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1.
Neurol Res ; 41(10): 867-874, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31221056

RESUMO

Objectives: To investigate the effect of purmorphamine (PUR), a Shh co-receptor Smoothened (Smo) agonist, on postoperative cognitive dysfunction (POCD) rat models. Methods: Eighteen-month-old male Sprague-Dawley rats were subjected to intramedullary fixation of a tibial fracture with 7% chloral hydrate anesthesia to mimic human clinical surgery. PUR was administered via an intraperitoneal injection at a dose of 15mg/kg/day for 3 consecutive days at 6 h after surgery. The aged rats were sacrificed after performing a Morris water maze test 1, 3, and 7 days postoperatively to evaluate the expression of related proteins at the appointed time. Results: Compared to the POCD + vehicle group and sham + PUR group, the POCD + PUR group restored neurological deficit (P = 0.01). PUR administration induced upregulation of Shh expression on postoperative day 1 (P = 0.02), which continued on the third day (P = 0.008) but dropped by the 7th day (P = 0.03). Immunofluorescent analysis, similar to western blot analysis, showed a significant increase in the autophagy-marker LC3 (P = 0.006) as well as p62 degradation (P = 0.000) in the dentate gyrus of the aged rats (P = 0.000) after PUR treatment. Importantly, LC3 was mainly found in the presynaptic and postsynaptic membranes of the hippocampus. Conclusions: These results indicate a link between Shh and autophagy in the rat model of POCD, providing new insights into Shh signaling pathway-mediated mechanisms of neuroprotection and cognitive repair after POCD. It also provides a potential entry point for the development of clinical drugs.

2.
J Cell Biochem ; 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30775803

RESUMO

Postoperative cognitive dysfunction (POCD) is a common complication in elderly patients who undergo surgery involving anesthesia. Its underlying mechanisms remain unclear. Autophagy plays an important role in the damage and repair of the nervous system and is associated with the development of POCD. Using a rat model, adenosine monophosphate-activated protein kinase α1 (AMPKα1), an important autophagy regulator, was found to be significantly downregulated in rats with POCD that was induced by sevoflurane anesthesia or by appendectomy. Overexpression of AMPKα1-ameliorated POCD, as indicated by decreased escape latencies and increased target quadrant swimming times, swimming distances, and platform crossing times during Morris water maze tests. AMPKα1 overexpression activated autophagy signals by increasing the expression of light chain 3 II (LC3-II) and Beclin1 and decreasing the expression of p62 in the hippocampus of rats with POCD. Moreover, blocking autophagy by 3-methyladenine partly attenuated AMPKα1-mediated POCD improvement. Furthermore, overexpression of AMPKα1 could upregulate the expression of p-AMPK and Sirt1 in the hippocampus of rats with POCD. Intriguingly, inhibiting AMPK signals via Compound C effectively attenuated AMPKα1-mediated POCD improvement, concomitant with the downregulation of p-AMPK, Sirt1, LC3-II, and Beclin1 and the upregulation of p62. We thus concluded that overexpression of AMPKα1 can improve POCD via the AMPK-Sirt1 and autophagy signaling pathway.

3.
Front Neurosci ; 12: 116, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29535606

RESUMO

Endoplasmic reticulum (ER) stress occurring in stringent conditions is critically involved in neuronal survival and death. Resveratrol is a non-flavonoid polyphenol that has neuroprotective effects against many neurological disorders. Here, we investigated the potential protective effects of resveratrol in an in vitro ER stress model mimicked by tunicamycin (TM) treatment in neuronal HT22 cells. We found that TM dose-dependently decreased cell viability and increased apoptosis, which were both significantly attenuated by resveratrol treatment. Resveratrol markedly reduced the expression or activation of ER stress-associated factors, including GRP78, CHOP, and caspase-12. The results of immunocytochemistry and western blot showed that resveratrol promoted autophagy in TM-treated cells, as evidenced by increased LC3II puncta number, bcelin1 expression and LC3II/LC3I ratio. Pretreatment with the autophagy inhibitor chloroquine could reduce the protective effects of resveratrol. In addition, the expression of Sirt3 protein and its downstream enzyme activities were significantly increased in resveratrol-treated HT22 cells. To confirm the involvement of Sirt3-mediated mechanisms, siRNA transfection was used to knockdown Sirt3 expression in vitro. The results showed that downregulation of Sirt3 could partially prevented the autophagy and protection induced by resveratrol after TM treatment. Our study demonstrates a pivotal role of Sirt3-mediated autophagy in mediating resveratrol-induced protection against ER stress in vitro, and suggests the therapeutic values of resveratrol in ER stress-associated neuronal injury conditions.

