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1.
Neurobiol Dis ; 197: 106528, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38740348

RESUMO

BACKGROUND: Brain injury has been suggested as a risk factor for neurodegenerative diseases. Accordingly, defects in the brain's intrinsic capacity to repair injury may result in the accumulation of damage and a progressive loss of brain function. The G2019S (GS) mutation in LRRK2 (leucine rich repeat kinase 2) is the most prevalent genetic alteration in Parkinson's disease (PD). Here, we sought to investigate how this LRRK2-GS mutation affects repair of the injured brain. METHODS: Brain injury was induced by stereotaxic injection of ATP, a damage-associated molecular pattern (DAMP) component, into the striatum of wild-type (WT) and LRRK2-GS mice. Effects of the LRRK2-GS mutation on brain injury and the recovery from injury were examined by analyzing the molecular and cellular behavior of neurons, astrocytes, and monocytes. RESULTS: Damaged neurons express osteopontin (OPN), a factor associated with brain repair. Following ATP-induced damage, monocytes entered injured brains, phagocytosing damaged neurons and producing exosome-like vesicles (EVs) containing OPN through activation of the inflammasome and subsequent pyroptosis. Following EV production, neurons and astrocytes processes elongated towards injured cores. In LRRK2-GS mice, OPN expression and monocytic pyroptosis were decreased compared with that in WT mice, resulting in diminished release of OPN-containing EVs and attenuated elongation of neuron and astrocyte processes. In addition, exosomes prepared from injured LRRK2-GS brains induced neurite outgrowth less efficiently than those from injured WT brains. CONCLUSIONS: The LRRK2-GS mutation delays repair of injured brains through reduced expression of OPN and diminished release of OPN-containing EVs from monocytes. These findings suggest that the LRRK2-GS mutation may promote the development of PD by delaying the repair of brain injury.


Assuntos
Lesões Encefálicas , Exossomos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Monócitos , Mutação , Osteopontina , Animais , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Camundongos , Exossomos/metabolismo , Exossomos/genética , Osteopontina/metabolismo , Osteopontina/genética , Lesões Encefálicas/metabolismo , Lesões Encefálicas/genética , Monócitos/metabolismo , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Neurônios/patologia , Masculino , Astrócitos/metabolismo
2.
Glia ; 69(4): 1037-1052, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33300228

RESUMO

The brain has an intrinsic capacity to repair injury, but the specific mechanisms are largely unknown. In this study, we found that, despite their incipient death, damaged neurons play a key repair role with the help of monocytes infiltrated from blood. Monocytes phagocytosed damaged and/or dying neurons that expressed osteopontin (OPN), with possible subsequent activation of their inflammasome pathway, resulting in pyroptosis. During this process, monocytes released CD63-positive exosome-like vesicles containing OPN. Importantly, following the exosome-like vesicles, neuron and astrocyte processes elongated toward the injury core. In addition, exosomes prepared from the injured brain contained OPN, and enhanced neurite outgrowth of cultured neurons in an OPN-dependent manner. Thus, our results introduce the concept that neurons in the injured brain that are destined to die perceive the stressful condition and begin the regeneration processes through induction of OPN, ultimately executing the repair process with the help of monocytes recruited from the circulation.


Assuntos
Monócitos , Osteopontina , Encéfalo/metabolismo , Monócitos/metabolismo , Neurônios/metabolismo , Osteopontina/metabolismo , Fagocitose
3.
Biochem Biophys Res Commun ; 534: 240-247, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33272569

RESUMO

Mild hypothermia is a well-established technique for alleviating neurological injuries in clinical surgery. RNA-binding protein motif 3 (RBM3) has been identified as a crucial factor in mediating hypothermic neuroprotection, providing its induction as a promising strategy for mimicking therapeutic hypothermia. However, little is known about molecular control of RBM3 and signaling pathways affected by hypothermia. In the present study, human SH-SY5Y neuroblastoma cells were used as a neural cell model. Screening of signaling pathways showed that cold exposure led to inactivation of ERK and AMPK pathways, and activation of FAK and PLCγ pathways, with activities of p38, JNK and AKT pathways moderately changed. Next, various small molecule inhibitors specific to these signaling pathways were applied. Interestingly, only FAK-specific inhibitor exhibited a significant inhibitory effect on hypothermia-induced RBM3 gene transcription and protein expression. Likewise, FAK silencing using siRNA technique significantly abrogated the induction of RBM3 by hypothermia. Moreover, FAK inhibition accounted for an inactivation of Src, a known kinase downstream of FAK. Next, either the silencing of Src by siRNA or its inactivation by a chemical inhibitor, strongly blocked the induction of RBM3 by cooling. Notably, in HEK293 and PC12 cells, FAK/Src activation was also shown to be indispensable for hypothermia-stimulated RBM3 expression. Lastly, the CCK8 and Western blot assays showed that both FAK/Src inacitivation and their knockdown substantially abrogate the neuroprotective effects of mild hypothermia against rotenone in SH-SY5Y cells. These data suggest that FAK/Src signaling axis regulates the transcription of Rbm3 gene and mediates neuroprotective effects of mild hypothermia.


Assuntos
Temperatura Baixa , Quinase 1 de Adesão Focal/metabolismo , Neurônios/metabolismo , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Proteínas de Ligação a RNA/biossíntese , Transdução de Sinais , Animais , Linhagem Celular Tumoral , Regulação da Expressão Gênica , Células HEK293 , Humanos , Sistema de Sinalização das MAP Quinases , NF-kappa B/metabolismo , Neurônios/enzimologia , Proteínas de Ligação a RNA/genética , Ratos , Rotenona/toxicidade , Transcrição Gênica
4.
Korean J Physiol Pharmacol ; 25(6): 565-574, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34697267

RESUMO

Astrocytes are activated in response to brain damage. Here, we found that expression of Kir4.1, a major potassium channel in astrocytes, is increased in activated astrocytes in the injured brain together with upregulation of the neural stem cell markers, Sox2 and Nestin. Expression of Kir4.1 was also increased together with that of Nestin and Sox2 in neurospheres formed from dissociated P7 mouse brains. Using the Kir4.1 blocker BaCl2 to determine whether Kir4.1 is involved in acquisition of stemness, we found that inhibition of Kir4.1 activity caused a concentration-dependent increase in sphere size and Sox2 levels, but had little effect on Nestin levels. Moreover, induction of differentiation of cultured neural stem cells by withdrawing epidermal growth factor and fibroblast growth factor from the culture medium caused a sharp initial increase in Kir4.1 expression followed by a decrease, whereas Sox2 and Nestin levels continuously decreased. Inhibition of Kir4.1 had no effect on expression levels of Sox2 or Nestin, or the astrocyte and neuron markers glial fibrillary acidic protein and ß-tubulin III, respectively. Taken together, these results indicate that Kir4.1 may control gain of stemness but not differentiation of stem cells.

5.
J Cell Biochem ; 121(2): 1192-1204, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31468584

RESUMO

The neural cell adhesion molecule (NCAM) plays critical roles in multiple cellular processes in neural cells, mesenchymal stem cells, and various cancer cells. However, the effect and mechanism of NCAM in human melanoma cells are still unclear. In this study, we found that NCAM regulated the proliferation, apoptosis, autophagy, migration, and epithelial-to-mesenchymal transition of human melanoma cells by determining the biological behavior of NCAM knockdown A375 and M102 human melanoma cells. Further studies revealed that NCAM knockdown impaired the organization of actin cytoskeleton and reduced the phosphorylation of cofilin, an actin-cleaving protein. When cells were transfected with cofilin S3A (dephosphorylated cofilin), biological behavior similar to that of NCAM knockdown cells was observed. Research on the underlying molecular mechanism showed that NCAM knockdown suppressed activation of the Src/Akt/mTOR pathway. Specific inhibitors of Src and PI3K/Akt were employed to further verify the relationship between Src/Akt/mTOR signaling and cofilin, and the results showed that the phosphorylation level of cofilin decreased following inhibition of the Src/Akt/mTOR pathway. These results indicated that NCAM may regulate the proliferation, apoptosis, autophagy, migration, and epithelial-to-mesenchymal transition of human melanoma cells via the Src/Akt/mTOR/cofilin pathway-mediated dynamics of actin cytoskeleton.


