SummaryInflammatory bowel disease (IBD) may result from exaggerated stimulation of the mucosal immune system by luminal bacterial flora. Bacterial products are recognized by pattern recognition receptors such as Toll-like receptors (TLRs), which are key regulators of the innate immune system. Therefore, the expression of TLR2, TLR3 and TLR4 in colonic biopsy samples taken from children with active IBD were studied and compared to controls. Colonic biopsy samples were collected from macroscopically inflamed and noninflamed regions of the mucosa of 12 children with freshly diagnosed IBD (fdIBD) and 23 children with relapsed IBD (rIBD). Specimens were also obtained from eight controls. TLR2, TLR3 and TLR4 mRNA expression and protein levels were determined by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot. We found higher TLR2 and TLR4 mRNA and protein levels in the inflamed colonic mucosa of children with fdIBD and rIBD compared to controls. In the non-inflamed colonic mucosa of children with fdIBD and rIBD, TLR2 and TLR4 mRNA and protein levels were similar to controls. TLR2 and TLR4 mRNA and protein levels also did not differ between children with fdIBD or rIBD in either inflamed or noninflamed colonic mucosa. TLR3 mRNA expression and protein levels were similar in all groups studied. Our results of increased levels of TLR2 and TLR4 in the inflamed colonic mucosa of children with IBD confirm the hypothesis that innate immunity has an important role in the pathogenesis of this disease.

Hypertension causes cardiac hypertrophy characterized by low-grade inflammation. Toll-like receptors (TLRs), members of the innate immune system, contribute to cardiac failure. We hypothesized that hypertension is accompanied by enhanced TLR4 expression and activity. Cardiac TLR4 expression was determined in untreated spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY;4,8, 16 weeks). Besides, hearts of 8-week-old rats were stimulated with the endogenous TLR4 ligand heparansulfate (HS); the proinflammatory mRNA pattern was assessed (tumor necrosis factor-a (TNF-a), interleukin (IL)-6, monocyte chemotactic protein (MCP)-1). Additionally, we induced hypertension in WKY by L-NAME (N x -nitro-L-argininemethylester hydrochloride). In both hypertension models the effect of ramipril on TLR4 density was assessed. Cardiac TLR4 distribution was investigated by fluorescence-activated cell sorting analysis. Blood pressure (BP) and heart weight/body weight ratio (HW/BW) were elevated in SHR. Constitutive TLR4 expression was augmented in adolescent and adult, but not young SHR compared with WKY. TLR4 staining was pronounced in cardiomyocytes. HS entailed an aggravated TNF-a and IL-6 mRNA response in cardiac tissue, which was significantly pronounced in SHR. Ramipril (10 mg kg À1 per day) reduced BP, HW/BW and TLR4 expression in SHR. L-NAME also augmented TLR4 expression in WKY. Ramipril (1 mg kg À1 per day) lowered BP but TLR4 expression remained unaffected. High-dose ramipril (10 mg kg À1 per day) however decreased TLR4 expression. Starting from adolescence SHR demonstrated enhanced cardiac TLR4 expression. TLR4 was also upregulated in L-NAME induced hypertension. Thus, enhanced TLR4 expression might be linked to the development and maintenance of hypertension. Finally, the antihypertensive, anti-inflammatory action of angiotensin-converting-enzyme inhibition had no effect on TLR4 expression in therapeutic doses but in a high-dose model.

The alteration of TLR2 and TLR4 expression in the duodenal mucosa of patients with CD supports the potential implication of innate immune system in the pathomechanism of this disease.

Toll-like receptors (TLRs) are an evolutionarily conserved family of cell membrane receptors that are part of the innate immunity system playing an important role as a first response to tissue injury. TLR2 and TLR4 are constitutively expressed on renal epithelium, and their expression is enhanced following renal ischemia/reperfusion (I/R) injury. Genetic deletion of either TLR2 or TLR4 protects from renal I/R injury. However, it is not known whether deletion of both combined protects the kidney more than a deletion of either one alone. Therefore, we performed renal I/R injury in mice lacking TLR2, TLR4, and TLR2/4, respectively. Our results demonstrate that there are no significant differences regarding protection from renal I/R injury in TLR2/4((-/-)) compared with either TLR2((-/-)) or TLR4((-/-)) gene-targeted mice as determined by histological evaluation and renal functional parameters. Furthermore, there was no difference in the number of apoptotic tubular cells and in nuclear translocation of nuclear factor kappa-B (NF-kappaB) between the TLR-gene-targeted groups. In parallel, in vitro experiments did not demonstrate an additional effect of the double genetic deletion compared with the single gene deletion with respect to tumor necrosis factor (TNF)-alpha and interleukin (IL)-8 production in hypoxic isolated proximal tubular epithelial cells of the respective animals. In conclusion, a double genetic deletion of TLR2 and TLR4 confers a similar protection following renal I/R injury compared with single deletions of TLR2 and TLR4.

