Expression of cyclooxygenase-2 in embryonic and fetal tissues during organogenesis and late pregnancy

6-Gingerol Improves In Vitro Porcine Embryo Development by Reducing Oxidative Stress

6-Gingerol, the main active ingredient in ginger, exhibits a variety of biological activities, such as antioxidant, anti-inflammatory, and anticancer activities, and can affect cell development. However, the effects of 6-gingerol on mammalian reproductive processes, especially early embryonic development, are unclear. This study explored whether 6-gingerol can be used to improve the quality of in vitro-cultured porcine embryos. The results showed that 5 μM 6-gingerol significantly increased the blastocyst formation rates of porcine early embryos. 6-Gingerol attenuated intracellular reactive oxygen species accumulation and autophagy, increased intracellular glutathione levels, and increased mitochondrial activity. In addition, 6-gingerol upregulated NANOG, SRY-box transcription factor 2, cytochrome c oxidase subunit II, mechanistic target of rapamycin kinase, and RPTOR independent companion of MTOR complex 2 while downregulating Caspase 3, baculoviral IAP repeat containing 5, autophagy related 12, and Beclin 1. Most importantly, 6-gingerol significantly increased the levels of p-extracellular regulated protein kinase 1/2 while reducing the levels of p-c-Jun N-terminal kinase 1/2/3 and p-p38. These results indicate that 6-gingerol can promote the development of porcine early embryos in vitro.

Prenatal Activation of Glucocorticoid Receptors Induces Memory Impairment in a Sex-Dependent Manner: Role of Cyclooxygenase-2

Prenatal exposure to dexamethasone (DEX) results in long-lasting effects on cognitive functions such as learning and memory impairment. However, the mechanisms underlying these DEX-induced deleterious effects are not well known. Here, we assessed whether cyclooxygenase-2 (COX-2) is involved in the impact of prenatal exposure to DEX on learning and memory during adulthood. Pregnant Sprague-Dawley rats received daily injections of either DEX (0.2 mg/kg; i.p.) or saline from gestation day (GD) 14 until GD21. Gene and protein expression of COX-2, as well as presynaptic (synaptophysin) and postsynaptic (postsynaptic density protein-95) proteins, were monitored in the dorsal and ventral hippocampi of adult male and female offspring. A different cohort of adult male and female rat offspring was given daily injections of either vehicle or a specific COX-2 inhibitor (celecoxib 10 mg/kg, i.p.) for 5 consecutive days and was subsequently subjected to Morris water maze memory test. Prenatal DEX enhanced the expression of COX-2 protein and cox-2 mRNA in the dorsal hippocampus of adult female but not male rats. This enhanced COX-2 expression was associated with reduced expression in pre- and postsynaptic proteins and altered memory acquisition and retention. Administration of COX-2-specific inhibitor alleviated prenatal DEX-induced memory impairment in adult female rats. This study suggests that prenatal activation of glucocorticoid receptors stimulates COX-2 gene and protein expression and impairs hippocampal-dependent spatial memory in female but not male rat offspring. Furthermore, COX-2 selective inhibitors can be used to alleviate the long-lasting deleterious effects of corticosteroid medication during pregnancy.

Prostaglandins F2α and E2 in rat placenta and fetal membrane: a comprehensive immunohistochemistry of their synthetic enzymes and in vivo tissue levels during normal pregnancy

We determined a comprehensive immunohistochemistry of putative isoforms of enzymes for prostaglandin (PG) F₂α and PGE₂ biosynthesis and these PGs levels in placenta and fetal membrane of normal pregnant rats in vivo. Placenta and fetal membrane showed positive immunoreactions for phospholipase A₂ group 4A, but not group 2A, and cyclooxygenase (COX)-1 rather than COX-2. They showed positive immunoreactions for at least one isoform of each of PGF synthase and PGE synthase with tissue-dependent variations. PGF₂α and PGE₂ levels in both tissues were highest on day 12 and declined and remained low thereafter. Obtained data would be the basic information on the primary PGs synthesis in rat placenta and fetal membrane in normal pregnancy.

New insights into the obligatory nature of cyclooxygenase-2 and PGE2 during early chick embryogenesis

Temporal expression patterns and activity of two cyclooxygenase (COX-1 and COX-2) isoforms were analysed during early chick embryogenesis to evaluate their roles in development. COX-2 inhibition with etoricoxib resulted in significant structural anomalies such as anophthalmia (born without one or both eyes), phocomelia (underdeveloped or truncated limbs), and gastroschisis (an opening in the abdominal wall), indicating its significance in embryogenesis. Furthermore, the levels of PGE₂, PGD₂, PGF_2α, and TXB₂ were assessed using quantitative LC-MS/MS to identify which effector prostanoid (s) had their synthesis initiated by COX-2. COX-2 inhibition was only shown to reduce the level of PGE₂ significantly_, and hence it could be inferred that the later could be largely under the regulation of activated COX-2 in chick embryos. The compensatory increase in the activity of COX-1 observed in the etoricoxib-treated group helped to maintain the levels of PGD₂, PGF_2α, and TXB₂. Though the roles of these three prostanoids in embryogenesis need to be further clarified, it appears that their contribution to the observed developmental anomalies is minimal. This study has shown that COX-2 is functionally active during chick embryogenesis, and it plays a central role in the structural configuration of several organs and tissues through its downstream effector molecule PGE₂.

Over-the-counter analgesics during pregnancy: a comprehensive review of global prevalence and offspring safety

BACKGROUND

Analgesia during pregnancy is often necessary. Due to their widespread availability, many mothers opt to use over-the-counter (OTC) analgesics. Those analgesic compounds and their metabolites can readily cross the placenta and reach the developing foetus. Evidence for safety or associations with adverse health outcomes is conflicting, limiting definitive decision-making for healthcare professionals.

