Fatty Liver Transplantation Research Articles

Effectiveness of metformin for the reversal of cold-ischemia-induced damage in hepatosteatosis

BackgroundPrimary dysfunction and rejection are more common in donor liver tissues with steatosis. AMP-activated protein kinase (AMPK) assumes organ-protective functions during ischemia. Metformin was used for the activation of AMPK in hepatocytes. The aim of this study is to investigate the effectiveness of metformin administration for the reversal of cold-ischemia-induced damage in hepatosteatosis. Material and methodsSeven-week-old C7BL56 male-mice (n = 109) were separated into four groups depending on diet type and metformin use. A specific diet model was followed for 10 weeks to induce hepatosteatosis. A group of the animals was administered with metformin for the last four weeks via oral gavage. After resection, the liver tissues were perfused and kept for 0–6–12–24 h in the UW solution. Histopathological examinations were performed, and Western blot was utilized to analyze p-AMPK and AMPK expression levels. ResultsHepatosteatosis decreased significantly with metformin. The steatotic liver group had more prominent pericentral inflammation, necrosis as well as showing a decreased and more delayed AMPK response than the non-fat group. All these alterations could be corrected using metformin. ConclusionMetformin can increase the resistance of livers with hepatosteatosis to cold-ischemia-induced damage, which in turn may pave the way for successful transplantation of fatty living-donor livers.

Exosomes derived from bone marrow mesenchymal stem cells alleviate biliary ischemia reperfusion injury in fatty liver transplantation by inhibiting ferroptosis

Fatty liver grafts are susceptible to ischemia reperfusion injury (IRI), increasing the risk of biliary complications after liver transplantation (LT). Ferroptosis, a newly recognized programmed cell death, is expected to be a novel therapeutic target for IRI. We investigated whether exosomes derived from heme oxygenase 1-modified bone marrow mesenchymal stem cells (HExos) relieve ferroptosis and protect biliary tracts from IRI in a rat fatty liver transplantation model. Rats were fed with a methionine choline deficient (MCD) diet for 2 weeks to induce severe hepatic steatosis. Steatotic grafts were implanted and HExos were administered after liver transplantation. A series of functional assays and pathological analysis were performed to assess ferroptosis and biliary IRI. The HExos attenuated IRI following liver transplantation, as demonstrated by less ferroptosis, improved liver function, less Kupffer and T cell activation, and less long-term biliary fibrosis. MicroRNA (miR)-204-5p delivered by HExos negatively regulated ferroptosis by targeting a key pro-ferroptosis enzyme, ACSL4. Ferroptosis contributes to biliary IRI in fatty liver transplantation. HExos protect steatotic grafts by inhibiting ferroptosis, and may become a promising strategy to prevent biliary IRI and expand the donor pool.

Circadian rhythms and the liver.

This narrative review briefly describes the mammalian circadian timing system, the specific features of the liver clock, also by comparison with other peripheral clocks, the role of the liver clock in the preparation of food intake, and its relationship with energy metabolism. It then goes on to provide a chronobiological perspective of the pathophysiology and management of several types of liver disease, with a particular focus on metabolic-associated fatty liver disease (MAFLD), decompensated cirrhosis and liver transplantation. Finally, it provides some insight into the potential contribution of circadian principles and circadian hygiene practices in preventing MAFLD, improving the prognosis of advanced liver disease and modulating liver transplantation outcomes.

Tissue-resident memory T cells in chronic liver diseases: Phenotype, development and function.

Tissue-resident memory (TRM) T cells are a unique subset of memory T cells that are critical for the first line of defense against pathogens or antigens in peripheral non-lymphoid tissues such as liver, gut, and skin. Generally, TRM cells are well adapted to the local environment in a tissue-specific manner and typically do not circulate but persist in tissues, distinguishing them from other memory T cell lineages. There is strong evidence that liver TRM cells provide a robust adaptive immune response to potential threats. Indeed, the potent effector function of hepatic TRM cells makes it essential for chronic liver diseases, including viral and parasite infection, autoimmune liver diseases (AILD), nonalcoholic fatty liver disease (NAFLD), hepatocellular carcinoma (HCC) and liver transplantation. Manipulation of hepatic TRM cells might provide novel promising strategies for precision immunotherapy of chronic liver diseases. Here, we provide insights into the phenotype of hepatic TRM cells through surface markers, transcriptional profiles and effector functions, discuss the development of hepatic TRM cells in terms of cellular origin and factors affecting their development, analyze the role of hepatic TRM cells in chronic liver diseases, as well as share our perspectives on the current status of hepatic TRM cell research.

