Open Access Research

Extracellular matrix proteins and displacement of cultured fibroblasts from duodenal biopsies in celiac patients and controls

Leda Roncoroni13*, Luca Elli1, Maria Teresa Bardella1, Gianluca Perrucci2, Michele Ciulla2, Vincenza Lombardo1, Carolina Tomba1, Dario Conte1 and Luisa Doneda3

Author Affiliations

1 Center for the Prevention and Diagnosis of Celiac Disease, Gastroenterology Unit II, Fondazione IRCCS Ca’ Granda - Ospedale Maggiore Policlinico and Università degli Studi di Milano, Via F. Sforza 35, Milan, 20122, Italy

2 Department of Clinical and Community Sciences, Università degli Studi di Milano, Via F. Sforza 35, Milan, 20122, Italy

3 Department of Biomedical, Surgical and Odontoiatric Sciences, Università degli Studi di Milano, Via Festa del Perdono 7, Milan, 20122, Italy

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Journal of Translational Medicine 2013, 11:91  doi:10.1186/1479-5876-11-91

Published: 8 April 2013

Abstract

Background

Celiac disease (CD) is mainly characterised by villous atrophy and mucosal architectural rearrangement. The fibroblasts (FBs) are the most abundant mesenchymal cell type in the intestinal mucosa and are responsible for both the architectural arrangement of the villi and the formation of the extracellular matrix (ECM). This study aimed at the evaluation of both the intracellular distribution of different proteins involved in ECM and FBs characterisation, and the cellular displacement of primary FBs obtained from duodenal endoscopic biopsies of healthy subjects and celiac patients.

Methods

Primary healthy and celiac duodenal FBs were evaluated by means of immuno-fluorescence assay for collagen type I and IV, fibronectin, actin, alpha-Smooth Muscle Actin (alpha-SMA), Fibroblast Surface Protein (FSP) and transglutaminase type 2 (TG2). The geometric indexes of the fluorescence signals were investigated by image analysis software (Image J, NIH). Both morphology and kinetic were evaluated during a 72 hours time course movie. TG2 medium activity was evaluated by means of ELISA.

Results

All the cells examined were immunopositive for FSP, alpha-SMA, actin, collagen I, collagen IV and TG2. CD cells showed a signet collagen-I and collagen-IV pattern, as compared to the controls being characterised by a spindle geometry. Moreover, the collagen signals in CD FBs showed a significantly higher circularity index (major orthogonal diameter ratio) than the controls (p < 0.0001), whereas the perimeter and area ratio were significantly lower (p < 0.0001). The TG2 signal had a decreased area (p < 0.05), but a two-fold increased medium activity. The time course highlighted a reduction of the displacement of CD FBs.

Conclusions

The isolated primary CD FBs showed a different collagen and TG2 pattern of distribution associated with a different cellular displacement. The reasons for such CD cell peculiar characteristics are yet unknown but they might represent a factor in the progression of the intestinal damage.

Keywords:
Celiac disease; Fibroblasts; Extracellular matrix; Collagen; Tissue transglutaminase; Transglutaminase type 2