Prostaglandin signaling regulates renal multiciliated cell specification and maturation.

Multiciliated cells (MCCs) are specialized epithelia with apical bundles of motile cilia that direct fluid flow. MCC dysfunction is associated with human diseases of the respiratory, reproductive, and central nervous systems. Further, the appearance of renal MCCs has been cataloged in several kidney conditions, where their function is unknown. Despite their pivotal health importance, many aspects of MCC development remain poorly understood. Here, we utilized a chemical screen to identify molecules that affect MCC ontogeny in the zebrafish embryo kidney, and found prostaglandin signaling is essential both for renal MCC progenitor formation and terminal differentiation. Moreover, we show that prostaglandin activity is required downstream of the transcription factor ets variant 5a (etv5a) during MCC fate choice, where modulating prostaglandin E2 (PGE2) levels rescued MCC number. The discovery that prostaglandin signaling mediates renal MCC development has broad implications for other tissues, and could provide insight into a multitude of pathological states.

Genome-Wide Analysis Indicates a Complete Prostaglandin Pathway from Synthesis to Inactivation in Pacific White Shrimp, Litopenaeus vannamei.

Prostaglandins (PGs) play many essential roles in the development, immunity, metabolism, and reproduction of animals. In vertebrates, arachidonic acid (ARA) is generally converted to prostaglandin G2 (PGG2) and H2 (PGH2) by cyclooxygenase (COX); then, various biologically active PGs are produced through different downstream prostaglandin synthases (PGSs), while PGs are inactivated by 15-hydroxyprostaglandin dehydrogenase (PGDH). However, there is very limited knowledge of the PG biochemical pathways in invertebrates, particularly for crustaceans. In this study, nine genes involved in the prostaglandin pathway, including a COX, seven PGSs (PGES, PGES2, PGDS1/2, PGFS, AKR1C3, and TXA2S), and a PGDH were identified based on the Pacific white shrimp (Litopenaeus vannamei) genome, indicating a more complete PG pathway from synthesis to inactivation in crustaceans than in insects and mollusks. The homologous genes are conserved in amino acid sequences and structural domains, similar to those of related species. The expression patterns of these genes were further analyzed in a variety of tissues and developmental processes by RNA sequencing and quantitative real-time PCR. The mRNA expression of PGES was relatively stable in various tissues, while other genes were specifically expressed in distant tissues. During embryo development to post-larvae, COX, PGDS1, GDS2, and AKR1C3 expressions increased significantly, and increasing trends were also observed on PGES, PGDS2, and AKR1C3 at the post-molting stage. During the ovarian maturation, decreasing trends were found on PGES1, PGDS2, and PGDH in the hepatopancreas, but all gene expressions remained relatively stable in ovaries. In conclusion, this study provides basic knowledge for the synthesis and inactivation pathway of PG in crustaceans, which may contribute to the understanding of their regulatory mechanism in ontogenetic development and reproduction.

Prostaglandin production by the microalga with heterologous expression of cyclooxygenase.

Prostaglandins (PGs) are the physiologically active compounds synthesized from C20 polyunsaturated fatty acids (PUFAs) by cyclooxygenase (COX) and a series of PG synthases, and are utilized as pharmaceuticals. Currently, commercialized PGs are mainly produced by chemical synthesis under harsh conditions. By contrast, bioproduction of PGs can be an alternative, environmental-friendly, and inexpensive process with genetic engineering of model plants, although these conventional host organisms contain a limited quantity of PG precursors. In this study, we established an efficient PG production process using the genetically engineered microalga Fistulifera solaris which is rich in C20 PUFAs. A cox gene derived from the red alga Agarophyton vermiculophyllum was introduced into F. solaris. As a result, a transformant clone with high cox expression produced PGs (i.e., PGD2 , PGE2 , PGF2α , and 15-ketoPGF2α derived from arachidonic acid, and PGD3 , PGE3 , and PGF3α derived from eicosapentaenoic acid) as revealed by liquid chromatography/mass spectrometry. The total content of PGs was 1290.4 ng/g of dry cell weight, which was higher than that produced in the transgenic plant reported previously. The results obtained in this study indicate that the C20 PUFA-rich microalga functionally expressing COX is a promising host for PG bioproduction.

