ABSTRACT
Hay muchos factores implicados en la incidencia de la enfermedad de Alzheimer que, en combinación, terminan por impedir o dificultar las funciones neuronales normales. Actualmente, poco se conoce sobre la regulación del calcio, antes de la enfermedad y durante la misma. La inestabilidad interna de los niveles de calcio se asocia a un mayor riesgo vascular, condición prevalente en un gran número de individuos ya comprometidos por la enfermedad de Alzheimer. Esta revisión proporciona una reevaluación de los mecanismos moleculares de la ATPasa dependiente de Ca2+ del retículo sarcoendoplásmico (SERC-A) en la enfermedad y analiza los aspectos más destacados de la función de los canales de calcio dependientes de voltaje; de esta manera, se podrán abrir nuevas alternativas de tratamiento. Estos mecanismos de regulación son clínicamente relevantes, ya que se ha implicado la función irregular de SERC-A en diversas alteraciones de la función cerebral.
There are many factors involved in the incidence of Alzheimer's disease that, in combination, impede or hinder normal neuronal functions. Little is currently known about calcium regulation before and during the disease. Internal instability of calcium levels is associated with increased vascular risk, a prevalent condition in a high number of individuals already compromised by Alzheimer's disease. This review provides a reevaluation of the molecular mechanism of the sarcoendoplasmic reticulum calcium ATPase (SERC-A) in the disease and discusses salient aspects of voltage-gated calcium channel function; in these way new alternatives could be open for its treatment. These regulation mechanisms are clinically relevant since the irregular functions of SERC+A has been implicated in pathologies of brain function.
Subject(s)
Calcium Metabolism Disorders , Alzheimer Disease , Receptors, N-Methyl-D-Aspartate , Calcium-Transporting ATPases , Endoplasmic ReticulumABSTRACT
Resumen Introducción: la enfermedad de Wilson es una enfermedad heterogénea causada por mutaciones en el gen ATP7B. La presentación clínica es variable, en fenotipos hepáticos y neuropsiquiátricos. El objetivo de este estudio es describir una cohorte retrospectiva de pacientes. Materiales y métodos: estudio retrospectivo descriptivo de pacientes atendidos en el Hospital Pablo Tobón Uribe desde enero de 2004 a septiembre de 2017. Resultados: se reportaron 27 pacientes, 17 hombres y 10 mujeres. El tiempo de seguimiento medio fue de 2,18 años, el 40% presentó síntomas neurológicos; el 29%, psiquiátricos; y el 85%, alteración hepática. En el laboratorio, el 85% presentó ceruloplasmina baja; 55%, cobre urinario alto; en casos con biopsia hepática, 7 tenían depósito de cobre en coloraciones especiales. En neuroimágenes, el 84% presentó hallazgos sugestivos de enfermedad de Wilson y en 3 casos se documentó una mutación genética patogénica. Durante el seguimiento, el 51% mejoró clínica o bioquímicamente, el 11% se mantuvo estable y el 18% se deterioró. El 88% de los casos sobrevivió al final del seguimiento. Conclusiones: este estudio es la cohorte retrospectiva más grande de Colombia. Los resultados son base para nuevos estudios poblacionales buscando de manera activa la enfermedad para documentarla en su fase preclínica y, de este modo, impactar en el pronóstico.
Abstract Introduction: Wilson's disease is a heterogeneous disorder caused by mutations in the ATP7B gene. Its clinical presentation is variable in hepatic and neuropsychiatric phenotypes. The aim of this study is to describe a retrospective cohort of patients. Materials and methods: A descriptive retrospective study was carried out in patients treated at the Hospital Pablo Tobón Uribe from January 2004 to September 2017. Results: 27 patients were reported, 17 men and 10 women. The mean follow-up time was 2.18 years. 40% of the patients had neurological symptoms, 29% psychiatric symptoms, and 85% hepatic impairment. Lab tests showed that 85% had low ceruloplasmin and 55% had increased urinary copper. In cases that underwent liver biopsy, 7 had special copper colorations. Neuroimaging revealed that 84% had findings suggestive of Wilson's disease and a pathogenic genetic mutation was documented in 3 cases. During follow-up, 51% improved clinically or biochemically, 11% remained stable, and 18% deteriorated. 88% of cases survived at the end of follow-up. Conclusions: This study is the largest retrospective cohort carried out in Colombia. The results are the basis for new population-based studies actively seeking this disease to describe its preclinical development and thus impact prognosis.
