Laia Tolosa

Laia Tolosa
  • PhD
  • PostDoc Position at Instituto de Investigación Sanitaria La Fe

About

83
Publications
16,169
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3,272
Citations
Current institution
Instituto de Investigación Sanitaria La Fe
Current position
  • PostDoc Position

Publications

Publications (83)
Article
Full-text available
Drug-induced cholestasis is one of the major mechanisms implicated in drug-induced hepatotoxicity that poses a serious problem in terms of patient morbidity and mortality, healthcare system expenses and efficacy of newly developed drugs. Impaired bile acid homeostasis due to transporter alterations, hepatocellular injury or canalicular abnormalitie...
Article
Full-text available
The evolving landscape of chemical risk assessment is increasingly focused on developing tiered, mechanistically driven approaches that avoid the use of animal experiments. In this context, adverse outcome pathways have gained importance for evaluating various types of chemical-induced toxicity. Using hepatic steatosis as a case study, this review...
Article
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Liver tissue engineering offers a remarkable tool for toxicological screening and an approach to disease modeling, and provides an alternative solution to liver transplantation in treating end-stage liver diseases. As the liver is a highly specialized multicellular organ, distinctive features such as diversity of cell types, extracellular matrix co...
Article
Full-text available
Hepatotoxicity poses a significant concern in drug design due to the potential liver damage that can be caused by new drugs. Among common manifestations of hepatotoxic damage is lipid accumulation in hepatic tissue, resulting in liver steatosis or phospholipidosis. Carboxylic derivatives are prone to interfere with fatty acid metabolism and cause l...
Article
Hazard assessment (HA) requires toxicity tests to allow deriving protective points of departure (PoDs) for risk assessment irrespective of a compound's mode of action (MoA). The scope of in vitro test batteries (ivTB) thereby necessitated for systemic toxicity is still unclear. We explored the protectiveness regarding systemic toxicity of an ivTB w...
Article
Full-text available
Cell-based liver therapies based on retrieving and steadying failed metabolic function(s) for acute and chronic diseases could be a valuable substitute for liver transplants, even though they are limited by the low engraftment capability and reduced functional quality of primary human hepatocytes (PHH). In this paper we propose the use of gelatin-h...
Article
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Hepatotoxicity or drug-induced liver injury (DILI) is a major safety issue in drug development as a primary reason for drug failure in clinical trials and the main cause for post-marketing regulatory measures like drug withdrawal. Idiosyncratic DILI (iDILI) is a patient-specific, multifactorial, and multicellular process that cannot be recapitulate...
Article
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Background High-throughput pharmaco-toxicological testing frequently relies on the use of established liver-derived cell lines, such as HepG2 cells. However, these cells often display limited hepatic phenotype and features of neoplastic transformation that may bias the interpretation of the results. Alternate models based on primary cultures or dif...
Article
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Drug-induced liver injury (DILI) is a major clinical problem in terms of patient morbidity and mortality, cost to healthcare systems and failure of the development of new drugs. The need for consistent safety strategies capable of identifying a potential toxicity risk early in the drug discovery pipeline is key. Human DILI is poorly predicted in an...
Article
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...
Article
Full-text available
Clinical hepatocyte transplantation short-term efficacy has been demonstrated; however, some major limitations , mainly due to the shortage of organs, the lack of quality of isolated cells and the low cell engraftment after transplantation, should be solved for increasing its efficacy in clinical applications. Cellular stress during isolation cause...
Article
Full-text available
Drug-induced liver injury (DILI) is one of the most common and serious adverse drug reactions and a major cause of drug development failure and withdrawal. Although different molecular mechanisms are implicated in DILI, enhanced ROS levels have been described as a major mechanism. Human-derived cell models are increasingly used in preclinical safet...
Article
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Typical protocols to differentiate induced pluripotent stem cells (iPSCs) from hepatocyte-like cells (HLCs) imply complex strategies that include transfection with key hepatic transcription factors and the addition to culture media of nutrients, growth factors, and cytokines. A main constraint to evaluate the hepatic phenotype achieved arises from...
Article
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Nonalcoholic fatty liver disease (NAFLD) is now the leading cause of chronic liver disease in western countries. The molecular mechanisms leading to NAFLD are only partially understood, and effective therapeutic interventions are clearly needed. Therefore, preclinical research is required to improve knowledge about NAFLD physiopathology and to iden...
