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1.
Cell ; 135(5): 813-24, 2008 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-19041747

RESUMO

N-acylphosphatidylethanolamines (NAPEs) are a relatively abundant group of plasma lipids of unknown physiological significance. Here, we show that NAPEs are secreted into circulation from the small intestine in response to ingested fat and that systemic administration of the most abundant circulating NAPE, at physiologic doses, decreases food intake in rats without causing conditioned taste aversion. Furthermore, (14)C-radiolabeled NAPE enters the brain and is particularly concentrated in the hypothalamus, and intracerebroventricular infusions of nanomolar amounts of NAPE reduce food intake, collectively suggesting that its effects may be mediated through direct interactions with the central nervous system. Finally, chronic NAPE infusion results in a reduction of both food intake and body weight, suggesting that NAPE and long-acting NAPE analogs may be novel therapeutic targets for the treatment of obesity.


Assuntos
Regulação do Apetite , Fosfatidiletanolaminas/fisiologia , Amidas , Animais , Peso Corporal , Gorduras na Dieta/metabolismo , Endocanabinoides , Etanolaminas , Hipotálamo/metabolismo , Intestino Delgado/metabolismo , Camundongos , Camundongos Obesos , Atividade Motora , Obesidade/metabolismo , Ácidos Palmíticos/metabolismo , Fosfatidiletanolaminas/sangue , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Espectrometria de Massas em Tandem
2.
Sensors (Basel) ; 21(9)2021 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-33923058

RESUMO

Electric cell-substrate impedance sensing (ECIS) has been used as a real-time impedance-based method to quantify cell behavior in tissue culture. The method is capable of measuring both the resistance and capacitance of a cell-covered microelectrode at various AC frequencies. In this study, we demonstrate the application of high-frequency capacitance measurement (f = 40 or 64 kHz) for the sensitive detection of both the micromotion and wound-healing migration of human mesenchymal stem cells (hMSCs). Impedance measurements of cell-covered electrodes upon the challenge of various concentrations of carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP), from 0.1 to 30 µM, were conducted using ECIS. FCCP is an uncoupler of mitochondrial oxidative phosphorylation (OXPHOS), thereby reducing mitochondrial ATP production. By numerically analyzing the time-series capacitance data, a dose-dependent decrease in hMSC micromotion and wound-healing migration was observed, and the effect was significantly detected at levels as low as 0.1 µM. While most reported works with ECIS use the resistance/impedance time series, our results suggest the potential use of high-frequency capacitance time series for assessing migratory cell behavior such as micromotion and wound-healing migration.


Assuntos
Células-Tronco , Cicatrização , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona , Impedância Elétrica , Humanos , Mitocôndrias
3.
BMC Pregnancy Childbirth ; 20(1): 217, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32295527

RESUMO

BACKGROUND: The incidence of female stroke has increased gradually and has begun occurring at a younger age in recent years. Given that women live longer than men, stroke would cause more negative and longer-term impacts on the rest of the lives of women. There are few related studies on Asian women. We aimed to evaluate stroke risk in Asian women following hypertensive pregnancy disorders. METHODS: Using the Taiwan National Health Insurance database, we designed a retrospective study that included pregnant women between 2000 and 2013. We selected an age-matched control group of women without hypertensive pregnancy disorders at a 1:3 ratio. The endpoint was any episode of stroke; otherwise, the patients were tracked until December 31, 2013. After the index date until the end of 2013, Cox proportional hazards analysis was used to compare the risk of incident stroke. The risk factors for stroke were determined using Cox proportional regression to calculate the hazard ratio (HR) compared with the control group. RESULTS: During the follow-up period, the Kaplan-Meier analysis indicated that patients with hypertensive pregnancy disorders had a significantly higher risk of developing stroke than did patients without hypertensive pregnancy disorders (log-rank test P < 0.001). Multivariate Cox regression analysis demonstrated that the case group had a 2.134-fold increased risk of stroke (HR = 2.134; 95% CI = 1.817-2.505; P < 0.001). CONCLUSION: Our study provided evidence of an increased risk of stroke in patients with hypertensive pregnancy disorders. Compared with those without such disorders, the patients who had experienced the disorders had a 2.134-fold (P < 0.001) higher risk of developing stroke in the future.