Subject(s)
Humans , Male , Female , Child , Adolescent , Adult , Copper , Hepatolenticular Degeneration , Signs and Symptoms , Disease , Retrospective Studies , Genetics , LiverABSTRACT
P1B-ATPases are a group of proteins that can transport heavy metal ions across membranes by hydrolyzing ATP and they are a subclass of the P-type ATPase family. It was found that P1B-ATPases are mainly responsible for the active transport of heavy metal ions in plants and play an important role in the regulation of heavy metal homeostasis in plants. In this paper, we dissusses the mechanism of P1B-ATPases from the structure and classification of P1B-ATPases, and review the current research progress in the function of P1B-ATPases, in order to provide reference for future research and application of P1B-ATPases in improving crop quality and ecological environment management.
Subject(s)
Adenosine Triphosphatases/metabolism , Biological Transport , Metals, Heavy , Plants/enzymologyABSTRACT
Background: Studies have showed that proton pump inhibitor (PPI) can inhibit the expression of V-ATPases and influence the glycolysis of gastric cancer cells. V-ATPases have important significance on malignant biological behavior of tumor. Aims: To explore the mechanisms of PPI on gastric cancer via inhibiting glycolysis and glutamine metabolism. Methods: In the cell experiment, gastric cancer cell lines were cultured with PPI and knockdown of related molecules, cell proliferation was determined by CCK-8 assay, cell apoptosis was detected by flow cytometry. mRNA and protein expressions of related molecules were detected by quantitative PCR and Western blotting, respectively. In the animal experiment, nude mice were divided into blank control group, 0.9% NaCl solution group, pantoprazole sodium group, and PKM2 group, body weight, feeding behavior, tumor size and expressions of related pathway molecule in tumor tissue were compared. Results: PPI could inhibit the proliferation and induce apoptosis of gastric cancer cells. PPI could suppress the expression of related molecules of glycolysis and glutamine metabolism. Knocking down PKM2 or PI3K could inhibit proliferation and induce apoptosis of gastric cancer cells. Silencing V-ATPases inhibited the expression of related molecules of glycolysis and glutamine metabolism in gastric cancer cells. PPI therapy delayed tumor growth and reduced cachexia in tumor-bearing mice. Conclusions: PPI may inhibit cell proliferation and induce cell apoptosis by influencing glycolysis and glutamine metabolism of gastric cancer cells via suppressing V-ATPases and PI3K pathway, thus to play an anti-tumor role.
ABSTRACT
The hepatic endoplasmic reticulum (ER)-anchored cytochromes P450 (P450s) are mixed-function oxidases engaged in the biotransformation of physiologically relevant endobiotics as well as of myriad xenobiotics of therapeutic and environmental relevance. P450 ER-content and hence function is regulated by their coordinated hemoprotein syntheses and proteolytic turnover. Such P450 proteolytic turnover occurs through a process known as ER-associated degradation (ERAD) that involves ubiquitin-dependent proteasomal degradation (UPD) and/or autophagic-lysosomal degradation (ALD). Herein, on the basis of available literature reports and our own recent findings of as well as experimental studies, we discuss the therapeutic and pathophysiological implications of altered P450 ERAD and its plausible clinical relevance. We specifically (i) describe the P450 ERAD-machinery and how it may be repurposed for the generation of antigenic P450 peptides involved in P450 autoantibody pathogenesis in drug-induced acute hypersensitivity reactions and liver injury, or viral hepatitis; (ii) discuss the relevance of accelerated or disrupted P450-ERAD to the pharmacological and/or toxicological effects of clinically relevant P450 drug substrates; and (iii) detail the pathophysiological consequences of disrupted P450 ERAD, contributing to non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) under certain synergistic cellular conditions.
