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1.
Front Neurol ; 14: 1247693, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37840925

RESUMO

Objectives: To determine whether high HbA1c levels are related to short-and long-term functional outcomes in patients with ischemic stroke (IS) and whether this association differs according to the IS subtype and the patient's age. Methods: The data of 7,380 IS patients admitted to 16 hospitals or regional stroke centers in South-Korea, between May 2017 and December 2019, were obtained from the Clinical Research Collaboration for Stroke-Korea-National Institute of Health database and retrospectively analyzed. Among these patients, 4,598 were followed-up for one-year. The HbA1c levels were classified into three groups (<5.7, 5.7 to <6.5%, ≥6.5%). Short-and long-term poor functional outcomes were defined using the modified Rankin Scale score of 2 to 6 at three-months and one-year, respectively. IS subtypes were categorized according to the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification. Results: There was an association between higher HbA1c (≥6.5%) and poor functional outcomes at three-months in all patients (three-months; OR, 1.299, 95% CI 1.098, 1.535, one-year; OR, 1.181, 95% CI 0.952, 1.465). When grouped by age, the associations after both 3 months and 1 year observed in younger adult group (<65 years), but not in group aged 65 years and older (three-months; <65 years OR, 1.467, 95% CI 1.112, 1.936, ≥65 years OR, 1.220, 95% CI 0.987, 1.507, p for interaction = 0.038, one-year; <65 years OR, 1.622, 95% CI 1.101, 2.388, ≥65 years OR, 1.010, 95% CI 0.778, 1.312, p for interaction = 0.018). Among younger adult group, the higher HbA1c level was related to short-and long-term functional loss in patients with the small vessel occlusion subtype (three-months; OR, 2.337, 95%CI 1.334, 4.095, one-year; OR, 3.004, 95% CI 1.301, 6.938). However, in patients with other TOAST subtypes, a high HbA1c level did not increase the risk of poor outcomes, regardless of the age of onset. Conclusion: High HbA1c levels increase the risk of short-and long-term poor functional outcomes after IS onset. However, this association differs according to stroke subtype and age. Thus, pre-stroke hyperglycemia, reflected by HbA1c, may be a significant predictor for a poor prognosis after ischemic stroke, particular in young- and middle-aged adults.

2.
Biochem Biophys Rep ; 29: 101201, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35198737

RESUMO

Aging leads to cognitive impairments characterized by reduced hippocampal functions that are associated with impairment of long-term potentiation of CA1 synapses. Here, we assessed the safety and efficacy of modified (-)-gallocatechin gallate (GCG)-enriched green tea extract (HTP-GTE) in ameliorating the cognitive dysfunctions in late middle-aged murine model. We developed a novel HTP-GTE that was enriched with GCG via epimerization that involved heating. We compared the effects of oral administrations of conventional green tea and HTP-GTE in young and aged male C57/BL6 mice, and examined the changes in the hippocampal functions related to aging process. The functional outcome was assessed by the electrophysiological experiments to measure the long-term potentiation (LTP). HTP-GTE improved the age-related cognitive impairments via restoring long-term synaptic plasticity. We also identified that GCG was the main active component responsible for the HTP-GTE effect. The main molecular pathway in ameliorating the age-related cognitive dysfunctions involved protein kinase A (PKA) which was shown to be modulated by HTP-GTE. Thus, HTP-GTE has a therapeutic potential as a dietary supplement which may aid to rescue the impaired cognitive functions at the early phase of aging process through the modulation of LTP threshold.