Assuntos
Hipertensão Induzida pela Gravidez/epidemiologia , Acidente Vascular Cerebral/epidemiologia , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Feminino , Previsões , Humanos , Incidência , Estimativa de Kaplan-Meier , Gravidez , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Taiwan/epidemiologia , Adulto Jovem
4.
J Biomech Eng ; 142(9)2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32280990

RESUMO

In this study, we investigated the cellular mechanosensitive responses to a low intensity ultrasound (LIUS) stimulation (ISATA = 1 mW/cm2, pressure = 10 kPa). The dose and temporal effects at cell-substrate adhesion (CSA) at the basal level and cell-cell adhesion (CCA) at the apical level are reported in detail. A model of mouse mammary gland epithelial cells (EpH4) and the phosphorylation of mechanosensitive 130 kDa Crk-associated substrate (p130CAS) as an indicator for cellular responses were used. The intensity of phospho-p130CAS was found to be dependent on LIUS stress level, and the p130CAS was phosphorylated after 1 min stimulation at CSA. The phospho-p130CAS was also found to increase significantly at CCA upon LIUS stimulation. We confirmed that the cellular responses to ultrasound are immediate and dose dependent. Ultrasound affects not only CSA but also CCA. An E-cadherin knockout (EpH4ECad-/-) model also confirmed that phosphorylation of p130CAS at CCA is related to E-cadherins.


Assuntos
Proteína Substrato Associada a Crk , Animais , Caderinas/metabolismo , Adesão Celular , Camundongos , Fosforilação , Transdução de Sinais
5.
Sensors (Basel) ; 20(11)2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32517325

RESUMO

Electric cell-substrate impedance sensing (ECIS) is an attractive method for monitoring cell behaviors in tissue culture in real time. The time series impedance fluctuations of the cell-covered electrodes measured by ECIS are the phenomena accompanying cellular micromotion as cells continually rearrange their cell-cell and cell-substrate adhesion sites. Accurate assessment of these fluctuations to extract useful information from raw data is important for both scientific and practical purposes. In this study, we apply discrete wavelet transform (DWT) to analyze the concentration-dependent effect of cytochalasin B on human umbilical vein endothelial cells (HUVECs). The sampling rate of the impedance time series is 1 Hz and each data set consists of 2048 points. Our results demonstrate that, in the Daubechies (db) wavelet family, db1 is the optimal mother wavelet function for DWT-based analysis to assess the effect of cytochalasin B on HUVEC micromotion. By calculating the energy, standard deviation, variance, and signal magnitude area of DWT detail coefficients at level 1, we are able to significantly distinguish cytotoxic concentrations of cytochalasin B as low as 0.1 µM, and in a concentration-dependent manner. Furthermore, DWT-based analysis indicates the possibility to decrease the sampling rate of the micromotion measurement from 1 Hz to 1/16 Hz without decreasing the discerning power. The statistical measures of DWT detail coefficients are effective methods for determining both the sampling rate and the number of individual samples for ECIS-based micromotion assays.


Assuntos
Impedância Elétrica , Células Endoteliais da Veia Umbilical Humana/citologia , Análise de Ondaletas , Adesão Celular , Eletrodos , Humanos
6.
Sensors (Basel) ; 20(9)2020 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-32380706

RESUMO

The most common oral cancer is squamous cell carcinoma (SCC) and its highest occurrence is in the tongue. Almost 30% of patients with one primary head and neck tumor will have a second primary malignancy. In recent studies, two novel plant extracts, andrographolide and cannabidiol (CBD), have been exploited for their anticancer effects. Here, we investigated the cytotoxic effects of these two compounds on SCC-25 cells, a human tongue squamous carcinoma cell line, and compared the outcomes with two chemotherapeutic drugs, cisplatin and fluorouracil. Electric cell substrate impedance sensing (ECIS) system was applied to measure frequency- and time-dependent impedance of SCC-25 cell-covered electrodes and to further assess subtle changes in cell morphology and micromotion in response to different concentrations (0, 10, 30, 100, and 300 µM) of these compounds. AlamarBlue and Annexin V/7-AAD binding assays were used to measure the concentration dependent changes in viability and apoptosis of SCC-25 cells. Our results demonstrate that 24 hours after exposure to 30 µM CBD can significantly decrease the micromotion rate, damage the integrity of cell morphology, reduce cell viability, and induce higher apoptosis in treated SCC-25 cells, while the other three drugs attain similar effects at the concentration of 100 µM or higher. The apoptosis-induced changes in cell morphology and micromotion monitored by ECIS correlate well with biochemical assays. Thus, both frequency- and time-dependent impedance measurements using ECIS can be used to real-time follow cancer cell activities in response to anticancer drugs with different temporal cytotoxicity profiles.


