Circulating Plasma and Exosomal microRNAs as Indicators of Drug-Induced Organ Injury in Rodent Models

Extracellular vesicles as potential biomarkers and treatment options for liver failure: A systematic review up to March 2022

Introduction

Extracellular vesicles (EVs) carrying functional cargoes are emerging as biomarkers and treatment strategies in multiple liver diseases. Nevertheless, the potential of EVs in liver failure remains indistinct. In this systematic review, we comprehensively analyzed the potential of EVs as biomarkers of liver failure and the therapeutic effects and possible mechanisms of EVs for liver failure.

Methods

We conducted a systematic review by comprehensively searching the following electronic databases: PubMed, Web of Science, Embase and Cochrane Central Register of Controlled Trials from inception to March 2022. The used text words (synonyms and word variations) and database-specific subject headings included "Extracellular Vesicles", "Exosomes", "Liver Failure", "Liver Injury", etc.

Results

A total of 1479 studies were identified. After removing 680 duplicate studies and 742 irrelevant studies, 57 studies were finally retained and analyzed. Fourteen studies revealed EVs with functional cargoes could be used to make the diagnosis of liver failure and provide clues for early warning and prognostic assessment of patients with liver failure. Forty-three studies confirmed the administration of EVs from different sources alleviated hepatic damage and improved survival through inhibiting inflammatory response, oxidative stress as well as apoptosis or promoting hepatocyte regeneration and autophagy.

Conclusions

EVs and their cargoes can be used not only as superior biomarkers of early warning, early diagnosis and prognostic assessments for liver failure, but also as potentially effective treatment options for liver failure. In the future, large-scale studies are urgently needed to verify the diagnostic, predictive and therapeutic value of EVs for liver failure.

Nucleic acids and proteins carried by exosomes from various sources: Potential role in liver diseases

Exosomes are extracellular membrane-encapsulated vesicles that are released into the extracellular space or biological fluids by many cell types through exocytosis. As a newly identified form of intercellular signal communication, exosomes mediate various pathological and physiological processes by exchanging various active substances between cells. The incidence and mortality of liver diseases is increasing worldwide. Therefore, we reviewed recent studies evaluating the role of exosomes from various sources in the diagnosis and treatment of liver diseases.

Bioinspired soft nanovesicles for site-selective cancer imaging and targeted therapies

Cell-to-cell communication within the heterogeneous solid tumor environment plays a significant role in the uncontrolled metastasis of cancer. To inhibit the metastasis and growth of cancer cells, various chemically designed and biologically derived nanosized biomaterials have been applied for targeted cancer therapeutics applications. Over the years, bioinspired soft nanovesicles have gained tremendous attention for targeted cancer therapeutics due to their easy binding with tumor microenvironment, natural targeting ability, bio-responsive nature, better biocompatibility, high cargo capacity for multiple therapeutics agents, and long circulation time. These cell-derived nanovesicles guard their loaded cargo molecules from immune clearance and make them site-selective to cancer cells due to their natural binding and delivery abilities. Furthermore, bioinspired soft nanovesicles prevent cell-to-cell communication and secretion of cancer cell markers by delivering the therapeutics agents predominantly. Cell-derived vesicles, namely, exosomes, extracellular vesicles, and so forth have been recognized as versatile carriers for therapeutic biomolecules. However, low product yield, poor reproducibility, and uncontrolled particle size distribution have remained as major challenges of these soft nanovesicles. Furthermore, the surface biomarkers and molecular contents of these vesicles change with respect to the stage of disease and types. Here in this review, we have discussed numerous examples of bioinspired soft vesicles for targeted imaging and cancer therapeutic applications with their advantages and limitations. Importance of bioengineered soft nanovesicles for localized therapies with their clinical relevance has also been addressed in this article. Overall, cell-derived nanovesicles could be considered as clinically relevant platforms for cancer therapeutics. This article is categorized under: Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Clinical implications of exosome-derived noncoding RNAs in liver

Exosomes, one of three main types of extracellular vesicles, are ~30-100 nm in diameter and have a lipid bilayer membrane. They are widely distributed in almost all body fluids. Exosomes have the potential to regulate unknown cellular and molecular mechanisms in intercellular communication, organ homeostasis, and diseases. They are critical signal carriers that transfer nucleic acids, proteins, lipids, and other substances into recipient cells, participating in cellular signal transduction and material exchange. ncRNAs are non-protein-coding genes that account for over 90% of the genome and include microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs). ncRNAs are crucial for physiological and pathological activities in the liver by participating in gene transcription, posttranscriptional epigenetic regulation, and cellular processes through interacting with DNA, RNA, or proteins. Recent evidence from both clinical and preclinical studies indicates that exosome-derived noncoding RNAs (ncRNAs) are highly involved in the progression of acute and chronic liver diseases by regulating hepatic lipid metabolism, innate immunity, viral infection, fibrosis, and cancer. Therefore, exosome-derived ncRNAs have promising potential and clinical implications for the early diagnosis, targeted therapy, and prognosis of liver diseases.

Pathogenic and Potential Therapeutic Roles of Exosomes Derived From Immune Cells in Liver Diseases

Liver diseases, such as viral hepatitis, alcoholic hepatitis and cirrhosis, nonalcoholic steatohepatitis, and hepatocellular carcinoma place a heavy burden on many patients worldwide. However, the treatment of many liver diseases is currently insufficient, and the treatment may be associated with strong side effects. Therapies for liver diseases targeting the molecular and cellular levels that minimize adverse reactions and maximize therapeutic effects are in high demand. Immune cells are intimately involved in the occurrence, development, and prognosis of liver diseases. The immune response in the liver can be suppressed, leading to tolerance in homeostasis. When infection or tissue damage occurs, immunity in the liver is activated rapidly. As small membrane vesicles derived from diverse cells, exosomes carry multiple cargoes to exert their regulatory effects on recipient cells under physiological or pathological conditions. Exosomes from different immune cells exert different effects on liver diseases. This review describes the biology of exosomes and focuses on the effects of exosomes from different immune cells on pathogenesis, diagnosis, and prognosis and their therapeutic potential in liver diseases.

