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1.
J Org Chem ; 89(4): 2238-2246, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38296256

RESUMO

Visible-light-induced regioselective cascade radical cyclization of α-bromocarbonyls for the synthesis of benzazepine derivatives is described. In the presence of fac-Ir(ppy)3 (2.0 mol %) as a photocatalyst, 2,6-lutidine as a base, and dichloromethane as a solvent, the reactions proceed smoothly to afford seven-membered rings in good yields. This protocol features a broad substrate scope, excellent functional group tolerance, and mild reaction conditions. Preliminary mechanistic studies reveal that the generation of the α-carbon radical is more prone to react with the 1,1-diphenylethylene tethered acrylamide to generate the stable seven-membered heterocycle.

2.
J Org Chem ; 88(23): 16556-16565, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37971950

RESUMO

Herein, an N-heterocyclic carbene (NHC)-catalyzed tandem cyclization/addition/cyclization reaction of 2-isocyanobiaryls and α-bromo-N-cinnamylamides for the synthesis of 2-pyrrolidinone-functionalized phenanthridines is developed. This protocol features a radical cascade process, broad substrate scope, and good functional group compatibility under metal- and oxidant-free reaction conditions.

3.
Dalton Trans ; 52(33): 11591-11600, 2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37548591

RESUMO

Exploiting efficient and stable photocatalysts is the primary goal of photocatalytic water splitting for H2 production. In this work, a sea urchin-like bimetallic NiCo2O4-decorated ZnIn2S4 heterojunction was fabricated via a solvent evaporation method. Investigation shows that the introduction NiCo2O4 can expand the UV-vis absorption range, enhance the absorption intensity, promote the charge separation, decrease the charge transfer resistance, induce more active sites, and decrease the H2 evolution overpotential of the composite. Besides, the charge transfer between NiCo2O4 and ZnIn2S4 follows a Z-scheme route based on the ˙OH radical capture experiments; this can preserve the strong oxidation-reduction reaction ability of photogenerated electrons and holes, leading to a faster H2 evolution rate, which reaches 17.28 mmol g-1 h-1 over the 4.8%-NiCo2O4/ZnIn2S4 composite under 300 W Xe lamp irradiation in 20 vol% triethanolamine (TEOA) solution and is 3.0 times higher than that of ZnIn2S4. In addition, NiCo2O4/ZnIn2S4 also has excellent stability during 5 consecutive cycles. This work provides an effective method for constructing a highly effective Z-scheme heterojunction system for photocatalytic H2 production.

4.
Org Lett ; 25(32): 6072-6076, 2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37550857

RESUMO

A novel and efficient strategy for the synthesis of a series of structurally interesting benzazepine derivatives via an N-heterocyclic carbene-catalyzed regioselective intramolecular radical cyclization has been developed. This protocol features good regioselectivity, good functional-group compatibility, and wide substrate scope, providing a transition-metal- and oxidant-free pathway to access the seven-membered rings under mild reaction conditions. Additionally, further transformation of benzazepines and a large-scale experiment were also conducted.

5.
NPJ Sci Food ; 7(1): 35, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37460765

RESUMO

More Americans are consuming diets higher in saturated fats and refined sugars than ever before. These trends could have serious consequences for the older population because high-fat diet (HFD) consumption, known to induce neuroinflammation, has been shown to accelerate and aggravate memory declines. We have previously demonstrated that short-term HFD consumption, which does not evoke obesity-related comorbidities, produced profound impairments to hippocampal-dependent memory in aged rats. These impairments were precipitated by increases in proinflammatory cytokines, primarily interleukin-1 beta (IL-1ß). Here, we explored the extent to which short-term HFD consumption disrupts hippocampal synaptic plasticity, as measured by long-term potentiation (LTP), in young adult and aged rats. We demonstrated that (1) HFD disrupted late-phase LTP in the hippocampus of aged, but not young adult rats, (2) HFD did not disrupt early-phase LTP, and (3) blockade of the IL-1 receptor rescued L-LTP in aged HFD-fed rats. These findings suggest that hippocampal memory impairments in aged rats following HFD consumption occur through the deterioration of synaptic plasticity and that IL-1ß is a critical driver of that deterioration.