Assuntos
Antineoplásicos , Carcinoma de Células Escamosas , Cisplatino , Neoplasias Bucais , Antineoplásicos/farmacologia , Apoptose , Carcinoma de Células Escamosas/tratamento farmacológico , Linhagem Celular Tumoral , Cisplatino/farmacologia , Eletroquímica , Humanos , Língua
7.
Sensors (Basel) ; 19(14)2019 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-31330904

RESUMO

Electric cell-substrate impedance sensing (ECIS) is an emerging technique for sensitively monitoring morphological changes of adherent cells in tissue culture. In this study, human mesenchymal stem cells (hMSCs) were exposed to different concentrations of carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP) for 20 h and their subsequent concentration-dependent responses in micromotion and wound healing migration were measured by ECIS. FCCP disrupts ATP synthesis and results in a decrease in cell migration rates. To detect the change of cell micromotion in response to FCCP challenge, time-series resistances of cell-covered electrodes were monitored and the values of variance were calculated to verify the difference. While Seahorse XF-24 extracellular flux analyzer can detect the effect of FCCP at 3 µM concentration, the variance calculation of the time-series resistances measured at 4 kHz can detect the effect of FCCP at concentrations as low as 1 µM. For wound healing migration, the recovery resistance curves were fitted by sigmoid curve and the hill slope showed a concentration-dependent decline from 0.3 µM to 3 µM, indicating a decrease in cell migration rate. Moreover, dose dependent incline of the inflection points from 0.3 µM to 3 µM FCCP implied the increase of the half time for wound recovery migration. Together, our results demonstrate that partial uncoupling of mitochondrial oxidative phosphorylation reduces micromotion and wound healing migration of hMSCs. The ECIS method used in this study offers a simple and sensitive approach to investigate stem cell migration and its regulation by mitochondrial dynamics.


Assuntos
Técnicas de Cultura de Células , Impedância Elétrica , Células-Tronco Mesenquimais/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/farmacologia , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Humanos , Mitocôndrias/efeitos dos fármacos
8.
J Cell Biochem ; 119(4): 3716-3724, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29236309

RESUMO

The induction of bone morphogenetic protein (BMP)2 in injured and arthritis articular cartilage has been proposed, but the precise mechanism has not been clearly clarified. Our previous study has found that leptin could stimulate the BMP2 autocrine effect to increase the anabolic collagen II expression when it initiates the catabolic response in human chondrocytes. It has been suggested that this BMP2 autocrine effect contributes to a reparative role in leptin-stimulated human chondrocytes. In this study, we further determined whether this BMP2 autocrine effect also affect the expressions of catabolic matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motif (ADAMTS). Human primary and SW1353 chondrocytes were used in this study. It was shown that leptin could induce the expressions of MMP1, 3, and 13 and ADAMTS4 and 5 in both human primary and SW1353 chondrocytes. Leptin-increased MMP1/13 (not MMP3) and ADAMTS4 (not ADAMTS5) expressions were affected by the leptin-upregulated BMP2 and its specific downstream Smad1/5 signaling. Moreover, both HDAC3 and 4 are involved in regulating leptin-induced BMP2 upregulation and then affect MMP1 and 13 and ADAMTS4 expression. Both HDAC3 and 4 also affect leptin-increased MMP3 mRNA expression but not through BMP2 autocrine effect of leptin induction. Our results further elucidated the role of BMP2 autocrine effect in matrix-degrading enzymes expressions under leptin stimulation. The findings in this study provide new insights into the possible mechanism of BMP2 induction in leptin-stimulated chondrocytes and in leptin-induced OA development.


