Background:Spinocerebellar ataxia type 2(SCA2)is a neurodegenerative disease marked by significant clinical and genetic heterogeneity,primarily caused by expanded CAG mutations in the ATXN2 gene.The unstable expansion...Background:Spinocerebellar ataxia type 2(SCA2)is a neurodegenerative disease marked by significant clinical and genetic heterogeneity,primarily caused by expanded CAG mutations in the ATXN2 gene.The unstable expansion of CAG repeats disrupts the genetic stability of animal models,which is detrimental to disease research.Methods:In this study,we established a mouse model in which CAG repeats do not undergo microsatellite instability(MSI)across generations.A humanized ATXN2 cDNA with four CAA interruptions within 73 CAG expansions was inserted into the Rosa26 locus of C57BL/6J mice.A 23 CAG control mouse model was also generated to verify ATXN2 integration and expression.Results:In our model,the number of CAG repeats remained stable during transmission,with no CAG repeat expansion observed in 64 parent-to-offspring transmissions.Compared with SCA2-Q23 mice,SCA2-Q73 mice exhibited progressive motor impairment,reduced Purkinje cell count and volume(indicative of cell atrophy),and muscle atrophy.These observations in the mice suggest that the behavioral and neuropathological phenotypes may reflect the features of SCA2 patients.RNA-seq analysis of the gastrocnemius muscle in SCA2-Q73 mice showed significant changes in muscle differentiation and development gene expression at 56 weeks,with no significant differences at 16 weeks compared to SCA2-Q23 mice.The expression level of the Myf6 gene significantly changed in the muscles of aged mice.Conclusion:In summary,the establishment of this model not only provides a stable animal model for studying CAG transmission in SCA2 but also indicates that the lack of long-term neural stimulation leads to muscle atrophy.展开更多
Background:KIT proto-oncogene,receptor tyrosine kinase(KIT,CD117)and platelet-derived growth factor-alpha(PDGFRA)are key drivers of gastrointestinal stromal tumors(GIST),but resistance to targeted therapy often arises...Background:KIT proto-oncogene,receptor tyrosine kinase(KIT,CD117)and platelet-derived growth factor-alpha(PDGFRA)are key drivers of gastrointestinal stromal tumors(GIST),but resistance to targeted therapy often arises from tumor protein p53(p53)alterations and loss of cell cycle control.However,the role of p53 status in GIST therapeutic potential has rarely been studied,so this study aimed to employ both wild-type andmutant p53 GIST models to investigate how p53 dysfunction influences the efficacy of p53 pathway-targeted therapies.Methods:The efficacy of the mouse double minute 2 homolog(MDM2)inhibitor(HDM201)and the Wee1 G2 checkpoint kinase(Wee1)inhibitor(adavosertib)was confirmed in both p53 wild-type(p53 WT)and p53 mutant(p53 MT)GIST cells.The anti-proliferative effects were assessed using the Cell Counting Kit-8(CCK-8)assay.Flow cytometry(FACS)and immunoblotting were employed to evaluate apoptosis and the expression of proteins related to drug efficacy.These findings were further validated in a xenograft model.Results:HDM201 selectively inhibited growth and triggered apoptosis in p53WT GIST cells,while adavosertib was effective mainly in p53 MT cells.Western blot analysis revealed thatHDM201 increased p53 and p21 levels in p53WT cells,and adavosertib affectedWee1 and phospho-cdc2 expression in both p53WT and p53 MT cells.In a xenograft mouse model,HDM201 significantly reduced the tumor volume and weight in p53WTGIST cells,whereas p53MT tumors showed only a moderate size reduction with adavosertib,without significant changes.Conclusions:Our results highlight the importance of p53 status in guiding GIST treatment.p53 WT tumors respond toMDM2 inhibitors,while p53 MTtumors show greater sensitivity toWee1 inhibitors,supporting p53 pathway targeting as a promising strategy for GIST patients.展开更多
