In Silico Design, Synthesis, and Evaluation of PROTAC Against Hematopoietic Prostaglandin D Synthase.

Chemical protein knockdown technology using proteolysis-targeting chimeras (PROTACs) to hijack the endogenous ubiquitin-proteasome system is a powerful strategy to degrade disease-related proteins. This chapter describes in silico design of a hematopoietic prostaglandin D synthase (H-PGDS) degrader, PROTAC(H-PGDS), using a docking simulation of the ternary complex of H-PGDS/PROTAC/E3 ligase as well as the synthesis of the designed PROTAC(H-PGDS)s and evaluation of their H-PGDS degradation activity.

Association between Postoperative Adjuvant Vasodilator Therapy and In-Hospital Mortality for Non-Occlusive Mesenteric Ischemia: A Nationwide Observational Study.

BACKGROUND: Although several clinical guidelines recommend vasodilator therapy for non-occlusive mesenteric ischemia (NOMI) and immediate surgery when bowel necrosis is suspected, these recommendations are based on limited evidence. METHODS: In this retrospective nationwide observational study, we used information from the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2018 to identify patients with NOMI who underwent abdominal surgeries on the day of admission. We compared patients who received postoperative vasodilator therapy (vasodilator group) with those who did not (control group). Vasodilator therapy was defined as venous and/or arterial administration of papaverine and/or prostaglandin E1 within 2 days of admission. The primary outcome was in-hospital mortality. Secondary outcomes included the prevalence of additional abdominal surgery performed ≥3 days after admission and short bowel syndrome. RESULTS: We identified 928 eligible patients (149 in the vasodilator group and 779 in the control group). One-to-four propensity score matching yielded 149 and 596 patients for the vasodilator and control groups, respectively. There was no significant difference in in-hospital mortality between the groups (control vs. vasodilator, 27.5% vs. 30.9%; risk difference, 3.4%; 95% confidence interval, -4.9 to 11.6; p=0.42) and no significant difference in the prevalences of abdominal surgery, bowel resection ≥3 days after admission, and short bowel syndrome. CONCLUSIONS: Postoperative vasodilator use was not significantly associated with a reduction in in-hospital mortality or additional abdominal surgery performed ≥3 days after admission in surgically treated NOMI patients.

Inflammation assessment and therapeutic monitoring based on highly sensitive and multi-level electrochemical detection of PGE2.

Prostaglandin E2 (PGE2), an eicosane, regulates the physiological activity of inflammatory cells and represents a potential therapeutic target for facilitating tissue repair in vivo. In our work, an electrochemical immunosensor employing Ketjen black-Au nanoparticles (KB-Au) and poly tannic acid nanospheres conjugated with anti-PGE2 polyclonal antibody (PTAN-Ab) was designed to ultra-sensitively analyze PGE2 levels secreted by living cells and tissues. Antibody assembly strategies were explored to achieve signal amplification. Moreover, we studied the therapy effects of docosahexaenoic acid (DHA), arachidonic acid (AA), hyaluronic acid (HA), and small molecule 15-hydroxyprostaglandin dehydrogenase inhibitor (SW033291) on inflammation and evaluated the protective functions of HA and SW033291 in a murine model subjected to colitis induced by dextran sulfate sodium (DSS) using the developed sensor. The sensor exhibited a linear range of 10-5-106 fg/mL and a detection limit (LOD) of 10-5 fg/mL. Fetal bovine serum (FBS) samples were used to achieve high recovery of target analytes. This study not only presents an effective strategy for ultra-sensitively monitoring PGE2 but also provides valuable insights into assessing the degree of inflammation and the therapeutic effect of related drugs. Research on human health monitoring and regenerative medicine could greatly benefit from the findings.

2-(3-(Chloromethyl)benzoyloxy)benzoic Acid Reduces Prostaglandin E-2 Concentration, NOX2 and NFKB Expression, ROS Production, and COX-2 Expression in Lipopolysaccharide-Induced Mice.

