Exosome-mediated delivery of Cas9 ribonucleoprotein complexes for tissue-specific gene therapy of liver diseases

CRISPR-Cas9 gene editing has emerged as a powerful therapeutic technology, but the lack of safe and efficient in vivo delivery systems, especially for tissue-specific vectors, limits its broad clinical applications. Delivery of Cas9 ribonucleoprotein (RNP) owns competitive advantages over other options; however, the large size of RNPs exceeds the loading capacity of currently available delivery vectors. Here, we report a previously unidentified genome editing delivery system, named exosome^RNP, in which Cas9 RNPs were loaded into purified exosomes isolated from hepatic stellate cells through electroporation. Exosome^RNP facilitated effective cytosolic delivery of RNP in vitro while specifically accumulated in the liver tissue in vivo. Exosome^RNP showed vigorous therapeutic potential in acute liver injury, chronic liver fibrosis, and hepatocellular carcinoma mouse models via targeting p53 up-regulated modulator of apoptosis (PUMA), cyclin E1 (CcnE1), and K (lysine) acetyltransferase 5 (KAT5), respectively. The developed exosome^RNP provides a feasible platform for precise and tissue-specific gene therapies of liver diseases.

[Polycystic liver disease]

Polycystic liver disease (PLD) includes three entities in adults : biliary hamartomas which develop as a result of ductal plate malformation, autosomal dominant polycystic liver disease (ADPLD) and autosomal dominant polycystic kidney disease (ADPKD) which occur in the setting of genetic disorders. Hamartomas are asymptomatic and benign. PLD are marked by a steady growth of cysts over time, clinically silent in the majority of cases. Symptomatic forms mainly affect women due to the influence of estrogens on the growth of cysts therefore estrogen treatments are contraindicated in this setting. Diagnosis is based on imaging. Complications are rare but must be identified early in order to offer appropriate care in an expert center.

Current standard values of health utility scores for evaluating cost-effectiveness in liver disease: A meta-analysis

BACKGROUND

Health utility assessments have been developed for various conditions, including chronic liver disease. Health utility scores are required for socio-economic evaluations, which can aid the distribution of national budgets. However, the standard health utility assessment scores for specific health conditions are largely unknown.

AIM

To summarize the health utility scores, including the EuroQOL 5-dimensions 5-levels (EQ-5D-5L), EuroQol-visual analogue scale, short from-36 (SF-36), RAND-36, and Health Utilities Index (HUI)-Mark2/Mark3 scores, for the normal population and chronic liver disease patients.

METHODS

A systematic literature search of PubMed and MEDLINE, including the Cochrane Library, was performed. Meta-analysis was performed using the RevMan software. Multiple means and standard deviations were combined using the StatsToDo online web program.

RESULTS

The EQ-5D-5L and SF-36 can be used for health utility evaluations during antiviral therapy for hepatitis C. HUI-Mark2/Mark3 indicated that the health utility scores of hepatitis B patients are roughly 30% better than those of hepatitis C patients.

CONCLUSION

The EQ-5D-5L is the most popular questionnaire for health utility assessments. Health assessments that allow free registration would be useful for evaluating health utility in patients with liver disease.

Thrombocytopenia in chronic liver disease: Physiopathology and new therapeutic strategies before invasive procedures

Chronic liver disease is characterized by several hematological derangements resulting in a complex and barely rebalanced haemostatic environment. Thrombocytopenia is the most common abnormality observed in these patients and recent advances have led to researchers focus the attention on the multifactorial origin of thrombocytopenia and on the key role of thrombopoietin (TPO) in its physiopathology. Severe thrombocytopenia (platelet count < 50000/μL) complicates the management of patients with chronic liver disease by increasing the potential risk of bleeding for invasive procedures, which may be therefore delayed or canceled even if lifesaving. In the very last years, the development of new drugs which exceed the limits of the current standard of care (platelet transfusions, either immediately before or during the procedure) paves the way to a new scenario in the management of this population of patients. Novel agents, such as the TPO-receptor agonists avatrombopag and lusutrombopag, have been developed in order to increase platelet production as an alternative to platelet transfusions. These agents have demonstrated a good profile in terms of efficacy and safety and will hopefully allow reducing limitations and risks associated with platelet transfusion, without any delay in scheduled interventions. Altogether, it is expected that patients with chronic liver disease will be able to face invasive procedures with one more string in their bow.

