RESUMO
Traumatic brain injury (TBI) has consequences that last for years following injury. While TBI can precipitate a variety of diffuse pathologies, the mechanisms involved in injury-induced neuronal membrane disruption remain elusive. The lysosomal cysteine protease, Cathepsin B (Cath B), and specifically its redistribution into the cytosol has been implicated in cell death. Little is known about Cath B or neuronal membrane disruption chronically following diffuse TBI. Therefore, the current study evaluated Cath B and diffuse neuronal membrane disruption over a more chronic post-injury window (6â h-4â w). We evaluated Cath B in adult male Sprague-Dawley rats following central fluid percussion injury (CFPI). Expression of Cath B, as well as Cath B-associated pro (Bak and AIF) and anti-apoptotic (Bcl-xl) proteins, were assessed using western blot analysis. Cath B activity was also assessed. Localization of Cath B was evaluated in the membrane disrupted and non-disrupted population following CFPI using immunohistochemistry paired with quantitative image analysis and ultrastructural verification. There was no difference in expression or activity of Cath B or any of the associated proteins between sham and CFPI at any time post-injury. Immunohistological studies, however, showed a sub-cellular re-localization of Cath B at 2â w and 4â w post-injury in the membrane disrupted neuronal population as compared to the time-point matched non-disrupted neurons. Both membrane disruption and Cath B relocalization appear linked to neuronal atrophy. These observations are indicative of a late secondary pathology that represents an opportunity for therapeutic treatment of these neurons following diffuse TBI. Summary Statement Lysosomal cathepsin B relocalizes to the cytosol in neurons with disrupted plasmalemmal membranes weeks following diffuse brain injury. Both the membrane disrupted and cathepsin B relocalized neuronal subpopulations displayed smaller soma and nucleus size compared to non-pathological neurons, indicating atrophy.
Assuntos
Lesões Encefálicas Difusas , Lesões Encefálicas Traumáticas , Animais , Atrofia/metabolismo , Atrofia/patologia , Lesões Encefálicas Difusas/metabolismo , Lesões Encefálicas Difusas/patologia , Lesões Encefálicas Traumáticas/patologia , Catepsina B/análise , Catepsina B/metabolismo , Masculino , Neurônios/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
The aim was to study biophysical and chemical changes during low-temperature long-time (LTLT) heat treatment of pork by measuring cathepsin B+L activity, surface hydrophobicity of myofibrils, particle size of myofibrils and effect on meat toughness as indicated by Allo-Kramer shear force. Longissimus thoracis et lumborum muscles were divided into large pieces, vacuum packaged and cooked in water baths at 53, 58, 63, 68 and 73 °C for 1, 8 and 24 h. The results showed that the meat toughness was markedly lower at temperatures of 53 °C and 58 °C and decreased with increasing holding time. Myofibrillar surface hydrophobicity increased with temperature, but not with time, indicating aggregation and/or gelation phenomena took place. Treatments with the lowest shear force values generally had smaller particles and were associated with high cathepsin B+L activity. A mechanism by which these cathepsins might affect the aggregation dynamics and change the mechanical properties of meat is proposed.
Assuntos
Catepsina B/análise , Catepsina L/análise , Culinária/métodos , Proteínas Musculares/química , Carne de Porco/análise , Animais , Músculo Esquelético/química , Miofibrilas/química , Resistência ao Cisalhamento , Suínos , Temperatura , Fatores de Tempo , VácuoRESUMO
Trastuzumab deruxtecan (T-DXd: DS-8201a) is an anti-human epidermal growth factor receptor 2 (HER2) Ab-drug conjugated with deruxtecan (DXd), a derivative of exatecan. The objective of this study was to characterize T-DXd-induced lung toxicity in cynomolgus monkeys. Trastuzumab deruxtecan was injected i.v. into monkeys once every 3 weeks for 6 weeks (10, 30, and 78.8 mg/kg) or for 3 months (3, 10, and 30 mg/kg). To evaluate the involvement of DXd alone in T-DXd-induced toxicity, DXd monohydrate was given i.v. to monkeys once a week for 4 weeks (1, 3, and 12 mg/kg). Interstitial pneumonitis was observed in monkeys given T-DXd at 30 mg/kg or more. The histopathological features of diffuse lymphocytic infiltrates and slight fibrosis were similar to interstitial lung diseases (ILD)/pneumonitis related to anticancer drugs in patients, with an incidence that was dose-dependent and dose-frequency-dependent. Monkeys receiving DXd monohydrate did not suffer lung toxicity, although the DXd exposure level was higher than that of DXd in the monkeys given T-DXd. The HER2 expression in monkey lungs was limited to the bronchial level, although the lesions were found at the alveolar level. Immunohistochemical analysis confirmed that T-DXd localization was mainly in alveolar macrophages, but not pulmonary epithelial cells. These findings indicate that monkeys are an appropriate model for investigating T-DXd-related ILD/pneumonitis. The results are also valuable for hypothesis generation regarding the possible mechanism of T-DXd-induced ILD/pneumonitis in which target-independent uptake of T-DXd into alveolar macrophages could be involved. Further evaluation is necessary to clarify the mechanism of ILD/pneumonitis in patients with T-DXd therapy.
