RESUMO
Diabetic rats display cognition impairments accompanied by activation of NF-κB signalling and increased Aß expression. Ghrelin has been suggested to improve cognition in diabetic rats. In this study, we investigated the role of ghrelin on cognition and NF-κB mediated Aß production in diabetic rats. A diabetic rat model was established with streptozotocin (STZ) injection, and diabetic rats were intracerebroventricularly administered with ghrelin or (D-lys3)-GHRP-6 (DG). Our results showed that diabetic rats had cognition impairment in the Morris water maze test, accompanied by the higher expression of Aß in the hippocampus. Western blot analysis showed that diabetic rats exhibited significantly decreased levels of GHSR-1a and protein phosphatase 1 (PP1) in the hippocampus and increased activation of the IKK/NF-κB/BACE1 pathway. Chronic ghrelin administration upregulated hippocampal PP1 expression, suppressed IKK/NF-κB/BACE1 mediated Aß production, and improved cognition in STZ-induced diabetic rats. These effects were reversed by DG. Then, primary rat hippocampal neurons were isolated and treated with high glucose, followed by Ghrelin and DG, PP1 or IKK. Similar to the in vivo results, high glucose suppressed the expression levels of GHSR-1a and PP1, activated the IKK/NF-κB/BACE1 pathway, increased Aß production. Ghrelin suppressed IKK/NF-κB/BACE1 induced Aß production. This improvement was reversed by DG and a PP1 antagonist and was enhanced by the IKK antagonist. Our findings indicated that chronic ghrelin administration can suppress IKK/NF-κB/BACE1 mediated Aß production in primary neurons with high glucose treatment and improve the cognition via PP1 upregulation in diabetic rats.
Assuntos
Peptídeos beta-Amiloides/metabolismo , Cognição/fisiologia , Diabetes Mellitus Experimental/metabolismo , Grelina/metabolismo , Neurônios/metabolismo , Proteína Fosfatase 1/metabolismo , Transdução de Sinais , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Células Cultivadas , Cognição/efeitos dos fármacos , Diabetes Mellitus Experimental/psicologia , Grelina/administração & dosagem , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/ultraestrutura , Quinase I-kappa B/metabolismo , Masculino , NF-kappa B/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Estreptozocina/administração & dosagem , Sinapses/efeitos dos fármacos , Sinapses/ultraestrutura , Regulação para CimaRESUMO
Beta-amyloid (Aß), the hallmark protein in Alzheimer's disease (AD), induces neurotoxicity that involves oxidative stress and mitochondrial dysfunction, leading to cell death. Carnosic acid (CA), a polyphenolic diterpene isolated from the herb rosemary (Rosemarinus officinalis), was investigated in our study to assess its neuroprotective effect and underlying mechanism against Aß-induced injury in human neuroblastoma SH-SY5Y cells. We found that CA pretreatment alleviated the Aß25-35-induced loss of cell viability, inhibited both Aß1-42 accumulation and tau hyperphosphorylation, reduced reactive oxygen species generation, and maintained the mitochondrial membrane potential. Moreover, CA increased the microtubule-associated protein light chain 3 (LC3)-II/I ratio and decreased SQSTM1(p62), indicating that CA could induce autophagy. Autophagy inhibitor 3-methyladenine (3-MA) attenuated the neuroprotective effect of CA, suggesting that autophagy was involved in the neuroprotection of CA. It was also observed that CA activated AMP-activated protein kinase (AMPK) but inhibited mammalian target of rapamycin (mTOR). Furthermore, blocking AMPK with si-AMPKα successfully inhibited the upregulation of LC3-II/I, prevented the downregulation of phosphorylation of mTOR and SQSTM1(p62), indicating that CA induced autophagy in SH-SY5Y cells via the activation of AMPK. These results suggested that CA might be a potential agent for preventing AD.