Assuntos
Apoptose , Autofagia , Antígeno CD56/metabolismo , Movimento Celular , Proliferação de Células , Transição Epitelial-Mesenquimal , Melanoma/patologia , Fatores de Despolimerização de Actina/genética , Fatores de Despolimerização de Actina/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Antígeno CD56/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Melanoma/genética , Melanoma/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Células Tumorais Cultivadas , Quinases da Família src/genética , Quinases da Família src/metabolismo
6.
Biol Pharm Bull ; 43(2): 334-339, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31735734

RESUMO

Benzoylaconitine (BAC), the main hydrolysate of aconitine, is a lower toxic monoester type alkaloid considered as the pharmacodynamic constituent in Aconitum species. In this study, the effects and mechanisms of BAC on production of inflammatory cytokines interleukin (IL)-6 and IL-8 were investigated in IL-1ß-stimulated human synovial SW982 cells. The SW982 cells were incubated with BAC (0, 5 and 10 µM) before stimulating with IL-1ß (10 ng/mL). The results revealed that BAC suppressed gene and protein expression of IL-6 and IL-8 induced by IL-1ß. BAC decreased activation of mitogen-activated protein kinase (MAPK) and phosphorylation of Akt. BAC also inhibited degradation of inhibitor of kappaB (IκB)-α, phosphorylation and nuclear transposition of p65 protein. The results demonstrate that BAC exerts an anti-inflammatory effect dependent on MAPK, Akt and nuclear factor-κB (NF-κB) pathways in human synovial cells stimulated with IL-1ß, suggesting that BAC may be exploited as a potential therapeutic agent for rheumatoid arthritis (RA) treatment.


Assuntos
Aconitina/análogos & derivados , Interleucina-1beta , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Aconitina/química , Aconitina/farmacologia , Artrite Reumatoide/metabolismo , Linhagem Celular , Sobrevivência Celular , Humanos , Interleucina-1beta/metabolismo , Fosforilação , Sarcoma Sinovial , Transdução de Sinais , eIF-2 Quinase/metabolismo
7.
Biotechnol Lett ; 42(4): 657-668, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31989342

RESUMO

The ubiquitous proteoglycan, biglycan (BGN) acts as an important modulator, regulating key molecular pathways of metabolism and brain function. Autophagy is documented as a defining feature of neurodegeneration in Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). In the present study, we found that BGN protected neuronal cells from nitric oxide (NO)-induced cell apoptosis. However, it is still unclear that whether the neuroprotective effect of BGN relates to autophagy. Here, we discovered that an NO donor, sodium nitroprusside (SNP) induced autophagy in human SH-SY5Y neuroblastoma cells, including activating LC3B and inhibiting p62. Inhibiting autophagy by 3MA aggravated NO-induced cell death, otherwise promoting autophagy by Rapamycin rescued NO-triggered cell death. Notably, BGN downregulated by NO, significantly protected SH-SY5Y cells against NO-induced neurotoxicity by inhibiting the activation of autophagy-dependent AMPK signaling pathway. Moreover, BGN overexpression also diminished NO-induced the elevation of intracellular reactive oxygen species (ROS) level, but not NO content. These findings suggest that BGN protects neuroblastoma cells from NO-induced death by suppressing autophagy-dependent AMPK-mTOR signaling and intracellular ROS level.


Assuntos
Biglicano/metabolismo , Neuroblastoma/metabolismo , Óxido Nítrico/efeitos adversos , Nitroprussiato/química , Espécies Reativas de Oxigênio/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/metabolismo
8.
J Cell Mol Med ; 23(10): 7010-7020, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31436914