OBJECTIVE AND RATIONALE

This review provides a detailed and objective overview of research in this field. We consider the global prevalence of OTC analgesia during pregnancy, explain the current mechanistic understanding of how analgesic compounds cross the placenta and reach the foetus, and review current research on exposure associations with offspring health outcomes.

SEARCH METHODS

A comprehensive English language literature search was conducted using PubMed and Scopus databases. Different combinations of key search terms were used including 'over-the-counter/non-prescription analgesics', 'pregnancy', 'self-medication', 'paracetamol', 'acetaminophen', 'diclofenac', 'aspirin', 'ibuprofen', 'in utero exposure', 'placenta drug transport', 'placental transporters', 'placenta drug metabolism' and 'offspring outcomes'.

OUTCOMES

This article examines the evidence of foetal exposure to OTC analgesia, starting from different routes of exposure to evidence, or the lack thereof, linking maternal consumption to offspring ill health. There is a very high prevalence of maternal consumption of OTC analgesics globally, which is increasing sharply. The choice of analgesia selected by pregnant women differs across populations. Location was also observed to have an effect on prevalence of use, with more developed countries reporting the highest consumption rates. Some of the literature focuses on the association of in utero exposure at different pregnancy trimesters and the development of neurodevelopmental, cardiovascular, respiratory and reproductive defects. This is in contrast to other studies which report no associations.

WIDER IMPLICATIONS

The high prevalence and the challenges of reporting exact consumption rates make OTC analgesia during pregnancy a pressing reproductive health issue globally. Even though some healthcare policy-making authorities have declared the consumption of some OTC analgesics for most stages of pregnancy to be safe, such decisions are often based on partial review of literature. Our comprehensive review of current evidence highlights that important knowledge gaps still exist. Those areas require further research in order to provide pregnant mothers with clear guidance with regard to OTC analgesic use during pregnancy.

Asiatic acid supplementation during the in vitro culture period improves early embryonic development of porcine embryos produced by parthenogenetic activation, somatic cell nuclear transfer and in vitro fertilization

Asiatic acid is a pentacyclic triterpene enriched in the medicinal herb Centella asiatica, and it has been suggested to possess free radical scavenging and anti-apoptotic properties. The purpose of the current study was to explore the effects of asiatic acid on porcine early-stage embryonic development and the potential mechanisms for any observed effects. The results showed that 10 μM asiatic acid supplementation during the in vitro culture period dramatically improved developmental competence in porcine embryos derived from parthenogenetic activation (PA), somatic cell nuclear transfer (SCNT) and in vitro fertilization (IVF). Further analysis revealed that asiatic acid attenuated H₂O₂-induced intracellular reactive oxygen species (ROS) generation. Notably, asiatic acid not only enhanced intracellular GSH levels but also attenuated mitochondrial dysfunction. Gene expression analysis revealed that asiatic acid upregulated expression of the antioxidant-related gene Sod-1 and the blastocyst formation related gene Cox-2, while downregulating expression of the apoptosis-related gene Caspase-9 in SCNT blastocysts. These results suggest that asiatic acid exerts beneficial effects on early embryonic development in porcine embryos and that asiatic acid may be useful for improving the in vitro production of porcine embryos.

COX-1/COX-2 inhibition activities and molecular docking study of newly designed and synthesized pyrrolo[3,4-c]pyrrole Mannich bases

In the present paper we describe the biological activity of newly designed and synthesized series of pyrrolo[3,4-c]pyrrole Mannich bases (7a-n). The Mannich bases were obtained in good yields by one-pot, three-component condensation of pyrrolo[3,4-c]pyrrole scaffold (6a-c) with secondary amines and an excess of formaldehyde solution in C₂H₅OH. The chemical structures of the compounds were characterized by ¹H NMR, ¹³C NMR, FT-IR, and elemental analysis. Moreover, single crystal X-ray diffraction has been recorded for compound 7l. All synthesized derivatives were investigated for their potencies to inhibit COX-1 and COX-2 enzymes by colorimetric inhibitor screening assay. In order to analyse the intermolecular interactions between theligands and cyclooxygenase, experimental data were supported with the results of molecular docking simulations. According to the results, all of the tested compounds inhibited the activity of COX-1 and COX-2.

Cardio-renal safety of non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used therapeutic class in clinical medicine. These are sub-divided based on their selectivity for inhibition of cyclooxygenase (COX) isoforms (COX-1 and COX-2) into: (1) non-selective (ns-NSAIDs), and (2) selective NSAIDs (s-NSAIDs) with preferential inhibition of COX-2 isozyme. The safety and pathophysiology of NSAIDs on the renal and cardiovascular systems have continued to evolve over the years following short- and long-term treatment in both preclinical models and humans. This review summarizes major learnings on cardiac and renal complications associated with pharmaceutical inhibition of COX-1 and COX-2 with focus on preclinical to clinical translatability of cardio-renal data.

Laminarin improves developmental competence of porcine early stage embryos by inhibiting oxidative stress

Laminarin (LMA), a β-glucan mixture with good biocompatibility, improves the growth performance and immune response when used as food additives and nutraceuticals. The aim of the present research was to explore the effects of LMA on porcine early stage embryo development, as well as the underlying mechanisms. The results showed that the developmental competence of porcine early stage embryos was dramatically improved after LMA supplementation during the in vitro culture period. The presence of 20 μg/mL LMA during the in vitro culture period significantly improved cleavage rate, blastocyst formation rates, hatching rate, and total cell number in the blastocyst compared to that in the control group. Notably, LMA attenuated the intracellular reactive oxygen species generation induced by H₂O₂. Furthermore, LMA not only increased intracellular glutathione levels, but also ameliorated mitochondrial membrane potential. In addition, the expression of a zygotic genome activation related gene (YAP1), pluripotency-related genes (OCT4, NANOG, and SOX2), and hatching-related genes (COX2, GATA4, and ITGA5) were up-regulated following LMA supplementation during porcine early stage embryo development. These results demonstrate that LMA has beneficial effects on the development of porcine early stage embryos via regulation of oxidative stress. This evidence provides a novel method for embryo development improvement associated with exposure to LMA.