Identification and Isolation of Type II NKT Cell Subsets in Human Blood and Liver.

BackgroundSteatotic livers are more prone to rejection, but are often transplanted owing to the shortage of available organs. Type II NKT (T2NKT) cells are liver-resident lymphocytes that react to lipids presented by CD1d. The role of T2NKT cells in rejection of fatty liver transplants is unclear, partly because of a lack of T2NKT cell markers and their very low frequency in blood. Here, we quantify human T2NKT cells in blood and liver tissue by flow cytometry and provide a strategy for their enrichment and expansion.MethodsHuman T2NKT cells were identified as CD3+ CD56+ CD161+ TCR-γᵹ- TCRVα7.2- and TCRVα24- cells. T2NKT cells were enriched from blood by sequential positive selection using CD56 and CD3 microbeads. These were subsequently FACS-sorted to purity then expanded in vitro for 3 weeks using anti-CD3/CD28 beads and TGF-β1.ResultsThe frequency of human T2NKT cells in blood was very low (0.8 ± 0.4% of CD3+ T cells) but they were a more abundant population in liver (6.3 ± 0.9%). Enriched T2NKT cells expressed the transcription factor PLZF. A novel subset of FoxP3+ T2NKT cells was discovered in blood and liver tissue. T2NKT cells were expanded in culture by 15- to 28-fold over 3 weeks, during which time they maintained expression of all identifying markers, including PLZF and FoxP3.ConclusionsOur work defines new strategies for identifying and isolating T2NKT cells from human blood and liver tissue. We showed that this rare population can be expanded in vitro in order to obtain experimentally amenable cell numbers. Further, we identified a novel T2NKT cell subset that stably expresses FoxP3, which might play a role in regulating innate-like lymphocyte responses in steatotic liver transplants.

Reactive Oxygen Species Induce Fatty Liver and Ischemia-Reperfusion Injury by Promoting Inflammation and Cell Death.

Liver transplantation is the ultimate method for treating end-stage liver disease. With the increasing prevalence of obesity, the number of patients with non-alcoholic fatty liver, a common cause of chronic liver disease, is on the rise and may become the main cause of liver transplantation in the future. With the increasing gap between the number of donor livers and patients waiting for liver transplantation and the increasing prevalence of non-alcoholic fatty liver, the proportion of steatosis livers among non-standard donor organs is also increasing. Ischemia-reperfusion injury has historically been the focus of attention in the liver transplantation process, and severe ischemia-reperfusion injury leads to adverse outcomes of liver transplantation. Studies have shown that the production of reactive oxygen species and subsequent oxidative stress play a key role in the pathogenesis of hepatic ischemia and reperfusion injury and non-alcoholic fatty liver. Furthermore, the sensitivity of fatty liver transplantation to ischemia-reperfusion injury has been suggested to be related to the production of reactive oxygen species (ROS) and oxidative stress. In ischemia-reperfusion injury, Kupffer cell and macrophage activation along with mitochondrial damage and the xanthine/xanthine oxidase system promote marked reactive oxygen species production and the inflammatory response and apoptosis, resulting in liver tissue injury. The increased levels of ROS and lipid peroxidation products, vicious circle of ROS and oxidative stress along with mitochondrial dysfunction promoted the progress of non-alcoholic fatty liver. In contrast to the non-fatty liver, a non-alcoholic fatty liver produces more reactive oxygen species and suffers more serious oxidative stress when subjected to ischemia-reperfusion injury. We herein review the effects of reactive oxygen species on ischemia-reperfusion injury and non-alcoholic fatty liver injury as well as highlight several treatment approaches.

Nonalcoholic fatty liver disease and liver transplantation

The rising prevalence of nonalcoholic fatty liver disease (NAFLD) is now the second largest indication for liver transplantation in Western countries, but viral hepatitis B and end-stage alcohol-related liver disease are still the main indications in China. With the improvement of people's living standards, the prevalence of metabolic syndrome, and the number of NAFLD patients has also gradually increased. At the same time, with the hepatitis B vaccination popularization and the nucleos(t)ide analogues and other drugs uses, it is predicted that NAFLD-related end-stage liver disease may become one of the main indications for liver transplantation in our country in the future. This article reviews the research progress of NAFLD and liver transplantation.

