Brush cells in the human duodenojejunal junction: an ultrastructural study - PubMed (original) (raw)

Brush cells in the human duodenojejunal junction: an ultrastructural study

Manrico Morroni et al. J Anat. 2007 Jul.

Abstract

Brush cells have been identified in the respiratory and gastrointestinal tract mucosa of many mammalian species. In humans they are found in the respiratory tract and the gastrointestinal apparatus, in both the stomach and the gallbladder. The function of brush cells is unknown, and most morphological data have been obtained in rodents. To extend our knowledge of human brush cells, we performed an ultrastructural investigation of human small intestine brush cells. Six brush cells identified in five out of more than 300 small intestine biopsies performed for gastrointestinal tract disorders were examined by transmission electron microscopy. Five brush cells were located on the surface epithelium and one in a crypt. The five surface brush cells were characterized by a narrow apical pole from which emerged microvilli that were longer and thicker than those of enterocytes. The filamentous core extended far into the cell body without forming the terminal web. Caveolae were abundant. Filaments were in the form of microfilaments and intermediate filaments. Cytoplasmic projections containing filaments were found on the basolateral surface of brush cells. In a single cell, axons containing vesicles and dense core granules were in close contact both with the basal and the lateral surface of the cell. The crypt brush cell appeared less mature. We concluded that human small intestine brush cells share a similar ultrastructural biology with those of other mammals. They are polarized and well-differentiated cells endowed with a distinctive cytoskeleton. The observation of nerve fibres closely associated with brush cells, never previously described in humans, lends support to the hypothesis of a receptor role for these cells.

PubMed Disclaimer

Figures

Fig. 1

Fig. 1

Toluidine blue-stained semithin section of a human intestinal villous portion. A cell among the enterocytes (arrow) has been identified as a brush cell by electron microscopy. Some lymphocytes (L) and goblet cells (*) among the enterocytes are also evidenced. E, epithelium; LP, lamina propria. Scale bar = 13.5 µm.

Fig. 2

Fig. 2

General appearance of a human small intestinal brush cell: note the narrow apex and the tuft of microvilli (Mi). The cellular surface forms finger-like projections (arrowheads). Inset: enlargement of the apex showing the long filamentous core (FC) and caveolae (Ca). The cytoplasmic projections also contain filaments. Gl, glycogen; RER, rough endoplasmic reticulum. Scale bar = 0.7 µm; inset scale bar = 0.4 µm.

Fig. 3

Fig. 3

High magnification of the apical part of the brush cell shown in Fig. 1. Note both the long bundles of straight filaments (FC) extending from the core of microvilli (Mi) deep into the cytoplasm and a cytoplasmic projection (*) on the lateral border penetrating into the enterocyte (E). F, filaments; G, Golgi apparatus; Ly, lysosomes; M, mitochondria; N, nucleus. Scale bar = 0.25 µm.

Fig. 4

Fig. 4

Two nerve fibres (arrows) in contact both with the basal and with the lateral portion of a human small intestine brush cell (BC). Inset: high magnification showing vesicles and dense core granules in the basal axon. Scale bar = 1.3 µm; inset scale bar = 0.2 µm.

Fig. 5

Fig. 5

High magnification of the apical part of the brush cell (BC) shown in Fig. 4. Note the close contact with the lateral nerve fibre (arrow). Scale bar = 0.45 µm.

Fig. 6

Fig. 6

Human small intestinal crypt. A brush cell (BC) between two goblet cells (GC). Note the immature appearance of the cell. L, lumen. Scale bar = 1.3 µm.

References

    1. Barkla DH, Whitehead RH, Foster H, Tutton PJM. Tuft (caveolated) cells in two human colon carcinoma cell lines. Am J Pathol. 1988;132:521–525. - PMC - PubMed
    1. Basset F, Poirier J, Le Crom M, Turiaf J. Ultrastructural study of the human bronchiolar epithelium. Z Zellforsch Mikrosk Anat. 1971;116:425–442. - PubMed
    1. Carstens PHB, Broghamer WL, Hire D. Malignant fibrillo-caveolated cell carcinoma of the human intestinal tract. Hum Pathol. 1976;7:505–517. - PubMed
    1. Cerezo L, Price G. Absence of cilia and basal bodies with predominance of brush cells in the respiratory mucosa from a patient with immotile cilia syndrome. Ultrastruct Pathol. 1985;8:381–382. - PubMed
    1. Chang L-Y, Mercer RR, Crapo JD. Differential distribution of brush cells in the rat lung. Anat Rec. 1986;216:49–54. - PubMed

Publication types

MeSH terms

LinkOut - more resources