3.
Exp Neurol ; 342: 113736, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33945790

RESUMO

Severe neonatal intraventricular hemorrhage (IVH) patients incur long-term neurologic deficits such as cognitive disabilities. Recently, the intraventricular transplantation of allogeneic human umbilical cord blood-derived mesenchymal stem cells (MSCs) has drawn attention as a therapeutic potential to treat severe IVH. However, its pathological synaptic mechanism is still elusive. We here demonstrated that the integration of the somatosensory input was significantly distorted by suppressing feed-forward inhibition (FFI) at the thalamocortical (TC) inputs in the barrel cortices of neonatal rats with IVH by using BOLD-fMRI signal and brain slice patch-clamp technique. This is induced by the suppression of Hebbian plasticity via an increase in tumor necrosis factor-α expression during the critical period, which can be effectively reversed by the transplantation of MSCs. Furthermore, we showed that MSC transplantation successfully rescued IVH-induced learning deficits in the sensory-guided decision-making in correlation with TC FFI in the layer 4 barrel cortex.


Assuntos
Córtex Cerebral/fisiologia , Hemorragia Cerebral Intraventricular/terapia , Disfunção Cognitiva/terapia , Transplante de Células-Tronco Mesenquimais/métodos , Plasticidade Neuronal/fisiologia , Tálamo/fisiologia , Animais , Animais Recém-Nascidos , Células Cultivadas , Córtex Cerebral/diagnóstico por imagem , Hemorragia Cerebral Intraventricular/diagnóstico por imagem , Hemorragia Cerebral Intraventricular/fisiopatologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/fisiopatologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Humanos , Potenciais Pós-Sinápticos Inibidores/fisiologia , Imageamento por Ressonância Magnética/métodos , Masculino , Ratos , Ratos Sprague-Dawley , Tálamo/diagnóstico por imagem
4.
Sci Rep ; 11(1): 910, 2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33441611

RESUMO

Post-menopausal depression (PMD) is a common psychological disorder accompanied by a cognitive deficit, which is caused by a series of uncontrolled emotional disruptions by strong environmental stressors during menopause. To overcome PMD-induced cognitive deficit, Green tea has been suggested as a dietary supplement because of its ameliorating effect on cognitive dysfunction induced by normal aging or neurodegenerative syndromes; however, its clinical use to improve PMD-accompanied cognitive deficit is still limited due to the controversy for the active ingredients and ambiguous mechanism of its action. Here, we developed modified high-temperature-processed green tea extract (HTP-GTE), which showed lower neuronal toxicity than the conventional green tea extract (GTE). We also demonstrated that HTP-GTE administration prevented the development of learned helplessness (LH) in a rat post-menopausal model. Additionally, HTP-GTE improved LH-induced cognitive impairments simultaneously with rescued the long-term synaptic plasticity. This occurred via the restoration of silent synapse formation by increasing the hippocampal BDNF-tyrosine receptor kinase B pathway in the helpless ovariectomized (OVX) rats. Likewise, we also identified that (-)-gallocatechin gallate was the main contributor of the HTP-GTE effect. Our findings suggested that HTP-GTE has a potential as a preventive nutritional supplement to ameliorate cognitive dysfunctions associated with PMD.


Assuntos
Catequina/análogos & derivados , Disfunção Cognitiva/dietoterapia , Pós-Menopausa/psicologia , Animais , Antioxidantes/farmacologia , Catequina/metabolismo , Catequina/farmacologia , Transtornos Cognitivos/dietoterapia , Depressão/dietoterapia , Depressão/metabolismo , Suplementos Nutricionais , Feminino , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-Dawley , Sinapses/efeitos dos fármacos , Chá/metabolismo
5.
Artigo em Inglês | MEDLINE | ID: mdl-32872339

RESUMO

Cardiovascular disease (CVD) is the leading cause of death globally, although the mortality rate has declined with improved technology and risk factor control. The incidence rate of stroke, one of the CVDs, is increasing in young adults, whereas it is decreasing in the elderly. The risk factors for CVD may differ between young adults and the elderly. Previous studies have suggested that cadmium was a potential CVD risk factor in the overall and middle-aged to elderly populations. We assessed the associations between cadmium and CVD events in the Korean population aged 20-59 years using the 2008-2013 and 2016 Korea National Health and Nutrition Examination Survey (KNHANES), a population-based cross-sectional study. Among 10,626 participants aged 20-59 years, those with high blood cadmium (BCd) level (>1.874 µg/L, 90th percentile) were higher associated with stroke and hypertension (stroke: odds ratio (OR), 2.39; 95% confidence interval (CI), 1.03-5.56; hypertension: OR, 1.46; 95% CI, 1.20-1.76). The strongest association between high blood cadmium concentrations and hypertension was among current smokers. Ischemic heart disease (IHD) was not associated with high blood cadmium level. These findings suggest that high blood cadmium levels may be associated with prevalent stroke and hypertension in the Korean population under 60 years of age.


