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1.
Exp Cell Res ; 433(1): 113804, 2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37806378

RESUMO

Alcohol dehydrogenase 1 (ADH1) is an alcohol-oxidizing enzyme with poorlydefined biology. Here we report that ADH1 is highly expressed in kidneys of mice with lethal endotoxemia and is transcriptionally upregulated in tubular cells by lipopolysaccharide (LPS) stimuli through TLR4/NF-κB cascade. The Adh1 knockout (Adh1KO) mice with lethal endotoxemia displayed increased susceptibility to acute kidney injury (AKI) but not systemic inflammatory response. Adh1KO mice develop more severe tubular cell apoptosis in comparison to Adh1 wild-type (Adh1WT) mice during course of lethal endotoxemia. ADH1 deficiency facilitates the LPS-induced tubular cell apoptosis in a caspase-dependent manner. Mechanistically, ADH1 deficiency dampens tubular mitophagy that relies on PINK1-Parkin pathway characterized by the reduced membrane potential, reactive oxygen species (ROS) and release of fragmented mtDNA to cytosol. Kidney-specific overexpression of PINK1 and Parkin by adeno-associated viral vector 9 (AAV9) delivery ameliorates AKI exacerbation in Adh1KO mice with lethal endotoxemia. Our study supports the notion that ADH1 is critical for blockade of tubular apoptosis mediated by mitophagy, allowing the rapid identification and targeting of alcohol-metabolic route applicable to septic AKI.

2.
World J Stem Cells ; 15(4): 150-164, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37180997

RESUMO

Acute respiratory distress syndrome (ARDS) is a common and clinically devastating disease that causes respiratory failure. Morbidity and mortality of patients in intensive care units are stubbornly high, and various complications severely affect the quality of life of survivors. The pathophysiology of ARDS includes increased alveolar-capillary membrane permeability, an influx of protein-rich pulmonary edema fluid, and surfactant dysfunction leading to severe hypoxemia. At present, the main treatment for ARDS is mechanical treatment combined with diuretics to reduce pulmonary edema, which primarily improves symptoms, but the prognosis of patients with ARDS is still very poor. Mesenchymal stem cells (MSCs) are stromal cells that possess the capacity to self-renew and also exhibit multilineage differentiation. MSCs can be isolated from a variety of tissues, such as the umbilical cord, endometrial polyps, menstrual blood, bone marrow, and adipose tissues. Studies have confirmed the critical healing and immunomodulatory properties of MSCs in the treatment of a variety of diseases. Recently, the potential of stem cells in treating ARDS has been explored via basic research and clinical trials. The efficacy of MSCs has been shown in a variety of in vivo models of ARDS, reducing bacterial pneumonia and ischemia-reperfusion injury while promoting the repair of ventilator-induced lung injury. This article reviews the current basic research findings and clinical applications of MSCs in the treatment of ARDS in order to emphasize the clinical prospects of MSCs.

3.
Life Sci ; 322: 121653, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37011875

RESUMO

AIMS: Inflammation-coupling tubular damage (ICTD) contributes to pathogenesis of septic acute kidney injury (AKI), in which insulin-like growth factor-binding protein 7 (IGFBP-7) serves as a biomarker for risk stratification. The current study aims to discern how IGFBP-7 signalling influences ICTD, the mechanisms that underlie this process and whether blockade of the IGFBP-7-dependent ICTD might have therapeutic value for septic AKI. MATERIALS AND METHODS: In vivo characterization was carried out in B6/JGpt-Igfbp7em1Cd1165/Gpt mice subjected to cecal ligation and puncture (CLP). Transmission electron microscopy, immunofluorescence, flow cytometry, immunoblotting, ELISA, RT-qPCR and dual-luciferase reporter assays were used to determine mitochondrial functions, cell apoptosis, cytokine secretion and gene transcription. KEY FINDINGS: ICTD augments the transcriptional activity and protein secretion of tubular IGFBP-7, which enables an auto- and paracrine signalling via deactivation of IGF-1 receptor (IGF-1R). Genetic knockout (KO) of IGFBP-7 provides renal protection, improves survival and resolves inflammation in murine models of cecal ligation and puncture (CLP), while administering recombinant IGFBP-7 aggravates ICTD and inflammatory invasion. IGFBP-7 perpetuates ICTD in a NIX/BNIP3-indispensable fashion through dampening mitophagy that restricts redox robustness and preserves mitochondrial clearance programs. Adeno-associated viral vector 9 (AAV9)-NIX short hairpin RNA (shRNA) delivery ameliorates the anti-septic AKI phenotypes of IGFBP-7 KO. Activation of BNIP3-mediated mitophagy by mitochonic acid-5 (MA-5) effectively attenuates the IGFBP-7-dependent ICTD and septic AKI in CLP mice. SIGNIFICANCE: Our findings identify IGFBP-7 is an auto- and paracrine manipulator of NIX-mediated mitophagy for ICTD escalation and propose that targeting the IGFBP-7-dependent ICTD represents a novel therapeutic strategy against septic AKI.


