Lipocalin-type prostaglandin D synthase in human male reproductive organs and seminal plasma

Back pain exercise therapy remodels human epigenetic profiles in buccal and human peripheral blood mononuclear cells: an exploratory study in young male participants

Background

With its high and increasing lifetime prevalence, back pain represents a contemporary challenge for patients and healthcare providers. Monitored exercise therapy is a commonly prescribed treatment to relieve pain and functional limitations. However, the benefits of exercise are often gradual, subtle, and evaluated by subjective self-reported scores. Back pain pathogenesis is interlinked with epigenetically mediated processes that modify gene expression without altering the DNA sequence. Therefore, we hypothesize that therapy effects can be objectively evaluated by measurable epigenetic histone posttranslational modifications and proteome expression. Because epigenetic modifications are dynamic and responsive to environmental exposure, lifestyle choices-such as physical activity-can alter epigenetic profiles, subsequent gene expression, and health traits. Instead of invasive sampling (e.g., muscle biopsy), we collect easily accessible buccal swabs and plasma. The plasma proteome provides a systemic understanding of a person's current health state and is an ideal snapshot of downstream, epigenetically regulated, changes upon therapy. This study investigates how molecular profiles evolve in response to standardized sport therapy and non-controlled lifestyle choices.

Results

We report that the therapy improves agility, attenuates back pain, and triggers healthier habits. We find that a subset of participants' histone methylation and acetylation profiles cluster samples according to their therapy status, before or after therapy. Integrating epigenetic reprogramming of both buccal cells and peripheral blood mononuclear cells (PBMCs) reveals that these concomitant changes are concordant with higher levels of self-rated back pain improvement and agility gain. Additionally, epigenetic changes correlate with changes in immune response plasma factors, reflecting their comparable ability to rate therapy effects at the molecular level. We also performed an exploratory analysis to confirm the usability of molecular profiles in (1) mapping lifestyle choices and (2) evaluating the distance of a given participant to an optimal health state.

Conclusion

This pre-post cohort study highlights the potential of integrated molecular profiles to score therapy efficiency. Our findings reflect the complex interplay of an individual's background and lifestyle upon therapeutic exposure. Future studies are needed to provide mechanistic insights into back pain pathogenesis and lifestyle-based epigenetic reprogramming upon sport therapy intervention to maintain therapeutic effects in the long run.

The metabolomics changes in epididymal lumen fluid of CABS1 deficient male mice potentially contribute to sperm deformity

Introduction

Epididymal lumen fluids provides a stable microenvironment for sperm maturation. Ca2+ binding protein CABS1 is known to maintain structural integrity of mouse sperm flagella during epididymal transit of sperm. Besides, CABS1 was reported to contain anti-inflammatory peptide sequences and be present in both human saliva and plasma. However, little is known about the role of CABS1 in regulation of the microenvironment of epididymal lumen fluids.

Methods

To further confirm the role of CABS1 in epididymis, we identified the expression of CABS1 in epididymal lumen fluids. Moreover, high performance liquid chromatography, coupled with tandem mass spectrometry technique was used to analyze the metabolic profiles and in vivo microperfusion of the cauda epididymis and inductively coupled plasma mass spectrometry (ICP-MS) assays was used to detect the concentration of metal ion of mouse cauda epididymal lumen fluids in CABS1 deficient and normal mice.

Results

The results showed that CABS1 is present in epididymal lumen fluids, and the concentration of calcium in epididymal lumen fluids is not changed in Cabs1-/- male mice. Among 34 differential metabolites identified in cauda epididymis, 21 were significantly upregulated while 13 were significantly downregulated in KO cauda epididymis. Pathway analysis identified pyrimidine metabolism, inositol phosphate metabolism, arachidonic acid metabolism, purine metabolism and histidine metabolism as relevant pathways in cauda epididymis.

Discussion

The perturbations of mitochondrial dysfunction and inflammation may be the crucial reason for the poor performance of Cabs1-/- sperm.

Understanding seminal plasma in male infertility: emerging markers and their implications

Infertility affects a significant proportion of the reproductive-aged population, with male-associated factors contributing to over half of the cases. However, current diagnostic tools have limitations, leading to an underestimation of the true prevalence of male infertility. While traditional semen parameters provide some insights, they fail to determine the true fertility potential in a substantial number of instances. Therefore, it is crucial to investigate additional molecular targets responsible for male infertility to improve understanding and identification of such cases. Seminal plasma, the main carrier of molecules derived from male reproductive glands, plays a crucial role in reproduction. Amongst its multifarious functions, it regulates processes such as sperm capacitation, sperm protection and maturation, and even interaction with the egg's zona pellucida. Seminal plasma offers a non-invasive sample for urogenital diagnostics and has shown promise in identifying biomarkers associated with male reproductive disorders. This review aims to provide an updated and comprehensive overview of seminal plasma in the diagnosis of male infertility, exploring its composition, function, methods used for analysis, and the application of emerging markers. Apart from the application, the potential challenges of seminal plasma analysis such as standardisation, marker interpretation and confounding factors have also been addressed. Moreover, we have also explored future avenues for enhancing its utility and its role in improving diagnostic strategies. Through comprehensive exploration of seminal plasma's diagnostic potential, the present analysis seeks to advance the understanding of male infertility and its effective management.

Impact of COVID-19 on sperm quality and the prostaglandin and polyamine systems in the seminal fluid

BACKGROUND

The implications of SARS-CoV-2 infection on male fertility remain largely unknown. Besides their well-known pro- and anti-inflammatory actions, prostaglandins and polyamines are present in semen, where they play key roles in sperm quality.

OBJECTIVES

To analyze semen parameters, oxidative profile and the seminal fluid prostaglandin and polyamine systems in samples collected from individuals without coronavirus disease 2019 diagnosis and men who recovered from coronavirus disease 2019.

MATERIALS AND METHODS

This study compared semen collected from men without positive coronavirus disease 2019 diagnosis with samples obtained from individuals 1-6 months and 7-30 months post SARS-CoV-2 infection. Semen parameters, thiobarbituric acid reactive substances, cyclooxygenase 2 expression by fluorescence immunocytochemistry and immunoblotting, prostaglandin levels by enzyme immunoassay, ornithine decarboxylase activity by a radioactive assay, and polyamine and acetylated polyamine levels by thin-layer chromatography were assessed.

RESULTS

In both groups of semen samples from coronavirus disease 2019 recovered men, sperm vitality, total and progressive sperm motility, and putrescine levels were significantly decreased when compared with samples from the uninfected group. In contrast, lipid peroxidation, leukocyte-associated cyclooxygenase 2 expression, and prostaglandin D2 levels were higher in semen from coronavirus disease 2019 recovered men than in samples from uninfected individuals. While sperm concentration and morphology, ornithine decarboxylase activity, and N-acetylputrescine levels were statistically diminished in semen obtained up to 6 months after coronavirus disease 2019 recovery, these parameters remained unchanged when samples were collected 7-30 months after coronavirus disease 2019 recovery. Coronavirus disease 2019 vaccination did not show negative effects on any of the parameters evaluated.

DISCUSSION AND CONCLUSION

Our work provides insights into the detrimental impact of coronavirus disease 2019 on several sperm parameters, in some cases, even more than a year after SARS-CoV-2 infection, which would be accompanied by alterations in the seminal fluid prostaglandin and polyamine profiles. Therefore, future treatments targeting the prostaglandin and polyamine pathways in coronavirus disease 2019 recovered men could lead to a successful reinstatement of semen parameters.