Assuntos
Cádmio/sangue , Doenças Cardiovasculares/epidemiologia , Exposição Ambiental/efeitos adversos , Adulto , Idoso , Cádmio/toxicidade , Doenças Cardiovasculares/sangue , Estudos Transversais , Poluentes Ambientais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , República da Coreia/epidemiologia , Adulto Jovem
6.
BMJ Open ; 10(9): e035725, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32907895

RESUMO

OBJECTIVES: Although lead is a potential risk factor for cardiovascular diseases such as stroke, research on this association in the Korean population remains limited. Therefore, we aimed to investigate the association between lead level and stroke in Korean adults. DESIGN: A population-based cross-sectional study. SETTING: The Korea National Health and Nutrition Examination Survey 2008-2013, which enrolled a representative sample of the Korean population. PARTICIPANTS: We excluded participants younger than 20 years, missing weight data, pregnant or lactating, and missing blood lead and stroke data. A total of 11 510 participants were included in this analysis. PRIMARY AND SECONDARY OUTCOME MEASUREMENT: The participants were classified by blood lead concentration into the low-level (≤2.189 µg/dL, n=5756) and high-level (>2.189 µg/dL, n=5754) groups. The main outcome, stroke, was assessed by information from physician diagnosis, prevalence of stroke or treatment for stroke. The ORs and 95% CIs were calculated to evaluate the association between blood lead level and stroke using multivariate logistic regression analysis. RESULTS: Although blood lead level was not significantly associated with stroke (OR: 1.30, 95% CI: 0.66-2.58) in the multivariate-adjusted model, in individuals with hypertension, the high-level group was 2.36-fold higher odds of stroke (OR: 2.36, 95% CI: 1.02-5.44) compared to that in the low-level group. No association was observed in individuals with normotension (OR: 0.42, 95% CI: 0.13-1.38, p for interaction=0.007). CONCLUSION: The association between blood lead concentration and stroke may be influenced by hypertension status. Our findings suggest the need for closer attention to lead exposure in patients with hypertension.


Assuntos
Chumbo , Acidente Vascular Cerebral , Adulto , Estudos Transversais , Feminino , Humanos , Lactação , Inquéritos Nutricionais , República da Coreia/epidemiologia , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia
7.
J Ethnopharmacol ; 260: 112988, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-32446926

RESUMO

ETHNOPHAMACOLOGICAL RELEVANCE: Sam So Eum (SSE), used in traditional Korean medicine, has been prescribed for the treatment of various ailments including emesis, and fever for centuries. SSE is known by several different names (Shen Su Yin in traditional Chinese medicine; Jin So In traditional Japanese Kampo medicine). It is a mixture of medicinal plants including Panax ginseng C. A. Mey., Perilla frutescens (L.) Britton, and Peucedanum praeruptorum Dunn. Studies have revealed that SSE has many pharmacological effects including anti-inflammatory, anti-cancer, and anti-allergic properties, but its toxic effects have not been evaluated in vivo. Recently, the use of traditional medicinal herbs to treat various diseases has increased, owing to increased number of studies supporting their efficacy. However, safety evaluations for toxicity and other adverse effects have not been extensive. It is commonly considered that natural products extracted from traditional medicinal herbs are safer than synthetic drugs, but this lacks a scientific basis. Thus, in this study, we evaluated the toxicity of SSE in male and female rats. AIM OF THE STUDY: To evaluated the safety of SSE in male and female rats. MATERIALS AND METHODS: SSE was administered orally for 13 weeks at 1000, 2000, and 4000 mg kg-1·day-1, and then the rats were maintained for 4 weeks without SSE administration (recovery evaluation). RESULTS: We observed the animals for changes in clinical signs, including hematological parameters, and food consumption; serum chemistry profiling and urinalysis were also carried out. Creatinine levels in the serum were significantly increased following oral administration of SSE at 2000 and 4000 mg kg-1·day-1 in male and female rats, but returned to the normal levels during the recovery period. In addition, SSE administration does not cause kidney and liver toxicity. Thus, we determined that the no-observed-adverse-effect level of SSE is 4000 mg kg-1·day-1. The no-observed-effect level of SSE was determined to be 1000 mg kg-1·day-1, because serum creatinine was increased by oral administration of SSE at 2000 and 4000 mg kg-1·day-1 in male and female rats. CONCLUSIONS: SSE administration does not cause toxicity at 4000 mg kg-1·day-1 in male and female rats.


Assuntos
Creatinina/sangue , Extratos Vegetais/toxicidade , Testes de Toxicidade , Administração Oral , Animais , Relação Dose-Resposta a Droga , Feminino , Masculino , Nível de Efeito Adverso não Observado , Extratos Vegetais/administração & dosagem , Ratos , Ratos Sprague-Dawley
8.
J Korean Med Sci ; 34(48): e307, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31833264

RESUMO

BACKGROUND: Although previous studies have highlighted the importance of serum uric acid as a risk factor of metabolic syndrome, no study has previously used a national Korean survey to examine the association between serum uric acid level and metabolic syndrome. This study aimed to investigate this association among Korean adults, to determine whether it varies by age and gender, and to identify optimal serum uric acid level cutoffs for predicting the presence of metabolic syndrome by gender and age. METHODS: We included 5,758 Korean adults (aged ≥ 19 years) who participated in the seventh Korea National Health and Nutrition Examination Survey (KNHANES VII-1), 2016. Logistic regression analyses were performed to examine the association between serum uric acid and the presence of metabolic syndrome. Receiver operating characteristic analyses were used to assess optimal uric acid cutoff values for predicting the presence of metabolic syndrome. RESULTS: High serum uric acid levels were found to be associated with risk of metabolic syndrome. Area under the receiver operating characteristic curve (AUC) analyses of uric acid levels for the detection of metabolic syndrome produced good performances. Women subjects had significantly higher AUC values than men subjects, but this gender difference may also have been influenced by age. Among men, AUC values of those in their 20s, 30s, or 40s were significantly higher than those in their 70s (P < 0.05). The optimal uric acid cutoff was 6.05 mg/dL for men and 4.45 mg/dL for women, and men had higher cutoffs than women in all age groups. CONCLUSION: Among Korean adults, serum uric acid levels were found to be strongly associated with the presence of metabolic syndrome. More importantly, our findings suggest that derived optimal cutoff values of uric acid might offer a useful means of diagnosing metabolic syndrome in clinical settings.


Assuntos
Síndrome Metabólica/diagnóstico , Ácido Úrico/sangue , Adulto , Idoso , Área Sob a Curva , Feminino , Humanos , Modelos Logísticos , Masculino , Síndrome Metabólica/epidemiologia , Pessoa de Meia-Idade , Inquéritos Nutricionais , Prevalência , Curva ROC , República da Coreia/epidemiologia , Adulto Jovem
9.
PLoS One ; 14(11): e0224941, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31770379

RESUMO

Notch signaling is an evolutionarily conserved pathway that regulates cell-cell interactions through binding of Notch family receptors to their cognate ligands. Notch signaling has an essential role in vascular development and angiogenesis. Recent studies have reported that Notch may be implicated in Alzheimer's disease (AD) pathophysiology. We measured the levels of soluble Notch1 (sNotch1) in the plasma samples from 72 dementia patients (average age 75.1 y), 89 subjects with amnestic mild cognitive impairment (MCI) (average age 73.72 y), and 150 cognitively normal controls (average age 72.34 y). Plasma levels of sNotch1 were 25.27% lower in dementia patients as compared to healthy control subjects. However, the level of Notch1 protein was significantly increased in human brain microvascular endothelial cells (HBMECs) after amyloid-beta treatment. Also, Notch1 mRNA level was significantly increased in HBMECs and iPSC-derived neuronal cells from AD patient compared to normal control. These results indicate that altered expression of Notch1 might be associated with the risk of Alzheimer's disease.


