Abstract:Objective To compare the advantages and disadvantages of APP / PS1 transgenic AD model mice and wild?type(WT) mice in a variety of behavioral experiments, and summarize the precautions, assessment criteria, and applications of these experiments to provide a basis for the study of animal cognition?related behavior. Methods Y maze, type Ⅰ and Ⅱ T mazes, new?object recognition test, open?field test, and rotarod tests were adopted to detect the motor ability, exploratory behavior, learning and memory ability, new?object recognition ability, activeness, fear of open field,　and the coordination of central nervous system in 3? and 6?month?old APP / PS1 transgenic and WT mice. Results Six?month?old APP / PS1 transgenic mice showed significantly lower working memory than WT mice of the same age. This is　indicated by a significant increase in the spontaneous return in the Y maze, and a significant decrease in spontaneous　alternations and return in 6?month?old AD mice compared tothe 3?month?old a AD mice,while no such discrimination is　found in WT mice. The scores and memory time of 6?month?old AD mice in the type Ⅰ T maze(reward type) were　significantly decreased compared with WT mice, and the learning time in the type Ⅱ T maze(punishment type) was　significantly increased, indicating a weaker learning ability, slower memory retrieval, and lower accuracy in AD mice　compared with WT mice. In the open?field test, the total distance and speed were significantly decreased in 6?month?old AD　mice compared with WT mice of the same age. The number of entries in the central area and the ratio of central to　peripheral area and the number of rearings were significantly decreased in AD mice, indicating that exploratory behavior was　significantly decreased in AD compared with WT mice of the same age, and the degree of fear in the open field was higher.　However, there was no difference between APP / PS1 and WT mice in the latency to fall in the rotarod test, indicating no　difference in central coordination abilities. Conclusions The Y maze test can be operated easily and has a short time　course, and is suitable for detecting working memory, but the test circle for a single animal is longer. The T maze assesses　the animal’s exploratory nature, which can accurately determine the learning and memory ability, and reflects the ability of　memory retrieval; however, the test circle is long. The new?object recognition test was designed based on the rodents’　curiosity of new objects, and could accurately reflect their ability to recognize objects. However, operation of the　experimental equipment is complicated, and the test is easily affected by an animal’s stress behavior. The open?field test is　mainly used to measure motor and exploration abilities, activity, and fear of open field, based on the animal’s fear of open　field and curiosity about a new environment; however, the experimental result are easily affected by stress state. The rotarod　test directly reflects the body’s coordination and anti?fatigue ability and indirectly reflects the animal’s diurnal rhythm, and　can be used as an auxiliary index for learning and memory ability.

Abstract:Objective To establish a mouse femoral bone defect model and explore the effect of a GelMA hydrogel　on bone regeneration and repair. Methods Forty 8?week?old female C57BL/6N mice were randomly divided into four　groups: bone defect group (n= 10), 5% GelMA group (n= 10), 10% GelMA group (n= 10), and 15% GelMA　group (n= 10). At 2 weeks after modeling, HE staining was used to observe the femur structure. Masson staining was　used to observe the morphology of femoral collagen fibers. OCN immunohistochemical staining was used to analyze bone?specific protein expression levels. Results GelMA was well injectable and injected into bone defects using PCR pipettes.　HE staining showed that the 10% GelMA group had a better bone repair effect than bone defect, 5% GelMA, and 15%　GelMA groups, and the tissue structure of the defect site was more complete. Masson staining showed more osteogenic　collagen fibers in the 10% GelMA group. RT?qPCR analysis showed that OCN expression in the bone defect site in the 10%　GelMA group was significantly higher than that in the bone defect group (P< 0?? 001), 5% GelMA group (P< 0?? 01),　and 15% GelMA group (P< 0?? 01). Osterix expression in the bone defect site in the 10% GelMA group was significantly　higher than that in the bone defect group (P< 0?? 001), 5% GelMA group (P< 0?? 001), and 15% GelMA group (P<0?? 01); OCN immunohistochemical staining showed that bone?specific protein expression in the repair area in the 10%　GelMA group was significantly higher than that in the bone defect group (P< 0?? 01), 5% GelMA group (P< 0?? 01), and　15% GelMA group (P< 0?? 05). Conclusions A mouse bone defect model to evaluate the repair effect of injectable　regenerative scaffolds was established and applied to the screening and therapeutic effect evaluation of injectable　regenerative scaffolds based on GelMA, which provides an experimental basis to carrying out studies in related fields.

