RESUMO
The intention of this Special Issue is to elucidate the role of apoptosis and cellular senescence in different pathological processes, such as cancer and aging [...].
Assuntos
Envelhecimento , Neoplasias , Humanos , Envelhecimento/patologia , Apoptose , Senescência Celular , Neoplasias/patologiaRESUMO
In the search for Alzheimer's disease (AD) therapies, most animal models focus on familial AD, which accounts for a small fraction of cases. The majority of AD cases arise from stress factors, such as oxidative stress, leading to neurological changes (sporadic AD). Early in AD progression, dysfunction in γ-secretase causes the formation of insoluble Aß1-42 peptides, which aggregate into senile plaques, triggering neurodegeneration, cognitive decline, and circadian rhythm disturbances. To better model sporadic AD, we used a new AD rat model induced by intracerebroventricular administration of Aß1-42 oligomers (icvAß1-42) combined with melatonin deficiency via pinealectomy (pin). We validated this model by assessing spatial memory using the radial arm maze test and measuring Aß1-42 and γ-secretase levels in the frontal cortex and hippocampus with ELISA. The icvAß1-42 + pin model experienced impaired spatial memory and increased Aß1-42 and γ-secretase levels in the frontal cortex and hippocampus, effects not seen with either icvAß1-42 or the pin alone. Chronic melatonin treatment reversed memory deficits and reduced Aß1-42 and γ-secretase levels in both structures. Our findings suggest that our icvAß1-42 + pin model is extremely valuable for future AD research.
Assuntos
Doença de Alzheimer , Secretases da Proteína Precursora do Amiloide , Peptídeos beta-Amiloides , Modelos Animais de Doenças , Hipocampo , Melatonina , Fragmentos de Peptídeos , Pinealectomia , Memória Espacial , Animais , Melatonina/farmacologia , Melatonina/metabolismo , Peptídeos beta-Amiloides/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Ratos , Memória Espacial/efeitos dos fármacos , Masculino , Fragmentos de Peptídeos/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/tratamento farmacológico , Hipocampo/metabolismo , Hipocampo/efeitos dos fármacos , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/metabolismo , Transtornos da Memória/etiologia , Aprendizagem em Labirinto/efeitos dos fármacosRESUMO
Diabetic neuropathy (DN) is a common complication of long-lasting type 1 and type 2 diabetes, with no curative treatment available. Here, we tested the effect of the incretin mimetic liraglutide in DN in mice with early-stage type 1 diabetes bred in a standard laboratory or enriched environment. With a single i.p. injection of streptozotocin 150 mg/kg, we induced murine diabetes. Liraglutide (0.4 mg/kg once daily, i.p. for ten days since the eighth post-streptozotocin day) failed to decrease the glycemia in the diabetic mice; however, it alleviated their antinociceptive behavior, as tested with formalin. The second phase of the formalin test had significantly lower results in liraglutide-treated mice reared in the enriched environment vs. liraglutide-treated mice under standard conditions [2.00 (0.00-11.00) vs. 29.00 (2.25-41.50) s, p = 0.016]. Liraglutide treatment, however, decreased the threshold of reactivity in the von Fray test. A significantly higher neopterin level was demonstrated in the diabetic control group compared to treatment-naïve controls and the liraglutide-treated diabetic mice (p < 0.001). The glutamine/glutamate ratio in both liraglutide-treated groups, either reared under standard conditions (p = 0.003) or an enriched environment (p = 0.002), was significantly higher than in the diabetic controls. This study demonstrates an early liraglutide effect on pain sensation in two streptozotocin-induced diabetes mouse models by reducing some inflammatory and oxidative stress parameters.