RESUMO

Mild hypothermia and its key product, cold-inducible protein RBM3, possess robust neuroprotective effects against various neurotoxins. However, we previously showed that mild hypothermia fails to attenuate the neurotoxicity from MPP+ , one of typical neurotoxins related to the increasing risk of Parkinson disease (PD). To better understand the role of mild hypothermia and RBM3 in PD progression, another known PD-related neurotoxin, rotenone (ROT) was utilized in this study. Using immunoblotting, cell viability assays and TUNEL staining, we revealed that mild hypothermia (32°C) significantly reduced the apoptosis induced by ROT in human neuroblastoma SH-SY5Y cells, when compared to normothermia (37°C). Meanwhile, the overexpression of RBM3 in SH-SY5Y cells mimicked the neuroprotective effects of mild hypothermia on ROT-induced cytotoxicity. Upon ROT stimulation, MAPK signalling like p38, JNK and ERK, and AMPK and GSK-3ß signalling were activated. When RBM3 was overexpressed, only the activation of p38, JNK and ERK signalling was inhibited, leaving AMPK and GSK-3ß signalling unaffected. Similarly, mild hypothermia also inhibited the activation of MAPKs induced by ROT. Lastly, it was demonstrated that the MAPK (especially p38 and ERK) inhibition by their individual inhibitors significantly decreased the neurotoxicity of ROT in SH-SY5Y cells. In conclusion, these data demonstrate that RBM3 mediates mild hypothermia-related neuroprotection against ROT by inhibiting the MAPK signalling of p38, JNK and ERK.


Assuntos
Temperatura Baixa , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neuroproteção/efeitos dos fármacos , Neurotoxinas/toxicidade , Proteínas de Ligação a RNA/metabolismo , Rotenona/toxicidade , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Citoproteção/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Humanos , Hipotermia Induzida
9.
Cancer Sci ; 110(2): 608-616, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30548112

RESUMO

Sine oculis homeobox 1 (Six1) is a homeodomain transcription factor that is aberrantly expressed in a variety of human cancers, including colorectal cancer (CRC). Six1 has been reported to play a key role in the proliferation and migration of CRC cells but the underlying molecular mechanisms are still poorly characterized. In the present study, we found that Six1 overexpression promoted the proliferation and migration of CRC cells. Consistently, Six1 knockdown (KD) significantly inhibited proliferation and migration of CRC cells. In addition, we showed that Six1 promoted proliferation and migration of CRC cells through activation of Wnt/ß-catenin signaling, as evidenced by promotion of nuclear localization of ß-catenin. Silencing of ß-catenin expression with siRNA or inhibiting Wnt signaling with a specific inhibitor, xav939, significantly blocked Six1-induced nuclear localization of ß-catenin and mitigated Six1-promoted proliferation and migration of CRC cells. We further confirmed the involvement of ß-catenin in Six1-promoted proliferation and migration of CRC cells by activation of Wnt signaling with lithium chloride (LiCl) in Six1 KD CRC cells and results showed that LiCl restores defective ß-catenin nuclear localization and proliferation and migration of CRC cells. Taken together, these results suggest that Six1 homeoprotein promotes the proliferation and migration of CRC cells by activating the Wnt/ß-catenin signaling pathway, and strategies targeting Six1 may be promising for the treatment of CRC.


Assuntos
Movimento Celular/genética , Proliferação de Células/genética , Neoplasias Colorretais/genética , Proteínas de Homeodomínio/genética , Via de Sinalização Wnt/genética , beta Catenina/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Células HCT116 , Humanos , RNA Interferente Pequeno/genética , Transdução de Sinais/genética
10.
Int J Mol Sci ; 20(22)2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31739592

RESUMO

Celastrol, a triterpene isolated from the root of traditional Chinese medicine Thunder of God Vine, possesses anti-cancer and anti-inflammatory activity to treat rheumatoid disease or as health product. Necroptosis is considered as a new approach to overcome chemotherapeutics resistance. However, whether celastrol exerts necroptosis leading to gastric cancer cell death is still unclear. Here, for the first time we showed that celastrol induced necroptosis in HGC27 and AGS gastric cancer cell lines. More importantly, celastrol down-regulated biglycan (BGN) protein, which is critical for gastric cancer migration and invasion. Furthermore, celastrol activated receptor-interacting protein 1 and 3 (RIP1 and RIP3) and subsequently promoted the translation of mixed-lineage kinase domain-like (MLKL) from cytoplasm to plasma membrane, leading to necroptosis of gastric cancer cell, which was blocked by over-expression BGN. In addition, celastrol suppressed the release of pro-inflammatory cytokines TNF-α and IL-8 in HGC27 and AGS cells, which was reversed by over-expression BGN. Taken together, we identified celastrol as a necroptosis inducer, activated RIP1/RIP3/MLKL pathway and suppressed the level of pro-inflammatory cytokines by down-regulating BGN in HGC-27 and AGS cells, which supported the feasibility of celastrol in gastric cancer therapy.


