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1.
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
2.
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
3.
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
4.
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
5.
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
6.
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
7.
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
8.
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
9.
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
10.
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
11.
Phytomedicine ; 123: 155198, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38006806

RESUMO

BACKGROUND AND PURPOSE: Epiberberine (EPI) is one of the most important bioalkaloid found in the rhizome of Coptis chinensis, which has been observed to exhibit pharmaceutical effects against gastric cancer (GC). Nevertheless, the potential mechanism of EPI against GC cells still remains unclear. This study aimed to identify the core receptor on GC cells through which EPI inhibited the growth of GC cells and to explore the underlying inhibitory mechanisms. METHODS: To identify hub receptor targets that respond to EPI treatment, RNA sequencing (RNA-Seq) data from a tumor-bearing mouse model were analyzed using bioinformatics method and molecular docking. The binding interaction between EPI and GABRB3 was validated through western blotting based-cellular thermal shift assay (WB-CETSA). To further verify the binding region between EPI and GABRB3 through circular dichroism (CD) chromatography, fragments of the extracellular and transmembrane domains of the GABRB3 protein were expressed and purified in vitro. Stable cell lines with the overexpression or knockdown of GABRB3 were established using the recombinant lentivirus system. MTT ((3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide)) assay, colony formation assay, invasion and migration experiments, and flow cytometry were conducted to validate the inhibitory effect of EPI on the GC cells via GABRB3. Additionally, western blotting was utilized to explore the potential inhibitory mechanisms. RESULTS: Through the combination of multiple bioinformatics methods and molecular docking, we found that the γ-aminobutyric acid type A receptor subunit -ß3 (GABRB3) might be the critical receptor target in response to EPI treatment. The results of WB-CETSA analysis indicated that EPI significantly promoted the thermostability of the GABRB3 protein. Importantly, EPI could directly bind to GABRB3 and alter the secondary structure of GABRB3 fragments similar to the natural agonist, γ-aminobutyric acid (GABA). The EPI-induced suppression of the malignant phenotype of GC cells was dependent on the presence of GABRB3. GABRB3 expression was positively correlated with TP53 in patients with GC. The binding of EPI to GABRB3 stimulated p53 accumulation in GC cells. This activated the p21/CDK1/cyclinB1 pathway, resulting in G2/M cell cycle arrest, and induced the Bcl-2/BAX/Caspase axis-dependent cell apoptosis. CONCLUSION: This study revealed the target receptor for EPI in GC cells and provided new insights into its anticancer mechanisms.


Assuntos
Berberina/análogos & derivados , Neoplasias Gástricas , Humanos , Camundongos , Animais , Neoplasias Gástricas/genética , Proliferação de Células , Linhagem Celular Tumoral , Receptores de GABA/metabolismo , Proteína Supressora de Tumor p53 , Simulação de Acoplamento Molecular , Pontos de Checagem da Fase G2 do Ciclo Celular , Apoptose
12.
Pest Manag Sci ; 80(3): 1382-1399, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37926485

RESUMO

BACKGROUND: γ-Aminobutyric acid (GABA) receptors (GABARs) are validated targets of insecticides. Bicyclophosphorothionates are a group of insecticidal compounds that act as noncompetitive antagonists of GABARs. We previously reported that the analogs exhibit various degrees of selectivity for housefly versus rat GABARs, depending on substitutions at the 3- and 4-positions. We here sought to elucidate the unsolved mechanisms of the receptor selectivity using quantitative structure-activity relationship (QSAR), molecular docking, and molecular dynamics approaches. RESULTS: Three-dimensional (3D)-QSAR studies using Topomer comparative molecular field analysis quantitatively demonstrated how the introduction of a small alkyl group at the 3-position of bicyclophosphorothionates contributes to the housefly versus rat GABAR selectivity. To investigate the molecular mechanisms of the selective action, bicyclophosphorothionates were docked into housefly Resistance to dieldrin (RDL) GABAR and rat α1ß2γ2 GABAR homology models built using the published 3D-structures of human GABARs as templates. The results of molecular docking and molecular dynamics simulations revealed that the 2'Ala and 6'Thr residues of the RDL subunit within the channel are the key amino acids for binding to the housefly GABARs, whereas the 2'Ser residue of γ2 subunit plays a crucial role in binding to rat GABARs. CONCLUSION: We revealed the molecular mechanisms underlying the selective antagonistic action of bicyclophosphorothionates on housefly versus rat GABARs. The information presented should help design and develop novel, safe GABAR-targeting insecticides. © 2023 Society of Chemical Industry.