Differential transcriptome study on the damage of testicular tissues caused by chronic infection of T. gondii in mice

BACKGROUND

Toxoplasma gondii is an intracellular protozoan parasite that is widely distributed in humans and warm-blooded animals. T. gondii chronic infections can cause toxoplasmic encephalopathy, adverse pregnancy, and male reproductive disorders. In male reproduction, the main function of the testis is to provide a stable place for spermatogenesis and immunological protection. The disorders affecting testis tissue encompass abnormalities in the germ cell cycle, spermatogenic retardation, or complete cessation of sperm development. However, the mechanisms of interaction between T. gondii and the reproductive system is unclear. The aims were to study the expression levels of genes related to spermatogenesis, following T. gondii infection, in mouse testicular tissue.

METHODS

RNA-seq sequencing was carried out on mouse testicular tissues from mice infected or uninfected with the T. gondii type II Prugniaud (PRU) strain and validated in combination with real-time quantitative PCR and immunofluorescence assays.

RESULTS

The results showed that there were 250 significant differentially expressed genes (DEGs) (P < 0.05, |log2fold change| ≧ 1). Bioinformatics analysis showed that 101 DEGs were annotated to the 1696 gene ontology (GO) term. While there was a higher number of DEGs in the biological process classification as a whole, the GO enrichment revealed a significant presence of DEGs in the cellular component classification. The Arhgap18 and Syne1 genes undergo regulatory changes following T. gondii infection, and both were involved in shaping the cytoskeleton of the blood-testis barrier (BTB). The number of DEGs enriched in the MAPK signaling pathway, the ERK1/2 signaling pathway, and the JNK signaling pathway were significant. The PTGDS gene is located in the Arachidonic acid metabolism pathway, which plays an important role in the formation and maintenance of BTB in the testis. The expression of PTGDS is downregulated subsequent to T. gondii infection, potentially exerting deleterious effects on the integrity of the BTB and the spermatogenic microenvironment within the testes.

CONCLUSIONS

Overall, our research provides in-depth insights into how chronic T. gondii infection might affect testicular tissue and potentially impact male fertility. These findings offer a new perspective on the impact of T. gondii infection on the male reproductive system.

Arachidonic Acid Pathways and Male Fertility: A Systematic Review

Arachidonic acid (AA) is a polyunsaturated fatty acid that is involved in male fertility. Human seminal fluid contains different prostaglandins: PGE (PGE₁ and PGE₂), PGF_2α, and their specific 19-hydroxy derivatives, 18,19-dehydro derivatives of PGE₁ and PGE₂. The objective of this study is to synthesize the available literature of in vivo animal studies and human clinical trials on the association between the AA pathway and male fertility. PGE is significantly decreased in the semen of infertile men, suggesting the potential for exploitation of PGE agonists to improve male fertility. Indeed, ibuprofen can affect male fertility by promoting alterations in sperm function and standard semen parameters. The results showed that targeting the AA pathways could be an attractive strategy for the treatment of male fertility.

Oral exposure to DEHP may stimulate prostatic hyperplasia associated with upregulation of COX-2 and L-PGDS expressions in male adult rats

Di-(2-ethylhexyl) phthalate (DEHP), a typical environmental endocrine disruptor (EED), can disrupt estrogen and androgen secretion and metabolism process, thus inducing dysfunctional reproduction such as impaired gonadal development and spermatogenesis disorder. Prostaglandin synthases (PGS) catalyze various prostaglandins biosynthesis, involved in inflammatory cascade and tumorigenesis. Yet, little is known about how PGS may impact prostatic hyperplasia development and progression. This study concentrates predominantly on the potential prostatic toxicity of DEHP exposure and the mediating role of PGS. In vivo study, adult male rats were administered via oral gavage 30 μg/kg/d, 90 μg/kg/d, 270 μg/kg/d, 810 μg/kg/d DEHP or vehicle for four weeks. The results elucidated that low-dose DEHP may cause the proliferation of the prostate with an increased PCNA/TUNEL ratio. Given the importance of estrogens and androgens in prostatic hyperplasia, our first objective was to evaluate the levels of sex hormones. DEHP improved the ratio of estradiol (E₂)/testosterone (T) in a dose-dependent manner and upregulated estrogen receptor alpha (ERα) and androgen receptor (AR) expressions. Prostaglandin synthases, including cyclooxygenase-2 (COX-2) and lipocalin-type prostaglandin D synthase (L-PGDS), were significantly upregulated in the ventral prostate. COX-2 and L-PGDS might mediate the tendency of prostatic hyperplasia induced by low-dose DEHP through estradiol/androgen regulation and imbalance between proliferation and apoptosis in vivo. These findings provide the first evidence that prostaglandin synthases contribute to the tendency toward benign prostatic hyperplasia induced by DEHP. Further investigations will have to be performed to facilitate an improved understanding of the role of prostaglandin synthases in DEHP-induced prostatic lesions.

Using Experimental Models to Decipher the Effects of Acetaminophen and NSAIDs on Reproductive Development and Health

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin (acetylsalicylic acid), diclofenac and ibuprofen (IBU), and analgesic drugs, such as acetaminophen (APAP, or paracetamol), are widely used to treat inflammation and pain. APAP and IBU are over-the-counter drugs and are among the most commonly taken drugs in the first trimester of pregnancy, even in combination. Furthermore, these drugs and their metabolites are released in the environment, and can be frequently detected in wastewater, surface water, and importantly in drinking water. Although their environmental concentrations are much lower than the therapeutics doses, this suggests an uncontrolled low-dose exposure of the general population, including pregnant women and young children, two particularly at risk populations. Epidemiological studies show that exposure to these molecules in the first and second trimester of gestation can favor genital malformations in new-born boys. To investigate the cellular, molecular and mechanistic effects of exposure to these molecules, ex vivo studies with human or rodent gonadal explants and in vivo experiments in rodents have been performed in the past years. This review recapitulates recent data obtained in rodent models after in utero or postnatal exposure to these drugs. The first part of this review discusses the mechanisms by which NSAIDs and analgesics may impair gonadal development and maturation, puberty development, sex hormone production, maturation and function of adult organs, and ultimately fertility in the exposed animals and their offspring. Like other endocrine disruptors, NSAIDs and APAP interfere with endocrine gland function and may have inter/transgenerational adverse effects. Particularly, they may target germ cells, resulting in reduced quality of male and female gametes, and decreased fertility of exposed individuals and their descendants. Then, this review discusses the effects of exposure to a single drug (APAP, aspirin, or IBU) or to combinations of drugs during early embryogenesis, and the consequences on postnatal gonadal development and adult reproductive health. Altogether, these data may increase medical and public awareness about these reproductive health concerns, particularly in women of childbearing age, pregnant women, and parents of young children.