4.
Pharmacol Biochem Behav ; 163: 101-109, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29037878

RESUMO

Antipsychotic agents have been reported to promote hippocampal neurogenesis and improve cognitive deficits; yet, the molecular mechanisms underlying these actions remain unclear. In the present study, we used a murine model of schizophrenia induced by 5-day intraperitoneal injection with the non-competitive N-methyl-d-aspartate receptor antagonist MK801 (0.3mg/kg/day) to assess cognitive behavioral deficits, changes in Notch signaling, and cellular proliferation in the hippocampus of adult male C57BL/6 mice after 2-week administration of risperidone (Rip, 0.2mg/kg/day) or vehicle. We then utilized in vivo stereotaxic injections of a lentivirus expressing a short hairpin RNA (shRNA) for Notch1 into the dentate gyrus to examine the role of Notch1 in the observed actions of Rip. We found that Rip ameliorated cognitive deficits and restored cell proliferation in MK801-treated mice in a manner associated with the up-regulation of Notch signaling molecules, including Notch1, Hes1, and Hes5. Moreover, these effects were abolished by pretreatment with Notch1 shRNA. Our results suggest that the ability of Rip to improve cognitive function in schizophrenia is mediated in part by Notch signaling.


Assuntos
Transtornos Cognitivos/tratamento farmacológico , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Receptor Notch1/metabolismo , Risperidona/farmacologia , Esquizofrenia/patologia , Transdução de Sinais/efeitos dos fármacos , Animais , Transtornos Cognitivos/induzido quimicamente , Hipocampo/metabolismo , Hipocampo/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Risperidona/uso terapêutico , Esquizofrenia/metabolismo
5.
Behav Brain Res ; 309: 1-8, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27131779

RESUMO

Sirtuin 1 (Sirt1) is a class III histone deacetylase involved in neuroprotection induced by hyperbaric oxygen preconditioning (HBO-PC) in animal models of ischemia. However, the underlying mechanisms remain to be illustrated. In the present study, rats exposed to middle cerebral artery occlusion (MCAO) were used to establish an ischemic stroke model. The infarct volume ratio, neurobehavioral score, and expressions of Sirt1, nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and superoxide dismutase 1 (SOD1) were evaluated at 7 days after reperfusion, and the level of malondialdehyde (MDA) was used to assess oxidative stress. HBO-PC increased the expression of Sirt1 and reduced infarct volume ratio and neurobehavioral deficit in MCAO rats. Meanwhile, HBO-PC also increased expression of Nrf2, HO-1, and SOD1 and decreased MDA content. Furthermore, either Sirt1 or Nrf2 knockdown by short interfering RNA (siRNA) inhibited the expression of Nrf2, HO-1, and SOD1 and eliminated the neuroprotective effects of HBO-PC. Taken together, the results suggest that the Nrf2/antioxidant defense pathway is involved in the long lasting neuroprotective effects of Sirt1 induced by HBO-PC against transient focal cerebral ischemia.


Assuntos
Isquemia Encefálica/terapia , Encéfalo/irrigação sanguínea , Oxigenação Hiperbárica , Precondicionamento Isquêmico , Neuroproteção , Sirtuína 1/metabolismo , Animais , Antioxidantes/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Modelos Animais de Doenças , Heme Oxigenase-1/metabolismo , Malondialdeído/metabolismo , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/fisiologia , RNA Interferente Pequeno , Distribuição Aleatória , Ratos Sprague-Dawley , Transdução de Sinais , Sirtuína 1/antagonistas & inibidores , Sirtuína 1/genética , Superóxido Dismutase-1/metabolismo
6.
Acta Pharmacol Sin ; 34(5): 636-43, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23603984

RESUMO

Autophagy, a process for the degradation of protein aggregates and dysfunctional organelles, is required for cellular homeostasis and cell survival in response to stress and is implicated in endogenous protection. Ischemic preconditioning is a brief and nonlethal episode of ischemia, confers protection against subsequent ischemia-reperfusion through the up-regulation of endogenous protective mechanisms. Emerging evidence shows that autophagy is associated with the protective effect of ischemic preconditioning. This review summarizes recent progress in research on the functions and regulations of the autophagy pathway in preconditioning-induced protection and cellular survival.


Assuntos
Autofagia , Precondicionamento Isquêmico , Animais , Sobrevivência Celular , Humanos , Precondicionamento Isquêmico/métodos , Transdução de Sinais
7.
Iran Red Crescent Med J ; 15(10): e7704, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24693369

RESUMO

BACKGROUND: Botulinum toxin type A (BTX-A) has been reported to be effective for the therapy for migraine. The purpose of this study was to investigate the effect of BTX-A on the immunoreactive levels of calcitonin gene-related peptide (CGRP) and substance P (SP) in the jugular plasma and medulla oblongata of migraine in rats induced by nitroglycerin (NTG), and then to evaluate and compare the effectiveness of fixed (muscle)-sites and acupoint-sites injection of BTX-A for migraine therapy of patients in a randomly controlled trial extending over four months. MATERIALS AND METHODS: Rats with NTG-induced migraine were subcutaneously injected with vehicle or BTX-A (5 U/kg or 10 U/kg bodyweight). CGRP- and SP-like immunoreactivity (CGRP-LI and SP-LI) were determined by radioimmunoassay. In clinical trials, sixty patients respectively received BTX-A (2.5 U each site, 25 U per patient) at fixed-sites (group F, n = 30) including occipitofrontalis, corrugator supercili, temporalis and trapezius or at acupoint-sites (group A, n = 30) including EX-HN3, EX-HN5, GV20, GB8, GB20 and BL10. RESULTS: Local BTX-A injection suppressed NTG-induced CGRP-LI and SP-LI levels in jugular plasma and oblongata. BTX-A injection for both groups with migraine significantly reduced the attack frequency, intensity, duration and associated symptoms. The efficacy of BTX-A for migraine in group A (93% improvement) was more significant than that in group F (83% improvement) (P < 0.01). CONCLUSIONS: The evidence that BTX-A decreases NTG-induced CGRP-LI and SP-LI levels in trigeminovascular system suggests that BTX-A attenuates migraine by suppression of neuropeptide release. BTX-A injections for migraine at acupoint-sites and fixed-sites are effective. Acupoint-sites BTX-A administration shows more efficacy for migraine than fixed-sites application.

8.
Bing Du Xue Bao ; 28(4): 462-70, 2012 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-22978174

RESUMO

Tumor suppressor p53, known as 'the guardian of the genome', has the ability to prevent the emergence of transformed cells by the induction of cell cycle arrest and apoptosis. Otherwise, there were researches about the function of p53, such as NDA repair, regulating metabolism and maternal reproduction in recent years. Furthermore, there was a new function for p53 in antiviral apoptosis mentioned in the research, Integration of interferon-alpha/beta signaling to p53 responses in tumour suppression and antiviral defense. In order to define the antiviral function of p53, many target genes has been defined, such as IRF9, IRF5, ISG15 and TLR3. All of these implied there must be a complex mechanism for role of p53 in antiviral innate immunity, adaptive immunity and inflammation.


Assuntos
Imunidade , Proteína Supressora de Tumor p53/metabolismo , Vírus , Animais , Fenômenos Fisiológicos Celulares , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/virologia , Proteína Supressora de Tumor p53/genética , Vírus/imunologia
9.
J Zhejiang Univ Sci ; 5(7): 827-34, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15495311

RESUMO

This paper proposes a new approach for multi-objective robust control. The approach extends the standard generalized l2 (Gl2) and generalized H2 (GH2) conditions to a set of new linear matrix inequality (LMI) constraints based on a new stability condition. A technique for variable parameterization is introduced to the multi-objective control problem to preserve the linearity of the synthesis variables. Consequently, the multi-channel multi-objective mixed Gl2/GH2 control problem can be solved less conservatively using computationally tractable algorithms developed in the paper.


Assuntos
Algoritmos , Retroalimentação , Modelos Lineares , Análise Numérica Assistida por Computador , Processamento de Sinais Assistido por Computador , Teoria de Sistemas
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