RESUMO
Chemotherapy is still one of the main therapeutic approaches in cancer therapy. Nevertheless, its poor selectivity causes severe toxic side effects that, together with the development of drug resistance in tumor cells, results in a limitation for its application. Tumor-targeted drug delivery is a possible choice to overcome these drawbacks. As well as monoclonal antibodies, peptides are promising targeting moieties for drug delivery. However, the development of peptide-drug conjugates (PDCs) is still a big challenge. The main reason is that the conjugates have to be stable in circulation, but the drug or its active metabolite should be released efficiently in the tumor cells. For this purpose, suitable linker systems are needed that connect the drug molecule with the homing peptide. The applied linker systems are commonly categorized as cleavable and non-cleavable linkers. Both the groups possess advantages and disadvantages that are summarized briefly in this manuscript. Moreover, in this review paper, we highlight the benefit of oxime-linked anthracycline-peptide conjugates in the development of PDCs. For instance, straightforward synthesis as well as a conjugation reaction proceed in excellent yields, and the autofluorescence of anthracyclines provides a good tool to select the appropriate homing peptides. Furthermore, we demonstrate that these conjugates can be used properly in in vivo studies. The results indicate that the oxime-linked PDCs are potential candidates for targeted tumor therapy.
Assuntos
Antineoplásicos , Neoplasias , Humanos , Daunorrubicina/uso terapêutico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Oximas/uso terapêutico , Peptídeos/química , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Preparações Farmacêuticas/metabolismoRESUMO
Swiprosin-1 (EFhD2) is a molecule that triggers structural adaptation of isolated adult rat cardiomyocytes to cell culture conditions by initiating a process known as cell spreading. This process mimics central aspects of cardiac remodeling, as it occurs subsequent to myocardial infarction. However, expression of swiprosin-1 in cardiac tissue and its regulation in vivo has not yet been addressed. The expression of swiprosin-1 was analyzed in mice, rat, and pig hearts undergoing myocardial infarction or ischemia/reperfusion with or without cardiac protection by ischemic pre- and postconditioning. In mouse hearts, swiprosin-1 protein expression was increased after 4 and 7 days in myocardial infarct areas specifically in cardiomyocytes as verified by immunoblotting and histology. In rat hearts, swiprosin-1 mRNA expression was induced within 7 days after ischemia/reperfusion but this induction was abrogated by conditioning. As in cultured cardiomyocytes, the expression of swiprosin-1 was associated with a coinduction of arrestin-2, suggesting a common mechanism of regulation. Rno-miR-32-3p and rno-miR-34c-3p were associated with the regulation pattern of both molecules. Moreover, induction of swiprosin-1 and ssc-miR-34c was also confirmed in the infarct zone of pigs. In summary, our data show that up-regulation of swiprosin-1 appears in the postischemic heart during cardiac remodeling and repair in different species.
Assuntos
Remodelamento Atrial/genética , Proteínas de Ligação ao Cálcio/biossíntese , Regulação da Expressão Gênica , Precondicionamento Isquêmico Miocárdico , Proteínas dos Microfilamentos/biossíntese , Infarto do Miocárdio/genética , Traumatismo por Reperfusão/genética , Remodelação Ventricular/genética , Animais , Remodelamento Atrial/fisiologia , Proteínas de Ligação ao Cálcio/genética , Células Cultivadas , Camundongos , MicroRNAs/biossíntese , MicroRNAs/genética , Proteínas dos Microfilamentos/genética , Infarto do Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Ratos , Traumatismo por Reperfusão/metabolismo , Suínos , Remodelação Ventricular/fisiologia , beta-Arrestina 1/biossíntese , beta-Arrestina 1/genéticaRESUMO
BACKGROUND: Here we examined myocardial microRNA (miRNA) expression profile in a sensory neuropathy model with cardiac diastolic dysfunction and aimed to identify key mRNA molecular targets of the differentially expressed miRNAs that may contribute to cardiac dysfunction. METHODS: Male Wistar rats were treated with vehicle or capsaicin for 3 days to induce systemic sensory neuropathy. Seven days later, diastolic dysfunction was detected by echocardiography, and miRNAs were isolated from the whole ventricles. RESULTS: Out of 711 known miRNAs measured by miRNA microarray, the expression of 257 miRNAs was detected in the heart. As compared to vehicle-treated hearts, miR-344b, miR-466b, miR-98, let-7a, miR-1, miR-206, and miR-34b were downregulated, while miR-181a was upregulated as validated also by quantitative real time polymerase chain reaction (qRT-PCR). By an in silico network analysis, we identified common mRNA targets (insulin-like growth factor 1 (IGF-1), solute carrier family 2 facilitated glucose transporter member 12 (SLC2a-12), eukaryotic translation initiation factor 4e (EIF-4e), and Unc-51 like autophagy activating kinase 2 (ULK-2)) targeted by at least three altered miRNAs. Predicted upregulation of these mRNA targets were validated by qRT-PCR. CONCLUSION: This is the first demonstration that sensory neuropathy affects cardiac miRNA expression network targeting IGF-1, SLC2a-12, EIF-4e, and ULK-2, which may contribute to cardiac diastolic dysfunction. These results further support the need for unbiased omics approach followed by in silico prediction and validation of molecular targets to reveal novel pathomechanisms.
