TGF-beta1 Transgenic Mouse Model of Thoracic Irradiation: Modulation of MMP-2 and MMP-9 in the Lung Tissue

To investigate the effects of TGF-β1 on the two gelatinases （MMP-2 and MMP-9）, and their roles in lung remodeling after irradiation-induced lung injury. Expressions of TGF-β1 were measured with western blot, and expressions of MMP-2 and MMP-9 were analyzed with zymography in a TGF-β1 transgenic mouse model after thoracic irradiation with 12 Gy. We found expressions of TGF-β1 in the lung from the transgenic mice were three folds as compared to those from control mice. With densitometrical analysis, we found a significant decrease in MMP-9 activity in lung homogenates from the transgenic mice as compared with those from non-transgenic control mice 8 weeks after sham-irradiation （relative MMP-9 activity： C： 1. 000±0. 1091; TG： 0. 4772±0. 470 （n=8, P〈0.05）. But MMP-2 was constitutively expressed in the lung homogenates from the transgenic mice as compared to those from control mice 8 weeks after sham-irradiation （relative MMP-2 activity 8 weeks after sham-irradiation： C： 1. 000±0. 1556, TG： 1. 0075±0. 1472）. Eight weeks after thoracic irradiation with 12 Gy, we observed a significant increase of MMP-2 and MMP-9 activity in lung homogenates from both transgenic and normal mice. In TGF-β1 transgenic mice relative MMP-9 activity was increased to 1. 5321±0. 2217 folds 8 weeks after thoracic irradiation with 12 Gy as compared to those after sham-irradiation （1. 000±0. 2153）, and relative MMP-2 activity was increased to 1. 7142 ± 0. 4231 folds. Our results show that TGF-β1 itself down-regulates activity of MMP-9, thereby decreases ECM degradation in lungs of TGF-β1 transgenic mice. Also we find that ionizing irradiation upregulates both MMP-2 and MMP-9 activity. Over-expressions of MMP-9 and MMP-2 after lung irradiation are involved in the inflammatory response associated with radiation-induced lung injury, and maybe further in radiation-induced lung fibrosis.

Comparative study of histopathology changes between the PS1/APP double transgenic mouse model and Aβ_(1-40)-injected rat model of Alzheimer disease

Objective To identify the genetype of the PS1/APP double transgenie mouse model, then to analyse the histopathological changes in the brain and compare the differences between the transgenie mice models and Aβ1-40-injeeted rats models of Alzheimer disease. Methods The modified congo red staining, Nissl＇s staining and immunohistology staining was used to observe the Aβ deposits, activation of astrocyte respectively. Results ①The PS1/APP transgenic mouse extensively displayed Aβ deposits in the cortex and hippocampal structures, and GFAP positive cells were aggregated in mass and surrounded the congo red-positive plaque. ②The Aβ1-40-intrahippocmnpal-injeeted rat model showed the Aβ plaque deposits in the dentate gyrus of the hippocampus, with the astrocyte surrounded. The neurons loss was significant in the injection point and pin hole of injection with Nissl＇s staining methods. GFAP-positive cells increased significantly compared with the uninjected lateral of the hippocampus. Conclusion Although Aβ1-40-injected rat models could simulate some characteristic pathological features of human Alzheimer diseases, Aβ deposits and neurons loss in partial hippocampal, it would not simulate the progressive degenenration in the brain of AD. The double transgenie PS1/APP mice could simulate the specific pathogenesis and progressive changes of AD, mainly is Aβ deposits and the spongiocyte response , while no neurons loss were observed in this model.