INTRODUCTION: Inflammation is a fundamental response to various insults, including microbial invasion and tissue injury. While aspirin (ASA) has been widely used for its anti-inflammatory properties, its adverse effects and limitations highlight the need for novel therapeutic alternatives. Recently, a novel salicylic acid derivative, 2-((3-(chloromethyl)benzoyl)oxy)benzoic acid (3-CH2Cl), has emerged as a potential substitute for ASA, offering a simpler, environmentally friendly synthesis and a promising safety profile. AIM OF THE STUDY: This research aims to evaluate the anti-inflammatory mechanism of 3-CH2Cl in a lipopolysaccharide (LPS)-induced mouse model, focusing on its effects on prostaglandin E-2 (PGE-2) concentration, NOX2 and NFkB expression, ROS production, and COX-2 expression. MATERIAL AND METHODS: Utilizing BALB/C mice subjected to LPS-induced inflammation, we investigated the therapeutic potential of 3-CH2Cl. The study included synthesis and tablet preparation, experimental design, peripheral blood plasma PGE-2 measurement, splenocyte isolation and COX-2 expression analysis, nitric oxide and ROS measurement, and immunohistochemical analysis of NOX2 and NFkB expression. RESULTS: 3-CH2Cl significantly reduced PGE-2 levels (p=0.005), NO concentration in liver homogenates (p=0.005) and plasma (p=0.0011), and expression of NOX2 and NFkB in liver (p<0.0001) and splenocytes (p=0.0036), demonstrating superior anti-inflammatory activity compared to ASA. Additionally, it showed potential in decreasing COX-2 expression in splenocytes. CONCLUSION: 3-CH2Cl exhibits potent anti-inflammatory properties, outperforming ASA in several key inflammatory markers in an LPS-induced inflammation model. The reduction of COX-2 expression, alongside the reduction of pro-inflammatory cytokines and oxidative stress markers, suggest it as a promising therapeutic agent for various inflammatory conditions.

Inducible Deletion of the Prostaglandin EP3 Receptor in Kidney Tubules of Male and Female Mice Has No Major Effect on Water Homeostasis.

The prostaglandin E2 (PGE2) receptor EP3 has been detected in the thick ascending limb (TAL) and the collecting duct of the kidney, where its actions are proposed to inhibit water reabsorption. However, EP3 is also expressed in other cell types, including vascular endothelial cells. The aim here was to determine the contribution of EP3 in renal water handling in male and female adult mice by phenotyping a novel mouse model with doxycycline-dependent deletion of EP3 throughout the kidney tubule (EP3-/- mice). RNAscope demonstrated that EP3 was highly expressed in the cortical and medullary TAL of adult mice. Compared to controls EP3 mRNA expression was reduced by >80% in whole kidney (RT-qPCR) and non-detectable (RNAscope) in renal tubules of EP3-/- mice. Under basal conditions, there were no significant differences in control and EP3-/- mice of both genders in food and water intake, bodyweight, urinary output or clinical biochemistries. No differences were detectable between genotypes in handling of an acute water load, or in their response to the vasopressin analogue dDAVP. No differences in water handling were observed when PGE2 production was enhanced using a 1% NaCl load. Expression of proteins involved in kidney water handling were not different between genotypes. This study demonstrates that renal tubular EP3 is not essential for body fluid homeostasis in males or females, even when PGE2 levels are high. The mouse model is a novel tool for examining the role of EP3 in kidney function independently of potential developmental abnormalities or systemic effects.

Liposomal quercetin: A promising strategy to combat hepatic insulin resistance and inflammation in type 2 diabetes mellitus.

In type 2 diabetes mellitus, hepatic insulin resistance is intricately associated with oxidative stress and inflammation. Nonetheless, the lack of therapeutic interventions directly targeting hepatic dysfunction represents a notable gap in current treatment options. Flavonoids have been explored due to their potential anti-diabetic effects. However, these compounds are associated with low bioavailability and high metabolization. In the present study, four flavonoids, kaempferol, quercetin, kaempferol-7-O-glucoside and quercetin-7-O-glucoside, were studied in a cellular model of hepatic insulin resistance using HepG2 cells. Quercetin was selected as the most promising flavonoid and incorporated into liposomes to enhance its therapeutic effect. Quercetin liposomes had a mean size of 0.12 µm, with an incorporation efficiency of 93 %. Quercetin liposomes exhibited increased efficacy in modulating insulin resistance. This was achieved through the modulation of Akt expression and the attenuation of inflammation, particularly via the NF-κB pathway, as well as the regulation of PGE2 and COX-2 expression. Furthermore, quercetin liposomes displayed a significant advantage over free quercetin in attenuating the production of reactive pro-oxidant species. These findings open new avenues for developing innovative therapeutic strategies to manage diabetes, emphasizing the potential of quercetin liposomes as a promising approach for targeting both hepatic insulin resistance and associated inflammation.