Assuntos
Camptotecina/análogos & derivados , Imunoconjugados/efeitos adversos , Imunoconjugados/metabolismo , Doenças Pulmonares Intersticiais/induzido quimicamente , Macaca fascicularis , Trastuzumab/efeitos adversos , Trastuzumab/metabolismo , Animais , Camptotecina/administração & dosagem , Camptotecina/efeitos adversos , Camptotecina/metabolismo , Catepsina B/análise , Esquema de Medicação , Feminino , Imunoconjugados/administração & dosagem , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Doenças Pulmonares Intersticiais/metabolismo , Doenças Pulmonares Intersticiais/patologia , Masculino , Receptor ErbB-2/metabolismo , Fatores de Tempo , Trastuzumab/administração & dosagemRESUMO
Pressure ulcers (PUs) are a common clinical issue lacking effective treatment and validated pharmacological therapy in hospital settings. Ischemia-reperfusion injury of deep tissue, especially muscle, plays a vital role in the formation and development of the overwhelming majority of PUs. However, muscular protein expression study in PUs has not been reported. Herein, we aimed to investigate the muscular proteins profiles in PUs and to explore the pathological mechanism of PUs. The iTRAQ LC-MS/MS was conducted to detect the protein profiles in clinical muscle samples of PUs. The GO and KEGG pathways analyses were performed for annotation of differentially expressed proteins. Protein-protein interaction (PPI) network was constructed by STRING online database, and hub proteins were validated by the immunoblotting. Based on proteomics results, we found a number of proteins that were differentially expressed in PU muscle samples compared with the normal and identified unique proteins expression patterns between these two groups, suggesting that they might involve in pathological process of the disease. Importantly, cathepsin B and D, as well as other autophagy-lysosome and apoptosis associated proteins were identified. Further experiments characterize the expression of these proteins and their regulation in the process of apoptosis and autophagy. These findings may provide novel insights into the mechanisms of lysosome-associated pathways involved in the initiation of PUs. This is the first study linking proteomics to PUs muscle tissues, which indicated cathepsin B and D might be key drug target for PUs.
Assuntos
Cromatografia Líquida , Proteínas Musculares/análise , Músculo Esquelético/química , Úlcera por Pressão/metabolismo , Proteoma , Proteômica , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Proteínas Reguladoras de Apoptose/análise , Proteínas Relacionadas à Autofagia/análise , Biomarcadores/análise , Estudos de Casos e Controles , Catepsina B/análise , Catepsina D/análise , Biologia Computacional , Humanos , Músculo Esquelético/patologia , Úlcera por Pressão/patologia , Mapas de Interação de ProteínasRESUMO
An interferometric reflectance spectroscopy-based biosensor for the determination of cathepsin B (Cat B) as a cancer-related enzyme has been fabricated. For this purpose, the nanoporous anodic alumina (NAA) was fabricated electrochemically. The NAA was then modified with the amino-silane coupling agent. After that, human serum albumin (HSA) was immobilized into the NAA pores by using glutaraldehyde as a cross-linking agent. Subsequently, the carboxylic group of HSA was activated with N-ethyl-N'-(3-(dimethylamino)propyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS) to attach to thionine (TH) as a photoprobe to fabricate the labeled HSA (HSA-TH). HSA-TH plays a significant role in this sensor to determine cathepsin B as a model analyte for the development of the interferometric reflectance spectroscopy-based biosensor for the measurement of protease. The attached TH adsorbed the illuminated white light on NAA modified with HSA-TH. Therefore, the intensity of the reflected light to the charge-coupled device (CCD) detector decreased in the wavelength range 450-1050 nm. In the presence of Cat B, HAS-TH cleaved into short peptide fragments and washed away by flow cell system. Since TH was removed from NAA, the intensity of the reflected light increased. The peak area has a logarithmic relationship with the concentration of Cat B in the range 0.5 to 64.0 nM. The limit of detection of the biosensor sensor was 0.08 nM. The optical sensor was used for the determination of Cat B in a human serum sample. Graphical abstract Schematic presentation of biosensor for the determination of the cathepsin B which is based on nanoporous anodic alumina modified with HSA-thionine. The principle response of the optical biosensor is based on detecting changes in the intensity of the reflected light after cleaving the immobilized HSA-thionine by cathepsin B into short peptide fragments.
