Prostaglandin D2 Synthase Expression Research Articles

Involvement of the prostaglandin D2 signal pathway in retinoid-inducible gene 1 (RIG1)-mediated suppression of cell invasion in testis cancer cells

Retinoid-inducible gene 1 (RIG1), also called tazarotene-induced gene 3, belongs to the HREV107 gene family, which contains five members in humans. RIG1 is expressed in high levels in well-differentiated tissues, but its expression is decreased in cancer tissues and cancer cell lines. We found RIG1 to be highly expressed in testicular cells. When RIG1 was expressed in NT2/D1 testicular cancer cells, neither cell death nor cell viability was affected. However, RIG1 significantly inhibited cell migration and invasion in NT2/D1 cells. We found that prostaglandin D2 synthase (PTGDS) interacted with RIG1 using yeast two-hybrid screens. Further, we found PTGDS to be co-localized with RIG1 in NT2/D1 testis cells. In RIG1-expressing cells, elevated levels of prostaglandin D2 (PGD2), cAMP, and SRY-related high-mobility group box 9 (SOX9) were observed. This indicated that RIG1 can enhance PTGDS activity. Silencing of PTGDS expression significantly decreased RIG1-mediated cAMP and PGD2 production. Furthermore, silencing of PTGDS or SOX9 alleviated RIG1-mediated suppression of migration and invasion. These results suggest that RIG1 will suppress cell migration/invasion through the PGD2 signaling pathway. In conclusion, RIG1 can interact with PTGDS to enhance its function and to further suppress NT2/D1 cell migration and invasion. Our study suggests that RIG1-PGD2 signaling might play an important role in cancer cell suppression in the testis.

Abstract 4003: Involving of PGD2 signal pathway in the RIG1-mediated suppression of cell invasion in testis cells

Abstract Retinoid-inducible gene 1 (RIG1), also called tazarotene induced gene 3 (TIG3), belongs to the HREV107 gene family that contains five members in humans. Proteins of the HREV107 family share four conserved domains, a proline-rich motif located at the N-terminus, followed by a conserved H-box, the NC domain and a C-terminal transmembrane domain. RIG1 is expressed in high levels in well-differentiated tissues, but the expression of RIG1 decreases in cancer tissues and cancer cell lines. RIG1 stimulates cellular differentiation of keratinocytes, which is mediated by the activation of type I tissue transglutaminase. In addition, RIG1 was shown to inhibit the RAS signal pathways in cervical and gastric cancer cells. However, the direct interactions of RIG1/Type I tissue transglutaminase or RIG1/RAS were observed in cervical cancer cells. Until now, the mechanisms of anti-cancer /induced-cellular differentiation effects caused by RIG1 induced proteins have not been reported. We have found that Prostaglandin D2 synthase (PTGDS) interacted with RIG1 by yeast two hybrid screens. Further, we found PTGDS immunoprecipitated with RIG1 in NT2/D1 testis cell lysate. We also found PTGDS co-localized with RIG1 at the endomembrane. In RIG1-transfected cell, increasing expression of PGD2 production can be observed after stimulating by PTGDS. Thus, this indicated RIG1 can enhance PTGDS activity. Otherwise, cAMP and SOX9 are targets for PGD2 signaling. Our results revealed that cAMP but not SOX9 were upregulated in RIG1-expressing NT2/D1 testis cells. Pervious study indicated that RIG1 is a phospholipid-metabolizing enzyme (PLA) which involved in the phospholipid metabolism and the PLA activity is essential for the PGD2 production. RIG1 upregulated the PGD2 and cAMP production will not be affected in PLA inhibitor AACOCF3 treated-RIG1-expressing NT2/D1 cells. Silencing of PTGDS expression significantly decreased RIG1-mediated cAMP and PGD2 production. These results suggested that RIG1-induced PGD2 production is mediated by increasing the PTGDS activity but not PLA activity of RIG1. Either cell death or cell viability was not affected in RIG1-expressing cells. However, RIG1 significantly inhibited the cell migration and invasion in NT2/D1 cells. Knockdown of PTGDS expression but not treating cells with AACOCF3 can alleviated RIG1-induced invasion and migration suppression of NT2/D1 cells. This result indicated that RIG1 will cause cell invasion suppression though the PGD2 signaling pathway. In conclusion, RIG1 can interact with PTGDS to enhance its function and further suppress the NT2/D1 cell migration and invasion. Our study suggested that RIG1-PGD2 signaling might play an important role in cell differentiation of testis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4003. doi:1538-7445.AM2012-4003