ABSTRACT
La enfermedad de Wilson es una condición genética autosómica recesiva poco frecuente. Se ha identificado el gen ATP7B como el que codifica la proteína transportadora de cobre y su deficiencia lleva al acúmulo del metal en el cerebro, hígado y otros órganos vitales. Su diagnóstico clínico precoz es esencial para mejorar la calidad de vida del paciente. A continuación, se presenta el caso de un paciente de 20 años, masculino, con un cuadro clínico de 2 años de evolución de desinhibición, impulsividad, anartria y apraxia de la marcha, movimientos distónicos faciales y en 4 extremidades. Al examen físico se evidenció el anillo de Kayser Flescher a nivel ocular. En Resonancia Magnética Encefálica hiperintensidad en ganglios de la base y mesencéfalo en T2. Ceruloplasmina en suero 4.08 mg/dL. Cobre sérico 26.03ug/dL y cobre en orina de 24 horas 224.30ug/ 24h. Se confirma el diagnóstico de Enfermedad de Wilson, tratándose con D- Penicilamina, evidenciándose una evolución adecuada, con mejoría notable del cuadro neurológico. El tratamiento precoz permite una evolución favorable temprana del paciente, disminuyendo las secuelas neurológicas secundarias a la enfermedad; de ahí la importancia del reporte del presente caso.(AU)
BackgroundWilson's disease is a rare autosomal recessive genetic condition. The ATP7B gene has been identified as the one that encodes the copper transport protein and its deficiency leads to the accumulation of metal in the brain, liver and other vital organs. Your early clinical diagnosis is essential to improve the quality of life of the patient. Following we present the clinical case of a 20-year-old male patient who since 2 years ago, presented disinhibition, impulsivity, anartria and gait apraxia, facial dystonic movements and in extremities. To the physical exam, Kayser Flescher ring was present. In Brain Magnetic Resonance hyperintensity in Basal Ganglia and Midbrain. Serum Ceruloplasmin 4.08. Serum Copper 26.03. Urinary Cupper 224.30. The diagnosis of Wilson's disease is confirmed, treating with D-Penicillamine, evidencing an adequate evolution, with notable improvement of the neurological symptoms. Early treatment allows a favorable early evolution of the patient, reducing the neurological sequelae secondary to the disease; so that the importance of the report of this case.(AU)
Subject(s)
Humans , Male , Adult , Copper-Transporting ATPases/analysis , Hepatolenticular Degeneration/complications , Hepatolenticular Degeneration/diagnostic imaging , Ceruloplasmin/chemistryABSTRACT
Abstract: We present a different and rare manifestation of Darier's disease, namely linear Darier's disease. Only a few cases have been described in the literature. The case report is a male patient, 60 years old, presenting brown to red papules and plaques with hyperkeratosis distributed on the abdomen, following Blaschko's lines, with 6 years' evolution. It was a difficult diagnosis until the dermatological workup and biopsy.
Subject(s)
Humans , Male , Middle Aged , Darier Disease/diagnosis , Photography , Acitretin/administration & dosage , Keratolytic Agents/administration & dosage , Darier Disease/pathology , Darier Disease/drug therapy , Medical IllustrationABSTRACT
OBJECTIVE@#The current study aimed to elucidate the effect of vanillin on behavioral changes, oxidative stress, and histopathological changes induced by potassium bromate (KBrO3), an environmental pollutant, in the cerebellum of adult mice.@*METHODS@#The animals were divided into four groups: group 1 served as a control, group 2 received KBrO3, group 3 received KBrO3 and vanillin, and group 4 received only vanillin. We then measured behavioral changes, oxidative stress, and molecular and histological changes in the cerebellum.@*RESULTS@#We observed significant behavioral changes in KBrO3-exposed mice. When investigating redox homeostasis in the cerebellum, we found that mice treated with KBrO3 had increased lipid peroxidation and protein oxidation in the cerebellum. These effects were accompanied by decreased Na+-K+ and Mg2+ ATPase activity and antioxidant enzyme gene expression when compared to the control group. Additionally, there was a significant increase in cytokine gene expression in KBrO3-treated mice. Microscopy revealed that KBrO3 intoxication resulted in numerous degenerative changes in the cerebellum that were substantially ameliorated by vanillin supplementation. Co-administration of vanillin blocked the biochemical and molecular anomalies induced by KBrO3.@*CONCLUSION@#Our results demonstrate that vanillin is a potential therapeutic agent for oxidative stress associated with neurodegenerative diseases.