Assuntos
Proteína ADAMTS4/metabolismo , Proteína Morfogenética Óssea 2/metabolismo , Condrócitos/metabolismo , Metaloproteinase 13 da Matriz/metabolismo , Metaloproteinase 1 da Matriz/metabolismo , Proteína ADAMTS4/genética , Western Blotting , Proteína Morfogenética Óssea 2/genética , Ensaio de Imunoadsorção Enzimática , Humanos , Leptina , Metaloproteinase 1 da Matriz/genética , Metaloproteinase 13 da Matriz/genética , Reação em Cadeia da Polimerase em Tempo Real , Proteína Smad1/genética , Proteína Smad1/metabolismo , Proteína Smad5/genética , Proteína Smad5/metabolismo
9.
J Cell Physiol ; 232(6): 1448-1457, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27731497

RESUMO

Low shear stress has been proposed to play a reparative role in modulating cartilage homeostasis. Recently, epidemiological studies have found a positive correlation between the resistin level in serum and synovial fluid and osteoarthritis (OA) severity in patients. However, the effect of moderate shear stress on the catabolic stimulation of resistin in OA chondrocytes remains unclear. Hence, this study was to investigate whether low shear stress could regulate resistin-induced catabolic cyclooxygenase (COX)-2 expression in human OA chondrocytes and the underlying mechanism. Human OA chondrocytes and SW1353 chondrosarcoma cells were used in this study. Two modes of low shear stress (2 dyn/cm2 ), pre-shear and post-shear, were applied to the chondrocytes. A specific activator and siRNAs were used to investigate the mechanism of low shear stress-regulated COX-2 expression of resistin induction. We found that human OA chondrocytes exposed to different modes of low shear stress elicit an opposite effect on resistin-induced COX-2 expression: pre-shear for a short duration attenuates the resistin effect by inhibiting the transcription factor nuclear factor (NF)-κB-p65 subunit and the cAMP response element binding protein; however, post-shear over a longer duration enhances the resistin effect by activating only the NF-κB-p65 subunit. Moreover, our results demonstrated that the regulation of both shear modes in resistin-stimulated COX-2 expression occurs through increasing AMP-activated protein kinase activation and then sirtuin 1 expression. This study elucidates the detailed mechanism of low shear stress regulating the resistin-induced catabolic COX-2 expression and indicates a possible reparative role of moderate shear force in resistin-stimulated OA development. J. Cell. Physiol. 232: 1448-1457, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Condrócitos/enzimologia , Ciclo-Oxigenase 2/genética , Osteoartrite/enzimologia , Osteoartrite/patologia , Resistina/farmacologia , Estresse Mecânico , Proteínas Quinases Ativadas por AMP/metabolismo , Idoso , Linhagem Celular Tumoral , Condrócitos/efeitos dos fármacos , Condrócitos/patologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Ciclo-Oxigenase 2/metabolismo , Humanos , Pessoa de Meia-Idade , Modelos Biológicos , NF-kappa B/metabolismo , Osteoartrite/genética , Regiões Promotoras Genéticas/genética , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/metabolismo
10.
Am J Physiol Cell Physiol ; 311(6): C1040-C1047, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27784677

RESUMO

The conventional approach to assessing cancer invasion is primarily for end-point analysis, which does not provide temporal information on the invasion process or any information on the interactions between invading cells and the underlying adherent cells. To alleviate these limitations, the present study exploited electric cell-substrate impedance sensing (ECIS) to monitor the invasion of ovarian cancer cells (SKOV-3) through an adherent monolayer of human umbilical vein endothelial cells (HUVECs). Impedance was measured at 4 kHz of AC voltage or was measured as a function of AC frequency (25 Hz to 60 kHz). By measuring impedance at 4-kHz AC, we found that the invasion of SKOV-3 cells through the HUVEC monolayer was manifested as a rapid decrease in transendothelial electrical resistance in real time. The invasion was augmented in the presence of hepatocyte growth factor (HGF). The enhancing effect of HGF was attenuated by c-Met inhibitor (SU11274). By measuring the frequency-dependent impedance of SKOV-3 cells over time, we found that HGF-enhanced SKOV-3 cell invasion was accomplished with reduced junctional resistance (Rb), increased average cell-substrate separation (h), and increased micromotion. SU11274 attenuated the effects of HGF on Rb, h, and micromotion in the SKOV-3 monolayer. SU11274 also increased the barrier function of the HUVEC monolayer by increasing Rb and decreasing h In conclusion, this study demonstrated an improved method for monitoring and studying the interactions between cancer cells and the underlying adherent cells during invasion in real time. Alterations in cellular biophysical properties (Rb, h) associated with cancer transendothelial invasion were detected.


