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Novel human liver-tropic AAV variants define transferable domains that markedly enhance the human tropism of AAV7 and AAV8.

Recent clinical successes have intensified interest in using adeno-associated virus (AAV) vectors for therapeutic gene delivery. The liver is a key clinical target, given its critical physiological functions and involvement in a wide range of genetic diseases. Here, we report the bioengineering of a set of next-generation AAV vectors, named AAV-SYDs (where "SYD" stands for Sydney, Australia), with increased human hepato-tropism in a liver xenograft mouse model repopulated with primary human hepatocytes. We followed a two-step process that staggered directed evolution and domain-swapping approaches. Using DNA-family shuffling, we first mapped key AAV capsid regions responsible for efficient human hepatocyte transduction in vivo. Focusing on these regions, we next applied domain-swapping strategies to identify and study key capsid residues that enhance primary human hepatocyte uptake and transgene expression. Our findings underscore the potential of AAV-SYDs as liver gene therapy vectors and provide insights into the mechanism responsible for their enhanced transduction profile.

AAV

Selection and evaluation of clinically relevant AAV variants in a xenograft liver model.

Recombinant adeno-associated viral (rAAV) vectors have shown early promise in clinical trials. The therapeutic transgene cassette can be packaged in different AAV capsid pseudotypes, each having a unique transduction profile. At present, rAAV capsid serotype selection for a specific clinical trial is based on effectiveness in animal models. However, preclinical animal studies are not always predictive of human outcome. Here, in an attempt to further our understanding of these discrepancies, we used a chimaeric human-murine liver model to compare directly the relative efficiency of rAAV transduction in human versus mouse hepatocytes in vivo. As predicted from preclinical and clinical studies, rAAV2 vectors functionally transduced mouse and human hepatocytes at equivalent but relatively low levels. However, rAAV8 vectors, which are very effective in many animal models, transduced human hepatocytes rather poorly-approximately 20 times less efficiently than mouse hepatocytes. In light of the limitations of the rAAV vectors currently used in clinical studies, we used the same murine chimaeric liver model to perform serial selection using a human-specific replication-competent viral library composed of DNA-shuffled AAV capsids. One chimaeric capsid composed of five different parental AAV capsids was found to transduce human primary hepatocytes at high efficiency in vitro and in vivo, and provided species-selected transduction in primary liver, cultured cells and a hepatocellular carcinoma xenograft model. This vector is an ideal clinical candidate and a reagent for gene modification of human xenotransplants in mouse models of human diseases. More importantly, our results suggest that humanized murine models may represent a more precise approach for both selecting and evaluating clinically relevant rAAV serotypes for gene therapeutic applications.

Animals

[Criteria selection for the preliminary evaluation of the efficacy of antihypoxic agents].

Mathematical description is suggested of oxygen consumption by mitochondria suspension in the presence of orto-benzoquinone derivatives. An analysis of the equations obtained, in vivo conditions taken into account, has shown that the efficiency of hydrogen consumption is mainly determined by the constant value of oxidation rate of quinone reduced form, poorely depends on the substrate concentration and activity of quinone-reducing enzymes. The constant value of oxidation rate may serve as a criterion of directed synthesis of antihypoxants.

Drug Evaluation, Preclinical

Long-term efficacy of tubercidin against schistosomiasis japonica and mansoni in primates.

Schistosomiasis japonica in capuchin msnkeys (Cebus apella) and schistosomiasis mansoni in baboons (Papio cyanocephalus and P. hamadryas) were completely arrested for 6 months in every infected primate receiving a single treatment with tubercidin (Tu), administered after prior absorption into 20% of their red cells. It is very likely that a single treatment with Tu sequestered in only 15% of the hosts' red cells would also be 100% effective for prolonged periods of time, but that with lower doses some relapses would be expected. Babbons with patent Schistosoma mansoni infections were rechallenged with S. mansoni cercariae 4 months after treatment with Tu. Although Tu eliminated almost all the sexually mature female worms from the primary infection but spared most of the males for continuing sojourn within their hosts, the baboons retained their full susceptibility to reinfection, as indicated by worm burdens and fecal egg excretion. However, the granulomatous reaction in the rechallenged Tu-treated baboons to new masses of eggs trapped in their livers appeared to be less intense than was seen in animals with primary infections.