Article
This read-across case study characterises thirteen, structurally similar carboxylic acids demonstrating the application of in vitro and in silico human-based new approach methods, to determine biological similarity. Based on data from in vivo animal studies, the read-across hypothesis is that all analogues are steatotic and so should be considered...
Article
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Phenols are regarded as highly toxic chemicals. Their effects are difficult to study in in vitro systems because of their ambiguous fate (degradation, auto-oxidation and volatility). In the course of in vitro studies of a series of redox-cycling phenols, we found evidences of cross-contamination in several in vitro high-throughput test systems, in...
Article
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The liver plays an important role in xenobiotic metabolism and represents a primary target for toxic substances. Many different in vitro cell models have been developed in the past decades. In this study, we used RNA-sequencing (RNA-Seq) to analyze the following human in vitro liver cell models in comparison to human liver tissue: cancer-derived ce...
Article
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Drug-induced liver injury (DILI) remains a major cause of drug development failure, post-marketing warnings and restriction of use. An improved understanding of the mechanisms underlying DILI is required for better drug design and development. Enhanced reactive oxygen species (ROS) levels may cause a wide spectrum of oxidative damage, which has bee...
Chapter
The development of suitable and reproducible liver cell models is fundamental for regenerative medicine, drug screening, and disease modeling. Human primary hepatocytes are the gold standard not only for hepatic cell therapy but also for preclinical toxicological screening or the study of liver disease; however, their limited availability, variabil...
Article
Safety evaluation of thousands of chemicals that are directly added to or come in contact with food is needed. Due to the central role of the liver in intermediary and energy metabolism and in the biotransformation of foreign compounds, the hepatotoxicity assessment is essential. New approach methodologies have been proposed for the safety evaluati...
Article
Full-text available
The only curative treatment for severe end-stage liver disease (ESLD) is liver transplantation (LT) but it is limited by the shortage of organ donors. The increase of the incidence of liver disease has led to develop new therapeutic approaches such as liver cell transplantation. Current challenges that limit a wider application of this therapy incl...
Article
Full-text available
Clinical hepatocyte transplantation short-term efficacy has been demonstrated; however, some major limitations, mainly due to the shortage of organs, the lack of quality of isolated cells and the low cell engraftment after transplantation, should be solved for increasing its efficacy in clinical applications. Cellular stress during isolation causes...
Article
Full-text available
Background: Familial hypercholesterolemia type IIA (FH) is due to mutations in the low-density lipoprotein receptor (LDLR) resulting in elevated levels of low-density lipoprotein cholesterol (LDL-c) in plasma and in premature cardiovascular diseases. As hepatocytes are the only cells capable of metabolizing cholesterol, they are therefore the targ...
Article
Pluripotent stem cells have been investigated as a renewable source of therapeutic hepatic cells, in order to overcome the lack of transplantable donor hepatocytes. Whereas different studies were able to correct hepatic defects in animal models, they focused on the most mature phenotype of hepatocyte‐like cells (HLCs) derived from pluripotent stem...
Article
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Drug-induced liver injury (DILI) cannot be accurately predicted by animal models. In addition, currently available in vitro methods do not allow for the estimation of hepatotoxic doses or the determination of an acceptable daily intake (ADI). To overcome this limitation, an in vitro/in silico method was established that predicts the risk of human D...
Article
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Drug-induced liver injury (DILI) constitutes one of the most frequent reasons of restricted-use warnings as well as withdrawals of drugs in postmarketing and poses an important concern for the pharmaceutical industry. The current hepatic in vivo and in vitro models for DILI detection have shown clear limitations, mainly for studies of long-term hep...
Article
Drug-induced liver injury is a major cause of drug discovery failure in clinical trials and a leading cause of liver disease. Current preclinical drug testing does not predict hepatotoxicity which highlights the importance of developing highly predictive cell-based models. The use of stem cell technology and differentiation into hepatocyte-like cel...
Article
Full-text available
Drug-induced liver injury (DILI) has a considerable impact on human health and is a major challenge in drug safety assessments. DILI is a frequent cause of liver injury and a leading reason for post-approval drug regulatory actions. Considerable variations in the expression levels of both cytochrome P450 (CYP) and conjugating enzymes have been desc...
