Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-38432286

RESUMO

PURPOSE: To develop and externally validate an automatic artificial intelligence (AI) tool for delineating gross tumor volume (GTV) in patients with esophageal squamous cell carcinoma (ESCC), which can assist in neo-adjuvant or radical radiation therapy treatment planning. METHODS AND MATERIALS: In this multi-institutional study, contrast-enhanced CT images from 580 eligible ESCC patients were retrospectively collected. The GTV contours delineated by 2 experts via consensus were used as ground truth. A 3-dimensional deep learning model was developed for GTV contouring in the training cohort and internally and externally validated in 3 validation cohorts. The AI tool was compared against 12 board-certified experts in 25 patients randomly selected from the external validation cohort to evaluate its assistance in improving contouring performance and reducing variation. Contouring performance was measured using dice similarity coefficient (DSC) and average surface distance. Additionally, our previously established radiomics model for predicting pathologic complete response was used to compare AI-generated and ground truth contours, to assess the potential of the AI contouring tool in radiomics analysis. RESULTS: The AI tool demonstrated good GTV contouring performance in multicenter validation cohorts, with median DSC values of 0.865, 0.876, and 0.866 and median average surface distance values of 0.939, 0.789, and 0.875 mm, respectively. Furthermore, the AI tool significantly improved contouring performance for half of 12 board-certified experts (DSC values, 0.794-0.835 vs 0.856-0.881, P = .003-0.048), reduced the intra- and interobserver variations by 37.4% and 55.2%, respectively, and saved contouring time by 77.6%. In the radiomics analysis, 88.7% of radiomic features from ground truth and AI-generated contours demonstrated stable reproducibility, and similar pathologic complete response prediction performance for these contours (P = .430) was observed. CONCLUSIONS: Our AI contouring tool can improve GTV contouring performance and facilitate radiomics analysis in ESCC patients, which indicates its potential for GTV contouring during radiation therapy treatment planning and radiomics studies.

2.
Eur J Nucl Med Mol Imaging ; 50(9): 2787-2801, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37145165

RESUMO

PURPOSE: This study aimed to establish a near infrared fluorescent (NIRF) probe based on an EGFR&c-Met bispecific antibody for visualization of esophageal cancer (EC) and metastatic lymph nodes (mLNs). METHODS: EGFR and c-Met expression were assessed by immunohistochemistry. EGFR&c-Met bispecific antibody EMB01 was labeled with IRDye800cw. The binding of EMB01-IR800 was assessed by enzyme linked immunosorbent assay, flow cytometry, and immunofluorescence. Subcutaneous tumors, orthotopic tumors, and patient-derived xenograft (PDX) were established for in vivo fluorescent imaging. PDX models using lymph nodes with or without metastasis were constructed to assess the performance of EMB01-IR800 in differential diagnosis of lymph nodes. RESULTS: The prevalence of overexpressing EGFR or c-Met was significantly higher than single marker either in EC or corresponding mLNs. The bispecific probe EMB01-IR800 was successfully synthesized, with strong binding affinity. EMB01-IR800 showed strong cellular binding to both Kyse30 (EGFR overexpressing) and OE33 (c-Met overexpressing) cells. In vivo fluorescent imaging showed prominent EMB01-IR800 uptake in either Kyse30 or OE33 subcutaneous tumors. Likewise, EMB01-IR800 exhibited superior tumor enrichment in both thoracic orthotopic esophageal squamous cell carcinoma and abdominal orthotopic esophageal adenocarcinoma models. Moreover, EMB01-IR800 produced significantly higher fluorescence in patient-derived mLNs than in benign lymph nodes. CONCLUSION: This study demonstrated the complementary overexpression of EGFR and c-Met in EC. Compared to single-target probes, the EGFR&c-Met bispecific NIRF probe can efficiently depict heterogeneous esophageal tumors and mLNs, which greatly increased the sensitivity of tumor and mLN identification.


