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Objective • To explore whether different test indicators and observation periods in contextual fear conditioning test affect the detection effectiveness of learning and memory ability of 5XFAD transgenic mice. Methods • Twelve 4-month-old female 5XFAD transgenic progeny mice and 14 4-month-old female LM progeny mice were selected, which were produced by crossing male 5XFAD transgenic mice and female C57BL/6 mice, to conduct open field test and contextual fear conditioning test in succession. Total distance and velocity in open field test and average motion index in the first 60 s of training stage in contextual fear conditioning test of the two groups of mice were used to evaluate the difference of locomotor activity. Besides, the first 180 s, 181-360 s and the first 300 s of testing stage for observation were selected to evaluate the selection effects on percent freeze and activity suppression ratio. Then further investigation was launched to explore the effects of different observation periods on the detection effectiveness of percent freeze and activity suppression ratio. Results • The differences of total distance and total velocity of the two groups of mice in open field test were not statistically significant, however the average motion index in the first 60 s of training stage in contextual fear conditioning test of 5XFAD transgenic mice was significantly higher than that of LM mice (P=0.027). The comparison of percent freeze among the three groups of observation periods of LM mice had significant difference (both P<0.05), while there was no statistical significance in activity suppression ratio. The comparisons of percent freeze and activity suppression ratio among the three groups of observation periods of 5XFAD mice had no significant difference. The differences of percent freeze between 5XFAD mice and LM mice was not statistically significant during the three observation periods. However, the activity suppression ratio of 5XFAD mice was significantly higher than that of LM mice in the first 180 s (P=0.038), in the other two observation periods the difference of activity suppression ratio between the two groups of mice was not statistically significant. Conclusion • The average motion index detected in training stage in contextual fear conditioning test is more sensitive than total distance and total velocity detected in open field test for evaluating locomotor activity of 5XFAD mice. In contextual fear conditioning test, different observation periods have effects on the value of percent freeze provided by single strain of mice, while the value of activity suppression ratio remains unaffected. Activity suppression ratio is more precise than percent freeze to reflect the cognitive deficiency of 5XFAD mice. It is more accurate to select the first 180 s of testing stage for observation.
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The transition from spermatogonia to spermatocytes and the initiation of meiosis are key steps in spermatogenesis and are precisely regulated by a plethora of proteins. However, the underlying molecular mechanism remains largely unknown. Here, we report that Src homology domain tyrosine phosphatase 2 (Shp2; encoded by the protein tyrosine phosphatase, nonreceptor type 11 [Ptpn11] gene) is abundant in spermatogonia but markedly decreases in meiotic spermatocytes. Conditional knockout of Shp2 in spermatogonia in mice using stimulated by retinoic acid gene 8 (Stra8)-cre enhanced spermatogonial differentiation and disturbed the meiotic process. Depletion of Shp2 in spermatogonia caused many meiotic spermatocytes to die; moreover, the surviving spermatocytes reached the leptotene stage early at postnatal day 9 (PN9) and the pachytene stage at PN11-13. In preleptotene spermatocytes, Shp2 deletion disrupted the expression of meiotic genes, such as disrupted meiotic cDNA 1 (Dmc1), DNA repair recombinase rad51 (Rad51), and structural maintenance of chromosome 3 (Smc3), and these deficiencies interrupted spermatocyte meiosis. In GC-1 cells cultured in vitro, Shp2 knockdown suppressed the retinoic acid (RA)-induced phosphorylation of extracellular-regulated protein kinase (Erk) and protein kinase B (Akt/PKB) and the expression of target genes such as synaptonemal complex protein 3 (Sycp3) and Dmc1. Together, these data suggest that Shp2 plays a crucial role in spermatogenesis by governing the transition from spermatogonia to spermatocytes and by mediating meiotic progression through regulating gene transcription, thus providing a potential treatment target for male infertility.
