Prostaglandin D2 Synthase Expression Research Articles

Prognostic analysis of prostaglandin D2 synthase in diffuse large B-cell lymphoma

PurposeWe aimed to analyse the correlation between prostaglandin D2 synthase (PTGDS) and a diffuse large B-cell lymphoma (DLBCL) prognosis.MethodsWe retrospectively collected two hundred paraffin-embedded tissue specimens that were pathologically diagnosed as DLBCL in the Fujian Tumour Hospital between January 2014 and December 2018. An abundance of paraffin-embedded tumour tissues were obtained. Twenty patients with lymphocyte-rich, benign, tissue-reactive, hypertrophic tonsillitis were selected as controls. Wax blocks were selected for primary cases and the controls were screened by professional pathologists. The levels of prostaglandin D2 synthase (PTGDS) and the EMT-related molecules, E-cadherin and vimentin, were detected by immunohistochemistry in clinical samples. A chi-square test revealed the correlations between PTGDS expression and clinicopathological characteristics, including age, sex, primary site, clinical stage, immunotyping, and International Prognostic Index (IPI) score. The Kaplan–Meier survival analysis was performed, and the diagnostic value was evaluated by receiver operating characteristic (ROC) curve analysis.ResultsA total of 138 cases (69%) were found to be PTGDS positive (> 30% positive cells). PTGDS staining was negative (< 30% positive cells) in 62 cases (31%). We collected the corresponding clinicopathological information and found that PTGDS expression was not significantly related to the patients’ age, tumour stage, presence of extranodal invasion, or IPI score. According to the follow-up data, patients with low PTGDS expression had poor progression-free survival (PFS) and overall survival (OS), with 2-year PFS and OS rates of 41.7% and 50%, respectively. The 2-year PFS and OS rates of PTGDS-positive patients were 89.3% and 92.9%, respectively (P < 0.0001), and the differences were significant.ConclusionWe found that the expression level of PTGDS is significantly correlated with the prognosis of diffuse large B-cell lymphoma.

Sex-differences in prostaglandin signaling: a semi-systematic review and characterization of PTGDS expression in human sensory neurons

There is increasing evidence of sex differences in underlying mechanisms causing pain in preclinical models, and in clinical populations. There are also important disconnects between clinical pain populations and the way preclinical pain studies are conducted. For instance, osteoarthritis pain more frequently affects women, but most preclinical studies have been conducted using males in animal models. The most widely used painkillers, nonsteroidal anti-inflammatory drugs (NSAIDs), act on the prostaglandin pathway by inhibiting cyclooxygenase (COX) enzymes. The purpose of this study was to analyze the preclinical and clinical literature on the role of prostaglandins and COX in inflammation and pain. We aimed to specifically identify studies that used both sexes and investigate whether any sex-differences in the action of prostaglandins and COX inhibition had been reported, either in clinical or preclinical studies. We conducted a PubMed search and identified 369 preclinical studies and 100 clinical studies that matched our inclusion/exclusion criteria. Our analysis shows that only 17% of preclinical studies on prostaglandins used both sexes and, out of those, only 19% analyzed or reported data separated by sex. In contrast, 79% of the clinical studies analyzed used both sexes. However, only 6% of those reported data separated by sex. Interestingly, 14 out of 15 preclinical studies and 5 out of 6 clinical studies that analyzed data separated by sex have identified sex-differences. This builds on the increasing evidence of sex-differences in prostaglandin signaling and the importance of sex as a biological variable in data analysis. The preclinical literature identifies a sex difference in prostaglandin D2 synthase (PTGDS) expression where it is higher in female than in male rodents in the nervous system. We experimentally validated that PTGDS expression is higher in female human dorsal root ganglia (DRG) neurons recovered from organ donors. Our semi-systematic literature review reveals a need for continued inclusivity of both male and female animals in prostaglandins studies and data analysis separated by sex in preclinical and clinical studies. Our finding of sex-differences in neuronal PTGDS expression in humans exemplifies the need for a more comprehensive understanding of how the prostaglandin system functions in the DRG in rodents and humans.

AT56 Exerts Anti-Tumor Effects in Peripheral T Cell Lymphoma By Regulating HMOX1-Mediated Ferroptosis