Assuntos
Abietanos/farmacologia , Peptídeos beta-Amiloides/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Doença de Alzheimer/prevenção & controle , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismoRESUMO
SIRT3 is a member of Sirtuins family, which belongs to NAD(+) dependent class III histone deacetylases. Emerging evidence suggests that SIRT3 plays a pivotal role in regulating mitochondrial function. Mitochondrial dysfunction is a main pathogenesis of Parkinson's disease (PD). Here, we have investigated the protective effect of SIRT3 for PD cell model. The rotenone-induced human neuroblastoma SH-SY5Y cells damage was used as PD cell model. The lentiviral vectors were used to over-expression or knockdown SIRT3 expression. The cell viability was analyzed using MTT method. The apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were measured by flow cytometer. Superoxide dismutase (SOD) and glutathione (GSH) were detected by using automated microplate reader. The accumulation of α-synuclein was determined by immunofluorescence staining. SIRT3 knockdown significantly worsen rotenone-induced decline of cell viability (p < 0.01) and enhanced cell apoptosis (p < 0.01), exacerbated the decrease of SOD (p < 0.05) and GSH (p < 0.05), and augmented the accumulation of α-synuclein (p < 0.05). While SIRT3 overexpression dramatically increased cell viability (p < 0.01), and decreased cell apoptosis (p < 0.01), prevented the accumulation of α-synuclein (p < 0.05), suppressed the reducing of SOD (p < 0.05) and GSH (p < 0.01), decreased ROS generation (p < 0.05), and alleviated MMP collapse (p < 0.01) induced by rotenone. SIRT3 has neuroprotective effect in PD cell model and could be developed into a therapeutic agent for PD patients.
Assuntos
Fármacos Neuroprotetores/metabolismo , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/metabolismo , Rotenona/toxicidade , Sirtuína 3/biossíntese , Linhagem Celular Tumoral , Sobrevivência Celular , Técnicas de Silenciamento de Genes , Humanos , Transtornos Parkinsonianos/genética , Sirtuína 3/genéticaRESUMO
Recent evidence suggests that glutamate-induced cytotoxicity contributes to autophagic neuron death and is partially mediated by increased oxidative stress. Salidroside has been demonstrated to have neuroprotective effects in glutamate-induced neuronal damage. The precise mechanism of its regulatory role in neuronal autophagy is, however, poorly understood. This study aimed to probe the effects and mechanisms of salidroside in glutamate-induced autophagy activation in cultured rat cortical neurons. Cell viability assay, Western blotting, coimmunoprecipitation, and small interfering RNA were performed to analyze autophagy activities during glutamate-evoked oxidative injury. We found that salidroside protected neonatal neurons from glutamate-induced apoptotic cell death. Salidroside significantly attenuated the LC3-II/LC3-I ratio and expression of Beclin-1, but increased (SQSTM1)/p62 expression under glutamate exposure. Pretreatment with 3-methyladenine (3-MA), an autophagy inhibitor, decreased LC3-II/LC3-I ratio, attenuated glutamate-induced cell injury, and mimicked some of the protective effects of salidroside against glutamate-induced cell injury. Molecular analysis demonstrated that salidroside inhibited cortical neuron autophagy in response to glutamate exposure through p53 signaling by increasing the accumulation of cytoplasmic p53. Salidroside inhibited the glutamate-induced dissociation of the Bcl-2-Beclin-1 complex with minor affects on the PI3K/Akt/mTOR signaling pathways. These data demonstrate that the inhibition of autophagy could be responsible for the neuroprotective effects of salidroside on glutamate-induced neuronal injury.
Assuntos
Autofagia/efeitos dos fármacos , Córtex Cerebral/metabolismo , Glucosídeos/farmacologia , Ácido Glutâmico/toxicidade , Neurônios/metabolismo , Fenóis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Córtex Cerebral/patologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/patologia , Ratos , Ratos Sprague-DawleyRESUMO
Virus-like particle (VLP) of JC polyomavirus (JCPyV) is capable of packaging and delivering exogenous DNA into human cells and can be used for mediating therapeutic gene expression. However, many human cells express the JCPyV receptor. Thus, wild-type VLP can transduce a wide range of human cells nonspecifically. This study tested the feasibility of using a modified VLP with a IgG binding domain (Z domain) of protein A in its capsid for targeted gene delivery. The Z domain of protein A isolated from the membrane of Staphylococcus aureus was inserted into the NH3-terminus of VP1, the major JCPyV capsular protein. The recombinant VLP-Z was produced using Escherichia coli. Electron-microscopic analysis showed that VLP-Z has a viral-like structure. A hemagglutination test showed that VLP-Z has hemagglutination activity. VP(1) was detected in the nuclei of HeLa cells by immunostaining after VLP-Z inoculation, suggesting that VLP-Z is viable and can enter the cell nucleus. Inoculating HeLa cells with pEGFP-N(1) plasmid packaged in VLP-Z has resulted in enhanced green fluorescent protein expression in the cells. In addition, a binding assay showed that VLP-Z was able to bind IgG through the interaction of the Z domain in VLP-Z and IgG. These data suggest that VLP-Z could be armed with cell-specific antibody and be used to deliver therapeutic genes to target cells.