Mitochondrial Hepatopathy

Mitochondrial hepatopathies are a subset of mitochondrial diseases defined by primary dysfunction of hepatocyte mitochondria leading to a phenotype of hepatocyte cell injury, steatosis, or liver failure. Increasingly, the diagnosis is established by new sequencing approaches that combine analysis of both nuclear DNA and mitochondrial DNA and allow for timely diagnosis in most patients. Despite advances in diagnostics, for most affected children their disorders are relentlessly progressive, and result in substantial morbidity and mortality. Treatment remains mainly supportive; however, novel therapeutics and a more definitive role for liver transplantation hold promise for affected children.

Extracellular vesicles derived from mesenchymal stem/stromal cells: The regenerative impact in liver diseases

Liver dysfunctions are classified into acute and chronic diseases, which comprise a heterogeneous group of pathological features and a high mortality rate. Liver transplantation remains the gold-standard therapy for most liver diseases, with concomitant limitations related to donor organ shortage and lifelong immunosuppressive therapy. A concept in liver therapy intends to overcome these limitations based on the secreted extracellular vesicles (EVs; microvesicles and exosomes) by mesenchymal stem/stromal cells (MSCs). A significant number of studies have shown that factors released by MSCs could induce liver repair and ameliorate systemic inflammation through paracrine effects. It is well known that this paracrine action is based not only on the secretion of cytokines and growth factors but also on EVs, which regulate pathways associated with inflammation, hepatic fibrosis, integrin-linked protein kinase signaling, and apoptosis. Herein, we extensively discuss the differential effects of MSC-EVs on different liver diseases and on cellular and animal models and address the complex molecular mechanisms involved in the therapeutic potential of EVs. In addition, we cover the crucial information regarding the type of molecules contained in MSC-EVs that can be effective in the context of liver diseases. In conclusion, outcomes on MSC-EV-mediated therapy are expected to lead to an innovative, cell-free, noninvasive, less immunogenic, and nontoxic alternative strategy for liver treatment and to provide important mechanistic information on the reparative function of liver cells.

Mesenchymal Stem Cells and Their Small Extracellular Vesicles as Crucial Immunological Efficacy for Hepatic Diseases

Mesenchymal stem cell small extracellular vesicles (MSC-sEVs) are a priority for researchers because of their role in tissue regeneration. sEVs act as paracrine factors and carry various cargos, revealing the state of the parent cells and contributing to cell–cell communication during both physiological and pathological circumstances. Hepatic diseases are mainly characterized by inflammatory cell infiltration and hepatocyte necrosis and fibrosis, bringing the focus onto immune regulation and other regulatory mechanisms of MSCs/MSC-sEVs. Increasing evidence suggests that MSCs and their sEVs protect against acute and chronic liver injury by inducing macrophages (MΦ) to transform into the M2 subtype, accelerating regulatory T/B (Treg/Breg) cell activation and promoting immunosuppression. MSCs/MSC-sEVs also prevent the proliferation and differentiation of T cells, B cells, dendritic cells (DCs), and natural killer (NK) cells. This review summarizes the potential roles for MSCs/MSC-sEVs, including immunomodulation and tissue regeneration, in various liver diseases. There is also a specific focus on the use of MSC-sEVs for targeted drug delivery to treat hepatitis.

Coronavirus disease 2019 and the liver

PURPOSE OF REVIEW

The objective of this review is to examine the epidemiology and pathogenesis of liver injury in coronavirus disease 2019 (COVID-19) and the impact of COVID-19 on patients with chronic liver disease (CLD) and liver transplant recipients.

RECENT FINDINGS

Abnormal liver chemistries occur in up to 60% of COVID-19 patients and are typically mild. COVID-19- associated liver injury may be because of direct viral cytopathic effect, immune-mediated damage, hypoxia, drug-induced liver injury (DILI), or exacerbation of CLD. COVID-19 patients with CLD and who are liver transplant recipients are at risk for severe disease and mortality. COVID-19 precipitated hepatic decompensation in 20-46% of cirrhotic patients. Alcohol consumption and cases of acute alcohol- associated hepatitis increased during the COVID-19 pandemic. Corticosteroids and calcineurin inhibitors are well tolerated to use during COVID-19 but immunomodulators have been associated with mortality. Less than 50% of transplant recipients produce adequate antibody titers after COVID-19 vaccination.

SUMMARY

COVID-19 patients with CLD should be monitored for liver injury and hepatic decompensation. Patients with CLD and liver transplant recipients should be considered for targeted COVID-19 pharmacotherapeutics and advised vaccination against COVID-19, including a third booster dose. CLD treatments and immunosuppression in liver transplant recipients could generally continue without interruption during COVID-19 infection, with the possible exception of immunomodulators.

