RESUMEN
Data on the participation of microbiota in the development of Parkinson's disease allow us to discuss the ability of bacterial preparations to influence the processes leading to neurodegeneration. We studied the effect of oral administration of Limosilactobacillus fermentum U-21 lyophilisate on a model of Parkinson's disease in rats induced by combined intranigral injection of LPS and systemic administration of paraquat. The toxins significantly increased the number of missteps in the "narrowing beam walking" test, but a tendency to a decrease in this parameter was shown after treatment with U-21. It should be noted that U-21 did not reduce the neuronal death in the substantia nigra, but mitigated the inflammatory glial response, decreased the accumulation of phosphorylated α-synuclein and complement protein C3. Our study demonstrated the efficiency of the combined model of parkinsonism and reduction of proinflammatory changes under the influence of pharmabiotic without changes in the nigral neuronal death and motor deficits.
Asunto(s)
Modelos Animales de Enfermedad , Lipopolisacáridos , Sustancia Negra , alfa-Sinucleína , Animales , Ratas , alfa-Sinucleína/metabolismo , Masculino , Sustancia Negra/efectos de los fármacos , Sustancia Negra/metabolismo , Sustancia Negra/patología , Lipopolisacáridos/farmacología , Lipopolisacáridos/toxicidad , Paraquat , Enfermedad de Parkinson/patología , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo , Ratas Wistar , Complemento C3/metabolismo , Enfermedades Neuroinflamatorias/patología , Enfermedades Neuroinflamatorias/tratamiento farmacológicoRESUMEN
We performed a comparative assessment of the immunohistochemical distribution of markers of mitochondrial fission (Drp-1), mitochondrial fusion (Mfn-2), and mitochondrial biogenesis (PGC-1α) in pyramidal neurons of different zones of the hippocampus in mice with intrahippocampal administration of ß-amyloid peptide 25-35. The most pronounced changes in the dynamics associated with a decrease in the amount of the fission marker and an increase in the amount of the fusion marker were observed in the CA3 field on day 38 after peptide administration. In the CA1 field, a significant decrease in the marker of mitochondrial biogenesis PGC-1α was found on day 38, which can indicate a decrease in the intensity of mitochondrial biogenesis. Early mitochondrial changes can play an important role in the pathogenesis of all types of memory impairment in Alzheimer's disease.
Asunto(s)
Enfermedad de Alzheimer , Ratones , Animales , Enfermedad de Alzheimer/metabolismo , Dinámicas Mitocondriales , Hipocampo/metabolismo , Mitocondrias/metabolismo , Péptidos beta-Amiloides/metabolismoRESUMEN
A comparative assessment of the expression of the mitochondrial fission marker Drp1 and the autophagy marker LC3 in neurons and endothelial cells in the hippocampus and entorhinal cortex during progression of cognitive deficit was performed in animals with intrahippocampal administration of ß-amyloid. In both brain regions, the expression of Drp1 and LC3 in neuronal and endothelial cells was enhanced. The peak of cognitive impairment corresponded to the maximum expression of Drp1 and LC3 in hippocampal neurons and was preceded by an increase in the number of Drp1+ and LC3+ endothelial cells in this brain region. These data attests to a possible role of aberrant mitochondrial dynamics and autophagy of endothelial cells in the impairment of brain plasticity in the Alzheimer's type neurodegeneration.
Asunto(s)
Enfermedad de Alzheimer , Autofagia , Encéfalo , Mitocondrias , Neuronas , Animales , Ratones , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Modelos Animales de Enfermedad , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Encéfalo/metabolismo , Células Endoteliales/metabolismo , Neuronas/metabolismo , Precursor de Proteína beta-Amiloide/metabolismoRESUMEN
Sixty and 90 days after unilateral intranigral injection of LPS to Wistar rats (10 µg), activation of microglia, neuronal death, and formation of synuclein-positive inclusions were observed in the substantia nigra, but not in dopaminergic neurons. Astrocytes were characterized by increased expression of gliofibrillary protein GFAP, vimentin, complement protein C3, aquaporin-4, and connexin-43. At later stages, GFAP expression decreased, but the distribution of aquaporin-4 and connexin-43 remained disordered, and neuronal degeneration deteriorated. Thus, reactive changes in astrocytes after LPS administration can cause long-term disturbances of the neurogliovascular coupling. The observed functional and morphological alterations in the astroglia can be the cause of progressive disturbances in the substantia nigra.