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BACKGROUND: The inducible forebrain-specific cholecystokinin receptor-2 (CCKR-2) double transgenic (tTA/tetO-CCKR-2 tg, abbreviated as dtg) mice are an ideal model of anxiety-related diseases. However, there is still a lack of model identification and life related data OBJECTIVE: To identify the genomic DNA of the offspring and the specific expression of CCKR-2 transgene in the forebrain, and to analyze the survival probability of dtg mice. METHODS: α-CaMKII/tTA single transgenic mice and tetO-CCKR-2 single transgenic mice were cross-fertilized to construct a dtg mouse model. The genomic DNA was extracted from the tail of the offspring, and the genotypes were detected by PCR and agarose gel electrophoresis. Wild-type (WT) mice were used as controls. In situ hybridization was used to detect the expression of CCKR-2. Survival of dtg mice and WT mice (30 females and 30 males) was observed and recorded within 2 years. The study protocol was approved by the Experimental Animal Ethics Committee of Southwest Medical University, with an approval No. 20150068. RESULTS AND CONCLUSION: Agarose gel electrophoresis results showed the molecular weight of the PCR products of dtg mice was consistent with the expected target gene fragment. In situ hybridization results showed a strong signal of CCKR-2 was detected in the forebrain of dtg mice, but hardly present in the WT mice. The median survival time of dtg mice was 76 weeks in females and 77 weeks in males. The survival probability was decreased with age in dtg mice. The survival probability of WT mice was significantly better than that of dtg mice (P < 0.001). There was no significant sex difference between males and females of dtg mice (P=0.577). Therefore, the specific expression of CCKR-2 transgene in the forebrain can be identified using PCR amplification, genomic DNA extraction, agarose gel electrophoresis, and in situ hybridization. tTA/tetO-CCKR-2 double transgenic induction may shorten the survival time of mice, but no significant difference is observed between the females and males of dtg mice.
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Objective@#To investigate the role of HIV-1 envelope protein gp120 in cognitive impairment induced by neuronal damage.@*Methods@#Western blot and immunofluorescence assay were used to detect microglia activation, inflammatory factor expression and neuronal damage after gp120 treatment. Neuronal damage and neurocognitive performance in gp120-transgenic mice were evaluated using immunohistochemical staining and behavioral analysis, respectively.@*Results@#In vivo and in vitro experiments showed that HIV-1 gp120 significantly induced the expression of caspase-1 and IL-1β, and indirectly caused neuronal synaptic shortening and neuronal damage (P<0.05). Compared with wild-type mice, gp120-transgenic mice showed significant cortical and hippocampal glial activation, neuronal loss, dendritic damage and neurocognitive disorders.@*Conclusions@#HIV-1 gp120 might cause neuronal damage through activating the release of inflammatory factor by microglia and involve in neurocognitive impairment.
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Objective To investigate the role of HIV-1 envelope protein gp120 in cognitive im-pairment induced by neuronal damage. Methods Western blot and immunofluorescence assay were used to detect microglia activation, inflammatory factor expression and neuronal damage after gp120 treatment. Neu-ronal damage and neurocognitive performance in gp120-transgenic mice were evaluated using immunohisto-chemical staining and behavioral analysis, respectively. Results In vivo and in vitro experiments showed that HIV-1 gp120 significantly induced the expression of caspase-1 and IL-1β, and indirectly caused neuro-nal synaptic shortening and neuronal damage (P<0. 05). Compared with wild-type mice, gp120-transgenic mice showed significant cortical and hippocampal glial activation, neuronal loss, dendritic damage and neu-rocognitive disorders. Conclusions HIV-1 gp120 might cause neuronal damage through activating the re-lease of inflammatory factor by microglia and involve in neurocognitive impairment.
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OBJECTIVE@#To construct a HIV-1 gp120 transgenic mouse model (gp120) with 7 nicotinic acetylcholine receptor (7nAChR) gene knockout.@*METHODS@#The 7nAChR gene knockout mice (7R) were crossed with HIV-1gp120 transgenic mice (gp120) to generate F1 generation mice. We selected the F1 mice with the genotype of 7R/gp120 to mate to obtain the F2 mice. The genotypes of the F3 mice were identified by PCR, and the protein expressions in the double transgenic animal model was analyzed by immunohistochemistry. BV2 cells were treated with gp120 protein and 7nAChR inhibitor, and the expressions of IL-1β and TNF- were detected using ELISA.@*RESULTS@#The results of PCR showed the bands of the expected size in F3 mice. Two F3 mice with successful double gene editing (7R/gp120) were obtained, and immunohistochemistry showed that the brain tissue of the mice did not express 7 nAChR but with high gp120 protein expression. In the cell experiment, treatment with gp120 promoted the secretion of IL-1β and TNF- in BV2 cells, while inhibition of 7nAChR significantly decreased the expression of IL-1β and TNF- ( < 0.001).@*CONCLUSIONS@#By mating gp120 Tg mice with 7R mice, we obtained gp120 transgenic mice with 7nAChR gene deletion, which serve as a new animal model for exploring the role of 7nAChR in gp120-induced neurotoxicity.
