Animal Models and Experimental Medicine最新文献

Background: Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in recent years, but the pathogenesis is not fully understood. Therefore, it is important to establish an effective animal model for studying NAFLD.

Methods: Adult zebrafish were fed a normal diet or a high-fat diet combined with egg yolk powder for 30 days. Body mass index (BMI) was measured to determine overall obesity. Serum lipids were measured using triglyceride (TG) and total cholesterol (TC) kits. Liver lipid deposition was detected by Oil Red O staining. Liver injury was assessed by measuring glutathione aminotransferase (AST) and glutamic acid aminotransferase (ALT) levels. Reactive oxygen species (ROS) and malondialdehyde (MDA) were used to evaluate oxidative damage. The level of inflammation was assessed by qRT-PCR for pro-inflammatory factors. H&E staining was used for pathological histology. Caspase-3 immunofluorescence measured apoptosis. Physiological disruption was assessed via RNA-seq analysis of genes at the transcriptional level and validated by qRT-PCR.

Results: The high-fat diet led to significant obesity in zebrafish, with elevated BMI, hepatic TC, and TG. Severe lipid deposition in the liver was observed by ORO and H&E staining, accompanied by massive steatosis and ballooning. Serum AST and ALT levels were elevated, and significant liver damage was observed. The antioxidant system in the body was severely imbalanced. Hepatocytes showed massive apoptosis. RNA-seq results indicated that several physiological processes, including endoplasmic reticulum stress, and glucolipid metabolism, were disrupted.

Conclusion: Additional feeding of egg yolk powder to adult zebrafish for 30 consecutive days can mimic the pathology of human nonalcoholic fatty liver disease.

Background: Staphylococcus aureus can cause serious infections by secreting many superantigen exotoxins in "carrier" or "pathogenic" states. HLA DQ and HLA DR humanized mice have been used as a small animal model to study the role of two molecules during S. aureus infection. However, the contribution of HLA DP to S. aureus infection is unknown yet.

Methods: In this study, we have produced HLA DP401 and HLA DRA0101 humanized mice by microinjection of C57BL/6J zygotes. Neo-floxed IAβ^+/- mice were crossbred with Ella-Cre and further crossbred with HLA DP401 or HLA-DRA0101 humanized mice. After several rounds of traditional crossbreeding, we finally obtained HLA DP401-IAβ^-/- and HLA DRA-IAβ^-/- humanized mice, in which human DP401 or DRA0101 molecule was introduced into IAβ^-/- mice deficient in endogenous murine MHC class II molecules. A transnasal infection murine model of S. aureus pneumonia was induced in the humanized mice by administering 2 × 10⁸  CFU of S. aureus Newman dropwise into the nasal cavity. The immune responses and histopathology changes were further assessed in lungs in these infected mice.

Results: We evaluated the local and systemic effects of S. aureus delivered intranasally in HLA DP401-IAβ^-/- and HLA DRA-IAβ^-/- transgenic mice. S. aureus Newman infection significantly increased the mRNA level of IL 12p40 in lungs in humanized mice. An increase in IFN-γ and IL-6 protein was observed in HLA DRA-IAβ^-/- mice. We observed a declining trend in the percentage of F4/80⁺ macrophages in lungs in HLA DP401-IAβ^-/- mice and a decreasing ratio of CD4⁺ to CD8⁺ T cells in lungs in IAβ^-/- mice and HLA DP401-IAβ^-/- mice. A decreasing ratio of Vβ3⁺ to Vβ8⁺ T cells was also found in the lymph node of IAβ^-/- mice and HLA DP401-IAβ^-/- mice. S. aureus Newman infection resulted in a weaker pathological injury in lungs in IAβ^-/- genetic background mice.

Conclusion: These humanized mice will be an invaluable mouse model to resolve the pathological mechanism of S. aureus pneumonia and study what role DP molecule plays in S. aureus infection.

Background: The effect of platelet factor 4 (PF4) on bone marrow mesenchymal stem cells (BMMSCs) and osteoporosis is poorly understood. Therefore, this study aimed to evaluate the effects of PF4-triggered bone destruction in mice and determine the underlying mechanism.

Methods: First, in vitro cell proliferation and cell cycle of BMMSCs were assessed using a CCK8 assay and flow cytometry, respectively. Osteogenic differentiation was confirmed using staining and quantification of alkaline phosphatase and Alizarin Red S. Next, an osteoporotic mouse model was established by performing bilateral ovariectomy (OVX). Furthermore, the PF4 concentrations were obtained using enzyme-linked immunosorbent assay. The bone microarchitecture of the femur was evaluated using microCT and histological analyses. Finally, the key regulators of osteogenesis and pathways were investigated using quantitative real-time polymerase chain reaction and Western blotting.

Results: Human PF4 widely and moderately decreased the cell proliferation and osteogenic differentiation ability of BMMSCs. Furthermore, the levels of PF4 in the serum and bone marrow were generally increased, whereas bone microarchitecture deteriorated due to OVX. Moreover, in vivo mouse PF4 supplementation triggered bone deterioration of the femur. In addition, several key regulators of osteogenesis were downregulated, and the integrin α5-focal adhesion kinase-extracellular signal-regulated kinase (ITGA5-FAK-ERK) pathway was inhibited due to PF4 supplementation.

Conclusions: PF4 may be attributed to OVX-induced bone loss triggered by the suppression of bone formation in vivo and alleviate BMMSC osteogenic differentiation by inhibiting the ITGA5-FAK-ERK pathway.

Background: Acute pancreatitis (AP) is a severe disorder that leads to high morbidity and mortality. Appropriate reference genes are important for gene analysis in AP. This study sought to study the expression stability of several reference genes in the golden Syrian hamster, a model of AP.

