bacterial infection can evoke shock , acute respiratory failure , multiple organ failure , and disseminated intravascular coagulation ( dic ) , resulting in a high mortality rate .
lipopolysaccharide ( lps ) , a major component of the outer membrane of gram - negative bacteria , initiates the cascade of pathophysiological reactions called endotoxin shock .
a number of mediators including lipid mediators , cytokines , free radicals , complement fragments , coagulatory factors , and proteases contribute to the pathogenesis of endotoxin shock [ 26 ] . among them
, the products generated from neutrophils are recognized to play important roles . activated neutrophils release various types of mediators including proteases and oxygen radicals .
protease - antiprotease imbalance is involved in a variety of inflammatory diseases [ 8 , 9 ] .
because neutrophil elastase exerts the most injurious effects on many substrates ( e.g. elastin , type i  iv collagen , fibronectin , laminin , and proteoglycans ) , it can be a key mediator of tissue injury .
indeed , neutrophil elastase and cathepsin g - deficient mice have shown resistance to lethal effects of lps . further
, deficiency of secretory leukoprotease inhibitor also reportedly caused higher mortality from endotoxin shock with higher production of il-6 and high mobility group-1 .
in addition , fitzal and co - workers have shown that blockade of pancreatic proteases in the intestinal lumen ameliorates systemic inflammation induced by intravenous administration of lps .
uti is a multivalent kunitz - type serine protease inhibitor that is found in human urine and blood .
uti reportedly inhibits neutrophil elastase activity in vitro [ 15 , 16 ] and trypsin activity in patients with pancreatitis .
although the therapeutic effects of uti on circulatory shock have been recognized , especially in japan , the current understanding of the target mechanisms / pathways remains unsatisfactory .
tani and colleagues reported that uti protects against septic shock induced by gram - negative bacteria in vivo , but only estimated clinical signs such as cardiac index , blood pressure , lactic acid , blood glucose , and blood base values .
however , these studies have a critical limit in that the animals were treated with human - derived uti as a foreign protein ; the direct effect of uti on inflammatory diseases including systemic inflammatory response ( sirs ) syndrome has never been examined in knock - out mice .
at first , the role of uti in systemic inflammation using mice deficient in uti gene   was investigated .
both uti ( / ) and wild - type ( c57/bl6 : wt ) mice were injected intraperitoneally ( i.p . ) with vehicle or lps at a dose of 1  mg / kg body weight .
evaluation of coagulatory and fibrinolytic parameters and white blood cell ( wbc ) counts at 72  h after i. p. challenge showed that fibrinogen levels were significantly greater in lps - challenged wt mice ( p<0.05 ) and lps - challenged uti ( / ) mice ( p<0.01 ) than in vehicle - challenged mice with the same genotypes . in the presence of lps
, they were also significantly higher in uti ( / ) mice than in wt mice ( p<0.05 ) .
wbc counts significantly decreased after lps challenge in uti ( / ) mice ( p<0.01 versus other groups ) .
lps appeared to shorten pt when compared to vehicle treatment in uti ( / ) mice , although this difference did not reach significance . in the presence of lps ,
prothrombin time was significantly shorter in uti ( / ) mice than in wt mice ( p<0.05 ) .
histopathological changes in the lung , kidney , and liver of both genotypes at 72  h after lps challenge revealed severe neutrophilic inflammation in uti ( / ) lungs challenged with lps . in contrast
lps challenge induced neutrophilic infiltration around glomeruli and in the interstinum of the kidneys of both genotypes . however , the severity was more prominent in uti ( / ) mice than in wt mice in the presence of lps .
lps caused wide spread centrilobular vacuolation of hepatocytes and neutrophilic infiltration in livers of both genotypes . in the presence of lps
the protein expression of interleukin ( il)-1 , macrophage inflammatory protein ( mip)-1 , mip-2 , macrophage chemoattractant protein ( mcp)-1 , and keratinocyte chemoattractant   in the lung , kidney , and liver 72  h after lps administration was evaluated . in the lung ,
lps challenge caused significant elevation of il-1 , mip-1 , mip-2 , mcp-1 , and keratinocyte - derived chemoattractant ( kc ) levels in uti ( / ) mice when compared to vehicle challenge ( p<0.01 ) . in wt mice ,
lps treatment significantly enhanced the expression of il-1 , mip-1 , mip-2 , mcp-1 , and kc when compared to vehicle challenge . in the presence of lps ,
the lung expression of mcp-1 was significantly greater in uti ( / ) mice than in wt mice ( p<0.05 ) .
