Animal Models of Human Disease 3.0

Background: Animal studies remain fundamental to cardiovascular drug and device development, yet their ability to predict human responses is increasingly being questioned. The US Food and Drug Administration (FDA)’s April 2025 roadmap supports alternative testing approaches that strategically reduce animal use while increasing human relevance by combining laboratory methods, computer simulations, and artificial intelligence. This review examines AI-enabled alternative methodologies for cardiovascular safety assessment within established validation frameworks and regulatory acceptance programs. We describe machine learning approaches for predicting cardiac safety risks, automated analysis of human heart cells, and patient-specific computer simulations for evaluating medical devices. These tools can improve our understanding of biological mechanisms, focus limited animal studies on critical questions, and accelerate decision-making. Regulatory acceptance requires rigorous validation appropriate to each specific use and decision context. Conclusion: We outline practical steps for establishing credibility, including transparent data documentation, independent testing, and identifying where models can be reliably applied, and identify remaining challenges in data standardization and regulatory readiness. With ongoing alignment between regulators, standards bodies, and product developers, these alternative approaches could significantly reduce reliance on animal testing in cardiovascular research while maintaining or improving the quality of evidence. Full article

Cytochrome P450, family 7, subfamily b, polypeptide 1 (CYP7B1) is a widely expressed enzyme involved in the hydroxylation of sterols. Generated by transposon technology in zygotes, male rats lacking Cyp7b1 expression in homozygosis showed an absence of Cyp7b1 mRNA expression in the liver, small intestine, adipose tissue, and muscle. Elevated levels of 25-hydroxycholesterol were found in the liver of mutant rats. After overnight fasting, plasma triglyceride (TG) levels were increased in the homozygous rats. In agreement with this, increased hepatic secretion of very-low-density lipoprotein-TG (VLDL) in fasting rats treated with tyloxapol and decreased low-density receptor protein (LDLr) on the hepatocyte plasma membranes were observed. The decrease in LDLr was not due to decreased mRNA expression but to increased expressions of its proteases (Psck9 and Mylip). RNA sequencing identified Fasn, Igfbp2, and Pcsk9 as targets of the Cyp7b1 absence. However, the hepatic protein contents of IGFBP2 were increased in Cyp7b1-deficient rats, accompanied by a normal glucose tolerance test. HepG2 cells lacking CYP7B1 showed increased expressions of FASN and IGFBP2. These results suggest a role of CYP7B1 in the control of hepatic IGFBP2 and VLDL-TG secretion as a prediabetes sign exerted through 25-hydroxycholesterol and transcriptional or translational mechanisms depending on the species. Full article

Diabetes remains a global health challenge, characterized by persistent hyperglycemia and gradual depletion or impairment of pancreatic β-cells. Current treatments focus on managing glycemic control, but do not mitigate β-cell mass. Verapamil, an FDA-approved calcium channel blocker for hypertension, has shown potential therapeutic action towards β-cells in the context of diabetes. In this study, we investigated the cytoprotective and metabolic efficacy of verapamil on mouse-derived MIN6 β-cells under metabolic and diabetogenic stressors like high glucose, toxins, and an inflammatory cytokine cocktail, as well as investigated a zebrafish model. At safe, non-toxic doses, verapamil elevated the levels of cholecystokinin (CCK), an incretin associated with β-cell preservation and enhanced mitochondrial respiration. Notably, pretreatment and co-treatment of verapamil in the presence of stressors offered substantial protection and preserved mitochondrial function, whereas post-treatment effects were moderate and model dependent. In the zebrafish model, verapamil promoted β-cell recovery and regeneration before, during, and after targeted ablation. The drug seemed to work in several ways: inducing proliferation, reducing stress on β cells, boosting their energy production, and activating survival signals. Together, our data aligned with earlier human clinical trials showing that verapamil administration preserved β-cell mass and function in patients with recent-onset type 1 diabetes. The high efficacy, affordability, and broad mechanisms of action make verapamil a desirable therapeutic candidate for diabetes. Nevertheless, further mechanistic studies and long-term clinical trials are warranted to establish its utility in diabetes management. Full article

Percocypris pingi is an endangered protected fish species in China. Its albino variants exhibit growth retardation and physiological abnormalities. Understanding its albinism mechanism holds significant scientific importance for molecular breeding programs and disease model development. This study integrated transcriptomic and proteomic analyses, combined with histopathological and molecular biological techniques, to systematically compare molecular differences in skin tissues between albino and wild-type P. pingi, with a focus on elucidating the multidimensional regulatory mechanisms underlying skin albinism. Our findings suggest that albinism in P. pingi is synergistically driven by hyperactivation of ubiquitin-mediated proteolysis (which suppressed TYR/TYRP1 enzymatic activity and disrupted the pH homeostasis of melanosomes), and inhibition of calcium signaling (which impeded melanin transport). This discovery provides novel insights into the mechanisms of pigment loss in fish species and offers a valuable reference for molecular breeding of endangered species as well as research on pigmentation-related disorders. Full article

