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Lung cancer is the leading cause of death worldwide for both men and women. Surgery can be offered as a radical treatment at stages I and II and selected cases of stage III (III A). Whereas at more advanced stages, combined modalities of treatment are applied: radiochemotherapy (IIIB) and molecularly targeted treatment (small molecule tyrosine kinase inhibitors, VEGF receptor inhibitors, monoclonal antibodies, and immunological treatment with monoclonal antibodies). Combination treatment, composed of radiotherapy and molecular therapy, is increasingly employed in locally advanced and metastatic lung cancer management. Recent studies have indicated a synergistic effect of such treatment and modification of immune response. The combination of immunotherapy and radiotherapy may result in the enhancement of the abscopal effect. Anti-angiogenic therapy, in combination with RT, is associated with high toxicity and should be not recommended. In this paper, the authors discuss the role of molecular treatment and the possibility of its concurrent use with radiotherapy in non-small cell lung cancer (NSCLC).
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Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Masculino , Feminino , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/radioterapia , Terapia de Alvo Molecular , Anticorpos Monoclonais/uso terapêutico , Imunoterapia , Antígeno B7-H1RESUMO
Photodynamic therapy is an unconventional yet increasingly common method of treating dermatological diseases and cancer that is implemented more often in adults than in children. Current clinical uses include treatment of actinic keratosis, superficial basal cell carcinomas, and acne. Despite its high efficiency, photodynamic therapy support supplements have recently been reported in the literature, including calcitriol (1,25-dihydroxycholecalciferol), the active form of vitamin D, and vitamin D3 cholecalciferol. In clinical trials, photodynamic therapy enhanced with vitamin D or D3 supplementation has been reported for treatment of squamous cell skin cancers, actinic keratosis, and psoriasis. Experimental research on the effect of photodynamic therapy with vitamin D or D3 has also been carried out in breast cancer cell lines and in animal models. The aim of this review is to evaluate the usefulness and effectiveness of vitamin D and D3 as supports for photodynamic therapy. For this purpose, the Pubmed and Scopus literature databases were searched. The search keyword was: "vitamin D in photodynamic therapy". In the analyzed articles (1979-2022), the authors found experimental evidence of a positive effect of vitamin D and D3 when used in conjunction with photodynamic therapy. An average of 6-30% (in one case, up to 10 times) increased response to photodynamic therapy was reported in combination with vitamin D and D3 as compared to photodynamic therapy alone. Implementing vitamin D and D3 as a supplement to photodynamic therapy is promising and may lead to further clinical trials and new clinical methodologies.
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Ceratose Actínica , Fotoquimioterapia , Animais , Calcitriol/farmacologia , Calcitriol/uso terapêutico , Colecalciferol/farmacologia , Colecalciferol/uso terapêutico , Suplementos Nutricionais , Ceratose Actínica/tratamento farmacológico , Vitamina D/farmacologia , Vitamina D/uso terapêutico , VitaminasRESUMO
Photodynamic therapy is a mode of treatment whereby local irradiation of an administered photosensitizer with light of a specific wavelength generates cytotoxic reactive oxygen species. Despite the upward trend in the popularity of this method in adults, it is not yet commonly used in the treatment of children. Due to certain limitations, underdeveloped treatment regimens and potential side effects, the use of photodynamic therapy in the pediatric population is still in the initial phases of evaluation in clinical trials. METHOD: This study is a review of articles in English from the databases PubMed and Web of Science retrieved by applying the search term "photodynamic therapy in children" from 2000-2020. RESULTS: Based on the literature review, we analyze selected pediatric clinical cases in which photodynamic therapy was used for treatment in children. Examples of photodynamic therapy for treatment of dermatological diseases, diseases of the mucosa of the upper respiratory tract, halitosis, eye diseases and brain tumors are described. The paper describes the effectiveness of anti-cancer photodynamic therapy, including its use in antibacterial therapy. CONCLUSIONS: The results of the analysis suggest the potential of photodynamic therapy for the treatment of various diseases in children.
