Search Results (115)

The G protein-coupled receptor GPR18, engaged by pro-resolving and cannabinoid-related lipid ligands, plays a vascular bed-specific protective role in endothelial function. The aim of the present study was to establish the vasoreactivity and passive biomechanical properties of the thoracic aorta and femoral artery of adult GPR18 knockout compared with wildtype mice, using ex vivo myography, arterial morphology, and immunohistochemistry. The results revealed heightened receptor-independent contractility, loss of prostanoid-dependent contractile responses, altered vascular smooth muscle cell (VSMC) calcium handling, and an attenuated stress–tension relationship in the thoracic aorta of GPR18 knockout mice. This phenotype was almost entirely reversed in the femoral artery, with attenuated receptor-independent contractility, unchanged VSMC calcium handling, and a heightened stress–tension relationship in GPR18 knockout mice. These vascular bed-specific differences highlight the need to consider tissue context in the development of GPR18-based vasculoprotective therapies for cardiovascular disease. Full article

Algae-derived bioactives have emerged as promising nutraceuticals due to their ability to modulate key molecular pathways under physiological stress. Arthrospira platensis (Spirulina), a cyanobacterium widely recognized for its antioxidant and anti-inflammatory properties, is proposed as a functional supplement to preserve smooth muscle physiology. Progressive strength training (PST) can induce oxidative stress and disrupt electromechanical coupling in the uterus, potentially impairing female reproductive function. This study investigated whether supplementation with A. platensis prevents PST-induced uterine dysfunction and elucidated the molecular mechanisms involved. Virgin Wistar rats were divided into five groups: sedentary with saline (GS), sedentary with A. platensis (GAP100), adapted control (GC), PST-trained (GT), and PST-trained with A. platensis (GTAP100). An eight-week water-jump PST protocol was applied. Uterine contractile responses were recorded in isolated organ baths after cumulative KCl stimulation, in the absence or presence of pathway-specific inhibitors targeting nitric oxide synthase, cyclooxygenase, NADPH oxidase, or superoxide dismutase. Histological evaluations of uterine and ovarian tissues were also performed. PST increased contractile efficacy and myometrial thickness, associated with oxidative stress and activation of NO, COX, and NADPH oxidase pathways. Supplementation with A. platensis attenuated these alterations by enhancing NO signaling, stimulating relaxant prostanoids, and reducing superoxide production. These protective effects were abolished by inhibitors, confirming mechanistic involvement. Overall, our findings provide molecular evidence that A. platensis supplementation preserves uterine smooth muscle physiology under high-intensity resistance training, supporting its potential as a nutraceutical strategy for female reproductive health. Full article

Minimally invasive surgery is known to lessen postoperative stress and complications compared with open procedures, yet its molecular effects on immunity and cancer-related mechanisms remain unclear. This study examined immune and inflammatory responses after robot-assisted (RS) versus open (OS) colorectal cancer surgery. Sixty-one patients (RS = 30; OS = 31) were enrolled. Blood samples were collected before surgery and at 8, 24, and 72 h post-incision. Cytokines, growth factors, and prostanoids were measured using multiplex immunoassays and mass spectrometry to assess systemic immune and inflammatory changes. Surgery type markedly influenced perioperative immune profiles. RS induced stronger activation of Th1-associated cytokines, including IFNγ and IP-10, suggesting enhanced cellular immune responsiveness. In contrast, Th2 cytokines and other immunosuppressive mediators—such as IL-4, IL-10, and G-CSF—showed smaller or transient increases after RS, whereas OS triggered broader and more sustained elevations. Angiogenic factors (VEGF-A, PDGF-BB, FGF2) rose significantly after OS but remained comparatively lower and returned to baseline faster after RS, indicating a weaker proangiogenic response. Similarly, postoperative surges in prostaglandins linked to inflammation and tumor progression (PGE₂, PGF₂α) were blunted and resolved earlier following RS. Overall, the robotic approach was associated with reduced inflammatory and immunosuppressive activity, faster recovery of immune balance, and diminished biochemical signals favoring angiogenesis and potential tumor regrowth, suggesting a potential protective effect against pathogens and cancer-promoting mechanisms after colorectal tumor resection. Full article

