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1.
Brain Behav Immun ; 120: 499-512, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38944162

RESUMO

The gut microbiota and neurological development of neonatal mice are susceptible to environmental factors that may lead to altered behavior into adulthood. However, the role that changed gut microbiota and neurodevelopment early in life play in this needs to be clarified. In this study, by modeling early-life environmental changes by cross-fostering BALB/c mice, we revealed the effects of the environment during the critical period of postnatal development on adult social behavior and their relationship with the gut microbiota and the nervous system. The neural projections exist between the ascending colon and oxytocin neurons in the paraventricular nuclei (PVN), peripheral oxytocin levels and PVN neuron numbers decreased after cross-fostering, and sex-specific alteration in gut microbiota and its metabolites may be involved in social impairments and immune imbalances brought by cross-fostering via the gut-brain axis. Our findings also suggest that social cognitive impairment may result from a combination of PVN oxytocinergic neurons, gut microbiota, and metabolites.

2.
J Psychiatry Neurosci ; 49(3): E192-E207, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38816029

RESUMO

BACKGROUND: Recent studies have identified empathy deficit as a core impairment and diagnostic criterion for people with autism spectrum disorders; however, the improvement of empathy focuses primarily on behavioural interventions without the target regulation. We sought to compare brain regions associated with empathy-like behaviours of fear and pain, and to explore the role of the oxytocin-oxytocin receptor system in fear empathy. METHODS: We used C57BL mice to establish 2 models of fear empathy and pain empathy. We employed immunofluorescence histochemical techniques to observe the expression of c-Fos throughout the entire brain and subsequently quantified the number of c-Fos-positive cells in different brain regions. Furthermore, we employed chemogenetic technology to selectively manipulate these neurons in Oxt-Cre-/+ mice to identify the role of oxytocin in this process. RESULTS: The regions activated by fear empathy were the anterior cingulate cortex, basolateral amygdala, nucleus accumbens, paraventricular nucleus (PVN), lateral habenula, and ventral and dorsal hippocampus. The regions activated by pain empathy were the anterior cingulate cortex, basolateral amygdala, nucleus accumbens, and lateral habenula. We found that increasing the activity of oxytocin neurons in the PVN region enhanced the response to fear empathy. This enhancement may be mediated through oxytocin receptors. LIMITATIONS: This study included only male animals, which restricts the broader interpretation of the findings. Further investigations on circuit function need to be conducted. CONCLUSION: The brain regions implicated in the regulation of fear and pain empathy exhibit distinctions; the activity of PVN neurons was positively correlated with empathic behaviour in mice. These findings highlight the role of the PVN oxytocin pathway in regulating fear empathy and suggest the importance of oxytocin signalling in mediating empathetic responses.


Assuntos
Empatia , Medo , Camundongos Endogâmicos C57BL , Neurônios , Ocitocina , Núcleo Hipotalâmico Paraventricular , Animais , Ocitocina/metabolismo , Masculino , Núcleo Hipotalâmico Paraventricular/metabolismo , Medo/fisiologia , Empatia/fisiologia , Neurônios/metabolismo , Camundongos , Receptores de Ocitocina/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Dor/fisiopatologia , Dor/psicologia , Camundongos Transgênicos
3.
Anal Chem ; 94(33): 11573-11581, 2022 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-35943780

RESUMO

Energy deprivation and reduced levels of hydrogen sulfide (H2S) in the brain is closely associated with Alzheimer's disease (AD). However, there is currently no fluorescent probe for precise exploration of both H2S and adenosine triphosphate (ATP) to directly demonstrate their relationship and their dynamic pattern changes. Herein, we developed a two-photon fluorescent probe, named AD-3, to simultaneously image endogenous H2S and ATP from two emission channels of fluorescent signals in live rat brains with AD. The probe achieved excellent selectivity and good detection linearity for H2S in the 0-100 µM concentration range and ATP in the 2-5 mM concentration range, respectively, with a detection limit of 0.19 µM for H2S and 0.01 mM for ATP. Fluorescence imaging in live cells reveals that such probe could successfully apply for simultaneous imaging and accurate quantification of H2S and ATP in neuronal cells. Further using real-time quantitative polymerase chain reaction and Western blots, we confirmed that H2S regulates ATP synthesis by acting on cytochrome C, cytochrome oxidase subunit 3 of complex IV, and protein 6 of complex I in the mitochondrial respiratory chain. Subsequently, we constructed a high-throughput screening platform based on AD-3 probe to rapidly screen the potential anti-AD drugs to control glutamate-stimulated oxidative stress associated with abnormal H2S and ATP levels. Significantly, AD-3 probe was found capable of imaging of H2S and ATP in APP/PS1 mice, and the concentration of H2S and ATP in the AD mouse brain was found to be lower than that in wild-type mice.