Chapter
Full-text available
Adult hepatocyte transplantation is limited by scarce availability of suitable donor liver tissue for hepatocyte isolation. New cell-based therapies are being developed to supplement whole-organ liver transplantation, to reduce the waiting-list mortality rate, and to obtain more sustained and significant metabolic correction. Fetal livers and unsui...
Chapter
Human hepatic cells have been used for drug safety risk evaluations throughout early development phases. They provide rapid, cost-effective early feedback to identify drug candidates with potential hepatotoxicity. This unit presents a cell-based assay to evaluate the risk of liver damage associated with steatogenic drugs. Detailed protocols for cel...
Article
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Background and Aims: Drug-induced steatosis is a major reason for drug failure in clinical trials and post-marketing withdrawal; and therefore, predictive biomarkers are essential. These could be particularly relevant in non-alcoholic fatty liver disease (NAFLD), where most patients show features of the metabolic syndrome and are prescribed with co...
Article
Determining long-term hepatotoxicity of new drugs is essential for the pharmaceutical industry development; however, it is limited by the lack of suitable cell-based models able to maintain hepatic functions over time. In the present work we explored the suitability of a new cellular model called Human Hepatocytes Upcytes (HHU) which preserves live...
Article
Introduction: The need for alternatives to animal experimentation and traditional testing methods has been widely discussed in recent years. This has led scientists and regulatory authorities to investigate alternative methods for toxicity testing. High-content screening (HCS) has emerged as a powerful tool in predictive toxicology since it permit...
Article
Introduction: Drug attrition rates due to hepatotoxicity are an important safety issue considered in drug development. The HepG2 hepatoma cell line is currently being used for drug-induced hepatotoxicity evaluations, but its expression of drug-metabolizing enzymes is poor compared with hepatocytes. Different approaches have been proposed to upgrad...
Article
Full-text available
Drug-induced liver injury (DILI) is a frequent cause of failure in both clinical and post-approval stages of drug development, and poses a key challenge to the pharmaceutical industry. Current animal models offer poor prediction of human DILI. Although several human cell-based models have been proposed for the detection of human DILI, human primary...
Article
The worldwide shortage of donor livers for organ and hepatocyte transplantation has prompted the search for alternative therapies for intractable liver diseases. Cell-based therapy is envisaged as a useful therapeutic option to recover and stabilize the lost metabolic function for acute liver failure, end-stage and congenital liver diseases, or for...
Article
The capacity of human hepatic cell-based models to predict hepatotoxicity depends on the functional performance of cells. The major limitations of human hepatocytes include the scarce availability and rapid loss of the hepatic phenotype. Hepatoma cells are readily available and easy to handle, but are metabolically poor compared with hepatocytes. R...
Article
Only a few in vitro assays have been proposed to evaluate the steatotic potential of new drugs. The present study examines the utility of HepaRG cells as a cell-based assay system for screening drug-induced liver steatosis. A high-content screening assay was run to evaluate multiple toxicity-related cell parameters in HepaRG cells exposed to 28 com...
Article
Drug-induced liver injury (DILI) is a significant leading cause of hepatic dysfunction, drug failure during clinical trials and post-market withdrawal of approved drugs. Many cases of DILI are unexpected reactions of an idiosyncratic nature that occur in a small group of susceptible individuals. Intensive research efforts have been made to understa...
Article
Full-text available
Background: Hepatic cell therapy has become a viable alternative to liver transplantation for life-threatening liver diseases. However, the supply of human hepatocytes is limited due to the shortage of suitable donor organs required to isolate high-quality cells. Human pluripotent stem cells reflect a potential renewable source for generating func...
Article
Hepatoma cell lines are frequently used as in vitro alternatives to primary human hepatocytes. Cell lines are characterized by their unlimited life span, stable phenotype, high availability, and easy handling. However, their major limitation is the lower expression of some metabolic activities compared with hepatocytes. HepG2 is a human hepatoma th...
Article
Cytotoxicity assays were among the first in vitro bioassay methods used to predict toxicity of substances to various tissues. In vitro cytotoxicity testing provides a crucial means for safety assessment and screening, and for ranking compounds. The choice of using a particular cytotoxicity assay technology may be influenced by specific research goa...