Introduction: Accumulating evidence indicates that prostaglandin D2 synthase (PTGDS) plays important roles in various diseases, including tumor. Ferroptosis, a recently recognized form of cell death, has been found to participate in the development of hematologic tumor, especially lymphoma. Here, we investigated the effects of AT56, the specific inhibitor of PTGDS, and its regulatory role on ferroptosis in peripheral T cell lymphoma (PTCL). Methods: Lymph node biopsies from 112 de novo PTCL patients and 38 reactive hyperplasia cases. RNA-sequencing and Tandem mass tag (TMT)-mass spectrometry were conducted in PTCL cells treated with AT56. C11-BODIPY was used to detect the level of lipid ROS. Xenograft PTCL mice model was established to evaluate drug efficacy. Co-immunoprecipitation (Co-IP) and confocal immunofluorescence (IF) were performed to validate protein interaction. Plasmids of HMOX1-WT and HMOX1-H25A were synthesized and transfected into PTCL cells. Results: Firstly, we explored the expression and function of PTGDS in PTCL. The expression level of PTGDS in tumor tissue (n=112) was found to be higher than control group. Survival analysis revealed that elevated PTGDS expression predicted inferior prognosis in PTCL patients. Gene ontology (GO) analysis indicated that AT56 treatment was associated with biological processes involved in tumor progression, such as cell death, apoptosis, and cell cycle. Then, AT56 could inhibit the proliferation of PTCL cells in a dose- and time-dependent manner. Analysis based on TMT-mass spectrometry revealed the differential expression of ferroptosis-associated proteins after AT56 treatment. As erastin and sorafenib are ferroptosis inducers, AT56 significantly enhanced their effects on the accumulation of lipid ROS (Fig. 1), a classic biomarker of ferroptosis. Besides, ferrostatin-1(Fer-1), a specific ferroptosis inhibitor reversed AT56-induced lipid ROS accumulation and cell proliferation inhibition. Furthermore, the combined drug effects of AT56 and sorafenib was revealed in xenograft mice model, indicating the regulatory role of AT56 on ferroptosis in PTCL. As ferroptosis is characterized by its dependence on iron accumulation, reactive oxygen species (ROS) production, lipid peroxidation, we further explored the specific mechanism by which AT56 regulated ferroptosis process. In our study, ferroptosis-associated molecules (NRF2, KEAP1) and iron-associated molecules (NCOA4, FTH, FTL) were aberrantly expressed after AT56 treatment, indicating ferroptosis activation, while the expression of lipid and ROS-associated molecules (ACSL4, xCT, GPX4) displayed compensatory changes. As expected, deferoxamine (DFO), an iron chelator, rescued the effect of AT56 on cell proliferation and lipid ROS accumulation. Elevated level of Fe2+ was found in tumor tissue from mice receiving AT56, indicating that the role of AT56 on ferroptosis mainly depended on iron accumulation. High expression of NCOA4 indicated the involvement of autophagy in ferroptosis process induced by AT56. Chloroquine, a common autophagy inhibitor, could partly reverse AT56-induced accumulation of lipid ROS and Fe2+, and expression of Fe2+ storage protein, suggesting the dependence of AT56-induced ferroptosis on autophagy in PTCL cells. Structure analysis based on TMT-mass spectrometry identified HMOX1, a regulator of heme catabolism and autophagy, as PTGDS-interacting protein, and further Co-IP and IF assays validated their co-localization and interaction in PTCL cells. Besides, HMOX1 knockdown could rescue AT56-induced cell proliferation inhibition and Fe2+ accumulation (Fig. 2). Furthermore, point mutation of HMOX1 (H25A) was found to inhibit its regulatory role on ferroptosis. Conclusions: Taken together, our investigations identified for the first time that high expression of PTGDS was associated with poor prognosis in PTCL patients. AT56 exerted potent anti-tumor effects in PTCL via promoting ferroptosis process, which was mediated by HMOX1 and partly dependent on autophagy. Our in vitro and in vivo study revealed the synergistic effect and mechanism of AT56 and sorafenib, providing a novel AT56-based treatment paradigm for PTCL patients. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Glycoprotein PTGDS promotes tumorigenesis of diffuse large B-cell lymphoma by MYH9-mediated regulation of Wnt\u2013\u03b2-catenin\u2013STAT3 signaling

Glycoprotein prostaglandin D2 synthase (PTGDS) is a member of the lipocalin superfamily and plays dual roles in prostaglandins metabolism and lipid transport. PTGDS has been involved in various cellular processes including the tumorigenesis of solid tumors, yet its role in carcinogenesis is contradictory and the significance of PTGDS in hematological malignancies is ill-defined. Here, we aimed to explore the expression and function of PTGDS in diffuse large B-cell lymphoma (DLBCL), especially the potential role of PTGDS inhibitor, AT56, in lymphoma therapy. Remarkable high expression of PTGDS was found in DLBCL, which was significantly correlated with poor prognosis. PTGDS overexpression and rhPTGDS were found to promote cell proliferation. Besides, in vitro and in vivo studies indicated that PTGDS knockdown and AT56 treatment exerted an anti-tumor effect by regulating cell viability, proliferation, apoptosis, cell cycle, and invasion, and enhanced the drug sensitivity to adriamycin and bendamustine through promoting DNA damage. Moreover, the co-immunoprecipitation-based mass spectrum identified the interaction between PTGDS and MYH9, which was found to promote DLBCL progression. PTGDS inhibition led to reduced expression of MYH9, and then declined activation of the Wnt-β-catenin-STAT3 pathway through influencing the ubiquitination and degradation of GSK3-β in DLBCL. The rescue experiment demonstrated that PTGDS exerted an oncogenic role through regulating MYH9 and then the Wnt-β-catenin-STAT3 pathway. Based on point mutation of glycosylation sites, we confirmed the N-glycosylation of PTGDS in Asn51 and Asn78 and found that abnormal glycosylation of PTGDS resulted in its nuclear translocation, prolonged half-life, and enhanced cell proliferation. Collectively, our findings identified for the first time that glycoprotein PTGDS promoted tumorigenesis of DLBCL through MYH9-mediated regulation of Wnt-β-catenin-STAT3 signaling, and highlighted the potential role of AT56 as a novel therapeutic strategy for DLBCL treatment.