Abstract:Objective To explore the use of bio?orthogonal click chemistry indocyanine green (ICG) labeling of adipose tissue?derived mesenchymal stem cells (ADSC) and in vivo cell tracking. Methods ADSCs were isolated and cultured, and then incubated with N?azidoacetylmannosamine?tetraacylated ( Ac4ManNAz) and Dibenzocyclooctyne?indocyanine green (DBCO?ICG) using bio?orthogonal click chemistry, and their cell viability was evaluated. ICG labeling was confirmed by laser confocal microscopy imaging. After ICG labeling, in vivo ADSC tracking was performed by near?infrared Ⅱ fluorescence imaging in acute liver injured mice. Liver tissue sections were also collected to analyze ADSC homing. Moreover, the therapeutic effects of ICG?labeled ADSCs on serum levels of alanine aminotransferase (ALT) and aspartate transaminase (AST) and on pathological changes were also evaluated. Results ICG labeling of ADSCs could be achieved by bio?orthogonal click chemistry. Notably, ADSC viability and their therapeutic effects on acute liver injury, including serum ALT and AST and hepatic morphology, were not affected by this method. Near?infrared Ⅱ fluorescence imaging revealed the hepatic accumulation and homing of transplanted ADSCs in vivo and ex vivo. Conclusions Bio?orthogonal click chemistry may provide a promising new strategy for ADSC labeling and in vivo cell tracking.

Abstract:Objective To explore the mechanism of ferroptosis in a rat model of myocardial ischemia?reperfusion injury (MIRI), basing on the theory of heartache governing liver. Methods SD rats were divided into a blank group (n=10), sham operation group (n= 10), model group (n= 10), Conggan Zhixin recipe group(CGZX group)(n= 10), and Shexiang Baoxin Pill group (SXBX group)(n= 10) in accordance with a random number table. Except in blank and sham operation groups, all groups underwent ligation of the anterior descending coronary artery and ischemia?reperfusion to establish a myocardial ischemia?reperfusion injury model. The drug was administered by gavage at 24 h after model establishment. The gavage cycle was 14 days, and the frequency was once a day. Blood was collected from the abdominal aorta on day 16, and serum contents of creatine kinase isoenzyme (CK?MB), cardiac troponin T (cTnT), superoxide dismutase (SOD), malondialdehyde (MDA), and polyunsaturated fatty acid (PUFA) were analyzed by ELISA. The harvested heart was stained with HE to observe pathological morphology of myocardial tissue and with Prussian blue to observe iron deposition of myocardial cells. Mitochondrial morphology after ferroptosis was observed in ventricular muscle by electron microscopy. mRNA and protein expression of Nrf2 and ACSL4 in the myocardium was measured by PCR and Western Blot, respectively. Results Compared with the normal group, rats in the model group had obvious myocardial tissue and ultrastructure damage under the electron microscope, broken or loose myofilaments, swollen mitochondria in myocardial tissue, and a large amount of dark brown iron deposition in myocardial cells. The serum contents of CK?MB, cTnT, MDA, and PUFA were increased (P< 0?? 01), while the SOD content was decreased (P< 0?? 01). Moreover, mRNA and protein expression of Nrf2 and ACSL4 in the myocardium was increased significantly (P< 0?? 01). Compared with the model group, Conggan Zhixin recipe significantly improved edema and degeneration of myocardial tissue, reduced the iron deposition of myocardial cells and the degree of cell crest relaxation, significantly reduced the serum contents of MDA, PUFA, CK?MB, and cTnT (P< 0?? 01), upregulated SOD (P< 0?? 01)and Nrf2 expression in myocardial tissue, and downregulated the mRNA and protein expression of ACSL4 (P< 0?? 01). Conclusions Conggan Zhixin recipe has a myocardial protective effect on MIRI rats, which may be related to regulation of the Nrf2?ACSL4 pathway and inhibition of myocardial cell ferroptosis.

Abstract:Objective To supplement basic research data and explore the value of tree shrews as an experimental animal in heart research. Methods Ten adult tree shrews, half male and half female, were selected to perform limb lead electrocardiograms. The common parameters of echocardiography of rats were used to assess the echocardiography of tree shrews. The cardiac structure and functions of tree shrews were assessed. HE staining was used to observe heart morphology. Results Tree shrew showed a sinus rhythm and electrocardiographic parameters (P wave, QRS complex, and T wave) similar to human normal electrocardiographic patterns. The heart of tree shrews consisted of four chambers, including two atria and two ventricles. Early diastolic filling (E) and atrial kick (A) waves were detected. The left ventricular wall thickness of tree shrews was measured by B? and M?type echocardiography, and indicators, such as ejection fraction (EF) and fractional shorting ( FS), were obtained. The cardiac wall was divided into the epicardium, myocardium, and endocardium. The ventricular wall consisted of three layers: superficial ( subepicardial ), middle, and deep (subendocardial). Conclusions Tree shrew have the potential to be used as heart disease models for scientific research.