Assuntos
Insuficiência Cardíaca Diastólica/etiologia , MicroRNAs/genética , Polineuropatias/complicações , Animais , Capsaicina/toxicidade , Modelos Animais de Doenças , Fator de Iniciação 4E em Eucariotos/genética , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Proteínas Facilitadoras de Transporte de Glucose/genética , Insuficiência Cardíaca Diastólica/genética , Fator de Crescimento Insulin-Like I/genética , Masculino , Polineuropatias/induzido quimicamente , Proteínas Serina-Treonina Quinases/genética , Ratos , Ratos WistarRESUMO
Nitric oxide (NO) deficiency is common in pulmonary diseases, but its effect on pulmonary remodelling is still controversial. As pulmonary parathyroid hormone-related protein (PTHrP) expression is a key regulator of pulmonary fibrosis and development, the effect of chronic NO deficiency on the pulmonary PTHrP system and its relationship with oxidative stress was addressed. NO bioavailability in adult rats was reduced by systemic administration of L-NAME via tap water. To clarify the role of NO synthase (NOS)-3-derived NO on pulmonary expression of PTHrP, NOS-3-deficient mice were used. Captopril and hydralazine were used to reduce the hypertensive effect of L-NAME treatment and to interfere with the pulmonary renin-angiotensin system (RAS). Quantitative RT-PCR and immunoblot techniques were used to characterize the expression of key proteins involved in pulmonary remodelling. L-NAME administration significantly reduced pulmonary NO concentration and caused oxidative stress as characterized by increased pulmonary nitrite concentration and increased expression of NOX2, p47phox and p67phox. Furthermore, L-NAME induced the pulmonary expression of PTHrP and of its corresponding receptor, PTH-1R. Expression of PTHrP and PTH-1R correlated with the expression of two well-established PTHrP downstream targets, ADRP and PPARγ, suggesting an activation of the pulmonary PTHrP system by NO deficiency. Captopril reduced the expression of PTHrP, profibrotic markers and ornithine decarboxylase, but neither that of PTH-1R nor that of ADRP and PPARγ. All transcriptional changes were confirmed in NOS-3-deficient mice. In conclusion, NOS-3-derived NO suppresses pulmonary PTHrP and PTH-1R expression, thereby modifying pulmonary remodelling.
