Resolvin Research Articles

Semaphorin3B promotes an anti-inflammatory and pro-resolving phenotype in macrophages from rheumatoid arthritis patients in a MerTK-dependent manner.

Previous works from our group show that Semaphorin3B (Sema3B) is reduced in RA and plays a protective role in a mouse arthritis model. In turn, MerTK plays a protective function in murine arthritis models, is expressed by synovial tissue macrophages and is linked to remission in patients with RA. In this study, we examined the role of Sema3B in the phenotypic characteristics of RA macrophages and the implication of MerTK. Peripheral blood monocytes from RA patients were differentiated into IFN-γ (RA MØIFN-γ) or M-CSF (RA MØM-CSF) macrophages and stimulated with LPS, Sema3B or their combination. Alternatively, RA fibroblast like synoviocytes (FLS) were stimulated with RA MØIFN-γ and RA MØM-CSF supernatants. Gene expression was determined by qPCR and protein expression and activation by flow cytometry, ELISA and western blot. Sema3B down-regulated the expression of pro-inflammatory mediators, in both RA MØIFN-γ and RA MØM-CSF. We observed a similar reduction in RA FLS stimulated with the supernatant of Sema3B-treated RA MØIFN-γ and RA MØM-CSF. Sema3B also modulated cell surface markers in macrophages towards an anti-inflammatory phenotype. Besides, MerTK expression and activation was up-regulated by Sema3B, just as GAS6 expression, Resolvin D1 secretion and the phagocytic activity of macrophages. Importantly, the inhibition of MerTK and neuropilins 1 and 2 abrogated the anti-inflammatory effect of Sema3B. Our data demonstrate that Sema3B modulates the macrophage characteristics in RA, inducing a skewing towards an anti-inflammatory/pro-resolving phenotype in a MerTK-dependant manner. Therefore, here we identify a new mechanism supporting the protective role of Sema3B in RA pathogenesis.

ChemR23 signaling ameliorates brain injury via inhibiting NLRP3 inflammasome-mediated neuronal pyroptosis in ischemic stroke

BackgroundInflammatory response has been recognized as a pivotal pathophysiological process during cerebral ischemia. ChemR23 signaling is involved in the pathophysiology of various inflammatory diseases. Nevertheless, the role of ChemR23 signaling in ischemic stroke remains largely unknown.MethodsPermanent ischemic stroke mouse model was accomplished by middle cerebral artery occlusion (MCAO). Resolvin E1 (RvE1) or chemerin-9 (C-9), the agonists of ChemR23, were administered by intracerebroventricular (i.c.v) injection before MCAO induction. Then, analysis of neurobehavioral deficits and brain sampling were done at Day 1 after MCAO. The brain samples were further analyzed by histological staining, immunofluorescence, RNA sequencing, ELISA, transmission electron microscope, and western blots. Furthermore, oxygen–glucose deprivation (OGD) was employed in SH-SY5Y to mimic MCAO in vitro, and ChemR23 signaling pathway was further studied by overexpression of ChemR23 or administration of related agonists or antagonists. Analysis of cell death and related pathway markers were performed.ResultsChemR23 expression was upregulated following MCAO. Under in vitro and in vivo ischemic conditions, ChemR23 deficiency or inhibition contributed to excessive NLRP3-mediated maturation and release of IL-1β and IL-18, as well as enhanced cleavage of GSDMD-N and neuronal pyroptosis. These influences ultimately aggravated brain injury and neuronal damage. On the other hand, ChemR23 activation by RvE1 or C-9 mitigated the above pathophysiological abnormalities in vivo and in vitro, and overexpression of ChemR23 in SH-SY5Y cells also rescued OGD-induced neuronal pyroptosis. Blockade of NLRP3 mimics the protective effects of ChemR23 activation in vitro.ConclusionOur data indicated that ChemR23 modulates NLRP3 inflammasome-mediated neuronal pyroptosis in ischemic stroke. Activation of ChemR23 may serve as a promising potential target for neuroprotection in cerebral ischemia.

Simulated Microgravity Affects Pro-Resolving Properties of Primary Human Monocytes.