Assuntos
Imunoglobulina G/metabolismo , Vírus JC/genética , Staphylococcus aureus/genética , Proteínas do Capsídeo/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Marcação de Genes , Técnicas de Transferência de Genes , Vetores Genéticos/genética , Proteínas de Fluorescência Verde , Células HeLa , Humanos , Vírus JC/ultraestrutura , Plasmídeos/genética , Proteína Estafilocócica A/genética , Staphylococcus aureus/metabolismo , Vírion/ultraestruturaRESUMO
Diabetes has been regarded as an independent risk factor for Alzheimer's disease (AD). Our previous study found that diabetes activated autophagy, but lysosome function was impaired. Autophagy-lysosome dysfunction may be involved in Aß deposition in diabetic cognitive impairment. In the present study, we used STZ-induced diabetic rats and SH-SY5Y cells to investigate whether diabetes inhibits autophagosome fusion with lysosomes. We found that in the in vivo study, STZ-induced diabetic rats exhibited cognitive dysfunction, and the lysosome function-related factors CTSL, CTSD, and Rab7 were decreased (P < 0.05). In an in vitro study, the mRFP-GFP-LC3 assay showed that the fusion of autophagosomes with lysosomes was partly blocked in SH-SY5Y cells. High glucose treatment downregulated the number of autophagolysosomes, downregulated CTSD, CTSL, and Rab7 expression (P < 0.05), and then influenced the function of ACP2 to partly block the fusion of autophagosomes and lysosomes to inhibit Aß clearance. These findings indicate that high glucose treatment affected lysosome function, interfered with the fusion of autophagosomes with lysosomes, and partly blocked autophagic flux to influence Aß clearance.
Assuntos
Diabetes Mellitus Experimental , Neuroblastoma , Ratos , Humanos , Animais , Autofagossomos/metabolismo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/metabolismo , Neuroblastoma/metabolismo , Autofagia , Lisossomos/metabolismo , Glucose/metabolismoRESUMO
Intracerebral hemorrhage (ICH), which has high mortality and disability rate is associated with microglial pyroptosis and neuroinflammation, and the effective treatment methods are limited Epigallocatechin-3-gallate (EGCG) has been found to play a cytoprotective role by regulating the anti-inflammatory response to pyroptosis in other systemic diseases. However, the role of EGCG in microglial pyroptosis and neuroinflammation after ICH remains unclear. In this study, we investigated the effects of EGCG pretreatment on neuroinflammation-mediated neuronal pyroptosis and the underlying neuroprotective mechanisms in experimental ICH. EGCG pretreatment was found to remarkably improved neurobehavioral performance, and decreased the hematoma volume and cerebral edema in mice. We found that EGCG pretreatment attenuated the release of hemin-induced inflammatory cytokines (IL-1ß, IL-18, and TNF-α). EGCG significantly upregulated the expression of heme oxygenase-1 (HO-1), and downregulated the levels of pyroptotic molecules and inflammatory cytokines including Caspase-1, GSDMD, NLRP3, mature IL-1ß, and IL-18. EGCG pretreatment also decreased the number of Caspase-1-positive microglia and GSDMD along with NLRP3-positive microglia after ICH. Conversely, an HO-1-specific inhibitor (ZnPP), significantly inhibited the anti-pyroptosis and anti-neuroinflammation effects of EGCG. Therefore, EGCG pretreatment alleviated microglial pyroptosis and neuroinflammation, at least in part through the Caspase-1/GSDMD/NLRP3 pathway by upregulating HO-1 expression after ICH. In addition, EGCG pretreatment promoted the polarization of microglia from the M1 phenotype to M2 phenotype after ICH. The results suggest that EGCG is a potential agent to attenuate neuroinflammation via its anti-pyroptosis effect after ICH.