Abstract:Objective To measure the expression levels of CGRP, Syn, GFAP, Caspase 3, and IL?1β after indole?3?propionic acid treatment of rats with spinal cord injury, and investigate the effect and mechanism of indole?3?propionic acid in motor and sensory functions in rats. Methods A total of 105 SD rats were randomly divided into three groups: sham operation, normal saline, and indole?3?propionic acid. The spinal cord injury model was established by striking the spinal cord with heavy objects, and then indole?3?propionic acid was injected into the abdomen. On days 1 and 3 day, and weeks 1 ~ 4, an incline plate test, BBB score, and tail dump test were performed to evaluate changes in motorand sensory functions of rats. Expression of CGRP, Syn, GFAP, Caspase 3, and IL?1β in the spinal cord of rats at each time point was detected by immunofluorescence and Western Blot. Coexpression of CGRP with GAP43 and Necab2 was observed by double immunofluorescence. Results (1)The inclined plate test and BBB scores of the indole?3?propionic acid group were significantly higher than those of the normal saline group (P< 0.05). The latency of the tail flick test in the indole?3?propionic acid group was significantly higher than that in the normal saline group from day 3 after the operation, and returned to almost normal at week 3 after the operation (P< 0.05). (2) CGRP and Syn?positive cells reached a peak in normal saline and indole?3?propionic acid groups at week 2 after the operation, and significantly more cells were observed in the indole?3?propionic acid group than in the normal saline group (P< 0.05). GFAP?positive cells in saline and indole?3?propionic acid groups reached a peak at week 2 after the operation and then decreased, but the number of cells in the indole?3?propionic acid group was significantly lower than that in the normal saline group (P<0?? 05). Caspase 3?positive cells in indole?3?propionic acid and normal saline groups decreased gradually after the operation, and the number of caspase 3?positive cells in the indole?3?propionic acid group was significantly lower than that in the normal saline group (P< 0.05). (3)At week 2 after the operation, CGRP and GAP43 were obviously coexpressed, and CGRP and Necab2 were complementary in adjacent cells. (4)At week 2 after the operation, CGRP and Syn expression in the indole?3?propionic acid group was significantly higher than that in the normal saline group, while GFAP, Caspase 3, and IL?1β protein expression was significantly lower than that in the normal saline group (P< 0.05). Conclusions A high dose of indole?3?propionic acid after spinal cord injury significantly enhanced the expression levels of CGRP and Syn, and CGRP was complementary to Necab2 and coexpressed with GAP43, which is beneficial to the calcium ion balance, regeneration, and synaptic remodeling. By inhibiting expression of GFAP, Caspase 3, and IL?1β in the spinal cord, the tissue inflammatory response to injury was reduced, astrocyte activity was inhibited, and apoptosis in the spinal cord was reduced, which was beneficial to the survival of nerve cells in the injured area, preventing the formation of glial scars in spinal cord tissue, restoring the sensory and motor functions of limbs, and rebuilding the morphological structure of spinal cord tissue.

Abstract:Objective To investigate the role of Agtr1a in regulating LPS?induced inflammation after LBP deletion in primary hepatocytes of LBP knockout (Lbp^{-/ -} ) mice. Methods Primary hepatocytes of WT and Lbp^{-/ -} groups were isolated by a two?step perfusion method to establish an inflammation model induced by LPS. Agtr1a expression in Lbp^{-/ -} mouse primary hepatocytes was inhibited by losartan and siRNA. Cells were divided into a control group A (blank control), LPS group A (LPS stimulation), and losartan group (LPS stimulation was applied after 3 h of losartan treatment). Cells were divided into a control group B (blank control), LPS group B (LPS stimulation), negative control group (LPS stimulation was applied after 12 h of si?NC transfection), and interference group (LPS was applied after 12 h of si?agtr1a transfection). Primary hepatocytes in the WT group were divided into a control group (blank control) and LPS group (LPS stimulated). Western Blot was used to confirm knockout of LBP protein in Lbp^{-/ -} mouse primary hepatocytes. Changes in Agtr1a expression in primary hepatocytes of WT and Lbp^{-/ -} mice under LPS stimulation were verified by Western Blot. CCK8 assays, qPCR, and Western Blot were used to investigate the inhibitory effects of losartan and si?agtr1a on inflammation in primary hepatocytes of Lbp^{-/ -} mice. Results LBP protein was completely knocked out in primary liver cells of Lbp^{-/ -} mice. Compared with the wildtype group, Agtr1a expression in primary hepatocytes of Lbp^{-/ -} mice was significantly increased under LPS induction (P< 0?? 001). The cell survival rate of the inhibitor group was significantly increased (P< 0?? 01). Expression of proinflammatory factors in inhibitor and interference groups was significantly decreased (P< 0?? 01). Expression of inflammation?related protein p?ERK was also significantly decreased (P< 0?? 01). Conclusions Upregulation of Agtr1a expression in primary hepatocytes of Lbp^{-/ -} mice after LPS stimulation compensates for the effect of lipopolysaccharide?binding protein to promote inflammation. Inhibition of Agtr1a expression significantly reduces the LPS?induced inflammatory response in primary hepatocytes of Lbp^{-/ -} mice.