Assuntos
Doença de Alzheimer , Sulfeto de Hidrogênio , Trifosfato de Adenosina , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/metabolismo , Animais , Corantes Fluorescentes , Ácido Glutâmico , Células HeLa , Humanos , Sulfeto de Hidrogênio/análise , Camundongos , Fótons , Ratos
4.
Neural Plast ; 2020: 6283754, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32273890

RESUMO

The motor and nonmotor symptoms of PD involve several brain regions. However, whether α-syn pathology originating from the SNc can directly lead to the pathological changes in distant cerebral regions and induce PD-related symptoms remains unclear. Here, AAV9-synapsin-mCherry-human SNCA (A53T) was injected into the unilateral SNc of mice. Motor function and olfactory sensitivity were evaluated. Our results showed that AAV9-synapsin-mCherry-human SNCA was continuously expressed in SNc. The animals showed mild motor and olfactory dysfunction at 7 months after viral injection. The pathology in SNc was characterized by the loss of dopaminergic neurons accompanied by ER stress. In the striatum, hα-syn expression was high, CaMKß-2 and NR2B expression decreased, and active synapses reduced. In the olfactory bulb, hα-syn expression was high, and aging cells in the mitral layer increased. The results suggested that hα-syn was transported in the striatum and OB along the nerve fibers that originated from the SNc and induced pathological changes in the distant cerebral regions, which contributed to the motor and nonmotor symptoms of PD.


Assuntos
Neurônios/patologia , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Parte Compacta da Substância Negra/metabolismo , Parte Compacta da Substância Negra/patologia , Sinapses/patologia , alfa-Sinucleína/metabolismo , Adenoviridae/fisiologia , Animais , Vetores Genéticos/fisiologia , Masculino , Camundongos Endogâmicos C57BL , Bulbo Olfatório/metabolismo , Bulbo Olfatório/patologia , alfa-Sinucleína/administração & dosagem
5.
Med Sci Monit ; 25: 240-247, 2019 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-30617247

RESUMO

BACKGROUND This study observed the incidence of in-stent restenosis (ISR) after percutaneous coronary intervention (PCI) and discusses the risk factors of ISR based on clinical data, coronary angiography, and stent features, to provide a theoretical basis for the prevention and treatment of ISR. MATERIAL AND METHODS We selected 1132 cases who received stent implantation at the Shaanxi People's Hospital from June 2014 to June 2016 and were followed up by coronary angiography within 1 year. Based on coronary angiography, the cases were divided into ISR and non-ISR groups. ISR was defined as a reduction in lumen diameter by over 50% after PCI. The ISR group consisted of 93 cases and the non-ISR group consisted of 1039 cases. Medical history, biochemical indicators, features of coronary artery lesions, and stent status were analyzed retrospectively. Risk factors of ISR were identified by univariate and multivariate logistic regression analyses. RESULTS Among 1132 cases, 93 cases had ISR, with the overall incidence of 8.21%. Univariate and multivariate logistic regression analyses indicated that postoperative hypersensitive C-reactive protein (hs-CRP) levels (OR=2.309, 1.579-3.375 mg/L), postoperative homocysteine (HCY) levels (OR=2.202, 1.268-3.826 µmol/L), history of diabetes (OR=1.955,1.272-3.003), coronary bifurcation lesions (OR=3.785, 2.246-6.377), and stent length (OR=1.269, 1.179-1.365 mm) were independent risk factors of ISR after PCI (P<0.05). CONCLUSIONS Elevated hs-CRP and HCY levels after PCI, history of diabetes, coronary bifurcation lesions, and greater stent length were associated with a higher risk of ISR. Patients with a higher risk of ISR should receive routine follow-up and intense medication management after PCI to control the risk factors and to reduce ISR.