Similarity on neural stem cells and brain tumor stem cells in transgenic brain tumor mouse models

Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are still unclear. In this study, we used stable doxycycline-inducible transgenic mouse brain tumor models （c-myc/SV40Tag＋/Tet-on＋） to explore the malignant trans- formation potential of neural stem cells by observing the differences of neural stem cells and brain tumor stem cells in the tumor models. Results showed that chromosome instability occurred in brain tumor stem cells. The numbers of cytolysosomes and autophagosomes in brain tumor stem cells and induced neural stem cells were lower and the proliferative activity was obviously stronger than that in normal neural stem cells. Normal neural stem cells could differentiate into glial fibrillary acidic protein-positive and microtubule associated protein-2-positive cells, which were also negative for nestin. However, glial fibrillary acidic protein/nestin, microtubule associated protein-2/nestin, and glial fibrillary acidic protein/microtubule associated protein-2 double-positive cells were found in induced neural stem cells and brain tumor stem cells. Results indicate that induced neural stem cells are similar to brain tumor stem cells, and are possibly the source of brain tumor stem cells.

Development of a humanized HLA-A30 transgenic mouse model

Background:There are remarkable genetic differences between animal major histocompatibility complex(MHC)systems and the human leukocyte antigen(HLA)system.HLA transgenic humanized mouse model systems offer a much better method to study the HLA-A-related principal mechanisms for vaccine development and HLA-Arestricted responses against infection in human.Methods:A recombinant gene encoding the chimeric HLA-A30 monochain was constructed.This HHD molecule contains the following:α1-α2 domains of HLA-A30,α3 and cytoplasmic domains of H-2D~b,linked at its N-terminus to the C-terminus of humanβ2m by a 15-amino-acid peptide linker.The recombinant gene encoding the chimeric HLA-A30 monochain cassette was introduced into bacterial artificial chromosome(BAC)CH502-67J3 containing the HLA-A01 gene locus by Red-mediated homologous recombination.Modified BAC CH502-67J3 was microinjected into the pronuclei of wild-type mouse oocytes.This humanized mouse model was further used to assess the immune responses against influenza A virus(H1N1)pdm09 clinically isolated from human patients.Immune cell population,cytokine production,and histopathology in the lung were analyzed.Results:We describe a novel humanβ2m-HLA-A30(α1α2)-H-2D~b(α3 transmembrane cytoplasmic)(HHD)monochain transgenic mouse strain,which contains the intact HLA-A01 gene locus including 49 kb 5’-UTR and 74 kb 3’-UTR of HLA-A01*01.Five transgenic lines integrated into the large genomic region of HLA-A gene locus were obtained,and the robust expression of exogenous transgene was detected in various tissues from A30-18#and A30-19#lines encompassing the intact flanking sequences.Flow cytometry revealed that the introduction of a large genomic region in HLA-A gene locus can influence the immune cell constitution in humanized mice.Pdm09 infection caused a similar immune response among HLA-A30 Tg humanized mice and wild-type mice,and induced the rapid increase of cytokines,including IFN-γ,TNF-α,and IL-6,in both HLA-A30 humanized Tg mice and wild-type mice.The expression of HLA-A30 transgene was dramatically promoted in tissues from A30-9#line at 3 days post-infection(dpi).Conclusions:We established a promising preclinical research animal model of HLA-A30 Tg humanized mouse,which could accelerate the identification of novel HLA-A30-restricted epitopes and vaccine development,and support the study of HLA-A-restricted responses against infection in humans.

Evodiamine derivatives improve cognitive abilities in APP^(swe)/PS1^(ΔE9) transgenic mouse models of Alzheimer's disease

Background: Alzheimer's disease(AD) is a complex neurodegenerative disease. Due to the complexity of its molecular pathogenesis and the interaction of the numerous factors involved, the etiology and pathogenesis of AD have not been fully elucidated. Therefore, effective treatment for AD remains to be developed. Evodiamine, a quinolone alkaloid, has been found to improve learning and memory ability to in the APP^(swe)/PS1^(ΔE9) mouse model of dementia. However, the cytotoxicity and physicochemical properties of evodiamine have limited its use in the treatment of AD.Methods: Evodiamine and its derivatives were effectively synthesized by EDCImediated condensation at room temperature. These target compounds contained 1 thio-and 21 oxo-evodiamine derivatives with different substituted groups. The cytotoxicity of evodiamine and its derivatives and the neuroprotective effects of the evodiamine derivatives against H_2O_2-induced cell loss in SH-SY5 Y cells were investigated using the WST-8 assay. The Morris water-maze test was used to detect the effect of evodiamine and its derivatives on improving learning and memory in APP^(swe)/PS1^(ΔE9) mice.Results: In this study, a series of oxo-and thio-evodiamine derivatives was synthesized. Several derivatives showed lower cytotoxicity and stronger neuroprotective effects than evodiamine and elicited enhanced cognitive improvement, especially in the test of spatial memory in APP^(swe)/PS1^(ΔE9) mice.Conclusion: Our study provides insights for developing novel evodiamine derivatives for chemical intervention and treatment of AD.

Contributions of transgenic mouse studies on the research of hepatitis B virus and hepatitis C virus-induced hepatocarcinogenesis

Transgenic mouse technology has enabled the investigation of the pathogenic effects, including those on development, immunological reactions and carcinogenesis, of viral genes directly in living organism in a real-time manner. Although viral hepatocarcinogenesis comprises multiple sequences of pathological events, that is, chronic necroinflammation and the subsequent regeneration of hepatocytes that induces the accumulation of genetic alterations and hepatocellular carcinoma(HCC), the direct action of viral proteins also play significant roles. The pathogenesis of hepatitis B virus X and hepatitis C virus(HCV) core genes has been extensively studied by virtue of their functions as a transactivator and a steatosis inducer, respectively. In particular, the mechanism of steatosis in HCV infection and its possible association with HCC has been well studied using HCV core gene transgenic mouse models. Although transgenic mouse models have remarkable advantages, they are intrinsically accompanied by some drawbacks when used to study human diseases. Therefore, the results obtained from transgenic mouse studies should be carefully interpreted in the context of whether or not they are well associated with human pathogenesis.

Establishment of transgenic mouse harboring hepatitis B virus (adr subtype) genomes

INTRODUCTIONHepatitis B virus (HBV) belongs to the group ofhepatovirus, a major pathogen of human acute andchronic hepatitis B[1 4], which has a very closeassociation with human hepatocellular carcinoma(HCC)[5-8], For example, a statistical data from ahospital in Shanghai showed that 80% of HCCpatients were positive for HBsAg ( personalcommunication).

Construction of transgenic vector of mouse dentin sialoprotein

Objective To construct transgenic vectors of mouse DSP.Methods To construct pcDNA3.1 CX by substituting CMV promoter of pcDNA3.1 with promoter cβ actin,and establish the ultimate transgenic vector by cloning DSP coding sequence into pcDNA3.1 CX.Result s Enzyme digestion and sequencing are consistent with expected.Conclusion The transgenic vector of mouse DSP was constructed successfully.

Generation and characterization of a transgenic mouse model for pancreatic cancer

AIM： To generate a SV40Tag transgenic tumor animal model and to study the mechanism underlying tumorigenesis. METHODS： A mammary gland expression vector containing SV40Tag DNA was generated. Transgene fragments were microinjeted into fertilized eggs of FVB mice. The genetically manipulated embryos were transferred into the oviducts of pseudo-pregnant female mice. PCR and Northern blot analysis were used for genotype analysis of F1 and F2 mice. Transgene expression was detected by RT-PCR and immunohistochemistry. RESULTS： SV40Tag gene was detected in two lines of transgenic mice. One of them delivered the transgene to F1 and a tumor was found in the pancreas of these mice. RT-PCR and immunohistochemistry showed that SV40Tag gene was expressed in the tumor. Pathological characterization of the transgenic mice demonstrated that the tumor belonged to pancreatic cystic neoplasm. CONCLUSION： SV40Tag transgenic mouse model can be successfully established. The transgenic mice develop a pancreatic tumor, which can be used for investigation of the molecular mechanism of tumorigenesis in vivo.

Anticancer and cytotoxic properties of the latex of Calotropis procera in a transgenic mouse model of hepatocellular carcinoma

AIM： To evaluate the anticancer property of the dried latex （DL） of Calotropis procera, a tropical medicinal plant, in the X15-myc transgenic mouse model of hepatocellular carcinoma and to elucidate its mechanism of action in cell culture. METHODS： The young transgenic mice were orally fed with the aqueous suspension of DL （400 mg/kg for 5 d/wk） for 15 wk and their liver was examined for histopathological changes at 20 wk. Serum levels of vascu- lar endothelial growth factor （VEGF） were also measured in these animals. To characterize the active fraction, DL was extracted with petroleum ether followed by methanol. The methanolic extract was sub-fractionated on a silica gel G column using a combination of non-polar and polar solvents and eleven fractions were obtained. Each fraction was analysed for cytotoxic effect on hepatoma （Huh7） and non-hepatoma （COS-1） cell lines and nontransformed hepatocytes （AML12） using tetrazolium （MTT） assay. Finally, the mechanism of cell death was investigated by measuring the levels of Bcl2, caspase 3 and DNA fragmentation. RESULTS： DL treatment of mice showed a complete protection against hepatocarcinogenesis. No adverse effect was observed in these animals. The serum VEGF level was significantly lowered in the treated mice as compared to control animals. Cell culture studies revealed that the methanolic extract of DL as well as its fraction 8 induced extensive cell death in both Huh-7 and COS-1 cells while AML12 cells were spared. This was accompanied by extensive fragmentation of DNA in Huh-7 and COS-1 cells. No change in the levels of canonical markers of apoptosis such as Bcl2 and caspase 3 was observed. CONCLUSION： DL of C. procera has the potential for anti-cancer therapy due to its differentJable targets and non-interference with regular pathway of apoptosis.

A mini review: Tau transgenic mouse models and olfactory dysfunction in Alzheimer's Disease

Alzheimer's Disease(AD) is a chronic neurodegenerative disease that usually takes many years from preclinical phase to prodromal phase characterized by mild symptoms before the onset of dementia. Once diagnosed with AD, the brain is already severely damaged and the disease will process quickly to the most severe stages since there is no medications that reverse the neuronal injuries in the brain. Thus, simple, inexpensive, and widely available methods for detecting potential AD patients during their preclinical phases are urgently needed. In such case, olfactory testing may offer a chance for early diagnosis of AD. However, there are limitations in these olfactory tests due to the complexity of the brain areas it extends to and the frequently olfactory fatigue occurred in the behavioral olfactory tests. Great efforts have been done epidemiologically to investigate the correlation between olfactory functions and possibility of developing AD. Different patterns of olfactory dysfunction have been found in AD at early stages and even mild cognitive impairment(MIC), but the cause of the dysfunction remained unclear. Various kinds of AD animal models have been used in the field to clarify the existence of olfactory dysfunctions and thus study the underling mechanism of the dysfunction. In this review we discuss(1) the function of Tau physiologically and pathologically;(2) the genetic background and biological characteristics of the most commonly used Tau transgenic mice;(3) the structural and molecule basis of olfaction;(4) the possible relationship between Tau pathology and olfactory dysfunction. Finally, we suggest that the tau transgenic mouse models may be helpful in studying the possible mechanisms of the dysfunction.

A novel transgenic mouse model of Chinese CharcotMarie-Tooth disease type 2L

We previously found that the K141N mutation in heat shock protein B8 （HSPB8） was responsible for Charcot-Marie-Tooth disease type 2L in a large Chinese family. The objective of the present study was to generate a transgenic mouse model bearing the K141N mutation in the human HSPB8 gene, and to determine whether this K141NHSPB8 transgenic mouse model would manifest the clinical phenotype of Charcot-Marie-Tooth disease type 2L, and consequently be suitable for use in studies of disease pathogenesis. Transgenic mice overexpressing K141N HSPB8 were generated using K141N mutant HSPB8 cDNA cloned into a pCAGGS plasmid driven by a human cytomegalovirus expression system. PCR and western blot analysis confirmed integration of the KI41NHSPB8 gene and widespread expression in tissues of the transgenic mice. The K141N HSPB8 transgenic mice exhibited decreased muscle strength in the hind limbs and impaired motor coordination, but no obvious sensory disturbance at 6 months of age by behavioral assessment. Electrophysiological analysis showed that the compound motor action potential amplitude in the sciatic nerve was significantly decreased, but motor nerve conduction velocity remained normal at 6 months of age. Pathological analysis of the sciatic nerve showed reduced myelinated fiber density, notable axonal edema and vacuolar degeneration in K141N HSPB8 transgenic mice, suggesting axonal involvement in the peripheral nerve damage in these animals. These findings indicate that the KI4mHSPB8 transgenic mouse successfully models Charcot-Marie-Tooth disease type 2L and can be used to study the pathogenesis of the disease.

mRNA Expression of Vimentin Gene in Lens of Transgenic Mouse and DNA Amplification in Human Cataracts

Purpose:To investigate the role of vimentin gene in cataractogenesis.Methods:The12.7kb chicken vimentin genes were microinjected into the male pronuclei of 918 fertilized mice eggs.841injected embryos were transferred into oviducts of pseudopregnant recipient females.of which 12pregnant mice gave birth to 49offsping mice.The integration and expression of exogenous gene in the offsping were analysed by Southern and Northern blot byhridizations,In the human senile cataract,the lens vimentin gene was analyzed with the chicken vi-mentin gene probe.Results:It showed that four of F1offspring were transgenic mice in which the chicken vimenttin gene was integrated in their genomes.The transgenic band was12kb,similar to the12.7kb chicken vimentin fragment injected.One2kbvi-mentin mRNAwas visualized on E2 mouse lens blot.which revealed that the chicken vimentin gene was efficiently expressed in this transgenic mouse.In the humansenile cataract lens,12kb BamHI-restricted vimentin fragments displayed a stronger hybridization signal than that of the control lens in Southern blot anal-ysis,It implies that the Formation of human senile cataract may be associated with the amplification of vimentin gene.Conclusions:We have successfully developed four transgenic mice bearing chicken vimentin gene and having mRNA expression which can be used for further study.It is to be observed if the normal lens cell function is affected by the expressed product and cataract occurs in our transgenic mice.The cause of the gene ampli-fication in human ctaract remains for further investigation.Eye Science 1995;11:113-116.

Liuwei Dihuang Decoction improves cognitive impairments via regulating immune system in APP/PS1 transgenic mouse, a mouse model of Alzheimer disease

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 3 H-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 ConAand 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.

PR-Set7 is Degraded in a Conditional Cul4A Transgenic Mouse Model of Lung Cancer

Background and objective Maintenance of genomic integrity is essential to ensure normal organismal development and to prevent diseases such as cancer.PR-Set7(also known as Set8)is a cell cycle regulated enzyme that catalyses monomethylation of histone 4 at Lys20(H4K20me1)to promote chromosome condensation and prevent DNA damage.Recent studies show that CRL4CDT2-mediated ubiquitylation of PR-Set7 leads to its degradation during S phase and after DNA damage.This might occur to ensure appropriate changes in chromosome structure during the cell cycle or to preserve genome integrity after DNA damage.Methods We developed a new model of lung tumor development in mice harboring a conditionally expressed allele of Cul4A.We have therefore used a mouse model to demonstrate for the first time that Cul4A is oncogenic in vivo.With this model,staining of PR-Set7 in the preneoplastic and tumor lesions in Adeno Cre-induced mouse lungs was performed.Meanwhile we identified higher protein level changes ofγ-tubulin and pericentrin by IHC.Results The level of PR-Set7 down-regulated in the preneoplastic and adenocarcinomous lesions following over-expression of Cul4A.We also identified higher levels of the proteins pericentrin andγ-tubulin in Cul4A mouse lungs induced by Adeno Cre.Conclusion PR-Set7 is a direct target of Cul4A for degradation and involved in the formation of lung tumors in the conditional Cul4A transgenic mouse model.