Asunto(s)
Acuaporinas , Enfermedad de Parkinson , Ratas , Animales , Enfermedad de Parkinson/metabolismo , Ratas Wistar , Lipopolisacáridos/metabolismo , Proteína Ácida Fibrilar de la Glía/metabolismo , Sustancia Negra/metabolismo , Microglía/metabolismo , Neuronas Dopaminérgicas/metabolismo , Acuaporinas/metabolismo , Conexinas/metabolismoRESUMEN
Transplantation of a mixed astrocyte and neuron culture is of interest in the development of cell therapies for neurodegenerative diseases. In this case, an assessment of engraftment requires a detailed morphological characterization, in particular an analysis of the neuronal and glial populations. In the experiment performed, human iPSC-derived neural progenitors transplanted into a rat striatum produced a mixed neuron and astrocyte population in vivo by the sixth month after transplantation. The morphological characteristics and neurochemical profile of the xenografted astrocytes were similar to those of mature human astroglia. Unlike neurons, astrocytes migrated to the surrounding structures and the density and pattern of their distribution in the striatum and cerebral cortex differed, which indicates that the microenvironment affects human glia integration. The graft was characterized by the zonal features of glial cell morphology, which was a reflection of cell maturation in the central area, glial shaft formation around the transplanted neurons, and migration to the surrounding structures.
RESUMEN
The damage to the enteric nervous system structures and the localization of total and phosphorylated α-synuclein, the main pathomorphological marker of parkinsonism, were studied by immunomorphological methods on small intestine wholemounts from rats with parkinsonism induced by systemic administration of paraquat. Reduced density of neurons in the myenteric ganglia and degenerative changes with accumulation of phosphorylated α-synuclein in sympathetic afferents to the small intestine were revealed. Phosphorylated α-synuclein was also found in non-neuronal cells located outside the ganglia. The revealed changes presumably reflect the initial stage of spreading of the pathological process during the development of Parkinson's disease.
Asunto(s)
Sistema Nervioso Entérico , Enfermedad de Parkinson , Trastornos Parkinsonianos , Animales , Sistema Nervioso Entérico/patología , Intestino Delgado/patología , Neuronas/patología , Enfermedad de Parkinson/patología , Trastornos Parkinsonianos/inducido químicamente , RatasRESUMEN
One of the most common models of sporadic form of Alzheimer's disease is injection of streptozotocin into the lateral ventricles of rat brain. In 3 months after this injection, an increase in the expression of astroglia in the corpus callosum and a decrease in the thickness of the corpus callosum and intensity of its staining with luxol fast blue were observed. This can reflect a decrease in the content of myelinated fibers. In layer V of the sensorimotor cortex, intensive degeneration of neurons was revealed. The lateral ventricles were significantly enlarged and the expression of PSA-NCAM protein, a marker of immature neurons, was reduced in subventricular zone, which can be associated with disturbed neurogenesi.
Asunto(s)
Enfermedad de Alzheimer/patología , Astrocitos/patología , Cuerpo Calloso/patología , Ventrículos Laterales/patología , Fibras Nerviosas Mielínicas/patología , Corteza Sensoriomotora/patología , Enfermedad de Alzheimer/inducido químicamente , Enfermedad de Alzheimer/metabolismo , Animales , Astrocitos/metabolismo , Biomarcadores/metabolismo , Cuerpo Calloso/metabolismo , Modelos Animales de Enfermedad , Expresión Génica , Indoles , Inyecciones Intraventriculares , Ventrículos Laterales/metabolismo , Masculino , Fibras Nerviosas Mielínicas/metabolismo , Molécula L1 de Adhesión de Célula Nerviosa/genética , Molécula L1 de Adhesión de Célula Nerviosa/metabolismo , Neuronas/metabolismo , Neuronas/patología , Ratas , Ratas Wistar , Corteza Sensoriomotora/metabolismo , Ácidos Siálicos/genética , Ácidos Siálicos/metabolismo , Técnicas Estereotáxicas , Estreptozocina/administración & dosificaciónRESUMEN
We assessed changes of olfactory bulbs in rata with 6-hydroxydopamine destruction of the substantia nigra. The expression of marker proteins of immature and differentiated neurons and glia (vimentin, PSA-NCAM, tyrosine hydroxylase, and S100) was analyzed by immunohistochemical and morphometric methods. The number of periglomerular dopamine neurons and astroglia in the olfactory bulbs increased on the side of toxin injection and expression of PSA-NCAM and vimentin increased in the rostral migratory stream. Destruction of the substantia nigra shifted differentiation of neuronal progenitors towards the dopaminergic phenotype and increased their survival in the olfactory bulbs, which can be explained by increased expression of PSA-NCAM.