Extracellular vesicles in inflammation: Focus on the microRNA cargo of EVs in modulation of liver diseases

Extracellular vesicles (EVs) are heterogeneous nanometer-ranged particles that are released by cells under both normal and pathological conditions. EV cargo comprises of DNA, protein, lipids cargo, metabolites, mRNA, and non-coding RNA that can modulate the immune system by altering inflammatory response. EV associated miRNAs contribute to the pathobiology of alcoholic liver disease, non-alcoholic liver disease, viral hepatitis, acetaminophen-induced liver injury, fibrosis, and hepatocellular carcinoma. In context of liver diseases, EVs, via their cargo, alter the inflammatory response by communicating with different cell types within the liver and between liver and other organs. Here, the role of EVs and its associated miRNA in inter-cellular communication in different liver disease and as a potential biomarker and therapeutic target is reviewed.

Role of MicroRNA-155 in Triptolide-induced hepatotoxicity via the Nrf2-Dependent pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Triptolide (TP), the main bioactive and toxic ingredient of Tripterygium wilfordii Hook F, causes severe toxicity, particularly for hepatotoxicity. However, the underlying mechanisms for its hepatotoxicity are not entirely clear.

AIM OF THE STUDY

The purpose of the study was to explore the role of miR-155, a microRNA closely related to various liver injuries and a regulator of the nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway, in TP-induced liver injury in vitro and in vivo.

MATERIALS AND METHODS

First, in vitro L02 cells were treated with different concentrations of TP. The protein levels of Nrf2 and its downstream genes Heme oxygenase1 (HO-1) were determined by Western blot. The mRNA expression of miR-155, Nrf2, NAD(P)H: quinone oxidoreductase 1 (NQO1) and HO-1 were measured using qRT-PCR. And we transfected miR-155 inhibitor and miminc before TP treatment to determine the mRNA and/or protein levels of miR-155, Nrf2 and HO-1. Then, we further confirmed the interaction between miR-155 and Nrf2 pathway in TP-induced hepatic injury in BALB/C mice. The degree of liver injury was determined by HE staining and serum biochemical. The mRNA expression of miR-155 was examined with qRT-PCR and Nrf2 and HO-1 gene expression in liver were evaluated by immunohistochemistry and/or Western blot.

RESULTS

The results showed that TP significantly induced the expression of miR-155 both in L02 cells and in rodents liver tissue, and the inhibition of miR-155 could mitigate the hepatic damages caused by TP. Further experiments demonstrated that the inhibition of miR-155 reversed the down-regulation of Nrf2 and HO-1 by TP, while the miR-155 mimic enhanced the effects of TP. Animal experiments also showed that the inhibition of miR-155 by miR-155 antagomir reversed the decrease of Nrf2 induced by TP administration.

CONCLUSIONS

These results indicated that miR-155 played an important role in TP-induced hepatotoxicity by regulating the Nrf2 signaling pathway.

Effect of Edaravone on MicroRNA Expression in Exosomes after Hepatic Ischemia-reperfusion Injury

BACKGROUND AND OBJECTIVE

Hepatic ischemia-reperfusion injury (HIRI) results in serious complications after liver resection and transplantation. Edaravone (ED) has a protective effect on IRI. This study was designed to evaluate whether ED could protect the liver of rats from HIRI injury and explored its exosomal miRNA-related mechanism.

METHODS

The sham group, hepatic ischemia/reperfusion (IR group), and hepatic ischemia/reperfusion + edaravone (ED group) models were established. We determined the protective effect of ED by measuring alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA), superoxide dismutase (SOD); enzyme-linked immunosorbent assay for tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β); hematoxylin-eosin staining and immunohistochemistry for histopathological changes. Exosomal miRNAs were subjected to second-generation sequencing to identify their differential expression. The results were analyzed using bioinformatics methods and validated using real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

HIRI rats showed higher levels of ALT, AST, oxidative stress, and inflammatory markers; ED attenuated these effects. The sequencing results showed 6 upregulated and 13 downregulated miRNAs in the IR vs. sham groups, 10 upregulated and 10 downregulated miRNAs in the ED vs. IR groups. PC-3p-190-42101 was screened as an overlapping differentially expressed miRNA, and RT-qPCR validation showed that its expression in HIRI rats was significantly decreased; ED prevented this downregulation. Moreover, the expression of PC-3P-190-42101 was significantly correlated with the level of inflammatory factors.

CONCLUSION

These findings indicate that ED can regulate the level of inflammatory factors by affecting the expression of miRNA PC-3p-190-42101 in plasma exosomes to protect the liver from IRI.

Dysregulated MicroRNAs as Biomarkers or Therapeutic Targets in Cisplatin-Induced Nephrotoxicity: A Systematic Review

The purpose of this systematic review was to map out and summarize scientific evidence on dysregulated microRNAs (miRNAs) that can be possible biomarkers or therapeutic targets for cisplatin nephrotoxicity and have already been tested in humans, animals, or cells. In addition, an in silico analysis of the two miRNAs found to be dysregulated in the majority of studies was performed. A literature search was performed using eight databases for studies published up to 4 July 2021. Two independent reviewers selected the studies and extracted the data; disagreements were resolved by a third and fourth reviewers. A total of 1002 records were identified, of which 30 met the eligibility criteria. All studies were published in English and reported between 2010 and 2021. The main findings were as follows: (a) miR-34a and miR-21 were the main miRNAs identified by the studies as possible biomarkers and therapeutic targets of cisplatin nephrotoxicity; (b) the in silico analysis revealed 124 and 131 different strongly validated targets for miR-34a and miR-21, respectively; and (c) studies in humans remain scarce.