6.
bioRxiv ; 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37163097

RESUMO

Adult neural stem and progenitor cells (NSPCs) reside in the dentate gyrus (DG) of the hippocampus throughout the lifespan of most mammalian species. In addition to generating new neurons, NSPCs may alter their niche via secretion of growth factors and cytokines. We recently showed that adult DG NSPCs secrete vascular endothelial growth factor (VEGF), which is critical for maintaining adult neurogenesis. Here, we asked whether NSPC-derived VEGF alters hippocampal function independent of adult neurogenesis. We found that loss of NSPC-derived VEGF acutely impaired hippocampal memory, caused neuronal hyperexcitability and exacerbated excitotoxic injury. We also found that NSPCs generate substantial proportions of total DG VEGF and VEGF disperses broadly throughout the DG, both of which help explain how this anatomically-restricted cell population could modulate function broadly. These findings suggest that NSPCs actively support and protect DG function via secreted VEGF, thereby providing a non-neurogenic functional dimension to endogenous NSPCs.

7.
Org Lett ; 24(31): 5791-5796, 2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-35916599

RESUMO

A novel visible-light-mediated difluoroalkylation of 1-(allyloxy)-2-(1-arylvinyl)benzenes and 1-(1-arylvinyl)-2-(vinyloxy)benzenes for the synthesis of bis-difluoroalkylated benzoxepines and 2H-chromenes is developed. This method features mild reaction conditions, good regioselectivity, a wide substrate scope, good functional-group compatibility, and late-stage modification. Preliminary mechanistic studies reveal that the generation of the CF2CO2Et radical is more prone to reaction with the double bond of the aryl group.

8.
J Neurosci ; 2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35882560

RESUMO

A rod-shaped appendage called a primary cilium projects from the soma of most central neurons in the mammalian brain. The importance of cilia within the nervous system is highlighted by the fact that human syndromes linked to primary cilia dysfunction, collectively termed ciliopathies, are associated with numerous neuropathologies, including hyperphagia-induced obesity, neuropsychiatric disorders, and learning and memory deficits. Neuronal cilia are enriched with signaling molecules, including specific G protein-coupled receptors (GPCRs) and their downstream effectors, suggesting they act as sensory organelles that respond to neuromodulators in the extracellular space. We previously showed that GPCR ciliary localization is disrupted in neurons from mouse models of the ciliopathy Bardet-Biedl syndrome (BBS). Based on this finding we hypothesized that mislocalization of ciliary GPCRs may impact receptor signaling and contribute to the BBS phenotypes. Here, we show that disrupting localization of the ciliary GPCR dopamine receptor 1 (D1) in male and female mice, either by loss of a BBS protein or loss of the cilium itself, specifically in D1-expressing neurons, results in obesity. Interestingly, the weight gain is associated with reduced locomotor activity, rather than increased food intake. Moreover, loss of a BBS protein or cilia on D1-expressing neurons leads to a reduction in D1-mediated signaling. Together, these results indicate that cilia impact D1 activity in the nervous system and underscore the importance of neuronal cilia for proper GPCR signaling.SIGNIFICANCE STATEMENT:Most mammalian neurons possess solitary appendages called primary cilia. These rod-shaped structures are enriched with signaling proteins, such as G protein-coupled receptors (GPCRs), suggesting they respond to neuromodulators. This study examines the consequences of disrupting ciliary localization of the GPCR dopamine receptor 1 (D1) in D1-expressing neurons. Remarkably, mice that have either abnormal accumulation of D1 in cilia or loss of D1 ciliary localization become obese. In both cases the obesity is associated with lower locomotor activity rather than overeating. As D1 activation increases locomotor activity, these results are consistent with a reduction in D1 signaling. Indeed, we found that D1-mediated signaling is reduced in brain slices from both mouse models. Thus, cilia impact D1 signaling in the brain.

9.
J Org Chem ; 87(15): 10277-10284, 2022 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-35791911

RESUMO

Visible-light-induced radical cascade acylation/cyclization/aromatization of N-propargyl aromatic amines and acyl oxime esters for the construction of 3-acylated quinolines is developed. This approach uses acyl oxime esters as the precursor of acyl radicals as well as acylation reagents, Eosin Y as the photocatalyst, and acetonitrile as the solvent, providing a convenient route toward 3-acylated quinolines via the C-C bond cleavage of acyl oxime esters.

