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1.
J Hepatol ; 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38977136

ABSTRACT

BACKGROUND & AIMS: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common cause of chronic liver disease. Its limited treatment options warrant novel pre-clinical models for target selection and drug validation. We have established and extensively characterized a primary human steatotic hepatocyte in vitro model system that could guide treatment strategies for MASLD. METHODS: Cryopreserved primary human hepatocytes from five donors varying in sex and ethnicity were cultured with free fatty acids (FFA) in 3D collagen sandwich for 7 days and the development of MASLD was followed by assessing classical hepatocellular functions. As proof of concept, the effects of the drug Firsocostat (GS-0976) on in vitro MASLD phenotypes were evaluated. RESULTS: Incubation with FFA induced steatosis, insulin resistance, mitochondrial dysfunction, inflammation, and alterations in prominent human gene signatures similar to patients with MASLD, indicating the recapitulation of human MASLD in this system. As the application of Firsocostat rescued clinically observed fatty liver disease pathologies, it highlights the ability of the in vitro system to test drug efficacy and potentially characterize their mode of action. CONCLUSIONS: Altogether, our human MASLD in vitro model system could guide the development and validation of novel targets and drugs for the treatment of MASLD. IMPACT AND IMPLICATIONS: Due to low drug efficacy and high toxicity, a clinical treatment option for MASLD is limited. To facilitate earlier stop-go decisions in drug development, we have established a primary human steatotic hepatocyte in vitro model. As the model recapitulates clinically relevant MASLD characteristics at high phenotypic resolution, it can serve as a pre-screening platform and guide target identification and validation in MASLD therapy.

2.
Breast Cancer Res ; 26(1): 87, 2024 May 30.
Article in English | MEDLINE | ID: mdl-38816770

ABSTRACT

BACKGROUND: Despite progress understanding the mechanisms underlying tumor spread, metastasis remains a clinical challenge. We identified the choline-producing glycerophosphodiesterase, EDI3 and reported its association with metastasis-free survival in endometrial cancer. We also observed that silencing EDI3 slowed cell migration and other cancer-relevant phenotypes in vitro. Recent work demonstrated high EDI3 expression in ER-HER2+ breast cancer compared to the other molecular subtypes. Silencing EDI3 in ER-HER2+ cells significantly reduced cell survival in vitro and decreased tumor growth in vivo. However, a role for EDI3 in tumor metastasis in this breast cancer subtype was not explored. Therefore, in the present work we investigate whether silencing EDI3 in ER-HER2+ breast cancer cell lines alters phenotypes linked to metastasis in vitro, and metastasis formation in vivo using mouse models of experimental metastasis. METHODS: To inducibly silence EDI3, luciferase-expressing HCC1954 cells were transduced with lentiviral particles containing shRNA oligos targeting EDI3 under the control of doxycycline. The effect on cell migration, adhesion, colony formation and anoikis was determined in vitro, and significant findings were confirmed in a second ER-HER2+ cell line, SUM190PT. Doxycycline-induced HCC1954-luc shEDI3 cells were injected into the tail vein or peritoneum of immunodeficient mice to generate lung and peritoneal metastases, respectively and monitored using non-invasive bioluminescence imaging. Metabolite levels in cells and tumor tissue were analyzed using targeted mass spectrometry and MALDI mass spectrometry imaging (MALDI-MSI), respectively. RESULTS: Inducibly silencing EDI3 reduced cell adhesion and colony formation, as well as increased susceptibility to anoikis in HCC1954-luc cells, which was confirmed in SUM190PT cells. No influence on cell migration was observed. Reduced luminescence was seen in lungs and peritoneum of mice injected with cells expressing less EDI3 after tail vein and intraperitoneal injection, respectively, indicative of reduced metastasis. Importantly, mice injected with EDI3-silenced cells survived longer. Closer analysis of the peritoneal organs revealed that silencing EDI3 had no effect on metastatic organotropism but instead reduced metastatic burden. Finally, metabolic analyses revealed significant changes in choline and glycerophospholipid metabolites in cells and in pancreatic metastases in vivo. CONCLUSIONS: Reduced metastasis upon silencing supports EDI3's potential as a treatment target in metastasizing ER-HER2+ breast cancer.


Subject(s)
Breast Neoplasms , Receptor, ErbB-2 , Receptors, Estrogen , Animals , Female , Humans , Mice , Cell Line, Tumor , Receptor, ErbB-2/metabolism , Receptor, ErbB-2/genetics , Breast Neoplasms/pathology , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Receptors, Estrogen/metabolism , Disease Models, Animal , Cell Movement , Gene Knockdown Techniques , Tumor Burden , Neoplasm Metastasis , Lung Neoplasms/secondary , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Cell Proliferation
3.
J Hepatol ; 80(2): 268-281, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37939855

