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1.
Small ; 20(24): e2307901, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38185718

RESUMO

Cardiovascular disease is the cause of death in ≈50% of hemodialysis patients. Accumulation of uremic solutes in systemic circulation is thought to be a key driver of the endothelial dysfunction that underlies elevated cardiovascular events. A challenge in understanding the mechanisms relating chronic kidney disease to cardiovascular disease is the lack of in vitro models that allow screening of the effects of the uremic environment on the endothelium. Here, a method is described for microfabrication of human blood vessels from donor cells and perfused with donor serum. The resulting donor-derived microvessels are used to quantify vascular permeability, a hallmark of endothelial dysfunction, in response to serum spiked with pathophysiological levels of indoxyl sulfate, and in response to serum from patients with chronic kidney disease and from uremic pigs. The uremic environment has pronounced effects on microvascular integrity as demonstrated by irregular cell-cell junctions and increased permeability in comparison to cell culture media and healthy serum. Moreover, the engineered microvessels demonstrate an increase in sensitivity compared to traditional 2D assays. Thus, the devices and the methods presented here have the potential to be utilized to risk stratify and to direct personalized treatments for patients with chronic kidney disease.


Assuntos
Doenças Cardiovasculares , Microvasos , Humanos , Microvasos/patologia , Animais , Suínos , Insuficiência Renal/terapia , Medição de Risco , Doadores de Tecidos , Engenharia Tecidual/métodos , Indicã/sangue
2.
Eur Radiol ; 32(10): 6575-6587, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35759017

RESUMO

OBJECTIVE: This study aimed to incorporate clinicopathological, sonographic, and mammographic characteristics to construct and validate a nomogram model for predicting disease-free survival (DFS) in patients with triple-negative breast cancer (TNBC). METHODS: Patients diagnosed with TNBC at our institution between 2011 and 2015 were retrospectively evaluated. A nomogram model was generated based on clinicopathological, sonographic, and mammographic variables that were associated with 1-, 3-, and 5-year DFS determined by multivariate logistic regression analysis in the training set. The nomogram model was validated according to the concordance index (C-index) and calibration curves in the validation set. RESULTS: A total of 636 TNBC patients were enrolled and divided into training cohort (n = 446) and validation cohort (n = 190). Clinical factors including tumor size > 2 cm, axillary dissection, presence of LVI, and sonographic features such as angular/spiculated margins, posterior acoustic shadows, and presence of suspicious lymph nodes on preoperative US showed a tendency towards worse DFS. The multivariate analysis showed that no adjuvant chemotherapy (HR = 6.7, 95% CI: 2.6, 17.5, p < 0.0005), higher axillary tumor burden (HR = 2.7, 95% CI: 1.0, 7.1, p = 0.045), and ≥ 3 malignant features on ultrasound (HR = 2.4, CI: 1.1, 5.0, p = 0.021) were identified as independent prognostic factors associated with poorer DFS outcomes. In the nomogram, the C-index was 0.693 for the training cohort and 0.694 for the validation cohort. The calibration plots also exhibited excellent consistency between the nomogram-predicted and actual survival probabilities in both the training and validation cohorts. CONCLUSIONS: Clinical variables and sonographic features were correlated with the prognosis of TNBCs. The nomogram model based on three variables including no adjuvant chemotherapy, higher axillary tumor load, and more malignant sonographic features showed good predictive performance for poor survival outcomes of TNBC. KEY POINTS: • The absence of adjuvant chemotherapy, heavy axillary tumor load, and malignant-like sonographic features can predict DFS in patients with TNBC. • Mammographic features of TNBC could not predict the survival outcomes of patients with TNBC. • The nomogram integrating clinicopathological and sonographic characteristics is a reliable predictive model for the prognostic outcome of TNBC.


Assuntos
Nomogramas , Neoplasias de Mama Triplo Negativas , Intervalo Livre de Doença , Humanos , Prognóstico , Estudos Retrospectivos , Neoplasias de Mama Triplo Negativas/diagnóstico por imagem , Neoplasias de Mama Triplo Negativas/patologia
3.
J Orthop Traumatol ; 23(1): 6, 2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35061119

