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1.
Glia ; 71(4): 848-865, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36447422

RESUMO

Microglial cells are crucial in maintaining central nervous system (CNS) homeostasis and mediating CNS disease pathogenesis. Increasing evidence supports that alterations in the mechanical properties of CNS microenvironments influence glial cell phenotypes, but the mechanisms regulating microglial cell function remain elusive. Here, we examined the mechanosensitive Piezo1 channel in microglial cells, particularly, how Piezo1 channel activation regulates pro-inflammatory activation and production of pro-inflammatory cytokines, using BV2 and primary microglial cells. Piezo1 expression in microglial cells was detected both at mRNA and protein levels. Application of Piezo1 channel activator Yoda1 induced Ca2+ flux to increase intracellular Ca2+ concentration that was reduced by treatment with ruthenium red, a Piezo1 inhibitor, or Piezo1-specific siRNA, supporting that Piezo1 functions as a cell surface Ca2+ -permeable channel. Priming with lipopolysaccharide (LPS) induced microglial cell activation and production of TNF-α and IL-6, which were inhibited by treatment with Yoda1. Furthermore, LPS priming induced the activation of ERK, p38 MAPKs, and NF-κB. LPS-induced activation of NF-κB, but not ERK and p38, was inhibited by treatment with Yoda1. Yoda1-induced inhibition was blunted by siRNA-mediated depletion of Piezo1 expression and, furthermore, treatment with BAPTA-AM to prevent intracellular Ca2+ increase. Collectively, our results support that Piezo1 channel activation downregulates the pro-inflammatory function of microglial cells, especially production of TNF-α and IL-6, by initiating intracellular Ca2+ signaling to inhibit the NF-κB inflammatory signaling pathway. These findings reveal Piezo1 channel activation as a previously unrecognized mechanism regulating microglial cell function, raising an interesting perspective on targeting this molecular mechanism to alleviate neuroinflammation and associated CNS pathologies.


Assuntos
Lipopolissacarídeos , NF-kappa B , NF-kappa B/metabolismo , Lipopolissacarídeos/toxicidade , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Microglia/metabolismo , Transdução de Sinais , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo
2.
J Membr Biol ; 255(2-3): 357-361, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35322298

RESUMO

Large-conductance Ca2+-activated K+ (BKCa) channel and L-type voltage-dependent Ca2+ channel (L-VDCC) play important roles in regulating uterine contractility. The uterus stretch, occurring during pregnancy, is a critical factor to trigger uterine contraction. However, how mechanical stimuli impact the two channels remains unknown. Here we investigated the effects of exposure to mechanical stretches with varying magnitudes and durations on expressions of the two channels in rat uterine smooth muscle cells. Our results show that stretch down-regulates the BKCa channel expression but upregulates the L-VDCC expression. These findings are helpful to better understand the roles of L-VDCC and BKCa channel in stretch-triggered uterine contraction.


Assuntos
Canais de Cálcio Tipo L , Canais de Potássio Ativados por Cálcio de Condutância Alta , Miócitos de Músculo Liso , Contração Uterina , Útero , Animais , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo L/metabolismo , Feminino , Canais de Potássio Ativados por Cálcio de Condutância Alta/genética , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Miócitos de Músculo Liso/fisiologia , Gravidez , Ratos , Útero/fisiologia
3.
Acta Biochim Biophys Sin (Shanghai) ; 54(5): 716-724, 2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35593463

RESUMO

Esophageal squamous cell carcinoma (ESCC) is a common subtype of esophageal cancer with high incidence. Surgery remains the main strategy for treatment of ESCC at early stage. However, the treatment outcome is unsatisfactory. Therefore, finding new therapeutics is of great importance. In the present study, we measured the level of NEDD4L, an ubiquitin protein ligase, in clinical samples and investigated the effects of NEDD4L on cell viability, cell cycle progression, and glutamine metabolism in TE14 cells determined by CCK-8 assay, flow cytometry and biochemical analysis, respectively. The results show that NEDD4L is significantly decreased in ESCC specimens, and its decreased expression is associated with a poor clinical outcome. Overexpression of NEDD4L significantly inhibits cell viability, cell cycle progression, and glutamine metabolism in TE14 cells. Mechanistic study indicates that NEDD4L regulates tumor progression through ubiquitination of c-Myc and modulation of glutamine metabolism. NEDD4L inhibits cell viability, cell cycle progression, and glutamine metabolism in ESCC by ubiquitination of c-Myc to decrease the expressions of GLS1 and SLC1A5. Our findings highlight the importance of NEDD4L/c-Myc signaling in ESCC.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Genes myc , Proteínas Proto-Oncogênicas c-myc , Humanos , Sistema ASC de Transporte de Aminoácidos/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/metabolismo , Glutamina/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transdução de Sinais , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Genes myc/genética
4.
J Cell Physiol ; 236(10): 6897-6906, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33650160