Assuntos
Hemorragia Cerebral , Heme Oxigenase-1 , Microglia , Doenças Neuroinflamatórias , Fármacos Neuroprotetores , Animais , Camundongos , Caspases/metabolismo , Caspases/farmacologia , Hemorragia Cerebral/tratamento farmacológico , Hemorragia Cerebral/genética , Hemorragia Cerebral/metabolismo , Citocinas/metabolismo , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Interleucina-18/metabolismo , Interleucina-18/farmacologia , Microglia/efeitos dos fármacos , Microglia/metabolismo , Doenças Neuroinflamatórias/tratamento farmacológico , Doenças Neuroinflamatórias/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Piroptose/efeitos dos fármacos , Piroptose/genética , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêuticoRESUMO
OBJECTIVE: To investigate the evolution of cognitive function and its influence factors, so as to provide evidence for guiding treatment of cognitive impairment after stroke. METHODS: A total of 98 cases of patients with stroke admitted in the First and Second Affiliated Hospital of Medical College of Xi'an Jiaotong University and Shaanxi Provincial People's Hospital between April and September 2009 were enrolled and recruited. Mini-mental state examination (MMSE) and Montreal cognitive function rating scale (MoCA) were adopted to assess the evolution of cognition at acute phase (within 2 weeks), 6 weeks, and 12 weeks after stroke among patients within 2 weeks after onset, questionnaire score ≤ 56, without aphasia and consciousness disturbance and at least one side of upper extremities muscle force ≥ grade 3. RESULTS: When using MMSE scale as criteria, the incidence of cognitive impairment was 24.5% at acute phase, 12.1% at 6 weeks and 9.9% at 12 weeks after stroke, while the incidence was 86.8%, 68.2%, and 38.0% respectively when using MoCA scale as criteria. The scales of MMSE and MoCA were increased and the incidence of cognitive impairment was decreased within 12 weeks after stroke. Logistic regression analysis indicated that, advanced age (ß = -0.124), hypertension (ß = -3.705), low education level(ß = 0.560) and depression after stroke (ß = 4.613) were related with cognitive impairment after stroke (all P values < 0.05); low education level(ß = 0.710), coronary heart disease (ß = -3.649), elevated total cholesterol (TC) (ß = -3.361) and low density lipid cholesterol (LDL-C) (ß = -5.833), and depression (ß = -3.612) delayed recovery of cognition after stroke. CONCLUSIONS: The cognitive function improves and the incidence of cognitive impairment lowers as the time goes on within 12 weeks after stroke. The factors that may affect the improvement of cognitive function include low educational level, coronary heart disease, elevated TC and LDL-C, and post-stroke depression.
Assuntos
Cognição , Acidente Vascular Cerebral/psicologia , Idoso , Transtornos Cognitivos/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Fatores de Risco , Acidente Vascular Cerebral/complicações , Inquéritos e QuestionáriosRESUMO
Stroke is one of the most devastating complications after bone fracture. However, due to the rarity of the complication, the risk factor for post fracture stroke remains unknown. We retrospectively reviewed 2914 fractured adults referred to the first affiliated hospital of Xi'an Jiaotong University, a regional referral center of China, from January 2008 to May 2013. As a result, among the 2914 patients, 13 of them had newly onset stroke within a median of 4â¯days after bone fractures (ranging from 1 to 25â¯days). The overall prevalence of post fracture stroke was 0.446%. The post fracture stroke prevalence in patients older than 68â¯years old was 3.542%. Compared to patients with vertebral (0.124%) and femur (0.619%) fractures, patients with hip fractures had a higher prevalence of post fracture stroke (2.320%) (Pâ¯<â¯0.001). Univariate analysis showed that hyperlipidemia, history of prior fracture, more comorbidities, higher CHADS2 score and higher neutrophil counts at admission were more often observed among patients who had post fracture stroke (Pâ¯<â¯0.05). With the multiple logistic regression analysis, we identified that history of prior fracture was an independent risk factor for post fracture ischemic stroke (ORâ¯=â¯6.417, 95% CIâ¯=â¯1.581-26.051, Pâ¯=â¯0.009). Our study illustrates that the history of prior fracture is associated with a 6.4-fold increase in the risk of post fracture ischemic stroke.
Assuntos
Fraturas Ósseas/complicações , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Adulto , Fatores Etários , Idoso , China , Comorbidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores de RiscoRESUMO
SIRT3 is a class III histone deacetylase that modulates energy metabolism, genomic stability and stress resistance. It has been implicated as a potential therapeutic target in a variety of neurodegenerative diseases, including Parkinson's disease (PD). Our previous study demonstrates that SIRT3 had a neuroprotective effect on a rotenone-induced PD cell model, however, the exact mechanism is unknown. In this study, we investigated the underlying mechanism. We established a SIRT3 stable overexpression cell line using lentivirus infection in SH-SY5Y cells. Then, a PD cell model was established using rotenone. Our data demonstrate that overexpression of SIRT3 increased the level of the autophagy markers LC3 II and Beclin 1. After addition of the autophagy inhibitor 3-MA, the protective effect of SIRT3 diminished: the cell viability decreased, while the apoptosis rate increased; α-synuclein accumulation enhanced; ROS production increased; antioxidants levels, including SOD and GSH, decreased; and MMP collapsed. These results reveal that SIRT3 has neuroprotective effects on a PD cell model by up-regulating autophagy. Furthermore, SIRT3 overexpression also promoted LKB1 phosphorylation, followed by activation of AMPK and decreased phosphorylation of mTOR. These results suggest that the LKB1-AMPK-mTOR pathway has a role in induction of autophagy. Together, our findings indicate a novel mechanism by which SIRT3 protects a rotenone-induced PD cell model through the regulation of autophagy, which, in part, is mediated by activation of the LKB1-AMPK-mTOR pathway.