Differential expression of prostaglandin D2 synthase (PTGDS) in patients with attention deficit–hyperactivity disorder and bipolar disorder

As marker genes for bipolar disorder (BP) and attention deficit hyperactivity disorder (ADHD) are not fully identified, we carried out a complete genome analysis to search for genes differentially expressed in ADHD and BP. We recruited 39 patients (30 ADHD, 9 BP), aged 7 to 23 years. For evaluation of the psychiatric diagnosis, we used a semi-structured interview based on the K-SADS-PL (DSM-IV). RNA was extracted from peripheral blood and analyzed with the GeneChip® Human Genome U133-Plus 2.0 (Affymetrix). For the validation of differentially expressed genes, real-time PCR was used. Hybridization and subsequent statistical analysis found 502 probe-sets with significant differences in expression in ADHD and BP patients. Of these, 82 had highly significant differences. Neuregulin (NRG1), cathepsins B and D (CTSB, CTSD) and prostaglandin-D2-synthase (PTGDS) were chosen for semi-quantitative mRNA determination. The expression of PTGDS was statistically increased in ADHD relative to BP patients (p=0.01). We found no such differential expression with NRG1, CTSB and CTSD genes (p>0.05). The gene coding for PTGDS was found to be more expressed in patients with ADHD relative to patients with BP, indicating a possible link with the differential etiology of ADHD. The experimental approach we have used is, at least in part, validated by the detection of proteins directly concerned with brain functions, and shows a possible way forward for studies of the connection between brain function genes and psychiatric disorders. Confirmation of our findings requires a larger sample of patients with clearly-defined phenotypes.

Pharmacogenomics of Metabolic Effects of Rosiglitazone

Thiazolidinediones are increasingly used drugs for the treatment of Type 2 diabetes. The individual response to thiazolidinedione therapy, ranging from the variable degree of metabolic improvement to harmful side-effects, is empirical, yet the underlying mechanisms remain elusive. In order to assess the pharmacogenomic component of thiazolidinediones' metabolic action, we compared the effect of rosiglitazone in two genetically defined models of metabolic syndrome, polydactylous (PD) and BN.SHR4 inbred rat strains, with their insulin-sensitive, normolipidemic counterpart, the Brown Norway (BN) rat. 5-month-old male rats were fed a high-fat diet for 4 weeks, and the experimental groups received rosiglitazone (0.4 mg/100 g body weight) during the last 2 weeks of high-fat diet feeding. We assessed metabolic and morphometric profiles, oxidative stress parameters and gene expression in white adipose tissue. In many followed parameters, we observed genetic background-specific effects of rosiglitazone administration. The mass and the sensitivity of visceral adipose tissue to insulin-stimulated lipogenesis increased with rosiglitazone treatment only in PD, correlating with a PD-specific significant increase in expression of prostaglandin D2 synthase. The glucose tolerance was enhanced in all strains, although fasting plasma glucose was increased by rosiglitazone in BN and BN.SHR4. Among the markers of lipid peroxidation, we observed the rosiglitazone-driven increase of plasma-conjugated dienes only in BN.SHR4. The genes with genotype-specific expression change included ADAM metallopeptidase domain 7, aquaporin 9, carnitine palmitoyltransferase 1B, caveolin 1, catechol-O-methyl transferase, leptin and prostaglandin D2 synthase 2. Rosiglitazone's effects on lipid deposition and insulin sensitivity of peripheral tissues are largely dependent on the genetic background it acts upon.

