Journal: PLoS ONE

Article Title: Dimer-Dependent Intrinsic/Basal Activity of the Class B G Protein-Coupled Receptor PAC1 Promotes Cellular Anti-Apoptotic Activity through Wnt/β-Catenin Pathways that Are Associated with Dimer Endocytosis

doi: 10.1371/journal.pone.0113913

Figure Lengend Snippet: (A) Western blotting of endogenous PACAP in CHO-K1 and neuro2a cells. As shown CHO-K1 had no detectable endogenous PACAP, while neuro2a cells produced endogenous PACAP. (B) The expression of PAC1-YFP and M-PAC1-YFP detected by immunofluorescence. Shown were immunofluorescence results of PAC1-CHO and M-PAC1-CHO cells cultured in DMEM with 0.5% CS-FBS at 37°C overnight, which indicated that both PAC1 and M-PAC1 trafficked normally to the plasma membrane and 0.5% CS-FBS induced no significant receptors endocytosis. (C) Fluorescence densities assays. Shown were the YFP fluorescence densities in the whole cell lysate detected using the Victor3 1420 multi-label counter with excitation (460±30 nm) and emission (535±30 nm), indicating that the expression levels of PAC1-YFP in CHO cells were equal to those of M-PAC1-YFP. (D) Western blotting assays using reductive SDS-PAGE. Western blotting with a goat polyclonal IgG against the C-terminus of PAC1 in the reductive condition showed that there were similar bands with the molecular weight about 160 kD in PAC1-CHO and M-PAC1-CHO, but not in CHO. (E) The cell viabilities of PAC1-CHO and M-PAC1-CHO cells promoted by PACAP. The data were plotted as the fold changes of the treatment without PACAP (0 nM). After the cells were submitted the addition of PACAP (1–100 nM) in the absence of CS-FBS for 24 h, MTT assays showed that PACAP exerted more significant proliferative effects on M-PAC1-CHO than on PAC1-CHO (*, P<0.01, M-PAC1-CHO vs. PAC1-CHO), indicating that the activation level of PAC1 by PACAP was lower than that of M-PAC1. (F) The intracellular cAMP levels induced by PACAP (1–100 nM) in PAC1-CHO and M-PAC1-CHO cells. After the data were plotted as the fold changes of the treatment with 0 nM PACAP, it was shown that the intracellular cAMP levels in M-PAC1-CHO cells induced by PACAP were significantly higher than the intracellular cAMP levels in PAC1-CHO cells induced by PACAP (*, P<0.01, M-PAC1-CHO vs. PAC1-CHO). The data were represented as the means ± S.E. of three independent experiments.

Article Snippet: To knockdown the endogenous PACAP in neuro2a neuroblastoma cells, cells that were seeded in 6-well plates in DMEM with 10% CS-FBS and cultured to 80% confluence were transfected for 6 h with 4 μg per well PACAP shRNA plasmid (Santa Cruz Biotechnology, USA) using lipofectamine LTX and Opti-MEM medium (Invitrogen, USA), after which the cells were washed and incubated with DMEM and 10% CS-FBS for 24 h. Then, puromycin (PM) (10 μg/mL) was added, and the cells were cultured for another 24 h. The cells were harvested for western blot analysis and were probed with a rabbit polyclonal anti-PACAP IgG (Santa Cruz Biotechnology, USA) that was raised against the C-terminus of PACAP and that recognizes both rodent and human PACAP.

Techniques: Western Blot, Produced, Expressing, Immunofluorescence, Cell Culture, Clinical Proteomics, Membrane, Fluorescence, SDS Page, Molecular Weight, Activation Assay

