Ulinastatin-mediated protection against zymosan-induced multiple organ dysfunction in rats

Ulinastatin Alleviates Rhabdomyolysis-Induced Acute Kidney Injury by Suppressing Inflammation and Apoptosis via Inhibiting TLR4/NF-κB Signaling Pathway

Acute kidney injury (AKI) is an important complication of rhabdomyolysis (RM), but there is lack of effective treatments. Ulinastatin (UTI) is a broad-spectrum serine protease inhibitor isolated and purified from human urine with strong anti-inflammatory and cytoprotective actions. The aim of this research was to investigate the effect and potential mechanism of UTI on RM-induced AKI (RM-AKI). We established RM-induced AKI model and myoglobin (Mb)-stimulated NRK-52E cell model. In vivo, twenty-four rats were randomly divided into three groups (n = 8): control, RM-AKI, and RM-AKI + UTI. In vitro, the NRK-52E cells were divided into six groups according to the different treatment method. Mb-stimulated NRK-52E cells were treated with UTI or si-TLR4 transfection to characterize the mechanisms of UTI in RM-AKI. Indicators of the kidney injury, cell viability, cell cycle, oxidative stress, inflammation, apoptosis, and TLR4/NF-κB signaling pathway were assessed. In vivo and in vitro, UTI significantly decreased the expression of TLR4 and p65. In vivo, UTI significantly improved renal function and reduced inflammatory reaction and kidney injury. In vitro, UTI protected NRK-52E cells from Mb stimulation by suppressing cell cytotoxicity, cell cycle inhibition, overproduction of ROS, inflammation, and apoptosis. Additionally, UTI played a protective role by downregulating the TLR4 expression. The results indicate that UTI alleviates RM-AKI by suppressing the inflammatory response and apoptosis via inhibiting TLR4/NF-κB signaling pathway. Our study provides a new mechanism for the protective effect of UTI on RM-AKI.

Effects of ulinastatin on renal perfusion evaluated by Doppler ultrasonography in a porcine model of septic shock

The present study aimed to evaluate the effect of ulinastatin (UTI) on renal perfusion using Doppler ultrasonography in a porcine model of septic shock induced by smoking inhalation and live methicillin-resistant Staphylococcus aureus instillation. A total of 32 healthy Landrace pigs were randomly assigned into the following four groups: Sham group (SH; n=5), septic shock group (SS; n=9), septic shock treated with vancomycin (15 mg/kg) group (VAN; n=9) and septic shock treated with UTI (50,000 U/kg) + vancomycin (UTI; n=9) group. Renal perfusion was evaluated by contrast-enhanced ultrasound (CEUS) at baseline and at the end of the protocol (24 h). The spectrum of interlobar or arcuate artery was selected to calculate the corrected resistive index (cRI). Sulphur hexafluoride microbubbles were bolus injected via a venous catheter. The peak intensity (Pi) and area under curve (AUC) were calculated using a time-intensity curve. Compared with the baseline group, cRI was increased significantly at the end of the protocol, except for that in the SH group, whereas Pi decreased significantly after injury in all experimental groups but was higher in the UTI group compared with that in the SS and VAN groups (both P<0.001). Linear correlation was found between the cardiac output (CO) and Pi (R²=0.752; P<0.001). The AUC was significantly decreased after injury in the SS and VAN groups compared with the baseline group. All parameters detected by CEUS were improved in the UTI group, and significant differences were found between the UTI and SS or VAN group (all P<0.05). In conclusion, acute renal injury, which occasionally occurs during septic shock, is accompanied with a significantly lower perfusion rate in the renal microcirculation. By contrast, UTI can significantly improve renal perfusion, which can be reliably evaluated using CEUS.

