Molecular regulation of urothelial renewal and host defenses during infection with uropathogenic Escherichia coli.
Uropathogenic Escherichia coli (UPEC), the principal cause of urinary tract infection in women, attaches to the superficial facet cell layer of the bladder epithelium (urothelium) via its FimH adhesin. Attachment triggers exfoliation of bacteria-laden superficial facet cells, followed by rapid reconstitution of the urothelium through differentiation of underlying basal and intermediate cells. We have used DNA microarrays to define the molecular regulators of urothelial renewal and host defense expressed in adult C57Bl/6 female mice during the early phases of infection with isogenic virulent (FimH+) or avirulent (FimH-) UPEC strains. The temporal evolution and cellular origins of selected responses were then characterized by real time quantitative reverse transcriptase-PCR, in situ hybridization, and immunohistochemical analyses. Well before exfoliation is evident, FimH-mediated attachment suppresses transforming growth factor-beta (Bmp4) and Wnt5a/Ca(2+) signaling to promote subsequent differentiation of basal/intermediate cells. The early transcriptional responses to attachment also include induction of regulators of proliferation (e.g. epidermal growth factor family members), induction of the ETS transcription factor Elf3, which transactivates genes involved in epithelial differentiation and host defense (inducible nitric-oxide synthase), induction of modulators, and mediators of pro-inflammatory responses (e.g. Socs3, Cebp/delta, Bcl3, and CC/CXC chemokines), induction of modulators of apoptotic responses (A20), and induction of intermediate cell tight junction components (claudin-4). Both early and late phases of the host response exhibit remarkable specificity for the FimH+ strain and provide new insights about the molecular cascade mobilized to combat UPEC-associated urinary tract infection.
Mysorekar
Indira U
IU
Department of Molecular Biology and Pharmacology, Washington University School of Medicine, 660 S Euclid Avenue, St. Louis, MO 63110, USA.
Mulvey
Matthew A
MA
Hultgren
Scott J
SJ
Gordon
Jeffrey I
JI
D018829:Adhesins, Bacterial / Q000235:genetics*; D018830:Adhesins, Escherichia coli; D000818:Animals; D017209:Apoptosis; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation; D002455:Cell Division; D062506:Claudin-4; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000472:pathogenicity*; D005260:Female; D036781:Fimbriae Proteins; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D020411:Oligonucleotide Array Sequence Analysis; D011485:Protein Binding; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D050783:Proto-Oncogene Proteins c-ets; D018075:RNA, Complementary / Q000378:metabolism; D051880:Receptors, Notch; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism; D014552:Urinary Tract Infections / Q000378:metabolism; D019459:Urothelium / Q000378:metabolism* / Q000382:microbiology*; D051153:Wnt Proteins; D000071818:Wnt-5a Protein
D018829:Adhesins, Bacterial; D018830:Adhesins, Escherichia coli; C568157:CLDN4 protein, human; D062506:Claudin-4; C568158:Cldn4 protein, mouse; D004268:DNA-Binding Proteins; C105529:ELF3 protein, human; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D018075:RNA, Complementary; D051880:Receptors, Notch; D014157:Transcription Factors; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; C438615:Wnt5a protein, mouse; C058769:fimH protein, E coli; D036781:Fimbriae Proteins; D002118:Calcium