Previous research has demonstrated that the transient bilateral common carotid artery occlusion and reperfusion (BCCAO/R) effectively models early brain inflammation resulting from sudden hypoperfusion and subsequent reperfusion. According to studies showing that diet and nutrition strongly influence brain neuroplasticity, in this study we evaluated whether kaempferol (KAM), a dietary flavonoid, offers neuroprotection in a rat BCCAO/R model. Adult Wistar rats were gavage fed a single dose of KAM (40 mg) six hours before surgery. Comprehensive lipidomic and molecular analyses were conducted on samples from the frontal and temporal-occipital cortices, as well as the plasma. In the frontal cortex, KAM elevated anti-inflammatory N-acylethanolamines palmitoylethanolamide (PEA), oleoylethanolamide (OEA), and docosahexaenoylethanolamide (DHAEA) and reduced oxidized arachidonic acid metabolites. KAM also downregulated cyclooxygenase- 2 (COX-2) protein and selectively decreased the endocannabinoid 2-arachidonoylglycerol (2-AG), showing a shift in AA metabolism. These molecular changes correlated with increased levels of peroxisome proliferator-activated receptor alpha (PPARα) and cannabinoid receptors CB1R and CB2R, supporting activation of both nuclear and membrane-bound anti-inflammatory pathways. No significant changes were observed in the temporal-occipital cortex. In plasma, DHAEA levels increased similarly to those in the cortex. However, rises in PEA and OEA were detected only in sham-operated KAM-treated animals, suggesting possible central redistribution under hypoperfusion/reperfusion stress. In summary, these findings demonstrate that KAM exerts dual anti-inflammatory effects by inhibiting COX-2-mediated prostanoid synthesis and promoting PPARα-driven lipid signaling. This dual mechanism highlights the potential of KAM as a dietary intervention to reduce neuroinflammation associated with hypoperfusion–reperfusion challenges. Full article

The vascular 5-HT sympatho-modulation may involve inhibitory or potentiating pathways: nitric oxide (NO), endothelium-dependent hyperpolarization (EDH)-K⁺ channels, prostanoids, angiotensin II (Ang-II), or endothelin. Compared to males, female rats show differences in the serotonergic sympatho-regulation; therefore, we aimed to study the involvement of indirect pathways via 5-HT_1D-mediated inhibition and 5-HT_2A/3-mediated potentiation of vascular noradrenergic neurotransmission in females. An i.v. bolus of different inhibitors/blockers of modulators/mediators (NO, K⁺ channels, prostanoids, Ang-II, or endothelin) was administered prior to the infusion of the agonists, L-694,247 (5-HT_1D), TCB-2 (5-HT_2A), or 1-PBG (5-HT₃), in female pithed rats. In these conditions, the vascular sympathetic outflow was electrically stimulated to assess the vasopressor responses. The L-694,247 vascular sympatho-inhibition was abolished by a non-selective K⁺ channel blocker, tetraethylammonium. The 1-PBG sympatho-excitatory vascular effect was not modified by any of the inhibitors tested, whereas TCB-2 sympatho-potentiation was blocked solely by losartan (Ang-II type 1 receptor antagonist). Moreover, Ang-II levels were increased after TCB-2 infusion in females. The EDH pathway mediates the 5-HT_1D-induced sympatho-inhibition, while the 5-HT_2A-evoked sympatho-excitatory effect is associated with Ang-II. In contrast, the 5-HT₃ sympatho-potentiation does not involve any indirect pathway. These findings advance current understanding of the complex interactions between 5-HT and vascular homeostasis in female rats. Full article

