Prostaglandin Metabolites Analysis in Urine by LC-MS/MS.

The analysis of prostaglandin urinary metabolites is valuable for assessing physiological processes and identifying disease biomarkers. These metabolites, derived from the breakdown of prostaglandins, offer a noninvasive means to gauge prostaglandin production and its potential impact on various biological functions. We report an efficient LC-MS method of four commonly analyzed prostaglandin urinary metabolites including tetranor-PGEM (derived from PGE2), tetranor-PGDM, 11ß-PGF2α, and 2,3-dinor-11ß-PGF2α (derived from PGD2). Each metabolite possesses distinct characteristics and clinical applications, collectively contributing to our understanding of prostaglandin-mediated pathways.

Uterine rupture following prostaglandins use in second trimester medical abortion: Fact or fiction? A systematic review.

BACKGROUND: Prostaglandins (PGs) have emerged as key drugs in second trimester medical abortion (STMA) and are currently a cornerstone in obstetric practice. Nevertheless, the application of PGs, integral to labor and abortion procedures, is not risk-free, and has been associated with several complications, particularly maternal fever and uterine rupture (UR). OBJECTIVES: The main outcome of the present systematic review was to assess the safety of PGs use in STMA, particularly in scarred uterus (SC). SEARCH STRATEGY: The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. We performed a comprehensive systematic review by searching multiple databases, including MEDLINE, EMBASE, Global Health, The Cochrane Library, Health Technology Assessment Database, and the research registers of Web of Science during the years 1990-2022. SELECTION CRITERIA: Only articles regarding cases of UR occurred after the use of PGs for STMA were included in the article. We excluded papers regarding UR during first trimester abortion induction of labor or pregnancy or unrelated to PGs use for STMA. Risk of bias was assessed employing a modified version of the "Newcastle-Ottawa Scale" (NOS). DATA COLLECTION AND ANALYSIS: A total of 178 studies were initially identified as potentially meeting the criteria for inclusion in the review. After full text evaluation, 110 other articles were excluded and 67 studies that suited the inclusion criteria were included. A total of 19 of the included studies were judged to have a high risk of bias. Given the heterogeneous nature of the findings, we opted for a narrative synthesis of the results. MAIN RESULTS AND CONCLUSIONS: PGs appear to be an effective pharmacologic tool for STMA; however, their use is not entirely risk-free. STMA requires well-equipped obstetric centers with skilled clinicians and surgeons prepared for emergencies. Ultrasonographic scans should be routinely performed during STMA management, since a UR can also be silent during the induction of labor. Intrapartum transabdominal, transperineal, and transvaginal ultrasound may have the diagnostic potential to early recognize this obstetric emergency, to facilitate rapid medical and surgical treatment, improving the outcome.

Dysregulation of the Arachidonic Acid Pathway in Cystic Fibrosis: Implications for Chronic Inflammation and Disease Progression.

Cystic fibrosis (CF) is the most common fatal genetic disease among Caucasian people, with over 2000 mutations in the CFTR gene. Although highly effective modulators have been developed to rescue the mutant CFTR protein, unresolved inflammation and persistent infections still threaten the lives of patients. While the central role of arachidonic acid (AA) and its metabolites in the inflammatory response is widely recognized, less is known about their impact on immunomodulation and metabolic implications in CF. To this end, here we provided a comprehensive analysis of the AA metabolism in CF. In this context, CFTR dysfunction appeared to complexly disrupt normal lipid processing, worsening the chronic airway inflammation, and compromising the immune responses to bacterial infections. As such, potential strategies targeting AA and its inflammatory mediators are being investigated as a promising approach to balance the inflammatory response while mitigating disease progression. Thus, a deeper understanding of the AA pathway dysfunction in CF may open innovative avenues for designing more effective therapeutic interventions.

Effect of intrafollicular administration of PGE2 or PGF2α in early estrus on ovulation, hemorrhagic anovulatory follicles formation, progesterone secretion and pregnancy outcome in the mare.

