Unregulated inflammation underlies many diseases, including sepsis. Much interest lies in targeting anti-inflammatory mechanisms to develop new treatments. One such target is the anti-inflammatory protein annexin A1 (AnxA1) and its receptor, FPR2/ALX. Using intravital videomicroscopy, we investigated the role of AnxA1 and FPR2/ALX in a murine model of endotoxin-induced cerebral inflammation [intraperitoneal injection of lipopolysaccharide (LPS)]. An inflammatory response was confirmed by elevations in proinflammatory serum cytokines, increased cerebrovascular permeability, elevation in brain myeloperoxidase, and increased leukocyte rolling and adhesion in cerebral venules of wild-type (WT) mice, which were further exacerbated in AnxA1-null mice. mRNA expression of TLR2, TLR4, MyD-88, and Ly96 was also assessed. The AnxA1-mimetic peptide, AnxA1(Ac2-26) (100 μg/mouse, ∼33 μmol) mitigated LPS-induced leukocyte adhesion in WT and AnxA1-null animals without affecting leukocyte rolling, in comparison to saline control. AnxA1(Ac2-26) effects were attenuated by Boc2 (pan-FPR antagonist, 10 μg/mouse, ∼12 nmol), and by minocycline (2.25 mg/mouse, ∼6.3 nmol). The nonselective Fpr agonists, fMLP (6 μg/mouse, ∼17 nmol) and AnxA1(Ac2-26), and the Fpr2-selective agonist ATLa (5 μg/mouse, ∼11 nmol) were without effect in Fpr2/3(-/-) mice. In summary, our novel results demonstrate that the AnxA1/FPR2 system has an important role in effecting the resolution of cerebral inflammation in sepsis and may, therefore, provide a novel therapeutic target.

Background Structured, systematic methods to formulate consensus recommendations, such as the Delphi process or nominal group technique, among others, provide the opportunity to harness the knowledge of experts to support clinical decision making in areas of uncertainty. They are widely used in biomedical research, in particular where disease characteristics or resource limitations mean that high-quality evidence generation is difficult. However, poor reporting of methods used to reach a consensus – for example, not clearly explaining the definition of consensus, or not stating how consensus group panellists were selected – can potentially undermine confidence in this type of research and hinder reproducibility. Our objective is therefore to systematically develop a reporting guideline to help the biomedical research and clinical practice community describe the methods or techniques used to reach consensus in a complete, transparent, and consistent manner. Methods The ACCORD (ACcurate COnsensus Reporting Document) project will take place in five stages and follow the EQUATOR Network guidance for the development of reporting guidelines. In Stage 1, a multidisciplinary Steering Committee has been established to lead and coordinate the guideline development process. In Stage 2, a systematic literature review will identify evidence on the quality of the reporting of consensus methodology, to obtain potential items for a reporting checklist. In Stage 3, Delphi methodology will be used to reach consensus regarding the checklist items, first among the Steering Committee, and then among a broader Delphi panel comprising participants with a range of expertise, including patient representatives. In Stage 4, the reporting guideline will be finalised in a consensus meeting, along with the production of an Explanation and Elaboration (E&E) document. In Stage 5, we plan to publish the reporting guideline and E&E document in open-access journals, supported by presentations at appropriate events. Dissemination of the reporting guideline, including a website linked to social media channels, is crucial for the document to be implemented in practice. Discussion The ACCORD reporting guideline will provide a set of minimum items that should be reported about methods used to achieve consensus, including approaches ranging from simple unstructured opinion gatherings to highly structured processes.

In recent years, studies have focused on the resolution of inflammation, which can be achieved by endogenous anti-inflammatory agonists such as Annexin A1 (AnxA1). Here, we investigated the effects of mast cells (MCs) on early LPS-induced neutrophil recruitment and the involvement of the AnxA1-formyl peptide receptor 2/ALX (FPR2/ALX or lipoxin A 4 receptor) pathway. EXPERIMENTAL APPROACHIntravital microscopy (IVM) was used to visualize and quantify the effects of LPS (10 μg per mouse i.p.) on murine mesenteric cellular interactions. Furthermore, the role that MCs play in these inflammatory responses was determined in vivo and in vitro, and effects of AnxA1 mimetic peptide Ac2-26 were assessed. KEY RESULTSLPS increased both neutrophil endothelial cell interactions within the mesenteric microcirculation and MC activation (determined by IVM and ruthenium red dye uptake), which in turn lead to the early stages of neutrophil recruitment. MC recruitment of neutrophils could be blocked by preventing the pro-inflammatory activation (using cromolyn sodium) or enhancing an antiinflammatory phenotype (using Ac2-26) in MCs. Furthermore, MCs induced neutrophil migration in vitro, and MC stabilization enhanced the release of AnxA1 from neutrophils. Pharmacological approaches (such as the administration of FPR pan-antagonist Boc2, or the FPR2/ALX antagonist WRW4) revealed neutrophil FPR2/ALX to be important in this process. CONCLUSIONS AND IMPLICATIONSData presented here provide evidence for a role of MCs, which are ideally positioned in close proximity to the vasculature, to act as sentinel cells in neutrophil extravasation and resolution of inflammation via the AnxA1-FPR2/ALX pathway.