RESUMO

Vascular stiffening, an early and common characteristic of cardiovascular diseases (CVDs), stimulates vascular smooth muscle cell (VSMC) proliferation which reciprocally accelerates the progression of CVDs. However, the mechanisms by which extracellular matrix stiffness accompanying vascular stiffening regulates VSMC proliferation remain largely unknown. In the present study, we examined the role of the intermediate-conductance Ca2+ -activated K+  (IKCa ) channel in the matrix stiffness regulation of VSMC proliferation by growing A7r5 cells on soft and stiff polydimethylsiloxane substrates with stiffness close to these of arteries under physiological and pathological conditions, respectively. Stiff substrates stimulated cell proliferation and upregulated the expression of the IKCa channel. Stiff substrate-induced cell proliferation was suppressed by pharmacological inhibition using TRAM34, an IKCa channel blocker, or genetic depletion of the IKCa channel. In addition, stiff substrate-induced cell proliferation was also suppressed by reducing extracellular Ca2+ concentration using EGTA or intracellular Ca2+ concentration using BAPTA-AM. Moreover, stiff substrate induced activation of extracellular signal-regulated kinases (ERKs), which was inhibited by treatment with TRAM34 or BAPTA-AM. Stiff substrate-induced cell proliferation was suppressed by treatment with PD98059, an ERK inhibitor. Taken together, these results show that substrates with pathologically relevant stiffness upregulate the IKCa channel expression to enhance intracellular Ca2+ signaling and subsequent activation of the ERK signal pathway to drive cell proliferation. These findings provide a novel mechanism by which vascular stiffening regulates VSMC function.


Assuntos
Sinalização do Cálcio , Proliferação de Células , Dimetilpolisiloxanos/química , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Mecanotransdução Celular , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Animais , Técnicas de Cultura de Células , Linhagem Celular , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/genética , Ratos
5.
J Cell Mol Med ; 24(6): 3739-3744, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32065503

RESUMO

Mechanical stimulation is an important factor regulating mesenchymal stem cell (MSC) functions such as proliferation. The Ca2+ -activated K+ channel, KCa 3.1, is critically engaged in MSC proliferation but its role in mechanical regulation of MSC proliferation remains unknown. Here, we examined the KCa 3.1 channel expression and its role in rat bone marrow-derived MSC (BMSC) proliferation in response to mechanical stretch. Application of mechanical stretch stimulated BMSC proliferation via promoting cell cycle progression. Such mechanical stimulation up-regulated the KCa 3.1 channel expression and pharmacological or genetic inhibition of the KCa 3.1 channel strongly suppressed stretch-induced increase in cell proliferation and cell cycle progression. These results support that the KCa 3.1 channel plays an important role in transducing mechanical forces to MSC proliferation. Our finding provides new mechanistic insights into how mechanical stimuli regulate MSC proliferation and also a viable bioengineering approach to improve MSC proliferation.


Assuntos
Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Estresse Mecânico , Animais , Proliferação de Células , Masculino , Ratos Sprague-Dawley
6.
Mol Pharm ; 16(5): 1839-1850, 2019 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-30974944

RESUMO

Protein tyrosine phosphatase 1B (PTP1B) is a widely confirmed target of the type 2 diabetes mellitus (T2DM) treatment. Herein, we reported a highly specific PTP1B inhibitor 2,2',3,3'-tetrabromo-4,4',5,5'-tetrahydroxydiphenylmethane (compound 1), which showed promising hypoglycemic activity in diabetic BKS db mice. With the IC50 value of 2.4 µM, compound 1 could directly bind to the catalytic pocket of PTP1B through a series of hydrogen bonds. Surface plasmon resonance analysis revealed that the target affinity [KD (equilibrium dissociation constant) value] of compound 1 binding to PTP1B was 2.90 µM. Moreover, compound 1 could activate the insulin signaling pathway in C2C12 skeletal muscle cells. We further evaluated the long-term effects of compound 1 in diabetic BKS db mice. Notably, oral administration of compound 1 significantly reduced the blood glucose levels of diabetic mice with increasing insulin sensitivity. In addition, the dyslipidemia of diabetic mice was also significantly improved by compound 1 gavage. The histological experiments showed that compound 1 treatment significantly ameliorated the disordered hepatic and pancreatic architecture and increased the glycogen content in the liver tissues as well as improved the insulin secretion function of pancreas. Taken together, our results manifested that the natural product compound 1 was a highly specific PTP1B inhibitor, which could activate insulin signaling pathway and ameliorate hyperglycemia and dyslipidemia in diabetic BKS db mice.