Assuntos
Diabetes Mellitus Experimental , Neuropatias Diabéticas , Ácido Glutâmico , Glutamina , Liraglutida , Neopterina , Animais , Liraglutida/farmacologia , Liraglutida/uso terapêutico , Camundongos , Neuropatias Diabéticas/tratamento farmacológico , Neuropatias Diabéticas/metabolismo , Neuropatias Diabéticas/etiologia , Glutamina/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Masculino , Ácido Glutâmico/metabolismo , Neopterina/metabolismo , Estreptozocina , Analgésicos/farmacologia , Analgésicos/uso terapêuticoRESUMO
(1) Background: The aim of the work is the evaluation of in vitro antiproliferative and pro-apoptotic activity of four benzimidazole derivatives containing colchicine-like and catechol-like moieties with methyl group substitution in the benzimidazole ring against highly invasive breast cancer cell line MDA-MB-231 and their related impairment of tubulin dynamics. (2) Methods: The antiproliferative activity was assessed with the MTT assay. Alterations in tubulin polymerization were evaluated with an in vitro tubulin polymerization assay and a docking analysis. (3) Results: All derivatives showed time-dependent cytotoxicity with IC50 varying from 40 to 60 µM after 48 h and between 13 and 20 µM after 72 h. Immunofluorescent and DAPI staining revealed the pro-apoptotic potential of benzimidazole derivatives and their effect on tubulin dynamics in living cells. Compound 5d prevented tubulin aggregation and blocked mitosis, highlighting the importance of the methyl group and the colchicine-like fragment. (4) Conclusions: The benzimidazole derivatives demonstrated moderate cytotoxicity towards MDA-MB-231 by retarding the initial phase of tubulin polymerization. The derivative 5d containing a colchicine-like moiety and methyl group substitution in the benzimidazole ring showed potential as an antiproliferative agent and microtubule destabilizer by facilitating faster microtubule aggregation and disrupting cellular and nuclear integrity.
Assuntos
Antineoplásicos , Apoptose , Neoplasias da Mama , Hidrazonas , Tubulina (Proteína) , Feminino , Humanos , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Benzimidazóis/farmacologia , Benzimidazóis/química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Hidrazonas/química , Hidrazonas/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Polimerização , Relação Estrutura-Atividade , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/farmacologia , Moduladores de Tubulina/químicaRESUMO
Aging and neurodegenerative diseases share common hallmarks, including mitochondrial dysfunction and protein aggregation. Moreover, one of the major issues of the demographic crisis today is related to the progressive rise in costs for care and maintenance of the standard living condition of aged patients with neurodegenerative diseases. There is a divergence in the etiology of neurodegenerative diseases. Still, a disturbed endogenous pro-oxidants/antioxidants balance is considered the crucial detrimental factor that makes the brain vulnerable to aging and progressive neurodegeneration. The present review focuses on the complex relationships between oxidative stress, autophagy, and the two of the most frequent neurodegenerative diseases associated with aging, Alzheimer's disease (AD) and Parkinson's disease (PD). Most of the available data support the hypothesis that a disturbed antioxidant defense system is a prerequisite for developing pathogenesis and clinical symptoms of ADs and PD. Furthermore, the release of the endogenous hormone melatonin from the pineal gland progressively diminishes with aging, and people's susceptibility to these diseases increases with age. Elucidation of the underlying mechanisms involved in deleterious conditions predisposing to neurodegeneration in aging, including the diminished role of melatonin, is important for elaborating precise treatment strategies for the pathogenesis of AD and PD.
Assuntos
Doença de Alzheimer , Melatonina , Doenças Neurodegenerativas , Doença de Parkinson , Humanos , Idoso , Antioxidantes/metabolismo , Melatonina/uso terapêutico , Doença de Parkinson/tratamento farmacológico , Doença de Alzheimer/metabolismo , Estresse Oxidativo , Envelhecimento/metabolismo , Doenças Neurodegenerativas/metabolismo , Fatores de RiscoRESUMO
Endothelial cells are constantly exposed to environmental stress factors that, above a certain threshold, trigger cellular senescence and apoptosis. The altered vascular function affects new vessel formation and endothelial fitness, contributing to the progression of age-related diseases. This narrative review highlights the complex interplay between senescence, oxidative stress, extracellular vesicles, and the extracellular matrix and emphasizes the crucial role of angiogenesis in aging and Alzheimer's disease. The interaction between the vascular and nervous systems is essential for the development of a healthy brain, especially since neurons are exceptionally dependent on nutrients carried by the blood. Therefore, anomalies in the delicate balance between pro- and antiangiogenic factors and the consequences of disrupted angiogenesis, such as misalignment, vascular leakage and disturbed blood flow, are responsible for neurodegeneration. The implications of altered non-productive angiogenesis in Alzheimer's disease due to dysregulated Delta-Notch and VEGF signaling are further explored. Additionally, potential therapeutic strategies such as exercise and caloric restriction to modulate angiogenesis and vascular aging and to mitigate the associated debilitating symptoms are discussed. Moreover, both the roles of extracellular vesicles in stress-induced senescence and as an early detection marker for Alzheimer's disease are considered. The intricate relationship between endothelial senescence and angiogenesis provides valuable insights into the mechanisms underlying angiogenesis-related disorders and opens avenues for future research and therapeutic interventions.