Article
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Crigler-Najjar type 1 disease is a rare inherited metabolic disease characterized by high levels of unconjugated bilirubin due to the complete absence of hepatic UDP-glucuronosyl transferase activity. Hepatocyte transplantation has been proposed as an alternative treatment for Crigler-Najjar syndrome, but is still limited by the quality, and the lo...
Article
High-content screening is the application of automated microscopy and image analysis to both cell biology and drug discovery. Over the last decade, this technique has emerged as a useful technology that allows the simultaneous measurement of different parameters at a single-cell level. Hepatotoxicity is a compelling reason for drug nonapprovals and...
Article
La lesión del hígado por fármacos es una de las causas principales de enfermedad hepática y de retirada del mercado de fármacos autorizados. Son varios los modelos de células hepáticas utilizados durante el desarrollo de fármacos para la valoración temprana de su seguridad. Los estudios basados en hepatocitos cultivados han contribuido al conocimie...
Chapter
Drug-induced liver injury is a significant leading cause of hepatic dysfunction, drug failures during clinical trials and post-market withdrawal of approved drugs. Hepatotoxicity may result from either the drug itself or, more frequently, the bioactivation process and the production of reactive metabolites. Evaluation of potential hepatotoxicity re...
Article
Introduction: The liver is the most important target for drug-induced toxicity. This vulnerability results from functional liver features and its role in the metabolic elimination of most drugs. Drug-induced liver injury is a significant leading cause of acute, chronic liver disease and an important safety issue when developing new drugs. Areas c...
Article
Full-text available
Hepatocyte transplantation is an alternative therapy to orthotopic liver transplantation for the treatment of liver diseases. However, the supply of hepatocytes is limited given the shortage of organs available to isolate good-functioning quality cells. Neonatal livers may be a potential source alternative to adult livers to obtain good-performing...
Article
A frequent mechanism for drug-induced liver injury (DILI) is mitochondrial impairment, and early evaluation of new drugs for their potential to cause mitochondrial dysfunction is becoming an important task for drug development. To this end, we designed a high-content screening assay to study mitochondrial-induced hepatotoxicity in HepG2 cells in de...
Article
Full-text available
Vascular endothelial growth factor (VEGF), originally described as a factor with a regulatory role in vascular growth and development, it is also known for its direct effects on neuronal cells. The discovery in the past decade that transgenic mice expressing reduced levels of VEGF developed late-onset motoneuron pathology, reminiscent of amyotrophi...
Article
Mango (Mangifera indica L.) stem bark extract (MSBE) is a natural product with biological properties and mangiferin is the major component. This paper reported the evaluation of the protective effects of MSBE and mangiferin against the toxicity induced in HepG2 cells by tert-butyl hydroperoxide or amiodarone. Nuclear morphology, cell viability, int...
Article
No consensus exists on how to address possible toxicity of nanomaterials as they interfere with most in vitro screening tests based on colorimetric and fluorimetric probes such as the dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay for detection of oxidative species. In the present research, nanomaterial interaction with DCFH-DA was studied...
Chapter
Mesenchymal stem cells (MSCs) are multipotent cells, able to differentiate into elements of the mesodermal lineage. Bone marrow and adipose tissue represent the main sources for MSCs isolation. In the last decade, several studies have reported the plasticity of MSCs toward a hepatocyte-like phenotype. Both types of cells have been cultured under si...
Article
Use of the HepG2 cell line to assess hepatotoxicity induced by bioactivable compounds is hampered by their low cytochrome P450 expression. To overcome this limitation, we have used adenoviral transfection to develop upgraded HepG2 cells (ADV-HepG2) expressing the major P450 enzymes involved in drug metabolism (CYP1A2, CYP2D6, CYP2C9, CYP2C19, and C...
Article
The chemical synthesis of 4-N-carboxybutyl-5-fluorocytosine (II) in solution phase starting from 5-fluorocytosine and the solid phase synthesis of Arg-Gln-Trp-Arg-Arg-Trp-Trp-Gln-Arg-NH(2) attached to the 4-N-carboxybutyl-5-fluorocytosine residue at the N-terminus of the peptide (III) via peptide bond formation is reported. The target compound exhi...
