查看更多>>摘要：Background:This study aimed to construct and characterize a humanized influenza mouse model expressing hST6GAL1.Methods:Humanized fragments,consisting of the endothelial cell-specific K18 pro-moter,human ST6GAL1-encoding gene,and luciferase gene,were microinjected into the fertilized eggs of mice.The manipulated embryos were transferred into the ovi-ducts of pseudopregnant female mice.The offspring were identified using PCR.Mice exhibiting elevated expression of the hST6GAL1 gene were selectively bred for propa-gation,and in vivo analysis was performed for screening.Expression of the humanized gene was tested by performing immunohistochemical (IHC) analysis.Hematologic and biochemical analyses using the whole blood and serum of humanized hST6GAL1 mice were performed.Results:Successful integration of the human ST6GAL1 gene into the mouse genome led to the overexpression of human SiaT ST6GAL1.Seven mice were identified as car-rying copies of the humanized gene,and the in vivo analysis indicated that hST6GAL1 gene expression in positive mice mirrored influenza virus infection characteristics.The IHC results revealed that hST6GAL1 was expressed in the lungs of humanized mice.Moreover,the hematologic and biochemical parameters of the positive mice were within the normal range.Conclusion:A humanized influenza mouse model expressing the hST6GAL1 gene was successfully established and characterized.
查看更多>>摘要：Background:Apolipoprotein E4 (ApoE4) allele is the strongest genetic risk factor for late-onset Alzheimer's disease,and it can aggravate depressive symptoms in non-AD patients.However,the impact of ApoE4 on AD-associated depression-like behaviors and its underlying pathogenic mechanisms remain unclear.Methods:This study developed a 5xFAD mouse model overexpressing human ApoE4 (E4FAD).Behavioral assessments and synaptic function tests were conducted to ex-plore the effects of ApoE4 on cognition and depression in 5xFAD mice.Changes in peripheral and central lipid metabolism,as well as the levels of serotonin (5-HT) and γ-aminobutyric acid (GABA) neurotransmitters in the prefrontal cortex,were examined.In addition,the protein levels of 24-dehydrocholesterol reductase/glycogen synthase kinase-3 beta/mammalian target of rapamycin (DHCR24/GSK3β/mTOR) and postsyn-aptic density protein 95/calmodulin-dependent protein kinase Ⅱ/brain-derived neu-rotrophic factor (PSD95/CaMK-Ⅱ/BDNF) were measured to investigate the molecular mechanism underlying the effects of ApoE4 on AD mice.Results:Compared with 5xFAD mice,E4FAD mice exhibited more severe depression-like behaviors and cognitive impairments.These mice also exhibited increased amyloid-beta deposition in the hippocampus,increased astrocyte numbers,and de-creased expression of depression-related neurotransmitters 5-HT and GABA in the prefrontal cortex.Furthermore,lipid metabolism disorders were observed in E4FAD,manifesting as elevated low-density lipoprotein cholesterol and reduced high-density lipoprotein cholesterol in peripheral blood,decreased cholesterol level in the prefron-tal cortex,and reduced expression of key enzymes and proteins related to cholesterol synthesis and homeostasis.Abnormal expression of proteins related to the DHCR24/GSK3β/mTOR and PSD95/CaMK-Ⅱ/BDNF pathways was also observed.Conclusion:This study found that ApoE4 overexpression exacerbates depression-like behaviors in 5xFAD mice and confirmed that ApoE4 reduces cognitive function in these mice.The mechanism may involve the induction of central and peripheral lipid metabolism disorders.Therefore,modulating ApoE expression or function to restore cellular lipid homeostasis may be a promising therapeutic target for AD comorbid with depression.This study also provided a better animal model for studying AD comorbid with depression.
查看更多>>摘要：Background:Nonalcoholic steatohepatitis (NASH) is characterized by liver steatosis,inflammation,and even fibrosis.NASH is likely to develop into cirrhosis and liver can-cer,the major causes of liver related deaths.We aimed to study the effect of probiot-ics on NASH via the gut-liver axis.Methods:Thirty male Sprague-Dawley rats were divided into three groups.A con-trol group of 10 rats was fed on a standard chow for 16 weeks.Twenty rats fed on a high-fat diet for 8 weeks were separated to two groups: a model group (10 rats) fed on vehicle for 8 weeks and a treatment group (10 rats) supplemented with binary Bacillus subtilis for 8 weeks.Hepatic expression of IL-6 and TNF-ɑ and ileum expression of IL-17 and occludin were measured.Results:The high-fat diet caused inflammation of the liver and ileum in rats.Binary Bacillus subtilis treatment reduces liver inflammation through the intestinal liver axis.Increased levels of IL-6 and TNF-α were detected in rats fed a high-fat diet,which were reduced to lower levels after treatment with binary Bacillus subtilis .In rats on the high-fat diet,elevated IL-17 levels and decreased occludin levels were observed.Treatment with Bacillus subtilis reduced IL-17 levels and restored the expression of occludin.Conclusion:Binary Bacillus subtilis has a beneficial effect on liver inflammation and intestinal damage.