Subject(s)
Animals , Mice , Antioxidants , Metabolism , Behavior, Animal , Benzaldehydes , Pharmacology , Bromates , Toxicity , Cerebellum , Metabolism , Pathology , Cytokines , Genetics , Metabolism , Environmental Pollutants , Toxicity , Gene Expression , Lipid Peroxidation , Oxidative Stress , Rotarod Performance TestABSTRACT
Objective The purpose of this study was to develop the mechanism of vacuolar H+-ATPase regulation of vaginal microenvironment.Methods In this research,53 women were divided into three groups.Their age,serum estradiol (E2),serum follicle stimulating hormone (FSH),vaginal pH value,and mRNA expression of vacuolar H +-ATPase (VHA) on the ectocervical-vaginal epithelial cells were analyzed.Results (1) As serum E2 levels decreased,the vaginal pH values increased and VHA mRNA declined (P ＜ 0.01).(2) Immunohistochemistry scores decreased in the three groups.VHA expression decreased in human ectocervical-vaginal epithelial tissues except basal cells.(3) The expression of VHA was positive correlated with estradiol,while negative correlated with age and vaginal pH value (P ＜ 0.01).Conclusions Estradiol could regulate the genetic transcription and synthetic of VHA protein under vaginal microenvironment.
ABSTRACT
Obesity and diabetes has become a major epidemic across the globe. Controlling obesity has been a challenge since this would require either increased physical activity or reduced caloric intake; both are difficult to enforce. There has been renewed interest in exploiting pathways such as uncoupling protein 1 (UCP1)-mediated uncoupling in brown adipose tissue (BAT) and white adipose tissue to increase energy expenditure to control weight gain. However, relying on UCP1-based thermogenesis alone may not be sufficient to control obesity in humans. On the other hand, skeletal muscle is the largest organ and a major contributor to basal metabolic rate and increasing energy expenditure in muscle through nonshivering thermogenic mechanisms, which can substantially affect whole body metabolism and weight gain. In this review we will describe the role of Sarcolipin-mediated uncoupling of Sarcoplasmic Reticulum Calcium ATPase (SERCA) as a potential mechanism for increased energy expenditure both during cold and diet-induced thermogenesis.
Subject(s)
Humans , Adipose Tissue, Brown , Adipose Tissue, White , Basal Metabolism , Diabetes Mellitus , Energy Intake , Energy Metabolism , Hand , Metabolism , Motor Activity , Muscle, Skeletal , Obesity , Sarcoplasmic Reticulum Calcium-Transporting ATPases , Thermogenesis , Weight GainABSTRACT
PURPOSE: This study was conducted to investigate whether a proton pump inhibitor (PPI) could enhance chemosensitivity via the inhibition of vacuolar-type H⁺ ATPase (V-ATPase) in cervical cancer. MATERIALS AND METHODS: The expression of V-ATPase was evaluated in 351 formalin-fixed, paraffin-embedded human cervical cancer tissues using immunohistochemistry and compared with clinicopathologic risk factors for disease prognosis. The influence of cell proliferation and apoptosis following V-ATPase siRNA transfection or esomeprazole pretreatment was assessed in cervical cancer cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and enzyme-linked immunosorbent assay, respectively. RESULTS: Immunohistochemical analysis revealed that V-ATPase was expressed in about 60% of cervical cancer tissue samples (211/351), and the expression was predominantly found in adenocarcinoma histology (p=0.016). Among patients with initially bulky cervical cancer (n=89), those with V-ATPase expression had shorter disease-free survival (p=0.005) and overall survival (p=0.023). Co-treatment with V-ATPase siRNA or esomeprazole with paclitaxel significantly decreased the cell proliferation of cervical cancer cell lines, including HeLa and INT407, compared to cell lines treated with paclitaxel alone (p < 0.01). Moreover, V-ATPase siRNA or esomeprazole followed by paclitaxel significantly increased the expression of active caspase-3 in these cells compared to cells treated with paclitaxel alone (both, p < 0.05). CONCLUSION: V-ATPase was predominantly expressed in cervical adenocarcinoma, and the expression of V-ATPases was associated with poor prognosis. The inhibition of V-ATPase via siRNA or PPI (esomeprazole) might enhance the chemosensitivity of paclitaxel in cervical cancer cells.
