Neutrophil Elastase Inhibitor Following Liver Resection: A Matched Cohort Study

Intrahepatic neutrophil accumulation and extracellular trap formation are associated with posthepatectomy liver failure

BACKGROUND

Posthepatectomy liver failure (PHLF) represents a life-threatening complication with limited therapeutic options. Neutrophils play a critical and dynamic role during regeneratory processes, but their role in human liver regeneration is incompletely understood, especially as underlying liver disease, detectable in the majority of patients, critically affects hepatic regeneration. Here we explored intrahepatic neutrophil accumulation and neutrophil extracellular traps (NETs) in patients with PHLF and validated the functional relevance of NETs in a murine partial hepatectomy (PHx) model.

METHODS

We investigated the influx of neutrophils, macrophages, eosinophils, and mast cells and the presence of their respective extracellular traps in liver biopsies of 35 patients undergoing hepatectomy (10 patients with PHLF) before and after the initiation of liver regeneration by fluorescence microscopy. In addition, NET formation and neutrophil activation were confirmed by plasma analysis of 99 patients (24 patients with PHLF) before and up to 5 days after surgery. Furthermore, we inhibited NETs via DNase I in a murine PHx model of mice with metabolically induced liver disease.

RESULTS

We detected rapid intrahepatic neutrophil accumulation, elevated levels of myeloperoxidase release, and NET formation in regenerating human livers, with a significantly higher increase of infiltrating neutrophils and NETs in patients with PHLF. Circulating markers of neutrophil activation, including elastase, myeloperoxidase, and citrullinated histone H3, correlated with markers of liver injury. In a murine PHx model, we showed that the inhibition of NET accelerated hepatocyte proliferation and liver regeneration.

CONCLUSIONS

Patients with PHLF showed accelerated intrahepatic neutrophil infiltration and NET formation, which were associated with liver damage. Further, we identified postsurgical myeloperoxidase levels as predictive markers for adverse outcomes and observed that blocking NETs in a murine PHx model accelerated tissue regeneration.

Essential Involvement of Neutrophil Elastase in Acute Acetaminophen Hepatotoxicity Using BALB/c Mice

Intense neutrophil infiltration into the liver is a characteristic of acetaminophen-induced acute liver injury. Neutrophil elastase is released by neutrophils during inflammation. To elucidate the involvement of neutrophil elastase in acetaminophen-induced liver injury, we investigated the efficacy of a potent and specific neutrophil elastase inhibitor, sivelestat, in mice with acetaminophen-induced acute liver injury. Intraperitoneal administration of 750 mg/kg of acetaminophen caused severe liver damage, such as elevated serum transaminase levels, centrilobular hepatic necrosis, and neutrophil infiltration, with approximately 50% mortality in BALB/c mice within 48 h of administration. However, in mice treated with sivelestat 30 min after the acetaminophen challenge, all mice survived, with reduced serum transaminase elevation and diminished hepatic necrosis. In addition, mice treated with sivelestat had reduced NOS-II expression and hepatic neutrophil infiltration after the acetaminophen challenge. Furthermore, treatment with sivelestat at 3 h after the acetaminophen challenge significantly improved survival. These findings indicate a new clinical application for sivelestat in the treatment of acetaminophen-induced liver failure through mechanisms involving the regulation of neutrophil migration and NO production.

A randomized controlled trial of effect of 15- or 25-minute intermittent Pringle maneuver on hepatectomy for hepatocellular carcinoma

BACKGROUND

The feasibility and safety of using longer ischemic interval during intermittent Pringle maneuver for hepatectomy in patients with hepatocellular carcinoma are still unclear. The aim of this study was to compare the short-term outcomes of hepatectomy using intermittent Pringle maneuver with an ischemic interval of 25 minutes versus 15 minutes in hepatocellular carcinoma patients.