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Despite significant advances in early diagnosis and treatment, cancer is one of the leading causes of death. Photodynamic therapy (PDT) is a therapy for the treatment of many diseases, including cancer. This therapy uses a combination of a photosensitizer (PS), light irradiation of appropriate length and molecular oxygen. The photodynamic effect kills cancer cells through apoptosis, necrosis, or autophagy of tumor cells. PDT is a promising approach for eliminating various cancers but is not yet as widely applied in therapy as conventional chemotherapy. Currently, natural compounds with photosensitizing properties are being discovered and identified. A reduced toxicity to healthy tissues and a lower incidence of side effects inspires scientists to seek natural PS for PDT. In this review, several groups of compounds with photoactive properties are presented. The use of natural products has been shown to be a fruitful approach in the discovery of novel pharmaceuticals. This review focused on the anticancer activity of furanocoumarins, polyacetylenes, thiophenes, tolyporphins, curcumins, alkaloid and anthraquinones in relation to the light-absorbing properties. Attention will be paid to their phototoxic and anti-cancer effects on various types of cancer.
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Produtos Biológicos/uso terapêutico , Neoplasias/tratamento farmacológico , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Produtos Biológicos/química , Humanos , Fármacos Fotossensibilizantes/químicaRESUMO
BACKGROUND AND OBJECTIVES: Whole-body radiation exposure has been shown to alter the pharmacokinetics of certain drugs in both animal models and humans, but little is known about the effect of radiation on psychoactive medications. These drugs may have altered pharmacokinetics when administered during or after space travel or therapeutic or accidental radiation exposure, resulting in reduced efficacy or increased toxicity. METHODS: Methamphetamine was used to determine the effects of acutely administered 1, 3, and 6 Gy radiation on drug pharmacokinetics and pharmacodynamics. Male Wistar rats were exposed to 0, 1, 3, or 6 Gy X-ray radiation on day 0. The serum pharmacokinetics of subcutaneously administered 1 mg/kg methamphetamine was determined on day 3. Methamphetamine-induced (1 mg/kg) locomotor activity was measured on day 5. Brain methamphetamine concentrations were determined 2 h after methamphetamine administration (1 mg/kg) on day 6. Renal and hepatic serum biomarkers were assessed on days 3 and 6, with liver histology performed on day 6. RESULTS: While serum half-life and unchanged methamphetamine urine clearance were unaffected by any radiation dose, maximum methamphetamine concentrations and methamphetamine and amphetamine metabolite area under the serum concentration-time curve values from 0 to 300 min were significantly reduced after 6 Gy radiation exposure. Additionally, methamphetamine-induced locomotor activity and the brain to serum methamphetamine concentration ratio were significantly elevated after 6 Gy radiation. CONCLUSIONS: While 1-6 Gy radiation exposure did not affect methamphetamine elimination, 6 Gy exposure had effects on both subcutaneous absorption and brain distribution. These effects should be considered when administering drugs during or after radiation exposure.
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Metanfetamina , Anfetamina/farmacocinética , Animais , Meia-Vida , Fígado , Masculino , Metanfetamina/farmacocinética , Ratos , Ratos WistarRESUMO
BACKGROUND: Several disease states commonly associated with methamphetamine (METH) use produce liver dysfunction, and in the bile duct ligation (BDL) model of hepatic dysfunction, rats with liver injury are more sensitive to METH effects. Additionally, both female rats and humans are known to be more sensitive to METH than males. In consideration of known sex-dependent differences in METH pharmacokinetics, this study sought to determine the potential interaction between sex and liver dysfunction variables on METH pharmacokinetics. METHODS: Sham or BDL surgery was performed on male and female rats on day 0. Serum biomarker and pharmacokinetics studies with 3 mg/kg subcutaneous (SC) METH were performed on day 7. METH-induced weight loss was measured on day 8. Liver histology evaluation and brain METH concentration measurements were performed on day 9. RESULTS: While BDL surgery produced significantly elevated alanine aminotransferase and bile duct proliferation in male compared to female rats, there were no significant interactions between sex and liver function in the pharmacokinetic parameters. Both liver dysfunction and female sex, however, were associated with significantly slower METH serum clearance and significantly higher brain METH concentrations (p < .05). CONCLUSIONS: BDL-induced hepatic dysfunction produces substantial reductions in METH clearance and increased brain METH concentrations in both male and female rats, despite less liver injury in females. This preclinical model may be useful to identify and correct potential liver dysfunction comorbidity-related problems with future pharmacotherapy for stimulant use disorder with METH prior to expensive clinical trials.
