Tetrahydroxy Stilbene Glucoside Ameliorates Cognitive Impairments and Pathology in APP/PS1 Transgenic Mice

Cognitive impairment is the main clinical manifestation of Alzheimer's disease(AD),and amyloid-β(AB)deposition and senile plaques are the characteristic neuropathological hallmarks in AD brains.This study aimed to explore the effect and mechanism of tetrahydroxy stilbene glucoside(TSG)on cognitive function in APP/PS 1 mice during long-term administration.Here,we treated APP/PS1 model mice of AD with different doses of TSG(50 mg/kg and 100 mg/kg)for 5 to 17 months by gavage,and we further observed whether TSG could ameliorate the cognitive decline in APP/PS1 mice using behavioral tests,and investigated the possible mechanisms by immunohistochemistry and Western blotting.Our results showed that TSG treatment rescued the spatial and non-spatial learning and memory impairments of APP/PS1 mice at Morris water maze test and novel object recognition test.Furthermore,Aβ40/42 deposition in the cortex and hippocampus of APP/PS1 mice treated with TSG was significantly reduced compared to the wild type mice using the immunohistochemical technique.Finally,Western blotting showed that TSG primarily decreased the APP expression to avoid the Aβplaque deposition in the cortex and hippocampus of mice.These results reveal the beneficial effects of TSG in APP/PSI-AD mice,which may be associated with the reduction of Aβdeposits in the brain.

Establishment of Hamster-and Human-PRNP Transgenic Mice

Objective To create transgenic mice expressing hamster- and human-PRNP as a model tor understanding the physiological function and pathology of prion protein （PrP）, as well as the mechanism of cross-species transmission of transmissible spongiform encephalopathies （TSEs）. Methods Hamster and human-PRNP transgenic mice were established by conventional methods. The copy number of integrated PRNP in various mouse lines was mapped by real-time PCR. PRNP mRNA and protein levels were determined by semi-quantitative RT-PCR, real-time RT-PCR, and western blot analysis. Histological analyses of transgenic mice were performed by hematoxylin and eosin （H ＆ E） staining and immunohistochemical （IHC） methods. Results Integrated PRNP copy number in various mouse lines was 53 （Tg-haPrP1）, 18 （Tg-huPrP1）, 3 （Tg-huPrP2）, and 16 （Tg-huPrP5）, respectively. Exogenous PrPs were expressed at both the transcriptional and translational level. Histological assays did not detect any abnormalities in brain or other organs. Conclusion We have established one hamster-PRNP transgenic mouse line and three human-PRNP transgenic mouse lines. These four transgenic mouse lines provide ideal models for additional research.

Carboxymethytl Pachymaram Up-Regulates Dendritic Cell's Function in Hepatitis B Virus Transgenic Mice in vitro

The effect ofcarboxymethytl pachymaram （ CMP ） on the function of dendritic cells（DCs） derived from spleens of hepatitis B virus transgenic mice are studied in vitro. The phenotypes of DCs are tested by flow cytometry （FCM）, cytokines measured by ELISA. The expression of DCs＇ phenotypes in IdBV transgenic mice are low （CD80^＋CD11c^＋：59.12±11.53 vs 9,60±4.53, p〈0.01; CD80^＋ MHC-Ⅱ^＋： 44.86±12.31 vs 9.80±5,72, p〈0.01, normal mice vs HBV transgenic mice）, the ability of DCs stimulating T lymphocytes proliferation decreases （0.37±0.11 vs 0.20±0,11, p〈0.05, normal mice vs HBV transgenic mice）, levels of IL-12 and IFN-y decrease whereas the level of IL-10 increases; CMP can enhance DCs＇ ability of stimulating T lymphocytes proliferation, facilitate the secretion of IL-12 and IFNp, inhibit the secretion of IL-10, thus up regulates DCs function. The results show a good prospective use of CMP on the treatment of chronic hepatitis B.

Protective Effects of Overexpression of bcl-xl Gene on Local Cerebral Infarction in Transgenic Mice Undergoing Permanent Occlusion of Middle Cerebral Artery

In order to investigate the protective effects of the overexpression of bcl-xl gene on local cerebral infarction in the transgenic mice subject to permanent occlusion of middle cerebral artery, the models of bcl-xl transgenic mice were established and subjected to cerebral infarction by intraluminal occlusion of the middle cerebral artery. The infarct volume and the neurological scores were observed and comparison between the wild type mice and the transgenic mice was made. It was found that the infarct volume and the neurological scores in the transgenic mice were significantly decreased as compared with those in the wild type mice. It was suggested that the overexpression of bcl-xl gene in transgenic mice could reduce the infarct volume and improve the neurological function of the mice.