Objectives:Proteasomes,multi-subunit proteases,are key actors of cellular protein catabolism and a number of regulatory processes.The detection of subtle proteasome functioning in tumors may contribute to our understa...Objectives:Proteasomes,multi-subunit proteases,are key actors of cellular protein catabolism and a number of regulatory processes.The detection of subtle proteasome functioning in tumors may contribute to our understanding of the mechanisms of cancer development.The current study aimed to identify the role of low molecular mass protein 2(LMP2),a proteasome immune subunit,in the development of mouse colon 26(C26)adenocarcinoma.Methods:The functions of the LMP2 subunit in tumor development in Balb/c mice were studied using its irreversible inhibitor KZR-504.LMP2 activity was detected by the hydrolysis of the fluorogenic substrate Ac-Pro-Ala-Leu-AMC.Western blotting and Quantitative Reverse Transcription Polymerase Chain Reaction(qRT-PCR)were used.We applied fluorescent tests for cell proliferation and apoptosis.M2 macrophages were obtained by polarization of mouse bone marrow-derived macrophages using the corresponding cytokines.Results:KZR-504 showed high specificity only for the LMP2 subunit and had no negative effect on C26 cells in culture.However,KZR-504 suppressed the formation of tumor conglomerates(by 74%,p<0.001)after C26 cell transplantation in vivo,inhibited the expression of chitinase-<3-like protein 3(Chil3)gene(by 90%,p<0.001),a key marker of immunosuppressive M2 macrophages,in the tumor<microenvironment,and reduced the tumor weight compared to the control(by 48%,p<0.01).KZR-504 also suppressed<the expression of Chil3(by 68%,p<0.05)and arginase-1(Arg1)(by 90%,p<0.001),another marker gene,in M2<<macrophages and violated M0-M2 macrophage polarization in culture.Conclusion:We discovered earlier unknown functions of the proteasome LMP2 subunit to facilitate the formation of tumor conglomerates and maintain Chil3 and Arg1 expression in immunosuppressive M2 macrophages.Our work demonstrates that the proteasome LMP2 subunit can be a target for antitumor treatment.展开更多
In the present study, we hypothesized that 5-hydroxymethyl-2-furfural could attenuate ischemic brain damage by reducing oxidative injury. Thus, mice were subjected to bilateral common carotid artery occlusion to estab...In the present study, we hypothesized that 5-hydroxymethyl-2-furfural could attenuate ischemic brain damage by reducing oxidative injury. Thus, mice were subjected to bilateral common carotid artery occlusion to establish a model of permanent forebrain ischemia. The mice were intraperitoneally injected with 5-hydroxymethyl-2-furfura130 minutes before ischemia or 5 minutes after ischemia. The survival time of mice injected with 5-hydroxymethyl-2-furfural was longer compared with untreated mice. The mice subjected to ischemia for 30 minutes and reperfusion for 5 minutes were intraperitoneally injected with 5-hydroxymethyl-2-furfural 5 minutes prior to reperfusion, which increased superoxide dismutase content and reduced malondialdehyde content, similar to the effects of Edaravone, a hydroxyl radical scavenger used for the treatment of stroke. These findings indicate that intraperitoneal injection of 5-hydroxymethyl-2-furfural can prolong the survival of mice with permanent forebrain ischemia. This outcome may be mediated by its antioxidative effects.展开更多
To study the cartilage differentiation of mouse mesenchymal stem cells （MSCs） induced by cartilage-derived morphogenetic proteins-2 in vitro, the MSCs were isolated from mouse bone marrow and cultured in vitro. The ...To study the cartilage differentiation of mouse mesenchymal stem cells （MSCs） induced by cartilage-derived morphogenetic proteins-2 in vitro, the MSCs were isolated from mouse bone marrow and cultured in vitro. The cells in passage 3 were induced into chondrogenic differentiation with different concentrations of recombinant human cartilage-derived morphogenetic proteins-2 （0, 10, 20, 50 and 100 ng/mL）. After 14 days of induction, morphology of cells was observed under phase-contrast microscope. Collagen Ⅱ mRNA and protein were examined with RT-PCR, Western blotting and immunocytochemistry respectively and the sulfate glycosaminoglycan was measured by Alcian blue staining. RT-PCR showed that CDMP-2 could promote expression of collagen Ⅱ mRNA in an dose-dependant manner, especially at the concentration of 50 ng/mL and 100 ng/mL. Immunocytochemistry and Western blotting revealed a similar change. Alcian blue staining exhibited deposition of typical cartilage extracellular matrix. Our results suggest that mouse bone marrow mesencymal stem cells can differentiate into chondrogenic phonotype with the induction of CDMP-2 in vitro, which provides a basis for further research on the role of CDMP-2 in chondrogenesis.展开更多