Assuntos
Invasividade Neoplásica/patologia , Neoplasias Ovarianas/patologia , Linhagem Celular , Linhagem Celular Tumoral , Impedância Elétrica , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Fator de Crescimento de Hepatócito/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Neoplasias Ovarianas/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo
11.
J Lipid Res ; 56(8): 1403-18, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25640749

RESUMO

The purpose of this review is to summarize our current understanding of the physiological roles of apoA-IV in metabolism, and to underscore the potential for apoA-IV to be a focus for new therapies aimed at the treatment of diabetes and obesity-related disorders. ApoA-IV is primarily synthesized by the small intestine, attached to chylomicrons by enterocytes, and secreted into intestinal lymph during fat absorption. In circulation, apoA-IV is associated with HDL and chylomicron remnants, but a large portion is lipoprotein free. Due to its anti-oxidative and anti-inflammatory properties, and because it can mediate reverse-cholesterol transport, proposed functions of circulating apoA-IV have been related to protection from cardiovascular disease. This review, however, focuses primarily on several properties of apoA-IV that impact other metabolic functions related to food intake, obesity, and diabetes. In addition to participating in triglyceride absorption, apoA-IV can act as an acute satiation factor through both peripheral and central routes of action. It also modulates glucose homeostasis through incretin-like effects on insulin secretion, and by moderating hepatic glucose production. While apoA-IV receptors remain to be conclusively identified, the latter modes of action suggest that this protein holds therapeutic promise for treating metabolic disease.


Assuntos
Apolipoproteínas A/metabolismo , Metabolismo , Animais , Cirurgia Bariátrica , Regulação da Expressão Gênica , Humanos
12.
Am J Physiol Gastrointest Liver Physiol ; 308(6): G472-81, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25591862

RESUMO

Apolipoprotein A-IV (apoA-IV) is secreted by the small intestine on chylomicrons into intestinal lymph in response to fat absorption. Many physiological functions have been ascribed to apoA-IV, including a role in chylomicron assembly and lipid metabolism, a mediator of reverse-cholesterol transport, an acute satiety factor, a regulator of gastric function, and, finally, a modulator of blood glucose homeostasis. The purpose of this review is to update our current view of intestinal apoA-IV synthesis and secretion and the physiological roles of apoA-IV in lipid metabolism and energy homeostasis, and to underscore the potential for intestinal apoA-IV to serve as a therapeutic target for the treatment of diabetes and obesity-related disease.


Assuntos
Apolipoproteínas A/metabolismo , Encéfalo/metabolismo , Metabolismo Energético , Glucose/metabolismo , Intestino Delgado/metabolismo , Metabolismo dos Lipídeos , Resposta de Saciedade , Animais , Quilomícrons/metabolismo , Ingestão de Alimentos , Comportamento Alimentar , Homeostase , Humanos , Absorção Intestinal , Transdução de Sinais
13.
Cardiovasc Res ; 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38870316

RESUMO

AIMS: SCUBE2 (Signal peptide-CUB-epidermal growth factor-like domain-containing protein 2) is a secreted or membrane-bound protein originally identified from endothelial cells (ECs). Our previous work showed that SCUBE2 forms a complex with E-cadherin and stabilizes epithelial adherens junctions (AJs) to promote epithelial phenotypes. However, it remains unclear whether SCUBE2 also interacts with vascular endothelial (VE)-cadherin and modulates EC barrier function. In this study, we investigated whether and how SCUBE2 in ECs regulates vascular barrier maintenance. METHODS AND RESULTS: We showed that SCUBE2 colocalized and interacted with VE-cadherin and VE-protein tyrosine phosphatase (VE-PTP) within EC AJs. Furthermore, SCUBE2 knockdown disrupted EC AJs and increased EC permeability. Expression of EC SCUBE2 was suppressed at both mRNA and protein levels via the nuclear factor-κB (NF-κB) signaling pathway in response to pro-inflammatory cytokines or permeability-inducing agents. In line with these findings, EC-specific deletion of Scube2 (EC-KO) in mice impaired baseline barrier function and worsened vascular leakiness of peripheral capillaries after local injection of histamine or vascular endothelial growth factor. EC-KO mice were also sensitive to pulmonary vascular hyperpermeability and leukocyte infiltration in response to acute endotoxin- or influenza virus-induced systemic inflammation. Meanwhile, EC-specific SCUBE2-overexpressing mice were protected from these effects. Molecular studies suggested that SCUBE2 acts as a scaffold molecule enabling VE-PTP to dephosphorylate VE-cadherin, which prevents VE-cadherin internalization and stabilizes EC AJs. As such, loss of SCUBE2 resulted in hyperphosphorylation of VE-cadherin at tyrosine 685, which led to its endocytosis, thus destabilizing EC AJs and reducing barrier function. All of these effects were exacerbated by inflammatory insults. CONCLUSIONS: We found that SCUBE2 contributes to vascular integrity by recruiting VE-PTP to dephosphorylate VE-cadherin and stabilize AJs, thereby promoting EC barrier function. Moreover, our data suggest that genetic overexpression or pharmacological upregulation of SCUBE2 may help to prevent vascular leakage and edema in inflammatory diseases.

