Interleukin 18--binding protein ameliorates liver ischemia--reperfusion injury

Interleukin-18 and High-Mobility-Group-Protein B1 are Early and Sensitive Indicators for Cell Damage During Normothermic Machine Perfusion after Prolonged Cold Ischemic Storage of Porcine Liver Grafts

In the era of organ machine perfusion, experimental models to optimize reconditioning of (marginal) liver grafts are needed. Although the relevance of cytokine signatures in liver transplantation has been analyzed previously, the significance of molecular monitoring during normothermic machine perfusion (NMP) remains elusive. Therefore, we developed a porcine model of cold ischemic liver graft injury after prolonged static cold storage (SCS) and subsequent NMP: Livers obtained from ten minipigs underwent NMP for 6 h directly after procurement (control group) or after 20 h of SCS. Grafts after prolonged SCS showed significantly elevated AST, ALT, GLDH and GGT perfusate concentrations, and reduced lactate clearance. Bile analyses revealed reduced bile production, reduced bicarbonate and elevated glucose concentrations after prolonged SCS. Cytokine analyses of graft perfusate simultaneously demonstrated an increase of pro-inflammatory cytokines such as Interleukin-1α, Interleukin-2, and particularly Interleukin-18. The latter was the only significantly elevated cytokine compared to controls, peaking as early as 2 h after reperfusion (11,012 ng/ml vs. 1,493 ng/ml; p = 0.029). Also, concentrations of High-Mobility-Group-Protein B1 were significantly elevated after 2 h of reperfusion (706.00 ng/ml vs. 148.20 ng/ml; p < 0.001) and showed positive correlations with AST (r² = 0.846) and GLDH (r² = 0.918) levels. Molecular analyses during reconditioning of liver grafts provide insights into the degree of inflammation and cell damage and could thereby facilitate future interventions during NMP reducing acute and chronic graft injury.

The Efficacy of Combined Medication With Methylprednisolone and Erythropoietin in the Treatment of Ischemia-Reperfusion Injury to the Spinal Cord in Patients With Cervical Spondylotic Myelopathy

Introduction

Cervical myelopathy (CM) is caused by degenerative or congenital changes in the discs and soft tissues of the cervical spine, leading to chronic compression of the spinal cord. The current treatment for moderate-to-severe CM is surgical decompression, which is effective in most cases; however, it can cause inflammation of the nervous system and spinal cord reperfusion injury, resulting in perioperative neurological complications and suboptimal neurological recovery. The aim of this study was to investigate the therapeutic effects of the combination of erythropoietin and methylprednisolone in the treatment of ischemia-reperfusion injury to the spinal cord and to analyze its effects on the levels of interleukin-1 beta (IL-1β), interleukin-1 receptor antagonist (IL-1RA), and interleukin-8 (IL-8).

Materials and methods

This study included 110 patients admitted to the hospital due to cervical spondylotic myelopathy. They were randomized into two groups of 55 patients each: a control and an observation group. In both groups of patients, fusion internal fixation and anterior cervical discectomy were performed. The difference, however, was that the control group received a rapid intravenous injection of 30 mg/kg methylprednisolone 30 minutes prior to spinal cord decompression, while the observation group received an intravenous injection of 30 mg/kg methylprednisolone and 3,000 U/kg erythropoietin 30 minutes before spinal cord decompression. The study was approved by the Hospital Ethical Committee of the Dow University of Health Sciences, Karachi. The neurological function of both groups of patients was assessed before the procedure and three months after the treatment using the Japanese Orthopedic Association (JOA) method of assessing spinal cord function (40-point rating method). Enzyme-linked immunosorbent assay (ELISA) was performed to measure the levels of neuron-specific enolase (NSE), S-100β, IL-1RA, IL-1β, and IL-8 in both groups. The quality of life of patients in both groups was assessed three months after the treatment with the World Health Organization Quality of Life assessment instrument (WHOQOL-100).

Results

Before the treatment, there was no significant variance between the two groups in the JOA score and the 40-point rating method. Similarly, there was no significant difference in the levels of IL-1β, IL-1RA, and IL-8 between the two groups (p-value = 0.262, 0.387, and 0.154 respectively) prior to the treatment. Three months after the treatment, the levels of IL-1β and IL-8 in the observation group were 21.83 ±3.65 ng/l and 357.07 ±32.36 ng/l respectively, both lower than the control group value (p-value = 0.026, 0.028 respectively). The level of IL-1RA in follow-up was 21.59 ±1.15 ng/l, which was higher than that in the control group. Three months after the treatment, all the WHOQOL-100 parameters of the observation group for psychology, physiology, social relations, independence, spirituality, environment, and general quality of life were higher than those of the control group; the variance among the groups was statistically significant (p-value: <0.001).

Conclusions

The combination therapy with erythropoietin and methylprednisolone is effective for ischemia-reperfusion injuries of the spinal cord. It also reduces S-100β and NSE, inhibits IL-1β, and increases IL-8 and IL-1RA. Therefore, it preserves and improves spinal nerve function and the quality of life of patients.