Assuntos
Compostos Benzidrílicos , Diabetes Mellitus Tipo 2 , Hipoglicemiantes , Extratos Vegetais , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Animais , Masculino , Camundongos , Administração Oral , Compostos Benzidrílicos/administração & dosagem , Compostos Benzidrílicos/química , Compostos Benzidrílicos/farmacologia , Compostos Benzidrílicos/uso terapêutico , Domínio Catalítico , Linhagem Celular , Diabetes Mellitus Tipo 2/tratamento farmacológico , Glicogênio/metabolismo , Ligação de Hidrogênio , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Concentração Inibidora 50 , Insulina/metabolismo , Resistência à Insulina , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Simulação de Acoplamento Molecular , Mioblastos/efeitos dos fármacos , Mioblastos/metabolismo , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Proteína Tirosina Fosfatase não Receptora Tipo 1/química , Proteína Tirosina Fosfatase não Receptora Tipo 1/isolamento & purificação , Rodófitas/química , Transdução de Sinais/efeitos dos fármacos
7.
Mar Drugs ; 17(1)2019 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-30641913

RESUMO

RNA-binding proteins (RBPs) lie at the center of posttranscriptional regulation and the dysregulation of RBPs contributes to diabetes. Therefore, the modulation of RBPs is anticipated to become a potential therapeutic approach to diabetes. CYC27 is a synthetic derivative of marine bromophenol BDB, which is isolated from red alga Rhodomela confervoides. In this study, we found that CYC27 significantly lowered the blood glucose levels of diabetic BKS db mice. Moreover, CYC27 effectively ameliorated dyslipidemia in BKS db mice by reducing their total serum cholesterol (TC) and triglyceride (TG) levels. Furthermore, CYC27 was an insulin-sensitizing agent with increased insulin-stimulated phosphorylation of insulin receptors and relevant downstream factors. Finally, to systemically study the mechanisms of CYC27, label-free quantitative phosphoproteomic analysis was performed to investigate global changes in phosphorylation. Enriched GO annotation showed that most regulated phosphoproteins were related to RNA splicing and RNA processing. Enriched KEGG analysis showed that a spliceosome-associated pathway was the predominant pathway after CYC27 treatment. Protein-protein interaction (PPI) analysis showed that CYC27 modulated the process of mRNA splicing via phosphorylation of the relevant RBPs, including upregulated Cstf3 and Srrt. Our results suggested that CYC27 treatment exerted promising anti-diabetic effects by sensitizing the insulin signaling pathways and modulating RNA splicing-associated RBPs.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Bifenil Polibromatos/farmacologia , Proteínas de Ligação a RNA/metabolismo , Rodófitas/química , Animais , Glicemia/análise , Glicemia/efeitos dos fármacos , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/genética , Modelos Animais de Doenças , Regulação da Expressão Gênica , Humanos , Hipoglicemiantes/síntese química , Concentração Inibidora 50 , Insulina/metabolismo , Masculino , Camundongos , Fosforilação/efeitos dos fármacos , Bifenil Polibromatos/síntese química , Mapas de Interação de Proteínas/efeitos dos fármacos , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Splicing de RNA/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
8.
BMC Pediatr ; 18(1): 198, 2018 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-29933752

RESUMO

BACKGROUND: Hemolytic streptococcus gangrene is a life threatening invasive bacterial infection. Hemolytic streptococcus gangrene in the danger triangle of the face is too lethal to operate. A case of the confirmed hemolytic streptococcus gangrene in the danger triangle of the face caused by Group A beta-hemolytic streptococcus (GAS) in 20-months old boy is presented to draw attention of clinicians to this uncommon but frequently fatal infection. CASE PRESENTATION: Previously healthy 20 months old boy suddenly developed paranasal gangrene on the left side of the danger triangle of the face, followed by rapidly progressive thrombocytopenia and hepatitis. The clinical features, liver function, and hematological and serological parameters resembled to a description of streptococcal toxic shock syndrome (STSS). Aggressive antibiotics, substitutional and supportive therapy were conducted without surgical debridement of facial tissues. Prompt diagnosis and aggressive timely treatment completely cured the disease in 28 days. CONCLUSIONS: The present case report demonstrates prompt diagnosis and timely treatment as a strategy to cure the fatal hemolytic streptococcus gangrene located in too risky body part to operate.