Differential compensation of two cyclooxygenases in renal homeostasis is independent of prostaglandin-synthetic capacity under basal conditions.

The distinct functions of each cyclooxygenase (COX) isoform in renal homeostasis have been the subject of intense investigation for many years. We took the novel approach of using 3 characterized mouse lines, where the prostaglandin (PG)-endoperoxide synthase genes 1 and 2 ( Ptgs1 and Ptgs2) substitute for one another to delineate distinct roles and the potential for COX isoform substitution. Flipped Ptgs genes generate a reversed COX-expression pattern in the kidney, where the knockin COX-2 is highly expressed. Normal nephrogenesis was sustained in all 3 strains at the postnatal stage d 8 (P8). Knockin COX-1 can temporally restore renal function and delay but not prevent renal pathology consequent to COX-2 deletion. Loss of COX-2 in adult COX-1 > COX-2 mice results in severe nephropathy, which leads to impaired renal function. These defects are partially rescued by the knockin COX-2 in Reversa mice, whereas COX-2 can compensate for the loss of COX-1 in COX-2 > COX-1 mice. Intriguingly, the highly expressed knockin COX-2 enzyme barely makes any PGs or thromboxane in neonatal P8 or adult mice, demonstrating that prostanoid biosynthesis requires native COX-1 and cannot be rescued by the knockin COX-2. In summary, the 2 COX isoforms can preferentially compensate for some renal functions, which appears to be independent of the PG-synthetic capacity.-Li, X., Mazaleuskaya, L. L., Ballantyne, L. L., Meng, H., FitzGerald, G. A., Funk, C. D. Differential compensation of two cyclooxygenases in renal homeostasis is independent of prostaglandin-synthetic capacity under basal conditions.

Two controls of cell proliferation underlie cancer relapse.

Much progress has been made in understanding the basis of cancer. Current therapies can effectively shrink tumors. But they frequently relapse, metastasize to other locations, and are lethal. Effective therapies are very much needed for preventing this relapse. Creation of a eukaryotic organism commences with one original stem cell, a fertilized egg, which multiplies and differentiates. Mutations of normal stem cells can produce cancer stem cells (CSC). These cells may resist chemotherapy, proliferate, and produce new tumors. Human chorionic gonadotrophin (hCG) is composed of two proteins (alpha and beta) that bind to the cell membrane and activate a number of intracellular pathways. hCG has been shown to activate the proliferation of cancer stem cells. Cyclin dependent regulation of the adult cells is created in normal differentiation and replaces the hCG regulation of stem cells. To selectively kill the cancer stem cells conventional cancer therapies could be followed with a therapy based on inactivating human chronic gonadotrophin (HCG). For example chemically modified prostaglandins like RU486 prevent binding of the unmodified steroid to hCG and inactivate hCG.

Inflammation and CB2 signaling drive novel changes in the ocular lipidome and regulate immune cell activity in the eye.