Muscle hypertrophy in transgenic mice due to over-expression of porcine myostatin mutated at its cleavage site

Myostatin, a member of the transforming growth factor beta（TGF-β） superfamily, is a dominant inhibitor that acts to limit skeletal muscle growth and development. In this study, we generated transgenic mice that express porcine myostatin containg mutations at its cleavage site（RSRR） to evaluate its effect on muscle mass. Results showed that the weight of four skeletal muscles including gastrocnemius, rectus femoris, tibialis anterior, and pectoralis increased by 17.83 and 28.39%, 21.76 and 28.70%, 34.31 and 41.62%, 53.21 and 27.54% in transgenic male and female mice, respectively, compared to their corresponding non-transgenic control mice. Measurement of muscle fiber size and number indicated that the mean myofiber size increased by 50.73 and 61.30% in transgenic male and female mice respectively compared to the non-transgenic controls. However, there was no difference in the number of myofiber between transgenic and non-transgenic male mice. These results clearly demonstrated that the increase in skeletal muscle mass in transgenic mice is caused by hypertrophy instead of hyperplasia.

Inducible overexpression of porcine homeobox A10 in the endometrium of transgenic mice

Homeobox A10 （HOXA 10） is a well-known transcription factor that plays an important role in directing endometrial differ- entiation and establishing the conditions required for implantation. Interestingly, the expression level of HOXAIO may be associated with litter size. To study the effects of the porcine HOXAIO promoter fragment on the expression of HOXAIO gene in vivo, we generated a transgenic mouse model using pronuclear microinjection, and measured the expression of HOXAIO in the endometrium. There was no difference in the expression level of HOXAIO between transgenic and wild- type mice in the absence of hormone stimulation. However, following treatment with progesterone and estradiol benzoate, the expression level of HOXAIO was significantly increased in transgenic mice compared with that of wild-type mice. Fur- thermore, the litter size of transgenic females was larger than that of wild-type females （7.02±1.73 vs. 6.48＋1.85; P=0.14）. Moreover, the difference of litter size was greater in the later parities （7.33±1.62 vs. 6.37±2.02; P=0.08） compared with the first parity （6.76±1.81 vs. 6.61v1.67; P=0.77） between transgenic and wild-type mice. Therefore, our transgenic mouse model provides exciting insights regarding the actions of HOXAIO and its hormone-inducible promoter in vivo. The present study offers valuable proof of principle to develop transgenic pigs with a hormone-inducible promoter regulating HOXAIO to alter litter size.

The Establishment of Double-Transgenic Mice that Co-Express the appA and MxA Genes Mediated by Type A Spermatogonia In vivo

Type A spermatogonial stem cells are the only immortal diploid cells in the postnatal animal that undergo self-renewal through the lifetime of an animal and transmit genes to subsequent generations. In this paper, the generation and characterization of double-transgenic mice co-expressing the Escherichia coli appA gene and human MxA gene generated via the in vivo transfection of type A spermatogonial cells were reported for the ifrst time. The dicistronic expression vector pcDNA-appA-MxA（AMP） and ExGen500 transfection reagent were injected into the testicular tissue of 7-d-old male ICR mice. The mice that underwent testis-mediated gene transfer were mated with wild-type female mice, and the integration and expression of the foreign genes in the offspring were evaluated. Transgenic mice that co-expressed appA and MxA showed a gene integration rate of 8.89%（16/180）. The transgenic mice were environmentally friendly, as the amount of phosphorous remaining in the manure was reduced by as much as 11.1%by the appA gene （P〈0.05）;these animals also exhibited a strong anti-viral phenotype.

