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Urologic and gynaecologic patients often manifest congenital and/or acquired tissue and organ dysfunctions that require surgical reconstruction to recreate the normal genitourinary system functions. Such reconstruction is still a challenge due to the limited availability of suitable tissues, especially for severe urethral and vaginal replacement. Traditional intervention methods have varying degrees of donor site morbidity or inherent side effects. Interestingly, tissue engineering is a growing field that aims to replace or regenerate these dysfunctional tissues and organs with autologous cells, biomaterials, or a combination of both. Experience gained from tissue engineering suggests that the use of acellular matrices alone is not successful in supporting tissue growth over large surfaces. Cellular constituents need to be isolated, cultured and grown in vitro on scaffolds, then transplanted in vivo, in order to achieve successful three-dimensional tissue regeneration. Biomaterials are the backbone for cell-seeded reconstruction of the genitourinary tissues. Several research teams have explored a different cell culture approach based on self-assembly. This innovative technique relies on the capacity of cells cultured in the presence of ascorbate to secrete and deposit their own extracellular matrix forming a tissue-like substance. The mechanical and physical strength properties of these reconstructed tissues are similar to that of natural native tissues in certain models. Tissue engineered substitutes for urethral and vaginal mucosa were produced and subcutaneously grafted with success opening the way to new therapeutic strategies to correct genitourinary defects.

Nuclear factor κB (NF-κB) plays a key regulatory role in host cell responses toHelicobacter pyloriinfection in humans. Although mice are routinely used as a model to studyH. pyloripathogenesis, the role of NF-κB in murine cell responses to helicobacters has not been studied in detail. We thus investigated the abilities of differentHelicobacterisolates to induce NF-κB-dependent responses in murine gastric epithelial cells (GECs) and in transgenic mice harboring an NF-κB-responsivelacZreporter gene.H. pyloriandHelicobacter felisstrains up-regulated the synthesis in mouse GECs of the NF-κB-dependent chemokines KC (CXCL1) and MIP-2 (CXCL2). These responses werecagpathogenicity island (cagPAI) independent and could be abolished by pretreatment with a pharmacological inhibitor of NF-κB. Consistent with the in vitro data, experimentalHelicobacterinfection of transgenic mice resulted in increased numbers of GECs with nuclear β-galactosidase activity, which is indicative of specific NF-κB activation. The numbers of β-galactosidase-positive cells in mice were significantly increased at day 1 postinoculation with wild-typeH. pyloristrains harboring or not harboring a functionalcagPAI, compared to naive animals (P= 0.007 andP= 0.04, respectively). Strikingly, however, no differences were observed in the levels of gastric NF-κB activation at day 1 postinoculation withH. felisor at day 30 or 135 postinoculation withH. pylori. This work demonstrates for the first time the induction of NF-κB activation within gastric mucosal cells during acuteH. pyloriinfection. Furthermore, the data suggest that helicobacters may be able to regulate NF-κB signaling during chronic infection.

Helicobacter pylori has been reported to induce interleukin-6 (IL-6) production in monocytes/macrophages and in chronically inflamed gastric tissues. The mechanism by which H. pylori induces IL-6 production in macrophages, however, has not been investigated. To identify the H. pylori factor responsible for this activity, we fractionated soluble proteins from H. pylori strain 26695 by ion exchange and size exclusion chromatography and screened the fractions for IL-6-inducing activity on RAW 264.7 macrophages. A single protein was purified and identified by mass spectrometry as H. pylori heat shock protein 60 (HSP60). Consistent with the observed IL-6-inducing activity of H. pylori HSP60, soluble protein extracts of H. pylori 26695 and SS1 strains that were depleted of this protein by affinity chromatography had dramatically reduced IL-6-inducing activities. The immunopurified HSP60 stimulated IL-6 production in macrophages. When stimulated with H. pylori HSP60 or intact bacteria, peritoneal macrophages from mice deficient in Toll-like receptor (TLR)-2, TLR-4, TLR-2/TLR-4, and myeloid differentiation factor 88 produced the same amount of IL-6 than macrophages from wild-type mice, demonstrating the independence of H. pylori HSP60 responses from these signaling molecules. H. pylori HSP60-induced IL-6 mRNA expression, and NF-kappaB activation in RAW 264.7 cells was abrogated in the presence of MG-132, a proteasome inhibitor. In contrast, inhibitors of protein kinase A or C, mitogen-activated protein kinase kinase, and phosphoinositide 3-kinase had no effect on IL-6 mRNA levels. This study demonstrates the induction of innate immune responses by H. pylori HSP60, thereby implicating this highly conserved protein in the pathophysiology of chronic gastritis.