This experiment was performed to evaluate whether intrafollicular treatment of PGE2 or PGF2α administered in early estrus would induce normal ovulation, progesterone production (Experiment 1) and pregnancy (Experiment 2). In Experiment 1, mares in estrus after 2 days of endometrial edema were injected in all largest dominant follicles (28-35 mm in diameter) with 0.5 mL of sterile water containing 500 µg PGE2 (n = 6), 125 µg PGF2α (n = 6) or placebo (n = 7) (Hour 0). Ultrasound examinations were performed daily, until ovulation or anovulation was detected, and daily blood samples were taken for 8 days. In Experiment 2, mares with a dominant follicle ≥35 mm after at least three days of slight-to-moderate endometrial edema, were injected with 500 µg PGE2 diluted in 0.5 mL of sterile water for injection in the follicle (PGE2 group; n = 9 mares and 11 dominant follicles). No puncture was performed in the control group (n = 9 mares and 11 dominant follicles). Mares from both groups were inseminated. In Experiment 1, all mares (6/6) in the PGE2 group ovulated within 24 h of treatment. The mean interval from intrafollicular injection to ovulation was shorter (P < 0.001) in PGE2 mares (24 ± 0 h) than in control mares (77 ± 9 h). Mares from the PGF2α group developed hemorrhagic anovulatory follicles (HAF) more often (7/7) than control mares (2/7); P < 0.05). The progesterone concentration in mares from the PGF2α group was lower (P < 0.004) than control mares in the early post-ovulatory period. The first significant increase in post-ovulatory progesterone concentration occurred earlier (P < 0.05) in mares from the control group than in mares from the PGF2α and PGE2 groups. In Experiment 2, more mares from the control group (7/9, 78 %) became pregnant than from the PGE2 group (2/9, 22 %) (P = 0.015). In conclusion, PGE2 alone induced follicle collapse in all treated mares within 24 h of administrations, while PGF2α blocked ovulation and induced formation of HAFs. However, the post-ovulatory rise in progesterone production was delayed and the fertility reduced in mares with ovulation induced by PGE2 compared to control mares.

m6A mRNA methylation in brown fat regulates systemic insulin sensitivity via an inter-organ prostaglandin signaling axis independent of UCP1.

Brown adipose tissue (BAT) regulates systemic metabolism by releasing signaling lipids. N6-methyladenosine (m6A) is the most prevalent and abundant post-transcriptional mRNA modification and has been reported to regulate BAT adipogenesis and energy expenditure. Here, we demonstrate that the absence of m6A methyltransferase-like 14 (METTL14) modifies the BAT secretome to improve systemic insulin sensitivity independent of UCP1. Using lipidomics, we identify prostaglandin E2 (PGE2) and prostaglandin F2a (PGF2a) as BAT-secreted insulin sensitizers. PGE2 and PGF2a inversely correlate with insulin sensitivity in humans and protect mice from high-fat-diet-induced insulin resistance by suppressing specific AKT phosphatases. Mechanistically, METTL14-mediated m6A promotes the decay of PTGES2 and CBR1, the genes encoding PGE2 and PGF2a biosynthesis enzymes, in brown adipocytes via YTHDF2/3. Consistently, BAT-specific knockdown of Ptges2 or Cbr1 reverses the insulin-sensitizing effects in M14KO mice. Overall, these findings reveal a novel biological mechanism through which m6A-dependent regulation of the BAT secretome regulates systemic insulin sensitivity.

Arachidonic acid directly activates the human DP2 receptor.