Assuntos
Adenocarcinoma , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Adenocarcinoma/patologia , Receptores ErbB , Linhagem Celular Tumoral
3.
Insights Imaging ; 14(1): 2, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36600110

RESUMO

OBJECTIVE: To improve the current imaging understanding of MRI or CT for hepatic epithelioid haemangioendothelioma (HEHE) to aid in its successful preoperative diagnosis. METHODS: The imaging features of 15 patients (median age 38.6, range 20-71; 7 M/8 F) from eight institutions with pathologically confirmed HEHE were retrospectively analysed. Additionally, the CT/MR imaging features of 180 patients in 15 literature publications were collected, analysed and compared with our case series. RESULTS: Fifteen patients underwent CT and MRI (n = 2), CT (n = 9) or MR (n = 8) scans. A total of 92.9% (13/14) of the patients were initially diagnosed with other lesions on imaging. A total of 86.7% (13/15) were multifocal. Nodules (11/15, 73.3%) were predominantly peripheral in distribution (12/15, 80.0%). Some cases were associated with hepatic capsular retraction (13/15, 86.7%), "target signs" (8/15, 53.3%) and "lollipop signs" (5/15, 33.3%). Peripheral enhancement of various shapes in the early phase with a progressive centripetal filling was the most common pattern of enhancement (12/15, 80.0%). Abnormal vascularity was seen in 50.7% (6/15) of the patients. Suspicious tumour thromboses in the inferior vena cava were seen in 3 (20.0%) of the patients. Two of the 15 patients (13.3%) had a history of smoking. CONCLUSIONS: HEHEs have common distinctive features, including multifocal lesions that are predominantly peripheral, "target signs", "lollipop signs", hepatic capsular retraction and peripheral enhancement of various shapes in the early phase with progressive centripetal filling. Additional aggressive imaging features that may be valuable clues to the diagnosis can be identified by CT or MRI.

4.
Front Endocrinol (Lausanne) ; 13: 1069528, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36518242

RESUMO

Background: Colorectal cancer (CRC) is still one of the most frequently diagnosed malignancy around the world. The complex etiology and high heterogeneity of CRC necessitates the identification of new reliable signature to identify different tumor prognosis, which may help more precise understanding of the molecular properties of CRC and identify the appropriate treatment for CRC patients. In this study, we aimed to identify a combined immune and metabolism gene signature for prognosis prediction of CRC from large volume of CRC transcriptional data. Methods: Gene expression profiling and clinical data of HCC samples was retrieved from the from public datasets. IRGs and MRGs were identified from differential expression analysis. Univariate and multivariate Cox regression analysis were applied to establish the prognostic metabolism-immune status-related signature. Kaplan-Meier survival and receiver operating characteristic (ROC) curves were generated for diagnostic efficacy estimation. Real-time polymerase chain reaction (RT-PCR), Western blot and immunohistochemistry (IHC) was conducted to verified the expression of key genes in CRC cells and tissues. Results: A gene signature comprising four genes (including two IRGs and two MRGs) were identified and verified, with superior predictive performance in discriminating the overall survival (OS) of high-risk and low-risk compared to existing signatures. A prognostic nomogram based on the four-gene signature exhibited a best predictive performance, which enabled the prognosis prediction of CRC patients. The hub gene ESM1 related to CRC were selected via the machine learning and prognostic analysis. RT-PCR, Western blot and IHC indicated that ESM1 was high expressed in tumor than normal with superior predictive performance of CRC survival. Conclusions: A novel combined MRGs and IRGs-related prognostic signature that could stratify CRC patients into low-and high- risk groups of unfavorable outcomes for survival, was identified and verified. This might help, to some extent, to individualized treatment and prognosis assessment of CRC patients. Similarly, the mining of key genes provides a new perspective to explore the molecular mechanisms and targeted therapies of CRC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Colorretais , Neoplasias Hepáticas , Humanos , Prognóstico , Nomogramas , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/genética
5.
Molecules ; 27(21)2022 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-36364436

