Rho inhibitor prevents ischemia-reperfusion injury in rat steatotic liver

Exploring the potential of drug repurposing for liver diseases: A comprehensive study

Drug repurposing involves the investigation of existing drugs for new indications. It offers a great opportunity to quickly identify a new drug candidate at a lower cost than novel discovery and development. Despite the importance and potential role of drug repurposing, there is no specific definition that healthcare providers and the World Health Organization credit. Unfortunately, many similar and interchangeable concepts are being used in the literature, making it difficult to collect and analyze uniform data on repurposed drugs. This research was conducted based on understanding general criteria for drug repurposing, concentrating on liver diseases. Many drugs have been investigated for their effect on liver diseases even though they were originally approved (or on their way to being approved) for other diseases. Some of the hypotheses for drug repurposing were first captured from the literature and then processed further to test the hypothesis. Recently, with the revolution in bioinformatics techniques, scientists have started to use drug libraries and computer systems that can analyze hundreds of drugs to give a short list of candidates to be analyzed pharmacologically. However, this study revealed that drug repurposing is a potential aid that may help deal with liver diseases. It provides available or under-investigated drugs that could help treat hepatitis, liver cirrhosis, Wilson disease, liver cancer, and fatty liver. However, many further studies are needed to ensure the efficacy of these drugs on a large scale.

Sclareol attenuates liver fibrosis through SENP1-mediated VEGFR2 SUMOylation and inhibition of downstream STAT3 signaling

Liver fibrosis is a key global health care burden. Sclareol, isolated from Salvia sclarea, possesses various biological activities. Its effect on liver fibrosis remains unknown. This study was proposed to evaluate the antifibrotic activity of sclareol (SCL) and explore its underlying mechanisms. Stimulated hepatic stellate cells served as an in vitro liver fibrosis model. The expression of fibrotic markers was assessed by western blot and real-time PCR. Two classical animal models, bile duct-ligated rats and carbon tetrachloride-treated mice, were utilized for the in vivo experiments. The liver function and fibrosis degree were determined by serum biochemical and histopathological analyses. VEGFR2 SUMOylation was analyzed using coimmunoprecipitation assay. Our results indicated that SCL treatment restricted the profibrotic propensity of activated HSCs. In fibrotic rodents, SCL administration alleviated hepatic injury and reduced collagen accumulation. Mechanistic studies indicated that SCL downregulated the protein level of SENP1 and enhanced VEGFR2 SUMOylation in LX-2 cells, which affected its intracellular trafficking. Blockade of the interaction between VEGFR2 and STAT3 was observed, resulting in the suppression of downstream STAT3 phosphorylation. Our findings demonstrated that SCL has therapeutic efficacy against liver fibrosis through mediating VEGFR2 SUMOylation, suggesting that SCL may be a potential candidate compound for its treatment.

Downregulation of thrombomodulin contributes to ischemia-reperfusion injury in mice with steatotic liver

AIM

Ischemia-reperfusion (IR) injury is one of the most critical complications commonly associated with liver surgery, including liver transplantation. Steatotic livers are particularly vulnerable to IR injury. However, the underlying mechanisms of this increased susceptibility have not fully been understood. In the present study, we used heterogeneous thrombomodulin (TM)-knockout (KO) (TM^+/- ) mice, which express about 50% functional activity of TM as compared with wild type, to investigate whether dysregulation of TM enhances IR injury in steatotic livers.

METHODS

Steatotic livers were induced using choline-deficient diets (CDD) in mice. The biological activity of TM was assessed using the productivity of protein C. Susceptibility to IR injury was compared between steatotic livers and non-steatotic livers and also assessed in TM-KO mice. We investigated whether recombinant TM (rTM) and the lectin-like domain of TM (rTM-D1) ameliorated IR injury in steatotic livers.

RESULTS

Protein C activity was significantly decreased to less than 20% in CDD-fed mice compared with mice with non-steatotic livers. Steatotic livers showed exaggerated IR injury compared with non-steatotic livers. Recombinant TM (rTM) and the lectin-like domain of TM (rTM-D1), which has anti-inflammatory effects, ameliorated IR injury in steatotic livers. TM^+/- mice showed increased susceptibility to IR injury, and rTM ameliorated the increased IR injury in TM^+/- mice.

CONCLUSION

We conclude that downregulation of TM increases susceptibility to hepatic IR injury in steatotic livers and that rTM ameliorates hepatic IR injury through anti-inflammatory action.

Role of hepatic stellate cells in liver ischemia-reperfusion injury

Liver ischemia-reperfusion injury (IRI) is a major complication of liver trauma, resection, and transplantation. IRI may lead to liver dysfunction and failure, but effective approach to address it is still lacking. To better understand the cellular and molecular mechanisms of liver IRI, functional roles of numerous cell types, including hepatocytes, Kupffer cells, neutrophils, and sinusoidal endothelial cells, have been intensively studied. In contrast, hepatic stellate cells (HSCs), which are well recognized by their essential functions in facilitating liver protection and repair, have gained less attention in their role in IRI. This review provides a comprehensive summary of the effects of HSCs on the injury stage of liver IRI and their associated molecular mechanisms. In addition, we discuss the regulation of liver repair and regeneration after IRI by HSCs. Finally, we highlight unanswered questions and future avenues of research regarding contributions of HSCs to IRI in the liver.