Abstract:Objective To observe the effect of early exercise intervention on motor dysfunction in a Parkinson′s disease (PD) model in rats, and to explore the cumulative effect of early exercise on improving motor dysfunction. Methods Male specific pathogen?free SD rats were randomly divided into four groups: sham?operated quiet (SHAM?S), sham?operated exercise (SHAM?E), PD quiet (PDS), and PD exercise (PDE) groups. A unilateral PD rat model was established by injecting 6?hydroxydopamine (6?OHDA) into the right medial forebrain bundle (MFB) of rats. The exercise group started running on a treadmill at 24 hours after surgery. Rats were assessed for behavioral functions using cylindrical and grid tests every 7 days after modeling. Tyrosine hydroxylase ( TH) content in striatum ( Str) was assessed by immunohistochemistry and western blotting on days 14 and 28 after modeling. Results (1)The number of TH+ cells in Str on the affected side of PD model rats was significantly decreased and then gradually decreased over time. The number of TH+ cells in Str on the affected side of PDE group rats was significantly increased, but there was no significant change over time. (2)The cylinder test score of PD model rats was significantly increased, but there was no significant change over time. In the PDE group, no statistically significant difference was found in test scores on days 1, 4, 7, 11, and 14. However, the scores were significantly decreased on days 21 and 28, indicating significant recovery in left forelimb activity. (3)The number of forelimb drops on the affected side was significantly increased in the PDS group, but did not show any significant change over time. Conversely, the number of forelimb drops on the affected side of PDE group rats was significantly decreased and continued to decrease over time. (4)Additionally, the number of grids and total steps of PDS group rats were significantly decreased at each time point, exhibiting a significant downward trend over time. Conversely, PDE group of rats showed a significant increase starting from day 4 and did not show any significant change over time. Conclusions Unilateral MFB injection of 6?OHDA into rats leads to motor dysfunction. Early exercise intervention effectively improves the motor dysfunction of PD model rats, while also suppressing the decrease in dopamine content in the substantia nigra striatum. Moreover, the effect of exercise intervention increases over time.

Abstract:Objective To study the modeling characteristics of hepatitis B virus (HBV) infection in animal models and to provide references for standardizing animal models of HBV infection. Methods We retrieved relevant literature published in the previous decade from the China National Knowledge Infrastructure, VIP, WanFang, and PubMed databases. The type of experimental animal, modeling method, timing of administration, positive controls, and high?frequency detection indicators were recorded and analyzed. Results In total, 59 articles that met the criteria were included. The main animals used for HBV infection models were C57BL/6 and BALB/ c mice. The most frequently used modeling method was hydrodynamic injection, and other method included intravenous, adeno?associated virus (AAV)?HBV infection, intraperitoneal injection, transgenic method, hypodermic injection, and natural infection. All positive controls were treated with antiviral drugs, with lamivudine being the most frequently used drug. Most drugs were administered for 14 days. The main detection indicators were serum virologic indices, including HBsAg, HBV DNA, and HBeAg. Some studies combined pathological examination of liver puncture tissue and aminotransferase levels to evaluate disease progression following HBV infection. Conclusions This study screened the most widely used animal models of HBV infection and the evaluation indicators, summarized the principle and specific method of modeling, and evaluated different HBV infection models by data mining to provide a reference for model application.