Assuntos
Doença de Alzheimer , Humanos , Células Endoteliais , Envelhecimento , Senescência Celular , Estresse OxidativoRESUMO
We synthesized a series of novel indole compounds containing aroylhydrazone moieties and evaluated them in mice to check their anticonvulsant activity. In the present study the most potent C3-modified derivative 3e, containing 2-furyl fragment was evaluated in kainate (KA)-induced status epilepticus (SE) and the consequences on oxidative stress and inflammation in the hippocampus in mice were explored. Melatonin was used as positive control while the melatonin receptor antagonist Luzindol was studied alone or in combination with melatonin or 3e, respectively. After intraperitoneal (i.p.) pre-treatment with melatonin 3e, Luzindol + melatonin and Luzindol + 3e for 7 days (melatonin and 3e-30 mg kg-1 or 60 mg kg-1, Luzindol 10 mg kg-1) the animals were i.p. injected with KA (30 mg kg-1, i.p.). The 3e decreased the SE-induced seizure intensity while melatonin suppressed seizures at the higher dose of 60 mg kg-1. Luzindol blocked the anticonvulsant effect of both Mel and 3e. The dose-dependent antioxidant effect of 3e measured by reduced glutathione (GSH) and total GSH in the hippocampus, was comparable to the effect of melatonin. Luzindol fully blocked the effect of melatonin but affected partially the antioxidant activity of 3e. The KA-induced increased amplifier of neuroinflammation high-mobility group box protein 1 (HMGB1) was neither alleviated by melatonin, nor by 3e. The activation by this DNA-binding protein receptor for advanced glycation end products (RAGE) was not affected by SE, melatonin and 3e pre-treatment. Our results suggest that the novel indole derivate 3e, containing 2-furyl fragment, might be clinically useful as an adjunct therapy against SE and concomitant oxidative stress.
Assuntos
Melatonina , Estado Epiléptico , Animais , Anti-Inflamatórios/farmacologia , Anticonvulsivantes/efeitos adversos , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Hipocampo/metabolismo , Ácido Caínico/toxicidade , Melatonina/metabolismo , Melatonina/farmacologia , Melatonina/uso terapêutico , Camundongos , Estresse Oxidativo , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/tratamento farmacológico , Estado Epiléptico/metabolismoRESUMO
The hallmark of aging is an organism's difficulty to maintain proper homeostasis, leading to a disrupted balance between the endogenous antioxidant system and the production of free radicals, a progressive inflammatory process, and increased susceptibility to (neurodegenerative diseases [...].
Assuntos
Antioxidantes , Doenças Neurodegenerativas , Humanos , Antioxidantes/farmacologia , Radicais Livres , HomeostaseRESUMO
The pineal gland regulates the aging process via the hormone melatonin. The present report aims to evaluate the effect of pinealectomy (pin) on behavioral and oxidative stress-induced alterations in cholesterol and sphingomyelin (SM) levels in young adult, mature and aging rats. Sham and pin rats aged 3, 14 and 18 months were tested in behavioral tests for motor activity, anxiety, and depression. The ELISA test explored oxidative stress parameters and SM in the hippocampus, while total cholesterol was measured in serum via a commercial autoanalyzer. Mature and aged sham rats showed low motor activity and increased anxiety compared to the youngest rats. Pinealectomy affected emotional responses, induced depressive-like behavior, and elevated cholesterol levels in the youngest rats. However, removal of the pineal gland enhanced oxidative stress by diminishing antioxidant capacity and increasing the MDA level, and decreased SM level in the hippocampus of 14-month-old rats. Our findings suggest that young adult rats are vulnerable to emotional disturbance and changes in cholesterol levels resulting from melatonin deficiency. In contrast, mature rats with pinealectomy are exposed to an oxidative stress-induced decrease in SM levels in the hippocampus.