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Ductos Biliares/fisiologia , Estimulantes do Sistema Nervoso Central/farmacocinética , Metanfetamina/farmacocinética , Animais , Ductos Biliares/cirurgia , Estimulantes do Sistema Nervoso Central/farmacologia , Feminino , Ligadura , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/fisiopatologia , Hepatopatias , Masculino , Metanfetamina/farmacologia , RatosRESUMO
RATIONALE: Asthma exacerbations often occur due to infectious triggers, but determining whether infection is present and whether it is bacterial or viral remains clinically challenging. A diagnostic strategy that clarifies these uncertainties could enable personalized asthma treatment and mitigate antibiotic overuse. OBJECTIVES: To explore the performance of validated peripheral blood gene expression signatures in discriminating bacterial, viral, and noninfectious triggers in subjects with asthma exacerbations. METHODS: Subjects with suspected asthma exacerbations of various etiologies were retrospectively selected for peripheral blood gene expression analysis from a pool of subjects previously enrolled in emergency departments with acute respiratory illness. RT-PCR quantified 87 gene targets, selected from microarray-based studies, followed by logistic regression modeling to define bacterial, viral, or noninfectious class. The model-predicted class was compared to clinical adjudication and procalcitonin. RESULTS: Of 46 subjects enrolled, 7 were clinically adjudicated as bacterial, 18 as viral, and 21 as noninfectious. Model prediction was congruent with clinical adjudication in 15/18 viral and 13/21 noninfectious cases, but only 1/7 bacterial cases. None of the adjudicated bacterial cases had confirmatory microbiology; the precise etiology in this group was uncertain. Procalcitonin classified only one subject in the cohort as bacterial. 47.8% of subjects received antibiotics. CONCLUSIONS: Our model classified asthma exacerbations by the underlying bacterial, viral, and noninfectious host response. Compared to clinical adjudication, the majority of discordances occurred in the bacterial group, due to either imperfect adjudication or model misclassification. Bacterial infection was identified infrequently by all classification schemes, but nearly half of subjects were prescribed antibiotics. A gene expression-based approach may offer useful diagnostic information in this population and guide appropriate antibiotic use.
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Asma/etiologia , Asma/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Asma/sangue , Infecções Bacterianas/complicações , Criança , Estudos de Coortes , Serviço Hospitalar de Emergência , Feminino , Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Pró-Calcitonina/sangue , Estudos Retrospectivos , Viroses/complicações , Adulto JovemRESUMO
INTRODUCTION: One possible way of iron loss is sweating. It is unclear how physical activity performed by untrained individuals affects the iron status in sweat. OBJECTIVE: The purpose of this study was to analyse iron concentration in sweat during 4-week exercise training to determine the changes in iron excretion during follow-up exercises. MATERIAL AND METHODS: 43 untrained volunteers participated in the study, 29 of whom completed the full exercise programme. The training programme consisted of exercises on a cycle ergometer and cross-trainer. In the first week, participants exercised for 8 minutes on each device, in the second for 10 minutes, and in the third and fourth weeks they exercised for 15 min on each device. Intensity was submaximal and defined as 85% of maximal heart rate. A sterile sweat patch was placed on the skin between shoulder blades. RESULTS: Concentration of iron on the first and the fifteenth day of exercises was comparable and statistically insignificant. Iron concentration was highly increased on the last day of training in comparison with first (p<0.001) and fourteenth day (p<0.006). The median of iron concentration in 29 samples on the first day of sampling was 21.2 ppb, in the fifteenth - 52.5 ppb, and on the twenty-eighth day - 286.2 ppb. In relation with the sodium concentration, the iron content was also increased on the twenty-eighth day of the training programme (p<0.005). CONCLUSIONS: Iron sweat loss significantly increased during the 4-week exercise programme. A possible explanation may be improvement in the thermoregulation mechanism and secretory activity of sweat glands. Iron sweat loss may be an indicator of iron deficiency observed in active individuals.