Assuntos
Óxido de Alumínio/química , Técnicas Biossensoriais , Catepsina B/análise , Técnicas Eletroquímicas , Fenotiazinas/química , Albumina Sérica Humana/química , Catepsina B/metabolismo , Eletrodos , Humanos , Fenômenos Ópticos , Tamanho da Partícula , Porosidade , Propriedades de SuperfícieRESUMO
Antibody-drug conjugates (ADCs) employ overexpressed cell surface antigens to deliver cytotoxic payloads inside cancer cells. However, the relationship between target expression and ADC efficacy remains ambiguous. In this manuscript, we have addressed a part of this ambiguity by quantitatively investigating the effect of antigen expression levels on ADC exposure within cancer cells. Trastuzumab-valine-citrulline-monomethyl auristatin E was used as a model ADC, and four different cell lines with diverse levels of human epidermal growth factor receptor 2 (HER2) expression were used as model cells. The pharmacokinetics (PK) of total trastuzumab, released monomethyl auristatin E (MMAE), and total MMAE were measured inside the cells and in the cell culture media following incubation with two different concentrations of ADC. In addition, target expression levels, target internalization rate, and cathepsin B and MDR1 protein concentrations were determined for each cell line. All the PK data were mathematically characterized using a cell-level systems PK model for ADC. It was found that SKBR-3, MDA-MB-453, MCF-7, and MDA-MB-468 cells had â¼800,000, â¼250,000, â¼50,000, and â¼10,000 HER2 receptors per cell, respectively. A strong linear relationship (R 2 > 0.9) was observed between HER2 receptor count and released MMAE exposure inside the cancer cells. There was an inverse relationship found between HER2 expression level and internalization rate, and cathepsin B and multidrug resistance protein 1 (MDR1) expression level varied slightly among the cell lines. The PK model was able to simultaneously capture all the PK profiles reasonably well while estimating only two parameters. Our results demonstrate a strong quantitative relationship between antigen expression level and intracellular exposure of ADCs in cancer cells. SIGNIFICANCE STATEMENT: In this manuscript, we have demonstrated a strong linear relationship between target expression level and antibody-drug conjugate (ADC) exposure inside cancer cells. We have also shown that this relationship can be accurately captured using the cell-level systems pharmacokinetics model developed for ADCs. Our results indirectly suggest that the lack of relationship between target expression and efficacy of ADC may stem from differences in the pharmacodynamic properties of cancer cells.
Assuntos
Antineoplásicos Imunológicos/farmacocinética , Imunoconjugados/farmacocinética , Neoplasias/tratamento farmacológico , Oligopeptídeos/farmacocinética , Receptor ErbB-2/metabolismo , Trastuzumab/farmacocinética , Subfamília B de Transportador de Cassetes de Ligação de ATP/análise , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos Imunológicos/análise , Antineoplásicos Imunológicos/uso terapêutico , Catepsina B/análise , Catepsina B/metabolismo , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Humanos , Imunoconjugados/análise , Imunoconjugados/uso terapêutico , Modelos Biológicos , Neoplasias/imunologia , Neoplasias/patologia , Oligopeptídeos/análise , Oligopeptídeos/uso terapêutico , Receptor ErbB-2/análise , Receptor ErbB-2/antagonistas & inibidores , Trastuzumab/análise , Trastuzumab/uso terapêuticoRESUMO
We develop a simple fluorescence method for the sensitive detection of cathepsin B activity based on the integration of a peptide-DNA conjugate with multiple cyclic signal amplification. This method can detect cathepsin B activity with an extremely low detection limit of 8.1 × 10-12 g mL-1 and a large dynamic range of 4 orders of magnitude from 1 × 10-11 to 1 × 10-7 g mL-1, and it can even measure cathepsin B activity at the single-cell level. This method can be further used for the screening of cathepsin B inhibitors.