Asunto(s)
Neuroglía/patología , Neuronas/patología , Bulbo Olfatorio/patología , Enfermedad de Parkinson Secundaria/patología , Sustancia Negra/patología , Adaptación Fisiológica , Animales , Biomarcadores/metabolismo , Modelos Animales de Enfermedad , Expresión Génica , Humanos , Inmunohistoquímica , Inyecciones Intraventriculares , Masculino , Actividad Motora/fisiología , Molécula L1 de Adhesión de Célula Nerviosa/genética , Molécula L1 de Adhesión de Célula Nerviosa/metabolismo , Neuroglía/metabolismo , Neuronas/metabolismo , Bulbo Olfatorio/metabolismo , Oxidopamina/administración & dosificación , Enfermedad de Parkinson Secundaria/inducido químicamente , Enfermedad de Parkinson Secundaria/genética , Enfermedad de Parkinson Secundaria/metabolismo , Ratas , Ratas Wistar , Proteínas S100/genética , Proteínas S100/metabolismo , Ácidos Siálicos/genética , Ácidos Siálicos/metabolismo , Técnicas Estereotáxicas , Sustancia Negra/metabolismo , Tirosina 3-Monooxigenasa/genética , Tirosina 3-Monooxigenasa/metabolismo , Vimentina/genética , Vimentina/metabolismoRESUMEN
BACKGROUND: In recent years the theme of the relationship of Alzheimers disease (AD) and metabolic disorders has been widely discussed. Nevertheless, it remains unclear whether AD is a direct cause of carbohydrate metabolism disorders or it is the presence of classical risk factors for type 2 diabetes mellitus (DM 2), primarily obesity, that significantly increases the risk of AD. AIM: To evaluate the separate contribution of two factors to the development of disorders of carbohydrate metabolism: (1) weight gain due to a high-calorie diet and (2) experimental-induced AD. METHODS: Male Wistar rats were injected with streptozocin (STZ) in the lateral ventricles of the brain to induce AD or saline (sham operated animals - SO) during stereotactic operations. After 2 weeks, the animals were divided into four groups: 1) the SO group, which was assigned to the normal calorie (NCD) diet (SO NCD); 2) the SO group, which was assigned to the high-calorie diet (SO HCD); 3) the group to which the norm-calorie diet was prescribed after the administration of STZ into the lateral ventricles of the brain (STZ NCD); 4) the group to which the HCD was assigned after the administration of STZ (STZ HCD). The animals were on a diet for 3 months. Intraperitoneal glucose tolerance tests were carried out before the diet and after 3 months. At the end of the study, a morphological assessment of brain tissue, pancreas, and liver was performed. RESULTS: 3 months after surgical interventions and the appointment of diets, the glycemic curves significantly differed in the 4 studied groups: normoglycemia persisted only in the SO + NCD group, while HCD and the STZ administration were accompanied by the development of hyperglycemia (p = 0.0001). The STZ + NСD group, which represented the isolated effect of AD, was also characterized by impaired carbohydrate metabolism. A morphological study showed that HCD leads to a more pronounced ectopic accumulation of fat in the liver and pancreas tissue than NCD. The administration of STZ, regardless of the diet, led to changes typical for the AD model an increase in the size of the ventricles of the brain, degeneration of white matter, and the accumulation of -amyloid in the hypothalamus. CONCLUSIONS: The STZ-induced brain damage typical for AD led to impaired carbohydrate metabolism regardless of diet and was an independent risk factor for hyperglycemia.