Assuntos
Face/patologia , Gangrena/complicações , Gangrena/microbiologia , Hepatite/complicações , Infecções Estreptocócicas/complicações , Streptococcus pyogenes , Trombocitopenia/complicações , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana , Diagnóstico Precoce , Humanos , Lactente , Masculino , Meropeném/uso terapêutico , Penicilina G/uso terapêutico , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/tratamento farmacológico , Vancomicina/uso terapêutico
9.
Microsc Microanal ; 23(5): 1013-1023, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28893340

RESUMO

Both fibronectin (FN) and filamentous actin (F-actin) fibers play a critical role for endothelial cells (ECs) in responding to shear stress and modulating cell alignment and functions. FN is dynamically coupled to the F-actin cytoskeleton via focal adhesions. However, it is unclear how ECs cooperatively remodel their subcellular FN matrix and intracellular F-actin cytoskeleton in response to shear stress. Current studies are hampered by the lack of a reliable and sensitive quantification method of FN orientation. In this study, we developed a MATLAB-based feature enhancement method to quantify FN and F-actin orientation. The role of F-actin in FN remodeling was also studied by treating ECs with cytochalasin D. We have demonstrated that FN and F-actin codistributed and coaligned parallel to the flow direction, and that F-actin alignment played an essential role in regulating FN alignment in response to shear stress. Our findings offer insight into how ECs cooperatively remodel their subcellular ECM and intracellular F-actin cytoskeleton in response to mechanical stimuli, and are valuable for vascular tissue engineering.


Assuntos
Actinas/metabolismo , Fibronectinas/metabolismo , Estresse Mecânico , Estresse Fisiológico/fisiologia , Citoesqueleto de Actina/fisiologia , Animais , Células Cultivadas , Citocalasina D/farmacologia , Células Endoteliais , Ratos , Ratos Sprague-Dawley
10.
J Mater Sci Mater Med ; 27(6): 106, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27107890

RESUMO

One of the major challenges in tissue engineering of small-diameter vascular grafts is to inhibit intimal hyperplasia and keep long-term patency after implantation. Rapid endothelialization of the grafts could be an effective approach. In this study, QK, a peptide mimicking vascular endothelial growth factor, was selected as the bioactive substrate and loaded in electrospun membranes for enhancement of vascular endothelial cell growth. In detail, QK peptide was firstly introduced with poly(ethylene glycol) diacrylate into a thiolated chitosan solution that could transfer into hydrogel. Then, suspensions or emulsions of poly(ethylene glycol)-b-poly(L-lactide-co-ε-caprolactone) (PELCL) containing QK peptide (with or without chitosan hydrogel) were electrospun into fibrous membranes. For comparison, the electrospun PELCL membrane without QK was also fabricated. Results of release behaviors showed that the electrospun membranes, especially that contained chitosan hydrogel prepared by suspension electrospinning, could successfully encapsulate QK peptide and maintain its secondary structure after released. In vitro cell culture studies exhibited that the release of QK peptide could accelerate the proliferation of vascular endothelial cells in the 9 days. It was suggested that the electrospun PELCL membranes loaded with QK peptide might have potential applications in vascular tissue engineering.


Assuntos
Células Endoteliais/efeitos dos fármacos , Membranas Artificiais , Peptídeos/farmacologia , Poliésteres/química , Polietilenoglicóis/química , Polímeros/química , Prótese Vascular , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Liberação Controlada de Fármacos , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Peptídeos/química
11.
Mol Genet Genomics ; 290(4): 1379-91, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25666462

RESUMO

Previous studies have indicated that hormonal control is essential for plant root growth. The root of the carrot is an edible vegetable with a high nutritional value. However, molecular mechanisms underlying hormone-mediated root growth of carrot have not been illustrated. Therefore, the present study collected carrot root samples from four developmental stages, and performed transcriptome sequencing to understand the molecular functions of plant hormones in carrot root growth. A total of 160,227 transcripts were generated from our transcriptome, which were assembled into 32,716 unigenes with an average length of 1,453 bp. A total of 4,818 unigenes were found to be differentially expressed between the four developmental stages. In total, 87 hormone-related differentially expressed genes were identified, and the roles of the hormones are extensively discussed. Our results suggest that plant hormones may regulate carrot root growth in a phase-dependent manner, and these findings will provide valuable resources for future research on carrot root development.