10.
J Neurosci ; 42(20): 4215-4228, 2022 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-35440489

RESUMO

Traumatic brain injury (TBI) is associated with an increased risk of cognitive, psychiatric, and neurodegenerative complications that may develop after injury. Increased microglial reactivity following TBI may underlie chronic neuroinflammation, neuropathology, and exaggerated responses to immune challenges. Therefore, the goal of this study was to force turnover of trauma-associated microglia that develop after diffuse TBI and determine whether this alleviated chronic inflammation, improved functional recovery and attenuated reduced immune reactivity to lipopolysaccharide (LPS) challenge. Male mice received a midline fluid percussion injury (mFPI) and 7 d later were subjected to a forced microglia turnover paradigm using CSF1R antagonism (PLX5622). At 30 d postinjury (dpi), cortical gene expression, dendritic complexity, myelin content, neuronal connectivity, cognition, and immune reactivity were assessed. Myriad neuropathology-related genes were increased 30 dpi in the cortex, and 90% of these gene changes were reversed by microglial turnover. Reduced neuronal connectivity was evident 30 dpi and these deficits were attenuated by microglial turnover. TBI-associated dendritic remodeling and myelin alterations, however, remained 30 dpi independent of microglial turnover. In assessments of functional recovery, increased depressive-like behavior, and cognitive impairment 30 dpi were ameliorated by microglia turnover. To investigate microglial priming and reactivity 30 dpi, mice were injected intraperitoneally with LPS. This immune challenge caused prolonged lethargy, sickness behavior, and microglial reactivity in the TBI mice. These extended complications with LPS in TBI mice were prevented by microglia turnover. Collectively, microglial turnover 7 dpi alleviated behavioral and cognitive impairments associated with microglial priming and immune reactivity 30 dpi.SIGNIFICANCE STATEMENT A striking feature of traumatic brain injury (TBI), even mild injuries, is that over 70% of individuals have long-term neuropsychiatric complications. Chronic inflammatory processes are implicated in the pathology of these complications and these issues can be exaggerated by immune challenge. Therefore, our goal was to force the turnover of microglia 7 d after TBI. This subacute 7 d postinjury (dpi) time point is a critical transitional period in the shift toward chronic inflammatory processes and microglia priming. This forced microglia turnover intervention in mice attenuated the deficits in behavior and cognition 30 dpi. Moreover, microglia priming and immune reactivity after TBI were also reduced with microglia turnover. Therefore, microglia represent therapeutic targets after TBI to reduce persistent neuroinflammation and improve recovery.


Assuntos
Lesões Encefálicas Difusas , Lesões Encefálicas Traumáticas , Disfunção Cognitiva , Animais , Lesões Encefálicas Difusas/metabolismo , Lesões Encefálicas Difusas/patologia , Lesões Encefálicas Traumáticas/patologia , Disfunção Cognitiva/metabolismo , Inflamação/metabolismo , Lipopolissacarídeos/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo
11.
Exp Neurol ; 353: 114058, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35358498

RESUMO

Traumatic brain injury (TBI) impairs the ability to restore homeostasis in response to stress, indicating hypothalamic-pituitary-adrenal (HPA)-axis dysfunction. Many stressors result in sleep disturbances, thus mechanical sleep fragmentation (SF) provides a physiologically relevant approach to study the effects of stress after injury. We hypothesize SF stress engages the dysregulated HPA-axis after TBI to exacerbate post-injury neuroinflammation and compromise recovery. To test this, male and female mice were given moderate lateral fluid percussion TBI or sham-injury and left undisturbed or exposed to daily, transient SF for 7- or 30-days post-injury (DPI). Post-TBI SF increases cortical expression of interferon- and stress-associated genes characterized by inhibition of the upstream regulator NR3C1 that encodes glucocorticoid receptor (GR). Moreover, post-TBI SF increases neuronal activity in the hippocampus, a key intersection of the stress-immune axes. By 30 DPI, TBI SF enhances cortical microgliosis and increases expression of pro-inflammatory glial signaling genes characterized by persistent inhibition of the NR3C1 upstream regulator. Within the hippocampus, post-TBI SF exaggerates microgliosis and decreases CA1 neuronal activity. Downstream of the hippocampus, post-injury SF suppresses neuronal activity in the hypothalamic paraventricular nucleus indicating decreased HPA-axis reactivity. Direct application of GR agonist, dexamethasone, to the CA1 at 30 DPI increases GR activity in TBI animals, but not sham animals, indicating differential GR-mediated hippocampal action. Electrophysiological assessment revealed TBI and SF induces deficits in Schaffer collateral long-term potentiation associated with impaired acquisition of trace fear conditioning, reflecting dorsal hippocampal-dependent cognitive deficits. Together these data demonstrate that post-injury SF engages the dysfunctional post-injury HPA-axis, enhances inflammation, and compromises hippocampal function. Therefore, external stressors that disrupt sleep have an integral role in mediating outcome after brain injury.