The Immunological Mechanisms and Immune-Based Biomarkers of Drug-Induced Liver Injury

Drug-induced liver injury (DILI) has become one of the major challenges of drug safety all over the word. So far, about 1,100 commonly used drugs including the medications used regularly, herbal and/or dietary supplements, have been reported to induce liver injury. Moreover, DILI is the main cause of the interruption of new drugs development and drugs withdrawn from the pharmaceutical market. Acute DILI may evolve into chronic DILI or even worse, commonly lead to life-threatening acute liver failure in Western countries. It is generally considered to have a close relationship to genetic factors, environmental risk factors, and host immunity, through the drug itself or its metabolites, leading to a series of cellular events, such as haptenization and immune response activation. Despite many researches on DILI, the specific biomarkers about it are not applicable to clinical diagnosis, which still relies on the exclusion of other causes of liver disease in clinical practice as before. Additionally, circumstantial evidence has suggested that DILI is mediated by the immune system. Here, we review the underlying mechanisms of the immune response to DILI and provide guidance for the future development of biomarkers for the early detection, prediction, and diagnosis of DILI.

Exosomes: Emerging Therapy Delivery Tools and Biomarkers for Kidney Diseases

Exosomes are nanometer-sized small EVs coated with bilayer structure, which are released by prokaryotic and eukaryotic cells. Exosomes are rich in a variety of biologically active substances, such as proteins, nucleotides, and lipids. Exosomes are widely present in various body fluids and cell culture supernatants, and it mediates the physiological and pathological processes of the body through the shuttle of these active ingredients to target cells. In recent years, studies have shown that exosomes from a variety of cell sources can play a beneficial role in acute and chronic kidney disease. In particular, exosomes derived from mesenchymal stem cells have significant curative effects on the prevention and treatment of kidney disease in preclinical trials. Besides, some encapsulated substances are demonstrated to exert beneficial effects on various diseases, so they have attracted much attention. In addition, exosomes have extensive sources, stable biological activity, and good biocompatibility and are easy to store and transport; these advantages endow exosomes with superior diagnostic value. With the rapid development of liquid biopsy technology related to exosomes, the application of exosomes in the rapid diagnosis of kidney disease has become more prominent. In this review, the latest development of exosomes, including the biosynthesis process, the isolation and identification methods of exosomes are systematically summarized. The utilization of exosomes in diagnosis and their positive effects in the repair of kidney dysfunction are discussed, along with the specific mechanisms. This review is expected to be helpful for relevant studies and to provide insight into future applications in clinical practice.

Mesenchymal Stem Cell-Derived Exosomes: Applications in Regenerative Medicine

Exosomes are a type of extracellular vesicles, produced within multivesicular bodies, that are then released into the extracellular space through a merging of the multivesicular body with the plasma membrane. These vesicles are secreted by almost all cell types to aid in a vast array of cellular functions, including intercellular communication, cell differentiation and proliferation, angiogenesis, stress response, and immune signaling. This ability to contribute to several distinct processes is due to the complexity of exosomes, as they carry a multitude of signaling moieties, including proteins, lipids, cell surface receptors, enzymes, cytokines, transcription factors, and nucleic acids. The favorable biological properties of exosomes including biocompatibility, stability, low toxicity, and proficient exchange of molecular cargos make exosomes prime candidates for tissue engineering and regenerative medicine. Exploring the functions and molecular payloads of exosomes can facilitate tissue regeneration therapies and provide mechanistic insight into paracrine modulation of cellular activities. In this review, we summarize the current knowledge of exosome biogenesis, composition, and isolation methods. We also discuss emerging healing properties of exosomes and exosomal cargos, such as microRNAs, in brain injuries, cardiovascular disease, and COVID-19 amongst others. Overall, this review highlights the burgeoning roles and potential applications of exosomes in regenerative medicine.

Epigenetic Mechanisms Involved in Cisplatin-Induced Nephrotoxicity: An Update

Cisplatin is an antineoplastic drug used for the treatment of many solid tumors. Among its various side effects, nephrotoxicity is the most detrimental. In recent years, epigenetic regulation has emerged as a modulatory mechanism of cisplatin-induced nephrotoxicity, involving non-coding RNAs, DNA methylation and histone modifications. These epigenetic marks alter different signaling pathways leading to damage and cell death. In this review, we describe how different epigenetic modifications alter different pathways leading to cell death by apoptosis, autophagy, necroptosis, among others. The study of epigenetic regulation is still under development, and much research remains to fully determine the epigenetic mechanisms underlying cell death, which will allow leading new strategies for the diagnosis and therapy of this disease.

Serum microRNAs predict response of patients with chronic hepatitis B to antiviral therapy

OBJECTIVES

To investigate the feasibility of using serum microRNAs to predict the response of chronic hepatitis B (CHB) patients to antiviral therapy over 48 weeks.

METHODS

Sixty-five CHB patients were divided into responder and non-responder groups according to whether hepatitis B e antigen seroconversion occurred at week 48. Serum microRNAs were dynamically detected.

RESULTS

At baseline, the responder group had lower miR-122-5p (P = 0.006) and higher miR-1307-3p (P = 0.018) than the non-responder group. After therapy, miR-320a-3p and miR-320c were higher in the responder group than the non-responder group (P = 0.043 and 0.031, respectively). In the responder group, 9 microRNAs-let-7d-5p, let-7f-5p, let-7i-5p, miR-126-3p, miR-1307-3p, miR-181a-5p, miR-21-5p, miR-425-5p and miR-652-3p-were significantly lower at week 48 than at baseline (P < 0.05); however, miR-320a-3p was significantly elevated after therapy (P < 0.001). In the non-responder group, miR-122-5p significantly decreased after therapy compared with baseline (P = 0.005). Finally, miR-122-5p was positively correlated with titer of hepatitis B virus DNA (r = 0.438, P = 0.008) and hepatitis B e antigen (r = 0.610, P < 0.001), and miR-320a-3p was negatively correlated with hepatitis B virus DNA titer (r = -0.366, P = 0.028) at baseline.