Assuntos
Injúria Renal Aguda , Sepse , Somatomedinas , Camundongos , Animais , Mitofagia/fisiologia , Injúria Renal Aguda/metabolismo , Sepse/metabolismo , Inflamação/complicações , Proteínas de Membrana/metabolismo , Proteínas Mitocondriais/metabolismo
4.
Int J Biol Sci ; 18(13): 5168-5184, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35982894

RESUMO

High-dose ascorbate confers tubular mitophagy responsible for septic acute kidney injury (AKI) amelioration, yet its biological roles in immune regulation remain poorly understood. Methods: The role of tubular mitophagy in macrophage polarization upon high-dose ascorbate treatment was assessed by fluorescence-activated cell sorter analysis (FACS) in vitro and by immunofluorescence in AKI models of LPS-induced endotoxemia (LIE) from Pax8-cre; Atg7 flox/flox mice. The underlying mechanisms were revealed by RNA-sequencing, gene set enrichment analysis (GSEA), luciferase reporter, chromatin immunoprecipitation (ChIP) and adeno-associated viral vector serotype 9 (AAV9) delivery assays. Results: High-dose ascorbate enables conversion of macrophages from a pro-inflammatory M1 subtype to an anti-inflammatory M2 subtype in murine AKI models of LIE, leading to decreased renal IL-1ß and IL-18 production, reduced mortality and alleviated tubulotoxicity. Blockade of tubular mitophagy abrogates anti-inflammatory macrophages polarization under the high-dose ascorbate-exposed coculture systems. Similar abrogations are verified in LIE mice with tubular epithelium-specific ablation of Atg7, where the high-dose ascorbate-inducible renal protection and survival improvement are substantially weaker than their control littermates. Mechanistically, high-dose ascorbate stimulates tubular secretion of serpin family G member 1 (SerpinG1) through maintenance of mitophagy, for which nuclear factor-erythroid 2 related factor 2 (NRF2) transactivation is required. SerpinG1 perpetuates anti-inflammatory macrophages to prevent septic AKI, while kidney-specific disruption of SerpinG1 by adeno-associated viral vector serotype 9 (AAV9)-short hairpin RNA (shRNA) delivery thwarts the anti-inflammatory macrophages polarization and anti-septic AKI efficacy of high-dose ascorbate. Conclusion: Our study identifies SerpinG1 as an intermediate of tubular mitophagy-orchestrated myeloid function during septic AKI and reveals a novel rationale for ascorbate-based therapy.


Assuntos
Injúria Renal Aguda , Ácido Ascórbico , Proteína Inibidora do Complemento C1 , Macrófagos , Fator 2 Relacionado a NF-E2 , Injúria Renal Aguda/tratamento farmacológico , Animais , Ácido Ascórbico/farmacologia , Proteína Inibidora do Complemento C1/genética , Rim , Túbulos Renais/metabolismo , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/genética , Ativação Transcricional
5.
World J Gastroenterol ; 26(33): 4945-4959, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32952341