Understanding the pathogenesis of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and clarifying antiviral immunity in hosts are critical aspects for the development of vaccines and antivirals.Mice are freq...Understanding the pathogenesis of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and clarifying antiviral immunity in hosts are critical aspects for the development of vaccines and antivirals.Mice are frequently used to generate animal models of infectious diseases due to their convenience and ability to undergo genetic manipulation.However,normal adult mice are not susceptible to SARS-CoV-2.Here,we developed a viral receptor(human angiotensin-converting enzyme 2,hACE2)pulmonary transfection mouse model to establish SARS-CoV-2 infection rapidly in the mouse lung.Based on the model,the virus successfully infected the mouse lung 2 days after transfection.Viral RNA/protein,innate immune cell infiltration,inflammatory cytokine expression,and pathological changes in the infected lungs were observed after infection.Further studies indicated that neutrophils were the first and most abundant leukocytes to infiltrate the infected lungs after viral infection.In addition,using infected CXCL5-knockout mice,chemokine CXCL5 was responsible for neutrophil recruitment.CXCL5 knockout decreased lung inflammation without diminishing viral clearance,suggesting a potential target for controlling pneumonia.展开更多
AIM:To examine whether the ob/ob mouse model of obesity is accompanied by enteric nervous system ab-normalities such as altered motility METHODS:The study examined the distribution of the P2X 2 receptor (P2X 2 R) in m...AIM:To examine whether the ob/ob mouse model of obesity is accompanied by enteric nervous system ab-normalities such as altered motility METHODS:The study examined the distribution of the P2X 2 receptor (P2X 2 R) in myenteric neurons of female ob/ob mice. Specifically, we used immunohistochemistry to analyze the co-expression of the P2X 2 R with neuronal nitric oxide synthase (nNOS), choline acetyltrans-ferase (ChAT), and calretinin (CalR) in neurons of the small intestine myenteric plexus in ob/ob and control female mice In these sections, we used scanning confocal microscopy to analyze the co-localization of these markers as well as the neuronal density (cm 2 ) and area profile (μm2) of P2X 2 R-positive neurons In addition, enteric neurons were labeled using the nicotinamide adenine dinucleotide (NA H) diaphorase method and analyzed with light microscopy as an alternate means by which to analyze neuronal density and areaRESULTS:In the present study, we observed a 29 6% increase in the body weight of the ob/ob animals (OG) compared to the control group (CG) In addition, the average small intestine area was increased by approxi-mately 29 6% in the OG compared to the CG Immu-noreactivity (IR) for the P2X 2 R, nNOS, ChAT and CalR was detectable in the myenteric plexus, as well as in the smooth muscle, in both groups This IR appeared to be mainly cytoplasmic and was also associated with the cell membrane of the myenteric plexus neurons, where it outlined the neuronal cell bodies and their processes P2X 2 R-IR was observed to co-localize 100% with that for nNOS, ChAT and CalR in neurons of both groups In the ob/ob group, however, we observed that the neuronal density (neuron/cm 2 ) of P2X 2 R-IR cells was in-creased by 62% compared to CG, while that of NOS-IR and ChAT-IR neurons was reduced by 49% and 57%, respectively, compared to control mice The neuronal density of CalR-IR neurons was not different between the groups Morphometric studies further demonstrated that the cell body profile area (μm2) of nNOS-IR, ChAT-IR and CalR-IR neurons was increased by 34%, 20% and 55%, respectively, in the OG compared to controls Staining for NA H diaphorase activity is widely used to detect alterations in the enteric nervous system; however, our qualitative examination of NA H-diaphorase positive neurons in the myenteric ganglia revealed an overall similarity between the two groups CONCLUSION:We demonstrate increases in P2X2R expression and alterations in nNOS, ChAT and CalR IR in ileal myenteric neurons of female ob/ob mice compared to wild-type controls.展开更多