Market Needs and Methodologies Associated with Patient Lipidomic Diagnoses and Analyses.

This chapter conducts an in-depth exploration of the impact of musculoskeletal (MSK) disorders and injuries, with a specific emphasis on their consequences within the older population demographic. It underscores the escalating demand for innovative interventions in MSK tissue engineering. The chapter also highlights the fundamental role played by lipid signaling mediators (LSMs) in tissue regeneration, with relevance to bone and muscle recovery. Remarkably, Prostaglandin E2 (PGE2) emerges as a central orchestrator in these regenerative processes. Furthermore, the chapter investigates the complex interplay between bone and muscle tissues, explaining the important influence exerted by LSMs on their growth and differentiation. The targeted modulation of LSM pathways holds substantial promise as a beneficial way for addressing muscle disorders. In addition to these conceptual understandings, the chapter provides a comprehensive overview of methodologies employed in the identification of LSMs, with a specific focus on the Liquid Chromatography-Mass Spectrometry (LC-MS). Furthermore, it introduces a detailed LC MS/MS-based protocol tailored for the detection of PGE2, serving as an invaluable resource for researchers immersed in this dynamic field of study.

Lipid metabolites and nitric oxide production in the cerebrospinal fluid and plasma of dogs with meningoencephalitis of unknown origin and idiopathic epilepsy: a pilot study.

Introduction: Idiopathic epilepsy (IE) and meningoencephalomyelitis of unknown origin (MUO) are common causes of brain diseases leading to seizures in dogs. In this study, the concentrations of 196 lipid metabolites and nitrogen oxide (NO) production in the cerebrospinal fluid (CSF) and plasma of dogs with MUO or IE were measured using a LC-MS/MS and a NOx analyzer, respectively. Methods: Nine clinically healthy dogs and 11 and 12 dogs with IE and MUO, respectively, were included in the study. Results: Lipid analysis revealed variations in the levels of four and six lipid metabolites in CSF and plasma, respectively, between the groups. The levels of 6-keto-prostaglandin (PG) F1α (PGF1α), 20-carboxy arachidonic acid (20-carboxy-AA), 9-hydroxyoctadecadienoic acid, and lyso-platelet-activating factor were high in the CSF of dogs with MUO. In addition, the plasma levels of 11,12-dihydroxyeicosatrienoic acid, 20-carboxy-AA, and oleoylethanolamide were high in dogs with IE, and those of PGF1α were high in dogs with MUO. NO production levels were high in CSF but not in plasma in dogs with MUO or IE. Discussion: It remains unknown whether these changes represent the cause or effect of diseases of the central nervous system; however, lipid metabolites and NO production in CSF and plasma may be used as diagnostic biomarkers and could be exploited for treating idiopathic or inflammatory epilepsy in dogs.

Prostaglandin A3 regulates the colony development of Odontotermes formosanus by reducing worker proportion.

Subterranean termites cause significant economic losses worldwide due to their destruction of agricultural and forest plants. In the past, soil termiticides were commonly used to control subterranean termites because they were effective and affordable. However, due to growing environmental concerns, these harmful substances have become less popular as they cause damage to non-target organisms and lead to environmental contamination. Baits crafted from plants and other easily metabolized compounds serve as excellent alternatives. In this study, we gathered branches from the promising plant, Magnolia grandiflora L. (MGL), along with branches from five other tree species that are potential food for termites. These branches were used as food to observe the population growth of Odontotermes formosanus. Additionally, a mix of branches from all six species was used to feed the control group (MIX). The study results showed that MGL nutrition significantly inhibited worker development, resulting in a significantly lower worker-to-soldier ratio (WSR). Furthermore, LC‒MS/MS analysis revealed that the level of prostaglandin A3 (PGA3) in workers significantly increased when they were under MGL nutrition. Additionally, ICP-MS analysis indicated a significant increase in calcium concentrations in the branches of MGL and combs under MGL nutrition. Moreover, there was a significant increase in peroxidase (POD) activity in workers under MGL nutrition. These findings suggest that the inhibitory effect of MGL nutrition on worker development may be due to excessive PGA3 synthesis, as Ca2+ and POD are involved in the synthesis process of PGs in insects. Subsequent verification experiments strongly support this hypothesis, as the WSR of colonies fed PGA3-added MIX was significantly lower than that of the MIX alone. This study introduces a new concept for developing environmentally friendly biological control methods for O. formosanus and sheds light on the potential role of PGs in termite development. Supplementary Information: The online version contains supplementary material available at 10.1007/s44297-024-00030-3.