RESUMO

BACKGROUND: Intestinal mucosal barrier dysfunction plays an important role in the pathogenesis of ulcerative colitis (UC). Recent studies have revealed that impaired autophagy is associated with intestinal mucosal dysfunction in the mucosa of colitis mice. Resveratrol exerts anti-inflammatory functions by regulating autophagy. AIM: To investigate the effect and mechanism of resveratrol on protecting the integrity of the intestinal mucosal barrier and anti-inflammation in dextran sulfate sodium (DSS)-induced ulcerative colitis mice. METHODS: Male C57BL/6 mice were divided into four groups: negative control group, DSS model group, DSS + resveratrol group, and DSS + 5-aminosalicylic acid group. The severity of colitis was assessed by the disease activity index, serum inflammatory cytokines were detected by enzyme-linked immunosorbent assay. Colon tissues were stained with haematoxylin and eosin, and mucosal damage was evaluated by mean histological score. The expression of occludin and ZO-1 in colon tissue was evaluated using immunohistochemical analysis. In addition, the expression of autophagy-related genes was determined using reverse transcription-polymerase chain reaction and Western-blot, and morphology of autophagy was observed by transmission electron microscopy. RESULTS: The resveratrol treatment group showed a 1.72-fold decrease in disease activity index scores and 1.42, 3.81, and 1.65-fold decrease in the production of the inflammatory cytokine tumor necrosis factor-α, interleukin-6 and interleukin-1ß, respectively, in DSS-induced colitis mice compared with DSS group (P < 0.05). The expressions of the tight junction proteins occludin and ZO-1 in DSS model group were decreased, and were increased in resveratrol-treated colitis group. Resveratrol also increased the levels of LC3B (by 1.39-fold compared with DSS group) and Beclin-1 (by 1.49-fold compared with DSS group) (P < 0.05), as well as the number of autophagosomes, which implies that the resveratrol may alleviate intestinal mucosal barrier dysfunction in DSS-induced UC mice by enhancing autophagy. CONCLUSION: Resveratrol treatment decreased the expression of inflammatory factors, increased the expression of tight junction proteins and alleviated UC intestinal mucosal barrier dysfunction; this effect may be achieved by enhancing autophagy in intestinal epithelial cells.


Assuntos
Colite , Animais , Autofagia , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colo , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Mucosa Intestinal , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Resveratrol/farmacologia
6.
Am J Physiol Renal Physiol ; 316(6): F1273-F1281, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-31017010

RESUMO

Acute kidney injury (AKI) initiated by sepsis remains a thorny problem despite recent advancements in its clinical management. Having been found to be activated during AKI, fibroblast growth factor-inducible molecule 14 (Fn14) may be a potential therapeutic target because of its involvement in the molecular basis of injury. Here, we report that LPS induces apoptosis of mouse cortical tubule cells mediated by Fn14, for which simultaneous Toll-like receptor (TLR)4 activation is required. Mechanistically, TLR4 activation by lipopolysaccharide, through disassociating E3 ligase SCFFbxw7α from Fn14, dismantles Lys48-linked polyubiquitination of Fn14 and stabilizes it. Pharmacological deactivation of Fn14 with monoclonal antibody ITEM-2 provides effective protection against lethal sepsis and AKI in mice. Our study underscores an adaptive mechanism whereby TLR4 regulates SCFFbxw7α-dependent Fn14 stabilization during inflammatory tubular damage and further supports investigation of targeting Fn14 in clinical trials of patients with septic AKI.


Assuntos
Injúria Renal Aguda/metabolismo , Proteína 7 com Repetições F-Box-WD/metabolismo , Túbulos Renais/metabolismo , Macrófagos/metabolismo , Sepse/complicações , Receptor de TWEAK/metabolismo , Injúria Renal Aguda/genética , Injúria Renal Aguda/microbiologia , Injúria Renal Aguda/patologia , Animais , Apoptose , Modelos Animais de Doenças , Proteína 7 com Repetições F-Box-WD/genética , Túbulos Renais/microbiologia , Túbulos Renais/patologia , Macrófagos/microbiologia , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Estabilidade Proteica , Células RAW 264.7 , Sepse/microbiologia , Transdução de Sinais , Receptor de TWEAK/genética , Receptor 4 Toll-Like/metabolismo
7.
Exp Cell Res ; 378(1): 21-31, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30844390

