Circulating miR-21, miR-210 and miR-146a as potential biomarkers to differentiate acute tubular necrosis from hepatorenal syndrome in patients with liver cirrhosis: a pilot study

Noncoding RNA-Mediated Epigenetic Regulation in Hepatic Stellate Cells of Liver Fibrosis

Liver fibrosis is a significant contributor to liver-related disease mortality on a global scale. Despite this, there remains a dearth of effective therapeutic interventions capable of reversing this condition. Consequently, it is imperative that we gain a comprehensive understanding of the underlying mechanisms driving liver fibrosis. In this regard, the activation of hepatic stellate cells (HSCs) is recognized as a pivotal factor in the development and progression of liver fibrosis. The role of noncoding RNAs (ncRNAs) in epigenetic regulation of HSCs transdifferentiation into myofibroblasts has been established, providing new insights into gene expression changes during HSCs activation. NcRNAs play a crucial role in mediating the epigenetics of HSCs, serving as novel regulators in the pathogenesis of liver fibrosis. As research on epigenetics expands, the connection between ncRNAs involved in HSCs activation and epigenetic mechanisms becomes more evident. These changes in gene regulation have attracted considerable attention from researchers in the field. Furthermore, epigenetics has contributed valuable insights to drug discovery and the identification of therapeutic targets for individuals suffering from liver fibrosis and cirrhosis. As such, this review offers a thorough discussion on the role of ncRNAs in the HSCs activation of liver fibrosis.

Renal dysfunctions and liver disease: a brief update on management with particular attention to hepatorenal syndrome

In 2015 the International Club of Ascites gave an accurate, exact and new definition of acute renal injury in cirrhotic patient, identifying objective criteria of severity and recoding hepatorenal syndrome as a particular form of renal dysfunction for which excessive renal vasoconstriction is one of the main, but not the only, pathophysiological mechanisms. In this review we tried to outline new pathophysiological and therapeutic insights, and to summarize the most recent recommendations. Vasopressor such as terlipressin and norepinephrine, in combination with albumin, still represent the first line therapy. However, the new discoveries in the pathophysiology of the disease have led the search for new pharmacological approaches, although, to date, the only definitive remedy is represented by liver (or simultaneous liver-kidney) transplantation.

Acute Kidney Injury in Patients with Liver Disease

AKI is commonly encountered in patients with decompensated cirrhosis, and it is associated with unfavorable outcomes. Among factors specific to cirrhosis, hepatorenal syndrome type 1, also referred to as hepatorenal syndrome-AKI, is the most salient and unique etiology. Patients with cirrhosis are vulnerable to traditional causes of AKI, such as prerenal azotemia, acute tubular injury, and acute interstitial nephritis. In addition, other less common etiologies of AKI specifically related to chronic liver disease should be considered, including abdominal compartment syndrome, cardiorenal processes linked to cirrhotic cardiomyopathy and portopulmonary hypertension, and cholemic nephropathy. Furthermore, certain types of GN can cause AKI in cirrhosis, such as IgA nephropathy or viral hepatitis related. Therefore, a comprehensive diagnostic approach is needed to evaluate patients with cirrhosis presenting with AKI. Management should be tailored to the specific underlying etiology. Albumin-based volume resuscitation is recommended in prerenal AKI. Acute tubular injury and acute interstitial nephritis are managed with supportive care, withdrawal of the offending agent, and, potentially, corticosteroids in acute interstitial nephritis. Short of liver transplantation, vasoconstrictor therapy is the primary treatment for hepatorenal syndrome type 1. Timing of initiation of vasoconstrictors, the rise in mean arterial pressure, and the degree of cholestasis are among the factors that determine vasoconstrictor responsiveness. Large-volume paracentesis and diuretics are indicated to relieve intra-abdominal hypertension and renal vein congestion. Direct-acting antivirals with or without immunosuppression are used to treat hepatitis B/C-associated GN. In summary, AKI in cirrhosis requires careful consideration of multiple potentially pathogenic factors and the implementation of targeted therapeutic interventions.