CONCLUSIONS

The dynamic fluctuations of serum microRNAs might predict the efficacy of antiviral therapy for CHB.

Biomarkers of drug-induced liver injury: a mechanistic perspective through acetaminophen hepatotoxicity

Introduction: Liver injury induced by drugs is a serious clinical problem. Many circulating biomarkers for identifying and predicting drug-induced liver injury (DILI) have been proposed.Areas covered: Biomarkers are mainly predicated on the mechanistic understanding of the underlying DILI, often in the context of acetaminophen overdose. New panels of biomarkers have emerged that are related to recovery/regeneration rather than injury following DILI. We explore the clinical relevance and limitations of these new biomarkers including recent controversies. Extracellular vesicles have also emerged as a promising vector of biomarkers, although the biological role for EVs may limit their clinical usefulness. New technological approaches for biomarker discovery are also explored.Expert opinion: Recent clinical studies have validated the efficacy of some of these new biomarkers, cytokeratin-18, macrophage colony-stimulating factor receptor, and osteopontin for DILI prognosis. Low prevalence of DILI is an inherent limitation to DILI biomarker development. Furthering mechanistic understanding of DILI and leveraging technological advances (e.g. machine learning/omics) is necessary to improve upon the newest generation of biomarkers. The integration of omics approaches with machine learning has led to novel insights in cancer research and DILI research is poised to leverage these technologies for biomarker discovery and development.

Mechanism of idiosyncratic drug induced liver injury (DILI): unresolved basic issues

Clinical features of idiosyncratic drug induced liver injury (DILI) are well described in cases that have been assessed for causality using the Roussel Uclaf Causality Assessment Method (RUCAM), but our understanding of the mechanistic steps leading to injury is fragmentary. The difficulties describing mechanistic events can be traced back to the lack of an animal model of experimental idiosyncratic DILI that can mimic the genetic requirements of human idiosyncratic DILI. However, immune tolerance plays a dominant role in the immune response of the liver, and impairment of immune tolerance with immune checkpoint inhibitors increases DILI in both humans and animals. This may provide one method to study the individual steps involved. In general. the human DILI liver is a secret keeper providing little insight into what occurs in the diseased organ. Sufficient evidence exists that most idiosyncratic cases are mediated by the adaptive immune system, which depends on stimulation of the innate immune system, but the triggering factors are unknown. It is attractive to hypothesize that the gut microbiome plays a role; however, it is very difficult to study. Similarly, exosomes are likely to play an important role in communication between hepatic cells and the immune system, but there is a lack of data on blood exosomes in affected patients. Reactive metabolites are likely to play an important role. This is supported by the current analysis, which revealed an association between metabolism by cytochrome P450 and drugs most commonly involved in causing idiosyncratic DILI with causality verified by RUCAM. Circumstantial evidence suggests that reactive oxygen species (ROS) generated by cytochrome P450 could be responsible for the initial steps of injury, but details are unknown. In conclusion, most of the mechanistic steps leading to idiosyncratic DILI remain unclear.

MicroRNAs in toxic acute kidney injury: Systematic scoping review of the current status

Acute kidney injury induced by nephrotoxic agents is common, increasing in incidence and associated with considerable morbidity and mortality in developing countries. MicroRNAs are stable biomarkers that can be detected in extracellular fluids. This systematic scoping review aims to describe published research on urinary and circulating microRNAs in toxic acute kidney injury in both animal and human studies. We conducted a literature search, using EMBASE and Medline, for articles on urinary and circulating microRNA in nephrotoxic injuries to February 2020. A total of 21 publications studied acute kidney injury from 12 different toxic agents. Cisplatin was the most common nephrotoxic agent (n = 10), followed by antibiotics (n = 4). There were no randomized controlled trials. An increase in urinary miR-218 predicted acute kidney injury in six different studies, suggesting it is a promising biomarker for nephrotoxin-induced acute kidney injury. There were many factors that prevented a more comprehensive synthesis of microRNA performance including highly variable models, no consistent protocols for RNA isolation, cDNA synthesis and PCR amplification, and variability in normalization methods using reference controls. In conclusion, while microRNAs are promising biomarkers to study nephrotoxic acute kidney injury, the replication of most positive findings is not assessable due to deficient reporting of negative outcomes. A very narrow range of poisons have been studied, and more human data are required. In particular, further studies are needed on the most important causes of nephrotoxic injury, such as pesticides, chemicals, snake envenoming, and medicines other than aminoglycosides and cisplatin.

Growth in Proportion and Disparities of HIV PrEP Use Among Key Populations Identified in the United States National Goals: Systematic Review and Meta-analysis of Published Surveys

BACKGROUND

Pre-exposure prophylaxis (PrEP) use among populations most vulnerable to HIV as identified in the national HIV prevention goals is not fully known. This systematic review assessed trends of lifetime self-reported PrEP use and disparities among key populations.

METHODS

We used the CDC HIV/AIDS Prevention Research Synthesis cumulative database of electronic and manual searches in MEDLINE, CINAHL, EMBASE, and PsycINFO from 2000 to 2019 to identify English-language primary studies reporting PrEP use. Two reviewers independently screened citations, extracted data, and assessed the risk of bias with the modified Newcastle-Ottawa Scale. We estimated pooled proportions and crude/adjusted odds ratio.

