Exploration of the Activity of DNA Located Outside of Cellular Nucleus to Amplify Inflammation in Inflammatory Bowel Disease in Children Through Biological Pathway Cyclic GMP-AMP Synthase (cGAS) - Stimulator of Interferon Genes (STING) (ROXANE)

June 14, 2023 updated by: Centre Hospitalier Régional d'Orléans

Pro-inflammatory Role of Extracellular DNA in Inflammatory Bowel Disease in Children: Study of the cGAS-STING Pathway

Frequency of Inflammatory Bowel Diseases in children (IBD)-Crohn's disease (CD), Ulcerative colitis (UC) is constantly increasing. Pediatric-onset IBD represent a different nosological entity (from adult IBD) because of their major inflammatory activity, their significant anatomical extent and their stenotic and/or fistulizing character sometimes from diagnosis. Intestinal lesions are due to dysregulation of the intestinal immune system but the cause is unknown. The investigators hypothesize that extranuclear DNA participates in the amplification of the inflammatory response at the intestinal and blood levels during pediatric IBD through the cGAS-STING pathway. The investigators will analyse blood and fecal samples, and colonic biopsies issued from ill children and control participants on age of 6 to 17 years. The investigators think that this study will provide a better understanding of the mechanisms involved in pediatric IBD, assess the place of the cGAS-STING pathway, identify potential biomarkers of pediatric IBD and new potential therapeutic targets based in particular on the inhibition of the cGAS-STING pathway.

Study Overview

Detailed Description

Inflammatory Bowel Diseases in children (IBD)-Crohn's disease (CD), ulcerative colitis (UC) are severe pathology that can affect the entire digestive tract. Their annual incidence is however constantly increasing.

IBD are complex multifactorial pathologies whose cause is still unknown today. IBD occurs on a predisposing genetic background in the presence of exogenous factors and alteration of the intestinal microbiota. Intestinal lesions are due to dysregulation of the intestinal immune system with increased secretion of pro-inflammatory cytokines at the expense of anti-inflammatory cytokines.

Pediatric-onset IBD represent a different nosological entity (from adult IBD) because of their major inflammatory activity, their significant anatomical extent and their stenotic and/or fistulizing character sometimes from diagnosis. Their impact is not only individual (growth retardation, puberty delay, psychological disorders) but also family/parental, school and social. These particularities justify that biomedical research focuses on it in a more specific way.

Extracellular and extranuclear DNA (enDNA) play a major role in innate immunity by stimulating pro-inflammatory responses and activating type I interferon production. The pro-inflammatory action of enDNA is mediated by enzyme cGAS, protein STING, toll-like receptor 9 (TLR9), and the inflammasome complex NLRP3.

The investigators hypothesize that enDNA participates in the amplification of the inflammatory response at the intestinal and blood levels during pediatric IBD through the cGAS-STING pathway. They also hypothesize that there are links between the cGAS-STING pathway and other pathways involved in pediatric IBD such as NOD2 and Autophagy. The investigators will analyse blood and fecal samples, and colonic biopsies issued from ill children and controls on age of 6 to 17 years. The investigators think that this study will provide a better understanding of the mechanisms involved in pediatric IBD, assess the place of the cGAS-STING pathway, identify potential biomarkers of pediatric IBD and new potential therapeutic targets based in particular on the inhibition of the cGAS-STING pathway.

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

      • Orléans, France
        • Recruiting
        • CHR Orléans
        • Contact:
          • Georges DIMITROV, MD
        • Principal Investigator:
          • Georges DIMITROV

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Participants aged from 6 years inclusive to 17 years inclusive
  • Boys and girls
  • Presenting an IBD or suspicion of IBD
  • Requiring a colonoscopy for diagnosis or follow-up or other reason (abdominal pain, diarrhoea, rectal bleeding, weight loss) not confirming the diagnosis of Crohn's disease or Ulcerative Colitis
  • Active IBD if:

    • CD: PCDAI score >5 and CRP>20mg/L and faecal calprotectin> 400 µg/g
    • UC: PUCAI score>10 and faecal calprotectin>250 µg/g
  • IBD in remission if:

    • CD: PCDAI score<5 and CRP<20mg/L and faecal calprotectin<400 µg/g
    • UC: PUCAI score <10 and faecal calprotectin < 250 µg/g
  • Patients and their parents who gave their consent to participate in the study

Exclusion Criteria:

  • Refusal of the participant and/or one of his two parents
  • Body weight less than or equal to 20 kg
  • Blood hemoglobin level less than or equal to 9 g/dl
  • Refusal or contraindication to general anesthesia
  • Co-existing severe chronic pathology and/or treatment that could interfere with the results of the study; example: trisomy 21, treatment with growth hormone etc.
  • Protected person (under guardianship or curatorship)
  • Person under legal protection
  • Person not affiliated to a social security scheme
  • Pregnant or breastfeeding woman