Aberrant type 2 inflammatory responses are the underlying cause of the pathophysiology of allergic asthma, allergic rhinitis and other atopic diseases with an alarming prevalence in relevant parts of the western world. A bulk of evidence points out the important role of the DP2 receptor in this inflammation processes. A screening of different polyunsaturated fatty acids (PUFAs) at a fluorescence resonance energy transfer (FRET)-based DP2 receptor conformation sensor expressed in HEK cells revealed an agonistic effect of the prostaglandin (PG) D2 precursor arachidonic acid (AA) on DP2 receptor activity of about 80% of the effect induced by PGD2 In a combination of experiments at the conformation sensor and using a BRET-based G protein activation sensor expressed together with DP2 receptor-wt in HEK cells, we found that arachidonic acid act as a direct activator of the DP2 receptor but not DP1 receptor, in a concentration range considered physiologically relevant. Pharmacological inhibition of cyclooxygenases and lipoxygenases as well as cytochrome P450 did not lead to a diminished arachidonic acid response on the DP2 receptor, confirming a direct action of arachidonic acid on the receptor. Significance Statement We identified the prostaglandin precursor arachidonic acid to directly activate the DP2 receptor, a G protein-coupled receptor that is known to play an important role in type 2 inflammation.

Which approach is better for labor induction: simultaneous or sequential administration of oxytocin and intrauterine balloon-a systematic review and a meta-analysis.

OBJECTIVE: To compare the efficacy of simultaneous and sequential administration of oxytocin and intrauterine balloons in labor induction. METHODS: The databases of Cochrane Library, Web of Science, PubMed, ClinicalTrials.gov, and Embase were thoroughly searched from their inception to November 2023. Randomized controlled trials (RCTs) investigating the simultaneous and sequential use of oxytocin and intrauterine balloons for labor induction in pregnancy were included. The meta-analysis was performed using RevMan 5.3 statistical software. Heterogeneity among the selected studies was evaluated using the I2 statistic. Dichotomous outcomes were estimated using relative risk (RR) with corresponding 95% confidence intervals (CI), while continuous outcomes were measured as the mean difference (MD). RESULTS: A total of eight studies, involving a total of 1,315 nulliparous and multiparous women with an unfavorable cervix, were included in the systematic review. Moreover, a subgroup analysis was conducted, separately evaluating nulliparous and multiparous women. Compared with the sequential groups, simultaneous use of oxytocin and intrauterine balloons resulted in a significantly higher rate of delivery within 24h in nulliparas (RR = 1.30, 95%CI:1.04, 1.63, p = 0.02), a higher rate of vaginal delivery within 24h in multiparas (RR = 1.32, 95%CI:1.15,1.51, p < 0.00001), a superior rate of delivery within 12h and a shorter time to delivery in both nulliparas and multiparas. No statistically significant differences were observed in cesarean delivery and maternal and neonatal adverse outcomes between the sequential and simultaneous groups. CONCLUSIONS: These findings provide support for the simultaneous use of intrauterine balloons and oxytocin during labor induction in nulliparous women. Additionally, this approach may also prove beneficial for multiparas.

Temporal dissociation of COX-2-dependent arachidonic acid and 2-arachidonoylglycerol metabolism in RAW264.7 macrophages.

Cyclooxygenase-2 converts arachidonic acid to prostaglandins (PGs) and the endocannabinoid, 2-arachidonoylglycerol (2-AG), to PG glyceryl esters (PG-Gs). The physiological function of PG biosynthesis has been extensively studied, but the importance of the more recently discovered PG-G synthetic pathway remains incompletely defined. This disparity is due in part to a lack of knowledge of the physiological conditions under which PG-G biosynthesis occurs. We have discovered that RAW264.7 macrophages stimulated with Kdo2-lipid A (KLA) produce primarily PGs within the first 12 h followed by robust PG-G synthesis between 12 h and 24 h. We suggest that the amount of PG-Gs quantified is less than actually synthesized, because PG-Gs are subject to a significant level of hydrolysis during the time course of synthesis. Inhibition of cytosolic phospholipase A2 by giripladib does not accelerate PG-G synthesis, suggesting the differential time course of PG and PG-G synthesis is not due to the competition between arachidonic acid and 2-AG. The late-phase PG-G formation is accompanied by an increase in the level of 2-AG and a concomitant decrease in 18:0-20:4 diacylglycerol (DAG). Inhibition of DAG lipases by KT-172 decreases the levels of 2-AG and PG-Gs, indicating that the DAG-lipase pathway is involved in delayed 2-AG metabolism/PG-G synthesis. These results demonstrate that physiologically significant levels of PG-Gs are produced by activated RAW264.7 macrophages well after the production of PGs plateaus.