ABSTRACT

BACKGROUND & AIMS: Cholemic nephropathy (CN) is a severe complication of cholestatic liver diseases for which there is no specific treatment. We revisited its pathophysiology with the aim of identifying novel therapeutic strategies. METHODS: Cholestasis was induced by bile duct ligation (BDL) in mice. Bile flux in kidneys and livers was visualized by intravital imaging, supported by MALDI mass spectrometry imaging and liquid chromatography-tandem mass spectrometry. The effect of AS0369, a systemically bioavailable apical sodium-dependent bile acid transporter (ASBT) inhibitor, was evaluated by intravital imaging, RNA-sequencing, histological, blood, and urine analyses. Translational relevance was assessed in kidney biopsies from patients with CN, mice with a humanized bile acid (BA) spectrum, and via analysis of serum BAs and KIM-1 (kidney injury molecule 1) in patients with liver disease and hyperbilirubinemia. RESULTS: Proximal tubular epithelial cells (TECs) reabsorbed and enriched BAs, leading to oxidative stress and death of proximal TECs, casts in distal tubules and collecting ducts, peritubular capillary leakiness, and glomerular cysts. Renal ASBT inhibition by AS0369 blocked BA uptake into TECs and prevented kidney injury up to 6 weeks after BDL. Similar results were obtained in mice with humanized BA composition. In patients with advanced liver disease, serum BAs were the main determinant of KIM-1 levels. ASBT expression in TECs was preserved in biopsies from patients with CN, further highlighting the translational potential of targeting ASBT to treat CN. CONCLUSIONS: BA enrichment in proximal TECs followed by oxidative stress and cell death is a key early event in CN. Inhibiting renal ASBT and consequently BA enrichment in TECs prevents CN and systemically decreases BA concentrations. IMPACT AND IMPLICATIONS: Cholemic nephropathy (CN) is a severe complication of cholestasis and an unmet clinical need. We demonstrate that CN is triggered by the renal accumulation of bile acids (BAs) that are considerably increased in the systemic blood. Specifically, the proximal tubular epithelial cells of the kidney take up BAs via the apical sodium-dependent bile acid transporter (ASBT). We developed a therapeutic compound that blocks ASBT in the kidneys, prevents BA overload in tubular epithelial cells, and almost completely abolished all disease hallmarks in a CN mouse model. Renal ASBT inhibition represents a potential therapeutic strategy for patients with CN.


Subject(s)
Carrier Proteins , Cholestasis , Kidney Diseases , Liver Diseases , Membrane Glycoproteins , Organic Anion Transporters, Sodium-Dependent , Symporters , Humans , Mice , Animals , Cholestasis/complications , Cholestasis/metabolism , Kidney/metabolism , Symporters/metabolism , Bile Acids and Salts/metabolism , Liver/metabolism , Bile Ducts/metabolism , Liver Diseases/metabolism , Sodium
4.
Arch Toxicol ; 97(11): 3005-3017, 2023 11.
Article in English | MEDLINE | ID: mdl-37615677

ABSTRACT

Exposure to multiple substances is a challenge for risk evaluation. Currently, there is an ongoing debate if generic "mixture assessment/allocation factors" (MAF) should be introduced to increase public health protection. Here, we explore concepts of mixture toxicity and the potential influence of mixture regulation concepts for human health protection. Based on this analysis, we provide recommendations for research and risk assessment. One of the concepts of mixture toxicity is additivity. Substances may act additively by affecting the same molecular mechanism within a common target cell, for example, dioxin-like substances. In a second concept, an "enhancer substance" may act by increasing the target site concentration and aggravating the adverse effect of a "driver substance". For both concepts, adequate risk management of individual substances can reliably prevent adverse effects to humans. Furthermore, we discuss the hypothesis that the large number of substances to which humans are exposed at very low and individually safe doses may interact to cause adverse effects. This commentary identifies knowledge gaps, such as the lack of a comprehensive overview of substances regulated under different silos, including food, environmentally and occupationally relevant substances, the absence of reliable human exposure data and the missing accessibility of ratios of current human exposure to threshold values, which are considered safe for individual substances. Moreover, a comprehensive overview of the molecular mechanisms and most susceptible target cells is required. We conclude that, currently, there is no scientific evidence supporting the need for a generic MAF. Rather, we recommend taking more specific measures, which focus on compounds with relatively small ratios between human exposure and doses, at which adverse effects can be expected.


Subject(s)
Drug-Related Side Effects and Adverse Reactions , Polychlorinated Dibenzodioxins , Humans , Food , Public Health , Risk Assessment
5.
Epigenetics Chromatin ; 16(1): 30, 2023 Jul 06.
Article in English | MEDLINE | ID: mdl-37415213

ABSTRACT

Fatty liver disease or the accumulation of fat in the liver, has been reported to affect the global population. This comes with an increased risk for the development of fibrosis, cirrhosis, and hepatocellular carcinoma. Yet, little is known about the effects of a diet containing high fat and alcohol towards epigenetic aging, with respect to changes in transcriptional and epigenomic profiles. In this study, we took up a multi-omics approach and integrated gene expression, methylation signals, and chromatin signals to study the epigenomic effects of a high-fat and alcohol-containing diet on mouse hepatocytes. We identified four relevant gene network clusters that were associated with relevant pathways that promote steatosis. Using a machine learning approach, we predict specific transcription factors that might be responsible to modulate the functionally relevant clusters. Finally, we discover four additional CpG loci and validate aging-related differential CpG methylation. Differential CpG methylation linked to aging showed minimal overlap with altered methylation in steatosis.