Assuntos
Lesões Encefálicas Traumáticas , Privação do Sono , Animais , Lesões Encefálicas Traumáticas/metabolismo , Feminino , Hipocampo/metabolismo , Inflamação/metabolismo , Potenciação de Longa Duração , Masculino , Camundongos , Privação do Sono/complicações , Privação do Sono/metabolismo
12.
Zhongguo Dang Dai Er Ke Za Zhi ; 24(1): 85-89, 2022 Jan 15.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-35177181

RESUMO

OBJECTIVES: To study the value of heparin-binding protein (HBP) in the diagnosis of severe infection in children. METHODS: This study was a prospective observational study. The medical data of children who were admitted to the pediatric intensive care unit due to infection from January 2019 to January 2020 were collected. According to the diagnostic criteria for severe sepsis and sepsis, the children were divided into a severe sepsis group with 49 children, a sepsis group with 82 children, and a non-severe infection group with 33 children. The three groups were compared in terms of related biomarkers such as plasma HBP, serum C-reactive protein, serum procalcitonin, and platelet count. The receiver operating characteristic (ROC) curve was plotted to investigate the value of plasma HBP level in the diagnosis of severe infection (including severe sepsis and sepsis). RESULTS: The severe sepsis and sepsis groups had a significantly higher plasma HBP level on admission than the non-severe infection group (P<0.05). Compared with the sepsis and non-severe groups, the severe sepsis group had significantly higher serum levels of C-reactive protein and procalcitonin and a significantly lower platelet count (P<0.05). Plasma HBP level had an area under the ROC curve of 0.590 in determining severe infection, with a sensitivity of 38.0% and a specificity of 82.4% (P<0.05). CONCLUSIONS: There is an increase in plasma HBP level in children with severe infection, and plasma HBP level has a lower sensitivity but a higher specificity in the diagnosis of severe infection and can thus be used as one of the markers for the judgment of severe infection in children.


Assuntos
Proteínas Sanguíneas , Sepse , Peptídeos Catiônicos Antimicrobianos , Biomarcadores , Proteína C-Reativa/análise , Criança , Humanos , Pró-Calcitonina , Estudos Prospectivos , Curva ROC , Sepse/diagnóstico
13.
Materials (Basel) ; 14(22)2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34832497

RESUMO

The performance of cover concrete is acknowledged as a major factor governing the degradation of concrete structures. Curing plays a vital role in the development of concrete durability. The effects of different water-binder ratios and mineral admixtures on the curing water demand of concrete were studied by the surface water absorption test. Combined with the characteristics of the hydration heat and chemically bound water of the composition cementing material system, the law of variation for curing water demand was analyzed. The results show that the addition of mineral admixtures can reduce the early hydration rate and hydration exothermic characteristics, and the hydration degree decreases with the increase of mineral admixtures. Due to the filling effect and active effect, the addition of fly ash (FA) and ground granulated blast slag (GGBS) reduces the curing water demand. The curing water demand of cover concrete decreases with the increase of mineral admixture content, and the curing water demand of pure water is the maximum and that of mix FA and GGBS is the minimum. Moreover, there is a strong correlation between the cumulative curing water demand and the chemically bound water content, indicating that the power of water migration mainly comes from the hydration activity of the cementing material system. The results provide a theoretical basis for the fine control of a concrete curing system.

14.
J Cell Biol ; 220(10)2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34427634

RESUMO

The in vivo physiological function of liquid-liquid phase separation (LLPS) that governs non-membrane-bound structures remains elusive. Among LLPS-prone proteins, TAR DNA-binding protein of 43 kD (TDP-43) is under intense investigation because of its close association with neurological disorders. Here, we generated mice expressing endogenous LLPS-deficient murine TDP-43. LLPS-deficient TDP-43 mice demonstrate impaired neuronal function and behavioral abnormalities specifically related to brain function. Brain neurons of these mice, however, did not show TDP-43 proteinopathy or neurodegeneration. Instead, the global rate of protein synthesis was found to be greatly enhanced by TDP-43 LLPS loss. Mechanistically, TDP-43 LLPS ablation increased its association with PABPC4, RPS6, RPL7, and other translational factors. The physical interactions between TDP-43 and translational factors relies on a motif, the deletion of which abolished the impact of LLPS-deficient TDP-43 on translation. Our findings show a specific physiological role for TDP-43 LLPS in the regulation of brain function and uncover an intriguing novel molecular mechanism of translational control by LLPS.


Assuntos
Encéfalo/metabolismo , Proteínas de Ligação a DNA/metabolismo , Animais , Camundongos , Camundongos Endogâmicos C57BL
15.
J Neurosci ; 41(7): 1597-1616, 2021 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-33452227

RESUMO

Traumatic brain injury (TBI) can lead to significant neuropsychiatric problems and neurodegenerative pathologies, which develop and persist years after injury. Neuroinflammatory processes evolve over this same period. Therefore, we aimed to determine the contribution of microglia to neuropathology at acute [1 d postinjury (dpi)], subacute (7 dpi), and chronic (30 dpi) time points. Microglia were depleted with PLX5622, a CSF1R antagonist, before midline fluid percussion injury (FPI) in male mice and cortical neuropathology/inflammation was assessed using a neuropathology mRNA panel. Gene expression associated with inflammation and neuropathology were robustly increased acutely after injury (1 dpi) and the majority of this expression was microglia independent. At 7 and 30 dpi, however, microglial depletion reversed TBI-related expression of genes associated with inflammation, interferon signaling, and neuropathology. Myriad suppressed genes at subacute and chronic endpoints were attributed to neurons. To understand the relationship between microglia, neurons, and other glia, single-cell RNA sequencing was completed 7 dpi, a critical time point in the evolution from acute to chronic pathogenesis. Cortical microglia exhibited distinct TBI-associated clustering with increased type-1 interferon and neurodegenerative/damage-related genes. In cortical neurons, genes associated with dopamine signaling, long-term potentiation, calcium signaling, and synaptogenesis were suppressed. Microglial depletion reversed the majority of these neuronal alterations. Furthermore, there was reduced cortical dendritic complexity 7 dpi, reduced neuronal connectively 30 dpi, and cognitive impairment 30 dpi. All of these TBI-associated functional and behavioral impairments were prevented by microglial depletion. Collectively, these studies indicate that microglia promote persistent neuropathology and long-term functional impairments in neuronal homeostasis after TBI.SIGNIFICANCE STATEMENT Millions of traumatic brain injuries (TBIs) occur in the United States alone each year. Survivors face elevated rates of cognitive and psychiatric complications long after the inciting injury. Recent studies of human brain injury link chronic neuroinflammation to adverse neurologic outcomes, suggesting that evolving inflammatory processes may be an opportunity for intervention. Here, we eliminate microglia to compare the effects of diffuse TBI on neurons in the presence and absence of microglia and microglia-mediated inflammation. In the absence of microglia, neurons do not undergo TBI-induced changes in gene transcription or structure. Microglial elimination prevented TBI-induced cognitive changes 30 d postinjury (dpi). Therefore, microglia have a critical role in disrupting neuronal homeostasis after TBI, particularly at subacute and chronic timepoints.


Assuntos
Lesões Encefálicas Traumáticas/patologia , Córtex Cerebral/patologia , Encefalite/patologia , Microglia/patologia , Neurônios/patologia , Animais , Sinalização do Cálcio/genética , Expressão Gênica/efeitos dos fármacos , Interferons , Potenciação de Longa Duração , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Compostos Orgânicos/farmacologia , Desempenho Psicomotor/efeitos dos fármacos , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/antagonistas & inibidores , Supressão Genética
16.
Neurobiol Stress ; 13: 100240, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33344696