RESULTS

We identified 95 eligible studies including 95,854 US-based survey respondents. A few studies (6.3%) focused on persons who inject drugs. In 2015-2017, men who have sex with men (MSM) had highest proportion of individuals who used PrEP over their lifetime [13.9% (95% confidence interval: 8.8 to 21.1), k (number of surveys) = 49] followed by Hispanic/Latinos [11.5 (7.1 to 18.1), 12], transgender women [11.2 (5.8 to 20.6), 5], and blacks [9.9 (8.3 to 11.8), 18]. Odds of PrEP use increased by 34%/year [odds ratio = 1.34/year (95% confidence interval: 1.09 to 1.64)] and significantly increased over time among MSM [1.53/year (1.21-1.93)] and blacks [1.44 (1.13-1.83)]. People in the Southern United States [9.9 (4.7-19.7), 8] and youth [7.3 (4.7-11.2), 8] had lower rates and did not demonstrate growth [0.94 (0.29-3.18); 0.82 (0.43-1.55)]. Odds of reporting lifetime PrEP use was twice [2.07 (1.27-3.38)] as great among MSM than non-MSM.

CONCLUSIONS

Proportions of PrEP use in published surveys have been growing, but remain low for people in the Southern United States and youth, and understudied in persons who inject drugs. Limitations include few studies in certain years, whereas strengths include a large number of respondents. Culturally tailored approaches targeting vulnerable populations are essential in increasing PrEP use to reduce disparities in HIV acquisition.

The potential diagnostic and therapeutic applications of exosomes in drug-induced liver injury

Drug-induced liver injury (DILI) has gradually become a global public medical problem, which can be caused by more than 1000 currently available drugs. Unfortunately, the diagnosis and treatment of DILI are limited and imperfect. Exosomes can be secreted by a variety of cells and tissues in the body, rich in cell-type specific proteins, nucleic acids and lipids, which has been widely studied as an important intercellular communication vehicle in liver diseases. Emerging data suggest that circulating exosomes and their cargos can be used as minimally-invasive sources of potential molecular biomarkers for the early detection, monitoring and evaluation of DILI. Exosomes in the urine were also found to contain proteins or RNAs that were indicative of DILI. In addition, exosomes derived from mesenchymal stem cell or hepatocyte are considered potential therapeutic agents to promote liver regenerative responses, modulate inflammatory response and deduce hepatocytes apoptosis. Based on the current findings, we suggest the potential applications of exosomes as biomarkers and therapeutics for DILI.

Extracellular vesicles: Roles and applications in drug-induced liver injury

Extracellular vesicles (EV) are defined as nanosized particles, with a lipid bilayer, that are unable to replicate. There has been an exponential increase of research investigating these particles in a wide array of diseases and deleterious states (inflammation, oxidative stress, drug-induced liver injury) in large part due to increasing recognition of the functional capacity of EVs. Cells can package lipids, proteins, miRNAs, DNA, and RNA into EVs and send these discrete packages of molecular information to distant, recipient cells to alter the physiological state of that cell. EVs are innately heterogeneous as a result of the diverse molecular pathways that are used to generate them. However, this innate heterogeneity of EVs is amplified due to the diversity in isolation techniques and lack of standardized nomenclature in the literature making it unclear if one scientist's "exosome" is another scientist's "microvesicle." One goal of this chapter is to provide the contextual understanding of EV origin so one can discern between divergent nomenclature. Further, the chapter will explore the potential protective and harmful roles that EVs play in DILI, and the potential of EVs and their cargo as a biomarker. The use of EVs as a therapeutic as well as a vector for therapeutic delivery will be discussed.

Extracellular vesicles in hepatology: Physiological role, involvement in pathogenesis, and therapeutic opportunities

Since the first descriptions of hepatocyte-released exosome-like vesicles in 2008, the number of publications describing Extracellular Vesicles (EVs) released by liver cells in the context of hepatic physiology and pathology has grown exponentially. This growing interest highlights both the importance that cell-to-cell communication has in the organization of multicellular organisms from a physiological point of view, as well as the opportunity that these circulating organelles offer in diagnostics and therapeutics. In the present review, we summarize systematically and comprehensively the myriad of works that appeared in the last decade and lighted the discussion about the best opportunities for using EVs in liver disease therapeutics.

Novel hepatotoxicity biomarkers of extracellular vesicle (EV)-associated miRNAs induced by CCl4

Recent findings have revealed that extracellular vesicles (EVs) are secreted from cells and circulate in the blood. EVs are classified as exosomes (40-100 nm), microvesicles (50-1,000 nm) or apoptotic bodies (500-2,000 nm). EVs contain mRNAs, microRNAs, and DNAs and have the ability to transfer them from cell to cell. Recently, especially in humans, the diagnostic accuracy of tumor cell type-specific EV-associated miRNAs as biomarkers has been found to be more than 90 %. In addition, microRNAs contained in EVs in blood are being identified as specific biomarkers of chemical-induced inflammation and organ damage. Therefore, microRNAs contained in the EVs released into the blood from tissues and organs in response to adverse events such as exposure to chemical substances and drugs are expected to be useful as novel biomarkers for toxicity assessment. In this study, C57BL/6 J male mice orally dosed with carbon tetrachloride (CCl4) were used as a hepatotoxicity animal model. Here, we report that not only the known hepatotoxicity biomarkers miR-122 and miR-192 but also 42 novel EV-associated biomarkers were upregulated in mice dosed with CCl4. Some of these novel biomarkers may be expected to be able to use for better understanding the mechanism of toxicity. These results suggest that our newly developed protocol using EV-associated miRNAs as a biomarker would accelerate the rapid evaluation of toxicity caused by chemical substances and/or drugs.

