CRISPR/Cas9-Mediated Mutation of αA-Crystallin Gene Induces Congenital Cataracts in Rabbits

Through the Cat-Map Gateway: A Brief History of Cataract Genetics

Clouding of the transparent eye lens, or cataract(s), is a leading cause of visual impairment that requires surgical replacement with a synthetic intraocular lens to effectively restore clear vision. Most frequently, cataract is acquired with aging as a multifactorial or complex trait. Cataract may also be inherited as a classic Mendelian trait-often with an early or pediatric onset-with or without other ocular and/or systemic features. Since the early 1990s, over 85 genes and loci have been genetically associated with inherited and/or age-related forms of cataract. While many of these underlying genes-including those for lens crystallins, connexins, and transcription factors-recapitulate signature features of lens development and differentiation, an increasing cohort of unpredicted genes, including those involved in cell-signaling, membrane remodeling, and autophagy, has emerged-providing new insights regarding lens homeostasis and aging. This review provides a brief history of gene discovery for inherited and age-related forms of cataract compiled in the Cat-Map database and highlights potential gene-based therapeutic approaches to delay, reverse, or even prevent cataract formation that may help to reduce the increasing demand for cataract surgery.

Proteostatic Remodeling of Small Heat Shock Chaperones─Crystallins by Ran-Binding Protein 2─and the Peptidyl-Prolyl cis-trans Isomerase and Chaperone Activities of Its Cyclophilin Domain

Disturbances in protein phase transitions promote protein aggregation─a neurodegeneration hallmark. The modular Ran-binding protein 2 (Ranbp2) is a cytosolic molecular hub for rate-limiting steps of phase transitions of Ran-GTP-bound protein ensembles exiting nuclear pores. Chaperones also regulate phase transitions and proteostasis by suppressing protein aggregation. Ranbp2 haploinsufficiency promotes the age-dependent neuroprotection of the chorioretina against phototoxicity by proteostatic regulations of neuroprotective substrates of Ranbp2 and by suppressing the buildup of polyubiquitylated substrates. Losses of peptidyl-prolyl cis-trans isomerase (PPIase) and chaperone activities of the cyclophilin domain (CY) of Ranbp2 recapitulate molecular effects of Ranbp2 haploinsufficiency. These CY impairments also stimulate deubiquitylation activities and phase transitions of 19S cap subunits of the 26S proteasome that associates with Ranbp2. However, links between CY moonlighting activity, substrate ubiquitylation, and proteostasis remain incomplete. Here, we reveal the Ranbp2 regulation of small heat shock chaperones─crystallins in the chorioretina by proteomics of mice with total or selective modular deficits of Ranbp2. Specifically, loss of CY PPIase of Ranbp2 upregulates αA-Crystallin, which is repressed in adult nonlenticular tissues. Conversely, impairment of CY's chaperone activity opposite to the PPIase pocket downregulates a subset of αA-Crystallin's substrates, γ-crystallins. These CY-dependent effects cause age-dependent and chorioretinal-selective declines of ubiquitylated substrates without affecting the chorioretinal morphology. A model emerges whereby inhibition of Ranbp2's CY PPIase remodels crystallins' expressions, subdues molecular aging, and preordains the chorioretina to neuroprotection by augmenting the chaperone capacity and the degradation of polyubiquitylated substrates against proteostatic impairments. Further, the druggable Ranbp2 CY holds pan-therapeutic potential against proteotoxicity and neurodegeneration.

Unraveling the role of Xist in X chromosome inactivation: insights from rabbit model and deletion analysis of exons and repeat A

X chromosome inactivation (XCI) is a process that equalizes the expression of X-linked genes between males and females. It relies on Xist, continuously expressed in somatic cells during XCI maintenance. However, how Xist impacts XCI maintenance and its functional motifs remain unclear. In this study, we conducted a comprehensive analysis of Xist, using rabbits as an ideal non-primate model. Homozygous knockout of exon 1, exon 6, and repeat A in female rabbits resulted in embryonic lethality. However, X∆ReAX females, with intact X chromosome expressing Xist, showed no abnormalities. Interestingly, there were no significant differences between females with homozygous knockout of exons 2-5 and wild-type rabbits, suggesting that exons 2, 3, 4, and 5 are less important for XCI. These findings provide evolutionary insights into Xist function.