Cyclooxygenase-2 (COX-2)-dependent mechanisms mediate sleep responses to microbial and thermal stimuli.

Prostaglandins (PGs) play a crucial role in sleep regulation, yet the broader physiological context that leads to the activation of the prostaglandin-mediated sleep-promoting system remains elusive. In this study, we explored sleep-inducing mechanisms potentially involving PGs, including microbial, immune and thermal stimuli as well as homeostatic sleep responses induced by short-term sleep deprivation using cyclooxygenase-2 knockout (COX-2 KO) mice and their wild-type littermates (WT). Systemic administration of 0.4 µg lipopolysaccharide (LPS) induced increased non-rapid-eye movement sleep (NREMS) and fever in WT animals, these effects were completely absent in COX-2 KO mice. This finding underscores the essential role of COX-2-dependent prostaglandins in mediating sleep and febrile responses to LPS. In contrast, the sleep and fever responses induced by tumor necrosis factor α, a proinflammatory cytokine which activates COX-2, were preserved in COX-2 KO animals, indicating that these effects are independent of COX-2-related signaling. Additionally, we examined the impact of ambient temperature on sleep. The sleep-promoting effects of moderate warm ambient temperature were suppressed in COX-2 KO animals, resulting in significantly reduced NREMS at ambient temperatures of 30 °C and 35 °C compared to WT mice. However, rapid-eye-movement sleep responses to moderately cold or warm temperatures did not differ between the two genotypes. Furthermore, 6 h of sleep deprivation induced rebound increases in sleep with no significant differences observed between COX-2 KO and WT mice. This suggests that while COX-2-derived prostaglandins are crucial for the somnogenic effects of increased ambient temperature, the homeostatic responses to sleep loss are COX-2-independent. Overall, the results highlight the critical role of COX-2-derived prostaglandins as mediators of the sleep-wake and thermoregulatory responses to various physiological challenges, including microbial, immune, and thermal stimuli. These findings emphasize the interconnected regulation of body temperature and sleep, with peripheral mechanisms emerging as key players in these integrative processes.

Prostaglandin-related genes are differentially expressed in equine endometrium with different biopsy grade, degrees of inflammation, and fibrosis.

Prostaglandins have many roles in the equine reproductive tract, including but not limited to luteolysis, luteal support, ovulation, transport through the uterine tube, uterine contraction, embryonic mobility, inflammation, and fibrosis. Altered secretion of inflammatory proteins are likely to disrupt the balance of endometrial function and could impair fertility. Our overall goal was to measure the expression of several prostaglandin- and inflammation-related genes in mares with different degrees of endometrial histological changes. Our hypothesis was that mares with neutrophilic and lymphocytic plasmocytic inflammation, fibrosis, or different biopsy grades would have altered concentrations of prostaglandin E2 (PGE2) and F2α (PGF2α), as well as altered expression of inflammation- and prostaglandin-related genes, compared to mares with minimal to no histological changes on biopsy evaluation. Forty-five endometrial biopsies from estrous mares were assessed by a reproductive pathologist for the degree of neutrophilic inflammation, lymphocytic and plasmocytic inflammation, and fibrosis, and a biopsy grade was assigned based on the Kenney-Doig system. A low-volume uterine lavage was collected from a subset of twenty-six mares prior to biopsy collection and was used to measure PGE2 and PGF2α concentrations via ELISA. Total RNA was extracted from biopsies and mRNA expression was evaluated for twenty-five genes of interest. A restricted maximum likelihood linear model was used to compare differences of mRNA expression, with a statistical significance set at P < 0.05. There was no difference in the abundance of PGE2 or PGF2α between any of the variables tested. Mares with endometrial biopsy grade I had lower expression of NF-kB, PTGS1 and HPGD compared to grade IIA or IIB (P < 0.05). Mares with neutrophilic inflammation had decreased expression of NF-kB, PTGS1, PTGER4, CBR1, mPGES2 and PTGIS compared to mares without inflammation. Mares with mild or minimal endometrial fibrosis had increased expression of mPGES2 and PTGIS, compared to mares with moderate endometrial fibrosis. In conclusion, several genes were identified to be differentially expressed in mares with histological changes compared to mares with no to minimal histological changes. The presence of inflammation and fibrosis may alter the concentration of prostaglandins in endometrial tissue, which could impair many of the uterine reproductive and immune functions during estrus, affecting early embryo survival.