Subject(s)
Humans , Adenocarcinoma , Adenosine Triphosphatases , Antineoplastic Agents , Apoptosis , Caspase 3 , Cell Line , Cell Proliferation , Disease-Free Survival , Enzyme-Linked Immunosorbent Assay , Esomeprazole , Immunohistochemistry , Paclitaxel , Prognosis , Proton Pump Inhibitors , Proton Pumps , Protons , Risk Factors , RNA, Small Interfering , Transfection , Uterine Cervical Neoplasms , Vacuolar Proton-Translocating ATPasesABSTRACT
Objective To investigate the association between polymorphisms of Ca2 + -ATPase isomer 2 gene (PMCA2) in plasma membrane and the development of sudden deafness .Methods Totally ,164 patients were investigated and hearing tests were conducted .According to the results of audiometry ,they were divided into two groups ,sensorineural hearing loss group(n= 82) and normal hearing group(n= 82) .Polymorphisms of two single nucleotide loci rs2289274 and rs6790640 in the PMCA2 gene were de-termined by polymerase chain reaction followed by allele specific amplication analysis .Results In the sudden deafness group ,fre-quencies of genotypes AA ,AG and GG in the rs2289274 locus were 55 .8% ,17 .4% and 26 .8% respectively ,while frequencies of al-leles A and G in the same locus were 64 .5% and 35 .5% respectively ;in the sensorineural hearing loss group ,were 26 .8% ,28 .0%and 45 .2% respectively ,while frequencies of alleles A and G were 41 .1% and 58 .9% .And ,in the sudden deafness group ,frequen-cies of genotypes CC ,CT and TT in the rs2289274 locus were18 .3% ,35 .4% and 46 .3% respectively ,while frequencies of alleles C and T in the same locus were 36 .3% and 63 .7% ;in the normal hearing group ,were 2 .4% ,63 .4% and 34 .1% respectively ,while frequencies of alleles C and T were34 .1% and 65 .9% ,respectively .Genotypes distribution of two sites and their allele frequencies of the two groups ,some differences of them had statistical significance(P< 0 .05) .Conclusion It is suggested that genetic polymor-phism of the rs2289274 and rs6790640 loci in the PMCA2 gene might be a susceptible factor for sudden deafness .
ABSTRACT
Acidic environment of organelles of eukaryotic cells plays an important role in endocytosis, the secretion of lysoso-mal enzymes and other physiological activities.V-ATPase (vacuolar ATPases) and CLC (chloride channel) family are widely distribu-ted and present in virtually all eukaryotic cells in intracellular membranes and in the plasma membrane.They are responsible for the a-cidification of the vesicular interior.In this paper, the distribution, structure, mechanism of action and physiological and pathological significance of V-ATPase and CLC protein are discussed.
ABSTRACT
Aroclor 1254, a polychlorinated biphenyl, is present in the environment in low concentration but references on its toxic effects on liver cell membrane proteins and the mechanism of actions are not abundantly available. Therefore, the present study was undertaken to investigate the low level, sub-acute dose and exposure duration dependent effects of Aroclor 1254 on total, Na+, K+, Ca2+ and Mg2+-ATPases of the mouse liver. The hypotheses tested in the present study were, (a) whether the low, environmentally available dose and the exposure durations of Aroclor 1254 affects the membrane-bound ion dependent ATPases, and (b) if a response was observed, whether it is a direct or indirect effects of the toxicant. Groups of mice were exposed to different doses (0.1 and 1mg kg-1 body weight d-1) and exposure durations (4 d, 8 d and 12 d) of Aroclor 1254. The results indicated significant exposure duration dependent changes in the specific activity of the selected membrane bound ATPases. As the observed changes were mostly enzyme stimulation after toxication through oral administration, the effects of the Aroclor were possibly indirect, through complex chain of reactions.