Asunto(s)
Enfermedad de Alzheimer , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Hiperglucemia , Enfermedad de Alzheimer/inducido químicamente , Animales , Hiperglucemia/inducido químicamente , Masculino , Ratas , Ratas Wistar , Factores de Riesgo , Estreptozocina/efectos adversosRESUMEN
Here we present new approaches to better understanding multidrug resistance (MDR) development in cancer cells, such as identification of components of a complex process of MDR evolution. Recent advances in the studies of MDR are discussed: 1) chemotherapy agents might be involved in the selection of cancer stem cells resulting in the elevated drug resistance and enhanced tumorigenicity; 2) cell-cell interactions have a great effect on the MDR emergence and evolution; 3) mechanotransduction is an important signaling mechanism in cell-cell interactions; 4) proteins of the ABC transporter family which are often involved in MDR might be transferred between cells via microvesicles (epigenetic MDR regulation); 5) proteins providing cell-to-cell transfer of functional P-glycoprotein (MDR1 protein) via microvesicles have been investigated; 6) P-glycoprotein may serve to regulate apoptosis, as well as transcription and translation of target genes/proteins. Although proving once again that MDR is a complex multi-faceted process, these data open new approaches to overcoming it.
Asunto(s)
Resistencia a Múltiples Medicamentos , Neoplasias/patología , Transportadoras de Casetes de Unión a ATP/genética , Transportadoras de Casetes de Unión a ATP/metabolismo , Comunicación Celular/efectos de los fármacos , Resistencia a Antineoplásicos , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/patologíaRESUMEN
Parkinson's disease (PD) is the second most common severe neurodegenerative disorder that is characterized by progressive degeneration of dopaminergic neurons (DA neurons) in the substantia nigra pars compacta (SNpc) region of the brain. In the present study, we investigated the effects of the synthetic regulatory peptides Semax (analog of an ACTH 4-10 fragment (ACTH4-10)) and Selank (analog of immunomodulatory taftsin) on behavior of rats with 6-hydroxidopamine (6-OHDA) induced PD-like parkinsonism. It was showed that both peptides did not affect motor activity of rats in elevated cross shaped maze and passive defensive behavior of the animals. At the same time, Selank decreased level of anxiety of rats with toxic damage of DA neurons in elevated cross shaped maze. Previously such effects of Selank were revealed in healthy rodents (rats and mice) with different models of psycho-emotional stress. Therefore, toxic damage of substantia nigra does not affect the response of the rat organism on this peptide.
Asunto(s)
Enfermedad de Parkinson/tratamiento farmacológico , Trastornos Parkinsonianos/tratamiento farmacológico , Hormona Adrenocorticotrópica/análogos & derivados , Hormona Adrenocorticotrópica/uso terapéutico , Animales , Ansiedad/tratamiento farmacológico , Modelos Animales de Enfermedad , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/metabolismo , Masculino , Oligopéptidos/uso terapéutico , Oxidopamina/toxicidad , Enfermedad de Parkinson/etiología , Trastornos Parkinsonianos/inducido químicamente , Porción Compacta de la Sustancia Negra/efectos de los fármacos , Porción Compacta de la Sustancia Negra/metabolismo , Fragmentos de Péptidos/uso terapéutico , RatasRESUMEN
Glioblastoma multiforme (GBL) is the most common and aggressive brain neoplasm. A standard therapeutic approach for GBL involves combination therapy consisting of surgery, radiotherapy, and chemotherapy. The latter is based on temozolomide (TMZ). However, even by applying such a radical treatment strategy, the mean patient survival time is only 14.6 months. Here we review the molecular mechanisms underlying the resistance of GBL cells to TMZ including genetic and epigenetic mechanisms. Present data regarding a role for genes and proteins MGMT, IDH1/2, YB-1, MELK, MVP/LRP, MDR1 (ABCB1), and genes encoding other ABC transporters as well as Akt3 kinase in developing resistance of GBL to TMZ are discussed. Some epigenetic regulators of resistance to TMZ such as microRNA and EZH2 are reviewed.