Background: Type 2 diabetes (T2D), the most common form of diabetes, is associated with a significantly elevated risk of cardiovascular and cerebrovascular complications. However, circulating metabolic signatures that reliably predict the transition to insulin resistance, and are potentially linked to increased vascular risk, remain incompletely characterized. Rodent models, particularly those induced by a high-fat diet (HFD) combined with low-dose streptozotocin (STZ), are widely used to study the progression of T2D. However, the systemic metabolic shifts associated with this model, especially at the plasma level, are poorly defined. Methods: In this study, we performed untargeted liquid chromatography–mass spectrometry (LC-MS)-based metabolomic profiling on plasma samples from control, HFD-only (obese, insulin-sensitive), and HFD + STZ (obese, insulin-resistant) C57BL/6 mice. Results: In the HFD + STZ cohort, plasma profiles showed a global shift toward lipid classes; depletion of aromatic and branched-chain amino acids (BCAAs); accumulation of phenylalanine-derived co-metabolites, consistent with gut–liver axis dysregulation; elevations in glucose, fructose-6-phosphate, and nucleoside catabolites, indicating impaired glucose handling and heightened nucleotide turnover; increased free fatty acids, reflecting membrane remodeling and lipotoxic stress; and higher cAMP, thyroxine, hydrocortisone, and uric acid, consistent with endocrine and redox imbalance. By contrast, HFD-only mice exhibited elevations in aromatic amino acids and BCAAs relative to controls, a pattern compatible with early obesity-associated adaptation while insulin signaling remained partially preserved. KEGG analysis revealed disturbances in carbohydrate metabolism, amino acid degradation, nucleotide turnover, and hormone-related pathways, and HMDB mapping linked these changes to T2D, obesity, heart failure, and renal dysfunction. Conclusion: Collectively, these findings delineate insulin resistance-specific plasma signatures of metabolic inflexibility and inflammatory stress in the HFD + STZ model, distinguishing it from HFD alone and supporting its utility for mechanistic studies and biomarker discovery. Importantly, this plasma metabolomics study shows that insulin-sensitive and insulin-resistant states exhibit distinct variation in circulating metabolites and cardiovascular risk factors, underscoring the translational value of plasma profiling. Full article

In chronic kidney disease (CKD) research, animal models such as the unilateral ureteral obstruction (UUO) rodent model are crucial to understanding disease progression, particularly renal fibrosis. Despite its widespread use, the molecular mechanisms driving CKD remain incompletely understood. Given the interplay between metabolism and fibrosis, a comprehensive metabolomic analysis of UUO renal tissue is necessary. This study involved untargeted multiplatform analysis using liquid chromatography (LC), gas chromatography (GC), and capillary electrophoresis (CE) coupled with mass spectrometry (MS) to examine murine kidney tissue from the UUO model. The results highlight metabolic changes associated with tubulointerstitial fibrosis, which affect pathways such as the tricarboxylic acid (TCA) cycle, the urea cycle, and lipid metabolism. In particular, fibrosis impacts the lipidomic profile, with decreases in most lipid classes and increases in specific glycerophospholipids, hexosylceramides, and cholesterol esters. These findings demonstrate the value of a multiplatform approach in elucidating metabolic alterations in CKD, providing information on the underlying molecular mechanisms and paving the way for further research. Full article

Patient-derived xenograft (PDX) models are powerful tools in cancer research, offering an accurate platform for evaluating cancer treatment efficacy and predicting responsiveness. However, these models necessitate surgical techniques for tumor tissue transplantation and face challenges with non-uniform tumor growth among animals. To address these issues, we attempted to develop a new PDX modeling method using high-grade serous ovarian cancer (HGSC), a fatal disease with a 5-year survival rate of 29%, which requires personalized research due to its morphological, genetic, and molecular heterogeneities. In this study, we developed a new patient-derived cancer cell xenograft (PDCX) model with high engraftment efficiency (64%) that utilizes primary cancer cells instead of patient tissues. Primary cancer cells can be stably cryopreserved for extended periods (up to 485 days), and when transplanted into female NSGA mice, they maintain morphological and molecular characteristics without significant genetic differences compared to their original primary tumors. Furthermore, PDCX models can be easily produced using a syringe, allowing for uniform tumor sizes across multiple animals. Additionally, M2 PDCXs exhibited a significantly faster growth rate compared to M2 PDTXs. Consequently, our PDCX model offers a streamlined approach for evaluating personalized cancer treatments with minimal experimental variability. Full article