RESUMO
Thymectomy is routinely carried out in patients with myasthenia gravis (MG) and thymomas. However, there is still a dispute as to whether MG patients with thymic hyperplasia should undergo thymectomy. We aimed to investigate the pathological findings in the thymus in patients with co-existing MG and thymic hyperplasia or thymomas treated with thymectomy, as well as effects of immunosuppression. Thirty-three patients with MG were selected and grouped accordingly: patients with no thymic abnormalities, patients with thymic hyperplasia, and patients with thymomas. All patients were treated with methylprednisolone alongside immunosuppression. A separate cohort of 24 MG patients with thymic hyperplasia or thymomas and treated with thymectomy were selected. As controls, 5 patients with thymomas or thymic carcinoma without MG were selected. Expression of CD5, extracellular regulated protein kinases1/2 mitogen activated protein kinase (ERK1/2MAPKs) and CD95 ligand (FasL) in the thymus was examined. Methylprednisolone and immunosuppressive therapy are highly effective in MG patients with normal thymus tissue and MG patients with thymic hyperplasia compared to MG patients with thymomas alone. CD5 expression was highest in MG patients with thymic hyperplasia, correlating with expression of ERK1/2MAPKs. FasL expression was similar across all groups. Thymomas may be distinguished from thymic hyperplasia by expression of CD5 and ERK1/2MAPKs. Thymectomy is the preferred treatment for MG patients with thymomas but may not be necessary in MG patients with thymic hyperplasia who are treated with immunosuppressive therapy.
Assuntos
Biomarcadores Tumorais/metabolismo , Imunossupressores/uso terapêutico , Miastenia Gravis/patologia , Timoma/patologia , Hiperplasia do Timo/patologia , Neoplasias do Timo/patologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , Proteína Ligante Fas/metabolismo , Feminino , Seguimentos , Humanos , Molécula 3 de Adesão Intercelular/metabolismo , Masculino , Pessoa de Meia-Idade , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Miastenia Gravis/tratamento farmacológico , Miastenia Gravis/metabolismo , Prognóstico , Estudos Retrospectivos , Timoma/tratamento farmacológico , Timoma/metabolismo , Hiperplasia do Timo/tratamento farmacológico , Hiperplasia do Timo/metabolismo , Neoplasias do Timo/tratamento farmacológico , Neoplasias do Timo/metabolismo , Adulto JovemRESUMO
ß-Amyloid (Aß) accumulation in the brain is the major pathophysiology of Alzheimer disease (AD). Hypertension is a risk factor for AD by promoting Aß deposition. Traditional Chinese medicinal compound tongxinluo (TXL) can improve blood circulation and endothelium-dependent vasodilation. This study investigates the effects of TXL on cognition and Aß using spontaneously hypertensive rats (SHRs). TXL was intragastrically administered to SHRs at low-dose, mid-dose and high-dose for 15, 30 or 60days. Cognition was evaluated with a Morris Water Maze (MWM). Aß in the brain was detected by western blot, ELISA and Thioflavin-S staining. Western blot and RT-PCR were employed to exam the expression of receptor for advanced glycation end products (RAGE), low-density lipoprotein receptor-related protein-1 (LRP-1) and amyloid precursor protein (APP). After TXL treatment for 60days, compared with the vehicle, the number of crossed platform and the time spent in the target quadrant increased in parallel with the increasing length of treatment in MWM. Moreover, the Aß in the hippocampus significantly decreased compared to the vehicle group, both in western blot and ELISA. Additionally, TXL reduced RAGE expression in a dose- and time-depended manner, but LRP-1 expression had no difference between TXL groups and vehicle groups. Furthermore, the ß-secretase expression was significantly decreased compared to the vehicle group, but APP expression had no difference. In conclusion, TXL improved cognition and decreased Aß in SHRs in a dose- and time-dependent manner, the underlying mechanism may involved in inhibiting RAGE and ß-secretase expression.
