The alterations of microvasculature, tyrosine phosphorylation, and lipid peroxidation in kidney of rats treated with valproic acid / Alteraciones de la microvasculatura, fosforilación de tirosina y peroxidación lipídica en riñones de ratas tratadas con ácido valproico

SUMMARY: Valproic acid (VPA), an antiepileptic drug, has been demonstrated to damage histology and to change tyrosine phosphorylation patterns with increased oxidative stress in perirenal tissues. This study aimed to investigate the effect of VPA on microstructure, tyrosine phosphorylation, and lipid peroxidation of rat kidney. Adult male rats were divided into control and VPA-treated groups intraperitoneally injected with normal saline and VPA 500 mg/kgBW for 10 consecutive days, respectively (n = 7 each). The blood serum was examined for biochemical levels. The kidney tissues were routinely processed for histological observation. Total proteins from kidney were extracted to assay the malondialdehyde (MDA) levels and phosphorylation expression. The results showed that VPA significantly decreased blood glucose levels while tend to increase urea nitrogen and creatinine. MDA levels in VPA group were significantly higher that of control. Renal cortex of VPA-treated animals revealed vasodilatations. Although the ratio of a renal phosphorylated 72 kDa protein/ beta actin expression seemed to be not different in both groups, VPA significantly decreased the intensity of beta actin. In conclusion, VPA dilates renal microvasculature with increasing of MDA but suppresses the actin expression.

RESUMEN: Se ha demostrado que el ácido valproico (AVP), un fármaco antiepiléptico, daña la histología y cambia los patrones de fosforilación de la tirosina con el aumento del estrés oxidativo en los tejidos perirrenales. Este estudio tuvo como objetivo investigar el efecto del AVP en la microestructura, la fosforilación de la tirosina y la peroxidación lipídica del riñón de rata. Se dividieron ratas macho adultas en grupos control y tratados con AVP. Durante 10 días consecutivos fueron inyectadas por vía intraperitoneal con solución salina normal y 500 mg / kg de PC respectivamente (n = 7 cada uno). Se analizó el suero sanguíneo para determinar los niveles bioquímicos. Los tejidos renales se procesaron de forma rutinaria para la observación histológica. Las proteínas totales del riñón se extrajeron para analizar los niveles de malondialdehído (MDA) y la expresión de la fosforilación. Los resultados mostraron que el AVP disminuyó significativamente los niveles de glucosa en la sangre, mientras que tienden a aumentar el nitrógeno ureico y la creatinina. Los niveles de MDA en el grupo de AVP fueron significativamente más altos que los del control. La corteza renal de los animales tratados con AVP reveló vasodilataciones. Aunque la proporción de una expresión de proteína / actina de 72 kDa fosforilada renal no parece ser diferente en ambos grupos, el AVP disminuyó significativamente la intensidad de la actina beta. En conclusión, el AVP dilata la microvasculatura renal al aumentar el MDA, pero suprime la expresión de actina.

Localization and changes of tyrosine phosphorylated proteins and ß actin in epididymis of rats treated with valproic acid / Localización y cambios de las proteínas tirosina fosforiladas y la ß actina en epidídimos de ratas tratadas con ácido valproico

Tyrosine phosphorylated proteins have been localized and identified in male reproductive tissues such as testis and capacitated/ acrosome reacted sperm except epididymis. The changes of such proteins are associated with decreased sperm quality of valproic acid treatment. This study aimed to investigate the presence and alterations of protein phosphorylation in epididymal epithelium and fluid of rats treated VPA. Sixteen adult male rats were divided into control and VPA-treated groups (n=8/ each). Treated rats were injected with VPA (500 mg/ kgBW, intraperitoneally) for 10 consecutive days. At the end of experiment, the monoclonal antiphosphotyrosine (clone 4G10) was used for immunohistochemistry to probe tyrosine phosphorylated proteins and also to examine the expression of such proteins using immuno-Western blotting in epididymal tissue and fluid. The result showed that positive reactivity of phosphorylated proteins was clearly observed in cytoplasmic principle cells, nuclei of apical & basal cells and sperm mass surrounded with epididymal fluids. The profiles of phosphorylated proteins in epididymal fluid were 182, 127, 80, 70, 57, 45, 34, and 31 kDas, respectively. Interestingly, VPA affected the changes of phosphorylated proteins and β actin in head, body, and tail epididymal fluids. We conclude that tyrosine phosphorylated proteins were detected in epididymal epithelium and fluid. The expressions of those proteins and actin were altered under VPA treating.

Las proteínas tirosina fosforiladas han sido localizadas e identificadas en tejidos reproductores masculinos tales como testículos y espermatozoides, capacitados a nivel acrosómico, excepto en el epidídimo. Los cambios de estas proteínas están asociadas con una disminución de la calidad del esperma en el tratamiento con ácido valproico (AVP). Este estudio tuvo como objetivo investigar la presencia y las alteraciones de la fosforilación de proteínas en el epitelio epididimal y en el fluido espermático de ratas tratadas con AVP. Dieciséis ratas macho adultas se dividieron en dos grupos: control y tratadas con AVP (n = 8 / cada uno). A las ratas tratadas se les inyectó AVP por vía intraperitoneal (500 mg / kg de peso corporal) durante 10 días consecutivos. Al final del experimento, se realizó inmunohistoquímica con la anti-fosfotirosina monoclonal (clon 4G10) para sondear las proteínas tirosina fosforiladas y también para examinar la expresión de tales proteínas usando inmunotransferencia Western, en tejido y fluido epididimarios. El resultado mostró reactividad positiva de proteínas fosforiladas en células citoplásmicas principales, en los núcleos de las células apicales y basales y en la masa de esperma rodeada por fluidos epididimarios. Los perfiles de proteínas fosforiladas en el fluido epididimal fueron 182, 127, 80, 70, 57, 45, 34 y 31 kDas, respectivamente. El AVP provocó cambios en las proteínas fosforiladas y en la β actina de los fluidos epididimarios de cabeza, cuerpo y cola del epidídimo. Concluimos que las proteínas tirosina fosforiladas se detectaron en el epitelio y el fluido epididimarios. Las expresiones de esas proteínas y de la β actina se alteraron bajo tratamiento con AVP.

Myostatin promotes distinct responses on protein metabolism of skeletal and cardiac muscle fibers of rodents

Myostatin is a novel negative regulator of skeletal muscle mass. Myostatin expression is also found in heart in a much less extent, but it can be upregulated in pathological conditions, such as heart failure. Myostatin may be involved in inhibiting protein synthesis and/or increasing protein degradation in skeletal and cardiac muscles. Herein, we used cell cultures and isolated muscles from rats to determine protein degradation and synthesis. Muscles incubated with myostatin exhibited an increase in proteolysis with an increase of Atrogin-1, MuRF1 and LC3 genes. Extensor digitorum longus muscles and C2C12 myotubes exhibited a reduction in protein turnover. Cardiomyocytes showed an increase in proteolysis by activating autophagy and the ubiquitin proteasome system, and a decrease in protein synthesis by decreasing P70S6K. The effect of myostatin on protein metabolism is related to fiber type composition, which may be associated to the extent of atrophy mediated effect of myostatin on muscle.

Sodium nitroprusside has leishmanicidal activity independent of iNOS

Abstract: INTRODUCTION: Leishmaniasis is a zoonotic disease caused by protozoa of the genus Leishmania . Cutaneous leishmaniasis is the most common form, with millions of new cases worldwide each year. Treatments are ineffective due to the toxicity of existing drugs and the resistance acquired by certain strains of the parasite. METHODS: We evaluated the activity of sodium nitroprusside in macrophages infected with Leishmania (Leishmania) amazonensis . Phagocytic and microbicidal activity were evaluated by phagocytosis assay and promastigote recovery, respectively, while cytokine production and nitrite levels were determined by ELISA and by the Griess method. Levels of iNOS and 3-nitrotyrosine were measured by immunocytochemistry. RESULTS: Sodium nitroprusside exhibited in vitro antileishmanial activity at both concentrations tested, reducing the number of amastigotes and recovered promastigotes in macrophages infected with L. amazonensis . At 1.5µg/mL, sodium nitroprusside stimulated levels of TNF-α and nitric oxide, but not IFN-γ. The compound also increased levels of 3-nitrotyrosine, but not expression of iNOS, suggesting that the drug acts as an exogenous source of nitric oxide. CONCLUSIONS: Sodium nitroprusside enhances microbicidal activity in Leishmania -infected macrophages by boosting nitric oxide and 3-nitrotyrosine.

The anthelmintic albendazole affects in vivo the dynamics and the detyrosination-tyrosination cycle of rat brain microtubules

Albendazole (ABZ) is an anthelmintic benzimidazole drug widely used in human and veterinary medicine. ABZ has binding affinity to both mammalian and helminth parasite tubulin. In the current work, we have performed in vitro assays and in vivo experiments in which rats were given ABZ orally to better characterize the action of the drug on the polymerization of rat brain microtubules and on the detyrosination/tyrosination cycle that occurs on the COOH-terminal end of alpha-tubulin. The results showed that ABZ inhibits brain microtubule polymerization in vitro, and significantly delayed microtubule assembly in vivo. The tyrosination reaction cycle was not affected in vitro; however, in rats to which the drug was administered orally, the levels of in vitro tyrosination were reduced when compared to the controls with mock treatment. These results suggest that this apparent inhibition would be due to a decrease in the amount of substrate caused by the depolymerizing effect of ABZ and the subsequent tyrosination in the intact brain with endogenous tyrosine. In conclusion, ABZ strongly affects tubulin dynamics both in vivo and in vitro. The outcome of these experiments is a contribution to the understanding of the molecular mechanisms involved in the antimicrotubular action of benzimidazole compounds.