Subject(s)
Adenosine Triphosphatases/drug effects , Adenosine Triphosphatases/metabolism , Animals , Antithyroid Agents/pharmacology , Cell Membrane/drug effects , Cell Membrane/enzymology , /pharmacology , Dose-Response Relationship, Drug , Liver/drug effects , Liver/enzymology , Male , MiceABSTRACT
ATP2A2 is a member of ATP2As family, it encodes SERCA2b, a sarco (endo) plasmic reticulum calcium transport ATPases (SERCAs). As the main function of SERCA2b is to transport calcium from the cytosol to the sarco(endo) plasmic reticulum, it plays a vital role in numerous calcium-related signaling pathways involving control of tumor growth, differentiation, angiogenesis, metastasis and apoptosis. Recent studies have identified the accurate change of ATP2A2 expression in some tumors, which makes the first step in investigating how ATP2A2 participates in tumorigenesis and whether it can be taken as a new tumor marker and target for treatment. Here we made a comprehensive review on the role of ATP2A2 in tumorigenesis, and it is believed that the abnormal expression of ATP2A2 can damage the calcium homeostasis between cytosol and sarco (endo) plasmic reticulum, accelerating malignant proliferation, migration and angiogenesis of the tumor. Moreover, we also discussed the prospect of research and application of ATP2A2.
ABSTRACT
Local anesthetics used in dentistry have myotoxic effects. Articaine, also known as carticaine, is one of the local anesthetics most widely used in clinical dentistry. The aim of this work was to describe its effect on the sarcoplasmic reticulum Ca-ATPase isolated from medial pterygoid muscle. Ca-ATPase enzymatic activity was determined by a colorimetric method and ATP-dependent calcium uptake with a radioisotopic technique. Articaine inhibited both Ca-ATPase activity and calcium uptake in a concentrationdependent manner. Both inhibitory effects became evident at articaine concentrations lower than those employed in clinical dentistry. Half-maximal inhibitory concentrations (Ki) were 15.1± 1.8 mM (n = 6) and 25.2 ± 1.6 mM (n = 6) for enzymatic activity and calcium uptake, respectively. Preincubation of sarcoplasmic reticulum membranes with articaine enhanced Ca-ATPase activity in the absence of calcium ionophore, suggesting an ionophoriclike effect of the local anesthetic. We conclude that the inhibitory effect of articaine on the sarcoplasmic reticulum Ca-ATPase isolated from medial pterygoid muscle is due to a direct interaction of the anesthetic with the enzyme and to the increased membrane permeability to calcium induced by this drug.
Los anestésicos locales de uso odontológico tienen efectos miotóxicos. La carticaína, también conocida como articaína, es uno de los anestésicos locales más usados en la clínica odontológica actual. El objetivo del trabajo fue describir el efecto de la carticaína sobre la Ca-ATPasa del retículo sarcoplásmico aislada del músculo pterigoideo interno. La actividad enzimática de la bomba de calcio se determinó por un método colorimétrico y se utilizó un método radioisotópico a fin de determinar la captación de calcio dependiente de ATP. La carticaína inhibió la actividad enzimática y la captación de calcio en función de su concentración. Ambos efectos se observaron a concentraciones de carticaína menores a las utilizadas en la clínica. Las concentraciones de carticaína necesarias para inhibir la actividad Ca-ATPásica y la captación de calcio a la mitad de su valor máximo (Ki) fueron 15.1 ± 1.8 mM (n = 6) y 25.2 ± 1.6 mM (n = 6) respectivamente. La preincubación con carticaína de las membranas de retículo sarcoplásmico del músculo pterigoideo interno, en ausencia de ionóforo de calcio, incrementó la actividad de la enzima, evidenciando un efecto ionofórico del anestésico local. Concluimos que el efecto inhibitorio de la carticaína sobre la Ca-ATPasa de retículo sarcoplásmico del músculo pterigoideo interno se debe a la acción directa del anestésico local sobre la enzima y al incremento de la permeabilidad de la membrana del retículo sarcoplásmico al calcio inducido por esta droga.