Severe acute respiratory syndrome coronavirus 2(SARSCo V-2)infection can result in more severe syndromes and poorer outcomes in patients with diabetes and obesity.However,the precise mechanisms responsible for the com...Severe acute respiratory syndrome coronavirus 2(SARSCo V-2)infection can result in more severe syndromes and poorer outcomes in patients with diabetes and obesity.However,the precise mechanisms responsible for the combined impact of coronavirus disease 2019(COVID-19)and diabetes have not yet been elucidated,and effective treatment options for SARS-Co V-2-infected diabetic patients remain limited.To investigate the disease pathogenesis,K18-h ACE2 transgenic(h ACE2^(Tg))mice with a leptin receptor deficiency(h ACE2-Lepr^(-/-))and high-fat diet(h ACE2-HFD)background were generated.The two mouse models were intranasally infected with a 5×10^(5) median tissue culture infectious dose(TCID_(50))of SARSCo V-2,with serum and lung tissue samples collected at 3days post-infection.The h ACE2-Lepr^(-/-)mice were then administered a combination of low-molecular-weight heparin(LMWH)(1 mg/kg or 5 mg/kg)and insulin via subcutaneous injection prior to intranasal infection with1×10^(4) TCID_(50)of SARS-Co V-2.Daily drug administration continued until the euthanasia of the mice.Analyses of viral RNA loads,histopathological changes in lung tissue,and inflammation factors were conducted.Results demonstrated similar SARS-Co V-2 susceptibility in h ACE2^(Tg)mice under both lean(chow diet)and obese(HFD)conditions.However,compared to the h ACE2-Lepr^(+/+)mice,h ACE2-Lepr^(-/-)mice exhibited more severe lung injury,enhanced expression of inflammatory cytokines and hypoxia-inducible factor-1α(HIF-1α),and increased apoptosis.Moreover,combined LMWH and insulin treatment effectively reduced disease progression and severity,attenuated lung pathological changes,and mitigated inflammatory responses.In conclusion,preexisting diabetes can lead to more severe lung damage upon SARS-Co V-2 infection,and LMWH may be a valuable therapeutic approach for managing COVID-19patients with diabetes.展开更多
This study examined the expression and distribution of angiopoietin-1/-2 （Ang-1/-2） in the endometrium of early pregnant mice. The expression of Ang-1/-2 was detected by immunohistochemical staining and in situ hybr...This study examined the expression and distribution of angiopoietin-1/-2 （Ang-1/-2） in the endometrium of early pregnant mice. The expression of Ang-1/-2 was detected by immunohistochemical staining and in situ hybridization respectively. Computerized image analysis system was used to measure the average optical intensity of Ang-1/-2 in endometria at different time points after gestation. Mice were randomly divided into 5 groups： control group, D2 group （2 days after pregnancy）, D4 group （4 days after pregnancy）, D6 group （6 days after pregnancy） and D8 group （8 days after pregnancy）, each containing 15 mice. The results showed that the expression of Ang-1 and Ang-2 was very different among 4 groups （P〈0.01）. Immunohistochemical staining revealed that Ang-1 was localized in the cytoplasma of stromal cells 2 days after pregnancy （day 2）, and in luminal epithelial cells on day 4. The protein of Ang-2 was mainly expressed in the cytoplasma of glandular epithelia and stromal cells. With gestation time, the positive reactions of Ang-1/-2 were stronger in the endometria of the pregnant mice （P〈0.01）. In situ hybridization showed Ang-I mRNA in stromal cells on day 2. Hybridization signal was localized in both stromal cells and vessel epithelial cells on day 4; Ang-2 mRNA was expressed in stromal cells and glandular epithelia on day 2; high mRNA levels appeared in stromal cells, glandular epithelia and vascular endothelia on day 4; an increasing in mRNA expression of Ang-1/-2 was observed on day 6 and day 8 （P〈0.01）. It is suggested that Ang-1/-2 may play an important role in the cross-talk between blastocyst and maternal endometrium during the process of embryo implantation.展开更多