Assuntos
Melatonina , Glândula Pineal , Animais , Emoções , Melatonina/farmacologia , Estresse Oxidativo , Glândula Pineal/fisiologia , Glândula Pineal/cirurgia , Ratos , EsfingomielinasRESUMO
One of the pathological hallmarks of Alzheimer's disease (AD) associated with its progression that contributes to ß-amyloid (Aß) generation is oxidative stress (OS). Clinical data suggest that melatonin is a potent antioxidant that might be effective in the adjunctive therapy of this neurodegenerative disease. The present study aimed to explore the role of melatonin on behavioral changes and markers of OS in three rat models, namely, pinealectomy (pin) model of melatonin deficit, intracerebroventricular (icv)Aß1-42 model of AD, and combination of both pin and Aß1-42 model (pin+icvAß1-42). The chronic injection with vehicle/melatonin (50 mg/kg, i.p. for 40 days) started on the same day of sham/pin and icv vehicle/Aß1-42 infusion procedures. Anxiety in the open field and the elevated plus-maze test and cognitive responses in the object recognition test were tested between the 30th-35th day after the surgical procedures. Markers of OS in the frontal cortex (FC) and hippocampus were detected by the ELISA method. Melatonin treatment corrected the exacerbated anxiety response only in the pin+icvAß1-42 model while it alleviated the cognitive impairment in the three models. Pinealectomy disturbed the antioxidant system via enhanced SOD activity and decreased GSH levels both in the FC and hippocampus. The Aß1-42 model decreased the SOD activity in the FC and elevated the MDA level in the two brain structures. The pin+icvAß1-42 model impaired the antioxidant system and elevated lipid peroxidation. Melatonin supplementation restored only the elevated MDA level of icvAß1-42 and pin+icvAß1-42 model in the hippocampus. In conclusion, our study reveals that the pin+icvAß1-42 rat model triggers more pronounced anxiety and alterations in markers of OS that may be associated with melatonin deficit concomitant to icvAß1-42-induced AD pathology.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/toxicidade , Disfunção Cognitiva/tratamento farmacológico , Melatonina/farmacologia , Transtornos da Memória/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Pinealectomia/efeitos adversos , Doença de Alzheimer/etiologia , Doença de Alzheimer/patologia , Animais , Antioxidantes/farmacologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/patologia , Modelos Animais de Doenças , Masculino , Aprendizagem em Labirinto , Transtornos da Memória/etiologia , Transtornos da Memória/patologia , Ratos , Ratos Sprague-DawleyRESUMO
Based on the pharmacophore model of melatonin (MT1) receptor, we recently synthesized a series of indole derivatives that showed anticonvulsant activity with low neurotoxicity and hepatotoxicity in rodents. In the present study, the three most potent C3-modified derivatives with hydrazine structure 3c, 3e, and 3f, with 2-chlorophenyl, 2-furyl, and 2-thienyl fragments, respectively, were selected, and their neurobiological activity was explored in mice. In Experiment #1, the dose-dependent anxiolytic effect of a single i.p. administration of the novel compounds at doses of 10, 30, and 60 mg/kg were studied in the open field (OF) test. In Experiment#2, the analgesic effect of 3c, 3e, and 3f (30-100 mg/kg) was tested in the hot plate test and formalin test. Experiment#3 was designed to assess the antidepressant-like activity of 3c, 3e, and 3f (10-60 mg/kg). The forced swimming test (FST) and tail suspension test (TST)-induced effect on markers of oxidative stress in the frontal cortex (FC), and the hippocampus was evaluated. Melatonin was used in the same doses as melatonin analogs in all three experiments as a positive control. Desipramine (10 mg/kg) was also applied as a control in the FST. The three melatonin analogs bearing hydrazide/hydrazone substitution at 3C of the indol scaffold demonstrated improved antidepressant-like activity compared to the melatonin. The tested substances are devoided of anxiolytic effects. The antioxidant activity of the melatonin analogs and analgesic potential is comparable to that of melatonin. The 3C substitution with hydrazide/hydrazone moiety substantially contributes to the antidepressant and antioxidant activity of the melatonin analogs.