MicroRNAs in kidney injury and disease

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by degrading or repressing the translation of their target messenger RNAs. As miRNAs are critical regulators of cellular homeostasis, their dysregulation is a crucial component of cell and organ injury. A substantial body of evidence indicates that miRNAs are involved in the pathophysiology of acute kidney injury (AKI), chronic kidney disease and allograft damage. Different subsets of miRNAs are dysregulated during AKI, chronic kidney disease and allograft rejection, which could reflect differences in the physiopathology of these conditions. miRNAs that have been investigated in AKI include miR-21, which has an anti-apoptotic role, and miR-214 and miR-668, which regulate mitochondrial dynamics. Various miRNAs are downregulated in diabetic kidney disease, including the miR-30 family and miR-146a, which protect against inflammation and fibrosis. Other miRNAs such as miR-193 and miR-92a induce podocyte dedifferentiation in glomerulonephritis. In transplantation, miRNAs have been implicated in allograft rejection and injury. Further work is needed to identify and validate miRNAs as biomarkers of graft function and of kidney disease development and progression. Use of combinations of miRNAs together with other molecular markers could potentially improve diagnostic or predictive power and facilitate clinical translation. In addition, targeting specific miRNAs at different stages of disease could be a promising therapeutic strategy.

Hepatorenal Syndrome Type 1: From Diagnosis Ascertainment to Goal-Oriented Pharmacologic Therapy

Hepatorenal syndrome type 1 (HRS-1) is a serious form of AKI that affects individuals with advanced cirrhosis with ascites. Prompt and accurate diagnosis is essential for effective implementation of therapeutic measures that can favorably alter its clinical course. Despite decades of investigation, HRS-1 continues to be primarily a diagnosis of exclusion. Although the diagnostic criteria dictated by the International Club of Ascites provide a useful framework to approach the diagnosis of HRS-1, they do not fully reflect the complexity of clinical scenarios that is often encountered in patients with cirrhosis and AKI. Thus, diagnostic uncertainty is often faced. In particular, the distinction between HRS-1 and acute tubular injury is challenging with the currently available clinical tools. Because treatment of HRS-1 differs from that of acute tubular injury, distinguishing these two causes of AKI has direct implications in management. Therefore, the use of the International Club of Ascites criteria should be enhanced with a more individualized approach and attention to the other phenotypic aspects of HRS-1 and other types of AKI. Liver transplantation is the most effective treatment for HRS-1, but it is only available to a small fraction of the affected patients worldwide. Thus, pharmacologic therapy is necessary. Vasoconstrictors aimed to increase mean arterial pressure constitute the most effective approach. Administration of intravenous albumin is an established co-adjuvant therapy. However, the risk for fluid overload in patients with cirrhosis with AKI is not negligible, and interventions intended to expand or remove volume should be tailored to the specific needs of the patient. Norepinephrine and terlipressin are the most effective vasoconstrictors, and their use should be determined by availability, ease of administration, and attention to optimal risk-benefit balance for each clinical scenario.

MiR-210-5p regulates STAT3 activation by targeting STAT5A in the differentiation of dermal fibroblasts

Elucidating the molecular mechanism of the microRNAs in skin fibrosis is critical for identifying a novel therapeutic strategy for hypertrophic scar (HS). In this study, it was shown that miR-210-5p is induced by TGFβ, and that overexpression of miR-210-5p promoted the differentiation of human dermal fibroblasts (HDFs) into myofibroblasts. STAT5A is required for TGFβ-induced STAT3 activity. Here, we show that miR-210-5p attenuated TGFβ-induced STAT3 signaling pathway by suppressing the expression of STAT5A. Taken together, the present study suggests that TGFβ-induced miR-210-5p reduced STAT5A expression, leading to aberrant activation of STAT3, and facilitate skin fibrosis in HDFs.

microRNAs as Novel Therapeutics in Cancer

Simple Summary

Over the last few years, we have witnessed incredible advancements in anti-tumor drug development. microRNAs, a class of small non-coding RNAs dysregulated in all cancers, have been recently elected as candidate therapeutics for treating a variety of diseases, including cancer. The scope of this review is to give some insight into the role of the most relevant microRNAs in cancer. We will focus on examining their biological role in tumor development while also providing a broad overview of microRNAs as therapeutics. There is a dedicated focus on the different methods available for microRNA delivery in addition to the efforts being made to increase the specificity of these delivery methods. Finally, we discuss the ongoing clinical trials that are using microRNAs for cancer treatment.