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Exercício Físico , Ferro/análise , Suor/química , Adulto , Feminino , Humanos , Ferro/metabolismo , Pessoa de Meia-Idade , Sudorese , Adulto JovemRESUMO
Pathophysiological conditions such as fibrosis, inflammation, and tumor progression are associated with modification of the extracellular matrix (ECM). These modifications create ligands that differentially interact with cells to promote responses that drive pathological processes. Within the tumor stroma, fibroblasts are activated and increase the expression of type I collagen. In addition, activated fibroblasts specifically express fibroblast activation protein-α (FAP), a post-prolyl peptidase. Although FAP reportedly cleaves type I collagen and contributes to tumor progression, the specific pathophysiologic role of FAP is not clear. In this study, the possibility that FAP-mediated cleavage of type I collagen modulates macrophage interaction with collagen was examined using macrophage adhesion assays. Our results demonstrate that FAP selectively cleaves type I collagen resulting in increased macrophage adhesion. Increased macrophage adhesion to FAP-cleaved collagen was not affected by inhibiting integrin-mediated interactions, but was abolished in macrophages lacking the class A scavenger receptor (SR-A/CD204). Further, SR-A expressing macrophages localize with activated fibroblasts in breast tumors of MMTV-PyMT mice. Together, these results demonstrate that FAP-cleaved collagen is a substrate for SR-A-dependent macrophage adhesion, and suggest that by modifying the ECM, FAP plays a novel role in mediating communication between activated fibroblasts and macrophages.
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Colágeno Tipo I/metabolismo , Gelatinases/metabolismo , Macrófagos/citologia , Proteínas de Membrana/metabolismo , Receptores Depuradores Classe A/metabolismo , Serina Endopeptidases/metabolismo , Animais , Mama/metabolismo , Mama/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Adesão Celular , Células Cultivadas , Endopeptidases , Feminino , Humanos , Integrinas/metabolismo , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos Endogâmicos C57BL , Proteínas Recombinantes/metabolismoRESUMO
Cadmium ions are notorious environmental pollutants. To adapt to cadmium-induced deleterious effects plants have developed sophisticated defense mechanisms. However, the signaling pathways underlying the plant response to cadmium are still elusive. Our data demonstrate that SnRK2s (for SNF1-related protein kinase2) are transiently activated during cadmium exposure and are involved in the regulation of plant response to this stress. Analysis of tobacco (Nicotiana tabacum) Osmotic Stress-Activated Protein Kinase activity in tobacco Bright Yellow 2 cells indicates that reactive oxygen species (ROS) and nitric oxide, produced mainly via an l-arginine-dependent process, contribute to the kinase activation in response to cadmium. SnRK2.4 is the closest homolog of tobacco Osmotic Stress-Activated Protein Kinase in Arabidopsis (Arabidopsis thaliana). Comparative analysis of seedling growth of snrk2.4 knockout mutants versus wild-type Arabidopsis suggests that SnRK2.4 is involved in the inhibition of root growth triggered by cadmium; the mutants were more tolerant to the stress. Measurements of the level of three major species of phytochelatins (PCs) in roots of plants exposed to Cd(2+) showed a similar (PC2, PC4) or lower (PC3) concentration in snrk2.4 mutants in comparison to wild-type plants. These results indicate that the enhanced tolerance of the mutants does not result from a difference in the PCs level. Additionally, we have analyzed ROS accumulation in roots subjected to Cd(2+) treatment. Our data show significantly lower Cd(2+)-induced ROS accumulation in the mutants' roots. Concluding, the obtained results indicate that SnRK2s play a role in the regulation of plant tolerance to cadmium, most probably by controlling ROS accumulation triggered by cadmium ions.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Cloreto de Cádmio/farmacologia , Cádmio/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Estresse Fisiológico , Adaptação Fisiológica , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Transporte Biológico , Citoplasma/genética , Citoplasma/metabolismo , Ativação Enzimática , Técnicas de Inativação de Genes , Ferro/metabolismo , Microscopia Confocal , Mutação , Óxido Nítrico/metabolismo , Fitoquelatinas/metabolismo , Células Vegetais/efeitos dos fármacos , Células Vegetais/enzimologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/enzimologia , Proteínas Serina-Treonina Quinases/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Nicotiana/efeitos dos fármacos , Nicotiana/enzimologia , Nicotiana/genéticaRESUMO