RESUMO

Gulf War illness is associated with a combination of exposure to war-related chemical agents and traumatic stress. Currently, there are no effective treatments, and the pathophysiology remains elusive. Neurological problems are among the most commonly reported symptoms. In this study, we investigated the glutamatergic system in the hippocampi of mice exposed to war-related chemical agents and stress. Mice developed Gulf War illness-like symptoms, including mood deficits, cognitive impairments, and fatigue. They exhibited the following pathological changes in hippocampi: elevated extracellular glutamate levels, impaired glutamatergic synapses, astrocyte atrophy, loss of interneurons, and decreased neurogenesis. LDN/OSU-215111 is a small-molecule that can strengthen the structure and function of both the astrocytic processes and the glutamatergic synapses that together form the tripartite synapses. We found that LDN/OSU-215111 effectively prevented the development of mood and cognitive deficits in mice when treatment was implemented immediately following the exposure. Moreover, when symptoms were already present, LDN/OSU-215111 still significantly ameliorated these deficits; impressively, benefits were sustained one month after treatment cessation, indicating disease modification. LDN/OSU-215111 effectively normalized hippocampal pathological changes. Overall, this study provides strong evidence that restoration of tripartite glutamatergic synapses by LDN/OSU-215111 is a potential therapy for Gulf War illness.

17.
Materials (Basel) ; 12(16)2019 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-31405259

RESUMO

A certain amount of ferroaluminate cement (FAC) was substituted for MgO during the magnesium phosphate cement (MPC) preparation to obtain the MPC-FAC composite cement. The influence of FAC on the strength, water resistance, pH, and setting time of MPC-FAC composite cement were examined. The microstructure and chemical composition were also analyzed by adopting scanning electron microscopic energy-dispersive spectrometer and X-ray diffraction, respectively. The study showed that setting time of MPC-FAC composite cement was dramatically prolonged when FAC substitution for MgO was between 30 and 40 wt %. The strength of MPC-FAC did not decrease during the early curing time (1 h and 1 d), whereas it increased during the late curing time (3, 7, and 28 days). Moreover, the existence of FAC decreased the hydrated product K-struvite during the early curing time and thus dramatically enhanced the water-resistance of MPC-FAC. With the addition of FAC, a large number of cementitious materials of AFt and AFm, as well as flocculent colloidal substances of AH3, C-S-H, and FH3, were generated during the hydration of MPC, which were filled in the internal pore of the hydrate. Thus, the internal compactness of the sample increased, while the compact protective covering layer was generated on the surface to enhance the water resistance and strength in the late curing time.

18.
Alzheimers Res Ther ; 11(1): 75, 2019 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-31439023

RESUMO

BACKGROUND: The lack of effective treatment options for Alzheimer's disease (AD) is of momentous societal concern. Synaptic loss is the hallmark of AD that correlates best with impaired memory and occurs early in the disease process, before the onset of clinical symptoms. We have developed a small-molecule, pyridazine-based series that enhances the structure and function of both the glial processes and the synaptic boutons that form the tripartite synapse. Previously, we have shown that these pyridazine derivatives exhibit profound efficacy in an amyloid precursor protein AD model. Here, we evaluated the efficacy of an advanced compound, LDN/OSU-0215111, in rTg4510 mice-an aggressive tauopathy model. METHODS: rTg4510 mice were treated orally with vehicle or LDN/OSU-0215111 (10 mg/kg) daily from the early symptomatic stage (2 months old) to moderate (4 months old) and severe (8 months old) disease stages. At each time point, mice were subjected to a battery of behavioral tests to assess the activity levels and cognition. Also, tissue collections were performed on a subset of mice to analyze the tripartite synaptic changes, neurodegeneration, gliosis, and tau phosphorylation as assessed by immunohistochemistry and Western blotting. At 8 months of age, a subset of rTg4510 mice treated with compound was switched to vehicle treatment and analyzed behaviorally and biochemically 30 days after treatment cessation. RESULTS: At both the moderate and severe disease stages, compound treatment normalized cognition and behavior as well as reduced synaptic loss, neurodegeneration, tau hyperphosporylation, and neuroinflammation. Importantly, after 30 days of treatment cessation, the benefits of compound treatment were sustained, indicating disease modification. We also found that compound treatment rapidly and robustly reduced tau hyperphosphorylation/deposition possibly via the inhibition of GSK3ß. CONCLUSIONS: The results show that LDN/OSU-0215111 provides benefits for multiple aspects of tauopathy-dependent pathology found in Alzheimer's disease including tripartite synapse normalization and reduction of toxic tau burden, which, in turn, likely accounted for normalized cognition and activity levels in compound-treated rTg4510 mice. This study, in combination with our previous work regarding the benefit of pyridazine derivatives against amyloid-dependent pathology, strongly supports pyridazine derivatives as a viable, clinically relevant, and disease-modifying treatment for many of the facets of Alzheimer's disease.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Transportador 2 de Aminoácido Excitatório , Piridazinas/farmacologia , Sinapses/efeitos dos fármacos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Comportamento Animal/efeitos dos fármacos , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Piridazinas/administração & dosagem , Piridazinas/análise , Sinapses/patologia
19.
Neuroscience ; 411: 237-254, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31146008