Assuntos
Reestenose Coronária/etiologia , Intervenção Coronária Percutânea/efeitos adversos , Stents/efeitos adversos , Idoso , Proteína C-Reativa/análise , China , Angiografia Coronária/efeitos adversos , Doença da Artéria Coronariana/complicações , Vasos Coronários/fisiopatologia , Feminino , Seguimentos , Homocisteína/análise , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco
6.
Behav Brain Funct ; 14(1): 7, 2018 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-29554926

RESUMO

BACKGROUND: Following a social defeat, the balanced establishment and extinction of aversive information is a beneficial strategy for individual survival. Abnormal establishment or extinction is implicated in the development of mental disorders. This study investigated the time course of the establishment and extinction of aversive information from acute social defeat and the temporal responsiveness of the basolateral amygdala (BLA), ventral hippocampus (vHIP) and medial prefrontal cortex (mPFC) in this process. METHODS: Mouse models of acute social defeat were established by using the resident-intruder paradigm. To evaluate the engram of social defeat, the intruder mice were placed into the novel context at designated time to test the social behavior. Furthermore, responses of BLA, vHIP and mPFC were investigated by analyzing the expression of immediate early genes, such as zif268, arc, and c-fos. RESULTS: The results showed after an aggressive attack, aversive memory was maintained for approximately 7 days before gradually diminishing. The establishment and maintenance of aversive stimulation were consistently accompanied by BLA activity. By contrast, vHIP and mPFC response was inhibited from this process. Additionally, injecting muscimol (Mus), a GABA receptor agonist, into the BLA alleviated the freezing behavior and social fear and avoidance. Simultaneously, Mus treatment decreased the zif268 and arc expression in BLA, but it increased their expression in vHIP. CONCLUSION: Our data support and extend earlier findings that implicate BLA, vHIP and mPFC in social defeat. The time courses of the establishment and extinction of social defeat are particularly consistent with the contrasting BLA and vHIP responses involved in this process.


Assuntos
Complexo Nuclear Basolateral da Amígdala/metabolismo , Extinção Psicológica/fisiologia , Medo/fisiologia , Hipocampo/metabolismo , Consolidação da Memória/fisiologia , Córtex Pré-Frontal/metabolismo , Animais , Medo/psicologia , Genes Precoces/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Distribuição Aleatória , Comportamento Social
7.
J Nutr Biochem ; 125: 109570, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38218348

RESUMO

High salt diet (HSD) is a risk factor of hypertension and cardiovascular disease. Although clinical data do not clearly indicate the relationship between HSD and the prevalence of Alzheimer's disease (AD), animal experiments have shown that HSD can cause hyperphosphorylation of tau protein and cognition impairment. However, whether HSD can accelerate the progression of AD by damaging the function of neurovascular unit (NVU) in the brain is unclear. Here, we fed APP/PS1 mice (an AD model) or wild-type mice with HSD and found that the chronic HSD feeding increased the activity of enzymes related to tau phosphorylation, which led to tau hyperphosphorylation in the brain. HSD also aggravated the deposition of Aß42 in hippocampus and cortex in the APP/PS1 mice but not in the wild-type mice. Simultaneously, HSD caused the microglia proliferation, low expression of Aqp-4, and high expression of CD31 in the wild-type mice, which were accompanied with the loss of pericytes (PCs) and increase in blood brain barrier (BBB) permeability. As a result, wild-type mice fed with HSD performed poorly in Morris Water Maze and object recognition test. In the APP/PS1 mice, HSD feeding for 8 months worsen the cognition and accompanied the loss of PCs, the activation of glia, the increase in BBB permeability, and the acceleration of calcification in the brain. Our data suggested that HSD feeding induced the AD-like pathology in wild-type mice and aggravated the development of AD-like pathology in APP/PS1 mice, which implicated the tau hyperphosphorylation and NVU dysfunction.