Space-related stressors such as microgravity are associated with cellular and molecular alterations of the immune and inflammatory homeostasis that have been linked to the disorders that astronauts suffer from during their missions. Most of the research of the past 30 years has consistently established that innate adaptive immune cells represent a target of microgravity, which leads to their defective or dysfunctional activation, as well as to an altered ability to produce soluble mediators-e.g., cytokines/chemokines and bioactive lipids-that altogether control tissue homeostasis. Bioactive lipids include a vast array of endogenous molecules of immune origin that control the induction, intensity and outcome of the inflammatory events. However, none of the papers published so far focus on a newly characterized class of lipid mediators called specialized pro-resolving mediators (SPMs), which orchestrate the "resolution of inflammation"-i.e., the active control and confinement of the inflammatory torrent mostly driven by eicosanoids. SPMs are emerging as crucial players in those processes that avoid acute inflammation to degenerate into a chronic event. Given that SPMs, along with their metabolism and signaling, are being increasingly linked to many inflammatory disorders, their study seems of the outmost importance in the research of pathological processes involved in space-related diseases, also with the perspective of developing therapeutic countermeasures. Here, we show that microgravity, simulated in the rotary cell culture system (RCCS) developed by NASA, rearranges SPM receptors both at the gene and protein level, in human monocytes but not in lymphocytes. Moreover, RCCS treatment reduces the biosynthesis of a prominent SPM like resolvin (Rv) D1. These findings strongly suggest that not only microgravity can impair the functioning of immune cells at the level of bioactive lipids directly involved in proper inflammation, but it does so in a cell-specific manner, possibly perturbing immune homeostasis with monocytes being primary targets.

Increased Resolvin E1 Production by Peripheral Blood Mononuclear Cells in Periodontitis Patients: Pilot Study.

This study quantified the production of the pro-resolving agent Resolvin E1 by peripheral blood mononuclear cells (PBMC) from 20 systemically healthy volunteers with and without periodontitis after stimulation with lipopolysaccharide (LPS) from Porphyromonas gingivalis (Pg). Ten periodontitis patients and 10 healthy volunteers (30-50 years old), matched by age and sex, were recruited. Peripheral blood mononuclear cells were isolated and stimulated in culture plates for 24 hours with Pg LPS. Resolvin E1 levels were measured in the supernatants by enzyme-linked immunosorbent assay. Significantly higher production of Resolvin E1 was observed in both groups when stimulated with LPS compared to baseline levels (p<0.001). A significant increase in Resolvin E1 was observed in the presence of Lipopolysaccharide in the patients with periodontitis compared to the healthy group (p=0.0019). Resolvin E1 levels may reflect a measure of resolution of inflammation that warrants further clinical investigation.

Impact of Specialized Pro-Resolving Lipid Mediators on Craniofacial and Alveolar Bone Regeneration: Scoping Review.

Craniofacial bone defects caused by tumors, trauma, long-term tooth loss, or periodontal disease are a major challenge in the field of tissue engineering. In periodontitis and peri-implantitis, reconstructive therapy is also a major challenge for the dental surgeon. Lipoxins, resolvins, protectins, and maresins, known as specialized pro-resolving lipid mediators (SPMs), have been widely studied in the field of dental, oral, and craniofacial research for bone regeneration for their actions in restoring tissue homeostasis and promoting tissue healing and regeneration. Therefore, this study focuses on a survey of the use of SPMs for craniofacial and alveolar bone regeneration. Thus, electronic searches of five databases were performed to identify pre-clinical studies that evaluated the actions of SMPs on craniofacial and alveolar bone regeneration. Of the 523 articles retrieved from the electronic databases, 19 were included in the analysis. Resolvin (Rv) E1 was the mostly assessed SPM (n=8), followed by maresins (Ma) R1 (n=3), lipoxins (Lx) A4 (n=3), RvD1 (n=3), RvD2 (n=1), LxB4 (n=1), and maresin (M)-CTR3 (n=1). Meta-analysis showed that SPMs increased the newly formed bone by 14.85% compared to the control group (p<0.00001), decreased the area of the remaining defect by 0.35 mm2 (p<0.00001), and decreased the linear distance between the defect to the bone crest by 0.53 mm (p<0.00001). RvE1 reduced inflammatory bone resorption in periodontal defects and calvarial osteolysis and enhanced bone regeneration when RvE1 was combined with a bovine bone graft. RvD2 induced active resolution of inflammation and tissue regeneration in periapical lesions, while RvD1 controlled the inflammatory microenvironment in calvarial defects in rats, promoting bone healing and angiogenesis. MaR1 induced the proliferation and migration of mesenchymal stem cells, osteogenesis, and angiogenesis in calvarial defects, and benzo (b)-LxA4 and LxA4 promoted bone regeneration calvarial and alveolar bone defects in rats, inducing regeneration under inflammatory conditions. In summary, SPMs have emerged as pivotal contributors to the resolution of inflammation and the facilitation of bone neoformation within craniofacial and alveolar bone defects. These results are based on pre-clinical studies, in vivo and in vitro, and provide an updated review regarding the impact of SPMs in tissue engineering.

Chemokine‑like receptor 1‑positive cells are present in the odontoblast layer in tooth tissue in rats and humans.

