RESUMO
BACKGROUND: Chitosan, the N-deacetylated derivative of chitin, is a cationic polyelectrolyte due to the presence of amino groups, one of the few occurring in nature. The use of chitosan in protein and drug delivery systems is being actively researched and reported in the literature RESULTS: In this study, we used chitosan-coated levodopa liposomes to investigate the behavioral character and the expression of phosphorylated extracellular signal-regulated kinase (ERK1/2), dopamine- and cAMP-regulated phos-phoprotein of 32 kDa (DARPP-32) and FosB/AFosB in striatum of rat model of levodopa-induced dyskinesia (LID). We found that scores of abnormal involuntary movement (AIM) decreased significantly in liposome group (P < 0.05), compared with levodopa group. Levels of phospho-ERK1/2, phospho-Thr34 DARPP-32 and FosB/AFosB in striatum decreased significantly in liposome group lesion side compared with levodopa group (P < 0.05). However, both of two groups above have significantly differences compared with the control group (P < 0.05). CONCLUSION: Chitosan-coated levodopa liposomes may be useful in reducing dyskinesias inducing for Parkinson disease. The mechanism might be involved the pathway of signaling molecular phospho-ERK1/2, phospho-Thr34 DARPP-32 and AFosB in striatum
Assuntos
Animais , Masculino , Dopaminérgicos/farmacologia , Levodopa/farmacologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Quitosana/farmacologia , Discinesia Induzida por Medicamentos/metabolismo , Discinesia Induzida por Medicamentos/prevenção & controle , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Doença de Parkinson/tratamento farmacológico , Fosforilação/efeitos dos fármacos , Materiais Biocompatíveis/farmacologia , Imuno-Histoquímica , Distribuição Aleatória , Western Blotting , Reprodutibilidade dos Testes , Resultado do Tratamento , Proteínas Proto-Oncogênicas c-fos/análise , Proteínas Proto-Oncogênicas c-fos/efeitos dos fármacos , Ratos Sprague-Dawley , Corpo Estriado/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases , MAP Quinases Reguladas por Sinal Extracelular/análise , MAP Quinases Reguladas por Sinal Extracelular/efeitos dos fármacos , Discinesia Induzida por Medicamentos/etiologia , Fosfoproteína 32 Regulada por cAMP e Dopamina/análise , Fosfoproteína 32 Regulada por cAMP e Dopamina/efeitos dos fármacos , Nanopartículas , LipossomosRESUMO
The present study is to explore the change process and distribution of phosphorylated DARPP-32 (p-DARPP-32) in rat brain including cortex, hippocampus and striatum and to further deduce whether p-DARPP-32 was possibly involved in epilepsy induced by repetitive low doses of pentylenetetrazol (PTZ). PTZ-induced epilepsy model in rat was established with 30 male SD rats randomly divided into 6 groups, control group and five trial groups [PTZ 1 h, PTZ 6 h, PTZ 24 h, PTZ 48 h and PTZ 72 h respectively, after onset of status epilepticus (SE)]. Immunohistochemistry and immunofluorescence double-labeling were used to detect the temporal time change and distribution of p-DARPP-32 expression and to analyze the coexpression of DARPP-32 and p-DARPP-32 in rat brain after the onset of PTZ-induced generalized SE. The results showed that there was a temporal time change of p-DARPP-32 expression in rat brain after the onset of SE. The number of p-DARPP-32-positive cells increased significantly and reached the peaks at the ends of 1 hour and 6 hours after the onset of SE, but decreased at the end of 24 hours. The moderate to strong p-DARPP-32-immunopositive neurons were observed in cortex, hippocampus and striatum, and located in cell cytoplasm and cell nucleus. Further immunofluorescence double-labeling revealed that denser colocalization of p-DARPP-32 and DARPP-32 in the neurons existed in the area mentioned above. Therefore, PTZ-induced SE may cause phosphorylation of DARPP-32 in rat brain. The temporal time change and distribution of p-DARPP-32 suggest that phosphorylation of DARPP-32 may be involved in PTZ-induced epilepsy in rat brain including cortex, hippocampus and striatum, and p-DARPP-32 may play a central role in the onset of SE.
Assuntos
Animais , Masculino , Ratos , Córtex Cerebral , Metabolismo , Corpo Estriado , Metabolismo , Fosfoproteína 32 Regulada por cAMP e Dopamina , Metabolismo , Hipocampo , Metabolismo , Neurônios , Metabolismo , Pentilenotetrazol , Ratos Sprague-Dawley , Estado Epiléptico , MetabolismoRESUMO
<p><b>OBJECTIVE</b>To investigate the significance of DARPP-32 protein expression in gastric carcinoma tissue and cell lines.</p><p><b>METHODS</b>The expression of DARPP-32 protein in normal gastric mucosa and gastric carcinoma tissue was evaluated by immunohistochemical staining using streptavidin-biotin complex technique. The expression in gastric carcinoma tissue and cell lines was evaluated by Western blotting.</p><p><b>RESULTS</b>The expression rate of DARPP-32 protein in gastric adenocarcinoma tissue (92.7%) was significantly higher than that in normal gastric mucosa (52.6%, P < 0.05). There was no significant association between DARPP-32 protein expression and degree of tumor differentiation, local invasion and distant metastasis. As compared with adjacent non-carcinomatous gastric mucosa, both DARPP-32 and its truncated isoform t-DARPP were overexpressed in gastric adenocarcinoma tissue (t = 2.45, P = 0.015); and t-DARPP overexpression was more frequently seen. Expression of DARPP-32 and t-DARPP could also be detected in human gastric cancer cell lines. The expression of DARPP-32 protein was obviously reduced in SGC7901 drug-resistant cell strains.</p><p><b>CONCLUSIONS</b>DARPP-32 is overexpressed in gastric carcinoma. It may play an important role in gastric carcinogenesis. The underlying signal pathways in neoplastic gastric epithelium may also be related to the multi-drug resistance property of gastric cancer cells.</p>