Ischemia/Reperfusion Injury of Fatty Liver Is Protected by A2AR and Exacerbated by A1R Stimulation through Opposite Effects on ASK1 Activation.

Hepatic ischemia/reperfusion injury (IRI) is aggravated by steatosis and is a main risk factor in fatty liver transplantation. Adenosine receptors (ARs) are emerging as therapeutic targets in liver diseases. By using cellular and in vivo systems of hepatic steatosis and IRI, here we evaluated the effects of pharmacological A2AR and A1R activation. The A2AR agonist CGS21680 protected the primary steatotic murine hepatocyte from IR damage and the activation of ASK1 and JNK. Such an effect was attributed to a phosphatidylinositol-3-kinase (PI3K)/Akt-dependent inhibition of ASK1. By contrast, the A1R agonist CCPA enhanced IR damage, intracellular steatosis and oxidative species (OS) production, thereby further increasing the lipid/OS-dependent ASK1-JNK stimulation. The CGS2680 and CCPA effects were nullified by a genetic ASK1 downregulation in steatotic hepatoma C1C7 cells. In steatotic mice livers, CGS21680 protected against hepatic IRI and ASK1/JNK activation whereas CCPA aggravated hepatic steatosis and IRI, and enhanced ASK1 and JNK stimulation. These results evidence a novel mechanism of CGS21680-mediated hepatoprotection, i.e., the PI3K/AKT-dependent inhibition of ASK1, and they show that CGS21680 and CCPA reduces and enhances the IRI of fatty liver, respectively, by preventing or increasing the activation of the cytotoxic ASK1/JNK axis. They also indicate the selective employment of A2AR agonists as an effective therapeutic strategy to prevent IRI in human fatty liver surgery.

Augmenter of liver regeneration ameliorates ischemia-reperfusion injury in steatotic liver via inhibition of the TLR4/NF-κB pathway.

Hepatocytes from donors with preexisting hepatic steatosis exhibited increased sensitivity to ischemia-reperfusion injury (IRI) during liver transplantation. Augmenter of liver regeneration (ALR) protected the liver against IRI, but the mechanism was not clarified. Therefore, the hypothesis that ALR attenuated IRI in steatotic liver by inhibition of inflammation and downregulation of the Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway was examined. C57BL/6 mice were subjected to a methionine-choline-deficient (MCD) diet to induce liver steatosis. Mice were transfected with ALR-containing adenovirus 3 days prior to partial warm hepatic IRI. After 30 min of ischemia and 6 h of reperfusion injury, liver function, hepatic injury, the inflammatory response and TLR4/NF-κB signaling pathway activation were assessed. ALR maintained liver function and alleviated hepatic injury as indicated by the decreased levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), preserved hepatic structure and reduced apoptosis. ALR also reduced the IRI-induced inflammatory response by suppressing Kupffer cell activation, inhibiting neutrophil chemotaxis and reducing inflammatory cytokine production. Further investigation using reverse transcription-quantitative PCR, western blotting and immunohistochemistry revealed that ALR reduced TLR4/NF-κB signaling pathway activation, which led to a decreased synthesis of inflammatory cytokines. ALR functioned as a regulator of the IRI-induced inflammatory response by suppressing the TLR4/NF-κB pathway, which supports the use of ALR in therapeutic applications for fatty liver transplantation.

Minimally Invasive Sleeve Gastrectomy as a Surgical Treatment for Nonalcoholic Fatty Liver Disease in Liver Transplant Recipients

BackgroundObesity is a major public health burden that affects the transplant community because of its key role in fatty liver disease and transplantation outcomes. ObjectivesTo evaluate the role of sleeve gastrectomy in treating recurrent and de novo nonalcoholic fatty liver disease (NAFLD) in liver transplant recipients. SettingA university hospital. MethodsWe describe 2 obese liver transplant recipients with recurrent and de novo NAFLD who underwent minimally invasive metabolic and bariatric surgery. ResultsThe surgery was performed successfully, with much of the operative time consumed by enterolysis. There were no intraoperative or postoperative complications. At last follow-up appointment (16 months postoperatively), there was a mean reduction in weight (31.98 kg), body mass index (10.2 kg/m2), glycosylated hemoglobin (1.05%), alanine aminotransferase (38 IU/L), steatosis score (0.34), and fibrosis score (0.05). The mean decrease in 6-month postoperative hepatic fat quantification was 6%. ConclusionsThese cases show that metabolic and bariatric surgery in obese, posttransplant recipients with recurrent and de novo nonalcoholic steatohepatitis lead to improved steatosis and reduced obesity and obesity-associated comorbidities.