Assuntos
Doença de Alzheimer/metabolismo , Receptor Notch1/metabolismo , Proteína ADAM10/genética , Proteína ADAM10/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Peptídeos beta-Amiloides/metabolismo , Estudos de Casos e Controles , Demência/metabolismo , Feminino , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Masculino , Pessoa de Meia-Idade , Neurônios/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor Notch1/sangue , Receptor Notch1/genética
10.
Neuroimage ; 188: 335-346, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30553043

RESUMO

Neuroplasticity is considered essential for recovery from brain injury in developing brains. Recent studies indicate that it is especially effective during early postnatal development and during the critical period. The current study used functional magnetic resonance imaging (fMRI) and local field potential (LFP) electrophysiological recordings in rats that experienced neonatal hypoxic-ischemic (HI) injury during the critical period to demonstrate that physical exercise (PE) can improve cortical plasticity even when performed during adulthood, after the critical period. We investigated to what extent the blood oxygen level-dependent (BOLD)-fMRI responses were increased in the contralesional spared cortex, and how these increases were related to the LFP electrophysiological measurements and the functional outcome. The balance of excitation and inhibition was assessed by measuring excitatory and inhibitory postsynaptic currents in stellate cells in the primary somatosensory (S1) cortex, which was compared with the BOLD-fMRI responses in the contralesional S1 cortex. The ratio of inhibitory postsynaptic current (IPSC) to excitatory postsynaptic current (EPSC) at the thalamocortical (TC) input to the spared S1 cortex was significantly increased by PE, which is consistent with the increased BOLD-fMRI responses and improved functional outcome. Our data clearly demonstrate in an experimental rat model of HI injury during the critical period that PE in adulthood enhances neuroplasticity and suggest that enhanced feed-forward inhibition at the TC input to the S1 cortex might underlie the PE-induced amelioration of the somatosensory deficits caused by the HI injury. In summary, the results of the current study indicate that PE, even if performed beyond the critical period or during adulthood, can be an effective therapy to treat neonatal brain injuries, providing a potential mechanism for the development of a potent rehabilitation strategy to alleviate HI-induced neurological impairments.


Assuntos
Potenciais Pós-Sinápticos Excitadores/fisiologia , Hipóxia-Isquemia Encefálica/fisiopatologia , Hipóxia-Isquemia Encefálica/reabilitação , Potenciais Pós-Sinápticos Inibidores/fisiologia , Plasticidade Neuronal/fisiologia , Condicionamento Físico Animal/fisiologia , Córtex Somatossensorial/fisiopatologia , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Eletroencefalografia , Hipóxia-Isquemia Encefálica/diagnóstico por imagem , Imageamento por Ressonância Magnética , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Córtex Somatossensorial/diagnóstico por imagem
11.
Front Pharmacol ; 8: 839, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29201007