Prostaglandin D2 synthase/prostaglandin D2/TWIST2 signaling inhibits breast cancer proliferation.

Though the past few years have witnessed exciting achievements in targeted and immunotherapeutic treatments of all breast cancer subtypes, yet the decline in breast cancer mortality has been slowed, urging the need for further expanding options of high-quality treatments. Prostaglandin D2 synthase (PTGDS)/prostaglandin D2 (PGD2) play important roles in a variety of cancer types and show tissue-specificity, however, there are limited relevant reports in breast cancer. Therefore, the aims of the present study were to investigate the effects of PTGDS/PGD2 in breast cancer by large-scale bioinformatic analysis and in vitro experiments conducted on human breast cancer cell lines. Results of our study indicated that patients with high levels of PTGDS expression showed a reduced potential of tumor proliferation. PGD2 treatment significantly inhibited the proliferation and migration of breast cancer cells, which was mediated by the reduced expression of TWIST2. Overexpression of TWIST2 reversed the inhibitory effects of PGD2 on breast cancer cell proliferation. These results provided the novel evidence that PTGDS may play a significant role in modulating breast cancer growth, with implications for its potential use in treating breast cancer.

Targeting Glycosylated Ptgds Displays Anti-Tumor Activities in Diffuse Large B-Cell Lymphoma through Down-Regulation of Wnt Pathway

Introduction: Prostaglandin D2 Synthase (PTGDS), a member of lipocalin superfamily, plays a dual role in catalyzing the conversion of PGH2 to PGD2 and transporting lipophilic substances. PTGDS protein is with different degrees of glycosylation. AT56 is a selective, competitive, and highly bioavailable inhibitor of PTGDS. However, the function and mechanism of PTGDS in diffuse large B-cell lymphoma (DLBCL) remains ill defined. Herein, we aimed to investigate the functional significance of PTGDS and proposed a novel therapeutic strategy for DLBCL. Methods: Lymph node biopsies from 53 de novo DLBCL patients and 28 reactive hyperplasia cases, and peripheral blood mononuclear cells (PBMCs) from healthy volunteers were collected with informed consents. CD19+ B cells were purified by CD19+ magnetic microbeads. The expression levels of PTGDS in DLBCL cell lines and serum were detected by western blotting and ELISA, respectively. Lentivirus vectors were transfected to stably knockdown or overexpress PTGDS. After the treatment of Tunicamycin (Tun), an N-glycosylation inhibitor, western blotting and immunofluorescence were performed to validate the molecular weight and location of PTGDS protein. Results: We first evaluated the expression of PTGDS in DLBCL. Upregulation of PTGDS mRNA in DLBCL cells was identified based on Oncomine database (Fig.1A). Then, the expression level of PTGDS protein in tumor tissue (n=53) was validated to be higher in comparison with control group (Fig.1B). Furthermore, survival analysis revealed that PTGDS high expression was associated with reduced overall survival of DLBCL patients (Fig.1C). Moreover, high level of soluble PTGDS protein was detected in the serum of DLBCL patients (n=53, Fig.1D). High expression of PTGDS was also confirmed in DLBCL cells by western blotting (Fig.2A). The biological function of PTGDS in progression of DLBCL was further verified. Gene ontology and KEGG analysis revealed that PTGDS was enriched in cellular process and biological regulation (Fig.2B). After the treatment with rhPTGDS, increased proliferation of DLBCL cell was observed in a dose-dependent manner (Fig.2D), and overexpression of PTGDS also promoted cell growth (Fig.2E). Furthermore, knockdown of PTGDS (shPTGDS) significantly restrained cell proliferation (Fig.2F), promoted cell cycle arrest (Fig.2G) and cell apoptosis (Fig.2H). AT56 suppressed the proliferation of DLBCL cells in a dose- and time-dependent manner (Fig. 3A). Additionally, with the treatment of AT56, DLBCL cells exhibited induced G0/G1 phase arrest (Fig. 3B) and increased cell apoptosis (Fig. 3C). As Bendamustine and Adriamycin were found to decrease the mRNA level of PTGDS (Fig. 3D), we further observed that AT56 enhanced sensitivity to them in cell proliferation (Fig. 3E) and cell apoptosis (Fig. 3F). Next, we explored the underlying mechanism of PTGDS in DLBCL progression. The expression of Wnt pathway molecules, such as p-LRP6, β-catenin, p-GSK3-β, Lef-1, p-STAT3, were decreased with treatment of AT56 in dose-dependent manner (Fig. 4A). Besides, STAT3 inhibitor WP1066 was found to restore the proliferation promotion (Fig. 4B) caused by PTGDS overexpression. Moreover, we validated that Wnt pathway activator Wnt3a could restore the phenotype changes caused by AT56, including cell proliferation (Fig. 4C), cell apoptosis (Fig. 4D) and cell cycle (Fig. 4E). Glycosylation, a kind of post-translational modification, could significantly alter protein function and then cellular characteristics. Protein Blast analysis indicated the potential glycosylation sites (Fig. 5A) on PTGDS protein (Ser29, Asn51 and Asn78). Furthermore, Tunicamycin was used to inhibit the N-glycosylation of protein and molecular weight of PTGDS changed from 37kD to 21kD (Fig.5B). Besides, the deglycosylation could promote the translocation of PTGDS into the nucleus (Fig.5C-D), indicating the potential role of glycosylated PTGDS in DLBCL. Conclusions : Our investigations identified for the first time the aberrant overexpression of PTGDS in DLBCL, which was associated with poor prognosis. AT56 exerted anti-tumor effect via inhibiting Wnt pathway. Besides, PTGDS protein in DLBCL cells were highly glycosylated and deglycosylation promoted its translocation into nucleus, indicating the mechanism of PTGDS in DLBCL. Further investigation is warranted to substantiate PTGDS as a promising therapeutic target in DLBCL. Disclosures No relevant conflicts of interest to declare.

