trajectories remains unclear. Therefore, we performed a head-to-head comparison of neuroimaging (tau-PET, TSPO-PET, structural MRI) and plasma biomarkers (NfL, GFAP) as prognostic tools for longitudinal clinical trajectories in ß-amyloid (Aß)-negative CBS. METHODS: We included patients with clinically diagnosed Aß-negative CBS with clinical follow-up data who underwent baseline structural MRI and plasma-NfL analysis for assessing neurodegeneration, [18F]PI-2620-PET for assessing tau pathology, [18F]GE-180-PET for assessing microglia activation, and plasma-GFAP analysis for assessing astrocytosis. To quantify tau and microglia load, we assessed summary scores of whole-brain, cortical, and subcortical PET signal. For structural MRI analysis, we quantified subcortical and cortical gray matter volume. Plasma NfL and GFAP values were assessed using Simoa-based immunoassays. Symptom progression was determined using a battery of cognitive and motor tests (i.e., Progressive Supranuclear Palsy Rating Scale [PSPRS]). Using linear mixed models, we tested whether the assessed biomarkers at baseline were associated with faster symptom progression over time (i.e., time × biomarker interaction). RESULTS: Overall, 21 patients with Aß-negative CBS with ∼2-year clinical follow-up data were included. Patients with CBS with more widespread global tau-PET signal showed faster clinical progression (PSPRS: B/SE = 0.001/0.0005, p = 0.025), driven by cortical rather than subcortical tau-PET. By contrast, patients with higher global [18F]GE-180-PET readouts showed slower clinical progression (PSPRS: B/SE = -0.056/0.023, p = 0.019). No association was found between gray matter volume and clinical progression. Concerning fluid biomarkers, only higher plasma-NfL (PSPRS: B/SE = 0.176/0.046, p < 0.001) but not GFAP was associated with faster clinical deterioration. In a subsequent sensitivity analysis, we found that tau-PET, TSPO-PET, and plasma-NfL showed significant interaction effects with time on clinical trajectories when tested in the same model. DISCUSSION: [18F]PI-2620 tau-PET, [18F]GE-180 TSPO-PET, and plasma-NfL show prognostic potential for clinical progression in patients with Aß-negative CBS with probable 4-repeat tauopathy, which can be useful for clinical decision-making and stratifying patients in clinical trials.


Assuntos
Degeneração Corticobasal , Doenças Neurodegenerativas , Tauopatias , Humanos , Filamentos Intermediários , Peptídeos beta-Amiloides , Biomarcadores , Progressão da Doença , Receptores de GABA
18.
J Agric Food Chem ; 72(4): 2347-2361, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38231789

RESUMO

In the pursuit of novel insecticides with high activity and a unique mode of action on the GABA receptor, a series of phenylpyrazole esterified derivatives (PEs) were synthesized using an improved Pinner reaction with high selectivity. Lewis acid catalysis was employed in a one-step solvent-thermal method to convert the cyano group of fipronil into an ester unit. FeCl3 was found to exhibit the highest selectivity for PEs synthesis, yielding PEs at 96.4%, with the byproduct being phenylpyrazole amide (PE0) at 2.1%. Initial biological assays indicated superior insecticidal activity of the target compounds against Plutella xylostella and Mythimna separata compared to fipronil. Particularly, the smaller and shorter ester units, PE3, PE5, and PE8, demonstrated 2-2.5 times higher insecticidal activity against P. xylostella than fipronil. The higher activity of ester units compared to amide and acylhydrazone units can be attributed to the enhanced lipid solubility of PEs. Additionally, it may be due to the impact of PEs on the neurotransmitter nACh or the coordination of calcium and chloride ions with the ester's -C═O and -O- bonds, blocking the chloride ion channel. Hydrophobic parameters were confirmed by reversed-phase high-performance liquid chromatography (HPLC), indicating the enhanced lipophilicity conferred by the ester units of PEs. Molecular docking and CoMFA analysis preliminarily validated the strong interactions and structure-activity relationships between PEs and the GABA receptor and nACh receptor in P. xylostella. Furthermore, under simulated natural sunlight, PEs exhibited photodegradation capabilities, transforming back into fipronil parent fragments and enhancing their insecticidal activity. Moreover, PEs displayed excellent fluorescent properties, enabling self-detection of residues. These research findings provide new insights and directions for the development of efficient pesticides, with potential wide applications in the fields of medicine and biosensors.