Assuntos
Moscas Domésticas , Inseticidas , Ratos , Animais , Humanos , Receptores de GABA/metabolismo , Inseticidas/química , Moscas Domésticas/metabolismo , Simulação de Acoplamento Molecular , Antagonistas GABAérgicos/química
13.
J Cereb Blood Flow Metab ; 44(3): 397-406, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37795635

RESUMO

Neuroinflammation is associated with a number of brain diseases, making it a common feature of cerebral pathology. Among the best-known biomarkers for neuroinflammation in Positron Emission Tomography (PET) research is the 18 kDa translocator protein (TSPO). This study aims to investigate the binding kinetics of a novel TSPO PET radiotracer, [18F]LW223, in mice and specifically assess its volume of non-displaceable binding (VND) in brain as well as investigate the use of simplified analysis approaches for quantification of [18F]LW223 PET data. Adult male mice were injected with [18F]LW223 and varying concentrations of LW223 (0.003-0.55 mg/kg) to estimate VND of [18F]LW223. Dynamic PET imaging with arterial input function studies and radiometabolite studies were conducted. Simplified quantification methods, standard uptake values (SUV) and apparent volume of distribution (VTapp), were investigated. [18F]LW223 had low VND in the brain (<10% of total binding) and low radiometabolism (∼15-20%). The 2-tissue compartment model provided the best fit for [18F]LW223 PET data, although its correlation with SUV90-120min or VTapp allowed for [18F]LW223 brain PET data quantification in healthy animals while using simpler experimental and analytical approaches. [18F]LW223 has the required properties to become a successful TSPO PET radiotracer.


Assuntos
Doenças Neuroinflamatórias , Receptores de GABA , Masculino , Camundongos , Animais , Receptores de GABA/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Proteínas de Transporte/metabolismo
14.
Eur J Nucl Med Mol Imaging ; 51(2): 455-467, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37801139

RESUMO

PURPOSE: Despite the revealed role of immunological dysfunctions in the development and progression of Alzheimer's disease (AD) through animal and postmortem investigations, direct evidence regarding the impact of genetic factors on microglia response and amyloid-ß (Aß) deposition in AD individuals is lacking. This study aims to elucidate this mechanism by integrating transcriptomics and TSPO, Aß PET imaging in clinical AD cohort. METHODS: We analyzed 85 patients with PET/MR imaging for microglial activation (TSPO, [18F]DPA-714) and Aß ([18F]AV-45) within the prospective Alzheimer's Disease Immunization and Microbiota Initiative Study Cohort (ADIMIC). Immune-related differentially expressed genes (IREDGs), identified based on AlzData, were screened and verified using blood samples from ADIMIC. Correlation and mediation analyses were applied to investigate the relationships between immune-related genes expression, TSPO and Aß PET imaging. RESULTS: TSPO uptake increased significantly both in aMCI (P < 0.05) and AD participants (P < 0.01) and showed a positive correlation with Aß deposition (r = 0.42, P < 0.001). Decreased expression of TGFBR3, FABP3, CXCR4 and CD200 was observed in AD group. CD200 expression was significantly negatively associated with TSPO PET uptake (r =-0.33, P = 0.013). Mediation analysis indicated that CD200 acted as a significant mediator between TSPO uptake and Aß deposition (total effect B = 1.92, P = 0.004) and MMSE score (total effect B =-54.01, P = 0.003). CONCLUSION: By integrating transcriptomics and TSPO PET imaging in the same clinical AD cohort, this study revealed CD200 played an important role in regulating neuroinflammation, Aß deposition and cognitive dysfunction.


Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Perfilação da Expressão Gênica , Doenças Neuroinflamatórias , Tomografia por Emissão de Pósitrons/métodos , Estudos Prospectivos , Receptores de GABA/genética , Receptores de GABA/metabolismo
15.
Brain Behav Immun ; 116: 259-266, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38081435

RESUMO

The COVID-19 pandemic has exerted a global impact on both physical and mental health, and clinical populations have been disproportionally affected. To date, however, the mechanisms underlying the deleterious effects of the pandemic on pre-existing clinical conditions remain unclear. Here we investigated whether the onset of the pandemic was associated with an increase in brain/blood levels of inflammatory markers and MRI-estimated brain age in patients with chronic low back pain (cLBP), irrespective of their infection history. A retrospective cohort study was conducted on 56 adult participants with cLBP (28 'Pre-Pandemic', 28 'Pandemic') using integrated Positron Emission Tomography/ Magnetic Resonance Imaging (PET/MRI) and the radioligand [11C]PBR28, which binds to the neuroinflammatory marker 18 kDa Translocator Protein (TSPO). Image data were collected between November 2017 and January 2020 ('Pre-Pandemic' cLBP) or between August 2020 and May 2022 ('Pandemic' cLBP). Compared to the Pre-Pandemic group, the Pandemic patients demonstrated widespread and statistically significant elevations in brain TSPO levels (P =.05, cluster corrected). PET signal elevations in the Pandemic group were also observed when 1) excluding 3 Pandemic subjects with a known history of COVID infection, or 2) using secondary outcome measures (volume of distribution -VT- and VT ratio - DVR) in a smaller subset of participants. Pandemic subjects also exhibited elevated serum levels of inflammatory markers (IL-16; P <.05) and estimated BA (P <.0001), which were positively correlated with [11C]PBR28 SUVR (r's ≥ 0.35; P's < 0.05). The pain interference scores, which were elevated in the Pandemic group (P <.05), were negatively correlated with [11C]PBR28 SUVR in the amygdala (r = -0.46; P<.05). This work suggests that the pandemic outbreak may have been accompanied by neuroinflammation and increased brain age in cLBP patients, as measured by multimodal imaging and serum testing. This study underscores the broad impact of the pandemic on human health, which extends beyond the morbidity solely mediated by the virus itself.