Journal: PLoS ONE

Article Title: Dimer-Dependent Intrinsic/Basal Activity of the Class B G Protein-Coupled Receptor PAC1 Promotes Cellular Anti-Apoptotic Activity through Wnt/β-Catenin Pathways that Are Associated with Dimer Endocytosis

doi: 10.1371/journal.pone.0113913

Figure Lengend Snippet: (A) The remaining cell viabilities of PAC1-CHO, M-PAC1-CHO and pcDNA-CHO cells 48 h after serum withdrawal. When the data were plotted as the percentage of the initial cell viability without serum withdrawal, it was shown that PAC1-CHO had remaining cell viability (57.34±5.91%) that was significantly higher than that of M-PAC1-CHO (36.96±6.85%) or pcDNA-CHO (37.89±7.11%) (*, P<0.01, PAC1-CHO vs. pcDNA-CHO and M-PAC1-CHO). (B) The intracellular caspase3 activities after serum withdrawal. The reactions of pcDNA-CHO were considered not result from PAC1 because pcDNA-CHO did not express PAC1 or PACAP; therefore, all the data were plotted as fold changes in pcDNA-CHO. As shown, PAC1-CHO had significantly lower caspase3 activity than M-PAC1-CHO or pcDNA-CHO (*, P<0.01, PAC1-CHO vs. pcDNA-CHO and M-PAC1-CHO), whereas there was no significant difference between M-PAC1-CHO and pcDNA-CHO. (C) The intracellular Bcl-2 levels after serum withdrawal. After the data were plotted as the fold changes of pcDNA-CHO, it was shown that PAC1-CHO had significantly higher Bcl-2 level about 2 folds of that in M-PAC1-CHO or pcDNA-CHO (*, P<0.01, PAC1-CHO vs. pcDNA-CHO and M-PAC1-CHO). The data were represented as the means ± S.E. of three independent experiments. (D) The detection of β-catenin, cyclin D1 and c-myc levels in PAC1-CHO, M-PAC1-CHO and pcDNA-CHO cells by western blotting. The western blotting results and the statistical analysis showed that the levels of β-catenin, cyclin D1 and c-myc (tow targets of β-catenin) in PAC1-CHO cells were significantly higher than those in M-PAC1-CHO or pcDNA-CHO cells (*, P<0.01, PAC1-CHO vs. pcDNA-CHO and M-PAC1-CHO). These findings indicated that overexpression of wild type PAC1 endowed CHO with anti-apoptotic activities against serum withdrawal, suggesting that PAC1 had ligand independent basal activity, while M-PAC1 did not. And Wnt/β-catenin signals were involved in the anti-apoptotic activity of PAC1-CHO. The data were represented as the means ± S.E. of three independent experiments.

Article Snippet: To knockdown the endogenous PACAP in neuro2a neuroblastoma cells, cells that were seeded in 6-well plates in DMEM with 10% CS-FBS and cultured to 80% confluence were transfected for 6 h with 4 μg per well PACAP shRNA plasmid (Santa Cruz Biotechnology, USA) using lipofectamine LTX and Opti-MEM medium (Invitrogen, USA), after which the cells were washed and incubated with DMEM and 10% CS-FBS for 24 h. Then, puromycin (PM) (10 μg/mL) was added, and the cells were cultured for another 24 h. The cells were harvested for western blot analysis and were probed with a rabbit polyclonal anti-PACAP IgG (Santa Cruz Biotechnology, USA) that was raised against the C-terminus of PACAP and that recognizes both rodent and human PACAP.

Techniques: Activity Assay, Western Blot, Over Expression

Journal: PLoS ONE

Article Title: Dimer-Dependent Intrinsic/Basal Activity of the Class B G Protein-Coupled Receptor PAC1 Promotes Cellular Anti-Apoptotic Activity through Wnt/β-Catenin Pathways that Are Associated with Dimer Endocytosis