Assuntos
Daucus carota/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Plantas/biossíntese , Raízes de Plantas/genética , Transcriptoma/genética , Análise por Conglomerados , Daucus carota/crescimento & desenvolvimento , Daucus carota/metabolismo , Ontologia Genética , Sequenciamento de Nucleotídeos em Larga Escala , Anotação de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Fatores de Tempo
12.
Pflugers Arch ; 465(2): 221-32, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23179380

RESUMO

The large conductance Ca(2+)-activated K(+) (BK(Ca)) channel in vascular smooth muscle cell (VSMC) is an important potassium channel that can regulate vascular tone. Recent work has demonstrated that abnormalities in BK(Ca) channel function are associated with changes in cell proliferation and the onset of vascular disease. However, until today there are rare reports to show whether this channel is involved in VSMC proliferation in response to fluid shear stress (SS). Here we investigated a possible role of BK(Ca) channel in VSMC proliferation under laminar SS. Rat aortic VSMCs were plated in parallel-plate flow chambers and exposed to laminar SS with varied durations and magnitudes. VSMC proliferation was assessed by measuring proliferating cell nuclear antigen (PCNA) expression and DNA synthesis. BK(Ca) protein and gene expression was determined by flow cytometery and RT-PCR. The involvement of BK(Ca) in SS-induced inhibition of proliferation was examined by BK(Ca) inhibition using a BK(Ca) specific blocker, iberiotoxin (IBTX), and by BK(Ca) transfection in BK(Ca) non-expressing CHO cells. The changes in [Ca(2+)](i) were determined using a calcium-sensitive dye, fluo 3-AM. Membrane potential changes were detected with a potential-sensitive dye, DiBAC(4)(3). We found that laminar SS inhibited VSMC proliferation and stimulated BK(Ca) channel expression. Furthermore, laminar SS induced an increase in [Ca(2+)](i) and membrane hyperpolarization. Besides in VSMC, the inhibitory effect of BK(Ca) channel activity on cell proliferation in response to SS was also confirmed in BK(Ca)-transfected CHO cells showing a decline in proliferation. Blocking BK(Ca) channel reversed its inhibitory effect, providing additional support for the involvement of BK(Ca) in SS-induced proliferation reduction. Our results suggest, for the first time, that BK(Ca) channel mediates laminar SS-induced inhibition of VSMC proliferation. This finding is important for understanding the mechanism by which SS regulates VSMC proliferation, and should be helpful in developing strategies to prevent flow-initiated vascular disease formation.


Assuntos
Proliferação de Células , Canais de Potássio Ativados por Cálcio de Condutância Alta/fisiologia , Músculo Liso Vascular/fisiologia , Miócitos de Músculo Liso/fisiologia , Estresse Mecânico , Animais , Células CHO , Cálcio/metabolismo , Cricetinae , Cricetulus , Replicação do DNA , Expressão Gênica , Canais de Potássio Ativados por Cálcio de Condutância Alta/genética , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Masculino , Potenciais da Membrana , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/metabolismo , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ratos , Ratos Sprague-Dawley , Imagens com Corantes Sensíveis à Voltagem
13.
J Nanosci Nanotechnol ; 13(6): 3874-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23862421

