RESUMEN
Parkinson's disease (PD) is characterized by the presence of cytoplasmic inclusions composed of alpha-synuclein (alpha-syn) in dopaminergic neurons. This suggests a pivotal role of dopamine (DA) on PD development. Here, we show that DA modulates differently the stability of protofibrils (PF) and fibrils (F) composed of wild type or variants of alpha-syn (A30P and A53T) as probed by high hydrostatic pressure (HHP). While in the absence of DA, all alpha-syn PF exhibited identical stability, in its presence, the variant-composed PF acquired a greater stability (DAPFwt < DAPFA30P = DAPFA53T), implying that they would last longer, which could shed light onto why these mutations are so aggressive. When alpha-syn was incubated for long times (18 days) in the presence of DA, we observed the formation of F by electronic microscopy, suggesting that the PF trapped in the presence of DA in short times can evolve into F. The stability of F was also altered by DA. DAFwt was more labile than Fwt, indicating that the former would be more susceptible to breakage. PFA30P and DAPFA30P, when added to mesencephalic and cortical neurons in culture, decreased the number and length of neurites and increased the number of apoptotic cells. Surprisingly, these toxic effects of PFA30P and DAPFA30P were practically abolished with HHP treatment, which was able to break the PF into smaller aggregates, as seen by atomic force microscopy. These results suggest that strategies aimed at breaking and/or clearing these aggregates is promising in alleviating the symptoms of PD.
Asunto(s)
Dopamina/farmacología , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , Sustitución de Aminoácidos , Dopamina/metabolismo , Estabilidad de Medicamentos , Variación Genética , Humanos , Presión Hidrostática , Técnicas In Vitro , Microscopía de Fuerza Atómica , Microscopía Electrónica , Complejos Multiproteicos , Neuronas/metabolismo , Enfermedad de Parkinson/etiología , Enfermedad de Parkinson/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/efectos de los fármacos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Agua/química , alfa-Sinucleína/efectos de los fármacos , alfa-Sinucleína/genéticaRESUMEN
This work presents different applications in progress with the aid of the atomic force microscopy (AFM) technique for biomedical and biotechnological applications, comprising both the acquisition of three-dimensional images and spectroscopic force measurements, in the following systems: first, low-density lipoprotein (LDL)-glycosaminoglycans; second, lectins-polysaccharides; third, mycobacterium leprae cellular wall and Vesicular Stomatites Virus (VSV) with fibronectin laminin, and lipidic membranes; fourth, DNA-complex; and fifth, actin, as well as the development of surface functionalizing protocols and image restoration by means of mathematical techniques.