14.
Am J Physiol Cell Physiol ; 304(4): C382-91, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23325413

RESUMO

It was previously demonstrated in isolated renal vascular smooth muscle cells (VSMCs) that integrin-mediated mechanotransduction triggers intracellular Ca(2+) mobilization, which is the hallmark of myogenic response in VSMCs. To test directly whether integrin-mediated mechanotransduction results in the myogenic response-like behavior in renal VSMCs, cell traction force microscopy was used to monitor cell traction force when the cells were pulled with fibronectin-coated or low density lipoprotein (LDL)-coated paramagnetic beads. LDL-coated beads were used as a control for nonintegrin-mediated mechanotransduction. Pulling with LDL-coated beads increased the cell traction force by 61 ± 12% (9 cells), which returned to the prepull level after the pulling process was terminated. Pulling with noncoated beads had a minimal increase in the cell traction force (12 ± 9%, 8 cells). Pulling with fibronectin-coated beads increased the cell traction force by 56 ± 20% (7 cells). However, the cell traction force was still elevated by 23 ± 14% after the pulling process was terminated. This behavior is analogous to the changes of vascular resistance in pressure-induced myogenic response, in which vascular resistance remains elevated after myogenic constriction. Fibronectin is a native ligand for α(5)ß(1)-integrins in VSMCs. Similar remanent cell traction force was found when cells were pulled with beads coated with ß(1)-integrin antibody (Ha2/5). Activation of ß(1)-integrin with soluble antibody also triggered variations of cell traction force and Ca(2+) mobilization, which were abolished by the Src inhibitor. In conclusion, mechanical force transduced by α(5)ß(1)-integrins triggered a myogenic response-like behavior in isolated renal VSMCs.


Assuntos
Integrina alfa5/fisiologia , Integrina beta1/fisiologia , Mecanotransdução Celular , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/fisiologia , Artéria Renal/citologia , Animais , Sinalização do Cálcio , Adesão Celular , Células Cultivadas , Integrina alfa5/metabolismo , Integrina beta1/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Resistência ao Cisalhamento , Vasoconstrição
15.
Gels ; 8(3)2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35323300

RESUMO

Mesenchymal stem cells (MSCs) possess immunomodulatory properties and capacity for endogenous regeneration. Therefore, MSC therapy is a promising treatment strategy for COVID-19. However, the cells cannot stay in the lung long enough to exert their function. The extracellular matrix from porcine bladders (B-ECM) has been shown not only to regulate cellular activities but also to possess immunoregulatory characteristics. Therefore, it can be hypothesized that B-ECM hydrogel could be an excellent scaffold for MSCs to grow and could anchor MSCs long enough in the lung so that they can exhibit their immunomodulatory functions. In this study, ECM degradation products and a co-culture system of MSCs and macrophages were developed to study the immunomodulatory properties of ECM and MSCs under septic conditions. The results showed that B-ECM degradation products could decrease pro-inflammatory and increase anti-inflammatory cytokines from macrophages. In an in vivo mimicking co-culture system, MSCs cultured on B-ECM hydrogel exhibited immunomodulatory properties at both gene and protein levels. Both B-ECM degradation products and MSC conditioned medium supported the wound healing of alveolar epithelial cells. The results from the study could offer a basis for investigation of immunomodulation by ECM and MSCs before conducting in vivo experiments, which could later be applied in regenerative medicine.