Assuntos
Peptídeos beta-Amiloides/efeitos dos fármacos , Cognição/efeitos dos fármacos , Medicamentos de Ervas Chinesas/metabolismo , Medicamentos de Ervas Chinesas/uso terapêutico , Doença de Alzheimer/fisiopatologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/fisiologia , Precursor de Proteína beta-Amiloide/genética , Animais , Encéfalo/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Hipocampo/metabolismo , Hipertensão/etiologia , Hipertensão/terapia , Masculino , Medicina Tradicional Chinesa , Ratos , Ratos Endogâmicos SHR , Ratos WistarRESUMO
ß-Amyloid (Aß) deposition has a central role in the pathogenesis of Alzheimer disease (AD). Previous studies have indicated that as a risk factor for AD, diabetes mellitus (DM) could induce Aß deposition in the brain, but the mechanism is not fully elucidated. Autophagy-lysosome is a cellular pathway involved in protein and organelle degradation. In the present study, we used streptozotocin (STZ)-induced diabetic rats to investigate whether autophagy-lysosome is related to Aß1-42 clearance in DM. We found that DM rats had a longer escape latency and less frequent entry into the target zone than that of the control group (p<0.05) in the Morris water maze test. Meanwhile, hippocampal neuron damage and apoptosis (p<0.05) were found in the DM rats. The Aß1-42 expression in the hippocampus significantly increased in the DM group compared with the control group (p<0.05). The markers of autophagy, beclin-1 and LC3 II, were increased (p<0.05), whereas LC3 I was decreased (p<0.05), and the ratio of LC3 II / I was increased as the time advanced (p<0.01). LAMP1 and LAMP2, which are the markers of lysosome function, were decreased in the hippocampus of DM rats (p<0.05). The Aß1-42 deposition was correlated with beclin-1, LC3 II, and LC3 I positively (p<0.05), but with LAMP1 and LAMP2 negatively (p<0.05). These findings indicate that DM activated autophagy, but lysosome function was impaired. Autophagy-lysosome dysfunction may be involved in the Aß deposition in diabetic cognitive impairment.
Assuntos
Peptídeos beta-Amiloides/metabolismo , Antibióticos Antineoplásicos/toxicidade , Autofagia/efeitos dos fármacos , Diabetes Mellitus Experimental/metabolismo , Lisossomos/efeitos dos fármacos , Fragmentos de Peptídeos/metabolismo , Estreptozocina/toxicidade , Animais , Encéfalo/patologia , Encéfalo/ultraestrutura , Diabetes Mellitus Experimental/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Marcação In Situ das Extremidades Cortadas , Lisossomos/ultraestrutura , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , RNA Mensageiro , Ratos , Ratos Sprague-DawleyRESUMO
Diabetes mellitus (DM) has been regarded as an important risk factor for Alzheimer's disease (AD), and diabetic patients and animals have shown cognitive dysfunction. More research has shown that the amyloid-ß (Aß), which is a hallmark of AD, was found deposited in the hippocampus of diabetic rats. This Aß accumulation is regulated by the receptor for advanced glycation end products (RAGE) and low-density lipoprotein receptor-related protein (LRP-1). However, the expression of RAGE and LRP-1 in diabetic rats is not very clear. In the present study, we used streptozotocin (STZ)-induced diabetic rats to investigate whether the expression of RAGE and LRP-1 is related to Aß1-42 deposition at the hippocampus, prefrontal lobe, and amygdala in DM. We found that diabetic rats had longer escape latency and less frequency of entrance into the target zone than that of the control group (P < 0.05) in the Morris water maze (MWM) test. The Aß1-42 expression in the hippocampus and prefrontal lobe significantly increased in the DM group compared to the control group (P < 0.05). RAGE increased (P < 0.05), while LRP-1 decreased (P < 0.05) in the hippocampus tissue and prefrontal lobe tissue of DM rats. The Aß1-42 deposition was correlated with RAGE positively (P < 0.05), but with LRP-1 negatively (P < 0.05). Further, the expression levels of Aß1-42, RAGE, and LRP-1 were not changed in the amygdala between the diabetic rats and the control group. These findings indicated that upregulating RAGE and/or downregulating LRP-1 at the hippocampus and the prefrontal lobe contributed to the Aß1-42 accumulation and then further promoted the cognitive impairment of diabetic rats.