Assuntos
Catepsina B/análise , DNA/química , Técnicas de Amplificação de Ácido Nucleico , Peptídeos/química , Catepsina B/metabolismo , DNA/genética , DNA/metabolismo , Células HEK293 , Células HeLa , Humanos , Imagem Óptica , Peptídeos/genética , Peptídeos/metabolismoRESUMO
Imaging of an active protease with an exquisite specificity in the presence of highly homologous proteins within a living cell is a very challenging task. Herein, we disclose a new method called "Activity-based Reporter Gene Technology" (AbRGT). This method provides an opportunity to study the function of "active protease" with an unprecedented specificity. As a proof-of-concept, we have applied this method to study the function of individual caspase protease in both intrinsic and extrinsic apoptosis signaling pathways. The versatility of this method is demonstrated by studying the function of both the initiator and effector caspases, independently. The modular fashion of this technology provides the opportunity to noninvasively image the function of cathepsin-B in a caspase-dependent cell death pathway. As a potential application, this method is used as a tool to screen compounds that are potent inhibitors of caspases and cathepsin-B proteases. The fact that this method can be readily applied to any protease of interest opens up huge opportunities for this technology in the area of target validation, high-throughput screening, in vivo imaging, diagnostics, and therapeutic intervention.
Assuntos
Caspases/análise , Genes Reporter , Análise de Célula Única/métodos , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Inibidores de Caspase/farmacologia , Caspases/genética , Catepsina B/análise , Catepsina B/genética , Linhagem Celular Tumoral , Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/química , Proteínas de Fluorescência Verde/análise , Proteínas de Fluorescência Verde/genética , Células HEK293 , Humanos , Microscopia Confocal , Microscopia de Fluorescência , Estudo de Prova de Conceito , Proteínas Recombinantes de Fusão/análise , Proteínas Recombinantes de Fusão/genética , Rodaminas/química , Estaurosporina/farmacologiaRESUMO
Cathepsin B plays key roles in tumor progression with its overexpression being associated with invasive and metastatic phenotypes and is a primary target of protease activated antibody-directed prodrug therapy. It therefore represents a potential therapeutic and diagnostic target and effort has been made to develop fluorescent probes to report on Cathepsin B activity in cells and animal models of cancer. We have designed, synthesized, and thoroughly evaluated four novel "turn on" probes that employ a lysosomotropic dansylcadaverine dye to report on Cathepsin B activity. Enzyme activity assays using a recombinant human enzyme and cancer cell lysates coupled with confocal microscopy experiments demonstrated that one of the probes, derivatized with the self-immolative prodrug linker p-aminobenzyl alcohol, can selectively report on Cathepsin B in biological samples including live cells.