Background:Terpinen-4-ol(T4O),a key constituent of tea tree essential oil and various aromatic plants,has shown promising antiproliferative and pro-apoptotic effects in melanoma and other cancer types.However,its effi...Background:Terpinen-4-ol(T4O),a key constituent of tea tree essential oil and various aromatic plants,has shown promising antiproliferative and pro-apoptotic effects in melanoma and other cancer types.However,its efficacy against cutaneous squamous cell carcinoma(cSCC)remains unclear.Thus,in this study,we investigated the in vivo and in vitro effects of T4O on cSCC cell lines and preliminarily explored its impacting pathways.Methods:Using CCK8 and assay colony formation,we assessed the viability of cSCC A431,SCL-1,and COLO-16 cells treated with T40 at varying concentrations(0,1,2,and 4μM).Flow cytometry was employed to evaluate T4O’s effect on cSCC cell’s cycle progression and apoptosis induction.Additionally,western blotting was utilized to examine the expression intensities of N-cadherin and E-cadherin,two indicative markers of the epithelial-mesenchymal transition(EMT)pathway.T4O’s in vivo effect on inhibiting tumor progression was evaluated on an established xenograft tumor model.Then,the molecular mechanisms of T4O’s antitumor effect were explored by an integrated genome-wide transcriptomics and proteomics study on cSCC A431c cells.Finally,calpain-2’s potential mediator role in T4O’s anti-tumor mechanism was investigated in calpain-2 knockdown cell lines prepared via siRNA transfection.Result:It’s demonstrated that T4O treatment inhibited cSCC proliferation,clonogenicity,migration,and invasion while inducing apoptosis and suppressing the EMT pathway.T4O administration also inhibited cSCC tumorigenesis in the xenograft tumor model.RNA-sequencing and iTRAQ analysis detected significant upregulation of calpain-2 expression in T4O-treated cSCC cells.Western blotting confirmed that T4O significantly increased calpain-2 expression and promoted proteolytic cleavage ofβ-catenin and caspase-12,two calpain-2 target proteins.Importantly,siRNA-mediated calpain-2 knockdown relieved T4O’s suppressive effect on cSCC cell proliferation and motility.Mechanistically,T4O upregulates calpain-2 expression and promotes the cleavage ofβ-catenin and caspase-12,with siRNA-mediated calpain-2 knockdown mitigating T4O’s suppressive effects.Conclusion:These findings suggest that T4O’s antitumor activity in cSCC is mediated through the upregulation of calpain-2 expression and subsequent modulation ofβ-catenin and caspase-12.展开更多
GPX-GI is a cytosolic tetrameric Se-dependent glutathione peroxidase, similar in properties to GPX-1. Unlike the almost ubiquitous GPX-1, GPX-GI is mainly expressed in the epithelium of gastrointestinal tract. GPX-GI ...GPX-GI is a cytosolic tetrameric Se-dependent glutathione peroxidase, similar in properties to GPX-1. Unlike the almost ubiquitous GPX-1, GPX-GI is mainly expressed in the epithelium of gastrointestinal tract. GPX-GI contributes to at least fifty percent of GPX activity in rodent small intestmal epithelium. The total GPX activity consists of at least 70% of selenium-dependent GPX activity in this compartment.By analyzing a panel of mouse mterspecies DNA from the Jackson Laboratory's backcross resource,we mapped Gpx2 gene to mouse chromosome 12 between D12Mit4 and D12Mit5, near the Ccs1 locus which contains a colon cancer susceptibility gene. A pseudogene, Gpx2-ps is mapped to mouse chromosome 7.Comparison of Gpx2 gene expression in three pairs of C57BL/6Ha and ICR/Ha mice which are respectively resistant and sensitive to dimethylhydrazine-induced colon cancer, we found a higher Gpx2 mRNA level in C57BL/6Ha colon than ICR/Ha colon. Interestingly, a lower level of GPX activity is found in the resistant strain of mice. Because GPX-1 has three times higher specific activity than GPX GI, our data suggest that the decreased GPX activity may result from a higher level of Gpx2 gene expression in those cells co-express GPx1 gene展开更多
