Fig 2: PTGS1 (COX1) knock-down reversed intermittent hypoxia with re-oxygenation (IHR)-induced up-regulation of MAOA hyperactivity. Representative micrographs of immunofluorescence staining in SH-SY5Y neuron cells with or without the knock-down of PTGS1 under IHR versus normoxic (NOX) conditions are given for (A) COX1, and (B) MAOA. IHR resulted in over-expressions of COX1, and MAOA hyperactivity, both of which were reversed with the knock-down of COX1. DAPI (blue) is used for staining the nuclei. Localizations of the two molecules are indicated in green. All the micrographs are a merge of the two stainings. Quantified values are stratified based on the response to IHR stimuli and PTGS1 SiRNA transfection. Kruskal–Wallis test with post-hoc analysis was used for comparisons between four groups. * p < 0.05. ** p < 0.01.

Fig 3: Expression of MAO-A in vivo and in vitro. (A). Representative immunohistochemical staining of HK II, PDH and MAO-A in GC tumour and paracancerous tissues. (B). Survival curve of MAO-A expression in gastric cancer patients. (C). Expression of MAO-A in cultured GES-1 and GC cell lines. n=4. *P < 0.05, **P < 0.01 compared with GES-1. All of the values are presented as the means ± SEM.Abbreviations: AGS, MGC803, and NCI-N87, human gastric cancer cell lines; GC, gastric cancer; GES-1, gastric epithelial cell line; HK II, hexokinase II; MAO-A, monoamine oxidase-A; PDH, pyruvate dehydrogenase.

Fig 4: The impact of flutamide on expression of putative androgen-regulated receptivity genes.To investigate if androgens produced by ESC could affect expression of putative androgen-regulated endometrial receptivity genes, ESC were co-treated with the anti-androgen flutamide and the expression of osteopontin (SPP1), monoamine oxidase (MAOA) and endothelin receptor B (EDNRB) were assessed. (A) Concentrations of mRNAs encoding SPP1 were significantly increased in decidualized ESC after 4 (p < 0.05) and 8 days treatment (p < 0.001) and significantly reduced in ESC co-treated with flutamide (n = 8, p < 0.05) at 8 days. (B) Concentrations of secreted SPP1 were detected by ELISA and calculated as fold change relative to decidualized ESC. SPP1 was not detected in supernatants from control cultures (ND). Co-treatment with flutamide significantly reduced secretion of SPP1 (n = 8, p < 0.01) and reduced the relative secretion of SPP1 by ~40%. (C) Concentrations of mRNAs encoding MAOA were significantly increased in decidualized ESC after 1 (p < 0.001), 2 (p < 0.001) and 4 days treatment (p < 0.05). MAOA mRNA expression was significantly increased relative to control in ESC co-treated with flutamide for 8 days (n = 8, p < 0.05). (D) Western blot analysis of MAOA expression from homogenates of ESC treated for 8 days revealed that MAOA protein was detected in control and decidualized ESC (n = 8 patients per treatment), and significantly increased in ESC co-treated with flutamide relative to control and decidualized ESC (n = 8, p < 0.001 and p < 0.01). Representative blots from 4 matched patients are shown. Loading control b-actin (red, 43 kDa), MAOA (green, 60 kDa). (E) Concentrations of mRNAs encoding EDNRB tended to be increased at each time point and were significantly increased in decidualized ESC after 8 days treatment (n = 8, p < 0.001). EDNRB mRNA expression was reduced in ESC co-treated with flutamide (F) Western blot analysis of EDNRB expression from homogenates of ESC treated for 8 days revealed that EDNRB protein was detected in control and decidualized ESC (n = 8 patients per treatment), and significantly increased in ESC treated to decidualize (p < 0.05). Co-treatment with flutamide significantly reduced concentrations EDNRB detected relative to decidualized ESC (n = 8, p < 0.001). Representative blots from 4 matched patients are shown. Loading control b-actin (red, 43 kDa), EDNRB (green, 50 kDa). *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.

Fig 5: Tph2 mRNA level (a) and protein (b) levels. Maoa mRNA level (c) and protein (d) levels in the hippocampus of experimental and control mice. Gene expression is presented as the number of cDNA copies per 100 cDNA copies of Polr2a. Protein levels were assessed in chemiluminescence relative units and normalized to GAPDH chemiluminescence relative units. N = 7–9.