Targeting the Hepatic Microenvironment to Improve Ischemia/Reperfusion Injury: New Insights into the Immune and Metabolic Compartments

Hepatic ischemia/reperfusion injury (IRI) is mainly characterized by high activation of immune inflammatory responses and metabolic responses. Understanding the molecular and metabolic mechanisms underlying development of hepatic IRI is critical for developing effective therapies for hepatic IRI. Recent advances in research have improved our understanding of the pathogenesis of IRI. During IRI, hepatocyte injury and inflammatory responses are mediated by crosstalk between the immune cells and metabolic components. This crosstalk can be targeted to treat or reverse hepatic IRI. Thus, a deep understanding of hepatic microenvironment, especially the immune and metabolic responses, can reveal new therapeutic opportunities for hepatic IRI. In this review, we describe important cells in the liver microenvironment (especially non-parenchymal cells) that regulate immune inflammatory responses. The role of metabolic components in the diagnosis and prevention of hepatic IRI are discussed. Furthermore, recent updated therapeutic strategies based on the hepatic microenvironment, including immune cells and metabolic components, are highlighted.

Macrophage nuclear factor erythroid 2-related factor 2 deficiency promotes innate immune activation by tissue inhibitor of metalloproteinase 3-mediated RhoA/ROCK pathway in the ischemic liver

BACKGROUND AND AIMS

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator of reactive oxygen species (ROS) and inflammation and has been implicated in both human and murine inflammatory disease models. We aimed to characterize the roles of macrophage-specific Nrf2 in liver ischemia/reperfusion injury (IRI).

APPROACH AND RESULTS

First, macrophage Nrf2 expression and liver injury in patients undergoing OLT or ischemia-related hepatectomy were analyzed. Subsequently, we created a myeloid-specific Nrf2-knockout (Nrf2M-KO ) strain to study the function and mechanism of macrophage Nrf2 in a murine liver IRI model. In human specimens, macrophage Nrf2 expression was significantly increased in liver tissues after transplantation or hepatectomy. Interestingly, lower Nrf2 expressions correlated with more severe liver injury postoperatively. In a mouse model, we found Nrf2M-KO mice showed worse hepatocellular damage than Nrf2-proficient controls based on serum biochemistry, pathology, ROS, and inflammation. In vitro, Nrf2 deficiency promoted innate immune activation and migration in macrophages on toll-like receptor (TLR) 4 stimulation. Microarray profiling showed Nrf2 deletion caused markedly lower transcriptional levels of tissue inhibitor of metalloproteinase 3 (Timp3). ChIP-seq, PCR, and luciferase reporter assay further demonstrated Nrf2 bound to the promoter region of Timp3. Moreover, a disintegrin and metalloproteinase (ADAM) 10/ROCK1 was specifically increased in Nrf2-deficient macrophages. Increasing Timp3 expression effectively inhibited ADAM10/ROCK1 expression and rescued the Nrf2M-KO -mediated inflammatory response on TLR4 stimulation in vitro. Importantly, Timp3 overexpression, recombinant Timp3 protein, or ROCK1 knockdown rescued Nrf2M-KO -related liver IRI by inhibiting macrophage activation.

CONCLUSIONS

In conclusion, macrophage Nrf2 mediates innate proinflammatory responses, attenuates liver IRI by binding to Timp3, and inhibits the RhoA/ROCK pathway, which provides a therapeutic target for clinical organ IRI.

Rho-Kinase as a Therapeutic Target for Nonalcoholic Fatty Liver Diseases

Nonalcoholic fatty liver disease (NAFLD) is a major public health problem and the most common form of chronic liver disease, affecting 25% of the global population. Although NAFLD is closely linked with obesity, insulin resistance, and type 2 diabetes mellitus, knowledge on its pathogenesis remains incomplete. Emerging data have underscored the importance of Rho-kinase (Rho-associated coiled-coil-containing kinase [ROCK]) action in the maintenance of normal hepatic lipid homeostasis. In particular, pharmacological blockade of ROCK in hepatocytes or hepatic stellate cells prevents the progression of liver diseases such as NAFLD and fibrosis. Moreover, mice lacking hepatic ROCK1 are protected against obesity-induced fatty liver diseases by suppressing hepatic de novo lipogenesis. Here we review the roles of ROCK as an indispensable regulator of obesity-induced fatty liver disease and highlight the key cellular pathway governing hepatic lipid accumulation, with focus on de novo lipogenesis and its impact on therapeutic potential. Consequently, a comprehensive understanding of the metabolic milieu linking to liver dysfunction triggered by ROCK activation may help identify new targets for treating fatty liver diseases such as NAFLD.