Assuntos
Biglicano/metabolismo , Inflamação/complicações , Inflamação/metabolismo , Necroptose/efeitos dos fármacos , Neoplasias Gástricas/etiologia , Neoplasias Gástricas/metabolismo , Triterpenos/farmacologia , Biomarcadores , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Citocinas/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Mediadores da Inflamação/metabolismo , Necroptose/genética , Triterpenos Pentacíclicos , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Neoplasias Gástricas/patologia
11.
Biochemistry ; 56(46): 6098-6110, 2017 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-29087193

RESUMO

In humans, primary microRNA (pri-miRNA) processing starts from precise cleavage of the stem loop, which is catalyzed by the Drosha-DGCR8 complex. However, the significant inconsistencies in the expression levels among primary, precursor, and mature miRNAs clearly indicate that many other factors may be involved in this regulation. Here, we utilize a newly developed RNA affinity technique to isolate such factors. In this study, a tRNA-scaffolded aptamer (tRSA)-based RNA affinity tag, by directly fusing primary let-7 miRNA to the 3'-end of tRSA, is employed to pull down the protein components specifically binding to pri-let-7. We show that La protein binds to pri-let-7 via its La motif and significantly promotes the processing efficiency of pri-let-7 in vitro and in cells. In addition, we demonstrate that La protein is associated with DGCR8, but not Drosha, in an RNA-dependent manner. Interestingly, the RNA binding capacity of La motif is important for miRNA processing. Hence, we propose that La protein is an important microprocessor component regulating miRNA processing efficiency by association with DGCR8 to regulate formation of the DGCR8-Drosha complex for miRNA processing.


Assuntos
MicroRNAs/metabolismo , Fosfoproteínas/metabolismo , Precursores de RNA/metabolismo , Proteínas de Ligação a RNA/metabolismo , Células HEK293 , Humanos , MicroRNAs/química , Modelos Moleculares , Conformação de Ácido Nucleico , Fosfoproteínas/genética , Interferência de RNA , Precursores de RNA/química , Processamento Pós-Transcricional do RNA , Regulação para Cima
12.
Mol Cell Biochem ; 435(1-2): 175-183, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28536952

RESUMO

The neural cell adhesion molecule (NCAM), a key member of the immunoglobulin-like CAM family, was reported to regulate the migration of bone marrow-derived mesenchymal stem cells (BMSCs). However, the detailed cellular behaviors including lamellipodia formation in the initial step of directional migration remain largely unknown. In the present study, we reported that NCAM affects the lamellipodia formation of BMSCs. Using BMSCs from Ncam knockout mice we found that Ncam deficiency significantly impaired the migration and the directional lamellipodia formation of BMSCs. Further studies revealed that Ncam knockout decreased the activity of cofilin, an actin-cleaving protein, which was involved in directional protrusions. To explore the molecular mechanisms involved, we examined protein tyrosine phosphorylation levels in Ncam knockout BMSCs by phosphotyrosine peptide array analyses, and found that the tyrosine phosphorylation level of ß1 integrin, a protein upstream of cofilin, was greatly upregulated in Ncam-deficient BMSCs. Notably, by blocking the function of ß1 integrin with RGD peptide or ROCK inhibitor, the cofilin activity and directional lamellipodia formation of Ncam knockout BMSCs could be rescued. Finally, we found that the effect of NCAM on tyrosine phosphorylation of ß1 integrin was independent of the fibroblast growth factor receptor. These results indicated that NCAM regulates directional lamellipodia formation of BMSCs through ß1 integrin signal-mediated cofilin activity.