Establishment of transgenic mouse lineages containing copies of anintegrated pSPORT1 plasmid

Objective: To establish transgenic mouse lineages containing copies of a stably integratedpSPORT1 plasmid by microinjection into fertilized eggs and to provide an efficient animal model for studyinggene mutations in vivo. Methods and Results: 2594 fertilized eggs from KM white mice were injected withpSPORT1 DNA and transferred into the oviducts of 103 pseudopregnant females. from which 237 offspringswere obtained. 40 of these offsprings were identified positive for the forgeign gene by PCR analysis and 38were reproved positive by Southern blot analysis. Finally, eight of the stout mice whose genornes were integrated with intact pSPORT1 vectors, verified by Southern blotting analysis, were chosen as founders to establish the transgenic mouse lineages. The experimental results inchoated that the pregnant rate of recipientfemales and the Positive rate of offsprings were dramatically influenced by the structure of the transgene(linearized or circular ) and the mode of egg-transfer. The integration rate of linearized transgene was significantly higher than that of the circular transgene,and female with two-side oviduct transfer of fertilized eggs waseasy to have baby mice. Conclusion: (1 ) Transgenic mouse lineages containing copies of a stably integratedPSPORT 1 plasmid were established; (2 ) The linearized transgene and two-side oviduct transfer of fertilizedeggs is more efficient in preparing transgenic mice.

Mouse models of epithelial ovarian cancer for preclinical studies

Epithelial ovarian cancer(EOC) is the leading cause of gynecological cancer-related mortality in the developed world. EOC is a heterogeneous disease represented by several histological and molecular subtypes. Therefore, exploration of relevant preclinical animal models that consider the heterogenic nature of EOC is of great importance for the development of novel therapeutic strategies that can be translated clinically to combat this devastating disease. In this review, we discuss recent progress in the development of preclinical mouse models for EOC study as well as their advantages and limitations.

Transgenic dry eye mouse models: powerful tools to study dry eye disease

Dry eye disease(DED) is one of the most common chronic multifactorial ocular surface diseases with high prevalence and complex pathogenesis. DED results in several ocular discomforts, vision fluctuation, and even potential damage of the ocular surface, bringing heavy burdens both on individuals and the society. The pathology of DED consists of tear film hyperosmolarity and immune responses on the ocular surface. Mice are widely used for developing models that simulate human DED features for investigating its pathogenesis and treatment. DED can be classified into aqueous-deficiency dry eye(ADDE) and evaporative dry eye(EDE). ADDE can be further divided into Sj?gren syndrome dry eye(SSDE) and non-Sj?gren syndrome dry eye(NSSDE). SSDE mouse models include natural strains, typified by non-obese diabetic(NOD) mice, and genetically engineered ones, like Aire-/-and Id3 knockout mice. Intrinsic EDE mainly refers to meibomian gland dysfunction(MGD). Eda-/-Tabby, Sod1-/-, Elovl1-/-are the most common transgenic MGD mouse models. Transgenic mouse models provide useful tools for studying the pathogenesis of DED and evaluating its novel therapies. This review compares the major transgenic dry eye mouse models and discusses their applications in DED research.

Designing and generating a mouse model:frequently asked questions

Genetically engineered mouse(GEM)models are commonly used in biomedical research.Generating GEMs involve complex set of experimental procedures requiring sophisticated equipment and highly skilled technical staff.Because of these reasons,most research institutes set up centralized core facilities where custom GEMs are created for research groups.Researchers,on the other hand,when they begin thinking about generating GEMs for their research,several questions arise in their minds.For example,what type of model(s)would be best useful for my research,how do I design them,what are the latest technologies and tools available for developing my model(s),and finally how to breed GEMs in my research.As there are several considerations and options in mouse designs,and as it is an expensive and time-consuming endeavor,careful planning upfront can ensure the highest chance of success.In this article,we provide brief answers to several frequently asked questions that arise when researchers begin thinking about generating mouse model(s)for their work.