RESUMO

BACKGROUND: The goal of this study was to assess short-term outcomes in single compartment osteoarthritis patients associated with the coronal tibiofemoral subluxation (CTFS) of the knee joint after Oxford unicompartmental knee arthroplasty (OUKA), and to establish the potential impact of the degree of CTFS on operative outcomes. METHODS: Data pertaining to 183 patients with medial compartment osteoarthritis that underwent OUKA treatment between February 2016 and June 2019 were retrospectively analyzed. The presence and degree of severity of CTFS were assessed using preoperative weight-bearing anteroposterior X-ray images of the knee. Patients were stratified into three subgroups based upon the observed degree of subluxation: a normal group, a mild subluxation group (CTFS < 0.5 cm), and a severe subluxation group (CTFS ≥ 0.5 cm). Anterior and posterior X-ray examination of the knee was conducted at the time of most recent follow-up for each patient to assess the degree of CTFS correction following OUKA. Clinical function was assessed using Oxford knee score (OKS) and Hospital for Special Surgery score (HSS) values, while pain was rated using visual-analog scale (VAS) scores. The mechanical femoral tibial angle (mFTA), range of motion (ROM), and complication rates in these three groups were additionally compared. RESULTS: The average follow-up duration for patients in this study was 24.1 months (range: 17-32 months). There were no significant differences in patient age, sex, body mass index (BMI), follow-up duration, mFTA, ROM, OKS, HSS, or VAS scores among these three groups (P > 0.05). After surgery, OKS and HSS scores declined significantly, but no differences in these scores were observed among groups (P > 0.05). Of these patients, 135 (73.8%) were satisfied with the operation, of whom 80 (43.7%) were very satisfied. There were no significant differences in ROM or VAS scores among groups (P > 0.05). The degree of CTFS for patients in the mild and severe subluxation groups was significantly improved following OUKA relative to preoperative values such that the degree of postoperative CTFS did not differ significantly among these groups (P > 0.05). Postoperative mFTA was also significantly improved in these three patient subgroups (P < 0.05). No patients experienced operative complications over the follow-up period. CONCLUSIONS: OUKA can successfully improve clinical symptoms in patients with single compartmental osteoarthritis. Moreover, OUKA can effectively correct CTFS of the knee in these patients, and the degree of preoperative CTFS has no impact on surgical efficacy. LEVEL OF EVIDENCE: III.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Osteoartrite do Joelho , Estudos de Casos e Controles , Humanos , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/cirurgia , Amplitude de Movimento Articular , Estudos Retrospectivos , Resultado do Tratamento
4.
J Biol Chem ; 294(7): 2407-2421, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30578299

RESUMO

Hyperglycemia and insulin resistance accelerate atherosclerosis by an unclear mechanism. The two factors down-regulate insulin receptor substrate-1 (IRS-1), an intermediary of the insulin/IGF-I signaling system. We previously reported that IRS-1 down-regulation leads to vascular smooth muscle cell (VSMC) dedifferentiation and that IRS-1 deletion from VSMCs in normoglycemic mice replicates this response. However, we did not determine IRS-1's role in mediating differentiation. Here, we sought to define the mechanism by which IRS-1 maintains VSMC differentiation. High glucose or IRS-1 knockdown decreased p53 levels by enhancing MDM2 proto-oncogene (MDM2)-mediated ubiquitination, resulting in decreased binding of p53 to Krüppel-like factor 4 (KLF4). Exposure to nutlin-3, which dissociates MDM2/p53, decreased p53 ubiquitination and enhanced the p53/KLF4 association and differentiation marker protein expression. IRS-1 overexpression in high glucose inhibited the MDM2/p53 association, leading to increased p53 and p53/KLF4 levels, thereby increasing differentiation. Nutlin-3 treatment of diabetic or Irs1-/- mice enhanced p53/KLF4 and the expression of p21, smooth muscle protein 22 (SM22), and myocardin and inhibited aortic VSMC proliferation. Injecting normoglycemic mice with a peptide disrupting the IRS-1/p53 association reduced p53, p53/KLF4, and differentiation. Analyzing atherosclerotic lesions in hypercholesterolemic, diabetic pigs, we found that p53, IRS-1, SM22, myocardin, and KLF4/p53 levels are significantly decreased compared with their expression in nondiabetic pigs. We conclude that IRS-1 is critical for maintaining VSMC differentiation. Hyperglycemia- or insulin resistance-induced IRS-1 down-regulation decreases the p53/KLF4 association and enhances dedifferentiation and proliferation. Our results suggest that enhancing IRS-1-dependent p53 stabilization could attenuate the progression of atherosclerotic lesions in hyperglycemia and insulin-resistance states.


Assuntos
Diferenciação Celular , Hiperglicemia/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Complexos Multiproteicos/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Aterosclerose/genética , Aterosclerose/metabolismo , Aterosclerose/patologia , Humanos , Hiperglicemia/genética , Hiperglicemia/patologia , Proteínas Substratos do Receptor de Insulina/genética , Resistência à Insulina , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/genética , Camundongos , Camundongos Knockout , Complexos Multiproteicos/genética , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , Estabilidade Proteica , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Suínos , Proteína Supressora de Tumor p53/genética
5.
J Cell Physiol ; 234(12): 23232-23242, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31155724