RESUMO

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies globally. Peptide-based tumor-targeted imaging is critical for ESCC imaging. In this study, we aim to identify a peptide-targeting IGF2BP2 that specifically binds to human ESCC for near-infrared imaging of esophageal cancer. Applying phage display techniques, we identified a peptide target for IGF2BP2 which was confirmed to be highly expressed in ESCC cell lines or tumor tissue and may serve as an imaging target for ESCC. We conjugated the peptide to the NIRF group, Cy5, and further evaluated the targeting efficacy of the probe at a cellular level and in animal tumor models. The Cy5 conjugated peptide (P12-Cy5) showed a high binding affinity to human ESCC cells in vitro. In vivo, optical imaging also validated the tumor-targeting ability of P12-Cy5 in KYSE-30-bearing subcutaneous ESCC tumor models. Furthermore, the results of biodistribution showed a significantly higher fluorescence intensity in tumors compared to scrambled peptide, which is consistent with in vivo observations. In summary, an IGF2BP2-targeted peptide was successfully identified. In vitro and in vivo experiments confirmed that P12-Cy5 has high affinity, specificity and tumor-targeting properties. Thus, P12-Cy5 is a prospective NIR probe for the imaging of ESCC.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Animais , Humanos , Carcinoma de Células Escamosas do Esôfago/diagnóstico por imagem , Neoplasias Esofágicas/metabolismo , Distribuição Tecidual , Estudos Prospectivos , Linhagem Celular Tumoral , Peptídeos/química , Proteínas de Ligação a RNA/metabolismo
6.
J Control Release ; 349: 327-337, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35787917

RESUMO

Transcatheter arterial chemoembolization (TACE), the mainstream treatment for hepatocellular carcinoma (HCC), is a method of blocking tumor blood vessels with a mixture of lipiodol and chemotherapeutics. And the contrast-enhanced computed tomography (CT) is the commonly used way for follow-up of HCC after TACE. However, it is noteworthy that when lipiodol deposition plays an embolic effect, it also produces high-density artifacts in CT images. These artifacts usually conceal the enhancement effect of iodine contrast agents. As a result, the residual region is difficult to be visualized. To overcome this obstacle, we developed one kind of Lu3+/Gd3+ doped fluoride nanoprobe modified with Dp-PEG2000 to realize CT/MRI dual-modality imaging of HCC. Compared with lipiodol or ioversol, the obtained PEGylated product LG-PEG demonstrated a greater density value in high keV CT images. In vitro experiments showed the lipiodol artifacts can be removed in virtual non-contrast (VNC) imaging, but the density of ioversol was also removed at the same time. However, the LG-PEG synthesized in this work can still maintain a high density in VNC imaging, which indicates that LG-PEG can exploit its advantages to the full in VNC imaging. Furthermore, LG-PEG successfully exerted tumor enhancement effects in the in vivo VNC images of HCC with lipiodol deposition. In addition, LG-PEG exhibited a strong T2 enhancement effect with low biological toxicity and less side-effect on the main organ and blood. Thus, the LG-PEG reported in this research can serve as an effective and safe VNC contrast agent for HCC imaging after TACE.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Iodo , Neoplasias Hepáticas , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Meios de Contraste , Óleo Etiodado , Fluoretos , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/terapia , Polietilenoglicóis , Tomografia Computadorizada por Raios X/métodos , Ácidos Tri-Iodobenzoicos
7.
Mol Pharm ; 19(10): 3563-3575, 2022 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-35420035

RESUMO

The survival rate of esophageal squamous carcinoma (ESCC) after surgical resection is estimated to be only 30.3% due to the difficulty in identifying microinfiltration and subtle metastases. In this study, we explored the value of near-infrared fluorescence in the second window (NIR-II) using an epidermal growth factor receptor (EGFR)-targeted probe (cetuximab-IR800) for the intraoperative navigation of ESCC in xenograft mouse models. Immunohistochemical results showed that EGFR was aberrantly expressed in 94.49% (120/127) of ESCC tissues and 90.63% (58/64) of metastatic lymph nodes. Western blot results demonstrated that EGFR protein was highly expressed in ESCC cell lines. Flow cytometry data revealed that cetuximab-IR800 showed a stronger binding specificity in EGFR-positive KYSE-30 cells than in A2780 control cells (P < 0.01). In vivo imaging data showed that the ratio of mean fluorescent intensity (MFI) and tumor to background (TBR) was significantly higher in KYSE-30 subcutaneous tumors with the infusion of cetuximab-IR800 than in those with the infusion of IgG1-IR800 (P < 0.05). Surgical navigation with NIR-II imaging showed that the TBR in orthotopic ESCC was significantly higher than that of NIR in the first window (NIR-I) (2.11 ± 0.46 vs 1.58 ± 0.31, P < 0.05), and NIR-II was more sensitive than NIR-I in detecting subcentimeter metastases (94.87% (37/39) vs 58.97% (23/39), P < 0.001). In conclusion, cetuximab-IR800 with high specificity for ESCC was first used in NIR-II surgical navigation. This probe showed better imaging resolution and higher sensitivity in detecting subtle metastases derived from an orthotopic ESCC model than NIR-I, which indicates that NIR-II has promise in guiding precise surgery for ESCC patients.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Neoplasias Ovarianas , Animais , Linhagem Celular Tumoral , Cetuximab , Receptores ErbB/metabolismo , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/diagnóstico por imagem , Feminino , Xenoenxertos , Humanos , Imunoglobulina G , Camundongos , Camundongos Nus , Micrometástase de Neoplasia
8.
Biomater Sci ; 10(1): 243-257, 2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-34846385

