RESUMO
Emerging evidence from multiple studies indicates that Parkinson's disease (PD) patients suffer from a spectrum of autonomic and respiratory motor deficiencies in addition to the classical motor symptoms attributed to substantia nigra degeneration of dopaminergic neurons. Animal models of PD show a decrease in the resting respiratory rate as well as a decrease in the number of Phox2b-expressing retrotrapezoid nucleus (RTN) neurons. The aim of this study was to determine the extent to which substantia nigra pars compact (SNc) degeneration induced RTN biomolecular changes and to identify the extent to which RTN pharmacological or optogenetic stimulations rescue respiratory function following PD-induction. SNc degeneration was achieved in adult male Wistar rats by bilateral striatal 6-hydroxydopamine injection. For proteomic analysis, laser capture microdissection and pressure catapulting were used to isolate the RTN for subsequent comparative proteomic analysis and Ingenuity Pathway Analysis (IPA). The respiratory parameters were evaluated by whole-body plethysmography and electromyographic analysis of respiratory muscles. The results confirmed reduction in the number of dopaminergic neurons of SNc and respiratory rate in the PD-animals. Our proteomic data suggested extensive RTN remodeling, and that pharmacological or optogenetic stimulations of the diseased RTN neurons promoted rescued the respiratory deficiency. Our data indicate that despite neuroanatomical and biomolecular RTN pathologies, that RTN-directed interventions can rescue respiratory control dysfunction.
Assuntos
Neurônios/metabolismo , Doença de Parkinson/metabolismo , Insuficiência Respiratória/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/fisiologia , Corpo Estriado/metabolismo , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/fisiologia , Masculino , Vias Neurais/fisiologia , Neurônios/fisiologia , Parte Compacta da Substância Negra/metabolismo , Parte Compacta da Substância Negra/fisiologia , Proteômica , Ratos , Ratos Wistar , Respiração , Insuficiência Respiratória/terapia , Substância Negra/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/fisiologiaRESUMO
BACKGROUND: Diabetic wounds have become one of the most challenging public health issues of the 21st century, yet there is no effective treatment available. We have previously shown that the diabetic wound healing impairment is associated with increased inflammation and decreased expression of the regulatory microRNA miR-146a. We have conjugated miR-146a to cerium oxide nanoparticles (CNP-miR146a) to target reactive oxygen species (ROS) and inflammation. This study aimed to evaluate the consequences of CNP-miR146a treatment of diabetic wounds. STUDY DESIGN: Eight-millimeter wounds were created on the dorsal skin of Db/Db mice and treated with PBS or differing concentrations of CNP-mir146a (1; 10; 100; or 1,000 ng) at the time of wounding. Rate of wound closure was measured until the wounds were fully healed. At 4 weeks post-healing, a dumbbell-shaped skin sample was collected, with the healed wound in the center, and an Instron 5942 testing unit was used to measure the maximum load and modulus. RESULTS: Our data showed that diabetic wounds treated with PBS or 1 ng CNP-miR146a took 18 days to heal. Treatment with 10, 100, or 1,000 ng of CNP+miR-146a effectively enhanced healing, and wounds were fully closed at day 14 post-wounding. The healed skin from the CNP-miR146a-treated group showed a trend of improved biomechanical properties (increased maximum load and modulus), however it did not reach significance. CONCLUSIONS: We found that a 100-ng dose of CNP-miR146a improved diabetic wound healing and did not impair the biomechanical properties of the skin post-healing. This nanotechnology-based therapy is promising, and future studies are warranted to transfer this therapy to clinical application.