Recent advances in Otology: Current landscape and future direction.

Hearing is an essential sensation, and its deterioration leads to a significant decrease in the quality of life. Thus, great efforts have been made by otologists to preserve and recover hearing. Our knowledge regarding the field of otology has progressed with advances in technology, and otologists have sought to develop novel approaches in the field of otologic surgery to achieve higher hearing recovery or preservation rates. This requires knowledge regarding the anatomy of the temporal bone and the physiology of hearing. Basic research in the field of otology has progressed with advances in molecular biology and genetics. This review summarizes the current views and recent advances in the field of otology and otologic surgery, especially from the viewpoint of young Japanese clinician-scientists, and presents the perspectives and future directions for several topics in the field of otology. This review will aid next-generation researchers in understanding the recent advances and future challenges in the field of otology.

Hypercholesterolemia induced by spontaneous oligogenic mutations in rhesus macaques (Macaca mulatta).

BACKGROUND: A rhesus macaque with the fourth highest plasma cholesterol (CH) levels of 501 breeding macaques was identified 22 years ago. Seven offspring with gene mutations causing hypercholesterolemia were obtained. METHODS: Activity of low-density lipoprotein receptor (LDLR), plasma CH levels and mRNA expression levels of LDLR were measured after administration of 0.1% (0.27 mg/kcal) or 0.3% CH. RESULTS: Activity of p. (Cys82Tyr) of LDLR was 71% and 42% in the heterozygotes and a homozygote, respectively. The mRNA expression level of LDLR in the p. (Val241Ile) of membrane-bound transcription factor protease, site 2 (MBTPS2, S2P protein) was 0.83 times lower than normal levels. LDLR mRNA levels were increased for up to 4 weeks by administration of 0.3% CH before suddenly decreasing to 80% of the baseline levels after 6 weeks. CONCLUSION: Oligogenic mutations of p. (Cys82Tyr) in LDLR and p. (Val241Ile) in MBTPS2 (S2P) caused hypercholesterolemia exceeding cardiovascular risk levels under a 0.1% CH diet.

Advances in Zebrafish for Diabetes Mellitus with Wound Model.

Diabetic foot ulcers cause great suffering and are costly for the healthcare system. Normal wound healing involves hemostasis, inflammation, proliferation, and remodeling. However, the negative factors associated with diabetes, such as bacterial biofilms, persistent inflammation, impaired angiogenesis, inhibited cell proliferation, and pathological scarring, greatly interfere with the smooth progress of the entire healing process. It is this impaired wound healing that leads to diabetic foot ulcers and even amputations. Therefore, drug screening is challenging due to the complexity of damaged healing mechanisms. The establishment of a scientific and reasonable animal experimental model contributes significantly to the in-depth research of diabetic wound pathology, prevention, diagnosis, and treatment. In addition to the low cost and transparency of the embryo (for imaging transgene applications), zebrafish have a discrete wound healing process for the separate study of each stage, resulting in their potential as the ideal model animal for diabetic wound healing in the future. In this review, we examine the reasons behind the delayed healing of diabetic wounds, systematically review various studies using zebrafish as a diabetic wound model by different induction methods, as well as summarize the challenges and improvement strategies which provide references for establishing a more reasonable diabetic wound zebrafish model.

Progress in research on the reproductive function in the sand rat (Psammomys obesus): A review.

The Fat Sand Rat (Psammomys obesus, P. obesus) is a diurnal herbivore and phytophage, with seasonal reproductive behavior. The sexually active phase lasts from autumn to early spring and the sexually inactive phase from late spring to summer. In the past years, P. obesus has gained much attention as an animal model in biological and clinical research. It is a suitable model for diet-induced insulin resistance, non-insulin-dependent diabetes mellitus and obesity studies. In addition, the seasonal reproduction of P. obesus is gaining more and more attention. The current paper aims to review and sum up the progress in the understanding of the reproductive anatomo-histo-physiology of Psammomys obesus, in order to facilitate future research in this area and to expose further perspectives for researchers.

Batch and sampling time exert a larger influence on the fungal community than gastrointestinal location in model animals: A meaningful case study.