Animals

3D Cell Culture Models as a Platform for Studying Tumor Progression, Testing Treatment Responses, and Discovering Biomarkers.

In this chapter, we present a detailed protocol for establishing a three-dimensional (3D) multicellular tumor spheroids (MCTSs) model to simulate the tumor microenvironment (ME) associated with metabolic dysfunction-associated steatotic liver disease (MASLD) for the study of hepatocellular carcinoma (HCC) and colorectal cancer (CRC) cell aggressiveness, growth, and metastasis potential. The MASLD microenvironment (MASLD-ME) is recreated by embedding hepatic stellate cells in a collagen I matrix within a Boyden chamber system. The metabolic medium mimics MASLD conditions, enriched with high glucose, fructose, insulin, and fatty acids, to simulate metabolic stresses associated with the disease.In the protocol, cancer cells are loaded in the upper compartment to analyze their migration toward the MASLD-ME, thereby facilitating studies on cancer cell invasiveness and metastatic capacity. This method offers an adaptable, reproducible model to research disease progression and investigate therapeutic interventions, contributing to preclinical research on MASLD-related liver cancer pathophysiology and potential drug responses.

Humans

Hepatocyte suspensions and cultures as tools in experimental carcinogenesis.

Isolation of preneoplastic cell populations would greatly facilitate analysis of the development of liver carcinogenesis. Suspensions of intact single cells can be prepared in an almost quantitative yield by two-step perfusion of the isolated liver. In the first step the liver is perfused with a Ca2+-free buffer (or with EGTA) in order to irreversibly cleave the desmosomes; in the second step perfusion with Ca2+-activated collagenase dissolves the collagenous extracellular matrix. The resulting single-cell suspension will be a mixture of intact normal and preneoplastic hepatocytes, other liver cell types (mostly Kupffer and endothelial cells), damaged cells, and subcellular debris. Intact hepatocytes can be purified--e.g., by differential centrifugation--but separation of preneoplastic from normal cells has not yet been achieved. Density gradient separation or selection in culture on the basis of the unique properties of preneoplastic hepatocytes (e.g., drug resistance) may prove useful. The use of hepatocyte cultures and liver-derived epithelial cell lines as test systems and models for chemical carcinogenesis in vitro is briefly reviewed.

Animals

Modulation of metabolic, inflammatory and fibrotic pathways by semaglutide in metabolic dysfunction-associated steatohepatitis.

Metabolic dysfunction-associated steatohepatitis (MASH) is a chronic liver disease strongly associated with cardiometabolic risk factors. Semaglutide, a glucagon-like peptide-1 receptor agonist, improves liver histology in MASH, but the underlying signals and pathways driving semaglutide-induced MASH resolution are not well understood. Here we show that, in two preclinical MASH models, semaglutide improved histological markers of fibrosis and inflammation and reduced hepatic expression of fibrosis-related and inflammation-related gene pathways. Aptamer-based proteomic analyses of serum samples from patients with MASH in a clinical trial identified 72 proteins significantly associated with MASH resolution and semaglutide treatment, with most related to metabolism and several implicated in fibrosis and inflammation. An independent real-world cohort verified the pathophysiological relevance of this signature, showing that the same 72 proteins are differentially expressed in patients with MASH relative to healthy individuals. Taken together, these data suggest that semaglutide may revert the circulating proteome associated with MASH to the proteomic pattern observed in healthy individuals.

Humans

A brief history of gene therapy for ornithine transcarbamylase deficiency.