these results suggest that uti protects against systemic inflammation induced by intraperitoneal administration of lps , at least partly , through the inhibition of proinflamatory cytokine production / release .
in another series of studies , the role of uti in another type of sirs , acute lung inflammation induced by pulmonary exposure to lps , was examined . in brief , uti ( / ) and wt mice were intratracheally treated with vehicle or lps , and sacrificed 24  h later . in both genotypes , lps treatment induced significant increases in the numbers of total cells and neutrophils in bronchoalveolar lavage ( bal ) fluid as compared with vehicle treatment ( p<0.01 ) .
lps treatment caused greater and significant increases in the numbers of bal total cells ( p<0.05 ) and neutrophils ( p<0.01 ) in uti ( / ) mice than in wt mice . also , lps treatment increased the lung water content in both genotypes of mice ( p<0.05 ) when compared to vehicle treatment .
uti ( / ) mice , however , showed a significantly greater increase in lung water content when compared to wt mice ( p<0.05 ) following lps treatment .
lung specimens stained with hematoxylin and eosin 24  h after intratracheal instillation showed that in the presence of lps , wt mice showed moderate infiltration of neutrophils . in uti ( / ) mice , lps treatment led to a marked recruitment of neutrophils and interstitial edema .
vehicle administration alone caused no histological changes in either wt or uti ( / ) mice .
lps treatment induced significant elevation of the protein levels of il-1 , mip-1 , mcp-1 , and kc in lung homogenates when compared to vehicle treatment in both genotypes ( p<0.01 ) . in the presence of lps , the local expression of mcp-1 and kc was significantly higher in uti ( / ) mice than in wt mice ( p<0.05 for kc , p<0.01 for mcp-1 ) .
furthermore , immunohistochemical examination showed that in the presence of lps , immunoreactive 8-hydroxy-2'-deoxyguanosine was detected in the lungs of both strains of mice , but the staining was more prominent in uti ( / ) mice than in wt mice . on the other hand ,
immunoreactive nitrotyrosine was strongly detected only in uti ( / ) mice challenged with lps .
quantitative gene expression analyses of lung homogenates obtained 4  h after intratracheal challenge showed that compared to vehicle treatment , lps treatment resulted in significant elevation of gene expression for inducible nitric oxide synthase ( inos ) in both genotypes of mice ( p<0.05 ) . in the presence of lps ,
the local expression of inos was higher in uti ( / ) mice than in wt mice .
these results suggest that uti is also protective against acute lung inflammation induced by intratracheal administration of lps , at least in part , via the local suppression of proinflammatory cytokines   and antioxidation . in conclusion
, uti protects against sirs pathophysiology and subsequent organ damage induced by lps in mice , at least partly , via the modulation of the proinflammatory cytokine il-1 , as well as chemokines such as mip-2 , mcp-1 , and kc ( fig .  1 ) .
these in vivo results provide direct and novel molecular evidence for the  rescue  therapeutic potential of uti against systemic inflammatory responses syndrome such as dic , acute lung injury , and multiple organ dysfunction syndrome .
 urinary trypsin inhibitor ( uti ) , a serine protease inhibitor , has been widely used in japan as a drug for patients with acute inflammatory disorders such as disseminated intravascular coagulation ( dic ) , shock , and pancreatitis . 
 recent in vitro studies have demonstrated that serine protease inhibitors may have anti - inflammatory properties beyond their inhibition of neutrophil elastase at the site of inflammation . 
 however , the therapeutic effects of uti in vivo remain unclear . in this review 
 , we introduce the roles of uti in the experimental systemic inflammatory response induced by both intraperitoneal and intratracheal administration of lipopolysaccharide using uti deficient and wild - type mice . 
 our experiments suggest that uti can protect against systemic inflammatory response and subsequent organ injury induced by bacterial endotoxin , at least partly , through the inhibition of proinflammatory cytokine and chemokine expression . 
 uti may therefore present an attractive  rescue  
 therapeutic option for systemic inflammatory response syndromes such as dic , acute lung injury , and multiple organ dysfunction . 
Introduction
Role of UTI in Systemic Inflammation Induced by Intraperitoneal LPS Challenge
Role of UTI in Acute Lung Inflammation Induced by Intratracheal Challenge of LPS