Cluster of differentiation (CD)44 is a marker of dental pulp stem cells and is involved in odontoblast differentiation and calcification. Chemokine-like receptor 1 (CMKLR1), also known as chemerin receptor 23 (ChemR23) is also expressed in odontoblasts and dental pulp stem cells and is involved in inflammation suppression and tooth regeneration. Resolvin E1, a bioactive lipid, is a CMKLR1 ligand that mediates the chemerin-CMKLR1 interaction and suppresses pulpal inflammation. The present study clarified the intracellular and tissue localization of CD44 and CMKLR1 by immunohistochemical staining of normal pulp and pulp with pulpitis from 12-week-old male Wistar rat teeth or human teeth. In addition, the localization of CD44 and CMKLR1 in human dental pulp stem cells was observed by immunofluorescence staining. The present study also examined the involvement of resolvin E1 in inhibiting inflammation and calcification by western blotting. CD44- and CMKLR1-positive cells were confirmed in the odontoblast layer in normal dental pulp of rats and humans. CD44 was mainly localized in the cell membrane and CMKLR1 was mainly found in the cytoplasm of human dental pulp stem cells. CMKLR1 was also confirmed in the odontoblast layer in rats and humans with pulpitis but CD44 was not present. Following treatment of dental pulp stem cells with lipoteichoic acid, which imitates Gram-positive bacterial infection, resolvin E1 did not suppress the expression of cyclooxygenase-2 or of the odontoblast differentiation marker, dentin sialophosphoprotein. Furthermore, resolvin E1 induced the differentiation of dental pulp stem cells into odontoblasts even in the presence of the inflammatory stimulus.

Modulating the sEH/EETs Axis Restrains Specialized Proresolving Mediator Impairment and Regulates T Cell Imbalance in Experimental Periodontitis.

Epoxyeicosatrienoic acids (EETs) and other epoxy fatty acids are short-acting lipids involved in resolution of inflammation. Their short half-life, due to its metabolism by soluble epoxide hydrolase (sEH), limits their effects. Specialized proresolving mediators (SPMs) are endogenous regulatory lipids insufficiently synthesized in uncontrolled and chronic inflammation. Using an experimental periodontitis model, we pharmacologically inhibited sEH, examining its impact on T cell activation and systemic SPM production. In humans, we analyzed sEH in the gingival tissue of periodontitis patients. Mice were treated with sEH inhibitor (sEHi) and/or EETs before ligature placement and treated for 14 d. Bone parameters were assessed by microcomputed tomography and methylene blue staining. Blood plasma metabololipidomics were carried out to quantify SPM levels. We also determined T cell activation by reverse transcription-quantitative PCR and flow cytometry in cervical lymph nodes. Human gingival samples were collected to analyze sEH using ELISA and electrophoresis. Data reveal that pharmacological sEHi abrogated bone resorption and preserved bone architecture. Metabololipidomics revealed that sEHi enhances lipoxin A4, lipoxin B4, resolvin E2, and resolvin D6. An increased percentage of regulatory T cells over Th17 was noted in sEHi-treated mice. Lastly, inflamed human gingival tissues presented higher levels and expression of sEH than did healthy gingivae, being positively correlated with periodontitis severity. Our findings indicate that sEHi preserves bone architecture and stimulates SPM production, associated with regulatory actions on T cells favoring resolution of inflammation. Because sEH is enhanced in human gingivae from patients with periodontitis and connected with disease severity, inhibition may prove to be an attractive target for managing osteolytic inflammatory diseases.

Combinatorial Treatment by NPD1 Plus RvD1 Elicits Neurobehavioral Recovery and Increases Homeostatic Gene Expression after Experimental Ischemic Stroke

Stroke is the second leading cause of death worldwide and a high proportion of those who survive stroke develop severe cognitive impairments. Current therapies, tissue plasminogen activator (tPA) and thrombectomy, are ineffective for most patients affected by stroke. This research explores mechanisms and examines the potential of combined Neuroprotectin D1 (NPD1) and Resolvin D1 (RvD1) treatment in ischemic stroke.

ELV-N34 or RvD6-isomer Counteracts Damaging Astrocyte Phenotypes Protecting the Brain from Omicron BA.5 Sequelae

Neurodegenerative diseases induce astrocyte phenotypes that trigger inflammation and cell damage. This cell induction also takes place in post-acute neurological syndrome from SARS-CoV-2 infection. We found that the secretome from Omicron BA.5 infected human nasal epithelial or human lung cells induced the activation of human astrocytes to a reactive pro-inflammatory phenotype as defined by nuclear translocation of NF-kB/p65. Remarkably, the secretome from these cells incubated with Elovanoid (ELV)-N34 or Resolvin D6 (RvD6)-isomer (500nM) did not trigger the formation of reactive astrocytes. One of the factors involved is CXCL1, secreted by Omicron BA.5-infected nasal epithelial cells. So, when CXCL1 was administered intranasally to mice along with Interferon type I, the infiltration of fluorescein indicated a permeabilization of the neurovascular unit. Astrocytes are close to this barrier and contribute to restricting the access of damaging molecules to the brain parenchyma. Together, these results point to a specific way of entry of chemokines and cytokines as part of the secretome from infected cells that may play a role in long COVID brain sequelae.