Salt supplementation ameliorates developmental kidney defects in COX-2−/− mice

Deficiency of cyclooxygenase-2 (COX-2) activity in the early postnatal period causes impairment of kidney development leading to kidney insufficiency. We hypothesize that impaired NaCl reabsorption during the first days of life is a substantial cause for nephrogenic defects observed in COX-2−/− mice and that salt supplementation corrects these defects. Daily injections of NaCl (0.8 mg·g−1·day−1) for the first 10 days after birth ameliorated impaired kidney development in COX-2−/− pups resulting in an increase in glomerular size and fewer immature superficial glomeruli. However, impaired renal subcortical growth was not corrected. Increasing renal tubular flow by volume load or injections of KCl did not relieve the renal histomorphological damage. Administration of torsemide and spironolactone also affected nephrogenesis resulting in diminished glomeruli and cortical thinning. Treatment of COX-2−/− pups with NaCl/DOCA caused a stronger mitigation of glomerular size and induced a slight but significant growth of cortical tissue mass. After birth, renal mRNA expression of NHE3, NKCC2, ROMK, NCCT, ENaC, and Na+/K+-ATPase increased relative to postnatal day 2 in wild-type mice. However, in COX-2−/− mice, a significantly lower expression was observed for NCCT, whereas NaCl/DOCA treatment significantly increased NHE3 and ROMK expression. Long-term effects of postnatal NaCl/DOCA injections indicate improved kidney function with normalization of pathologically enhanced creatinine and urea plasma levels; also, albumin excretion was observed. In summary, we present evidence that salt supplementation during the COX-2-dependent time frame of nephrogenesis partly reverses renal morphological defects in COX-2−/− mice and improves kidney function.

Developmental effects of propyphenazone in analgesic and antipyretic combination with caffeine or paracetamol

The aim of the study was to determine the influence of an over-the-counter (OTC) mixture of propyphenazone with caffeine or paracetamol on prenatal development. Propyphenazone:caffeine and propyphenazone:paracetamol mixtures were prepared with constant 3:1 and 3:5 ratios, respectively. Three dose levels of each of the mixtures were administered separately in Tween-80 water suspension once a day to pregnant Wistar rats on gestation days 8-14. The low dose was similar to the OTC preparations, 2.1 mg/kg of propyphenazone, 0.7 mg/kg of caffeine or 3.5 mg/kg of paracetamol. The middle dose was 21.0, 7.0 or 35.0 mg/kg, and the highest 210.0, 70.0 or 350.0 mg/kg for propyphenazone, caffeine or paracetamol, respectively. On day 21 of gestation the fetuses were delivered by hysterectomy. Dead or live fetuses, resorptions and the number of implantation sites were counted. Live fetuses were examined for external, visceral and skeletal malformation. Postimplantation mortality was calculated. Dose-dependent effects in the middle and high dose groups on fetal body weight/length and placental weight were found. No increase in external or internal congenital anomalies was found in any of the mixture-exposed groups. Prenatal coadministration of propyphenazone with caffeine or paracetamol caused intrauterine growth retardation but did not increase external or internal congenital anomalies. The risk of midline defects (umbilical hernia and gastroschisis) is discussed.

Effects of Lipoic Acid Supplementation on Activities of Cyclooxygenases and Levels of Prostaglandins E2 and F2α Metabolites, in the Offspring of Rats with Streptozotocin-Induced Diabetes

Background. Our aim was to evaluate the protective effect of lipoic acid (LA) on fetal outcome of diabetic mothers. Methods. Diabetes was induced in female rats using streptozotocin and rats were made pregnant. Pregnant control (group 1; n = 9; and group 2; n = 7) or pregnant diabetic (group 3; n = 10; and group 4; n = 8) rats were treated daily with either LA (groups 2 and 4) or vehicle (groups 1 and 3) between gestational days 0 and 15. On day 15 of gestation, the fetuses, placentas, and membranes were dissected, examined morphologically, and then homogenized, to measure cyclooxygenase (COX) activities and metabolisms of prostaglandin (PG) E₂ (PGEM) and PGF₂α (PGFM) levels. The level of total glutathione was measured in the maternal liver and plasma and in all fetuses. Results. Supplementation of diabetic rats with LA was found to significantly (p < 0.05) reduce resorption rates in diabetic rats and led to a significant (p < 0.05) increase in liver, plasma, and fetuses total glutathione from LA-TD rats as compared to those from V-TD. Decreased levels of PGEM and elevated levels of PGFM in the fetuses, placentas, and membranes were characteristic of experimental diabetic gestation associated with malformation. The levels of PGEM in malformed fetuses from LA-TD mothers was significantly (p < 0.05) higher than those in malformed fetuses from V-TD rats. Conclusions. LA treatment did not completely prevent the occurrence of malformations. Thus, other factors may be involved in the pathogenesis of the diabetes-induced congenital malformations.

Gestation Related Gene Expression of the Endocannabinoid Pathway in Rat Placenta

Mammalian placentation is a vital facet of the development of a healthy and viable offspring. Throughout gestation the placenta changes to accommodate, provide for, and meet the demands of a growing fetus. Gestational gene expression is a crucial part of placenta development. The endocannabinoid pathway is activated in the placenta and decidual tissues throughout pregnancy and aberrant endocannabinoid signaling during the period of placental development has been associated with pregnancy disorders. In this study, the gene expression of eight endocannabinoid system enzymes was investigated throughout gestation. Rat placentae were obtained at E14.25, E15.25, E17.25, and E20, RNA was extracted, and microarray was performed. Gene expression of enzymes Faah, Mgll, Plcd4, Pld1, Nat1, Daglα, and Ptgs2 was studied (cohort 1, microarray). Biological replication of the results was performed by qPCR (cohort 2). Four genes showed differential expression (Mgll, Plcd4, Ptgs2, and Pld1), from mid to late gestation. Genes positively associated with gestational age were Ptgs2, Mgll, and Pld1, while Plcd4 was downregulated. This is the first comprehensive study that has investigated endocannabinoid pathway gene expression during rat pregnancy. This study provides the framework for future studies that investigate the role of endocannabinoid system during pregnancy.