In mares resistant to endometrial infection, periovulatory treatment with ecbolic drugs does not influence uterine clearance or luteal development.

We aimed to determine associations between experimentally impaired uterine clearance or treatment with ecbolic drugs on luteal development in estrous mares after insemination. In a crossover design, eight mares were treated with saline (CON), clenbuterol (CLEN), oxytocin (OXY) and carbetocin (CARB) from the day of first insemination until 2 days after ovulation. Between treatments, the mares rested for one cycle. Estrous mares were examined for the presence of free intrauterine fluid by transrectal ultrasound. Endometrial swabs for cytology and bacteriology were collected on days 1 and 14. Blood samples were collected daily before AI until day 14 after ovulation for determination of progesterone and PGF2α metabolites (PGFM). Differences between treatments were compared by a general linear model for repeated measures (SPSS 29). One mare was excluded because of a uterine infection in the control cycle. In all other mares, only minor amounts of free intrauterine fluid were present after insemination and decreased over time (P<0.05) with no treatment x time interaction. There was no effect of treatment on polymorphonucleated cells (PMN) in endometrial cytology after ovulation or PGFM secretion. Progesterone release from day 1-14 as well as pregnancy rate and conceptus size on day 14 was not influenced by treatment. In conclusion, treatment with clenbuterol does not impair uterine clearance in estrous mares resistant to endometritis. Repeated injection of the oxytocin analogue carbetocin during the early postovulatory period is not detrimental to corpus luteum function and can be recommended to enhance uterine clearance.

Travoprost Intracameral Implant Demonstrates Superior IOP Lowering Versus Topical Prostaglandin Analog Monotherapy in Patients with Open-Angle Glaucoma or Ocular Hypertension.

INTRODUCTION: This study was conducted to analyze and compare the intraocular pressure (IOP) treatment effect of the slow-eluting (SE) travoprost intracameral implant to the IOP treatment effect of topical prostaglandin analog (PGA) monotherapy in a subgroup of subjects who were on pre-study PGA monotherapy prior to enrollment in the two pivotal phase 3 trials of the travoprost intracameral implant. METHODS: A combined study population of 133 subjects from two phase 3 trials, who were on topical PGA monotherapy at screening, subsequently underwent a washout period from their topical PGA, and then were randomized and administered an SE travoprost intracameral implant. The subjects were analyzed for the IOP treatment effects of the pre-study topical PGA monotherapy and the in-study SE travoprost intracameral implant. Paired t-tests were used to compare the difference in screening minus post-washout baseline IOP versus month 3 minus post-washout baseline IOP. The IOP-lowering efficacy in eyes administered an SE travoprost intracameral implant was compared to the IOP lowering in the same eyes while on a topical PGA monotherapy prior to study entry. RESULTS: Pre-study topical PGA monotherapy and the SE travoprost intracameral implant demonstrated IOP treatment effects of -5.76 mmHg and -7.07 mmHg, respectively. The IOP-lowering treatment effect was significantly greater by 1.31 mmHg for the SE travoprost intracameral implant relative to pre-study PGA monotherapy (95% confidence interval: -2.01, -0.60; P = 0.0003). CONCLUSIONS: The SE travoprost intracameral implant demonstrated superior IOP-lowering treatment effect versus pre-study topical PGA monotherapy with a superiority margin that was both statistically significant and clinically meaningful. The greater IOP reduction from baseline while on the SE implant versus pre-study topical PGA monotherapy may be a reflection of the optimized adherence and continuous elution of PGA therapy into the anterior chamber achieved with the SE travoprost intracameral implant. TRIAL REGISTRATION: ClinicalTrials.gov identifiers, NCT03519386 and NCT03868124.