RESUMO

Arsenic trioxide (ATO, As2O3), an active ingredient of traditional Chinese medicine, has been approved by the U.S. Food and Drug Administration as an effective therapeutic agent for acute promyelocytic leukemia (APL). However, the application of ATO in treating advanced solid tumors like hepatocellular carcinoma (HCC) is still restricted by limited therapeutic efficacy and insufferable side effects. To solve this problem, we reported a general and facile strategy using human serum albumin (HSA) as a template for synthesizing a series of ATO-based nanoparticles with uniform single-albumin size. Then, we prepared a multifunctional drug delivery system (MDDS) based on MnAs/HSA termed MnAs/ICG/HSA-RGD, and tested its efficacy both in vitro and in vivo. Our results revealed that the photothermal effect of MnAs/ICG/HSA-RGD can not only cause irreversible damage to the tumor but also accelerate the discharge of As and Mn2+ ions, enabling responsive chemotherapy and magnetic resonance imaging. Interestingly, the expression of HSP90, vimentin, and MMP-9 in tumor cells was inhibited during the treatment, resulting in less metastasis and recurrence. Moreover, no apparent side effect has been observed during the treatment. Therefore, MnAs/ICG/HSA-RGD can be considered as a promising option for HCC with excellent therapeutic efficacy and minimum side effects.


Assuntos
Arsenitos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Nanopartículas , Carcinoma Hepatocelular/tratamento farmacológico , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Terapia Fototérmica , Albumina Sérica Humana
9.
Carbohydr Polym ; 246: 116589, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32747248

RESUMO

Inulin (IN), a fructan-type plant polysaccharide, is widely found in nature. The major plant sources of IN include chicory, Jerusalem artichoke, dahlia etc. Studies have found that IN possessed a wide array of biological activities, e.g. as a prebiotic to improve the intestinal microbe environment, regulating blood sugar, regulating blood lipids, antioxidant, anticancer, immune regulation and so on. Currently, IN is widely used in the food and pharmaceutical industries. IN can be used as thickener, fat replacer, sweetener and water retaining agent in the food industry. IN also can be applied in the pharmaceutics as stabilizer, drug carrier, and auxiliary therapeutic agent for certain diseases such as constipation and diabetes. This paper reviews the physiological functions of IN and its applications in the field of pharmaceutics, analyzes its present research status and future research direction. This review will serve as a one-in-all resource for the researchers who are interested to work on IN.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Hipoglicemiantes/farmacologia , Fatores Imunológicos/farmacologia , Inulina/farmacologia , Laxantes/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/metabolismo , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Glicemia/metabolismo , Cichorium intybus/química , Dahlia/química , Portadores de Fármacos/química , Excipientes/química , Excipientes/isolamento & purificação , Helianthus/química , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/metabolismo , Fatores Imunológicos/química , Fatores Imunológicos/isolamento & purificação , Fatores Imunológicos/metabolismo , Inulina/química , Inulina/isolamento & purificação , Inulina/metabolismo , Laxantes/química , Laxantes/isolamento & purificação , Laxantes/metabolismo , Lipídeos/sangue , Prebióticos/administração & dosagem , Edulcorantes/química , Edulcorantes/isolamento & purificação
10.
Biomed Pharmacother ; 125: 109869, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32007916

