ABSTRACT
La muerte celular programada y la fibrosis renal son procesos inherentes a la enfermedad renal crónica y, en tal sentido, ha sido recientemente descripta una clara desregulación de la maquinaria respiratoria mitocondrial en pacientes con enfermedad renal crónica asociada con un aumento del estrés oxidativo. Las células tubulares lesionadas vinculadas a los macrófagos intersticiales y miofibroblastos producen citoquinas y factores de crecimiento que promueven un estado inflamatorio, inducen la apoptosis de las células tubulares y facilitan la acumulación de matriz extracelular. La angiotensina II desempeña un papel central en la fibrogénesis renal y conduce a una rápida progresión de la enfermedad renal crónica. Los niveles crecientes de la angiotensina II inducen citoquinas pro-inflamatorias, la activación de NF-kB, moléculas de adhesión, quimiocinas, factores de crecimiento y estrés oxidativo. Toda la evidencia actual sugiere que la angiotensina II aumenta el estrés oxidativo mitocondrial, regula la inducción de apoptosis y condiciona al estado inflamatorio. Por lo tanto, existiría un papel determinante de las mitocondrias y el estrés oxidativo en el proceso inflamatorio renal. Finalmente, esta revisión resume nuestro actual conocimiento acerca de los posibles mecanismos que contribuirían con la apoptosis modulada por la inflamación y/o el estrés oxidativo durante la enfermedad renal crónica. Además, se propone un nuevo concepto de herramientas anti-inflamatorias que regulan el estrés oxidativo mitocondrial lo cual afectaría directamente al proceso inflamatorio y la apoptosis. Esta idea podría tener consecuencias atractivas sobre el tratamiento de patologías inflamatorias renales y de otras afines.
The apoptosis and renal fibrosis are processes inherent to the chronic kidney disease, and consequently a clear deregulation of the mitochondrial respiratory mechanism has been described in patients with chronic renal disease associated to an increase of the oxidative stress. The injured tubular cells linked to the interstitial macrophages and myofibroblasts produce cytokines and growth factors that encourage an inflammatory condition, inducing the apoptosis of the tubular cells and enabling the accumulation of the extracellular matrix. The angiotensin II has a central role in the renal fibrogenesis leading to a rapid progression of the chronic kidney disease. The growing levels of the angiotensin II induce pro-inflammatory cytokines, the activation of NF-kB, adhesion molecules,chemokines, growth factors, and oxidative stress. The current evidence suggests that the angiotensin II increases the mitochondrial oxidative stress, regulates the induction of the apoptosis and conditions the inflammatory process. Therefore the mitochondria and the oxidative stress would play a determinant role in the renal inflammatory process. Finally, this review summarizes our present knowledge regarding the possible mechanisms that would contribute to the apoptosis conditioned by inflammation and/or oxidative stress during the chronic renal disease. Additionally, a new concept of the anti-inflammatory tools is proposed to regulate the mitochondrial oxidative stress that would directly affect the inflammatory process and apoptosis. This concept could have positive consequences on the treatment of renal inflammatory pathologies and related diseases.
Subject(s)
Animals , Humans , Apoptosis/physiology , Mitochondria/metabolism , Mitochondria/pathology , Nephritis/etiology , Oxidative Stress/physiology , Renal Insufficiency, Chronic/etiology , Angiotensin II/metabolism , Cytoprotection , Ergocalciferols/pharmacology , Kidney Cortex/drug effects , Kidney Cortex/pathology , Kidney Tubules/drug effects , Kidney Tubules/pathology , NF-kappa B/metabolism , Nephritis/metabolism , Renal Insufficiency, Chronic/metabolism , Renal Insufficiency, Chronic/pathology , Vitamins/pharmacologyABSTRACT
Wilms tumor gene 1 (wt-1), a key regulator of mesenchymal-epithelial transformation, is downregulated during congenital obstructive nephropathy, leading to apoptosis. There is a functional interaction between WT-1 and inducible nitric oxide synthase (iNOS). In this regard, we reported that after neonatal unilateral ureteral obstruction, rosuvastatin prevents apoptosis through an increase in nitric oxide bioavailability, which in turn is linked to higher Hsp70 expression. Hence, the goal of this study was to determine whether a nitric oxide/Hsp70 interaction is involved in changes in WT-1 mRNA expression after ureteral obstruction. Neonatal rats submitted to experimental ureteral obstruction were treated with either vehicle or rosuvastatin for 14 days. Decreased nitric oxide and iNOS/Hsp70 expression associated wit h WT-1 low expression was shown in obstructed kidneys. Apoptosis was induced and it was associated with an increased Bax/BcL2 ratio. Conversely, iNOS/Hsp70 upregulation and an increased WT-1 mRNA expression, without an apoptotic response, were observed in the cortex of obstructed kidneys of rosuvastatin-treated rats. Nitric oxide also modulated Hsp70 and WT-1 mRNA expression in MDCK cells. Finally, in vivo experiments with nitric oxide modulators support our hypothesis that WT-1 mRNA expression is associated with nitric oxide level. Results suggest that rosuvastatin may modulate WT-1 mRNA expression through renal nitric oxide bioavailability, preventing neonatal obstruction-induced apoptosis associated with Hsp70 interaction.