RESUMO

The K63-linked ubiquitination of RIP1 coordinates survival/death homeostasis by driving transcription of genes downstream of RelA. Previously, we demonstrated that EGF-dependent RelA transactivation overcomes hypoxia-initiated apoptosis, yet the underlying mechanisms remain mysterious. We report here that UBXN1 deficiency empowers apoptosis resistance against hypoxia through triggering IκBα degradation, for which K63-linked ubiquitination of RIP1 is required. MiR-124-3p is a bona fide inhibitor upstream of UBXN1, thereby antagonizing the hypoxia-initiated apoptosis. UBXN1 repression by miR-124-3p restores the K63-linked ubiquitination of RIP1, IKKß phosphorylation, IκBα-RelA disassembly, RelA nuclear localization and transactivation of EGF gene as well as EGF secretion under hypoxia. Reconstitution of wild-type UBXN1, but not a truncated UBXN1ΔUBA mutant, or pharmacological inhibition of RelA transactivation in miR-124-3p-replete cells compromises the apoptosis-resistant phenotypes of miR-124-3p. Hypoxia transcriptionally downregulates miR-124-3p by disassociating RelA and RNAP II from its promoter. EGFR activation renders the K63-linked ubiquitination of RIP1 and hypoxic tolerance in conjunction with miR-124-3p. Our findings identify a pivotal role of miR-124-3p in ubiquitin conjugation of RIP1 against hypoxic damage and underscore that productive transcription of miR-124-3p by RelA and RNAP II might be a switching mechanism for this process.


Assuntos
Apoptose , MicroRNAs/genética , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Oxigênio/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ubiquitinação , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Hipóxia Celular , Células HEK293 , Humanos , Quinase I-kappa B/metabolismo , MicroRNAs/metabolismo , Células PC12 , RNA Polimerase II/metabolismo , Ratos , Fator de Transcrição RelA/metabolismo
8.
Shock ; 52(5): 522-531, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30499878

RESUMO

Although remote ischemic postconditioning (RIPC) was shown to confer cardioprotection against myocardial ischemia/reperfusion (I/R) injury in normal animals, whether RIPC-induced cardioprotection is altered in the presence of hypercholesterolemia, a comorbidity with acute myocardial infarction (AMI) patients has yet to be determined. Normal or 2% cholesterol chow was fed to male C57BL/6J mice for 12 weeks to induce hypercholesterolemia, then normal or hypercholesterolemic murine hearts were exposed to AMI by coronary artery ligation. RIPC was induced by four episodes of 5 min femoral artery occlusion followed by 5 min reperfusion immediately after myocardial reperfusion in mice. Following I/R, RIPC significantly attenuated postischemic infarct size, hindered cardiomyocyte apoptosis, improved cardiac systolic function, decreased phosphatase and tensin homolog deleted on chromosome ten (PTEN) expression, and further increased Akt and GSK-3ß phosphorylation in non-hypercholesterolemic, but not in hypercholesterolemic mice. Application of the PTEN inhibitor bisperoxovanadium (BpV) (1.0 mg/kg) reduced postischemic infarct size, attenuated cardiomyocyte apoptosis, and improved cardiac dysfunction in normal, but not in hypercholesterolemic mice. Further, increased dose of BpV (2 mg/kg or 10 mg/kg) failed to rescue the detrimental effects of hypercholesterolemia on I/R in mice following I/R. Especially important, we demonstrated that the combination BpV and RIPC exerted marked cardioprotective effects both in normal and hypercholesterolemic mice with I/R, indicating that PTEN inhibition restores RIPC-elicited myocardial protection in the presence of hypercholesterolemia. Our results demonstrated that hypercholesterolemia attenuated RIPC-induced cardioprotection against I/R injury by alteration of PTEN/Akt/GSK3ß signals, and inhibition of PTEN rescued RIPC-induced cardioprotection in the presence of hypercholesterolemia.