ESPEN guideline on clinical nutrition in liver disease

This update of evidence-based guidelines (GL) aims to translate current evidence and expert opinion into recommendations for multidisciplinary teams responsible for the optimal nutritional and metabolic management of adult patients with liver disease. The GL was commissioned and financially supported by ESPEN. Members of the guideline group were selected by ESPEN. We searched for meta-analyses, systematic reviews and single clinical trials based on clinical questions according to the PICO format. The evidence was evaluated and used to develop clinical recommendations implementing the SIGN method. A total of 85 recommendations were made for the nutritional and metabolic management of patients with acute liver failure, severe alcoholic steatohepatitis, non-alcoholic fatty liver disease, liver cirrhosis, liver surgery and transplantation as well as nutrition associated liver injury distinct from fatty liver disease. The recommendations are preceded by statements covering current knowledge of the underlying pathophysiology and pathobiochemistry as well as pertinent methods for the assessment of nutritional status and body composition.

Steatosis in Liver Transplantation: Current Limitations and Future Strategies.

In parallel with the pandemic of obesity and diabetes, the prevalence of nonalcoholic fatty liver disease has progressively increased. Nonalcoholic steatohepatitis (NASH), a subtype of nonalcoholic fatty liver disease has also augmented considerably being currently cirrhosis due to NASH the second indication for liver transplantation in the United States. Innovative treatments for NASH have shown promising results in phase 2 studies and are being presently evaluated in phase 3 trials. On the other hand, the high mortality on the liver transplant waitlist and the organ shortage has obligated the transplant centers to consider suboptimal grafts, such as steatotic livers for transplantation. Fatty livers are vulnerable to preservation injury resulting in a higher rate of primary nonfunction, early allograft dysfunction and posttransplant vascular and biliary complications. Macrosteatosis of more than 30% in fact is an independent risk factor for graft loss. Therefore, it needs to be considered into the risk assessment scores. Growing evidence supports that moderate and severe macrosteatotic grafts can be successfully used for liver transplantation with careful recipient selection. Protective strategies, such as machine-based perfusion have been developed in experimental setting to minimize preservation-related injury and are now on the verge to move into the clinical implementation. This review focuses on the current and potential future treatment of NASH and the clinical practice in fatty liver transplantation, highlights its limitations and optimal allocation, and summarizes the advances of experimental protective strategies, and their potential for clinical application to increase the acceptance and improve the outcomes after liver transplantation with high-grade steatotic livers.

Has Access to Hepatitis C Virus Therapy Changed for Patients With Mental Health or Substance Use Disorders in the Direct-Acting-Antiviral Period?

Direct-acting antivirals (DAA) for hepatitis C virus (HCV) became available in 2014, but the role of mental health or substance use disorders (MH/SUD) on access to treatment is unknown. The objective of this study was to examine the extent and predictors of HCV treatment in the pre-DAA and post-DAA periods in four large, diverse health care settings in the United States. We conducted a retrospective analysis of 29,544 adults with chronic HCV who did or did not receive treatment from January 1, 2011, to February 28, 2017. Kaplan-Meier curve was used to examine cumulative risk for receiving HCV treatment stratified by MH/SUD. Predictors of HCV treatment in the pre-DAA (January 1, 2011, to December 31, 2013) and post-DAA (January 1, 2014, to February 28, 2017) cohorts were analyzed using multivariate generalized estimating equations and a modified Poisson model. Overall, 21.7% (2,879/13,240) of those with chronic HCV post-DAA were treated compared with 3.5% (574/16,304) in the pre-DAA period. Compared with non-Hispanic whites, Hispanic whites (adjusted odds ratio [AOR] 0.36; 95% confidence interval [CI], 0.25, 0.52) were less likely to be treated in the post-DAA period. Those with concurrent nonalcoholic fatty liver disease (AOR 1.39; 95% CI, 1.05, 1.83), cirrhosis (AOR 2.00; 95% CI, 1.74, 2.31), and liver transplant (AOR 2.72; 95% CI, 1.87, 3.94) were more likely to be treated post-DAA. Those with MH/SUD were less likely to be treated both before (AOR 0.46; 95% CI, 0.36, 0.60) and after (AOR 0.63; 95% CI, 0.55, 0.71) DAA therapy was available. Overall, the cumulative risk for receiving HCV treatment from 2011 to 2017 among those with versus without MH/SUD was 13.6% versus 21.6%, respectively (P < 0.001). Conclusion: The volume of patients treated for HCV has increased in the post-DAA period, especially among those with liver-related comorbidities, but disparities in access to treatment continue among those with MH/SUD.