Fibroblast activation protein-α (FAP) is a serine protease that can provide target specificity to therapeutic agents because in adults its expression is restricted to pathologic sites, including cancer, fibrosis, arthritis, wounding, or inflammation. It is not expressed in most normal tissues. The majority of FAP is expressed by activated fibroblasts responding to the pathologic situations. FAP is typically found as a type II transmembrane protein physically attached to cells and with the bulk of the protein, including the catalytic domain, exposed to the extracellular space and accessible to small molecules. In this chapter, we review the structure, substrate specificities, signaling functions, and current design of FAP inhibitors. Evidence indicating the presence of FAP in multiple cancers, arthritis, fibrosis, keloids, and other pathologies is described and indicates possible roles for FAP in facilitating cell invasion and growth. Separate sections are devoted to the role of FAP in coordinating the stromal response to cancer, including a role in angiogenesis and a potential role in modulation of the antitumor immune response. Finally studies attempting to demonstrate the clinical potential of FAP are discussed, as well as some novel applications employing FAP in therapy or diagnosis. Throughout this review, effort is made to highlight areas where information is lacking and to highlight important questions that require further investigation.
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Microambiente Celular , Doença , Gelatinases/metabolismo , Proteínas de Membrana/metabolismo , Serina Endopeptidases/metabolismo , Animais , Microambiente Celular/efeitos dos fármacos , Endopeptidases , Gelatinases/antagonistas & inibidores , Gelatinases/química , Humanos , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/química , Especificidade de Órgãos/efeitos dos fármacos , Serina Endopeptidases/química , Inibidores de Serina Proteinase/farmacologia , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo , Células Estromais/patologiaRESUMO
Fibroblast activation protein-α (FAP) is a cell surface, serine protease of the post-prolyl peptidase family that is expressed in human breast cancer but not in normal tissues. Previously, we showed that FAP expression increased tumor growth rates in a mouse model of human breast cancer. Here the role of the proteolytic activities of FAP in promoting tumor growth, matrix degradation and invasion was investigated. Mammary fat pads of female SCID mice were inoculated with breast cancer cells that express FAP and the mice treated with normal saline or Val-boroPro (talabostat); Glu-boroPro (PT-630); or 1-[[(3-hydroxy-1-adamantyl)amino]acetyl]-2-cyano-(S)-pyrrolidine (LAF-237) that inhibit prolyl peptidases. Other mice were injected with breast cancer cells expressing a catalytically inactive mutant of FAP and did not receive inhibitor treatment. PT-630 and LAF-237 did not slow growth of tumors produced by any of the three cell lines expressing FAP. Talabostat slightly decreased the growth rates of the FAP-expressing tumors but because PT-630 and LAF-237 did not, the growth retardation was likely not related to the inhibition of FAP or the related post-prolyl peptidase dipeptidyl peptidase IV. Breast cancer cells expressing a catalytically inactive mutant of FAP (FAP(S624A)) also produced tumors that grew rapidly. In vitro studies revealed that cells expressing wild type FAP or FAP(S624A) degrade extracellular matrix (ECM) more extensively, accumulate higher levels of matrix metalloproteinase-9 (MMP-9) in conditioned medium, are more invasive in type I collagen gels, and have altered signaling compared to control transfectants that do not express FAP and form slow growing tumors. We conclude that the proteolytic activity of FAP participates in matrix degradation, but other functions of the protein stimulate increased tumor growth.