Knockout of TGF-β receptor II by CRISPR/Cas9 delays mesenchymal transition of Lens epithelium and posterior capsule opacification

Posterior capsule opacification (PCO) is the most common postoperative complication of cataract surgery. Transforming growth factor-β (TGF-β) is related to epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) that is proven to induce PCO formation in clinical and experimental studies. In this study, CRISPR sequences targeting exon of TGF-βRII were knocked out with lentiviral transfection in LECs. Rabbits' PCO model was established and recombinant adeno-associated virus (AAV) for transferring the gRNA of TGF βRII were intravitreally injected. SgRNA inhibited TGF-βRII expression and human LECs proliferation. In TGF-βRII knockout group, LECs motility and migration were suppressed, N-cadherin and vimentin expressions were significantly decreased, whereas E-cadherin was increased. The animal model showed that TGF-βRII knockout in vivo was effective in suppressing PCO. The current study suggested that the CRISPR/Cas9 endonuclease system could suppress TGF-βRII secretion, which participates in the EMT procedure of LECs in vitro and PCO in vivo. These findings might provide a new gene-editing approach and insight into a novel therapeutic strategy for PCO.

CRISPR/Cas9 Genome Editing for Tissue-Specific In Vivo Targeting: Nanomaterials and Translational Perspective

Clustered randomly interspaced short palindromic repeats (CRISPRs) and its associated endonuclease protein, i.e., Cas9, have been discovered as an immune system in bacteria and archaea; nevertheless, they are now being adopted as mainstream biotechnological/molecular scissors that can modulate ample genetic and nongenetic diseases via insertion/deletion, epigenome editing, messenger RNA editing, CRISPR interference, etc. Many Food and Drug Administration-approved and ongoing clinical trials on CRISPR adopt ex vivo strategies, wherein the gene editing is performed ex vivo, followed by reimplantation to the patients. However, the in vivo delivery of the CRISPR components is still under preclinical surveillance. This review has summarized the nonviral nanodelivery strategies for gene editing using CRISPR/Cas9 and its recent advancements, strategic points of view, challenges, and future aspects for tissue-specific in vivo delivery of CRISPR/Cas9 components using nanomaterials.

YIPF5 (p.W218R) mutation induced primary microcephaly in rabbits

Primary microcephaly (PMCPH) is a rare autosomal recessive neurodevelopmental disorder with a global prevalence of PMCPH ranging from 0.0013% to 0.15%. Recently, a homozygous missense mutation in YIPF5 (p.W218R) was identified as a causative mutation of severe microcephaly. In this study, we constructed a rabbit PMCPH model harboring YIPF5 (p.W218R) mutation using SpRY-ABEmax mediated base substitution, which precisely recapitulated the typical symptoms of human PMCPH. Compared with wild-type controls, the mutant rabbits exhibited stunted growth, reduced head circumference, altered motor ability, and decreased survival rates. Further investigation based on model rabbit elucidated that altered YIPF5 function in cortical neurons could lead to endoplasmic reticulum stress and neurodevelopmental disorders, interference of the generation of apical progenitors (APs), the first generation of progenitors in the developing cortex. Furthermore, these YIPF5-mutant rabbits support a correlation between unfolded protein responses (UPR) induced by endoplasmic reticulum stress (ERS), and the development of PMCPH, thus providing a new perspective on the role of YIPF5 in human brain development and a theoretical basis for the differential diagnosis and clinical treatment of PMCPH. To our knowledge, this is the first gene-edited rabbit model of PMCPH. The model better mimics the clinical features of human microcephaly than the traditional mouse models. Hence, it provides great potential for understanding the pathogenesis and developing novel diagnostic and therapeutic approaches for PMCPH.