Background: Prostanoid FP receptor agonists (FP agonists) are widely used as first-line therapies for glaucoma but differ in their potential to induce prostaglandin-associated periorbitopathy (PAP), which may affect surgical outcomes. While several studies have reported an association between PAP and trabeculectomy failure, the impact of these agents on tube shunt procedures such as Ahmed glaucoma valve (AGV) implantation is not well established. Methods: We retrospectively analyzed 298 eyes of 221 patients who underwent trabeculectomy (n = 162) or AGV implantation (n = 136) between 2018 and 2023. The eyes were stratified by preoperative FP agonist use into the high-PAP-inducing-potential (bimatoprost or travoprost) and low-PAP-inducing-potential (latanoprost or tafluprost) groups. The primary outcome was the cumulative 2-year surgical survival rate under three intraocular pressure (IOP)-based definitions. Results: In the trabeculectomy group, the high-PAP-potential group had significantly lower 2-year survival rates than the low-PAP-potential group under all definitions. Cox proportional hazards analysis identified use of a high-PAP-potential FP agonist as a significant risk factor for surgical failure. In the AGV group, a difference between groups was seen only under the most lenient definition, with no differences under stricter criteria. Conclusions: The preoperative use of high-PAP-potential FP agonists is associated with poorer outcomes after trabeculectomy. Although the effect on AGV implantation appears limited, it may still influence early postoperative results. These findings underscore the need to consider PAP risk and medication history when selecting surgical procedures for glaucoma. Full article

Neuropathic pain is a chronic condition driven by intertwined mechanisms of oxidative stress, inflammation, and cellular senescence. Nerve injury and metabolic stress elevate reactive oxygen and nitrogen species, disrupt mitochondrial function, and activate the DNA-damage response, which stabilizes p53 and induces p16/p21-mediated cell-cycle arrest. These events promote a senescence-associated secretory phenotype (SASP) rich in cytokines, chemokines, and prostanoids that amplify neuroimmune signaling. In the spinal dorsal horn and dorsal root ganglia, microglia and astroglia respond to redox imbalance and danger cues by engaging NF-κB and MAPK pathways, increasing COX-2–dependent prostaglandin synthesis, and releasing mediators such as IL-1β and BDNF that enhance synaptic transmission and reduce inhibitory tone through KCC2 dysfunction. At the periphery, persistent immune-glial cross-talk lowers activation thresholds of nociceptors and sustains ectopic firing, while impaired autophagy and mitophagy further exacerbate mitochondrial dysfunction and ROS production. Collectively, these processes establish a feed-forward loop in which redox imbalance triggers senescence programs and SASP, SASP perpetuates neuroinflammation, and neuroinflammation maintains central sensitization—thereby consolidating a self-sustaining redox–senescence–inflammatory circuit underlying neuropathic pain chronicity. Full article

Distention of the urinary bladder wall during filling stretches the urothelium and induces the release of chemical mediators, including adenosine 5′-triphosphate (ATP) and prostaglandins (PGs), that transmit signals between cells within the bladder wall. The urothelium also releases soluble nucleotidases (s-NTDs) that control the availability of ATP and its metabolites at receptor sites in umbrella cells and cells deeper in the bladder wall, as well as in the urine. This study investigated whether PGs regulate the intravesical breakdown of ATP by s-NTDs. Using a murine decentralized mucosa-only bladder model and an HPLC technology with fluorescence detection, we evaluated the decrease in ATP and increase in ADP, AMP, and adenosine (ADO) in intraluminal solutions (ILS) collected at the end of physiological bladder filling. PGD₂, PGE₂, and PGI₂, but not PGF_2α, inhibited the conversion of AMP (produced from ATP) to ADO, likely due to a suppressed intravesical release of s-AMPases. The effects of exogenous PGD₂, PGE₂, and PGI₂ were mediated by DP1/DP2, EP2, and IP prostanoid receptors, respectively. Activation of either DP1 or DP2 receptors by endogenous PGD₂ also led to AMP increase and ADO decrease in ILS-containing ATP substrate. Finally, PGs produced by either COX-1 or COX-2 inhibited the hydrolysis of AMP to ADO. Together, these observations suggest that (1) endogenous PGs (chiefly PGD₂, and to lesser degree PGE₂ and PGI₂) allow release of s-NTDs like s-ATPases and s-ADPases but impede the formation of ADO from intravesical ATP by inhibiting the release of s-NTDs/s-AMPases; (2) it is possible that high concentrations of PGD₂, PGE₂ and PGI₂, as anticipated in inflammation or bladder pain syndrome, delay the ADO production and prolong the action of excitatory purine mediators; and (3) either COX-1 and COX-2 are constitutively expressed in the mouse bladder mucosa or COX-2 is induced by distention of the urothelium during bladder filling. Full article