Tumour-Infiltrating Immune Cell-Based Subtyping and Signature Gene Analysis in Breast Cancer Based on Gene Expression Profiles.

Tumour-infiltrating immune cells have been indicated to play an important role in prognosis prediction and therapy sensitivity for breast cancer. In recent years, estimating the abundance of immune cells based on tumour transcriptome data has provided a novel way to analyse the clinical significance of various immune cell subsets. This study integrated breast cancer tissue transcriptome datasets from the Gene Expression Omnibus (GEO), the Cancer Genome Atlas-Breast Cancer (TCGA-BRCA) and the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) cohorts. A novel breast cancer immunotyping and a new prognostic model based on tumour-infiltrating immune cell subsets have been established, aiming to provide new clues regarding prognostic prediction and precision therapy for breast cancer. The key differentially expressed gene between different breast cancer immunotypes has also been identified. We performed unsupervised clustering analysis and construct a novel immunotyping which could classify breast cancer cases into immunotype A (B_cellhigh NKhigh CD8+_Thigh CD4+_memory_T_activatedhigh γδTlow Mast_cell_activatedlow Neutrophillow) and immunotype B (B_celllow NKlow CD8+_Tlow CD4+_memory_T_activatedlow γδThigh Mast_cell_activatedhigh Neutrophilhigh) in luminal B, HER2-enriched and basal-like subtypes. The 5-year (85.7% vs. 73.4%) and 10-year OS (75.60% vs. 61.73%) of immunotype A population were significantly higher than those of immunotype B. A novel tumour-infiltrating immune cell-based prognostic model had also been established and the result immunorisk score (IRS) could serve as a new prognostic factor for luminal B, HER2-enriched and basal-like breast cancer. The higher IRS was, the worse prognosis was. We further screened the differentially expressed genes between immunotype A and B and identified a novel breast cancer immune-related gene, prostaglandin D2 synthase (PTGDS) and higher PTGDS mRNA expression level was positively correlated with earlier TNM stage. Immune-related signaling pathways analysis and immune cell subsets correlation analysis revealed that PTGDS expression was related with abundance of B cells, CD4+ T cells and CD8+ T cells, which was finally validated by immunohistochemical and immunofluorescence staining. We established a novel immunotyping and a tumour-infiltrating immune cell-based prognostic prediction model in luminal B, HER2-enriched and basal-like breast cancer by analyzing the prognostic significance of multiple immune cell subsets. A novel breast cancer immune signature gene PTDGS was discovered, which might serve as a protective prognostic factor and play an important role in breast cancer development and lymphocyte-related immune response.

Delay in hepatocyte proliferation and prostaglandin D2 synthase expression for cholestasis due to endotoxin during partial hepatectomy in rats.