RESUMO

Insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding proteins-2 (IGFBP-2) function coordinately to stimulate osteoblast differentiation. Induction of AMP-activated protein kinase (AMPK) is required for differentiation and is stimulated by these two factors. These studies were undertaken to determine how these two peptides lead to activation of AMPK. Enzymatic inhibitors and small interfering RNA were utilized to attenuate calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) activity in osteoblasts, and both manipulations resulted in failure to activate AMPK, thereby resulting in inhibition of osteoblast differentiation. IGFBP-2 and IGF-I stimulated an increase in CaMKK2, and inhibition of IGFBP-2 binding its receptor resulted in failure to induce CaMKK2 and AMPK activation. Injection of a peptide that contained the IGFBP-2 receptor-binding domain into IGFBP-2-/- mice activated CaMKK2 and injection of a CaMKK2 inhibitor into normal mice inhibited both CamKK2 and AMPK activation in osteoblasts. We conclude that induction of CaMKK2 by IGFBP-2 and IGF-I in osteoblasts is an important signaling event that occurs early in differentiation and is responsible for activation of AMPK, which is required for optimal osteoblast differentiation.


Assuntos
Adenilato Quinase/metabolismo , Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina/metabolismo , Diferenciação Celular/fisiologia , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Osteoblastos/metabolismo , Células 3T3 , Animais , Ativação Enzimática/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoblastos/citologia , Osteogênese/fisiologia
6.
J Toxicol Pathol ; 32(4): 245-251, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31719751

RESUMO

Papillary renal cell carcinoma (PRCC) accounts for about 10 percent of all renal cell carcinomas, and the prognosis is poor for people with advanced disease. Interleukin-20 receptor subunit beta (IL20RB) is a single-pass type I membrane protein of the type II cytokine receptor family and is related to the pathogenesis of chronic inflammation and autoimmune diseases, including psoriasis, glaucoma, vitiligo, rheumatoid arthritis, and inflammatory bowel disease. However, little has been reported on IL20RB with respect to cancer, especially in PRCC. Thus, we performed this study to explore its biological characteristics in PRCC. Data from the TCGA database were used to analyze the expression and prognosis of IL20RB. qRT-PCR was used to detect the expression of IL20RB in PRCC cells in vitro. After knockdown of IL20RB with small interfering RNA (siRNA) technology, the proliferation, migration, and invasion of Ketr-3 cells and the expression of related proteins in the epithelial-mesenchymal transition (EMT) pathway were measured with Cell Counting Kit-8 (CCK-8), transwell, and western blot assays. The findings demonstrated that the expression of IL20RB was upregulated in both PRCC tissues and cells and that the high expression of IL20RB led to low overall survival (OS). Furthermore, after knockdown of IL20RB in vitro, the proliferation, migration, and invasion of Ketr-3 cells were reduced, and the expression of related proteins in the EMT pathway declined, suggesting that IL20RB plays a vital role in PRCC through the EMT pathway. These results reveal the biological significance of IL20RB in PRCC and provide new insight for future targeted drugs.

7.
J Biol Chem ; 292(5): 2009-2020, 2017 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-28003360

RESUMO

Diabetes is a major risk factor for the development of atherosclerosis, but the mechanism by which hyperglycemia accelerates lesion development is not well defined. Insulin and insulin-like growth factor I (IGF-I) signal through the scaffold protein insulin receptor substrate 1 (IRS-1). In diabetes, IRS-1 is down-regulated, and cells become resistant to insulin. Under these conditions, the IGF-I receptor signals through an alternate scaffold protein, SHPS-1, resulting in pathophysiologic stimulation of vascular smooth muscle cell (VSMC) migration and proliferation. These studies were undertaken to determine whether IRS-1 is functioning constitutively to maintain VSMCs in their differentiated state and, thereby, inhibit aberrant signaling. Here we show that deletion of IRS-1 expression in VSMCs in non-diabetic mice results in dedifferentiation, SHPS-1 activation, and aberrant signaling and that these changes parallel those that occur in response to hyperglycemia. The mice showed enhanced sensitivity to IGF-I stimulation of VSMC proliferation and a hyperproliferative response to vascular injury. KLF4, a transcription factor that induces VSMC dedifferentiation, was up-regulated in IRS-1-/- mice, and the differentiation inducer myocardin was undetectable. Importantly, these changes were replicated in wild-type mice during hyperglycemia. These findings illuminate a new function of IRS-1: that of maintaining cells in their normal, differentiated state. Because IRS-1 is down-regulated in states of insulin resistance that occur in response to metabolic stresses such as obesity and cytokine stimulation, the findings provide a mechanism for understanding how patients with metabolic stress and/or diabetes are predisposed to developing vascular complications.