COVID-19 and liver dysfunction: What nutritionists need to know

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 has brought serious challenges for the medical field. Patients with COVID-19 usually have respiratory symptoms. However, liver dysfunction is not an uncommon presentation. Additionally, the degree of liver dysfunction is associated with the severity and prognosis of COVID-19. Prevention, diagnosis, and treatment of malnutrition should be routinely recommended in the management of patients with COVID-19, especially in those with liver dysfunction. Recently, a large number of studies have reported that nutrition therapy measures, including natural dietary supplements, vitamins, minerals and trace elements, and probiotics, might have potential hepatoprotective effects against COVID-19-related liver dysfunction via their antioxidant, antiviral, anti-inflammatory, and positive immunomodulatory effects. This review mainly focuses on the possible relationship between COVID-19 and liver dysfunction, nutritional and metabolic characteristics, nutritional status assessment, and nutrition therapy to provide a reference for the nutritionists while making evidence-based nutritional decisions during the COVID-19 pandemic.

Osteosarcopenia in autoimmune cholestatic liver diseases: Causes, management, and challenges

Primary biliary cholangitis and primary sclerosing cholangitis (PSC) are the most common cholestatic liver diseases (CLD) in adults and are both characterized by an immune pathogenesis. While primary biliary cholangitis is a model autoimmune disease, with over 90% of patients presenting very specific autoantibodies against mitochondrial antigens, PSC is considered an immune mediated disease. Osteoporosis is the most common bone disease in CLD, resulting in frequent fractures and leading to significant morbidity. Further, sarcopenia is emerging as a frequent complication of chronic liver diseases with a significant prognostic impact and severe implications on the quality of life of patients. The mechanisms underlying osteoporosis and sarcopenia in CLD are still largely unknown and the association between these clinical conditions remains to be dissected. Although timely diagnosis, prevention, and management of osteosarcopenia are crucial to limit the consequences, there are no specific guidelines for management of osteoporosis and sarcopenia in patients with CLD. International guidelines recommend screening for bone disease at the time of diagnosis of CLD. However, the optimal monitoring strategies and treatments have not been defined yet and vary among centers. We herein aim to comprehensively outline the pathogenic mechanisms and clinical implications of osteosarcopenia in CLD, and to summarize expert recommendations for appropriate diagnostic and therapeutic approaches.

Mesenchymal Stromal/Stem Cells and Their Extracellular Vesicles Application in Acute and Chronic Inflammatory Liver Diseases: Emphasizing on the Anti-Fibrotic and Immunomodulatory Mechanisms

Various factors, including viral and bacterial infections, autoimmune responses, diabetes, drugs, alcohol abuse, and fat deposition, can damage liver tissue and impair its function. These factors affect the liver tissue and lead to acute and chronic liver damage, and if left untreated, can eventually lead to cirrhosis, fibrosis, and liver carcinoma. The main treatment for these disorders is liver transplantation. Still, given the few tissue donors, problems with tissue rejection, immunosuppression caused by medications taken while receiving tissue, and the high cost of transplantation, liver transplantation have been limited. Therefore, finding alternative treatments that do not have the mentioned problems is significant. Cell therapy is one of the treatments that has received a lot of attention today. Hepatocytes and mesenchymal stromal/stem cells (MSCs) are used in many patients to treat liver-related diseases. In the meantime, the use of mesenchymal stem cells has been studied more than other cells due to their favourable characteristics and has reduced the need for liver transplantation. These cells increase the regeneration and repair of liver tissue through various mechanisms, including migration to the site of liver injury, differentiation into liver cells, production of extracellular vesicles (EVs), secretion of various growth factors, and regulation of the immune system. Notably, cell therapy is not entirely excellent and has problems such as cell rejection, undesirable differentiation, accumulation in unwanted locations, and potential tumorigenesis. Therefore, the application of MSCs derived EVs, including exosomes, can help treat liver disease and prevent its progression. Exosomes can prevent apoptosis and induce proliferation by transferring different cargos to the target cell. In addition, these vesicles have been shown to transport hepatocyte growth factor (HGF) and can promote the hepatocytes'(one of the most important cells in the liver parenchyma) growths.