Assuntos
Tonsila do Cerebelo/metabolismo , Peptídeos beta-Amiloides/metabolismo , Diabetes Mellitus Experimental/metabolismo , Hipocampo/metabolismo , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Córtex Pré-Frontal/metabolismo , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Peptídeos beta-Amiloides/genética , Animais , Cognição , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Masculino , Aprendizagem em Labirinto , Ratos , Ratos Sprague-Dawley , Receptor para Produtos Finais de Glicação Avançada/genéticaRESUMO
Bone fracture occurs in stroke patients at different times during the recovery phase, prolonging recovery time and increasing medical costs. In this review, we discuss the potential risk factors for post-stroke bone fracture and preventive methods. Most post-stroke bone fractures occur in the lower extremities, indicating fragile bones are a risk factor. Motor changes, including posture, mobility, and balance post-stroke contribute to bone loss and thus increase risk of bone fracture. Bone mineral density is a useful indicator for bone resorption, useful to identify patients at risk of post-stroke bone fracture. Calcium supplementation was previously regarded as a useful treatment during physical rehabilitation. However, recent data suggests calcium supplementation has a negative impact on atherosclerotic conditions. Vitamin D intake may prevent osteoporosis and fractures in patients with stroke. Although drugs such as teriparatide show some benefits in preventing osteoporosis, additional clinical trials are needed to determine the most effective conditions for post-stroke applications.
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Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. Recently, increasing evidence suggests that intracellular ß-amyloid protein (Aß) alone plays a pivotal role in the progression of AD. Therefore, understanding the signaling pathway and proteins that control Aß internalization may provide new insight for regulating Aß levels. In the present study, the regulation of Aß internalization by p38 mitogen-activated protein kinases (MAPK) through low-density lipoprotein receptor-related protein 1 (LRP1) was analyzed in vivo. The data derived from this investigation revealed that Aß1-42 were internalized by neurons and astrocytes in mouse brain, and were largely deposited in mitochondria and lysosomes, with some also being found in the endoplasmic reticulum. Aß1-42-LRP1 complex was formed during Aß1-42 internalization, and the p38 MAPK signaling pathway was activated by Aß1-42 via LRP1. Aß1-42 and LRP1 were co- localized in the cells of parietal cortex and hippocampus. Furthermore, the level of LRP1-mRNA and LRP1 protein involved in Aß1-42 internalization in mouse brain. The results of this investigation demonstrated that Aß1-42 induced an LRP1-dependent pathway that related to the activation of p38 MAPK resulting in internalization of Aß1-42. These results provide evidence supporting a key role for the p38 MAPK signaling pathway which is involved in the regulation of Aß1-42 internalization in the parietal cortex and hippocampus of mouse through LRP1 in vivo.
Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Astrócitos/metabolismo , Hipocampo/metabolismo , Sistema de Sinalização das MAP Quinases , Neurônios/metabolismo , Lobo Parietal/metabolismo , Fragmentos de Peptídeos/metabolismo , Receptores de LDL/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/genética , Animais , Feminino , Hipocampo/patologia , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade , Camundongos , Lobo Parietal/patologia , Fragmentos de Peptídeos/genética , RNA Mensageiro/metabolismo , Receptores de LDL/genética , Proteínas Supressoras de Tumor/genética , Proteínas Quinases p38 Ativadas por Mitógeno/genéticaRESUMO
Vitamin D receptor (VDR) Cdx-2 polymorphism (rs11568820) has been indicated to be associated to cancer susceptibility. However, published studies reported mixed results. This meta-analysis was conducted to get a more accurate estimation of the association between Cdx-2 polymorphism and cancer risk.We identified 25 independent studies with a total of 34,018 subjects published prior to March 2015. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the susceptibility to cancer. Separate analyses were conducted on features of the population such as ethnicity, source of controls, and cancer types.Meta-analysis results showed that Cdx-2 polymorphism significantly increased cancer risk in the homozygous model in overall analysis. According to the further stratified analysis, significant association was found between Cdx-2 variant and cancer risk in American-Africans in the homozygous, recessive, and dominant comparison models. However, no significant associations were found in Caucasians and Asians. When stratified by different cancer types, significant association was observed between Cdx-2 variant and an increased risk of colorectal cancer in the homozygous, recessive, and dominant models. In addition, ovarian cancer susceptibility increased based on the homozygous and dominant comparison models.Our study indicated that VDR Cdx-2 polymorphism was associated with an increased cancer risk, particularly in American-Africans, colorectal, and ovarian cancers. However, other factors may impact on the association. Further multicenter studies are needed to confirm the effects of Cdx-2 polymorphism on cancer susceptibility.