Associations Between Resolvin D1 and Culprit Plaque Morphologies: An Optical Coherence Tomography Study in Patients with ST-Segment Elevation Myocardial Infarction.

As a specialized pro-resolving lipid mediator, resolvin D1 (RvD1) inhibits atherosclerosis progression in vivo by reducing regional oxidative stress and chronic inflammation. However, it is unclear how RvD1 is involved in human coronary artery disease. This study aims to investigate the association between plasma levels of RvD1 and culprit-plaque characteristics in patients with ST-segment elevation myocardial infarction (STEMI). A total of 240 STEMI patients undergoing optical coherence tomography (OCT) examination were analyzed. RvD1 levels were measured in patient plasma samples using an enzyme-linked immunosorbent assay. Logistic regression was performed to assess the association between RvD1 levels and various culprit plaque morphologies, and the receiver operating curve was used to search for an optimal cutoff threshold to predict certain pathological features. The median RvD1 level was 129.7 (56.6-297.8) pg/mL. According to multivariable logistic regression, high RvD1 was associated with plaque rupture (≥111.5 pg/mL, odds ratio [OR]: 2.09, 95% confidence interval [CI]: 1.20-3.66, P = 0.010), healed plaques (≥246.4 pg/mL, OR: 2.17, 95% CI: 1.11-4.24, P = 0.023), and calcification (≥293.38 pg/mL, OR: 2.10, 95% CI: 1.21-3.66, P = 0.008) at culprit lesions. Increased levels of RvD1 were associated with higher instability of coronary atherosclerotic plaques in STEMI patients.

Signatures of resolution reprogramming in amyloid‐challenged microglia

AbstractBackgroundSpecialized pro‐resolving mediators (SPMs) promote inflammatory resolution and homeostasis and are thought to have specific reprogramming effects on innate immune cells like monocytes and microglia. Decreased SPM levels have been correlated with chronic neuroinflammation, late‐stage Alzheimer’s disease (AD) and neuropathology in humans, yet few studies have explored the signatures ofMethodThe Ts65Dn mouse develops amyloid hyperexpression, neuroinflammation and neurodegeneration. We administered the SPM, Resolvin E1 (RvE1), for 1 month to control and Ts65Dn mice and measured memory using a series of tasks. We quantified resolution signaling responses using standard immunoblot. We measured microglial activation using immunofluorescence and cell characterization software. We then challenged Human innate immune cell culture models (monocytes and microglia) with amyloid‐beta and tau oligomer activation and/or administered RvE1 to promote resolution. We will employ RNASeq to learn how RvE1 resolution reprogramming affects transcriptional outcomes in these cell culture models.ResultRvE1 significantly reduced microglial activation and cytokine expression in the Ts65Dn mice, suggesting broad effects on central and peripheral innate immunity. We discovered that chronic RvE1 leads to compensatory response in specific G protein coupled receptors within the resolution family and in the PPAR‐gamma receptor and to specific signaling events. We are quantifying transcriptional outcomes to better define the nuclear program that underlies resolution.ConclusionWe have demonstrated that RvE1 modulates inflammation in a mouse model. Understanding the molecular signatures of resolution reprogramming in cells will be key to identifying prognostic indicators and molecular mechanisms.

Abstract A172: TP-317, a first-in-class resolvin E1 small molecule, drives adjuvant efficacy in solid tumors by engaging innate and adaptive anti-tumor immunity in the tumor microenvironment (TME) and has neoadjuvant potential