Leptin-mediated suppression of lipoprotein lipase cleavage enhances lipid uptake and facilitates lymph node metastasis in gastric cancer.

BACKGROUND: Lymph node metastasis (LNM) is the primary mode of metastasis in gastric cancer (GC). However, the precise mechanisms underlying this process remain elusive. Tumor cells necessitate lipid metabolic reprogramming to facilitate metastasis, yet the role of lipoprotein lipase (LPL), a pivotal enzyme involved in exogenous lipid uptake, remains uncertain in tumor metastasis. Therefore, the aim of this study was to investigate the presence of lipid metabolic reprogramming during LNM of GC as well as the role of LPL in this process. METHODS: Intracellular lipid levels were quantified using oil red O staining, BODIPY 493/503 staining, and flow cytometry. Lipidomics analysis was employed to identify alterations in intracellular lipid composition following LPL knockdown. Protein expression levels were assessed through immunohistochemistry, Western blotting, and enzyme-linked immunosorbent assays. The mouse popliteal LNM model was utilized to investigate differences in LNM. Immunoprecipitation and mass spectrometry were employed to examine protein associations. In vitro phosphorylation assays and Phos-tag sodium dodecyl-sulfate polyacrylamide gel electrophoresis assays were conducted to detect angiopoietin-like protein 4 (ANGPTL4) phosphorylation. RESULTS: We identified that an elevated intracellular lipid level represents a crucial characteristic of node-positive (N+) GC and further demonstrated that a high-fat diet can expedite LNM. LPL was found to be significantly overexpressed in N+ GC tissues and shown to facilitate LNM by mediating dietary lipid uptake within GC cells. Leptin, an obesity-related hormone, intercepted the effect exerted by ANGPTL4/Furin on LPL cleavage. Circulating leptin binding to the leptin receptor could induce the activation of inositol-requiring enzyme-1 (IRE1) kinase, leading to the phosphorylation of ANGPTL4 at the serine 30 residue and subsequently reducing its binding affinity with LPL. Moreover, our research revealed that LPL disrupted lipid homeostasis by elevating intracellular levels of arachidonic acid, which then triggered the cyclooxygenase-2/prostaglandin E2 (PGE2) pathway, thereby promoting tumor lymphangiogenesis. CONCLUSIONS: Leptin-induced phosphorylation of ANGPTL4 facilitates LPL-mediated lipid uptake and consequently stimulates the production of PGE2, ultimately facilitating LNM in GC.

Insights into the role of PGF2α in canine periparturient myometrium.

Parturition in dogs is subjected to complex hormonal regulation, with the involvement of prostaglandin F2α (PGF2α) still not fully understood. To investigate uterine inertia (UI), the most prevalent maternal reason for dystocia in the bitch, a better understanding of undisturbed uterine, especially myometrial function, is crucial. Our aim was to gain deeper insights into the role of PGF2α in the canine parturient myometrium. Uterine biopsies were obtained during medically indicated cesarean sections. To test for stimulatory effects of PGF2α in vitro, circular and longitudinal myometrial layer tissue strips were challenged with 50 pM, 0.5 µM, and 50 µM PGF2α. Prostaglandin-endoperoxide synthase 2 (PTGS2) and PGF2α-receptor (PTGFR) mRNA expressions were compared between primary UI (PUI) and obstructive dystocia (OD) samples in isolated parturient myometrium. PTGFR protein expression was assessed in full thickness uterine samples. PGF2α concentrations were analyzed in canine interplacental tissue around term. In the organ bath, the contractile response to PGF2α was limited to the circular layer at the highest dosage. Correspondingly, PTGFR immunohistochemical staining was significantly stronger in the circular layer (p ≤ 0.01). PTGS2 gene expression did not differ between PUI and OD, whereas PTGFR gene expression could not be quantified. Local uterine PGF2α concentrations correlated negatively with serum P4 levels and were the highest during prepartum luteolysis while being significantly lower in PUI. Conclusively, despite the significant increase in local PGF2α concentrations at birth, confirming the interplacental tissue as a production site, our results suggest that PGF2α might affect uterine contractility during labor, mainly indirectly.