Assuntos
Pulmão/metabolismo , Óxido Nítrico/deficiência , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Animais , Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , Pulmão/efeitos dos fármacos , Pneumopatias/tratamento farmacológico , Pneumopatias/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/metabolismo , Nitritos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Ratos , Sistema Renina-Angiotensina/efeitos dos fármacos , Sistema Renina-Angiotensina/fisiologiaRESUMO
Erythropoietin (EPO) has been shown to protect the heart against acute myocardial infarction in pre-clinical studies, however, EPO failed to reduce infarct size in clinical trials and showed significant safety problems. Here, we investigated cardioprotective effects of two selective non-erythropoietic EPO receptor ligand dimeric peptides (AF41676 and AF43136) lacking erythropoietic activity, EPO, and the prolonged half-life EPO analogue, darbepoetin in acute myocardial infarction (AMI) in rats. In a pilot study, EPO at 100U/mL significantly decreased cell death compared to vehicle (33.8±2.3% vs. 40.3±1.5%, p<0.05) in rat neonatal cardiomyocytes subjected to simulated ischemia/reperfusion. In further studies (studies 1-4), in vivo AMI was induced by 30min coronary occlusion and 120min reperfusion in male Wistar rats. Test compounds and positive controls for model validation (B-type natriuretic peptide, BNP or cyclosporine A, CsA) were administered iv. before the onset of reperfusion. Infarct size (IS) was measured by standard TTC staining. In study 1, 5000U/kg EPO reduced infarct size significantly compared to vehicle (45.3±4.8% vs. 59.8±4.5%, p<0.05). In study 2, darbepoetin showed a U-shaped dose-response curve with maximal infarct size-reducing effect at 5µg/kg compared to the vehicle (44.4±5.7% vs. 65.9±2.7%, p<0.01). In study 3, AF41676 showed a U-shaped dose-response curve, where 3mg/kg was the most effective dose compared to the vehicle (24.1±3.9% vs. 44.3±2.5%, p<0.001). The positive control BNP significantly decreased infarct size in studies 1-3 by approximately 35%. In study 4, AF43136 at 10mg/kg decreased infarct size, similarly to the positive control CsA compared to the appropriate vehicle (39.4±5.9% vs. 58.1±5.4% and 45.9±2.4% vs. 63.8±4.1%, p<0.05, respectively). This is the first demonstration that selective, non-erythropoietic EPO receptor ligand dimeric peptides AF41676 and AF43136 administered before reperfusion are able to reduce infarct size in a rat model of AMI. Therefore, non-erythropoietic EPO receptor peptide ligands may be promising cardioprotective agents.
Assuntos
Cardiotônicos/farmacologia , Eritropoetina/metabolismo , Infarto do Miocárdio/tratamento farmacológico , Miocárdio/metabolismo , Animais , Ligantes , Masculino , Infarto do Miocárdio/metabolismo , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Peptídeo Natriurético Encefálico/farmacologia , Projetos Piloto , Ratos , Ratos WistarRESUMO
CONTEXT: The activation of the renin-angiotensin-aldosterone system (RAAS) plays an important role in the pathophysiology of congestive heart failure, which is the reason that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin 2 receptor blockers (ARBs) have become established therapies for heart failure. However, it is still not known whether preventive treatment with losartan or enalapril can reduce symptoms of infarction-induced heart failure. Ultra-low dose (ULD) drug therapy is thought to exert specific activity, with a lower chance of side effects. OBJECTIVES ⢠The research team had hypothesized that preventive treatment with inhibitors of RAAS signaling-losartan, enalapril, and a preparation of a ULD antibody (ie, cardosten), which target the angiotensin type 1 (AT1) receptor-might alleviate pathological hypertrophy and/or functional decline in infarction-induced heart failure. METHODS: The research team treated male Wistar rats orally for 30 d with 20 mg/kg of losartan, 10 mg/kg enalapril, 5 or 7.5 mL/kg of cardosten, or a control solution, started 1 d prior to permanent coronary occlusion. A sham-operated group functioned as a second control group. SETTINGS: The study was conducted at the Department of Biochemistry of the Faculty of Medicine at the University of Szeged in Szeged, Hungary, in cooperation with the Pharmahungary Group, also in Szeged, Hungary, and with OOO "NPF" Materia Medica Holding Ltd in Moscow, Russia. OUTCOME MEASURES: To determine cardiac functional parameters in vivo, the research team inserted a catheter into the left ventricle of the rats and measured the parameters of ventricular pressure, and cardiac output was determined by thermodilution. Morphological parameters were measured after heart isolation in transverse sections by a digital caliper. RESULTS: A total of 30 d after permanent coronary ligation, both losartan and enalapril, significantly decreased mean arterial blood pressure (MABP), attenuated the development of the left-ventricular anterior-wall and septum hypertrophy, and reduced scar thickness compared with the vehicle control group. The deterioration of cardiac output and the increase in total peripheral resistance (TPR) due to coronary ligation were significantly inhibited by both losartan and enalapril. The effects of cardosten were comparable with those of losartan and enalapril on cardiac morphology, left ventricular function, and TPR; however, it did not influence MABP. Moreover, in contrast to losartan and enalapril, cardosten did not decrease the rate of survival. CONCLUSIONS: The study was the first to have demonstrated that preventive treatment with losartan, enalapril, or cardosten can attenuate pathological hypertrophy in infarction-induced heart failure in rats.
Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II , Inibidores da Enzima Conversora de Angiotensina , Enalapril , Insuficiência Cardíaca , Losartan , Infarto do Miocárdio/fisiopatologia , Sistema Renina-Angiotensina/efeitos dos fármacos , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Animais , Enalapril/farmacologia , Enalapril/uso terapêutico , Coração/efeitos dos fármacos , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/prevenção & controle , Testes de Função Cardíaca , Losartan/farmacologia , Losartan/uso terapêutico , Masculino , Ratos , Ratos WistarRESUMO
AIMS: Peroxynitrite-matrix metalloproteinase (MMP) signalling has been shown to contribute to myocardial ischaemia/reperfusion injury and heart failure and to be influenced by hyperlipidaemia in preclinical models. Therefore, here we investigated the correlation between the markers of peroxynitrite-MMP signalling and hyperlipidaemia in patients with significant coronary stenosis. METHODS: Five minutes before percutaneous coronary intervention (PCI), arterial blood samples were collected from 36 consecutive patients with coronary artery disease (CAD) selected for elective PCI. RESULTS: Serum nitrotyrosine positively correlated with MMP-9 activity (r = 0·54, P = 0·01), but not with MMP-2 activity. Nitrotyrosine positively correlated with total (r = 0·58; P < 0·01) and LDL cholesterol (r = 0·55; P < 0·01), serum triglyceride (r = 0·47; P < 0·05), and creatinine (r = 0·42; P < 0·05) and negatively correlated with HDL cholesterol (r = -0·46; P < 0·05) and with left ventricular ejection fraction (LVEF; r = -0·55; P < 0·05), respectively. MMP-2 activity correlated positively with total (r = 0·55; P < 0·05) and LDL cholesterol (r = 0·45; P < 0·05). In statin-treated patients, a significantly reduced serum nitrotyrosine was found as compared to statin naives; however, MMP activities and serum cholesterol levels were not different. MMP-9 activity correlated with urea nitrogen (r = 0·42; P < 0·05) and LVEF (r = -0·73; P < 0·01). Serum creatinine correlated negatively with LVEF (r = -0·50, P < 0·01). CONCLUSIONS: This is the first demonstration that (i) serum nitrotyrosine correlates with MMP-9 activity, (ii) lipid parameters correlate with nitrotyrosine and MMP-2 activity, (iii) myocardial function correlates with creatinine, nitrotyrosine and MMP-9 activity, and (iv) creatinine correlates with nitrotyrosine and urea nitrogen with MMP-9 activity in patients with CAD. Studying the biomarkers of peroxynitrite-MMP pathway in large prospective trials may reveal their diagnostic avails.
Assuntos
Doença da Artéria Coronariana/sangue , Coração/fisiologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Tirosina/análogos & derivados , Idoso , Biomarcadores/metabolismo , Doença da Artéria Coronariana/fisiopatologia , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Metabolismo dos Lipídeos/fisiologia , Masculino , Nitrogênio/metabolismo , Projetos Piloto , Tirosina/metabolismo , Ureia/químicaRESUMO
Aneuploidy plays very important role in tumor development as the consequence of either congenital or acquired mutations. In order to evaluate the adverse effects of various aneugens, the knowledge of the spontaneous frequency of numerical chromosome abnormalities in healthy population is fundamental. In our study we analyzed the spontaneous rate of numerical and structural chromosome aberrations in peripheral blood lymphocytes of 2145 healthy individuals, with special attention to the influence of biological (gender, age) and life-style factors (smoking, different occupational exposure). Correlation between aneuploidy and risk of cancer development were investigated according to National Cancer Registry data followed for 1-23 years. In the whole population the average frequency of aneuploid cells was 1.77±0.06%. This value increased by age linearly (r2=0.81) regardless of occupational exposures. Gender (biological factor) or smoking (life style factor) did not influence the values, however, the occupation of individuals modified the frequency of numerical aberrations. Individuals who worked at workplaces with radiation hazard had the lowest (1.44±0.10%), and those working in the chemical industry had the highest (1.89±0.05%) values of aneuploidy, respectively. We could not find any correlation between numerical and structural chromosome aberrations. In our population studied 97 individuals developed cancer and only those who had ≤2% aneuploidy survived more than 12 years in good health conditions. To our knowledge, this study has the highest case number investigated up to now. Our results support that aneuploidy, similarly to structural chromosomal aberrations, might be an additional cytogenetic biomarker of the genetic instability.