Eicosanoid Biosynthesis in Male Reproductive Development: Effects of Perinatal Exposure to NSAIDs and Analgesic Drugs

Increasing rates of infertility associated with declining sperm counts and quality, as well as increasing rates of testicular cancer are contemporary issues in the United States and abroad. These conditions are part of the Testicular Dysgenesis Syndrome, which includes a variety of male reproductive disorders hypothesized to share a common origin based on disrupted testicular development during fetal and neonatal stages of life. Male reproductive development is a highly regulated and complex process that relies on an intricate coordination between germ, Leydig, and Sertoli cells as well as other supporting cell types, to ensure proper spermatogenesis, testicular immune privilege, and endocrine function. The eicosanoid system has been reported to be involved in the regulation of fetal and neonatal germ cell development as well as overall testicular homeostasis. Moreover, non-steroidal anti-inflammatory drugs (NSAIDs) and analgesics with abilities to block eicosanoid synthesis by targeting either or both isoforms of cyclooxygenase enzymes, have been found to adversely affect male reproductive development. This review will explore the current body of knowledge on the involvement of the eicosanoid system in male reproductive development, as well as discuss adverse effects of NSAIDs and analgesic drugs administered perinatally, focusing on toxicities reported in the testis and on major testicular cell types. Rodent and epidemiological studies will be corroborated by findings in invertebrate models for a comprehensive report of the state of the field, and to add to our understanding of the potential long-term effects of NSAID and analgesic drug administration in infants.

Arachidonic Acid in Follicular Fluid of PCOS Induces Oxidative Stress in a Human Ovarian Granulosa Tumor Cell Line (KGN) and Upregulates GDF15 Expression as a Response

Polycystic ovarian ovary syndrome (PCOS) is the main cause of ovulatory infertility and a common reproductive endocrine disease of women in reproductive age. In addition, nearly half of PCOS patients are associated with obesity, and their total free fatty acids tend to increase. Arachidonic acid (AA) is a polyunsaturated fatty acid. Oxidation products of AA reacting with various enzymes[cyclooxygenases (COX), lipoxygenases (LOX), cytochrome P450s (CYP)] can change cellular mitochondrial distribution and calcium ion concentration, and increase reactive oxygen species (ROS) production. In this study, we analyzed the follicular fluid fatty acids and found higher levels of C20:4n6 (AA) in PCOS patients than in normal control subjects. Also, to determine whether AA induces oxidative stress (OS) in the human ovarian granulosa tumor cell line (KGN) and affects its function, we treated KGN cells with or without reduced glutathione (GSH) and then stimulated them with AA. The results showed that AA significantly reduced the total antioxidant capacity (TAC) and activity of antioxidant enzymes and increased the malondialdehyde (MDA), ROS and superoxide anion(O_2-)levels in KGN cells. In addition, AA was also found to impair the secretory and mitochondrial functions of KGN cells and induce their apoptosis. We further investigated the downstream genes affected by AA in KGN cells and its mechanism of action. We found that AA upregulated the expression of growth differentiation factor 15 (GDF15), which had a protective effect on inflammation and tissue damage. Therefore, we investigated whether AA-induced OS in KGN cells upregulates GDF15 expression as an OS response.Through silencing of GDF15 and supplementation with recombinant GDF15 (rGDF15), we found that GDF15, expressed as an OS response, protected KGN cells against AA-induced OS effects, such as impairment of secretory and mitochondrial functions and apoptosis. Therefore, this study suggested that AA might induce OS in KGN cells and upregulate the expression of GDF15 as a response to OS.

Biochemical and Structural Characteristics, Gene Regulation, Physiological, Pathological and Clinical Features of Lipocalin-Type Prostaglandin D2 Synthase as a Multifunctional Lipocalin

Lipocalin-type prostaglandin (PG) D₂ synthase (L-PGDS) catalyzes the isomerization of PGH₂, a common precursor of the two series of PGs, to produce PGD₂. PGD₂ stimulates three distinct types of G protein-coupled receptors: (1) D type of prostanoid (DP) receptors involved in the regulation of sleep, pain, food intake, and others; (2) chemoattractant receptor-homologous molecule expressed on T helper type 2 cells (CRTH2) receptors, in myelination of peripheral nervous system, adipocyte differentiation, inhibition of hair follicle neogenesis, and others; and (3) F type of prostanoid (FP) receptors, in dexamethasone-induced cardioprotection. L-PGDS is the same protein as β-trace, a major protein in human cerebrospinal fluid (CSF). L-PGDS exists in the central nervous system and male genital organs of various mammals, and human heart; and is secreted into the CSF, seminal plasma, and plasma, respectively. L-PGDS binds retinoic acids and retinal with high affinities (Kd < 100 nM) and diverse small lipophilic substances, such as thyroids, gangliosides, bilirubin and biliverdin, heme, NAD(P)H, and PGD₂, acting as an extracellular carrier of these substances. L-PGDS also binds amyloid β peptides, prevents their fibril formation, and disaggregates amyloid β fibrils, acting as a major amyloid β chaperone in human CSF. Here, I summarize the recent progress of the research on PGD₂ and L-PGDS, in terms of its “molecular properties,” “cell culture studies,” “animal experiments,” and “clinical studies,” all of which should help to understand the pathophysiological role of L-PGDS and inspire the future research of this multifunctional lipocalin.

Nanoproteomic Approach for Isolation and Identification of Potential Biomarkers in Human Urine from Adults with Normal Weight, Overweight and Obesity

In this work, previously synthesized and characterized core-shell silica nanoparticles (FCSNP) functionalized with immobilized molecular bait, Cibacron blue, and a porous polymeric bis-acrylamide shell were incubated with pooled urine samples from adult women or men with normal weight, overweight or obesity for the isolation of potential biomarkers. A total of 30 individuals (15 woman and 15 men) were included. FCSNP allowed the capture of a variety of low molecular weight (LMW) proteins as evidenced by mass spectrometry (MS) and the exclusion of high molecular weight (HMW) proteins (>34 kDa) as demonstrated by SDS-PAGE and 2D SDS-PAGE. A total of 36 proteins were successfully identified by MS and homology database searching against the Homo sapiens subset of the Swiss-Prot database. Identified proteins were grouped into different clusters according to their abundance patterns. Four proteins were found only in women and five only in men, whereas 27 proteins were in urine from both genders with different abundance patterns. Based on these results, this new approach represents an alternative tool for isolation and identification of urinary biomarkers.

The Vehicle Determines the Destination: The Significance of Seminal Plasma Factors for Male Fertility

Of all human infertility cases, up to 50% show contributing factors leading to defects in the male reproductive physiology. Seminal plasma (SP) is the biological fluid derived from the male accessory sex gland which carries spermatozoa passing throughout the male and female reproductive tract during ejaculation. It contains a complicated set of heterogeneous molecular structures, including proteins, cell-free nucleic acid (DNA, microRNA and LncRNA), and small-molecule metabolites as well as inorganic chemicals (ions). For a long time, the substantial significance of seminal plasma factors’ functions has been underestimated, which is restricted to spermatozoa transport and protection. Notably, significant advancements have been made in dissecting seminal plasma components, revealing new insights into multiple aspects of sperm function, as well as fertilization and pregnancy outcomes in recent years. In this review, we summarize the state-of-art discoveries regarding SP compositions and their implications in male fertility, particularly describing the novel understanding of seminal plasma components and related modifications using “omics” approaches and mainly focusing on proteome and RNA-seq data in the latest decade. Meanwhile, we highlighted the proposed mechanism of the regulation of SP molecules on immunomodulation in the female reproductive tract. Moreover, we also discussed the proteins investigated as non-invasive diagnosis biomarkers for male infertility in the clinic.

"Emerging role of Novel Seminal Plasma Bio-markers in Male Infertility: A Review"

Male infertility has emerged as an important cause of infertility worldwide. There are many factors affecting male fertility and research is going on to know impact of various factors on sperm functions. Semen analysis is gold standard diagnostic test for male infertility, but it is crude method for estimation of male infertility as seminal composition gets affected by environmental factors, infections, other pathologies, hence, results of semen analysis either becomes normal/ambiguous, leading to failure of diagnosis and delayed treatment. Hence, with need of newer, better tests for assessing male factor infertility, seminal plasma is being tested for biomarkers. Seminal plasma is considered gold mine for male fertility as it contains molecules from male reproductive glands which play important role in sperm function. Study of seminal plasma molecules can give an idea about sperm concentration, motility, morphology and cause of infertility and can serve as biomarkers for male infertility. Present review briefs on some of these novel seminal plasma biomarkers which may play significant role in male fertility and can be used in future for better identification, assessment of infertile males.

