The Protective Effects of Trypsin Inhibitor on Hepatic Ischemia-Reperfusion Injury and Liver Graft Survival

Effect of intraoperative dexmedetomidine on hepatic ischemia-reperfusion injury in pediatric living-related liver transplantation: A propensity score matching analysis

Background

Hepatic ischemia-reperfusion injury (HIRI) is largely unavoidable during liver transplantation (LT). Dexmedetomidine (DEX), an α2-adrenergic agonist, exerts a variety of organ-protective effects in pediatric populations. However, evidence remains relatively limited about its hepatoprotective effects in pediatric living-related LT.

Methods

A total of 121 pediatric patients undergoing living-related LT from June 2015 to December 2018 in our hospital were enrolled. They were classified into DEX or non-DEX groups according to whether an infusion of DEX was initiated from incision to the end of surgery. Primary outcomes were postoperative liver graft function and the severity of HIRI. Multivariate logistic regression and propensity score matching (PSM) analyses were performed to identify any association.

Results

A 1:1 matching yielded 35 well-balanced pairs. Before matching, no significant difference was found in baseline characteristics between groups except for warm ischemia time, which was longer in the non-DEX group (44 [38–50] vs. 40 [37–44] min, p = 0.017). After matching, the postoperative peak lactic dehydrogenase levels decreased significantly in the DEX group than in the non-DEX group (622 [516–909] vs. 970 [648–1,490] IU/L, p = 0.002). Although there was no statistical significance, a tendency toward a decrease in moderate-to-extreme HIRI rate was noted in the DEX group compared to the non-DEX group (68.6% vs. 82.9%, p = 0.163). Patients in the DEX group also received a significantly larger dosage of epinephrine as postreperfusion syndrome (PRS) treatment (0.28 [0.17–0.32] vs. 0.17 [0.06–0.30] µg/kg, p = 0.010). However, there were no significant differences between groups in PRS and acute kidney injury incidences, mechanical ventilation duration, intensive care unit, and hospital lengths of stay. Multivariate analysis revealed a larger graft-to-recipient weight ratio (odds ratio [OR] 2.657, 95% confidence interval [CI], 1.132–6.239, p = 0.025) and intraoperative DEX administration (OR 0.333, 95% CI, 0.130–0.851, p = 0.022) to be independent predictors of moderate-to-extreme HIRI.

Conclusion

This study demonstrated that intraoperative DEX could potentially decrease the risk of HIRI but was associated with a significant increase in epinephrine requirement for PRS in pediatric living-related LT. Further studies, including randomized controlled studies, are warranted to provide more robust evidence.

Research progress of ulinastatin in the treatment of liver diseases

Ulinastatin (UTI) is a trypsin inhibitor observed in urine. UTI can treat some diseases by inhibiting the broad-spectrum hydrolysis activity of various enzymes and other pharmacological effects. UTI can widely treat pancreatitis, systemic multiple organ dysfunction syndrome, circulatory failure, and toxic shock clinically. The liver is a major metabolic organ of the human body. Various biological metabolic reactions require the liver's participation. When various physical and chemical factors drive the body, it will damage the liver to varying degrees. As a clinically effective drug, UTI is also known to treat some liver diseases. This article mainly describes UTI's research progress in treating septic liver injury, hepatitis, liver fibrosis, autoimmune liver disease with liver failure, and liver ischemia-reperfusion injury.

Ulinastatin Inhibits the Formation and Progression of Experimental Abdominal Aortic Aneurysms

AIMS

Aortic mural inflammatory damage takes a vital part in abdominal aortic aneurysm (AAA). Recently, ulinastatin (UTI) has attracted attention for its anti-inflammatory function. Our study aimed to evaluate potential influences of UTI on experimental AAA.

METHODS

A mouse model of AAA was induced by infusion of porcine pancreatic elastase (PPE) into the abdominal aorta. Mice were treated with UTI (50,000 U/kg/day i.p.) beginning either immediately or on the 4th day after PPE infusion, with treatment being continued until the 14th day. UTI effects were assessed by aortic diameter measurements and aortic histopathological analysis.

RESULTS

Significant and time-dependent aortic diameter enlargement persisted in the control mice from day 0. In the UTI group, aortic diameter increased, and depletion of aortic mural smooth muscle cells and elastin was significantly -attenuated. Simultaneously, mural CD68+ macrophages, CD8+ T-cell and B220+ B-cell density, as well as neoangiogenesis were suppressed by UTI. In addition, delayed UTI treatment could still effectively limit aneurysm expansion.

CONCLUSIONS

UTI treatment limits the formation and growth of experimental AAA, and UTI may be a potential treatment for early AAA disease.