RESUMO

Ixeris sonchifolia (IS), principally its dried form, is widely used as traditional and folk medicines in some Asian countries, especially China. In this review, we summarized its traditional uses, chemical constituents, quality control measures, pharmacological activities, therapeutic evaluation, toxicity evaluation and clinical applications. 130 chemical constituents isolated from IS have been reported, including flavones, sesquiterpenes, triterpenes, phenylpropanoids, organic acids and others. They showed various pharmacological activities, such as protecting cardiocerebral vascular system, anticancer effect and antiviral etc. The quality control evaluation studies, clinical applications, other possible applications and suggestions for future research also were discussed. The aim of this review is to critically appraise the available literature and suggest directions for further development of IS to improve its medical value and use.


Assuntos
Asteraceae/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Animais , Estudos Clínicos como Assunto , Avaliação Pré-Clínica de Medicamentos , Humanos , Medicina Tradicional/métodos , Medicina Tradicional/normas , Estrutura Molecular , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/uso terapêutico , Relação Estrutura-Atividade
11.
Front Oncol ; 10: 614096, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33659211

RESUMO

Gastric cancer (GC) is one of the most common malignancies with high mortality and substantial morbidity. Although the traditional treatment strategies for GC revolve around surgery, radiotherapy, and chemotherapy, none have been able to optimally treat most affected patients. To improve clinical outcomes and overcome potential GC resistance, we established a three-dimensional (3D) culturing platform that accurately predicts drug responses in a time- and cost-effective manner. We collected tumor tissues from patients following surgeries and cultured them for 3 days using our protocol. We first evaluated cell proliferation, viability, and apoptosis using the following markers: Ki67 and cleaved caspase 3 (Cas3). We demonstrated that cell viability was maintained for 72 h in culture and that the tumor microenvironments and vascular integrities of the tissues were intact throughout the culture period. We then administered chemotherapeutics to assess drug responses and found differential sensitivity across different patient-derived tissues, enabling us to determine individualized medication plans. Overall, our study validated this rapid, cost-effective, scalable, and reproducible protocol for GC tissue culture that can be employed for drug response assessments. Our 3D culture platform paves a new way for personalized medication in GC and other tumors and can greatly impact future oncological research.

12.
Cell Biosci ; 7: 56, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29118968

RESUMO

BACKGROUND: Diffuse intrinsic pontine glioma is an infiltrative, often high-grade glioma of the brainstem that is not amenable to surgical resection. The current treatment of DIPG by radiation therapy showed dramatically improvement of patient's condition, however, the tumor recurs rapidly. More and more studies are focused on the genetic and epigenetic drivers of DIPGs, which may provide more and more novel therapy target for DIPG. EZH2 has been proved to be a potential therapeutic target for H3K27M-mutant pediatric gliomas recently. Meanwhile, BET family protein is a hot target in many different types of cancers, including DIPG. In this study, we performed the treatment of both EZH2 and BET inhibitor for DIPG cells. RESULTS: The combination of these two inhibitors exhibited better inhibition of the tumor growth both in vitro and in vivo compared to use the inhibitor individually. This inhibition was performed by blocking the proliferation and promoting the cell apoptosis. Meanwhile, combination treatment of these two inhibitors would also affect the epigenetic markers which were abnormal in the tumors of the certain set of genes. CONCLUSION: Thus we provided a novel therapy strategy for clinical treatment of DIPG.

13.
J Org Chem ; 73(18): 7236-45, 2008 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-18712926

RESUMO

The reactivity of (2-alkenyl-3-pentene-1,5-diyl)iron complexes toward olefin metathesis, cycloaddition, and mild oxidations (MnO 2 or mCPBA) was examined. Cycloaddition reactions were observed to occur with modest diastereoselectivity (33-63% de). Decomplexation of the (3-pentenediyl) ligand may be accomplished by oxidation with either CAN or alkaline hydrogen peroxide to afford vinylcyclopropanecarboxylates or divinylcyclopropanecarboxylates. Reduction of the latter, followed by Cope rearrangement generates cycloheptadienylmethanols. These studies demonstrate that (2-alkenyl-3-pentene-1,5-diyl)iron complexes can serve as organometallic scaffolds for the preparation of a wide variety of structural motifs containing up to 5 contiguous stereocenters.