Uveitis is inflammation of the uvea which consists of the iris, ciliary body and the choroid of the eye. Uveitis can lead to impaired vision and is responsible for 10% of all cases of blindness globally. Using an endotoxin-induced uveitis (EIU) rodent model, our previous data implicated the endogenous cannabinoid system (ECS) in the amelioration of many of the components of the inflammatory response. Here, we test the hypothesis that the reduction in inflammatory mediators in the EIU model by the CB2 agonist, HU308, is associated with changes in ECS endogenous ligands as well as related lipids, prostaglandins (PGs), 2-acyl glycerols, and lipoamines. Analysis of leukocytes and neutrophils, CB2 mRNA, and 26 lipids in the eye of WT mice after EIU induction and HU308 treatment were compared to the same analyses in the CB2 knock-out (CB2 KO) mouse. Endothelial leukocyte adhesion and neutrophil migration were significantly increased in both WT and CB2 KO after EIU. HU308 significantly reduced the leukocyte adhesion and neutrophil recruitment in the WT animals. HU308 also significantly reduced leukocyte adhesion in the CB2 KO mouse, yet, had no effect on neutrophil infiltration suggesting an important off-target effect of HU308. Lipidomics profiles revealed significant increases in 6 non-ECS lipids after EIU in the WT and that HU308 effectively reduced these back to control levels; in addition, HU308 increased levels of 2-acyl glycerols and decreased all N-acyl glycines. CB2 KOs with saline-injection compared to WT had significantly elevated levels of 2-acyl glycerols, whereas levels of N-oleoyl ethanolamine (OEA), N-stearoyl ethanolamine (SEA), and PGE2 were reduced. CB2 KOs with EIU had 13 lipids that were significantly lower than WT with EIU including 4 N-acyl glycines. HU308 had no effect on lipid concentrations in the CB2 KOs with EIU, however, it did cause further reductions on 3 additional lipids compared to saline controls. HU308 appears to be acting at a non-CB2 target for the reduction of leukocyte infiltration in the EIU model; however, our data suggest that HU308 is working through CB2 to reduce neutrophil migration and for the regulation of multiple lipid signaling pathways including PGs, lipoamines, and 2-acyl glycerols. These data implicate ocular CB2 as a key component of lipid signaling in the eye and part of the regulatory processes of inflammation.

Prostaglandin synthesis enzymes' gene transcription in bitches with endometritis.

Endometritis is a major cause of infertility in many domestic species. However, until now the pathogenesis of the endometritis in the bitch is unclear. The aim of this study was to evaluate the gene transcription pattern of prostaglandin (PG) synthesis enzymes (cyclooxygenase [COX2], PTGES-1 and PGFS) in the endometrium of bitches with or without endometritis. Thirty mixed breed bitches in dioestrus, aged between 1 and 5 years, and weighing between 10 and 30 kg were used. After ovariohysterectomy (OVX), uterine biopsy samples were collected from the middle part of both horns. Then, endometrial epithelium was collected using the cytobrush method and mRNA analysis was performed by real-time RT-PCR. Data were analysed with Kruskal-Wallis anova using the sas® software. Uterine condition was identified by endometrial biopsies (normal endometria [n = 11; NE], acute endometritis [n = 10; AE] and chronic endometritis [n = 9; CE]). The COX2, PTGES-1 and PGFS/AKR1C3 mRNA expression in bitches with and without endometritis was similar. Except for PGFS/AKR1C3, gene transcription of COX2 and PTGES-1 was significantly increased in AE compared with CE. In addition, COX2 gene transcription was significantly increased in AE compared with NE. In contrast, no differences were found for COX2, PTGES-1 and PGFS/AKR1C3 mRNA expression in the samples of NE compared with CE.

Role of long-chain acyl-coenzyme A synthetases in the regulation of arachidonic acid metabolism in interleukin 1ß-stimulated rat fibroblasts.

Acyl coenzyme A synthetase long-chain family members (ACSLs) are a family of enzymes that convert long-chain free fatty acids into their acyl-CoAs and play an important role in fatty acid metabolism. Here we show the role of ACSL isozymes in interleukin (IL)-1ß-induced arachidonic acid (AA) metabolism in rat fibroblastic 3Y1 cells. Treatment of 3Y1 cells with triacsin C, an ACSL inhibitor, markedly enhanced the IL-1ß-induced prostaglandin (PG) biosynthesis. Small interfering RNA-mediated knockdown of endogenous Acsl4 expression increased significantly the release of AA metabolites, including PGE2, PGD2, and PGF2α, compared with replicated control cells, whereas knockdown of Acsl1 expression reduced the IL-1ß-induced release of AA metabolites. Experiments with double knockdown of Acsl4 and intracellular phospholipase A2 (PLA2) isozymes revealed that cytosolic PLA2α, but not calcium-independent PLA2s, is involved in the Acsl4 knockdown-enhanced PG biosynthesis. Electrospray ionization mass spectrometry of cellular phospholipids bearing AA showed that the levels of some, if not all, phosphatidylcholine (PC) and phosphatidylinositol species in Acsl4 knockdown cells were decreased after IL-1ß stimulation, while those in control cells were not so obviously decreased. In Acsl1 knockdown cells, the levels of some AA-bearing PC species were reduced even in the unstimulated condition. Collectively, these results suggest that Acsl isozymes play distinct roles in the control of AA remodeling in rat fibroblasts: Acsl4 acts as the first step of enzyme for AA remodeling following IL-1ß stimulation, and Acsl1 is involved in the maintenance of some AA-containing PC species.