Infection is a frequent complication of liver transplantation or partial hepatectomy (PH) and sometimes results in cholestasis. We examined factors involved in infection-induced cholestasis after PH, employing a rat PH model and lipopolysaccharide (LPS) as a bacterial toxin. Male Sprague-Dawley rats were subjected to 70% PH and/or LPS injection, and tissues were harvested at 0, 24, 72 and 168 h. Gene expression was analyzed by microarray analysis and reverse transcription-quantitative polymerase chain reaction, and protein levels and localization were analyzed by western blotting and immunohistochemistry, respectively. Plasma bile acid levels were significantly higher in the LPS + PH group than in the PH group. Ribonucleotide reductase regulatory subunit M2 and proliferating cell nuclear antigen peaked at 24 and 72 h in the PH group and LPS + PH group, respectively, indicating a delay in cell proliferation in the latter group. The sodium-dependent taurocholate cotransporting polypeptide and organic-anion-transporting polypeptide 1a1 and 1a2 were reduced in the PH group at 24 h, and were not further decreased in the LPS + PH group. Chemokine ligand 9 (Cxcl9), a chemokine involved in M2 macrophage polarization, increased after 24 h in the LPS and the LPS + PH groups. The number and shape of Cxcl9-positive cells were similar to CD163-positive cells, suggesting that such cells produced the chemokine. Hematopoietic prostaglandin D2 synthase (Ptgds2) was only detected in hepatocytes of the LPS + PH group exhibiting a delay in cell proliferation. Thus, Kupffer cells activated with LPS were suggested to be responsible for a delay in hepatocyte proliferation after PH.

Multiple sevoflurane exposures during pregnancy inhibit neuronal migration by upregulating prostaglandin D2 synthase

BackgroundThe second trimester is a period of neurogenesis and neuronal migration, which may be affected by exposure to anesthetics. Studies have suggested that multiple anesthetic exposures may have a significant impact on neuronal migration. MethodsPregnant C57BL/6 mice at embryonic day 14.5 were randomly divided into four groups: Con x 1, Sev x 1, Con x 2, and Sev x 2. Cortical neuronal migration in offspring mice was detected by GFP immunostaining, and the number of cells in the cortex was analyzed. ResultsDual exposure to sevoflurane, not single sevoflurane exposure, caused neuronal migration deficits. Dual exposure to sevoflurane increased the expression of prostaglandin D2 synthase (Ptgds). Furthermore, Ptgds siRNA attenuated neuronal migration deficits induced by dual sevoflurane exposure. ConclusionOur study suggests that multiple sevoflurane exposures in pregnant mice may induce neuronal migration deficits in offspring mice. Additional studies comprising long-term behavioral tests are required to confirm the effects of sevoflurane exposure during pregnancy.

A Parkinson's disease gene, DJ-1, regulates anti-inflammatory roles of astrocytes through prostaglandin D2 synthase expression

A Parkinson's disease gene, DJ-1, regulates anti-inflammatory roles of astrocytes through prostaglandin D2 synthase expression

A Parkinson's disease gene, DJ-1, regulates anti-inflammatory roles of astrocytes through prostaglandin D2 synthase expression

Dysfunctional regulation of inflammation may contribute to the progression of neurodegenerative diseases. The results of this study revealed that DJ-1, a Parkinson's disease (PD) gene, regulated expression of prostaglandin D2 synthase (PTGDS) and production of prostaglandin D2 (PGD2), by which DJ-1 enhanced anti-inflammatory function of astrocytes. In injured DJ-1 knockout (KO) brain, expression of tumor necrosis factor-alpha (TNF-α) was more increased, but that of anti-inflammatory heme oxygenase-1 (HO-1) was less increased compared with that in injured wild-type (WT) brain. Similarly, astrocyte-conditioned media (ACM) prepared from DJ-1-KO astrocytes less induced HO-1 expression and less inhibited expression of inflammatory mediators in microglia. With respect to the underlying mechanism, we found that PTGDS that induced expression of HO-1 was lower in DJ-1 KO astrocytes and brains compared with their WT counterparts. In addition, PTGDS levels increased in the injured brain of WT mice, but barely in that of KO mice. We also found that DJ-1 regulated PTGDS expression through Sox9. Thus, Sox9 siRNAs reduced PTGDS expression in WT astrocytes, and Sox9 overexpression rescued PTGDS expression in DJ-1 KO astrocytes. In agreement with these results, ACM from Sox9 siRNA-treated astrocytes and that from Sox9-overexpression astrocytes exerted opposite effects on HO-1 expression and anti-inflammation. These findings suggest that DJ-1 positively regulates anti-inflammatory functions of astrocytes, and that DJ-1 dysfunction contributes to the excessive inflammatory response in PD development.

Astrocyte-Derived Exosomes Treated With a Semaphorin 3A Inhibitor Enhance Stroke Recovery via Prostaglandin D2 Synthase.