Avian H9N2 viruses have wide host range among the influenza A viruses.However,knowledge of H9N2 mammalian adaptation is limited.To explore the molecular basis of the adaptation to mammals,we performed serial lung pass...Avian H9N2 viruses have wide host range among the influenza A viruses.However,knowledge of H9N2 mammalian adaptation is limited.To explore the molecular basis of the adaptation to mammals,we performed serial lung passaging of the H9N2 strain A/chicken/Hunan/8.27 YYGK3W3-OC/2018(3W3)in mice and identified six mutations in the hemagglutinin(HA)and polymerase acidic(PA)proteins.Mutations L226Q,T511I,and A528V of HA were responsible for enhanced pathogenicity and viral replication in mice;notably,HA-L226Q was the key determinant.Mutations T97I,I545V,and S594G of PA contributed to enhanced polymerase activity in mammalian cells and increased viral replication levels in vitro and in vivo.PA-T97I increased viral polymerase activity by accelerating the viral polymerase complex assembly.Our findings revealed that the viral replication was affected by the presence of PA-97I and/or PA-545V in combination with a triple-point HA mutation.Furthermore,the double-and triple-point PA mutations demonstrated antagonistic effect on viral replication when combined with HA-226Q.Notably,any combination of PA mutations,along with double-point HA mutations,resulted in antagonistic effect on viral replication.We also observed antagonism in viral replication between PA-545V and PA-97I,as well as between HA-528V and PA-545V.Our findings demonstrated that several antagonistic mutations in HA and PA proteins affect viral replication,which may contribute to the H9N2 virus adaptation to mice and mammalian cells.These findings can potentially contribute to the monitoring of H9N2 field strains for assessing their potential risk in mammals.展开更多
Purpose:To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure(IOP) and retinal ganglion cells(RGCs) numbers in mice of various ages. Methods:A quantitative assessment of the pat...Purpose:To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure(IOP) and retinal ganglion cells(RGCs) numbers in mice of various ages. Methods:A quantitative assessment of the pathophysiology of the DBA/2J mice was performed and the C57/BL6 mice was used as control. The IOP was measured by the servo-null micropipette system; the regional patterns of the loss of RGCs were determined by cell count of retrogradely-labeled RGCs. Results:The baseline IOP for DBA/2J mice at 7 weeks was (16.6 ± 1.2)mm Hg.Then IOP increased extend to 12 months, with the peak of (25.2 ± 1.2)mm Hg at 6 months of age. Retinal ganglion cell numbers did not decrease relative to control until 12 months of age(P=0.006), when the loss was proportionally higher in peripheral regions(P<0.05). Conclusion:The elevation in IOP precedes the loss of RGCs by several months. RGCs cell loss occurs particularly in peripheral regions of the retina. These findings expand our understanding of the changes in DBA/2J mice and provide information for experiments design when they are used as a glaucoma model for future studies of RGCs degeneration in glaucoma.展开更多
Background: Host genetic background and sex, play central roles in defining the pathogenesis of type 2 diabetes(T2 D), obesity and infectious diseases. Our previous studies demonstrated the utilization of genetically ...Background: Host genetic background and sex, play central roles in defining the pathogenesis of type 2 diabetes(T2 D), obesity and infectious diseases. Our previous studies demonstrated the utilization of genetically highly diverse inbred mouse lines, namely collaborative cross(CC), for dissecting host susceptibility for the development of T2 D and obesity, showing significant variations following high-fat(42% fat) diet(HFD). Here, we aimed to assessing the host genetic background and sex effects on T2 D and obesity development in response to oral-mixed bacterial infection and HFD using the CC lines.Materials and Methods: Study cohort consists of 97 mice from 2 CC lines(both sexes), maintained on either HFD or Standard diet(CHD) for 12 weeks. At week 5 a group of mice from each diet were infected with Porphyromonas gingivalis(Pg) and Fusobacterium nucleatum(Fn) bacteria(control groups without infection). Body weight(BW) and glucose tolerance ability were assessed at the end time point of the experiment.Results: The CC lines varied(P <.05) at their BW gain and glucose tolerance ability(with sex effect) in response to diets and/or infection, showing opposite responses despite sharing the same environmental conditions. The combination of diet and infection enhances BW accumulation for IL1912, while restraints it for IL72. As for glucose tolerance ability, only females(both lines) were deteriorated in response to infection.Conclusions: This study emphasizes the power of the CC mouse population for the characterization of host genetic makeup for defining the susceptibility of the individual to development of obesity and/or impaired glucose tolerance.展开更多