Abstract

In the last 20 years, the functional roles for miRNAs in gene regulation have been well established. MiRNAs act as regulators in virtually all biological pathways and thus have been implicated in numerous diseases, including cancer. They are particularly relevant in regulating the basic hallmarks of cancer, including apoptosis, proliferation, migration, and invasion. Despite the substantial progress made in identifying the molecular mechanisms driving the deregulation of miRNAs in cancer, the clinical translation of these important molecules to therapy remains in its infancy. The paucity of vehicles available for the safe and efficient delivery of miRNAs and ongoing concerns for toxicity remain major obstacles to clinical application. Novel formulations and the development of new vectors have significantly improved the stability of oligonucleotides, increasing the effectiveness of therapy. Furthermore, the use of specific moieties for delivery in target tissues or cells has increased the specificity of treatment. The use of new technologies has allowed small but important steps toward more specific therapeutic delivery in tumor tissues and cells. Although a long road remains, the path ahead holds great potential. Currently, a few miRNA drugs are under investigation in human clinical trials with promising results ahead.

microRNA-125b-5p is a promising novel plasma biomarker for alveolar echinococcosis in patients from the southern province of Qinghai

Background

Alveolar echinococcosis (AE) is caused by parasitic infection by Echinococcus multilocularis. Its diagnosis is usually based on clinical symptoms, ultrasound, and other imaging methods. MicroRNAs (miRNAs) play important roles in disease processes and can exist in a highly stable cell-free form in body fluids. It is important to identify specific, sensitive diagnostic markers for early diagnosis and evaluation of AE. In this study, we examined hsa-miR-125b-5p as a potential plasma biomarker of E. multilocularis infection.

Methods

Plasma samples from patients with AE and healthy individuals were screened for the presence of five miRNAs using miRNA chips. We used quantitative polymerase chain reaction to measure miRNA expression levels in plasma and liver tissue samples from patients with AE.

Results

hsa-miR-125b-5p was stably upregulated in the plasma and liver tissue samples from patients with AE.

Conclusions

The results suggest that hsa-miR-125b-5p may be a promising biomarker for early, non-invasive diagnosis of AE.

Profiling circulating microRNAs in patients with cirrhosis and acute-on-chronic liver failure

Background & Aims

MicroRNAs (miRNAs) circulate in several body fluids and can be useful biomarkers. The aim of this study was to identify blood-circulating miRNAs associated with cirrhosis progression and acute-on-chronic liver failure (ACLF).

Methods

Using high-throughput screening of 754 miRNAs, serum samples from 45 patients with compensated cirrhosis, decompensated cirrhosis, or ACLF were compared with those from healthy individuals (n = 15). miRNA levels were correlated with clinical parameters, organ failure, and disease progression and outcome. Dysregulated miRNAs were evaluated in portal and hepatic vein samples (n = 33), liver tissues (n = 17), and peripheral blood mononuclear cells (PBMCs) (n = 16).

Results

miRNA screening analysis revealed that circulating miRNAs are dysregulated in cirrhosis progression, with 51 miRNAs being differentially expressed among all groups of patients. Unsupervised clustering and principal component analysis indicated that the main differences in miRNA expression occurred at decompensation, showing similar levels in patients with decompensated cirrhosis and those with ACLF. Of 43 selected miRNAs examined for differences among groups, 10 were differentially expressed according to disease progression. Moreover, 20 circulating miRNAs were correlated with model for end-stage liver disease and Child-Pugh scores. Notably, 11 dysregulated miRNAs were associated with kidney or liver failure, encephalopathy, bacterial infection, and poor outcomes. The most severely dysregulated miRNAs (i.e. miR-146a-5p, miR-26a-5p, and miR-191-5p) were further evaluated in portal and hepatic vein blood and liver tissue, but showed no differences. However, PBMCs from patients with cirrhosis showed significant downregulation of miR-26 and miR-146a, suggesting a extrahepatic origin of some circulating miRNAs.

Conclusions

This study is a repository of circulating miRNA data following cirrhosis progression and ACLF. Circulating miRNAs were profoundly dysregulated during the progression of chronic liver disease, were associated with failure of several organs and could have prognostic utility.

Lay summary

Circulating miRNAs are small molecules in the blood that can be used to identify or predict a clinical condition. Our study aimed to identify miRNAs for use as biomarkers in patients with cirrhosis or acute-on-chronic liver failure. Several miRNAs were found to be dysregulated during the progression of disease, and some were also related to organ failure and disease-related outcomes.

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Circulating miRNAs are dysregulated with cirrhosis progression and in patients with ACLF.

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Patient decompensation is associated with important changes in the levels of circulating miRNAs.

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A total of 11 circulating miRNAs were identified as associated with organ failure and 7 with poor outcome.

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The miRNAs most dysregulated during cirrhosis progression were miR-146a, miR-26a, and miR-191.

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miR-146a was dysregulated in PBMCs of patients with decompensated cirrhosis vs. compensated cirrhosis.