Expression of Prostaglandin D2 Synthase in Activated Eosinophils in Nasal Polyps

To clarify the relationship between prostaglandin D2 production and eosinophil accumulation. Screening and diagnostic tests. Nineteen patients with chronic rhinosinusitis. Nasal polyps were obtained from 19 patients at endoscopic sinus surgery. Eosinophils in nasal polyps were counted after hematoxylin-eosin staining and immunostaining with antibodies against 2 eosinophil markers-major basic protein and EG2. Hematopoietic prostaglandin D2 synthase (HPGDS) expression was examined by semiquantitative Western blot analysis and by immunohistochemical staining with anti-HPGDS antibody. Nasal polyps were divided into 3 groups by the degree of eosinophilic infiltration. Western blot analysis revealed that HPGDS was more intensely and frequently expressed in the group with high infiltration than in the groups with low or medium infiltration. Hematopoietic prostaglandin D2 synthase was immunohistochemically found in a subpopulation of EG2-positive eosinophils that had accumulated in the nasal polyps but not in the EG2-negative resting eosinophils. The ratio of HPGDS-positive eosinophils to EG2-positive eosinophils in the group with high eosinophil infiltration (mean+/-SD, 64.8%+/-19.2%) was twice that in the group with low eosinophil infiltration (30.5%+/-13.8%). Prostaglandin D2 was actively produced by an EG2 and HPGDS double-positive subpopulation of activated eosinophils that had infiltrated into nasal polyps.

Prostaglandin D 2 synthase enzymes and PPARγ are co-expressed in mouse 3T3-L1 adipocytes and human tissues

Peroxisome proliferator-activated receptor γ (PPARγ) is a critical regulator of adipocyte differentiation. Whilst 15-deoxy-Δ 12,14-prostaglandin J 2 (15-d-PGJ 2) has been identified as a putative endogenous ligand for this transcription factor, it is unclear whether the enzymes necessary for 15-d-PGJ 2 biosynthesis are co-expressed with PPARγ. Prostaglandin D 2 synthase (PGDS) enzymes represent the terminal enzymatic components responsible for 15-d-PGJ 2 production. Both glutathione (GSH)-dependent and GSH-independent PGDS isoenzymes exist. We have, therefore, examined the expression of PGDS isoenzymes in mouse 3T3-L1 adipocytes, and various human tissues. The GSH-independent PGDS was found to be expressed in 3T3-L1 cells both before and after their differentiation into adipocytes. By contrast, we were unable to detect expression of the GSH-dependent PGDS at any stage during the adipose conversion of 3T3-L1 cells. Quantitative analysis of mRNA levels for PPARγ and each PGDS isoenzyme revealed their co-expression in a number of human tissues and cell types, including adipose tissue, placenta, prostate, and macrophages. These data reveal the potential for de novo 15-d-PGJ 2 synthesis in the context of PPARγ expression, suggesting that this prostaglandin may contribute to PPARγ signalling in vivo.

Prostaglandin D2 Synthase Secreted in the Caput Epididymidis Displays Spatial and Temporal Delay Between Messenger RNA and Protein Expression During Postnatal Development1

Highly regionalized protein secretory activity is established progressively throughout the epididymal tubule during postnatal development. Prostaglandin D(2) synthase (PGDS) is a major protein in the ovine epididymis, the secretion of which is restricted to the proximal part of the epididymis. We investigated the mRNA and protein expression of PGDS during ontogenesis. PGDS mRNA was present in the testis and epididymis in the 50-day-old sheep fetus and persisted until 4 mo of age (2 mo before puberty) without mRNA translation in the epididymis. At 4.5 mo, mRNA was present in all of the epididymis, but translation occurred in only the proximal caput. The secreted protein present in the lumen from the caput to the cauda had the same molecular mass and isoelectric point (pI) characteristics as the testicular form. At 5.5 mo, both mRNA and protein expression were restricted to the proximal caput. The protein secreted accumulated in the cauda but was not processed after secretion as it is in the adult animal; no changes in molecular mass or pI were observed. Our results show that for at least one gene (PGDS), transcriptional and posttranscriptional regulation during postnatal development is linked to the presence of unidentified translation factors present in testicular fluid.