Background and Purpose- Exosomes play a pivotal role in neurogenesis. In the peri-infarct area after stroke, axons begin to regenerate but are inhibited by astrocyte scar formation. The direct effect and underlying molecular mechanisms of astrocyte-derived exosomes on axonal outgrowth after ischemia are not known. Methods- Using a semaphorin 3A (Sema3A) inhibitor, we explored neuronal signaling during axonal outgrowth after ischemia in rats subjected to middle cerebral artery occlusion and in cultured cortical neurons challenged with oxygen-glucose deprivation. Furthermore, we assessed whether this inhibitor suppressed astrocyte activation and regulated astrocyte-derived exosomes to enhance axonal outgrowth after ischemia. Results- In rats subjected to middle cerebral artery occlusion, we administered a Sema3A inhibitor into the peri-infarct area from 7 to 21 days after occlusion. We found that phosphorylated high-molecular weight neurofilament-immunoreactive axons were increased, glial fibrillary acidic protein-immunoreactive astrocytes were decreased, and functional recovery was promoted at 28 days after middle cerebral artery occlusion. In cultured neurons, the Sema3A inhibitor decreased Rho family GTPase 1, increased R-Ras, which phosphorylates Akt and glycogen synthase kinase 3β (GSK-3β), selectively increased phosphorylated GSK-3β in axons, and thereby enhanced phosphorylated high-molecular weight neurofilament-immunoreactive axons after oxygen-glucose deprivation. In cultured astrocytes, the Sema3A inhibitor suppressed activation of astrocytes induced by oxygen-glucose deprivation. Exosomes secreted from ischemic astrocytes treated with the Sema3A inhibitor further promoted axonal elongation and increased prostaglandin D2 synthase expression on microarray analysis. GSK-3β+ and prostaglandin D2 synthase+ neurons were robustly increased after treatment with the Sema3A inhibitor in the peri-infarct area. Conclusions- Neuronal Rho family GTPase 1/R-Ras/Akt/GSK-3β signaling, axonal GSK-3β expression, and astrocyte-derived exosomes with prostaglandin D2 synthase expression contribute to axonal outgrowth and functional recovery after stroke.

Investigation on the role and mechanism of prostagland in D2 synthase in non-small cell lung cancer

Objective: To investigate prostaglandin D2 synthase (PTGDS) expression in non-small cell lung carcinoma (NSCLC) and clarify whether PTGDS could be a biomarke. Methods: Firstly, the protein expression level of PTGDS in adenocarcinoma (ADC) and squamous cell carcinoma (SCC) were analyzed respectively through Gene Expression Omnibus (GEO)dataset. Then, the results were verified by using tissue microarray (TMA). At last, in order to explore the inner mechanism, lung adenocarcinoma cell lines A549 and Calu-3 were selected to over-express PTGDS, and then transwell chamber assay and Western blotting were used to detect associated changes. Results: PTGDS expression is down-regulated in both ADC and SCC, however, no statistical difference has been found between the two groups, and PTGDS was only related to the progression of ADC. Furthermore, After over-expression of PTGDS, the invasiveness of ADC cells was significantly decreased. Western blotting showed that the inner mechanisms may be related to mitogen-activated protein kinase (MAPK) signal pathway. Conclusions: This study revealed that PTGDS was down-regulated in NSCLC and only related to the development of ADC. It may be a potential biomarker for the diagnosis and prognosis of NSCLC. However, whether it could be used for the treatment of NSCLC still needs more research.

Mannose receptor modulates macrophage polarization and allergic inflammation through miR-511-3p

Mannose receptor (MRC1/CD206) has been suggested to mediate allergic sensitization and asthma to multiple glycoallergens, including cockroach allergens. We sought to determine the existence of a protective mechanism through which MRC1 limits allergic inflammation through its intronic miR-511-3p. We examined MRC1-mediated cockroach allergen uptake by lung macrophages and lung inflammation using C57BL/6 wild-type (WT) and Mrc1-/- mice. The role of miR-511-3p in macrophage polarization and cockroach allergen-induced lung inflammation in mice transfected withadeno-associated virus (AAV)-miR-511-3p (AAV-cytomegalovirus-miR-511-3p-enhanced green fluorescent protein) was analyzed. Gene profiling of macrophages with or without miR-511-3p overexpression was also performed. Mrc1-/- lung macrophages showed a significant reduction in cockroach allergen uptake compared with WT mice, and Mrc1-/- mice had an exacerbated lung inflammation with increased levels of cockroach allergen-specific IgE and TH2/TH17 cytokines in a cockroach allergen-induced mouse model compared with WT mice. Macrophages from Mrc1-/- mice showed significantly reduced levels of miR-511-3 and an M1 phenotype, whereas overexpression of miR-511-3p rendered macrophages to exhibit a M2 phenotype. Furthermore, mice transfected with AAV-miR-511-3p showed a significant reduction in cockroach allergen-induced inflammation. Profiling of macrophages with or without miR-511-3p overexpression identified 729 differentially expressed genes, wherein expression of prostaglandin D2 synthase (Ptgds) and its product PGD2 were significantly downregulated by miR-511-3p. Ptgds showed a robust binding to miR-511-3p, which might contribute to the protective effect of miR-511-3p. Plasma levels of miR-511-3p were significantly lower in human asthmatic patients compared with nonasthmatic subjects. These studies support a critical but previously unrecognized role of MRC1 and miR-511-3p in protection against allergen-induced lung inflammation.