Assuntos
Inseticidas , Mariposas , Animais , Inseticidas/química , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Mariposas/metabolismo , Receptores de GABA/metabolismo , Amidas , Ésteres , Ácido gama-Aminobutírico
19.
Epilepsia ; 65(1): 204-217, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37746768

RESUMO

OBJECTIVE: γ-Aminobutyric acid type A (GABAA ) receptor subunit gene mutations are major causes of various epilepsy syndromes, including severe kinds such as Dravet syndrome. Although the GABAA receptor is a major target for antiseizure medications, treating GABAA receptor mutations with receptor channel modulators is ineffective. Here, we determined the effect of a novel treatment with 4-phenylbutyrate (PBA) in Gabrg2+/Q390X knockin mice associated with Dravet syndrome. METHODS: We used biochemistry in conjunction with differential tagging of the wild-type and the mutant alleles, live brain slice surface biotinylation, microsome isolation, patch-clamp whole-cell recordings, and video-monitoring synchronized electroencephalographic (EEG) recordings in Gabrg2+/Q390X mice to determine the effect of PBA in vitro with recombinant GABAA receptors and in vivo with knockin mice. RESULTS: We found that PBA reduced the mutant γ2(Q390X) subunit protein aggregates, enhanced the wild-type GABAA receptor subunits' trafficking, and increased the membrane expression of the wild-type receptors. PBA increased the current amplitude of GABA-evoked current in human embryonic kidney 293T cells and the neurons bearing the γ2(Q390X) subunit protein. PBA also proved to reduce endoplasmic reticulum (ER) stress caused by the mutant γ2(Q390X) subunit protein, as well as mitigating seizures and EEG abnormalities in the Gabrg2+/Q390X mice. SIGNIFICANCE: This research has unveiled a promising and innovative approach for treating epilepsy linked to GABAA receptor mutations through an unconventional antiseizure mechanism. Rather than directly modulating the affected mutant channel, PBA facilitates the folding and transportation of wild-type receptor subunits to the cell membrane and synapse. Combining these findings with our previous study, which demonstrated PBA's efficacy in restoring GABA transporter 1 (encoded by SLC6A1) function, we propose that PBA holds significant potential for a wide range of genetic epilepsies. Its ability to target shared molecular pathways involving mutant protein ER retention and impaired protein membrane trafficking suggests broad application in treating such conditions.


Assuntos
Epilepsias Mioclônicas , Epilepsia , Fenilbutiratos , Camundongos , Humanos , Animais , Receptores de GABA-A/genética , Receptores de GABA-A/metabolismo , Receptores de GABA/metabolismo , Epilepsias Mioclônicas/tratamento farmacológico , Epilepsias Mioclônicas/genética , Epilepsias Mioclônicas/complicações , Convulsões/complicações , Epilepsia/genética , Ácido gama-Aminobutírico , Estresse do Retículo Endoplasmático/genética
20.
Metab Brain Dis ; 39(1): 67-76, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37966694

RESUMO

Brain damage caused by ethanol abuse may lead to permanent damage, including severe dementia. The aim of this study was to investigate the effects of ginger powder on ethanol-induced cognitive disorders by examining oxidative damage and inflammation status, and the gene expression of N-methyl-D-aspartate (NMDA) and γ-Aminobutyric acid (GABA)-A receptors in the hippocampus of male rats. 24 adult male Sprague-Dawley rats were allocated randomly to four groups as follows control, ethanol (4g/kg/day, by gavage), ginger (1g/kg/day, by gavage), and ginger-ethanol. At the end of the study, memory and learning were evaluated by the shuttle box test. Moreover, to explore mechanisms involved in ethanol-induced cognitive impairment and the protective effect of ginger, the expression of Nuclear factor kappa B (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), NMDA receptor, and GABA-A receptor was measured along with inflammatory and oxidative biomarkers in the hippocampus tissue. The results showed that ethanol could induce cognitive impairment in the ethanol group, while pretreatment with ginger could reverse it. The gene expression of the NF-κB/ Tumor necrosis factor (TNF)-α/Interleukin (IL)-1ß pathway and NMDA and GABA-A receptors significantly increased in the ethanol group compared to the control group. While pretreatment with ginger could significantly improve ethanol-induced cognitive impairment through these pathways in the ginger-ethanol group compared to the ethanol group (P < 0.05). It can be concluded that ginger powder could ameliorate ethanol-induced cognitive impairment by modulating the expression of NMDA and GABA-A receptors and inhibiting oxidative damage and the NF-κB/TNF-α/IL-1ß pathway in the rat hippocampus.


Assuntos
Disfunção Cognitiva , Ratos , Animais , Masculino , Ratos Sprague-Dawley , Receptores de GABA-A/metabolismo , N-Metilaspartato/metabolismo , N-Metilaspartato/farmacologia , Etanol/toxicidade , NF-kappa B/metabolismo , Receptores de GABA/metabolismo , Pós/metabolismo , Pós/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Extratos Vegetais/metabolismo , Hipocampo/metabolismo , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
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