Assuntos
Glicogênio Sintase Quinase 3 beta/metabolismo , Hipercolesterolemia , Pós-Condicionamento Isquêmico , PTEN Fosfo-Hidrolase , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Compostos de Vanádio/farmacologia , Animais , Hipercolesterolemia/tratamento farmacológico , Hipercolesterolemia/metabolismo , Hipercolesterolemia/patologia , Masculino , Camundongos , PTEN Fosfo-Hidrolase/antagonistas & inibidores , PTEN Fosfo-Hidrolase/metabolismo
9.
Oncotarget ; 8(41): 70967-70981, 2017 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-29050336

RESUMO

Cell apoptosis is one of the main pathological alterations during oxidative stress (OS) injury. Previously, we corroborated that nuclear factor-κB (NF-κB) transactivation confers apoptosis resistance against OS in mammalian cells, yet the underlying mechanisms remain enigmatic. Here we report that microRNA-19a (miR-19a) transcriptionally regulated by reactive oxygen species (ROS) production and NF-κB deactivation prevents OS-initiated cell apoptosis through cylindromatosis (CYLD) repression. CYLD contributes to OS-initiated cell apoptosis, for which NF-κB deactivation is essential. MiR-19a directly represses CYLD via targeting 3' UTR of CYLD, thereby antagonizing OS-initiated apoptosis. CYLD repression by miR-19a restores the IKKß phosphorylation, RelA disassociation from IκBα, IκBα polyubiquitination and degradation, RelA recruitment at VEGF gene promoter as well as VEGF secretion in the context of OS. Either pharmacological deactivation of NF-κB or genetic upregulation of CYLD compromises the apoptosis-resistant phenotypes of miR-19a. Furthermore, miR-19a is transcriptionally downregulated upon OS in two distinct processes that require ROS production and NF-κB deactivation. VEGF potentiates the ability of miR-19a to activate NF-κB and render apoptosis resistance. Our findings underscore a putative mechanism whereby CYLD repression-mediated and NF-κB transactivation-dependent miR-19a regulatory feedback loop prevents cell apoptosis in response to OS microenvironment.

10.
Biochim Biophys Acta Mol Basis Dis ; 1863(6): 1678-1689, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28412322

RESUMO

Apoptosis of DA neurons is a contributing cause of disability and death for Parkinson's disease (PD). Akt may become a potential therapeutic target for PD since Akt has been deactivated during DA neuron apoptosis. We previously demonstrated that Akt confers apoptosis resistance against 6-OHDA in DA neuron-like PC12 cells, yet the underlying mechanisms accounted for this are not fully understood. Here we report that microRNA-130b (miR-130b)-dependent and cylindromatosis (CYLD) repression-mediated Akt ubiquitination renders apoptosis resistance of PC12 cells to 6-OHDA, which elicits histone H3 deacetylation-induced transcriptional downregulation of miR-130b vice versa. CYLD deficiency ubiquitinates Akt at Lys63, thereby phosphorylating Akt and antagonizing 6-OHDA-initiated apoptosis. MiR-130b targetedly represses CYLD and increases apoptosis resistance to 6-OHDA. CYLD repression by miR-130b restores Akt ubiquitination and activation, GSK3ß and FoxO3a phosphorylation, FoxO3a removal from Bim promoter as well as Bim downregulation during 6-OHDA administration. CYLD deficiency-mediated Akt activation is instrumental for the apoptosis-resistant phenotypes of miR-130b. In addition, 6-OHDA transcriptionally downregulates miR-130b through recruitment of HDAC3 at the promoter. Furthermore, EPO potentiates the ability of miR-130b to activate Akt and augment apoptosis resistance. Our findings identify the apoptosis-resistant function of miR-130b and suggest that histone H3 deacetylation plays a pivotal role in regulating miR-130b transcription in response to 6-OHDA.


Assuntos
Apoptose/efeitos dos fármacos , Resistência a Medicamentos/efeitos dos fármacos , Histonas/metabolismo , MicroRNAs/metabolismo , Oxidopamina/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transcrição Gênica/efeitos dos fármacos , Ubiquitinação/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Animais , Células PC12 , Ratos
11.
Exp Cell Res ; 347(1): 52-59, 2016 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-27443256