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Antígenos de Neoplasias/metabolismo , Neoplasias da Mama/patologia , Gelatinases/metabolismo , Proteínas de Membrana/metabolismo , Invasividade Neoplásica/patologia , Serina Endopeptidases/metabolismo , Animais , Antígenos de Neoplasias/genética , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/secundário , Linhagem Celular Tumoral , Proliferação de Células , Dipeptidil Peptidase 4/genética , Dipeptidil Peptidase 4/metabolismo , Endopeptidases , Feminino , Gelatinases/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Invasividade Neoplásica/genética , Metástase Neoplásica/genética , Metástase Neoplásica/patologia , Serina Endopeptidases/genéticaRESUMO
SNF1-related protein kinases 2 (SnRK2s) are plant-specific enzymes involved in environmental stress signaling and abscisic acid-regulated plant development. Here, we report that SnRK2s interact with and are regulated by a plant-specific calcium-binding protein. We screened a Nicotiana plumbaginifolia Matchmaker cDNA library for proteins interacting with Nicotiana tabacum osmotic stress-activated protein kinase (NtOSAK), a member of the SnRK2 family. A putative EF-hand calcium-binding protein was identified as a molecular partner of NtOSAK. To determine whether the identified protein interacts only with NtOSAK or with other SnRK2s as well, we studied the interaction of an Arabidopsis thaliana orthologue of the calcium-binding protein with selected Arabidopsis SnRK2s using a two-hybrid system. All kinases studied interacted with the protein. The interactions were confirmed by bimolecular fluorescence complementation assay, indicating that the binding occurs in planta, exclusively in the cytoplasm. Calcium binding properties of the protein were analyzed by fluorescence spectroscopy using Tb(3+) as a spectroscopic probe. The calcium binding constant, determined by the protein fluorescence titration, was 2.5 ± 0.9 × 10(5) M(-1). The CD spectrum indicated that the secondary structure of the protein changes significantly in the presence of calcium, suggesting its possible function as a calcium sensor in plant cells. In vitro studies revealed that the activity of SnRK2 kinases analyzed is inhibited in a calcium-dependent manner by the identified calcium sensor, which we named SCS (SnRK2-interacting calcium sensor). Our results suggest that SCS is involved in response to abscisic acid during seed germination most probably by negative regulation of SnRK2s activity.
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Proteínas de Ligação ao Cálcio/metabolismo , Cálcio/metabolismo , Regulação da Expressão Gênica de Plantas , Nicotiana/metabolismo , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Arabidopsis , Proteínas de Arabidopsis , Cálcio/farmacologia , Regulação para Baixo , Germinação , Proteínas de Plantas , Proteínas Quinases/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Estrutura Secundária de Proteína/efeitos dos fármacos , Nicotiana/enzimologia , Técnicas do Sistema de Duplo-HíbridoRESUMO
Several studies focusing on elucidating the mechanism of NO (nitric oxide) signalling in plant cells have highlighted that its biological effects are partly mediated by protein kinases. The identity of these kinases and details of how NO modulates their activities, however, remain poorly investigated. In the present study, we have attempted to clarify the mechanisms underlying NO action in the regulation of NtOSAK (Nicotiana tabacum osmotic stress-activated protein kinase), a member of the SNF1 (sucrose non-fermenting 1)-related protein kinase 2 family. We found that in tobacco BY-2 (bright-yellow 2) cells exposed to salt stress, NtOSAK is rapidly activated, partly through a NO-dependent process. This activation, as well as the one observed following treatment of BY-2 cells with the NO donor DEA/NO (diethylamine-NONOate), involved the phosphorylation of two residues located in the kinase activation loop, one being identified as Ser158. Our results indicate that NtOSAK does not undergo the direct chemical modifications of its cysteine residues by S-nitrosylation. Using a co-immunoprecipitation-based strategy, we identified several proteins present in immunocomplex with NtOSAK in salt-treated cells including the glycolytic enzyme GAPDH (glyceraldehyde-3-phosphate dehydrogenase). Our results indicate that NtOSAK directly interacts with GAPDH in planta. Furthermore, in response to salt, GAPDH showed a transient increase in its S-nitrosylation level which was correlated with the time course of NtOSAK activation. However, GADPH S-nitrosylation did not influence its interaction with NtOSAK and did not have an impact on the activity of the protein kinase. Taken together, the results support the hypothesis that NtOSAK and GAPDH form a cellular complex and that both proteins are regulated directly or indirectly by NO.