Oligodendrocyte precursor cells synthesize neuromodulatory factors.

NG2 protein-expressing oligodendrocyte progenitor cells (OPC) are a persisting and major glial cell population in the adult mammalian brain. Direct synaptic innervation of OPC by neurons throughout the brain together with their ability to sense neuronal network activity raises the question of additional physiological roles of OPC, supplementary to generating myelinating oligodendrocytes. In this study we investigated whether OPC express neuromodulatory factors, typically synthesized by other CNS cell types. Our results show that OPC express two well-characterized neuromodulatory proteins: Prostaglandin D2 synthase (PTGDS) and neuronal Pentraxin 2 (Nptx2/Narp). Expression levels of the enzyme PTGDS are influenced in cultured OPC by the NG2 intracellular region which can be released by cleavage and localizes to glial nuclei upon transfection. Furthermore PTGDS mRNA levels are reduced in OPC from NG2-KO mouse brain compared to WT cells after isolation by cell sorting and direct analysis. These results show that OPC can contribute to the expression of these proteins within the CNS and suggest PTGDS expression as a downstream target of NG2 signaling.

Aeroallergens Derived from Alternaria alternata Stimulate COX2‐dependent Expression of Antioxidant Defense Enzymes in Human Bronchial Epithelial Cells

Alternaria aeroallergens stimulate allergic inflammation and exacerbation of respiratory distress in patients with asthma. Our previous studies have demonstrated that release of ATP and subsequent increases in intracellular [Ca2+] was the result of Alternaria induced oxidative stress. Stimulation of Human Bronchial Epithelial Cells (HBECs) with Alternaria extract for 12 hours induced the expression of several phase II antioxidant enzymes, including cyclooxygenase 2 (COX2) which exhibited a 19 fold increase in mRNA expression. HBE cells loaded with CellRox™ Orange, a fluorogenic probe used for detecting oxidative stress, revealed that blocking COX2 inhibited resveratrol mediated inhibition of Alternaria induced oxidative stress. Furthermore induction of COX2 following Alternaria exposure was associated with an increase in expression of prostaglandin D2 synthase and PGD2 secretion into the extracellular media. Moreover, 15‐deoxy Δ12,14‐protaglandin J2 (15d‐PGJ2) a metabolic product of PGD2 was also shown to decrease Alternaria induced oxidative stress. These results suggest that upregulation of COX2 following sustained exposure to Alternaria induces PGD2 synthesis and subsequent formation of 15d‐PGJ2, a known activator of Nrf2 signaling and ultimately, increased expression of phase II antioxidant enzymes.

Prostaglandin D2 synthase related to estrogen in the female reproductive tract

Prostaglandin D2 synthase (PTGDS), also known as a glutathione-independent prostaglandin D synthase, catalyzes prostaglandin H2 to prostaglandin D2 that exhibits functions that include regulation of the central nervous system, contraction/relaxation of smooth muscle and inhibition of platelet aggregation. Gene profiling data based on our previous study indicated that PTGDS is significantly increased during development, differentiation and remodeling of the oviduct in chickens in response to estrogen. Therefore, the aims of the present study were to investigate expression of PTGDS in the oviduct and examine if the relationship between PTGDS and estrogen is conserved during development and remodeling of the oviduct. Results of our study indicate d that PTGDS expression is specifically localized to the luminal (LE) and glandular epithelial (GE) cells of the chicken oviduct in response to diethylstilbestrol, a synthetic estrogen. In addition, PTGDS expression increased during the regeneration phase of the oviduct in concert with increasing concentrations of estrogen in the circulation of laying hens during induced molting. Moreover, PTGDS mRNA and protein were expressed abundantly in GE of ovarian carcinoma, but not in normal ovaries. These results provide the first evidence that PTGDS is a novel estrogen-stimulated gene in oviductal epithelial cells, as well as a candidate biomarker for diagnosis of ovarian carcinoma.

A role for prostaglandins in rapid cycling suggested by episode-specific gene expression shifts in peripheral blood mononuclear cells: a preliminary report.