Methods: AP was induced in golden Syrian hamster by intraperitoneal injection of ethanol (1.35 g/kg) and palmitoleic acid (2 mg/kg). The expression of candidate genes, including Actb, Gapdh, Eef2, Ywhaz, Rps18, Hprt1, Tubb, Rpl13a, Nono, and B2m, in hamster pancreas at different time points (1, 3, 6, 9, and 24 h) posttreatment was analyzed using quantitative polymerase chain reaction. The expression stability of these genes was calculated using BestKeeper, Comprehensive Delta CT, NormFinder, and geNorm algorithms and RefFinder software.

Results: Our results show that the expression of these reference genes fluctuated during AP, of which Ywhaz and Gapdh were the most stable genes, whereas Tubb, Eef2, and Actb were the least stable genes. Furthermore, these genes were used to normalize the expression of TNF-α messenger ribonucleic acid in inflamed pancreas.

Conclusions: In conclusion, Ywhaz and Gapdh were suitable reference genes for gene expression analysis in AP induced in Syrian hamster.

Background: Diabetes-induced oxidative stress can have adverse effects on sperm and its DNA integrity. The Ashrasi date palm (ADP) has potent antioxidant properties. The aim of this study was to evaluate the antioxidant effect of ADP hydroalcoholic extract on sperm parameters and sperm DNA fragmentation in diabetic rats.

Methods: Forty male rats were randomly divided into five groups (n = 7): 1, control; 2, diabetic; 3-5, diabetic + ADP (30, 90 and 270 mg/kg for groups 3, 4 and 5, respectively). After preparation of ADP extract and its phytochemical screening, it was administered orally to rats, once a day for 5 weeks. At the end of the study, sperm parameters and sperm DNA fragmentation in all groups were investigated.

Results: At doses of 90 and 270 mg/kg, ADP extract significantly increased the sperm viability compared to diabetic group 2 (p = 0.04 and p = 0.03, respectively) and resulted in a significant decrease in immotile sperm (p = 0.002 and p = 0.006, respectively). At a dose of 270 mg/kg, a considerable enhancement of forward sperm motility was observed (p = 0.04) and there was a significant decrease in sperm DNA fragmentation (p = 0.04).

Conclusions: The findings of the present study show for the first time that the hydroalcoholic extract of ADP has protective and antioxidant effects against diabetes-induced oxidative stress and can improve sperm parameters and protect sperm DNA integrity.

Pulmonary hypertension (PH) is clinically divided into 5 major types, characterized by elevation in pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR), finally leading to right heart failure and death. The pathogenesis of this arteriopathy remains unclear, leaving it impossible to target pulmonary vascular remodeling and reverse the deterioration of right ventricular (RV) function. Different animal models have been designed to reflect the complex mechanistic origins and pathology of PH, roughly divided into 4 categories according to the modeling methods: non-invasive models in vivo, invasive models in vivo, gene editing models, and multi-means joint modeling. Though each model shares some molecular and pathological changes with different classes of human PH, in most cases the molecular etiology of human PH is poorly known. The appropriate use of classic and novel PH animal models is essential for the hunt of molecular targets to reverse severe phenotypes.

Background: Hypertension and dyslipidemia are considered reversible risk factors for cardiovascular disease. The purpose of this study was to explore the impact of traditional and nontraditional blood lipid profiles on the risk of left ventricular hypertrophy (LVH) and to explore the superposition effect of dyslipidemia combined with hypertension.

Methods: Data on 9134 participants (53.5 ± 10.3 years old) from the Northeast China Rural Cardiovascular Health Study (NCRCHS) were statistically analyzed. The blood lipid profile was measured by total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total glyceride (TG), and calculated nontraditional blood lipid indices including non-HDL-C, atherosclerosis index (AI), TC/HDL-C, and residual cholesterol (RC).

Results: After the adjustment of age and gender, the odds ratios (ORs) of LVH in patients with hypertension, high LDL-C, high non-HDL-C, high AI, and high TC/HDL-C were 3.97 (3.31-4.76), 1.27 (1.02-1.59), 1.21 (1.04-1.39), 1.33 (1.15-1.53), and 1.42 (1.22-1.65), respectively. After full adjustment of potential confounding factors, high AI and TC/HDL-C were associated with LVH rather than traditional blood lipid indices. The combination of hypertension and nontraditional dyslipidemia (defined by high AI and TC/HDL-C) was associated with the highest risk of LVH, especially in participants under 45 years of age. The risk was more significant in men, 5.09-fold and 6.24-fold, respectively, compared with 3.66-fold and 4.01-fold in women.

Conclusions: People with dyslipidemia defined by nontraditional blood lipid indices (high AI and high TC/HDL-C) and hypertension were more likely to develop LVH.

Object: Early-life neglect has irreversible emotional effects on the central nervous system. In this work, we aimed to elucidate distinct functional neural changes in medial prefrontal cortex (mPFC) of model rats.

Methods: Maternal separation with early weaning was used as a rat model of early-life neglect. The excitation of glutamatergic and GABAergic neurons in rat mPFC was recorded and analyzed by whole-cell patch clamp.

Results: Glutamatergic and GABAergic neurons of mPFC were distinguished by typical electrophysiological properties. The excitation of mPFC glutamatergic neurons was significantly increased in male groups, while the excitation of mPFC GABAergic neurons was significant in both female and male groups, but mainly in terms of rest membrane potential and amplitude, respectively.

Conclusions: Glutamatergic and GABAergic neurons in medial prefrontal cortex showed different excitability changes in a rat model of early-life neglect, which can contribute to distinct mechanisms for emotional and cognitive manifestations.