Asunto(s)
Antineoplásicos Alquilantes/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Dacarbazina/análogos & derivados , Resistencia a Antineoplásicos , Glioblastoma/tratamiento farmacológico , Animales , Antineoplásicos Alquilantes/química , Antineoplásicos Alquilantes/metabolismo , Barrera Hematoencefálica , Encéfalo/enzimología , Encéfalo/metabolismo , Encéfalo/patología , Neoplasias Encefálicas/enzimología , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Dacarbazina/metabolismo , Dacarbazina/uso terapéutico , Epigénesis Genética , Glioblastoma/enzimología , Glioblastoma/genética , Glioblastoma/terapia , Humanos , TemozolomidaRESUMEN
Glioblastomas (GBL) are the most common and aggressive brain tumors. They are distinguished by high resistance to radiation and chemotherapy. To find novel approaches for GBL classification, we obtained 16 primary GBL cell cultures and tested them with real-time PCR for mRNA expression of several genes (YB-1, MGMT, MELK, MVP, MDR1, BCRP) involved in controlling cell proliferation and drug resistance. The primary GBL cultures differed in terms of proliferation rate, wherein a group of GBL cell cultures with low proliferation rate demonstrated higher resistance to temozolomide. We found that GBL primary cell cultures characterized by high proliferation rate and lower resistance to temozolomide expressed higher mRNA level of the YB-1 and MDR1 genes, whereas upregulated expression of MVP/LRP mRNA was a marker in the group of GBL with low proliferation rate and high resistance. A moderate correlation between expression of YB-1 and MELK as well as YB-1 and MDR1 was found. In the case of YB-1 and MGMT expression, no correlation was found. A significant negative correlation was revealed between mRNA expression of MVP/LRP and MELK, MDR1, and BCRP. No correlation in expression of YB-1 and MVP/LRP genes was observed. It seems that mRNA expression of YB-1 and MVP/LRP may serve as a marker for GBL cell cultures belonging to distinct groups, each of which is characterized by a unique pattern of gene activity.
Asunto(s)
Antineoplásicos Alquilantes/toxicidad , Proliferación Celular/efectos de los fármacos , Dacarbazina/análogos & derivados , Partículas Ribonucleoproteicas en Bóveda/metabolismo , Proteína 1 de Unión a la Caja Y/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Dacarbazina/toxicidad , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Glioblastoma/metabolismo , Glioblastoma/patología , Humanos , Inmunohistoquímica , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Temozolomida , Células Tumorales Cultivadas , Partículas Ribonucleoproteicas en Bóveda/genética , Proteína 1 de Unión a la Caja Y/genéticaRESUMEN
A single intraperitoneal injection to rats of the mitochondria-targeted plastoquinone antioxidant SkQR1 at dose 1 µmol/kg significantly improved reproduction by the rats of the passive avoidance conditional reflex. In vitro experiments on hippocampal slices showed that a single intraperitoneal injection of SkQR1 24 h before the preparation of the slice significantly increases the synaptic transmission efficiency of the pyramidal neurons of the CA1 field. The findings indicate that SkQR1 has a positive effect on memory processes.
Asunto(s)
Memoria/efectos de los fármacos , Mitocondrias/metabolismo , Plastoquinona/análogos & derivados , Células Piramidales/metabolismo , Rodaminas/farmacología , Animales , Masculino , Plastoquinona/farmacología , Células Piramidales/patología , Ratas , Ratas WistarRESUMEN
The goal of this work was to study the mechanisms of ABC family transport proteins' regulation by a new-generation antitumor drug - the proteasome inhibitor bortezomib (Velcade). ABC transporters determine the multidrug resistance of tumor cells (MDR). We confirmed our previously discovered observation that bortezomib affects the expression of genes involved in the formation of MDR (ABCB1 gene, also known as MDR1, and ABCC1-MRP1), reducing the amount of their mRNA. This effect was found to depend on Akt kinase activity: the Akt activity inhibitor Ly 294002 increased the amount of MRP1 mRNA in KB 8-5 cells. It was also shown that bortezomib increased the amount of Akt kinase phosphorylated form in cell lines of malignant cells KB 8-5 and K 562/i-S9 that overexpressed ABCB1 transporter (Pgp), and did not affect the amount of activated Akt in the corresponding wild-type cells. When exposed to bortezomib, selection of resistant to it cell variants was much faster for a Pgp-overexpressing cell population (compared to wild-type cells). It is shown that bortezomib affects the amount of MRP1 gene mRNA, relocating the multifunctional protein YB-1, dependent on Akt activity, from cytoplasm to nuclei of MCF-7 breast cancer cells. The data indicate that the transcriptional activity of YB-1 might be one of the mechanisms that determine the effect of bortezomib on the amount of MRP1 gene mRNA.
Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Ácidos Borónicos/farmacología , Inhibidores Enzimáticos/farmacología , Expresión Génica/efectos de los fármacos , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Inhibidores de Proteasoma , Proteínas Proto-Oncogénicas c-akt/metabolismo , Pirazinas/farmacología , Subfamilia B de Transportador de Casetes de Unión a ATP , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Bortezomib , Línea Celular Tumoral , Humanos , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteína 1 de Unión a la Caja Y/genéticaRESUMEN
Some new data concerning the role of transport proteins of the ABC family in multidrug resistance (MDR) of human tumor cells, and problems connected with regulation of these proteins are considered. MDR is a complex phenomenon that may be caused simultaneously by several mechanisms functioning in one and the same cell. Among them there may be the alterations of activity of several transport proteins. Activation of these proteins may be associated with alterations of activities of different cell protective systems and of the signal transduction pathways involved in regulation of proliferation, differentiation, and apoptosis. Clinical significance of multifactor MDR is discussed.
Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Resistencia a Múltiples Medicamentos , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Animales , Proteínas de Unión al ADN/metabolismo , Humanos , Neoplasias/metabolismo , Transducción de Señal , Células Madre/metabolismo , Células Madre/patologíaRESUMEN
The aim of the present work was to identify the features of the actions of neurotensin on administration into the substantia nigra or dorsal cervical nucleus on the reproduction of passive avoidance reactions in rats. The results showed that the action of neurotensin administered into the substantia nigra was accompanied by sharp reductions in passive avoidance reactions, while administration into the dorsal cervical nucleus, conversely, led to increases in these reactions and slowing of their extinction. The effects of microinjections of the serotonin 5-HT(1A) receptor agonist 8-hydroxydipropylaminotetraline (8-OH-DPAT) into these brain structures were analogous to the effects of neurotensin. The different behavioral effects of administration of neurotensin corresponded to identifiable changes in the levels of serotonin and its metabolite 5-hydroxyindoleacetic acid in the caudate nuclei of the brain. These data led to the conclusion that the effects of neurotensin on passive avoidance behavior are associated with the regulation of the emotional state of the animals via actions on the functions of brain serotoninergic structures.
Asunto(s)
8-Hidroxi-2-(di-n-propilamino)tetralin/farmacología , Reacción de Prevención/fisiología , Neurotensina/fisiología , Receptor de Serotonina 5-HT1A/metabolismo , Agonistas de Receptores de Serotonina/farmacología , Sustancia Negra/fisiología , Animales , Reacción de Prevención/efectos de los fármacos , Núcleo Caudado/efectos de los fármacos , Núcleo Caudado/metabolismo , Vértebras Cervicales , Condicionamiento Clásico/efectos de los fármacos , Condicionamiento Clásico/fisiología , Reacción de Fuga/efectos de los fármacos , Reacción de Fuga/fisiología , Masculino , Microinyecciones , Neurotensina/administración & dosificación , Ratas , Receptor de Serotonina 5-HT1A/efectos de los fármacos , Médula Espinal/efectos de los fármacos , Médula Espinal/fisiología , Sustancia Negra/efectos de los fármacosRESUMEN
Imatinib mesylate (imatinib) is a new generation preparation that is now successfully used for treatment of cancer, particularly for chemotherapy of chronic myeloid leukemia (CML). Imatinib inhibits the activity of chimeric kinase BCR-ABL, which is responsible for the development of CML. The goal of this study was to investigate the role of a multidrug resistance protein, P-glycoprotein (Pgp), in the evolution of CML treated with imatinib. We demonstrate here that although imatinib is a substrate for Pgp, cultured CML cells (strain K562/i-S9), overexpressing active Pgp, do not exhibit imatinib resistance. Studies of CML patients in the accelerated phase have shown variations in the number of Pgp-positive cells (Pgp+) among individual patients treated with imatinib. During treatment of patients with imatinib for 6-12 months, the number of Pgp-positive cells significantly increased in most patients. The high number of Pgp+ cells remained in patients at least for 4.5 years and correlated with active Rhodamine 123 (Rh123) efflux. Such correlation was not found in the group of imatinib-resistant patients examined 35-60 months after onset of imatinib therapy: cells from the imatinib-resistant patients exhibited efficient Rh123 efflux irrespectively of Pgp expression. We also compared the mode of Rh123 efflux by cells from CML patients who underwent imatinib treatment for 6-24 months and the responsiveness of patients to this therapy. There were significant differences in survival of patients depending on the absence or the presence of Rh123 efflux. In addition to Pgp, patients' cells expressed other transport proteins of the ABC family. Our data suggest that treatment with imatinib causes selection of leukemic stem cells characterized by expression of Pgp and other ABC transporters.
Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Antineoplásicos/uso terapéutico , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Piperazinas/uso terapéutico , Pirimidinas/uso terapéutico , Benzamidas , Evolución Biológica , Transporte Biológico , Colorantes Fluorescentes/metabolismo , Humanos , Mesilato de Imatinib , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/mortalidad , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/metabolismo , Rodamina 123/metabolismoRESUMEN
The effects of YB-1 gene on the expression level of P-glycoprotein and drug resistance of tumor cells were studied in cultured HCT116 colon cancer cells. Transitory transfection of chimeric YB-1/GFP gene rendered HCT116 cells a selective advantage in a medium with vinblastine, which caused translocation of the chimeric protein into cell nuclei. This was paralleled by an increase in the expression of P-glycoprotein (multiple drug resistance protein).
Asunto(s)
Resistencia a Múltiples Medicamentos/genética , Resistencia a Antineoplásicos/genética , Proteína 1 de Unión a la Caja Y/fisiología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Línea Celular Tumoral , Núcleo Celular/metabolismo , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Microscopía Fluorescente , Transporte de Proteínas/efectos de los fármacos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Vinblastina/farmacología , Proteína 1 de Unión a la Caja Y/genética , Proteína 1 de Unión a la Caja Y/metabolismoRESUMEN
The multifunctional mammalian protein YB-1 is a member of the large DNA- and RNA-binding protein family with an evolutionarily ancient cold-shock domain. YB-1 is involved in multiple DNA- and mRNA-dependent events and regulates gene expression at various levels. It can be found both in the nucleus and the cytoplasm. Bound to DNA in the cell nucleus, YB-1 functions as a transcription factor interacting with inverted CCAAT-box (Y-box) in promoters and enhancers of multiple genes. In particular, YB-1 regulates activity of the multidrug resistance (MDR) genes MDR1 and LRP. In tumors, YB-1 has been suggested to be an early and global marker of MDR. In this study, we compared amounts of YB-1 mRNAs and intracellular localization of YB-1 protein in six pairs of drug sensitive and drug resistant sublines of diverse tumors. We have shown that neither great increase in the level of YB-1 mRNA nor substantial increase in the number of cells with nuclear localization of YB-1 are obligatory traits of drug resistant tumor cell populations. However, the cells with highest amounts of YB-1 mRNA also demonstrated increased quantities of MDR1, MRP1, BCRP, and LRP mRNAs encoding different MDR proteins. Transfection of two different populations of drug-sensitive cells with YB-1 cDNA led to increase in the amount of YB-1 mRNA. The quantities of MRP1 and LRP mRNAs increased in both populations. Introduction of YB-1 small hairpin RNA (shRNA) resulted in decreased amounts of YB-1 mRNA, as well as MRP1, LRP, and MDR1 mRNAs (in three different cell lines). Our data suggest that although YB-1 regulates several MDR genes, it could not be regarded as a global marker of already formed drug resistant tumor cell populations. It is most likely that at the first steps of MDR development YB-1 activity is necessary for propagation of resistant cell populations rather than for maintenance of drug resistance.