Assuntos
Desdiferenciação Celular , Regulação para Baixo , Hiperglicemia/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Animais , Humanos , Hiperglicemia/genética , Hiperglicemia/patologia , Fator 4 Semelhante a Kruppel , Camundongos , Camundongos Knockout , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo
8.
AAPS PharmSciTech ; 18(6): 2067-2076, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27995466

RESUMO

Diosgenin (DSG), a well-known steroid sapogenin derived from Dioscorea nipponica Makino and Dioscorea zingiberensis Wright, has a variety of bioactivities. However, it shows low oral bioavailability due to poor aqueous solubility and strong hydrophobicity. The present study aimed to develop DSG nanocrystals to increase the dissolution and then improve the oral bioavailability and biopharmaceutical properties of DSG. DSG nanocrystals were prepared by the media milling method using a combination of pluronic F127 and sodium dodecyl sulfate as surface stabilizers. The physicochemical properties of the optimal DSG nanocrystals were characterized using their particle size distribution, morphology, differential scanning calorimetry, powder X-ray diffraction, Fourier transform infrared spectroscopy data, and solubility and dissolution test results. Pharmacokinetic studies of the DSG coarse suspension and its nanocrystals were performed in rats. The particle size and polydispersity index of DSG nanocrystals were 229.0 ± 3.7 nm and 0.163 ± 0.064, respectively. DSG retained its original crystalline state during the manufacturing process, and its chemical structure was not compromised by the nanonizing process. The dissolution rate of the freeze-dried DSG nanocrystals was significantly improved in comparison with the original DSG. The pharmacokinetic studies showed that the AUC0-72h and C max of DSG nanocrystals increased markedly (p < 0.01) in comparison with the DSG coarse suspension by about 2.55- and 2.01-fold, respectively. The use of optimized nanocrystals is a good and efficient strategy for oral administration of DSG due to the increased dissolution rate and oral bioavailability of DSG nanocrystals.


Assuntos
Diosgenina/síntese química , Diosgenina/metabolismo , Nanopartículas/química , Nanopartículas/metabolismo , Administração Oral , Animais , Disponibilidade Biológica , Varredura Diferencial de Calorimetria/métodos , Diosgenina/administração & dosagem , Avaliação Pré-Clínica de Medicamentos/métodos , Liofilização/métodos , Masculino , Nanopartículas/administração & dosagem , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Difração de Raios X
9.
J Biol Chem ; 290(18): 11578-90, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25787077

RESUMO

Insulin-like growth factor-binding protein-2 (IGFBP-2) functions coordinately with IGF-I to stimulate cellular proliferation and differentiation. IGFBP-2 binds to receptor tyrosine phosphatase ß (RPTPß), and this binding in conjunction with IGF-I receptor stimulation induces RPTPß polymerization leading to phosphatase and tensin homolog inactivation, AKT stimulation, and enhanced cell proliferation. To determine the mechanism by which RPTPß polymerization is regulated, we analyzed the protein(s) that associated with RPTPß in response to IGF-I and IGFBP-2 in vascular smooth muscle cells. Proteomic experiments revealed that IGF-I stimulated the intermediate filament protein vimentin to bind to RPTPß, and knockdown of vimentin resulted in failure of IGFBP-2 and IGF-I to stimulate RPTPß polymerization. Knockdown of IGFBP-2 or inhibition of IGF-IR tyrosine kinase disrupted vimentin/RPTPß association. Vimentin binding to RPTPß was mediated through vimentin serine phosphorylation. The serine threonine kinase PKCζ was recruited to vimentin in response to IGF-I and inhibition of PKCζ activation blocked these signaling events. A cell-permeable peptide that contained the vimentin phosphorylation site disrupted vimentin/RPTPß association, and IGF-I stimulated RPTPß polymerization and AKT activation. Integrin-linked kinase recruited PKCζ to SHPS-1-associated vimentin in response to IGF-I and inhibition of integrin-linked kinase/PKCζ association reduced vimentin serine phosphorylation. PKCζ stimulation of vimentin phosphorylation required high glucose and vimentin/RPTPß-association occurred only during hyperglycemia. Disruption of vimetin/RPTPß in diabetic mice inhibited RPTPß polymerization, vimentin serine phosphorylation, and AKT activation in response to IGF-I, whereas nondiabetic mice showed no difference. The induction of vimentin phosphorylation is important for IGFBP-2-mediated enhancement of IGF-I-stimulated proliferation during hyperglycemia, and it coordinates signaling between these two receptor-linked signaling systems.