Assuntos
Cadaverina/análogos & derivados , Catepsina B/análise , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/metabolismo , Neoplasias/diagnóstico por imagem , Compostos de Aminobifenil/química , Cadaverina/síntese química , Cadaverina/metabolismo , Catepsina B/metabolismo , Catepsina L/análise , Catepsina L/metabolismo , Linhagem Celular Tumoral , Humanos , Hidrólise , Cinética , Microscopia Confocal , Estrutura Molecular , Imagem Óptica , Proteínas Recombinantes/análise , Proteínas Recombinantes/metabolismo , Relação Estrutura-AtividadeRESUMO
In this study, the diagnostic value of Schistosoma japonicum cathepsin B (SjCatB) was evaluated as an antigen for the early detection of S. japonicum infection. SjCatB is a key protease used by the cercaria to penetrate the intact skin of the host for transdermal infection. The early exposure of the host's immune system to this enzyme may elicit early production of antibodies against this molecule. Therefore, the recombinant SjCatB (rSjCatB) was expressed in Escherichia coli with N-terminal 6xHis-tag. rSjCatB was tested for its performance as a diagnostic antigen using indirect enzyme-linked immunosorbent assay (ELISA) with sera from experimentally infected mice collected at > 8 weeks post-infection. Showing 100% sensitivity and 95.0% specificity in the ELISA, rSjCatB was then evaluated with sera from experimentally infected mice collected at 1-7 weeks post-infection to determine how early the antibodies can be detected. Results showed that as early as 6 weeks post-infection, 2 of the 3 infected mice were found to be positive with the antibodies against SjCatB. Furthermore, the potential of the recombinant antigen in detecting human schistosomiasis was evaluated with archived serum samples collected from individuals who had been diagnosed with S. japonicum infection by stool examination. Results showed 86.7% sensitivity and 96.7% specificity suggesting its high diagnostic potential for human schistosomiasis. In addition, SjCatB showed minimal cross-reaction with the sera collected from patients with other parasitic diseases. In conclusion, the results of this study suggest that SjCatB will be useful in the development of a sensitive and specific early detection test for S. japonicum infection.
Assuntos
Catepsina B/análise , Ensaio de Imunoadsorção Enzimática/métodos , Schistosoma japonicum/enzimologia , Esquistossomose Japônica/diagnóstico , Animais , Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/análise , Antígenos de Helmintos/genética , Antígenos de Helmintos/imunologia , Ásia , Catepsina B/genética , Catepsina B/imunologia , Reações Cruzadas , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Schistosoma japonicum/genética , Schistosoma japonicum/imunologia , Schistosoma japonicum/isolamento & purificação , Esquistossomose Japônica/sangue , Esquistossomose Japônica/parasitologia , Sensibilidade e Especificidade , Zoonoses/sangue , Zoonoses/diagnóstico , Zoonoses/parasitologiaRESUMO
Both protease overexpression and local pH changes are key signatures of cancer. However, the sensitive detection of protease activities and the accurate measurement of pH in a tumor environment remain challenging. Here, we develop a dual-response DNA probe that can simultaneously monitor protease activities and measure the local pH by translocation through α-hemolysin (αHL). The DNA probe bears a short peptide containing phenylalanine at a pre-designed position. Enzymatic cleavage of the peptide either exposes or removes the N-terminal phenylalanine that can form a complex with cucurbit[7]uril. Translocation of the DNA hybrid through αHL generates current signatures that can be used to quantify protease activities. Furthermore, the current signatures possess a pH-dependent pattern that reflects the local pH. Our results demonstrate that the versatile DNA probe may be further explored for simultaneously measuring multiple parameters of a complex system such as single cells in the future.
Assuntos
Técnicas Biossensoriais/métodos , Catepsina B/análise , Sondas de DNA/química , Leucil Aminopeptidase/análise , Nanoporos , Proteínas Hemolisinas/química , Concentração de Íons de Hidrogênio , Limite de DetecçãoRESUMO
There is a strong demand for bioanalytical techniques to rapidly detect protease activities with high sensitivity and high specificity. This study reports an activity-based electrochemical method toward this goal. Nanoelectrode arrays (NEAs) fabricated with embedded vertically aligned carbon nanofibers (VACNFs) are functionalized with specific peptide substrates containing a ferrocene (Fc) tag. The kinetic proteolysis curves are measured with continuously repeated ac voltammetry, from which the catalytic activity is derived as the inverse of the exponential decay time constant based on a heterogeneous Michaelis-Menten model. Comparison of three peptide substrates with different lengths reveals that the hexapeptide H2N-(CH2)4-CO-Pro-Leu-Arg-Phe-Gly-Ala-NH-CH2-Fc is the optimal probe for cathepsin B. The activity strongly depends on temperature and is the highest around the body temperature. With the optimized peptide substrate and measuring conditions, the limit of detection of cathepsin B activity and concentration can reach 2.49 × 10-4 s-1 and 0.32 nM, respectively. The peptide substrates show high specificity to the cognate proteases, with negligible cross-reactions among three cancer-related proteases cathepsin B, ADAM10, and ADAM17. This electrochemical method can be developed into multiplex chips for rapid profiling of protease activities in cancer diagnosis and treatment monitoring.