Assuntos
Doença de Alzheimer , Camundongos , Animais , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Camundongos Transgênicos , Proteínas tau/metabolismo , Dieta , Cognição , Cloreto de Sódio na Dieta/efeitos adversos , Modelos Animais de Doenças , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Presenilina-1/genética , Presenilina-1/metabolismo
8.
J Mater Chem B ; 12(23): 5619-5627, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38770837

RESUMO

Abnormal neuronal polarity leads to early deficits in Alzheimer's disease (AD) by affecting the function of axons. Precise and rapid evaluation of polarity changes is very important for the early prevention and diagnosis of AD. However, due to the limitations of existing detection methods, the mechanism related to how neuronal polarity changes in AD is unclear. Herein, we reported a ratiometric fluorescent probe characterized by neutral molecule to disclose the polarity changes in nerve cells and the brain of APP/PS1 mice. Cy7-K showed a sensitive and selective ratiometric fluorescence response to polarity. Remarkably, unlike conventional intramolecular charge transfer fluorescent probes, the fluorescence quantum yield of Cy7-K in highly polar solvents is higher than that in low polar solvents due to the transition of neutral quinones to aromatic zwitterions. Using the ratiometric fluorescence imaging, we found that beta-amyloid protein (Aß) inhibits the expression of histone deacetylase 6, thereby increasing the amount of acetylated Tau protein (AC-Tau) and ultimately enhancing cell polarity. There was a high correlation between polarity and AC-Tau. Furthermore, Cy7-K penetrated the blood-brain barrier to image the polarity of different brain regions and confirmed that APP/PS1 mice had higher polarity than Wild-type mice. The probe Cy7-K will be a promising tool for assessing the progression of AD development by monitoring polarity.


Assuntos
Doença de Alzheimer , Corantes Fluorescentes , Proteínas tau , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/metabolismo , Doença de Alzheimer/diagnóstico , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Animais , Proteínas tau/metabolismo , Proteínas tau/análise , Camundongos , Acetilação , Imagem Óptica , Humanos , Camundongos Transgênicos , Estrutura Molecular
9.
J Colloid Interface Sci ; 639: 263-273, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36805751

RESUMO

Constructing well-defined nanostructures consisting of the multiple components with distinctive features are a promising but challenging strategy to develop advanced electroactive materials for energy storage applications. Herein, heterogeneous Ni-Co phosphide/phosphate with a specific hollow sea-urchin-like structure has been synthesized as advanced electroactive materials for both hybrid supercapacitor (HSC) and alkaline zinc-metal battery (AZB) applications. The heterogeneous Ni-Co phosphide/phosphate combines the merits of improved electrolyte interfacial property from the specific hollow sea-urchin-like structure, high electron-conductivity of phosphide, and better ion adsorption and solid diffusion property of phosphate. As a result, the Ni-Co phosphide/phosphate achieves a high capacity to 180.7 mA h g-1 at 1 A g-1, excellent rate capability of 51% capacity retention when the specific current increases by 50 times, and stable cycling stability of 85% capacity retention when cycled for 1000 cycles. Ex situ test was conducted to investigate the formation mechanism for the hollow and sea-urchin-like structure, which can be ascribed to the anion exchange reaction between pre-formed hydroxide and CO32- ions. When used to assemble HSCs with reduced graphene oxide (RGO), the HSCs exhibit a high specific energy of 49.4 W h kg-1, an ultrahigh specific power to 11.7 kW kg-1, and an eminent cycling stability over 10,000 cycles. Meanwhile, Ni2Co-P/POx-based AZB also achieves both high-energy and high-power performance with the specific energy of 308.0 W h kg-1 at 828.4 W kg-1 and 117.4 W h kg-1 at 30.8 kW kg-1. These results above suggest that heterogeneous Ni-Co phosphide/phosphate has great potential to be used as a candidate for both HSC and AZB applications.