RESUMO
Betulinic acid (BA) is a natural pentacyclic triterpene with diverse biological activities. However, its low water solubility limits its pharmaceutical application. The conversion of pharmaceutically active molecules into ionic liquids (ILs) is a promising strategy to improve their physicochemical properties, stability, and/or potency. Here, we report the synthesis and characterization of 15 novel ILs containing a cation ethyl ester of a polar, non-polar, or charged amino acid [AAOEt] and an anion BA. Except for [ValOEt][BA], we observed preserved or up to 2-fold enhanced cytotoxicity toward hormone-dependent breast cancer cells MCF-7. The estimated IC50 (72 h) values within the series varied between 4.8 and 25.7 µM. We found that the most cytotoxic IL, [LysOEt][BA]2, reduced clonogenic efficiency to 20% compared to that of BA. In addition, we evaluated the effect of a 72 h treatment with BA or [LysOEt][BA]2, the most cytotoxic compound, on the thermodynamic behavior of MCF-7 cells. Based on our data, we suggest that the charged amino acid lysine included in the novel ILs provokes cytotoxicity by a mechanism involving alteration in membrane lipid organization, which could be accompanied by modulation of the visco-elastic properties of the cytoplasm.
RESUMO
Herein we report on the synthesis and sensor activity of a novel pH sensitive probe designed as highly water-soluble fluorescent micelles by grafting of 1,8-naphthalimide-rhodamine bichromophoric FRET system (RNI) to the PMMA block of a well-defined amphiphilic diblock copolymer-poly(methyl methacrylate)-b-poly(methacrylic acid) (PMMA48-b-PMAA27). The RNI-PMMA48-b-PMAA27 adduct is capable of self-assembling into micelles with a hydrophobic PMMA core, containing the anchored fluorescent probe, and a hydrophilic shell composed of PMAA block. Novel fluorescent micelles are able to serve as a highly sensitive pH probe in water and to internalize successfully HeLa and HEK cells. Furthermore, they showed cell specificity and significantly higher photostability than that of a pure organic dye label such as BODIPY. The valuable properties of the newly prepared fluorescent micelles indicate the high potential of the probe for future biological and biomedical applications.
Assuntos
Corantes Fluorescentes/química , Micelas , Nanopartículas/química , Sobrevivência Celular/efeitos dos fármacos , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Células HEK293 , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Naftalimidas/síntese química , Naftalimidas/química , Ácidos Polimetacrílicos/síntese química , Ácidos Polimetacrílicos/química , Ácidos Polimetacrílicos/toxicidade , Rodaminas/síntese química , Rodaminas/química , Água/químicaRESUMO
BACKGROUND: Common butterbur (Petasites hybridus L.) is a traditional medicinal plant with numerous therapeutic properties among which is its recently uncovered anti-tumor activity. The present study aims to examine the activity of a standardized Bulgarian Petasites hybridus L. root extract, containing the active ingredients petasins, on the human breast cancer cell line MDA-MB-231 and non-cancerous MCF-10A cells. Specifically, we examined cell death, oxidative stress, and nuclear factor kappa-B (NF-κB) signaling. METHODS: A standardized butterbur powdered extract containing a minimum of 15% petasins was used. A lipophilic extract was obtained from subterranean portion of the plant of Bulgarian populations of Petasites hybridus using liquid-liquid extraction after completely removing pyrrolizidine alkaloids. The induction of apoptosis and necrosis was analyzed by flow cytometry, and oxidative stress biomarkers and NF-κB were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: Petasites hybridus L. root extract triggered apoptosis in a cancer-specific fashion and induced a moderate oxidative stress characterized by diminished glutathione (GSH) levels and elevated malondialdehyde (MDA) levels in MDA-MB-231 72 h after treatment. NF-κB levels were higher in cancer cells after treatment with IC50 and IC75 doses, this suggested that the NF-κB pathway was activated in response to oxidative stress leading to the induction of apoptosis. MCF-10A cells were affected to a lesser extent by the Petasites hybridus extract, and the adaptive response of their antioxidant defense system halted oxidative stress. CONCLUSIONS: Overall, these results indicate that Petasites hybridus L. root extract selectively acts as a pro-oxidant in breast cancer cells and thus represents a potential therapeutic option for cancer treatment with fewer side effects.
