Interleukin 6 plays a role in the migration of magnetically levitated mesenchymal stem cells spheroids

Mesenchymal stem cells (MSCs) reside quiescently within a specialised ‘niche’ environment in the bone marrow. However, following appropriate signalling cues, MSCs mobilise and migrate out from the niche, typically toward either sites of injury (a regenerative response) or toward primary tumours (an intrinsic homing response, which promotes MSCs as cellular vectors for therapeutic delivery). To date, very little is known about MSC mobilisation. By adopting a 3D MSC niche model, whereby MSC spheroids are cultured within a type I collagen gel, recent studies have highlighted interleukin-6 (IL-6) as a key cytokine involved in MSC migration. Herein, the ability of IL-6 to induce MSC migration was further investigated, and the key matrix metalloproteinases used to effect cell mobilisation were identified. Briefly, the impact of IL-6 on the MSC migration in a two-dimensional model systems was characterised—both visually using an Ibidi chemotaxis plate array (assessing for directional migration) and then via a standard 2D monolayer experiment, where cultured cells were challenged with IL-6 and extracted media tested using an Abcam Human MMP membrane antibody array. The 2D assay displayed a strong migratory response toward IL-6 and analysis of the membrane arrays data showed significant increases of several key MMPs. Both data sets indicated that IL-6 is important in MSC mobilisation and migration. We also investigated the impact of IL-6 induction on MSCs in 3D spheroid culture, serving as a simplistic model of the bone marrow niche, characterised by fluorescently tagged magnetic nanoparticles and identical membrane antibody arrays. An increase in MMP levels secreted by cells treated with 1 ng/mL IL-6 versus control conditions was noted in addition to migration of cells away from the central spheroid mass

Credit limits and heterogeneity in general equilibrium models with a finite number of agents

We introduce two-period general equilibrium models with heterogeneous producers and financial frictions. Any agent can borrow to realize their productive project but the debt repayment does not exceed a fraction (so-called credit limit) of the project's value. Our framework allows us to investigate the aggregate and distributional effects of credit limits and heterogeneity of agents. The connection between credit limits, welfare, and efficiency is also explored

Keratinocyte growth factor for the treatment of the acute respiratory distress syndrome (KARE): a randomised, double-blind, placebo-controlled phase 2 trial

<p>(<b>A</b>) Immunofluorescence signal for dystrophin is significantly reduced in the SSI heart (bottom left panel) compared with the immunofluorescent signal in the SHAM heart (upper left panel), and the SHAM+ALLN (upper right panel) and SSI+ALLN (bottom right panel) myocardium. (<b>B</b>) Protein levels of dystrophin in the SHAM, SSI, SHAM+ALLN and SSI+ALLN hearts were measured 24 h after the CLP procedure and were expressed in arbitrary units (AUs). α-Tubulin was used to determine equivalent loading conditions. The results (n = 6 per group) are representative of three different experiments. Scale bars indicate 50 μm.</p

Novel anti-tumour necrosis factor receptor-1 (TNFR1) domain antibody prevents pulmonary inflammation in experimental acute lung injury.

BACKGROUND: Tumour necrosis factor alpha (TNF-α) is a pleiotropic cytokine with both injurious and protective functions, which are thought to diverge at the level of its two cell surface receptors, TNFR1 and TNFR2. In the setting of acute injury, selective inhibition of TNFR1 is predicted to attenuate the cell death and inflammation associated with TNF-α, while sparing or potentiating the protective effects of TNFR2 signalling. We developed a potent and selective antagonist of TNFR1 (GSK1995057) using a novel domain antibody (dAb) therapeutic and assessed its efficacy in vitro, in vivo and in a clinical trial involving healthy human subjects. METHODS: We investigated the in vitro effects of GSK1995057 on human pulmonary microvascular endothelial cells (HMVEC-L) and then assessed the effects of pretreatment with nebulised GSK1995057 in a non-human primate model of acute lung injury. We then tested translation to humans by investigating the effects of a single nebulised dose of GSK1995057 in healthy humans (n=37) in a randomised controlled clinical trial in which subjects were subsequently exposed to inhaled endotoxin. RESULTS: Selective inhibition of TNFR1 signalling potently inhibited cytokine and neutrophil adhesion molecule expression in activated HMVEC-L monolayers in vitro (P<0.01 and P<0.001, respectively), and also significantly attenuated inflammation and signs of lung injury in non-human primates (P<0.01 in all cases). In a randomised, placebo-controlled trial of nebulised GSK1995057 in 37 healthy humans challenged with a low dose of inhaled endotoxin, treatment with GSK1995057 attenuated pulmonary neutrophilia, inflammatory cytokine release (P<0.01 in all cases) and signs of endothelial injury (P<0.05) in bronchoalveolar lavage and serum samples. CONCLUSION: These data support the potential for pulmonary delivery of a selective TNFR1 dAb as a novel therapeutic approach for the prevention of acute respiratory distress syndrome. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT01587807

Diagnostic accuracy of pulmonary host inflammatory mediators in the exclusion of ventilator-acquired pneumonia.