Abstract:Objective To discuss the elements of establishment and test indexes of osteoporosis animal models to provide a reference for standardization of the osteoporosis animal model. Methods Literature related to animal models of osteoporosis in the past 10 years was retrieved from China Knowledge Network, Wanfang, VIP, and PubMed databases. These data were analyzed using Excel and SPSS Modeler 18?? 0 to summarize the types of experimental animals, modeling method, and test indexes. Results A total of 457 studies were screened and included. Animal models of primary osteoporosis were mainly established in ovariectomized rat. The animal models of secondary osteoporosis were mainly established by glucocorticoid drugs. The main test indexes were bone mineral density, serum biochemical indexes related to bone metabolism, bone tissue morphology and pathological observations, bone microstructure, and bone biomechanics. Conclusions At present, ovariectomy and glucocorticoid induction in rats are the main method to establish osteoporosis models. A uniform standard has not been established for animal models of osteoporosis. Osteoporosis models require comprehensive evaluation by bone mineral density, serum biochemical indexes related to bone metabolism, bone tissue morphology and pathological observations, bone microstructure, and bone biomechanics.

Abstract:Connective tissue disease?interstitial lung disease is a common clinical rheumatic immune disease. Its etiology and pathogenesis are unknown, which causes a significant family and social burden to patients. Animal models are indispensable for research of CTD?ILD. Successful establishment of an animal model in line with the development of human disease is important to study the disease mechanism and develop therapeutic drugs. Therefore, by summarizing domestic and foreign literature on animal models related to CTD?ILD, this article summarizes the method, characteristics and shortcomings of model establishment to provide reference for researchers in related fields to select appropriate animal models.

Abstract:Hepatocellular carcinoma is one of the most common malignancies and has become the second leading cause of tumor?related death. With its morbidity and mortality increasing annually, studies on its pathogenesis, progression, tumor immune microenvironment, and new drug development need to be advanced. Zebrafish has become an irreplaceable model organism to simulate human diseases because of its high similarity in the genome, tissues, and organs. Zebrafish hepatocellular carcinoma models, including genetic and xenotransplantation models, have played an important role in revealing the genetic etiology of hepatocellular carcinoma, disease progression, functions and interactions of immune cells in the tumor microenvironment, and drug screening. This article systematically reviewed the development history of zebrafish hepatocellular carcinoma models, compared the advantages and disadvantages of various models, highlighted the shortcomings of existing models, and proposed the possible development direction of this research field in the future. This article reviews the important research progress of zebrafish hepatocellular carcinoma models in recent years to provide a reference for hepatocellular carcinoma related research.

Abstract:The Langendorff ex vivo heart perfusion model is a widely used technique used for investigating myocardial ischemia?reperfusion injury (MIRI) because of its notable advantages of high reproducibility, ease of drug administration, and low technical requirements. This model excludes confounding influences from other organ systems, neural pathways, and circulating factors, making it an ideal choice to study MIRI?related diseases. In this review, we provide a comprehensive assessment of the Langendorff perfusion technique, encompassing its procedural steps, animal selection criteria, perfusion modes, choice of perfusion buffer, relevant assessment indices, methods of inducing ischemia, and considerations for ischemia and reperfusion time intervals. We discuss the strengths and limitations of this model to aid researchers in its proper application in studying MIRI. By analyzing the relevant literature, this review serves as a valuable resource to enhance understanding and implementation of the Langendorff perfusion model in cardiac research.

Abstract:Mushroom poisoning is one of the most serious food safety problems in our country. More than 90% of deaths from mushroom poisoning are due to accidental ingestion of mushrooms containing amanitin. At present, many studies have focused on the toxicological mechanism, toxicokinetics, and treatment of amanitin poisoning, but comprehensive reviews on the establishment of animal models for various purposes are limited. Therefore, in accordance with the purpose and content of the experiment, this article reviews animal selection, types of poison and drugs, and injection method and doses to provide a theoretical basis and reference to establish animal models of amanitin poisoning.

Abstract:Diacetylmorphine (DAM) is a highly dependent central stimulant that produces severe neurotoxic effects over a long period. DAM is the most abused drug in our country and has become a serious public health issue endangering social stability. DAM induces nerve cell apoptosis, which has a great influence on human health. In this article, the mechanism of DAM addiction and withdrawal as well as its effects on neural factors are reviewed, providing a theoretical basis to study the mechanism of DAM toxicity in nerve cells.

Abstract:Exposure to ionizing radiation (IR) result in adverse health effects to individuals and overall public health. Establishing animal models to explore the mechanism of radiation damage is essential to develop and evaluate radiation countermeasures. The efficacy of protective drugs in humans overexposed to IR cannot be evaluated in clinical trials, and animal models that are consistent with human responses to IR and radiation countermeasures should be established. This article provides a brief review of the establishment and applications of animal models for IR research followed by introducing radiation?induced health damage.