Assuntos
Fatores de Despolimerização de Actina/metabolismo , Células da Medula Óssea/metabolismo , Movimento Celular , Integrina beta1/metabolismo , Células-Tronco Mesenquimais/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Fatores de Despolimerização de Actina/genética , Animais , Células da Medula Óssea/citologia , Células Cultivadas , Integrina beta1/genética , Células-Tronco Mesenquimais/citologia , Camundongos , Camundongos Knockout , Moléculas de Adesão de Célula Nervosa/genética , Pseudópodes/genética , Pseudópodes/metabolismo
13.
Mol Cell Biochem ; 411(1-2): 289-98, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26476925

RESUMO

The migration and proliferation of EPCs are crucial for re-endothelialization in vascular repair and development. Id1 has a regulatory role in the regulation of EPCs migration and proliferation. Based on these findings, we hypothesized that Id1 plays a regulatory role in modulating the migration and proliferation of EPCs by interaction with other factors. Herein, we report that the Id1 protein and E-box protein E2-2 regulate EPCs function with completely opposite effects. Id1 plays a positive role in the regulation of EPC proliferation and migration, while endogenous E2-2 appears to be a negative regulator. Immunoprecipitation and immunofluorescence assay revealed that the Id1 protein interacts and co-localizes with the E2-2 protein in EPCs. Further, endogenous E2-2 protein was found to block EPCs function via the inhibition of FGFR1 and VEGFR2 expression. The overexpression and silencing of Id1 have no direct regulatory role on VEGFR2 and FGFR1 expression. On the other hand, Id1 relieves the E2-2-mediated repression of FGFR1 and VEGFR2 expression to modulate EPCs proliferation, migration, and tube formation in vitro. In summary, we demonstrated that Id1 and E2-2 are critical regulators of EPCs function in vitro. Id1 interacts with E2-2 and relieves the E2-2-mediated repression of FGFR1 and VEGFR2 expression to modulate EPCs functions. Id1 and E2-2 may represent novel therapeutic targets for re-endothelialization in vascular damage and repair.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/fisiologia , Células Progenitoras Endoteliais/citologia , Proteína 1 Inibidora de Diferenciação/fisiologia , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/fisiologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/fisiologia , Animais , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Masculino , Camundongos , Fator de Transcrição 4
14.
Nanotechnology ; 27(8): 085602, 2016 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26808687

RESUMO

Novel hierarchical chrysanthemum-flower-like carbon nanomaterials (CFL-CNMs) were synthesized by thermal chemical vapor deposition based on acetylene decomposition. A scanning electron microscope and a transmission electron microscope were employed to observe the morphology and structure of the unconventional nanostructures. It is found that the CFL-CNMs look like a blooming chrysanthemum with a stem rather than a spherical flower. The carbon flower has an average diameter of 5 µm, an average stem diameter of 150 nm, branch diameters ranging from 20 to 70 nm, and branch lengths ranging from 0.5 to 3 µm. The morphologies of the CFL-CNMs are unlike any of those previously reported. Fishbone-like carbon nanofibers with a spindle-shaped catalyst locating at the tip can also be found. Furthermore, the catalyst split was proposed to elucidate the formation mechanism of CFL-CNMs. A large and glomerate catalyst particle at the tip of the carbon nanofiber splits into smaller catalyst particles which are catalytic-active points for branch formation, resulting in the formation of CFL-CNMs.

15.
Mol Cell Biochem ; 402(1-2): 203-11, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25626893

RESUMO

Polyethyleneimine (PEI) is a cost-effective and non-viral vector for gene transfer, but the factors determining gene transfer efficiency and cytotoxicity of PEI in different mammalian cell lines remain largely unknown. In the present study, three different cell lines were chosen for investigation. Using pEGFP DNA and PEI, 21.5, 29.2, and 92.1 % of GFP-positive cells were obtained in BMSC, Hela, and 293T, respectively. In luciferase reporter assay, similar results were obtained (for luciferase activity, BMSC < Hela < 293T cells). By MTT test and cell apoptotic marker analysis, we demonstrated that high gene transfer efficiency is accompanied with high cytotoxicity of PEI. Moreover, we found that high expression level of caveolin-1 was accompanied with high gene transfer efficiency and cytotoxicity of PEI in 293T cells. More convincingly, caveolin-1 silencing in 293T could reduce both gene transfer efficiency and cytotoxicity of PEI. In contrast, caveolin-1 overexpression in BMSCs increases both gene transfer efficiency and cytotoxicity of PEI. Taken together, our study suggests that caveolin-1 may at least in part determine gene transfer efficiency and cytotoxicity of PEI in mammalian cell lines, providing caveolin-1 as a potential target for improving gene transfer efficiency when applying positively charged polyplexes to cell transfection.


Assuntos
Caveolina 1/fisiologia , Polietilenoimina/toxicidade , Animais , Genes Reporter , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Células HEK293 , Células HeLa , Humanos , Luciferases de Renilla/biossíntese , Luciferases de Renilla/genética , Camundongos , Transfecção
16.
Sci Total Environ ; 930: 172581, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38641112

RESUMO

The comprehensive analysis of multiple biological communities is essential for assessing diversities within mangrove ecosystems, yet such studies are infrequent. Environmental DNA (eDNA) facilitates the simultaneous exploration of organisms across various levels within a single ecosystem. In this investigation, 16S rRNA, cytochrome C oxidase I (COI), and Mito-fish primers were employed to characterize the microbiome, eukaryotic plankton, and fish communities, along with their intricate interactions, across 24 samples from three Chinese mangrove reservoirs. The resulting dataset encompasses 3779 taxonomic groups (genus level), spanning from the microbiome to vertebrates. Diversity analysis unveiled a higher level of stability in the microbiome community compared to plankton, underscoring the superior site-specificity of plankton. The association analysis revealed that biodiversity was primarily affected by temperature, turbidity, and fluorescent dissolved organic matter (fDOM). Notably, the physicochemical factors, turbidity, and fDOM had a more pronounced impact on the microbiome than on plankton, explaining their distinct sensitivities to site-specific conditions. Network analysis constructed 15 biological interaction subnetworks representing various community connections. The most connected genera in each subnetwork, highly responsive to different environmental factors, could serve as potential indicators of distinct ecosystem states. In summary, our findings represent the first comparison of the response sensitivities of different communities and the construction of their interaction networks in mangrove environments. These results contribute valuable insights into marine ecosystem dynamics and the role of environmental factors in shaping biodiversity.


Assuntos
Microbiota , Plâncton , RNA Ribossômico 16S , Áreas Alagadas , Plâncton/genética , DNA Ambiental , China , Monitoramento Ambiental , Biodiversidade , Animais , Ecossistema
17.
Cytotherapy ; 14(5): 608-20, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22277011

RESUMO

BACKGROUND AIMS: The widespread NG2-expressing neural progenitors in the central nervous system (CNS) are considered to be multifunctional cells with lineage plasticity, thereby possessing the potential for treating CNS diseases. Their lineages and functional characteristics have not been completely unraveled. The present study aimed to disclose the lineage potential of clonal NG2(+) populations in vitro and in vivo. METHODS: Twenty-four clones from embryonic cerebral cortex-derived NG2(+) cells were induced for oligodendrocyte, astrocyte, neuronal and chondrocyte differentiation. The expression profiles of neural progenitor markers chondroitin sulfate proteoglycan 4 (NG2), platelet-derived growth factor-α receptor (PDGFαR); nestin and neuronal cell surface antigen (A2B5) were subsequently sorted on cells with distinct differentiation capacity. Transplantation of these NG2(+) clones into the spinal cord was used to examine their lineage potential in vivo. RESULTS: In vitro differentiation analysis revealed that all the clones could differentiate into oligodendrocytes, and seven of them were bipotent (oligodendrocytes and astrocytes). Amazingly, one clone exhibited a multipotent capacity of differentiating into not only neuronal-glial lineages but also chondrocytes. These distinct subtypes were further found to exhibit phenotypic heterogeneity based on the examination of a spectrum of neural progenitor markers. Transplanted clones survived, migrated extensively and differentiated into oligodendrocytes, astrocytes or even neurons to integrate with the host spinal cord environment. CONCLUSIONS: These results suggest that NG2(+) cells contain heterogeneous progenitors with distinct differentiation capacities, and the immortalized clonal NG2(+) cell lines might provide a cell source for treating spinal cord disorders.


Assuntos
Antígenos/metabolismo , Diferenciação Celular , Sistema Nervoso Central/citologia , Sistema Nervoso Central/crescimento & desenvolvimento , Neurônios/citologia , Proteoglicanas/metabolismo , Medula Espinal/transplante , Células-Tronco , Animais , Astrócitos/citologia , Astrócitos/metabolismo , Linhagem da Célula , Células Cultivadas , Sistema Nervoso Central/metabolismo , Condrócitos/citologia , Condrócitos/metabolismo , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Oligodendroglia/citologia , Oligodendroglia/metabolismo , Gravidez , Ratos , Ratos Sprague-Dawley , Receptor A2B de Adenosina/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo , Telomerase/metabolismo
18.
Mol Cell Biochem ; 369(1-2): 95-104, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22766766

RESUMO

Angelicin is structurally related to psoralens, a well-known chemical class of photosensitizers used for its antiproliferative activity in treatment of different skin diseases. To verify the activity of angelicin, we employed human SH-SY5Y neuroblastoma cells to investigate its cytotoxicity, although its mechanism of action has not yet been fully elucidated. Here, we examined the cellular cytotoxicity of angelicin by cell viability assay, DNA fragmentation by DNA ladder assay, and activation of caspases and Bcl-2 family proteins by western blot analyses. The results of our investigation suggest that angelicin increased cellular cytotoxicity in a dose- and time-dependent manner with IC(50) of 49.56 µM at 48 h of incubation. In addition, angelicin dose-dependently downregulated the expression of anti-apoptotic proteins including Bcl-2, Bcl-xL, and Mcl-1 suggesting the involvement of the intrinsic mitochondria-mediated apoptotic pathway which did not participate in Fas/FasL-induced caspase-8-mediated extrinsic, MAP kinases, and PI3K/AKT/GSK-3ß pathway. Furthermore, we clarified the dose-dependent upregulation of caspase-9 and caspase-3 which indicated that angelicin-induced apoptosis is mediated primarily through the intrinsic caspase-mediated pathway. In particular, the caspase-3 inhibitor, DEVD-fmk, induced a reduction in angelicin-induced cytotoxicity which confirmed that the intrinsic caspase-dependent pathway during this apoptosis which did not prevent cytotoxicity using MAP kinases and GSK-3 inhibitor. Taken together, our data shows that angelicin is an effective apoptosis-inducing natural compound of human SH-SY5Y neuroblastoma cells which suggests that this compound may have a role in future therapies for human neuroblastoma cancer.


Assuntos
Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Furocumarinas/farmacologia , Caspase 3/metabolismo , Caspase 9/metabolismo , Linhagem Celular Tumoral , Fragmentação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Neuroblastoma/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais/efeitos dos fármacos
19.
Materials (Basel) ; 15(6)2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35329776

RESUMO

As a typical third-generation semiconductor material, silicon carbide (SiC) has been increasingly used in recent years. However, the outstanding performance of SiC component can only be obtained when it has a high-quality surface and low-damage subsurface. Due to the hard-brittle property of SiC, it remains a challenge to investigate the ductile machining mechanism, especially at the nano scale. In this study, a three-dimensional molecular dynamics (MD) simulation model of nanometric cutting on monocrystalline 3C-SiC was established based on the ABOP Tersoff potential. Multi-group MD simulations were performed to study the removal mechanism of SiC at the nano scale. The effects of both cutting speed and undeformed cutting thickness on the material removal mechanism were considered. The ductile machining mechanism, cutting force, hydrostatic pressure, and tool wear was analyzed in depth. It was determined that the chip formation was dominated by the extrusion action rather than the shear theory during the nanocutting process. The performance and service life of the diamond tool can be effectively improved by properly increasing the cutting speed and reducing the undeformed cutting thickness. Additionally, the nanometric cutting at a higher cutting speed was able to improve the material removal rate but reduced the quality of machined surface and enlarged the subsurface damage of SiC. It is believed that the results can promote the level of ultraprecision machining technology.

20.
Mol Med Rep ; 25(3)2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35088893

RESUMO

Subsequently to the publication of this paper, while performing a careful re­examination of the scientific integrity of the data included in their publications, the authors have realized that they inadvertently used the incorrect western blotting images in Fig. 2B of this article, However, still having access to their original data, the authors were able to reassemble Fig. 2 correctly, and the corrected version of this figure is shown below. Note that this error did not significantly affect the results or the conclusions reported in this paper, and all the authors agree to this Corrigendum. The authors thank the Editor of Molecular Medicine Reports for granting them the opportunity to publish this corrigendum, and apologize to the readership for any inconvenience caused. [the original article was published on Molecular Medicine Reports 14: 1709­1713, 2016; DOI: 10.3892/mmr.2016.5411].

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