Octocorals have proven to be a prolific source of bioactive natural products, exhibiting a wide spectrum of pharmacological activities. Among octocorals, Pennatulaceans, commonly known as sea pens, are among the most dominant soft coral species living in benthic communities. Nonetheless, reports on bioactivity and chemical investigations of this genus are scarce. This prompted us to shed light on the pharmacological potential of the extracts of the sea pen Pennatula phosphorea, Linneus 1758, and gain an overview of its metabolome. Crude octocoral extracts, obtained with a modified Kupchan extraction protocol, were assessed for their bioactivity potential, revealing the hexanic extract to exert anti-inflammatory effects and interesting protective properties in an in vitro model of sarcopenia and in auditory HEI-OC1 cisplatin-treated cells, while the chloroformic extract was active in reducing A375 melanoma cell viability in a concentration-dependent manner. An untargeted metabolomic analysis unveiled that P. phosphorea collects a wide array of glycerophospholipids and phosphosphingolipids belonging to the ceramide phosphoinositol class, which were exclusive or more abundant in the hexanic extract. Their proven anti-inflammatory and cytoprotective effects could demonstrate the activity shown by the P. phosphorea hexanic extract. In addition, a group of prostaglandins, eluted mainly in the chloroformic extract, were putatively annotated. Since prostanoids from marine origin have been demonstrated to exert cytotoxic and anti-proliferative properties against various cancer cell lines, the presence of PGs in the P. phosphorea chloroform extract could justify its anti-melanoma activity. This is the first report on the presence of glycerophospholipids, phosphosphingolipids, and prostaglandins, along with the identification of novel congeners, in sea pens. Full article

The increasing incidence of cutaneous squamous cell carcinoma (cSCC), together with the ominous risks of metastasis and recurrence, underscores the importance of identifying novel therapies and validated biomarkers to augment patient management, particularly in the context of well-established and advanced disease. Following a brief overview of the well-recognized epidemiology, clinical features, and diagnosis of cSCC, the current review is focused on risk factors, most prominently excessive exposure to ultraviolet radiation (UVR) as a cause of persistent, pro-tumorigenic mutagenesis, and immune suppression. The next phase of the review encompasses an evaluation of the search for key driver mutations in the pathogenesis of cSCC, including the role of these and other mutations in the formation of immunologically reactive neoepitopes. With respect to additional mechanisms of tumorigenesis, immune evasion is prioritized, specifically the involvement of cell-free and infiltrating cellular mediators of immune suppression. Prominent amongst the former are the cytokine, transforming growth factor-β1 (TGF-β1), the prostanoid, prostaglandin E2, and the emerging immune suppressive nucleoside adenosine. In the case of the latter, tumor-infiltrating and circulating regulatory T cells have been implicated as being key players. The final sections of the review are focused on an update of the immunotherapy of established and advanced disease, as well as on the search for novel, reliable lesional and systemic biomarkers with the potential to guide patient management. Full article