Age-related Changes in Familial Hypertrophic Cardiomyopathy Phenotype in Transgenic Mice and Humans

β-myosin heavy chain mutations are the most frequently identified basis for hypertrophic cardiomyopathy （HCM）. A transgenic mouse model （αMHC403） has been extensively used to study various mechanistic aspects of HCM. There is general skepticism whether mouse and human disease features are similar. Herein we compare morphologie and functional characteristics, and disease evolu- tion, in a transgenic mouse and a single family with a MHC mutation. Ten male αWHC403 transgenic mice （at -5 weeks, -12 weeks, and -24 weeks） and 10 HCM patients from the same family with a β-myosin heavy chain mutation were enrolled. Morphometric, conventional echocardiographic, tissue Doppler and strain analytic characteristics of transgenic mice and HCM patients were assessed. Ten male transgenic mice （αMHC403） were examined at ages -5 weeks, -12 weeks, and -24 Weeks. In the transgenic mice, aging was associated with a significant increase in septal （0.59±0.06 vs. 0.64±-0.05 vs. 0.69±0.11 mm, P〈0.01） and anterior wall thickness （0.58±0.1 vs. 0.62±0.07 vs. 0.80-1-0.16 mm, P〈0.001）, which was coincident with a significant decrease in circumferential strain （-22%=1=4% vs. -20%-4-3% vs. -19%-4-3%, P=0.03）, global longitudinal strain （-19%-4-3% vs. -17%-4-2% vs. -16%±3%, P=0.001） and E/A ratio （1.9±0.3 vs. 1.7-4-0.3 vs. 1.4-4-0.3, P=0.01）. The HCM patients were classified into 1st generation （n=6; mean age 534-6 years）, and 2nd generation （n=4; mean age 32＋8 years）. Septal thickness （2.2±0.9 vs. 1.4±0.1 cm, P〈0.05）, left atrial （LA） volume （62±16 vs. 41±5 mL, P=0.03）, E/A ratio （0.77±0.21 vs. 1.1±0.1, P=0.01）, E/e＇ ratio （25±10 vs. 12±2, P=0.03）, global left ventricular （LV） strain （-14%±3% vs. -20%±3%, P=0.01） and global LV early diastolic strain rate （0.76±0.17 s1 vs. 1.3±0.2 s-1, P=0.01） were significantly worse in the older generation. In β-myosin heavy chain muta- tions, transgenic mice and humans have similar progression in morphologic and functional abnormali- ties. The αMHC4±3 transgenic mouse model closely recapitulates human disease.

The characteristics of hDPP4 transgenic mice subjected to aerosol MERS coronavirus infection via an animal nose-only exposure device

Background: Middle East respiratory syndrome coronavirus(MERS-Co V), which is not fully understood in regard to certain transmission routes and pathogenesis and lacks specific therapeutics and vaccines, poses a global threat to public health.Methods: To simulate the clinical aerosol transmission route, h DPP4 transgenic mice were infected with MERS-Co V by an animal nose-only exposure device and compared with instillation-inoculated mice. The challenged mice were observed for 14 consecutive days and necropsied on days 3, 5, 7, and 9 to analyze viral load, histopathology, viral antigen distribution, and cytokines in tissues.Results: MERS-Co V aerosol-infected mice with an incubation period of 5-7 days showed weight loss on days 7-11, obvious lung lesions on day 7, high viral loads in the lungs on days 3-9 and in the brain on days 7-9, and 60% survival. MERS-Co V instillation-inoculated mice exhibited clinical signs on day 1, obvious lung lesions on days 3-5, continuous weight loss, 0% survival by day 5, and high viral loads in the lungs and brain on days 3-5. Viral antigen and high levels of proinflammatory cytokines and chemokines were detected in the aerosol and instillation groups. Disease, lung lesion, and viral replication progressions were slower in the MERS-Co V aerosol-infected mice than in the MERS-Co V instillation-inoculated mice.Conclusion: h DPP4 transgenic mice were successfully infected with MERS-Co V aerosols via an animal nose-only exposure device, and aerosol-and instillation-infected mice simulated the clinical symptoms of moderate diffuse interstitial pneumonia. However, the transgenic mice exposed to aerosol MERS-Co V developed disease and lung pathology progressions that more closely resembled those observed in humans.

Global view of transcriptome in the brains of aged NR2B transgenic mice

NR2B subunits are involved in regulating aging, in particular, age-related learning and memory deficits. We examined 19-month-old NR2B transgenic mice and their littermate controls. First, we detected expression of the NR2B subunit gene, Grin2b, in the neocortex of transgenic mice using real-time PCR. Next, we used microarrays to examine differences in neocortical gene expression. Pathway and signal-net analyses identified multiple pathways altered in the transgenic mice, in-cluding the P53, Jak-STAT, Wnt, and Notch pathways, as well as regulation of the actin cytoskeleton and neuroactive ligand-receptor interactions. Further signal-net analysis highlighted the P53 and insulin-like growth factor pathways as key regulatory pathways. Our results provide new insight into understanding the molecular mechanisms of NR2B regulated age-related memory storage, normal organismal aging and age-related disease.