Prostaglandins in the Inflamed Central Nervous System: Potential Therapeutic Targets.

The global burden of neurological disorders is evident, yet there remains limited efficacious therapeutics for their treatment. There is a growing recognition of the role of inflammation in diseases of the central nervous system (CNS); among the numerous inflammatory mediators involved, prostaglandins play a crucial role. Prostaglandins are small lipid mediators derived from arachidonic acid via multi-enzymatic pathways. The actions of prostaglandins are varied, with each prostaglandin having a specific role in maintaining homeostasis. In the CNS, prostaglandins can have neuroprotective or neurotoxic properties depending on their specific G-protein receptor. These G-protein receptors have varying subfamilies, tissue distribution, and signal transduction cascades. Further studies into the impact of prostaglandins in CNS-based diseases may contribute to the clarification of their actions, hopefully leading to the development of efficacious therapeutic strategies. This review focuses on the roles played by prostaglandins in neural degeneration, with a focus on Alzheimer's Disease, Multiple Sclerosis, and Amyotrophic Lateral Sclerosis in both preclinical and clinical settings. We further discuss current prostaglandin-related agonists and antagonists concerning suggestions for their use as future therapeutics.

Role of oxylipins in ovarian function and disease: A comprehensive review.

Ovaries are essential for healthy female reproduction, with the follicles as their fundamental functional units, which consist of an oocyte and surrounding granulosa cells. The development and formation of follicles in the ovaries are closely linked to reproductive health. Oxylipins refer to oxidative metabolites produced from the oxidation of polyunsaturated fatty acids, either through automatic oxidation or with the help of specific enzymes. They play crucial regulatory roles in the immune system, oxidative stress, and inflammatory reactions and are intimately linked to the development of numerous illnesses, such as diabetes, heart disease, asthma, and Alzheimer's disease. Furthermore, oxylipins have a complex relationship with ovarian function, and both prostaglandins and leukotrienes produced by arachidonic acid affect processes such as follicle growth and development, ovulation, and hormone regulation. The synthesis and metabolism of oxylipins in the ovaries are finely regulated. Oxylipin dysregulation has been linked to various ovarian diseases, including endometriosis, polycystic ovary syndrome, ovarian cancer, and premature ovarian insufficiency. In addition, potential therapeutic targets and interventions targeting the oxylipin pathway for the treatment of ovarian diseases have become a prominent research focus, including regulating the enzymes responsible for oxylipin synthesis, using anti-inflammatory agents, and regulating lipid metabolism. Recent research has been directed towards improving the reproductive outcomes of women with ovarian diseases through this series of interventions. An overview of the role of oxylipins in ovarian function and disease is provided in this article, which will aid researchers in understanding the current state of the field and in identifying future directions.

Prostanoid signaling in retinal vascular diseases.