Xenogenic collagen matrices are used in clinical practice for soft tissue augmentation around teeth and implants, either alone or biofunctionalized with injectable platelet-rich fibrin (iPRF). Their direct interaction with inflammatory cells may influence both healing and destructive inflammation processes. Therefore, expression of cyclooxygenases (COX-1 and COX-2) and prostanoids (PGE2 and TXB2) was studied in THP-1 monocyte/macrophage cultures exposed to porcine collagen matrices (a non-cross-linked monolayer scaffold composed of collagen type I, collagen type III, and elastin (MLCM), a bilayer scaffold made of collagen types I and III (BLCM), and a volume-stable cross-linked monolayer scaffold (VSCM)). The study showed that VSCM and MLCM significantly reduced PGE2 concentrations in THP-1 monocyte cultures. iPRF further reduced PGE2 concentrations when exposed to MLCM. In contrast, incubation of THP-1 monocytes with VSCM and BLCM resulted in a significant increase in TXB2 concentrations compared with control conditions. Incubation of macrophages with MLCM, VSCM, and BLCM increased PGE2 concentrations, with VSCM and BLCM additionally increasing TXB2 concentrations. iPRF in macrophage cultures with VSCM and BLCM also resulted in increased PGE2 and TXB2 concentrations compared with control conditions. Confocal microscopy revealed no visible differences in COX-1 immunoexpression in monocytes and macrophages cultured with collagen matrices, either with or without iPFR. Weak positive COX-2 immunofluorescence was observed in monocytes, while moderate positive immunofluorescence was detected in macrophages. In conclusion, it can be suggested that the studied collagen matrices interact with monocytes/macrophages, with MLCM exhibiting the highest compatibility. Full article

The urothelium and lamina propria (LP) contribute to sensations of bladder fullness by releasing multiple mediators, including prostaglandins (PGs) and adenosine 5′-triphosphate (ATP), that activate or modulate functions of cells throughout the bladder wall. Mediators that are simultaneously released in response to bladder distention likely influence each other’s mechanisms of release and action. This study investigated whether PGs could alter the extracellular hydrolysis of ATP by soluble nucleotidases (s-NTDs) released in the LP of nondistended or distended bladders. Using an ex vivo murine detrusor-free bladder model to access the LP during bladder filling and a sensitive HPLC-FLD detection methodology, we evaluated the decrease in ATP and the increase in adenosine 5′-diphosphate (ADP), adenosine 5′-monophosphate (AMP), and adenosine by s-NTDs released in the LP. Endogenous PGE₂ increased the spontaneous but not the distention-induced release of s-NTD via EP2 and EP3 prostanoid receptors, whereas exogenous PGE₂ increased the spontaneous s-NTD release via EP3, EP4, and FP receptors and the distention-induced s-NTD release via EP1-4 and FP receptors. Endogenous PGF_2α, PGD₂, and PGI₂ did not change the s-NTD release. Exogenous PGD₂ increased the spontaneous s-NTD release via DP2 receptors and the distention-induced s-NTD release via DP1 and DP2 receptors. Exogenous PGF_2α increased the spontaneous but not the distention-induced release of s-NTD via FP receptors. It is possible that higher concentrations of PGE₂, PGF_2α, and PGD₂ (as expected in inflammation, bladder pain syndrome, or overactive bladder) potentiate the release of s-NTDs and the consecutive degradation of ATP as a safeguard mechanism to prevent the development of excessive bladder excitability and overactivity by high amounts of extracellular ATP. Full article

Background: Prostaglandins are naturally occurring local mediators that can participate in the modulation of the cardiovascular system through their interaction with Gs/Gi-coupled receptors in different tissues and cells, including platelets. Thrombin is one of the most important factors that regulates platelet reactivity and coagulation. Clinical trials have consistently shown that omega-3 fatty acid supplementation lowers the risk for cardiovascular mortality and morbidity. Since omega-3 fatty acids are the main precursors of PGE3 in vivo, it would be relevant to investigate the effects of PGE3 on Thrombin Receptor Activating Peptide (TRAP-6)-induced platelet reactivity to determine the receptors and possible mechanisms of action of these compounds. Methods: We have measured platelet aggregation, P-selectin expression, and vasodilator-stimulated phosphoprotein (VASP) phosphorylation to evaluate platelet reactivity induced by TRAP-6 to determine the effects of PGE3 on platelet function. Results: We assessed the ability of DG-041, a selective prostanoid EP3 receptor antagonist, and of ONO-AE3-208, a selective prostanoid EP4 receptor antagonist, to modify the effects of PGE3. PGE3 inhibited TRAP-6-induced platelet aggregation and activation. This inhibition was enhanced in the presence of a Gi-coupled EP3 receptor antagonist and abolished in the presence of a Gs-coupled EP4 receptor antagonist. The effects of PGE3 were directly related to changes in cAMP, assessed by VASP phosphorylation. Conclusions: The general effects of PGE3 on human platelet reactivity are the consequence of a balance between activatory and inhibitory effects at receptors that have contrary effects on adenylate cyclase. These results indicate a potential mechanism by which omega-3 fatty acids underlie cardioprotective effects. Full article