METHODOLOGY

Literature from 1985 to 2019 was searched from various databases including PUBMED, SCOPUS, Google Scholar on seminal plasma biomarkers using keywords: "seminal plasma protein biomarkers", "novel seminal plasma markers and male infertility", "hormones in seminal plasma and male infertility", "oxidative stress and male infertility", "Reactive Oxygen Species and sperm DNA", "immunoinfertility".

INCLUSION CRITERIA

All full length original or review articles or abstracts on seminal plasma markers and male infertility published in English language in various peer-reviewed journals were considered.

EXCLUSION CRITERIA

Articles published in languages other than English were excluded from the study.

RESULTS

Seminal plasma is a big reservoir of molecules derived from the various male reproductive glands which can be used as potential biomarkers of male fertility.

CONCLUSION

Hence, seminal plasma biomarkers can be used in future for better assessment of male factor infertility, its causes and may play an important role in management of male factor infertility.

The prostaglandin synthases, COX-2 and L-PGDS, mediate prostate hyperplasia induced by low-dose bisphenol A

This study aimed to identify prostaglandin synthases (PGS) that mediate bisphenol A (BPA)-induced prostatic hyperplasia and explore their underlying mechanisms. In an in vivo study, male adult Sprague–Dawley rats were treated with different concentrations of BPA (10, 30, 90, or 270 μg/kg, i.g., daily), or with vehicle for 4 weeks. Results revealed that low-dose BPA induced prostatic hyperplasia with increased PCNA/TUNEL ratio. It significantly upregulated the expression of cyclooxygenase-2 (COX-2) and NF-κB in the dorsolateral prostate (P < 0.05) and the expression of lipocalin-type prostaglandin D synthase (L-PGDS) in ventral prostate (P < 0.05). The level of estradiol (E₂)/testosterone (T) and expression of androgen receptor (AR) and estrogen receptor α (ERα) were also altered. In vitro studies showed that low-dose BPA (0.1–10 nM) promoted the proliferation of human prostate fibroblasts and epithelial cells, and significantly upregulated the expression of COX-2 and L-PGDS in the cells. The two types of cell proliferation induced by BPA were inhibited by COX-2 inhibitor (NS398) and L-PGDS inhibitor (AT56), with increased apoptosis level. These findings suggested that COX-2 and L-PGDS could mediate low-dose BPA-induced prostatic hyperplasia through pathways involved in cell proliferation and apoptosis, which might be related to the functions of ERα and AR. The role of COX-2/NF-κB pathway in dorsolateral prostate requires further research.

The enzymology of the human prostanoid pathway

Prostanoids are short-lived autocrine and paracrine signaling molecules involved in a wide range of biological functions. They have been shown to be intimately involved in many different disease states when their regulation becomes dysfunctional. In order to fully understand the progression of any disease state or the biological functions of the well state, a complete evaluation of the genomics, proteomics, and metabolomics of the system is necessary. This review is focused on the enzymology for the enzymes involved in the synthesis of the prostanoids (prostaglandins, prostacyclins and thromboxanes). In particular, the isolation and purification of the enzymes, their enzymatic parameters and catalytic mechanisms are presented.

Role of Seminal Plasma Proteins in Effective Zygote Formation- A Success Road to Pregnancy

Seminal plasma proteins contributed by secretions of accessory glands plays a copious role in fertilization. Their role is overlooked for decades and even now, as Artificial Reproduction Techniques (ART) excludes the plasma components in the procedures. Recent evidences suggest the importance of these proteins starting from imparting fertility status to men, fertilization and till successful implantation of the conceptus in the female uterus. Seminal plasma is rich in diverse proteins, but a major part of the seminal plasma is constituted by very lesser number of proteins. This makes isolation and further research on non abundant protein a tough task. With the advent of much advanced proteomic techniques and bio informatics tools, studying the protein component of seminal plasma has become easy and promising. This review is focused on the role of seminal plasma proteins on various walks of fertilization process and thus, the possible exploitation of seminal plasma proteins for understanding the etiology of male related infertility issues. In addition, a compilation of seminal plasma proteins and their functions has been done.

Lipidomics biomarkers in women with polycystic ovary syndrome (PCOS) using ultra-high performance liquid chromatography-quadrupole time of flight electrospray in a positive ionization mode mass spectrometry

Polycystic ovary syndrome (PCOS), characterized by oligo-anovulation and androgen excess is considered a high-risk condition for metabolic disorders. Herein, untargeted metabolomics analysis was applied to women with PCOS, aiming to provide deeper insights into lipidomics biomarkers signature of PCOS, for better diagnosis and management. This was a cross-sectional study in which 15 Caucasian women with PCOS and 15 Caucasian healthy, age-matched women were enrolled. Lipidomics analysis was performed using Ultra-High Performance Liquid Chromatography-Quadrupole Time of Flight Electrospray Mass Spectrometry. Partial Least Squares Discriminant Analysis retrieved the most important discriminative metabolites. Significantly increased levels of triacylglycerol (18:2/18:2/0-18:0) in addition to cholestane-3beta, 5alpha, 6beta-triol (18:0/0:0) and cholestane-5alpha (18:1/0:0) appeared as valuable variables to differentiate subjects with PCOS from controls. Acyl-carnitine 2-hydroxylauroylcarnitine was significantly elevated in PCOS in opposition to decreased phosphocholines metabolites (18:1/18:4, 18:3/18:2), to suggest a metabolic pattern linked to lipid peroxidation. A high fat intake or reduced fat energy consumption during nighttime due to diminished ability to switch to lipid oxidation during fasting time possibly contribute to hypertriglyceridemia found in PCOS. Furthermore, inflammatory mediators including metabolites of the prostaglandin (PG) E2 pathway and oxo-leukotrienes (LT) were increased in patients with PCOS. Potential lipidomics biomarkers were identified that could stratify between women with PCOS and healthy controls. The results show particular alterations in acylglycerols, PGs and LTs and phosphocholines and carnitine metabolites. The lipidomics profiles of PCOS indicate a higher risk of developing metabolic diseases.

Expression of prostaglandin (PG) D synthase lipocalin and hematopoietic type and PG D receptor during restart of spermatogenesis following downregulation using a slow release GnRH agonist implant in the dog

Prostaglandin D and the associated prostaglandin D synthases (PGDS) and receptor (DP) are considered to be involved in spermatogenesis. However, the interplay of the PGDS-DP system in male reproduction is far from being understood. The expression of PGDS lipocalin (L) and hematopoietic (H) type and DP was studied in the GnRH agonist-downregulated canine testis (week, w 0) and during recrudescence of spermatogenesis after implant removal (w 3, 6, 9, 12). H-PGDS, L-PGDS and DP were present in the adult (CG), juvenile (JG) and downregulated canine testis at the mRNA level. PGDS immunohistochemistry revealed positive staining in the cytoplasm of Leydig cells (LCs) of all samples i.e., no difference between groups. mRNA expression (ratio) of L-, H-PGDS and DP did not differ between groups w 0-12 and CG. In contrast, significant differences were found for L-PGDS (p = 0.0388), H-PGDS (p < 0.001) and DP (p < 0.001) for the groups at downregulation (w0, suprelorin group, SG, profact group, PRG) compared with the control groups (JG, CG). L-PGDS expression was lowest in JG, whereas H-PGDS was significantly lower in CG compared with JG and at downregulation (p < 0.001 to p < 0.01). The highest ratio for H-PGDS and DP was observed in the dogs treated with buserelin acetate (PRG). Our data show that the PGDS-DP system is expressed in juvenile and adult canine testes and that downregulation of the testicular endocrine and germinative function significantly affects H-PGDS, L-PGDS and DP mRNA expression indicating a role in the regulation of spermatogenesis.