10.
Front Cardiovasc Med ; 9: 836514, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35800169

RESUMO

Cardiac resynchronization therapy (CRT) for heart failure requires transvenous insertion of a left ventricular pacing lead through the coronary sinus. However, repeated intraoperative dislocations often occur. Therefore, we describe a novel technique that uses the loop technique to treat patients with repeated intraoperative dislocations during transvenous left ventricular lead implantation to stabilize the lead in its final position. In five patients with repeated intraoperative dislocation during transvenous left ventricular lead implantation, the loop technique was successfully used to stabilize the lead in its final position. The pacing and sensing parameters were satisfactory in all patients at implantation and 12 months post-operatively. Compared with the pre-operative values, the 12-month post-operative values for the left ventricular ejection fraction were significantly increased and the left ventricular end systolic dimension and left ventricular end diastolic dimension were significantly decreased (P < 0.05). The left ventricular ejection fraction of these 5 patients increased by more than 15%. CRT significantly improved the left ventricular structure and function of these 5 patients. During the 1-, 3-, 6-, and 12-month follow-ups, no left ventricular lead dislocations were observed. This loop technique is safe and effective and can be considered for repeated intraoperative dislocation during transvenous left ventricular lead implantation through the coronary sinus of a CRT device.

11.
J Colloid Interface Sci ; 607(Pt 1): 61-67, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34492354

RESUMO

Rechargeable alkaline nickel-zinc (Ni-Zn) batteries are attracting increased attention owing to their exceptional inherent safety and high specific capacity. Unfortunately, the limited power and cycling performances of these Ni-Zn batteries are still challenging. Herein, bimetal nickel-cobalt sulfide/ reduced graphene oxide (NiCo-S/RGO) composites with tunable compositions are synthesized by rational designing precursor and subsequent sulfidation treatment. NiCo-S is evenly anchored on RGO surface, resulting in increased number of electrochemical active sites, accelerated electrolyte ion diffusion, and enhanced electrical conductivity. Particularly, by tuning the Ni and Co composition ratios in NiCo-S, NiCo-S/RGO with a Ni to Co ratio of 2:1 (NiCo-S-2/RGO) shows a specific capacity of 145.7 mA h g-1 at 1 A g-1 and long-life cycling retention of 84.7% after 1000 cycles, and the above performances are superior than the controlled samples with other Ni to Co ratios. Furthermore, the as-assembled alkaline zinc batteries of NiCo-S-2/RGO//Zn deliver an impressive specific energy of 333.2 W h kg-1, showing great potential in practical applications. This experiment hopefully provides new idea for construction of high-performance electrodes of aqueous rechargeable batteries.

12.
Neuropeptides ; 96: 102268, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35841876

RESUMO

According to many in the field,the prevalence of Alzheimer's disease (AD) in type II diabetes (T2DM) populations is considerably higher than that in the normal population. Human islet amyloid polypeptide (hIAPP) is considered to be a common risk factor for T2DM and AD. Preliminary observations around T2DM animal model show that the decrease of adult neural stem cells (NSCs) in the subventricular zone (SVZ) is accompanied by olfactory dysfunction. Furthermore, impaired olfactory function could serve as to an early predictor of neurodegeneration,which is associated with cognitive impairment. However, the synergistic effects between hIAPP and amyloid-beta (Aß) 1-42 in the brain and the neurodegeneration remains to be further clarified. In this study, olfactory capacity, synaptic density, status of NSC in SVZ, and status of newborn neurons in olfactory bulb (OB) were assessed 6 months after stereotactic injection of oligomer Aß1-42 into the dens gyrus (DG) of hIAPP-/+ mice or wild-type homogenous mice. Our results set out that Aß42 and amylin co-localized into OB and raised Aß42 deposition in hIAPP-/+ mice compared with wild-type brood mice. In addition, 6 months after injection of Aß1-42 in hIAPP-/+ mice, these mice showed increased olfactory dysfunction, significant loss of synapses, depletion of NSC in SVZ, and impaired cell renewal in OB. Our present study suggested that the synergistic effects between hIAPP and Aß1-42 impairs olfactory function and was associated with decreased neurogenesis in adults with SVZ.