Assuntos
Cicloeptanos/síntese química , Ciclopropanos/síntese química , Compostos Férricos/química , Compostos de Vinila/síntese química , Alcenos/química , Ciclização , Cicloeptanos/química , Ciclopropanos/química , Compostos Férricos/síntese química , Ligantes , Modelos Moleculares , Conformação Molecular , Oxirredução , Estereoisomerismo , Compostos de Vinila/química
14.
Zhonghua Yi Xue Za Zhi ; 86(6): 394-8, 2006 Feb 14.
Artigo em Chinês | MEDLINE | ID: mdl-16677549

RESUMO

OBJECTIVE: To investigate the regulation of heat shock protein (HSP)27/activating transcription factor (ATF)-5 complex in podocytes induced by high glucose and relevant mechanisms. METHODS: Mice kidney podocytes were cultured in culture fluid with D-glucose at normal concentration (5.5 mol/L) (Group NG) or with D-glucose at high concentration (30 mmol/L) (Group HG) cells of these 2 groups were collected at different time points after glucose stimulation to detect the cell apoptosis by Hoechst 33342 staining and fluorescence microscopy and flow cytometry. Western blotting was used to analyze the activation of extracellular signal-regulated kinase (ERK = MAPK) and p38 signaling pathway. The HSP27/ATF5 complex was assessed by co-immunoprecipitation. ERK pathway blocker PD98059 and p38 signal pathway blocker SB203580 were added into the culture fluid of Group HG and Group NG respectively, and then the podocytes were collected at different time points to detect the high glucose-induced HSP27/ATF5 complex and cell apoptosis. RESULTS: The apoptotic rate of the podocytes of Group HG 24 hours after high glucose incubation was 14.3% +/- 6.2%, and that 48 h after was 27.2% +/- 8.9%, significantly higher than that of Group NG (10.6% +/- 2.7%, P < 0.05). HSP27/ATF5 complex could detected in the cells of Group NG too, however, the level of HSP27/ATF5 complex in Group HG 12 hours after incubation was 195% +/- 36% that of Group NG (P < 0.05). Both the ERK signal pathway and p38 signal pathway of Group HG began to be activated 10 min after incubation, peaked 30 min after, remained at the highest level till 1 hour after, and returned almost to the baseline level 2 hours after. No activation of these 2 pathways was observed in Group NG. The HSP27/ATF5 complex level of the PD98059 + high glucose group was 109% +/- 19% that of Group NG, significantly lower than that of Group HG (211% +/- 46% that of Group NG, P < 0.05). The apoptotic rate of the PD98059 + high glucose group was 51% +/- 4%, significantly higher than that of PD98059 + normal glucose group (16% +/- 3%, P < 0.05) and that of Group HG (27% +/- 9%, P < 0.05). The apoptotic rate of the SB203580 + HG group was 16% +/- 6%, significantly lower than that of Group HG (27% +/- 9%, P < 0.05). The HSP27/ATF5 complex level of the SB230580 + HG group was 290% +/- 43% that of Group NG, not significantly different from that of Group HG (231% +/- 20% that of Group NG, P > 0.05). CONCLUSION: High glucose stimulates the formation of HSP27/ATF5 complex in podocytes through ERK signaling pathway but not P38 signaling pathway, and the HSP27/ATF5 complex may have a regulatory effect in podocyte apoptosis induced by high glucose.


Assuntos
Fatores Ativadores da Transcrição/metabolismo , Apoptose/efeitos dos fármacos , Glucose/farmacologia , Proteínas de Choque Térmico/metabolismo , Proteínas de Neoplasias/metabolismo , Podócitos/efeitos dos fármacos , Animais , Western Blotting , Células Cultivadas , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Flavonoides/farmacologia , Citometria de Fluxo , Proteínas de Choque Térmico HSP27 , Imidazóis/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Microscopia de Fluorescência , Chaperonas Moleculares , Complexos Multiproteicos/metabolismo , Podócitos/citologia , Podócitos/metabolismo , Piridinas/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
15.
Cell Physiol Biochem ; 17(1-2): 57-68, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16543722

