Regulation of Actg1 and Gsta2 is possible mechanism by which capsaicin alleviates apoptosis in cell model of 6-OHDA-induced Parkinson's disease
BIOSCIENCE REPORTS
Authors: Liu, Jiahui; Liu, Hong; Zhao, Zhenxiang; Wang, Jianfeng; Guo, Dandan; Liu, Yiming
Abstract
The present study aimed to identify the gene expression changes conferred by capsaicin in the cell model of 6-OHDA-induced Parkinson's disease, to disclose the molecular mechanism of action of capsaicin. We used capsaicin-treated and paraffin-embedded wax blocks containing substantia nigra tissue from 6-OHDA-induced Parkinson's disease rats to analyze transcriptional changes using Affymetrix GeneChip Whole Transcript Expression Arrays. A total of 108 genes were differentially expressed in response to capsaicin treatment, and seven of these genes were selected for further analysis: Olr724, COX1, Gsta2, Rab5a, Potef, Actg1, and Acadsb, of which Actg1 (actin gamma 1) was down-regulated and Gsta2 (Glutathione S-transferase alpha 2) was up-regulated. We successfully overexpressed Actg1 and Gsta2 in vitro. CCK-8 detection and flow cytometry demonstrated that overexpression of Actg1 and Gsta2 increased apoptosis in the 6-OHDA-induced Parkinson's disease cell model. The imbalance between Actg1 and Gsta2 may be one of the mechanisms of cell damage in Parkinson's disease (PD). Capsaicin can protect the cells and reduce the apoptosis rate by regulating Actg1 and Gsta2.
Lower PRDM2 expression is associated with dopamine-agonist resistance and tumor recurrence in prolactinomas
BMC CANCER
Authors: Gao, Hua; Wang, Fei; Lan, Xiaolei; Li, Chuzhong; Feng, Jie; Bai, Jiwei; Cao, Lei; Gui, Songbai; Hong, Lichuan; Zhang, Yazhuo
Abstract
Background: Dopamine agonists (DAs) are the first-line treatment for prolactinomas, which account for 25-30% of functioning pituitary adenomas, and bromocriptine (BRC) is the only commercially available DAs in China. However, tumors are resistant to therapy in 5-18% of patients. Methods: The exomes of six responsive prolactinomas and six resistant prolactinomas were analyzed by whole-exome sequencing. Results: Using stringent variant calling and filtering parameters, ten somatic variants that were mainly associated with DNA repair or protein metabolic processes were identified. New resistant variants were identified in multiple genes including PRDM2, PRG4, MUC4, DSPP, DPCR1, RP1L1, MX2, POTEF, C1orf170, and KRTAP10-3. The expression of these genes was then quantified by real-time reverse-transcription PCR (RT-qPCR) in 12 prolactinomas and 3 normal pituitary glands. The mRNA levels of PRDM2 were approximately five-fold lower in resistant prolactinomas than in responsive tumors (p < 0.05). PRDM2 protein levels were lower in resistant prolactinomas than in responsive tumors, as determined by Western blotting and immunohistochemical analysis (p < 0.05). Overexpression of PRDM2 upregulated dopamine receptor D2 (D2DR) and inhibited the phosphorylation of ERK1/2 in MMQ cells. PRDM2 showed a synergistic effect with BRC on the inhibition of prolactin (PRL) secretion and MMQ cell viability, and low PRDM2 expression was associated with tumor recurrence. Conclusions: PRDM2 downregulation may play a role in dopamine-agonist resistance and tumor recurrence in prolactinomas.