The application and progression of CRISPR/Cas9 technology in ophthalmological diseases

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated nuclease (Cas) system is an adaptive immune defence system that has gradually evolved in bacteria and archaea to combat invading viruses and exogenous DNA. Advances in technology have enabled researchers to enhance their understanding of the immune process in vivo and its potential for use in genome editing. Thus far, applications of CRISPR/Cas9 genome editing technology in ophthalmology have included gene therapy for corneal dystrophy, glaucoma, congenital cataract, Leber's congenital amaurosis, retinitis pigmentosa, Usher syndrome, fundus neovascular disease, proliferative vitreoretinopathy, retinoblastoma and other eye diseases. Additionally, the combination of CRISPR/Cas9 genome editing technology with adeno-associated virus vector and inducible pluripotent stem cells provides further therapeutic avenues for the treatment of eye diseases. Nonetheless, many challenges remain in the development of clinically feasible retinal genome editing therapy. This review discusses the development, as well as mechanism of CRISPR/Cas9 and its applications and challenges in gene therapy for eye diseases.

International Harmonization of Nomenclature and Diagnostic Criteria (INHAND): Nonproliferative and Proliferative Lesions of the Rabbit

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions Project (www.toxpath.org/inhand.asp) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and non-proliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in most tissues and organs from the laboratory rabbit used in nonclinical safety studies. Some of the lesions are illustrated by color photomicrographs. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous lesions as well as lesions induced by exposure to test materials. Relevant infectious and parasitic lesions are included as well. A widely accepted and utilized international harmonization of nomenclature for lesions in laboratory animals will provide a common language among regulatory and scientific research organizations in different countries and increase and enrich international exchanges of information among toxicologists and pathologists.

CRISPR-Cas9: A Preclinical and Clinical Perspective for the Treatment of Human Diseases

At present, the idea of genome modification has revolutionized the modern therapeutic research era. Genome modification studies have traveled a long way from gene modifications in primary cells to genetic modifications in animals. The targeted genetic modification may result in the modulation (i.e., either upregulation or downregulation) of the predefined gene expression. Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated nuclease 9 (Cas9) is a promising genome-editing tool that has therapeutic potential against incurable genetic disorders by modifying their DNA sequences. In comparison with other genome-editing techniques, CRISPR-Cas9 is simple, efficient, and very specific. This enabled CRISPR-Cas9 genome-editing technology to enter into clinical trials against cancer. Besides therapeutic potential, the CRISPR-Cas9 tool can also be applied to generate genetically inhibited animal models for drug discovery and development. This comprehensive review paper discusses the origin of CRISPR-Cas9 systems and their therapeutic potential against various genetic disorders, including cancer, allergy, immunological disorders, Duchenne muscular dystrophy, cardiovascular disorders, neurological disorders, liver-related disorders, cystic fibrosis, blood-related disorders, eye-related disorders, and viral infection. Finally, we discuss the different challenges, safety concerns, and strategies that can be applied to overcome the obstacles during CRISPR-Cas9-mediated therapeutic approaches.

Genetically Modified Rabbits for Cardiovascular Research

Rabbits are one of the most used experimental animals for investigating the mechanisms of human cardiovascular disease and lipid metabolism because they are phylogenetically closer to human than rodents (mice and rats). Cholesterol-fed wild-type rabbits were first used to study human atherosclerosis more than 100 years ago and are still playing an important role in cardiovascular research. Furthermore, transgenic rabbits generated by pronuclear microinjection provided another means to investigate many gene functions associated with human disease. Because of the lack of both rabbit embryonic stem cells and the genome information, for a long time, it has been a dream for scientists to obtain knockout rabbits generated by homologous recombination-based genomic manipulation as in mice. This obstacle has greatly hampered using genetically modified rabbits to disclose the molecular mechanisms of many human diseases. The advent of genome editing technologies has dramatically extended the applications of experimental animals including rabbits. In this review, we will update genetically modified rabbits, including transgenic, knock-out, and knock-in rabbits during the past decades regarding their use in cardiovascular research and point out the perspectives in future.

Gene Editing in Rabbits: Unique Opportunities for Translational Biomedical Research

The rabbit is a classic animal model for biomedical research, but the production of gene targeted transgenic rabbits had been extremely challenging until the recent advent of gene editing tools. More than fifty gene knockout or knock-in rabbit models have been reported in the past decade. Gene edited (GE) rabbit models, compared to their counterpart mouse models, may offer unique opportunities in translational biomedical research attributed primarily to their relatively large size and long lifespan. More importantly, GE rabbit models have been found to mimic several disease pathologies better than their mouse counterparts particularly in fields focused on genetically inherited diseases, cardiovascular diseases, ocular diseases, and others. In this review we present selected examples of research areas where GE rabbit models are expected to make immediate contributions to the understanding of the pathophysiology of human disease, and support the development of novel therapeutics.