Subject(s)
Epigenomics , Hepatocytes , Mice , Animals , Hepatocytes/metabolism , Liver/metabolism , Ethanol , Epigenesis, Genetic , DNA Methylation
6.
Rev. Rol enferm ; 46(5): 282-290, may. 2023. ilus, tab
Article in Spanish | IBECS | ID: ibc-220387

ABSTRACT

El cáncer gestacional se puede definir como el cáncer que ocurre durante el embarazo o durante el primer año posterior al parto. Entre ellos, el cáncer de mama ocupa el primer lugar en frecuencia con una incidencia en aumento y que se sitúa cerca de 1 por cada 3.000 mujeres embarazadas. En la mujer embarazada el diagnóstico de cáncer representa un desafío en términos de manejo clínico, debido a la necesidad de garantizar la seguridad materna y asegurar el estado de gestación. Este tiende a retrasarse y detectarse en estadios más tardíos debido a que los síntomas asociados pueden relacionarse fácilmente con una situación normal de gestación. Las embarazadas diagnosticadas de cáncer deben ser evaluadas por un comité multidisciplinario de tumores, especializado en cáncer durante el embarazo. Uno de los tratamientos utilizados para el abordaje del cáncer de mama es la quimioterapia antineoplásica, que debe ser administrada en un hospital, atendiendo a diferentes factores como son el estado general del paciente, las posibles enfermedades previas, el tipo, estadio y localización del tumor, así como la semana de gestación en la que se encuentra la mujer. A partir de la semana 13-14 de gestación puede iniciarse el tratamiento, siendo los regímenes más utilizados a día de hoy: ciclos de 3 semanas de FAC (5-fluorouracilo, doxorrubicina y ciclofosfamida), FEC (5-fluorouracilo, epirubicina y ciclofosfamida), AC (doxorrubicina y ciclofosfamida) y EC (epirubicina y ciclofosfamida) o epirubicina semanal como monoterapia. Asimismo, destaca el uso de los taxanos (paclitaxel como agente único). La enfermera constituye un pilar fundamental dentro del equipo multidisciplinario de tumores, especializado en cáncer de mama durante el embarazo, que atenderá y acompañará a la embarazada durante todo el proceso de la enfermedad. El cáncer de mama, y más en la embarazada, conlleva una serie de cambios en su vida que requieren diferentes procesos de adaptación física, psicológica y social (AU)


Gestational cancer can be defined as cancer that occurs during pregnancy or within the first year after delivery. Among them, breast cancer occupies the first place in frequency with an increasing incidence that is situated at about 1 per 3.000 pregnant women. In pregnant women, the diagnosis of cancer represents a challenge in terms of clinical management, due to the need to guarantee maternal safety and ensure the state of pregnancy. This tends to be delayed and detected at later stages because the associated symptoms can be easily related to a normal pregnancy situation. Pregnant women diagnosed with cancer should be evaluated by a multidisciplinary tumor team, specialized in cancer during pregnancy. One of the treatments used to address breast cancer is antineoplastic chemotherapy, which must be administered in a hospital, taking into account different factors such as the general condition of the patient, possible previous diseases, the type, stage and location of the tumor, as well as the week of gestation in which the woman is. Treatment can be started from week 13-14 of gestation, the most widely used regimens to date are: 3-week cycles of FAC (5-fluorouracil, doxorubicin and cyclophosphamide), FEC (5-fluorouracil, epirubicin and cyclophosphamide), AC (doxorubicin and cyclophosphamide) and EC (epirubicin and cyclophosphamide) or weekly epirubicin as monotherapy. Likewise, the use of taxanes (paclitaxel as a single agent) stands out. The nurse is a fundamental pillar within the multidisciplinary team of tumors, specialized in breast cancer during pregnancy, who will care for and accompany the pregnant woman throughout the disease process. Breast cancer, and more in pregnant women, entails a series of changes in their lives that require different processes of physical, psychological and social adaptation. (AU)


Subject(s)
Humans , Female , Pregnancy , Pregnancy Complications, Neoplastic , Breast Neoplasms/diagnosis , Breast Neoplasms/drug therapy , Antineoplastic Agents , Nursing Care
7.
BMC Nurs ; 22(1): 15, 2023 Jan 13.
Article in English | MEDLINE | ID: mdl-36639785

ABSTRACT

BACKGROUND: Animal models are increasingly used in Nursing science to study care approaches. Despite the scientific relevance and the ethical debate surrounding the use of experimental animals, there is a scarcity of scholarly literature exploring this topic in Nursing Schools. AIM: To evaluate perceptions and attitudes of nursing students enrolled in a Pharmacology course on the use of experimental animals and implementation of alternative methods, by comparing the experience for two academic years. An interdisciplinary collaboration has also been developed. METHODS: A descriptive cross-sectional, quantitative study was developed. Undergraduate nursing students were enrolled in the Pharmacology subject at the University of Leon (Spain). The study was carried out in the Pharmacology facilities. Students followed a two-session practical class regarding experimental animals and alternative methods in the Pharmacology course (Degree in Nursing) in two different academic years (2019-20/2020-21). At the end of the activity, they answered a questionnaire to assess their opinions on the use of experimental animals and alternative methods in Pharmacology and the 3Rs principle. RESULTS: A comparison of the students' perception with and without direct participation in the evaluation of promazine effects in mice was made. A total of 190 students participated in the teaching experience, providing high scores in all items (4-5 out of 5 points) regarding the teaching experience. Students became also aware of the advantages and disadvantages on the use of experimental animals, as well as the ethical considerations to bear in mind for their use and the need for alternative methods. CONCLUSIONS: In the students' opinion, the total replacement of animals by alternative techniques was very difficult, and they preferred to do the practice face-to-face. The alternative method designed was useful for the students to accept the employment of experimental animals in biomedical research and education, and know the legislation applied in the protection of animals.