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Animals , Mice , Disease Models, Animal , Glycoproteins , Mice, Knockout , Mice, Transgenic , Tumor Necrosis Factor-alpha , alpha7 Nicotinic Acetylcholine Receptor , MetabolismABSTRACT
@#This study aims to discuss the therapeutic effect of magnesium isoglycyrrhizinate on hepatitis B virus(HBV)transgenic mouse and its effect on cellular immunity and liver inflammation. The changes of serum aspartate aminotransferase(AST)and alanine aminotransferase(ALT)activity, the difference of serum hepatitis B surface antigen(HBsAg), liver tissue HBsAg mRNA, and the pathological morphological changes of liver tissue were detected to investigate the hepatic inflammatory lesions and the efficacy of magnesium isoglycyrrhizinate in HBV transgenic mouse. Peripheral blood lymphocytes were classified by flow cytometry, and serum cytokines were detected by cytometric bead array(CBA)to explore the mechanism of magnesium isoglycyrrhizinate to reduce hepatic inflammatory lesions in HBV transgenic mouse. After grouping HBV transgenic mouse with serum transaminase activity and 35 days of continuous administration, serum transaminases level in magnesium isoglycyrrhizinate ［15 mg/(kg ·d)］ group was significantly lower than that in control group(P< 0. 05), serum HBsAg protein and liver tissue HBsAg mRNA increased with time, but there was no significant difference between the two groups. The main pathological changes of liver were liver cell swelling, necrosis and focal inflammatory cell infiltration, and the pathological changes of liver in magnesium isoglycyrrhizinate group were lighter than those in control group. The number of CD8+ cells in the blood of magnesium isoglycyrrhizinate group was significantly less than that in the control group(P< 0. 05)and the CD4+/CD8+ cell ratio was significantly higher than that in the control group(P< 0. 05). The content of inflammatory cytokines in serum of magnesium isoglycyrrhizinate group decreased significantly(P< 0. 05). Magnesium isoglycyrrhizinate can regulate the immune function of HBV transgenic mouse, decrease the infiltration of inflammatory cells in hepatic tissue and hepatocyte injury, but do not affect the expression of hepatocyte HBsAg.
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Objective: To establish the transgenic mice-derived allografts (MDAs) so as to provide an appropriate experiment model of pancreatic cancer. Methods: By using the tissue fragments derived from transgenic mice with pancreatic cancer named LSL-KrasG12D/+; Trp53fl/+; Pdx1-Cre (KPC) mice and subcutaneous transplant technique, we constructed the MDAs. We evaluated the histopathological characteristics of MDAs and infiltration of immune cells by H&E staining, Masson's staining and immunohistochemical method. Results: MDAs could mimic the pathological morphology, proliferation and fibrosis of pancreatic cancer precisely. Besides, the infiltration of immune cells in MDAs tumor was the same as that of pancreatic cancer. Conclusion: MDAs are an effective model to mimic the development of pancreatic cancer.
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OBJECTIVE To investigate the effect and mechanisms of Liuwei Dihuang Decoction (LW)on cognition in PrP-hAβPPswe/PS1ΔE9(APP/PS1)transgenic mice.METHODS LW was adminis-trated with oral for 3 months.The locomotor activity test was performed to investigate the spontaneous motor activity of mice. The Morris water maze test and shuttle box test were performed to investigate the spatial learning and memory and active avoidance response respectively.The Αβ deposits and neuron loss in the hippocampus was detected by immunofluorescence staining and nissl staining respectively. The flow cytometry was employed to investigate the lymphocyte subsets of the mice.The 3H-thymidine incorporation was performed to investigate the splenocytes proliferation. RESULTS The treatment of LW ameliorated the impairments of spatial learning and memory and active and passive avoidance in APP/PS1 mice. The administration of LW alleviated neuron loss in the brain, suppressed amyloid-β (Αβ) deposits in the hippocampus of APP/PS1 mice. The treatment of LW significantly increased ConA-and LPS-induced proliferation of splenocytes,increased CD3+T cells and CD19+B cells in the spleen lymphocytes and reduced Gr1+cells in APP/PS1 mice.CONCLUSION This data indicated the adminis-tration of LW ameliorated behavioral and pathological deterioration via regulating immune function.