Genome engineering technologies in rabbits

The rabbit has been recognized as a valuable model in various biomedical and biological research fields because of its intermediate size and phylogenetic proximity to primates. However, the technology for precise genome manipulations in rabbit has been stalled for decades, severely limiting its applications in biomedical research. Novel genome editing technologies, especially CRISPR/Cas9, have remarkably enhanced precise genome manipulation in rabbits, and shown their superiority and promise for generating rabbit models of human genetic diseases. In this review, we summarize the brief history of transgenic rabbit technology and the development of novel genome editing technologies in rabbits.

CRISPR-Cas systems: Overview, innovations and applications in human disease research and gene therapy

Genome editing is the modification of genomic DNA at a specific target site in a wide variety of cell types and organisms, including insertion, deletion and replacement of DNA, resulting in inactivation of target genes, acquisition of novel genetic traits and correction of pathogenic gene mutations. Due to the advantages of simple design, low cost, high efficiency, good repeatability and short-cycle, CRISPR-Cas systems have become the most widely used genome editing technology in molecular biology laboratories all around the world. In this review, an overview of the CRISPR-Cas systems will be introduced, including the innovations, the applications in human disease research and gene therapy, as well as the challenges and opportunities that will be faced in the practical application of CRISPR-Cas systems.

Genetic deletion of a short fragment of glucokinase in rabbit by CRISPR/Cas9 leading to hyperglycemia and other typical features seen in MODY-2

Glucokinase (GCK) is a key enzyme in glucose sensing and glycemic regulation. In humans, mutations in the GCK gene cause maturity-onset diabetes of the young 2 (MODY-2), a disease that is characterized by an early-onset and persistent hyperglycemia. It is known that Gck knockout (KO) is lethal in mice with Gck KO mice dying within 2 weeks after birth. Therefore, Gck KO mice are not suitable for preclinical study and have limited suitability to study the pathophysiological role of glucokinase in vivo. Here, we report the generation of a novel rabbit with a non-frameshift mutation of GCK gene (GCK-NFS) by cytoplasm microinjection of Cas9 mRNA and gRNA. These GCK-NFS rabbits showed typical features of MODY-2 including hyperglycemia and glucose intolerance with similar survival rate and weight compared to wild-type (WT) rabbits. The diabetic phenotype including pancreatic and renal dysfunction was also found in the F1-generation rabbits, indicating that the genetic modification is germline transmissible. Treatment of GCK-NFS rabbit with glimepiride successfully reduced the fasting blood glucose drastically and improved its islet function. In conclusion, this novel GCK mutant rabbit generated with the CRISPR/Cas9 system mimics most, if not all, histopathological and functional defects seen in MODY-2 patients such as hyperglycemia and will be a valuable rabbit model for preclinical studies and drug screening for diabetes as well as for studying the pathophysiological role of glucokinase.

Recent developments in regenerative ophthalmology

Regenerative medicine (RM) is one of the most promising disciplines for advancements in modern medicine, and regenerative ophthalmology (RO) is one of the most active fields of regenerative medicine. This review aims to provide an overview of regenerative ophthalmology, including the range of tools and materials being used, and to describe its application in ophthalmologic subspecialties, with the exception of surgical implantation of artificial tissues or organs (e.g., contact lens, artificial cornea, intraocular lens, artificial retina, and bionic eyes) due to space limitations. In addition, current challenges and limitations of regenerative ophthalmology are discussed and future directions are highlighted.

Video recording and light intensity change analysis during cataract surgery using an animal model

PURPOSE

To estimate light exposure changes during cataract surgery through intraoperative images simulated from the "patient's perspective" using an animal model.

METHODS

In this experimental study, a 3-mm maculostomy was performed through the posterior globe's surface of 15 porcine eyes. Eyes were fixated to a glass slide and placed over an iPad camera. Video footage of a cataract surgery was obtained through the maculostomy for each eye, keeping light exposure parameters and focus constant. Seventy-five images, five from each eye, were extracted at pre-determined points, and mean gray value (MGV), a light intensity measure, was calculated. Differences in MGV between discrete surgical steps were evaluated using multiple one-sample t-tests.