Nonalcoholic fatty liver disease and liver transplantation - Where do we stand?

Nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NAFLD/NASH) is a challenging and multisystem disease that has a high socioeconomic impact. NAFLD/NASH is a main cause of macrovesicular steatosis and has multiple impacts on liver transplantation (LT), on patients on the waiting list for transplant, on post-transplant setting as well as on organ donors. Current data indicate new trends in the area of chronic liver disease. Due to the increased incidence of metabolic syndrome (MetS) and its components, NASH cirrhosis and hepatocellular carcinoma caused by NASH will soon become a major indication for LT. Furthermore, due to an increasing incidence of MetS and, consequently, NAFLD, there will be more steatotic donor livers and less high quality organs available for LT, in addition to a lack of available liver allografts. Patients who have NASH and are candidates for LT have multiple comorbidities and are unique LT candidates. Finally, we discuss long-term grafts and patient survival after LT, the recurrence of NASH and NASH appearing de novo after transplantation. In addition, we suggest topics and areas that require more research for improving the health care of this increasing patient population.

Meloxicam increases epidermal growth factor receptor expression improving survival after hepatic resection in diet-induced obese mice

BackgroundPatients with fatty liver have delayed regenerative responses, increased hepatocellular injury, and increased risk for perioperative mortality. Currently, no clinical therapy exists to prevent liver failure or improve regeneration in patients with fatty liver. Previously we demonstrated that obese mice have markedly reduced levels of epidermal growth factor receptor in liver. We sought to identify pharmacologic agents to increase epidermal growth factor receptor expression to improve hepatic regeneration in the setting of fatty liver resection. MethodsLean (20% calories from fat) and diet-induced obese mice (60% calories from fat) were subjected to 70% or 80% hepatectomy. ResultsUsing the BaseSpace Correlation Engine of deposited gene arrays we identified agents that increased hepatic epidermal growth factor receptor. Meloxicam was identified as inducing epidermal growth factor receptor expression across species. Meloxicam improved hepatic steatosis in diet-induced obese mice both grossly and histologically. Immunohistochemistry and Western blot analysis demonstrated that meloxicam pretreatment of diet-induced obese mice dramatically increased epidermal growth factor receptor protein expression in hepatocytes. After 70% hepatectomy, meloxicam pretreatment ameliorated liver injury and significantly accelerated mitotic rates of hepatocytes in obese mice. Recovery of liver mass was accelerated in obese mice pretreated with meloxicam (by 26% at 24 hours and 38% at 48 hours, respectively). After 80% hepatectomy, survival was dramatically increased with meloxicam treatment. ConclusionLow epidermal growth factor receptor expression is a common feature of fatty liver disease. Meloxicam restores epidermal growth factor receptor expression in steatotic hepatocytes. Meloxicam pretreatment may be applied to improve outcome after fatty liver resection or transplantation with steatotic graft.

Retraction: "Safety limitations of fatty liver transplantation can be extended to 40%: Experience of a single centre in China", by Yu Z., Yu S., Zhang L., Feng X., Zhang M., etal.

The above article, published online on 13 October 2016 in Wiley OnlineLibrary (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor in Chief, Mario U. Mondelli, and John Wiley & Sons Ltd. see accompanying Editorial Note It has come to the attention of the Editors that the article may have contained data referring to the use of organs retrieved from executed prisoners and not from donors after cardiac death (DCD), thus breaching international organ donation ethical standards. Further information is contained in the accompanying Editorial link. REFERENCE Yu Z, Sun Z, Yu S, etal. Safety limitations of fatty liver transplantation can be extended to 40%: experience of a single centre in China. Liver Int. 2016; doi: 10.1111/liv.13244.