Assuntos
Aneuploidia , Aberrações Cromossômicas/estatística & dados numéricos , Exposição Ocupacional/efeitos adversos , Fumar/efeitos adversos , Adulto , Idoso , Feminino , Humanos , Hungria/epidemiologia , Cariótipo , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
The development of peptide-based pharmaceutics is a hot topic in the pharmaceutical industry and in basic research. However, from the research and development perspective there is an unmet need for new, alternative, solid-phase peptide synthesizers that are highly efficient, automated, robust, able to synthetize peptides in parallel, inexpensive (to obtain and operate), have potential to be scaled up, and even comply with the principles of green chemistry. Moreover, a peptide synthesizer of this type could also fill the gap in university research, and therefore speed the advancement of peptide-based pharmaceutical options. This paper presents a Tecan add-on peptide synthesizer (TaPSy), which has operational flexibility (coupling time: 15-30 min), can handle all manual synthesis methods, and is economical (solvent use: 34.5 mL/cycle, while handling 0.49 mmol scale/reactor, even with ≤3 equivalents of activated amino acid derivatives). Moreover, it can carry out parallel synthesis of up to 12 different peptides (0.49 mmol scale in each). TaPSy uses no heating or high pressure, while it is still resistant to external influences (operating conditions: atmospheric pressure, room temperature 20-40 ËC, including high [>70%] relative humidity). The system's solvent can also be switched from DMF to a green and biorenewable solvent, γ-valerolactone (GVL), without further adjustment. The designed TaPSy system can produce peptides with high purity (>70%), even with the green GVL solvent alternative. In this paper we demonstrate the optimization path of a newly developed peptide synthesizer in the context of coupling reagents, reaction time and reagent equivalents applying for a synthesis of a model peptide. We compare the results by analytical characteristics (purity of raw material, crude yield, yield) and calculated overall cost of the syntheses of one mg of crude peptide using a specified set of reaction conditions.
Assuntos
Procedimentos Cirúrgicos Robóticos , Técnicas de Síntese em Fase Sólida , Humanos , Técnicas de Síntese em Fase Sólida/métodos , Peptídeos , SolventesRESUMO
Following the introduction of mono- and then dual hormone (incretin) receptor agonists into therapy, attention was turned to multiple receptor stimulation, with the additional activation of the glucagon receptor, as a new option for the pharmaceutical treatment of type 2 diabetes and obesity. In addition to its role in carbohydrate metabolism, the article reviews the other important physiological tasks of glucagon, especially its participation in intrainsular paracrine regulation, energy expenditure and the shaping of appetite and food consumption. It covers the potential benefits of the triple combination and briefly touches data on the efficacy and safety of the first triple receptor agonist drug, retatrutide, in preclinical human studies. Further confirmation of the promising results may represent progress in the treatment of these forms of disease and their accompanying conditions, such as steatosis hepatis. Orv Hetil. 2023; 164(42): 1656-1664.
Assuntos
Diabetes Mellitus Tipo 2 , Receptor do Peptídeo Semelhante ao Glucagon 1 , Receptores de Glucagon , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Obesidade/tratamento farmacológico , Receptores de Glucagon/agonistas , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistasRESUMO
Curcuminoids (CUs) of antitumor and various other potential biological activities have extremely low water solubility therefore special formulation was elaborated. New fast dissolving reconstitution dosage forms of four CUs were prepared as fibrous form of 2-hydroxypropyl-ß-cyclodextin (HP-ß-CD). In the electrospinning process HP-ß-CD could act both as solubilizer and fiber-forming agent. The solubilization efficiency of the CU-HP-ß-CD systems was determined with phase-solubility measurements. The electrospun CUs were amorphous and uniformly distributed in the fibers according to XRD analysis and Raman mappings. The fibrous final products had fast (<5 min) and complete dissolution. In typical iv. infusion reconstitution volume (20 mL) fibers containing 40-80 mg of CU could be dissolved, which is similar to the currently proposed dose (<120 mg/m2). The in vitro cytostatic effect data showed that the antitumor activity of the CU-HP-ß-CD complexes was similar or better compared to the free APIs.