A multicenter randomized controlled trial comparing administration of antithrombin III after liver resection (HiSCO-05 trial)

BACKGROUND

Posthepatectomy liver failure is a poor prognostic factor after hepatectomy. Various preventive treatments have been tried; however, there are no clinical trials that use posthepatectomy liver failure as the primary endpoint, and the clinical effects of posthepatectomy liver failure have not been fully verified. The aim of this study was to investigate whether administration of antithrombin III can prevent posthepatectomy liver failure in patients with coagulopathy after hepatectomy. This study also evaluated the safety of AT-III administration after hepatectomy.

METHODS

The current study enrolled 141 patients diagnosed with coagulopathy after hepatectomy between October 2015 and September 2018 at 7 hospitals in Hiroshima, Japan (HiSCO group). Patients were randomized to undergo either administration of antithrombin III (n = 64) or non-administration (n = 77). The primary endpoint was the incidence of posthepatectomy liver failure. This randomized controlled trial was registered with the University Medical Information Network Clinical Trial Registry (UMIN000018852).

RESULTS

Treatment for postoperative coagulopathy was performed safely without adverse events. The incidence of posthepatectomy liver failure was similar in both treatment groups (nonadministration of antithrombin III group, 28.5%, versus administration of antithrombin III group, 28.1%; P = .953) The rate of morbidity was higher in the administration group than the non-administrated group (17.2% vs 11.7%, P = .351). Following the multivariate analysis of the whole study group, body mass index ≥25, total bilirubin ≥1.5 mg/dL, and the disseminated intravascular coagulation score ≥5 postoperatively were the independent risk factors for posthepatectomy liver failure.

CONCLUSION

This study showed that the administration of antithrombin III resulted in no significant difference in preventing posthepatectomy liver failure, possibly through suppressing coagulopathy.

Impact of previous history of choledochojejunostomy on the incidence of organ/space surgical site infection after hepatectomy

PURPOSE

Impact of previous history of choledochojejunostomy (PCJ) on the incidence of organ/space surgical site infection (SSI) after hepatectomy remains unclear. The aim of this study was to investigate the incidence and causes of SSI after hepatectomy.

METHODS

Patients who underwent hepatectomy of ≤1 Couinaud's sector between January 2011 and September 2019 were retrospectively analyzed. Incidence of and risk factors for organ/space SSI (Clavien-Dindo grade ≥2) after hepatectomy were investigated.

RESULTS

Among 750 hepatectomies, 18 patients (2.4%) had a medical history of PCJ. Incidence of organ/space SSI was higher in patients with PCJ (50%) than in those without PCJ (3%, P < 0.001), and the trend was consistent even after estimated propensity score matched cohort. Multivariate analysis showed PCJ was a strong risk factor for organ/space SSI (grade ≥2), with the highest odds ratios (OR) among all other clinicopathological risk factors (OR, 32.25; P < 0.001). Among hepatectomies with PCJ, pneumobilia (OR, 12.25; P = 0.015), operation time ≥171 min (OR, 12.25; P = 0.016), and liver steatosis (OR, 24.00; P ≤ 0.005) were associated with organ/space SSI after hepatectomy.

CONCLUSION

Previous history of choledochojejunostomy was a strong risk factor for organ/space SSI after hepatectomy. The high rate of organ/space SSI after hepatectomy with PCJ might be attributed to intrahepatic bile duct contamination, increased operation time, and histological liver steatosis.

Circular RNA Microarray Analyses in Hepatic Ischemia-Reperfusion Injury With Ischemic Preconditioning Prevention

Ischemic preconditioning (IPC) represents an effective intervention to relieve hepatic ischemia-reperfusion injury (IRI). Systematic detection of circRNA expression revealing the protection effect of IPC still remains to be elucidated. Here, we applied a microarray to detect circRNA and mRNA expression in ischemic liver with and without IPC (n = 3 in each group). Compared with the sham group, there were 39 circRNAs and 432 mRNAs increased and 38 circRNAs and 254 mRNAs decreased (fold change ≥1.5, P < 0.05) in the group of hepatic IRI. As the result of IPC intervention, 43 circRNAs and 64 mRNAs were increased, and 7 circRNAs and 31 mRNAs were decreased in the IPC group when compared with IRI. We then identified circRNA_017753 as the most possible target that may closely relate to IPC protective signaling and predicted Jade1 as the target related to circRNA_017753. Three possible circRNA-miRNA-mRNA axes were constructed that may play a vital role in protective mechanisms in IPC. The study for the first time systematically detects the dysregulated circRNAs and mRNAs in response to hepatic IRI and IPC intervention. Our profile and bioinformatic analysis provide numerous novel clues to understanding the pathophysiologic mechanism of IPC protection against hepatic IRI.

Nonalcoholic Steatohepatitis Promoting Kinases

Nonalcoholic hepatitis (NASH) is the progressive inflammatory form of nonalcoholic fatty liver disease. Although the mechanisms of hepatic inflammation in NASH remain incompletely understood, emerging literature implicates the proinflammatory environment created by toxic lipid-induced hepatocyte injury, termed lipotoxicity. Interestingly, numerous NASH-promoting kinases in hepatocytes, immune cells, and adipocytes are activated by the lipotoxic insult associated with obesity. In the current review, we discuss recent advances in NASH-promoting kinases as disease mediators and therapeutic targets. The focus of the review is mainly on the mitogen-activated protein kinases including mixed lineage kinase 3, apoptosis signal-regulating kinase 1, c-Jun N-terminal kinase, and p38 MAPK; the endoplasmic reticulum (ER) stress kinases protein kinase RNA-like ER kinase and inositol-requiring protein-1α; as well as the Rho-associated protein kinase 1. We also discuss various pharmacological agents targeting these stress kinases in NASH that are under different phases of development.

