resolvin-e2 and Inflammation

Cardiovascular disease (CVD) represents a global burden with a prevalence that continues increasing progressively. CVD comprises a group of disorders of the heart and blood vessels including coronary heart disease, cerebrovascular disease and peripheral arterial disease. This group of disorders is associated with an inflammatory process which can participate in the pathophysiology of these diseases. Inflammation resolution is an active process involving the participation of pro-resolving mediators such as lipoxins, resolvins, protectins and maresins. Pro-resolving mediators are bioactive molecules generated from omega-3 polyunsaturated fatty acids (PUFAs); among these eicosapentaenoic acid (EPA; C20:5n3) and docosahexaenoic acid (DHA; C22:6n3) are the precursors of resolvins. Pro-resolving mediators orchestrate the correct resolution of inflammation and also stimulate tissue regeneration. Their deregulation can lead to chronic inflammation involving CVD. The discovery of these novel lipid mediators opens a new range of possibilities for the design of anti-inflammatory agents with therapeutic potential for a wide variety of diseases. The present work summarizes the available data about the general characteristics, structure and biosynthesis of resolvins and their relation as protective compounds in CVD.

Topics: Animals; Anti-Inflammatory Agents; Cardiovascular Diseases; Docosahexaenoic Acids; Drug Discovery; Eicosapentaenoic Acid; Humans; Inflammation

Research on the formation of novel enzymatic oxygenation products derived from the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) has revealed the endogenous formation of several novel autacoids that have been termed resolvins and protectins. The elucidation of the chemical structures of resolvins and protectins, and the assessment of their endogenous functions, are providing a new understanding of the role of endogenous omega-3 fatty acid-derived lipid mediators in tissue protection, counteraction of inflammation and the activation of inflammation resolution. This review emphasizes the structural aspects of resolvin biosynthesis and metabolic inactivation, which are of central importance for understanding the current and future development of therapeutically relevant, stable analogs that may activate inflammation resolution.

Topics: Animals; Anti-Inflammatory Agents; Aspirin; Docosahexaenoic Acids; Eicosapentaenoic Acid; Humans; Inflammation; Lipoxins; Molecular Structure; Signal Transduction; Structure-Activity Relationship

A well-integrated host inflammatory response is essential in maintaining health and fighting disease. It is important to achieve a complete understanding of the cellular and molecular events that govern the resolution of acute inflammation. Because novel lipid-derived mediators, called resolvins and protectins in animal models, control the duration and magnitude of inflammation, the mapping of these resolution circuits may provide new ways of understanding the molecular basis of many inflammatory diseases. This article provides an overview of recent studies on resolvin and protectin biosynthesis and of advances in understanding the actions of these novel anti-inflammatory and proresolving lipid mediators. These new families of lipid-derived mediators were originally isolated from experimental murine models of acute inflammation identified during the natural spontaneous resolution phase. They are biosynthesized from omega-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) and possess potent anti-inflammatory, proresolving, and antifibrotic actions in vivo. Taken together, these findings suggest that defective resolution mechanisms may underlie the inflammatory phenotypes that are believed to characterize many common human diseases. The new families of endogenous proresolving and anti-inflammatory agonists constitute a new genus of anti-inflammatories.

Topics: Acute Disease; Animals; Anti-Inflammatory Agents; Disease Models, Animal; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Humans; Inflammation; Inflammation Mediators; Lipoxins

Acute inflammation and its resolution are essential processes for tissue protection and homeostasis. In this context, specialized proresolving mediators derived from polyunsaturated fatty acids are of interest. In this study, we report that resolvin E2 (RvE2) from eicosapentaenoic acid is endogenously produced during self-limited murine peritonitis in both the initiation and resolution phases. RvE2 (1-10 nM) carries potent leukocyte-directed actions that include: 1) regulating chemotaxis of human neutrophils; and 2) enhancing phagocytosis and anti-inflammatory cytokine production. These actions appear to be mediated by leukocyte G-protein-coupled receptors as preparation of labeled RvE2 gave direct evidence for specific binding of radiolabeled RvE2 to neutrophils (K(d) 24.7 ± 10.1 nM) and resolvin E1 activation of recombinant G-protein-coupled receptors was assessed. In addition to the murine inflammatory milieu, RvE2 was also identified in plasma from healthy human subjects. RvE2 rapidly downregulated surface expression of human leukocyte integrins in whole blood and dampened responses to platelet-activating factor. Together, these results indicate that RvE2 can stimulate host-protective actions throughout initiation and resolution in the innate inflammatory responses.