8.
J Exp Clin Cancer Res ; 42(1): 25, 2023 Jan 20.
Article in English | MEDLINE | ID: mdl-36670508

ABSTRACT

BACKGROUND: Intrinsic or acquired resistance to HER2-targeted therapy is often a problem when small molecule tyrosine kinase inhibitors or antibodies are used to treat patients with HER2 positive breast cancer. Therefore, the identification of new targets and therapies for this patient group is warranted. Activated choline metabolism, characterized by elevated levels of choline-containing compounds, has been previously reported in breast cancer. The glycerophosphodiesterase EDI3 (GPCPD1), which hydrolyses glycerophosphocholine to choline and glycerol-3-phosphate, directly influences choline and phospholipid metabolism, and has been linked to cancer-relevant phenotypes in vitro. While the importance of choline metabolism has been addressed in breast cancer, the role of EDI3 in this cancer type has not been explored. METHODS: EDI3 mRNA and protein expression in human breast cancer tissue were investigated using publicly-available Affymetrix gene expression microarray datasets (n = 540) and with immunohistochemistry on a tissue microarray (n = 265), respectively. A panel of breast cancer cell lines of different molecular subtypes were used to investigate expression and activity of EDI3 in vitro. To determine whether EDI3 expression is regulated by HER2 signalling, the effect of pharmacological inhibition and siRNA silencing of HER2, as well as the influence of inhibiting key components of signalling cascades downstream of HER2 were studied. Finally, the influence of silencing and pharmacologically inhibiting EDI3 on viability was investigated in vitro and on tumour growth in vivo. RESULTS: In the present study, we show that EDI3 expression is highest in ER-HER2 + human breast tumours, and both expression and activity were also highest in ER-HER2 + breast cancer cell lines. Silencing HER2 using siRNA, as well as inhibiting HER2 signalling with lapatinib decreased EDI3 expression. Pathways downstream of PI3K/Akt/mTOR and GSK3ß, and transcription factors, including HIF1α, CREB and STAT3 were identified as relevant in regulating EDI3 expression. Silencing EDI3 preferentially decreased cell viability in the ER-HER2 + cells. Furthermore, silencing or pharmacologically inhibiting EDI3 using dipyridamole in ER-HER2 + cells resistant to HER2-targeted therapy decreased cell viability in vitro and tumour growth in vivo. CONCLUSIONS: Our results indicate that EDI3 may be a potential novel therapeutic target in patients with HER2-targeted therapy-resistant ER-HER2 + breast cancer that should be further explored.


Subject(s)
Breast Neoplasms , Humans , Female , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Phosphatidylinositol 3-Kinases , Cell Line, Tumor , Choline/metabolism , Choline/therapeutic use , RNA, Small Interfering , Receptor, ErbB-2/metabolism , Drug Resistance, Neoplasm/genetics , Phospholipases/genetics
9.
Rev. Rol enferm ; 45(9): 44-51, Sept. 2022. ilus
Article in Spanish | IBECS | ID: ibc-211102

ABSTRACT

En las últimas décadas se han producido una serie de cambios a nivel sanitario y farmacológico que han aumentado la esperanza de vida de la sociedad, dando lugar a un notable incremento de personas mayores.El envejecimiento progresivo junto con las comorbilidades asociadas, se traduce en un perfil de paciente susceptible de sufrir polimedicación y, por consiguiente, fenómenos tales como prescripción inadecuada, reacciones adversas a medicamentos o interacciones farmacológicas. Esta situación genera la mayor parte de las admisiones hospitalarias en personas de más de 65 años, lo que conlleva un aumento del empleo de los recursos sanitarios y un incremento del gasto farmacéutico.Para poder optimizar las prescripciones en los pacientes mayores pluripatológicos, reduciendo la prescripción potencialmente inadecuada y las reacciones adversas a medicamentos, existen diversas herramientas a nivel mundial. Estas las podemos englobar en dos grandes grupos, por una parte, los métodos implícitos que se basan en juicios críticos y, por otro lado, los métodos explícitos en los cuales se emplean criterios definidos basados en datos científicos y creados por grupos de expertos a través de métodos de generación de consenso, generalmente método Delphi. Los criterios STOPP/START representan el método explícito más adecuado para la detección de prescripción potencialmente inadecuada en comparación con el resto de herramientas disponibles, aunque continúan las investigaciones con el objetivo de optimizarse. (AU)


In the last decades there have been a series of changes at the health and pharmacological level that have increased the life expectancy of society, leading to a notable increase in the number of seniors.Progressive aging with associated comorbidities, translates into a patient profile susceptible to polymedication and therefore, phenomena such as inappropriate prescription, adverse drug reactions or drug interactions. This situation generates the majority of hospital admissions in people over 65 years, which leads to an increase in the use of healthcare resources and an increase in pharmaceutical spending.In order to optimize prescriptions in multipathological senior patients, reducing potentially inappropriate prescription and adverse drug reactions, there are various tools worldwide. These can be grouped into two large groups, on the one hand, the implicit methods that are based on critical judgments, and on the other hand, the explicit methods in which defined criteria based on scientific data and created by groups of experts through consensus-building methods, usually the Delphi. The STOPP / START criteria represent the most appropriate explicit method for the detection of potentially inappropriate prescription compared to the rest of the available tools, although research continues with the aim of optimization. (AU)


Subject(s)
Humans , Nurse's Role , Inappropriate Prescribing , Nursing Care , Aging , Polypharmacy
10.
Toxicol Lett ; 368: 33-46, 2022 Sep 01.
Article in English | MEDLINE | ID: mdl-35963427

ABSTRACT

The accumulation of lipid droplets in hepatocytes is a key feature of drug-induced liver injury (DILI) and can be induced by a subset of hepatotoxic compounds. In the present study, we optimized and evaluated an in vitro technique based on the fluorescent dye Nile Red, further named Nile Red assay to quantify lipid droplets induced by the exposure to chemicals. The Nile Red assay and a cytotoxicity test (CTB assay) were then performed on cells exposed concentration-dependently to 60 different compounds. Of these, 31 were known to induce hepatotoxicity in humans, and 13 were reported to also cause steatosis. In order to compare in vivo relevant blood concentrations, pharmacokinetic models were established for all compounds to simulate the maximal blood concentrations (Cmax) at therapeutic doses. The results showed that several hepatotoxic compounds induced an increase in lipid droplets at sub-cytotoxic concentrations. To compare how well (1) the cytotoxicity test alone, (2) the Nile Red assay alone, and (3) the combination of the cytotoxicity test and the Nile Red assay (based on the lower EC10 of both assays) allow the differentiation between hepatotoxic and non-hepatotoxic compounds, a previously established performance metric, the Toxicity Separation Index (TSI) was calculated. In addition, the Toxicity Estimation Index (TEI) was calculated to determine how well blood concentrations that cause an increased DILI risk can be estimated for hepatotoxic compounds. Our findings indicate that the combination of both assays improved the TSI and TEI compared to each assay alone. In conclusion, the study demonstrates that inclusion of the Nile Red assay into in vitro test batteries may improve the prediction of DILI compounds.


Subject(s)
Chemical and Drug Induced Liver Injury , Drug-Related Side Effects and Adverse Reactions , Fatty Liver , Chemical and Drug Induced Liver Injury/etiology , Fatty Liver/chemically induced , Hepatocytes , Humans , Oxazines/toxicity
11.
Arch Toxicol ; 96(11): 2967-2981, 2022 11.
Article in English | MEDLINE | ID: mdl-35962801

ABSTRACT

Hypoalbuminemia (HA) is frequently observed in systemic inflammatory diseases and in liver disease. However, the influence of HA on the pharmacokinetics and toxicity of compounds with high plasma albumin binding remained insufficiently studied. The 'lack-of-delivery-concept' postulates that HA leads to less carrier mediated uptake of albumin bound substances into hepatocytes and to less glomerular filtration; in contrast, the 'concept-of-higher-free-fraction' argues that increased concentrations of non-albumin bound compounds facilitate hepatocellular uptake and enhance glomerular filtration. To address this question, we performed intravital imaging on livers and kidneys of anesthetized mice to quantify the spatio-temporal tissue distribution of the mycotoxin ochratoxin A (OTA) based on its auto-fluorescence in albumin knockout and wild-type mice. HA strongly enhanced the uptake of OTA from the sinusoidal blood into hepatocytes, followed by faster secretion into bile canaliculi. These toxicokinetic changes were associated with increased hepatotoxicity in heterozygous albumin knockout mice for which serum albumin was reduced to a similar extent as in patients with severe hypoalbuminemia. HA also led to a shorter half-life of OTA in renal capillaries, increased glomerular filtration, and to enhanced uptake of OTA into tubular epithelial cells. In conclusion, the results favor the 'concept-of-higher-free-fraction' in HA; accordingly, HA causes an increased tissue uptake of compounds with high albumin binding and increased organ toxicity. It should be studied if this concept can be generalized to all compounds with high plasma albumin binding that are substrates of hepatocyte and renal tubular epithelial cell carriers.


Subject(s)
Hypoalbuminemia , Mycotoxins , Ochratoxins , Animals , Hypoalbuminemia/metabolism , Kidney/metabolism , Liver/metabolism , Mice , Mycotoxins/metabolism , Ochratoxins/chemistry , Serum Albumin/metabolism , Tissue Distribution
12.
J Hepatol ; 77(5): 1386-1398, 2022 11.
Article in English | MEDLINE | ID: mdl-35863491

ABSTRACT

BACKGROUND & AIMS: Pluripotent stem cell (PSC)-derived hepatocyte-like cells (HLC) have enormous potential as a replacement for primary hepatocytes in drug screening, toxicology and cell replacement therapy, but their genome-wide expression patterns differ strongly from primary human hepatocytes (PHH). METHODS: We differentiated human induced pluripotent stem cells (hiPSC) via definitive endoderm to HLC and characterized the cells by single-cell and bulk RNA-seq, with complementary epigenetic analyses. We then compared HLC to PHH and publicly available data on human fetal hepatocytes (FH) ex vivo; we performed bioinformatics-guided interventions to improve HLC differentiation via lentiviral transduction of the nuclear receptor FXR and agonist exposure. RESULTS: Single-cell RNA-seq revealed that transcriptomes of individual HLC display a hybrid state, where hepatocyte-associated genes are expressed in concert with genes that are not expressed in PHH - mostly intestinal genes - within the same cell. Bulk-level overrepresentation analysis, as well as regulon analysis at the single-cell level, identified sets of regulatory factors discriminating HLC, FH, and PHH, hinting at a central role for the nuclear receptor FXR in the functional maturation of HLC. Combined FXR expression plus agonist exposure enhanced the expression of hepatocyte-associated genes and increased the ability of bile canalicular secretion as well as lipid droplet formation, thereby increasing HLCs' similarity to PHH. The undesired non-liver gene expression was reproducibly decreased, although only by a moderate degree. CONCLUSION: In contrast to physiological hepatocyte precursor cells and mature hepatocytes, HLC co-express liver and hybrid genes in the same cell. Targeted modification of the FXR gene regulatory network improves their differentiation by suppressing intestinal traits whilst inducing hepatocyte features. LAY SUMMARY: Generation of human hepatocytes from stem cells represents an active research field but its success is hampered by the fact that the stem cell-derived 'hepatocytes' still show major differences to hepatocytes obtained from a liver. Here, we identified an important reason for the difference, specifically that the stem cell-derived 'hepatocyte' represents a hybrid cell with features of hepatocytes and intestinal cells. We show that a specific protein (FXR) suppresses intestinal and induces liver features, thus bringing the stem cell-derived cells closer to hepatocytes derived from human livers.