RESUMO

Recent evidences have demonstrated an important role for glomerular visceral epithelial cell (podocyte) in the development and progression of diabetic nephropathy. We investigated the high-glucose (HG)-triggered signaling pathway and its role in matrix metalloproteinase (MMP) production in murine podocytes. The activity of 92-kDa (MMP-9) gelatinase, but not of 72 kDa (MMP-2), in an HG medium significantly increased during incubation of 2 to 3 days and decreased during incubation of more than 5 days revealed by Gelatin zymography. Opposite to the increases in MMP-9 activity, HG medium produced significant decreases in the protein levels of alpha5(IV) collagen. Changes in MMP-9 activity were associated with the same pattern as MMP-9 mRNA levels in podocytes exposed to HG media. HG medium rapidly activated ERK1/2 MAPK in podocytes. Moreover, ERK1/2 activation was required for HG-induced enhancement of MMP-9 activity and a decrease in the level of alpha5(IV) collagen. HG incubation rapidly induced an increase in the nuclear accumulation of Ets-1 protein. Blocking the ERK pathway suppressed HG-induced expression and nuclear accumulation of transcriptional factor Ets-1, and MMP-9 mRNA expression. We suggest that short- or long-term exposure to HG concentrations increases or decreases MMP-9 production and alpha5(IV) collagen expression in podocytes, this may contribute to the GBM abnormality caused by an imbalance in extracellular matrix (ECM) synthesis and degradation, and may play a critical role in the pathogenesis of proteinuria in diabetic nephropathy.


Assuntos
Colágeno Tipo IV/biossíntese , Glucose/farmacologia , Metaloproteinase 9 da Matriz/biossíntese , Podócitos/efeitos dos fármacos , Podócitos/metabolismo , Animais , Sequência de Bases , Células Cultivadas , Nefropatias Diabéticas/etiologia , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/metabolismo , Flavonoides/farmacologia , Glucose/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Metaloproteinase 9 da Matriz/genética , Camundongos , Proteína Proto-Oncogênica c-ets-1/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
16.
Cell Physiol Biochem ; 16(4-6): 207-16, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16301820

RESUMO

The unregulated synthesis of glomerular basement membrane (GBM) components, extracelluar matrix (ECM) proteins, or the secretion of ECM-degradation enzymes, matrix metalloproteinases (MMPs), by podocytes under pathological conditions might be major factors in GBM damage. The present study examined the effects and the underlying molecular mechanism of transforming growth factor beta1 (TGFbeta1) on the production of gelatinase in cultured murine podocytes. Our results showed that TGFbeta1 is the most potent inducer of MMP-9 secretion in both a dose- and time-dependent manner, but has very little effect on MMP-2 secretion. TGFbeta1 upregulated MMP-9 mRNA levels, but did not affect the expression of matrix mettaloproteinases TIMP-1 mRNA. TGFbeta1 induced activation of both Smad2 and extracellular signal-regulated kinases (ERK1/2). However, blockade of Smad2 signaling pathway by Staurosporine did not affect the TGFbeta1-stimulated secretion of MMP-9, whereas inhibition of activation of ERK1/2 by PD98059 abolished TGFbeta1-stimulated secretion of MMP-9 and expression of MMP-9 mRNA. Protein levels of the transcriptional factor Ets-1 increased and were sustained for 12 h by TGFbeta1-stimulation. Our data also showed that blockage of ERK1/2 activation by PD98059 led to a reduction in the level of Ets-1 protein and to a consequent decrease in MMP-9 mRNA levels. These results demonstrate that TGFbeta1 can induce the production of MMP-9 in podocytes through the ERK1/2 MAPK pathway, and suggested that an increase in MMP-9 enzymatic activities may be involved in the damage of the GBM in response to inflammatory factors, ultimately leading to glomerulosclerosis.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Sistema de Sinalização das MAP Quinases , Metaloproteinase 9 da Matriz/biossíntese , Podócitos/enzimologia , Proteína Proto-Oncogênica c-ets-1/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Animais , Células Cultivadas , Flavonoides/farmacologia , Regulação Enzimológica da Expressão Gênica , Metaloproteinase 9 da Matriz/genética , Camundongos , Podócitos/efeitos dos fármacos , Podócitos/metabolismo , Proteína Smad2/metabolismo , Estaurosporina/farmacologia , Fator de Crescimento Transformador beta1
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA