Repeated transplantation of hepatocytes prevents fulminant hepatitis in a rat model of Wilson's disease

Research progress in stem cell therapy for Wilson disease

Wilson disease (WD), also known as hepatolenticular degeneration, is an autosomal recessive disorder characterized by disorganized copper metabolism caused by mutations in the ATP7B gene. Currently, the main treatment options for WD involve medications such as d-penicillamine, trientine hydrochloride, zinc acetate, and liver transplantation. However, there are challenges that encompass issues of poor compliance, adverse effects, and limited availability of liver sources that persist. Stem cell therapy for WD is currently a promising area of research. Due to the advancement in stem cell directed differentiation technology in vitro and the availability of sufficient stem cell donors, it is expected to be a potential treatment option for the permanent correction of abnormal copper metabolism. This article discusses the research progress of stem cell therapy for WD from various sources, as well as the challenges and future prospects of the clinical application of stem cell therapy for WD.

Navigating the CRISPR/Cas Landscape for Enhanced Diagnosis and Treatment of Wilson's Disease

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) system continues to evolve, thereby enabling more precise detection and repair of mutagenesis. The development of CRISPR/Cas-based diagnosis holds promise for high-throughput, cost-effective, and portable nucleic acid screening and genetic disease diagnosis. In addition, advancements in transportation strategies such as adeno-associated virus (AAV), lentiviral vectors, nanoparticles, and virus-like vectors (VLPs) offer synergistic insights for gene therapeutics in vivo. Wilson's disease (WD), a copper metabolism disorder, is primarily caused by mutations in the ATPase copper transporting beta (ATP7B) gene. The condition is associated with the accumulation of copper in the body, leading to irreversible damage to various organs, including the liver, nervous system, kidneys, and eyes. However, the heterogeneous nature and individualized presentation of physical and neurological symptoms in WD patients pose significant challenges to accurate diagnosis. Furthermore, patients must consume copper-chelating medication throughout their lifetime. Herein, we provide a detailed description of WD and review the application of novel CRISPR-based strategies for its diagnosis and treatment, along with the challenges that need to be overcome.

Nano-Mediated Molecular Targeting in Diagnosis and Mitigation of Wilson Disease

Wilson disease, a rare genetic disorder resulting from mutations in the ATP7B gene disrupts copper metabolism, leading to its harmful accumulation in hepatocytes, the brain, and other organs. It affects roughly 1 in 30,000 individuals, with 1 in 90 being gene carriers. Beyond gene mutations, the disease involves complex factors contributing to copper imbalance. Ongoing research seeks to unravel intricate molecular pathways, offering fresh insights into the disease's mechanisms. Simultaneously, there is a dedicated effort to develop effective therapeutic strategies. Nanotechnology-driven formulations are showing promise for both treatment and early diagnosis of Wilson disease. This comprehensive review covers the entire spectrum of the condition, encompassing pathophysiology, potential biomarkers, established and emerging therapies, ongoing clinical trials, and innovative nanotechnology applications. This multifaceted approach holds the potential to improve our understanding, diagnosis, and management of Wilson's disease, which remains a challenging and potentially life-threatening disorder.

Neurological-Type Wilson Disease: Epidemiology, Clinical Manifestations, Diagnosis, and Management

Wilson disease (WD) is a complex metabolic disorder caused by disruptions to copper regulation within the body, leading to an unregulated accumulation of copper within various tissues. A less understood organ affected by the collection of copper is the brain, which further leads to the generation of oxygen-free radicals and resultant demyelination. Healthcare providers must keep the neurological form of WD in their list of differentials when patients present with diverse neurological manifestations. The initial step to diagnosis will be to distinguish the characteristic disease presentation with a thorough history and physical and neurological examination. A high clinical disease suspicion of WD should warrant further investigation by laboratory workup and imaging modalities to support the clinical findings and confirm the diagnosis of WD. Once a WD diagnosis is established, the healthcare provider should treat the underlying biological process of WD symptomatically. This review article discusses the epidemiology and pathogenesis of the neurological form of WD, its clinical and behavioral implications, diagnostic features, and treatment modalities (current and emerging therapies), further aiding healthcare professionals in early diagnosis and management strategies.

Wilson Disease in Children

The silver anniversary of the discovery of the Wilson disease gene ATP7B was a couple of years ago, and we continue to make progress both in our understanding of copper transportation using animal models as well as earlier diagnosis by availing of genetic testing. Wilson disease is multisystemic and the hepatic manifestations are seen more frequently in childhood, whereas neurologic manifestations are more common in adults; presentation may range from subtle changes to end-stage liver disease with or without encephalopathy as well as neuropsychiatric manifestations. Treatment remains with zinc and chelating agents such as D-penicillamine and trientine but newer agents and gene therapy are in clinical trials. Liver transplantation becomes necessary when medical therapy is not enough. Molecular diagnosis and genetic counseling is important.

CRISPR-targeted genome editing of human induced pluripotent stem cell-derived hepatocytes for the treatment of Wilson's disease

Background & Aims

Wilson’s disease (WD) is an autosomal recessive disorder of copper metabolism caused by loss-of-function mutations in ATP7B, which encodes a copper-transporting protein. It is characterized by excessive copper deposition in tissues, predominantly in the liver and brain. We sought to investigate whether gene-corrected patient-specific induced pluripotent stem cell (iPSC)-derived hepatocytes (iHeps) could serve as an autologous cell source for cellular transplantation therapy in WD.

Methods

We first compared the in vitro phenotype and cellular function of ATP7B before and after gene correction using CRISPR/Cas9 and single-stranded oligodeoxynucleotides (ssODNs) in iHeps (derived from patients with WD) which were homozygous for the ATP7B R778L mutation (ATP7B^R778L/R778L). Next, we evaluated the in vivo therapeutic potential of cellular transplantation of WD gene-corrected iHeps in an immunodeficient WD mouse model (Atp7b^-/-/ Rag2^-/-/ Il2rg^-/-; ARG).

Results

We successfully created iPSCs with heterozygous gene correction carrying 1 allele of the wild-type ATP7B gene (ATP7B^WT/-) using CRISPR/Cas9 and ssODNs. Compared with ATP7B^R778L/R778L iHeps, gene-corrected ATP7B^WT/- iHeps restored in vitro ATP7B subcellular localization, its subcellular trafficking in response to copper overload and its copper exportation function. Moreover, in vivo cellular transplantation of ATP7B^WT/- iHeps into ARG mice via intra-splenic injection significantly attenuated the hepatic manifestations of WD. Liver function improved and liver fibrosis decreased due to reductions in hepatic copper accumulation and consequently copper-induced hepatocyte toxicity.

Conclusions

Our findings demonstrate that gene-corrected patient-specific iPSC-derived iHeps can rescue the in vitro and in vivo disease phenotypes of WD. These proof-of-principle data suggest that iHeps derived from gene-corrected WD iPSCs have potential use as an autologous ex vivo cell source for in vivo therapy of WD as well as other inherited liver disorders.

Lay summary

Gene correction restored ATP7B function in hepatocytes derived from induced pluripotent stem cells that originated from a patient with Wilson’s disease. These gene-corrected hepatocytes are potential cell sources for autologous cell therapy in patients with Wilson’s disease.

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Correction of the ATP7B R778L mutation restored the subcellular localization of ATP7B in iHeps.

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The copper exportation capability of ATP7B was restored in gene-corrected iHeps.

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Gene-corrected iHeps reduced hepatic copper accumulation and copper-induced hepatic toxicity in mice with Wilson’s disease.

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Gene-corrected iHeps are potential ex vivo cell sources for therapy in Wilson’s disease.

Wilson's Disease: An Update on the Diagnostic Workup and Management

Wilson's disease (WD) is a rare autosomal recessive disorder of hepatocellular copper deposition. The diagnostic approach to patients with WD may be challenging and is based on a complex set of clinical findings that derive from patient history, physical examination, as well as laboratory and imaging testing. No single examination can unequivocally confirm or exclude the disease. Timely identification of signs and symptoms using novel biomarkers and modern diagnostic tools may help to reduce treatment delays and improve patient prognosis. The proper way of approaching WD management includes, firstly, early diagnosis and prompt treatment introduction; secondly, careful and lifelong monitoring of patient compliance and strict adherence to the treatment; and, last but not least, screening for adverse effects and evaluation of treatment efficacy. Liver transplantation is performed in about 5% of WD patients who present with acute liver failure at first disease presentation or with signs of decompensation in the course of liver cirrhosis. Increasing awareness of this rare inherited disease among health professionals, emphasizing their training to consider early signs and symptoms of the illness, and strict monitoring are vital strategies for the patient safety and efficacy of WD therapy.

Recent advances in Wilson disease

Wilson disease (WD) is rare genetic disorder that presents with varied phenotype that can at times make the diagnosis challenging. Medical treatments are available, but there are still unmet needs for patients. Since life-long therapy is necessary, adherence to medical therapy and best practices for monitoring and individualizing therapy continue to evolve. Studies are ongoing that address some of these issues. In the current review we focused our attention to recent advances in the diagnosis of WD, current medical treatments, future potential therapies and treatment monitoring. We include discussion of new methodology for detection and quantitation of ophthalmologic signs of WD, new brain imaging modalities for early detection of neurologic involvement in patients and potential new diagnostic methodology using blood samples that may be applicable to newborn screening and adult disease diagnosis. In addition, there are new strategies aimed at improving adherence and outcomes with currently available therapies, including once daily chelation dosing and discussion of the efficacy of different zinc salt compounds. With respect to new therapies with different mechanisms of action, we discuss studies on Bis-choline tetrathiomolybdate (TTM) in patients, pre-clinical studies of a novel chelator methanobactin and other animal studies exploring cures for WD with gene therapy using adeno-associated vectors (AAVs) that introduce ATP7B into liver cells. There are also promising advances in the more accurate measurement of non-ceruloplasmin bound copper and exchangeable copper in the circulation which would potentially help with monitoring and individualization of treatment and possibly play a role in future disease diagnosis.

Wilson disease-treatment perspectives

Wilson disease (WD) is a genetic disorder caused by pathological tissue copper accumulation with secondary damage of affected organs (mainly, but not limited to, the liver and brain). The main clinical symptoms of WD are, in concordance with the pathogenesis, hepatic and/or neuropsychiatric. Current treatment options for WD, based on drugs leading to negative copper body balance like chelators or zinc salts, were introduced more than 40 years ago and are generally effective in the majority of WD cases if used lifelong. However, especially in neurological patients, treatment may lead to neurological deterioration, which is often irreversible. Further, almost 50% of neurologically affected WD patients present with persistent neurological deficits despite the use of anti-copper treatment. In addition, up to 30% of patients treated with the widely used drug, d-penicillamine, present with adverse events related to treatment, which often leads to treatment discontinuation. Finally, almost 25% of WD patients do not adhere with anti-copper treatment, partially due to drug-related adverse events and complex treatment regimens (3 times daily, before meals, etc.). These limitations with current treatments have led to the search for other WD treatment possibilities. Currently, research is mainly focused on: (I) new agents with better safety profiles and less neurological deterioration properties compared with traditional chelators, e.g., tetrathiomolybdate salts or central nervous system-penetrable trientine, with the aim to provide more effective copper removal from brain tissue; (II) other non-chelating drugs that lead to removal of copper from cells [e.g., methanobactin (currently in preclinical studies)]; (III) cell and gene therapy. In this article, current research on future treatments for WD is reviewed.

Therapeutic potential of hepatocyte-like-cells converted from stem cells from human exfoliated deciduous teeth in fulminant Wilson's disease

Wilson’s disease (WD) is an inherited metabolic disease arising from ATPase copper transporting beta gene (ATP7B) mutation. Orthotoropic liver transplantation is the only radical treatment of fulminant WD, although appropriate donors are lacking at the onset of emergency. Given the hepatogenic capacity and tissue-integration/reconstruction ability in the liver of stem cells from human exfoliated deciduous teeth (SHED), SHED have been proposed as a source for curing liver diseases. We hypothesized the therapeutic potential of SHED and SHED-converted hepatocyte-like- cells (SHED-Heps) for fulminant WD. SHED and SHED-Heps were transplanted into WD model Atp7b-mutated Long-Evans Cinnamon (LEC) rats received copper overloading to induce a lethal fulminant liver failure. Due to the superior copper tolerance via ATP7B, SHED-Hep transplantation gave more prolonged life-span of fulminant LEC rats than SHED transplantation. The integrated ATP7B-expressing SHED-Heps showed more therapeutic effects on to restoring the hepatic dysfunction and tissue damages in the recipient liver than the integrated naïve SHED without ATP7B expression. Moreover, SHED-Heps could reduce copper-induced oxidative stress via ATP7B- independent stanniocalcin 1 secretion in the fulminant LEC rats, suggesting a possible role for paracrine effect of the integrated SHED-Heps. Taken together, SHED-Heps offer a potential of functional restoring, bridging, and preventive approaches for treating fulminant WD.

Animal models of Wilson disease

Wilson disease (WD) is an autosomal recessive disorder of copper metabolism manifesting with hepatic, neurological and psychiatric symptoms. The limitations of the currently available therapy for WD (particularly in the management of neuropsychiatric disease), together with our limited understanding of key aspects of this illness (e.g. neurological vs. hepatic presentation) justify the ongoing need to study WD in suitable animal models. Four animal models of WD have been established: the Long-Evans Cinnamon rat, the toxic-milk mouse, the Atp7b knockout mouse and the Labrador retriever. The existing models of WD all show good similarity to human hepatic WD and have been helpful in developing an improved understanding of the human disease. As mammals, the mouse, rat and canine models also benefit from high homology to the human genome. However, important differences exist between these mammalian models and human disease, particularly the absence of a convincing neurological phenotype. This review will first provide an overview of our current knowledge of the orthologous genes encoding ATP7B and the closely related ATP7A protein in C. elegans, Drosophila and zebrafish (Danio rerio) and then summarise key characteristics of rodent and larger mammalian models of ATP7B-deficiency.

Repeated versus single transplantation of mesenchymal stem cells in carbon tetrachloride-induced liver injury in mice

Despite its numerous limitations, liver transplants are the only definite cure for end-stage liver disease. Various stem cell populations may contribute to liver regeneration, of which there is accumulating evidence of the contribution of mesenchymal stem cells (MSCs). This study examines the hypothesis that repeated infusions of human bone marrow-derived MSCs (hBMMSCs)can improve liver injury in an experimental model. MSCs were intravenously transplanted into immunosuppressed mice with carbon tetrachloride (CCl(4))-induced liver fibrosis. Transplanting 3x10(6) MSCs in three divided doses improved survival,liver fibrosis and necrosis compared with injection of the same number of MSCs in a single dose. This was accompanied by increased influence on the expression of the fibrogenic/fibrolytic related genes Col1a1, Timp1 and Mmp13 in the repeated transplant group. Repeat administration of MSCs was three times more effective in homing of PKH-tagged transplanted cells 3 weeks post-transplant compared with the single transplant group. The benefits of repeated transplants may be of considerable significance in clinical trials on liver failure.

New Tools in Experimental Cellular Therapy for the Treatment of Liver Diseases

The current standard of care for end stage liver disease is orthotopic liver transplantation (OLT). Through improvement in surgical techniques, immunosuppression, and general medical care, liver transplantation has become an effective treatment over the course of the last half-century. Unfortunately, due to the limited availability of donor organs, there is a finite limit to the number of patients who will benefit from this therapy. This review will discuss current research in experimental cellular therapies for acute, chronic, and metabolic liver failure that may be appropriate when liver transplantation is not an immediate option.

Transplantation of ATP7B-transduced bone marrow mesenchymal stem cells decreases copper overload in rats

BACKGROUND

Recent studies have demonstrated that transplantation of ATP7B-transduced hepatocytes ameliorates disease progression in LEC (Long-Evans Cinnamon) rats, a model of Wilson's disease (WD). However, the inability of transplanted cells to proliferate in a normal liver hampers long-term treatment. In the current study, we investigated whether transplantation of ATP7B-transduced bone marrow mesenchymal stem cells (BM-MSCs) could decrease copper overload in LEC rats.

MATERIALS AND METHODS

The livers of LEC rats were preconditioned with radiation (RT) and/or ischemia-reperfusion (IRP) before portal vein infusion of ATP7B-transduced MSCs (MSCsATP7B). The volumes of MSCsATP7B or saline injected as controls were identical. The expression of ATP7B was analyzed by real-time quantitative polymerase chain reaction (RT-PCR) at 4, 12 and 24 weeks post-transplantation. MSCATP7B repopulation, liver copper concentrations, serum ceruloplasmin levels, and alanine transaminase (ALT) and aspartate transaminase (AST) levels were also analyzed at each time-point post-transplantation.

RESULTS

IRP-plus-RT preconditioning was the most effective strategy for enhancing the engraftment and repopulation of transplanted MSCsATP7B. This strategy resulted in higher ATP7B expression and serum ceruloplasmin, and lower copper concentration in this doubly preconditioned group compared with the saline control group, the IRP group, and the RT group at all three time-points post-transplantation (p<0.05 for all). Moreover, 24 weeks post-transplantation, the levels of ALT and AST in the IRP group, the RT group, and the IRP-plus-RT group were all significantly decreased compared to those of the saline group (p<0.05 compared with the IRP group and RT group, p<0.01 compared with IRP-plus-RT group); ALT and AST levels were significantly lower in the IRP-plus-RT group compared to either the IRP group or the RT group (p<0.01 and p<0.05. respectively).

CONCLUSIONS

These results demonstrate that transplantation of MSCsATP7B into IRP-plus-RT preconditioned LEC rats decreased copper overload and was associated with an increase in MSC engraftment and repopulation.

Dietary copper triggers onset of fulminant hepatitis in the Long-Evans cinnamon rat model

AIM: To investigate the impact of dietary copper given at different time points on the onset of fulminant hepatitis.

METHODS: The Long-Evans cinnamon (LEC) rat model of Wilson’s disease (WD) was used to study the impact of high dietary copper (hCu) on the induction of fulminant hepatitis at early or late time points of life. High Cu diet was started in rat pups or in adults (month 5) for three months. Animals that received reduced dietary copper (rCu) throughout their lifetime served as a control. Hepatitis-associated serum markers (alanine aminotransferase, aspartate transaminase, bilirubin) were analyzed in animal groups receiving hCu or rCu. Liver copper content and liver histology were revealed at sacrifice. A set of 5 marker genes previously found to be affected in injured liver and which are related to angiogenesis (Vegfa), fat metabolism (Srebf1), extracellular matrix (Timp1), oxidative stress (Hmox1), and the cell cycle (Cdkn1a) were analyzed by real-time polymerase chain reaction.

RESULTS: Regardless of the time point when hCu was started, LEC rats (35/36) developed fulminant hepatitis and died. Animals receiving rCu (36/36) remained healthy, did not develop hepatitis, and survived long term without symptoms of overt disease, although liver copper accumulated in adult animals (477 ± 75 μg/g). With regard to start of hCu, onset of fulminant hepatitis was significantly (P < 0.001) earlier in adults (35 ± 9 d) that showed pre-accumulation of liver copper as compared to the pup group (77 ± 15 d). Hepatitis-associated serum markers, liver copper and liver histology, as well as gene expression, were affected in LEC rats receiving hCu. However, except for early and rapid onset of hepatitis, biochemical and molecular markers were similar at the early and late time points of disease.

CONCLUSION: Rapid onset of fulminant hepatitis in asymptomatic LEC rats with elevated liver copper suggests that there is a critical threshold of liver copper which is important to trigger the course of WD.

Longitudinal analysis of serum miR-122 in a rat model of Wilson's disease

PURPOSE

MicroRNA-122 (miR-122) has recently been shown to represent a novel biomarker of liver disease. However, the presence of serum miR-122 after liver injury was mostly studied at singular time points. The course of serum miR-122 was determined at consecutive time points during the onset of disease.

METHODS

Fulminant hepatitis was induced by a high-copper diet in Long-Evans Cinnamon (LEC) rats that were used as models for Wilson's disease (WD). Levels of serum miR-122, alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and liver histology were determined.

RESULTS

Toxic copper given to isolated hepatocytes induced release of miR-122 into the tissue culture medium. Levels of serum miR-122 were highly elevated (21.9 ± 5) in LEC rats after high-copper diet in fulminant hepatitis, whereas healthy rats showed low (<0.6) baseline levels of miR-122. Levels of miR-122 in the serum of LEC rats after high-copper diet continuously increased for about 4 weeks prior to the onset of fulminant hepatitis. In most of the animals (77.8%), significantly increased levels of miR-122 were detected about 2 weeks (13.7 ± 2 days) earlier as compared to hepatitis-associated serum markers ALT, AST, and bilirubin. Analysis of miR-122 in survivors after cell-based therapy of WD demonstrated a rapid decrease of miR-122 levels following hepatocyte transplantation. miR-122 expression in the serum was normalized to baseline levels in most of the (4/5) survivors.

CONCLUSION

Our results suggest that longitudinal analysis of miR-122 allows detection of severe liver disease at an early stage and might be excellently suited to monitor therapy, at least when severe liver disease can be restored as observed after cell-based therapy of WD.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (doi:10.1007/s12072-012-9348-5) contains supplementary material, which is available to authorized users.