Clinical and Radiographic Status and PISF Levels of PGE2 Around Cement and Screw Retained Implants.

BACKGROUND: The aim was to assess the peri-implant clinicoradiographic status and prostaglandin E2 (PGE2) levels in peri-implant sulcular fluid (PISF) samples collected from individuals with cement-retained and crew-retained implants. METHODS: In this observational study, participants with cement-retained and screw-retained implants were enrolled. A questionnaire was utilized to gather demographic information and assess the educational background of the participants. Peri-implant modified plaque and bleeding indices, probing depth, and crestal bone loss were measured. Subsequently, PISF samples were collected, and corresponding volumes were recorded. Commercial kits employing enzyme-linked immunosorbent assay were employed to quantify PGE2 levels. The sample size was determined, and group comparisons were conducted using the Student t test and the Mann-Whitney U-test. Logistic regression models were constructed to evaluate the correlation between PGE2 levels and clinicoradiographic and demographics. The predefined level of significance was established at P < .05. RESULTS: Sixty-seven participants, consisting of 33 with cement-retained implants and 34 with screw-retained implants, were included in the study. The mean ages for individuals with cement and screw-retained implants were 54.2 ± 8.7 and 58.7 ± 7.4 years, respectively. The majority of participants had completed university-level education. Reportedly, 87.9% and 82.4% of individuals with cement and screw-retained implants, respectively brushed teeth twice daily. No significant differences were observed in clinicoradiographic parameters, PGE2 volume, and levels between cement-retained and screw-retained implants. There was no correlation between PGE2 levels and peri-implant clinicoradiographic parameters among individuals with either cement-retained or screw-retained implants. CONCLUSIONS: Cement-retained and screw-retained implants exhibit a consistent peri-implant clinicoradiographic status, accompanied by stable levels of PGE2 in PISF provided oral hygiene maintenance regimens are stringently followed.

Myeloid Cell mPGES-1 Deletion Attenuates Calcium Phosphate-induced Abdominal Aortic Aneurysm in Male Mice.

Microsomal PGE2 synthase (mPGES)-1 is the key enzyme responsible for synthesizing inflammatory prostaglandin E2 (PGE2). Our previous studies have shown that deletion mPGES-1 in myeloid cells hinders atherogenesis, suppresses vascular proliferative response to injury and enhances survival after myocardial infarction. Here we aimed to further explore the influence of myeloid cell mPGES-1 deletion in abdominal aortic aneurysm (AAA) formation. The AAA was triggered by applying 0.5 M calcium phosphate (CaPO4) to the infrarenal aorta of both myeloid mPGES-1 knockout (Mac-mPGES-1-KO) and their littermate control Mac-mPGES-1-WT mice. AAA induction was assessed by calculating the expansion of the infrarenal aortic diameter 4 weeks after CaPO4 application. The maximum diameters of the aortas were measured by morphometry and the mean maximal diameters were calculated. Paraffin sections of the infrarenal aortas were examined for morphological analysis and immunohistochemical staining. The results showed that myeloid cell mPGES-1 deletion significantly mitigated AAA formation, including reducing expansion of the infrarenal aorta, preventing elastic lamellar degradation, and decreasing aortic calcium deposition. Immunohistochemical staining further indicated that macrophage infiltration and matrix metalloproteinase 2 (MMP2) expression was attenuated in the Mac-mPGES-1-KO aortas. Consistently, in vitro experiments showed that expression of pro-inflammatory cytokines and MMPs was significantly reduced when mPGES-1 was lacking in the primary cultured peritoneal macrophages. These data altogether demonstrated that deletion of mPGES-1 in myeloid cells may attenuate AAA formation and targeting myeloid cell mPGES-1 could potentially offer an effective strategy for the treatment and prevention of vascular inflammatory diseases.

Magnesium malate-modified calcium phosphate bone cement promotes the repair of vertebral bone defects in minipigs via regulating CGRP.

Active artificial bone substitutes are crucial in bone repair and reconstruction. Calcium phosphate bone cement (CPC) is known for its biocompatibility, degradability, and ability to fill various shaped bone defects. However, its low osteoinductive capacity limits bone regeneration applications. Effectively integrating osteoinductive magnesium ions with CPC remains a challenge. Herein, we developed magnesium malate-modified CPC (MCPC). Incorporating 5% magnesium malate significantly enhances the compressive strength of CPC to (6.18 ± 0.49) MPa, reduces setting time and improves disintegration resistance. In vitro, MCPC steadily releases magnesium ions, promoting the proliferation of MC3T3-E1 cells without causing significant apoptosis, proving its biocompatibility. Molecularly, magnesium malate prompts macrophages to release prostaglandin E2 (PGE2) and synergistically stimulates dorsal root ganglion (DRG) neurons to synthesize and release calcitonin gene-related peptide (CGRP). The CGRP released by DRG neurons enhances the expression of the key osteogenic transcription factor Runt-related transcription factor-2 (RUNX2) in MC3T3-E1 cells, promoting osteogenesis. In vivo experiments using minipig vertebral bone defect model showed MCPC significantly increases the bone volume fraction, bone density, new bone formation, and proportion of mature bone in the defect area compared to CPC. Additionally, MCPC group exhibited significantly higher levels of osteogenesis and angiogenesis markers compared to CPC group, with no inflammation or necrosis observed in the hearts, livers, or kidneys, indicating its good biocompatibility. In conclusion, MCPC participates in the repair of bone defects in the complex post-fracture microenvironment through interactions among macrophages, DRG neurons, and osteoblasts. This demonstrates its significant potential for clinical application in bone defect repair.

Noradrenaline and Adrenoreceptors Are Involved in the Regulation of Prostaglandin I2 Production in the Porcine Endometrium after Experimentally Induced Inflammation.

Endometritis is a common disease in animals, leading to disruption of reproductive processes and economic losses. Noradrenergic control of prostaglandin (PG)I2 formation by inflamed endometrium is unknown. We determined the involvement of α1-, α2- and ß-adrenoreceptors (ARs) in noradrenaline-influenced PGI synthase (PGIS) protein abundance and PGI2 release from porcine (1) endometrial explants with Escherichia coli (E. coli)-induced inflammation in vivo, and (2) E. coli lipopolysaccharide (LPS)-treated endometrial epithelial cells. Experiment 1. E. coli suspension (E. coli group) or saline (CON group) was injected into the uterine horns. In both groups, noradrenaline increased endometrial PGIS abundance and PGI2 release versus the control values, and it was higher in the E. coli group than in the CON group. In the CON group, a noradrenaline stimulating effect on both parameters takes place through α1D-, α2C- and ß2-ARs. In the E. coli group, noradrenaline increased PGIS abundance and PGI2 release via α1A-, α2(B,C)- and ß(1,2)-ARs, and PGI2 release also by α2A-ARs. Experiment 2. LPS and noradrenaline augmented the examined parameters in endometrial epithelial cells versus the control value. In LPS-treated cells, ß(1,2)-ARs mediate in noradrenaline excitatory action on PGIS protein abundance and PGI2 release. ß3-ARs also contribute to PGI2 release. Under inflammatory conditions, noradrenaline via ARs increases PGI2 synthesis and release from the porcine endometrium, including epithelial cells. Our findings suggest that noradrenaline may indirectly affect processes regulated by PGI2 in the inflamed uterus.

Prostaglandin I2 signaling prevents angiotensin II-induced atrial remodeling and vulnerability to atrial fibrillation in mice.

