RESUMO
Glioblastoma multiforme (GBM) is a highly aggressive type of brain tumour. Patients with GBM respond poorly to chemotherapy and have poor survival outcomes. Neuron-glial antigen 2 (NG2), also known as chondroitin sulphate proteoglycan 4 (CSPG4), has been shown to contribute to critical processes, such as cell survival, proliferation, and chemotherapy resistance, during glioma progression. In this study, we found that furanodienone (FUR), a diene-type sesquiterpene isolated from the rhizomes of Rhizoma curcumae, exhibited a potential cytotoxic effect on temozolomide (TMZ)-resistant GBM cells in vitro by inhibiting CSPG4 and related signalling pathways. Studies investigating the mechanism demonstrated that FUR suppressed CSPG4-Akt-ERK signalling, inflammatory responses, and cytokine levels but activated caspase-dependent pathways and mitochondrial dysfunction. Furthermore, an immunofluorescence assay and a dual-luciferase reporter assay revealed that inhibition of EGR1-mediated transcription might have contributed to the FUR-dependent blockade of CSPG4 signalling and glioma cell survival. These results established a link between FUR-induced CSPG4 inhibition and the suppression of EGR1-dependent transcription. Attenuation of ERK1/2 and cytokine signalling might have generated the EGR1-dependent negative feedback loop of the CSPG4 pathway during FUR-induced apoptosis. These findings suggested that FUR could be a therapeutic candidate for the treatment of malignant glioma via targeting CSPG4 signalling.
Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteína 1 de Resposta de Crescimento Precoce/fisiologia , Furanos/farmacologia , Glioblastoma/tratamento farmacológico , Sesquiterpenos/farmacologia , Temozolomida/uso terapêutico , Adulto , Apoptose/efeitos dos fármacos , Apoptose/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Proteoglicanas de Sulfatos de Condroitina/genética , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Resistencia a Medicamentos Antineoplásicos/genética , Furanos/administração & dosagem , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sesquiterpenos/administração & dosagem , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Temozolomida/administração & dosagem , Transcrição Gênica/efeitos dos fármacosRESUMO
Aggregated amyloid-ß protein (Aß) and Aß-induced neuronal apoptosis have been implicated as critical factors in the pathophysiology of Alzheimer's disease (AD). Certain preclinical results have indicated that the increased accumulation of protein aggregates in AD-affected neurons activates the unfolded protein response (UPR), a pathological phenomenon, which predominantly mediates the aberrant endoplasmic reticulum (ER) stress and apoptotic cascades in neuronal cells. In the present study, we confirmed that Santacruzamate A (STA, a natural product isolated from a Panamanian marine cyanobacterium) attenuates Aß protein fragment 25-35 (Aß25-35)-induced toxicity in PC12 cells and rescues cognitive deficits in APPswe/PS1dE9 mice by enhancing ER stress tolerance. We first demonstrated the anti-apoptotic effects of STA by evaluating caspase-3 activity, annexin V/propidium iodide (PI) staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Behavioral testing of STA-treated APPswe/PS1dE9 mice showed that the pronounced memory impairments were ameliorated and that the consolidated memories were stably maintained over a 2-week period. The mechanistic studies provided evidence that STA inhibited Aß25-35-induced UPR and ER stress by regulating the ER retention signal (KDEL) receptor, which reinforced the retention of resident chaperones in the ER lumen. Furthermore, STA regulated the expression of the mitochondrial intermembrane space assembly protein 40 (Mia40) and augmenter of liver regeneration (ALR), which ultimately attenuated the mitochondrial fission and apoptosis pathways. Together, our present findings suggest that the KDEL receptor and Mia40-ALR play a role in mitigating Aß25-35-induced neurotoxicity, which might in turn positively regulate learning and memory. These observations support that STA may be a promising agent for reversing the progression of AD.
RESUMO
A pair of chiral template induced anionic homochiral frameworks constructed from achiral components has been synthesized. Ion-exchange of counter cations with polar or chiral organic cations enhances the SHG efficiency of the frameworks. The enantioselective sensing of chiral alkamines can be achieved by the SHG response.