Urinary trypsin inhibitor reduces C-X-C chemokine production in rat liver ischemia/reperfusion

The Protective Roles of Urinary Trypsin Inhibitor in Brain Injury Following Fat Embolism Syndrome in a Rat Model

Fat embolism syndrome (FES) is a common complication following long bone fracture; fat droplets are released into the blood circulation and form embolisms, mainly in lung and brain. However, the potential mechanisms involved remain to be clarified. In this study, the mechanism of brain injury following FES and the protective effects of urinary trypsin inhibitor (UTI)—a serine protease inhibitor—were investigated. Sixty male Sprague-Dawley rats were divided randomly into sham, FES and FES+UTI treatment groups. The FES model was established using tail vein injection of glycerol trioleate, and UTI was administered by intraperitoneal injection immediately following FES. Brain/lung water content evaluation, Evans blue content and magnetic resonance imaging examination were used to assess the effects of UTI. Furthermore, immunohistochemistry and western blot were also applied to explore the protective mechanism of UTI following FES. The results of oil red O staining indicated that the FES model was successfully established. UTI could significantly attenuate blood-brain-barrier (BBB) disruption, as seen through brain edema evaluation and Evans blue content examination. Immunofluorescence staining results indicated that the TLR4-JNK pathway was involved in brain injury after FES; this effect could be quenched by UTI treatment. Furthermore, UTI could decrease the levels of downstream target proteins of the TLR4-JNK pathway, phosphorylated-NF- κB (p65) and p53 in brain. Our results showed that UTI could alleviate BBB injury after FES through blocking activity of the TLR4-JNK pathway.

Ulinastatin inhibits cerebral ischemia-induced apoptosis in the hippocampus of gerbils

Ulinastatin is a urinary trypsin inhibitor, originally extracted and purified from human urine. Ulinastatin has cytoprotective effects against ischemic injury in several organs. In the present study, the neuroprotective effects of ulinastatin following ischemic cerebral injury in the hippocampus of gerbils was investigated. To induce transient global ischemia in gerbils, the common carotid arteries were occluded using aneurysm clips for 5 min, and the clips were then removed. Ulinastatin was subcutaneously injected into the gerbils once a day for 7 days at doses of 50,000 or 100,000 U/kg. The gerbils were confronted with a step-down avoidance task, following which tissue samples from the gerbils were examined using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, western blot analysis for B-cell lymphoma (Bcl-2) and Bcl-2-associated X protein (Bax), immunohistochemistry for caspase-3 and immunofluorescence for 5-bromo-2′-deoxyuridine. The numbers of TUNEL-positive and caspase-3-positive cells in the hippocampal CA1 region increased following cerebral ischemia. The expression of Bax in the hippocampus increased, while the expression of Bcl-2 in the hippocampus decreased following cerebral ischemia. These results confirmed that apoptosis in the hippocampus was enhanced following cerebral ischemia in gerbils. The levels of cell proliferation in the hippocampal dentate gyrus were also enhanced by ischemia, which is possibly an adaptive mechanism to compensate for excessive levels of apoptosis. Ulinastatin treatment inhibited ischemia-induced apoptosis by suppressing apoptosis-associated molecules, and thus ameliorated ischemia-induced short-term memory impairment. The cell proliferation in the hippocampus was also suppressed following ulinastatin treatment. These results suggested the use of ulinastatin as a therapeutic agent for patients with cerebral stroke.

Ulinastatin prevents acute lung injury led by liver transplantation

BACKGROUND

Little is known regarding the effect of ulinastatin (UTI) on acute lung injury (ALI) induced by orthotopic liver transplantation. This study aims to investigate the protective effect of UTI on ALI induced by orthotopic autologous liver transplantation (OALT) in a rat model and to explore the potential underlying mechanism.

MATERIALS AND METHODS

Rats were randomly allocated into the following four groups (n = 8 each): (i) sham control group (group sham); (ii) model group (underwent OALT) (group model); (iii) low-dose UTI-treated group (group u1), with UTI (50 U/g) administered intravenously both before the portal vein was occluded and after liver reperfusion started; and (iv) high-dose UTI-treated group (group uh), with UTI (100 U/g) given in the same way as group ul. The lung pathologic parameters, lung water content, and levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, malondialdehyde (MDA), superoxide dismutase (SOD) activity, RanBP-type and C3HC4-type zinc finger-containing protein 1 (RBCK1), and peroxiredoxin-2 (Prx-2) were assessed 8 h after OALT was performed.

RESULTS

According to histology, there was severe damage in the lung of group model accompanied by increases in the TNF-α, IL-1β, IL-6, and MDA levels and decreases in SOD activity and the expression of RBCK1 and Prx-2. UTI treatment significantly reduced the pathologic scores, lung water content, and TNF-α, IL-1β, IL-6, and MDA levels while restoring the SOD activity and expression of RBCK1 and Prx-2. Furthermore, compared with group u1, treatment with a high dose of UTI resulted in a better protective effect on the lung when assessed by the TNF-α, IL-1β, IL-6, and MDA levels and SOD activity.

CONCLUSIONS

UTI dose-dependently attenuates ALI that is induced by OALT in this rat model, which is mainly due to the suppression of the inflammatory response and oxidant stress, which may, in turn, be mediated by the upregulation of RBCK1 and Prx-2 expression.

Urinary Trypsin Inhibitor Ameliorates Seawater Immersion-Induced Intestinal Mucosa Injury via Antioxidation, Modulation of NF-κB Activity, and Its Related Cytokines in Rats with Open Abdominal Injury

Objective. To investigate the role of oxidative stress, NF-κB activity, and its related cytokines in the pathogenesis of seawater immersion after open abdominal injury (SI-OAI) and whether UTI treatment can attenuate SI-OAI induced IMI. Methods. Wistar rats were randomly divided into three groups: C group, S group, and U group. The rats in C group only suffered from anesthesia and surgical operation, whereas the rats in S group and U group received caudal vein injection of normal saline without/with 50,000 U/kg body weight of UTI. The activities of TNF-α, IL-6, SOD, MDA, ROS, NF-κB, and IκB-β were monitored by ELISA, biochemical methods, EMSA, and Western blot, respectively. Results. The plasma inflammatory mediators and the contents of MDA, ROS, and NF-κB in intestine as well as the pathological scores in ileal mucosa were significantly increased in rats after SI-OAI, accompanied by a reduction in SOD activities and IκB-β levels. UTI treatment significantly attenuated intestinal histopathological changes with evidence of a decrease in all of the parameters, except for upregulation of the levels of SOD and IκB-β protein. Conclusion. UTI can attenuate SI-OAI induced IMI via inhibition of NF-κB activity, subsequently inhibiting the expression of inflammatory cytokines and by combating oxidative stress.

Protective effects of urinary trypsin inhibitor on vascular permeability following subarachnoid hemorrhage in a rat model

AIMS

Inflammation and apoptosis play important roles in increasing vascular permeability following subarachnoid hemorrhage (SAH). The objective of this study was to evaluate whether urinary trypsin inhibitor (UTI), a serine protease inhibitor, attenuates vascular permeability by its antiinflammatory and antiapoptotic effects after experimental SAH.

METHODS

Subarachnoid hemorrhage models were established in adult male Sprague-Dawley rats by endovascular perforation. UTI was administered by intraperitoneal injection immediately following SAH. Brain edema was assessed by magnetic resonance imaging (MRI) at 24 h after SAH. Neurological deficits, brain water content, vascular permeability, malondialdehyde (MDA) concentration, and myeloperoxidase (MPO) activity were evaluated. Immunohistochemical staining and Western blot were used to explore the underlying protective mechanism of UTI.

RESULTS

Urinary trypsin inhibitor 50,000 U/kg significantly attenuated brain edema and neurological deficits and reduced vascular permeability at 24 h after SAH. MDA concentration and MPO activity in hippocampus were significantly decreased with UTI treatment. Furthermore, the levels of phosphorylated JNK, NF-κB (p65), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and proapoptotic protein p53, caspase-3 were elevated in the microvascular endothelial cells of the hippocampus after SAH, which were alleviated with UTI treatment.

CONCLUSION

Urinary trypsin inhibitor reduced vascular permeability after SAH through its antiinflammatory and antiapptotic effects via blocking the activity of JNK, NF-κB, and p53.

Ulinastatin improves pulmonary function in severe burn-induced acute lung injury by attenuating inflammatory response

BACKGROUND

Acute systemic inflammatory response to severe skin burn injury mediates burn-induced acute lung injury. Ulinastatin is potentially an effective intervention, because it attenuates the systemic inflammatory response induced by endotoxin and improves myocardial function during ischemic shock and reperfusion.

METHODS

Rats received full-thickness burn wounds to 30% total body surface area followed by delayed resuscitation. The treatment group received 50,000 U/kg of ulinastatin and the burn group was given vehicle only. A sham group was not burned but otherwise was treated identically. After killing, blood and lung samples were harvested for histology and measurement of inflammatory mediators.

RESULTS

Administration of ulinastatin significantly decreased the mRNA and protein levels of tumor necrosis factor-alpha, interleukin-1β, -6, and -8 both locally and systemically in burn-injured rats. The secretion of neutrophil elastase and myeloperoxidase in the lung and the expression of intercellular adhesion molecule-1 on the surface of lung epithelium were inhibited by ulinastatin. Ulinastatin also reduced the increase in pulmonary microvascular permeability. Consistent with these findings, ulinastatin ameliorated the lung edema and pulmonary oxygenation in burn-injured rats.

CONCLUSIONS

These results indicate that the inhibitory effects of ulinastatin on inflammatory mediator production, neutrophil activation, and microvascular permeability are associated with the recovery of pulmonary functions in severe burn-induced acute lung injury and suggest that ulinastatin may serve as a potential therapeutic administration in critical burn care.

Urinary trypsin inhibitor attenuates seawater-induced acute lung injury by influencing the activities of nuclear factor-ĸB and its related inflammatory mediators

BACKGROUND

Few data are available on the role of neutrophil elastase (NE) and nuclear factor-κB (NF-κB) in the course of seawater drowning-induced acute lung injury (SWD-ALI), and there is no evidence on the value of giving urinary trypsin inhibitor (UTI) in the case of SWD-ALI.

OBJECTIVE

To investigate the role of NF-κB and NE in the pathogenesis of SWD-ALI and whether UTI treatment can attenuate SWD-ALI in rabbits.

METHODS

Rabbits were randomly assigned to control, seawater drowning, and UTI treatment groups. The rabbits in the control group only suffered from intubation, whereas the rabbits in the seawater drowning group and the UTI treatment group received arterial injection of normal saline without/with 50,000 U/kg body weight of UTI after instillation of seawater into an endotracheal catheter. The activities or contents of NF-κB, MPO, NE, TNF-α, and IL-10 in lung tissue were measured by nonradioactive EMSA, biochemical methods, and ELISA, respectively.

RESULTS

After the seawater challenge, all of the rabbits demonstrated immediate drops in arterial PaO(2)/FiO(2) and pronounced pulmonary edema and inflammatory cell infiltration with evidence of an increase in the ratio of wet weight to dry weight, lung permeability index, lung injury scores, and the activities or contents of NF-κB, NE, MPO, TNF-α, and IL-10. UTI treatment markedly attenuated lung histopathological changes with evidence of a decrease in all of the parameters, except for upregulation of IL-10. Arterial PaO(2)/FiO(2) was significantly improved after 6 h of UTI treatment.

CONCLUSION

These results suggest that NF-κB and NE play an important role in SWD-ALI. UTI protects against SWD-ALI, at least partly, through inhibition of the enhanced local activity of NF-κB, contents of TNF-α and NE, and infiltration of neutrophils and promotion of the level of IL-10.

Preventive effect of urinary trypsin inhibitor on the development of liver fibrosis in mice

Urinary trypsin inhibitor (UTI) is a serine protease inhibitor produced in the liver that inhibits the production and activation of various cytokines, notably transforming growth factor-β (TGF-β), which are associated with the progression of liver fibrosis. However, the various roles of endogenous UTI in liver fibrosis have not been examined. This study, therefore, examined the long-term effects of UTI deficiency during both steady-state conditions and thioacetamide (TA)-induced liver fibrosis. Furthermore, the effects of continuous exogenous UTI administration were examined. Analyses of liver fibrosis marker, hyaluronic acid (HA), TGF-β concentrations and histological findings at 30 weeks of age showed that homozygous UTI-knockout (KO) mice had higher HA and TGF-β concentrations than did heterozygous UTI-KO mice and wild-type mice, although there was no histological evidence of liver fibrosis in these mice. TA treatment for 20 weeks also resulted in greater HA and TGF-β levels in homozygous mice than in heterozygous and wild-type mice. Furthermore, homozygous mice had more severe liver fibrosis based on histological analyses. HA and TGF-β levels were lower in homozygous UTI-KO mice that were continuously administered UTI versus those given distilled water. These findings indicate that UTI deficiency leads to the production of HA and hepatic TGF-β and that administering exogenous UTI can ameliorate these changes. We conclude that endogenous UTI is produced in the liver to suppress the production and activation of TGF-β and that administering exogenous UTI may be therapeutically beneficial for preventing liver fibrosis.

Urinary trypsin inhibitor as a therapeutic option for endotoxin-related inflammatory disorders

IMPORTANCE OF THE FIELD

Urinary trypsin inhibitor (UTI), a serine protease inhibitor, has been widely used as a drug for patients with inflammatory disorders such as pancreatitis, shock and disseminated intravascular coagulation (DIC). Previous in vitro studies have demonstrated that serine protease inhibitors may have anti-inflammatory properties at sites of inflammation. However, the therapeutic effects of UTI in vivo remain unclarified, as commercial UTI has been developed to act against humans, with the activity and selectivity toward the relevant animal UTI being less characterized.

AREAS COVERED IN THIS REVIEW

In this review, we introduce the roles of UTI in experimental endotoxin (lipopolysaccharide; LPS)-related inflammatory disorders using UTI-deficient (-/-) and corresponding wild-type mice.

WHAT THE READER WILL GAIN

Our experiments using genetic approach suggest that endogenous UTI can protect against the systemic inflammatory response and subsequent organ injury induced by LPS, at least partly, through the inhibition of pro-inflammatory cytokine and chemokine expression, which provide important in vivo evidence and understanding about a protective role of UTI in inflammatory conditions.

TAKE HOME MESSAGE

Using genetically targeted mice selectively lacking UTI, UTI has been evidenced to provide an attractive 'rescue' therapeutic option for endotoxin-related inflammatory disorders such as DIC, acute lung injury and acute liver injury.

Anti-inflammatory actions of serine protease inhibitors containing the Kunitz domain

INTRODUCTION

Protease inhibitors, including the Kunitz, Kazal, serpin and mucus families, play important roles in inhibiting protease activities during homeostasis, inflammation, tissue injury, and cancer progression. Interestingly, in addition to their anti-protease activity, protease inhibitors also often possess other intrinsic properties that contribute to termination of the inflammatory process, including modulation of cytokine expression, signal transduction and tissue remodeling. In this review we have tried to summarize recent findings on the Kunitz family of serine proteinase inhibitors and their implications in health and disease.

MATERIALS AND METHODS

A systematic search was performed in the electronic databases PubMed and ScienceDirect up to October 2009. We tried to limit the review to anti-inflammatory actions and actions not related to protease inhibition.

RESULTS AND CONCLUSION

Recent studies have demonstrated that the Kunitz inhibitors are not only protease inhibitors, but can also prevent inflammation and tissue injury and subsequently promote tissue remodeling.

The hepatic microcirculation: mechanistic contributions and therapeutic targets in liver injury and repair

The complex functions of the liver in biosynthesis, metabolism, clearance, and host defense are tightly dependent on an adequate microcirculation. To guarantee hepatic homeostasis, this requires not only a sufficient nutritive perfusion and oxygen supply, but also a balanced vasomotor control and an appropriate cell-cell communication. Deteriorations of the hepatic homeostasis, as observed in ischemia/reperfusion, cold preservation and transplantation, septic organ failure, and hepatic resection-induced hyperperfusion, are associated with a high morbidity and mortality. During the last two decades, experimental studies have demonstrated that microcirculatory disorders are determinants for organ failure in these disease states. Disorders include 1) a dysregulation of the vasomotor control with a deterioration of the endothelin-nitric oxide balance, an arterial and sinusoidal constriction, and a shutdown of the microcirculation as well as 2) an overwhelming inflammatory response with microvascular leukocyte accumulation, platelet adherence, and Kupffer cell activation. Within the sequelae of events, proinflammatory mediators, such as reactive oxygen species and tumor necrosis factor-alpha, are the key players, causing the microvascular dysfunction and perfusion failure. This review covers the morphological and functional characterization of the hepatic microcirculation, the mechanistic contributions in surgical disease states, and the therapeutic targets to attenuate tissue injury and organ dysfunction. It also indicates future directions to translate the knowledge achieved from experimental studies into clinical practice. By this, the use of the recently introduced techniques to monitor the hepatic microcirculation in humans, such as near-infrared spectroscopy or orthogonal polarized spectral imaging, may allow an early initiation of treatment, which should benefit the final outcome of these critically ill patients.

Role of neutrophils in the pathogenesis of acute inflammatory liver injury

Polymorphonuclear leukocytes (neutrophils) are essential in the defense against invading microorganisms, tissue trauma or any inciting inflammatory signals. Hepatic infiltration of neutrophils is an acute response to recent or ongoing liver injury, hepatic stress or unknown systemic inflammatory signals. Once neutrophils reach the liver, they can cause mild-to-severe tissue damage and consequent liver failure. For neutrophils to appear in the liver, neutrophils have to undergo systemic activation (priming) by inflammatory mediators such as cytokines, chemokines, complement factors, immune complexes, opsonized particles and other biologically active molecules, e.g., platelet activating factor. Neutrophils accumulated in the hepatic microvasculature (sinusoids and postsinusoidal venules) can extravasate (transmigrate) into the hepatic parenchyma if they receive a signal from distressed cells. Transmigration can be mediated by a chemokine gradient established towards the hepatic parenchyma and generally involves orchestration by adhesion molecules on neutrophils (beta(2) integrins) and on endothelial cells (intracellular adhesion molecules, ICAM-1). After transmigration, neutrophils adhere to distressed hepatocytes through their beta(2) integrins and ICAM-1 expressed on hepatocytes. Neutrophil contact with hepatocytes mediate oxidative killing of hepatocytes by initiation of respiratory burst and neutrophil degranulation leading to hepatocellular oncotic necrosis. Neutrophil-mediated liver injury has been demonstrated in a variety of diseases and chemical/drug toxicities. Relevant examples are discussed in this review.

Urinary trypsin inhibitor reduces inflammatory response in kidney induced by lipopolysaccharide

Human 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 septic shock and pancreatitis. Lipopolysaccharide (LPS) triggers the sepsis syndrome by activating monocytes to produce proinflammatory cytokines, including tumor necrosis factor alpha (TNFalpha), which potently stimulate the activation of neutrophils. The inhibitory mechanism of UTI on the systemic inflammatory response induced by the intraperitoneal injection of LPS in the kidney is unclear. This study was undertaken to examine the inhibitory effects of UTI on renal injury associated with the systemic inflammatory response induced by LPS stimulation, with emphasis on systemic TNFalpha and the activation of neutrophils in rat kidney. The systemic inflammatory response syndrome was induced by LPS treatment. Serum and renal TNFalpha, renal cytokine-induced neutrophil chemoattractant-1 (CINC-1) and myeloperoxidase (MPO) levels, as well as renal function after LPS stimulation, were evaluated. UTI (50,000 U/kg) inhibited LPS-induced increases in the serum and renal tissue levels of TNFalpha, as well as the renal tissue levels of CINC-1 and MPO after LPS stimulation. UTI (50,000 U/kg) also inhibited the production of serum TNFalpha associated with the systemic inflammatory response syndrome induced by LPS stimulation, thereby attenuating neutrophil infiltration into renal tissues and subsequent neutrophil-mediated renal injury. These findings may have important implications in understanding the biologic functions of UTI. UTI may prove useful in protecting against acute renal injury associated with a systemic inflammatory response.

Bikunin (Urinary Trypsin Inhibitor): Structure, Biological Relevance, And Measurement

Inflammatory processes, such as phagocytosis, coagulation, and vascular dilation, promote the release of serine proteases by neutrophils, macrophages, mast cells, lymphocytes, and the epithelial or endothelial cells. These proteases further facilitate the release of inflammatory cytokines and growth factors as well as take part in signal-cell proliferation through protease-activated receptors (PARs). Controlling the action of this cascade is necessary to prevent further damage to the normal tissues. One of the main anti-inflammatory response mediators is bikunin (Bik) that is responsible for inhibiting the activity of many serine proteases such as trypsin, thrombin, chymotrypsin, kallikrein, plasmin, elastase, cathepsin, Factors IXa, Xa, XIa, and XlIa. During the acute-phase response, Bik is released into plasma from proinhibitors primarily due to increased elastase activity. Bik is a glycoprotein, also referred to as urinary trypsin inhibitor, which in plasma inhibits the trypsin family of serine proteases by binding to either of the two Kunitz-binding domains. Bik also accumulates in urine. In conditions such as infection, cancer, tissue injury during surgery, kidney disease, vascular disease, coagulation, and diabetes, the concentrations of Bik in plasma and urine are increased. Several trypsin inhibitory assays for urine and immunoassays for both blood and urine have been described for measuring Bik. In addition to presenting the synthesis, structure, and pathophysiology of Bik, we will summarize various diagnostic approaches for measuring Bik. Analysis of Bik may provide a rapid approach in assessing various conditions involving the inflammatory processes.

Effects of a protease inhibitor, ulinastatin, on coagulation and fibrinolysis in abdominal surgery

PURPOSE

Ulinastatin is well known to inhibit the activity of polymorphonuclear leukocyte elastase (PMNE). The PMNE concentration correlates with the activities of coagulation and fibrinolysis. The purpose of the present study was to investigate the effects of ulinastatin, a protease inhibitor, on coagulation and fibrinolysis in abdominal surgery.

METHODS

Thirty patients, aged 40 to 70 years, with American Society of Anesthesiologists (ASA) physical status I or II, scheduled for major abdominal surgery, were enrolled. Anesthesia was induced with midazolam and thiopental, and was maintained with sevoflurane, nitrous oxide in oxygen, and an epidural block. An infusion of ulinastatin, 6000 units x kg(-1) in 30 min, was started 1 h after the start of surgery in the ulinastatin group (15 patients). In the control group (15 patients), no protease inhibitors were infused. White blood cell count; platelet count; prothrombin time; activated partial thromboplastin time; and plasma concentrations of PMNE, antithrombin (AT), fibrin/fibrinogen degradation product (FDP), fibrinogen, plasminogen, plasmin-(alpha2) plasmin inhibitor complex (PIC), and thrombin-antithrombin complex (TAT) were measured before, at the end of, and 12 h after surgery.

RESULTS

TAT, PIC, and FDP after surgery were significantly lower in the ulinastatin group than in the control group. AT was decreased in the control group but not in the ulinastatin group, with significant differences between the two groups.

CONCLUSION

Ulinastatin could inhibit coagulation and fibrinolysis in abdominal surgery.

Role of neutrophils in acute inflammatory liver injury

Hepatic infiltration of polymorphonuclear leukocytes (neutrophils) is an early response to tissue injury, cellular stress or systemic inflammation. Neutrophil activation is vital for host-defense and the removal of cell debris but can also cause additional tissue damage or even liver failure. In order to prevent the detrimental effects of neutrophils without compromising host-defense reactions, it is important to understand the mechanisms of neutrophil hepatotoxicity. The first step in the pathophysiology is the priming and recruitment of neutrophils into the liver vasculature by inflammatory mediators, e.g. cytokines, chemokines, or complement factors. Most critical for parenchymal cell damage is the accumulation in sinusoids, which does not depend on cellular adhesion molecules. The next step is the extravasation into the parenchyma. This process requires a chemotactic signal from hepatocytes or already extravasated neutrophils and depends on cellular adhesion molecules on neutrophils (beta(2) or beta(1) integrins) and on endothelial cells (intercellular or vascular cell adhesion molecules). The third step is the direct contact with target cells (hepatocytes), which involves beta(2) integrins and triggers the full activation of the neutrophil with a long-lasting adherence-dependent oxidant stress and degranulation. The oxidants diffuse into hepatocytes and trigger an intracellular oxidant stress, mitochondrial dysfunction and eventually cause oncotic necrotic cell death. Neutrophil-derived proteases facilitate extravasation and are involved in the regulation of inflammatory mediator production. Based on these mechanisms, it appears that strengthening of the intracellular defense mechanisms in hepatocytes may be the most promising therapeutic approach to selectively prevent neutrophil-mediated tissue damage without compromising their host-defense function.

Protective effects of ulinastatin on proliferation and cytokine release of splenocytes from rats with severe acute pancreatitis

AIM

To clarify the contributions of ulinastatin to cellular immune responses in vivo, we examined the functional alterations of splenocytes and quantitatively evaluated the effects of ulinastatin on the splenocyte function during experimental severe acute pancreatitis.

METHODS

Severe acute pancreatitis was induced in rats by retrograde injection of 3% sodium deoxycholate. Thirty minutes after induction of pancreatitis, the rats were randomly assigned to four groups, receiving either saline or 50,000 U/kg of ulinastatin, respectively. Splenocytes were obtained aseptically and stimulated with concanavalin A for 24 h. Then the proliferative activity of cultured splenocytes was measured by using an MTT cellular proliferation assay, and the cytokine concentrations in the culture supernatants were measured by enzyme-linked immunosorbent assays.

RESULTS

Upon stimulation, the release of interleukin-2, interleukin-10, and interferon-gamma was significantly decreased in the splenocytes from rats with pancreatitis as compared with those from sham operation and control groups. The splenocyte proliferation was also significantly suppressed in this group. In contrast, the proliferative as well as the cytokine-releasing capacities of the splenocytes from rats treated with ulinastatin were significantly increased as compared with those from rats with pancreatitis.

CONCLUSIONS

The deficiencies in proliferation and cytokine release in response to antigen stimulation demonstrated an anergic state of splenocytes during severe acute pancreatitis. Treatment with ulinastatin contributed to the recovery of the immune function by improving proliferative responses and cytokine release of splenocytes. These data suggest that a protease-modulating therapy may be an effective strategy for the treatment of immunosuppression induced by severe acute pancreatitis.

Mechanisms of Liver Injury. II. Mechanisms of neutrophil-induced liver cell injury during hepatic ischemia-reperfusion and other acute inflammatory conditions

Polymorphonuclear leukocytes (neutrophils) are a vital part of the innate immune response to microbial infections and tissue trauma, e.g., ischemia-reperfusion injury, in many organs including the liver. However, an excessive inflammatory response can lead to a dramatic aggravation of the existing injury. To design interventions, which selectively target the detrimental effects of neutrophils, a detailed understanding of the pathophysiology is critical. Systemic or local exposure to proinflammatory mediators causes activation and priming of neutrophils for reactive oxygen formation and recruits them into the vascular beds of the liver without causing tissue injury. However, generation of a chemotactic signal from the parenchyma will trigger extravasation and an attack on target cells (e.g., hepatocytes). Adhesion to the target induces degranulation with release of proteases and formation of reactive oxygen species including hydrogen peroxide and hypochlorous acid, which can diffuse into hepatocytes and induce an intracellular oxidant stress and mitochondrial dysfunction. Various neutrophil-derived proteases are involved in transmigration and cell toxicity but can also promote the inflammatory response by processing of proinflammatory mediators. In addition, necrotic cells release mediators, e.g., high-mobility group box-1, which further promotes neutrophilic hepatitis and tissue damage. On the basis of these evolving insights into the mechanisms of neutrophil-mediated liver damage, the most selective strategies appear not to interfere with the cytotoxic potential of neutrophils, but rather strengthen the target cells' defense mechanisms including enhancement of the intracellular antioxidant defense systems, activation of cell survival pathways, or initiation of cell cycle activation and regeneration.

Severe alcoholic hepatitis with extremely high neutrophil count successfully treated by granulocytapheresis

We report a severe alcoholic hepatitis (SAH) patient with an extremely high WBC count, high serum bilirubin and low prothrombin time (PT) successfully treated with granulocytapheresis. After neutrophil-elastase inhibitor failed to reduce WBC count, methylprednisolone pulse therapy was performed. However, WBC count continued to be elevated to 97,190/microl (neutrophils 97.0%) despite improvement of total bilirubin and PT. After 5 sessions of granulocytapheresis and ulinastatin administration, increased serum IL-6, IL-8, neutrophil-elastase and WBC count gradually decreased. We could conclude that granulocytapheresis and ulinastatin can be very effective in reducing cytokines and neutrophil-elastase, and in improving the general status of SAH patients.

Pathophysiology and diagnostic value of urinary trypsin inhibitors

Inflammation is an important indicator of tissue injury. In the acute form, there is usually accumulation of fluids and plasma components in the affected tissues. Platelet activation and the appearance in blood of abnormally increased numbers of polymorphonucleocytes, lymphocytes, plasma cells and macrophages usually occur. Infectious disorders such as sepsis, meningitis, respiratory infection, urinary tract infection, viral infection, and bacterial infection usually induce an inflammatory response. Chronic inflammation is often associated with diabetes mellitus, acute myocardial infarction, coronary artery disease, kidney diseases, and certain auto-immune disorders, such as rheumatoid arthritis, organ failures and other disorders with an inflammatory component or etiology. The disorder may occur before inflammation is apparent. Markers of inflammation such as C-reactive protein (CRP) and urinary trypsin inhibitors have changed our appraisal of acute events such as myocardial infarction; the infarct may be a response to acute infection and (or) inflammation. We describe here the pathophysiology of an anti-inflammatory agent termed urinary trypsin inhibitor (uTi). It is an important anti-inflammatory substance that is present in urine, blood and all organs. We also describe the anti-inflammatory agent bikunin, a selective inhibitor of serine proteases. The latter are important in modulating inflammatory events and even shutting them down.

Attenuation of graft ischemia-reperfusion injury by urinary trypsin inhibitor in mouse intestinal transplantation

AIM: Ischemia/reperfusion (I/R) injury is one of the major obstacles for intestinal transplantation (ITx). Urinary trypsin inhibitor (Ulinastatin, UTI) suppresses proteases and stabilizes lysosomal membranes. We supposed that Ulinastatin would diminish I/R injury of intestinal graft.

METHODS: UTI- treated group and untreated control group were investigated by histological assessment at 1.5, 4, 24, and 72 h after ITx. Myeloperoxidase (MPO) activity was used as the activity of neutrophils, and malondialdehyde (MDA) was used as an index of lipid peroxidation. TNFα and i-NOS mRNA expression in graft tissue were measured by semi-quantitative RT-PCR. CD11b⁺ Gr1⁺ cells in graft lamina propria were analyzed by flow cytometry.

RESULTS: Histological scores of the graft showed that the tissue injury was markedly attenuated by UTI treatment at different time points after ITx, with reduced MPO and MDA value in the grafts. The expression of TNFα and i-NOS mRNA was profoundly inhibited, while the infiltration of CD11b⁺ Gr1⁺ cells into the intestinal graft was decreased in UTI group.

CONCLUSION: Urinary trypsin inhibitor attenuates I/R injury in mouse intestinal transplantation by reducing monocytes infiltration and down-regulation of TNFα and i-NOS mRNA expression.

Urinary trypsin inhibitor reduces LPS-induced hypotension by suppressing tumor necrosis factor-alpha production through inhibition of Egr-1 expression

Although urinary trypsin inhibitor (UTI) has been shown to inhibit tumor necrosis factor (TNF)-alpha- production, the detailed mechanism(s) remains unclear. This study was undertaken to elucidate the molecular mechanism(s) underlying this inhibitory effect in monocytes in vitro and in rats given lipopolysaccharide (LPS). TNF-alpha production by monocytes stimulated with LPS (100 ng/ml) was inhibited by UTI at concentrations higher than 100 U/ml. Expression of early growth response factor-1 (Egr-1) and phosphorylation of extracellular signal-regulated protein kinases 1/2 in monocytes stimulated with LPS were inhibited by UTI. UTI (50,000 U/kg i.v.) inhibited LPS (5 mg/kg i.v.)-induced increases in lung tissue levels of Egr-1, TNF-alpha mRNA, and TNF-alpha in rats. UTI inhibited LPS-induced hypotension by inhibiting pulmonary induction of inducible nitric oxide synthase (iNOS). We previously demonstrated that anti-TNF-alpha antibody and aminoguanidine, a selective inhibitor of iNOS, reduced LPS-induced hypotension in this animal model. Furthermore, we also reported that reduction of LPS-induced coagulation abnormalities in rats did not affect inflammatory responses and hypotension in this animal model. Taken together, these observations strongly suggested that UTI inhibited LPS-induced production of TNF-alpha by inhibiting activation of the extracellular signal-regulated protein kinases 1/2-Egr-1 pathway in monocytes, which might at least partly contribute to reduction of hypotension through inhibition of iNOS induction in rats given LPS.

Protection from ischemic liver injury by activation of A2A adenosine receptors during reperfusion: inhibition of chemokine induction

Ischemia-reperfusion (I/R) injury occurs as a result of restoring blood flow to previously hypoperfused vessels or after tissue transplantation and is characterized by inflammation and microvascular occlusion. We report here that 4-[3-[6-amino-9-(5-ethylcarbamoyl-3,4-dihydroxy-tetrahydro-furan-2-yl)-9H-purin-2-yl]-prop-2-ynyl]-cyclohexanecarboxylic acid methyl ester (ATL146e), a selective agonist of the A(2A) adenosine receptor (A(2A)AR), profoundly protects mouse liver from I/R injury when administered at the time of reperfusion, and protection is blocked by the antagonist ZM241385. ATL146e lowers liver damage by 90% as assessed by serum glutamyl pyruvic transaminase and reduces hepatic edema and MPO. Most protection remains if ATL146e treatment is delayed for 1 h but disappears when delayed for 4 h after the start of reperfusion. In mice lacking the A(2A)AR gene, protection by ATL1465e is lost and ischemic injury of short duration is exacerbated compared with wild-type mice, suggesting a protective role for endogenous adenosine. I/R injury causes induction of hepatic transcripts for IL-1alpha, IL-1beta, IL-1Ra, IL-6, IL-10, IL-18, INF-beta, INF-gamma, regulated on activation, normal T cell expressed, and presumably secreted (RANTES), major intrinsic protein (MIP)-1alpha, MIP-2, IFN-gamma-inducible protein (IP)-10, and monocyte chemotactic protein (MCP)-1 that are suppressed by administering ATL146e to wild-type but not to A(2A)AR knockout mice. RANTES, MCP-1, and IP-10 are notable as induced chemokines that are chemotactic to T lymphocytes. The induction of cytokines may contribute to transient lymphopenia and neutrophilia that occur after liver I/R injury. We conclude that most damage after hepatic ischemia occurs during reperfusion and can be blocked by A(2A)AR activation. We speculate that inhibition of chemokine and cytokine production limits inflammation and contributes to tissue protection by the A(2A)AR agonist ATL146e.

The role of chemokines and chemokine receptors in alloantigen-independent and alloantigen-dependent transplantation injury

Transplantation injury and rejection involves the interplay of innate and acquired immune responses. Immune-related injury manifests itself in three temporal phases: early innate immune driven alloantigen-independent injury, acquired immune driven alloantigen-dependent injury, and chronic injury. Sequential waves of chemokine expression play a central role in regulating graft injury through the recruitment of phagocytes shortly after transplantation and activated lymphocytes and phagocytes in the weeks and years following transplantation. This review focuses on recent studies demonstrating the role of chemokines in transplantation.

Successful liver transplantation from agonal non-heart-beating donors in pigs

An effective way to overcome shortage of donors in liver transplantation (LTx) is to consider such from non-heart-beating donors (NHBDs). We investigated how a liver graft should be treated before and/or after procurement for successful LTx from an NHBD. Porcine LTx was performed with FR167653 (FR), a dual inhibitor of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), and/or prostaglandin E(1) (PG). Animals were allocated to an FR group (n=4, donors and recipients were treated with FR), a PG group (n=4, donors and recipients were treated with PG), or an FRPG group (n=4, donors and recipients were treated with both FR and PG). No recipients in the FR group and only two of four recipients in the PG group survived, whereas all recipients in the FRPG group survived. Suppression of TNF-alpha and IL-1beta and maintenance of microcirculation are the key to successful transplantation from NHBDs.

Nafamostat mesilate attenuates radical formation in the rat lung infused with endotoxin

We previously reported direct evidence of respiratory bursting by neutrophils in the pulmonary circulation of endotoxin-infused rats. To evaluate the effect of the protease inhibitor nafamostat mesilate (NM) on leukocyte-mediated radical formation in the pulmonary circulation of rats infused with endotoxin, we observed and measured the number of sticking leukocytes and quantified radical production in the pulmonary circulation of endotoxin-infused rats by means of a fluorescent imaging technique. Plasma C3a (desArg) was also measured using an enzyme-linked immunosorbent assay. Three groups (n = 5) of rats were infused with 4.5 mg/kg/h endotoxin (Et group), 50 microg/kg/h NM + endotoxin (NM group), or physiological saline (Ct group) for 2 h. The number of the leukocytes adhering within pulmonary capillaries, oxygen radical production in the rat pulmonary circulation, and plasma C3a (desArg) were all lower in the NM group than in the Et group. The leukocytes producing oxygen radicals were confirmed to be neutrophils by electron microscopic analysis of cerium deposition. We conclude that NM attenuates plasma C3a formation, neutrophil adherence to pulmonary capillaries, and their production of oxygen radical in rats infused with endotoxin.