Allelic variation in the canine Cox-2 promoter causes hypermethylation of the canine Cox-2 promoter in clinical cases of renal dysplasia

BACKGROUND

Novel allelic variants in the promoter of the canine cyclooxygenase-2 (Cox-2) gene are associated with renal dysplasia (RD). These variants consist of either deletions of putative SP1 transcription factor-binding sites or insertions of tandem repeats of SP1-binding sites located in the CpG island just upstream of the ATG translation initiation site. The canine Cox-2 gene was studied because Cox-2-deficient mice have renal abnormalities and a pathology that is strikingly similar to RD in dogs.

FINDINGS

The allelic variants were associated with hypermethylation of the Cox-2 promoter only in clinical cases of RD. The wild-type allele was never methylated, even in clinical cases that were heterozygous for a mutant allele. In cases that were biopsy-negative, the promoter remained unmethylated, regardless of the genotype. Methylated DNA was found in DNA from various adult tissues of dogs with clinical RD.

CONCLUSIONS

The mechanism of action of the allelic variation in the canine Cox-2 promoter most likely involves variation in the extent of epigenetic downregulation of this gene. This epigenetic downregulation must have occurred early in development because methylated Cox-2 promoter DNA sequences are found in various adult tissues.

Major malformations after first trimester exposure to aspirin and NSAIDs

The use of aspirin and other NSAIDs during the first trimester of pregnancy is widespread, despite inconclusive evidence regarding the possible risks for the baby. We present an overview of the current evidence relating to the associations between aspirin or NSAID use during the first trimester of pregnancy and the risk of congenital malformations. We systematically searched Medline, Embase, the Cochrane Library and the reference lists of all relevant articles from 1966 to March 2008 that examined the association between aspirin and NSAID use during the first trimester of pregnancy and the risk of congenital malformations in humans. We analyzed 30 studies that met the predefined inclusion criteria: 22 case-control studies, seven cohort studies and one randomized, controlled trial. There are not enough human data available to assess the effect of high-dose aspirin and NSAIDs in pregnant women, such as those used in the treatment of rheumatoid arthritis, osteoarthritis and pain relief. This review suggests that the exposure to aspirin or NSAIDs during the first trimester of pregnancy is associated with an increased risk of gastroschisis (aspirin), cardiac malformations (NSAIDs) and orofacial malformations (naproxen).

Pharmacogenetics of drug-induced birth defects: what is known so far?

A literature review was performed to collect information on the role of pharmacogenetics in six proposed teratogenic mechanisms associated with drug use during pregnancy: folate antagonism, oxidative stress, angiotensin-converting enzyme inhibition and angiotensin II receptor antagonism, cyclooxygenase-1 and -2 inhibition, 5-hydroxytryptamine-reuptake inhibition and drug transporters in the placenta. Data on the direct relationship between pharmacogenetics and drug-induced birth defects were found for folate metabolism, oxidative stress caused by phenytoin exposure and drug transporters in the placenta. Although no specific data to support pharmacogenetic-related birth defects were found for the NSAIDs, paroxetine and fluoxetine, it might be expected that polymorphisms modify their teratogenic effects. The usually low prevalence of drug-induced malformations impedes the demonstration of the contribution of pharmacogenetics. Large-scale studies, preferably case-control studies, are needed.

Exposure to non-steroidal anti-inflammatory drugs during pregnancy and the risk of selected birth defects: a prospective cohort study

Background

Since use of non-steroidal anti-inflammatory drugs (NSAIDs) during pregnancy is common, small increases in the risk of birth defects may have significant implications for public health. Results of human studies on the teratogenic risks of NSAIDs are inconsistent. Therefore, we evaluated the risk of selected birth defects after prenatal exposure to prescribed and over-the-counter NSAIDs.

Methods and Findings

We used data on 69,929 women enrolled in the Norwegian Mother and Child Cohort Study between 1999 and 2006. Data on NSAID exposure were available from a self-administered questionnaire completed around gestational week 17. Information on pregnancy outcome was obtained from the Medical Birth Registry of Norway. Only birth defects suspected to be associated with NSAID exposure based upon proposed teratogenic mechanisms and previous studies were included in the multivariable logistic regression analyses. A total of 3,023 women used NSAIDs in gestational weeks 0–12 and 64,074 women did not report NSAID use in early pregnancy. No associations were observed between overall exposure to NSAIDs during pregnancy and the selected birth defects separately or as a group (adjusted odds ratio 0.7, 95% confidence interval 0.4–1.1). Associations between maternal use of specific types of NSAIDs and the selected birth defects were not found either, although an increased risk was seen for septal defects and exposure to multiple NSAIDs based on small numbers (2 exposed cases; crude odds ratio 3.9, 95% confidence interval 0.9–15.7).

Conclusions

Exposure to NSAIDs during the first 12 weeks of gestation does not seem to be associated with an increased risk of the selected birth defects. However, due to the small numbers of NSAID-exposed infants for the individual birth defect categories, increases in the risks of specific birth defects could not be excluded.