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Objective To investigate the distribution of divalent metal transporter 1 (DMT1) in the cerebellum of APP/PS1 transgenic mouse. Methods Immunohistochemistry, immunofluorescence, and confocal laser scanning microscopy were used to analyze the relationship between DMTl and amyloid beta (Aβ) and their distribution in senile plaques. Western blotting was used to analyze DMT1 protein level in the APP/PS1 transgenic mouse cerebellum. Results DMTl and Aβ were mainly located in the amyloid plaques, which were predominately located in the molecular layer of the cerebellar cortex of the transgenic mouse. Only a few plaques could be seen in the Purkinje cell layer and granular layer. Confocal laser microscopy revealed the DMTl and Aβ were co-localized in senile plaques. Conclusion The abundant expression of DMTl protein suggests that DMTl and the divalent metal ions that it transports might be involved in the formation of Aβ senile plaques and other pathological processes in the cerebellum in Alzheimer' s disease.
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Objective To research the functional and structural change in TgAP-PswePS1 transgenic mice after intensive light exposure insult.Methods APPswe/PS1 transgenic mice at the age of 6 months old were grouped for experiments,the transgenic mice were replaced by light insult device for 6 months,while the control mice were kept in normal conditions.After 6 months light exposure,the eyes of control and experimental mice were examined with electroretinography (ERG).The retinal morphology change was investigated with H&E staining.All of the results were quantified and statistically analyzed.Results In the control group,the amplitudes of a and b wave in the rod response were (18.33 ±3.53) μV and (107.58 ± 14.72) μV,while (64.80 ±7.57) μV and (178.76 ± 14.47) μV for the amplitudes of a and b wave in the maximum response;After treated by 6 months of intensive light exposure,in experimental group mice,the amplitudes of a and b wave in the rod response were (17.92 ±4.89) μV and (21.83 ± 5.51) μV;While in the maximum response a striking decrease was detected with a wave (18.23 ±4.44) μV and b wave (24.50 ± 4.49) μV,by compared with control group,the difference were statistical significant (all P ＜ 0.05).Histopathological analysis found significant loss of outer nuclear layer,photoreceptor out segment,whereas controls remained little change in the retina.And the retinal thickness decreased significantly from (181.32 ± 13.47) μm in control group to (102.34 ±9.38) μm after light insults in experimental group,the difference was statistical significant (P =0.017).Conclusion Intensive light exposure can cause the retinal structural and functional disorder in the AP-Pswe/PS1 transgenic mouse.
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Objective To research the choroidal neovascularization (CNV)in TgAPPswePS1 transgenic mice after intensive light exposure injury.Methods Twenty TgAPPswe/PS1 transgenic mice at the age of 6 months were grouped for experiments.The treated groups of 12 mice were treated by a source of 10 000 lux cool full spectrum light for 6 months,12 hours per day;While the control groups of 8 mice were kept in normal conditions.The mice eyes of the experimental group and control group were examined with HE/Toluidin blue staining,the retinal structure was observed,and the number of CNV was counted.The expression of VEGF and Aβ were examined with immunofluorescence on the retinal pigment epithelial (RPE) flat mount.All of the results were quantified and statistically analyzed.Results After treated by 6 months of intensive light exposure in the experimental group,histopathological analysis has found significant loss of outer nuclear layer/photoreceptor out segment and outer plexiform layer as compared with the control group;At the same time,abnormal hypo-and hyper-pigmentation,vacuoles and disruption in the RPE layer,remarkable CNV were found in the experiment group by Toluidin blue staining,and the incidence of CNV was 18.75％.The VEGF expression domenstrated.a diffusive and deposition pattern along the neovessels which showed a significant increase of (6.59 ± 1.14) fold changes as compared with the control group.The difference was statistical significant (P ＜ 0.05).Then the Aβ deposits were positive expressed in the RPE layers after intensive light exposure treatment,and pathological deposition of Aβ in the RPE showed plaque like displayed by confocal Z-stack microscopy,and the drusenoid Aβ deposits were found alone with the neovessels on the RPE flat mount.The deposition of Aβ protein increased with (6.45 ± 2.93) fold changes as compared with the control group,and the difference was statistical significant.Conclusion CNV with degenerative changes in the outer retina can be induced by intensive light exposure in the APPswe/PS1 transgenic mouse.These results suggest that an Alzheimer's transgenic animal model might be an alternative animal model for CNV if combined with intensive light exposure.