The vasculature of the retina is exposed to systemic and local factors that have the capacity to induce several retinal vascular diseases, each of which may lead to vision loss. Prostaglandin signaling has arisen as a potential therapeutic target for several of these diseases due to the diverse manners in which these lipid mediators may affect retinal blood vessel function. Previous reports and clinical practices have investigated cyclooxygenase (COX) inhibition by nonsteroidal anti-inflammatory drugs (NSAIDs) to address retinal diseases with varying degrees of success; however, targeting individual prostanoids or their distinct receptors affords more signaling specificity and poses strong potential for therapeutic development. This review offers a comprehensive view of prostanoid signaling involved in five key retinal vascular diseases: retinopathy of prematurity, diabetic retinopathy, age-related macular degeneration, retinal occlusive diseases, and uveitis. Mechanistic and clinical studies of these lipid mediators provide an outlook for therapeutic development with the potential to reduce vision loss in each of these conditions.

A single, maximal dose of celecoxib, ibuprofen, or flurbiprofen does not reduce the muscle signalling response to plyometric exercise in young healthy adults.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) possess analgesic and anti-inflammatory properties by inhibiting cyclooxygenase (COX) enzymes. Conflicting evidence exists on whether NSAIDs influence signaling related to muscle adaptations and exercise with some research finding a reduction in muscle protein synthesis signaling via the AKT-mTOR pathway, changes in satellite cell signaling, reductions in muscle protein degradation, and reductions in cell proliferation. In this study, we determined if a single maximal dose of flurbiprofen (FLU), celecoxib (CEL), ibuprofen (IBU), or a placebo (PLA) affects the short-term muscle signaling responses to plyometric exercise. METHODS: This was a block randomized, double-masked, crossover design, where 12 participants performed four plyometric exercise bouts consisting of 10 sets of 10 plyometric jumps at 40% 1RM. Two hours before exercise, participants consumed a single dose of celecoxib (CEL 200 mg), IBU (800 mg), FLU (100 mg) or PLA with food. Muscle biopsy samples were collected before and 3-h after exercise from the vastus lateralis. Data were analyzed using a repeated measures (RM) ANOVA, ANOVA, or a Friedman test. Significance was considered at p < 0.05. RESULTS: We found no treatment effects on the mRNA expression of PTSG1, PTSG2, MYC, TBP, RPLOP, MYOD1, Pax7, MYOG, Atrogin-1, or MURF1 (all, p > 0.05). We also found no treatment effects on AKT-mTOR signaling or MAPK signaling measured through the phosphorylation status of mTORS2441, mTORS2448, RPS6 235/236, RPS 240/244, 4EBP1, ERK1/2, p38 T180/182 normalized to their respective total abundance (all, p > 0.05). However, we did find a significant difference between MNK1 T197/202 in PLA compared to FLU (p < .05). CONCLUSION: A single, maximal dose of IBU, CEL, or FLU taken prior to exercise did not affect the signaling of muscle protein synthesis, protein degradation, or ribosome biogenesis three hours after a plyometric training bout.

Preliminary Study on the Restoration of the Phospholipid Profile in Serum from Patients with COVID-19 by Treatment with Vitamin E.

SARS-CoV-2 is an obligatory intracellular pathogen that requires a lipid bilayer membrane for its transport to build its nucleocapsid envelope and fuse with the host cell. The biological membranes are constituted by phospholipids (PLs), and vitamin E (Vit E) protects them from oxidative stress (OS). The aim of this study was to demonstrate if treatment with Vit E restores the modified profile of the FA in PLs in serum from patients with coronavirus disease-19 (COVID-19). We evaluated Vit E, total fatty acids (TFAs), fatty acids of the phospholipids (FAPLs), total phospholipids (TPLs), 8-isoprostane, thromboxane B2 (TXB2), prostaglandins (PGE2 and 6-keto-PGF1α), interleukin-6 (IL-6), and C-reactive protein (CRP) in serum from 22 COVID-19 patients before and after treatment with Vit E and compared the values with those from 23 healthy subjects (HSs). COVID-19 patients showed a decrease in Vit E, TPLs, FAPLs, and TFAs in serum in comparison to HSs (p ≤ 0.01), and Vit E treatment restored their levels (p ≤ 0.04). Likewise, there was an increase in IL-6 and CRP in COVID-19 patients in comparison with HSs (p ≤ 0.001), and treatment with Vit E decreased their levels (p ≤ 0.001). Treatment with Vit E as monotherapy can contribute to restoring the modified FA profile of the PLs in the SARS-CoV-2 infection, and this leads to a decrease in lipid peroxidation, OS, and the inflammatory process.