The Influence of Interleukin (IL)-1β and IL-6 and Tumour Necrosis Factor-α on Prostaglandin Secretion from Porcine Myometrium during the First Third of Pregnancy

The present study was undertaken to determine the effect of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) on prostaglandin (PG)F2α and PGE2 secretion as well as cyclooxygenase-2 (COX-2) protein expression in myometrium collected on days 25, 30 and 40 of pregnancy in pigs. Myometrial slices were incubated for 16 h with IL-1β, IL-6 and TNF-α (1 or 10 ng/ml of medium) or two combinations of the three cytokines (1 or 10 ng/ml of each cytokine per combination). We demonstrated the stimulatory effect of IL-1β and IL-6 on PGF2α and PGE2 secretion from myometrium collected on all examined days of pregnancy, excepting of influence of IL-6 on release of PGF2α by tissue from day 30. In turn, TNF-α was able to stimulate only PGE2 secretion by myometrium of 40-day-pregnant gilts. The three cytokines applied in combination augmented release of PGE2 from myometrium collected on days 30 and 40 of pregnancy. Stimulation of PGE2 secretion by cytokines used individually was more frequent than that of PGF2α. Moreover, an enhancement in PGF2α and/or PGE2 release was accompanied by an increase of COX-2 protein expression. Our study shows the ability of cytokines to stimulate PGF2α and PGE2 release by porcine myometrium from the first third of pregnancy. Obtained data suggest that locally PGs produced in myometrium influencing the uterine contraction activity may be important for the maintenance of myometrial quiescence during pregnancy and confirm also that the complex cytokine network is an important regulatory mechanism of PGs production during pregnancy.

Novel allelic variants in the canine cyclooxgenase-2 (Cox-2) promoter are associated with renal dysplasia in dogs

Renal dysplasia (RD) in dogs is a complex disease with a highly variable phenotype and mode of inheritance that does not follow a simple Mendelian pattern. Cox-2 (Cyclooxgenase-2) deficient mice have renal abnormalities and a pathology that has striking similarities to RD in dogs suggesting to us that mutations in the Cox-2 gene could be the cause of RD in dogs. Our data supports this hypothesis. Sequencing of the canine Cox-2 gene was done from clinically affected and normal dogs. Although no changes were detected in the Cox-2 coding region, small insertions and deletions of GC boxes just upstream of the ATG translation start site were found. These sequences are putative SP1 transcription factor binding sites that may represent important cis-acting DNA regulatory elements that govern the expression of Cox-2. A pedigree study of a family of Lhasa apsos revealed an important statistical correlation of these mutant alleles with the disease. We examined an additional 22 clinical cases from various breeds. Regardless of the breed or severity of disease, all of these had one or two copies of the Cox-2 allelic variants. We suggest that the unusual inheritance pattern of RD is due to these alleles, either by changing the pattern of expression of Cox-2 or making Cox-2 levels susceptible to influences of other genes or environmental factors that play an unknown but important role in the development of RD in dogs.

Effects of NSAIDs on the Inner Ear: Possible Involvement in Cochlear Protection

Cyclooxygenase and lipoxygenase, two important enzymes involved in arachidonic acid metabolism, are major targets of non-steroidal anti-inflammatory drugs (NSAIDs). Recent investigations suggest that arachidonic cascades and their metabolites may be involved in maintaining inner ear functions. The excessive use of aspirin may cause tinnitus in humans and impairment of the outer hair cell functions in experimental animals. On the other hand, NSAIDs reportedly exhibit protective effects against various kinds of inner ear disorder. The present review summarizes the effects of NSAIDs on cochlear pathophysiology. NSAIDs are a useful ameliorative adjunct in the management of inner ear disorders.

Embryonic expression of cyclooxygenase-2 causes malformations in axial skeleton

Cyclooxygenases (COXs) have important functions in various physiological and pathological processes. COX-2 expression is highly induced by a variety of stimuli and is observed during certain periods of embryonic development. In this report, the direct effect of COX-2 expression on embryonic development is examined in a novel COX-2 transgenic mouse model that ubiquitously expresses human COX-2 from the early stages of embryonic development. COX-2 transgenic fetuses exhibit severe skeletal malformations and die shortly after birth. Skeletal malformations are localized along the entire vertebral column and rib cage and are linked to defective formation of cartilage anlagen. The cartilage anlagen of axial skeleton fail to properly develop in transgenic embryos because of impaired precartilaginous sclerotomal condensation, which results from the reduction of cell number in the sclerotome. Despite the ubiquitous expression of COX-2, the number of apoptotic cells is highly increased in the sclerotome of transgenic embryos but not in other tissues, suggesting that it is a tissue-specific response. Therefore, the loss of sclerotomal cells due to an increased apoptosis is probably responsible for axial skeletal malformations in transgenic fetuses. In addition, the sclerotomal accumulation of p53 protein is observed in transgenic embryos, suggesting that COX-2 may induce apoptosis via the up-regulation of p53. Our results demonstrate that the aberrant COX-2 signaling during embryonic development is teratogenic and suggest a possible association of COX-2 with fetal malformations of unknown etiology.

The effect of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 beta and IL-6 on chorioamnion secretion of prostaglandins (PG)F 2 alpha and E2 in pigs

The aim of the present study was to determine the effect of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) on prostaglandin (PG)F(2 alpha) and PGE(2) secretion as well as cyclooxygenase-2 (COX-2) protein expression in chorioamnion collected on days 25, 30 and 40 of pregnancy in pigs. Fetal membrane slices were incubated for 16 h with TNF-alpha, IL-1 beta, IL-6 (1 or 10 ng/ml of medium) or two combinations of the three cytokines (1 or 10 ng/ml of each cytokine per combination). We demonstrated the stimulatory effect of TNF-alpha, IL-1 beta and/or IL-6 on PGF(2 alpha) and PGE(2) secretion by the porcine fetal membranes. The medium content of these PGs depended on the cytokine type, treatment dose and day of pregnancy. Cytokine stimulation of PGE(2) was more pronounced than that of PGF(2 alpha). In addition, an increase in PGF(2 alpha) and/or PGE(2) secretion was usually associated with an augmentation of COX-2 protein expression. Our results support the notion concerning the possible role of cytokines in modulating production of PGs by fetal membranes during the first trimester of gestation.