Subject(s)
Induced Pluripotent Stem Cells , Pluripotent Stem Cells , Cell Differentiation , Hepatocytes/metabolism , Humans , Intestines
13.
JMIR Res Protoc ; 11(3): e32352, 2022 Mar 14.
Article in English | MEDLINE | ID: mdl-35285810

ABSTRACT

BACKGROUND: Previous research revealed several biological and environmental factors modulating cognitive functioning over a human's lifespan. However, the relationships and interactions between biological factors (eg, genetic polymorphisms, immunological parameters, metabolic products, or infectious diseases) and environmental factors (eg, lifestyle, physical activity, nutrition, and work type or stress at work) as well as their impact on cognitive functions across the lifespan are still poorly understood with respect to their complexity. OBJECTIVE: The goal of the Dortmund Vital Study is to validate previous hypotheses as well as generate and validate new hypotheses about the relationships among aging, working conditions, genetic makeup, stress, metabolic functions, the cardiovascular system, the immune system, and mental performance over the human lifespan with a focus on healthy working adults. The Dortmund Vital Study is a multidisciplinary study involving the Departments of Ergonomics, Immunology, Psychology and Neurosciences, and Toxicology at the Leibniz Research Centre for Working Environment and Human Factors at the Technical University of Dortmund (IfADo) in Germany, as well as several national and international partners. METHODS: The Dortmund Vital Study is designed as a combined cross-sectional and longitudinal study. Approximately 600 healthy subjects aged between 20 and 70 years will participate. A wide range of demographic, psychological, behavioral, sensory, cardiovascular, immunological, and biochemical data, a comprehensive electroencephalography (EEG)-based cognitive test battery as well as structural and functional magnetic resonance imaging (MRI) have been included in the study. RESULTS: The study was approved by the Ethics Committee of IfADo in October 2015. The baseline testing was conducted between 2016 and 2021 and will be repeated every 5 years (3 follow-up measures until 2035). As of March 2020 (until the outbreak of the COVID-19 pandemic), 593 participants have been enrolled. Some results from the cross-sectional part of the study were already published, further results will be published soon. Longitudinal data will be analyzed and published by 2025. CONCLUSIONS: We anticipate that the study will shed light on sources of interindividual differences in the alterations of cognitive functioning with increasing age and reveal biological and lifestyle markers contributing to work ability, longevity, and healthy aging on the one hand, and to risk factors for cognitive decline, mild cognitive impairment, or even dementia on the other hand. TRIAL REGISTRATION: ClinicalTrials.gov NCT05155397; https://clinicaltrials.gov/ct2/show/NCT05155397. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/32352.

14.
Hepatol Commun ; 6(1): 161-177, 2022 01.
Article in English | MEDLINE | ID: mdl-34558834

ABSTRACT

Mouse models are frequently used to study chronic liver diseases (CLDs). To assess their translational relevance, we quantified the similarity of commonly used mouse models to human CLDs based on transcriptome data. Gene-expression data from 372 patients were compared with data from acute and chronic mouse models consisting of 227 mice, and additionally to nine published gene sets of chronic mouse models. Genes consistently altered in humans and mice were mapped to liver cell types based on single-cell RNA-sequencing data and validated by immunostaining. Considering the top differentially expressed genes, the similarity between humans and mice varied among the mouse models and depended on the period of damage induction. The highest recall (0.4) and precision (0.33) were observed for the model with 12-months damage induction by CCl4 and by a Western diet, respectively. Genes consistently up-regulated between the chronic CCl4 model and human CLDs were enriched in inflammatory and developmental processes, and mostly mapped to cholangiocytes, macrophages, and endothelial and mesenchymal cells. Down-regulated genes were enriched in metabolic processes and mapped to hepatocytes. Immunostaining confirmed the regulation of selected genes and their cell type specificity. Genes that were up-regulated in both acute and chronic models showed higher recall and precision with respect to human CLDs than exclusively acute or chronic genes. Conclusion: Similarly regulated genes in human and mouse CLDs were identified. Despite major interspecies differences, mouse models detected 40% of the genes significantly altered in human CLD. The translational relevance of individual genes can be assessed at https://saezlab.shinyapps.io/liverdiseaseatlas/.


