SIRT1 in the BNST modulates chronic stress-induced anxiety of male mice via FKBP5 and corticotropin-releasing factor signaling.

Although clinical reports have highlighted association of the deacetylase sirtuin 1 (SIRT1) gene with anxiety, its exact role in the pathogenesis of anxiety disorders remains unclear. The present study was designed to explore whether and how SIRT1 in the mouse bed nucleus of the stria terminalis (BNST), a key limbic hub region, regulates anxiety. In a chronic stress model to induce anxiety in male mice, we used site- and cell-type-specific in vivo and in vitro manipulations, protein analysis, electrophysiological and behavioral analysis, in vivo MiniScope calcium imaging and mass spectroscopy, to characterize possible mechanism underlying a novel anxiolytic role for SIRT1 in the BNST. Specifically, decreased SIRT1 in parallel with increased corticotropin-releasing factor (CRF) expression was found in the BNST of anxiety model mice, whereas pharmacological activation or local overexpression of SIRT1 in the BNST reversed chronic stress-induced anxiety-like behaviors, downregulated CRF upregulation, and normalized CRF neuronal hyperactivity. Mechanistically, SIRT1 enhanced glucocorticoid receptor (GR)-mediated CRF transcriptional repression through directly interacting with and deacetylating the GR co-chaperone FKBP5 to induce its dissociation from the GR, ultimately downregulating CRF. Together, this study unravels an important cellular and molecular mechanism highlighting an anxiolytic role for SIRT1 in the mouse BNST, which may open up new therapeutic avenues for treating stress-related anxiety disorders.

BOP1 Silencing Suppresses Gastric Cancer Proliferation through p53 Modulation.

Block of proliferation 1 (BOP1) is a key protein involved in ribosome maturation and affects cancer progression. However, its role in gastric cancer (GC) remains unknown. This study aimed to explore the expression of BOP1 in GC and its potential mechanisms in regulating GC growth, and the relationship between BOP1 level in cancer tissues and survival was also analyzed. The expression of BOP1 was examined by immunohistochemistry (IHC) in a cohort containing 387 patients with primary GC. Cultured GC cells were treated by siRNA to knock down the BOP1 expression, and examined by CCK-8 assay and plate clone formation to assess cell proliferation in vitro. Apoptotic rate of cultured GC cells was detected by flow cytometry with double staining of AnnxinV/PI. The xenografted mouse model was used to assess GC cell proliferation in vivo. Western blot and IHC were also performed to detect the expression levels of BOP1, p53 and p21. Patients with higher level of BOP1 in cancer tissues had significantly poorer survival. BOP1 silencing significantly suppressed GC cell proliferation both in vitro and in vivo. It blocked cell cycle at G0/G1 phase and led to apoptosis of GC cells via upregulating p53 and p21. BOP1 silencing-induced suppression of cell proliferation was partly reversed by pifithrin-α (a p53 inhibitor). Our study demonstrated that BOP1 up-regulation may be a hallmark of GC and it may regulate proliferation of GC cells by activating p53. BOP1 might be considered a novel biomarker of GC proliferation, and could be a potential indicator of prognosis of GC patients. BOP1 might also be a potential target for the treatment of GC patients if further researched.

Triptolide inhibits viability and induces apoptosis in liver cancer cells through activation of the tumor suppressor gene p53.

The present study investigated the effect of triptolide on viability and apoptosis along with underlying mechanism in liver cancer cells. CCK-8 assay showed that triptolide treatment for 48 h significantly reduced the viability of HepG2 and QSG7701 cells at 50 µM concentration. Annexin V-FITC and propidium iodide staining showed that triptolide treatment of HepG2 cells at 50 µM concentrations induced apoptosis in 56.45% cells compared to only 2.36% cells in the control cultures. Western blot assay showed that treatment of HepG2 cells with 50 µM concentration of triptolide significantly induced phosphorylation of p53 in a 2 h-treatment. Phosphorylation of histone H2A.X indicator of DNA damage was induced by triptolide treatment after 12 h in HepG2 cells. The level of nuclear p53 in a 6 h-treatment with 0, 10, 20, 30, 40 and 50 µM concentration of triptolide was found to be 15.3, 19.6, 28.5, 43.7, 63.8 and 91.5%, respectively. Treatment of HepG2 cells with triptolide at 50 µM concentration caused a significant increase in the binding potential of p53 to DNA. Triptolide treatment of HepG2 cells caused a significant increase in the expression of p21, Bax and DR5 genes in HepG2 cells. It also increased the expression of miR-34b and miR-34c in HepG2 cells markedly. Treatment of HepG2 cells with p53 inhibitor, pifithrin-α prior to incubation with triptolide significantly prevented induction of cell apoptosis. Suppression of p53 expression by siRNA inhibited the expression of p53 as well as its target genes along with the prevention of apoptosis induction. In conclusion, triptolide inhibits viability and induces apoptosis in liver cancer cells through activation of the tumor suppressor gene p53. Thus, triptolide can be used for the treatment of liver cancer.

Anti-proliferative of physcion 8-O-ß-glucopyranoside isolated from Rumex japonicus Houtt. on A549 cell lines via inducing apoptosis and cell cycle arrest.

BACKGROUND: Lung cancers are leading causes of cancer death, and Rumex japonicus has been traditionally used in folk medicine as anti-microorganic, anti-inflammatory and anti-tumor agents. This study was designed to investigate the anti-proliferative activity of physcion 8-O-ß-glucopyranoside (PG) isolated from Rumex japonicus Houtt. on A549 cell lines. METHODS: In our present study, PG was isolated and identified from the ethanol extracts of R. japonicus. MTT method was used to evaluate the anti-proliferative activity of PG on A549 cell lines, and cell cycle distribution assay, apoptosis assay, and western blot analysis in vitro were used to explore the possible mechanisms. RESULTS: From the results of our present study, cell viability was obviously inhibited by PG, in a dose- and time-dependent manner. Our results also suggested that the anti-proliferative effect of PG was related to cell cycle arrest at the G2/M phase through repression of cdc2 and Cyclin B1 protein expression. In addition, the results of apoptosis assay and western blot analysis indicated that the anti-proliferative activity could be related to apoptosis via up-regulating the expressions of Bax, caspase-3 and caspase-7, and down-regulating the expressions of Bcl-2. CONCLUSIONS: In conclusion, the PG has significant anti-proliferative activity on A549 cell lines, and the possible mechanism was related to cell cycle arrest at the G2/M phase, and apoptosis via the regulations of Bax, Bcl-2, and caspase-3 and caspase-7.