Pulmonary and cardiorenal cyclooxygenase-1 (COX-1), -2 (COX-2), and microsomal prostaglandin E synthase-1 (mPGES-1) and -2 (mPGES-2) expression in a hypertension model

Hypertensive mice that express the human renin and angiotensinogen genes are used as a model for human hypertension because they develop hypertension secondary to increased renin-angiotensin system activity. Our study investigated the cellular localization and distribution of COX-1, COX-2, mPGES-1, and mPGES-2 in organ tissues from a mouse model of human hypertension. Male (n = 15) and female (n = 15) double transgenic mice (h-Ang 204/1 h-Ren 9) were used in the study. Lung, kidney, and heart tissues were obtained from mice at necropsy and fixed in 10% neutral buffered formalin followed by embedding in paraffin wax. Cut sections were stained immunohistochemically with antibodies to COX-1, COX-2, mPGES-1, and mPGES-2 and analyzed by light microscopy. Renal expression of COX-1 was the highest in the distal convoluted tubules, cortical collecting ducts, and medullary collecting ducts; while proximal convoluted tubules lacked COX-1 expression. Bronchial and bronchiolar epithelial cells, alveolar macrophages, and cardiac vascular endothelial cells also had strong COX-1 expression, with other renal, pulmonary, or cardiac microanatomic locations having mild-to-moderate expression. mPGES-2 expression was strong in the bronchial and bronchiolar epithelial cells, mild to moderate in various renal microanatomic locations, and absent in cardiac tissues. COX-2 expression was strong in the proximal and distal convoluted tubules, alveolar macrophages, and bronchial and bronchiolar epithelial cells. Marked mPGES-1 was present only in bronchial and bronchiolar epithelial cells; while mild-to-moderate expression was present in other pulmonary, renal, or cardiac microanatomic locations. Expression of these molecules was similar between males and females. Our work suggests that in hypertensive mice, there are (a) significant microanatomic variations in the pulmonary, renal, and cardiac distribution and cellular localization of COX-1, COX-2, mPGES-1, and mPGES-2, and (b) no differences in expression between genders.

Growth and differentiation factors for cartilage healing and repair

Chondrocyte differentiation and the maintenance of function requires both transient and long-lasting control through humoral factors, particularly under stress, repair and regeneration in vivo or in vitro as in cell and tissue culture. To date, humoral factors from all major classes of molecules are known to contribute: ions (calcium), steroids (estrogens), terpenoids (retinoic acid), peptides (PTHRP, PTH, insulin, FGFs) and complex proteins (IGF-1, BMPs). They may act indirectly through membrane receptors and signal pathways or directly on transcriptional control elements. Those molecules may reach chondrocytes via free diffusion or may be bound to collagens or proteoglycans on extracellular matrix superstructures becoming available on metabolic processing of collagens and/or proteoglycans. Depending on their position in the metabolic cascade controlling chondrocyte development and homeostasis, they may be used in tissue engineering and regenerative approaches towards cartilage repair by direct application, carrier-mediated release or genetic delivery.

A fetal cyclooxygenase-2 gene polymorphism is associated with placental malperfusion

Prostaglandin levels vary during pregnancy, mostly under the control of the inducible enzyme cyclooxygenase-2 (COX-2). The expression of COX-2 has been associated with ischemic events in the heart and brain, but its direct effect on human placental perfusion has not been previously examined. The purpose of this study was to investigate whether a functional polymorphism in the COX-2 gene that controls enzyme expression levels is associated with placental histopathologic lesions. Maternal and neonatal DNA from twin gestations were analyzed by a polymerase chain reaction-based assay for a single G to C nucleotide polymorphism at position -765 in the COX-2 gene promoter. Placental histopathology was evaluated in 6 major categories: meconium, malperfusion, inflammation, umbilical cord problems, villitis, and thrombosis. There was no significant association between placental histopathologic findings and polymorphisms of the COX-2 gene in the mother. In the fetus, carriage of the COX-2 C allele, which is correlated with decreased COX-2 gene expression, was negatively associated with lesions of placental ischemia/malperfusion (P = 0.02). Placental ischemic lesions were positively associated with intrauterine growth restriction (IUGR; P < 0.001). No other group of histopathologic lesions was associated with fetal polymorphisms in the COX-2 gene or with IUGR. Thus, a fetal polymorphism in the COX-2 gene influences the occurrence of placental malperfusion and ischemia, which may be of sufficient severity to promote or allow the development of IUGR.

Congenital ventricular septal defects and prenatal exposure to cyclooxygenase inhibitors

Ventricular septal defects (VSDs) are common congenital abnormalities which have been reported to be associated with maternal fever and various environmental factors. The aim of the present study was to evaluate the effect of prenatal exposure to cyclooxygenase (COX) inhibitors on heart defects. A retrospective statistical analysis was performed using data collected in our laboratory during various teratological studies carried out on albino CRL:(WI)WUBR Wistar strain rats from 1997 to 2004. The observations were compared with concurrent and historic control data, as well as findings from other developmental toxicological studies with selective and nonselective COX-2 inhibitors. Despite the lack of significant differences in the frequency of VSDs between drug-exposed and control groups, statistical analysis by the two-sided Mantel-Haenszel test and historical control data showed a higher incidence of heart defects in offspring exposed to nonselective COX inhibitors (30.06/10,000). Unlike other specific inhibitors, aspirin (46.26/10,000) and ibuprofen (106.95/10,000) significantly increased the incidence of the VSD when compared with various control groups (5.38-19.72/10,000). No significant differences in length or weight were detected between fetuses exposed to COX inhibitors and born with VSD and non-malformed offsprings. However, a statistically significant increase of fetal body length and decrease of body mass index were found in fetuses exposed to COX inhibitors when compared with untreated control. We conclude that prenatal exposure to COX inhibitors, especially aspirin and ibuprofen, increased the incidence of VSDs in rat offspring but was not related to fetal growth retardation.

Anti-inflammatory and immunosuppressive drugs and reproduction

Rheumatic diseases in women of childbearing years may necessitate drug treatment during a pregnancy, to control maternal disease activity and to ensure a successful pregnancy outcome. This survey is based on a consensus workshop of international experts discussing effects of anti-inflammatory, immunosuppressive and biological drugs during pregnancy and lactation. In addition, effects of these drugs on male and female fertility and possible long-term effects on infants exposed to drugs antenatally are discussed where data were available. Recommendations for drug treatment during pregnancy and lactation are given.

Expression of cyclooxygenase isoforms in developing rat placenta, human term placenta, and BeWo human trophoblast model

Cyclooxygenase (COX) catalyzes the rate-limiting step in the conversion of essential fatty acids (EFAs) to bioactive molecules such as prostaglandins (PGs), which play critical roles in many aspects of female reproduction and in fetal development. There are two primary related COX isoforms, the constitutively expressed COX-1 and the inducible COX-2. Although the expression of COX-1 and COX-2 has been demonstrated in the amnion, chorion, and decidua, relatively little information exists with regard to their expression and physiological function in the placenta during gestation. In this study, we have elucidated the spatial and temporal patterns of COX-1 and COX-2 expression in the labyrinthine and junctional zones of the developing rat placenta, in the human term placenta, and in the BeWo human trophoblast model using semiquantitative RT-PCR, Western blot, and immunohistochemical analyses. The mRNA and protein expression of COX-1 and COX-2 were demonstrated in the developing rat placenta with increasing expression observed toward parturition. COX-2 exhibited greater expression than COX-1 after mid-gestation and had a corresponding shift in spatial expression from the labyrinthine to the junctional zone at term. COX-1 and -2 were also expressed in human term placenta, while BeWo cells exhibited moderate expression of COX-1 and weak expression of COX-2. The results demonstrate that COX-1 and COX-2 are expressed in the rat and human placentas. The differential expression patterns in the rat placenta, especially of COX-2, imply that there may be gestational changes in the biosynthesis of PGs and other potential bioactive EFA metabolites. Establishing the expression of the COX isoforms provides a framework for future investigations into the functional and physiological significance of COX-1 and COX-2 in the placenta, particularly with respect to influencing normal pregnancy and fetal development, and to provide insights into therapeutic utilization of COX inhibitors in pregnancy.

Skeletal developmental effects of selective and nonselective cyclooxygenase-2 inhibitors administered through organogenesis and fetogenesis in Wistar CRL:(WI)WUBR rats

Cyclooxygenase (COX) inhibitors are the most commonly ingested drugs. The aim of the study was to evaluate the prenatal skeletal effect of selective (DFU) and nonselective (tolmetin, ibuprofen, piroxicam) COX-2 inhibitors. All the tested compounds were administered intragastrically to pregnant Wistar rats from 7 to 21 gestation day. The initial dose was set at 8.5mg/kg/dose for tolmetin and ibuprofen, 0.3 and 0.2mg/kg/dose for piroxicam and DFU. The middle dose was increased 10-times. The highest dose, except for ibuprofen, was elevated 100-times. The highest dose for ibuprofen was set at 200mg/kg/dose. Tolmetin and ibuprofen were administered three times a day. Piroxicam and DFU were dosed once daily. After routine teratological examinations, extremities of randomly selected 21-day-old fetuses were taken for histological, immunohistochemical and molecular studies. The proximal femoral epiphyses were separated and their ultrastructure evaluated. The expression of genes coding cytokines (IL-1alpha, IL-1beta, IL-6, TNF-alpha, TNF-beta) and proteins (COX-1, COX-2, cathepsin K, collagen types I, II and X; osteocalcin, osteopontin) was evaluated in femoral epiphyses by RNase Protection Assay and/or immunohistochemically. The articulate development was checked histologically and found undisturbed in any of the experimental groups. The epiphysis of the 21-day-old fetuses, presented physiological expression of COX-1 and COX-2, as well as cathepsin K, collagen types I, II and X; osteopontin, osteocalcin and TNF-alpha. Increased developmental skeletal variation was noted in groups exposed to the highest dose of nonselective drugs. Unlike the increased number of skeletal variations observed in fetuses exposed to highest doses of nonselective compounds, both groups of COX inhibitors did not disturb joint formation and morphology of femoral epiphyses when administered even in high maternal toxic doses.

Comparison of developmental toxicity of selective and non-selective cyclooxygenase-2 inhibitors in CRL:(WI)WUBR Wistar rats – DFU and piroxicam study

BACKGROUND

Cyclooxygenase (COX) inhibitors are one of the most often ingested drugs during pregnancy. Unlike general toxicity data, their prenatal toxic effects were not extensively studied before. The aim of the experiment was to evaluate the developmental toxicity of the non-selective (piroxicam) and selective (DFU; 5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulphonyl) phenyl-2(5H)-furanon) COX-2 inhibitors.

METHODS

Drugs were separately, orally once daily dosed to pregnant rats from day 8 to 21 (GD1=plug day). Doses were set at 0.3, 3.0 and 30.0mg/kg for piroxicam and 0.2, 2.0 and 20.0mg/kg for DFU. Fetuses were delivered on GD 21 and routinely examined. Comprehensive clinical and developmental measurements were done. The pooled statistical analysis for ventricular septal (VSD) and midline (MD) defects was performed for rat fetuses exposed to piroxicam, selective and non-selective COX-2 inhibitor based on present and historic data.