Fungi play a fundamental role in the intestinal ecosystem and health, but our knowledge of fungal composition and distribution in the whole gastrointestinal tract (GIT) is very limited. The physiological similarity between humans and pigs in terms of digestive and associated metabolic processes places, the pig in a superior position over other non-primate models. Here, we aimed to characterize the diversity and composition of fungi in the GIT of pigs. Using high-throughput sequencing, we evaluated the fungal community in different locations of GIT of 11 pigs with 128.41 ± 1.25 kg body weight acquired successively. Among them, five pigs are sacrificed in April 2019 (Batch 1) and the other six are sacrificed in January 2020 (Batch 2). All subjects with similar genetic backgrounds, housing, management, and diet. Finally, no significant difference is found in the α-diversity (Richness) of the fungal community among all intestinal segments. Basidiomycota and Ascomycota are the two predominant fungal phyla, but Batch 1 harbored a notably high abundance of Basidiomycota and Batch 2 harbored a high abundance of Ascomycota. Moreover, the two batches harbored completely different fungal compositions and core fungal genera. FUNGuild (Fungal Functional Guild) analysis revealed that most of the fungal species present in the GIT are saprotroph, plant pathogen, and animal endosymbiont. Our study is the first to report that even under the same condition, large variations in fungal composition in the host GIT still occur from batch-to-batch and sampling time. The implications of our observations serve as references to the development of better models of the human gut.

An imaging mass cytometry immunophenotyping panel for non-human primate tissues.

It has recently become clear that spatial organization contributes to cellular function and that expanding our knowledge on cellular organization is essential to further our understanding of processes in health and disease. Imaging mass cytometry enables high dimensional imaging of tissue while preserving spatial context and is therefore a suitable tool to unravel spatial relationships between cells. As availability of human tissue collected over the course of disease or infection is limited, preclinical models are a valuable source of such material. Non-human primate models are used for translational research as their anatomy, physiology and immune system closely resemble those of humans due to close evolutionary proximity. Tissue from non-human primate studies is often preserved large archives encompassing a range of conditions and organs. However, knowledge on antibody clones suitable for FFPE tissue of non-human primate origin is very limited. Here, we present an imaging mass cytometry panel development pipeline which enables the selection and incorporation of antibodies for imaging of non-human primate tissue. This has resulted in an 18-marker backbone panel which enables visualization of a broad range of leukocyte subsets in rhesus and cynomolgus macaque tissues. This high-dimensional imaging mass cytometry panel can be used to increase our knowledge of cellular organization within tissues and its effect on outcome of disease.

Establishing an effective gene knockdown system using cultured cells of the model fish medaka (Oryzias latipes).

In spite of the growing attention given to medaka (Oryzias latipes) as an excellent vertebrate model, an effective gene knockdown system has not yet been established using cultured cells of this fish species. In this study, a gene knockdown system using short interfering RNA (siRNA) in medaka cell lines was established through the optimization of transfection conditions. By extensive screening of several medaka cell lines and transfection reagents, OLHNI-2 cells and X-tremeGENE siRNA Transfection Reagent were selected as the best combination to achieve high transfection efficiency of siRNA without cytotoxic effect. Knockdown conditions were then refined using the endogenous heat shock protein 90 (Hsp90) genes as the siRNA targets. Among the parameters tested, cell density, serum concentration in the culture medium, and duration of transfection improved knockdown efficiency, where the target mRNA in cells transfected with each of the siRNAs was reduced from 12.0% to 26.7% of the control level. Our results indicate that the established knockdown system using siRNA is a promising tool for functional analysis of medaka genes in vitro.

Effect of dietary supplements on Se bioavailability: A comprehensive in vitro and in vivo study.

Selenium (Se) is an essential micronutrient for animals and humans, and it is present in many different forms with different levels of bioaccessibility in food. Based on the maldistribution of Se and overall low level of Se dietary intake in China, an integrated study was conducted in this thesis to provide references for the regulation of Se nutrition. An in vitro simulation test was used to monitor the concentration effects, the impacts of dietary supplement combinations on the bioaccessibility of Se were examined in rice, and a model animal experiment (in vivo) was used to evaluate the practicability of the Se nutrition regulation scheme. The main results were as follows: the bioaccessibility of Se was effectively increased by 30 mg·d-1 VE (VE), 300 mg·d-1 VC + 300 µg·d-1 VB9 (VC+VB9) and 30 mg·d-1 VE + 300 mg·d-1 VC + 300 µg·d-1 VB9 (3IN1) (P < 0.05). The results of the healthy broiler tests showed that the 3 treatments increased the weight and Se content of the broilers, and 3IN1 had the most significant effect (P < 0.05). VC+VB9 was the best at promoting GPx activity, while 3IN1 was the best at promoting SOD activity and the inhibition of MDA content in broilers. The results suggested that VE, VC+VB9 and 3IN1 can benefit the bioavailability of Se and the antioxidant capacity of the body. The results can be used as a scientific reference for Se nutrition regulation.

