NeuralCipher Research overview
The text below is the source article’s original abstract under a verified reuse license. cc by
Chronic exposure to elevated levels of manganese (Mn) causes a neurological disorder referred to as manganism, resembling pathological symptoms of Parkinson's disease (PD). The repressor element-1 silencing transcription factor (REST) induces neuroprotection in several neurological disorders, including PD and Mn toxicity. Tamoxifen (TX), a selective estrogen receptor modulator, has been shown to afford neuroprotective effects in various experimental models and increase REST expression via the non-genomic estrogen receptor (ER)/Wnt signaling in Cath. a-differentiated (CAD) neuronal cultures. The present study investigated whether TX enhances REST transcription through the genomic estrogen receptor (ER) pathway in CAD cells, using a combination of Western blotting, quantitative reverse transcription polymerase chain reaction (qRT-PCR), promoter activity assays, chromatin immunoprecipitation, electrophoretic mobility shift assays, and site-directed mutagenesis. The findings showed that the REST promoter sequences contained half-site estrogen response elements (ERE) motifs. The ER-α pathway primarily upregulated REST, as the ER-α selective agonist propylpyrazole triol (PPT) (1 μM) predominantly increased REST transcription and attenuated Mn (250 μM)-induced REST reduction in CAD cells. TX induced REST upregulation by activation of the genomic ER-α pathway, as it increased nuclear ER-α's interaction with cyclic adenosine monophosphate (AMP) response element (CREB)-binding protein and Sp1 and promoted ER-α binding to the half-site ERE in the REST promoter. Moreover, the ERE mutation in the REST promoter reduced TX-induced REST promoter activity, and TX reversed Mn-induced REST transcriptional repression. Our novel findings suggest that the genomic ER-α pathway plays a critical role in TX-induced REST upregulation and mitigation of Mn-induced decreases in REST expression.
Scientific assessment
Research question
Assess the question within the original study’s scope.
Methods & sample
Check the source article for study design and sample details.
Key findings
An editorially approved findings summary is not yet published for this record.
Limitations
Generalizability, bias and clinical meaning require separate assessment.
Methods, samples and clinical conclusions are not inferred from bibliographic metadata.