Assuntos
Neoplasias da Mama , Petasites , Humanos , Feminino , Espécies Reativas de Oxigênio , NF-kappa B , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/induzido quimicamente , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Apoptose , Linhagem CelularRESUMO
In light of the known neuroprotective properties of indole compounds and the promising potential of hydrazone derivatives, two series of aldehyde-heterocyclic hybrids combining those pharmacophores were synthesized as new multifunctional neuroprotectors. The obtained derivatives of indole-3-propionic acid (IPA) and 5-methoxy-indole carboxylic acid (5MICA) had good safety profiles: Hemolytic effects < 5% (200 µM) and IC50 > 150 µM were found in the majority of the SH-SY5Y and bEnd3 cell lines. The 2,3-dihydroxy, 2-hydroxy-4-methoxy, and syringaldehyde derivatives of 5MICA exhibited the strongest neuroprotection against H2O2-induced oxidative stress in SH-SY5Y cells and 6-OHDA-induced neurotoxicity in rat-brain synaptosomes. All the compounds suppressed the iron-induced lipid peroxidation. The hydroxyl derivatives were also the most active in terms of deoxyribose-degradation inhibition, whereas the 3,4-dihydroxy derivatives were able to decrease the superoxide-anion generation. Both series of compounds showed an increased inhibition of hMAO-B, with greater expression detected in the 5MICA hybrids. The in vitro BBB model with the bEnd3 cell line showed that some compounds increased the permeability of the endothelial monolayer while maintaining the tight junctions. The combined results demonstrated that the derivatives of IPA and 5MICA showed strong neuroprotective, antioxidant, MAO-B inhibitory activity and could be considered as prospective multifunctional compounds for the treatment of neurodegenerative disorders.
RESUMO
Fluorescent micellar carriers with controlled release of a novel anticancer drug were developed to enable intracellular imaging and cancer treatment simultaneously. The nanosized fluorescent micellar systems were embedded with a novel anticancer drug via the self-assembling behavior of well-defined block copolymers based on amphiphilic poly(acrylic acid)-block-poly(n-butyl acrylate) (PAA-b-PnBA) copolymer obtained by Atom Transfer Radical Polymerization (ATRP) and hydrophobic anticancer benzimidazole-hydrazone drug (BzH). Through this method, well-defined nanosized fluorescent micelles were obtained consisting of a hydrophilic PAA shell and a hydrophobic PnBA core embedded with the BzH drug due to the hydrophobic interactions, thus reaching very high encapsulation efficiency. The size, morphology, and fluorescent properties of blank and drug-loaded micelles were investigated using dynamic light scattering (DLS), transmission electron microscopy (TEM), and fluorescent spectroscopy, respectively. Additionally, after 72 h of incubation, drug-loaded micelles released 3.25 µM of BzH, which was spectrophotometrically determined. The BzH drug-loaded micelles were found to exhibit enhanced antiproliferative and cytotoxic effects on MDA-MB-231 cells, with long-lasting effects on microtubule organization, with apoptotic alterations and preferential localization in the perinuclear space of cancer cells. In contrast, the antitumor effect of BzH alone or incorporated in micelles on non-cancerous cells MCF-10A was relatively weak.