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Health Services Research
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Patients with samples
Blood and fecal samples, and colonic biopsies will be analysed and compared between 3 groups of participants :1/ Active IBD; 2/Inactive IBD; 3/Controls "non-IBD".
Blood and fecal samples will be performed
colonic biopsies will be analysed

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Amount of mRNA specific for colonic cGAS
Time Frame: Baseline
the comparison, between the 3 groups of patients, of the quantity of specific mRNA of colonic cGAS expressed as the number of "reads" during RNA sequencing (RNAseq), by a Mann-Whitney U test. It is planned from the outset to compare the groups 2 by 2, regardless of the result of an overall test such as a Kruskal-Wallis test.
Baseline

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
quantitative difference of amount of circulating mtDNA
Time Frame: Baseline
to find quantitative differences between the 3 groups concerning the circulating mtDNA, the circulating total DNA, by the qPCR technique: by specific primer sequences to identify the origin of the DNA (mitochondrial or nuclear). Results will be expressed by the -2∆∆Ct method ("fold increase") compared to the control.
Baseline
Cytokine response
Time Frame: Baseline
to find quantitative differences between the 3 groups concerning the cytokine response by Luminex®: in pg/ml or in ng/ml depending on the cytokines
Baseline
inflammatory / dysimmune response of cytokines
Time Frame: Baseline

to find quantitative differences between the 3 groups concerning the inflammatory / dysimmune response of cytokines, components of the cGAS-STING pathways autophagy, NOD2, intestinal mucins, integrins, cadherins by RNAseq type transcriptomic analysis in Transcript Per Million (TPM).

This outcome wil be mesured at the blood level abd the colonic level.

Baseline
Difference of DNA methylation by Methyl-Seq between the 3 groups
Time Frame: Baseline
to find quantitative differences between the 3 groups concerning the study of DNA methylation by Methyl-Seq. Results expessed in pourcentage of methylation. This outcome will be mesured at the bllod level and the colonic level.
Baseline
Activation (phosphorylation) of the components of the cGAS-STING pathway
Time Frame: Baseline
Activation (phosphorylation) of the components of the cGAS-STING pathway (proteins cGAS, p-CGAS, STING,p-STING,TBK1, p-TBK1,IRF-3, p-IRF-3) by Western-Blot
Baseline
plasma DNase activity
Time Frame: baseline
plasma DNase activity in Kunitz unitz
baseline
differences in microbial distribution
Time Frame: Baseline
search for quantitative differences in microbial distribution between the 3 groups by pyrosequencing RNA 16s of the microbiota at the fecal level
Baseline
quantity (number of "reads") of colonic STING-specific mRNA
Time Frame: Baseline
quantitative differences between the 3 groups concerning the quantity (number of "reads") of colonic STING-specific mRNA at the colonic level
Baseline
extracellular DNA by qPCR
Time Frame: Baseline
We will use specific primer sequences to identify the origin of the DNA (mitochondrial or nuclear). Results will be expressed by the -2∆∆Ct method ("fold increase") compared to the control. This outcome will be mesured at the colonic level.
Baseline
Amount of STING in the cytoplasm
Time Frame: Baseline
cytoplasmic presence of STING by histology, immunohistochemical staining and optical microscopy analysis. Results will be qualitative (present/absent; localization) and quantitative based on optical density (pourcentage of positive cells)
Baseline
Amount of cGAS in the cytoplasm
Time Frame: Baseline
cytoplasmic presence of cGAS by histology, immunohistochemical staining and optical microscopy analysis. Results will be qualitative (present/absent; localization) and quantitative based on optical density (pourcentage of positive cells)
Baseline
Amount of nuclear DNA in teh cytoplasm
Time Frame: Baseline
cytoplasmic presence of nuclear DNA by histology, immunohistochemical staining and optical microscopy analysis. Results will be qualitative (present/absent; localization) and quantitative based on optical density (pourcentage of positive cells)
Baseline
Amount of mitochondrial DNA in the cytoplasm
Time Frame: Baseline
cytoplasmic presence of mitochondrial DNA by histology, immunohistochemical staining and optical microscopy analysis. Results will be qualitative (present/absent; localization) and quantitative based on optical density (pourcentage of positive cells)
Baseline
Amount of colonic DNase activity
Time Frame: Baseline
Measurement of colonic DNase activity in Kunitz unitz
Baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Georges DIMITROV, MD, CHR d'Orléans

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 31, 2023

Primary Completion (Estimated)

June 1, 2026

Study Completion (Estimated)

June 1, 2026

Study Registration Dates

First Submitted

May 5, 2023

First Submitted That Met QC Criteria

June 14, 2023

First Posted (Actual)

June 23, 2023

Study Record Updates

Last Update Posted (Actual)

June 23, 2023

Last Update Submitted That Met QC Criteria

June 14, 2023

Last Verified

June 1, 2023

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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