Article
Full-text available
Hepatotoxicity is a major reason for drug nonapprovals and withdrawals. The multiparametric analysis of xenobiotic toxicity at the single cells level using flow cytometry and cellular imaging-based approaches, such as high-content screening (HCS) technology, could play a key role in the detection of toxicity and the classification of compounds base...
Article
Full-text available
BM-21 is an extract obtained from Thalassia testudinum marine plant with pharmacological properties. The effects of BM-21 and thalassiolin B (TB), its main component, on enzyme and transport proteins involved in drug metabolism and excretion in human cultured hepatocytes were evaluated. Cells were exposed for 48h to sub-cytotoxic concentrations of...
Article
Full-text available
Triglyceride accumulation in nonalcoholic fatty liver (NAFL) results from unbalanced lipid metabolism which, in the liver, is controlled by several transcription factors. The Foxa subfamily of winged helix/forkhead box (Fox) transcription factors comprises three members which play important roles in controlling both metabolism and homeostasis throu...
Data
Full-text available
List of primers used for quantitative RT-PCR. (PDF)
Data
Full-text available
Microarray expression analysis of lipid and carbohydrate metabolism genes altered by Foxa1 in human liver cells. (PDF)
Article
In a number of adverse drug reactions leading to hepatotoxicity, drug metabolism is thought to be involved by the generation of reactive metabolites from non-toxic drugs. The use of hepatoma cell lines, such as HepG2 cell line, for the evaluation of drug-induced hepatotoxicity is hampered by their low cytochrome P450 expression which makes impossib...
Article
Full-text available
In the present study, we developed a cell-based protocol for the identification of drugs able to induce steatosis. The assay measures multiple markers of toxicity in a 96-well plate format using high-content screening (HCS) technology. After treating HepG2 cells with increasing concentrations of the tested compounds, toxicity parameters were analyz...
Article
Alternative and/or complementary sources of cells such as hepatic progenitor cells (HPC) are under investigation for hepatic cell therapy purposes. Steatotic livers are those most commonly rejected for clinical transplantation and are also unsuitable for good quality hepatocyte isolation. Taken together these two facts, our aim was to investigate w...
Article
Storage of human hepatocytes is essential for their use in research and liver cell transplantation. However, cryopreservation and thawing (C/T) procedures have detrimental effects on the viability and functionality compared with fresh cells. The aim of this study was to upgrade the standard C/T methodology to obtain better quality hepatocytes for c...
Article
Besides glutamate excitotoxicity, the neuroinflammatory response is emerging as a relevant contributor to motoneuron loss in amyotrophic lateral sclerosis (ALS). In this regard, high levels of circulating proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) have been shown both in human patients and in animal models of ALS. The aim...
Article
The 6th European Framework Programme project LIINTOP was specifically raised to optimise and provide established protocols and experimental in vitro models for testing intestinal and liver absorption, metabolism and toxicity of molecules of pharmacological interest. It has been focused on some of the most promising existing liver and intestine in v...
Article
Full-text available
The accumulation of reactive microglia in the degenerating areas of amyotrophic lateral sclerosis (ALS) tissue is a key cellular event creating a chronic inflammatory environment that results in motoneuron death. We have developed a new culture system that consists in rat spinal cord embryonic explants in which motoneurons migrate outside the expla...
Article
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective degeneration and death of motoneurons in the spinal cord, brainstem and motor cortex which causes progressive muscle weakness and paralysis. Although the molecular mechanisms causing the disease remain unknown, excitotoxicity and loss of trophic suppor...
Article
Proinflammatory cytokines and pathogen components activate microglia to release several substances such as nitric oxide (NO) produced after the induction of type II nitric oxide synthase (iNOS). The present study was designed to elucidate the interaction between the proinflammatory cytokines interferon gamma (IFN-gamma) and tumor necrosis factor al...
Article
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective death of motoneurons. Recently, vascular endothelial growth factor (VEGF) has been identified as a neurotrophic factor and has been implicated in the mechanisms of pathogenesis of ALS and other neurological diseases. The potential neuroprotective effec...
Article
Wasting of skeletal muscle (cachexia) is associated with a variety of chronic or inflammatory disorders and has long been recognized as a poor prognostic sign. It is currently accepted that the cytokine tumor necrosis factor alpha (TNF-alpha; cachectin) plays a key role in the development of this condition. TNF-alpha-induced apoptotic cell death re...

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