Gene Expression of Proresolving Lipid Mediator Pathways Is Associated With Clinical Outcomes in Trauma Patients.

OBJECTIVES: Specialized proresolving lipid mediators have emerged as powerful modulators of inflammation and activators of resolution. Animal models show significant benefits of specialized proresolving lipid mediators on survival and wound healing after major burn trauma. To date, no studies have investigated specialized proresolving lipid mediators and their relation to other lipid mediator pathways in humans after trauma. Here we determine if patients with poor outcomes after trauma have dysregulated lipid mediator pathways. DESIGN: We studied blood leukocyte expression of 18 genes critical to the synthesis, signaling, and metabolism of specialized proresolving lipid mediators and proinflammatory lipid mediators, and we correlated these expression patterns with clinical outcomes in trauma patients from the Inflammation and the Host Response to Injury study. SETTING: Seven U.S. medical trauma centers. SUBJECTS: Ninety-six patients enrolled in the Inflammation and Host Response to Injury study, after blunt trauma and unambiguously classified as having uncomplicated or complicated recoveries. Twenty-eight healthy volunteers were enrolled as controls. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Within each patient, the 18 genes of interest were used to calculate scores for distinct families of lipid mediators, including resolvins, lipoxins, prostaglandins, and leukotrienes, as well as leukotriene to resolvin score ratios. Scores were built using a simple weighting scheme, taking into consideration both dependent and independent activities of enzymes and receptors responsible for lipid mediator biosynthesis and function. Individually, ALOX12, PTGS2, PTGES, PTGDS, ALOX5AP, LTA4H, FPR2, PTGER2, LTB4R, HPGD, PTGR1, and CYP4F3 were expressed differentially over 28 days posttrauma between patients with uncomplicated and complicated recoveries (p < 0.05). When all genes were combined into scores, patients with uncomplicated recoveries had differential and higher resolvin scores (p < 0.001) and lower leukotriene scores (p < 0.001). A final combined ratio was calculated for each patient, and posttrauma leukotriene score to resolvin score ratios were significantly lower in patients with uncomplicated clinical courses (p < 0.001). CONCLUSIONS: proresolving lipid mediator lipidomics and/or protein expression, and identifying associated therapeutic targets, may influence the clinical management of trauma patients.

Genetic polymorphisms in the prostaglandin pathway genes and risk of head and neck cancer.

OBJECTIVE: Previous studies examining the association between genetic variations in prostaglandin pathway and risk of head and neck cancer (HNC) have only included polymorphisms in the PTGS2 (COX2) gene. This study investigated the association between genetic polymorphisms of six prostaglandin pathway genes (PGDS, PTGDS, PTGES, PTGIS, PTGS1 and PTGS2), and risk of HNC. METHODS: Interviews regarding the consumption of alcohol, betel quid, and cigarette were conducted with 222 HNC cases and 214 controls. Genotyping was performed for 48 tag and functional single-nucleotide polymorphisms (SNPs). RESULTS: Two tag SNPs of PTGIS showed a significant association with HNC risk [rs522962: log-additive odds ratio (OR) = 1.42, 95% confidence interval (CI): 1.01-1.99 and dominant OR = 1.58, 95% CI: 1.02-2.47; rs6125671: log-additive OR = 1.49, 95% CI: 1.08-2.05 and dominant OR = 1.96, 95% CI: 1.16-3.32]. In addition, a region in PTGIS tagged by rs927068 and rs6019902 was significantly associated with risk of HNC (global P = 0.007). Finally, several SNPs interacted with betel quid and cigarette to influence the risk of HNC. CONCLUSIONS: Genetic variations in prostaglandin pathway genes are associated with risk of HNC and may modify the relationship between use of betel quid or cigarette and development of HNC.