查看更多>>摘要：Background:Severe trauma is associated with systemic inflammation and organ dys-function.Preclinical rodent trauma models are the mainstay of postinjury research but have been criticized for not fully replicating severe human trauma.The aim of this study was to create a rat model of multicompartmental injury which recreates profound traumatic injury.Methods:Male Sprague-Dawley rats were subjected to unilateral lung contusion and hemorrhagic shock (LCHS),multicompartmental polytrauma (PT) (unilateral lung con-tusion,hemorrhagic shock,cecectomy,bifemoral pseudofracture),or naïve controls.Weight,plasma toll-like receptor 4 (TLR4),hemoglobin,spleen to body weight ratio,bone marrow (BM) erythroid progenitor (CFU-GEMM,BFU-E,and CFU-E) growth,plasma granulocyte colony-stimulating factor (G-CSF) and right lung histologic injury were assessed on day 7,with significance defined as p values <0.05 (*).Results:Polytrauma resulted in markedly more profound inhibition of weight gain compared to LCHS (p=0.0002) along with elevated plasma TLR4 (p<0.0001),lower hemoglobin (p<0.0001),and enlarged spleen to body weight ratios (p=0.004).Both LCHS and PT demonstrated suppression of CFU-E and BFU-E growth compared to naïve (p<0.03,p<0.01).Plasma G-CSF was elevated in PT compared to both naïve and LCHS (p<0.0001,p=0.02).LCHS and PT demonstrated significant histologic right lung injury with poor alveolar wall integrity and interstitial edema.Conclusions:Multicompartmental injury as described here establishes a reproduc-ible model of multicompartmental injury with worsened anemia,splenic tissue en-largement,weight loss,and increased inflammatory activity compared to a less severe model.This may serve as a more effective model to recreate profound traumatic in-jury to replicate the human inflammatory response postinjury.
查看更多>>摘要：Background:Atherosclerosis is a chronic cardiovascular disease of great concern.However,it is difficult to establish a direct connection between conventional small animal models and clinical practice.The pig's genome,physiology,and anatomy reflect human biology better than other laboratory animals,which is crucial for studying the pathogenesis of atherosclerosis.Methods:We used whole-genome sequencing data from nine Bama minipigs to per-form a genome-wide linkage analysis,and further used bioinformatic tools to filter and identify underlying candidate genes.Candidate gene function prediction was performed using the online prediction tool STRING 12.0.Immunohistochemistry and immunofluorescence were used to detect the expression of proteins encoded by can-didate genes.Results:We mapped differential single nucleotide polymorphisms (SNPs) to genes and obtained a total of 102 differential genes,then we used GO and KEGG pathway enrichment analysis to identify four candidate genes,including SLA-1 ,SLA-2 ,SLA-3 ,and TAP2 .nsSNPs cause changes in the primary and tertiary structures of SLA-I and TAP2 proteins,the primary structures of these two proteins have undergone amino acid changes,and the tertiary structures also show slight changes.In addition,im-munohistochemistry and immunofluorescence results showed that the expression changes of TAP2 protein in coronary arteries showed a trend of increasing from the middle layer to the inner layer.Conclusions:We have identified SLA-I and TAP2 as potential susceptibility genes of atherosclerosis,highlighting the importance of antigen processing and immune re-sponse in atherogenesis.
查看更多>>摘要：Intimal hyperplasia (IH) is a negative vascular remodeling after arterial injury.IH occasionally occurs in elastase-induced abdominal aortic aneurysm (AAA) mouse models.This study aims to clarify the incidence and histological characteristics of IH in aneurysmal mice.A retrospective study was conducted by including 42 male elastase-induced mouse AAA models.The IH incidence,aortic diameters with or without IH,and hyperplasia lesional features of mice were analyzed.Among 42 elastase-induced AAA mouse models,10 mice developed mild IH (24％) and severe IH was found in only 2 mice (5％).The outer diameters of the AAA segments in mice with and without IH did not show significant difference.Both mild and severe IH lesions show strong smooth muscle cell positive staining,but endothelial cells were occasionally observed in severe IH lesions.There was obvious macrophage infiltration in the IH lesions of the AAA mouse models,especially in mice with severe IH.However,only a lower numbers of T cells and B cells were found in the IH lesion.Local cell-secreted matrix metalloproteinases (MMP) 2 was highly expressed in all IH lesions,but MMP9 was only overexpressed in severe lesions.In conclusion,this study is the first to demonstrate the occurrence of aneurysmal IH and its histological characteristics in an elastase-induced mouse AAA model.This will help researchers better understand this model,and optimize it for use in AAA-related research.
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