Cerebroprotective effect of Huanglian Jiedu decoction on amyloid protein precursor/presenilin-1 double transgenic mice

Huanglian Jiedu decoction （HLJDD） has been shown to improve cerebral blood flow, and reduce lipid peroxidation damage to the brain and its energy metabolism. The present study was designed to observe the cerebroprotective effect of HL.JDD on an Alzheimer＇s disease rodent model, presenilin-1/amyloid protein precursor double transgenic mice. HLJDD reduced serum interleukin-6 and interleukin-113 levels, decreased [3-amyloid precursor protein gene and senile plaque expression, resisted oxidation, and reduced free radical-induced injury, thereby improving the learning and memory of these mice. Moreover, HLJDD at 433 mg/kg per day exhibited better effects compared with that at 865 or 216 mg/kg per day, and donepezil hydrochloride at 30 mg/kg per day. Thus, these results suggest that HLJDD may have protective effects against Alzheimer＇s disease.

Antiviral Effects of Stichopus japonicus Acid Mucopolysaccharide on Hepatitis B Virus Transgenic Mice

Hepatitis B virus(HBV) is a significant global pathogen and efficient cure for HBV patients is still a challenging goal. We previously reported that acidic mucopolysaccharide from stichopus japonicus selenka(SJAMP) could inhibit HBs Ag and HBe Ag expression in vitro. However, the potential anti-HBV effects of SJAMP in vivo have not yet been explored. In this study, we show that SJAMP exhibits potent anti-HBV activity in HBV transgenic mice in a dose-dependent manner. Specifically, sixty HBV transgenic male BALB/c mice were randomly selected to receive the treatment of PBS, low dose SJAMP(30 mg kg^(-1)), middle dose SJAMP(40 mg kg^(-1)), high dose SJAMP(50 mg kg^(-1)) and IFN(45 IU kg^(-1)) for 30 d. SJAMP treatment suppressed serum HBV-DNA, and liver HBs Ag and HBc Ag levels in HBV-transgenic mice. The present study highlights the potential application of SJAMP in HBV therapy.

Protective effects on acute hypoxic-ischemic brain damage in mfat-1 transgenic mice by alleviating neuroinflammation

Acute hypoxic-ischemic brain damage(HIBD)mainly occurs in adults as a result of perioperative cardiac arrest and asphyxia.The benefits of n-3 polyunsaturated fatty acids(n-3 PUFAs)in maintaining brain growth and development are well documented.However,possible protective targets and underlying mechanisms of mfat-1 mice on HIBD require further investigation.The mfat-1 transgenic mice exhibited protective effects on HIBD,as indicated by reduced infarct range and improved neurobehavioral defects.RNA-seq analysis showed that multiple pathways and targets were involved in this process,with the anti-inflammatory pathway as the most significant.This study has shown for the first time that mfat-1 has protective effects on HIBD in mice.Activation of a G protein-coupled receptor 120(GPR120)-related anti-inflammatory pathway may be associated with perioperative and postoperative complications,thus innovating clinical intervention strategy may potentially benefit patients with HIBD.

Production of Transgenic Mice by Type-A Spermatogonia-Mediated Gene Transfer

Type-A spermatogonia first appear at between 3-7 d postnatally in mice and are the only immortalized diploid cells that reproduce in adulthood in these animals. In our current study, we explored the feasibility of producing stable transgenic mice using these cells. Enhanced pEGFP-N1 plasmids were suspended in ExGen500 transfection reagent and injected at different angles into the testes of 7-d-old male ICR mice. The resulting type-A spermatogonia-mediated gene transfer （TASMGT） mice were then mated with normal females at different stages of sexual maturity （6, 12, and 24 wk）. The integration and expression of the introduced EGFP gene was evaluated in the F1 transgenic offspring by PCR and Southern blotting analysis. The foreign gene integration rates for a low-dose group （15 μL gene suspension injected into each testis） and a high-dose group （30 μL suspensions injected） at the three stages of female sexual maturity tested were 11.76% （2/17）, 14.29% （3/21）, and 11.11% （2/18）, and 5% （1/20）, 5.56% （1/18）, and 0 （0/17）, respectively. The average integration rates for these two dose groups were 12.5% （7/56） and 3.64% （2/55）, respectively, which was a significant difference （P0.05）. Semi-quantitative RT-PCR analysis further showed that the introduced GFP gene was expressed in 3/9 integration mice. In addition, GFP expression was observed in the sperm cells from the TASMGT mice, and also in the embryos and F2 pups from the F1 generation transgenic mice. Hence, although the foreign gene integration rate for TASMGT is not high and the transgenic offspring show as yet unexplained defects, our results indicate that this method is a potentially feasible and reproducible new approach to creating transgenic mice.