Abstract Background: TP-317 is a novel salt of resolvin E1 (RvE1), an endogenous lipid agonist of ChemR23 that stimulates tumor debris phagocytosis/clearance by myeloid cells (Sulciner et al., 2018, J.Exp.Med). We recently reported TP-317 anti-tumor efficacy in murine solid tumors as monotherapy and in combination with immune checkpoint inhibitors (ICI) and chemotherapy (Kipper, 2023, Can. Res, 83 (7_Supp: 1135). Here we elaborate on the mechanism of action (MOA) of TP-317 in the adjuvant setting and report TP-317 efficacy in a neoadjuvant regimen Methods: 125-240 mm3 established subcutaneous murine melanoma (B16F10) and pancreatic (Panc02-H7; KPC) tumors were treated with placebo, TP-317 or ICI and tumors excised at 12-14 days for bulk RNAseq or flow cytometry. Placebo, TP-317 (300 ug/kg s.c. 2 hr prior to and Q6D after resection), cisplatin (5 mg/kg i.p. 24 hrs prior to resection) or anti-PD1 (8 mg/kg i.p. 24 hr prior to resection only) or TP-317 + anti-PD1 were evaluated in the LLC lung tumor model with tumors resected when reaching ~ 1500 mm3. Endpoints were lung/lymph node metastases or survival. Results: RNAseq analysis showed that adjuvant TP-317 broadly engages innate (macrophage, dendritic, NK cells) and adaptive (CD8, CD4, B cells) immune pathways in the TME of PANC2-H7, KPC and B16F10 models. Depletion studies suggest TP-317 efficacy is CD8- and NK cell-dependent, consistent with the RNAseq data and flow cytometry, which confirmed expression of ChemR23 (RvE1 receptor) on M1/M2 macrophages, conventional cDC1/cDC2, NK and lymphoid subsets. In the TME of PANC2-H7, KPC and B16-F10 models, TP-317 induced a gene signature with upregulated IFNg responses, effector CD8/NK receptors, antigen-presenting pathways, cDC1/NK cell cross-talk, and chemokines/cytokines involved in anti-tumor immunity. In the B16F10 model TP-317 + dual ICI combined therapy synergistically upregulated an IFNg response signature relative to dual ICI therapy. In the LLC resection model, TP-317 monotherapy reduced lung (p&amp;lt;0.05) and lymph node metastases (p&amp;lt;0.01) 19 days post-resection, but cisplatin was not effective. Neoadjuvant cisplatin or anti-PD1 monotherapy did not improve survival relative to placebo, but TP-317 combined with neoadjuvant anti-PD1 induced long term survival (&amp;gt;100 days) in 3 of 7 treated mice (p &amp;lt;0.05 vs placebo or anti-PD1). Conclusions: In adjuvant therapy of murine tumors, TP-317 broadly modulates innate/adaptive immune cell compartments in the TME, consistent with resetting the immunogenic tone and favoring anti-tumor immunity. Mechanistic synergy was observed for TP-317 combined with dual ICI therapy. TP-317 monotherapy shows metastasis control when initated prior to surgical resection and long term survival when combined with neoadjuvant anti-PD1 in the LLC model of NSCLC. Citation Format: John F Parkinson, Eva Rothenberger, Abigail Kelly, Diane Bielenberg, Ahmed Attaya, Sui Huang, Lance Pflieger, Wayne Klohs, Gary Mathias, Dipak Panigrahy. TP-317, a first-in-class resolvin E1 small molecule, drives adjuvant efficacy in solid tumors by engaging innate and adaptive anti-tumor immunity in the tumor microenvironment (TME) and has neoadjuvant potential [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A172.

The relationship between hepatocellular carcinoma and Resolvin D1

Aims: Liver cancer is the second most common cause of cancer death, and hepatocellular carcinoma (HCC) is the most common hepatic primary tumor. Hepatocellular carcinoma develops based on inflammation in the cirrhotic liver. The aim of our study was to determine the relationship between the decrease in Resolvin D1, the lipid mediator involved in the resolution, and hepatocarcinogenesis. Methods: Thirty patients with HCC, thirty patients with cirrhosis, and thirty healthy subjects followed in our clinic between March 2018 and June 2019 were included in the study. Routine laboratory test results of the patients were recorded from the institutional database. Resolvin D1 and other parameters of the study groups were compared. Results: The Resolvin D1 levels were found to be significantly different from each other group, with the ranking as follows: the HCC group (1.71 ± 1.46 ng/ml)&lt; the cirrhotic group (3.63 ± 2.92 ng/ml)&lt; the healthy control group (6.24 ± 3.18 ng/ml). Moreover, Resolvin D1 levels were negatively correlated with ?-fetoprotein (AFP) level and tumor stage. Conclusion: Reduced lipid mediators that aid in the resolution process cause an increase in pro-inflammatory cytokines involved in the development of hepatocellular carcinoma. A decrease in Resolvin D1 may serve as a biomarker contributing to the diagnosis of progression to HCC in cirrhotic patients by triggering chronic inflammation and hepatocarcinogenesis.