RESULTS

This technique allowed for the capture of a full-length cataract surgery through a 3-mm maculostomy. MGV range was 14.21-132.51. Light intensity was similar across surgeries and varied greatly through each procedure. A 24% decrease in MGV between post-hydrodissection and post-phacoemulsification stages was noted (difference - 18.36; 95% CI - 30.50 to - 6.22; p value = 0.006). A 22.4% decrease in light intensity was noted after phacoemulsification in comparison to the starting image (MGV difference - 16.78; 95% CI - 32.45 to - 1.12; p value: 0.0375). Light intensity was similar at the start and end of surgery (difference - 7.15; 95% CI - 19.35 to + 5.05; p value = 0.229).

CONCLUSIONS

Light intensity changes through different steps of cataract surgery and may be minimal after phacoemulsification completion. This video and data may serve as informational and educational tools for surgeons and patients.

CRISPR-induced exon skipping is dependent on premature termination codon mutations

In previous studies, CRISPR/Cas9 was shown to induce unexpected exon skipping; however, the mechanism by which this phenomenon is triggered is controversial. By analyzing 22 gene-edited rabbit lines generated using CRISPR/Cas9, we provide evidence of exon skipping at high frequency in premature termination codon-mutated rabbits but not in the rabbits with a premature termination codon mutation in exon 1 rabbits with non-frameshift or missense mutations. Our results suggest that CRISPR-mediated exon skipping depends on premature termination codon mutation-induced nonsense-associated altered splicing.

Functional validation of the albinism-associated tyrosinase T373K SNP by CRISPR/Cas9-mediated homology-directed repair (HDR) in rabbits

Background

Oculocutaneous albinism (OCA) is a group of autosomal recessive disorders characterized by reduced melanin that are caused by mutations in the gene encoding tyrosinase (TYR), which is the rate-limiting enzyme in the production of the pigment melanin. Many studies or meta-analyses have suggested an association between the TYR T373K SNP and OCA1, but there is limited biochemical and genetic evidence to support this association.

Methods

We overexpressed TYR-WT and TYR-T373K mutants on HK293T cells and tested the changes of melanin production and tyrosinase activity. Then we generated TYR-K373T knock-in (KI) rabbits by microinjection of ssDNA and synthesized RNAs targeting C1118A using CRISPR/Cas9-HDR to observe the formation of melanin.

Findings

We demonstrated that the T373K mutation in TYR can reduce tyrosinase activity, leading to an absence of melanin synthesis at the cell-level. The gene-edited TYR-K373T rabbits exhibited rescued melanin production in hair follicles and irises, as inferred from the evident decrease in pigmentation in TYR-T373K rabbits, thus providing functional validation of the albinism-associated T373K SNP at the animal level.

Interpretation

Our study provides the first animal-level functional validation of the albinism-associated TYR K373T SNP in rabbits, and these results will facilitate gene therapy of OCA1 in pre-clinical settings in the future.

Fund

The National Key Research and Development Program of China Stem Cell and Translational Research, the Strategic Priority Research Program of the Chinese Academy of Sciences, the Guangdong Province Science and Technology Plan Project, and the Program for JLU Science and Technology Innovative Research Team.

Spontaneous severe hypercholesterolemia and atherosclerosis lesions in rabbits with deficiency of low-density lipoprotein receptor (LDLR) on exon 7