Subject(s)
Animals , Male , Rabbits , Pterygoid Muscles/ultrastructure , Sarcoplasmic Reticulum/drug effects , Sarcoplasmic Reticulum/metabolism , Carticaine/pharmacology , Calcium/metabolism , Anesthetics, Local/pharmacologyABSTRACT
The role of the kidney in combating metabolic acidosis has been a subject of considerable interest for many years. The present study was aimed to determine whether there is an altered regulation of renal acid base transporters in acute and chronic acid loading. Male Sprague-Dawley rats were used. Metabolic acidosis was induced by administration of NH4Cl for 2 days (acute) and for 7days (chronic). The serum and urinary pH and bicarbonate were measured. The protein expression of renal acid base transporters [type 3 Na+/H+ exchanger (NHE3), type 1 Na+/HCO3- cotransporter (NBC1), Na-K+ ATPase, H(+)-ATPase, anion exchanger-1 (AE-1)] was measured by semiquantitative immunoblotting. Serum bicarbonate and pH were decreased in acute acid loading rats compared with controls. Accordingly, urinary pH decreased. The protein expression of NHE3, H(+)-ATPase, AE-1 and NBC1 was not changed. In chronic acid loading rats, serum bicarbonate and pH were not changed, while urinary pH was decreased compared with controls. The protein expression of NHE3, H(+)-ATPase was increased in the renal cortex of chronic acid loading rats. These results suggest that unaltered expression of acid transporters combined with acute acid loading may contribute to the development of acidosis. The subsequent increased expression of NHE3, H(+)-ATPase in the kidney may play a role in promoting acid excretion in the later stage of acid loading, which counteract the development of metabolic acidosis.
Subject(s)
Animals , Humans , Male , Rats , Acidosis , Adenosine Triphosphatases , Ammonium Chloride , Hydrogen-Ion Concentration , Immunoblotting , Kidney , Proton-Translocating ATPases , Quaternary Ammonium Compounds , Rats, Sprague-Dawley , Sodium-Hydrogen ExchangersABSTRACT
A promoção do crescimento vegetal pelos ácidos húmicos tem sido atribuída a ações similares a hormônios, devido à promoção do desenvolvimento e proliferação das raízes, resultando numa absorção mais eficiente de água e nutrientes. O objetivo deste trabalho foi analisar as mudanças na arquitetura radicular em plântulas de milho e no perfil de proteínas da membrana plasmática (MP) promovidas pelo tratamento com ácidos húmicos (AH) isolados de vermicomposto (20mg C L-1). O efeito da adição de ácido cítrico (AC), importante ácido orgânico presente nos exudados radiculares, sobre a bioatividade destes AH também foi investigada. Foram analisados o comprimento da raiz principal, o número de sítios de mitose, o número e comprimento de raízes laterais e a área radicular total. Para a análise do perfil protéico, vesículas da MP de células de raízes foram obtidas por fracionamento celular e as proteínas analisadas por eletroforese uni (1D) e bidimensional (2D). Observou-se que a adição de AC (0,005mM) aos AH estimularam a promoção do crescimento das raízes laterais (126 por cento), da área radicular (58 por cento) e do número de raízes laterais (55 por cento) em relação às plantas controle. A atividade da bomba de H+ da membrana plasmática, analisada como marcador bioquímico de indução do mecanismo do crescimento ácido, também foi significativamente estimulada (374 por cento) pela solução húmica suplementada com AC. O perfil protéico da MP revelou uma supressão da expressão das proteínas nesta membrana, induzida pelo tratamento com AH e, na presença de AC, esse efeito foi ainda mais evidente. Os resultados obtidos corroboram o mecanismo proposto para a bioatividade de AH no qual a ação de ácidos orgânicos exudados pelas plantas, tais como o AC, promove o rompimento da associação supramolecular dessas substâncias, tornando as moléculas bioativas presentes nos agregados húmicos mais acessíveis aos receptores celulares das raízes.