Distinct urinary glycoprotein signatures in prostate cancer patients

Novel biomarkers are needed to complement prostate specific antigen (PSA) in prostate cancer (PCa) diagnostic screening programs. Glycoproteins represent a hitherto largely untapped resource with a great potential as specific and sensitive tumor biomarkers due to their abundance in bodily fluids and their dynamic and cancer-associated glycosylation. However, quantitative glycoproteomics strategies to detect potential glycoprotein cancer markers from complex biospecimen are only just emerging. Here, we describe a glycoproteomics strategy for deep quantitative mapping of N- and O-glycoproteins in urine with a view to investigate the diagnostic value of the glycoproteome to discriminate PCa from benign prostatic hyperplasia (BPH), two conditions that remain difficult to clinically stratify. Total protein extracts were obtained, concentrated and digested from urine of six PCa patients (Gleason score 7) and six BPH patients. The resulting peptide mixtures were TMT-labeled and mixed prior to a multi-faceted sample processing including hydrophilic interaction liquid chromatography (HILIC) and titanium dioxide SPE based enrichment, endo-/exoglycosidase treatment and HILIC-HPLC pre-fractionation. The isolated N- and O-glycopeptides were detected and quantified using high resolution mass spectrometry. We accurately quantified 729 N-glycoproteins spanning 1,310 unique N-glycosylation sites and observed 954 and 965 unique intact N- and O-glycopeptides, respectively, across the two disease conditions. Importantly, a panel of 56 intact N-glycopeptides perfectly discriminated PCa and BPH (ROC: AUC = 1). This study has generated a panel of intact glycopeptides that has a potential for PCa detection.

Discovery of Novel Lipid Profiles in PCOS: Do Insulin and Androgen Oppositely Regulate Bioactive Lipid Production?

CONTEXT

Polycystic ovary syndrome (PCOS) is a complex syndrome showing clinical features of an endocrine/metabolic disorder, including hyperinsulinemia and hyperandrogenism. Polyunsaturated fatty acids (PUFAs) and their derivatives, both tightly linked to PCOS and obesity, play important roles in inflammation and reproduction.

OBJECTIVE

This study aimed to investigate serum lipid profiles in newly diagnosed patients with PCOS using lipidomics and correlate these features with the hyperinsulinemia and hyperandrogenism associated with PCOS and obesity.

DESIGN AND SETTING

Thirty-two newly diagnosed women with PCOS and 34 controls were divided into obese and lean subgroups. A PCOS rat model was used to validate results of the human studies.

MAIN OUTCOME MEASURES

Serum lipid profiles, including phospholipids, free fatty acids (FFAs), and bioactive lipids, were analyzed using gas chromatography-mass spectrometry (MS) and liquid chromatography-MS.

RESULTS

Elevation in phosphatidylcholine and a concomitant decrease in lysophospholipid were found in obese patients with PCOS vs lean controls. Obese patients with PCOS had decreased PUFA levels and increased levels of long-chain saturated fatty acids vs lean controls. Serum bioactive lipids downstream of arachidonic acid were increased in obese controls, but reduced in both obese and lean patients with PCOS vs their respective controls.

CONCLUSIONS

Patients with PCOS showed abnormal levels of phosphatidylcholine, FFAs, and PUFA metabolites. Circulating insulin and androgens may have opposing effects on lipid profiles in patients with PCOS, particularly on the bioactive lipid metabolites derived from PUFAs. These clinical observations warrant further studies of the molecular mechanisms and clinical implications of PCOS and obesity.

Expression of two WFDC1/ps20 isoforms in prostate stromal cells induces paracrine apoptosis through regulation of PTGS2/COX-2

BACKGROUND

WFDC1/Prostate stromal 20 (ps20) is a small secreted protein highly expressed within the prostate stroma. WFDC1/ps20 expression is frequently downregulated or lost in prostate cancer (PCa) and ps20 has demonstrated growth-suppressive functions in numerous tumour model systems, although the mechanisms of this phenomenon are not understood.

METHODS

Ps20 was cloned and overexpressed in DU145, PC3, LNCaP and WPMY-1 cells. Cellular growth, cell cycle and apoptosis were characterised. WPMY-1 stromal cells expressing ps20 were characterised by transcriptome microarray and the function of WPMY-1 conditioned media on growth of PCa cell lines was assessed.

RESULTS

Prostrate stromal 20 expression enhanced the proliferation of LNCaP cells, whereas stromal WPMY-1 cells were inhibited and underwent increased apoptosis. Prostrate stromal 20-expressing WPMY-1 cells secrete a potently proapoptotic conditioned media. Prostrate stromal 20 overexpression upregulates expression of cyclooxygenase-2 (COX-2) in LNCaP and WPMY-1 cells, and induces expression of a growth-suppressive phenotype, which inhibits proliferation of PCa cells by ps20-expressing WPMY-1 conditioned media. This growth suppression was subsequently shown to be dependent on COX-2 function.

CONCLUSIONS

This work posits that expression of ps20 in the prostate stroma can regulate growth of epithelial and other tissues through the prostaglandin synthase pathway, and thereby restricts development and progression of neoplasms. This provides a rational for selective pressure against ps20 expression in tumour- associated stroma.

Cyclooxygenase and prostaglandins in somatic cell populations of the testis

Prostaglandins (PGs) are synthesized through the action of the rate-limiting enzyme cyclooxygenase (COX) and further specific enzymes. The development ofCox-deficient mice in the 1990s gave insights into the reproductive roles of PGs. FemaleCox-knockout mice were subfertile or infertile. Interestingly, fertility was not affected in male mice deficient inCox, suggesting that PGs may not be critical for the functioning of the testis. However, this conclusion has recently been challenged by observations of important roles for PGs in both physiological and pathological processes in the testis. The two key somatic cell types in the testis, Leydig and Sertoli cells, express the inducible isoenzyme COX2 and produce PGs. Testicular COX2 expression in these somatic cells is regulated by hormonal input (FSH, prolactin (PRL), and testosterone) as well as by IL1β. PGs modulate steroidogenesis in Leydig cells and glucose uptake in Sertoli cells. Hence, the COX2/PG system in Leydig and Sertoli cells acts as a local modulator of testicular activity, and consequently may regulate spermatogenic efficiency. In addition to its expression in Leydig and Sertoli cells, COX2 has been detected in the seminiferous tubule wall, and in testicular macrophages and mast cells of infertile patients. These observations highlight the possible relevance of PGs in testicular inflammation associated with idiopathic infertility. Collectively, these data indicate that the COX2/PG system plays crucial roles not only in testicular physiology (i.e., development, steroidogenesis, and spermatogenesis), but more importantly in the pathogenesis or maintenance of infertility status in the male gonad. Further studies of these actions could lead to new therapeutic approaches to idiopathic male infertility.

