Animal Models of Human Pathology: Revision, Relevance and Refinements (3rd Edition)

A special issue of Biomedicines (ISSN 2227-9059). This special issue belongs to the section "Molecular and Translational Medicine".

Deadline for manuscript submissions: closed (31 March 2025) | Viewed by 24454

Special Issue Editor


E-Mail Website
Guest Editor
Institute of Pathology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
Interests: challenges in animal model research; translation; unbiased reporting of animal model characteristics and results; ethical justification
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The use of animal models of human pathology is accepted on the assumption that it benefits humans. However, recent publications have shown that research on animals faces serious challenges. The increasing number of potential targets, molecular pathways or treatment strategies, which have been recognized as promising in animal models, have failed when translated into human trials. We have reached the point where the clinical relevance of animal models needs urgent clarification.

Multiple methodological problems in animal research have already been exposed, such as poor experimental design, inadequate use of fundamental statistical principles (i.e., randomization, blinding, inadequate power, inadequate sample size, pseudo-replication, etc.) and nontransparent reporting, which results in low scientific validity and irreproducibility of results. However, research on animal models also requires comprehensive knowledge about the model, as well as an understanding of the complex pathogenesis of diseases, which involves both local and systemic effects in the body. Every animal model has its own characteristics, advantages and limitations. There are factors specific to the disease or animal model that can influence not only the severity of the disease but also underlying mechanisms, and, when these factors are not taken into account, research may result in the discovery of new targets and disease pathways that are of no scientific or clinical value. There are also animal-model-specific factors that can seriously affect the results and lead to false conclusions and failed translation. Although the overall animal health and welfare issues—such as animal clinical state, morbidity, mortality, humane endpoints and humane interventions, whole body necropsy findings, sampling principles and pathohistological diagnosis—are of vital importance in the interpretation of the molecular mechanisms or treatment strategies in an organism, this information is usually lacking or rarely properly addressed in animal model studies.

The purpose of this Special Issue is thus to promote the submissions of high-quality papers of basic research using animal models to understand diseases and underlying mechanisms or to investigate new treatment strategies in various human diseases such as cancer, bowel diseases, kidney injury, Parkinson’s disease, etc. New approaches towards the use of animal models or refinements of particular animal models of human pathology as well as methodological and welfare principles (such as experimental design and welfare or supportive measures in animal models) are also welcome.

Dr. Martina Perše
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Biomedicines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • animal models
  • biomarkers
  • human disease
  • pathology
  • translation
  • mechanisms
  • nephrology
  • gastroenterology
  • urology
  • neuroscience
  • cancer
  • experimental design
  • reproducibility
  • refinements

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

Related Special Issues

Published Papers (11 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Editorial

Jump to: Research, Review

6 pages, 206 KiB  
Editorial
Animal Models of Human Pathology: Revision, Relevance and Refinements
by Martina Perše
Biomedicines 2024, 12(11), 2418; https://doi.org/10.3390/biomedicines12112418 - 22 Oct 2024
Viewed by 2663
Abstract
Animal Models of Human Pathology [...] Full article

Research

Jump to: Editorial, Review

21 pages, 3504 KiB  
Article
Genotype-Based Housing as a Potential Confounder in Studies Using Transgenic Mouse Models—Insight from the A53T Mouse Model of Parkinson’s Disease
by Olga Dubljević, Miodrag Dragoj, Milica Potrebić Stefanović, Maja Srbovan, Miloš Stanojlović and Željko Pavković
Biomedicines 2025, 13(6), 1506; https://doi.org/10.3390/biomedicines13061506 - 19 Jun 2025
Viewed by 295
Abstract
Background/Objectives: Environmental factors, including the differences in genotype-based housing (GbH), can act as confounding variables in studies using transgenic mouse models, potentially influencing experimental outcomes and limiting their reproducibility and translational value. Despite the widespread use of transgenic models in preclinical studies, [...] Read more.
Background/Objectives: Environmental factors, including the differences in genotype-based housing (GbH), can act as confounding variables in studies using transgenic mouse models, potentially influencing experimental outcomes and limiting their reproducibility and translational value. Despite the widespread use of transgenic models in preclinical studies, the extent to which housing conditions can affect the behavioral and molecular parameters of interest remains poorly understood. This study aims to investigate how different GbH conditions influence visuo-spatial memory and gene expression in the A53T mouse model (JAX006823) of Parkinson’s disease (PD) during the pre-motor phase. Methods: A53T+ transgenic male mice and their non-transgenic littermates (A53T−) were housed in either mixed-genotype (MGH) or single-genotype (SGH) environments from postnatal day (PND) 30, with C57BL/6J mice serving as the controls. A behavioral assessment using the Novel Object Recognition and Object Location Tests was conducted at PND 180, followed by a qPCR analysis of Iba1, Gfapα, Bdnf, Tnfα, Il-1β, and Il-6 expression in the medial prefrontal cortex and the hippocampus. Results: The variations in GbH influenced behavior and mRNA expression differently in the A53T+ and A53T− animals. Specifically, the A53T− mice in SGH environments displayed behavioral and molecular profiles similar to the C57BL/6J controls, while the same was not evident in the MGH environments. In the A53T+ mice, the mRNA expression of Iba1, Gfapα, Bdnf, and Tnfα was sensitive to variations in GbH, while memory impairment was not. Conclusions: This study highlights the importance of considering environmental factors in studies using transgenic animal models. The obtained data suggests that GbH can influence the parameters of interest in preclinical research, implicating the need for the optimization of future study designs. Full article
Show Figures

Figure 1

19 pages, 2909 KiB  
Article
Optimization, Characterization and Pharmacological Validation of the Endotoxin-Induced Acute Pneumonitis Mouse Model
by Emese Ritter, Kitti Hohl, László Kereskai, Ágnes Kemény, Dóra Hargitai, Veronika Szombati, Anikó Perkecz, Eszter Pakai, Andras Garami, Ákos Zsembery, Zsuzsanna Helyes and Kata Csekő
Biomedicines 2025, 13(6), 1498; https://doi.org/10.3390/biomedicines13061498 - 18 Jun 2025
Viewed by 397
Abstract
Background/Objectives: In preclinical research of airway inflammation, the endotoxin (lipopolysaccharide: LPS)–induced acute interstitial pneumonitis is the most commonly used mechanism model. However, studies apply different LPS serotypes, doses, administration routes, and reference compounds, making result interpretation challenging and drawing conclusions difficult. Therefore, [...] Read more.
Background/Objectives: In preclinical research of airway inflammation, the endotoxin (lipopolysaccharide: LPS)–induced acute interstitial pneumonitis is the most commonly used mechanism model. However, studies apply different LPS serotypes, doses, administration routes, and reference compounds, making result interpretation challenging and drawing conclusions difficult. Therefore, here we aimed to optimize, characterize, and validate this model with dexamethasone in mice. Methods: Pneumonitis was induced by intratracheal LPS (0.25, 1, 2.5, 5 mg/kg; E. coli O111:B4) in C57BL/6J and NMRI mice; controls received phosphate-buffered saline (PBS). Dexamethasone (5 mg/kg i.p.) was used as a positive control. Respiratory functions were measured by restrained plethysmography 24 h after induction, and core body temperature was monitored. Lungs were excised and weighed, and then myeloperoxidase (MPO) activity and histopathological analysis were performed to assess pulmonary inflammation. Results: LPS-induced significant body weight loss, perivascular pulmonary edema, MPO activity increase, neutrophil infiltration, and respiratory function impairment in a dose-independent manner. However, LPS-induced hypothermia dynamics and duration were dose-dependent. The inhibitory effects of the reference compound dexamethasone were only detectable in the case of the 0.25 mg/kg LPS dose on most inflammatory parameters. These results did not differ substantially between C57BL/6J and NMRI mouse strains. Conclusions: Very low doses of LPS induce characteristic functional and morphological inflammatory alterations in the lung, which do not worsen in response to even 20 times higher doses. Since the effect of pharmacological interventions is likely to be detectable in the case of the 0.25 mg/kg LPS dose, we suggest this protocol for testing novel anti-inflammatory agents. Full article
Show Figures

Graphical abstract

23 pages, 8378 KiB  
Article
Immunogenicity of RSV Fusion Protein Adsorbed to Non-Pathogenic Bacillus subtilis Spores: Implications for Mucosal Vaccine Delivery in Nonclinical Animal Models
by Jianying Xiao, Hao Wang, Cheryl Callahan, Gregory O’Donnell, Silveria Rodriguez, Ryan P. Staupe, Carl J. Balibar and Michael P. Citron
Biomedicines 2025, 13(5), 1112; https://doi.org/10.3390/biomedicines13051112 - 3 May 2025
Viewed by 665
Abstract
Background/Objectives: Mucosal vaccines are rare but commercially desirable because of their real and theoretical biological advantages. Spores and vegetative forms from Bacillus have been used as probiotics due to their stability under various environmental conditions, including heat, gastric acidity, and moisture. Preclinical [...] Read more.
Background/Objectives: Mucosal vaccines are rare but commercially desirable because of their real and theoretical biological advantages. Spores and vegetative forms from Bacillus have been used as probiotics due to their stability under various environmental conditions, including heat, gastric acidity, and moisture. Preclinical studies have shown that Bacillus subtilis (B. subtilis) spores can serve as effective mucosal adjuvants. Our study aimed to evaluate B. subtilis spores as a mucosal adjuvant. Methods and Results: We demonstrate in rodents that the fusion protein (F) from respiratory syncytial virus (RSV), when combined with either heat-inactivated or live B. subtilis spores, elicits robust IgG binding and neutralizes antibody titers following both systemic and intranasal administration in mice. The spores facilitate TH-1 and local IgA responses, which could enhance antiviral protection. However, this vaccine failed to elicit measurable antibodies when immunized using a strict intranasal administration method in cotton rats. Conclusions: Our findings illustrate the differing immune responses between the two rodent species, highlighting the need for the careful consideration of validated methods when evaluating intranasal vaccines in preclinical studies. Full article
Show Figures

Figure 1

16 pages, 4839 KiB  
Article
Differential Effects of Canonical Androgens and 11-Ketotestosterone on Reproductive Phenotypes and Folliculogenesis in Mouse Model of PCOS
by Yi-Ru Tsai, Yen-Nung Liao, Cheng-Ju Tsai, Yu-Ang Lee, Shih-Min Hsia, Kuo-Chung Lan and Hong-Yo Kang
Biomedicines 2025, 13(5), 1077; https://doi.org/10.3390/biomedicines13051077 - 29 Apr 2025
Viewed by 525
Abstract
Background: Polycystic ovary syndrome (PCOS) is a common female endocrine disorder characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. While canonical androgens like testosterone (T) and dihydrotestosterone (DHT) are well studied in PCOS pathophysiology, the role of 11-ketotestosterone (11KT) remains unclear. [...] Read more.
Background: Polycystic ovary syndrome (PCOS) is a common female endocrine disorder characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. While canonical androgens like testosterone (T) and dihydrotestosterone (DHT) are well studied in PCOS pathophysiology, the role of 11-ketotestosterone (11KT) remains unclear. This study investigates the differential effects of these androgens on folliculogenesis, ovulation, and steroidogenesis using in vivo and in vitro models. Methods: Four-week-old female C57BL/6 mice received T, DHT, or 11KT for six weeks. The assessments included body weight, estrous cyclicity, serum hormone profiles, ovarian histology, and follicle classification. In parallel, large preantral follicles were cultured with each androgen to evaluate follicle growth, antrum formation, and ovulation capacity. Androgen receptor (AR) signaling and steroidogenic function were analyzed using western blotting, RT-qPCR, and luciferase reporter assays. Results: The DHT-treated mice exhibited increased weight gain, whereas 11KT-treated mice showed reduced weight gain. T and DHT disrupted the estrous cycle, while 11KT prolonged diestrus. All androgen treatments led to ovarian morphological changes, including follicular arrest and cystic features. In vitro, all androgens enhanced follicle growth, but only T and DHT inhibited ovulation. The AR expression was elevated across all androgen-treated groups, but only DHT significantly activated AR and CYP19A1 promoters. Conclusions: 11KT induces a distinct and milder PCOS-like phenotype compared to classical androgens, promoting follicle growth with minimal impact on ovulation or steroidogenic disruption. These findings underscore the heterogeneity of PCOS and suggest that different androgen profiles may drive diverse clinical phenotypes. By elucidating the distinct roles of different androgens, this may lead to better stratification of PCOS phenotypes based on predominant androgen types for more precise diagnosis and individualized management. Full article
Show Figures

Figure 1

13 pages, 2016 KiB  
Article
Analysis of Intervertebral Disc Degeneration Induced by Endplate Drilling or Needle Puncture in Complement C6-Sufficient and C6-Deficient Rabbits
by Amelie Kuhn, Markus Huber-Lang, Sebastian Weckbach, Jana Riegger, Graciosa Q. Teixeira, Volker Rasche, Jörg Fiedler, Cornelia Neidlinger-Wilke and Rolf E. Brenner
Biomedicines 2024, 12(8), 1692; https://doi.org/10.3390/biomedicines12081692 - 30 Jul 2024
Viewed by 962
Abstract
Previous studies indicate an implication of the terminal complement complex (TCC) in disc degeneration (DD). To investigate the functional role of TCC in trauma-induced DD in vivo, the model of endplate (EP) drilling was first applied in rabbits using a C6-deficient rabbit strain [...] Read more.
Previous studies indicate an implication of the terminal complement complex (TCC) in disc degeneration (DD). To investigate the functional role of TCC in trauma-induced DD in vivo, the model of endplate (EP) drilling was first applied in rabbits using a C6-deficient rabbit strain in which no TCC formation was possible. In parallel the model of needle puncture was investigated. Using a minimally invasive surgical intervention, lumbar rabbit intervertebral discs (IVDs) were treated with EP drilling or needle puncture. Degenerative effects of both surgical interventions were assessed by Pfirrmann grading and T2 quantification of the IVDs based on high-resolution MRI (11.7 T), as well as radiographic determination of disc height index. Pfirrmann grading indicated significant degenerative effects after EP drilling. Contrary to our assumption, no evidence was found that the absence of TCC formation in C6-deficient rabbits reduces the development of DD compared to C6-sufficient animals. EP drilling was proven to be suitable for application in rabbits. However, results of the present study do not provide clear evidence of a central functional role of TCC within DD and suggest that TCC deposition in DD patients may be primarily considered as a marker of complement activation during DD progression. Full article
Show Figures

Figure 1

19 pages, 3954 KiB  
Article
Evidence-Based Severity Assessment of Animal Models for Pancreatic Cancer
by Tim Schreiber, Ingo Koopmann, Jakob Brandstetter, Steven R. Talbot, Lea Goldstein, Lisa Hoffmann, Anna Schildt, Markus Joksch, Bernd Krause, Robert Jaster, Rupert Palme, Dietmar Zechner, Brigitte Vollmar and Simone Kumstel
Biomedicines 2024, 12(7), 1494; https://doi.org/10.3390/biomedicines12071494 - 5 Jul 2024
Cited by 1 | Viewed by 1937
Abstract
Animal models are crucial to preclinical oncological research and drug development. Animal experiments must be performed in accordance with the 3R principles of replacement and reduction, if possible, and refinement where these procedures remain crucial. In addition, European Union legislations demand a continuous [...] Read more.
Animal models are crucial to preclinical oncological research and drug development. Animal experiments must be performed in accordance with the 3R principles of replacement and reduction, if possible, and refinement where these procedures remain crucial. In addition, European Union legislations demand a continuous refinement approach, as well as pro- and retrospective severity assessment. In this study, an objective databased severity assessment was performed in murine models for pancreatic cancer induced by orthotopic, subcutaneous, or intravenous injection of Panc02 cells. Parameters such as body weight change, distress score, perianal temperature, mouse grimace scale, burrowing, nesting behavior, and the concentration of corticosterone in plasma and its metabolites in feces were monitored during tumor progression. The most important parameters were combined into a score and mapped against a reference data set by the Relative Severity Assessment procedure (RELSA) to obtain the maximum achieved severity for each animal (RELSAmax). This scoring revealed a significantly higher RELSAmax for the orthotopic model than for the subcutaneous and intravenous models. However, compared to animal models such as pancreatitis and bile duct ligation, the pancreatic cancer models are shown to be less severe. Data-based animal welfare assessment proved to be a valuable tool for comparing the severity of differently induced cancer models. Full article
Show Figures

Figure 1

Review

Jump to: Editorial, Research

58 pages, 2896 KiB  
Review
Epigenetic Modifications in the Retinal Pigment Epithelium of the Eye During RPE-Related Regeneration or Retinal Diseases in Vertebrates
by Eleonora Grigoryan and Yuliya Markitantova
Biomedicines 2025, 13(7), 1552; https://doi.org/10.3390/biomedicines13071552 - 25 Jun 2025
Viewed by 144
Abstract
The retinal pigment epithelium (RPE) is a cellular source of retinal regeneration in lower vertebrates and a cellular source of retinal diseases in mammals, including humans. Both processes are based on a genetic program for the conversion of RPE cells into cells of [...] Read more.
The retinal pigment epithelium (RPE) is a cellular source of retinal regeneration in lower vertebrates and a cellular source of retinal diseases in mammals, including humans. Both processes are based on a genetic program for the conversion of RPE cells into cells of other phenotypes: neural in the first case and mesenchymal in the second. RPE reprogramming in the neural direction is realized in tailed amphibians and bird embryos in vivo, but in higher vertebrates and humans, this process is realized in vitro. Epigenetic regulation determines the phenotypic plasticity of RPE cells, i.e., their choice of the cell differentiation pathway in animals of different classes. It has been suggested that the implementation of the genetic program for RPE reprogramming into different types of retinal neurons in adult amphibians and birds at the early stages of embryogenesis is conditioned by the specificity of the epigenetic landscape. The retinal RPE-dependent pathologies in mammals are characterized by different epigenetic signatures, and have a shared characteristic: specifically, a deficient epigenetic landscape (dysregulations in DNA methylation and histone modifications). Knowledge of the patterns and features of the epigenetic regulation of RPE cell behavior will allow us to obtain RPE cells that are in demand in medicine, from direct reprogramming with the possibility of epigenetically maintaining the cellular identities to the creation of neuro-regenerative technologies for the replacement therapy of RPE-dependent retinal pathologies in humans. Full article
Show Figures

Figure 1

19 pages, 3045 KiB  
Review
The Chicken Embryo: An Old but Promising Model for In Vivo Preclinical Research
by Annachiara Sarnella, Ylenia Ferrara, Cristina Terlizzi, Sandra Albanese, Serena Monti, Luca Licenziato and Marcello Mancini
Biomedicines 2024, 12(12), 2835; https://doi.org/10.3390/biomedicines12122835 - 13 Dec 2024
Viewed by 3229
Abstract
The chicken embryo has emerged as a valuable model for preclinical studies due to its unique combination of accessibility, affordability, and relevance to human biology. Its rapid development, external growth environment, and clear structural visibility offer distinct advantages over traditional mammalian models. These [...] Read more.
The chicken embryo has emerged as a valuable model for preclinical studies due to its unique combination of accessibility, affordability, and relevance to human biology. Its rapid development, external growth environment, and clear structural visibility offer distinct advantages over traditional mammalian models. These features facilitate the study of real-time biological processes, including tissue development, tumor growth, angiogenesis, and drug delivery, using various imaging modalities, such as optical imaging, magnetic resonance imaging, positron emission tomography, computed tomography, and ultrasound. The chicken embryo model also minimizes ethical concerns compared to mammalian models, as it allows for early-stage research without the complexity of a fully developed animal. Moreover, its ability to integrate human tumor cells into xenograft models provides a reliable platform for cancer research, enabling high-throughput screening of therapeutic interventions and tracking molecular dynamics in vivo. Advances in molecular imaging techniques further enhance the resolution and depth of data obtained from these studies, offering insights into cellular and molecular mechanisms underlying disease. Given its versatility, cost-effectiveness, and translational potential, the chicken embryo represents a promising tool for advancing preclinical research, particularly in drug development, cancer biology, and regenerative medicine. Full article
Show Figures

Figure 1

27 pages, 1416 KiB  
Review
Primary Bone Tumors and Breast Cancer-Induced Bone Metastases: In Vivo Animal Models and New Alternative Approaches
by Argia Ucci, Luca Giacchi and Nadia Rucci
Biomedicines 2024, 12(11), 2451; https://doi.org/10.3390/biomedicines12112451 - 25 Oct 2024
Cited by 3 | Viewed by 7940
Abstract
Bone is the preferential site of metastasis for the most common tumors, including breast cancer. On the other hand, osteosarcoma is the primary bone cancer that most commonly occurs and causes bone cancer-related deaths in children. Several treatment strategies have been developed so [...] Read more.
Bone is the preferential site of metastasis for the most common tumors, including breast cancer. On the other hand, osteosarcoma is the primary bone cancer that most commonly occurs and causes bone cancer-related deaths in children. Several treatment strategies have been developed so far, with little or no efficacy for patient survival and with the development of side effects. Therefore, there is an urgent need to develop more effective therapies for bone primary tumors and bone metastatic disease. This almost necessarily requires the use of in vivo animal models that better mimic human pathology and at the same time follow the ethical principles for the humane use of animal testing. In this review we aim to illustrate the main and more suitable in vivo strategies employed to model bone metastases and osteosarcoma. We will also take a look at the recent technologies implemented for a partial replacement of animal testing. Full article
Show Figures

Figure 1

31 pages, 4261 KiB  
Review
Preclinical Models of Hepatocellular Carcinoma: Current Utility, Limitations, and Challenges
by Antonio Cigliano, Weiting Liao, Giovanni A. Deiana, Davide Rizzo, Xin Chen and Diego F. Calvisi
Biomedicines 2024, 12(7), 1624; https://doi.org/10.3390/biomedicines12071624 - 22 Jul 2024
Cited by 6 | Viewed by 4033
Abstract
Hepatocellular carcinoma (HCC), the predominant primary liver tumor, remains one of the most lethal cancers worldwide, despite the advances in therapy in recent years. In addition to the traditional chemically and dietary-induced HCC models, a broad spectrum of novel preclinical tools have been [...] Read more.
Hepatocellular carcinoma (HCC), the predominant primary liver tumor, remains one of the most lethal cancers worldwide, despite the advances in therapy in recent years. In addition to the traditional chemically and dietary-induced HCC models, a broad spectrum of novel preclinical tools have been generated following the advent of transgenic, transposon, organoid, and in silico technologies to overcome this gloomy scenario. These models have become rapidly robust preclinical instruments to unravel the molecular pathogenesis of liver cancer and establish new therapeutic approaches against this deadly disease. The present review article aims to summarize and discuss the commonly used preclinical models for HCC, evaluating their strengths and weaknesses. Full article
Show Figures

Figure 1

Back to TopTop