Gut Microbiota Targeted Approach in the Management of Chronic Liver Diseases

The liver is directly connected to the intestines through the portal vein, which enables the gut microbiota and gut-derived products to influence liver health. There is accumulating evidence of decreased gut flora diversity and alcohol sensitivity in patients with various chronic liver diseases, including non-alcoholic/alcoholic liver disease, chronic hepatitis virus infection, primary sclerosing cholangitis and liver cirrhosis. Increased intestinal mucosal permeability and decline in barrier function were also found in these patients. Followed by bacteria translocation and endotoxin uptake, these will lead to systemic inflammation. Specific microbiota and microbiota-derived metabolites are altered in various chronic liver diseases studies, but the complex interaction between the gut microbiota and liver is missing. This review article discussed the bidirectional relationship between the gut and the liver, and explained the mechanisms of how the gut microbiota ecosystem alteration affects the pathogenesis of chronic liver diseases. We presented gut-microbiota targeted interventions that could be the new promising method to manage chronic liver diseases.

Intestinal failure-associated liver disease in the neonatal ICU: what we know and where we're going

PURPOSE OF REVIEW

Parenteral nutrition is an integral part of the care of infants in the neonatal ICU. However, prolonged use of parenteral nutrition can be associated with adverse outcomes, most notably parenteral nutrition-associated liver disease, now known as intestinal failure-associated liver disease (IFALD). This review highlights pertinent developments in the epidemiology of IFALD as it pertains to neonates and showcases recent advances in the pathophysiology, treatment, and outcomes of neonates with IFALD.

RECENT FINDINGS

The role of intravenous lipid emulsions in the pathogenesis, prevention, and treatment of IFALD remains a target for investigative studies. Recent data continues to support the use of fish-oil based intravenous lipids, but its use is limited due to concerns for essential fatty acid deficiency. Use of soy-based lipids and mixed lipids is not wrought with such concerns as these are often used at greater doses but their use is limited due to higher proinflammatory fatty acid content, increased phytosterols and decreased antioxidants, risk factors for the development of IFALD.

SUMMARY

Hepatic complications may limit the use of parenteral nutrition in the neonatal ICU. However, the pathophysiology of IFALD is continuing to be further elucidated and novel targets are being developed for the treatment of IFALD. As noninvasive disease monitoring strategies continue to be developed, early enteral nutrition ameliorates the risk of IFALD and should be considered when possible.

[Current status, challenges and reflections on stem cell therapy for liver diseases]

There are increasing number of clinical studies on the use of stem cells in the treatment of liver diseases. Most studies have shown that stem cells can significantly improve liver function and prolong survival in patients with decompensated cirrhosis and liver failure. However, the current study has high heterogeneity and few mechanistic research data, which cannot answer many key questions about stem cell therapy for liver diseases. This paper reviews the research status of stem cells, in order to clarify the existing problems and challenges, and puts forward some reflections and countermeasures, with hope to promote the clinical application of stem cells in the treatment of liver diseases.

[Clinical research in cell therapy of liver diseases: progress and challenges]

The high incidence of chronic liver disease is a serious threat to public health, and the current comprehensive internal medicine treatment is ineffective. Liver transplantation is limited by the shortage of liver source and post-transplant rejection, and thus unmet the clinical needs. More importantly, cell therapy shows great promise for the treatment of chronic liver disease. Over recent years, domestic and foreign scholars have carried out a variety of cell therapy preclinical and clinical trials for critical liver disease, and achieved certain results, providing new methods for the treatment of chronic liver diseases. This review discusses the cell therapy research status and application progress, various existing problems and challenges, and key issues of mesenchymal stem cells in the treatment of chronic liver diseases.

Mesenchymal Stem Cell-Derived Extracellular Vesicles in Liver Immunity and Therapy

Mesenchymal stem cells (MSCs), as the most common cell source for stem cell therapy, play an important role in the modulation of innate and adaptive immune responses and have been widely used in clinical trials to treat autoimmune and inflammatory diseases. Recent experimental and clinical studies have shown that MSC-derived extracellular vesicles (MSC-EVs) can inhibit the activation and proliferation of a variety of proinflammatory cells, such as Th1, Th17 and M1 macrophages, reducing the secretion of proinflammatory cytokines, while promoting the proliferation of anti-inflammatory cells, such as M2 macrophages and Tregs, and increasing the secretion of anti-inflammatory cytokines, thus playing a role in immune regulation and exhibiting immunomodulatory functions. Besides MSC-EVs are more convenient and less immunogenic than MSCs. There is growing interest in the role of MSC-EVs in liver diseases owing to the intrinsic liver tropism of MSC-EVs. In this review, we focus on the immunomodulatory effects of MSC-EVs and summarize the pivotal roles of MSC-EVs as a cell-free therapy in liver diseases, including NAFLD, AIH, acute liver failure, liver fibrosis and hepatic ischemia–reperfusion injury. Moreover, we provide a concise overview of the potential use and limits of MSC-EVs in clinical application.