In patients with aspirin-exacerbated respiratory disease (AERD), there is disparate regulation of prostaglandin E2 (PGE₂) and prostaglandin D₂ (PGD₂). Both prostanoids are synthesised by cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2). However, while the basal synthesis of PGE₂ tends to decrease, that of PGD₂ increases in patients with AERD. Furthermore, both behave differently in response to the inhibitory action of NSAIDs on COX-1: PGE₂ levels decrease while PGD₂ increases. Increased PGD₂ release correlates with nasal, bronchial, and extra-pulmonary symptoms caused by aspirin in AERD. The proposed hypothesis establishes that the answer to this paradoxical dissociation can be found in the airway epithelium. This is based on the observation that reduced COX-2 mRNA and/or protein expression is associated with reduced PGE₂ synthesis in cultured fibroblast and epithelial cells from AERD compared to patients with asthma who are aspirin-tolerant and healthy subjects. The low production of PGE₂ by the airway epithelium in AERD results in an excessive release of alarmins (TSLP, IL-33), which in turn contributes to activating group 2 innate lymphoid cells (ILC2s) and PGD₂ synthesis by mast cells and eosinophils. Aspirin, by further increasing the diminished PGE₂ regulation capacity in AERD, leads to respiratory reactions associated with the surge in PGD₂ from mast cells and eosinophils. In summary, the downregulation of COX-2 and the subsequent low production of PGE₂ by airway cells account for the apparently paradoxical increased production of PGD₂ by mast cells and eosinophils at the baseline and after aspirin provocation in patients with AERD. A better understanding of the role of the airway epithelium would contribute to elucidating the mechanism of AERD. Full article

Background: Prokinetic agents are effective in increasing gastrointestinal (GI) contractility and alleviating constipation, often caused by slow intestinal motility. Lubiprostone (LUB), known for activating CLC-2 chloride channels, increases the chloride ion concentration in the GI tract, supporting water retention and stool movement. Despite its therapeutic efficacy, the exact mechanisms underlying its pharmacological action are poorly understood. Here, we investigated whether LUB activates the canonical transient receptor potential cation channel type 4 (TRPC4) through stimulation with E-type prostaglandin receptor (EP) type 3. Methods: Using isotonic tension recordings on mouse colon strips, we examined LUB-induced contractility in both proximal and distal colon segments. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine mRNA levels of EP1-4 receptor subtypes in distal colonic muscular strips and isolated myocytes. The effects of a TRPC4 blocker and EP3 antagonist on LUB-stimulated contractions were also evaluated. Results: LUB showed significant contraction in the distal segment compared to the proximal segment. EP3 receptor mRNA levels were highly expressed in the distal colon tissue, which correlated with the observed enhanced contraction. Furthermore, LUB-induced spontaneous contractions in distal colon muscles were reduced by a TRPC4 blocker or EP3 antagonist, indicating that LUB-stimulated EP3 receptor activation may lead to TRPC4 activation and increased intracellular calcium in colonic smooth muscle. Conclusions: These findings suggest that LUB improves mass movement through indirect activation of the TRPC4 channel in the distal colon. The segment-specific action of prokinetic agents like LUB provides compelling evidence for a personalized approach to symptom management, supporting the defecation reflex. Full article