Subject(s)
Disease Models, Animal , Gene Expression Profiling , Liver Diseases/genetics , Transcriptome , Animals , Chronic Disease , Down-Regulation , Humans , Mice , Species Specificity , Up-Regulation
15.
Chem Biol Interact ; 351: 109728, 2022 Jan 05.
Article in English | MEDLINE | ID: mdl-34717914

ABSTRACT

An in vitro/in silico method that determines the risk of human drug induced liver injury in relation to oral doses and blood concentrations of drugs was recently introduced. This method utilizes information on the maximal blood concentration (Cmax) for a specific dose of a test compound, which can be estimated using physiologically-based pharmacokinetic modelling, and a cytotoxicity test in cultured human hepatocytes. In the present study, we analyzed if the addition of an assay that measures the inhibition of bile acid export carriers, like BSEP and/or MRP2, to the existing method improves the differentiation of hepatotoxic and non-hepatotoxic compounds. Therefore, an export assay for 5-chloromethylfluorescein diacetate (CMFDA) was established. We tested 36 compounds in a concentration-dependent manner for which the risk of hepatotoxicity for specific oral doses and the capacity to inhibit hepatocyte export carriers are known. Compared to the CTB cytotoxicity test, substantially lower EC10 values were obtained using the CMFDA assay for several known BSEP and/or MRP2 inhibitors. To quantify if the addition of the CMFDA assay to our test system improves the overall separation of hepatotoxic from non-hepatotoxic compounds, the toxicity separation index (TSI) was calculated. We obtained a better TSI using the lower alert concentration from either the CMFDA or the CTB test (TSI: 0.886) compared to considering the CTB test alone (TSI: 0.775). In conclusion, the data show that integration of the CMFDA assay with an in vitro test battery improves the differentiation of hepatotoxic and non-hepatotoxic compounds in a set of compounds that includes bile acid export carrier inhibitors.


Subject(s)
Cytotoxins/toxicity , Hepatocytes/drug effects , Toxicity Tests/methods , ATP Binding Cassette Transporter, Subfamily B, Member 11/antagonists & inhibitors , ATP Binding Cassette Transporter, Subfamily B, Member 11/metabolism , Cell Culture Techniques/methods , Cells, Cultured , Chemical and Drug Induced Liver Injury , Fluoresceins/metabolism , Humans , Mitochondria/drug effects , Multidrug Resistance-Associated Protein 2/antagonists & inhibitors , Multidrug Resistance-Associated Protein 2/metabolism
16.
Cells ; 10(10)2021 09 23.
Article in English | MEDLINE | ID: mdl-34685496

ABSTRACT

Mouse models of non-alcoholic fatty liver disease (NAFLD) are required to define therapeutic targets, but detailed time-resolved studies to establish a sequence of events are lacking. Here, we fed male C57Bl/6N mice a Western or standard diet over 48 weeks. Multiscale time-resolved characterization was performed using RNA-seq, histopathology, immunohistochemistry, intravital imaging, and blood chemistry; the results were compared to human disease. Acetaminophen toxicity and ammonia metabolism were additionally analyzed as functional readouts. We identified a sequence of eight key events: formation of lipid droplets; inflammatory foci; lipogranulomas; zonal reorganization; cell death and replacement proliferation; ductular reaction; fibrogenesis; and hepatocellular cancer. Functional changes included resistance to acetaminophen and altered nitrogen metabolism. The transcriptomic landscape was characterized by two large clusters of monotonously increasing or decreasing genes, and a smaller number of 'rest-and-jump genes' that initially remained unaltered but became differentially expressed only at week 12 or later. Approximately 30% of the genes altered in human NAFLD are also altered in the present mouse model and an increasing overlap with genes altered in human HCC occurred at weeks 30-48. In conclusion, the observed sequence of events recapitulates many features of human disease and offers a basis for the identification of therapeutic targets.


Subject(s)
Carcinoma, Hepatocellular/pathology , Diet, Western/adverse effects , Liver Neoplasms/pathology , Non-alcoholic Fatty Liver Disease/metabolism , Animals , Disease Models, Animal , Disease Progression , Liver/metabolism , Mice , Mice, Inbred C57BL
17.
Cell Rep ; 36(8): 109526, 2021 08 24.
Article in English | MEDLINE | ID: mdl-34433051

ABSTRACT

Epigenetic modifications (e.g. DNA methylation) in NAFLD and their contribution to disease progression and extrahepatic complications are poorly explored. Here, we use an integrated epigenome and transcriptome analysis of mouse NAFLD hepatocytes and identify alterations in glyoxylate metabolism, a pathway relevant in kidney damage via oxalate release-a harmful waste product and kidney stone-promoting factor. Downregulation and hypermethylation of alanine-glyoxylate aminotransferase (Agxt), which detoxifies glyoxylate, preventing excessive oxalate accumulation, is accompanied by increased oxalate formation after metabolism of the precursor hydroxyproline. Viral-mediated Agxt transfer or inhibiting hydroxyproline catabolism rescues excessive oxalate release. In human steatotic hepatocytes, AGXT is also downregulated and hypermethylated, and in NAFLD adolescents, steatosis severity correlates with urinary oxalate excretion. Thus, this work identifies a reduced capacity of the steatotic liver to detoxify glyoxylate, triggering elevated oxalate, and provides a mechanistic explanation for the increased risk of kidney stones and chronic kidney disease in NAFLD patients.


