Histone acetylation/deacetylation changes in patients with Coeliac Disease

Grant: 003/2024

• Title: Histone acetylation/deacetylation changes in patients with Coeliac Disease.
• Duration: 3 Years Project
• Principal Investigator: Fabiana Zingone, University of Padua, Italy

THE STUDY

Background

Coeliac disease (CeD) is an autoimmune, multifactorial enteropathy triggered by gluten ingestion in genetically predisposed individuals. The only treatment is a lifelong gluten-free diet (GFD), which typically results in symptom disappearance, normalization of serum autoantibodies, mucosal recovery, and prevention of long-term complications. However, 7-30% of patients are non-responsive to the diet (NR-CeD). Histone acetylation/deacetylation, regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs), is an epigenetic mechanism involved in intestinal inflammation. HDAC inhibitors can reduce this inflammation.

Hypothesis, Rationale and Aims

NR-CeD may be due to non-gluten-related conditions (false-NR) or persistent duodenal damage (true-NR), such as gluten contamination, slow responsiveness, or CeD complications.

We hypothesize that:

Histone acetylation and deacetylation in duodenal mucosa of CeD patients differ from non-CeD subjects and change during GFD, showing distinct pa􀁏erns in true-NR vs. false-NR.

Histone acetylation and deacetylation in lamina propria mononuclear cells (LPMC) and peripheral blood mononuclear cells (PBMC) change during GFD, with differences among responders, true-NR, and false-NR, and between CeD and non-CeD subjects.

Primary aim: to analyze and compare histone acetylation and HDAC expression in the duodenal mucosa of CeD patients at diagnosis versus non-CeD subjects and to identify changes during a GFD. This includes assessing differences in patterns between true-NR and false-NR.

Secondary aim: to investigate histone acetylation and HDAC expression/activity in LPMC and PBMC at diagnosis and on a GFD, discerning variations among responders, true-NR, and false-NR. Moreover, we will compare histone acetylation and HDAC expression/activity in PBMC in CeD patients with those in non-CeD subjects.

Research Plan (Experimental design and Methodologies)

The first part of the project has a retrospective design. Formalin-fixed paraffin-embedded biopsies from CeD patients will be retrieved from the Pathology archive of the Azienda Ospedale Università Padova at two different time points: at CeD diagnosis (T0) and after at least 6 months on a GFD (T1). Duodenal biopsies from non-CeD subjects will also be collected. Demographic, clinical, endoscopic, and histological characteristics of patients at both time points will be retrieved from medical records. Freshly cut sections will be analyzed by immunofluorescence (IF) for acetylated H3 and by immunohistochemistry (IHC) for HDAC expression.

The second part has a prospective design and will focus on HATs and HDAC activity and expression in specific immune cells. Clinical and serological responses to a GFD will be assessed at 6 and 12 months through urinary tests and questionnaires to monitor dietary compliance. Peripheral blood samples will be collected at diagnosis and after 6 and 12 months. Additionally, four biopsies from the second duodenum will be collected during endoscopy at baseline, and an additional four biopsies will be collected at follow-up from patients with NR-CeD.

Expected results and Impact on Celiac disease

We expected to anticipate distinct histone acetylation and HDAC expression patterns among CeD, controls, responders, false-NR, and true-NR patients. Moreover, we expect to identify unique epigenetic patterns in peripherical blood that correlate with intestinal mucosa expression and differ from non-CeD subjects. Finally, identifying epigenetic mechanisms in NR-CeD may reveal new therapeutic targets as adjuncts to GFD or alternative therapies.

This study will provide novel insights into epigenetic roles in CeD pathogenesis and treatment response. Moreover, predicting GFD response through epigenetic markers could lead to personalized treatment and offering alternative therapies for non-responders.