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Gliceraldeído-3-Fosfato Desidrogenases/fisiologia , Nicotiana/enzimologia , Óxido Nítrico/fisiologia , Osmose/fisiologia , Proteínas de Plantas/fisiologia , Proteínas Quinases/metabolismo , Salinidade , Estresse Fisiológico/fisiologia , Sequência de Aminoácidos , Células Cultivadas , Dados de Sequência Molecular , Proteínas Quinases/fisiologia , Nicotiana/citologiaRESUMO
BACKGROUND: The actin cytoskeleton is involved in the responses of plants to environmental signals. Actin bundles play the role of tracks in chloroplast movements activated by light. Chloroplasts redistribute in response to blue light in the mesophyll cells of Nicotiana tabacum. The aim of this work was to study the relationship between chloroplast responses and the organization of actin cytoskeleton in living tobacco cells. Chloroplast movements were measured photometrically as changes in light transmission through the leaves. The actin cytoskeleton, labeled with plastin-GFP, was visualised by confocal microscopy. RESULTS: The actin cytoskeleton was affected by strong blue and red light. No blue light specific actin reorganization was detected. EGTA and trifluoperazine strongly inhibited chloroplast responses and disrupted the integrity of the cytoskeleton. This disruption was reversible by Ca(2+) or Mg(2+). Additionally, the effect of trifluoperazine was reversible by light. Wortmannin, an inhibitor of phosphoinositide kinases, potently inhibited chloroplast responses but did not influence the actin cytoskeleton at the same concentration. Also this inhibition was reversed by Ca(2+) and Mg(2+). Magnesium ions were equally or more effective than Ca(2+) in restoring chloroplast motility after treatment with EGTA, trifluoperazine or wortmannin. CONCLUSION: The architecture of the actin cytoskeleton in the mesophyll of tobacco is significantly modulated by strong light. This modulation does not affect the direction of chloroplast redistribution in the cell. Calcium ions have multiple functions in the mechanism of the movements. Our results suggest also that Mg(2+) is a regulatory molecule cooperating with Ca(2+) in the signaling pathway of blue light-induced tobacco chloroplast movements.
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Actinas/metabolismo , Cloroplastos/metabolismo , Citoesqueleto/metabolismo , Nicotiana/metabolismo , Androstadienos/farmacologia , Calcimicina/metabolismo , Cálcio/metabolismo , Cloroplastos/efeitos da radiação , Citoesqueleto/efeitos da radiação , Regulação da Expressão Gênica de Plantas , Proteínas de Fluorescência Verde/genética , Luz , Magnésio/metabolismo , Glicoproteínas de Membrana/genética , Proteínas dos Microfilamentos/genética , Microscopia Confocal , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/efeitos da radiação , Sistemas do Segundo Mensageiro , Nicotiana/genética , Nicotiana/efeitos da radiação , Trifluoperazina/farmacologia , WortmaninaRESUMO
"Therapeutic angiogenesis" requires targeted delivery of growth factors for maximal benefit and limitation of potential hazards such as enhancement of tumor or plaque angiogenesis. Physiological distinctions between angiogenesis and collateral growth suggest the possibility of targeting selectively collateral endothelium. This article describes the generation of collateral-targeting single-chain antibodies (scFv). Membrane preparations of growing collateral arteries from rats were used to produce collateral-targeting antibodies (CTAs) via immunization of mice. ScFv were generated from CTA-producing hybridoma and cloned into the pV gene of M13 phages. Phages expressing collateral-targeting scFv (CT scFv) were selected via repeated exposure to activated collateral arteries followed by reamplification. CT scFv could specifically be amplified, selected, and sequenced. Phages expressing CT scFv bound selectively to proliferating collateral vessels as identified by positive Polycyclic Nuclear Antigen (PCNA) staining and homed specifically to collateral endothelium after in vivo injection but bound neither to control vessels nor to tumor vessels. This study reveals major differences between angiogenic and collateral endothelium and delivers a tool that will allow the stimulation of collateral growth without promoting tumor or plaque angiogenesis.