Assuntos
Proteína ADAM10/análise , Proteína ADAM17/análise , Secretases da Proteína Precursora do Amiloide/análise , Carbono/química , Catepsina B/análise , Técnicas Eletroquímicas/métodos , Eletrodos , Proteínas de Membrana/análise , Nanofibras/química , Proteína ADAM10/metabolismo , Proteína ADAM17/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Catepsina B/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Nanotecnologia , ProteóliseRESUMO
Recently, mucosal surfaces, especially fish skin and its secreted mucus, have attracted significant interest from immunologists. Amphiprion clarkii, a member of the family Pomacentridae, lives symbiosis with sea anemones and has a good resistance to common seawater bacterial diseases and parasites owing to the protection from its abundant skin mucus. In the present work, the activity of immune-related enzymes (lysozyme, protease, antiprotease, cathepsin B, alkaline phosphatase and peroxidase), the antibacterial activity against two Gram-positive bacteria and five Gram-negative bacteria, the antiparasitic activity against the pathogen of marine white spot disease (Cryptocaryon irritans theronts) and the physico-chemical stability (to pH and heat) of the skin mucus of A. clarkii were analysed. The results showed that the levels of lysozyme and peroxidase were very similar (from 2 to 4 Uâ¯mg-1 protein). However, cathepsin B was detected of 63.32 Uâ¯mg-1 protein and alkaline phosphatase was only 0.12 Uâ¯mg-1 protein. Moreover, protease showed a higher percentage of activity than antiprotease. A. clarkii skin mucus showed a strong antibacterial activity against Gram-negative bacteria, particularly against Aeromonas hydrophila and Vibrio parahaemolyticus but showed no effect on Gram-positive bacteria at the tested concentrations. The bactericidal activity functioned within a short time in a distinct time- and dose-dependent manner. SEM showed that after treated with A. clarkii skin mucus, the V. parahaemolyticus cells distorted and piled together, and the filaments appeared and became into cotton-shaped or quasi-honeycomb texture to adhere cells. Meanwhile, A. clarkii skin mucus showed an apparent antiparasitic activity against C. irritans theronts with a distinct dose- and time-dependent relationship. LM and SEM observation showed that after treated with skin mucus, the theronts quickly stopped their swimming and cilia movement, cells became rounded, cilia shed, small bubbles formed on the surface, cell nucleolus enlarged, cytoskeleton deformed, cell membranes ruptured and cell content leaked out. Antibacterial activity was not affected by 30-90⯰C heat treatment but was slightly suppressed by 100⯰C. In the pH treatment groups, antibacterial activity was not affected by the moderate pH treatment of 5.0-8.0, but slightly suppressed by weak acid and weak base. Therefore, we speculated that the skin mucus of A. clarkii might be a potential source of novel antibacterial and antiparasitic components for fish or human health-related applications. This study broadened our understanding of the role of skin mucus in the innate immune system and provided a basis for the further isolation and purification of active substances.
Assuntos
Doenças dos Peixes/enzimologia , Muco/química , Perciformes , Pele/química , Fosfatase Alcalina/análise , Animais , Catepsina B/análise , Doenças dos Peixes/microbiologia , Doenças dos Peixes/parasitologia , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Concentração de Íons de Hidrogênio , Muco/enzimologia , Muramidase/análise , Peroxidase/análise , Estabilidade Proteica , Pele/enzimologiaRESUMO
A core-shell nanostructure is fabricated with a pH-sensitive metal-organic framework shell and a peptide functionalized gold nanoparticle core via a mild synthetic route. The nanostructure can be applied as a dual-recognition switch in response to an acidic environment and enzyme activity, sequentially, leading to a stepwise-responsive strategy for imaging lysosomal cathepsin B.