Topics: Animals; Chemotaxis; Down-Regulation; Eicosapentaenoic Acid; Female; Humans; Immunity, Innate; Inflammation; Integrins; Male; Mice; Neutrophils; Phagocytosis; Platelet Activating Factor

Particulate matter in the air exacerbates airway inflammation (AI) in asthma; moreover, prenatal exposure to concentrated urban air particles (CAPs) and diesel exhaust particles (DEPs) predisposes the offspring to asthma and worsens the resolution of AI in response to allergens. We previously tested the hypothesis that such exposure impairs the pathways of specialized proresolving mediators that are critical for resolution and found declined Lipoxin A4 (LxA4) and Resolvin E2 (RvE2) levels in the "at-risk" pups of exposed mothers. Here, we hypothesized that supplementation with synthetic LxA4 or RvE2 via the airway can ameliorate AI after allergen exposure, which has not been tested in models with environmental toxicant triggers. BALB/c newborns with an asthma predisposition resultant from prenatal exposure to CAPs and DEPs were treated once daily for 3 days with 750 ng/mouse of LxA4 or 300 ng/mouse of RvE2 through intranasal instillation, and they were tested with the intentionally low-dose ovalbumin protocol that elicits asthma in the offspring of particle-exposed mothers but not control mothers, mimicking the enigmatic maternal transmission of asthma seen in humans. LxA4 and RvE2 ameliorated the asthma phenotype and improved AI resolution, which was seen as declining airway eosinophilia, lung tissue infiltration, and proallergic cytokine levels.

Topics: Animals; Asthma; Female; Humans; Infant, Newborn; Inflammation; Maternal Exposure; Mice; Pregnancy; Prenatal Exposure Delayed Effects; Vehicle Emissions

Agricultural workers, especially those who work in swine confinement facilities, are at increased risk for developing pulmonary diseases including asthma, chronic obstructive pulmonary disease, and chronic bronchitis due to exposures to fumes, vapors, and organic dust. Repetitive exposure to agricultural dust leads to unresolved inflammation, a common underlying mechanism that worsens lung disease. Besides occupational exposure to dusts, diet also significantly contributes to inflammation and disease progression. Since DHA (docosahexaenoic acid), a polyunsaturated omega-3 fatty acid and its bioactive metabolites have key roles in inflammation resolution, we rationalized that individuals chronically exposed to organic dusts can benefit from dietary modifications. Here, we evaluated the role of DHA in modifying airway inflammation in a murine model of repetitive exposure to an aqueous extract of agricultural dust (three-week exposure to swine confinement dust extract, HDE) and after a one-week resolution/recovery period. We found that mice fed a high DHA diet had significantly increased bronchoalveolar lavage fluid (BALF) levels of DHA-derived resolvins and lower TNFα along with altered plasma levels of endocannabinoids and related lipid mediators. Following the one-week recovery we identified significantly reduced BALF cellularity and cytokine/chemokine release along with increased BALF amphiregulin and resolvins in DHA diet-fed versus control diet-fed mice challenged with HDE. We further report observations on the effects of repetitive HDE exposure on lung Ym1+ and Arg-1+ macrophages. Overall, our findings support a protective role for DHA and identify DHA-derived resolvins and endocannabinoids among the potential mediators of DHA in altering airway inflammation in chronic agricultural dust exposure.