RESUMO

Apoptosis of neural cells is one of the main pathological features in hypoxic/ischemic brain injury. Nuclear factor-κB (NF-κB) might be a potential therapeutic target for hypoxic/ischemic brain injury since NF-κB has been found to be inactivated after hypoxia exposure, yet the underlying molecular mechanisms of NF-κB inactivation are largely unknown. Here we report that epidermal growth factor receptor (EGFR) activation prevents neuron-like PC12 cells apoptosis in response to hypoxia via restoring NF-κB-dependent transcriptional upregulation of cyclin D1. Functionally, EGFR activation by EGF stimulation mitigates hypoxia-induced PC12 cells apoptosis in both dose- and time-dependent manner. Of note, EGFR activation elevates IKKß phosphorylation, increases IκBα ubiquitination, promotes P65 nuclear translocation and recruitment at cyclin D1 gene promoter as well as upregulates cyclin D1 expression. EGFR activation also abrogates the decrease of IKKß phosphorylation, reduction of IκBα ubiquitination, blockade of P65 nuclear translocation and recruitment at cyclin D1 gene promoter as well as downregulation of cyclin D1 expression induced by hypoxia. Furthermore, NF-κB-dependent upregulation of cyclin D1 is instrumental for the EGFR-mediated cytoprotection against hypoxic apoptosis. In addition, the dephosphorylation of EGFR induced by either EGF siRNA transfection or anti-HB-EGF neutralization antibody treatment enhances hypoxic cytotoxicity, which are attenuated by EGF administration. Our results highlight the essential role of NF-κB-dependent transcriptional upregulation of cyclin D1 in EGFR-mediated cytoprotective effects under hypoxic preconditioning and support further investigation of EGF in clinical trials of patients with hypoxic/ischemic brain injury.


Assuntos
Ciclina D1/genética , Citoproteção/genética , Receptores ErbB/metabolismo , NF-kappa B/metabolismo , Transcrição Gênica , Regulação para Cima/genética , Animais , Hipóxia Celular/genética , Ciclina D1/metabolismo , Regulação para Baixo/genética , Células PC12 , Regiões Promotoras Genéticas , Ratos
12.
Sci Rep ; 6: 26910, 2016 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-27229174

RESUMO

Implantable biomedical microdevices enable the restoration of body function and improvement of health condition. As the interface between artificial machines and natural tissue, various kinds of microelectrodes with high density and tiny size were developed to undertake precise and complex medical tasks through electrical stimulation and electrophysiological recording. However, if only the electrical interaction existed between electrodes and muscle or nerve tissue without nutrition factor delivery, it would eventually lead to a significant symptom of denervation-induced skeletal muscle atrophy. In this paper, we developed a novel flexible tubular microelectrode integrated with fluidic drug delivery channel for dynamic tissue implant. First, the whole microelectrode was made of biocompatible polymers, which could avoid the drawbacks of the stiff microelectrodes that are easy to be broken and damage tissue. Moreover, the microelectrode sites were circumferentially distributed on the surface of polymer microtube in three dimensions, which would be beneficial to the spatial selectivity. Finally, the in vivo results confirmed that our implantable tubular microelectrodes were suitable for dynamic electrophysiological recording and simultaneous fluidic drug delivery, and the electrode performance was further enhanced by the conducting polymer modification.


Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Eletrodos Implantados , Implantes Experimentais , Dispositivos Lab-On-A-Chip , Músculo Esquelético/inervação , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Impedância Elétrica , Estimulação Elétrica , Feminino , Microeletrodos , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/cirurgia , Células PC12 , Polímeros/química , Polímeros/farmacologia , Implantação de Prótese/métodos , Ratos , Ratos Sprague-Dawley , Xilenos/química , Xilenos/farmacologia
13.
Neurosci Lett ; 610: 54-9, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26518240

RESUMO

Neuronal apoptosis is a contributing cause of disability and death in cerebral ischemia. Nuclear factor-κB (NF-κB) may become a potential therapeutic target for hypoxic/ischemic neuron damage because NF-κB is inactivated after hypoxia exposure. Vascular endothelial growth factor (VEGF) has been found to improve neurological function recovery in cerebral ischemic injury although the exact molecular mechanisms that underlie the neuroprotective function of VEGF remain largely unknown. Here we defined the mechanism by which VEGF antagonized neuron-like PC12 cells apoptosis induced by hypoxia mimetic agent cobalt chloride (CoCl2) is through restoration of NF-κB activity. Depletion of VEGF with small interfering RNA (siRNA) in PC12 cells conferred CoCl2-induced cytotoxicity which was mitigated by VEGF administration. Treatment of PC12 cells with VEGF attenuated the CoCl2-induced cytotoxicity in both dose- and time-dependent manner. Mechanistically, VEGF increased IκBα phosphorylation and ubiquitination, promoted P65 nuclear translocation as well as upregulated XIAP and CCND1 expression. Meanwhile, VEGF administration reversed the dysregulation of IκBα phosphorylation and ubiquitination, P65 nuclear translocation as well as XIAP and CCND1 expression induced by CoCl2. Notably, the VEGF-dependent cytoprotection was abolished by pretreatment with BAY 11-7085, a specific inhibitor of NF-κB. Our data suggest that VEGF/NF-κB signalling pathway represents an adaptive mechanism that protects neural cells against hypoxic damage.