RESULTS

Maternal toxicity, intrauterine growth retardation, and increase of external and skeletal variations were found in rats treated with the highest dose of piroxicam. Decrease of fetal length was the only signs of the DFU developmental toxicity observed in pups exposed to the highest compound dose. Lack of teratogenicity was found in piroxicam and DFU-exposed groups. Prenatal exposure to non-selective COX inhibitors increases the risk of VSD and MD when compared to historic control but not with selective COX-2 inhibitors.

CONCLUSION

Both selective and non-selective COX-2 inhibitors were toxic for rats fetuses when administered in the highest dose. Unlike DFU, piroxicam was also highly toxic to the dams. Prenatal exposure to selective COX-2 inhibitors does not increase the risk of ventricular septal and midline defects in rat when compared to non-selective drugs and historic control.

Anti-inflammatory pharmacotherapy during pregnancy

NSAIDs or cyclooxygenase inhibitors (COX inhibitors), including aspirin, are widely used to treat pain, fever and the articular symptoms of chronic rheumatic diseases. Manifestations of connective tissue or autoimmune diseases are commonly treated with glucocorticosteroids. The effect and side effects of NSAIDs depend on the isoforms of cyclooxygenases that they preferentially or selectively inhibit. The use of COX inhibitors has recently been associated with infertility and miscarriage. The classical nonselective COX inhibitors, including aspirin, do not increase the risk of congenital malformations in humans but administered in the latter part of gestation, they can affect pregnancy and the fetus. The ability of nonselective and selective COX inhibitors to prolong gestation has been used by obstetricians to inhibit premature delivery. The vascular effects of prostaglandin inhibitors can cause constriction of the fetal ductus arteriosus and reduce renal blood flow. These complications have been described for most nonselective COX inhibitors but are increasingly reported also for the selective COX-2 inhibitors. Aspirin, which causes irreversible inhibition of cyclooxygenases, differs from other NSAIDs with regard to indication, effects and side effects. Prematurity, which is increased in pregnancies of women with connective tissue diseases, is an additional risk factor for adverse effects of antenatal exposure to NSAIDs. Therefore, treatment with COX inhibitors should be discontinued at week 32 of gestation. The ability of NSAIDs to compromise reproductive function by inhibition of ovulation and as causative agents for miscarriage is still under debate. Glucocorticosteroids given in early pregnancy are a risk factor for the development of oral clefts. Therefore, the daily dose should be kept to <or= 15 mg during the first trimester. High doses of glucocorticosteroids in the second and third trimester are reserved for flares of autoimmune diseases. Intrauterine fetal growth restriction and premature delivery are possible side effects of high doses.

Gastrointestinal and hepatic toxicity of selective and non-selective cyclooxygenase-2 inhibitors in pregnant and non-pregnant rats

The aim of the study was to evaluate the toxicity of non-selective (tolmetin, ibuprofen and piroxicam) and selective (DFU) cyclooxygenase-2 inhibitors on pregnant and non-pregnant rats. The drugs were administered orally once (DFU, piroxicam) or three times (tolmetin, ibuprofen) a day from days 8 through 21 of gestation experiment in three doses. The initial dose was similar to the human antiinflammatory one and set as 8.5 mg/kg (tolmetin, ibuprofen), 0.3 mg/kg (piroxicam) and 0.2 mg/kg (DFU). The middle dose was increased 10 times and the highest one 100 times the initial dose. The highest dose for ibuprofen was set at 200mg/kg due to high mortality. On gestation/experimental day 21 animals were sacrificed, blood was collected and abdominal organs were taken for pathological examination. Activity of alanine and asparate aminotransferases and levels of total protein and urea were determined. Stomach, small and large intestines, and liver were grossly and histologically examined. Dose-dependent mortality, signs of gastrointestinal toxicity, and significant changes of biochemical parameters were found in groups exposed to non-selective COX inhibitors in both pregnant and non-pregnant rats. Mild regressive structural hepatic changes were observed. Significant decrease of protein level in non-pregnant rats treated with high DFU dose, and occasionally observed gastrointestinal changes were the only changes noted in groups exposed to the selective COX-2 inhibitor. Tolerability of non-selective COX inhibitors was lower in both pregnant and non-pregnant groups when compared with DFU. Insignificant mortality and histological changes were noted between pregnant and non-pregnant groups.

Developmental toxicity evaluation of ibuprofen and tolmetin administered in triple daily doses to Wistar CRL:(WI)WUBR rats

BACKGROUND

Ibuprofen and tolmetin are popular non-steroidal anti-inflammatory drugs. Previous animal studies taken with single daily doses showed their good prenatal tolerability. However, since both cyclooxygenase (COX) inhibitors have a short half-life, the current report presents drug developmental effects after triple daily doses administration, as they are used in human.

METHODS

Drugs were separately, orally dosed to pregnant rats triple daily 8 hr apart from day 8 to 21 (GD=1-plug day). The total daily doses were set at 25.5, 255.0, and 600.0 mg/kg for ibuprofen and 25.5, 255.0, and 2550.0 mg/kg for tolmetin. Fetuses were delivered on GD 21 and routinely examined. Comprehensive clinical and developmental measurements were done.

RESULTS

Maternal toxicity and intrauterine growth retardation were found in groups exposed to the highest doses of both drugs. An increase of external variations was reported in groups exposed to the middle and highest dose of ibuprofen and to the highest dose of tolmetin. Skeletal variations were significantly different only in litters treated with the highest doses of the drugs. Pooled statistical analysis showed a higher incidence of midline and ventricular septal (VSD) defect in rat fetuses exposed to COX inhibitors when compared with historical control data. For ibuprofen, the influence on VSD was similar to aspirin.

CONCLUSION

Both COX inhibitors were toxic to dams in the highest doses evaluated, which caused a significantly greater incidence of intrauterine growth retardation and developmental variations.