Assuntos
Catepsina B/análise , Nanopartículas Metálicas/química , Estruturas Metalorgânicas/química , Carbocianinas/química , Carbocianinas/toxicidade , Fluorescência , Corantes Fluorescentes/química , Corantes Fluorescentes/toxicidade , Ouro/química , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Imidazóis/química , Imidazóis/toxicidade , Lisossomos/metabolismo , Nanopartículas Metálicas/toxicidade , Estruturas Metalorgânicas/toxicidade , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Tamanho da Partícula , Peptídeos/química , Peptídeos/toxicidade , Zeolitas/química , Zeolitas/toxicidadeRESUMO
Glioblastoma (GBM) is the most lethal brain tumor also due to malignant and therapy-resistant GBM stem cells (GSCs) that are localized in protecting hypoxic GSC niches. Some members of the cysteine cathepsin family of proteases have been found to be upregulated in GBM. Cathepsin K gene expression is highly elevated in GBM tissue versus normal brain and it has been suggested to regulate GSC migration out of the niches. Here, we investigated the cellular distribution of cathepsins B, X and K in GBM tissue and whether these cathepsins are co-localized in GSC niches. Therefore, we determined expression of these cathepsins in serial paraffin sections of 14 human GBM samples and serial cryostat sections of two samples using immunohistochemistry and metabolic mapping of cathepsin activity using selective fluorogenic substrates. We detected cathepsins B, X and K in peri-arteriolar GSC niches in 9 out of 16 GBM samples, which were defined by co-expression of the GSC marker CD133, the niche marker stromal-derived factor-1α (SDF-1α) and smooth muscle actin as a marker for arterioles. The expression of cathepsin B and X was detected in stromal cells and cancer cells throughout the GBM sections, whereas cathepsin K expression was more restricted to arteriole-rich regions in the GBM sections. Metabolic mapping showed that cathepsin B, but not cathepsin K is active in GSC niches. On the basis of these findings, it is concluded that cathepsins B, X and K have distinct functions in GBM and that cathepsin K is the most likely GSC niche-related cathepsin of the three cathepsins investigated.
Assuntos
Catepsinas/metabolismo , Glioblastoma/patologia , Nicho de Células-Tronco , Adulto , Idoso , Idoso de 80 Anos ou mais , Arteríolas , Catepsina B/análise , Catepsina B/metabolismo , Catepsina K , Catepsina Z/análise , Catepsina Z/metabolismo , Catepsinas/análise , Glioblastoma/enzimologia , Glioblastoma/metabolismo , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , ProteóliseRESUMO
Let there be light: Chemiluminescence provides a bright detection signal against a dark background and offers an excellent signal-to-noise ratio for analysis. Now, a chemiluminescent probe for cathepsinâ B has been developed that provides a 16,000-fold improvement in sensitivity for detecting protease activity.
Assuntos
Catepsina B/análise , Luminescência , Corantes Fluorescentes/química , Limite de Detecção , Microscopia de Fluorescência , Razão Sinal-RuídoRESUMO
Until recently, chemiluminescence cell images could only be obtained using luciferase-activated probes. Moreover, chemiluminescence microscopy cell-imaging has not been demonstrated for natively expressed enzymes like cathepsinâ B. Herein, we describe the design, synthesis, and evaluation of the first chemiluminescence probe for the detection and imaging of cathepsinâ B. The probe activation mechanism relies on the release of a dioxetane intermediate, which undergoes chemiexcitation to emit green light with high efficiency under physiological conditions. Using the probe, we obtained clear images of cancerous leukemia and colon cells. This is the first demonstration of chemiluminescence cell images obtained by a probe for a natively expressed endogenous enzyme. We anticipate that the concept presented in this study will be broadly used to develop analogous probes for other important proteases relevant to biomolecular processes.