RESUMO

Postoperative cognitive dysfunction (POCD) may be driven by transference of the innate immune response to the brain after aseptic surgical damage. Macrophages are key mediators of innate immunity that can display a pro-inflammatory M1 phenotype or an anti-inflammatory M2 phenotype. Erythropoietin (EPO) is a hematopoietic hormone that exerts anti-inflammatory effects by influencing macrophage function. We hypothesized that EPO would prevent POCD by promoting macrophage phenotype switching to the M2 phenotype post-surgery. To evaluate the effects of EPO on POCD and macrophage polarization post-surgery, we administered EPO (5,000 U/kg) with or without an arginase inhibitor (amino-6-boronohexanoic acid, 10 mg/kg) to ICR mice before and after abdominal surgery. Forty-eight hours post-surgery, we assessed memory, synapse function, and macrophage/microglial phenotypes in the spleen and hippocampus. We also investigated M1/M2 phenotypes in RAW264.7 and BV2 cells stimulated with lipopolysaccharide and interferon-γ (M1 inducers) in the presence or absence of EPO. EPO prevented POCD, decreased surgery-related synaptic dysfunction, and attenuated pro-inflammatory cytokine generation in the hippocampus. Moreover, EPO suppressed M1-related genes expression and promoted M2 genes expression in the spleen and hippocampus post-surgery. Furthermore, EPO decreased the proportions of macrophages/microglia expressing an M1 surface marker (CD40) and increased those expressing an M2 surface marker (CD206). Arginase inhibition abolished the beneficial effects of EPO on POCD. In vitro, EPO treatment promoted switching of RAW264.7 and BV2 cells stimulated with M1 inducers to an M2 phenotype. In conclusion, EPO prevents POCD by promoting macrophage phenotype switching toward the M2 phenotype.

12.
Sci Rep ; 7(1): 13482, 2017 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-29044209

RESUMO

Some patients experience impaired cognitive functioning after surgery, a phenomenon referred to as postoperative cognitive dysfunction (POCD). Signs of POCD are closely associated with the development of systemic or hippocampal inflammation. However, the precise pathophysiological mechanisms of prevention/treatment options for POCD still remain unclear. After injury, the transcriptional factor nuclear factor-kappa B (NF-κB) is thought to regulate or stimulate inflammation amplification. Therefore, we designed a cell-penetrating fusion protein called nt-p65-TMD, which inhibits NF-κB p65 activation by translocating into the nucleus. In the present study, we discovered that nt-p65-TMD exerted effects on surgery-induced cognitive impairment in mice. Specifically, nt-p65-TMD exhibited strong immunoregulatory properties that were able to reduce surgery-induced elevations in cerebrovascular integrity impairment, subsequent peripheral immune-cell recruitment, and inflammation amplification, which ultimately lead to cognitive decline. The nt-p65-TMD has the unique ability to regulate and reduce systemic inflammation and inflammation amplification, suggesting a new strategy for preventing development of cognitive decline that occurs in POCD.


Assuntos
Anti-Inflamatórios/farmacologia , Disfunção Cognitiva/tratamento farmacológico , Complicações Pós-Operatórias/tratamento farmacológico , Fator de Transcrição RelA/antagonistas & inibidores , Animais , Anti-Inflamatórios/uso terapêutico , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Complicações Pós-Operatórias/metabolismo , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Fator de Transcrição RelA/metabolismo
13.
Cell Rep ; 19(13): 2707-2717, 2017 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-28658619

RESUMO

Recent work has shown that thalamocortical (TC) inputs can be plastic after the developmental critical period has closed, but the mechanism that enables re-establishment of plasticity is unclear. Here, we find that long-term potentiation (LTP) at TC inputs is transiently restored in spared barrel cortex following either a unilateral infra-orbital nerve (ION) lesion, unilateral whisker trimming, or unilateral ablation of the rodent barrel cortex. Restoration of LTP is associated with increased potency at TC input and reactivates anatomical map plasticity induced by whisker follicle ablation. The reactivation of TC LTP is accompanied by reappearance of silent synapses. Both LTP and silent synapse formation are preceded by transient re-expression of synaptic GluN2B-containing N-methyl-D-aspartate (NMDA) receptors, which are required for the reappearance of TC plasticity. These results clearly demonstrate that peripheral sensory deprivation reactivates synaptic plasticity in the mature layer 4 barrel cortex with features similar to the developmental critical period.