MicroRNA26a inhibits cisplatin-induced renal tubular epithelial cells apoptosis through suppressing the expression of transient receptor potential channel 6 mediated dynamin-related protein 1

Acute kidney injury (AKI) is a common adverse reaction of the anticancer drug. Among these chemotherapeutic agents, cisplatin, an effective chemotherapeutic drug, is extensively applied to the treatment of solid tumours, yet various adverse reactions, especially AKI, often limit their use. However, the pathogenesis of AKI caused by cisplatin remains poorly clarified. Therefore, we tested whether microRNAs, which have been certified as key regulators of disease are involved in this process. AKI mouse and HK2 cells were treated with cisplatin. Annexin V/PI staining and cleaved caspase-3 were used to assess apoptosis. Western blot analyses and qRT-PCR were used to evaluate the protein and mRNA level of TRPC6 and DRP1. miR-26a was remarkably decreased in cisplatin-induced AKI and in cisplatin co-cultured HK2 cells. Furthermore, we used a miR-26a mimics in vitro and found that apoptosis was alleviated than that in the control cells. We further verified that miR-26a protected against cisplatin-induced cell apoptosis by acting on transient receptor potential channel 6 (TRPC6) which can regulate the expression of dynamin-related protein 1 (DRP1), thus inhibited the mitochondrial apoptosis pathway. Therefore, the study unveiled that miR-26a/TRPC6/DRP1 is a novel protective pathway in cisplatin-induced AKI and may be targeted for the prevention and treatment of drug-related renal injury. SIGNIFICANCE OF THE STUDY: Our study found that miR-26a was significantly downregulated during cisplatin-induced AKI and during cisplatin co-cultured HK2 cells. Further, in vitro we used miR-26a mimic to intervene cells and found that apoptosis alleviated compared with control group. We further verified that miR-26a protected cisplatin-induced apoptosis by target transient receptor potential channel 6 (TRPC6) which can regulate the expression of dynamic-related protein 1 (DRP1) and inhibit the mitochondrial apoptosis pathway. Thus, miR-26a/TRPC6/DRP1 is a new protective pathway in cisplatin-induced AKI and may be targeted for the prevention and treatment of drug-related acute kidney injury.

Extracellular vesicles: Future diagnostic and therapeutic tools for liver disease and regeneration

Extracellular vesicles are membrane fragments that can be produced by all cell types. Interactions between extracellular vesicles and various liver cells constitute an emerging field in hepatology and recent evidences have established a role for extracellular vesicles in various liver diseases and physiological processes. Extracellular vesicles originating from liver cells are implicated in intercellular communication and fluctuations of specific circulating extracellular vesicles could constitute new diagnostic tools. In contrast, extracellular vesicles derived from progenitor cells interact with hepatocytes or non-parenchymal cells, thereby protecting the liver from various injuries and promoting liver regeneration. Our review focuses on recent developments investigating the role of various types of extracellular vesicles in acute and chronic liver diseases as well as their potential use as biomarkers and therapeutic tools.

Emerging Function and Clinical Values of Exosomal MicroRNAs in Cancer

Exosomes are a subset of membrane-bound extracellular vesicles with diameters ranging from 30 to 100 nm. Exosomes enclose a variety of molecules, such as lipids, proteins, and non-coding RNAs. In the past decades, microRNAs (miRNAs) have attracted great attention in cancer research, as they play an important role in the occurrence and development of cancer. Increasing evidence indicates that tumor cells communicate with not only other tumor cells but also cells present in the tumor microenvironment via secretion and transfer of exosomal miRNAs. More importantly, exosomal miRNAs are found to serve as signaling molecules to regulate tumor growth, angiogenesis, metastasis, sensitivity to chemotherapy, and immune evasion. Deregulated expression of exosomal miRNAs is an early event in carcinogenesis and may reflect the malignant characteristics of cancer. Owing to the wide existence and high stability of exosomal miRNAs in body fluids, they may represent a novel class of non-invasive biomarkers for cancer. In this review, we highlight the recent advances on the functional role of exosomal miRNAs in cancer pathogenesis. We also discuss the potential clinical utility of exosome-shuttled miRNAs as biomarkers for the diagnosis and treatment of cancer.

The diagnostic role of miR-122 in drug-induced liver injury: A systematic review and meta-analysis

BACKGROUND

Drug-induced liver injury (DILI) is a potentially severe adverse drug reaction especially in susceptible patients. But there are no sensitive or specific parameters to detecting DILI. The specific expression of miR-122 in the liver has been a hotspot in the evaluation of hepatic toxicity due to its high stability and sensitivity.

METHODS

We performed a systematic literature review through July 31, 2017 to identify studies which evolved DILI patients testing miR-122 without limiting a certain drug. According to the PRISMA statement, a meta-analysis: the diagnostic role of miR-122 in DILI was made. QUADAS-2 quality evaluation table was used to evaluate the quality of the documentary evidence, PRISMA flowchart and quality evaluation table were drawn with RevMan, use Stata to calculate the sensitivity and specificity of miR-122 in diagnosing DILI, ROC curve and Deeks funnel plot were also drawn by STATA.

RESULTS

Eleven studies involved 194 DILI patients and 251 controls, all were tested miR-122 (fold change). Sensitivity of miR-122 in diagnosing DILI was [0.85 (95% CI, 0.75-0.91), I = 53.46%] and specificity was [0.93 (95% CI, 0.86-0.97), I = 65.10%], the area under ROC curve was 0.95 (95% CI, 0.93-0.97). While in acetaminophen (APAP)-induced liver injury, the sensitivity was [0.82 (95%CI, 0.67-0.91), I = 65.77%] specificity was [0.96 (95%CI, 0.88-0.99), I = 31.46%], AUROC was 0.97 (95% CI, 0.95-0.98).

CONCLUSIONS

In this systematic review and meta-analysis, we found miR-122 have a high specificity in DILI, and a modest positive diagnostic effects. On the basis of the limited evidence, further research is needed to evaluate the long-term observation and more clinical data to testify miR-122 in diagnosing DILI.