doi: 10.1371/journal.pone.0113913

Figure Lengend Snippet: (A) Knockdown of endogenous PACAP and PAC1 with shRNA in Neuro2a. Western blotting assays showed that shRNA against PACAP significantly diminished the expression of endogenous PACAP in neuro2a/PACAP - , and further transfection with shRNA plasmids against PAC1 (+) to neuro2a/PACAP - cells decreased the PAC1 levels significantly, while control plasmids (-) did not interfere with expression of PAC1. The knockdown of PACAP and PAC1 in neuro2a produced a chance for the detection of the correlation of PAC1 down-regulation with its ligand independent basal activity. (B) The remaining cell viabilities of nero2a/PACAP - transfected with PAC1 shRNA plasmids (+) or control plasmid (-). After the data were plotted as the fold changes in the cells transfected with control plasmids (-), it was shown that down-regulation of PAC1 with PAC1 shRNA plasmids (+) decreased the remaining cell viabilities to almost a half of the remaining cell viabilities transfected with control plasmids (-) 48 h after serum withdrawal (*, P<0.01, shRNA + vs. shRNA-). (C) Western blotting of β-catenin, cyclin D1 and c-myc in the nero2a/PACAP - cells transfected with PAC1 shRNA plasmids (+) or control plasmids (-). After the relative protein levels were normalized by the corresponding levels of the control nucleoporin-p62 and plotted as the fold changes in the cells transfected with control plasmids (-), it was shown that PAC1 shRNA plasmids (+) significantly decreased the levels of β-catenin, cyclin D1 and c-myc compared with control plasmids (+)(*, P<0.01, shRNA+ vs. shRNA-). These data suggested that down-regulation of PAC1 in the natural cells such neuro2a with high expression of PAC1 inhibited the anti-apoptotic activities in the ligand free condition. The data were represented as the means ± S.E. of three independent experiments.

Article Snippet: To knockdown the endogenous PACAP in neuro2a neuroblastoma cells, cells that were seeded in 6-well plates in DMEM with 10% CS-FBS and cultured to 80% confluence were transfected for 6 h with 4 μg per well PACAP shRNA plasmid (Santa Cruz Biotechnology, USA) using lipofectamine LTX and Opti-MEM medium (Invitrogen, USA), after which the cells were washed and incubated with DMEM and 10% CS-FBS for 24 h. Then, puromycin (PM) (10 μg/mL) was added, and the cells were cultured for another 24 h. The cells were harvested for western blot analysis and were probed with a rabbit polyclonal anti-PACAP IgG (Santa Cruz Biotechnology, USA) that was raised against the C-terminus of PACAP and that recognizes both rodent and human PACAP.

Techniques: Knockdown, shRNA, Western Blot, Expressing, Transfection, Control, Produced, Activity Assay, Plasmid Preparation

Journal: Journal of Endocrinology

Article Title: Regulation of angiotensin II type 2 receptor gene expression in the adrenal medulla by acute and repeated immobilization stress

doi: 10.1530/joe-12-0181

Figure Lengend Snippet: Figure 7 Effects of cAMP and PACAP on AT2 receptor gene expression in PC12 cells. (A) PC12 cells were treated for 24 h with 1 mM dexamethasone (Dex) in the presence or absence of 200 mM CPT-cAMP (cAMP), a membrane-permeable cAMP analog. Subsequently, total RNA was isolated and AT2 receptor mRNA levels were determined by real-time RT-PCR. Data are normalized to Gapdh mRNA levels and expressed relative to vehicle-treated control, taken as 1. ***P!0.001 vs control; #P!0.05, ##P!0.01 vs Dex-treated group. (B) PC12 cells were treated for 7 h with 0.01 pM to 1000 nM PACAP 1–38. Subsequently, total RNA was isolated and Th, Dbh, and AT2 receptor mRNA levels were determined by real-time RT-PCR. Data are normalized to Gapdh mRNA levels and expressed relative to vehicle-treated control, taken as 1. ***P!0.001 vs control.

Article Snippet: In some experiments, cells were treated with dexamethasone alone or in combination with 200 mM 8-(4-chlorophenylthio)adenosine 30,50-cyclic monophosphate sodium salt (CPT-cAMP; Sigma– Aldrich), a membrane permeable cAMP analog, or with 0.01 pM to 1000 nM pituitary adenylate cyclase-activating polypeptide (PACAP) 1–38 (Tocris Bioscience, Minneapolis, MN, USA), dissolved in distilled water.

Techniques: Gene Expression, Membrane, Isolation, Quantitative RT-PCR, Control