Assuntos
Doença de Alzheimer , Diabetes Mellitus Tipo 2 , Transtornos do Olfato , Animais , Camundongos , Humanos , Ventrículos Laterais , Neurogênese , Bulbo Olfatório
13.
Front Aging Neurosci ; 14: 842380, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36004003

RESUMO

Multiple factors such as genes, environment, and age are involved in developing Parkinson's disease (PD) pathology. However, how various factors interact to cause PD remains unclear. Here, 3-month and 9-month-old hα-syn+⁣/- mice were treated with low-dose rotenone for 2 months to explore the mechanisms that underline the environment-gene-age interaction in the occurrence of PD. We have examined the behavior of mice and the PD-like pathologies of the brain and gut. The present results showed that impairments of the motor function and olfactory function were more serious in old hα-syn+/- mice with rotenone than that in young mice. The dopaminergic neuron loss in the SNc is more in old hα-syn+/- mice with rotenone than in young mice. Expression of hα-syn+/- is increased in the SNc of hα-syn+/- mice following rotenone treatment for 2 months. Furthermore, the number of activated microglia cells increased in SNc and accompanied the high expression of inflammatory cytokines, namely, TNF-α and IL-18 in the midbrain of old hα-syn+/- mice treated with rotenone. Meanwhile, we found that after treatment with rotenone, hα-syn positive particles deposited in the intestinal wall, intestinal microflora, and T lymphocyte subtypes of Peyer's patches changed, and intestinal mucosal permeability increased. Moreover, these phenomena were age-dependent. These findings suggested that rotenone aggravated the PD-like pathologies and affected the brain and gut of human α-syn+/- transgenic mice in an age-dependent manner.

14.
J Colloid Interface Sci ; 558: 291-300, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31604157

RESUMO

Transition metal selenides are very ideal as electroactive battery material for hybrid supercapacitors owing to their high electrochemical activity and metallic electrical conductivity, but their environmental friendly fabrication and complex structure construction is still a big challenge. Here, a simple low-temperature selenization method has been developed to green synthesize a series of Ni-Co selenide samples with a hierarchical nanoparticle/nanosheet structure. The hierarchical structure has been constructed by the recrystallization of sample during the selenization process, which can be greatly influenced by the Co composition. The specific hierarchical structure provides more electroactive sites for charge storage, and the optimized synergy between the Ni and Co compositions further greatly tunes the charge storage performance, as a result, the Ni0.67Co0.33Se2 shows the best performance with a specific capacity of 447 C g-1 at 1 A g-1, which is much higher than the Ni-Co selenides with the other Ni to Co ratios and the Ni-Co oxides. The Ni0.67Co0.33Se2 retains 97% of the specific capacity after 2000 cycles, demonstrating its excellent cycling stability. A hybrid supercapacitor has been assembled using Ni0.67Co0.33Se2 as the positive electrode, which shows both high specific energy and specific power performances.

15.
Biochim Biophys Acta Gen Subj ; 1864(1): 129422, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31491457

RESUMO

BACKGROUND: Previous studies suggested that fibrillar human IAPP (hIAPP) is more likely to deposit in ß-cells, resulting in ß-cell injury. However, the changes in the conformation of hIAPP in lipid environment and the mechanism involved in ß-cell damage are unclear. METHODS: Synthetic hIAPP was incubated with five types of free fatty acids and phospholipids 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-l-serine (POPS), which constitute the cell membrane. Thioflavin-T fluorescence assay was conducted to analyze the degree of hIAPP fibrosis, and circular dichroism spectroscopy was performed to detect the ß-fold formation of hIAPP. Furthermore, INS-1 cells were infected with human IAPP delivered by a GV230-EGFP plasmid. The effects of endogenous hIAPP overexpression induced by sodium palmitate on the survival, endoplasmic reticulum (ER) stress, and apoptosis of INS-1 cells were evaluated. RESULTS: The five types of free fatty acids can accelerate the fibrosis of hIAPP. Sodium palmitate also maintained the stability of fibrillar hIAPP. POPS, not POPC, accelerated hIAPP fibrosis. Treatment of INS-1 cells with sodium palmitate increased the expression of hIAPP, activated ER stress and ER stress-dependent apoptosis signaling pathways, and increased the apoptotic rate. CONCLUSION: Free fatty acids and anionic phospholipid can promote ß-fold formation and fibrosis in hIAPP. High lipid induced the overexpression of hIAPP and aggravated ER stress and apoptosis in INS-1 cells, which caused ß-cell death in high lipid environment. GENERAL SIGNIFICANCE: Our study reveals free fatty acids and hIAPP synergistically implicated in endoplasmic reticulum stress and apoptosis of islet ß-cells.