Uncontrolled BKPyV replication affects a significant proportion of pediatric renal transplant recipients, and is associated with unique features of epidemiology and risk factors such as young recipient age, obstructive uropathy and overall intensity of immunosuppressive therapy. BKPyV surveillance should be considered beyond 2 years posttransplant in pediatric patients at higher risk.

Fekete, Andrea, Á dám Vannay, Á gota Vér, Krisztina Rusai, Veronika Mü ller, György Reusz, Tivadar Tulassay, and Attila J. Szabó. Sex differences in heat shock protein 72 expression and localization in rats following renal ischemia-reperfusion injury. Am J Physiol Renal Physiol 291: F806 -F811, 2006. First published April 11, 2006 doi:10.1152/ajprenal.00080.2006.-Previously, we demonstrated gender differences in Na-K-ATPase (NKA) expression and function after renal ischemia-reperfusion (I/R) injury (Sex differences in the alterations of Na ϩ , K ϩ -ATPase following ischemia-reperfusion injury in the rat kidney. J Physiol 555: [471][472][473][474][475][476][477][478][479][480] 2004). Postischemic membrane destruction causes inhibition of NKA, whereas heat shock protein (HSP) 72 helps to preserve it. We tested the sex differences in postischemic expression of HSP72 and colocalization with NKA. The left renal pedicle of uninephrectomized female (F) and male (M) Wistar rats was clamped for 55 min followed by 2 (T2), 16 (T16), and 24 h (T24) of reperfusion. Uninephrectomized, sham-operated F and M rats served as controls. Postischemic blood urea nitrogen (BUN), serum creatinine, and renal histology were analyzed. HSP72 mRNA expression was detected by RT-PCR, protein levels by Western blot analysis. Fluorescent immunohistochemistry was performed to evaluate the localization of HSP72 and NKA ␣ 1-subunit. Postischemic BUN and creatinine were higher, and renal histology showed more rapid progression in M vs. F (P Ͻ 0.05). HSP72 mRNA expression was higher in F vs. M in control and in all I/R groups (P Ͻ 0.05). Similar changes were observed in HSP72 protein levels (F vs. M, P Ͻ 0.05, control, T2, T16, T24, respectively). Immunohistochemical localization of HSP72 and NKA ␣ 1 was similar in control F and M. In postischemic F kidneys, the majority of NKA ␣ 1 and HSP72 was colocalized on the basolateral membrane of tubular cells, whereas in M prominent staining was observed in the cytosol and apical domain. This study indicates that in female kidneys the higher basal and postischemic levels of HSP72 and different colocalization with NKA might contribute to the gender differences in renal I/R injury.

MR-proANP could accurately detect HF in children and adolescents. Its diagnostic performance was comparable with that of NT-proBNP, regardless of the underlying condition. Reference values are presented.

Summary Interleukin (IL)‐1 is a major contributor to inflammation and apoptosis during ischemia/reperfusion (I/R) injury. Its deleterious effects are primarily mediated by the activation of nuclear factor‐κB (NF‐κB). Receptor‐binding and signaling of IL‐1 can be blocked by the IL‐1 receptor antagonist (IL‐1ra). The aim of our study was to characterize effects and mechanisms of IL‐1ra administration on inflammation, apoptosis, and infiltration in renal I/R injury. Renal ischemia was induced in Lewis rats by clamping of the left renal artery for 45 min. Kidneys were removed for histological and molecular analysis 24 h or 5 days after reperfusion. IL‐1ra ameliorated I/R induced renal injury and inflammation. Furthermore, the number of apoptotic tubular cells was lower in IL‐1ra‐treated animals 24 h after ischemia, which was paralleled by a Bax/Bcl‐2 mRNA ratio towards anti‐apoptotic effects. IL‐1ra reduced the expression of monocyte chemoattractant protein‐1 (MCP‐1) mRNA at 24 h and 5 days and that of intracellular adhesion molecule‐1 (ICAM‐1) expression at 24 h in the ischemic reperfused kidneys. Our results indicate that IL‐1ra treatment ameliorates renal I/R injury and this protective effect might be mediated by reduced induction of NF‐κB mediated MCP‐1, ICAM‐1, and a decreased ratio between Bax and Bcl‐2 mRNA expression.