Assuntos
Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Vimentina/metabolismo , Sequência de Aminoácidos , Animais , Humanos , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , Camundongos , Dados de Sequência Molecular , Fosforilação/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Estrutura Quaternária de Proteína , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/química , Transdução de Sinais/efeitos dos fármacos , Suínos , Vimentina/química
10.
Cell Physiol Biochem ; 40(3-4): 807-817, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27915342

RESUMO

BACKGROUND: Breast cancer is characterized by a distinct metastatic pattern involving the regional lymph nodes, bone marrow, lung and liver. This study is aimed to investigate the effects of silencing the HAS-2 gene on the proliferation and apoptosis of human breast cancer cells. METHODS: MCF-7 cells were collected and assigned into control, scrambled siRNA and HAS-2- siRNA groups. After transfection, the morphological changes in the MCF-7 cells were observed using phase contrast microscopy. qRT-PCR and Western blot assays were used to detect the mRNA and protein expression of apoptosis-related proteins. CCK-8 and flow cytometry were performed to evaluate cell proliferation, the cell cycle and apoptosis. RESULTS: In the control and the scrambled siRNA groups, cells grew adhered to the wall and mainly showed a spindle shape with a clear nucleolus. Compared with the control and scrambled siRNA groups, increases in the number of cells in early apoptosis and metaphase cells in apoptosis were observed in the HAS-2-siRNA group. The HAS-2-siRNA group showed decreased expression of HAS-2 relative to that in the control and scrambled siRNA groups. No significant differences in cell proliferation, cell cycle distribution or apoptosis were noted between the control and scrambled siRNA groups. In the HAS-2-siRNA group, the cell proliferation ability decreased significantly, but the number of cells in the G0/G1 stage, the number of apoptotic cells and the expression of caspase-3 and caspase-9 increased significantly. CONCLUSION: Our findings indicate that HAS-2 gene silencing may inhibit proliferation and promote apoptosis in the MCF-7 human breast cancer cell line.


Assuntos
Apoptose , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Inativação Gênica , Neoplasias da Mama/ultraestrutura , Ciclo Celular , Proliferação de Células , Forma Celular , Células Clonais , Feminino , Glucuronosiltransferase/genética , Glucuronosiltransferase/metabolismo , Humanos , Hialuronan Sintases , Células MCF-7 , Transdução de Sinais/genética , Transfecção
11.
FASEB J ; 29(12): 4772-82, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26231202

RESUMO

Hyperglycemia leads to vascular smooth muscle cell (VSMC) dedifferentiation and enhances responses to IGF-I. Prior studies showed that hyperglycemia stimulated NADPH oxidase 4 (Nox4) synthesis, and IGF-I facilitated its recruitment to a signaling complex where it oxidized src, leading to AKT and MAPK activation. To determine the mechanism that led to these changes, we analyzed the roles of p62 (sequestrosome1) and PKCζ. Hyperglycemia induced a 4.9 ± 1.0-fold increase in p62/PKCζ association, and disruption of PKCζ/p62 using a peptide inhibitor or p62 knockdown reduced PKCζ activation (78 ± 6%). 3-Phosphoinoside-dependent protein kinase 1 was also recruited to the p62 complex and directly phosphorylated PKCζ, leading to its activation (3.1 ± 0.4-fold). Subsequently, activated PKCζ phosphorylated p65 rel, which led to increased Nox4 synthesis. Studies in diabetic mice confirmed these findings (6.0 ± 0.4-fold increase in p62/PKCζ) and their disruption of attenuated Nox4 synthesis (76 ± 9% reduction). PKCζ/p62 activation stimulated inflammatory cytokine production and enhanced IGF-I-stimulated VSMC proliferation. These results define the molecular mechanism by which PKCζ is activated in response to hyperglycemia and suggest that this could be a mechanism by which other stimuli such as cytokines or metabolic stress function to stimulate NF-κB activation, thereby altering VSMC sensitivity to IGF-I.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Citocinas/metabolismo , Proteínas de Choque Térmico/metabolismo , Hiperglicemia/metabolismo , Mediadores da Inflamação/metabolismo , Músculo Liso Vascular/metabolismo , NADPH Oxidases/metabolismo , NF-kappa B/metabolismo , Proteína Quinase C/metabolismo , Animais , Células Cultivadas , Ativação Enzimática , Camundongos , Camundongos Endogâmicos C57BL , Músculo Liso Vascular/citologia , Músculo Liso Vascular/enzimologia , NADPH Oxidase 4 , Fosforilação , Proteína Sequestossoma-1 , Suínos
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(6): 1959-65, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30053361