Normothermic liver preservation, current status and future directions

PURPOSE OF REVIEW

Normothermic machine perfusion (NMP) is an emerging technology for liver preservation. Early clinical results demonstrate beneficial effects in reconditioning high-risk grafts. This review discusses the role of normothermic perfusion as a tool to assess graft viability and as a platform for graft intervention and modification.

RECENT FINDINGS

The potential benefits of NMP extend far beyond organ reconditioning. Recent pilot studies have identified clinically relevant viability criteria, which now require validation in large randomized control trials prior to implementation. Furthermore, preclinical studies demonstrate tremendous potential for NMP as a method to extend the preservation period, thus improving transplant logistics as well as serve as a platform for graft-targeted interventions to optimize the preservation period.

SUMMARY

NMP is a multifunctional tool with potential to transform liver preservation and the field of transplantation. Large clinical trials are necessary to optimize perfusion protocols, clarify indications for NMP therapy and justify use as the standard preservation modality.

Protective effect of ulinastatin on hepatic ischemia reperfusion injury through autophagy activation in Chang liver cells

This study aimed to investigate the protective effect of ulinastatin in hepatic ischemia-reperfusion progress, involving its association with the role of autophagy during hypoxia-induced hypoxia-reoxygenation injury in vitro. The model of hepatic hypoxia/reoxygenation (H/R) injury in Chang liver cells was established. After treatment with ulinastatin at the doses of 10, 100, and 1000 U/mL in H/R liver cells, the cell proliferation was significantly increased, morphological damage was reduced, and the cell apoptosis rate was decreased. The protein levels of antiapoptotic myeloid cell leukemia-1 (Mcl-1) and caspase-3 were upregulated, and C-PARP protein was downregulated. Meanwhile, ulinastatin led to an increase in the messenger RNA and protein levels of autophagy maker Unc-like kinase 1 (ULK1), Beclin-1, and microtubule-associated protein 1 light chain 3 (LC-3) and a decrease in p62. Then, 3-methyladenine (3-MA), an inhibitor of autophagy, made morphological damage and cell apoptosis worsen in ulinastatin-treated H/R liver cells. And the expression levels of caspase-3, C-PARP, p62, Beclin-1, and LC-3, proteins were also reversed by 3-MA. Taken together, our results demonstrate that ulinastatin inhibited the hepatic H/R injury in Chang liver cells, which was, to some extent, related to the autophagy activation.

Multi-organ protection of ulinastatin in traumatic cardiac arrest model

Background

Post-cardiac arrest syndrome, which has no specific curative treatment, contributes to the high mortality rate of victims who suffer traumatic cardiac arrest (TCA) and initially can be resuscitated. In the present study, we investigated the potential of ulinastatin to mitigate multiple organ injury after resuscitation in a swine TCA model.

Methods

Twenty-one male pigs were subjected to hemodynamic shock (40% estimated blood loss in 20 min) followed by cardiac arrest (electrically induced ventricular fibrillation) and respiratory suspension for 5 min, and finally manual resuscitation. At 5 min after resuscitation, pigs were randomized to receive 80,000 U/kg ulinastatin (n = 7) or the same volume of saline (n = 9) in the TCA group. Pigs in the sham group (n = 5) were not exposed to bleeding or cardiac arrest. At baseline and at 1, 3, and 6 h after the return of spontaneous circulation, blood samples were collected and assayed for tumor necrosis factor-alpha, interleukin 6, and other indicators of organ injury. At 24 h after resuscitation, pigs were sacrificed and apoptosis levels were assessed in samples of heart, brain, kidney, and intestine.

Results

One pig died in the ulinastatin group and one pig died in the TCA group; the remaining animals were included in the final analysis. TCA and resuscitation caused significant increases in multiple organ function biomarkers in serum, increases in tumor necrosis factor-alpha, and interleukin 6 in serum and increases in the extent of apoptosis in key organs. All these increases were lower in the ulinastatin group.

Conclusion

Ulinastatin may attenuate multiple organ injury after TCA, which should be explored in clinical studies.

Electronic supplementary material

The online version of this article (10.1186/s13017-018-0212-3) contains supplementary material, which is available to authorized users.

Alpha-1-antitrypsin in cell and organ transplantation

Limited availability of donor organs and risk of ischemia-reperfusion injury (IRI) seriously restrict organ transplantation. Therapeutics that can prevent or reduce IRI could potentially increase the number of transplants by increasing use of borderline organs and decreasing discards. Alpha-1 antitrypsin (AAT) is an acute phase reactant and serine protease inhibitor that limits inflammatory tissue damage. Purified plasma-derived AAT has been well tolerated in more than 30 years of use to prevent emphysema in AAT-deficient individuals. Accumulating evidence suggests that AAT has additional anti-inflammatory and tissue-protective effects including improving mitochondrial membrane stability, inhibiting apoptosis, inhibiting nuclear factor kappa B activation, modulating pro- vs anti-inflammatory cytokine balance, and promoting immunologic tolerance. Cell culture and animal studies have shown that AAT limits tissue injury and promotes cell and tissue survival. AAT can promote tolerance in animal models by downregulating early inflammation and favoring induction and stabilization of regulatory T cells. The diverse intracellular and immune-modulatory effects of AAT and its well-established tolerability in patients suggest that it might be useful in transplantation. Clinical trials, planned and/or in progress, should help determine whether the promise of the animal and cellular studies will be fulfilled by improving outcomes in human organ transplantation.

