Clotting Dysfunction in Sepsis: A Role for ROS and Potential for Therapeutic Intervention

Lopes-Pires, Maria Elisa; Frade-Guanaes, Jéssica Oliveira; Quinlan, Gregory J.

doi:10.3390/antiox11010088

Cited by 30 publications

(22 citation statements)

References 172 publications

(139 reference statements)

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“…Inflammation and oxidative stress contribute to the pathogenesis of sepsis [ 47 ]. DEX exerts powerful roles in anti-inflammation, anti-oxidative stress, sympatholytic and organ-protection effects [ 48 ].…”

Section: Resultsmentioning

confidence: 99%

Dexmedetomidine Attenuates Lipopolysaccharide-Induced Sympathetic Activation and Sepsis via Suppressing Superoxide Signaling in Paraventricular Nucleus

Wang

et al. 2022

Antioxidants

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Sympathetic overactivity contributes to the pathogenesis of sepsis. The selective α2-adrenergic receptor agonist dexmedetomidine (DEX) is widely used for perioperative sedation and analgesia. We aimed to determine the central roles and mechanisms of DEX in attenuating sympathetic activity and inflammation in sepsis. Sepsis was induced by a single intraperitoneal injection of lipopolysaccharide (LPS) in rats. Effects of DEX were investigated 24 h after injection of LPS. Bilateral microinjection of DEX in the paraventricular nucleus (PVN) attenuated LPS-induced sympathetic overactivity, which was attenuated by the superoxide dismutase inhibitor DETC, cAMP analog db-cAMP or GABAA receptor antagonist gabazine. Superoxide scavenger tempol, NADPH oxidase inhibitor apocynin, adenylate cyclase inhibitor SQ22536 or PKA inhibitor Rp-cAMP caused similar effects to DEX in attenuating LPS-induced sympathetic activation. DEX inhibited LPS-induced superoxide and cAMP production, as well as NADPH oxidase, adenylate cyclase and PKA activation. The roles of DEX in reducing superoxide production and NADPH oxidase activation were attenuated by db-cAMP or gabazine. Intravenous infusion of DEX inhibited LPS-induced sympathetic overactivity, NOX activation, superoxide production, TNF-α and IL-1β upregulation in the PVN and plasma, as well as lung and renal injury, which were attenuated by the PVN microinjection of yohimbine and DETC. We conclude that activation of α2-adrenergic receptors with DEX in the PVN attenuated LPS-induced sympathetic overactivity by reducing NADPH oxidase-dependent superoxide production via both inhibiting adenylate cyclase-cAMP-PKA signaling and activating GABAA receptors. The inhibition of NADPH oxidase-dependent superoxide production in the PVN partially contributes to the roles of intravenous infusion of DEX in attenuating LPS-induced sympathetic activation, oxidative stress and inflammation.

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Section: Resultsmentioning

confidence: 99%

Dexmedetomidine Attenuates Lipopolysaccharide-Induced Sympathetic Activation and Sepsis via Suppressing Superoxide Signaling in Paraventricular Nucleus

Wang

et al. 2022

Antioxidants

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“…These events activate the coagulation cascade and increase the production of adhesion molecules, resulting in increased fibrin deposition, impaired fibrinolysis, and eventually accelerating thrombus formation that induces ischemic stroke and cardiovascular complications. (37). Natural antioxidants (secondary metabolites) play a crucial role in neutralizing ROS or inhibiting different oxidative enzymes linked to inflammatory pathways (38).…”

Section: Discussionmentioning

confidence: 99%

In vitro and in silico investigation of garlic’s (Allium sativum) bioactivity against 15-lipoxygenase mediated inflammopathies

Khan

Sharif

Salekeen

et al. 2023

J Herbmed Pharmacol

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Introduction: Garlic (Allium sativum) is widely used as a flavor-enhancing dietary ingredient and exhibits a wide spectrum of pharmacological effects. This study aimed to investigate the therapeutic effects of aqueous garlic extract to explore the bioactivity against 15-lipoxygenase (15-LOX) mediated inflammopathies. Methods: In this study, the antioxidant (DPPH free radical scavenging assay and reducing power assay), anti-inflammatory (hypotonicity-induced hemolysis assay and 15-LOX inhibition assay) and anticoagulation (serine protease inhibition assay and prothrombin time assay) effects of the aqueous garlic extract were investigated. Furthermore, in silico molecular docking and dynamic simulation analysis of reported small compounds of garlic against 15-LOX1 and 15-LOX2 were performed to figure out the most efficient phytochemical ligands and validate the anti-inflammatory potential. Results: The DPPH scavenging effect and the reducing power of the extract were found with the IC50 of 213.87 ± 1.49 μgmL-1 and EC50 of 124.78 ± 3.39 μgmL-1, respectively. In the hypotonicity-induced hemolysis and 15-LOX inhibition assay, the IC50 values were observed as 147.59 ± 2.98 μgmL-1 and 250.05 ± 8.48 μgmL-1, respectively. The extract inhibited serine protease activity with an IC50 of 301.33 ± 1.31 μgmL-1 and prevented blood coagulation for 10.05 ± 0.35 minutes in prothrombin time assay. The in silico study identified Rhamnetin as a potential 15-LOX1 and 15-LOX2 inhibitor, and it exhibited a stable interaction with the targets throughout the 100 ns dynamic simulation. Conclusion: The findings of this study provide molecular insights into garlic’s medicinal properties as well as its bioactive compounds, which can be potential therapeutic interventions for 15-LOX mediated inflammations.

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“…In addition, these cytokines act on macrophages to further change their polarization state and aggravate the in ammatory response [40,41]. Among these in ammatory signals, ROS are released by the body's immune system against pathogen infection [42]. It can induce neutrophil in ltration and increase protease production while producing numerous oxidative intermediates, which are associated with adverse effects of oxygen free radicals [43].…”

Section: Discussionmentioning

confidence: 99%

Protective Role of Metrnl in Host Immunity Defense during Sepsis by Promoting Macrophage Recruitment and Modulating Treg/Th17 Immune Cell Balance

Chen

Chen²,

Yang

et al. 2023

Preprint

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Background Metrnl is a new kind of adipokine, which is also known as meteorin-like because it is homologous to the neurotrophic factor meteorin (Metrn). Although the expression and function of Metrnl, including neurotrophic, immunomodulatory, and insulin resistance functions in different tissues, have been extensively studied, research on its role in sepsis has remained largely limited.Methods The present work analyzed the levels of Metrnl and cytokines in the circulation, such as tumor necrosis factor (TNF-α), interleukin (IL-1)β, IL-6, IL-8, together with IL-10 among septic adult patients. Clinical information was obtained from such patients, including sofa score, procalcitonin(PCT)count, and C-reactive count (CRP) at the time of entering the intensive care unit (ICU). We constructed a sepsis model in Metrnl-deficient or normal wild-type mice using cecal ligation and perforation to study its functions in bacterial burden, survival, cytokine/chemokine generation, peritoneal lavage fluid neutrophils, macrophage and lymphocyte recruitment, and Treg/Th17 immune cell balance after CLP-induced sepsis.Results The expression of Metrnl was remarkably elevated in the early phase of sepsis clinically. Its serum content in patients dying of sepsis slightly decreased relative to that in survivors. Furthermore, the concentration of Metrnl in septic cases when entering the ICU independently predicted the 28-day mortality. For septic patients who had low serum Metrnl content (≤ 359.40 pg/mL), the death risk increased by 2.3 folds relative to those who had a high serum content. It is reported that Metrnl is probably insufficient among patients dying of sepsis. Additionally, the content of Metrnl in the serum of septic patients when entering the ICU is markedly and negatively related to the levels of TNF-α, IL-1β, IL-6, IL-8, IL-17, PCT, and Sofa score. Collectively, Metrnl could be a potential therapeutic target for sepsis. A low-lethality non-severe sepsis (NSS) model was constructed, which suggested that Metrnl insufficiency elevated the death rate and reduced bacterial clearance during sepsis. For Metrnl-deficient mice, impaired sepsis immunity defense might be related to decreased macrophage recruitment and Treg/Th17 lymphocyte imbalance. Recombinant Metrnl administered to Metrnl-deficient mice abolished the immunity defense impairment following NSS while protecting the high-lethality severe sepsis (SS) model in wild-type (WT) mice. In addition, Metrnl-induced sepsis prevention was intricately associated with the increased recruitment of peritoneal macrophages and modulation of the Treg/TH17 immune cell balance. Furthermore, CCL3 exposure in Metrnl-deficient mice reduced peritoneal bacterial loads while improving survival during sepsis partially by promoting the recruitment of peritoneal macrophages. Furthermore, Metrnl regulated the polarization of M1 macrophages through the ROS signaling pathway and promoted macrophage phagocytosis, thereby killing Escherichia coli.Conclusions The present proof-of-concept work suggests that Metrnl-mediated recruitment of macrophages significantly affects sepsis defense in the host and modulates the Treg/Th17 immune cell balance. Findings in this work shed more light on the development of host-directed treatments that can be used to manipulate host immunity to treat sepsis.

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Clotting Dysfunction in Sepsis: A Role for ROS and Potential for Therapeutic Intervention

Cited by 30 publications

References 172 publications

Dexmedetomidine Attenuates Lipopolysaccharide-Induced Sympathetic Activation and Sepsis via Suppressing Superoxide Signaling in Paraventricular Nucleus

Dexmedetomidine Attenuates Lipopolysaccharide-Induced Sympathetic Activation and Sepsis via Suppressing Superoxide Signaling in Paraventricular Nucleus

In vitro and in silico investigation of garlic’s (Allium sativum) bioactivity against 15-lipoxygenase mediated inflammopathies

Protective Role of Metrnl in Host Immunity Defense during Sepsis by Promoting Macrophage Recruitment and Modulating Treg/Th17 Immune Cell Balance

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