Ulinastatin Protects Against LPS-Induced Acute Lung Injury By Attenuating TLR4/NF-κB Pathway Activation and Reducing Inflammatory Mediators

Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome, remain the leading causes of morbidity and mortality in intensive care units. Ulinastatin (UTI), a serine protease inhibitor, possesses anti-inflammatory properties and has been suggested to modulate lipopolysaccharide (LPS)-induced sepsis; thus, it is now widely used in the treatment of pancreatitis, sepsis, and septic shock. Toll-like receptor 4 (TLR4), an essential LPS signaling receptor, plays a critical role in the activation of innate immunity. The aim of this study was to investigate whether UTI alleviates ALI by attenuating TLR4 expression and to explore the underlying molecular mechanisms involved. Male C56BL/6 mice were administered UTI intravenously 1 h before and 6 h after exposure to LPS by intratracheal instillation. Human lung epithelial (BEAS-2B) cells were incubated with LPS in the presence or absence of UTI. An enzyme-linked immunosorbent assay was used to detect levels of inflammatory cytokines. Western blot analysis was performed to detect changes in TLR4 expression and nuclear factor-κB (NF-κB) activation. UTI significantly protected animals from LPS-induced ALI, decreasing the lung wet/dry weight ratio, ALI score, total cells, neutrophils, macrophages, myeloperoxidase activity, and malondialdehyde content, factors associated with lung histological damage. UTI treatment also markedly attenuated levels of TLR4 and other proinflammatory cytokines. Furthermore, UTI significantly attenuated LPS-induced increases in TLR4 protein expression and NF-κB activation in lung tissues. Similarly, UTI markedly attenuated TLR4 expression and NF-κB activation in LPS-stimulated BEAS-2B cells. These findings indicate that UTI ameliorates LPS-induced ALI by attenuating the TLR4/NF-κB pathway activation.

Ulinastatin inhibits renal tubular epithelial apoptosis and interstitial fibrosis in rats with unilateral ureteral obstruction

The effect of ulinastatin (UTI) on renal tubular epithelial apoptosis and interstitial fibrosis in rats with unilateral ureteral obstruction (UUO) was investigated. A total of 18 male Wistar rats were randomly divided into the following 3 groups: The Sham group (n=6), the UUO group (n=6), and the UTI group (n=6). In the UUO and UTI groups, the left ureter was ligated to establish a UUO model. Starting from day 1 after surgery, an intervention treatment was performed using normal saline (1 ml/kg/d) and UTI (40,000 unit/kg/d). On day 7 after surgery, 6 rats from each group were sacrificed. In the Sham group, the left ureter was only freed, not ligated; after 7 days of abdominal closure, all of the rats were sacrificed. Blood samples were collected prior to sacrificing the animals to measure the blood urea nitrogen (BUN) and serum creatinine (Scr). The incidence of renal interstitial lesions on the obstruction side was observed by hematoxylin and eosin, and Masson staining. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and immunohistochemical detection of apoptosis regulator Bax (Bax), apoptosis regulator Bcl-2 (Bcl-2) and caspase-3 were performed to observe the presence of renal tubular epithelial cell apoptosis. The UTI did not have a significant influence on the mouse BUN and Scr levels in any of the groups (P>0.05). Compared with that in the Sham group, renal tissue injury in the UUO group was significantly aggravated with renal tubular dilation, epithelial cell atrophy, renal interstitial inflammatory cell infiltration and fibrous tissue hyperplasia (P<0.01). Furthermore, the renal tubular epithelial TUNEL+ cell number and Bax and caspase-3 levels were increased, and the expression of Bcl-2 was decreased (P<0.01). Following the UTI treatment, the renal interstitial injury at the obstruction side was significantly attenuated (P<0.05), the renal tubular epithelial TUNEL+ cell number, and Bax and caspase-3 levels significantly decreased, and the expression of Bcl-2 was restored (P<0.05). UTI inhibited renal tubular epithelial apoptosis and interstitial fibrosis in UUO rats.

Effects of Ulinastatin on Perioperative Inflammatory Response and Pulmonary Function in Cardiopulmonary Bypass Patients