Assuntos
NF-kappa B/metabolismo , Fator A de Crescimento do Endotélio Vascular/farmacologia , Animais , Hipóxia Celular , Cobalto/farmacologia , Células PC12 , Ratos , Transdução de Sinais
14.
Artigo em Inglês | MEDLINE | ID: mdl-25570271

RESUMO

Owing to interacting with the living tissue directly, the electrode-tissue interface largely determines the performance of the whole bioelectronics devices. The miniaturization of biomedical electronic components requires interface materials to possess properties including excellent electrical performance, good biocompatibility and compatibility with microelectronic fabrication process. Considering the unique characteristics and wide applications in biomedical domain of conducting polymer and graphene, composite film consists of poly(3,4-ethylenedioxythiophene) (PEDOT) and graphene oxide (GO) is proposed as electrode-tissue interface in this work. The facilely electrochemically synthesized PEDOT/GO coating on microelectrodes shows low impedance, high charge storage capacity and good biocompatibility to act as electrode-tissue interface. As a result, the composite film is a potential biomaterial as electrode-tissue interface for tissue engineering and further implantable electrophysiological devices.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/química , Grafite/química , Óxidos/química , Polímeros/química , Engenharia Tecidual , Animais , Forma Celular , Espectroscopia Dielétrica , Eletrodos , Camundongos , Células NIH 3T3 , Células PC12 , Coelhos , Ratos , Espectrofotometria Ultravioleta
15.
Biomaterials ; 35(7): 2120-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24333027

RESUMO

One of the most significant components for implantable bioelectronic devices is the interface between the microelectrodes and the tissue or cells for disease diagnosis or treatment. To make the devices work efficiently and safely in vivo, the electrode-tissue interface should not only be confined in micro scale, but also possesses excellent electrochemical characteristic, stability and biocompatibility. Considering the enhancement of many composite materials by combining graphene oxide (GO) for its multiple advantages, we dope graphene oxide into poly(3,4-ethylenedioxythiophene) (PEDOT) forming a composite film by electrochemical deposition for electrode site modification. As a consequence, not only the enlargement of efficient surface area, but also the development of impedance, charge storage capacity and charge injection limit contribute to the excellent electrochemical performance. Furthermore, the stability and biocompatibility are confirmed by numerously repeated usage test and cell proliferation and attachment examination, respectively. As electrode-tissue interface, this biomaterial opens a new gate for tissue engineering and implantable electrophysiological devices.


Assuntos
Eletrodos , Grafite/química , Nanocompostos , Óxidos/química , Polímeros/química , Animais , Materiais Biocompatíveis , Microscopia Eletrônica de Varredura , Células PC12 , Espectroscopia Fotoeletrônica , Ratos , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Artigo em Chinês | MEDLINE | ID: mdl-21215209