RESUMO
BACKGROUND: Recently electroporation using biphasic pulses was successfully applied in clinical developments for treating tumours in humans and animals. We evaluated the effects of electrical treatment on cell adhesion behaviour of breast cancer cells and fibroblasts. By applying bipolar electrical pulses we studied short- and long-lived effects on cell adhesion and survival, actin cytoskeleton and cell adhesion contacts in adherent cancer cells and fibroblasts. METHODS: Two cancer cell lines (MDA-MB-231 and MCF-7) and one fibroblast cell line 3T3 were used. Cells were exposed to high field intensity (200 - 1000 V/cm). Cell adhesion and survival after electrical exposure were studied by crystal violet assay and MTS assay. Cytoskeleton rearrangement and cell adhesion contacts were visualized by actin staining and fluorescent microscope. RESULTS: The degree of electropermeabilization of the adherent cells elevated steadily with the increasing of the field intensity. Adhesion behaviour of fibroblasts and MCF-7 was not significantly affected by electrotreatment. Interestingly, treating the loosely adhesive cancer cell line MDA-MB-231 with 200 V/cm and 500 V/cm resulted in increased cell adhesion. Cell replication of both studied cancer cell lines was disturbed after electropermeabilization. Electroporation influenced the actin cytoskeleton in cancer cells and fibroblasts in different ways. Since it disturbed temporarily the actin cytoskeleton in 3T3 cells, in cancer cells treated with lower and middle field intensity actin cytoskeleton was well presented in stress fibers, filopodia and lamellipodia. The electrotreatment for cancer cells provoked preferentially cell-cell adhesion contacts for MCF-7 and cell-ECM contacts for MDA-MB- 231. CONCLUSIONS: Cell adhesion and survival as well as the type of cell adhesion (cell-ECM or cell-cell adhesion) induced by the electroporation process is cell specific. The application of suitable electric pulses can provoke changes in the cytoskeleton organization and cell adhesiveness, which could contribute to the restriction of tumour invasion and thus leads to the amplification of anti-tumour effect of electroporation-based tumour therapy.
RESUMO
Alkylphospholipids are a novel class of antineoplastic drugs showing remarkable therapeutic potential. Among them, erufosine (EPC3) is a promising drug for the treatment of several types of tumors. While EPC3 is supposed to exert its function by interacting with lipid membranes, the exact molecular mechanisms involved are not known yet. In this work, we applied a combination of several fluorescence microscopy and analytical chemistry approaches (i.e., scanning fluorescence correlation spectroscopy, line-scan fluorescence correlation spectroscopy, generalized polarization imaging, as well as thin layer and gas chromatography) to quantify the effect of EPC3 in biophysical models of the plasma membrane, as well as in cancer cell lines. Our results indicate that EPC3 affects lipid-lipid interactions in cellular membranes by decreasing lipid packing and increasing membrane disorder and fluidity. As a consequence of these alterations in the lateral organization of lipid bilayers, the diffusive dynamics of membrane proteins are also significantly increased. Taken together, these findings suggest that the mechanism of action of EPC3 could be linked to its effects on fundamental biophysical properties of lipid membranes, as well as on lipid metabolism in cancer cells.
Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/metabolismo , Microdomínios da Membrana/efeitos dos fármacos , Organofosfatos/farmacologia , Compostos de Amônio Quaternário/farmacologia , Feminino , Humanos , Bicamadas Lipídicas/química , Células MCF-7 , Fluidez de Membrana , Lipídeos de Membrana/química , Microdomínios da Membrana/ultraestruturaRESUMO
A series of Zn-doped hybrid materials based on silica from tetraethoxysilane (TEOS) and hydroxypropyl cellulose (HPC) were prepared by a sol-gel route. The structure, morphology and thermal behavior of synthesized hybrids were characterized by infrared (IR) spectroscopy, ultraviolet-visible spectroscopy (UV-Vis), transmission electron microscopy (TEM) and differential thermal analysis with thermogravimetric analysis (DTA/TG). The obtained materials were investigated for a potential biomedical application. The antibacterial properties of hybrids were investigated by measuring the inhibition zones formed around the materials containing different zinc content in presence of reference strains of Gram-positive and Gram-negative bacteria. The biocompatibility tests showed no cytotoxicity and genotoxicity, as well as no changes in actin cytoskeleton organization for hybrids with Zn content below 5â¯wt%.