The aim of this study was to investigate whether ulinastatin (UTL) has protective effects on perioperative proinflammatory cytokines and lung injury in cardiopulmonary bypass (CPB) patients. The study included 60 patients undergoing CPB who were randomly divided into a UTL group and a control group. Blood routine examination and inflammatory cytokines concentrations were detected after anesthetic induction (T1), immediately after aortic valve opening (T2), and 4 (T3) and 24 (T4) hours after weaning from CPB. Flow cytometry was used to detect TLR4 and HSP70 expressions. Arterial blood gas and respiratory function were analyzed at the same time points. Compared with the control group, the levels of IL-2, IL-8, TNF-α, NE, TLR4, PA - aDO2, and RI at T2 were significantly lower, whereas HSP70, PaO2, OI, Cd, and Cs were higher in the UTL group (all P < 0.05). Relative to the control group at T3, white blood cell count, TLR4, IL-2, IL-6, IL-8, TNF-α, NE, and RI decreased significantly, whereas IL-10, HSP70, PaO2, OI, and Cs increased in the UTL group (all P < 0.05). At T4, IL-2, IL-6, IL-8, TNF-α, TLR4, and PaCO2 in the UTL group were significantly lower, and PaO2, IL-10, HSP70, and Cs were higher than in the control group (all P < 0.05). Our data show strong evidence that UTL suppresses proinflammatory cytokine elevation and upregulates release of anti-inflammatory mediators, reducing pulmonary injury and improving pulmonary function after CPB.

Ulinastatin - a newer potential therapeutic option for multiple organ dysfunction syndrome

Despite significant improvements in medical and surgical management, multiple organ dysfunction syndrome (MODS) or multiple organ failure following conditions such as acute pancreatitis, severe sepsis, and traumatic, hemorrhagic, and endotoxin shocks is still accompanied with a high mortality rate. In light of the crucial role of immunologic derangement recently conceptualized in these conditions, ulinastatin, a urinary trypsin inhibitor, is considered as a potentially beneficial immunomodulator drug for MODS. Mechanisms involving protections against tissue organs and endothelial cell and anti-inflammatory effects by ulinastatin are dependent on the inhibition of polymorphonuclear leukocyte (PMN)-derived elastase, tumor necrosis factor α, and other pro-inflammatory cytokines and interleukins (IL-1, IL-6, and IL-8). Ulinastatin also suppresses the activation of PMN cells, macrophages, and platelets. Derived from these properties, ulinastatin has been investigated as a potential clinical therapy for indications including shock and pancreatitis and approved in Japan and China with ongoing clinical trials around the globe. Off-label potential uses of ulinastatin have been reported in preterm labor and hematological, hepatic, renal, and cardiovascular diseases including vasculitis syndromes such as Kawasaki disease.

Toll-like receptor 4-related immunostimulatory polysaccharides: Primary structure, activity relationships, and possible interaction models

Toll-like receptor (TLR) 4 is an important polysaccharide receptor; however, the relationships between the structures and biological activities of TLR4 and polysaccharides remain unknown. Many recent findings have revealed the primary structure of TLR4/MD-2-related polysaccharides, and several three-dimensional structure models of polysaccharide-binding proteins have been reported; and these models provide insights into the mechanisms through which polysaccharides interact with TLR4. In this review, we first discuss the origins of polysaccharides related to TLR4, including polysaccharides from higher plants, fungi, bacteria, algae, and animals. We then briefly describe the glucosidic bond types of TLR4-related heteroglycans and homoglycans and describe the typical molecular weights of TLR4-related polysaccharides. The primary structures and activity relationships of polysaccharides with TLR4/MD-2 are also discussed. Finally, based on the existing interaction models of LPS with TLR4/MD-2 and linear polysaccharides with proteins, we provide insights into the possible interaction models of polysaccharide ligands with TLR4/MD-2. To our knowledge, this review is the first to summarize the primary structures and activity relationships of TLR4-related polysaccharides and the possible mechanisms of interaction for TLR4 and TLR4-related polysaccharides.

Ulinastatin ameliorates acute kidney injury following liver transplantation in rats and humans

Acute kidney injury (AKI) is a common complication following orthotopic liver transplantation (OLT) that evidently affects prognosis. However, no effective treatment exists for AKI. The aim of the present study was to elucidate whether ulinastatin application during OLT in humans can reduce kidney damage and improve renal function. In addition, the underlying mechanisms of ulinastatin were investigated on a rat autologous OLT (AOLT) model. In total, 60 patients undergoing an OLT were randomly selected to receive ulinastatin (U group; n=30) or saline (C group; n=30) during the OLT surgery. The patient demographics, AKI incidence rate, recovery indicators and renal injury indexes were measured during the perioperative period. In addition to the clinical trials, 40 rats were subjected to an AOLT and were divided into the control (C-R), sham-operation and ulinastatin treatment groups. Pathological renal damage, biomarkers of inflammation and oxidative stress were measured to investigate the effects and possible mechanisms of ulinastatin on AKI. In the clinical trials, ulinastatin application was shown to attenuate the incidence of AKI following OLT (P<0.05) and reduce the serum levels of cystatin C and urinary β₂ microglobulin within 24 h of the OLT (P<0.05). Furthermore, ulinastatin was found to significantly improve the recovery of patients by reducing the time spent in the intensive care unit (P<0.01 vs. C group), the ventilation time and the hemodialysis rates (P<0.05 vs. C group). In the rat AOLT model, ulinastatin application was also shown to relieve renal pathological damage by reducing the serum cystatin C and creatinine levels. Notably, the levels of tumor necrosis factor-α, interleukin-6, hydrogen peroxide and reactive oxygen species were evidently reduced, while the level of superoxide dismutase was increased in the ulinastatin groups (P<0.05, vs. C-R group). In conclusion, ulinastatin application was demonstrated to protect against AKI following OLT by inhibiting inflammation and oxidation.

Effect of ulinastatin on paraquat-induced-oxidative stress in human type II alveolar epithelial cells

BACKGROUND:

Ulinastatin (UTI) is a urinary trypsin inhibitor extracted and purified from urine of males. This study aimed to explore the effects of UTI on paraquat-induced-oxidative stress in human type II alveolar epithelial cells.

METHODS:

The human type II alveolar epithelial cells, A549 cells, were cultured in vitro. The A549 cells were treated with different concentrations of paraquat (200, 400, 600, 800, 1 000, 1 200 µmol/L) and ulinastatin(0, 2 000, 4 000, 6 000, 8 000 U/mL) for 24 hours, the cell viability was measured by cell counting kit-8 and the median lethal concentration was selected. In order to establish an in vitro model of paraquat intoxication and to determine the safe dose of ulinastatin, we calculated LD50 using cell counting kit-8 to determine the survival rate of the cells. A549 cells were divided into normal control group, paraquat group and paraquat+ulinastatin group. The levels of malondialdehyde (MDA) and myeloperoxidase (MPO) were detected by biochemistry colorimetry, while the level of reactive oxygen spies (ROS) was detected by DCFH-DA assay.

RESULTS:

The survival rate of A549 cells treated with different concentrations of paraquat decreased in a concentration-dependent manner. Whereas there was no decrease in the survival rate of cells treated with 0–4 000 U/mL ulinastatin. The levels of MDA, MPO, and ROS were significantly higher in the paraquat group than in the normal control group after 24-hour-exposure. And the survival rate of the paraquat+ulinastatin group was higher than that of the paraquat group, but lower than that of the normal control group. The levels of MDA, MPO, and ROS were lower than those of the paraquat group.

CONCLUSION:

Ulinastatin can alleviate the paraquat-induced A549 cell damage by reducing oxidative stress.

Ulinastatin attenuates renal interstitial inflammation and inhibits fibrosis progression in rats under unilateral ureteral obstruction

The aim of the present study was to examine the protective effects of the urinary trypsin inhibitor ulinastatin (UTI) on renal interstitial inflammation and fibrosis in rats subjected to unilateral ureteral obstruction (UUO). A total of 24 male Wistar rats were randomly divided into the three groups; the sham operation (SOR) group (n=8), the UUO group (n=8) and the UUO+UTI group (post‑UUO UTI treatment, n=8). UUO was performed with complete ligation of the left ureter. As a medical intervention, saline (4 ml kg‑1 d‑1) and UTI (40000 units kg‑1 d‑1) were injected, respectively, into the animals of the corresponding groups on day one following surgery. The rats in all three groups were euthanized on day seven post surgery. Blood samples were harvested for blood urea nitrogen (BUN) and serum creatinine (Scr) content measurements. The degree of interstitial pathological changes in the tissues from the obstructed kidneys were observed through hematoxylin and eosin (H&E) and Masson staining. The CD68+ macrophage amount, tumor necrosis factor‑α (TNF‑α), interleukin 1β (IL‑1β), nuclear factor‑κB (NF‑κB), transforming growth factor‑β1 (TGF‑β1) and type I collagen (Col‑I) levels were examined immunohistochemically. The protein expression levels of NF‑κB were examined using western blot analysis. Total superoxide dismutase (SOD) activity and malondialdehyde (MDA) content of homogenates were measured spectrophotometrically. The results revealed that ulinastatin had no statistically significant effect on the BUN and Scr levels (P>0.05). However, in comparison with the SOR group, the UUO group exhibited significantly more severe renal interstitial pathological injury in terms of tubular dilation, epithelial atrophy, renal interstitial inflammatory cell infiltration and proliferation of fibrous tissues, as well as significantly elevated levels of interstitial CD68+ macrophages, IL‑1β, TNF‑α, NF‑κB, TGF‑β1 and Col‑I (P<0.01). UTI treatment significantly reduced UUO‑induced renal interstitial damage with reduced levels of interstitial CD68+ macrophages, IL‑1β, TNF‑α, NF‑κB, TGF‑β1 and Col‑I and MDA (P<0.05), and increased SOD levels (P<0.05). In conclusion, the present study indicated that UTI is able to effectively inhibit UUO‑side renal interstitial inflammatory reaction and fibrosis in UUO‑inflicted rats.