Clinical implications of diabetes in chronic liver disease: Diagnosis, outcomes and management, current and future perspectives

Diabetes mellitus (DM) is common in liver cirrhosis (LC). The pathophysiological association is bidirectional. DM is a risk factor of LC and LC is a diabetogenic condition. In the recent years, research on different aspects of the association DM and LC has been intensified. Nevertheless, it has been insufficient and still exist many gaps. The aims of this review are: (1) To discuss the latest understandings of the association of DM and LC in order to identify the strategies of early diagnosis; (2) To evaluate the impact of DM on outcomes of LC patients; and (3) To select the most adequate management benefiting the two conditions. Literature searches were conducted using PubMed, Ovid and Scopus engines for DM and LC, diagnosis, outcomes and management. The authors also provided insight from their own published experience. Based on the published studies, two types of DM associated with LC have emerged: Type 2 DM (T2DM) and hepatogenous diabetes (HD). High-quality evidences have determined that T2DM or HD significantly increase complications and death pre and post-liver transplantation. HD has been poorly studied and has not been recognized as a complication of LC. The management of DM in LC patients continues to be difficult and should be based on drug pharmacokinetics and the degree of liver failure. In conclusion, the clinical impact of DM in outcomes of LC patients has been the most studied item recently. Nevertheless many gaps still exist particularly in the management. These most important gaps were highlighted in order to propose future lines for research.

Review article: epidemiology, pathogenesis and management of liver disease in adults with cystic fibrosis

BACKGROUND

Cystic fibrosis-related liver disease (CFLD) is the leading cause of death in cystic fibrosis (CF), after pulmonary disease. To improve identification and management of this condition requires an understanding of the underlying disease mechanism.

AIMS

This review summarises the current understanding of CFLD epidemiology, pathology, diagnosis and management.

METHODS

Relevant reports on cystic fibrosis liver disease were identified using a literature search and summarised.

RESULTS

CFLD is a heterogeneous condition with several different co-existent pathologies, including environmental and genetic factors. Incidence of clinically significant CFLD continues at a linear rate into early adulthood and has been described in up to 25% of CF patients. Diagnosis strategies lack precision and patient risk stratification needs to look beyond Childs-Pugh scoring. Efficacious therapies are lacking and, at present, newer modulator therapies lack data in CFLD and carry an increased risk of hepatotoxicity. Outcomes of liver transplant are comparable to non-CF transplant indications.

CONCLUSIONS

The incidence of CFLD increases with age and hence is increasingly important to adult patients with CF. Effective therapies are lacking. For progress to be made a better understanding of pathogenesis and disease detection are required.

The promise of the gut microbiome as part of individualized treatment strategies

Variability in disease presentation, progression and treatment response has been a central challenge in medicine. Although variability in host factors and genetics are important, it has become evident that the gut microbiome, with its vast genetic and metabolic diversity, must be considered in moving towards individualized treatment. In this Review, we discuss six broad disease groups: infectious disease, cancer, metabolic disease, cardiovascular disease, autoimmune or inflammatory disease, and allergic and atopic diseases. We highlight current knowledge on the gut microbiome in disease pathogenesis and prognosis, efficacy, and treatment-related adverse events and its promise for stratifying existing treatments and as a source of novel therapies. The Review is not meant to be comprehensive for each disease state but rather highlights the potential implications of the microbiome as a tool to individualize treatment strategies in clinical practice. Although early, the outlook is optimistic but challenges need to be overcome before clinical implementation, including improved understanding of underlying mechanisms, longitudinal studies with multiple data layers reflecting gut microbiome and host response, standardized approaches to testing and reporting, and validation in larger cohorts. Given progress in the microbiome field with concurrent basic and clinical studies, the microbiome will likely become an integral part of clinical care within the next decade.

Autosomal Dominant Polycystic Kidney Disease in which the Polycystic Liver Volume Was Reduced by Rigorous Blood Pressure Control

Polycystic liver disease (PLD) is the most common extrarenal manifestation of autosomal dominant polycystic kidney disease (ADPKD). However, current treatments for PLD are only supportive. We experienced a case of enlarged kidneys and liver in a 53-year-old Japanese man with ADPKD who was on hemodialysis. He underwent renal transcatheter arterial embolization (TAE) for enlarged kidneys. His blood pressure (BP) decreased after renal TAE, and his liver volume decreased from 5,259 mL to 4,647 mL (11.6% reduction) within 1 year after renal TAE. This case suggests that rigorous blood pressure control may be beneficial for ameliorating enlarged PLD.