Assuntos
Privação Sensorial/fisiologia , Córtex Somatossensorial/fisiologia , Tálamo/fisiologia , Adulto , Animais , Humanos , Camundongos , Adulto Jovem
14.
Biochem Biophys Res Commun ; 484(2): 342-347, 2017 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-28131838

RESUMO

Agmatine suppresses peripheral sympathetic tone by modulating Cav2.2 channels in peripheral sympathetic neurons. However, the detailed cellular signaling mechanism underlying the agmatine-induced Cav2.2 inhibition remains unclear. Therefore, in the present study, we investigated the electrophysiological mechanism for the agmatine-induced inhibition of Cav2.2 current (ICav2.2) in rat celiac ganglion (CG) neurons. Consistent with previous reports, agmatine inhibited ICav2.2 in a VI manner. The agmatine-induced inhibition of the ICav2.2 current was also almost completely hindered by the blockade of the imidazoline I2 receptor (IR2), and an IR2 agonist mimicked the inhibitory effect of agmatine on ICav2.2, implying involvement of IR2. The agmatine-induced ICav2.2 inhibition was significantly hampered by the blockade of G protein or phospholipase C (PLC), but not by the pretreatment with pertussis toxin. In addition, diC8-phosphatidylinositol 4,5-bisphosphate (PIP2) dialysis nearly completely hampered agmatine-induced inhibition, which became irreversible when PIP2 resynthesis was blocked. These results suggest that in rat peripheral sympathetic neurons, agmatine-induced IR2 activation suppresses Cav2.2 channel voltage-independently, and that the PLC-dependent PIP2 hydrolysis is responsible for the agmatine-induced suppression of the Cav2.2 channel.


Assuntos
Agmatina/farmacologia , Canais de Cálcio Tipo N/efeitos dos fármacos , Gânglios Simpáticos/efeitos dos fármacos , Fosfatidilinositol 4,5-Difosfato/metabolismo , Fosfolipases Tipo C/metabolismo , Abdome , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Gânglios Simpáticos/metabolismo , Hidrólise , Masculino , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley
15.
Biochem Biophys Res Commun ; 477(3): 406-12, 2016 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-27320860

RESUMO

Agmatine, a putative endogenous ligand of imidazoline receptors, suppresses cardiovascular function by inhibiting peripheral sympathetic tone. However, the molecular identity of imidazoline receptor subtypes and its cellular mechanism underlying the agmatine-induced sympathetic suppression remains unknown. Meanwhile, N-type Ca(2+) channels are important for the regulation of NA release in the peripheral sympathetic nervous system. Therefore, it is possible that agmatine suppresses NA release in peripheral sympathetic nerve terminals by inhibiting Ca(2+) influx through N-type Ca(2+) channels. We tested this hypothesis by investigating agmatine effect on electrical field stimulation (EFS)-evoked contraction and NA release in endothelium-denuded rat superior mesenteric arterial strips. We also investigated the effect of agmatine on the N-type Ca(2+) current in superior cervical ganglion (SCG) neurons in rats. Our study demonstrates that agmatine suppresses peripheral sympathetic outflow via the imidazoline I2 receptor in rat mesenteric arteries. In addition, the agmatine-induced suppression of peripheral vascular sympathetic tone is mediated by modulating voltage-dependent N-type Ca(2+) channels in sympathetic nerve terminals. These results suggest a potential cellular mechanism for the agmatine-induced suppression of peripheral sympathetic tone. Furthermore, they provide basic and theoretical information regarding the development of new agents to treat hypertension.