Gene therapy encompasses the use of nucleic acids, including DNA and RNA, as therapeutic agents. This broad category includes approaches that permanently modify the genome to correct pathogenic variants, as well as strategies that restore gene expression without altering genomic DNA. In ornithine transcarbamylase (OTC) deficiency, the most common urea cycle disorder, the goal of somatic gene therapy is to restore hepatic expression of functional OTC enzyme and thereby reestablish urea cycle activity. Both viral and non-viral delivery platforms have been investigated in preclinical models and clinical studies to achieve therapeutic OTC expression. Despite contemporary medical therapy, individuals with OTC deficiency (OTCD) remain at risk for recurrent hyperammonemia which may result in neurocognitive impairment and reduced quality of life. Novel therapy that restores liver OTC expression and lessens chronic disease burden is highly desired. In this manuscript, we summarize the history of gene therapy development for OTC deficiency, spanning early preclinical investigations to contemporary clinical trials. Although a definitive cure through gene therapy has not yet been achieved, substantial progress has been made toward the development of safe and effective liver-directed nucleic acid therapeutics for this disorder.

Adeno-associated virus vector

Advances in Precision Editing Therapies for Alpha-1 Antitrypsin Deficiency.

Genome and RNA editing modalities have revolutionized precision gene therapy, offering a safer alternative to traditional gene replacement approaches. Alpha-1 antitrypsin deficiency (AATD) is a compelling model for precision medicine because the disease mechanism is well defined-mutations in a single gene are responsible for both liver and lung pathology. In this review, we summarize the current preclinical and clinical efforts for AATD, with an emphasis on genome and RNA editing strategies.

Humans

The use of the rat in the experimental investigation of the porphyrias.

The patterns of urinary porphyria excretion and hepatic porphyrin accumulation in hexachlorobenzene-treated rats is similar to that observed in overt porphyria cutanea tarda and may be attributed to a decrease in activity of hepatic uroporphyrinogen (UROGEN) decarboxylase. The 3.5 diethoxycarbonyl-1,4-dihydrocollidine (DDC)-treated rat has been evaluated as a model to test the porphyrinogenicity of drugs.

Animals

Intestinal blood vessel-associated macrophages and gut-vascular barrier dysfunction in cirrhosis.

BACKGROUND: Bacterial translocation in cirrhosis can trigger infection and hepatic decompensation, leading to systemic inflammation, organ failure and increased mortality. These infections often originate from the gastrointestinal tract after bacteria breach the intestinal barrier and disseminate to systemic sites. OBJECTIVE: In this study, we explore the mechanisms underlying intestinal barrier dysfunction in cirrhosis using an experimental cirrhosis model and patient-derived intestinal biopsies. DESIGN: We developed a murine model of cirrhosis through chronic administration of carbon tetrachloride for up to 20 weeks. We investigated both the intestinal epithelial and vascular compartments and performed single-cell transcriptomic profiling of myeloid cells isolated from cirrhotic mice and from individuals with compensated and decompensated cirrhosis. RESULTS: Our findings indicate that bacterial translocation in cirrhosis is the result of failure at multiple checkpoints, including aberrant epithelial cell death, vascular barrier damage and dysfunction of gut-vascular macrophages. In a preclinical model of cirrhosis, macrophages exhibited increased levels of monocyte-attracting chemokines, reduced bacterial clearance and impaired interactions with blood vessels. Importantly, depleting vascular-lining macrophages resulted in bacterial translocation to systemic sites, even in the absence of experimental liver disease. Transcriptional profiling of macrophages from duodenal biopsies of patients with cirrhosis indicated similar dysregulation of pathways supporting blood vessels and elevated expression of chemokines. CONCLUSIONS: This study emphasises the critical role of intestinal macrophages in preventing the dissemination of luminal bacteria and highlights the multifaceted breakdown of the intestinal barrier in cirrhosis and the importance of the gut-vascular barrier.

Animals

Effects of phytosterols supplementation on hepatic lipid metabolism and metabolic outcomes in obese rodent models: a systematic review and meta-analysis.