RESUMO

The administration of exogenous insulin into the hippocampus has the potential to enhance cognitive function and exert other beneficial effects. Elucidating the neurobiological substrates of insulin action and its underlying physiological mechanisms may further improve treatment efficacy. Previous work has shown that insulin affects synaptic plasticity, however there are discrepancies and contradictory conclusions between studies. Here, we used extracellular field recordings in mouse hippocampal slices to investigate how insulin acutely modulates synaptic transmission and synaptic plasticity, both of which are correlated with learning and memory processes. Our data demonstrate that insulin application inhibited basal excitatory synaptic transmission and promoted long-term potentiation (LTP) induction at hippocampal Schaffer collateral-CA1 synapses. Under similar conditions, insulin strongly activated the PI3K/AKT pathway, but had only a weak effect on the MAPK/ERK pathway. Although insulin-induced inhibition of field excitatory post-synaptic potentials (fEPSPs) was previously termed insulin-long-term depression (insulin-LTD), insulin application potentiated recovery from classically induced LTD. Further analysis suggests suppression of presynaptic neurotransmitter release contributed to the insulin-LTD. At low concentrations, insulin primarily inhibited fEPSPs; however, at high concentration, its effects were of mixed inhibition and enhancement in different recordings. Moreover, a broad spectrum protein kinase C blocker, cannabinoid receptor type 1 activator, or a high glucose concentration inhibited fEPSPs per se, and disturbed insulin's effect on fEPSP. Insulin also caused depotentiation during LTP expression and triggered depression during LTD recovery. Given the essential roles of dynamic synaptic transmission and plasticity in learning and memory, our data provide more evidence that insulin application may actively modulate hippocampal-dependent cognitive events.


Assuntos
Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Plasticidade Neuronal/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Animais , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Hipocampo/metabolismo , Masculino , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos
20.
Front Pharmacol ; 9: 1169, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30459599

RESUMO

Intracerebral hemorrhage is a fatal subtype of stroke, with crucial impact on public health. Surgical removal of the hematoma as an early-stage treatment for ICH can't improve long-term prognosis remarkably. Liangxue tongyu prescription (LP), a Traditional Chinese Medicine (TCM) formula, includes eight ingredients and has been used to treat ICH in the clinical. In the study, we elucidated the pharmacological efficacy and therapeutic efficacy of LP to dissect the mechanism of LP against ICH via network analysis and experimental validation. First, we discovered 34 potential compounds and 146 corresponding targets in LP based on network prediction. 24 signal pathway were obtained by the Clue Go assay based on potential compounds in LP against ICH. Second, we found that LP can not only decreased the level of high sensitive C reactive protein (HS-CRP), tumor necrosis factor-α (TNF-α), NF-kß, D-dimmer (D2D), estradiol (E2), S-100B, neuron specific enolase (NSE), and interleukin 1 (IL-1) in plasma on spontaneously hypertensive rats (SHRs), but also promoted cell proliferation and inhibited cell apoptosis on the glutamate-induced PC12 cell. The compounds including Taurine, Paeonol, and Ginsenoside Rb1 in LP can activate PI3K/AKT pathway. Third, from the three-factor two-level factorial design, compound combinations in LP, such as Taurine and Paeonol, Taurine and Geniposide, Ginsenoside Rg1, and Ginsenoside Rb1, had first-level interactions on cell proliferation. Compound combinations including Taurine and Paeonol, Ginsenoside Rg1 and Ginsenoside Rb1 had as significant increase in efficiency on inhibiting the apoptosis of PC12 cells at the low concentration and up-regulating of PI3K and AKT. Overall, our results suggested that LP had integrated therapeutic effect on ICH due to activities of anti-inflammatory, anti-coagulation, blood vessel protection, and protection neuron from excitotoxicity based on the way of "multi-component, multi-target, multi-pathway," and compound combination in LP can offer protection neuron from excitotoxicity at the low concentration by activation of the PI3K/Akt signal pathway.

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