Exogenous exosomes from mice with acetaminophen-induced liver injury promote toxicity in the recipient hepatocytes and mice

Exosomes are small extracellular membrane vesicles released from endosomes of various cells and could be found in most body fluids. The main functions of exosomes have been recognized as important mediators of intercellular communication and as potential biomarkers of various disease states. This study investigated whether exogenous exosomes from mice with acetaminophen (APAP)-induced liver injury can damage the recipient hepatic cells or promote hepatotoxicity in mice. We observed that exogenous exosomes derived from APAP-exposed mice were internalized into the primary mouse hepatocytes or HepG2 hepatoma cells and significantly decreased the viability of these recipient cells. They also elevated mRNA transcripts and proteins associated with the cell death signaling pathways in primary hepatocytes or HepG2 cells via exosomes-to-cell communications. In addition, confocal microscopy of ex vivo liver section showed that exogenously added exosomes were accumulated in recipient hepatocytes. Furthermore, plasma reactive oxygen species and hepatic TNF-α/IL-1β production were elevated in APAP-exosomes recipient mice compared to control-exosomes recipient mice. The levels of apoptosis-related proteins such as phospho-JNK/JNK, Bax, and cleaved caspase-3 were increased in mouse liver received APAP-exosomes. These results demonstrate that exogenous exosomes from APAP-exposed mice with acute liver injury are functional and stimulate cell death or toxicity of the recipient hepatocytes and mice.

Latest advances in diagnosing and predicting DILI: what was new in 2017?

Drug-induced liver injury (DILI) remains an increasingly recognized cause of hepatotoxicity and liver failure worldwide. In 2017, we continued to learn about predicting, diagnosing, and prognosticating drug hepatotoxicity. Areas covered: In this review, we selected from over 1200 articles from 2017 to synopsize updates in DILI. There were new HLA haplotypes associated with medications including HLA-C0401 and HLA-B*14. There has been continued work with quantitative systems pharmacology, particularly with the DILIsym® initiative, which employs mathematical representations of DILI mechanisms to predict hepatotoxicity in simulated populations. Additionally, knowledge regarding microRNAs (miRNAs) continues to expand. Some new miRNAs this past year include miRNA-223 and miRNA-605. Aside from miRNAs, other biomarkers for diagnosis, prognosis, and even prediction of DILI were explored. Studies on K18, OPN, and MCSFR have correlated DILI and liver-associated death within 6 months. Conversely, a new prognostic panel using apolipoportein-A1 and haptoglobin has been proposed to predict recovery. Further study of CDH5 has also provided researchers a possible new biomarker for prediction and susceptibility to DILI. Expert commentary: Although research on DILI remains quite promising, there is yet to be a reliable, simple method to predict, diagnose, and risk assess this form of hepatotoxicity.

Comparison of microRNA expressions for the identification of chemical hazards in in vivo and in vitro hepatic injury models

Biofluid-based biomarkers provide an efficient tool for hazard identification of chemicals. Here, we explored the potential of microRNAs (miRNAs) as biomarkers for hepatotoxicity of chemicals by linking in vitro to in vivo animal models. A search of the literature identified candidate circulating miRNA biomarkers of chemical-induced hepatotoxicity. The expression of candidate miRNAs (miR-122, miR-151a, miR-192, miR-193a, miR-194, miR-21, miR-29c), was determined by real-time reverse transcription-polymerase chain reaction in in vivo acute liver injury induced by acetaminophen, and then were further compared with those of in vitro cell assays. Candidate miRNAs, except miR-29c, were significantly or biologically upregulated by acetaminophen, at a dose that caused acute liver injury as confirmed by hepatocellular necrosis. Except miR-122 and miR-193a, other miRNAs elevated in in vivo models were confirmed by in vitro models using HepG2 cells, whereas they failed by in vitro models using human primary hepatocytes. These findings indicate that certain miRNAs may still have the potential of toxicological biomarkers in linking in vitro to in vivo hepatotoxicity.

miR-374a Regulates Inflammatory Response in Diabetic Nephropathy by Targeting MCP-1 Expression

The microRNA (mir)-374a has been implicated in several types of human cancer; however, its role in diabetic nephropathy (DN) remains unclear. Monocyte chemoattractant protein (MCP)-1 is a chemokine that recruits macrophages to inflammatory sites and is important for the development and progression of DN. However, the relationship between miR-374a and MCP-1 in DN is unknown. We addressed this in the present study by examining the expression of these factors in kidney tissue samples from DN patients and through loss- and gain-of-function experiments using HK2 human renal tubular epithelial cells. We found that miR-374a was downregulated whereas MCP-1 was upregulated in DN tissue. A bioinformatics analysis revealed that MCP-1 is a putative target of miR-374a. To confirm this relationship, HK2 cells treated with normal glucose (5.6 mmol/l D-glucose), high glucose (HG) (30 mmol/l D-glucose), or high osmotic pressure solution (5.6 mmol/l D-glucose + 24.4 mmol/l D-mannitol) were transfected with miR-374a mimic or inhibitor. miR-374a mimic reduced MCP-1 mRNA expression and migration of co-cultured U937 cells, whereas miR-374a inhibition had the opposite effects. Additionally, interleukin-6 and -18 and tumor necrosis factor-α levels were downregulated by transfection of miR-374a mimic. On the other hand, MCP-1 overexpression reversed the inhibitory effects of miR-374a in HK2 cells. Thus, miR-374a suppresses the inflammatory response in DN through negative regulation of MCP-1 expression. These findings suggest that therapeutic strategies that target the miR-374a/MCP-1 axis can be an effective treatment for DN.