RESUMO

Nanoscale materials (such as TiO2, hydroxyapatite nanoparticles) have gained much concern in the coating of implants for cell adhesion and growth to improve the osteoconductivity. However, due to attrition and corrosion, the wear particles would be generated from the joint in living organism, and influence the physiological function of synovial membranes in joint cavity. In this study, the potential cytotoxicity of anatase TiO2 nanoparticles (TiO2 NPs) on rat synovial cell line 364 (RSC-364) was investigated. After treatment with different concentrations of TiO2 NPs (0, 3, 30, 300 microg/ml), the viability of RSC-364 cells were decreased in a dose-dependent manner. TiO2 NPs exposure could disrupt the integrity of cell plasma membrane, leading to the increased leakage of lactate dehydrogenase (LDH) into the culture medium. TiO2 NPs were uptaken by RSC-364 cells. The ultrastructure of RSC-364 cells was changed such as nuclear shrinkage and mitochondrial swelling. The reactive oxygen species (ROS) was over-produced especially in the cells exposed to 30 and 300 microg/ml TiO2 NPs. The activities of endogeneous antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), were significantly decreased. The increased lipid peroxidation product (malondialdehyde, MDA) suggests the oxidative damage in cells. The flow cytometry detected that the cell cycle was blocked in G0/G1 phase, inhibiting the cell proliferation. These preliminary results indicate the oxidative stress injury and cytotoxicity of anatase TiO2 NPs on rat synovial cells. The reasonable and safe application of nanomaterials in artificial implants needs further study.


Assuntos
Divisão Celular/efeitos dos fármacos , Membrana Sinovial/efeitos dos fármacos , Titânio/farmacologia , Animais , Ciclo Celular , Linhagem Celular , Ratos , Membrana Sinovial/citologia
14.
Cell Prolif ; 56(4): e13385, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36562293

RESUMO

The increased proliferation of vascular smooth muscle cells (VSMCs) contributes to the pathogenesis of vascular diseases. The intermediate conductance calcium-activated potassium (IKCa ) channel plays a critical role in VSMC proliferation by raising the intracellular calcium concentration ([Ca2+ ]i ), but the underlying mechanism is still not unclear. Here we investigated the cooperation between IKCa and transient receptor potential canonical 1 (TRPC1) channels in mediating extracellular Ca2+ entry, which in turn activates downstream Ca2+ signalling in the regulation of VSMC proliferation using serum-induced cell proliferation model. Serum-induced cell proliferation was accompanied with up-regulation of IKCa expression and an increase in [Ca2+ ]i . Serum-induced cell proliferation and increase in [Ca2+ ]i were suppressed by IKCa inhibition with TRAM-34 or IKCa knockdown. Serum-induced cell proliferation was strongly reduced by the removal of extracellular Ca2+ with EGTA or intracellular Ca2+ with BAPTA-AM and, additionally, by TRPC1 knockdown. Moreover, the increase in [Ca2+ ]i induced by serum or by IKCa activation with 1-EBIO was attenuated by TRPC1 knockdown. Finally, serum induced ERK1/2 activation, which was attenuated by treatment with TRAM-34 or BAPTA-AM, as well as TRPC1 knockdown. Consistently, serum-induced cell proliferation was suppressed by ERK1/2 inhibition with PD98059. Taken together, these results suggest that the IKCa and TRPC1 channels cooperate in mediating Ca2+ influx that activates the ERK1/2 pathway to promote cell proliferation, thus providing new mechanistic insights into VSMC proliferation.


Assuntos
Músculo Liso Vascular , Canais de Potencial de Receptor Transitório , Músculo Liso Vascular/metabolismo , Canais de Potencial de Receptor Transitório/metabolismo , Cálcio/metabolismo , Sistema de Sinalização das MAP Quinases , Proliferação de Células , Canais de Cátion TRPC/metabolismo , Miócitos de Músculo Liso/metabolismo
15.
Biomaterials ; 300: 122183, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37302278

RESUMO

Developing new antimicrobial agents has become an urgent task to address the increasing prevalence of multidrug-resistant pathogens and the emergence of biofilms. Cationic antimicrobial peptides (AMPs) have been regarded as promising candidates due to their unique non-specific membrane rupture mechanism. However, a series of problems with the peptides hindered their practical application due to their high toxicity and low bioactivity and stability. Here, inspired by broadening the application of cell-penetrating peptides (CPPs), we selected five different sequences of cationic peptides which are considered as both CPPs and AMPs, and developed a biomimetic strategy to construct cationic peptide-conjugated liposomes with the virus-like structure for both enhancements of antibacterial efficacy and biosafety. The correlation between available peptide density/peptide variety and antimicrobial capabilities was evaluated from quantitative perspectives. Computational simulation and experimental investigations assisted to identify the optimal peptide-conjugated liposomes and revealed that the designed system provides high charge density for enhanced anionic bacterial membrane binding capability without compromised cytotoxicity, being capable of enhanced antibacterial efficacy of bacteria/biofilm of clinically important pathogens. The bio-inspired design has shown enhanced therapeutic efficiency of peptides and may promote the development of next-generation antimicrobials.