RESUMO

Effect of pulsed electric field on the drought resistance of crops is an important topic in biological effect of electric field. The changes in the photosynthetic system of leaf cells can be sensitively reflected by the kinetics parameters of delayed fluorescence. In order to reveal the effect of pulsed electric field and its mechanism on drought resistance of crop seedling, the germinating maize seeds were treated by pulsed electric field with electric field strength 200 kV·m-1, frequency 1Hz and pulse width 80ms. Then, PEG-6000 solution with -0.1 MPa osmotic potential to was used to form physiological drought of maize seedlings, the changes of dry leaf mass and the kinetics parameters, induced by LED were studied in this paper. The result showed that the dry leaf mass gradually increased under drought stress after applied with the electric field, which was significantly higher than that without external field, the relative growth rate was 45.6% (p<0.01). Besides, during the processes, the relative growth rate was between 5.8%~18.7%, the difference was significant (p<0.05) when there was no electric field, which indicated that the pulsed electric field promoted the leaf growth of maize seedling. The analysis of delayed fluorescence kinetic about leaf of maize seedling showed that the value of delayed fluorescence kinetics parameters, initial photon number I0, coherence time τ, decay factor ß and integral intensity I(T), under drought stress, showed fluctuation, These changes were response to drought stress made by leaf cells. The study also found that pulsed electric field increased delayed fluorescence kinetics parameters and the integrated intensity of leaf cells, which indicated that the pulsed electric field could improve the photosynthesis potential and the organize sequence of photosynthetic electron transport system in leaf cells, as the interaction between functional molecules was strengthened, the leaf photosynthetic capacity was enhanced under drought stress. The result of this study provides a reference to explain clearly the effect of the pulsed electric field on drought resistance of plants seedlings.

13.
J Fluoresc ; 25(4): 1023-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26018752

RESUMO

A novel coumarin-based fluorescent probe CF was synthesized for the detection of hydrazine both in aqueous solution and vapor state with high sensitivity and selectivity. Upon addition of hydrazine, the solution of probe CF in MeCN-H2O (3/7, v/v, buffered CH3COOH/CH3COONa) at pH 5.0 exhibited a remarkable change in emission color from pale green to light blue, which could be recognized with naked eyes. Applied in weak acid condition, probe CF could detect hydrazine selectively with large amount of unknown environments according to the competing tests. Besides, with the limit of detection 8.32 ppb (2.6 × 10(-7) M), probe CF could well meet the request (10 ppb) of the U.S. Environmental Protection Agency (EPA).

14.
J Biol Chem ; 288(22): 15641-53, 2013 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-23612968

RESUMO

Nox4-derived ROS is increased in response to hyperglycemia and is required for IGF-I-stimulated Src activation. This study was undertaken to determine the mechanism by which Nox4 mediates sustained Src activation. IGF-I stimulated sustained Src activation, which occurred primarily on the SHPS-1 scaffold protein. In vitro oxidation experiments indicated that Nox4-derived ROS was able to oxidize Src when they are in close proximity, and Src oxidation leads to its activation. Therefore we hypothesized that Nox4 recruitment to the plasma membrane scaffold SHPS-1 allowed localized ROS generation to mediate sustained Src oxidation and activation. To determine the mechanism of Nox4 recruitment, we analyzed the role of Grb2, a component of the SHPS-1 signaling complex. We determined that Nox4 Tyr-491 was phosphorylated after IGF-I stimulation and was responsible for Nox4 binding to the SH2 domain of Grb2. Overexpression of a Nox4 mutant, Y491F, prevented Nox4/Grb2 association. Importantly, it also prevented Nox4 recruitment to SHPS-1. The role of Grb2 was confirmed using a Pyk2 Y881F mutant, which blocked Grb2 recruitment to SHPS-1. Cells expressing this mutant had impaired Nox4 recruitment to SHPS-1. IGF-I-stimulated downstream signaling and biological actions were also significantly impaired in Nox4 Y491F-overexpressing cells. Disruption of Nox4 recruitment to SHPS-1 in aorta from diabetic mice inhibited IGF-I-stimulated Src oxidation and activation as well as cell proliferation. These findings provide insight into the mechanism by which localized Nox4-derived ROS regulates the sustained activity of a tyrosine kinase that is critical for mediating signal transduction and biological actions.


Assuntos
Estruturas da Membrana Celular/metabolismo , Diabetes Mellitus Experimental/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Quinases da Família src/metabolismo , Substituição de Aminoácidos , Animais , Antígenos de Diferenciação/genética , Antígenos de Diferenciação/metabolismo , Aorta/metabolismo , Aorta/patologia , Estruturas da Membrana Celular/genética , Estruturas da Membrana Celular/patologia , Células Cultivadas , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Ativação Enzimática/genética , Proteína Adaptadora GRB2/genética , Proteína Adaptadora GRB2/metabolismo , Humanos , Fator de Crescimento Insulin-Like I/genética , Camundongos , Mutação de Sentido Incorreto , NADPH Oxidase 4 , NADPH Oxidases/genética , Oxirredução , Ligação Proteica , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Transdução de Sinais/genética , Suínos , Domínios de Homologia de src , Quinases da Família src/genética
15.
J Clin Ultrasound ; 42(1): 9-15, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23564447