16.
Biosensors (Basel) ; 12(5)2022 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-35624596

RESUMO

Electric Cell-substrate Impedance Sensing (ECIS) is an impedance-based, real-time, and label-free measuring system for monitoring cellular activities in tissue culture. Previously, ECIS wound healing assay has been used to wound cells with high electric current and monitor the subsequent cell migration. In this study, we applied ECIS electric fence (EF) method, an alternative to electrical wounding, to assess the effects of different surface coatings on human keratinocyte (HaCaT) migration. The EF prevents inoculated cells from attaching or migrating to the fenced electrode surface while maintaining the integrity of the surface coating. After the EF is turned off, cells migrate into the cell-free area, and the increase in measured impedance is monitored. We cultured HaCaT cells on gold electrodes without coating or coated with poly-L-lysin (PLL), poly-D-lysine (PDL), or type-I collagen. We quantified migration rates according to the different slopes in the impedance time series. It was observed that either poly-L-lysine (PLL) or poly-D-lysine (PDL) limits cell adhesion and migration rates. Furthermore, the surface charge of the coated substrate in the culture condition positively correlates with the cell adhesion and migration process. Our results indicate that the EF method is useful for determining cell migration rates on specific surface coatings.


Assuntos
Queratinócitos , Lisina , Adesão Celular , Movimento Celular , Impedância Elétrica , Humanos
17.
Gastroenterology ; 138(5): 1997-2005, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20117110

RESUMO

BACKGROUND & AIMS: Cholecystokinin (CCK) is a satiation peptide released during meals in response to lipid intake; it regulates pancreatic digestive enzymes that are required for absorption of nutrients. We proposed that mice with a disruption in the CCK gene (CCK knockout [CCK-KO] mice) that were fed a diet of 20% butter fat would have altered fat metabolism. METHODS: We used quantitative magnetic resonance imaging to determine body composition and monitored food intake of CCK-KO mice using an automated measurement system. Intestinal fat absorption and energy expenditure were determined using a noninvasive assessment of intestinal fat absorption and an open circuit calorimeter, respectively. RESULTS: After consuming a high-fat diet for 10 weeks, CCK-KO mice had reduced body weight gain and body fat mass and enlarged adipocytes, despite the same level of food intake as wild-type mice. CCK-KO mice also had defects in fat absorption, especially of long-chain saturated fatty acids, but pancreatic triglyceride lipase did not appear to have a role in the fat malabsorption. Energy expenditure was higher in CCK-KO than wild-type mice, and CCK-KO mice had greater oxidation of carbohydrates while on the high-fat diet. Plasma leptin levels in the CCK-KO mice fed the high-fat diet were markedly lower than in wild-type mice, although levels of insulin, gastric-inhibitory polypeptide, and glucagon-like peptide-1 were normal. CONCLUSIONS: CCK is involved in regulating the metabolic rate and is important for lipid absorption and control of body weight in mice placed on a high-fat diet.


Assuntos
Colecistocinina/deficiência , Gorduras na Dieta/metabolismo , Absorção Intestinal , Obesidade/prevenção & controle , Aumento de Peso , Adiposidade , Animais , Biomarcadores/sangue , Manteiga , Calorimetria , Colecistocinina/genética , Gorduras na Dieta/sangue , Modelos Animais de Doenças , Ingestão de Alimentos , Metabolismo Energético , Ácidos Graxos/metabolismo , Leptina/sangue , Lipase/metabolismo , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Atividade Motora , Obesidade/genética , Obesidade/metabolismo , Obesidade/fisiopatologia , Fatores de Tempo
18.
Materials (Basel) ; 14(2)2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33477485