BMP4 Upregulation Is Associated with Acquired Drug Resistance and Fatty Acid Metabolism in EGFR-Mutant Non-Small-Cell Lung Cancer Cells

Lung cancer is the leading cause of cancer-associated deaths worldwide. In particular, non-small-cell lung cancer (NSCLC) cells harboring epidermal growth factor receptor (EGFR) mutations are associated with resistance development of EGFR tyrosine kinase inhibitor (EGFR-TKI) treatment. Recent findings suggest that bone morphogenetic proteins (BMPs) and microRNAs (miRNAs) might act as oncogenes or tumor suppressors in the tumor microenvironment. In this study, for the first time, we identified the potential roles of BMPs and miRNAs involved in EGFR-TKI resistance by analyzing datasets from a pair of parental cells and NSCLC cells with acquired EGFR-TKI resistance. BMP4 was observed to be significantly overexpressed in the EGFR-TKI-resistant cells, and its mechanism of action was strongly associated with the induction of cancer cell energy metabolism through the modulation of Acyl-CoA synthetase long-chain family member 4. In addition, miR-139-5p was observed to be significantly downregulated in the resistant NSCLC cells. The combination of miR-139-5p and yuanhuadine, a naturally derived antitumor agent, synergistically suppressed BMP4 expression in the resistant cells. We further confirmed that LDN-193189, a small molecule BMP receptor 1 inhibitor, effectively inhibited tumor growth in a xenograft nude mouse model implanted with the EFGR-TKI-resistant cells. These findings suggest a novel role of BMP4-mediated tumorigenesis in the progression of acquired drug resistance in EGFR-mutant NSCLC cells.

Exosomes and regenerative medicine: state of the art and perspectives

Exosomes have attracted the attention of the scientific community in recent years due to their widespread distribution, their possible functions as biomarkers of disease, and their great potential to be applied as therapeutic agents. Exosomes carry proteins and nucleic acids that can facilitate their uptake by distant target cells through endocytosis, such that exosomes could be targeted to a specific cell or cells to enhance or interfere with specific biological processes. This review will mainly focus on their roles in tissue repair and regenerative processes. Exosomal engineering and their potential applications in tissue regeneration are also reviewed here as an outlook for future research.

Extracellular vesicles as potential biomarkers for alcohol- and drug-induced liver injury and their therapeutic applications

Extracellular vesicles (EVs) are small membranous vesicles originating from various cells and tissues, including the liver parenchymal hepatocytes and nonparenchymal cells such as Kupffer and stellate cells. Recently, the pathophysiological role of EVs, such as exosomes and microvesicles, has been increasingly recognized based on their properties of intercellular communications. These EVs travel through the circulating blood and interact with specific cells and then deliver their cargos such as nucleic acids and proteins into recipient cells. In addition, based on their stabilities, circulating EVs from body fluids such as blood, cerebrospinal fluid, urine, saliva, semen, breast milk and amniotic fluids are being studied as a valuable source of potential biomarkers for providing information about the physiological status of original cells or tissues. In addition, EVs are considered potential therapeutic agents due to their ability for intercellular communications between different cell types within the liver and between various organs through transfer of their cargos. In this review, we have briefly described recent advances in the characteristics and pathophysiological roles of EVs in alcoholic liver disease (ALD) or drug-induced liver injury (DILI) and discuss their advantages in the discovery of potential biomarkers and therapeutic agents.

Biomarkers of drug-induced kidney injury

PURPOSE OF REVIEW

Drug-induced kidney injury (DIKI) is an important and potentially modifiable cause of acute kidney injury (AKI). The reliance on traditional markers of kidney injury to diagnose DIKI impedes early detection. Biomarkers of DIKI that facilitate early diagnosis and the identification of high-risk patients are essential to ameliorate the clinical burden of this complication.

RECENT FINDINGS

Recent progress in this area supports the potential utility of several biomarkers for the diagnosis of DIKI, for the prediction of outcomes and also for monitoring responses to potential nephrotoxic or beneficial therapies. Data regarding the impact of clinically relevant factors, such as chronic kidney disease, on biomarker levels represents a further recent advancement. Emerging novel biomarkers include microRNAs, which are showing promise as markers of drug-induced tubular damage. They may also have a role in elucidating the molecular mechanisms of AKI.

SUMMARY

There is compelling evidence to support the use of biomarkers for the early detection of DIKI. Ongoing research is required to delineate their role in prognostication and for the prediction of outcomes. The inclusion of biomarkers in more clinical studies of DIKI would be a welcome advance, which may accelerate their integration into clinical diagnostics.

Exosomal microRNAs as potential circulating biomarkers in gastrointestinal tract cancers: a systematic review protocol

BACKGROUND

Metastasis is the most frequent type of recurrence in gastrointestinal (GI) cancers, and there is an emerging potential for new diagnostic and therapeutic approaches, especially in the cases of metastatic GI carcinomas. The expression profiles of circulating exosomal microRNAs are of particular interest as novel non-invasive diagnostic and prognostic biomarkers for improved detection of GI cancers in body fluids, especially in the serum of patients with recurrent cancers. The aim of this study is to systematically review primary studies and identify the miRNA profiles of serum exosomes of GI cancers.

METHODS AND DESIGN

This systematic review will be reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidance. Relevant studies will be identified through a comprehensive search of the following main electronic databases: PubMed, Web of Science, Embase, Scopus, and Google Scholar, with no language restrictions (up to July 2017). Full copies of articles will be identified by a defined search strategy and will be considered for inclusion against pre-defined criteria. The quality assessment of the included studies will be performed by the Newcastle-Ottawa Scale (NOS). Data will be analyzed using Stata software V.12. Publication bias will be assessed by funnel plots, Beggs' and Eggers' tests. The levels of evidence for primary outcomes will be evaluated using the GRADE criteria.

DISCUSSION

The analysis of circulating exosomal miRNA profiles provides attractive screening and non-invasive diagnostic tools for the majority of solid tumors including GI cancers. There is limited information regarding the relationship between serum exosomal miRNA profiles and the pathological condition of patients with different GI cancers. Since there is no specific biomarker for GI cancers, we aim to suggest a number of circulating exosomal miRNA candidates as potential multifaceted GI cancer biomarkers for clinical utility.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017057129.