RESUMO

BACKGROUND: Myocardial functional recovery after revascularization is considered the "gold standard" for myocardial viability (MV) assessment. However, the patency of the revascularized coronary artery affects myocardial functional recovery in patients subjected to coronary artery bypass grafting (CABG). The influence of graft patency on viability results has not been widely studied. PURPOSE: We evaluated the effect of graft patency on the prediction of MV after CABG by myocardial contrast echocardiography (MCE) and low-dose dobutamine stress echocardiography (LD-DSE). METHODS: Fifty-three subjects with chronic ischemic heart disease scheduled for CABG were divided randomly into groups A (n = 26) and B (n = 27). They underwent MCE and LD-DSE preoperatively. Patients were followed up 12 months after CABG. Group B patients underwent multislice computed tomography angiography to assess CABG patency, and patients with obstructed grafts were excluded. Group A patients were not subjected to multislice CT angiography. The accuracy of MCE and LD-DSE for assessing MV between the two groups was compared. RESULTS: The accuracy and positive predictive values of MCE and LD-DSE for predicting MV were higher in group B than in group A (p < 0.05). CONCLUSIONS: Preoperative LD-DSE and MCE ability to predict MV depends on the patency of CABG.


Assuntos
Agonistas de Receptores Adrenérgicos beta 1 , Meios de Contraste , Ponte de Artéria Coronária , Dobutamina , Ecocardiografia sob Estresse , Isquemia Miocárdica/cirurgia , Fosfolipídeos , Hexafluoreto de Enxofre , Idoso , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores , Isquemia Miocárdica/diagnóstico por imagem , Variações Dependentes do Observador , Valor Preditivo dos Testes , Cuidados Pré-Operatórios , Sensibilidade e Especificidade , Resultado do Tratamento
16.
Kidney Int Rep ; 9(2): 451-463, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38344712

RESUMO

Introduction: Podocyte slit diaphragms are an important component of the glomerular filtration barrier. Podocyte injury frequently includes defects in slit diaphragms, and various mechanisms for these defects have been described, including altered endocytic trafficking of slit diaphragm proteins or oxidative stress. However, the potential relationship between endocytosis and oxidative stress in the context of slit diaphragm integrity has not been extensively considered. Methods: To examine the potential relationships between endocytosis, oxidative stress, and slit diaphragm integrity, we induced genetic or pharmacological disruption of endocytosis in Drosophila nephrocytes (the insect orthologue of podocytes) and cultured human podocytes. We then employed immunofluorescence microscopy to analyze protein localization and levels, and to quantify signal from reactive oxygen species (ROS) dyes. Immunoprecipitation from podocyte cell lysates was used to examine effects on slit diaphragm protein complex formation (i.e., nephrin/podocin and nephrin/ZO-1). Results: Disruption of endocytosis in nephrocytes and podocytes led to slit diaphragm defects, elevated levels of ROS (oxidative stress), and activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway. In nephrocytes with defective endocytosis, perturbation of Nrf2 signaling exacerbated slit diaphragm defects. Conversely, overexpression of Nrf2 target genes catalase or glucose-6-phosphate dehydrogenase (G6PD) significantly ameliorated slit diaphragm defects caused by disruption of endocytosis. Conclusion: Oxidative stress is an important consequence of defective endocytosis and contributes to the defects in slit diaphragm integrity associated with disruption of endocytic trafficking.

17.
J Immunol Methods ; 528: 113654, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38432292

RESUMO

Epitope mapping provides critical insight into antibody-antigen interactions. Epitope mapping of autoantibodies from patients with autoimmune diseases can help elucidate disease immunogenesis and guide the development of antigen-specific therapies. Similarly, epitope mapping of commercial antibodies targeting known autoantigens enables the use of those antibodies to test specific hypotheses. Anti-Neutrophil Cytoplasmic Autoantibody (ANCA) vasculitis results from the formation of autoantibodies to multiple autoantigens, including myeloperoxidase (MPO), proteinase-3 (PR3), plasminogen (PLG), and peroxidasin (PXDN). To perform high-resolution epitope mapping of commercial antibodies to these autoantigens, we developed a novel yeast surface display library based on a series of >5000 overlapping peptides derived from their protein sequences. Using both FACS and magnetic bead isolation of reactive yeast, we screened 19 commercially available antibodies to the ANCA autoantigens. This approach to epitope mapping resulted in highly specific, fine epitope mapping, down to single amino acid resolution in many cases. Our study also identified cross-reactivity between some commercial antibodies to MPO and PXDN, which suggests that patients with apparent autoantibodies to both proteins may be the result of cross-reactivity. Together, our data validate yeast surface display using maximally overlapping peptides as an excellent approach to linear epitope mapping.


