RESUMO
The current study presents two different approaches with a view to elucidating the interaction between thyroid hormones (TH) and apo-transferrin (aTf) and their role in myelination and remyelination. First, in vitro assays were conducted to determine the single and combined effects of aTf and triiodothyronine (T3) on oligodendroglial cell lineage proliferation and oligodendrocyte (OLG) maturation in primary cultures. Results revealed higher proliferation rates upon single aTf treatment but Control values upon T3 and aTf + T3 treatments. In addition, both aTf and T3 accelerated OLG maturation, with the greatest effects being exerted by combined aTf + T3 administration in terms of both myelin basic protein (MBP) expression and morphological complexity. Second, in vivo assays were carried out to establish single and combined effects of aTf and T3, as well as TH receptor (THR) inhibitor I-850, on remyelination following a CPZ-induced demyelination protocol. Results showed an increase in myelin deposition and the number of mature remyelinating OLG upon single treatments, but a synergic effect upon combined aTf + T3 treatment which was prevented by THR inhibition. It may be thus concluded that combined treatment yielded the most beneficial effects on OLG maturation parameters in vitro and remyelinating capacity in vivo when compared to single treatments. These findings may help explore the development of new target molecules in the treatment of demyelinating diseases.
Assuntos
Remielinização , Diferenciação Celular , Bainha de Mielina , Oligodendroglia , Hormônios Tireóideos , TransferrinaRESUMO
When disrupted, iron homeostasis negatively impacts oligodendrocyte (OLG) differentiation and impairs myelination. To better understand myelin formation and OLG maturation, in vivo and in vitro studies were conducted to evaluate the effect of iron deficiency (ID) not only on OLG maturation but also on astrocytes (AST) and microglial cells (MG). In vivo experiments in an ID model were carried out to describe maturational events during OLG and AST development and the reactive profile of MG during myelination when iron availability is lower than normal. In turn, in vitro assays were conducted to explore proliferating and maturational states of each glial cell type derived from control or ID conditions. Studies targeted NG2, PDGFRα, CNPAse, CC1, and MBP expression in OLG, GFAP and S100 expression in AST, and CD11b, ED1, and cytokine expression in MG, as well as BrDU incorporation in the three cell types. Our results show that ID affected OLG development at early stages, not only reducing their maturation capacity but also increasing their proliferation and affecting their morphological complexity. AST ID proliferated more than control ones and were more immature, much like OLG. Cytokine expression in ID animals reflected an anti-inflammatory state which probably influenced OLG maturation. These results show that ID conditions alter all glial cells and may impact myelin formation, which could be regulated by a mechanism involving a cross talk between AST, MG, and oligodendrocyte progenitors (OPC).
Assuntos
Anemia Ferropriva/metabolismo , Astrócitos/metabolismo , Ferro/metabolismo , Microglia/metabolismo , Oligodendroglia/metabolismo , Animais , Encéfalo/metabolismo , Diferenciação Celular/fisiologia , Homeostase/fisiologia , Bainha de Mielina/metabolismo , Ratos , Ratos WistarRESUMO
Introducción Existe evidencia epidemiológica que vincula factores de riesgo cardiovascular con la estenosis valvular aórtica. Recientemente se ha demostrado el desarrollo de estenosis valvular aórtica en un modelo de hipertensión arterial en animales. Planteamos la hipótesis de que el tratamiento con rosuvastatina modifica esta transformación. Objetivo Evaluar el efecto de la rosuvastatina sobre el desarrollo de estenosis valvular aórtica. Material y métodos Se instrumentaron conejos NZ machos (n = 43) con el modelo 1-riñón 1-clip de Goldblatt para generar hipertensión arterial. Los animales fueron aleatorizados a: HT (n = 17) que no recibió otro tratamiento, HT+R (n = 14) tratado con rosuvastatina 2,5 mg/kg/día y HT+R+C (n = 12) tratado con rosuvastatina 2,5 mg/kg/día + suplemento de colesterol dietético para mantener los niveles basales de colesterol plasmático. Un grupo control (GC) fue sometido a cirugía simulada (n = 15). Las características de la válvula aórtica se midieron por ecografía en condiciones basales y a los 3 y a los 6 meses de hipertensión arterial. Resultados A los 6 meses de seguimiento, los incrementos de PAS y PAD fueron más elevados en HT (49% y 40%, respectivamente; p < 0,001) en comparación con los grupos tratados con rosuvastatina (PAS = 23% y 25%; PAD = 28% y 26%; p < 0,001 para HT+R y HT+R+C, respectivamente). El colesterol total se redujo el 45,7% (p < 0,01) sólo en HT+R. El espesor valvar se incrementó en HT (0,50 ± 0,01 vs. 0,62 ± 0,02 mm; p < 0,01), sin mostrar diferencias en HT+R y HT+R+C. Finalmente, el área valvular aórtica mostró una reducción en HT (0,277 ± 0,024 vs. 0,208 ± 0,014 cm²; p < 0,05), sin cambios en HT+R y HT+R+C y un aumento no significativo en el GC (0,264 ± 0,022 vs. 0,32 ± 0,016 cm²; p = 0,07). Conclusiones La rosuvastatina atenúa la progresión de la estenosis valvular aórtica generada por hipertensión arterial. Esta protección podría ser mediada por efectos no hipolipemiantes de estas drogas.
Background There is epidemiological evidence associating cardiovascular risk factors with aortic valve stenosis. The development of aortic valve stenosis has been recently demonstrated in a hypertensive animal model. We hypothesize that treatment with rosuvastatin modifies this transformation. Objective To evaluate the effect of rosuvastatin on the development of aortic valve stenosis. Material and Methods Hypertension was induced in 43 male NZ rabbits by a onekidney, one-clip Goldblatt procedure. The animals were randomly assigned to 3 groups: HT (n=17) without treatment; HT+R (n=14) treated with rosuvastatin 2.5 mg/kg/day and HT+R+C (n=12) treated with rosuvastatin 2.5 mg/kg/day + cholesterol-enriched diet to keep baseline cholesterol levels. A control group (CG) underwent sham surgery (n=15). The characteristics of the aortic valve were measured by echocardiography at baseline, 3 and 6 months after inducing hypertension. Results After 6 months of follow-up, SBP and DBP presented greater increase in the group HT (49% and 40%, respectively; p<0.001) compared to groups treated with rosuvastatin (SBP = 23% and 25%; DBP = 28% and 26%; p <0.001 for HT+R and HT+R+C, respectively). Total cholesterol decreased by 45.7% (p <0.01) only in HT+R group. The aortic valve became thickened in the HT group (0.50 ± 0.01 vs. 0.62± 0.02 mm; p <0.01); there were no significant differences in HT+R and HT+R+C. Finally, the aortic valve area was reduced in HT (0.277 ± 0.024 vs. 0.208 ± 0.014 cm² ; p <0.05), had no differences in HT+R and HT+R+C, and presented a non-significant increase in CG (0.264 ± 0.022 vs. 0.32± 0.016 cm²; p=0.07). Conclusions Rosuvastatin slows the progression of aortic valve stenosis caused by hypertension. This protection might be independent of the lipid-lowering effect of the drug.
RESUMO
Introducción Existe evidencia epidemiológica que vincula factores de riesgo cardiovascular con la estenosis valvular aórtica. Recientemente se ha demostrado el desarrollo de estenosis valvular aórtica en un modelo de hipertensión arterial en animales. Planteamos la hipótesis de que el tratamiento con rosuvastatina modifica esta transformación. Objetivo Evaluar el efecto de la rosuvastatina sobre el desarrollo de estenosis valvular aórtica. Material y métodos Se instrumentaron conejos NZ machos (n = 43) con el modelo 1-riñón 1-clip de Goldblatt para generar hipertensión arterial. Los animales fueron aleatorizados a: HT (n = 17) que no recibió otro tratamiento, HT+R (n = 14) tratado con rosuvastatina 2,5 mg/kg/día y HT+R+C (n = 12) tratado con rosuvastatina 2,5 mg/kg/día + suplemento de colesterol dietético para mantener los niveles basales de colesterol plasmático. Un grupo control (GC) fue sometido a cirugía simulada (n = 15). Las características de la válvula aórtica se midieron por ecografía en condiciones basales y a los 3 y a los 6 meses de hipertensión arterial. Resultados A los 6 meses de seguimiento, los incrementos de PAS y PAD fueron más elevados en HT (49% y 40%, respectivamente; p < 0,001) en comparación con los grupos tratados con rosuvastatina (PAS = 23% y 25%; PAD = 28% y 26%; p < 0,001 para HT+R y HT+R+C, respectivamente). El colesterol total se redujo el 45,7% (p < 0,01) sólo en HT+R. El espesor valvar se incrementó en HT (0,50 ± 0,01 vs. 0,62 ± 0,02 mm; p < 0,01), sin mostrar diferencias en HT+R y HT+R+C. Finalmente, el área valvular aórtica mostró una reducción en HT (0,277 ± 0,024 vs. 0,208 ± 0,014 cm²; p < 0,05), sin cambios en HT+R y HT+R+C y un aumento no significativo en el GC (0,264 ± 0,022 vs. 0,32 ± 0,016 cm²; p = 0,07). Conclusiones La rosuvastatina atenúa la progresión de la estenosis valvular aórtica generada por hipertensión arterial. Esta protección podría ser mediada por efectos no hipolipemiantes de estas drogas.(AU)
Background There is epidemiological evidence associating cardiovascular risk factors with aortic valve stenosis. The development of aortic valve stenosis has been recently demonstrated in a hypertensive animal model. We hypothesize that treatment with rosuvastatin modifies this transformation. Objective To evaluate the effect of rosuvastatin on the development of aortic valve stenosis. Material and Methods Hypertension was induced in 43 male NZ rabbits by a onekidney, one-clip Goldblatt procedure. The animals were randomly assigned to 3 groups: HT (n=17) without treatment; HT+R (n=14) treated with rosuvastatin 2.5 mg/kg/day and HT+R+C (n=12) treated with rosuvastatin 2.5 mg/kg/day + cholesterol-enriched diet to keep baseline cholesterol levels. A control group (CG) underwent sham surgery (n=15). The characteristics of the aortic valve were measured by echocardiography at baseline, 3 and 6 months after inducing hypertension. Results After 6 months of follow-up, SBP and DBP presented greater increase in the group HT (49% and 40%, respectively; p<0.001) compared to groups treated with rosuvastatin (SBP = 23% and 25%; DBP = 28% and 26%; p <0.001 for HT+R and HT+R+C, respectively). Total cholesterol decreased by 45.7% (p <0.01) only in HT+R group. The aortic valve became thickened in the HT group (0.50 ± 0.01 vs. 0.62± 0.02 mm; p <0.01); there were no significant differences in HT+R and HT+R+C. Finally, the aortic valve area was reduced in HT (0.277 ± 0.024 vs. 0.208 ± 0.014 cm² ; p <0.05), had no differences in HT+R and HT+R+C, and presented a non-significant increase in CG (0.264 ± 0.022 vs. 0.32± 0.016 cm²; p=0.07). Conclusions Rosuvastatin slows the progression of aortic valve stenosis caused by hypertension. This protection might be independent of the lipid-lowering effect of the drug.(AU)
RESUMO
Introducción Existe evidencia epidemiológica que vincula factores de riesgo cardiovascular con la estenosis valvular aórtica. Recientemente se ha demostrado el desarrollo de estenosis valvular aórtica en un modelo de hipertensión arterial en animales. Planteamos la hipótesis de que el tratamiento con rosuvastatina modifica esta transformación. Objetivo Evaluar el efecto de la rosuvastatina sobre el desarrollo de estenosis valvular aórtica. Material y métodos Se instrumentaron conejos NZ machos (n = 43) con el modelo 1-riñón 1-clip de Goldblatt para generar hipertensión arterial. Los animales fueron aleatorizados a: HT (n = 17) que no recibió otro tratamiento, HT+R (n = 14) tratado con rosuvastatina 2,5 mg/kg/día y HT+R+C (n = 12) tratado con rosuvastatina 2,5 mg/kg/día + suplemento de colesterol dietético para mantener los niveles basales de colesterol plasmático. Un grupo control (GC) fue sometido a cirugía simulada (n = 15). Las características de la válvula aórtica se midieron por ecografía en condiciones basales y a los 3 y a los 6 meses de hipertensión arterial. Resultados A los 6 meses de seguimiento, los incrementos de PAS y PAD fueron más elevados en HT (49% y 40%, respectivamente; p < 0,001) en comparación con los grupos tratados con rosuvastatina (PAS = 23% y 25%; PAD = 28% y 26%; p < 0,001 para HT+R y HT+R+C, respectivamente). El colesterol total se redujo el 45,7% (p < 0,01) sólo en HT+R. El espesor valvar se incrementó en HT (0,50 ñ 0,01 vs. 0,62 ñ 0,02 mm; p < 0,01), sin mostrar diferencias en HT+R y HT+R+C. Finalmente, el área valvular aórtica mostró una reducción en HT (0,277 ñ 0,024 vs. 0,208 ñ 0,014 cm²; p < 0,05), sin cambios en HT+R y HT+R+C y un aumento no significativo en el GC (0,264 ñ 0,022 vs. 0,32 ñ 0,016 cm²; p = 0,07). Conclusiones La rosuvastatina atenúa la progresión de la estenosis valvular aórtica generada por hipertensión arterial. Esta protección podría ser mediada por efectos no hipolipemiantes de estas drogas.(AU)
Background There is epidemiological evidence associating cardiovascular risk factors with aortic valve stenosis. The development of aortic valve stenosis has been recently demonstrated in a hypertensive animal model. We hypothesize that treatment with rosuvastatin modifies this transformation. Objective To evaluate the effect of rosuvastatin on the development of aortic valve stenosis. Material and Methods Hypertension was induced in 43 male NZ rabbits by a onekidney, one-clip Goldblatt procedure. The animals were randomly assigned to 3 groups: HT (n=17) without treatment; HT+R (n=14) treated with rosuvastatin 2.5 mg/kg/day and HT+R+C (n=12) treated with rosuvastatin 2.5 mg/kg/day + cholesterol-enriched diet to keep baseline cholesterol levels. A control group (CG) underwent sham surgery (n=15). The characteristics of the aortic valve were measured by echocardiography at baseline, 3 and 6 months after inducing hypertension. Results After 6 months of follow-up, SBP and DBP presented greater increase in the group HT (49% and 40%, respectively; p<0.001) compared to groups treated with rosuvastatin (SBP = 23% and 25%; DBP = 28% and 26%; p <0.001 for HT+R and HT+R+C, respectively). Total cholesterol decreased by 45.7% (p <0.01) only in HT+R group. The aortic valve became thickened in the HT group (0.50 ñ 0.01 vs. 0.62ñ 0.02 mm; p <0.01); there were no significant differences in HT+R and HT+R+C. Finally, the aortic valve area was reduced in HT (0.277 ñ 0.024 vs. 0.208 ñ 0.014 cm² ; p <0.05), had no differences in HT+R and HT+R+C, and presented a non-significant increase in CG (0.264 ñ 0.022 vs. 0.32ñ 0.016 cm²; p=0.07). Conclusions Rosuvastatin slows the progression of aortic valve stenosis caused by hypertension. This protection might be independent of the lipid-lowering effect of the drug.(AU)