IL-18/IL-18BP and IL-22/IL-22BP: Two interrelated couples with therapeutic potential

Interleukin (IL)-18 and IL-22 are key components of cytokine networks that play a decisive role in (pathological) inflammation, host defense, and tissue regeneration. Tight regulation of cytokine-driven signaling, inflammation, and immunoactivation is supposed to enable nullification of a given deleterious trigger without mediating overwhelming collateral tissue damage or even activating a cancerous face of regeneration. In fact, feedback regulation by specific cytokine opponents is regarded as a major means by which the immune system is kept in balance. Herein, we shine a light on the interplay between IL-18 and IL-22 and their opponents IL-18 binding protein (IL-18BP) and IL-22BP in order to provide integrated information on their biology, pathophysiological significance, and prospect as targets and/or instruments of therapeutic intervention.

Effect of Hepatic Artery Spasm on a Rat Model of Hepatic Ischemia-Reperfusion Injury

OBJECTIVES

To investigate hemodynamic changes in the hepatic artery after hepatic ischemia-reperfusion injury (IRI) in rats via ultrasound (US) imaging and to discuss the protective effect of phentolamine (PHT) pretreatment on hepatic IRI.

METHODS

Fifty rats were randomly divided into 3 groups: a sham operation group (n = 10), a control ischemia-reperfusion group (n = 20), and a PHT pretreatment group (n = 20). Color Doppler flow imaging and contrast-enhanced US examinations were performed in each group at 30 minutes (n = 10) and 90 minutes (n = 10) after reperfusion. Blood samples were obtained to analyze serum alanine aminotransferase and aspartate aminotransferase levels, and liver tissue specimens were collected for pathologic analysis.

RESULTS

Using US, we found that hepatic artery resistance at 30 minutes after reperfusion in the control group was higher than that in the sham group (mean resistive index [RI] ± SD, 0.65 ± 0.09 versus 0.50 ± 0.09; P < .01), which was higher at 30 than 90 minutes (RI, 0.65 ± 0.09 versus 0.50 ± 0.08; P < .01) after reperfusion in the control group. However, the hepatic artery resistance and liver microcirculation in the PHT group were better than those in the control group at 30 minutes after reperfusion (RI, 0.54 ± 0.09 versus 0.65 ± 0.09; P < .05; time to peak, 31.94 ± 2.02 versus 48.34 ± 4.74 seconds; P < .01). Compared to the control group, the aspartate aminotransferase and alanine aminotransferase levels were significantly lower at 30 minutes after reperfusion in the PHT group (P < .05). A pathologic examination revealed a smaller hepatic artery diameter and a depressed vessel wall in the control group.

CONCLUSIONS

The hepatic artery can undergo a transient spasm during the hepatic IRI process, which can exacerbate liver damage. Phentolamine treatment can alleviate hepatic artery spasms, improve liver perfusion, and reduce liver injury by ameliorating the hepatic microcirculation.

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.

The effects of IL-18BP on mRNA expression of inflammatory cytokines and apoptotic genes in renal injury induced by infrarenal aortic occlusion

BACKGROUND

Renal injury is an important complication of infrarenal aortic occlusion (IAO), which is mainly encountered during the postoperative period. Aortic clamping procedure may lead to turbulent blood flow and eventually vasoconstriction at renal arterial level of the abdominal aorta. IL-18BP has well-known antioxidant and anti-inflammatory properties. In this study, we aimed to determine whether IL-18BP has anti-inflammatory, antiapoptotic, antioxidant, and protective effects on acute kidney damage induced by IAO rat model.

MATERIALS AND METHODS

A total of 30 adult male Wistar-Albino rats were equally and randomly separated to three groups as follows: SHAM laparotomy, ischemia-reperfusion (IR), and IR + IL-18BP. We applied 30-min IAO and 2-h reperfusion. Inflammatory cytokine levels (TNF-α, IL-1β, IL-18, IL-6, and IFN-γ) and oxidative stress parameters (TAS, TOS, and OSI) were measured. In addition to this, urea and creatinine levels, histopathology of kidney, mRNA expression levels of inflammatory cytokines, and apoptotic genes were investigated.

RESULTS

Urea and creatinine, tissue and serum levels of TNF-α, IL-6, IL-18, IFN-γ, and TOS, and oxidative stress index (OSI) were found significantly lower in IR + IL-18BP group, when compared to the IR group. Moreover, mRNA expression levels of inflammatory cytokines and apoptotic genes were prominently depressed in IR + IL-18BP pre-treatment group in histopathologic examination, there was a significant difference between the IR and other three groups (P < 0.001). These improvements were demonstrated with a total score of histopathologic damage. In our previous studies, we have demonstrated that IL-18BP has antioxidant, inflammatory, and protective effects on liver and spinal cord IR injury. Data established from the present study suggest that IL-18BP may exert anti-inflammatory, antiapoptotic, antioxidant, and protective effects on IAO-induced acute kidney injury in rats, and this would be the first study to be conducted in this field.

CONCLUSIONS

Data established from the present study suggest that IL-18BP may exert anti-inflammatory, antiapoptotic, antioxidant, and protective effects on IAO-induced acute kidney injury in rats.