Alterations in inter-alpha inhibitor protein expression after hypoxic-ischemic brain injury in neonatal rats

Hypoxic-ischemic (HI) brain injury is frequently associated with premature and/or full-term birth-related complications that reflect widespread damage to cerebral cortical structures. Inflammation has been implicated in the long-term evolution and severity of HI brain injury. Inter-Alpha Inhibitor Proteins (IAIPs) are immune modulator proteins that are reduced in systemic neonatal inflammatory states. We have shown that endogenous IAIPs are present in neurons, astrocytes and microglia and that exogenous treatment with human plasma purified IAIPs decreases neuronal injury and improves behavioral outcomes in neonatal rats with HI brain injury. In addition, we have shown that endogenous IAIPs are reduced in the brain of the ovine fetus shortly after ischemic injury. However, the effect of HI on changes in circulating and endogenous brain IAIPs has not been examined in neonatal rats. In the current study, we examined changes in endogenous IAIPs in the systemic circulation and brain of neonatal rats after exposure to HI brain injury. Postnatal day 7 rats were exposed to right carotid artery ligation and 8% oxygen for 2h. Sera were obtained immediately, 3, 12, 24, and 48h and brains 3 and 24h after HI. IAIPs levels were determined by a competitive enzyme-linked immunosorbent assay (ELISA) in sera and by Western immunoblots in cerebral cortices. Serum IAIPs were decreased 3h after HI and remained lower than in non-ischemic rats up to 7days after HI. IAIP expression increased in the ipsilateral cerebral cortices 24h after HI brain injury and in the hypoxic contralateral cortices. However, 3h after hypoxia alone the 250kDa IAIP moiety was reduced in the contralateral cortices. We speculate that changes in endogenous IAIPs levels in blood and brain represent constituents of endogenous anti-inflammatory neuroprotective mechanism(s) after HI in neonatal rats.

Pre-conditions for eliminating mitochondrial dysfunction and maintaining liver function after hepatic ischaemia reperfusion

The liver, the largest organ with multiple synthesis and secretion functions in mammals, consists of hepatocytes and Kupffer, stem, endothelial, stellate and other parenchymal cells. Because of early and extensive contact with the external environment, hepatic ischaemia reperfusion (IR) may result in mitochondrial dysfunction, autophagy and apoptosis of cells and tissues under various pathological conditions. Because the liver requires a high oxygen supply to maintain normal detoxification and synthesis functions, it is extremely susceptible to ischaemia and subsequent reperfusion with blood. Consequently, hepatic IR leads to acute or chronic liver failure and significantly increases the total rate of morbidity and mortality through multiple regulatory mechanisms. An increasing number of studies indicate that mitochondrial structure and function are impaired after hepatic IR, but that the health of liver tissues or liver grafts can be effectively rescued by attenuation of mitochondrial dysfunction. In this review, we mainly focus on the subsequent therapeutic interventions related to the conservation of mitochondrial function involved in mitigating hepatic IR injury and the potential mechanisms of protection. Because mitochondria are abundant in liver tissue, clarification of the regulatory mechanisms between mitochondrial dysfunction and hepatic IR should shed light on clinical therapies for alleviating hepatic IR‐induced injury.

[Effect of ulinastatin on serum levels of tumor necrosis factor-α, P-selectin, and thrombin-antithrombin complex in young rats with sepsis]

OBJECTIVE

To investigate the effect of ulinastatin (UTI) for early drug intervention on the serum levels of tumor necrosis factor-α (TNF-α), P-selectin, and thrombin-antithrombin complex (TAT) in young rats with sepsis.

METHODS

A total of 120 male rats aged 4 weeks were randomly divided into normal control group, sham-operation group, sepsis group, low-dose UTI group (50 000 U/kg), and high-dose UTI group (200 000 U/kg), with 24 rats in each group. Modified cecal ligation and puncture was performed to establish a rat model of sepsis, and the rats in the low- and high-dose UTI groups were given caudal vein injection of UTI after model establishment. ELISA was used to measure the serum levels of TNF-α, P-selectin, and TAT at 6, 12, and 24 hours after model establishment.