BACKGROUND: Excessive use of empirical antibiotics is common in critically ill patients. Rapid biomarker-based exclusion of infection may improve antibiotic stewardship in ventilator-acquired pneumonia (VAP). However, successful validation of the usefulness of potential markers in this setting is exceptionally rare. OBJECTIVES: We sought to validate the capacity for specific host inflammatory mediators to exclude pneumonia in patients with suspected VAP. METHODS: A prospective, multicentre, validation study of patients with suspected VAP was conducted in 12 intensive care units. VAP was confirmed following bronchoscopy by culture of a potential pathogen in bronchoalveolar lavage fluid (BALF) at >10(4) colony forming units per millilitre (cfu/mL). Interleukin-1 beta (IL-1β), IL-8, matrix metalloproteinase-8 (MMP-8), MMP-9 and human neutrophil elastase (HNE) were quantified in BALF. Diagnostic utility was determined for biomarkers individually and in combination. RESULTS: Paired BALF culture and biomarker results were available for 150 patients. 53 patients (35%) had VAP and 97 (65%) patients formed the non-VAP group. All biomarkers were significantly higher in the VAP group (p<0.001). The area under the receiver operator characteristic curve for IL-1β was 0.81; IL-8, 0.74; MMP-8, 0.76; MMP-9, 0.79 and HNE, 0.78. A combination of IL-1β and IL-8, at the optimal cut-point, excluded VAP with a sensitivity of 100%, a specificity of 44.3% and a post-test probability of 0% (95% CI 0% to 9.2%). CONCLUSIONS: Low BALF IL-1β in combination with IL-8 confidently excludes VAP and could form a rapid biomarker-based rule-out test, with the potential to improve antibiotic stewardship

Repair of Acute Respiratory Distress Syndrome in COVID-19 by Stromal Cells (REALIST-COVID Trial):A Multicentre, Randomised, Controlled Trial

RationaleMesenchymal stromal cells (MSCs) may modulate inflammation, promoting repair in COVID-19-related Acute Respiratory Distress Syndrome (ARDS).ObjectivesWe investigated safety and efficacy of ORBCEL-C (CD362-enriched, umbilical cord-derived MSCs) in COVID-related ARDS.MethodsThis multicentre, randomised, double-blind, allocation concealed, placebo-controlled trial (NCT03042143) randomised patients with moderate-to-severe COVID-related ARDS to receive ORBCEL-C (400million cells) or placebo (Plasma-Lyte148).MeasurementsThe primary safety and efficacy outcomes were incidence of serious adverse events and oxygenation index at day 7 respectively. Secondary outcomes included respiratory compliance, driving pressure, PaO2/FiO2 ratio and SOFA score. Clinical outcomes relating to duration of ventilation, length of intensive care unit and hospital stays, and mortality were collected. Long-term follow up included diagnosis of interstitial lung disease at 1 year, and significant medical events and mortality at 2 years. Transcriptomic analysis was performed on whole blood at day 0, 4 and 7.Main results60 participants were recruited (final analysis n=30 ORBCEL-C, n=29 placebo: 1 in placebo group withdrew consent). 6 serious adverse events occurred in the ORBCEL-C and 3 in the placebo group, RR 2.9(0.6-13.2)p=0.25. Day 7 mean[SD] oxygenation index did not differ (ORBCEL-C 98.357.2], placebo 96.667.3). There were no differences in secondary surrogate outcomes, nor mortality at day 28, day 90, 1 or 2 years. There was no difference in prevalence of interstitial lung disease at 1year nor significant medical events up to 2 years. ORBCEL-C modulated the peripheral blood transcriptome.ConclusionORBCEL-C MSCs were safe in moderate-to-severe COVID-related ARDS, but did not improve surrogates of pulmonary organ dysfunction. Clinical trial registration available at www.Clinicaltrialsgov, ID: NCT03042143. This article is open access and distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/)

Characterisation of eppin function: expression and activity in the lung

Eppin is a serine protease inhibitor expressed in male reproductive tissues. In this study we have demonstrated novel sites of eppin expression in myeloid and epithelial cell lines with further confirmation in primary myeloid cell types. Using immunohistochemistry and Western blotting, eppin was detected in the lungs of patients with Acute Respiratory Distress Syndrome and Cystic Fibrosis lung disease. Expression of eppin in monocytic cells was unaffected by stimulation with TLR agonists, cytokine stimulation and hormone receptor agonist stimulation. However, upregulated expression and secretion of eppin was observed following treatment of monocytes with epidermal growth factor (EGF). Incubation of recombinant eppin with monocytic cells resulted in significant inhibition of lipopolysaccharide (LPS)-induced chemokine production. Furthermore, eppin inhibited LPS- induced NF-κB activation by a mechanism which involved accumulation of phosphorylated IκBα. In an in vivo model of lung inflammation induced by LPS, eppin administration resulted in decreased recruitment of neutrophils to the lung with a concomitant reduction in the levels of the neutrophil chemokine MIP-2. Overall, these results suggest a role for eppin outside of the reproductive tract and that eppin may have a role in the innate immuneresponse in the lung