Assuntos
Diarileptanoides , Neoplasias , Excipientes , Humanos , Derivados da Hipromelose , Neoplasias/tratamento farmacológico , SolubilidadeRESUMO
In this study a new intravenous (i.v.) bolus dosage form of doxycycline was prepared by electrospinning. A tetracycline-type antibiotic with low water solubility (doxycycline (DOX)) was used with 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD) as solubilizer. The new solid formulation could be produced with high (~80 g/h) productivity rate using high-speed electrospinning (HSES) from a water-based precursor solution. Freeze-dried DOX-HP-ß-CD was also prepared from the same precursor solution as HSES for comparison. Raman mapping showed that the amorphous DOX was uniformly distributed in the fibrous powder making precise dosing of the API possible. The new formulation's viability as an i.v. bolus product was examined with reconstitution test. The samples contained 100 mg of pure DOX (similarly to the products currently on the market). To ensure i.v. bolus applicability, the dissolution was carried out in 1.5 mL water. The final DOX concentration was 66.7 mg/(mL solvent), which is 7 times higher than the currently marketed formulation. The drug release was followed by UV-VIS spectrophotometry. The results confirmed that the reconstitution solution could be applied as an i.v. bolus dosage form. Moreover, the work confirmed that the continuous high-speed electrospinning process can be a viable high productivity alternative to freeze-drying.
Assuntos
2-Hidroxipropil-beta-Ciclodextrina/química , Antibacterianos/administração & dosagem , Doxiciclina/administração & dosagem , Excipientes/química , Antibacterianos/química , Química Farmacêutica , Doxiciclina/química , Liberação Controlada de Fármacos , Liofilização , Pós , Solubilidade , Tecnologia Farmacêutica , Água/químicaRESUMO
In case of cancers with high mortality rate and lacking efficient medication there is a huge need of new, innovative treatments. Targeted tumor therapy, a real breakthrough in this field, is based on the concept that the antitumor agent is linked to a targeting molecule (e.g. peptide) specifically recognizing receptors or antigens that are tumor specific or overexpressed by tumor cells. The efficiency of this conjugate can be influenced by several factors. Among these, the structure of the targeting device, the type and number of the antitumor drug, its position in the conjugate and the chemical bonding of the drug to the targeting molecule are all important features that can determine receptor affinity and cellular uptake, and also the release and the cellular localization of the free drug or its active metabolite. Our goal in the framework of the grant NVKP_16-1-2016-0036 was to generate conjugates against cancers with high mortality rate. Through the below described studies, we introduce the course of the research process through which conjugates are optimized in order to develop more efficient drug candidates.
Assuntos
Neoplasias , Antineoplásicos , Linhagem Celular Tumoral , Humanos , Terapia de Alvo Molecular , PeptídeosRESUMO
Development of peptide-based conjugates for targeted tumour therapy is a current research topic providing new possibilities in cancer treatment. In this study, VHLGYAT heptapeptide selected by phage display technique for HT-29 human colon cancer was investigated as homing peptide for drug delivery. Daunomycin was conjugated to the N-terminus of the peptide directly or through Cathepsin B cleavable spacers. Conjugates showed moderate in vitro cytostatic effect. Therefore, sequence modifications were performed by Ala-scan and positional scanning resulting in conjugates with much higher bioactivity. Conjugates in which Gly was replaced by amino acids with bulky apolaric side chains provided the best efficacy. The influence of the cellular uptake, stability and drug release on the anti-tumour activity was investigated. It was found that mainly the difference in the cellular uptake of the conjugates generated the distinct effect on cell viability. One of the most efficient conjugate Dauâ¯=â¯Aoa-LRRY-VHLFYAT-NH2 showed tumour growth inhibition on orthotopically developed HT-29 colon cancer in mice with negligible toxic side effect compared to the free drug. We also indicate that this sequence is not specific to HT-29â¯cells, but it has a remarkable effect on many other cancer cells. Nevertheless, the Phe-containing conjugate was more active in all cases compared to the conjugate with the parent sequence. The literature data suggested that this sequence is highly overlapped with peptides that recognize Hsp70 membrane bound protein overexpressed in many types of tumours.