RESULTS

The sepsis group had significant increases in the serum levels of TNF-α, P-selectin, and TAT at 6 hours, and the serum levels of TNF-α and TAT continued to increase by 24 hours (P<0.05); P-selectin reached the peak at 12 hours and decreased slightly at 24 hours (P<0.05). The UTI groups had similar change patterns in the levels of P-selectin and TAT as the sepsis group. The UTI groups had significant increases in the level of TNF-α at 6 hours, but gradually decreased over time. The changes in serum levels of TNF-α, P-selectin, and TAT in the UTI groups were significantly smaller than in the sepsis group (P<0.05). The high-dose UTI group had significantly smaller changes in serum levels of TNF-α, P-selectin, and TAT than the low-dose UTI group (P<0.05).

CONCLUSIONS

Early intervention with UTI can significantly improve coagulation function and inhibit the production of TNF-α, P-selectin, and TAT in young rats with sepsis. High-dose UTI has a significantly greater effect than low-dose UTI.

[Effect of ulinastatin on serum levels of tumor necrosis factor-α, P-selectin, and thrombin-antithrombin complex in young rats with sepsis]

OBJECTIVE

To investigate the effect of ulinastatin (UTI) for early drug intervention on the serum levels of tumor necrosis factor-α (TNF-α), P-selectin, and thrombin-antithrombin complex (TAT) in young rats with sepsis.

METHODS

A total of 120 male rats aged 4 weeks were randomly divided into normal control group, sham-operation group, sepsis group, low-dose UTI group (50 000 U/kg), and high-dose UTI group (200 000 U/kg), with 24 rats in each group. Modified cecal ligation and puncture was performed to establish a rat model of sepsis, and the rats in the low- and high-dose UTI groups were given caudal vein injection of UTI after model establishment. ELISA was used to measure the serum levels of TNF-α, P-selectin, and TAT at 6, 12, and 24 hours after model establishment.

RESULTS

The sepsis group had significant increases in the serum levels of TNF-α, P-selectin, and TAT at 6 hours, and the serum levels of TNF-α and TAT continued to increase by 24 hours (P<0.05); P-selectin reached the peak at 12 hours and decreased slightly at 24 hours (P<0.05). The UTI groups had similar change patterns in the levels of P-selectin and TAT as the sepsis group. The UTI groups had significant increases in the level of TNF-α at 6 hours, but gradually decreased over time. The changes in serum levels of TNF-α, P-selectin, and TAT in the UTI groups were significantly smaller than in the sepsis group (P<0.05). The high-dose UTI group had significantly smaller changes in serum levels of TNF-α, P-selectin, and TAT than the low-dose UTI group (P<0.05).

CONCLUSIONS

Early intervention with UTI can significantly improve coagulation function and inhibit the production of TNF-α, P-selectin, and TAT in young rats with sepsis. High-dose UTI has a significantly greater effect than low-dose UTI.

Transplantation of bone marrow mesenchymal stem cells alleviates hepatic ischemia-reperfusion injury in rats

AIM: To assess the therapeutic effects of transplantation of bone marrow mesenchymal stem cells (BMSCs) on hepatic ischemia-reperfusion injury (HIRI) in rats and explore the underlying mechanism.

METHODS: BMSCs were isolated from bone tissues of SD rats, cultured, and identified. SD rats were randomly divided into three groups: a control group, an HIRI group and a BMSCs transplantation group. HIRI was induced by the pringle occlusion method. After hepatic ischemia-reperfusion injury induction, blood samples were taken at 1, 2, and 3 weeks. Serum alanine transaminase (ALT), aspartate transaminase (AST), malondialdehyde (MDA), superoxide dismutase (SOD), interleukin (IL)-18 and tumor necrosis factor-α (TNF-α) were determined. Liver pathological changes were assessed by HE staining after 2 wk. Expression of hepatocyte growth factor (HGF) and alpha-smooth muscle protein (α-SMA) in the liver was detected by RT-PCR and Western blot.

RESULTS: At 1 wk, the levels of serum ALT, AST, IL-18, TNF-α and MDA in the transplantation group and HIRI group were significantly higher than those in the control group (P < 0.05 for all), and the levels of serum SOD were lower than that in the control group (P < 0.05). At 2 wk, the levels of serum ALT, AST, IL-18, TNF-α and MDA in the transplantation group were significantly lower than those in the HIRI group (P < 0.05 for all), but the level of serum MDA was higher and the level of serum SOD was lower in the transplantation group than in the control group (P < 0.05 for both). Hepatic degeneration, necrosis and fibrosis in the transplantation group were reduced significantly compared with the HIRI group (P < 0.05). HGF expression in the liver tissue was significantly higher and α-SMA expression was significantly lower in the transplantation group than in the HIRI group (P < 0.05 for both).

CONCLUSION: Transplantation of BMSCs can alleviate hepatic ischemia-reperfusion injury via mechanism possibly associated with inhibiting inflammatory factors and enhancing anti-oxidation.