Non-alcoholic fatty liver disease and liver transplantation

Cirrhosis secondary to non-alcoholic steatohepatitis (NASH) is a common indication for liver transplant. In comparison to other cirrhotic patients, patients with NASH cirrhosis are more likely to be older and have the metabolic syndrome. Pre-transplant, patients require careful evaluation of cardiovascular risk. As the incidence of non-alcoholic fatty liver disease (NAFLD) is rising, a greater proportion of donor grafts have steatosis greater than 30%, which is associated with poor outcomes. Grafts with steatosis greater than 60% are unsuitable for transplant. Overall, post-transplant survival outcomes for patients with NASH cirrhosis are similar to those with cirrhosis without NASH. However, NASH cirrhosis is associated with a higher 30-day mortality, predominantly from an increase in cardiovascular events and infections. Following liver transplant, there is a significant risk of NASH recurrence, although this seldom results in allograft loss. Furthermore, a significant number of patients who had a liver transplant for other reasons develop NASH de novo. When patients with NASH cirrhosis are considered for transplant, one of the major challenges lies in identifying which patients are too high risk for surgery. This review aims to provide information to aid this decision making process, and to provide guidance on the peri-operative care strategies that can modify risk.

LXRα gene downregulation by lentiviral-based RNA interference enhances liver function after fatty liver transplantation in rats

Steatotic liver grafts, although accepted, increase the risk of poor posttransplantation liver function. However, the growing demand for adequate donor organs has led to the increased use of so-called marginal grafts. Liver X receptor alpha (LXRalpha) is important in fatty acid metabolism and interrelated with the specific ischemia-reperfusion injury in fatty liver transplantation. This study aimed to investigate whether LXRalpha RNA interference (RNAi) could improve the organ function of liver transplant recipients. Fifty Sprague-Dawley rats were fed with a high-fat diet and 56% alcohol. The livers of these animals had greater than 60% macrovesicular steatosis and were used as liver donors. The experimental donors were treated with 7X107 TU LXRalpha-RNAi-LV of a mixture injection and control donors with negative control-LV vector injection into the portal vein 72 hours before the operation. The effects of LXRalpha-RNAi-LV were assessed by serum aminotransferases, histology, immunostaining, and protein levels. The transcription of LXRalpha mRNA was assessed by reverse transcription-polymerase chain reaction. Compared with controls, LXRalpha RNAi inhibited the expression of LXRalpha at the mRNA (0.53+/-0.03 vs 0.94+/-0.02, P<0.05) and protein levels (0.51+/-0.08 vs 1.09+/-0.12, P<0.05). LXRalpha RNAi also decreased the expressions of sterol regulatory element-binding protein 1c (SREBP-1c) and CD36. LXRalpha RNAi consequently reduced fatty acid accumulation in hepatocytes. Compared with control animals, LXRalpha RNAi-treated group had lower serum alanine aminotransferase, aspartate aminotransferase, interleukin-1beta, and tumor necrosis factor-alpha levels and milder pathologic damages. TUNEL analysis revealed a significant reduction of apoptosis in the livers of rats treated with LXRalpha-RNAi-LV, and overall survival as determined by the Kaplan-Meier method was improved among rats treated with LXRalpha-RNAi-LV (P<0.05). LXRalpha-RNAi-LV treatment significantly downregulated LXRalpha expression and improve steatotic liver graft function and recipient survival after a fatty liver transplantation in rats.

Circulating RNA molecules as biomarkers in liver disease.

Liver disease is a major cause of morbidity and mortality worldwide. As in other fields of medicine, there is a stringent need for non-invasive markers to improve patient diagnostics, monitoring and prognostic ability in liver pathology. Cell-free circulating RNA molecules have been recently acknowledged as an important source of potential medical biomarkers. However, many aspects related to the biology of these molecules remain to be elucidated. In this review, we summarize current concepts related to the origin, transportation and possible functions of cell-free RNA. We outline current development of extracellular RNA-based biomarkers in the main forms of non-inherited liver disease: chronic viral hepatitis, hepatocellular carcinoma, non-alcoholic fatty liver, hepato-toxicity, and liver transplantation. Despite recent technological advances, the lack of standardization in the assessment of these markers makes their adoption into clinical practice difficult. We thus finally review the main factors influencing quantification of circulating RNA. These factors should be considered in the reporting and interpretation of current findings, as well as in the proper planning of future studies, to improve reliability and reproducibility of results.

Liver damage induced by diabetes mellitus

There is a complicated association between the liver and diabetes mellitus.Diabetes mellitus may cause various forms of liver damage,such as nonalcoholic fatty liver disease (NAFLD),hepatic cirrhosis,hepatocellular carcinoma,liver abscess,and liver transplant complications.With the growing epidemic of diabetes mellitus,this review investigates diabetes mellitus induced liver damage. Key words: Diabetes mellitus; Liver injury