Etiology of Liver Steatosis Influences the Severity of Ischemia/Reperfusion Injury and Survival After Liver Transplantation in Rats

Liver steatosis is a leading cause of graft disposal in liver transplantation, though the degree of steatosis is often the single factor determining acceptability of the graft. We investigated how the cause of liver steatosis affects graft function in rat orthotopic liver transplantation (OLT). OLT was performed using 2 types of steatotic liver grafts: the fasting and hyperalimentation (FHA) model and the methionine- and choline-deficient diet models. The FHA and 4-week feeding of a methionine- and choline-deficient diet (MCDD4wk) groups showed similar liver triglyceride levels without signs of steatohepatitis. Therefore, the 2 groups were compared in the following experiment. With 6-hour cold storage, the 7-day survival rate after OLT was far worse in the FHA than in the MCDD4wk group (0% versus 100%, P = 0.002). With 1-hour cold storage, the FHA group showed higher aspartate aminotransferase and alanine aminotransferase levels and histological injury scores in zones 1 and 2 at 24 hours after reperfusion than the normal liver and MCDD4wk groups. Intrahepatic microcirculation and tissue adenosine triphosphate levels were significantly lower in the FHA group after reperfusion. Hepatocyte necrosis, sinusoidal endothelial cell injury, and abnormal swelling of the mitochondria were also found in the FHA group after reperfusion. Tissue malondialdehyde levels were higher in the MCDD4wk group before and after reperfusion. However, the grafts up-regulated several antioxidant enzymes soon after reperfusion. Even though the degree of steatosis was equivalent, the 2 liver steatosis models possessed quite unique basal characteristics and showed completely different responses against ischemia/reperfusion injury and survival after transplantation. Our results demonstrate that the degree of fat accumulation is not a single determinant for the usability of steatotic liver grafts.

Pretreatment with a Phosphodiesterase-3 Inhibitor, Milrinone, Reduces Hepatic Ischemia-Reperfusion Injury, Minimizing Pericentral Zone-Based Liver and Small Intestinal Injury in Rats

BACKGROUND Severe pericentral zone (zone 3)-based liver injury (LI) may become intractable, with allograft dysfunction after liver transplantation. The phosphodiesterase-3 inhibitor, milrinone, has been reported to attenuate hepatic ischemia-reperfusion injury (IRI). This study clarified how hepatic IRI involved zone 3-based LI, in which zone milrinone was effective, and whether milrinone could improve small intestinal injury (SII) with hepatic IRI. MATERIAL AND METHODS Rats were divided into sham, ischemia-reperfusion (IR), or IR+milrinone groups (n=13 per group). Milrinone was administered intraportally via intrasplenic injection, and whole hepatic ischemia was induced for 30 min. Five hours after reperfusion, serum chemistry and histopathological findings were compared. Expression of CD34 for the detection of altered sinusoidal endothelium as sinusoidal capillarization and cleaved caspase-3 as an apoptosis marker were analyzed via immunohistochemistry. Survival rates were examined after 45 min of whole hepatic ischemia. RESULTS Serum aspartate aminotransferase and direct bilirubin levels were significantly decreased in the IR+milrinone group compared with those of the IR group. The degree of LI, sinusoidal capillarization and apoptosis at zone 3 in the IR group was significantly increased compared with those at the periportal zone (zone 1). These findings at zone 3 in the IR group were improved in the IR+milrinone group. SII with villus congestion and apoptosis in the IR group was significantly attenuated in the IR+milrinone group. The 7-day survival rate was significantly elevated in the IR+milrinone group as compared with that of the IR group. CONCLUSIONS A hepatic IRI model caused zone 3-based LI and SII, which were attenuated by intraportal administration of milrinone.

Inhibition of Rho-Kinase Downregulates Th17 Cells and Ameliorates Hepatic Fibrosis by Schistosoma japonicum Infection

BACKGROUND

Schistosomiasis is an immunopathogenic disease in which Th17 cells play vital roles. Hepatic granuloma formation and subsequent fibrosis are its main pathologic manifestations and the leading causes of hepatic cirrhosis, and effective therapeutic interventions are lacking. In this study, we explored the effects of fasudil, a selective RhoA-Rho-associated kinase (ROCK) inhibitor, on Th17 cells and the pathogenesis of schistosomiasis.

METHODS

Mice were infected with Schistosoma japonicum and treated with fasudil. The worm burden, hepatic granuloma formation, and fibrosis were evaluated. The roles of fasudil on Th17, Treg, and hepatic stellate cells were analyzed.

RESULTS

Fasudil therapy markedly reduced the granuloma size and collagen deposit in livers from mice infected with S. japonicum. However, fasudil therapy did not affect the worm burden in infected mice. The underlying cellular and molecular mechanisms were investigated. Fasudil suppressed the activation and induced the apoptosis of CD4⁺ T cells. Fasudil inhibited the differentiation and effector cytokine secretion of Th17 cells, whereas it upregulated Treg cells in vitro. It also restrained the in vivo interleukin (IL)-4 and IL-17 levels in infected mice. Fasudil directly induced the apoptosis of hepatic stellate cells and downregulated the expressions of hepatic fibrogenic genes, such as collagen type I (Col-I), Col-III, and transforming growth factor-1 (TGF-β1). These effects may contribute to its anti-pathogenic roles in schistosomiasis.

CONCLUSIONS

Fasudil inhibits hepatic granuloma formation and fibrosis with downregulation of Th17 cells. Fasudil might serve as a novel therapeutic agent for hepatic fibrosis due to schistosome infections and perhaps other disorders.

Vitamin A-coupled liposomal Rho-kinase inhibitor ameliorates liver fibrosis without systemic adverse effects

AIM

Rho-kinase (ROCK) inhibitor could ameliorate liver fibrosis by suppressing hepatic stellate cell (HSC) activation. However, because systemic administration of ROCK inhibitor causes serious adverse effects, we developed a drug delivery system selectively delivering ROCK inhibitor to HSCs. Here, we examined whether our developed vitamin A (VA)-coupled liposomal ROCK inhibitor reduced liver fibrosis in rats without causing systemic adverse effects.

METHODS

LX-2 HSCs were analyzed for morphological changes and the expression of profibrotic proteins. The inhibitory effects of VA-coupled liposomal ROCK inhibitor on liver fibrosis were confirmed in a rat model of liver fibrosis induced by i.p. injection of carbon tetrachloride. The degree of liver fibrosis, biochemical changes, and survival rates were also investigated.

RESULTS

Vitamin A-coupled liposomal ROCK inhibitor had an effect at approximately 1/100 the amount of the free ROCK inhibitor for inhibiting the activation of LX-2 cells and caused significant decreases in the expression levels of α-smooth muscle actin (SMA) and transforming growth factor (TGF)-β1. The degree of liver fibrosis was suppressed by treatment with VA-coupled liposomal ROCK inhibitor, and the expression of α-SMA and TGF-β1 in liver tissues was also significantly suppressed. In addition, serum levels of alanine aminotransferase and hyaluronic acid were significantly reduced, and there was no decline in kidney function, which has been noted as a systemic adverse effect of ROCK inhibitor. Furthermore, VA-coupled liposomal ROCK inhibitor improved survival rates in rats with liver fibrosis.

CONCLUSION

Vitamin A-coupled liposomal ROCK inhibitor efficiently suppressed liver fibrosis without causing systemic adverse effects.

Myeloid Notch1 deficiency activates the RhoA/ROCK pathway and aggravates hepatocellular damage in mouse ischemic livers

Notch signaling plays an emerging role in the regulation of immune cell development and function during inflammatory response. Activation of the ras homolog gene family member A/Rho-associated protein kinase (ROCK) pathway promotes leukocyte accumulation in tissue injury. However, it remains unknown whether Notch signaling regulates ras homolog gene family member A/ROCK-mediated immune responses in liver ischemia and reperfusion (IR) injury. This study investigated intracellular signaling pathways regulated by Notch receptors in the IR-stressed liver and in vitro. In a mouse model of IR-induced liver inflammatory injury, we found that mice with myeloid-specific Notch1 knockout showed aggravated hepatocellular damage, with increased serum alanine aminotransferase levels, hepatocellular apoptosis, macrophage/neutrophil trafficking, and proinflammatory mediators compared to Notch1-proficient controls. Unlike in the controls, myeloid Notch1 ablation diminished hairy and enhancer of split-1 (Hes1) and augmented c-Jun N-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 (JSAP1), JNK, ROCK1, and phosphatase and tensin homolog (PTEN) activation in ischemic livers. Disruption of JSAP1 in myeloid-specific Notch1 knockout livers improved hepatocellular function and reduced JNK, ROCK1, PTEN, and toll-like receptor 4 activation. Moreover, ROCK1 knockdown inhibited PTEN and promoted Akt, leading to depressed toll-like receptor 4. In parallel in vitro studies, transfection of lentivirus-expressing Notch1 intracellular domain promoted Hes1 and inhibited JSAP1 in lipopolysaccharide-stimulated bone marrow-derived macrophages. Hes1 deletion enhanced JSAP1/JNK activation, whereas clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9-mediated JSAP1 knockout diminished ROCK1/PTEN and toll-like receptor 4 signaling.

CONCLUSION

Myeloid Notch1 deficiency activates the ras homolog gene family member A/ROCK pathway and exacerbates hepatocellular injury by inhibiting transcriptional repressor Hes1 and inducing scaffold protein JSAP1 in IR-triggered liver inflammation; our findings underscore the crucial role of the Notch-Hes1 axis as a novel regulator of innate immunity-mediated inflammation and imply the therapeutic potential for the management of organ IR injury in transplant recipients. (Hepatology 2018;67:1041-1055).

Expression of prokineticin-receptor2(PK-R2) is a new prognostic factor in human colorectal cancer

The increased invasiveness of colorectal cancer cells is important for progression and metastasis to the surrounding organs. According to recent molecular biological studies, signaling through transmembrane Prokineticin-Receptor2(PK-R2) is likely involved in the ability of tumor cell to invade. However, no studies have evaluated the relationship between PK-R2 expression, ability of cancer to invade/metastasize, and patient prognosis in cases of resected colorectal cancer. Accordingly, we have examined these factors in the present study.

Immunohistochemical staining was performed to detect PK-R2 in the primary lesion and adjacent normal large intestine mucosa of 324 colorectal cancer patients who underwent resection surgery at our department. Additionally, we conducted clinicopathologic examinations and analyzed patient prognoses with the Kaplan-Meier method. Further, multivariate analysis was conducted using a cox-proportional hazard model.

PK-R2 expression was observed on the cellular membrane of the primary lesion in 147 of 324 cases (45.3%) of human colorectal cancer. PK-R2 expression was associated with a higher incidence of vascular invasion, lymph node metastasis, hepatic metastasis, and hematogenous metastasis. Further, prevalence of PK-R2 expression increased as tumor stage increased. In stage III curative resection cases, where recurrence is the most serious problem, cases that expressed PK-R2 had a significantly lower 5-year survival rate (82.1% versus 66.8%) and higher recurrence compared to those cases with no PK-R2 expression. In the multivariate analysis for prognosis, PK-R2 expression was found to be an independent factor(ratio2.621).

PK-R2 expression could be one of the new prognostic factors in human colorectal cancer.

Paeoniflorin alleviates non-alcoholic steatohepatitis in rats: Involvement with the ROCK/NF-κB pathway

Paeoniflorin (PF) is one of the major active ingredients of Paeonia lactiflora and has been suggested as a dietary therapy for non-alcoholic steatohepatitis (NASH); however, the involved mechanism remains obscure. The present work investigates the anti-inflammatory effects of PF and explores the possible mechanisms in a rat model of NASH. Male Sprague-Dawley rats were fed a high-cholesterol and high-fat (HCF) diet for 12weeks to induce the NASH model, and PF (20mg/kg/d) was orally administered to the NASH rats during the last four weeks of the study. Our results showed that PF significantly decreased serum alanine transferase (ALT) and aspartate transferase (AST) activities and also significantly decreased total levels of cholesterol (TC), low-density lipoprotein (LDL), and tumor necrosis factor alpha (TNF-α) (all P<0.05). Moreover, PF ameliorated the hepatic steatosis and inflammation and inhibited CD68 and transforming growth factor beta (TGF-β)-1 expression (both P<0.05). PF also down-regulated the activity of Rho kinase (ROCK) and suppressed the activation of the nuclear factor (NF)-κB signaling pathway in liver tissue. PF has liver protective and anti-inflammatory effects in HCF diet-induced NASH rats. The possible mechanisms may be associated with inhibition of the ROCK/NF-κB signaling pathway in the NASH liver.

h-Prune is associated with poor prognosis and epithelial-mesenchymal transition in patients with colorectal liver metastases

The prognosis of patients with colorectal liver metastases (CRLM) remains low despite advances in chemotherapy and surgery. The expression of h-prune (human homolog of Drosophila prune protein; HGNC13420), an exopolyphosphatase, is correlated with progression and aggressiveness in several cancers and promotes migration and invasion. We investigated the role of h-prune in CRLM. To investigate the role of h-prune, immunohistochemical analysis for h-prune was performed in 87 surgically resected specimens of CRLM obtained between 2001 and 2009 at the Hiroshima University Hospital. Immunohistochemical analysis revealed positive staining for h-prune in 24 (28%) cases. The overall survival rate was significantly lower in h-prune-positive cases than in h-prune-negative cases (p = 0.003). Multivariate analysis showed that h-prune positivity was the only independent factor related to poor overall survival of patients after curative hepatectomy of CRLM. In vitro and in vivo, h-prune-knocked-down and h-prune-overexpressing cells were analyzed. In vitro, h-prune was associated with increased cell motility and upregulation of epithelial-mesenchymal transition (EMT) markers. In a mouse model, h-prune was associated with invasion of the tumor and distant metastases. In summary, h-prune expression is a useful marker to identify high-risk patients for resectable colorectal liver metastasis. h-Prune expression is necessary for cancer cell motility and EMT and is associated with liver and lung metastasis in colorectal cancer cells. h-Prune could be a new prognostic marker and molecular target for CRLM.

Ischemia–reperfusion injury in patients with fatty liver and the clinical impact of steatotic liver on hepatic surgery

Hepatic steatosis is one of the most common hepatic disorders in developed countries. The epidemic of obesity in developed countries has increased with its attendant complications, including metabolic syndrome and non-alcoholic fatty liver disease. Steatotic livers are particularly vulnerable to ischemia/reperfusion injury, resulting in an increased risk of postoperative morbidity and mortality after liver surgery, including liver transplantation. There is growing understanding of the molecular and cellular mechanisms and therapeutic approaches for treating ischemia/reperfusion injury in patients with steatotic livers. This review discusses the mechanisms underlying the susceptibility of steatotic livers to ischemia/reperfusion injuries, such as mitochondrial dysfunction and signal transduction alterations, and summarizes the clinical impact of steatotic livers in the setting of hepatic resection and liver transplantation. This review also describes potential therapeutic approaches, such as ischemic and pharmacological preconditioning, to prevent ischemia/reperfusion injury in patients with steatotic livers. Other approaches, including machine perfusion, are also under clinical investigation; however, many pharmacological approaches developed through basic research are not yet suitable for clinical application.

Administration of antithrombin III attenuates posthepatectomy liver failure in hepatocellular carcinoma

BACKGROUND/AIMS

Coagulopathy can cause disseminated intravascular coagulation and posthepatectomy liver failure. Posthepatectomy liver failure predicts a poor prognosis after hepatectomy for hepatocellular carcinoma. Although antithrombin III reduces hypercoagulation, the impact of postoperative antithrombin III administration remains unknown. The aim of this study was to determine whether postoperative antithrombin III administration protects against the development of coagulation disorders.

METHODS

Data from 164 patients who received antithrombin III and 169 who did following curative hepatectomy for hepatocellular carcinoma were retrospectively collected and analyzed. To overcome bias due to different distributions of covariates for the two groups, a one-to-one match was created using propensity score analysis. After matching, patient outcomes were analyzed.

RESULTS

A multivariate analysis of the whole group revealed that antithrombin III activity of <50% on postoperative day 1 was an independent risk factor for posthepatectomy liver failure. After one-to-one matching, the rate of posthepatectomy liver failure was significantly lower in the AT-III-treated group than in the non-AT-III-treated group (16.3% (7/43) vs. 44.2% (19/43), p < 0.01).

CONCLUSIONS

Antithrombin III may attenuate posthepatectomy liver failure in hepatocellular carcinoma, possibly by suppressing coagulopathy.

Rho-kinase inhibitor targeting the liver prevents ischemia/reperfusion injury in the steatotic liver without major systemic adversity in rats

Rho-kinase (ROCK) inhibitors improve liver blood flow after ischemia/reperfusion (IR) injury, especially in the setting of steatosis, by decreasing the resistance of intrahepatic microcirculation through hepatic stellate cell (HSC) relaxation. However, the systemic administration of ROCK inhibitors causes severe hypotension; therefore, liver-specific ROCK inhibition is required. Here, we tested vitamin A (VA)-coupled liposomes carrying the ROCK inhibitor Y-27632 for targeted HSCs in steatotic rats. Rat livers with steatosis induced by a choline-deficient diet were subjected to IR injury. The delivery site and effect of the ROCK inhibitor were investigated. After liposomal Y-27632 injection, the survival rate after IR, the liver blood flow, the portal perfused pressure, and the hemodynamics were investigated. Immunohistochemical studies showed VA-coupled liposome accumulation in livers. Liposomal Y-27632 was 100-fold more effective in inhibiting HSC activation than free Y-27632. Liposomal Y-27632 improved the survival rate after IR injury, the liver blood flow, and the portal perfusion pressure without severe hypotension. In contrast, untargeted Y-27632 elicited severe systemic hypotension. We conclude that VA-coupled liposomes carrying the ROCK inhibitor yield enhanced drug accumulation in the liver and thus mitigate IR injury in the steatotic liver and reduce major systemic adversity.

Fatty liver creates a pro-metastatic microenvironment for hepatocellular carcinoma through activation of hepatic stellate cells

Fatty liver (FL) is associated with development of hepatocellular carcinoma (HCC). However, whether FL itself promotes the progression of HCC is unclear. We recently found that hepatic stellate cells (HSCs) were prominently activated in the steatotic liver. Here, we investigated whether steatotic livers promote HCC progression and whether HSCs of steatotic liver are associated with HCC progression. We implanted rat HCC cells into diet-induced steatotic livers in rats via portal vein injection. Thereafter, HSCs and HCC cells were co-implanted subcutaneously into nude rats. Migration and proliferation of HCC cells were measured, and activation of ERK and Akt in these cells was determined by western blotting. Chemokines secreted from HSCs and HCC cells were also evaluated by ELISA. Steatotic livers significantly promoted HCC metastasis compared with non-steatotic livers. Additionally, co-implantation of HCC cells with HSCs from steatotic livers produced significantly larger tumors in recipient rats as compared to those induced by HCC cells co-implanted with HSCs from normal livers (NLs). HSCs isolated from steatotic livers, compared with HSCs isolated from NLs, secreted greater amounts of interleukin-1α, vascular endothelial growth factor, and transforming growth factor-β. These cytokines may enhance the proliferation and migration of HCC cells by increasing the phosphorylation of ERK and Akt in HCC cells. Moreover, we noted that the Rho-kinase inhibitor deactivated activated HSCs and attenuated HCC progression. In conclusion, the rat steatotic liver microenvironment favors HCC metastasis, and this effect appears to be promoted by activated HSCs in the steatotic liver.

Hepatic ischemia and reperfusion injury: effects on the liver sinusoidal milieu

Ischemia-reperfusion injury is an important cause of liver damage occurring during surgical procedures including hepatic resection and liver transplantation, and represents the main underlying cause of graft dysfunction post-transplantation. Cellular and biochemical processes occurring during hepatic ischemia-reperfusion are diverse and complex, and include the deregulation of the healthy phenotype of all liver cellular components. Nevertheless, a significant part of these processes are still unknown or unclear. The present review aims at summarizing the current knowledge in liver ischemia-reperfusion, but specifically focusing on liver cell phenotype and paracrine interaction deregulations. Moreover, the most updated therapeutic strategies including pharmacological, genetic and surgical interventions, as well as some of the scientific controversies in the field will be described. Finally, the importance of considering the subclinical situation of liver grafts when translating basic knowledge to the bedside is discussed.

Protective activity of ischemic preconditioning on rat testicular ischemia: effects of Y-27632 and 5-hydroxydecanoic acid

BACKGROUND/PURPOSE

The aim of this study was to investigate the role of ischemic preconditioning (IPC) on ischemia/reperfusion (I/R)-induced injury of rat testis and determine the effects of 5-hydroxydecanoic acid (5-HD), a selective K(ATP) channel antagonist, and Y-27632, a selective Rho kinase inhibitor, on IPC.

METHODS

I/R injury was induced by 180 min ischemia and 60 min reperfusion of testis. There were 5 groups. Group 1 served as untreated controls. The rats in Group 2 were subjected to I/R only. In Group 3, 3 cycles of IPC (5 min transient ischemia plus 5 min reperfusion) were performed prior to I/R. In groups 4 and 5, the rats were treated as in Group 3 but received intraperitoneal injections of 0.3 mg/kg Y-27632 or 10 mg/kg 5-HD prior to IPC, respectively.

RESULTS

I/R led to severe histopathological lesions in the rat testis and significantly lowered the scoring. I/R resulted in significant elevation in tissue lipid peroxide levels, myeloperoxidase (MPO) activity, and total antioxidative capacity (TAC), total oxidative status, and oxidative stress index levels. Protective effects of IPC on I/R-induced testicular injury of rats were observed with the significant recovery in these biochemical parameters. Y-27632 treatment led to a significant decrease in MPO activity, but there were no significant changes in the remaining parameters. Effects of IPC were blocked by 5-HD except in the TAC levels.

CONCLUSION

Our results showed that IPC protected rat testis against I/R-induced injury via activation of KATP channels. Additionally, Rho kinase inhibition preserved the effects of IPC in testis.

Rho-kinase-dependent pathway mediates the hepatoprotective effects of sorafenib against ischemia/reperfusion liver injury in rats with nonalcoholic steatohepatitis

During liver transplantation, nonalcoholic steatohepatitis (NASH) aggravates ischemia/reperfusion (IR) injury by activating various kinases and subsequently releasing cytokines and chemokines. Nonetheless, the effect of the multikinase inhibitor sorafenib on IR liver injury in rats with NASH has never been explored. Our study was designed to determine this effect and associated mechanisms in NASH rats. Sorafenib was acutely administered to NASH rats with IR liver injury that were or were not chronically pretreated with the Rho-kinase-specific inhibitor fasudil. Then, the following were evaluated: mean arterial pressure; hepatic blood flow and microcirculatory dysfunction; hepatic inflammation (serum alanine aminotransferase); necrosis; apoptosis; leukocyte infiltration; CD45 staining; caspase levels and DNA fragmentation; various serum and hepatic cytokines; and proteins and genes of the Raf/mitogen-activated protein-extracellular signal-regulated kinase kinase (MEK)/extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase, and apoptosis pathways. In NASH rats with IR liver injury, hepatic inflammation, necrosis, apoptosis, leukocyte infiltration, and microcirculatory dysfunction were significantly attenuated by the acute administration of sorafenib through the inhibition of the hepatic release of macrophage inflammatory protein 2, keratinocyte chemoattractant, granulocyte-monocyte colony-stimulating factor, and hepatic caspase-3 and caspase-9 as well as DNA fragmentation. Furthermore, there was decreased expression of p-Raf1 (where p indicates the phosphorylated form), p-MEK1/2, p-ERK1/2, p-Rho-kinase, B cell lymphoma 2-associated death promoter, and B cell lymphoma 2-associated X protein at the protein and messenger RNA levels. Notably, the aforementioned beneficial effects of sorafenib were significantly abolished by chronic pretreatment with the Rho-kinase-specific inhibitor fasudil. This study demonstrated that the multikinase inhibitor sorafenib protects NASH rats from IR injury by interfering with the inflammation, necrotic, and apoptotic responses causing leukocyte-dependent hepatic microcirculatory dysfunction. The hepatoprotective effects of sorafenib seem to work through the inhibition of the Rho-kinase-dependent Raf/MEK/ERK pathway, which is up-regulated during IR injury in the livers of NASH rats.