Differences in the expression of chromosome 1 genes between lung telocytes and other cells: mesenchymal stem cells, fibroblasts, alveolar type II cells, airway epithelial cells and lymphocytes

Abstract

Telocytes (TCs) are a unique type of interstitial cells with specific, extremely long prolongations named telopodes (Tps). Our previous study showed that TCs are distinct from fibroblasts (Fbs) and mesenchymal stem cells (MSCs) as concerns gene expression and proteomics. The present study explores patterns of mouse TC-specific gene profiles on chromosome 1. We investigated the network of main genes and the potential functional correlations. We compared gene expression profiles of mouse pulmonary TCs, MSCs, Fbs, alveolar type II cells (ATII), airway basal cells (ABCs), proximal airway cells (PACs), CD8(+) T cells from bronchial lymph nodes (T-BL) and CD8(+) T cells from lungs (T-LL). The functional and feature networks were identified and compared by bioinformatics tools. Our data showed that on TC chromosome 1, there are about 25% up-regulated and 70% down-regulated genes (more than onefold) as compared with the other cells respectively. Capn2, Fhl2 and Qsox1 were over-expressed in TCs compared to the other cells, indicating that biological functions of TCs are mainly associated with morphogenesis and local tissue homoeostasis. TCs seem to have important roles in the prevention of tissue inflammation and fibrogenesis development in lung inflammatory diseases and as modulators of immune cell response. In conclusion, TCs are distinct from the other cell types.

Keywords: airway epithelial cells; alveolar type II cells; chromosome 1; fibroblasts; genes; lung; lymphocytes; mesenchymal stem cells; telocytes.

Fig. 1

Expression profiles of the selected genes as an active group on chromosome 1 of telocytes (TCs), isolated and cultured from mouse lungs, on days 5 (D5) and 10 (D10), as compared with mesenchymal stem cells (MSCs), fibroblasts (Fbs), alveolar type II (ATII), airway basal cells (ABCs), proximal airway cells (PACs), lymphocytes (Lym) from bronchial lymph nodes and lung respectively (A). The profiles for entire genes are described in Data S1. The selected core network and whole mouse network are linked by the documented functional interactions from various databases (see Material and methods). Genes in each network are indicated in red and some of their nearest neighbours are indicated by grey nodes. A group of TC genes up- or down-regulated more than onefold as compared with the other cells and present in TCs on days 5 and/or 10 was selected as TC-specific genes. Top 61 up- or down-regulated genes of each cell were also evaluated and their distribution within chromosome 1 genes showed the difference between cells (B). Details of the selected network in each cell type are in Figures S1–9.

Fig. 2

Hierarchical cluster analysis of the differentially expressed genes among telocytes (TCs), mesenchymal stem cells (MSCs), fibroblasts (Fbs), proximal airway cells (PACs), airway basal cells (ABCs) alveolar type II cells (ATII), and lymphocytes from lungs (T-LL) and bronchial lymph nodes (T-BL).