ObjectiveTo identify evidence on the reporting quality of consensus methodology and to select potential checklist items for the ACcurate COnsensus Reporting Document (ACCORD) project to develop a consensus reporting guideline.DesignSystematic review.Data sourcesEmbase, MEDLINE, Web of Science, PubMed, Cochrane Library, Emcare, Academic Search Premier and PsycINFO from inception until 7 January 2022.Eligibility criteriaStudies, reviews and published guidance addressing the reporting quality of consensus methodology for improvement of health outcomes in biomedicine or clinical practice. Reports of studies using or describing consensus methods but not commenting on their reporting quality were excluded. No language restrictions were applied.Data extraction and synthesisScreening and data extraction of eligible studies were carried out independently by two authors. Reporting quality items addressed by the studies were synthesised narratively.ResultsEighteen studies were included: five systematic reviews, four narrative reviews, three research papers, three conference abstracts, two research guidance papers and one protocol. The majority of studies indicated that the quality of reporting of consensus methodology could be improved. Commonly addressed items were: consensus panel composition; definition of consensus and the threshold for achieving consensus. Items least addressed were: public patient involvement (PPI); the role of the steering committee, chair, cochair; conflict of interest of panellists and funding. Data extracted from included studies revealed additional items that were not captured in the data extraction form such as justification of deviation from the protocol or incentives to encourage panellist response.ConclusionThe results of this systematic review confirmed the need for a reporting checklist for consensus methodology and provided a range of potential checklist items to report. The next step in the ACCORD project builds on this systematic review and focuses on reaching consensus on these items to develop the reporting guideline.Protocol registrationhttps://osf.io/2rzm9.

BACKGROUND AND PURPOSEGender differences in inflammation are well described, with females often showing more robust, oestrogen-associated responses. Here, we investigated the influence of gender, oestrogen and the anti-inflammatory protein annexin A1 (AnxA1) on lipopolysaccharide (LPS)-induced leukocyte-endothelial cell interactions in murine cerebral and mesenteric microvascular beds. EXPERIMENTAL APPROACHIntravital microscopy was used to visualize and quantify the effects of LPS (10 mg·per mouse i.p.) on leukocyte-endothelial interactions in male and female wild-type (WT) mice. The effects of ovariectomy Ϯ oestrogen replacement were examined in WT and AnxA1-null (AnxA1 -/-) female mice. KEY RESULTSLPS increased leukocyte adherence in the cerebral and mesenteric beds of both male and female WT mice; females showed exacerbated responses in the brain versus males, but not the mesentery. Ovariectomy further enhanced LPS-induced adhesion in the brain but not the mesentery; its effects were reversed by oestrogen treatment. OVX AnxA1 -/-mice also showed exaggerated adhesive responses to LPS in the brain. However, these were unresponsive to ovariectomy and, paradoxically, responded to oestrogen with a pronounced increase in basal and LPS-induced leukocyte adhesion in the cerebrovasculature. CONCLUSIONS AND IMPLICATIONSOur data confirm the fundamental role of AnxA1 in limiting the inflammatory response in the central and peripheral microvasculature. They also (i) show that oestrogen acts via an AnxA1-dependent mechanism to protect the cerebral, but not the mesenteric, vasculature from the damaging effects of LPS and (ii) reveal a paradoxical and potentially toxic effect of the steroid in potentiating the central response to LPS in the absence of AnxA1. AbbreviationsAnxA1, annexin A1; BBB, blood-brain barrier; E2, 17b-oestradiol; FPR, formylpeptide receptor; IVM, intravital microscopy; LPS, lipopolysaccharide; OVX, ovariectomized; VWBC, leukocyte rolling velocity BJP British Journal of Pharmacology