Assuntos
Apoptose/genética , Fibrose/genética , Células Secretoras de Insulina/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/genética , Amiloide/genética , Amiloide/metabolismo , Membrana Celular/genética , Membrana Celular/metabolismo , Estresse do Retículo Endoplasmático/genética , Ácidos Graxos não Esterificados/genética , Ácidos Graxos não Esterificados/metabolismo , Fibrose/metabolismo , Fibrose/patologia , Regulação da Expressão Gênica/genética , Humanos , Células Secretoras de Insulina/patologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/ultraestrutura , Metabolismo dos Lipídeos/genética , Lipídeos/genética , Ácido Palmítico/metabolismo , Fosfatidilcolinas/genética , Fosfatidilcolinas/metabolismo , Fosfatidilserinas/genética , Fosfatidilserinas/metabolismo , Conformação Proteica em Folha beta , Dobramento de Proteína
16.
Exp Neurol ; 334: 113490, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33007295

RESUMO

Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM) have a common pathology. Both diseases are characterized by local deposition of amyloid proteins in the brain or islet organ, but their phenotypes and clinical manifestation vary widely. Although the sources of islet amyloid polypeptide (IAPP) and amyloid beta (Aß) are independent, their fibrillar sequences are highly homologous. The prevalence of AD in T2DM populations is considerably higher than that in the normal population, but a mechanistic linkage remains elusive. Therefore, the present study aimed to explore the effects of Aß42 deposition in the brain on the persistently expression of human IAPP (hIAPP). Additionally, cognitive ability, synaptic plasticity, the state of neural stem cells and mitochondrial function were evaluated at 2 or 6 months after stereotaxically injected the oligomer Aß1-42 into the dentate gyrus of hIAPP (-/+) mice or the wild-type littermates. We found that Aß42 and amylin were co-located in hippocampus and Aß42 levels increased when Aß1-42 was injected in hIAPP transgenic mice compared with that of the wild-type littermates. Furthermore, at 6 months after Aß1-42 injection in hIAPP (-/+) mice, it exhibits exacerbated AD-related pathologies including Aß42 deposition, cognitive impairment, synapse reduction, neural stem cells exhaustion and mitochondrial dysfunction. Our present study suggested that hIAPP directly implicated the Aß42 production and deposition as an important linkage between T2DM and AD.


Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/toxicidade , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/patologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Fragmentos de Peptídeos/toxicidade , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/administração & dosagem , Animais , Linhagem Celular , Disfunção Cognitiva/genética , Giro Denteado/metabolismo , Giro Denteado/patologia , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Fragmentos de Peptídeos/administração & dosagem , Ligação Proteica/fisiologia
17.
Front Aging Neurosci ; 11: 225, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507407

RESUMO

The accumulation of human islet amyloid polypeptide (hIAPP) in pancreatic islets under induction by a high-fat diet plays a critical role in the development of type-2 diabetes mellitus (T2DM). T2DM is a risk factor of late-onset Alzheimer's disease (AD). Nevertheless, whether hIAPP in combination with hyperlipidemia may lead to AD-like pathological changes in the brain remains unclear. hIAPP transgenic mice were fed with a high-fat diet for 6 or 12 months to establish the T2DM model. The accumulation of amylin, the numbers of Fluoro-Jade C (FJC)-positive and ß-gal positive cells, and the deposition level of Aß42 in the hippocampi of the transgenic mice were detected by using brain sections. Cytoplasmic and membrane proteins were extracted from the hippocampi of the transgenic mice, and the ratio of membrane GLUT4 expression to cytoplasmic GLUT4 expression was measured through Western blot analysis. Changes in the cognitive functions of hIAPP transgenic mice after 12 months of feeding with a high-fat diet were evaluated. hIAPP transgenic mice fed with a high-fat diet for 6 or 12 months showed elevated blood glucose levels and insulin resistance; increased amylin accumulation, number of FJC-positive and ß-gal positive cells, and Aß42 deposition in the hippocampi; and reduced membrane GLUT4 expression levels. hIAPP transgenic mice fed with a high-fat diet for 12 months showed reductions in social cognitive ability and passive learning ability. A high-fat diet increased amylin accumulation in the hippocampi of hIAPP transgenic mice, which presented AD-like pathology and behavior characterized by neural degeneration, brain aging, Aß42 deposition, and impaired glucose utilization and cognition.