Intracerebroventricular transplantation of human amniotic epithelial cells ameliorates spatial memory deficit in the doubly transgenic mice coexpressing APPswe and PS1△E9.deleted genes

Background Human amniotic epithelial cells （HAECs）, which have characteristics of both embryonic and pluripotent stem cells, are therefore a candidate in cell therapy without creating legal or ethical problems. In the present study, we aimed to investigate the effects of intracerebroventricular transplantation of HAECs on doubly transgenic mice of Alzheimer＇s disease （AD） coexpressing presenilin-1 （PS1） and mutant Sweden amyloid precursor protein （APPswe） genes. Methods The offspring mice genotypes were detected using PCR identification of APPswe and PS1 gene. The doubly transgenic （TG） mice （n=20） and wild-type （WT） mice （n=20） were randomly divided into two groups respectively： the transplantation group treated with HAECs and the control group with phosphate buffered saline. Six radial arm water maze test was used to assess the spatial memory in the TG and WT mice. Amyloid plaques and neurofibrillary tangles were analyzed using congo red and acid-silver methenamine staining respectively. was used to track the survival of HAECs. Immunohistochemistry was used octamer-binding protein 4 （Oct-4） and Nanog in the HAECs. High performance measure acetylcholine in hippocampus. The density of cholinergic neurons in hippocampus was measured using acetylcholinesterase staining. Immunofluorescence cytochemistry to determine the expression of quid chromatography was used to basal forebrain and nerve fibers in Results Amyloid deposition occurred in hippocampus and frontal cortex in the double TG mice aged 8 months, but not in WT mice. The results also showed that transplanted HAECs can survive for at least 8 weeks and migrate to the third ventricle without immune rejection. The graft HAECs can also express the specific marker Oct-4 and Nanog of stem cell. Compared with the control group, transplantation of HAECs can not only significantly improve the spatial memory of the TG mice, but also increase acetylcholine concentration and the number of hippocampal cholinergic neurites. Conclusions These results demonstrate that intracerebroventricular transplantation of HAECs can improve the spatial memory of the double TG mice. The higher content of acetylcholine in hippocampus released by more survived cholinergic neurites is one of the causes of this improvement.

Immunization with HBsAg-Fc fusion protein induces a predominant production of Thl cytokines and reduces HBsAg level in transgenic mice

Background The Fc receptor associated pathway might improve the immune responses against hepatitis B virus （HBV） as previously described by us. In addition, the Fit3 ligand （FL） has been reported to potentiate antigen presenting cells in vivo and may act as a potential adjuvant to boost antigen-specific immune responses. In this study, the immune efficacies of a set of fusion proteins of HBsAg and Fc and/or FL were evaluated in HBsAg transgenic mice. Methods The fusion proteins composed of HBsAg and the Fc domain of murine IgG1 （HBsAg-Fc） and/or the Fit3 ligand, and yeast-derived recombinant HBsAg were used as immunogen to immunize HBsAg transgenic mice, respectively. Serum and liver HBsAg levels, serum anti-HBsAg and cytokine profile, and the activities of alanine aminotransferase （ALT）/AST were investigated after immunization. Results After six injections, the most pronounced decrease in serum and liver HBsAg levels was observed in the HBsAg-Fc immunized group. In addition, serum Thl cytokines and ALT/AST activities were highest in this group, indicating an effective induction of a favorable cellular immune response. Interestingly, the fusion protein containing HBsAg-Fc and the Fit3 ligand stimulated an alternative Thl-type immune response featured with high level productions of tumor necrosis factor a （TNF-a） and monocyte chemoabstractant protein 1 （MCP-1）, causing a more severe cytotoxicity in hepatocytes while showed less effective in reducing serum HBsAg level. Conclusion HBsAg-Fc is effective in eliciting both the humeral and cellular immune responses against HBsAg in HBsAg transgenic mice, which makes it a potential immunogen for the immunotherapy of chronic hepatitis B.