Assuntos
Catepsina B/análise , Corantes Fluorescentes/química , Luciferases/metabolismo , Medições Luminescentes , Imagem Óptica , Células 3T3 , Animais , Catepsina B/metabolismo , Células Cultivadas , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/metabolismo , Humanos , Camundongos , Estrutura Molecular , Células RAW 264.7RESUMO
Macrophages are specialized phagocytic cells involved in clearing invading pathogens. Previously we reported that engulfment and cell motility protein 1 (ELMO1) in macrophages mediates bacterial internalization and intestinal inflammation. Here we studied the role of ELMO1 in the fate of internalized targets. ELMO1 is present in the intracellular vesicles and enhances accumulation of the protein LC3B following engulfment of Salmonella or treatment with autophagy-inducing rapamycin. The protein ATG5 and the kinase ULK1 are involved in classical autophagy, while LC3-associated phagocytosis is ULK1 independent. ATG5 but not ULK1 cooperated with ELMO1 in LC3 accumulation after infection, suggesting the ELMO1 preferentially regulated LC3-associated phagocytosis. Because LC3-associated phagocytosis delivers cargo for degradation, the contribution of ELMO1 to the lysosome degradation pathways was evaluated by studying pH and cathepsin B activity. ELMO1-depleted macrophages showed a time-dependent increase in pH and a decrease in cathepsin B activity associated with bacterial survival. Together, ELMO1 regulates LC3B accumulation and antimicrobial responses involved in the clearance of enteric pathogens. This paper investigated how innate immune pathways involving ELMO1 work in a coordinated fashion to eliminate bacterial threats. ELMO1 is present in the phagosome and enhances bacterial clearance by differential regulation of lysosomal acidification and enzymatic activity.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Autofagia , Macrófagos/imunologia , Macrófagos/microbiologia , Infecções por Salmonella/patologia , Salmonella/crescimento & desenvolvimento , Salmonella/imunologia , Animais , Proteína 5 Relacionada à Autofagia/metabolismo , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Catepsina B/análise , Linhagem Celular , Modelos Animais de Doenças , Concentração de Íons de Hidrogênio , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/metabolismoRESUMO
Cysteine cathepsins often contribute to cancer progression due to their overexpression in the tumour microenvironment and therefore present attractive targets for non-invasive diagnostic imaging. However, the development of highly selective and versatile small molecule probes for cathepsins has been challenging. Here, we targeted tumour-associated cathepsin B using designed ankyrin repeat proteins (DARPins). The selective DARPin 8h6 inhibited cathepsin B with picomolar affinity (Ki = 35 pM) by binding to a site with low structural conservation in cathepsins, as revealed by the X-ray structure of the complex. DARPin 8h6 blocked cathepsin B activity in tumours ex vivo and was successfully applied in in vivo optical imaging in two mouse breast cancer models, in which cathepsin B was bound to the cell membrane or secreted to the extracellular milieu by tumour and stromal cells. Our approach validates cathepsin B as a promising diagnostic and theranostic target in cancer and other inflammation-associated diseases.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Catepsina B/análise , Microscopia Intravital/métodos , Técnicas de Sonda Molecular , Animais , Catepsina B/química , Cristalografia por Raios X , Modelos Animais de Doenças , Feminino , Camundongos , Ligação Proteica , Conformação ProteicaRESUMO
BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is a treatment option for peritoneal surface malignancies. The ability to detect microscopic foci of peritoneal metastasis intraoperatively may ensure the completeness of cytoreduction. In this study, we evaluated the suitability of a hand-held cathepsin-based fluorescent imaging system for intraoperative detection of appendiceal and colorectal peritoneal metastasis. METHODS: Peritoneal tumors and normal peritoneal tissues were collected from patients with appendiceal and colorectal peritoneal metastasis. Expression of different cathepsins (CTS-B, -D, -F, -G, -K, -L, -O, and -S) was determined by quantitative RT-PCR and immunohistochemistry. The hand-held cathepsin-based fluorescent imaging system was used to detect peritoneal xenografts derived from human colon cancer cells (HT29, LoVo and HCT116) in nu/nu mice. RESULTS: While the expression levels of CTS-B, -D, -L, and -S could be higher in peritoneal tumors than normal peritoneum with a median (range) of 6.1 (2.9-25.8), 2.0 (1.0-15.8), 1.4 (0.8-7.0), and 2.1 (1.6-13.9) folds by quantitative RT-PCR, respectively, CTS-B was consistently the major contributor of the overall cathepsin expression in appendiceal and colonic peritoneal tumors, including adenocarcinomas and low-grade appendiceal mucinous neoplasms. Using peritoneal xenograft mouse models, small barely visible colonic peritoneal tumors (<2.5 mm in maximum diameter) could be detected by the hand-held cathepsin-based fluorescent imaging system. CONCLUSIONS: Because cathepsin expression is higher in peritoneal tumors than underlying peritoneum, the hand-held cathepsin-based fluorescent imaging system could be useful for intraoperative detection of microscopic peritoneal metastasis during CRS-HIPEC and clinical trial is warranted.