Assuntos
Anti-Infecciosos , Peptídeos Penetradores de Células , Lipossomos/metabolismo , Plâncton , Membrana Celular/metabolismo , Bactérias , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Anti-Infecciosos/metabolismo , Antibacterianos/farmacologia , Antibacterianos/química , Peptídeos Penetradores de Células/farmacologia , Peptídeos Penetradores de Células/metabolismo , Biofilmes , Testes de Sensibilidade Microbiana
16.
Adv Mater ; 35(41): e2211059, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36934404

RESUMO

The neuromuscular junction (NMJ) is a peripheral synaptic connection between presynaptic motor neurons and postsynaptic skeletal muscle fibers that enables muscle contraction and voluntary motor movement. Many traumatic, neurodegenerative, and neuroimmunological diseases are classically believed to mainly affect either the neuronal or the muscle side of the NMJ, and treatment options are lacking. Recent advances in novel techniques have helped develop in vitro physiological and pathophysiological models of the NMJ as well as enable precise control and evaluation of its functions. This paper reviews the recent developments in in vitro NMJ models with 2D or 3D cultures, from organ-on-a-chip and organoids to biohybrid robotics. Related derivative techniques are introduced for functional analysis of the NMJ, such as the patch-clamp technique, microelectrode arrays, calcium imaging, and stimulus methods, particularly optogenetic-mediated light stimulation, microelectrode-mediated electrical stimulation, and biochemical stimulation. Finally, the applications of the in vitro NMJ models as disease models or for drug screening related to suitable neuromuscular diseases are summarized and their future development trends and challenges are discussed.


Assuntos
Sistemas Microfisiológicos , Junção Neuromuscular , Junção Neuromuscular/fisiologia , Neurônios Motores , Fibras Musculares Esqueléticas , Contração Muscular , Músculo Esquelético
17.
Biophys J ; 103(4): 777-85, 2012 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-22947939

RESUMO

Binding of selectins to P-selectin glycoprotein ligand-1 (PSGL-1) mediates tethering and rolling of leukocytes on the endothelium during inflammation. Previous measurements obtained with a flow-chamber assay have shown that mutations of three tyrosines at the PSGL-1 N-terminus (Y46, Y48, and Y51) increase the reverse rates and their sensitivity to the force of bonds with P- and L-selectin. However, the effects of these mutations on the binding affinities and forward rates have not been studied. We quantified these effects by using an adhesion frequency assay to measure two-dimensional affinity and kinetic rates at zero force. Wild-type PSGL-1 has 2.2- to 8.5-fold higher binding affinities for P- and L-selectin than PSGL-1 mutants with two of three tyrosines substituted by phenylalanines, and 9.6- to 49-fold higher affinities than the PSGL-1 mutant with all three tyrosines replaced. In descending order, the affinity decreased from wild-type to Y48/51F, Y46/51F, Y46/48F, and Y46/48/51F. The affinity differences were attributed to major changes in the forward rate and minor changes in the reverse rate, suggesting that these tyrosines regulate the accessibility of PSGL-1 to P- and L-selectin via electrostatic interactions, which is supported by molecular-dynamics simulations. Our results provide insights into the structure-function relationship of receptor-ligand binding at a single-residue level.


Assuntos
Substituição de Aminoácidos , Membrana Celular/metabolismo , Selectina L/metabolismo , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/metabolismo , Selectina-P/metabolismo , Tirosina , Animais , Células CHO , Cricetinae , Cricetulus , Humanos , Cinética , Glicoproteínas de Membrana/genética , Simulação de Dinâmica Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Eletricidade Estática
18.
Medicine (Baltimore) ; 101(48): e32082, 2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36482541

RESUMO

BACKGROUND: The risk factors for cardiovascular and cerebrovascular diseases in young and middle-aged people have not yet been determined. We conducted a meta-analysis to find the risk factors for cardiovascular and cerebrovascular diseases, in order to provide guidance for the prevention of diseases in the young and middle-aged population. METHODS: We searched PubMed, Embase, Cochrane Library from the establishment of the database to Mar 2022. We included case-control or cohort studies reporting risk factors for cardiovascular and cerebrovascular disease in young and middle-aged adults. We excluded repeated publication, research without full text, incomplete information or inability to conduct data extraction and animal experiments, reviews and systematic reviews. STATA 15.1 was used to analyze the data. RESULTS: The pooled results indicated that increased systolic blood pressure was significantly associated with increased risk of any stroke, ischemic stroke and hemorrhagic stroke. Body Mass Index (BMI), current smoking, hypertension, and diabetes were significantly associated with increased risk of any stroke and ischemic stroke. Atrial fibrillation was only significantly associated with increased risk of any stroke. Increased total cholesterol was significantly associated with an increased risk of ischemic stroke, whereas increased triglycerides were significantly associated with a decreased risk of ischemic stroke. In addition, increased hypertension was also significantly associated with an increased risk of acute coronary syndrome. CONCLUSION: Our pooled results show that BMI, current smoking, atrial fibrillation, hypertension, systolic blood pressure, and total cholesterol can be used as risk factors for cardiovascular and cerebrovascular diseases in young people, while triglycerides can be used as protective factors for cardiovascular and cerebrovascular diseases in young and middle-aged adults.