Assuntos
Antineoplásicos/uso terapêutico , Neoplasias do Colo/tratamento farmacológico , Daunorrubicina/análogos & derivados , Daunorrubicina/uso terapêutico , Oligopeptídeos/uso terapêutico , Pró-Fármacos/uso terapêutico , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Catepsina B/metabolismo , Proliferação de Células/efeitos dos fármacos , Técnicas de Visualização da Superfície Celular/métodos , Daunorrubicina/metabolismo , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Feminino , Células HT29 , Humanos , Camundongos SCID , Oligopeptídeos/síntese química , Oligopeptídeos/metabolismo , Pró-Fármacos/síntese química , Pró-Fármacos/metabolismo , Proteólise , Ratos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Chronic kidney disease (CKD) is a public health problem that increases the risk of cardiovascular morbidity and mortality. Heart failure with preserved ejection fraction (HFpEF) characterized by left ventricular hypertrophy (LVH) and diastolic dysfunction is a common cardiovascular complication of CKD. MicroRNA-212 (miR-212) has been demonstrated previously to be a crucial regulator of pathologic LVH in pressure-overload-induced heart failure via regulating the forkhead box O3 (FOXO3)/calcineurin/nuclear factor of activated T-cells (NFAT) pathway. Here we aimed to investigate whether miR-212 and its hypertrophy-associated targets including FOXO3, extracellular signal-regulated kinase 2 (ERK2), and AMP-activated protein kinase (AMPK) play a role in the development of HFpEF in CKD. CKD was induced by 5/6 nephrectomy in male Wistar rats. Echocardiography and histology revealed LVH, fibrosis, preserved systolic function, and diastolic dysfunction in the CKD group as compared to sham-operated animals eight and/or nine weeks later. Left ventricular miR-212 was significantly overexpressed in CKD. However, expressions of FOXO3, AMPK, and ERK2 failed to change significantly at the mRNA or protein level. The protein kinase B (AKT)/FOXO3 and AKT/mammalian target of rapamycin (mTOR) pathways are also proposed regulators of LVH induced by pressure-overload. Interestingly, phospho-AKT/total-AKT ratio was increased in CKD without significantly affecting phosphorylation of FOXO3 or mTOR. In summary, cardiac overexpression of miR-212 in CKD failed to affect its previously implicated hypertrophy-associated downstream targets. Thus, the molecular mechanism of the development of LVH in CKD seems to be independent of the FOXO3, ERK1/2, AMPK, and AKT/mTOR-mediated pathways indicating unique features in this form of LVH.
Assuntos
Expressão Gênica , Hipertrofia Ventricular Esquerda/etiologia , MicroRNAs/genética , Insuficiência Renal Crônica/complicações , Animais , Biópsia , Modelos Animais de Doenças , Ecocardiografia , Proteína Forkhead Box O3/genética , Proteína Forkhead Box O3/metabolismo , Perfilação da Expressão Gênica , Hipertrofia Ventricular Esquerda/diagnóstico , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Miócitos Cardíacos , Fosforilação , Ratos , Transdução de SinaisRESUMO
Matrix metalloproteinases (MMP) belong to a distinguished class of zinc-dependent endopeptidases. Zymography is a semi-quantitative tool for determining the activity of different MMP isoenzymes in a variety of biological samples. In substrate gel zymography, protein samples of different origin (tissue, cell lysates, plasma/serum, perfusates, other liquids) are separated in sodium dodecyl sulfate (SDS) polyacrylamide gels containing copolymerized substrate (gelatin, casein, elastin, etc.), and after incubation-enabling substrate cleavage by MMPs, MMP activities are detected after the gel staining as transparent bands against a dark-blue background. In situ zymography is a histological modification of substrate zymography in frozen sections, allowing detection of the localization of the MMP activities within the tissue. Here, we describe detailed experimental protocols of all abovementioned techniques and provide examples for several sample measurements.