Reappraising the spectrum of AKI and hepatorenal syndrome in patients with cirrhosis

The occurrence of acute kidney injury (AKI) in patients with end-stage liver disease constitutes one of the most challenging clinical scenarios in in-hospital and critical care medicine. Hepatorenal syndrome type 1 (HRS-1), which is a specific type of AKI that occurs in the context of advanced cirrhosis and portal hypertension, is associated with particularly high mortality. The pathogenesis of HRS-1 is largely viewed as a functional derangement that ultimately affects renal vasculature tone. However, new insights suggest that non-haemodynamic tubulo-toxic factors, such as endotoxins and bile acids, might mediate parenchymal renal injury in patients with cirrhosis, suggesting that concurrent mechanisms, including those traditionally associated with HRS-1 and non-traditional factors, might contribute to the development of AKI in patients with cirrhosis. Moreover, histological evidence of morphological abnormalities in the kidneys of patients with cirrhosis and renal dysfunction has prompted the functional nature of HRS-1 to be re-examined. From a clinical perspective, a diagnosis of HRS-1 guides utilization of vasoconstrictive therapy and decisions regarding renal replacement therapy. Patients with cirrhosis are at risk of AKI owing to a wide range of factors. However, the tools currently available to ascertain the diagnosis of HRS-1 and guide therapy are suboptimal. Short of liver transplantation, goal-directed haemodynamically targeted pharmacotherapy remains the cornerstone of treatment for this condition; improved understanding of the underlying pathogenic mechanisms might lead to better clinical outcomes. Here, we examine our current understanding of the pathophysiology of HRS-1 and existing challenges in its diagnosis and treatment.

let-7a suppresses liver fibrosis via TGFβ/SMAD signaling transduction pathway

Liver fibrosis is the most common pathological outcome and the most severe complication of chronic liver diseases. Accumulating evidence suggests that miRNAs are involved in cell proliferation, differentiation, apoptosis, as well as the occurrence and development of various diseases. In this study, we found that the expression of let-7a was markedly decreased in the liver tissue samples and blood samples from patients with liver fibrosis compared with healthy volunteers. Furthermore, let-7a was downregulated in the liver tissues and blood samples in mouse models of liver fibrosis. Further analysis indicated that let-7a suppresses the activation level of hepatic stellate cells (HSCs). In addition, overexpression of let-7a reduced cell viability and promoted apoptosis of HSCs. Western blot analysis showed that let-7a might inhibit HSCs through TGFβ/SMAD signaling pathway. The present study provides a potential accurate target and vital evidence to better understand the underlying pathogenesis for early diagnosis and treatment of liver fibrosis.

Quantification of circulating miR-125b-5p predicts survival in chronic hepatitis B patients with acute-on-chronic liver failure

AIMS

To analyze the role of serum miR-125b-5p in reflecting liver damage and predicting outcomes in chronic hepatitis B (CHB) patients with acute-on-chronic liver failure (ACLF).

METHODS

CHB patients with normal hepatic function (n = 100), moderate-to-severe liver damage (n = 90), and ACLF (n = 136) were included. Among hepatitis B virus (HBV)-ACLF patients, 86 and 50 were in the training and validation cohorts, respectively. Serum miR-125b-5p level was measured by quantitative real-time PCR.

RESULTS

Serum miR-125b-5p level increased with disease progression, and serum miR-125b-5p level was lower in surviving than in dead HBV-ACLF patients. Among HBV-ACLF patients, miR-125b-5p positively correlated with total bilirubin (TBil; r = 0.214, p < 0.05) and model for end-stage liver disease (MELD) score (r = 0.382, p < 0.001) and negatively correlated with prothrombin activity(PTA; r = -0.215, p < 0.05). MiR-122 showed a contrasting performance compared with miR-125b-5p. Cox regression analysis showed that miR-125b-5p, miR-122, and PTA were independent survival predictors for HBV-ACLF, and low miR-125b-5p and high miR-122 levels may predict a longer survival in HBV-ACLF. MiR-125b-5p (AUC = 0.814) had a higher performance for survival prediction in HBV-ACLF compared with miR-122 (AUC = 0.804), PTA (AUC = 0.762), MELD score (AUC = 0.799), and TBil (AUC = 0.670) alone; predictive effectiveness of miR-125b-5p was increased by combination with miR-122 (AUC = 0.898). MiR-125b-5p was an effective predictor of HBV-ACLF outcomes in the validation cohort.

CONCLUSIONS

MiR-125b-5p increase is associated with severity of liver damage; high serum miR-125b-5p may serve as a predictor for poor outcomes in HBV-ACLF cases.