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OBJECTIVE To investigate the effect of LW- AFC, a new formula of the main active components extracted from Liuwei Dihuang decoction, on treatment of Alzheimer disease (AD) in mouse models. METHODS After treatment LW- AFC, mice were cognitively evaluated in behavioral experiments. Neuron loss, amyloid-β(Αβ) deposition, and Αβ level were analyzed using Nissl staining, immunofluorescence, and an AlphaLISA assay, respectively. Multiplex bead analysis, a radioimmunoassay, immunochemiluminometry, and an ELISA were used to measure cytokine and hormone levels. Lymphocyte subsets were detected using flow cytometry. RESULTS LW-AFC ameliorated the cognitive impairment observed in APP/PS1 mice, including the impairment of object recognition memory, spatial learning and memory, and active and passive avoidance. In addition, LW-AFC alleviated the neuron loss in the hippocampus, suppressed Αβ deposition in the brain, and reduced the concentration of Aβ1- 42 in the hippocampus and plasma of APP/PS1 mice. LW-AFC treatment also significantly decreased the secretion of corticotropin-releasing hormone and gonadotropin-releasing hormone in the hypothalamus, and adrenocorticotropic hormone, luteinizing hormone, and follicle- stimulating hormone in the pituitary. Moreover, LW-AFC increased CD8+CD28+T cells, and reduced CD4+CD25+Foxp3+T cells in the spleen lymphocytes, down- regulated interleukin(IL)- 1β, IL- 2, IL- 6, IL- 23, granulocyte- macrophage colony stimulating factor, and tumor necrosis factor-α and -β, and up-regulated IL-4 and granulocyte colony stimulating factor in the plasma of APP/PS1 mice. CONCLUSION LW-AFC ameliorated the behavioral and pathological deterioration of APP/PS1 transgenic micevia the restoration of the NIM network to a greater extent than either memantineor donepezil, which supports the use of LW-AFC as a potential agent for AD therapy.
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Down syndrome cell adhesion molecule (DSCAM) is located within the Down syndrome critical region of chromosome 21. DSCAM is a broadly expressed neurodevelopmental protein involved in synaptogenesis, neurite outgrowth, and axon guidance. We previously demonstrated DSCAM overexpression in the cortex of amyloid precursor protein (APP) transgenic mice, suggesting possible regulatory interactions between APP and DSCAM. APP mice exhibit deficits in hippocampus-dependent learning and memory. In this preliminary study, we examined age-related changes in DSCAM expression within the hippocampus in 16 APP transgenic mice (1, 3, 6 and 12 months old). Hippocampus-dependent spatial memory was assessed in APP mice and age-matched wild type littermates (WTs) using the Morris water maze (MWM). The cellular distribution of hippocampal DSCAM and total expression at both mRNA and protein levels were measured by immunohistochemistry, qRT-PCR, and western blotting, respectively. APP mice exhibited spatial memory deficits in the MWM. Intense DSCAM immunoreactivity was observed in the dentate gyrus granule cell layer and hippocampal stratum pyramidale. Total hippocampal DSCAM mRNA and protein expression levels were substantially higher in APP mice than WTs at 1 and 3 months of age. Expression decreased with age in both groups but remained higher in APP mice. DSCAM is overexpressed in the hippocampus over the first 12 months of life in APP mice, but especially during maturation to adulthood. In conclusion, these results suggest an association between DSCAM and APP mice, which is characterized by neuropathology and behavioral deficits. These results provide some clues for future studies on the role of DSCAM overexpression in the precocious cognitive decline observed in APP transgenic mice.