Atrial fibrillation (AF) is the most common arrhythmia, and atrial fibrosis is a pathological hallmark of structural remodeling in AF. Prostaglandin I2 (PGI2) can prevent the process of fibrosis in various tissues via cell surface Prostaglandin I2 receptor (IP). However, the role of PGI2 in AF and atrial fibrosis remains unclear. The present study aimed to clarify the role of PGI2 in angiotensin II (Ang II)-induced AF and the underlying molecular mechanism. PGI2 content was decreased in both plasma and atrial tissue from patients with AF and mice treated with Ang II. Treatment with the PGI2 analog, iloprost, reduced Ang II-induced AF and atrial fibrosis. Iloprost prevented Ang II-induced atrial fibroblast collagen synthesis and differentiation. RNA-sequencing analysis revealed that iloprost significantly attenuated transcriptome changes in Ang II-treated atrial fibroblasts, especially mitogen-activated protein kinase (MAPK)-regulated genes. We demonstrated that iloprost elevated cAMP levels and then activated protein kinase A, resulting in a suppression of extracellular signal-regulated kinase1/2 and P38 activation, and ultimately inhibiting MAPK-dependent interleukin-6 transcription. In contrast, cardiac fibroblast-specific IP-knockdown mice had increased Ang II-induced AF inducibility and aggravated atrial fibrosis. Together, our study suggests that PGI2/IP system protects against atrial fibrosis and that PGI2 is a therapeutic target for treating AF.The prospectively registered trial was approved by the Chinese Clinical Trial Registry. The trial registration number is ChiCTR2200056733. Data of registration was 2022/02/12.

Effects of grain intervention on hypothalamic function and the metabolome of blood and milk in dairy cows.

BACKGROUND: The hypothalamus plays a crucial role in the health and productivity of dairy cows, yet studies on its functionality and its impact on peripheral circulation in these animals are relatively scarce, particularly regarding dietary interventions. Therefore, our study undertook a comprehensive analysis, incorporating both metabolomics and transcriptomics, to explore the effects of a grain-based diet on the functionality of the hypothalamus, as well as on blood and milk in dairy cows. RESULTS: The hypothalamic metabolome analysis revealed a significant reduction in prostaglandin E2 (PGE2) level as a prominent response to the grain-based diet introduction. Furthermore, the hypothalamic transcriptome profiling showed a notable upregulation in amino acid metabolism due to the grain-based diet. Conversely, the grain-based diet led to the downregulation of genes involved in the metabolic pathway from lecithin to PGE2, including phospholipase A2 (PLA2G4E, PLA2G2A, and PLA2G12B), cyclooxygenase-2 (COX2), and prostaglandin E synthase (PTGES). Additionally, the plasma metabolome analysis indicated a substantial decrease in the level of PGE2, along with a decline in adrenal steroid hormones (tetrahydrocortisol and pregnenolone) following the grain-based diet introduction. Analysis of the milk metabolome showed that the grain-based diet significantly increased uric acid level while notably decreasing PGE2 level. Importantly, PGE2 was identified as a critical metabolic marker in the hypothalamus, blood, and milk in response to grain intervention. Correlation analysis demonstrated a significant correlation among metabolic alterations in the hypothalamus, blood, and milk following the grain-based diet. CONCLUSIONS: Our findings suggest a potential link between hypothalamic changes and alterations in peripheral circulation resulting from the introduction of a grain-based diet.

Prostacyclin synthase deficiency exacerbates systemic inflammatory responses in lipopolysaccharide-induced septic shock in mice.

OBJECTIVES: Sepsis is a systemic inflammatory disorder characterized by life-threateningorgan dysfunction resulting from a dysregulated host response to infection. Prostacyclin (PGI2) is a bioactive lipid produced by PGI synthase (PGIS) and is known to play important roles in inflammatory reactions as well as cardiovascular regulation. However, little is known about the roles of PGIS and PGI2 in systemic inflammatory responses such as septic shock. METHODOLOGY: Systemic inflammation was induced by intraperitoneal injection of 5 mg/kg lipopolysaccharide (LPS) in wild type (WT) or PGIS knockout (KO) mice. Selexipag, a selective PGI2 receptor (IP) agonist, was administered 2 h before LPS injection and again given every 12 h for 3 days. RESULTS: Intraperitoneal injection of LPS induced diarrhea, shivering and hypothermia. These symptoms were more severe in PGIS KO mice than in WT micqe. The expression of Tnf and Il6 genes was notably increased in PGIS KO mice. In contrast, over 95% of WT mice survived 72 h after the administration of LPS, whereas all of the PGIS KO mice had succumbed by that time. The mortality rate of LPS-administrated PGIS KO mice was improved by selexipag administration. CONCLUSION: Our study suggests that PGIS-derived PGI2 negatively regulates LPS-induced symptoms via the IP receptor. PGIS-derived PGI2-IP signaling axis may be a new drug target for systemic inflammation in septic shock.