Assuntos
Neoplasias/genética , Receptores de Calcitriol/genética , Etnicidade , Predisposição Genética para Doença , Humanos , Neoplasias/classificação , Neoplasias/etnologia , Polimorfismo GenéticoRESUMO
PURPOSE: To explore the correlation of vascular risk factors for Alzheimer's disease (AD) in Chinese population. METHODS: A total of 123 outpatients with probable AD followed up for 3 years were investigated. Severity of cognitive impairment and functional ability was assessed using Mini-Mental State Examination (MMSE) and modified activities of daily living (ADLs), respectively. The incidence of vascular risk factors was studied in patients with AD. RESULTS: Univariate analysis showed significance difference in MMSE and ADL scores between patients with and without vascular risk factors (P < .05). Multiple regression analysis showed age, education, hyperhomocysteinemia, and hypertension were significant variables associated with annual MMSE, while there were no significant correlations between annual MMSE and sex, initial MMSE, diabetes, and so on. CONCLUSIONS: Vascular risk factors are common comorbidities in patients with AD in China, with younger, better educated ones showing faster cognitive decline. Hypertension and hyperhomocysteinemia may also aggravate the progression, and it is important to prevent and treat patients with AD.
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Doença de Alzheimer/etiologia , Hipertensão/complicações , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Povo Asiático , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Fatores de RiscoRESUMO
BACKGROUND: Little is known about the clinical features and treatment of Chinese patients with Parkinson disease (PD). METHODS: A large cross-sectional survey of clinical features, medication use, and motor complications was conducted in 901 consecutive PD patients, from 42 randomly selected university-affiliated hospitals in four urban economic regions of China, between December 2006 and May 2007. RESULTS: The 901 PD patients had age range 30 to 88, and median disease duration 50 months. Most (737, 81.8%) used L-dopa (median 375 mg/day), and often added low doses of other antiparkinsonian agents. Among L-dopa-treated patients, the prevalence of motor complications was low (dyskinesias: 8.5%; motor fluctuations: 18.6%), even among patients with disease duration ≥11 years (dyskinesias: 18.1%; motor fluctuations: 42.2%). Higher L-dopa use was associated with higher occurrence of dyskinesias (OR 2.44; 95% CI 1.20-5.13) and motor fluctuations (OR 2.48; 95% CI 1.49-4.14). Initiating PD treatment with L-dopa alone (OR 0.46; 95% CI 0.22-0.95) or in combination with other medications (OR 0.41; 95% CI 0.19-0.87) was associated with less dyskinesia than treatment initiated with non-L-dopa medication. CONCLUSIONS: Many Chinese PD patients are treated with low-dose L-dopa and added low-dose antiparkinsonian agents, with a low prevalence of motor complications, which might be influenced by Chinese culture.
Assuntos
Antiparkinsonianos/uso terapêutico , Características Culturais , Levodopa/uso terapêutico , Doença de Parkinson/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antiparkinsonianos/efeitos adversos , Povo Asiático , China , Estudos Transversais , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Discinesia Induzida por Medicamentos/etiologia , Feminino , Humanos , Levodopa/efeitos adversos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Doença de Parkinson/complicações , Doença de Parkinson/etnologia , Resultado do TratamentoRESUMO
Celastrol, an active component found in the Chinese herb tripterygium wilfordii has been identified as a neuroprotective agent for neurodegenerative diseases including Parkinson's disease (PD) through unknown mechanism. Celastrol can induce autophagy, which plays a neuroprotective role in PD. We tested the protective effect of celastrol on rotenone-induced injury and investigated the underlying mechanism using human neuroblastoma SH-SY5Y cells. The SH-SY5Y cells were treated with celastrol before rotenone exposure. The cells survival, apoptosis, accumulation of α-synuclein, oxidative stress and mitochondrial function, and autophagy production were analyzed. We found celastrol (500 nM) pre-treatment enhanced cell viability (by 28.99%, P<0.001), decreased cell apoptosis (by 54.38%, P<0.001), increased SOD and GSH (by 120.53% and 90.46%, P<0.01), reduced accumulation of α-synuclein (by 35.93%, P<0.001) and ROS generation (by 33.99%, P<0.001), preserved MMP (33.93±3.62%, vs. 15.10±0.71% of JC-1 monomer, P<0.001) and reduced the level of cytochrome C in cytosol (by 45.57%, P<0.001) in rotenone treated SH-SY5Y cells. Moreover, celastrol increased LC3-II/LC3 I ratio by 60.92% (P<0.001), indicating that celastrol activated autophagic pathways. Inhibiting autophagy by 3-methyladenine (3-MA) abolished the protective effects of celastrol. Our results suggested that celastrol protects SH-SY5Y cells from rotenone induced injuries and autophagic pathway is involved in celastrol neuroprotective effects.