Resolvin-D1 (RvD1) and Its Association with Markers of Inflammation, Endothelial Activation, Hemolysis and Clinical Correlates in Children with Sickle Cell Disease (SCD)

Introduction: Sickle Cell Disease (SCD) is an inflammatory and vaso-occlusive pathology. Multiple lipid mediators: resolvins, protectins and maresins, collectively known as Specialized Pro-resolving Mediators (SPMs), that are biosynthesized from Omega-3-PolyUnsaturated Fatty Acids (O3PUFAs), docosahexaenoic acid and eicosapentaenoic acid, appear to play a role in the resolution of inflammation. In a recent study, we have documented the presence of SPMs including Resolvin-D1 (RvD1), 17R-RvD3, and their pathway markers in plasma from both children with SCD and age-and race-matched controls with a significant increase in RvD1 levels noted in plasma from children with SCD. In an SCD mouse model exposed to hypoxia/reoxygenation, a previous study has shown that oral administration of 17R-RvD1, the longer acting isomer of RvD1, promotes resolution of SCD-associated inflammation and tissue damage. Objectives: We assessed whether there were any associations in children with SCD between baseline plasma levels of RvD1 and either markers of inflammation, endothelial activation and hemolysis or SCD-related clinical correlates. Methods: Multiplex assays were employed to assess endothelial activation markers (soluble adhesion molecules VCAM-1, ICAM-1 and E-selectin), and inflammatory cytokines (IL-1β, IL-4, IL-6, IL-10, TNF-α and CRP) in plasma. A 3-year retrospective review of individual SCD patient records was performed, and the number of painful episodes of vaso-occlusion or VOC, including those complicated by the occurrence of acute chest syndrome (ACS) were recorded. Total cumulative painful episodes over a 3-year period were included in the analysis. Spearman Rank Correlation was employed to assess the association between two variables. Results: Consistent with the published results, levels of endothelial activation markers (soluble VCAM-1 and soluble E-selectin), cytokines (IL-4, IL-6 and TNF-α), CRP and LDH were increased in SCD plasma compared to controls (Table-1). No significant associations were found in SCD between RvD1 or other lipid mediators and markers of endothelial activation or inflammation (Table-2). However, there were two significant associations noted between 5-HEPE and IL-1β, and between 12-HETE and IL-6. Plasma levels of the hemolytic marker LDH positively correlated with PGE2, TxB2, 7-HDHA, 5-HEPE and 5-HETE (Table-2). Review of medical history revealed 33 of 45 subjects (73%) had at least one VOC episode, and 17 (38%) had at least one ACS episode in the past 3 years. Subjects who had at least one ACS episode in the past 3 years also reported at least one VOC episode during the same period. There was no statistically significant difference in the RvD1 level by VOC [median RvD1 (ng/ml) of 0.056 in VOC -ve sub-group (n=12) vs 0.084 in VOC +ve sub-group (n=33), p=0.748] or ACS history [median RvD1 (ng/ml) of 0.060 in ACS -ve sub-group (n=28) vs 0.104 in ACS +ve sub-group (n=17), p=0.256]. There was no statistically significant association between levels of RvD1 and the total number of VOC/ACS in the past 3 years (correlation coefficient = -0.06, p=0.694). Summary and Conclusions: Because of the documented pro-resolving and anti-inflammatory effects of orally administered 17R-RvD1 in a mouse model of SCD, and elevated basal plasma levels of RvD1 in children with SCD, we investigated whether endogenous RvD1 provides protection against inflammation and clinical complications in SCD children. Other lipid mediators, which were synthesized from O3PUFAs and arachidonic acid, present in increased levels in SCD plasma and potentially involved in modulation of inflammation were also included in the analysis. Unlike in SCD mouse model in which exogenous RvD1 exerted anti-inflammatory effect in ex-vivo experiments and orally administered 17R-RvD1 promoted resolution of inflammation and down-regulated adhesion molecule expression and cytokine production, endogenous RvD1 did not show any significant association with markers of inflammation and endothelial activation or clinical correlates in a small group of SCD children under healthy condition. No significant findings were noted with other lipid mediators. Whether these lipid mediators modulate inflammation during crisis, pre- or post-crisis clinical conditions and whether their production is different during these clinical conditions compared to steady state healthy condition require further investigation.

Effect of Intra-ovarian Injection of Mesenchymal Stem Cells or its Conditioned Media on Repeated OPU-IVEP Outcomes in Jersey Heifers and Its Relationship with Follicular Fluid Inflammatory Markers.