PCV2 is considered the main pathogen of porcine circovirus diseases and porcine circovirus-associated diseases(PCVD/PCVAD). However, the exact mechanism underlying PCVD/PCVAD is currently unknown. Mouse models of PCV2...PCV2 is considered the main pathogen of porcine circovirus diseases and porcine circovirus-associated diseases(PCVD/PCVAD). However, the exact mechanism underlying PCVD/PCVAD is currently unknown. Mouse models of PCV2 are valuable experimental tools that can shed light on the pathogenesis of infection and will enable the evaluation of antiviral agents and vaccine candidates. In this review, we discuss the current state of knowledge of mouse models used in PCV2 research that has been performed to date, highlighting their strengths and limitations, as well as prospects for future PCV2 studies.展开更多
Mature eggs (at metaphase Ⅱ stage) produce a series of Ca2+ oscillation at fertilization. To define whether the fertilization-induced Ca2+ oscillation is restrict to the metaphase Ⅱ eggs and cell cycle dependent, mo...Mature eggs (at metaphase Ⅱ stage) produce a series of Ca2+ oscillation at fertilization. To define whether the fertilization-induced Ca2+ oscillation is restrict to the metaphase Ⅱ eggs and cell cycle dependent, mouse oocytes at prophase Ⅰ (arrested at germinal vesicle stage),metaphase Ⅰ, metaphase Ⅱ, as well as the pronuclear embryos at interphase of the first mitotic division derived from fertilization or parthenogenetic activation were inseminated after removal of zona pellucida. The results show that the fertilization-induced Ca2+ oscillation is not specific to metaphase Ⅱ eggs. This is supported by the fact that immature oocytes generated the Ca2+ oscillations at fertilization regardless of their nuclear progression from prophase Ⅰ to metaphase Ⅰ (in vitro matured) stage. More interestingly, it was first found that pronuclear embryos at interphase derived from parthenogenetic activation showed Ca2+ oscillations in response to fertilization while the zygotes at interphase did not after reinsemination or intracytoplasmic injection of sperm extracts which induce Ca2+ oscillations in MII eggs. This suggests that the ability of oocytes to generate Ca2+ oscillation in response to sperm penetration is not regulated in a cell cycle dependent manner but dependent on the cytoplasmic maturation.展开更多
Osteogenesis imperfecta（OI） comprises a group of heritable connective tissue disorders generally defined by recurrent fractures, low bone mass, short stature and skeletal fragility. Beyond the skeletal complications...Osteogenesis imperfecta（OI） comprises a group of heritable connective tissue disorders generally defined by recurrent fractures, low bone mass, short stature and skeletal fragility. Beyond the skeletal complications of OI,many patients also report intolerance to physical activity, fatigue and muscle weakness. Indeed, recent studies have demonstrated that skeletal muscle is also negatively affected by OI, both directly and indirectly. Given the well-established interdependence of bone and skeletal muscle in both physiology and pathophysiology and the observations of skeletal muscle pathology in patients with OI, we investigated the therapeutic potential of simultaneous anabolic targeting of both bone and skeletal muscle using a soluble activin receptor 2B（ACVR2B） in a mouse model of type Ⅲ OI（oim）. Treatment of 12-week-old oim mice with ACVR2 B for 4 weeks resulted in significant increases in both bone and muscle that were similar to those observed in healthy,wild-type littermates. This proof of concept study provides encouraging evidence for a holistic approach to treating the deleterious consequences of OI in the musculoskeletal system.展开更多