18.
Rev Sci Instrum ; 90(9): 095103, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31575227

RESUMO

Sliding electrical contact exists in various electrical equipment. However, its performance is significantly affected by the sliding condition such as the load, electricity, and the surface state of friction pairs. In this study, a novel instrument is designed and constructed for high-frequency microforce electrical sliding friction testing. The new instrument provides a unique experimental platform that enables high-frequency reciprocating friction and microforce loading, and it has an innovative data collection system that includes a cantilever beam structure to measure the microforce. In this instrument, parameters (positive force, friction, displacement, and voltage of frictional pair) are obtained and monitored in real time. The steel sheet and nickel-plated steel wire were used as materials to conduct an experiment, and the steel sheet morphology after the experiment was observed using a light microscope. Results show that the voltage and positive load significantly influence the friction coefficient and friction wear, which is crucial in understanding friction and wear behaviors.

19.
J Colloid Interface Sci ; 548: 233-243, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31004956

RESUMO

A novel and simple approach to preparing hierarchical zinc oxide/reduced graphene oxide (ZnO/RGO@RGO) composite is demonstrated using few-layered graphene oxide (GO) and metal zinc as starting materials following combined processes, including in-situ metal zinc reduction and catalyzed GO deoxygenation. Metal zinc can directly reduce GO sheets in aqueous GO suspension at room temperature to obtain a porous composite precursor (ZnO/RGO) with ZnO nanoparticles anchored on the RGO sheets. Then another RGO protecting layer is directly coated on the ZnO/RGO precursor to obtain the hierarchical ZnO/RGO@RGO composite. In this step, the exposed ZnO nanoparticles on the surface of ZnO/RGO play the role of catalyst to accelerate the deoxygenation of GO from the extra added GO aqueous suspension under mild hydrothermal condition. The reaction mechanism of metal zinc with GO aqueous suspension has been explored and the catalyst role of ZnO has been verified in this work. The prepared ZnO/RGO@RGO composite exhibited both stable cycling performance and good rate capability as anode for lithium-ion batteries. The method to prepare ZnO/RGO composite is economic and eco-friendly, and the ZnO catalyzing GO reduction opens a new approach to prepare graphene derivates.

20.
Exp Gerontol ; 108: 77-86, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29649571

RESUMO

Changes in mitochondrial structure and function are the initial factors of cell aging. Spermidine has an antiaging effect, but its effect on neuronal aging and mitochondrial mechanisms is unclear. In this study, mouse neuroblastoma (N2a) cells were treated with d­galactose (d­Gal) to establish cell aging to investigate the antiaging effect and mechanisms of spermidine. Changes in the cell cycle and ß-galactosidase activity were analyzed to evaluate the extent of cell aging. Stabilities of mitochondrial mRNA and mitochondrial membrane potential (MMP) were evaluated in the process of cell aging under different treatments. The mitochondrial function was also evaluated using the Seahorse Metabolic Analysis System combined with ATP production. The unfolded protein response (UPR) of the N2a cells was analyzed under different treatments. Results showed that spermidine pretreatment could delay the cell aging and could maintain the mitochondrial stability during d­Gal treatment. Spermidine increased the proportion of cells in the S phase and maintained the MMP. The oxygen utilization and ATP production in the N2a cells were reduced by d­Gal treatment but were partially rescued by the spermidine pretreatment. Spermidine ameliorated the N2a cell aging by promoting the autophagy and inhibiting the apoptosis except the UPR. These results showed that spermidine could ameliorate the N2a cell aging by maintaining the mitochondrial mRNA transcription, MMP and oxygen utilization during the d­Gal treatment.


Assuntos
Senescência Celular/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Espermidina/farmacologia , Envelhecimento/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Ciclo Celular , Linhagem Celular Tumoral , Galactose/toxicidade , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/fisiologia
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