Repeated Ovum Pick Up (OPU) could have a detrimental effect on ovarian function, reducing In Vitro Embryo Production (IVEP). The present study examined the therapeutic effect of adipose-derived Mesenchymal Stem Cells (MSCs) or its Conditioned Medium (ConM) on ovarian trauma following repeated OPU. Resolvin E1 (RvE1) and Interleukin-12 (IL-12) were investigated as biomarkers. Jersey heifers (n=8) experienced 11 OPU sessions including 5 pre-treatment and 6 treatment sessions. Heifers received intra-ovarian administration of MSCs or ConM (right ovary) and Dulbecco's Modified Phosphate Buffer Saline (DMPBS; left ovary) after OPU in sessions 5 and 8 and 2 weeks after session 11. The concentrations of RvE1 and IL-12 in follicular fluid was evaluated on sessions 1, 5, 6, 9, and 4 weeks after session 11. Following each OPU session, the IVEP parameters were recorded. Intra-ovarian administration of MSCs, ConM, and DMPBS did not affect IVEP parameters (p>0.05). The concentration of IL-12 in follicular fluid increased at the last session of pre-treatment (Session 5; p<0.05) and remained elevated throughout the treatment period. There was no correlation between IL-12 and IVEP parameters (p>0.05). However, RvE1 remained relatively high during the pre-treatment and decreased toward the end of treatment period (p<0.05). This in turn was associated with decline in some IVEP parameters (p<0.05). Intra-ovarian administration of MSCs or ConM during repeated OPU did not enhance IVEP outcomes in Bos taurus heifers. The positive association between RvE1 and some of IVEP parameters could nominate RvE1 as a promising biomarker to predict IVEP parameters following repeated OPU.

Serum resolvin D1 potentially predicts neurofunctional recovery, the risk of recurrence and death in patients with acute ischemic stroke.

Resolvin D1 (RvD1) represses inflammation, oxidative damage and neural injury related to acute ischemic stroke (AIS) progression. The present study aimed to explore the association of serum RvD1 with disease features, neurological recovery and prognosis in patients with AIS. A total of 212 patients with newly diagnosed AIS, whose serum RvD1 was quantified at admission and at discharge using an ELISA were enrolled in the current study. The modified Rankin scale (mRS) score was noted at 3 months after patient enrolment (M3), and patients were followed up for a median duration of 11.4 (range, 1.1-21.0) months. The median RvD1 in patients with AIS at admission was 1.07 (range, 0.11-9.29) ng/ml and it was negatively correlated with the neutrophil/lymphocyte ratio (r=-0.160; P=0.009) and C-reactive protein level (r=-0.272; P<0.001), but it was not correlated with comorbidities or other biochemical indexes. RvD1 at admission was lower in patients with mRS >2 at M3 (P=0.001), recurrence (P=0.001) or death (P=0.032) compared with that in patients without the aforementioned characteristics, which had a general ability to estimate mRS >2 at M3 [area under curve (AUC), 0.633], as well as lower risk of recurrence (AUC, 0.745) and death (AUC, 0.757) according to receiver operator characteristic (ROC) curve analyses. The median RvD1 was raised to 1.70 (range, 0.30-16.62) ng/ml at discharge. RvD1 at discharge was able to forecast mRS >2 at M3 (AUC, 0.678) and was able to predict the risk of recurrence (AUC, 0.796) and death (AUC, 0.826) in the ROC curve analyses. Increased serum RvD1 was associated with an attenuated inflammation status, and predicted improved neurological recovery, and lower risk of recurrence and death in patients with AIS. More specifically, its level at discharge exhibits a better prognostic utility than that at admission.

Lipid mediator resolvin D2 inhibits ATP currents in rat primary sensory neurons.

Resolvin D2 (RvD2), an endogenous lipid mediator derived from docosahexaenoic acid, has been demonstrated to have analgesic effects. However, little is known about the mechanism underlying RvD2 in pain relief. Herein, we demonstrate that RvD2 targeted the P2X3 receptor as an analgesic. The electrophysiological activity of P2X3 receptors was suppressed by RvD2 in rat dorsal root ganglia (DRG) neurons. RvD2 pre-application dose-dependently decreased α,β-methylene-ATP (α,β-meATP)-induced inward currents. RvD2 remarkably decreased the maximum response to α,β-meATP, without influencing the affinity of P2X3 receptors. RvD2 also voltage-independently suppressed ATP currents. An antagonist of the G protein receptor 18 (GPR18), O-1918, prevented the RvD2-induced suppression of ATP currents. Additionally, intracellular dialysis of the Gαi/o -protein antagonist pertussis toxin (PTX), the PKA antagonist H89, or the cAMP analog 8-Br-cAMP also blocked the RvD2-induced suppression. Furthermore, α,β-meATP-triggered depolarization of membrane potential along with the action potential bursts in DRG neurons were inhibited by RvD2. Lastly, RvD2 attenuated spontaneous nociceptive behaviors as well as mechanical allodynia produced by α,β-meATP in rats via the activation of the peripheral GPR18. These findings indicated that RvD2 inhibited P2X3 receptors in rat primary sensory neurons through GPR18, PTX-sensitive Gαi/o -proteins, and intracellular cAMP/PKA signaling, revealing a novel mechanism that underlies its analgesic effects by targeting P2X3 receptors.

