A Role for RAGE/TXNIP/Inflammasome Axis in Alveolar Macrophage Activation During ARDS (RIAMA): a Proof-of-concept Clinical Study

RAGE (the receptor for advanced glycation end-products) is a marker of alveolar type I cell injury and a pivotal mediator of acute inflammation and innate immunity. RAGE pathway is highly regulated; the interaction of the transmembrane receptor with its various ligands (e.g. HMGB1, S100A12) ultimately leads to NF-kB activation and RAGE upregulation itself, but precise RAGE functions and intracellular pathways remain underexplored. During ARDS, monocyte and macrophage activation could modulate alveolar inflammation and repair.

As RAGE is also expressed at the surface of monocytes/macrophages, we hypothesize that alveolar monocyte/macrophage activation may be mediated through a RAGE-TXNIP (thioredoxin interacting protein)-NLRP3/inflammasome intracellular pathway. The purpose of this observational prospective study is to compare alveolar monocyte/macrophage activation profiles (as assessed by Fluorescence-Activated Cell Sorting (FACS)) in mechanically ventilated patients with or without ARDS.

Study Overview

• Status: Completed
• Conditions: Acute Respiratory Distress Syndrome; Mechanical Ventilation
• Intervention / Treatment: Other: RAGE TXNIP Inflammasome axis

Detailed Description

BACKGROUND:

The receptor for advanced glycation end products (RAGE) was recently identified as a promising new marker of alveolar type I cell injury. RAGE is a member of the immunoglobulin superfamily that acts as a multiligand receptor and is involved in propagating inflammatory responses in various cell populations. While the precise function of RAGE remains unclear, the elevated levels of RAGE, and its soluble isoform sRAGE, correlate with severity of acute respiratory distress syndrome (ARDS) in human and animal studies.

RAGE pathway is highly regulated; the interaction of the transmembrane receptor with its various ligands (e.g. HMGB1, S100A12) ultimately leads to NF-kB activation and RAGE upregulation itself. During ARDS, monocyte and macrophage activation could modulate alveolar inflammation and repair. As RAGE is also expressed at the surface of monocytes/macrophages, we hypothesize that alveolar monocyte/macrophage activation may be mediated through a RAGE-TXNIP (thioredoxin interacting protein)-NLRP3/inflammasome intracellular pathway.

DESIGN NARRATIVE:

The purpose of this monocentric observational prospective pathophysiology study is to compare alveolar monocyte/macrophage activation profiles between patients with or without ARDS.

Using Fluorescence-Activated Cell Sorting (FACS) analysis, monocyte/macrophage activation profiles will be characterized in patients within the first 24 hours after onset of ARDS and in matched mechanically ventilated controls. Markers of M1 ("pro-inflammatory") or M2 ("anti-inflammatory") activation, along with RAGE, TXNIP, NLRP3 FACS labeling in alveolar monocytes/macrophages will be analyzed along with protein measurements (IL-1β, TXNIP, NLRP3, sRAGE, HMGB1, S100A12) in the bronchoalveolar lavage fluid.

• Study Type: Observational
• Enrollment (Actual): 20

Contacts and Locations

Study Locations

• France
  • Clermont-Ferrand, France, 63003
    • Chu Clermont-Ferrand

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 95 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

ICU patients without ARDS and under mechanical ventilation for less than 24 hours

Description

Inclusion Criteria:

• ICU patients without ARDS and under mechanical ventilation for less than 24 hours
• Patients within the first 24 hours after onset of moderate to severe ARDS according to the 2012 Berlin definition (ARDS group)

Exclusion Criteria:

• - Pregnancy
• Acute exacerbation of diabetes (ketoacidosis, hyperosmolar hyperglycemic state)
• Patient under mechanical ventilation for > 7 days
• Dialysis-dependent chronic renal failure
• Alzheimer's disease
• Amyloidosis
• Evolutive neoplastic lesion
• Chronic pulmonary disease requiring long-term oxygen therapy or mechanical ventilation
• Chemotherapy treatment in the last 30 days
• Severe neutropenia (<0.5 G/l)

Study Plan

How is the study designed?

Design Details

• Observational Models: Other
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
ARDS Group (acute respiratory distress syndrome); The purpose of this monocentric observational prospective pathophysiology study is to compare alveolar monocyte/macrophage activation profiles between patients with or without ARDS	Other: RAGE TXNIP Inflammasome axis
control group; The purpose of this monocentric observational prospective pathophysiology study is to compare alveolar monocyte/macrophage activation profiles between patients with or without ARDS	Other: RAGE TXNIP Inflammasome axis

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
FACS analysis of RAGE-TXNIP-NLRP3 pathway in alveolar monocytes/macrophages	FACS analysis of RAGE-TXNIP-NLRP3 pathway in alveolar monocytes/macrophages from patients within the first 24 hours after onset of ARDS (ARDS group) and from sex- and age-matched mechanically ventilated controls (control group)	at day1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
- FACS analysis of M1 ("pro-inflammatory") and M2 ("anti-inflammatory") markers	- FACS analysis of M1 ("pro-inflammatory") and M2 ("anti-inflammatory") markers (e.g., CD45, CD16, CD14, CD163, CD206, ICAM-1) in alveolar monocytes/macrophages from patients from both groups at baseline	at baseline
IL-1β, TXNIP, NLRP3, sRAGE, HMGB1, S100A12 measurements	- IL-1β, TXNIP, NLRP3, sRAGE, HMGB1, S100A12 measurements (duplicate ELISA) in the bronchoalveolar lavage fluid from patients from both groups at baseline	at baseline

Collaborators and Investigators

• Sponsor: University Hospital, Clermont-Ferrand
• Investigators: Principal Investigator: Mathieu JABAUDON, University Hospital, Clermont-Ferrand

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2015
• Primary Completion (Actual): September 1, 2016
• Study Completion (Actual): October 1, 2016

Study Registration Dates

• First Submitted: September 8, 2015
• First Submitted That Met QC Criteria: September 8, 2015
• First Posted (Estimate): September 10, 2015

Study Record Updates

• Last Update Posted (Actual): May 12, 2020
• Last Update Submitted That Met QC Criteria: May 9, 2020
• Last Verified: July 1, 2016

More Information

Terms related to this study

• Keywords: Inflammasome; Acute respiratory distress syndrome (ARDS); Receptor for advanced glycation end products (RAGE); Monocyte/Macrophage activation; Fluorescence-Activated Cell Sorting (FACS) analysis; Thioredoxin interacting protein (TXNIP); NOD-like receptor family, pyrin domain containing 3 (NLRP3)
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Lung Diseases; Infant, Newborn, Diseases; Lung Injury; Infant, Premature, Diseases; Respiratory Distress Syndrome; Respiratory Distress Syndrome, Newborn; Acute Lung Injury
• Other Study ID Numbers: CHU-0243