Assuntos
COVID-19 , Dor Crônica , Adulto , Humanos , Pandemias , Dor Crônica/metabolismo , Estudos Retrospectivos , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Envelhecimento , Receptores de GABA/metabolismo
16.
J Affect Disord ; 348: 283-296, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38159656

RESUMO

AIMS: To assess the effect of the translocator protein 18 kDa (TSPO) on postpartum depression and explore its mechanism. METHODS: Postpartum depression (PPD) mouse model was established, and flow cytometry, immunofluorescence, Western blot analysis, real-time quantitative PCR, adeno-associated virus (AAV), co-immunoprecipitation-mass spectrometry and immunofluorescence co-staining were used to detect the effect of TSPO ligand ZBD-2 on PPD mice. RESULTS: ZBD-2 inhibits the overactivation of microglia in the hippocampus and amygdala of PPD model mice. ZBD-2 not only inhibited the inflammation but also repressed the burst of reactive oxygen species (ROS) and mitochondrial ROS (mtROS). Meanwhile, ZBD-2 protects mitochondria from LPS-induced damages through inhibiting the influx of calcium. ZBD-2 modulated the calcium influx by increasing the level of translocase of the outer mitochondrial membrane 40 (TOM40) and reducing the interaction of TSPO and TOM40. In addition, the effect of ZBD-2 was partially dependent on anti-oxidative process. Knockdown of TOM40 by adeno-associated virus (AAV) in the hippocampus or amygdala dramatically reduced the effect of ZBD-2 on PPD, indicating that TOM40 mediates the effect of ZBD-2 on PPD. CONCLUSIONS: TOM40 is required for the effect of ZBD-2 on treating anxiety and depression in PPD mice. This study reveals the role of microglia TSPO in PPD development and provides the new therapeutic strategy for PPD.


Assuntos
Depressão Pós-Parto , Microglia , Animais , Feminino , Camundongos , Cálcio/metabolismo , Proteínas de Transporte , Depressão Pós-Parto/tratamento farmacológico , Depressão Pós-Parto/metabolismo , Homeostase , Microglia/metabolismo , Membranas Mitocondriais/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores de GABA/metabolismo
17.
J Med Chem ; 67(1): 17-37, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38113353

RESUMO

Mitochondria dysfunctions are typical hallmarks of cardiac disorders (CDs). The multiple tasks of this energy-producing organelle are well documented, but its pathophysiologic involvement in several manifestations of heart diseases, such as altered electromechanical coupling, excitability, and arrhythmias, is still under investigation. The human 18 kDa translocator protein (TSPO) is a protein located on the outer mitochondrial membrane whose expression is altered in different pathological conditions, including CDs, making it an attractive therapeutic and diagnostic target. Currently, only a few TSPO ligands are employed in CDs and cardiac imaging. In this Perspective, we report an overview of the emerging role of TSPO at the heart level, focusing on the recent literature concerning the development of TSPO ligands used for fighting and imaging heart-related disease conditions. Accordingly, targeting TSPO might represent a successful strategy to achieve novel therapeutic and diagnostic strategies to unravel the fundamental mechanisms and to provide solutions to still unanswered questions in CDs.