Arachidonate 15-lipoxygenase-mediated production of Resolvin D5n-3 DPA abrogates pancreatic stellate cell-induced cancer cell invasion.

Activation of pancreatic stellate cells (PSCs) to cancer-associated fibroblasts (CAFs) is responsible for the extensive desmoplastic reaction observed in PDAC stroma: a key driver of pancreatic ductal adenocarcinoma (PDAC) chemoresistance leading to poor prognosis. Specialized pro-resolving mediators (SPMs) are prime modulators of inflammation and its resolution, traditionally thought to be produced by immune cells. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based lipid mediator profiling PSCs as well as primary human CAFs express enzymes and receptors to produce and respond to SPMs. Human PSC/CAF SPM secretion profile can be modulated by rendering these cells activated [transforming growth factor beta (TGF-β)] or quiescent [all-trans retinoic acid (ATRA)]. ATRA-induced nuclear translocation of arachidonate-15-lipoxygenase (ALOX15) was linked to increased production of n-3 docosapentaenoic acid-derived Resolvin D5 (RvD5n-3 DPA), among other SPMs. Inhibition of RvD5n-3 DPA formation increases cancer cell invasion, whereas addback of this molecule reduced activated PSC-mediated cancer cell invasion. We also observed that circulating concentrations of RvD5n-3 DPA levels were decreased in peripheral blood of metastatic PDAC patients when compared with those measured in plasma of non-metastatic PDAC patients. Together, these findings indicate that RvD5n-3 DPA may regulate cancer-stroma cross-talk and invasion.

Promoting the proliferation of osteoarthritis chondrocytes by resolvin D1 regulating the NLRP3/caspase-1 signaling pathway

Osteoarthritis (OA) is a degenerative joint disease commonly found in middle-aged and older people. Chondrocytes are the only cells in joint cartilage that are difficult to heal after pyroptosis, and they will aggravate the wear and tear of joint cartilage and affect the progression of OA. Pyroptosis is a novel form of programmed cell death, and the classical pyroptosis pathway is a programmed cell death pattern mediated by inflammatory cysteine protease-1. Activation of NLRP3 leads to activation and cleavage of caspase-1 precursors, which in turn leads to activation and cleavage of GSDMD proteins and the release of proinflammatory factors. Resolvin D1 (RvD1) is a specialized pro-resolving mediator (SPM) derived from omega-3 unsaturated fatty acids that reduces inflammation and catabolic responses in OA chondrocytes. However, it is unclear whether RvD1 promotes OA chondrocyte proliferation and thus joint cartilage repair. Our results show that RvD1 regulates the NLRP3/caspase-1 signaling pathway by inhibiting the expression of caspase-1, promoting the proliferation of OA chondrocytes, promoting the repair of articular cartilage in rats and delaying the progression of osteoarthritis.

The impact of Resolvin E1 on bone regeneration in critical-sized calvarial defects of rat model-A gene expression and micro-CT analysis.

To investigate, invivo, the effect of local application of Resolvin E1 (RvE1) on the bone regeneration of critical-size defects (CSDs) in Wistar rats utilizing gene expression and micro-computed tomographic (micro-CT) analysis. The inflammation-resolving actions of RvE1 are well established. The molecular mechanism of its bone-regenerative actions has been of significant interest in recent years; however, there is limited information regarding the same. Thirty Wistar rats with a 5 mm induced critical-size calvarial defect were randomly allocated into four groups: no treatment/negative control (n = 5), treatment using bovine bone grafts/positive control (n = 5), treatment using local delivery of RvE1 (n = 11) and treatment using RvE1 mixed with bovine bone graft (n = 9). After 4 weeks, RNA isolation, complementary DNA synthesis and real-time polymerase chain reaction were used for genetic expression of alkaline phosphatase (ALP), osteocalcin (OCN) and osteopontin (OPN). The rats were sacrificed after 12 weeks and micro-CT imaging was performed to analyse the characteristics of the newly formed bone (NFB). The data were analysed using ANOVA and the least significant difference tests (α ≤ .05). The RvE1 + bovine graft group had statistically highest mean NFB (20.75 ± 2.67 mm3 ) compared to other groups (p < .001). Similarly, RvE1 + bovine graft group also demonstrated statistically highest mean genetic expression of ALP (31.71 ± 2.97; p = .008) and OPN (34.78 ± 3.62; p < .001) compared to negative control and RvE1 groups. Resolvin E1 with adjunct bovine bone graft demonstrated an enhanced bone regeneration compared to RvE1 or bovine graft alone in the calvarial defect of Wistar rats.