Assuntos
Anticorpos Anticitoplasma de Neutrófilos , Saccharomyces cerevisiae , Humanos , Mapeamento de Epitopos , Autoanticorpos , Mieloblastina , Autoantígenos , Peroxidase , Peptídeos
18.
Neurochem Res ; 38(3): 601-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23283697

RESUMO

The conditioned medium from B104 neuroblastoma cells (B104CM) induces proliferation of oligodendrocyte progenitor cells (OPCs) in vitro. However, the molecular events that occur during B104CM-induced proliferation of OPCs has not been well clarified. In the present study, using OPCs immunopanned from embryonic day 14 Sprague-Dawley rat spinal cords, we explored the activation of several signaling pathways and the expression of several important immediate early genes (IEGs) and cyclins in OPCs in response to B104CM. We found that B104CM can induce OPC proliferation through the activation of the extracellular signal-regulated kinases 1 and 2 (Erk1/2), but not PI3K or p38 MAPK signaling pathways in vitro. The IEGs involved in B104CM-induced OPC proliferation include c-fos, c-jun and Id2, but not c-myc, fyn, or p21. The cyclins D1, D2 and E are also involved in B104CM-stimulated proliferation of OPCs. The activation of Erk results in subsequent expression of IEGs (such as c-fos, c-jun and Id-2) and cyclins (including cyclin D1, D2 and E), which play key roles in cell cycle initiation and OPC proliferation. Collectively, these results suggest that the phosphorylation of Erk1/2 is an important molecular event during OPC proliferation induced by B104CM.


Assuntos
Proliferação de Células/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Transdução de Sinais/efeitos dos fármacos , Células-Tronco/citologia , Animais , Células Cultivadas , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Genes Precoces/fisiologia , Neuroblastoma/metabolismo , Ratos , Células-Tronco/efeitos dos fármacos
19.
Front Cardiovasc Med ; 10: 1164290, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37608814

RESUMO

Background: Coronary atherosclerotic heart disease is one of the most serious health and life-threatening diseases. There is no doubt that despite the increasing number of assessment methods used clinically, the prognosis assessment is still not ideal, and newer assessment methods are needed. Objective: To investigate the predictive value of quantitative flow ratio (QFR) for adverse events (vessel-oriented composite endpoint events/target lesion failure) in patients after percutaneous coronary intervention (PCI). Method: Eight studies involving 4,173 patients (5,688 vascular lesions) were included. These are studies on the relationship between QFR values and prognosis of adverse cardiac events after PCI. This meta-analysis was performed after quality assessment and data extraction of clinical trials data that met the inclusion criteria. Result: Each of the eight studies described the cut-off values for the best predictive ability of post-PCI QFR and the hazard ratio (HR) between QFR values and adverse events, respectively. The pooled HR of these studies was 4.72 (95% CI: 3.29-6.75). Concurrently, lower post-PCI QFR values were associated with the occurrence of individual clinical events (cardiac death/myocardial infarction/target vessel revascularization), with relative risk values of 6.51 (95% CI: 4.96-8.53), 4.83 (95% CI: 3.08-7.57), and 4.21 (95% CI: 2.66-6.68), respectively. Conclusion: QFR may have great potential in the assessment of prognosis. It is necessary to measure QFR value after PCI. A lower QFR value after PCI was an important predictor for experiencing adverse events.

20.
Ying Yong Sheng Tai Xue Bao ; 34(11): 3039-3044, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37997415

RESUMO

Premature senescence in greenhouse tomato is a significant challenge under long-season cultivation, due to suboptimal nutrient management during growth periods. We investigated the effects of microbial agents (T1), corn protein ferment (T2), and their combined application (T3) on photosynthetic characteristics and antioxidant enzyme activities in 'Saint Laurent 3689' tomato leaves, normal management served as the control (CK). We explored the physiological mechanism of delaying leaf senescence. Results showed that applying microbial agents or corn protein ferment individually led to improvements in leaf photosynthetic characteristics and antioxidant enzyme activities. The combined application yielded superior outcomes. Eighty days post the combined application of microbial agents and corn protein ferment (T3), chlorophyll (a+b) content, net photosynthetic rate, and the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in leaves increased by 16.4%, 30.9%, 23.4%, 33.0% and 40.3%, respectively, compared with the CK. Furthermore, plant height and stem diameter increased by 8.2% and 7.0%, while the total yield exhibited a significant increase of 9.9% compared with the CK 210 days post-treatment. In conclusion, the combined application of microbial agents and corn protein ferment has promising potential in enhancing chlorophyll content, net photosynthetic rate, and the activities of SOD, POD and CAT in tomato leaves. This approach effectively delayed leaf senescence, thereby promoting tomato growth and remarkably increasing the yield.


Assuntos
Solanum lycopersicum , Zea mays/metabolismo , Antioxidantes/metabolismo , Clorofila/metabolismo , Superóxido Dismutase/metabolismo , Peroxidases/metabolismo , Fotossíntese , Peroxidase/metabolismo , Folhas de Planta/fisiologia
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