Topics: Agricultural Workers' Diseases; Animals; Bronchoalveolar Lavage Fluid; Diet; Disease Models, Animal; Docosahexaenoic Acids; Dust; Eicosapentaenoic Acid; Endocannabinoids; Fatty Acids, Unsaturated; Inflammation; Inhalation Exposure; Lung; Macrophages, Alveolar; Male; Mice; Mice, Inbred C57BL; Respiratory Tract Diseases; Swine; Tumor Necrosis Factor-alpha

Sepsis is a big health problem and one of the most common causes of acute lung injury (ALI) leading to high mortality. Pro-resolving mediators play an important role in abrogating the inflammation and promoting tissue homeostasis restoration. ALI treatment is still a clinical health problem, so new therapies are needed. Here, we evaluated the effect of photobiomodulation treatment on the resolution process of ALI induced by lipopolysaccharide (LPS). Male Balb/c mice were submitted to LPS (ip) or vehicle and irradiated or not with light emitting diode (LED) 2 and 6 h after LPS or vehicle injection, and the parameters were investigated 3 and 7 days after the injections. Our results showed that after 3 days of LED treatment the blood and bronchoalveolar lavage (BAL) cells as well as interleukins (IL) including IL-6 and IL-17 were reduced. No differences were observed in the bone marrow cells, tracheal reactivity, and lipoxin A4 and resolvin E2. Indeed, after 7 days of LED treatment the bone marrow cells, lymphocytes, and lipoxin A4 were increased, while IL-6, IL-17, and IL-10 were decreased. No differences were observed in the blood cells and tracheal reactivity. Thus, our results showed that LED treatment attenuated ALI induced by sepsis by modulating the cell mobilization from their reserve compartments. In addition, we also showed later effects of the LED up to 7 days after the treatment. This study proposes photobiomodulation as therapeutic adjuvant to treat ALI.

Topics: Acute Lung Injury; Animals; Bone Marrow; Bronchoalveolar Lavage; Cell Movement; Cholinergic Agents; Cytokines; Eicosapentaenoic Acid; Inflammation; Lipopolysaccharides; Lipoxins; Low-Level Light Therapy; Lung; Male; Mice, Inbred BALB C; Muscle Contraction; Muscle, Smooth; Sepsis

E-series resolvins are biosynthesized from eicosapentaenoic acid during the resolution phase of acute inflammation and enhance inflammation resolution. However, the role of E-series resolvins in inflammation resolution is not yet known. Herein, we show that in human polymorphonuclear neutrophils (PMNs), resolvin E1 (RvE1) selectively enhances reactive oxygen species (ROS) generation induced by N-formylmethionyl-leucyl-phenylalanine. The RvE1-mediated enhancement is eliminated by a pan-antagonist of leukotriene B4 (LTB4) receptors, LY255283, or an NADPH oxidase inhibitor, diphenyleneiodonium. Thus, RvE1 enhances NADPH oxidase-mediated ROS generation via LTB4 receptors. Unlike RvE1, resolvins E2 and E3 do not show such activation of PMNs. Our findings suggest that RvE1 contributes to regulation of ROS generation, in accordance with the inflammatory state of the host.

Topics: Eicosapentaenoic Acid; Fatty Acids, Unsaturated; Humans; Inflammation; N-Formylmethionine Leucyl-Phenylalanine; NADPH Oxidases; Neutrophils; Onium Compounds; Reactive Oxygen Species; Receptors, Leukotriene B4; Tetrazoles

New classes of lipids such as lipoxins, resolvins, protectins and maresin are found to promote the resolution of inflammation. The resolving actions of these endogenous lipids are mediated by membrane receptors such as lipoxin A4 receptor/formyl peptide receptor 2 (ALX/FPR2) and cysteinyl leukotriene receptor 1 (CysLT1). Further, there exists G protein-coupled receptor 32 (GPR32), chemokine receptor-like (CMLKLR), LTB4 receptor 1 (BLT1) and unidentified high-affinity surface binding receptors in human polymorphonuclear leukocytes (PMN). In particular, RX-10001 (resolvin E1) and RX-10004 (synthetic analog of resolvin, phase II) are being studied clinically in many inflammatory diseases including dry eye, retinal disease, asthma, inflammatory bowel diseases, rheumatic arthritis and cardiovascular diseases by Resolvyx Pharmaceuticals. These novel lipid classes of inflammation resolving mediators might offers new opportunities for candidates of drugs modulating chronic inflammatory diseases. Here, the progress of resolvins as new drug candidates is introduced and research on the resolution phase of inflammation is emphasized.

Topics: Animals; Drugs, Investigational; Eicosapentaenoic Acid; Humans; Inflammation; Inflammation Mediators; Lipids; Receptors, Cytoplasmic and Nuclear