Free German abstract

A German translation of this abstract is freely available athttp://www.reproduction-online.org/content/149/4/R169/suppl/DC1.

Free Spanish abstract

A Spanish translation of this abstract is freely available athttp://www.reproduction-online.org/content/149/4/R169/suppl/DC2.

Multiple roles of the prostaglandin D2 signaling pathway in reproduction

Prostaglandins signaling molecules are involved in numerous physiological processes. They are produced by several enzyme-limited reactions upon fatty acids, which are catalyzed by two cyclooxygenases and prostaglandin synthases. In particular, the prostaglandins E2(PGE2), D2(PGD2), and F2(PGF2α) have been shown to be involved in female reproductive mechanisms. Furthermore, widespread expression of lipocalin- and hematopoietic-PGD2synthases in the male reproductive tract supports the purported roles of PGD2in the development of both embryonic and adult testes, sperm maturation, and spermatogenesis. In this review, we summarize the putative roles of PGD2signaling and the roles of both PGD2synthases in testicular formation and function. We review the data reporting the involvement of PGD2signaling in the differentiation of Sertoli and germ cells of the embryonic testis. Furthermore, we discuss the roles of lipocalin-PGD2synthase in steroidogenesis and spermatogenesis, in terms of lipid molecule transport and PGD2production. Finally, we discuss the hypothesis that PGD2signaling may be affected in certain reproductive diseases, such as infertility, cryptorchidism, and testicular cancer.

LC-MS/MS quantitation of esophagus disease blood serum glycoproteins by enrichment with hydrazide chemistry and lectin affinity chromatography

Changes in glycosylation have been shown to have a profound correlation with development/malignancy in many cancer types. Currently, two major enrichment techniques have been widely applied in glycoproteomics, namely, lectin affinity chromatography (LAC)-based and hydrazide chemistry (HC)-based enrichments. Here we report the LC–MS/MS quantitative analyses of human blood serum glycoproteins and glycopeptides associated with esophageal diseases by LAC- and HC-based enrichment. The separate and complementary qualitative and quantitative data analyses of protein glycosylation were performed using both enrichment techniques. Chemometric and statistical evaluations, PCA plots, or ANOVA test, respectively, were employed to determine and confirm candidate cancer-associated glycoprotein/glycopeptide biomarkers. Out of 139, 59 common glycoproteins (42% overlap) were observed in both enrichment techniques. This overlap is very similar to previously published studies. The quantitation and evaluation of significantly changed glycoproteins/glycopeptides are complementary between LAC and HC enrichments. LC–ESI–MS/MS analyses indicated that 7 glycoproteins enriched by LAC and 11 glycoproteins enriched by HC showed significantly different abundances between disease-free and disease cohorts. Multiple reaction monitoring quantitation resulted in 13 glycopeptides by LAC enrichment and 10 glycosylation sites by HC enrichment to be statistically different among disease cohorts.

Characteristic of PGDS potential regulation role on spermatogenesis in the Chinese mitten crab Eriocheir sinensis

Prostaglandin D synthase (PGDS) catalyzes the isomerization of PGH2 to produce PGD2 in the presence of sulfhydryl compounds. In this study, a full length PGDS gene comprising 1250 nucleotides from the Chinese mitten crab Eriocheir sinensis (Es-PGDS) was characterized, with a 615 bp open reading frame encoding 204 amino acid residues. Its deduced peptide has high homology with other species' PGDS protein. The Es-PGDS mRNA expression was tissue-related, with the highest expression observed in the hepatopancreas, accessory sex gland, testis and ovaries. We also detected the different stages of tissue expression and the enzyme activity for Es-PGDS in the testis and male crab hepatopancreas. The different expression patterns and its corresponding enzyme activity level indicated that PGDS is involving in the regulation of reproductive action during the period of rapid development in E. sinensis. Furthermore our research could arouse a heat debate on the PGDS reproductive function in invertebrate and further study will be needed to determine the molecular mechanism(s) linking PGDS functions to spermatogenesis and ontogenesis if this gene is to be exploited as a molecular biomarker in further studies of development.

Prostaglandin 15d-PGJ(2) inhibits androgen receptor signaling in prostate cancer cells

Androgen signaling, in particular overexpression of the androgen receptor (AR), is critical for the growth and progression of prostate cancer. Because the AR is amenable to targeting by small-molecule inhibitors, it remains the major druggable target for the advanced disease. Inflammation has also been implicated in the cancerous growth in the prostate. Here we show that 15-deoxy-Δ(12,14)-prostaglandin J(2) (15d-PGJ(2)), an endogenously produced antiinflammatory prostaglandin, targets the AR and acts as a potent AR inhibitor, rapidly repressing AR target genes, such as FKBP51 and TMPRSS2 in prostate cancer cells. However, exposure of prostate cancer cells to 15d-PGJ(2) does not simply evoke a general inhibition of nuclear receptor activity or transcription because under the same conditions, peroxisome proliferator-activated receptor-γ is activated by 15d-PGJ(2). Moreover, 15d-PGJ(2) rapidly triggers modifications of AR by small ubiquitin-related modifier-2/3 (SUMO-2/3), which may modulate the repressing effect of 15d-PGJ(2) on AR-dependent transcription. Chromatin immunoprecipitation assays indicate that the inhibitory effect of 15d-PGJ(2) on FKBP51 and TMPRSS2 expression occurs in parallel with the inhibition of the AR binding to the regulatory regions of these genes. However, the DNA-binding activity is not the only AR function targeted by 15d-PGJ(2) because the prostaglandin also blunted the androgen-dependent interaction between the AR amino and carboxy termini. In conclusion, our results identify 15d-PGJ(2) as a potent and direct inhibitor of androgen signaling, suggesting novel possibilities in restricting the AR activity in prostate cancer cells.

Cell signalling by reactive lipid species: new concepts and molecular mechanisms

The process of lipid peroxidation is widespread in biology and is mediated through both enzymatic and non-enzymatic pathways. A significant proportion of the oxidized lipid products are electrophilic in nature, the RLS (reactive lipid species), and react with cellular nucleophiles such as the amino acids cysteine, lysine and histidine. Cell signalling by electrophiles appears to be limited to the modification of cysteine residues in proteins, whereas non-specific toxic effects involve modification of other nucleophiles. RLS have been found to participate in several physiological pathways including resolution of inflammation, cell death and induction of cellular antioxidants through the modification of specific signalling proteins. The covalent modification of proteins endows some unique features to this signalling mechanism which we have termed the ‘covalent advantage’. For example, covalent modification of signalling proteins allows for the accumulation of a signal over time. The activation of cell signalling pathways by electrophiles is hierarchical and depends on a complex interaction of factors such as the intrinsic chemical reactivity of the electrophile, the intracellular domain to which it is exposed and steric factors. This introduces the concept of electrophilic signalling domains in which the production of the lipid electrophile is in close proximity to the thiol-containing signalling protein. In addition, we propose that the role of glutathione and associated enzymes is to insulate the signalling domain from uncontrolled electrophilic stress. The persistence of the signal is in turn regulated by the proteasomal pathway which may itself be subject to redox regulation by RLS. Cell death mediated by RLS is associated with bioenergetic dysfunction, and the damaged proteins are probably removed by the lysosome-autophagy pathway.