Effects of oocyte donor age and embryonic stage of development on transcription of genes coding for enzymes of the prostaglandins and progesterone synthesis pathways in bovine in vitro produced embryos.

The ability of early bovine embryos to produce prostaglandins (PGs) and progesterone (P4), and the role of these mediators in embryonic development and survival are poorly understood. In this study we tested the hypothesis that day 7 bovine embryos are able to transcribe genes coding for enzymes of the PGs (PTGS2, PGES, PGFS) and P4 (StAR, P450scc, 3ß-HSD) synthesis pathways, and that transcription levels of these genes are associated with developmental progression and heifer age-related [pre-pubertal (PP) versus post-pubertal cyclic (C)] oocyte competence. Compared with C heifer oocytes, PP heifer oocytes showed a lower (P < 0.0001) in vitro blastocyst rate, but in embryos developing until day 7, heifer age had no effect on quality grade. Day 7 quality grade 1-2 embryos were selected for RNA extraction and gene transcription analysis by qRT-PCR, in a 2 × 2 factorial design [age (PP or C) × embryonic stage (compact morulae and early blastocysts, CM + EBL, or blastocysts and expanded blastocysts, BL + BEX); 15 embryos/group]. Transcription levels of PTGS2, PGES, PGFS, P450scc and 3ß-HSD were not affected by heifer age but were higher (P < 0.01) in BL + BEX than in CM + EBL. In conclusion, the main limiting factor for embryo production from PP heifers is oocyte competence. Day 7 bovine embryos evidence transcription of genes coding for enzymes of PGs and P4 synthesis pathways, and transcription levels are associated with blastocyst differentiation. This prompts for an autocrine/paracrine action of PGs and P4 in early bovine embryonic development.

Cyclooxygenase-1-dependent prostaglandins mediate susceptibility to systemic inflammation-induced acute cognitive dysfunction.

Systemic inflammatory events often precipitate acute cognitive dysfunction in elderly and demented populations. Delirium is a highly prevalent neuropsychiatric syndrome that is characterized by acute inattention and cognitive dysfunction, for which prior dementia is the major predisposing factor and systemic inflammation is a frequent trigger. Inflammatory mechanisms of delirium remain unclear. We have modeled aspects of delirium during dementia by exploiting progressive neurodegeneration in the ME7 mouse model of prion disease and by superimposing systemic inflammation induced by the bacterial endotoxin lipopolysaccharide (LPS). Here, we have used this model to demonstrate that the progression of underlying disease increases the incidence, severity, and duration of acute cognitive dysfunction. This increasing susceptibility is associated with increased CNS expression of cyclooxygenase (COX)-1 in microglia and perivascular macrophages. The COX-1-specific inhibitor SC-560 provided significant protection against LPS-induced cognitive deficits, and attenuated the disease-induced increase in hippocampal and thalamic prostaglandin E2, while the COX-2-specific inhibitor NS-398 was ineffective. SC-560 treatment did not alter levels of the proinflammatory cytokines interleukin (IL)-1ß, tumor necrosis factor-α, IL-6, or C-X-C chemokine ligand 1 in blood or brain, but systemic IL-1RA blocked LPS-induced cognitive deficits, and systemic IL-1ß was sufficient to induce similar deficits in the absence of LPS. Furthermore, the well tolerated COX inhibitor ibuprofen was protective against IL-1ß-induced deficits. These data demonstrate that progressive microglial COX-1 expression and prostaglandin synthesis can underpin susceptibility to cognitive deficits, which can be triggered by systemic LPS-induced IL-1ß. These data contribute to our understanding of how systemic inflammation and ongoing neurodegeneration interact to induce cognitive dysfunction and episodes of delirium.

