Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
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Drug
Enzyme
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Target Concepts:
Gene/Protein
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Query: UMLS:C0034186 (
pyelonephritis
)
6,144
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The mechanisms that maintain sterility in the urinary tract are incompletely understood; however, recent studies stress the importance of antimicrobial peptides in protecting the urinary tract from infection.
Ribonuclease 7
(
RNase 7
), a potent antimicrobial peptide contributing to urinary tract sterility, is expressed by intercalated cells in the renal collecting tubules and is present in the urine at levels sufficient to kill bacteria at baseline. Here, we characterize the expression and function of
RNase 7
in the human urinary tract during infection. Both quantitative real-time PCR and enzyme-linked immunosorbant assays demonstrated increases in
RNASE7
expression in the kidney along with kidney and urinary
RNase 7
peptide concentrations with infection. While immunostaining localized
RNase 7
production to the intercalated cells of the collecting tubule during sterility, its expression during
pyelonephritis
was found to increase throughout the nephron but not in glomeruli or the interstitium. Recombinant
RNase 7
exhibited antimicrobial activity against uropathogens at low micromolar concentrations by disrupting the microbial membrane as determined by atomic force microscopy. Thus,
RNase 7
expression is increased in the urinary tract with infection and has antibacterial activity against uropathogens at micromolar concentrations.
...
PMID:Ribonuclease 7, an antimicrobial peptide upregulated during infection, contributes to microbial defense of the human urinary tract. 2353 95
Recent studies stress the importance of antimicrobial peptides in protecting the urinary tract from infection. Previously, we have shown that ribonuclease 7 (
RNase 7
) is a potent antimicrobial peptide that has a broad-spectrum antimicrobial activity against uropathogenic bacteria. The urothelium of the lower urinary tract and intercalated cells of the kidney produce
RNase 7
, but regulation of its antimicrobial activity has not been well defined. Here, we characterize the expression of an endogenous inhibitor, ribonuclease inhibitor (RI), in the urinary tract and evaluate its effect on the antimicrobial activity of
RNase 7
. Using RNA isolated from non-infected human bladder and kidney tissue, quantitative real-time polymerase chain reaction showed that RNH1, the gene encoding RI, is constitutively expressed throughout the urinary tract. With
pyelonephritis
, RNH1 expression and RI peptide production significantly decrease. Immunostaining localized RI production to the umbrella cells of the bladder and intercalated cells of the renal collecting tubule. In vitro assays showed that RI bound to
RNase 7
and suppressed its antimicrobial activity by blocking its ability to bind the cell wall of uropathogenic bacteria. Thus, these results demonstrate a new immunomodulatory role for RI and identified a unique regulatory pathway that may affect how
RNase 7
maintains urinary tract sterility.
...
PMID:An endogenous ribonuclease inhibitor regulates the antimicrobial activity of ribonuclease 7 in the human urinary tract. 2410 47