Verification of male infertility biomarkers in seminal plasma by multiplex selected reaction monitoring assay

Seminal plasma is a promising biological fluid to use for noninvasive clinical diagnostics of male reproductive system disorders. To verify a list of prospective male infertility biomarkers, we developed a multiplex selected reaction monitoring assay and measured the relative abundance of 31 proteins in 30 seminal plasma samples from normal, nonobstructive azoospermia and post-vasectomy individuals. Median levels of some proteins were decreased by more than 100-fold in nonobstructive azoospermia or post-vasectomy samples, in comparison with normal samples. To follow up the most promising candidates and measure their concentrations in seminal plasma, heavy isotope-labeled internal standards were synthesized and used to reanalyze 20 proteins in the same set of samples. Concentrations of candidate proteins in normal seminal plasma were found in the range 0.1-1000 μg/ml but were significantly decreased in nonobstructive azoospermia and post-vasectomy. These data allowed us to select, for the first time, biomarkers to discriminate between normal, nonobstructive azoospermia, and post-vasectomy (simulated obstructive azoospermia) seminal plasma samples. Some testis-specific proteins (LDHC, TEX101, and SPAG11B) performed with absolute or nearly absolute specificities and sensitivities. Cell-specific classification of protein expression indicated that Sertoli or germ cell dysfunction, but not Leydig cell dysfunction, was observed in nonobstructive azoospermia seminal plasma. The proposed panel of biomarkers, pending further validation, could lead to a clinical assay that can eliminate the need for testicular biopsy to diagnose the category of male infertility, thus providing significant benefits to patients as well as decreased costs associated with the differential diagnosis of azoospermia.

Isolation of lipocalin-type protein from rainbow trout seminal plasma and its localisation in the reproductive system

The lipocalin protein family is a large and diverse group of small extracellular proteins characterised by their ability to bind hydrophobic molecules. In the present study, we describe the isolation procedure for rainbow trout seminal plasma protein, characterised by a moderate migration rate during polyacrylamide gel electrophoresis, providing information regarding its basic features and immunohistochemical localisation. This protein was identified as a lipocalin-type protein (LTP). The molecular mass of LTP was found to be 18 848 Da and it was found to lack any carbohydrate components. Only a few Salmoniformes contain LTP in their seminal plasma. The abundance of LTP in the Sertoli and Leydig cells of the testes of the rainbow trout, as well as in secretory cells of the efferent duct, suggests that this protein is specific for rainbow trout milt, where it acts as a lipophilic carrier protein. Moreover, the specific localisation of LTP in the flagella of the spermatozoa suggests a role for LTP in sperm motility. Further experiments are necessary to identify the endogenous ligands for LTP in rainbow trout seminal plasma and to characterise the binding properties of this protein.

L-PGDS (betatrace protein) inhibits astrocyte proliferation and mitochondrial ATP production in vitro

L-PGDS is the most abundant protein present in the cerebrospinal fluid (CSF). Although CSF was believed to be homogenous in content, a previous study has showed that a marked concentration gradient of L-PGDS exists between the spinal CSF and the CSF in the subarachnoid space of patients with optic nerve disease (papilledema and normal-tension glaucoma). Astrocytes play a critical role in maintaining the integrity of axon function in the central nervous system and specifically in the optic nerve, and we therefore investigated the biochemical effects of L-PGDS on the proliferation of astrocytes and on the production of adenosine triphosphate (ATP) by astrocyte mitochondria. We found an inhibitory effect of L-PGDS on both proliferation of astrocytes and production of astrocyte ATP. The concentrations that inhibited astrocyte proliferation and ATP production were in the range measured in patients with idiopathic intracranial hypertension and in patients with normal-tension glaucoma. As the CSF is in contact with axons and mitochondria of the optic nerve (Bristow et al. Archives of Ophthalmology, 120, 791-796, 2002), we postulate that a change in the concentration of CSF protein such as L-PGDS could exercise a harmful effect on these structures.

Biochemical, functional, and pharmacological characterization of AT-56, an orally active and selective inhibitor of lipocalin-type prostaglandin D synthase

We report here that 4-dibenzo[a,d]cyclohepten-5-ylidene-1-[4-(2H-tetrazol-5-yl)-butyl]-piperidine (AT-56) is an orally active and selective inhibitor of lipocalin-type prostaglandin (PG) D synthase (L-PGDS). AT-56 inhibited human and mouse L-PGDSs in a concentration (3–250 μm)-dependent manner but did not affect the activities of hematopoietic PGD synthase (H-PGDS), cyclooxygenase-1 and -2, and microsomal PGE synthase-1. AT-56 inhibited the L-PGDS activity in a competitive manner against the substrate PGH₂ (K_m = 14 μm) with a K_i value of 75 μm but did not inhibit the binding of 13-cis-retinoic acid, a nonsubstrate lipophilic ligand, to L-PGDS. NMR titration analysis revealed that AT-56 occupied the catalytic pocket, but not the retinoid-binding pocket, of L-PGDS. AT-56 inhibited the production of PGD₂ by L-PGDS-expressing human TE-671 cells after stimulation with Ca²⁺ ionophore (5 μm A23187) with an IC₅₀ value of about 3 μm without affecting their production of PGE₂ and PGF_2α but had no effect on the PGD₂ production by H-PGDS-expressing human megakaryocytes. Orally administered AT-56 (<30 mg/kg body weight) decreased the PGD₂ production to 40% in the brain of H-PGDS-deficient mice after a stab wound injury in a dose-dependent manner without affecting the production of PGE₂ and PGF_2α and also suppressed the accumulation of eosinophils and monocytes in the bronco-alveolar lavage fluid from the antigen-induced lung inflammation model of human L-PGDS-transgenic mice.

Lipocalin-type prostaglandin D synthase is a powerful biomarker for severity of stable coronary artery disease

Lipocalin-type prostaglandin D synthase (L-PGDS), which is responsible for the biosynthesis of prostaglandin (PG) D(2), has been found to be present in the atherosclerotic plaque of the human coronary artery and also to be detectable in human serum. This multicenter cooperative study was designed to establish the diagnostic value of measuring serum L-PGDS for coronary artery disease. The study included 1013 consecutive patients suspected of having stable coronary artery disease who underwent diagnostic coronary angiography. Peripheral blood was collected prior to angiography. The serum level of L-PGDS, as determined by a sandwich ELISA, was 58.1 +/- 2.2, 62.0 +/- 1.8 and 80.6 +/- 2.6 microg/dl for patients with no stenotic lesion (N, n=241), single-vessel coronary artery disease (S, n=351), and multi-vessel coronary artery disease (M, n=421), respectively (N vs. S; P<0.001, S vs. M; P<0.01, N vs. M; P<0.001). Multiple regression analysis indicated that the most powerful independent predictor of the coronary severity score (Gensini Score) was the L-PGDS level (R=0.55, P<0.0001). The serum L-PGDS level is suitable to evaluate the severity of coronary artery disease. The measurement of serum L-PGDS can be a strategy for screening of stable coronary artery disease prior to coronary angiography.