Prostaglandin pathway gene expression in human placenta, amnion and choriodecidua is differentially affected by preterm and term labour and by uterine inflammation.

BACKGROUND: Elucidation of the biochemical pathways involved in activation of preterm and term human labour would facilitate the development of effective management and inform judgements regarding the necessity for preterm tocolysis and post-term induction. Prostaglandins act at all stages of human reproduction, and are potentially activators of labour. METHODS: Expression of 15 genes involved in prostaglandin synthesis, transport and degradation was measured by qPCR using tissue samples from human placenta, amnion and choriodecidua at preterm and full-term vaginal and caesarean delivery. Cellular localisation of eight prostaglandin pathway proteins was determined by immunohistochemistry. RESULTS: Expression of prostaglandin pathway genes was differentially affected by factors including gestational age at delivery, and the incidence and duration of labour. Chorioamnionitis/deciduitis was associated with upregulation of PTGS2 (prostaglandin-endoperoxide synthase 2 (prostaglandin G/H synthase and cyclooxygenase)), along with the inflammatory genes IL8 (interleukin 8), S100A8 (S100 calcium binding protein A8) and TLR2 (toll-like receptor 2), in amnion and choriodecidua, and with downregulation of CBR1 (carbonyl reductase 1) and HPGD (hydroxyprostaglandin dehydrogenase 15-(NAD)) in choriodecidua. Protein localisation differed greatly between the various maternal and fetal cell types. CONCLUSIONS: Preterm and term labour are associated with distinct prostaglandin pathway expression profiles; inflammation provokes specific changes, unrelated to the presence of labour; spontaneous and induced term labour are indistinguishable.

Expression of genes related to prostaglandin synthesis or signaling in human subcutaneous and omental adipose tissue: depot differences and modulation by adipogenesis.

OBJECTIVES: (1) To examine depot-specific PGE2 and PGF2α release and mRNA expression of enzymes or receptors involved in PG synthesis or signaling in human adipose tissues; (2) to identify changes in expression of these transcripts through preadipocyte differentiation; and (3) to examine associations between adipose tissue mRNA expression of these transcripts and adiposity measurements. METHODS: Fat samples were obtained surgically in women. PGE2 and PGF2α release by preadipocytes and adipose tissue explants was measured. Expression levels of mRNA coding for enzymes or receptors involved in PG synthesis or signaling were measured by RT-PCR. RESULTS: Cultured preadipocytes and explants from omental fat released more PGE2 and PGF2α than those from the subcutaneous depot and the corresponding transcripts showed consistent depot differences. Following preadipocyte differentiation, expression of PLA2G16 and PTGER3 mRNA was significantly increased whereas COX-1, COX-2, PTGIS, and PTGES mRNA abundance were decreased in both compartments (P ≤ 0.01 for all). Transcripts that were stimulated during adipogenesis were those that correlated best with adiposity measurements. CONCLUSION: Cells from the omental fat compartment release more PGE2 and PGF2α than those from the subcutaneous depot. Obesity modulates expression of PG-synthesizing enzymes and PG receptors which likely occurs through adipogenesis-induced changes in expression of these transcripts.

Biotechnological approach towards a highly efficient production of natural prostaglandins.

Prostaglandins (PGs) act as potent local hormones in nearly all tissues of the human body and are used for various medical applications. Heterologous expression of PG endoperoxide H-synthase from the alga, Gracilaria vermiculophylla, into E. coli and the application of this strain in biotransformation experiments resulted in a highly efficient conversion of arachidonic acid (ARA) yielding up to 130 mg natural PGs l(-1) in a laboratory scale approach. Detailed analyses of the products and production kinetics were performed, confirming a rapid conversion of ARA to PGs.

Downregulation of core clock gene Bmal1 attenuates expression of progesterone and prostaglandin biosynthesis-related genes in rat luteinizing granulosa cells.