Effect of GAPT Extract on Expression of Tau Protein and Its Phosphorylation Related Enzymes in Hippocampal Neurons of APPV717I Transgenic Mice

Objective：To investigate the effect of GAPT,an extract mixture from Radix Ginseng,Rhizoma Acor tatarinowii,Radix Polygalae and Radix Curcuma（containing ingredient of turmeric）,etc.on expression of tau protein and its phosphorylation related enzyme in hippocampal neurons of APPV717I transgenic mice.Methods：Sixty three-month-old APPV717I transgenic mice were randomly divided into model group,donepezil group[0.92 mg/（kg·d）],the low,medium and high dosage of GAPT groups[0.075,0.15,0.30 g/（kg·d）,12 in each group],and 12 three-month-old C57BL/6J mice were set as a normal control group,treatments were administered orally once a day respectively,and both the normal group and model group were given 0.5%sodium carboxymethyl cellulose solution.Immunohistochemistry（IHC）and Western blot analysis were used to detect the expression of total tau protein（Tau-5）,cyclin-dependent kinase 5（CDK5）and protein phosphatase 2A（PP2A）in hippocampal neurons of experimental mice after 8-month drug administration（11 months old）.Results：In the model group,the expression of Tau-5 and CDK5 were increased,whereas the expression of PP2A was decreased in hippocampal neurons,which were significantly different compared with that in the normal group（all P〈0.01）.IHC test indicated the number and area of either Tau-5 or CDK5 positive cells were decreased with a dose-depended way in GAPT groups,and an increase of PP2A.Compared with the model group,the changes were significant in GAPT groups（P〈0.05 or P〈0.01）.Similar results were shown by Western blot.Conclusion：GAPT could attenuate abnormal hyperphosphorylation of tau protein in hippocampal neurons of APPV717I transgenic mice via inhibiting the expression of CDK5 and activating the expression of PP2A.

Effect of the electro-acupuncture on senile plaques and its formation in APPD/PS1D double transgenic mice

Alzheimer’s disease(AD)is a progressive neurodegenerative disease and its incidence will increase with age and is aggravating.The senile plaques(SPs)are one of three main pathological features in AD patients,which are formed by amyloid b-protein(Ab)overaccumulation.b-amyloid precursor protein(APP),b-site APP cleavage(BACE1),and insulin degrading enzyme(IDE)proteins participate in the process of Ab production and degradation.At present,the pathogenesis of AD is not yet clear and the current treatment methods can only relief the related symptoms of AD.The electro-acupuncture(EA)is a traditional Chinese medicine treatment combined the acupuncture and electrical stimulation and the treatment effect can also be controlled by transform the electrical frequency.Thus,in this experiment,we carried out behavioral test,immunohistochemistry(IHC),and Western Blot(WB)after different period treatments to the model mice by electro-acupuncturing“Baihui”and“Shenshu”acupoints in APPt/PS1t double transgenic mice.It was found that the EA therapy can improve the ability of learning,memory and spatial exploration,and reduce the deposition of SPs in brain of AD model mice,and reduce the expressions of APP and BACE1,increase the expression of IDE protein.These results prompt that EA can effectively alleviate the pathological process of AD.We speculate that EA may play a comprehensive role in preventing the development of AD,considering the previous data.

Expression of biologically active human clotting factor Ⅸ(hFⅨ) in the mammary gland of transgenic mice

The DNA of human factor Ⅸ (hFⅨ) gene vector pMCⅨm, which had been proven to be able to express in in vitro and living cells, was introduced into 586 zygotes of Kunming White Mice by positive pressure microinjection technique with manual operation. The 499 survival embryos after microinjection were then transferred into pseudopregnant recipient mice and 216 F 0 pups were born. The analysis of PCR and Southern blot hybridization showed that, of the 216, 6 (2 females and 4 males) were integrated with foreign DNA in their genomes, giving an integration frequency of 3% (6/216). Two F\-0 female transgenic mice could express hFⅨ protein in their milk and the content was over 100 ng/mL as measured with ELISA. The biological activities of hFⅨ in the milk of two F\-0 mice were 44 67% and 79 43%, respectively.

Over-expression of CD163, CD169, and CD151 is not sufficient to improve the susceptibility to porcine reproductive and respiratory syndrome virus infection in transgenic mice

Porcine reproductive and respiratory syndrome virus(PRRSV)is a major pathogen that causes reproductive failure and respiratory disease in pigs,resulting in devastating economic losses worldwide[1].Porcine alveolar macrophages(PAMs)are the primary target cells of PRRSV[2],and the putative receptors,including CD163,CD169,and CD151,play key roles during infection[3–6].However,the understanding of PRRSV infection and pathogenesis is