Host Immunization with Recombinant Tick Antigen and Evaluation of Host Immune Response.

Ticks are classified as hematophagous arthropods and transfer a variety of pathogens-such as viruses, bacteria, and protozoans-to vertebrate hosts during blood feeding. These transmitted pathogens cause infectious diseases that continue to affect both humans and animals worldwide. Chemical acaricides are commonly used for tick control to prevent infectious diseases. However, the continuous use of acaricides leads to the emergence of acaricide-resistant tick species; thus, alternative methods for tick control are necessary. Vaccination of vertebrate hosts with tick-derived molecules is considered to be a better alternative against ticks than chemical acaricides because ticks feed on host blood for several days and also concentrate the host blood with antibodies. On the other hand, the host's immune responses against pathogens mainly take two pathways-Th1 (cell-mediated immunity) and Th2 (humoral immunity) pathways. Thus, the vaccine can suggest which immune pathway is more important for vaccination. This chapter describes the procedures of immunizing laboratory animals-mice-with a recombinant tick protein for the preliminary evaluation of its potential as an anti-tick vaccine candidate. In addition, the method of evaluating the antigen-specific antibody production in the host using ELISA is described, as is the subsequent tick-infestation challenge for determining the effectiveness of vaccination.

Corrigendum: Batch and sampling time exert a larger influence on the fungal community than gastrointestinal location in model animals: A meaningful case study.

[This corrects the article DOI: 10.3389/fnut.2022.1021215.].

Potential Vasculoprotective Effects of Blackcurrant (Ribes nigrum) Extract in Diabetic KK-Ay Mice.

Polyphenols are bioactive compounds found naturally in fruits and vegetables; they are widely used in disease prevention and health maintenance. Polyphenol-rich blackcurrant extract (BCE) exerts beneficial effects on vascular health in menopausal model animals. However, the vasculoprotective effects in diabetes mellitus (DM) and atherosclerotic vascular disease secondary to DM are unknown. Therefore, we investigated whether BCE is effective in preventing atherosclerosis using KK-Ay mice as a diabetes model. The mice were divided into three groups and fed a high-fat diet supplemented with 1% BCE (BCE1), 3% BCE (BCE2), or Control for 9 weeks. The mice in the BCE2 group showed a considerable reduction in the disturbance of elastic lamina, foam cell formation, and vascular remodeling compared to those in the BCE1 and Control groups. Immunohistochemical staining indicated that the score of endothelial nitric oxide synthase staining intensity was significantly higher in both BCE2 (2.9) and BCE1 (1.9) compared to that in the Control (1.1). Furthermore, the score for the percentage of alpha-smooth muscle actin was significantly lower in the BCE2 (2.9%) than in the Control (2.1%). Our results suggest that the intake of anthocyanin-rich BCE could have beneficial effects on the blood vessels of diabetic patients.

Planarians as an In Vivo Experimental Model for the Study of New Radioprotective Substances.

Ionising radiation causes the death of the most actively dividing cells, thus leading to depletion of the stem cell pool. Planarians are invertebrate flatworms that are unique in that their stem cells, called neoblasts, constantly replace old, damaged, or dying cells. Amenability to efficient RNAi treatments, the rapid development of clear phenotypes, and sensitivity to ionising radiation, combined with new genomic technologies, make planarians an outstanding tool for the discovery of potential radioprotective agents. In this work, using the well-known antioxidant N-acetylcysteine, planarians are, for the first time, shown to be an excellent model system for the fast and effective screening of novel radioprotective and radio-sensitising substances. In addition, a panel of measurable parameters that can be used for the study of radioprotective effects on this model is suggested.

A Decade in Review after Idiopathic Scoliosis Was First Called a Complex Trait-A Tribute to the Late Dr. Yves Cotrel for His Support in Studies of Etiology of Scoliosis.

Adolescent Idiopathic Scoliosis (AIS) is a prevalent and important spine disorder in the pediatric age group. An increased family tendency was observed for a long time, but the underlying genetic mechanism was uncertain. In 1999, Dr. Yves Cotrel founded the Cotrel Foundation in the Institut de France, which supported collaboration of international researchers to work together to better understand the etiology of AIS. This new concept of AIS as a complex trait evolved in this setting among researchers who joined the annual Cotrel meetings. It is now over a decade since the first proposal of the complex trait genetic model for AIS. Here, we review in detail the vast information about the genetic and environmental factors in AIS pathogenesis gathered to date. More importantly, new insights into AIS etiology were brought to us through new research data under the perspective of a complex trait. Hopefully, future research directions may lead to better management of AIS, which has a tremendous impact on affected adolescents in terms of both physical growth and psychological development.