Assuntos
Cardiopatias , Receptores de GABA , Humanos , Receptores de GABA/metabolismo , Membranas Mitocondriais/metabolismo , Cardiopatias/tratamento farmacológico , Cardiopatias/metabolismo , Ligantes
18.
Science ; 382(6677): 1389-1394, 2023 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-38060673

RESUMO

Fast synaptic neurotransmission in the vertebrate central nervous system relies primarily on ionotropic glutamate receptors (iGluRs), which drive neuronal excitation, and type A γ-aminobutyric acid receptors (GABAARs), which are responsible for neuronal inhibition. However, the GluD1 receptor, an iGluR family member, is present at both excitatory and inhibitory synapses. Whether and how GluD1 activation may affect inhibitory neurotransmission is unknown. In this work, by using a combination of biochemical, structural, and functional analyses, we demonstrate that GluD1 binds GABA, a previously unknown feature of iGluRs. GluD1 activation produces long-lasting enhancement of GABAergic synaptic currents in the adult mouse hippocampus through a non-ionotropic mechanism that is dependent on trans-synaptic anchoring. The identification of GluD1 as a GABA receptor that controls inhibitory synaptic plasticity challenges the classical dichotomy between glutamatergic and GABAergic receptors.


Assuntos
Inibição Neural , Plasticidade Neuronal , Receptores de GABA , Transmissão Sináptica , Ácido gama-Aminobutírico , Animais , Camundongos , Ácido gama-Aminobutírico/metabolismo , Glutamato Desidrogenase/metabolismo , Hipocampo/metabolismo , Receptores de GABA/metabolismo , Sinapses/fisiologia , Camundongos Knockout , Racemases e Epimerases/genética
19.
Biochem Pharmacol ; 218: 115888, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38084676

RESUMO

Osteoporosis is a significant global health concern, linked to reduced bone density and an increased fracture risk, with effective treatments still lacking. This study explored the potential of gamma-aminobutyric acid (GABA) and its receptors as a novel approach to promote osteogenesis and address osteoporosis. GABA concentrations up to 10 mM were well-tolerated by MC3T3-E1 preosteoblast, stimulating osteoblast differentiation and mineralization in a concentration- and time-dependent manner. In vivo experiments with zebrafish larvae demonstrated the ability of GABA to improve vertebral formation and enhanced bone density, indicating the potential therapeutic value for osteoporosis. Notably, GABA countered the adverse effects of prednisolone on vertebral formation, bone density, and osteogenic gene expression in zebrafish larvae, suggesting a promising therapeutic solution to counteract corticosteroid-induced osteoporosis. Moreover, our study highlighted the involvement of GABA receptors in mediating the observed osteogenic effects. By using GABAA, GABAB, and GABAC receptor antagonists, we demonstrated that blocking these receptors attenuated GABA-induced osteoblast differentiation and vertebral formation in both MC3T3-E1 cells and zebrafish larvae, underscoring the importance of GABA receptor interactions in promoting bone formation. In conclusion, these findings underscore the osteogenic potential of GABA and its ability to mitigate the detrimental effects of corticosteroids on bone health. Targeting GABA and its receptors could be a promising strategy for the development of novel therapeutic interventions to address osteoporosis. However, further investigations are warranted to fully elucidate the underlying molecular mechanism of GABA and its clinical applications in treating osteoporosis.


Assuntos
Osteoporose , Receptores de GABA , Animais , Receptores de GABA/metabolismo , Osteogênese , Peixe-Zebra , Ácido gama-Aminobutírico/farmacologia , Ácido gama-Aminobutírico/metabolismo , Osteoporose/metabolismo , Diferenciação Celular , Osteoblastos/metabolismo
20.
Int J Mol Sci ; 24(24)2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38139248

RESUMO

Inflammation involves the activation of innate immune cells and is believed to play an important role in the development and progression of both infectious and non-infectious diseases such as neurodegeneration, autoimmune diseases, pulmonary and cancer. Inflammation in the brain is marked by the upregulation of translocator protein (TSPO) in microglia. High TSPO levels are also found, for example, in macrophages in cases of rheumatoid arthritis and in malignant tumor cells compared to their relatively low physiological expression. The same applies for cyclooxgenase-2 (COX-2), which is constitutively expressed in the kidney, brain, thymus and gastrointestinal tract, but induced in microglia, macrophages and synoviocytes during inflammation. This puts TSPO and COX-2 in the spotlight as important targets for the diagnosis of inflammation. Imaging modalities, such as positron emission tomography and single-photon emission tomography, can be used to localize inflammatory processes and to track their progression over time. They could also enable the monitoring of the efficacy of therapy and predict its outcome. This review focuses on the current development of PET and SPECT tracers, not only for the detection of neuroinflammation, but also for emerging diagnostic measures in infectious and other non-infectious diseases such as rheumatic arthritis, cancer, cardiac inflammation and in lung diseases.


Assuntos
Artrite Reumatoide , Doenças não Transmissíveis , Humanos , Ciclo-Oxigenase 2/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Encéfalo/metabolismo , Biomarcadores/metabolismo , Artrite Reumatoide/diagnóstico por imagem , Artrite Reumatoide/patologia , Inflamação/metabolismo , Receptores de GABA/metabolismo , Proteínas de Transporte/metabolismo
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