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Animals , Amyloid beta-Protein Precursor/genetics , Cell Adhesion Molecules/metabolism , Hippocampus/metabolism , Age Factors , Brain/metabolism , Disease Models, Animal , Down Syndrome/metabolism , Genotype , Learning Disabilities/metabolism , Memory Disorders/metabolism , Mice, Inbred C57BL , Mice, TransgenicABSTRACT
PURPOSE: MicroRNAs (miRNAs) regulate various cellular functions, including development, cell proliferation, apoptosis, and tumorigenesis. Different signatures associated with various tissue types, diagnosis, progression, prognosis, staging, and treatment response have been identified by miRNA expression profiling of human tumors. miRNAs function as oncogenes or as tumor suppressors. The relationship between gastric cancer and miRNA garnered attention due to the high incidence of gastric cancer in Asian countries. miR-222/221 expression increases in gastric tumor tissues. The oncogenic effect of miR-222/221 was previously determined in functional studies and xenograft models. In this study, transgenic mice over-expressing miR-222/221 were generated to confirm the effect of miR-222/221 on gastric carcinogenesis. MATERIALS AND METHODS: At 6 weeks of age, 65 transgenic mice and 53 wild-type mice were given drinking water containing N-nitroso-N-methylurea (MNU) for 5 alternating weeks to induce gastric cancer. The mice were euthanized at 36 weeks of age and histologic analysis was performed. RESULTS: Hyperplasia was observed in 3.77% of the wild-type mice and in 18.46% of the transgenic mice (p=0.020). Adenoma was observed in 20.75% of the wild-type mice and 26.15% of the transgenic mice (p=0.522). Carcinoma was observed in 32.08% of the wild-type mice and 41.54% of the transgenic mice (p=0.341). The frequency of hyperplasia, adenoma, and carcinoma was higher in transgenic mice, but the difference was statistically significant only in hyperplasia. CONCLUSION: These results suggest that hyperplasia, a gastric pre-cancerous lesion, is associated with miR-222/221 expression but miR-222/221 expression does not affect tumorigenesis itself.
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Animals , Humans , Mice , Adenoma , Apoptosis , Asian People , Carcinogenesis , Cell Proliferation , Diagnosis , Drinking Water , Heterografts , Hyperplasia , Incidence , Mice, Transgenic , MicroRNAs , Oncogenes , Prognosis , Stomach NeoplasmsABSTRACT
Genetically-engineered mouse (GEM) models have provided significant contributions to our understanding of cancer biology and developing anticancer therapeutic strategies. The development of GEM models that faithfully recapitulate histopathological and clinical features of human cancers is one of the most pressing needs to successfully conquer cancer. In particular, doxycycline-inducible transgenic mouse models allow us to regulate (induce or suppress) the expression of a specific gene of interest within a specific tissue in a temporal manner. Leveraging this mouse model system, we can determine whether the transgene expression is required for tumor maintenance, thereby validating the transgene product as a target for anticancer drug development (target validation study). In addition, there is always a risk of tumor recurrence with cancer therapy. By analyzing recurrent tumors derived from fully regressed tumors after turning off transgene expression in tumor-bearing mice, we can gain an insight into the molecular basis of how tumor cells escape from their dependence on the transgene (tumor recurrence study). Results from such studies will ultimately allow us to predict therapeutic responses in clinical settings and develop new therapeutic strategies against recurrent tumors. The aim of this review is to highlight the significance of doxycycline-inducible transgenic mouse models in studying target validation and tumor recurrence.
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Animals , Humans , Mice , Biology , Doxycycline , Drug Delivery Systems , Mice, Transgenic , Recurrence , Transgenes , United NationsABSTRACT
Minor histocompatibility antigens are MHC-bound peptides and contribute to the generation of allo-responses after allogeneic transplantation. H60 is a dominant minor H antigen that induces a strong CD8 T-cell response in MHC-matched allogeneic transplantation settings. Here, we report establishment of a TCR transgenic mouse line named J15, wherein T cells express TCRs specific for H60 in complex with H-2K(b), and different fates of the thymocytes expressing J15 TCRs in various thymic antigenic environments. Thymocytes expressing the J15 TCRs were positively selected and differentiated into CD8+ single positive (SP) cells in the thymus of C57BL/6 mice, wherein the cognate antigen H60 is not expressed. However, thymocytes were negatively selected in thymus tissue where H60 was transgenically expressed under the control of the actin promoter, with double-positive stages of cells being deleted. Despite the ability of the H60H peptide (LTFHYRNL) variant to induce cytotoxic activity from H60-specific CTL lines at ~50% of the activity induced by normal H60 peptides (LTFNYRNL), J15-expressing thymocytes were positively selected in the thymus where the variant H60H was transgenically expressed. These results demonstrate that a single amino-acid change in the H60 epitope peptide influences the fate of thymocytes expressing the cognate TCR.