Assuntos
Agmatina/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo N/efeitos dos fármacos , Receptores de Imidazolinas/agonistas , Sistema Nervoso Simpático/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Animais , Estimulação Elétrica , Técnicas In Vitro , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
16.
J Cell Physiol ; 226(6): 1676-82, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21413025

RESUMO

Human adult dental pulp stem cells (hDPSCs) are a unique precursor population isolated from postnatal dental pulp and have the ability to regenerate a reparative dentin-like complex. In this study, we investigated the role of Asporin in hDPSCs, which was identified as a matrix protein in our previous dentin proteomic analysis. We isolated a clonogenic, highly proliferative population of cells from adult human dental pulp. These isolated hDPSCs were confirmed by fluorescence activated cell sorting (FACS) using stem cell-specific markers and have shown multilineage differentiation potential. The localization of Asporin was identified by immunohistochemistry in the globular calcification region in the junction of predentin and dentin. The gene and protein expression levels of Asporin were enhanced at the early stage of and then reduced during the late stage of differentiation of hDPSCs in mineralization media. ASPN knock-down using a lentiviral system suppressed the mineralization of hDPSCs. These results suggest that ASPN plays positive roles in the mineralization of hDPSCs and predentin to dentin.


Assuntos
Calcificação Fisiológica , Polpa Dentária/citologia , Proteínas da Matriz Extracelular/metabolismo , Células-Tronco/metabolismo , Adulto , Calcificação Fisiológica/genética , Diferenciação Celular , Separação Celular , Ensaio de Unidades Formadoras de Colônias , Dentina/citologia , Dentina/metabolismo , Proteínas da Matriz Extracelular/genética , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Células-Tronco Multipotentes/citologia , Células-Tronco Multipotentes/metabolismo , Transporte Proteico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Células-Tronco/citologia , Dente/citologia , Dente/metabolismo
17.
Korean Circ J ; 39(8): 317-21, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19949637

RESUMO

BACKGROUND AND OBJECTIVES: Carotid artery intima-media thickness (CIMT) has recently been recommended as a non-invasive tool for primary prevention of cardiovascular events; the association between CIMT and adverse cardiovascular events is well-known. We sought to evaluate the prevalence and significance of carotid artery plaque, especially in patients with coronary atherosclerosis. SUBJECTS AND METHODS: The study population consisted of 1,705 consecutive patients {933 males (54.7%); mean age, 59.7+/-10.9 years} who underwent coronary angiography and carotid artery scanning using high-resolution ultrasonography. Carotid plaque was defined as a focal structure encroaching into the arterial lumen by at least 50% of the surrounding IMT value or a thickness >1.2 mm. RESULTS: Carotid plaque was identified in 30.3% (516/1,705) of the patients. Of patients in whom the plaque location could be evaluated (n=1,027), carotid plaque was located at the common carotid artery {n=64/267 (24.0%)}, carotid bulb {n=194/267 (72.7%)}, and at both sites {n=9/267 (3.4%)}. The prevalence of hypertension (58.5% vs. 45.2%, p<0.001) and diabetes mellitus (30.6% vs. 23.5%, p=0.007) was higher in patients with carotid plaques. The patients with carotid plaques were older (65.4+/-8.9 years vs. 57.2+/-10.7 years, p<0.0001), had a thicker CIMT (0.89+/-0.20 mm vs. 0.77+/-0.16 mm, p<0.001), and higher fasting blood sugar (FBS) levels (132.1+/-60.7 mg/dL vs. 121.6+/-47.1 mg/dL, p<0.001) than those without carotid plaque. Patients with carotid plaque more frequently presented with acute coronary syndrome (32.4% vs. 23.9%, p<0.001) than those without carotid plaque. Significant coronary artery stenosis by coronary angiography (75.4% vs. 58.3%, p<0.001), especially multi-vessel disease (46.3% vs. 27.2%, p<0.001), was more frequent in patients with carotid plaques. On multivariate analysis, old age (>/=65 years), hypertension, and increased CIMT (>/=1.0 mm) were independent predictors of carotid plaque. Carotid plaque (odds ratio, 1.85; 95% confidence interval, 1.39-2.45; p<0.001) was an independent predictor of multivessel disease based on multivariate regression analysis. CONCLUSION: Carotid plaque was common (30.3%) in Korean patients with coronary atherosclerosis, but it is still relatively uncommon compared to Western populations. Carotid plaque was associated with old age, hypertension, and increased IMT, and was an independent predictor of multi-vessel disease.

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