Subject(s)
Epigenome , Glyoxylates/metabolism , Hepatocytes/metabolism , Hyperoxaluria/metabolism , Non-alcoholic Fatty Liver Disease/metabolism , Transcriptome , Animals , Epigenomics , Gene Expression Profiling , Humans , Hyperoxaluria/genetics , Male , Mice , Mice, Obese , Non-alcoholic Fatty Liver Disease/genetics , Risk Factors
18.
Clin Cancer Res ; 27(8): 2148-2158, 2021 04 15.
Article in English | MEDLINE | ID: mdl-33542080

ABSTRACT

PURPOSE: Expression-based classifiers to predict pathologic complete response (pCR) after neoadjuvant chemotherapy (NACT) are not routinely used in the clinic. We aimed to build and validate a classifier for pCR after NACT. PATIENTS AND METHODS: We performed a prospective multicenter study (EXPRESSION) including 114 patients treated with anthracycline/taxane-based NACT. Pretreatment core needle biopsies from 91 patients were used for gene expression analysis and classifier construction, followed by validation in five external cohorts (n = 619). RESULTS: A 20-gene classifier established in the EXPRESSION cohort using a Youden index-based cut-off point predicted pCR in the validation cohorts with an accuracy, AUC, negative predictive value (NPV), positive predictive value, sensitivity, and specificity of 0.811, 0.768, 0.829, 0.587, 0.216, and 0.962, respectively. Alternatively, aiming for a high NPV by defining the cut-off point for classification based on the complete responder with the lowest predicted probability of pCR in the EXPRESSION cohort led to an NPV of 0.960 upon external validation. With this extreme-low cut-off point, a recommendation to not treat with anthracycline/taxane-based NACT would be possible for 121 of 619 unselected patients (19.5%) and 112 of 322 patients with luminal breast cancer (34.8%). The analysis of the molecular subtypes showed that the identification of patients who do not achieve a pCR by the 20-gene classifier was particularly relevant in luminal breast cancer. CONCLUSIONS: The novel 20-gene classifier reliably identifies patients who do not achieve a pCR in about one third of luminal breast cancers in both the EXPRESSION and combined validation cohorts.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Biomarkers, Tumor/genetics , Breast Neoplasms/therapy , Clinical Decision-Making/methods , Neoadjuvant Therapy/methods , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/diagnosis , Breast Neoplasms/genetics , Chemotherapy, Adjuvant/methods , Datasets as Topic , Female , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Humans , Mastectomy , Middle Aged , Neoplasm Staging , Oligonucleotide Array Sequence Analysis , Patient Selection , Predictive Value of Tests , Prognosis , Prospective Studies , Treatment Outcome
19.
Arch Toxicol ; 94(1): 205-217, 2020 01.
Article in English | MEDLINE | ID: mdl-31919559

ABSTRACT

Inflammation has been recognized as essential for restorative regeneration. Here, we analyzed the sequential processes during onset of liver injury and subsequent regeneration based on time-resolved transcriptional regulatory networks (TRNs) to understand the relationship between inflammation, mature organ function, and regeneration. Genome-wide expression and TRN analysis were performed time dependently in mouse liver after acute injury by CCl4 (2 h, 8 h, 1, 2, 4, 6, 8, 16 days), as well as lipopolysaccharide (LPS, 24 h) and compared to publicly available data after tunicamycin exposure (mouse, 6 h), hepatocellular carcinoma (HCC, mouse), and human chronic liver disease (non-alcoholic fatty liver, HBV infection and HCC). Spatiotemporal investigation differentiated lobular zones for signaling and transcription factor expression. Acute CCl4 intoxication induced expression of gene clusters enriched for inflammation and stress signaling that peaked between 2 and 24 h, accompanied by a decrease of mature liver functions, particularly metabolic genes. Metabolism decreased not only in pericentral hepatocytes that underwent CCl4-induced necrosis, but extended to the surviving periportal hepatocytes. Proliferation and tissue restorative TRNs occurred only later reaching a maximum at 48 h. The same upstream regulators (e.g. inhibited RXR function) were implicated in increased inflammation and suppressed metabolism. The concomitant inflammation/metabolism TRN occurred similarly after acute LPS and tunicamycin challenges, in chronic mouse models and also in human liver diseases. Downregulation of metabolic genes occurs concomitantly to induce inflammation-associated genes as an early response and appears to be initiated by similar upstream regulators in acute and chronic liver diseases in humans and mice. In the acute setting, proliferation and restorative regeneration associated TRNs peak only later when metabolism is already suppressed.


Subject(s)
Chemical and Drug Induced Liver Injury, Chronic/genetics , Gene Regulatory Networks , Hepatitis, Chronic/genetics , Animals , Carbon Tetrachloride/toxicity , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/metabolism , Hepatitis B/genetics , Hepatitis B/metabolism , Hepatitis, Chronic/physiopathology , Humans , Liver Cirrhosis/genetics , Liver Cirrhosis/metabolism , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Male , Mice, Inbred C57BL , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/metabolism , Signal Transduction/drug effects , Signal Transduction/genetics
20.
Genome Biol ; 20(1): 227, 2019 11 08.
Article in English | MEDLINE | ID: mdl-31699133

ABSTRACT

We present the software Condition-specific Regulatory Units Prediction (CRUP) to infer from epigenetic marks a list of regulatory units consisting of dynamically changing enhancers with their target genes. The workflow consists of a novel pre-trained enhancer predictor that can be reliably applied across cell types and species, solely based on histone modification ChIP-seq data. Enhancers are subsequently assigned to different conditions and correlated with gene expression to derive regulatory units. We thoroughly test and then apply CRUP to a rheumatoid arthritis model, identifying enhancer-gene pairs comprising known disease genes as well as new candidate genes.


Subject(s)
Enhancer Elements, Genetic , Software , Animals , Arthritis, Experimental/genetics , Arthritis, Rheumatoid/genetics , Chromatin Immunoprecipitation Sequencing , Histone Code , Mice
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