RESUMO

OBJECTIVE: To study the features of electromyographic signals of orbicularis oculi muscle (OOM) of normal rabbits in various movement states, and to clarify relationships between functional actions of OOM and their electromyographic signals, hoping to obtain information concerning the electromyographic signals controlling OOM as reference for restoring the eye-closing function by artificial facial nerve prosthesis in patients with unilateral peripheral facial palsy. METHODS: The electromyographic signals were extracted from OOM of normal rabbits by implanted microelectrodes through upper and lower eyelids. Then the features of these electromyographic signals were analyzed in the time domain and the frequency domain. RESULTS: The peak values of the absolute electromyographic amplitude for natural continuous eye-opening event, natural continuous eye-closing state, natural eye-blinking movement and evoked eye-closing state were (28.8 ± 4.8) µV, (36.0 ± 4.7) µV, (398.8 ± 195.7) µV, and (715.4 ± 249.7) µV, respectively. The peak frequency values of the power spectrum density (PSD) of electromyographic signals for the four modes were (98 ± 17) Hz, (142 ± 22) Hz, (203 ± 58) Hz, and (349 ± 81) Hz, respectively. The electrical activities during the natural continuous eye-opening event and the natural continuous eye-closing state were stable and displayed low amplitudes. During the spontaneous blink state and the evoked eye-closing state, the electromyographic amplitudes markedly increased, and the increased level in the latter state was stronger than that in the former state. When rabbits continuously closed eyes or opened eyes, all of the peak values of the absolute voltage amplitudes were less than 50 µV. The absolute amplitude values of the starting site were between 50 µV and 60 µV during the spontaneous blink and the evoked eye-closing movements. The whole frequency band of the energy of PSD about OOM was between 0 Hz and 500 Hz, and the focus frequency range was between 20 Hz and 350 Hz.In the time domain, the difference was not significant for the electromyographic signals of OOM between the continuous eye-opening state and the continuous eye-closing movement (P > 0.05), but there were statistically significant differences in the other states for their pairwise comparisons (P < 0.05). In the frequency domain, there was no statistically significant difference for the peak frequency of PSD about the electromyographic signals when comparing the continuous eye-opening state with the continuous eye-closing event (P > 0.05). When comparing this item in the other movements with each other, however, the differences were statistically significant (P < 0.05). CONCLUSIONS: OOM relaxes when eyelid keeps continuously opening. The action of eyelid-closing is due to contraction of this muscle. Each state has its own features of the electromyographic signals for OOM, these features can be used as criteria for computers to judge and identify various movement states of OOM. However, it is difficult to distinguish the natural continuous eye-opening event from the natural continuous eye-closing state, based on the features of electromyographic signals in the time and frequency domain.


Assuntos
Pálpebras/inervação , Músculo Esquelético/fisiologia , Animais , Piscadela , Eletromiografia , Movimentos Oculares , Paralisia Facial , Masculino , Coelhos
17.
J Chromatogr A ; 1162(2): 154-61, 2007 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-17561026

RESUMO

This paper presents development of a parylene membrane microfilter device for single stage capture and electrolysis of circulating tumor cells (CTCs) in human blood, and the potential of this device to allow genomic analysis. The presence and number of CTCs in blood has recently been demonstrated to provide significant prognostic information for patients with metastatic breast cancer. While finding as few as five CTCs in about 7.5mL of blood (i.e., 10(10) blood cells in) is clinically significant, detection of CTCs is currently difficult and time consuming. CTC enrichment is performed by either gradient centrifugation of CTC based on their buoyant density or magnetic separation of epithelial CTC, both of which are laborious procedures with variable efficiency, and CTC identification is typically done by trained pathologists through visual observation of stained cytokeratin-positive epithelial CTC. These processes may take hours, if not days. Work presented here provides a micro-electro-mechanical system (MEMS)-based option to make this process simpler, faster, better and cheaper. We exploited the size difference between CTCs and human blood cells to achieve the CTC capture on filter with approximately 90% recovery within 10 min, which is superior to current approaches. Following capture, we facilitated polymerase chain reaction (PCR)-based genomic analysis by performing on-membrane electrolysis with embedded electrodes reaching each of the individual 16,000 filtering pores. The biggest advantage for this on-membrane in situ cell lysis is the high efficiency since cells are immobilized, allowing their direct contact with electrodes. As a proof-of-principle, we show beta actin gene PCR, the same technology can be easily extended to real time PCR for CTC-specific transcript to allow molecular identification of CTC and their further characterization.


Assuntos
Membranas Artificiais , Células Neoplásicas Circulantes/metabolismo , Polímeros/química , Xilenos/química , Linhagem Celular Tumoral , Eletrólise/instrumentação , Eletrólise/métodos , Genômica/instrumentação , Genômica/métodos , Humanos , Imuno-Histoquímica , Queratinas/análise , Masculino , Microscopia Eletrônica de Varredura , Células Neoplásicas Circulantes/patologia , Células Neoplásicas Circulantes/ultraestrutura , Reação em Cadeia da Polimerase
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