An Experimental Model of Neuromyelitis Optica Spectrum Disorder-Optic Neuritis: Insights Into Disease Mechanisms.

Background: Optic neuritis (ON) is a common inflammatory optic neuropathy, which often occurs in neuromyelitis optica spectrum disease (NMOSD). An experimental model of NMOSD-ON may provide insight into disease mechanisms. Objective: To examine the pathogenicity of autoantibodies targeting the astrocyte water channel aquaporin-4 [aquaporin-4 (AQP4)-immunoglobulin G (AQP4-IgG)] in the optic nerve. Materials and Methods: Purified IgG from an AQP4-IgG-positive NMOSD-ON patient was together with human complement (C) given to wild-type (WT) and type I interferon (IFN) receptor-deficient mice (IFNAR1-KO) as two consecutive intrathecal injections into cerebrospinal fluid via cisterna magna. The optic nerves were isolated, embedded in paraffin, cut for histological examination, and scored semi-quantitatively in a blinded fashion. In addition, optic nerves were processed to determine selected gene expression by quantitative real-time PCR. Results: Intrathecal injection of AQP4-IgG+C induced astrocyte pathology in the optic nerve with loss of staining for AQP4 and glial fibrillary acidic protein (GFAP), deposition of C, and demyelination, as well as upregulation of gene expression for interferon regulatory factor-7 (IRF7) and CXCL10. Such pathology was not seen in IFNAR1-KO mice nor in control mice. Conclusion: We describe induction of ON in an animal model for NMOSD and show a requirement for type I IFN signaling in the disease process.

Photoperiod-independent testicular development in the model newt Pleurodeles waltl.

Urodele amphibian newts have unique biological properties in male gametogenesis, in addition to their extreme regenerative capacity. Male newts are able to regenerate new testes even after reaching sexual maturity and can possess multiple testes. Notably, these animals maintain primordial germ cell-like cells in a tissue adjacent to the testis. Spermatogenesis proceeds while synchronizing in a region-specific manner in the testis. However, the newt species that have been used most commonly require 2-3 years to achieve sexual maturity, and spermatogenesis in these species shows seasonality. These traits have restricted the use of newts for studies on testicular development and spermatogenesis, and testis development in newts remains poorly characterized. Recently, the Iberian ribbed newt Pleurodeles waltl has been established as an emerging model organism. P. waltl reaches sexual maturity more quick after birth than do other newts and is capable of breeding year-round. Thus, P. waltl is expected to serve as an appealing experimental model for studying the mechanisms of male gametogenesis in the urodeles. In the present study, we use P. waltl to describe the entire developmental process of the newt testis from primordial gonad to maturity. Notably, the mature testes show synchronized progression of spermatogenesis along the anteroposterior axis. Additionally, we demonstrate that the process of spermatogenesis in P. waltl proceeds irrespective of day length. Our results show that P. waltl newts are a suitable model for investigating the process of testicular development. We also expect that these results will be useful for the maintenance of P. waltl bioresources.

Nucleated red blood cells participate in myocardial regeneration in the toad Bufo Gargarizan Gargarizan.

Heart regeneration is negligible in humans and mammals but remarkable in some ectotherms. Humans and mammals lack nucleated red blood cells (NRBCs), while ectotherms have sufficient NRBCs. This study used Bufo gargarizan gargarizan, a Chinese toad subspecies, as a model animal to verify our hypothesis that NRBCs participate in myocardial regeneration. NRBC infiltration into myocardium was seen in the healthy toad hearts. Heart needle-injury was used as an enlarged model of physiological cardiomyocyte loss. It recovered quickly and scarlessly. NRBC infiltration increased during the recovery. Transwell assay was done to in vitro explore effects of myocardial injury on NRBCs. In the transwell system, NRBCs could infiltrate into cardiac pieces and could transdifferentiate toward cardiomyocytes. Heart apex cautery caused approximately 5% of the ventricle to be injured to varying degrees. In the mildly to moderately injured regions, NRBC infiltration increased and myocardial regeneration started soon after the inflammatory response; the severely damaged region underwent inflammation, scarring, and vascularity before NRBC infiltration and myocardial regeneration, and recovered scarlessly in four months. NRBCs were seen in the newly formed myocardium. Enzyme-linked immunosorbent assay and Western blotting showed that the levels of tumor necrosis factor-α, interleukin- 1ß, 6, and11, cardiotrophin-1, vascular endothelial growth factor, erythropoietin, matrix metalloproteinase- 2 and 9 in the serum and/or cardiac tissues fluctuated in different patterns during the cardiac injury-regeneration. Cardiotrophin-1 could induce toad NRBC transdifferentiation toward cardiomyocytes in vitro. Taken together, the results suggest that the NRBC is a cell source for cardiomyocyte renewal/regeneration in the toad; cardiomyocyte loss triggers a series of biological processes, facilitating NRBC infiltration and transition to cardiomyocytes. This finding may guide a new direction for improving human myocardial regeneration.