BCG vaccination is associated with longitudinal changes in systemic eicosanoid levels in elderly individuals: A secondary outcome analysis.

We investigated how BCG vaccination affects the levels of certain eicosanoids, namely Leukotriene B4, 15-epimer of LXA4, prostaglandin F2, Lipoxin A4, Prostaglandin E2 and Resolvin D1 in the plasma of healthy elderly individuals (aged 60-80) before vaccination, one month post-vaccination (M1), and six months post-vaccination (M6). This study is part of the clinical trial "BCG Vaccine Study: Reducing COVID-19 Impact on the Elderly in Indian Hotspots," registered in the clinical trial registry (NCT04475302). While some primary outcomes have been previously reported, this analysis delves into the immunological outcomes. Our findings indicate that BCG vaccination leads to reduced plasma levels of 15-epi-LXA4, LXA4, PGE2, and Resolvin D1 at both M1 and M6. In contrast, there is a notable increase in circulating levels of LTB4 at these time points following BCG vaccination. This underscores the immunomodulatory effects of BCG vaccination and hints at its potential to modulate immune responses by dampening inflammatory reactions.

A simplified method for preventing postmortem alterations of brain prostanoids for true in situ level quantification.

Dramatic postmortem prostanoid (PG) enzymatic synthesis in the brain causes a significant artifact during PG analysis. Thus, enzyme deactivation is required for an accurate in situ endogenous PG quantification. To date, the only method for preventing postmortem brain PG increase with tissue structure preservation is fixation by head-focused microwave irradiation (MW), which is considered the gold standard method, allowing for rapid in situ heat-denaturation of enzymes. However, MW requires costly equipment that suffers in reproducibility, causing tissue loss and metabolite degradation if overheated. Our recent study indicates that PGs are not synthesized in the ischemic brain unless metabolically active tissue is exposed to atmospheric O2. Based on this finding, we proposed a simple and reproducible alternative method to prevent postmortem PG increase by slow enzyme denaturation before craniotomy. To test this approach, mice were decapitated directly into boiling saline. Brain temperature reached 100°C after ∼140 s during boiling, though 3 min boiling was required to completely prevent postmortem PG synthesis, but not free arachidonic acid release. To validate this fixation method, brain basal and lipopolysaccharide (LPS)-induced PG were analyzed in unfixed, MW, and boiled tissues. Basal and LPS-induced PG levels were not different between MW and boiled brains. However, unfixed tissue showed a significant postmortem increase in PG at basal conditions, with lesser differences upon LPS treatment compared to fixed tissue. These data indicate for the first time that boiling effectively prevents postmortem PG alterations, allowing for a reproducible, inexpensive, and conventionally accessible tissue fixation method for PG analysis.

Total Synthesis of (15R)- and (15S)-Prostaglandin A2.