Ovarian circadian oscillators have been implicated in the reproductive processes of mammals. However, there are few reports regarding the detection of ovarian clock-controlled genes (CCGs). The present study was designed to unravel the mechanisms through which CCG ovarian circadian oscillators regulate fertility, primarily using quantitative RT-PCR and RNA interference against Bmal1 in rat granulosa cells. Mature granulosa cells were prepared from mouse Per2-destabilized luciferase (dLuc) reporter gene transgenic rats. A real-time monitoring system of Per2 promoter activity was employed to detect Per2-dLuc oscillations. The cells exposed to luteinizing hormone (LH) displayed clear Per2-dLuc oscillations and a rhythmic expression of clock genes (Bmal1, Per1, Per2, Rev-erbα, and Dbp). Meanwhile, the examined ovarian genes (Star, Cyp19a1, Cyp11a1, Ptgs2, Lhcgr, and p53) showed rhythmic transcript profiles except for Hsd3b2, indicating that these rhythmic expression genes may be CCGs. Notably, Bmal1 small interfering (si)RNA treatment significantly decreased both the amplitude of Per2-dLuc oscillations and Bmal1 mRNA levels compared with nonsilencing RNA treatment in luteinizing granulosa cells. Depletion of Bmal1 by siRNA decreased the transcript levels of clock genes (Per1, Per2, Rev-erbα, and Dbp) and examined ovarian genes (Star, Cyp19a1, Cyp11a1, Ptgs2, Hsd3b2, and Lhcgr). Accordingly, knockdown of Bmal1 also inhibited the synthesis of progesterone and prostaglandin E2, which are associated with crucial reproductive processes. Collectively, these data suggest that ovarian circadian oscillators regulate the synthesis of steroid hormones and prostaglandins through ovarian-specific CCGs in response to LH stimuli. The present study provides new insights into the physiologic significance of Bmal1 related to fertility in ovarian circadian oscillators.

Conceptus-derived prostaglandins regulate gene expression in the endometrium prior to pregnancy recognition in ruminants.

In cattle, the blastocyst hatches from the zona pellucida on days 8-9 and then forms a conceptus that grows and elongates into an ovoid and then filamentous shape between days 9 and 16. The growing conceptus synthesizes and secretes prostaglandins (PGs) and interferon τ (IFNT). Our hypothesis was that the ovoid conceptus exerts a local effect on the endometrium prior to maternal recognition of pregnancy on day 16 in cattle. In study one, synchronized cyclic heifers received no blastocysts or 20 in vitro-produced blastocysts on day 7 and their uteri were collected on day 13. IFNT was not detected by RIA in the uterine flushing samples of pregnant heifers containing multiple ovoid conceptuses; however, total PG levels were higher in the uterine lumen of pregnant heifers than in that of cyclic heifers. Microarray analysis revealed that the expression of 44 genes was increased in the endometria of day 13 pregnant heifers when compared with that in the endometria of cyclic heifers, and many of these genes were classical Type I IFN-stimulated genes (ISGs). In studies two and three, the effects of infusing PGs at the levels produced by the elongating day 14 conceptus into the uterine lumen of cyclic ewes on ISG expression in the endometrium were determined. Results indicated that the infusion of PGs increased the abundance of several ISGs in the endometrium. These studies support the hypothesis that the day 13 conceptus secretes PGs that act locally in a paracrine manner to alter gene expression in the endometrium prior to pregnancy recognition in cattle.

NAD(P)H quinone oxidoreductase 1 (NQO1)-bioactivated pronqodine A regulates prostaglandin release from human synovial sarcoma cells.