Assuntos
Eletroforese em Gel de Poliacrilamida/métodos , Ensaios Enzimáticos/métodos , Metaloproteinases da Matriz/análise , Animais , Caseínas/metabolismo , Células Cultivadas , Elastina/metabolismo , Gelatina/metabolismo , Humanos , Metaloproteinases da Matriz/metabolismo , Coloração e Rotulagem/métodos , Especificidade por SubstratoRESUMO
BACKGROUND: Ischemic preconditioning (IPC) and ischemic postconditioning (IPoC) are currently among the most efficient strategies protecting the heart against ischemia/reperfusion injury. However, the effect of IPC and IPoC on functional recovery following ischemia/reperfusion is less clear, particularly with regard to the specific receptor-mediated signaling of the postischemic heart. The current article examines the effect of IPC or IPoC on the regulation and coupling of ß-adrenergic receptors and their effects on postischemic left ventricular function. METHODS AND RESULTS: The ß-adrenergic signal transduction was analyzed in 3-month-old Wistar rats for each of the intervention strategies (Sham, ischemia/reperfusion, IPC, IPoC) immediately and 7 days after myocardial infarction. Directly after the infarction a cardioprotective potential was demonstrated for both IPC and IPoC: the infarct size was reduced, apoptosis and production of reactive oxygen species were lowered, and the myocardial tissue was preserved. Seven days after myocardial ischemia, only IPC hearts showed significant functional improvement. Along with a deterioration in fractional shortening, IPoC hearts no longer responded adequately to ß-adrenergic stimulation. The stabilization of ß-adrenergic receptor kinase-2 via increased phosphorylation of Mdm2 (an E3-ubiquitin ligase) was responsible for desensitization of ß-adrenergic receptors and identified as a characteristic specific to IPoC hearts. CONCLUSIONS: Immediately after myocardial infarction, rapid and transient activation of ß-adrenergic receptor kinase-2 may be an appropriate means to protect the injured heart from excessive stress. In the long term, however, induction and stabilization of ß-adrenergic receptor kinase-2, with the resultant loss of positive inotropic function, leads to the functional picture of heart failure.
Assuntos
Precondicionamento Isquêmico Miocárdico/métodos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Receptores Adrenérgicos beta/metabolismo , Função Ventricular Esquerda/fisiologia , Animais , Modelos Animais de Doenças , Feminino , Traumatismo por Reperfusão Miocárdica/diagnóstico , Traumatismo por Reperfusão Miocárdica/metabolismo , Ratos , Ratos WistarRESUMO
Whereas high amounts of reactive oxygen species (ROS) contribute to cardiac damage following ischemia and reperfusion (IR), low amounts function as trigger molecules in the cardioprotection by ischemic preconditioning (IPC). The mitochondrial translocation and contribution of the hydrogen peroxide-generating protein p66shc in the cardioprotection by IPC is unclear yet. In the present study, we investigated the mitochondrial translocation of p66shc, addressed the impact of p66shc on ROS formation after IR, and characterized the role of p66shc in IR injury per se and in the cardioprotection by IPC. The amount of p66shc in subsarcolemmal (SSM) and interfibrillar mitochondria (IFM) isolated from wildtype mouse left ventricles (LV) was determined after 40 min normoxic perfusion and after 30 min ischemia and 10 min reperfusion without and with IPC. The p66shc content in SSM (in % of normoxic controls, n = 5) was 174 ± 16% (n = 6, p < 0.05) after IR, and was reduced to 128 ± 13% after IPC (n = 6, p = ns). In IFM, the amount of p66shc remained unchanged (IR: 81 ± 7%, n = 6; IPC: 110 ± 5%, n = 6, p = ns). IR induced an increase in ROS formation in SSM and IFM isolated from mouse wildtype LV, which was more pronounced in SSM than in IFM (1.18 ± 0.18 vs. 0.81 ± 0.16, n = 6, p < 0.05). In mitochondria from p66shc-knockout mice (p66shc-KO), the increase in ROS formation by IR was not different between SSM and IFM (0.90 ± 0.11 vs. 0.73 ± 0.08, n = 6, p = ns). Infarct size (in % of the left ventricle) was 51.7 ± 2.9% in wildtype and 59.7 ± 3.8% in p66shc-KO hearts in vitro and was significantly reduced to 35.8 ± 4.4% (wildtype) and 34.7 ± 5.6% (p66shc-KO) by IPC, respectively. In vivo, infarct size was 57.8 ± 2.9% following IR (n = 9) and was reduced to 40.3 ± 3.5% by IPC (n = 11, p < 0.05) in wildtype mice. In p66shc-knockout mice, infarct sizes were similar to those measured in wildtype animals (IR: 56.2 ± 4.3%, n = 11; IPC: 42.1 ± 3.9%, n = 13, p < 0.05). Taken together, the mitochondrial translocation of p66shc following IR and IPC differs between mitochondrial populations. However, similar infarct sizes after IR and preserved infarct size reductions by IPC in p66shc-KO mice suggest that p66shc-derived ROS are not involved in the cardioprotection by IPC nor do they contribute to IR injury per se.