Comparison of transgenerational reproductive toxicity induced by pristine and amino modified nanoplastics in Caenorhabditis elegans.

Certain modifications can aggravate the toxicity of nanoplastics. However, the influence of surface amino modification on transgenerational impairment induced by nanoplastics remains largely unclear. Pristine nanopolystyrene (NPS) and amino modified NPS (NPS-NH2) were used to determine their transgenerational toxicity in Caenorhabditis elegans. Exposure to 100 µg/L pristine NPS in parents (P0) cause a decrease in reproductive capacity in the F1-F3 generations and the damage on gonad development in the F1-F2 generations. In contrast, exposure to 10 µg/L NPS-NH2 caused toxicity on reproductive capacity and gonad development in the F1 generation. The toxic effects of NPS-NH2 on reproductive capacity and gonad development in the F1-F3 generations were more severe than those of pristine NPS. Moreover, amino modification could increase transgenerational toxicity of NPS in inducing apoptosis of germline and in affecting expressions of ced-1, ced-4, and ced-9. Our data demonstrate that surface modification of NPS with amino groups enhances transgenerational reproductive toxicity of NPS in C. elegans.

[Role of imbalance of M1/M2 subsets of bone marrow macrophages in the pathogenesis of immune-mediated aplastic anemia in mice].

Objective: To investigate the role of macrophages (Mø) in the pathogenesis of modified immune-mediated aplastic anemia (AA) mice model. Methods: Before the establishment of the F1 AA mice model by total-body irradiation combined with allogeneic lymphocyte infusion, the mice of the CLO+AA group were treated with clodronate (CLO) liposomes to remove macrophages, and those of the PBS+AA group were treated with phosphate-buffered saline (PBS) liposomes and used as control. The severity of AA was observed by bone marrow (BM) pathological examination and peripheral blood cell count. Flow cytometry (FCM) was used to detect the CD4(+)/CD8(+) T lymphocyte subsets in the BM and Mø subsets in the BM and spleen of each group. The levels of IFN-γ, TNF-α, G-CSF, GM-CSF, EPO, and TPO in the peripheral blood were detected using enzyme-linked immunosorbent assay. Finally, the relationships between inflammatory factors and Mø subsets were analyzed. Results: The BM fatty conversion of mice in the CLO+AA group was significantly alleviated compared with the PBS+AA group. Hemoglobin counts were (91.50±31.63) and (110.65±24.15) g/L, respectively, and the platelet counts were (90.85±121.90) × 10(6)/L and (461.13±483.45) ×10(6)/L, respectively. The differences were all statistically significant (all P<0.05) . After removing macrophages, the proportions of CD4(+) and CD8(+) T lymphocytes in BM of mice in the CLO+AA group decreased, but the reduction of CD8(+) T cells was more significant. The proportions of CD4(+) T cells and CD8(+) T cells in BM of the PBS+AA group were (18.5±10.17) % and (36.23±6.40) %, respectively, and in the CLO+AA group were (7.58±8.00) % and (6.67±5.78) %, respectively. Similarly, the percentage of macrophages in the spleen and BM in the CLO+AA group was significantly reduced compared with the PBS+AA group, most of which were M1 macrophages (P<0.05) . The levels of IFN-γ in peripheral blood of the PBS+AA and CLO+AA groups were (602.37±104.62) ng/L and (303.01±87.22) ng/L, respectively, the levels of TNF-α were (34.46±1.42) ng/L and (23.25±4.21) ng/L, respectively, the levels of GM-CSF were (9.32 ± 2.00) ng/L and (64.85±12.25) ng/L, respectively, the levels of G-CSF were (5 891.78±2 632.39) ng/L and (17 784.16±488.36) ng/L, respectively, the levels of EPO were (9 667.31±4 501.95) ng/L and (2 078.02±897.56) ng/L, respectively, and the levels of TPO were (6.36±2.09) ng/L and (11.67±2.86) ng/L, respectively (all P<0.05) . Conclusions: This study confirmed that macrophages were involved in the pathogenesis of AA, and the degree of BM damage in AA mice was improved by removing macrophages in advance. The imbalance of M1/M2 macrophages and the changes of IFN-γ and TNF-α may be important mechanisms that eventually lead to AA.