This study aimed to synthesize and quantitatively assess the available evidence on the effects of phytosterol supplementation on hepatic lipid metabolism and obesity-related metabolic outcomes in obese rodent models, integrating biochemical, histological, and molecular evidence. A systematic search was conducted in electronic databases (PubMed, EMBASE, and Web of Science). Data on study design, population, intervention, outcomes, and risk of bias were extracted and analyzed. A quantitative meta-analysis was performed. Meta-analysis showed reductions in body weight, serum triglycerides, total cholesterol, LDL-C, VLDL-C, glucose, liver weight, hepatic cholesterol, hepatic triglycerides, and nonalcoholic fatty liver disease activity score. No significant changes were observed for adiposity index, HDL-C, insulin, or hepatic expression of PPARα, FAS, and SREBP1c. Conversely, CPT1A expression was significantly increased following PS supplementation. Subgroup analyses indicated that the beneficial effects on lipid and hepatic outcomes were generally consistent across rodent species (mice, rats, and hamsters), obesity induction models, and routes of administration, although the magnitude of responses varied between strains, with C57BL/6 mice showing more pronounced metabolic improvements. Additional analyses suggested that treatment duration and phytosterol composition may modulate specific outcomes, whereas dose-response meta-regression identified dose-dependent associations for serum and hepatic cholesterol, and PPARα expression in dietary supplementation studies. Overall, the available preclinical evidence suggests that phytosterol supplementation may improve several metabolic and hepatic outcomes in rodent models of obesity. However, the substantial heterogeneity across studies highlights the need for standardized experimental protocols and future clinical studies before these findings can be translated to human health.

Animals

Scorpion venom peptides: Novel therapeutic approaches for inflammatory and hepatic disorders.

Chronic hepatic disorders, such as metabolic dysfunction associated steatohepatitis (MASH), alcohol associated liver disease (ALD), and viral hepatitis (Hepatitis B virus [HBV]/Hepatitis C virus [HCV]), are primarily driven by persistent immune-mediated inflammation and hepatic stellate cell activation leading to fibrosis, yet conventional therapies lack tissue and molecular specificity. Scorpion venom peptides, refined through evolutionary selection, provide highly potent, target specific scaffolds capable of modulating intrahepatic inflammatory networks. Recent in vivo preclinical studies indicate that voltage gated potassium (Kv1.3) channel blocking peptides, such as BmKK2, significantly reduce macrophage activation and inhibit downstream cytokine production, effectively ameliorating diet-induced steatohepatitis and tissue scarring in murine models. Engineered hepatotropic candidates, such as Smp76 and Mucroporin-M1, demonstrate dual therapeutic functions: they neutralize extracellular Hepatitis C particles and suppress key host transcription factors necessary for Hepatitis B replication. This review systematically examines scorpion venom peptides organized by disease category, covering their historical development, structural classification into disulfide-bridged and non-disulfide-bridged families, ion channel specificity, hepatic anti-inflammatory and antiviral mechanisms, and translational challenges including nano-formulation delivery strategies and computational drug design. These target-specific peptides are ultimately positioned as promising molecular leads that may bridge targeted immunomodulation with the resolution of chronic, progressive liver injury.

Anti-inflammatory effects

An adjuvant database for preclinical evaluation of vaccines and immunotherapeutics.

Adjuvants are immunostimulators used to enhance vaccine efficacy against infectious diseases. However, current methods for evaluating their efficacy and safety are limited, hindering large-scale screening. To address this, we developed a prototype Adjuvant Database (ADB) containing transcriptome data, generated using the same protocols as the widely used Open TG-GATEs (OTG) toxicogenomics database, covering 25 adjuvants across multiple species, organs, time points, and doses. This enabled cross-database integration of ADB and OTG. Transcriptomic patterns successfully distinguished each adjuvant regardless of organs or species. Using both databases, we built machine learning models to predict adjuvanticity and hepatotoxicity. Notably, we identified colchicine's adjuvant activity and FK565's liver toxicity through data-driven analysis. Overall, ADB combined with OTG offers a framework for transcriptomics-based, data-driven screening of adjuvant candidates.

Animals

[A modified screening model for potential cancerostatics by i.v. application of L 1210 ascites cells (author's transl)].

Intravenous application of L 1210 ascites cells failed to produce generalized leukemias. The treated animals died after 6-7 days within a short interval time, revealing the picture of massive tumor cell infiltrations in liver and spleen. Using histological and autoradiographical methods it has been established that the primary processes of ascites cell proliferations occur in liver and spleen. The tested reference substances, cytosine arabinoside and cyclophosphamide, showed in this modified model the same effects as after intraperitoneal application. The extremely short death interval of the control animals makes possible a more precise distinction between the death curves of control and test groups.

Animals