Volume 115, Issue 4, Pages 841-848 (October 1998) Differential lamina propria cell migration via basement membrane pores of inflammatory bowel disease mucosa  Mark E. McAlindon*, Trevor Gray‡, Alison Galvin§, Herbert F. Sewell§, Daniel K. Podolsky∥, Yashwant R. Mahida*  Gastroenterology  Volume 115, Issue 4, Pages 841-848 (October 1998) DOI: 10.1016/S0016-5085(98)70255-0 Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 1 Transmission electron micrograph of an untreated ileal mucosal sample with active Crohn's disease. Epithelial cells (E) lie on top of the basement membrane (arrow). A prominent tunnel (T), containing lymphocytes, is present in the lamina propria (bar = 2 μm). Gastroenterology 1998 115, 841-848DOI: (10.1016/S0016-5085(98)70255-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 2 Transmission electron micrograph of untreated mucosal sample with active ulcerative colitis. (A) Numerous PMNs (N) are present in the epithelium (E), in transit to the lumen (L). Two PMNs are migrating through a pore (asterisk) in the basement membrane (arrow). (B) A PMN (N) has migrated from the lamina propria, through the epithelium (E), into the lumen. A pore (asterisk) is present in the basement membrane (arrow). The lamina propria consists of extracellular matrix (M) and tunnels (T) containing cells. Bar = (A) 5 μm and (B) 1 μm. Gastroenterology 1998 115, 841-848DOI: (10.1016/S0016-5085(98)70255-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 2 Transmission electron micrograph of untreated mucosal sample with active ulcerative colitis. (A) Numerous PMNs (N) are present in the epithelium (E), in transit to the lumen (L). Two PMNs are migrating through a pore (asterisk) in the basement membrane (arrow). (B) A PMN (N) has migrated from the lamina propria, through the epithelium (E), into the lumen. A pore (asterisk) is present in the basement membrane (arrow). The lamina propria consists of extracellular matrix (M) and tunnels (T) containing cells. Bar = (A) 5 μm and (B) 1 μm. Gastroenterology 1998 115, 841-848DOI: (10.1016/S0016-5085(98)70255-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 3 Scanning electron micrograph of an untreated mucosal sample with active Crohn's disease. Loss of epithelial cells has led to a small, superficial ulcer, which is bordered by viable epithelial cells (E). The exposed basement membrane contains numerous pores. Arrows show cells at various stages of migration out of the lamina propria, via the basement membrane pores (bar = 30 μm). Gastroenterology 1998 115, 841-848DOI: (10.1016/S0016-5085(98)70255-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 4 Scanning electron micrograph of an untreated mucosal sample with active ulcerative colitis. Loss of epithelial cells (leading to a superficial ulcer) has exposed the basement membrane, which contains numerous large pores (some of which are shown by small arrows). Large arrows show cells migrating out of the lamina propria through some of the pores. A portion of the basement membrane (asterisk) has everted, exposing the underlying lamina propria matrix and cells. Epithelial cells (E) at the ulcer edge are also seen (bar = 30 μm). Gastroenterology 1998 115, 841-848DOI: (10.1016/S0016-5085(98)70255-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 5 Scanning electron micrographs of samples of (A) normal colonic mucosa and (B-D) mucosa with active ulcerative colitis after removal of epithelial cells (before culture). Numerous large, irregular basement membrane pores are present in the ulcerative colitis samples. (A) Analysis of scanning electron micrographs of the denuded normal mucosa showed that 0.01% of the surface area of the basement membrane is occupied by 19 pores. (B) In scanning electron micrographs of denuded ulcerative colitis sample, 22% of the surface area is occupied by 110 pores. (C and D) Areas of the basement membrane are virtually obliterated, leaving an irregular meshwork of underlying extracellular matrix and cells in tunnels. Bar = (A and B) 15 μm, (C) 30 μm, and (D) 25 μm. Gastroenterology 1998 115, 841-848DOI: (10.1016/S0016-5085(98)70255-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 5 Scanning electron micrographs of samples of (A) normal colonic mucosa and (B-D) mucosa with active ulcerative colitis after removal of epithelial cells (before culture). Numerous large, irregular basement membrane pores are present in the ulcerative colitis samples. (A) Analysis of scanning electron micrographs of the denuded normal mucosa showed that 0.01% of the surface area of the basement membrane is occupied by 19 pores. (B) In scanning electron micrographs of denuded ulcerative colitis sample, 22% of the surface area is occupied by 110 pores. (C and D) Areas of the basement membrane are virtually obliterated, leaving an irregular meshwork of underlying extracellular matrix and cells in tunnels. Bar = (A and B) 15 μm, (C) 30 μm, and (D) 25 μm. Gastroenterology 1998 115, 841-848DOI: (10.1016/S0016-5085(98)70255-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 5 Scanning electron micrographs of samples of (A) normal colonic mucosa and (B-D) mucosa with active ulcerative colitis after removal of epithelial cells (before culture). Numerous large, irregular basement membrane pores are present in the ulcerative colitis samples. (A) Analysis of scanning electron micrographs of the denuded normal mucosa showed that 0.01% of the surface area of the basement membrane is occupied by 19 pores. (B) In scanning electron micrographs of denuded ulcerative colitis sample, 22% of the surface area is occupied by 110 pores. (C and D) Areas of the basement membrane are virtually obliterated, leaving an irregular meshwork of underlying extracellular matrix and cells in tunnels. Bar = (A and B) 15 μm, (C) 30 μm, and (D) 25 μm. Gastroenterology 1998 115, 841-848DOI: (10.1016/S0016-5085(98)70255-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 5 Scanning electron micrographs of samples of (A) normal colonic mucosa and (B-D) mucosa with active ulcerative colitis after removal of epithelial cells (before culture). Numerous large, irregular basement membrane pores are present in the ulcerative colitis samples. (A) Analysis of scanning electron micrographs of the denuded normal mucosa showed that 0.01% of the surface area of the basement membrane is occupied by 19 pores. (B) In scanning electron micrographs of denuded ulcerative colitis sample, 22% of the surface area is occupied by 110 pores. (C and D) Areas of the basement membrane are virtually obliterated, leaving an irregular meshwork of underlying extracellular matrix and cells in tunnels. Bar = (A and B) 15 μm, (C) 30 μm, and (D) 25 μm. Gastroenterology 1998 115, 841-848DOI: (10.1016/S0016-5085(98)70255-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 6 Scanning electron micrograph of a colonic mucosal sample with active ulcerative colitis, denuded of epithelial cells and cultured for 24 hours. Numerous cells are migrating out of the lamina propria via pores in the basement membrane (arrows) (bar = 40 μm). Gastroenterology 1998 115, 841-848DOI: (10.1016/S0016-5085(98)70255-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 7 Phenotype of lamina propria cells migrating out of mucosal samples with active IBD (four ulcerative colitis, two Crohn's colitis), denuded of epithelial cells and cultured for 3, 3-24, or 24-48 hours. Phenotype of the cells was determined in cytospin preparations. Number of cells migrating per gram tissue per hour: 0-3 hours: 3.3 (±0.8) × 105; 3-24 hours: 1.1 (±0.3) × 105; 24-48 hours: 1.2 (±0.4) × 105 cells. Gastroenterology 1998 115, 841-848DOI: (10.1016/S0016-5085(98)70255-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions