Expression of ezrin in human embryonic, fetal, and normal adult tissues

Abstract

Ezrin, which cross-links the cytoskeleton and plasma membrane, was involved in a wide variety of cellular processes. Here, to investigate the distribution of ezrin, tissue microarray technology was employed to perform immunohistochemical experiments on human embryos, fetuses at 4 to 22 weeks' gestation, and adult tissue specimens. Results showed that ezrin was widely expressed in the gastrointestinal tract throughout the human developmental stages studied. At 6 to 8 weeks' gestation, ezrin was found in epithelial cells, and this staining pattern was particularly pronounced in the brush border of mature absorptive cells lining the villus in later developmental stages and adult tissues. Throughout neural development, ezrin was only expressed in the neural tube at 4 weeks' gestation. Ezrin was also detected in the cortex and medulla of the adrenal gland at 8 to 12 weeks' gestation, whereas its immunoreactivity was increased from the zona glomerulosa through the zona reticularis and was essentially undetectable in the adrenal medulla of adult tissues. Significant expression of ezrin was seen throughout development in the kidney, spleen, lymph nodes, and cells of stratified squamous epithelia. However, ezrin was undetectable in lung, liver, heart, and blood vessels. These results demonstrated that the expression pattern of ezrin was highly time specific and tissue specific.

Figure 1.

Western blotting analysis of extracts from two esophageal cancer cell lines by using different ezrin antibodies. (A) Blotted by using Ezrin/Radixin/Moesin Antibody (Cell Signaling Technology, #3142). This antibody has cross-reactivity with radixin and moesin and is recommended for detection of ezrin, radixin, and moesin. (B) Blotted by using Ezrin (C19) Antibody (Santa Cruz Biotechnology, sc6407). This antibody also has cross-reactivity with radixin and moesin and is recommended for detection of ezrin, radixin, and moesin. (C) Blotted by using Ezrin (3C12) Antibody (Lab Vision, #MS-661-P). This antibody is recommended for detection of ezrin.

Figure 2.

Expression of ezrin in the alimentary system and the nervous system of human embryonic, fetal, and normal adult tissues. Ezrin-positive reactivity was defined as those showing brown spotting. (A) Ezrin was positive in adult intestine (40×). (B) Ezrin protein was mainly expressed in the brush border (triangles) of the absorptive cells of the gastrointestinal tract (200×). (C) Immunoreactivity for ezrin was present in epithelial cells (triangles) and smooth muscle cells (arrows) of the gastrointestinal tract at 8 weeks’ gestation (200×). Ezrin was expressed in adult esophagus (D, 40×) but was undetectable in liver tissues (E, 40×). (F) Medullary epithelium and all nerve cells showed significant expression of ezrin at 4 weeks’ gestation (200×). (G–H) Ezrin was undetectable in the nervous system of fetuses and adults. (G) Cerebrum (40×). (H) Nerve fibers and cells of the cerebrum (200×). (I) Cerebellum (40×). (J) Cells of Purkinje cell layer (arrows), granular layer, and molecular layer of the cerebellum (200×).

Figure 3.

Expression of ezrin in the genitourinary system, endocrine system, and other systems of human embryonic, fetal, and normal adult tissues. (A) Ezrin showed a strong staining in epithelial cells of the acinus renis (40×). (B) Ezrin was strongly positive in the acinus renis (triangles) and epithelial cells of the pars convoluta of the proximal tubule (arrowheads) and moderately positive in epithelial cells of the distal tubule (arrows) at 22 weeks’ gestation (200×). (C) Ezrin was undetectable in adult thyroid (40×). (D) At 12 weeks’ gestation, adrenal cortex and medulla showed strong reactivity (200×). (E) Ezrin was positive in the adult adrenal gland (40×). (F) In normal adult adrenal gland, ezrin immunoreactivity was exhibited in cells of the zona reticularis (arrow) and decreased in the zona glomerulosa (rectangle) and undetectable entirely in the medulla (triangle) (200×). Ezrin was undetectable in adult heart (G, 40×) and lung (H, 40×) but weakly positive in adult spleen (I, 40×). (J) Ezrin protein was present in subcapsular lymphocytes of the thymus and pronounced in Hassall’s corpuscle epithelial cells (triangle) (200×).