Mammalian class Sigma glutathione S-transferases: catalytic properties and tissue-specific expression of human and rat GSH-dependent prostaglandin D2 synthases

GSH-dependent prostaglandin D2 synthase (PGDS) enzymes represent the only vertebrate members of class Sigma glutathione S-transferases (GSTs) identified to date. Complementary DNA clones encoding the orthologous human and rat GSH-dependent PGDS (hPGDS and rPGDS, respectively) have been expressed in Escherichia coli, and the recombinant proteins isolated by affinity chromatography. The purified enzymes were both shown to catalyse specifically the isomerization of prostaglandin (PG) H2 to PGD2. Each transferase also exhibited GSH-conjugating and GSH-peroxidase activities. The ability of hPGDS to catalyse the conjugation of aryl halides and isothiocyanates with GSH was found to be less than that of the rat enzyme. Whilst there is no difference between the enzymes with respect to their Km values for 1-chloro-2,4-dinitrobenzene, marked differences were found to exist with respect to their Km for GSH (8mM versus 0.3mM for hPGDS and rPGDS, respectively). Using molecular modelling techniques, amino acid substitutions have been identified in the N-terminal domain of these enzymes that lie outside the proposed GSH-binding site, which may explain these catalytic differences. The tissue-specific expression of PGDS also varies significantly between human and rat; amongst the tissues examined, variation in expression between the two species was most apparent in spleen and bone marrow. Differences in catalytic properties and tissue-specific expression of hPGDS and rPGDS appears to reflect distinct physiological roles for class Sigma GST between species. The evolution of divergent functions for the hPGDS and rPGDS is discussed in the context of the orthologous enzyme from chicken.

Mammalian class Sigma glutathione S-transferases: catalytic properties and tissue-specific expression of human and rat GSH-dependent prostaglandin D2 synthases

GSH-dependent prostaglandin D(2) synthase (PGDS) enzymes represent the only vertebrate members of class Sigma glutathione S-transferases (GSTs) identified to date. Complementary DNA clones encoding the orthologous human and rat GSH-dependent PGDS (hPGDS and rPGDS, respectively) have been expressed in Escherichia coli, and the recombinant proteins isolated by affinity chromatography. The purified enzymes were both shown to catalyse specifically the isomerization of prostaglandin (PG) H(2) to PGD(2). Each transferase also exhibited GSH-conjugating and GSH-peroxidase activities. The ability of hPGDS to catalyse the conjugation of aryl halides and isothiocyanates with GSH was found to be less than that of the rat enzyme. Whilst there is no difference between the enzymes with respect to their K(m) values for 1-chloro-2,4-dinitrobenzene, marked differences were found to exist with respect to their K(m) for GSH (8 mM versus 0.3 mM for hPGDS and rPGDS, respectively). Using molecular modelling techniques, amino acid substitutions have been identified in the N-terminal domain of these enzymes that lie outside the proposed GSH-binding site, which may explain these catalytic differences. The tissue-specific expression of PGDS also varies significantly between human and rat; amongst the tissues examined, variation in expression between the two species was most apparent in spleen and bone marrow. Differences in catalytic properties and tissue-specific expression of hPGDS and rPGDS appears to reflect distinct physiological roles for class Sigma GST between species. The evolution of divergent functions for the hPGDS and rPGDS is discussed in the context of the orthologous enzyme from chicken.