METHODS

A total of 344 patients with hepatocellular carcinoma undergoing hepatectomy were randomized to receive the intermittent Pringle maneuver with a 15-minute (n = 172) or 25-minute (n = 172) ischemic interval. Primary endpoint was transaminase-based postoperative hepatic injury, assessed by their peak values as well as area under the curve of the postoperative course of aminotransferases. Secondary endpoints included the intraoperative blood loss, transection speed, morbidity, mortality, and postoperative inflammatory reaction.

RESULTS

There were no significant differences between the 2 groups in the postoperative aminotransferase serum levels or their area under the curve values, but the 25-minute intermittent Pringle maneuver group was associated with significantly higher speed for liver transection (1.38 vs 1.23 cm²/min, P = .002) and a lower blood loss during transection (109 vs 166 mL, P < .001) than the 15-minute intermittent Pringle maneuver group. Postoperative complications, inflammatory cytokines serum levels, and 90-day mortality were comparable. Stratification analysis showed that the 25-minute intermittent Pringle maneuver did not aggravate the hepatic injury but resulted in a lower blood loss during transection and higher transection speed in hepatocellular carcinoma patient undergoing laparoscopic or open hepatectomy.

CONCLUSION

Intermittent Pringle maneuver with a 25-minute ischemic interval can be applied safely and efficiently in open or laparoscopic hepatectomy in patients with hepatocellular carcinoma patients.

Targeting Necrosis: Elastase-like Protease Inhibitors Curtail Necrotic Cell Death Both In Vitro and in Three In Vivo Disease Models

Necrosis is the main mode of cell death, which leads to multiple clinical conditions affecting hundreds of millions of people worldwide. Its molecular mechanisms are poorly understood, hampering therapeutics development. Here, we identify key proteolytic activities essential for necrosis using various biochemical approaches, enzymatic assays, medicinal chemistry, and siRNA library screening. These findings provide strategies to treat and prevent necrosis, including known medicines used for other indications, siRNAs, and establish a platform for the design of new inhibitory molecules. Indeed, inhibitors of these pathways demonstrated protective activity in vitro and in vivo in animal models of traumatic brain injury, acute myocardial infarction, and drug-induced liver toxicity. Consequently, this study may pave the way for the development of novel therapies for the treatment, inhibition, or prevention of a large number of hitherto untreatable diseases.

Neutrophil Elastase Inhibitor Sivelestat Attenuates Myocardial Injury after Cardioplegic Arrest in Rat Hearts

Purpose: Sivelestat, a neutrophil elastase inhibitor, attenuates global ischemia-induced myocardial damage and coronary endothelial dysfunction. Here, we investigated whether sivelestat exerts the cardioprotective effects against cardioplegic arrest in rat hearts.

Methods: Isolated Langendorff-perfused rat hearts were randomly allocated to three groups and subjected to 2-min infusions with St. Thomas’ Hospital cardioplegic solution No. 2 (STH2) and 30-min global ischemia followed by 60-min reperfusion as follows: (i) control (STH2 treatment only), (ii) sivelestat (19 μmol/L) infusion for the first 10 min of reperfusion, and (iii) sivelestat (19 μmol/L) infusion for 10 min before ischemia and for the first 10 min of reperfusion. Left ventricular developed pressure (LVDP) recovery and troponin T leakage were measured at the end of reperfusion. Coronary flow response to acetylcholine (ACh) was assessed.

Results: Single and multiple doses of sivelestat significantly improved LVDP recovery (69 ± 15 and 69 ± 14 vs 48 ± 15 [control]; p <0.05) and decreased troponin T leakage (0.4 ± 0.3 and 0.7 ± 0.5 vs 1.7 ± 0.6 [control]; p <0.05). Multiple doses of sivelestat significantly improved coronary flow response to ACh (121 ± 9 vs 105 ± 4; p <0.05).

Conclusions: Addition of sivelestat to STH2 attenuates myocardial injury after cardioplegic arrest in rat hearts. This cardioprotective effect was achieved even when sivelestat was administered during early reperfusion.