Matysiak-Budnik T, Terpend K, Alain S, Sanson le Pors M J, Desjeux J F, Mégraud F, Heyman M
INSERM CJF 97-10, Faculté Necker Enfants Malades, Paris, France.
Infect Immun. 1998 Dec;66(12):5785-91. doi: 10.1128/IAI.66.12.5785-5791.1998.
To study the influence of Helicobacter pylori on epithelial barrier function, bacteria, bacterial sonicates, or broth culture supernatants were incubated for 24 h with HT29-19A intestinal cells grown as monolayers. Subsequently, the monolayers were mounted in Ussing chambers, and electrical resistance (R), fluxes of 22Na (JNa) and 14C-mannitol (JMan) (markers of the paracellular pathway), and fluxes of horseradish peroxidase (HRP) in total (J3H-HRP), intact (JHRPi), and degraded forms were measured. H. pylori did not induce any modification of the paracellular pathway (R = 148 +/- 10 versus 174 +/- 16 Omega. cm2; JNa = 4.16 +/- 0.44 versus 3.51 +/- 0.41 microEq/h. cm2; JMan = 0.081 +/- 0.01 versus 0.058 +/- 0.009 micromol/h. cm2), nor did it modify J3H-HRP (2,201 +/- 255 versus 2, 110 +/- 210 ng/h. cm2 for H. pylori-infected and control cells, respectively). However, in the presence of H. pylori, we observed a significant increase in JHRPi (520 +/- 146 versus 171 +/- 88 ng/h. cm2). This effect was not dependent of the cag status of the strain and was not reproduced by the sonicates or the culture supernatants. It was related to the presence of urease, since a urease-negative mutant of H. pylori did not induce this effect. Ammonia and bafilomycin A1, two agents known to increase the endolysosomal pH, reproduced the increase in JHRPi. In conclusion, H. pylori does not affect directly the integrity of intercellular junctions of epithelial cells in vitro, but it increases the passage of intact HRP, probably by inhibition of the intralysosomal degradation due to the release of ammonia. The increased transport of intact macromolecules may contribute to the induction and maintenance of gastric inflammation by H. pylori.
为研究幽门螺杆菌对上皮屏障功能的影响，将细菌、细菌超声裂解物或肉汤培养上清液与单层生长的HT29 - 19A肠细胞孵育24小时。随后，将单层细胞置于尤斯灌流小室中，测量跨上皮电阻（R）、22Na通量（JNa）和14C - 甘露醇通量（JMan）（细胞旁途径的标志物）以及辣根过氧化物酶（HRP）的总通量（J3H - HRP）、完整形式通量（JHRPi）和降解形式通量。幽门螺杆菌未引起细胞旁途径的任何改变（R = 148±10对174±16Ω·cm2；JNa = 4.16±0.44对3.51±0.41μEq/h·cm2；JMan = 0.081±0.01对0.058±0.009μmol/h·cm2），也未改变J3H - HRP（幽门螺杆菌感染细胞和对照细胞分别为2201±255对2110±210 ng/h·cm2）。然而，在幽门螺杆菌存在的情况下，我们观察到JHRPi显著增加（520±146对171±88 ng/h·cm2）。这种效应不依赖于菌株是否携带cag致病岛，且超声裂解物或培养上清液无法重现该效应。它与脲酶的存在有关，因为幽门螺杆菌的脲酶阴性突变体不会诱导这种效应。氨和巴弗洛霉素A1这两种已知可提高内溶酶体pH值的试剂，重现了JHRPi的增加。总之，幽门螺杆菌在体外不会直接影响上皮细胞间连接的完整性，但它可能通过氨的释放抑制溶酶体内降解，从而增加完整HRP的通透。完整大分子转运的增加可能有助于幽门螺杆菌诱导和维持胃部炎症。