Ulinastatin attenuates experimental autoimmune encephalomyelitis by enhancing anti-inflammatory responses

Multiple sclerosis (MS) is a common inflammatory and demyelinating neurological disease. Experimental autoimmune encephalomyelitis (EAE), an animal model of MS, has been widely used to test MS treatment methods. Ulinastatin (UTI), a drug used to treat acute inflammatory disorders, has been tested in animal models of autoimmune inflammatory diseases, such as ulcerative colitis and crescentic glomerulonephritis. We recently found that UTI has a neuroprotective effect on EAE by reducing oligodendrocyte apoptosis and demyelination. The anti-inflammatory effects of UTI on EAE/MS, however, have never been investigated. We have therefore evaluated the anti-inflammatory effects of UTI in EAE and explored the mechanisms underlying this effect. EAE was induced in mice with and without UTI treatment. Inflammation and demyelination of spinal cords were evaluated by staining with hematoxylin and eosin and with Luxol fast blue, respectively. Inflammatory markers in serum were analyzed by the Luminex method, and spinal cords were evaluated by immunofluorescence and Western blotting. UTI significantly lowered the clinical and pathological scores and the serum concentrations of the inflammatory cytokines interleukin (IL)-1β, IL-6, and matrix metal protease-9 (MMP-9). UTI also reduced the expression of tumor necrosis factor-alpha (TNF-α)/nuclear factor kappaB (NF-κB)/inducible nitric oxide synthase (iNOS) proteins and decreased CD11b(+) cells in spinal cord lesions. UTI may protect against EAE in mice by suppressing inflammatory responses. We think that UTI might be a potential therapeutic agent for MS.

Ulinastatin inhibits unilateral ureteral obstruction-induced renal interstitial fibrosis in rats via transforming growth factor β (TGF-β)/Smad signalling pathways

This study aims to explore the protective effects and mechanisms of ulinastatin (UTI), which is a urinary trypsin inhibitor, of the renal interstitial fibrosis of rats subjected to unilateral ureteral obstruction (UUO). A total of 36 male Wistar rats were divided in random into three groups, namely, the sham operation (SOR) group (n=12), the UUO group (n=12), and the UTI treatment group (n=12). Six rats from each group were euthanised after unilateral ureteral obstruction operation on the seventh and fourteenth days, respectively. Blood samples were harvested for blood urea nitrogen (BUN) and serum creatinine (Scr) measurement. The interstitial pathological changes of the tissue from the obstructed kidneys were observed using haematoxylin-eosin (H&E) and Masson staining. The expression of the transforming growth factor β type 1 (TGF-β1), α-smooth muscle actin (α-SMA), type I collagen (Col-I), and phosphorylated Smad2/3 (p-Smad2/3) was determined using immunohistochemistry. The protein expression levels of TGF-β1, α-SMA, and p-Smad2/3 were examined using Western blot analysis. The results show that ulinastatin has no statistically significant effect on the BUN and Scr levels (P>0.05), but it can significantly reduce renal interstitial injury and suppress interstitial collagen deposits. The renoprotective effect of ulinastatin is likely realised through the TGF-β/Smad signalling pathways.