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Animals , Mice , Actins , Histocompatibility Antigens , Histocompatibility , Mice, Transgenic , Minor Histocompatibility Antigens , Peptides , T-Lymphocytes , Thymocytes , Thymus Gland , Transplantation, HomologousABSTRACT
Aim To observe the effects of effective fraction of Epimedium,Astragalus,Radix Puerariae on behavioral and pathological changes in a transgenic mouse model of Alzheimer’s disease.Methods Six-month-old APPswe /PS1 ΔE9 transgenic mice were ran-domly divided into 2 groups:model group and effective fraction group,1 0 mice each group.The mice in the effective fraction group were treated with the effective fraction of Astragalus,Radix Puerariae,Epimedium compound for 8 weeks.The C57BL/6J mice were used as negative control group.After 8 weeks,the learning and memory function were measured by Morris water maze,the pathological changes in brain tissue were ob-served by Modified Bielschowsky staining and Nissl 's staining.Results During place navigation trial,the escape latency in the APPswe /PS1 ΔE9 double transgenic model mice was longer than those of the mice of C57 (P 0.05 ). The Modified Bielschowsky staining shows that the neuron fibers of the cerebral cortex of APPswe /PS1 ΔE9 double transgenic mice were enlarged,swelling,and dense.There were senile plaques and nerve fiber tangles in the cerebral cortex of APPswe /PS1 ΔE9 double transgenic mice.The neuron fibers of mice in the effective fraction group were relieved;there was a small amount of senile plaque.The Nissl’s staining shows that the neurons of the cerebral cortex of APPswe /PS1 ΔE9 mice were edema, the number of cells were decreased.The mice in the effective fraction group were free of the disease.Con-clusion The double transgenic APPswe /PS1 ΔE9 mice of AD can simulate the specific pathogenesis of AD, which may be the efficient experimental animal model. The effective fraction of epimedium,astragalus and ra-dix puerariae may have a neuroprotective effect against AD via improving the learning and memory ability,and reduce the cerebral cortex nerve fiber tangles,senile plaques and neurons edema changes.
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Cre/LoxP site specific recombinase system is an effective tool for gene recombination in the body to produce specific gene deletion or inversion.The study of gene function is the experimental basis for the development of experimental animal models.Study the Cre/LoxP system,compare the different function characteristics of mouse models for Cre recombinase system in the research of ophthalmology,epecially in the tissue of retina,such as retinal pigment epithelium (RPE) cells,Müller cells and photoreceptor cells,get the Cre transgenic mouse model to establish proper experimental animal models of ophthalmology will lay a solid foundation for the research of the lack of single gene for a particular organization study.Here,the research progress of Cre/LoxP system,the Cre transgenic mouse models and eye specific Cre recombinant enzyme model mice will be summarized.
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Genistein is one of isoflavones mostly derived in a leguminous plant. It is well known as one of phytoestrogens that have structures similar to the principal mammalian estrogen. It has diverse biological functions including chemopreventive properties against cancers. Anticancer efficacies of genistein have been related with the epidemiological observations indicating that the incidence of some cancers is much lower in Asia, where diets are rich in soyfoods, than Western countries. This review deals with in vivo anticancer activities of genistein identified in animal studies being divided into its effects on carcinogenesis and cancer progression. Because animal studies have advantages in designing the experiments to suit the goals, they imply diverse information on the anticancer activity of genistein. The in vivo animal studies have adopted the specific animal models according to a developmental stage of cancer to prove the anticancer efficacies of genistein against diverse types of cancer. The numerous previous studies insist that genistein effectively inhibits carcinogenesis in the DMBA-induced animal cancer models by reducing the incidence of adenocarcinoma and cancer progression in the transgenic and xenograft animal models by suppressing the tumor growth and metastatic transition. Although the protective effect of genistein against cancer has been controversial, genistein may be a candidate for chemoprevention of carcinogenesis and cancer progression and may deserve to be the central compound supporting the epidemiological evidence.