Beta-trace protein-based equations for calculation of GFR in renal transplant recipients

Recently, we showed that serum beta-trace protein (BTP) is an alternative marker of glomerular filtration rate (GFR) in renal transplant recipients (RTR). We have now developed three BTP-based GFR formulae derived by multiple regression analyses from the patients who had participated in that study. Currently, we validated the diagnostic performance of these BTP-formulae in 102 consecutive RTR who underwent a technetium diethylenetriamine pentaacetic acid (DTPA) clearance for GFR measurement in comparison to the re-expressed Modification of Diet in Renal Disease (MDRD) equation and a recently proposed BTP-based equation (referred to as 'White equation'). The best-performing BTP formula was found to be: GFR = 89.85 x BTP(-0.5541)x urea(-0.3018). This equation estimated true GFR virtually without bias (+0.43 mL/min/1.73 m(2), not significant [NS]), while a small, but significant, overestimation was seen for the MDRD formula (+3.43 mL/min/1.73 m(2), p = 0.003). Precision and accuracies within 50% of true GFR (93.1% and 88.2%, respectively) tended to be higher for the BTP formula, but the differences did not reach significance. The White equation overestimated the true GFR by 9.43 mL/min/1.73 m(2)(p = 0.001), and was inferior with respect to precision and 50% accuracy (79.4%). BTP-based GFR calculations are reliable, and may serve as an alternative to the re-expressed MDRD equation.

Role of prostaglandin D2 and E2 terminal synthases in chronic rhinosinusitis

BACKGROUND

Prostaglandin (PG)D(2) and E(2), two major cyclooxygenase (COX) products, are generated by PGD(2) synthase (PGDS) and PGE(2) synthase (PGES), respectively, and appear to mediate airway inflammation.

OBJECTIVE

We sought to determine the role of PGDS and PGES in the pathophysiology of chronic rhinosinusitis (CRS).

METHODS

The study examined the expression of PGDS and PGES in nasal polyps of 22 CRS patients. As controls, uncinate process mucosae were obtained from 12 CRS patients not having nasal polyps and five subjects without sinusitis. Immunohistochemistry and quantitative real-time PCR were used to evaluate the expression.

RESULTS

Both PGDS and PGES were detected in nasal polyps by immunohistochemistry. Significantly greater levels of PGDS mRNA and lesser levels of PGES mRNA were observed in the nasal polyps as compared with uncinate process mucosae, and an inverse correlation between PGDS and PGES expression was observed. Levels of PGDS mRNA in nasal polyps were positively correlated with degree of infiltration by EG2+ eosinophils, whereas the levels of PGES were inversely correlated. Significantly increased levels of PGDS and conversely decreased levels of PGES were observed in asthmatics as compared with non-asthmatics. In addition, PGDS and PGES levels were positively and inversely correlated with the radiological severity of sinusitis, respectively.

CONCLUSIONS

These results suggest that PGDS and PGES display an opposite and important role in the pathophysiology of CRS such as polyp formation, and more specifically, a biased expression of these synthases might contribute to the development of CRS by affecting eosinophilic inflammation.

Different expression of lipocalin-type prostaglandin D synthase in rat epididymidis

This study was designed to explore the different expression of L-PGDS (lipocalin-type prostaglandin D synthase) in rat epididymidis and to gain further insight into the potential function of L-PGDS in male reproduction. The expression of L-PGDS in rat epididymidis was assessed using real-time quantitative PCR and immunoblotting. The distribution of L-PGDS in rat epididymidis was explored by immunohistochemical methods. The result of immunohistochemistry displayed that L-PGDS was mainly distributed in epididymidis and localized within the cytoplasm and the cilia of the epithelial cells. Real-time quantitative PCR and immunoblotting showed that L-PGDS was strikingly expressed in the caput epididymidis, while a moderate to weak expression was observed in the corpus and cauda epididymidis, the level of mRNA was 0.52+/-0.02 in the caput, 0.48+/-0.03 in the corpus and 0.32+/-0.01 in the cauda epididymidis, the level of protein expression in caput, corpus and the cauda groups was 1, 0.89+/-0.03 and 0.62+/-0.01, which suggested that L-PGDS may play certain kind of role during the process of the spermatozoa maturation.

Relationship between contents of lipocalin-type prostaglandin D synthase on the surface of infertility sperm and in seminal plasma

Lipocalin-type prostaglandin D synthase (L-PGDS) is localized in Leydig cells, sperm, and epithelial cells of the epididymis. The present study was to determine the correlation between content of this enzyme in seminal plasma and on the surface of sperm. We analyzed 90 semen samples. L-PGDS in seminal plasma was analyzed by an ELISA procedure. L-PGDS on sperm was analyzed by flow cytometry. The semen donors were categorized in three groups: normal, oligospermic, and azoospermic. According to results obtained, L-PGDS may have the ability to improve progressive motility of sperm, and L-PGDS in seminal plasma and on sperm surface may impact male fertility in the female reproductive tract.

Zebrafish and chicken lipocalin-type prostaglandin D synthase homologues: Conservation of mammalian gene structure and binding ability for lipophilic molecules, and difference in expression profile and enzyme activity

Lipocalin-type prostaglandin (PG) D synthase (L-PGDS) is a bifunctional protein possessing both the ability to synthesize PGD(2) and to serve as a carrier protein for lipophilic molecules. L-PGDS has been extensively studied in mammalian species, whereas little is known about non-mammalian forms. Here, we identified and characterized the L-PGDS homologues from non-mammals such as zebrafish and chicken. Phylogenetic analysis revealed that L-PGDSs of mammalian and non-mammalian organisms form a "L-PGDS sub-family" that has been evolutionally separated from other lipocalin gene family proteins. The genes for zebrafish and chicken L-PGDS homologues consisted of 6 exons, and all of the exon/intron boundaries were completely identical to those of mammalian L-PGDS genes. Zebrafish and chicken L-PGDS genes were clustered with several lipocalin genes in the chromosome, as in the case of mouse and human genes. Gene expression profiles were different among chicken, mouse, human, except for conservation of abundant expression in the brain and heart. The chicken L-PGDS homologue carried weak PGDS activity, whereas the zebrafish protein did not show any of the activity. However, when the amino-terminal region of the zebrafish L-PGDS homologue was exchanged for that of mouse L-PGDS carrying the Cys residue essential for PGDS activity, this chimeric protein showed weak PGDS activity. Both zebrafish and chicken L-PGDS homologues bound thyroxine and all-trans retinoic acid, like mammalian L-PGDSs and other lipocalin gene family proteins. These results indicate that non-mammalian and mammalian L-PGDS genes evolved from the same ancestral gene and that the non-mammalian L-PGDS homologue was the primordial form of L-PGDS but whose major function was and is to serve as a carrier protein for lipophilic molecules. During molecular evolution, the mammalian L-PGDS protein might have acquired effective PGDS activity through substitution of several amino acid residues, especially in the amino-terminal region including the Cys residue, which is essential for PGDS activity.

Positioning prostanoids of the D and J series in the immunopathogenic scheme

Prostaglandin D(2) (PGD(2)) is produced by a variety of immune and non-hematopoietic cells and appears to function in both an inflammatory and homeostatic capacity. Two genetically distinct PGD(2)-synthesizing enzymes have been identified to date, including hematopoietic- and lipocalin-type PGD synthases (H-PGDS and L-PGDS, respectively). Though the inter-species expression profiles of these two enzymes vary widely, H-PGDS is generally localized to the cytosolic aspect of immune and inflammatory cells, whereas L-PGDS is more resigned to tissue-based expression. PGD(2) activity is principally mediated through two unique G protein-coupled receptors (GPCR), designated DP(1) and DP(2). These receptors exhibit overlapping binding profiles, yet their respective agonists elicit generally distinctive responses. Additional to DP receptors, the PGD(2) metabolite 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)) binds the nuclear peroxisome proliferator-activated receptor gamma (PPARgamma) and has the facility to initiate a variety of anti-inflammatory phenotypes either through or independent of PPARgamma association. This review highlights the collective relevance of PGD(2) and its respective synthases, receptors, and metabolites in immunopathologic responses.