From both pharmaceutical and structural perspectives, the large family of prostaglandins represent a truly remarkable class of natural products. Prostaglandin A2 is a tissue hormone naturally found in human seminal plasma and in the sea whip Plexaura homomalla with yet poorly understood biological or therapeutic effects. Herein, a novel strategy for the stereoselective construction of both naturally occurring prostaglandin A2 epimers and first insights into their functional effects on the major inhibitory neurotransmitter γ-aminobutyric acid (GABA) type A receptors (GABAAR) are provided. The synthesis of both epimers was achieved in only 11 steps starting from commercially available 2,5-dimethoxy-tetrahydrofuran employing an organocatalytic domino-aldol reaction, a Mizoroki-Heck reaction, a Wittig reaction as well as an oxidation-decarboxylation sequence. The (15R)-epimer significantly reduced GABA-induced currents through GABAA receptors while its (15S)-epimer did not show any significant effect. These data suggest that (15R)-PGA2 might serve as a novel scaffold for the development of selective GABAA receptor modulators.

The regulation of the expression of prokineticin 1 and its receptors and its mechanism of action in the porcine corpus luteum.

Prokineticin 1 (PROK1) is an important factor in pregnancy establishment in pigs, acting at the embryo-maternal interface and the corpus luteum (CL). Estradiol-17ß (E2) is the primary pregnancy recognition signal in pigs, and its effects are augmented by luteotropic prostaglandin E2 (PGE2). On the contrary, prostaglandin F2α (PGF2α) exerts mainly a luteolytic effect. The present study aimed to elucidate whether E2, PGE2, and PGF2α regulate the expression of PROK1 and its receptors in the porcine CL and to determine the PROK1 effect on luteal endothelial cells and pathways that may be involved in this regulation. The effects of E2, PGE2, and PGF2α on the expressions of PROK1 and its receptors in the CL were studied using an in vitro model of ultrathin luteal tissue explants model. Additionally, the effects of E2 and PGE2 on the PROK1 system were determined using an in vivo approach, in which the hormones were administered into the uterine lumen to imitate their secretion by embryos. Endothelial cell proliferation was measured using the colorimetric method. E2 acting via estrogen receptors simulated the mRNA and protein expressions of PROK1 and PROKR1 in CL explants in vitro (p < 0.05). The simultaneous action of E2 with PGE2 enhanced the expression of luteal PROK1 mRNA in vitro (p < 0.05). Estradiol-17ß acting alone significantly increased PROK1 mRNA levels in vivo, whereas E2 simultaneously administered with PGE2 significantly elevated the PROK1 mRNA expression and PROKR1 mRNA and protein contents in CLs adjacent to uterine horns receiving hormonal infusion compared with CLs adjacent to placebo-treated uterine horns (p < 0.01). The PROK1 protein expression was significantly higher in the CLs of pigs treated with E2, PGE2, and E2 together with PGE2 than in the control group. PGF2α increased the PROK1 mRNA content in CLs on days 12 and 14 of the estrous cycle (p < 0.05). The expression of PROKR2 at the mRNA and protein levels remained unchanged in response to in vitro and in vivo treatments. PROK1 stimulated the proliferation of luteal endothelial cells by activating the MAPK, AKT, and mTOR pathways (p < 0.05). In summary, the luteal expressions of PROK1 and PROKR1 in early pregnancy are regulated by E2 and PGE2. PROK1 stimulates luteal angiogenesis by activating the MAPK, AKT, and mTOR pathways. The regulation of luteal PROK1 expression by PGF2α indicates PROK1's putative role during luteolysis. We conclude that PROK1-PROKR1 signaling supports luteal function during CL rescue in pregnancy in pigs.

Management of androgenic alopecia: a systematic review of the literature.

We aimed to determine the efficacy of the various available oral, topical, and procedural treatment options for hair loss in individuals with androgenic alopecia. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review of the National Library of Medicine was performed. Overall, 141 unique studies met our inclusion criteria. We demonstrate that many over the counter (e.g. topical minoxidil, supplements, low-level light treatment), prescription (e.g. oral minoxidil, finasteride, dutasteride), and procedural (e.g. platelet-rich plasma, fractionated lasers, hair transplantation) treatments successfully promote hair growth, highlighting the superiority of a multifaceted and individualized approach to management.