Complex Arrhythmia Syndrome in a Knock-In Mouse Model Carrier of the N98S Calm1 Mutation.

BACKGROUND: Calmodulin mutations are associated with arrhythmia syndromes in humans. Exome sequencing previously identified a de novo mutation in CALM1 resulting in a p.N98S substitution in a patient with sinus bradycardia and stress-induced bidirectional ventricular ectopy. The objectives of the present study were to determine if mice carrying the N98S mutation knocked into Calm1 replicate the human arrhythmia phenotype and to examine arrhythmia mechanisms. METHODS: Mouse lines heterozygous for the Calm1N98S allele (Calm1N98S/+) were generated using CRISPR/Cas9 technology. Adult mutant mice and their wildtype littermates (Calm1+/+) underwent electrocardiographic monitoring. Ventricular de- and repolarization was assessed in isolated hearts using optical voltage mapping. Action potentials and whole-cell currents and [Ca2+]i, as well, were measured in single ventricular myocytes using the patch-clamp technique and fluorescence microscopy, respectively. The microelectrode technique was used for in situ membrane voltage monitoring of ventricular conduction fibers. RESULTS: Two biologically independent knock-in mouse lines heterozygous for the Calm1N98S allele were generated. Calm1N98S/+ mice of either sex and line exhibited sinus bradycardia, QTc interval prolongation, and catecholaminergic bidirectional ventricular tachycardia. Male mutant mice also showed QRS widening. Pharmacological blockade and activation of ß-adrenergic receptors rescued and exacerbated, respectively, the long-QT phenotype of Calm1N98S/+ mice. Optical and electric assessment of membrane potential in isolated hearts and single left ventricular myocytes, respectively, revealed ß-adrenergically induced delay of repolarization. ß-Adrenergic stimulation increased peak density, slowed inactivation, and left-shifted the activation curve of ICa.L significantly more in Calm1N98S/+ versus Calm1+/+ ventricular myocytes, increasing late ICa.L in the former. Rapidly paced Calm1N98S/+ ventricular myocytes showed increased propensity to delayed afterdepolarization-induced triggered activity, whereas in situ His-Purkinje fibers exhibited increased susceptibility for pause-dependent early afterdepolarizations. Epicardial mapping of Calm1N98S/+ hearts showed that both reentry and focal mechanisms contribute to arrhythmogenesis. CONCLUSIONS: Heterozygosity for the Calm1N98S mutation is causative of an arrhythmia syndrome characterized by sinus bradycardia, QRS widening, adrenergically mediated QTc interval prolongation, and bidirectional ventricular tachycardia. ß-Adrenergically induced ICa.L dysregulation contributes to the long-QT phenotype. Pause-dependent early afterdepolarizations and tachycardia-induced delayed afterdepolarizations originating in the His-Purkinje network and ventricular myocytes, respectively, constitute potential sources of arrhythmia in Calm1N98S/+ hearts.

Uricase-deficient rat is generated with CRISPR/Cas9 technique.

Urate oxidase (uricase, Uox) is a big obstacle for scientists to establish stable animal models for studying hyperuricemia and associated disorders. Due to the low survival rate of uricase-deficient mice, we generated a Uox-knockout model animal from Sprague Dawley (SD) rats using the CRISPR/Cas9 technique by deleting exons 2 to 4 of the Uox gene. The uricase-deficient rats were named "Kunming-DY rats", and were apparently healthy with more than a 95% survival up to one year. The male rats' serum uric acid (SUA) increased to 48.3  ± 19.1 µg/ml, significantly higher than those of wild-type rats. Some indexes of the blood fat like total triglyceride, low density lipoprotein, and renal function indexes including blood urea nitrogen and serum creatinine were significantly different from those of wild-type rats, however, all the indexes were close to or in normal ranges. Histological renal changes including mild glomerular/tubular lesions were observed in these uricase-deficient rats. Thus, "Kunming-DY rats" with stable uricase-deficiency were successfully established and are an alternative model animal to study hyperuricemia and associated diseases mimicking human conditions.