Natural products have contributed to the elucidation of biological mechanisms as well as drug discovery research. Even now, the expectation for natural products is undiminished. We screened prostaglandin release inhibitors that had no effect on in vitro cyclooxygenase activity derived from natural product sources and discovered pronqodine A. Using spectral analysis and total synthesis, the structure of pronqodine A was shown to be a benzo[d]isothiazole-4,7-dione analogue. Evaluation of the biological activity of pronqodine A revealed that the NAD(P)H dehydrogenase quinone 1 (NQO1) converted pronqodine A into a two-electron reductive form. The reductive form underwent autoxidation and reversed to its native form immediately with the generation of reactive oxygen species. Further investigations proved that pronqodine A inhibited cyclooxygenase enzyme activity only in the presence of NQO1. Pronqodine A acts as a potential bioreductive compound, inhibiting prostaglandin release in selectively activated NQO1-expressing cells.

Effect of hCG and eCG treatments on prostaglandins synthesis in the porcine oviduct.

The oviduct plays a crucial role in fertilization, gamete maturation and embryo transport. Prostaglandins are some of the main factors determining its roles. The present study investigated the influence of oestrus synchronization and superovulation on prostaglandins synthesis in the porcine oviduct. Mature cross-bred gilts after exhibiting oestrous cycles were divided into four groups: I, cyclic; II, inseminated; III, synchronized and inseminated; and IV, superovulated and inseminated. Oviducts were collected on the third day of the oestrous cycle or after insemination and divided into isthmus and ampullary parts. This study demonstrated lower mRNA (in the isthmus and ampulla; p < 0.05, p < 0.001, respectively) and protein prostaglandin endoperoxide synthase 2 expression (in the isthmus; p < 0.001) in gilts treated with human chorionic gonadotrophin/equine chorionic gonadotrophin (hCG/eCG) compared with Group II that were inseminated only. In addition, hCG and eCG treatment decreased mPGES-1 mRNA levels in Groups III and IV, in both the isthmus (p < 0.01 in III, p < 0.001 in IV) and ampulla (p < 0.001). The prostaglandin E2 content of oviductal tissues was significantly lower in Groups III (p < 0.05) and IV (p < 0.01 in isthmus, p < 0.0001 in ampulla) compared with Group II. mRNA and protein levels of PGFS in Group IV in the oviductal isthmus were higher (p < 0.01) compared with the non-treated Group II. In effect, the amount of prostaglandin F2α in oviductal tissues of gilts treated with hCG/eCG was significantly elevated (p < 0.001 in isthmus of Groups III and IV; p < 0.05 in ampulla of Group IV). Differential expression of the factors analysed in gilts treated with exogenous gonadotrophins suggests that hCG/eCG stimulation affects prostaglandins synthesis pathway. These changes can alter oviduct functions and in turn affect gamete maturation and fertilization as well as development of embryos and their transport to the uterus.

Hair follicular expression and function of group X secreted phospholipase A2 in mouse skin.

Although perturbed lipid metabolism can often lead to skin abnormality, the role of phospholipase A(2) (PLA(2)) in skin homeostasis is poorly understood. In the present study we found that group X-secreted PLA(2) (sPLA(2)-X) was expressed in the outermost epithelium of hair follicles in synchrony with the anagen phase of hair cycling. Transgenic mice overexpressing sPLA(2)-X (PLA2G10-Tg) displayed alopecia, which was accompanied by hair follicle distortion with reduced expression of genes related to hair development, during a postnatal hair cycle. Additionally, the epidermis and sebaceous glands of PLA2G10-Tg skin were hyperplasic. Proteolytic activation of sPLA(2)-X in PLA2G10-Tg skin was accompanied by preferential hydrolysis of phosphatidylethanolamine species with polyunsaturated fatty acids as well as elevated production of some if not all eicosanoids. Importantly, the skin of Pla2g10-deficient mice had abnormal hair follicles with noticeable reduction in a subset of hair genes, a hypoplasic outer root sheath, a reduced number of melanin granules, and unexpected up-regulation of prostanoid synthesis. Collectively, our study highlights the spatiotemporal expression of sPLA(2)-X in hair follicles, the presence of skin-specific machinery leading to sPLA(2)-X activation, a functional link of sPLA(2)-X with hair follicle homeostasis, and compartmentalization of the prostanoid pathway in hair follicles and epidermis.