Over 12% of patients with bipolar disorder exhibit rapid cycling. The underlying biological mechanisms of this extreme form of bipolar disease are still unknown. This study aimed at replicating and extending findings of our previously published case report, where an involvement of prostaglandin synthesis-related genes in rapid cycling was first proposed. Psychopathological follow-up of the reported case was performed under cessation of celecoxib treatment. In a prospective observational study, patients with bipolar disorder (n = 47; of these, four had rapid cycling) or with monopolar depression (n = 97) were recruited over a period of three years. Repeated psychopathology measurements were conducted using standard instruments. Peripheral blood mononuclear cells (PBMC) were obtained during as many consecutive episodes as possible and processed for mRNA isolation and quantitative real-time reverse transcriptase polymerase chain reaction for prostaglandin D2 synthase (PTGDS), aldo-ketoreductase family 1, member C3 (AKR1C3), cyclooxygenase-2 (PAN means all splice variants) (COX2PAN ), prostaglandin-endoperoxide synthase 2 (PTGS2), and purinergic receptor P2X, ligand-gated ion channel 7 (P2RX7). The follow-up of our original case of a patient with rapid cycling who had shown impressive psychopathological improvement under celecoxib revealed complete loss of this effect upon discontinuation of the COX2 inhibitor. Episode-specific gene expression measurements in PBMC of four newly recruited rapid cycling patients confirmed the higher expression of PTGDS in depressive compared to manic phases. Additionally, higher relative expression of PTGS2/COX2PAN was found. No comparable alterations were observable in samples available from the remaining 43 patients with bipolar disorder and the 97 monopolar depressed patients, emphasizing the advantages of the rapid cycling condition with its rapid and frequent shifts for identification of gene expression changes. This study supports a role for prostaglandins in rapid cycling and advocates the cyclooxygenase cascade as a treatment target in this condition.

Modulation of lipocalin-type prostaglandin D2 synthase expression in catfish seminal vesicles by thyroid disrupting agents and hormones

Thyroid hormones play crucial role in several biological processes including reproduction. Disruption of normal thyroid status by environmental contaminants can cause severe impairment in reproductive functions. In our previous study, we reported down-regulation of a protein in seminal vesicular fluid of air-breathing catfish, Clarias gariepinus during experimentally induced hyperthyroidism. N-terminal amino acid sequence analysis followed by search in sequence database denoted it to be lipocalin-type prostaglandin D2 synthase (ptgds-b). In the present study, we cloned full-length cDNA of ptgds-b based on the N-terminal amino acid sequence. Surprisingly, Northern blot as well as RT-PCR analysis demonstrated the presence of ptgds-b transcript predominantly in seminal vesicles and developing testis. Further, ptgds-b mRNA significantly decreased in seminal vesicles following L-thyroxine overdose while there was an increased expression of ptgds-b after depletion of thyroid hormone by thiourea and withdrawal of the treatments reverted this effect. Treatment of catfish with human chorionic gonadotropin and estradiol significantly reduced ptgds-b expression. Taken together, we report ptgds-b as a thyroid hormone regulated protein in the seminal vesicles in addition to gonadotropin and estradiol. Further studies might explain the exclusive presence of ptgds-b in seminal vesicles and developing testis yet present data evaluated it as a putative biomarker for thyroid hormone disruption.

Abstract 5384: Hrev107 enhances prostaglandin D2 synthase-mediated cancer cells suppression in the testis.

Abstract Hrev107, also called HRASLS3 or PLA2G16, is a member of the HREV107 type II tumor suppressor gene family which includes HREV107, Retinoid-inducible gene 1 (RIG1), and HRASLS. The protein in this family contains an NC domain, with unknown function at the N-terminus, and a hydrophobic membrane-anchoring domain at the C-terminus. HREV107 has shown that expressed at high levels in differentiated tissues of post-meiotic testicular germ cells but not in human testicular germ cell tumors. Prostaglandin D2 (PGD2) has shown that can induce SOX-9 nuclear translocation and subsequent Sertoli cell differentiation. In addition, expression of the Prostaglandin D2 synthase (PTGDS) has been detected in the cellular lineage. This gives rise to the Sertoli cells, and the Sertoli cells appear to express the PTGDS only during the VI-VIII stages of the spermatogenic cycle after spermiation. These results suggested that PGD2 may play an important role in the testis differentiation. Our previous result showed that RIG1 (as RIG1 is expressed in the human species only) can interact with PTGDS. We further examined the effect of mouse Hrev107 on the growth of mouse testicular cells. When Hrev107 was expressed in TM3 or TM4 mouse testicular cancer cells, the cell migration and invasion were inhibited. Further, we found PTGDS was co-localized with Hrev107 in TM4 testis cells. In Hrev107-expressing NT2/D1 cells, elevated levels of PGD2, cAMP, and SRY-related high-mobility group box 9 (SOX9) were observed. This result indicated that Hrev107 can enhance PTGDS activity. Silencing of PTGDS expression significantly decreased h-REV107-mediated cAMP and PGD2 production. Furthermore, silencing of PTGDS or SOX9 alleviated Hrev107-mediated suppression of migration and invasion. These results suggest that Hrev107 will suppress cell migration/invasion through the PGD2 signaling pathway. In conclusion, Hrev107 can interact with PTGDS to enhance its function and to further suppress NT2/D1 cell migration and invasion. Citation Format: Fu-Ming Tsai, Chang-Chieh Wu, Rong-Yaun Shyu, Shun-Yuan Jiang. Hrev107 enhances prostaglandin D2 synthase-mediated cancer cells suppression in the testis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5384. doi:10.1158/1538-7445.AM2013-5384