Lipid mapping of colonic mucosa by cluster TOF-SIMS imaging and multivariate analysis in cftr knockout mice

Olivier Laprévote,Alexandre Seyer,Marc Brulet,Mario Ollero,Aleksander Edelman,Alain Brunelle,Janine Fritsch

doi:10.1194/jlr.m008870

Abstract

The cftr knockout mouse model of cystic fibrosis (CF) shows intestinal obstruction; malabsorption and inflammation; and a fatty acid imbalance in intestinal mucosa. We performed a lipid mapping of colon sections from CF and control (WT) mice by cluster time of flight secondary-ion mass spectrometry (TOF-SIMS) imaging to localize lipid alterations. Data were processed either manually or by multivariate statistical methods. TOF-SIMS analysis showed a particular localization for cholesteryl sulfate at the epithelial border, C16:1 fatty acid in Lieberkühn glands, and C18:0 fatty acid in lamina propria and submucosa. Significant increases in vitamin E (vE) and C16:0 fatty acid in the epithelial border of CF colon were detected. Principal component analysis (PCA) and partitioning clustering allowed us to characterize different structural regions of colonic mucosa according to variations in C14:0, C16:0, C16:1, C18:0, C18:1, C18:2, C20:3, C20:4, and C22:6 fatty acids; phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol glycerolipids; cholesterol; vitamin E; and cholesteryl sulfate. PCA on spectra from Lieberkühn glands led to separation of CF and WT individuals. This study shows for the first time the spatial distribution of lipids in colonic mucosa and suggests TOF-SIMS plus multivariate analyses as a powerful tool to investigate disease-related tissue spatial lipid signatures.

Highlights

The cftr knockout mouse model of cystic fibrosis (CF) shows intestinal obstruction; malabsorption and inflammation; and a fatty acid imbalance in intestinal mucosa
Colon sections from three WT and three CF mice were analyzed by TOF-SIMS in the negative ion mode
Some ion signatures are characteristic of the lamina propria and submucosa (C18:0) of Lieberkühn glands (LG) (C16:0) and the epithelial border (CS, C18:2)

Summary

Introduction

The cftr knockout mouse model of cystic fibrosis (CF) shows intestinal obstruction; malabsorption and inflammation; and a fatty acid imbalance in intestinal mucosa. Lipid mapping of colonic mucosa by cluster TOF-SIMS imaging and multivariate analysis in cftr knockout mice. Cystic fibrosis (CF), an autosomal recessive inherited disorder caused by mutations in the cystic fibrosis transmembrane regulator (CFTR) gene Among other symptoms, it is characterized by meconium ileus, one of the earliest manifestations, and in adults, distal intestinal obstruction [1], abnormal absorption and assimilation of nutrients [2], and chronic intestinal inflammation [3, 4]. The functions of CFTR, a chloride channel, in the intestine include fluid secretion and pH regulation by modulation of ClϪ, Na+, and bicarbonate transport through the epithelium [8] These two functions are not sufficient to explain all the pathologic manifestations associated with CF.

Methods

Results

Conclusion