Assuntos
Fibrilação Atrial , Transtornos Cerebrovasculares , Hipertensão , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Transtornos Cerebrovasculares/epidemiologia , Transtornos Cerebrovasculares/etiologia , Fatores de Risco , Hipertensão/epidemiologia , Colesterol
19.
Cell Stress Chaperones ; 27(3): 273-283, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35355227

RESUMO

Compared with normal cells, tumor cells mainly obtain energy through aerobic glycolysis. Hexokinase 2 (HK2) plays a key role in the regulation of tumor cell aerobic glycolysis, and targeting HK2 has become a new strategy for cancer treatment. However, little is known about the role of HK2 in colon cancer and the regulation of its targeted inhibitors. In this study, we found that the expression of HK2 in colorectal cancer tissues was significantly higher than that in adjacent tissues, and the expression level of HK2 in metastatic colorectal cancer was further increased. Meanwhile, the expression level of HK2 was closely related to clinical TNM stage and outcome of colorectal cancer patients. We provide here evidence that HK2 inhibitor 3-Bromopyruvate acid (3-BP) can significantly inhibit the survival and proliferation of colon cancer cells, and induce apoptosis through mitochondrial apoptosis signaling pathway. In addition, we found that 3-BP can also induce endoplasmic reticulum stress in colon cancer cells, the mechanism may be through the increase of intracellular calcium concentration. In vitro and in vivo experiments showed that inhibition of endoplasmic reticulum stress could further increase the proliferation inhibition and apoptosis induced by 3-BP. Collectively, our results show that HK2 is highly expressed in colorectal cancer. 3-BP, an inhibitor of HK2, can induce apoptosis and endoplasmic reticulum stress in colon cancer cells. Endoplasmic reticulum stress plays a protective role in cell death induced by 3-BP. This result suggested that targeting HK2 and endoplasmic reticulum stress may be a valuable strategy in targeted and combination therapy of colon cancer.


Assuntos
Neoplasias do Colo , Hexoquinase , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias do Colo/tratamento farmacológico , Combinação de Medicamentos , Estresse do Retículo Endoplasmático , Regulação Neoplásica da Expressão Gênica , Glicólise/fisiologia , Hexoquinase/genética , Hexoquinase/metabolismo , Humanos
20.
Cytotechnology ; 71(1): 1-14, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30478806

RESUMO

A critical limitation for tissue engineering and autologous therapeutic applications of bone marrow derived EPCs is their low frequency, which is even lower in number and activity level in patients with cardiovascular risk factors and other diseases. New strategies for obtaining and reserving sufficient ready-to-use EPCs for clinical use have hit major obstacles, because effects of serial passage and cryopreservation on EPC phenotype and functions are still needed to be explored. The present study aims at investigating effects of a limited number of culture passages as well as cryopreservation on EPC phenotype and functions. We isolated EPCs from rat bone marrow and cultured them up to passage 12 (totaling achievements of 40 population doublings). The phenotype and functions of fresh cultured and post-cryopreserved EPCs at passages 7 and 12, respectively, were evaluated. EPCs at passage 12 maintained the morphological characteristics, marker phenotype, Dil-ac-LDL uptake and FITC-UEA-1 binding functions, enhanced EPCs proliferation, tube formation and migration, but decreased CD133 expression compared with EPCs at passage 7. Cryopreservation caused limited impairment in EPC phenotype and functions. In brief, our results demonstrated that a limited number of culture passages and cryopreservation did not change EPC phenotype and functions, and can be used for the development of robust strategies and quality control criterion for obtaining sufficient and high-quality ready-to-use EPCs for tissue engineering and therapeutic applications.

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