The plant growth stimulation by humic acids (HA) has been attributed to a hormone-like effect as promoting the root development and proliferation, resulting in a more efficient water and nutrient absorption. This research aims to investigate how the humic acids isolated from vermicompost (20mg L-1) can modify the root architecture and the plasma membrane (PM) protein patterns in maize roots. It was also analyzed the effect of the citric acid (CA), an organic acid present in root exudates. The changes induced in the corn root system were estimated by measuring the taproot length, the amount of root mitotic sites and lateral roots, and the total root area. Plasma membrane vesicles were purified by cell fractionation and the protein patterns were analyzed by uni (1D) and bidimensional (2D) electrophoresis. The results show that the HA in solution with CA (0.005mM) increases the lateral root growth promotion (126 percent), the root area (58 percent), and the number of lateral roots (55 percent). The activity of the plasma membrane H+ pump, analyzed as a marker of the induction of the acid growth mechanism, was also enhanced (374 percent) by the humic solution supplemented with CA. Expression of several plasma membrane proteins was inhibited when plants were treated with HA and this effect was more pronounced upon CA supplementation. The obtained results corroborate the proposed mechanism for the HA bioactivity, by which under the action of root-exuded organic acids, such as CA, a disruption of the HA macrostructure is promoted releasing bioactive molecules presented in the humic aggregates, which becomes more accessible to the root cell receptors.
ABSTRACT
Objecfive To investigate the change of V-ATPase B subunits on epithelial to mesenchymal transition (EMT)in rat renal tubular epithelial cells (NRK52E) stimulated by transforming growth factor β1 (TGF-β1). Methods NRK52E cells were stimulated by TGF-β1 (10 μg/L)for O h(control),12 h,24 h,48 h,72 h after sefrum-free culture for 24 h.The mRNA and protein expression of E-cadherin,α-SMA,B2 and B1 subunits of V-ATPase were detected by real-time PCR,Western blotting and immunofluorescence. Results After stimulated by TGF-β1 (10 μg/L)for 48 h,the expression of α-SMA was markedly increased(P<0.05),but the expression of E-cadherin was dramatically decreased(P<0.05).Meanwhile,the expressions of V-ATPase subunit B2 was significantly increased (P<0.05).However,the B1 subunit distributed rarely in NRK 52E cells,and did not increase after TGF-β1 stimulation.Double-label immunofluoerscence staining also showed that the V-ATPase B2 subunit was increased in the cytosol.tending to accumulate to the cell membrane after TGF-β1 stimulation. Conclusions The main isoform of V-ATPase distributed in NRK52E cells is B2 subunit.B2 subunit is increased alone with TGF-β1-induced EMT.It may suggest that V-ATPase B2 subunit may play a potential role in TGF-β1-induced tubular EMT and renal fibrosis.
ABSTRACT
The regulatory function of á1B-adrenoceptors in mammalian heart homeostasis is controversial. The objective of the present study was to characterize the expression/activity of key proteins implicated in cardiac calcium handling (Na+/K+-ATPase and Ca2+-ATPases) and growth (ERK1/2, JNK1/2 and p38) in mice with cardiac-selective overexpression of constitutively active mutant á1B-adrenoceptor (CAMá1B-AR), which present a mild cardiac hypertrophy phenotype. Immunoblot assays showed that myocardial plasma membrane Ca2+-ATPase (PMCA) expression was increased by 30 percent in CAMá1B-AR mice (N = 6, P < 0.05), although there was no change in sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2) expression. Moreover, total Ca2+-ATPase activity was not modified, but a significant increase in the activity of the thapsigargin-resistant (PMCA) to thapsigargin-sensitive (SERCA) ratio was detected. Neither Na+/K+-ATPase activity nor the expression of á1 and á2 subunit isoforms was changed in CAMá1B-AR mouse hearts. Moreover, immunoblot assays did not provide evidence for an enhanced activation of the three mitogen-activated protein kinases studied in this stage of hypertrophy. Therefore, these findings indicate that chronic cardiac á1B-AR activation in vivo led to mild hypertrophy devoid of significant signs of adaptive modifications concerning primary intracellular calcium control and growth-related proteins, suggesting a minor pathophysiological role of this adrenergic receptor in mouse heart at this stage of development.