Rabbits (Oryctolagus cuniculus) have been the very frequently used as animal models in the study of human lipid metabolism and atherosclerosis, because they have similar lipoprotein metabolism to humans. Most of hyperlipidemia and atherosclerosis rabbit models are produced by feeding rabbits a high-cholesterol diet. Gene editing or knockout (KO) offered another means of producing rabbit models for study of the metabolism of lipids and lipoproteins. Even so, apolipoprotein (Apo)E KO rabbits must be fed a high-cholesterol diet to induce hyperlipidemia. In this study, we used the CRISPR/Cas9 system anchored exon 7 of low-density lipoprotein receptor (LDLR) in an attempt to generate KO rabbits. We designed two sgRNA sequences located in E7:g.7055-7074 and E7:g.7102-7124 of rabbit LDLR gene, respectively. Seven LDLR-KO founder rabbits were generated, and all of them contained biallelic modifications. Various mutational LDLR amino acid sequences of the 7 founder rabbits were subjected to tertiary structure modeling with SWISS-MODEL, and results showed that the structure of EGF-A domain of each protein differs from the wild-type. All the founder rabbits spontaneously developed hypercholesterolemia and atherosclerosis on a normal chow (NC) diet. Analysis of their plasma lipids and lipoproteins at the age of 12 weeks revealed that all these KO rabbits exhibited markedly increased levels of plasma TC (the highest of which was 1013.15 mg/dl, 20-fold higher than wild-type rabbits), LDL-C (the highest of which was 730.00 mg/dl, 35-fold higher than wild-type rabbits) and TG accompanied by reduced HDL-C levels. Pathological examinations of a founder rabbit showed prominent aortic atherosclerosis lesions and coronary artery atherosclerosis.In conclusion, we have reported the generation LDLR-KO rabbit model for the study of spontaneous hypercholesterolemia and atherosclerosis on a NC diet. The LDLR-KO rabbits should be a useful rabbit model of human familial hypercholesterolemia (FH) for the simulations of human primary hypercholesterolemia and such models would allow more exact research into cardio-cerebrovascular disease.

Generation of genetically-engineered animals using engineered endonucleases

The key to successful drug discovery and development is to find the most suitable animal model of human diseases for the preclinical studies. The recent emergence of engineered endonucleases is allowing for efficient and precise genome editing, which can be used to develop potentially useful animal models for human diseases. In particular, zinc finger nucleases, transcription activator-like effector nucleases, and the clustered regularly interspaced short palindromic repeat systems are revolutionizing the generation of diverse genetically-engineered experimental animals including mice, rats, rabbits, dogs, pigs, and even non-human primates that are commonly used for preclinical studies of the drug discovery. Here, we describe recent advances in engineered endonucleases and their application in various laboratory animals. We also discuss the importance of genome editing in animal models for more closely mimicking human diseases.

CRISPR/Cas9-mediated mosaic mutation of SRY gene induces hermaphroditism in rabbits

Hermaphroditism is a rare disorder that affects sexual development, resulting in individuals with both male and female sexual organs. Hermaphroditism is caused by anomalies in genes regulating sex determination, gonad development, or expression of hormones and their receptors during embryonic development during sexual differentiation. SRY is a sex-determination gene on the Y chromosome that is responsible for initiating male sex determination in mammals. In this study, we introduced CRISPR/Cas9-mediated mutations in the high-mobility-group (HMG) region of the rabbit SRY. As expected, SRY-mutant chimeric rabbits were diagnosed with hermaphroditism, characterized by possessing ovotestis, testis, ovary and uterus simultaneously. Histopathology analysis revealed that the testicular tissue was immature and lacked spermatogenic cells, while the ovarian portion appeared normal and displayed follicles at different stages. This is the first report of a rabbit hermaphroditism model generated by the CRISPR/Cas9 system. This novel rabbit model could advance our understanding of the pathogenesis of hermaphroditism, and identify novel therapies for human clinical treatment of hermaphroditism.

Principles and Applications of Rabbit Models for Atherosclerosis Research

Rabbits are one of the most used experimental animals for biomedical research, particularly as a bioreactor for the production of antibodies. However, many unique features of the rabbit have also made it as an excellent species for examining a number of aspects of human diseases such as atherosclerosis. Rabbits are phylogenetically closer to humans than rodents, in addition to their relatively proper size, tame disposition, and ease of use and maintenance in the laboratory facility. Due to their short life spans, short gestation periods, high numbers of progeny, low cost (compared with other large animals) and availability of genomics and proteomics, rabbits usually serve to bridge the gap between smaller rodents (mice and rats) and larger animals, such as dogs, pigs and monkeys, and play an important role in many translational research activities such as pre-clinical testing of drugs and diagnostic methods for patients. The principle of using rabbits rather than other animals as an experimental model is very simple: rabbits should be used for research, such as translational research, that is difficult to accomplish with other species. Recently, rabbit genome sequencing and transcriptomic profiling of atherosclerosis have been successfully completed, which has paved a new way for researchers to use this model in the future. In this review, we provide an overview of the recent progress using rabbits with specific reference to their usefulness for studying human atherosclerosis.