RESUMO

Magnesium alloys with coatings have the potential to be used for bone substitute alternatives since their mechanical properties are close to those of human bone. However, the surface modification of magnesium alloys to increase the surface biocompatibility and reduce the degradation rate remains a challenge. Here, FHA-Mg scaffolds were made of magnesium alloys and coated with fluorohydroxyapatite (FHA). Human mesenchymal stem cells (hMSCs) were cultured on FHA-Mg scaffolds and cell viability, proliferation, and osteogenic differentiation were investigated. The results showed that FHA-Mg scaffolds display a nano-scaled needle-like structure of aggregated crystallites on their surface. The average Mg2+ concentration in the conditioned media collected from FHA-Mg scaffolds (5.8-7.6 mM) is much lower than those collected from uncoated, Mg(OH)2-coated, and hydroxyapatite (HA)-coated samples (32.1, 17.7, and 21.1 mM, respectively). In addition, compared with hMSCs cultured on a culture dish, cells cultured on FHA-Mg scaffolds demonstrated better proliferation and comparable osteogenic differentiation. To eliminate the effect of osteogenic induction medium, hMSCs were cultured on FHA-Mg scaffolds in culture medium and an approximate 66% increase in osteogenic differentiation was observed three weeks later, indicating a significant effect of the nanostructured surface of FHA-Mg scaffolds on hMSC behaviors. With controllable Mg2+ release and favorable mechanical properties, porous FHA-Mg scaffolds have a great potential in cell-based bone regeneration.

19.
PLoS One ; 14(8): e0219351, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31408465

RESUMO

BACKGROUND: Pelvic inflammatory disease (PID) is an infectious disease that causes tubal occlusion and other pelvic and abdominal adhesions. The incidence of pelvic inflammatory disease (PID) has increased due to the sexually active status of the young population. This leads to a more serious problem and a larger effect than previously observed. However, there have been few studies on this topic in Asian populations. AIM: We aimed to evaluate the risk of preterm labor and/or ectopic pregnancy in Taiwanese women following PID. DESIGN: Using the Taiwan National Health Insurance Database, we designed a retrospective cohort study that included 12- to 55-year-old pregnant women between 2000 and 2010. We selected a 1:3 age-matched control group of non-PID women. The endpoint was any episode of preterm labor or ectopic pregnancy; otherwise, the patients were tracked until 31 December 2010. METHODS: The risk factors for preterm labor or ectopic pregnancy were explored. For cases included from the index date until the end of 2010, we analyzed the risk of incident preterm labor or ectopic pregnancy. With the use of a multivariate Cox proportional hazard regression analysis, we calculated the hazard ratio (HR) with a 95% CI and compared it with that of the control group. RESULTS: This study examined 30,450 patients with PID and 91,350 controls. During the follow-up period, patients in the PID group were more likely to develop preterm labor or ectopic pregnancy than patients in the control group. The cumulative incidence rates for developing preterm labor were 1.84% (561/30,450 individuals) in patients with PID and 1.63% (1492/91,350 individuals) in patients without PID. On the other hand, the cumulative incidence rate for developing ectopic pregnancy in patients with PID was 0.05% (14/30,450 individuals) but was only 0.04% (33/91,350 individuals) in patients without PID. Compared with those without PID, the patients with PID had a 1.864 times (P<0.001) higher risk of developing preterm labor and a 2.121 times (P = 0.003) higher risk of developing ectopic pregnancy. CONCLUSION: Our study provided evidence of an increased risk of preterm labor or ectopic pregnancy in PID patients.


Assuntos
Trabalho de Parto Prematuro/etiologia , Doença Inflamatória Pélvica/complicações , Gravidez Ectópica/etiologia , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Feminino , Humanos , Incidência , Pessoa de Meia-Idade , Trabalho de Parto Prematuro/epidemiologia , Gravidez , Gravidez Ectópica/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Taiwan/epidemiologia , Adulto Jovem
20.
Opt Express ; 16(15): 10900-11, 2008 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-18648403

RESUMO

We present a phase-imaging technique to quantitatively study the three-dimensional structure of cells. The method, based on the simultaneous dual-wavelength digital holography, allows for higher axial range at which the unambiguous phase imaging can be performed. The technique is capable of nanometer axial resolution. The noise level, which increases as a result of using two wavelengths, is then reduced to the level of a single wavelength. The method compares favorably to software unwrapping, as the technique does not produce non-existent phase steps. Curvature mismatch between the reference and object beams is numerically compensated. The 3D images of SKOV-3 ovarian cancer cells are presented.


Assuntos
Holografia/instrumentação , Imageamento Tridimensional/instrumentação , Interferometria/instrumentação , Microscopia/instrumentação , Neoplasias Ovarianas/patologia , Fotometria/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Linhagem Celular Tumoral , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Humanos , Aumento da Imagem/instrumentação , Interpretação de Imagem Assistida por Computador/instrumentação
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