Objective To analyze the excitotoxicity of monosodium glutamate (MSG) in the offspring cerebral cortex and hippocampal subregions after maternal oral administration of MSG. Methods Kunming mice were given per os MSG...Objective To analyze the excitotoxicity of monosodium glutamate (MSG) in the offspring cerebral cortex and hippocampal subregions after maternal oral administration of MSG. Methods Kunming mice were given per os MSG ( 4.0 g/kg ) at 17～21 days of pregnancy and their offspring behaviors were studied at 10, 20 , 30 days postnatally. By using immunohistochemical means, the involvement of Bcl-2 and Bax in the glutamate-induced cell death in cortical and hippocampal neurons were examined. Cell damage was assessed by direct cell counting. Results Administration of monosodium glutamate during the fetal period in mice resulted in a moderate increase in the expression of Bax in principal neurons in CA1, CA2, CA3, CA4 and in the cerebral cortex at postpartum 10, 20, 30 days in the offspring mice, whereas Bcl-2 protein expressions were reduced significantly in the same regions as compared with those of controls. Conclusion These findings suggest that glutamate toxicity results in cellular death via an apoptotic mechanism in which the Bcl-2/Bax-alpha molecular complex may be involved. The glutamate-induced apoptosis appears to be related to the modulation of Bcl-2 family gene products such as Bcl-2 and Bax.展开更多
Sequential exposure of mouse embryo cells to HSV-2 and TPA gave rise to a synergistic enhancement of the transformation frequency. The transformants were selected for their ability to form dense foci of cells in me...Sequential exposure of mouse embryo cells to HSV-2 and TPA gave rise to a synergistic enhancement of the transformation frequency. The transformants were selected for their ability to form dense foci of cells in medium containing 10% or 1%(low) fetal bovine serum. The average number of foci induced with HSV -2 followed by TPA was about 3 or 5(in low serum) fold greater than that induced with HSV- 2 alone. HSV- 2 antigen could be detected in about 10% of transformed cells before 27th passage with immunofluorescence technique. Of two cell lines established from single focus , one designated BL which was preferable to form foci in subcultures was tumorigenic after 21th passage. All of the tumors were sarcomas with interlacing bundles of pleomorphic fibroblasts. The other,designated NP was nontumorigenic until 50th passage. The BL cell line was composed of two distict cell types, i. e.,pigmented and unpigmented. No viral DNA sequences weredetected in the cells of tumors derived from BL cell line.展开更多
基金CAMS Innovation Fund for Medical Sciences,Grant/Award Number:CIFMS,2021-I2M-1-024The Joint Fund for the Department of Science and Technology of Yunnan Province-Kunming Medical University,Grant/Award Number:202201AY070001-007+1 种基金Open Research Fund Project of Yunnan Provincial Key Laboratory of Pharmacology of Natural Medicines,Grant/Award Number:YKLPNP-G2403The Science and Technology Leading Talent Program of Yunnan Province,Grant/Award Number:202405AB350002。
文摘Background:Spinocerebellar ataxia type 2(SCA2)is a neurodegenerative disease marked by significant clinical and genetic heterogeneity,primarily caused by expanded CAG mutations in the ATXN2 gene.The unstable expansion of CAG repeats disrupts the genetic stability of animal models,which is detrimental to disease research.Methods:In this study,we established a mouse model in which CAG repeats do not undergo microsatellite instability(MSI)across generations.A humanized ATXN2 cDNA with four CAA interruptions within 73 CAG expansions was inserted into the Rosa26 locus of C57BL/6J mice.A 23 CAG control mouse model was also generated to verify ATXN2 integration and expression.Results:In our model,the number of CAG repeats remained stable during transmission,with no CAG repeat expansion observed in 64 parent-to-offspring transmissions.Compared with SCA2-Q23 mice,SCA2-Q73 mice exhibited progressive motor impairment,reduced Purkinje cell count and volume(indicative of cell atrophy),and muscle atrophy.These observations in the mice suggest that the behavioral and neuropathological phenotypes may reflect the features of SCA2 patients.RNA-seq analysis of the gastrocnemius muscle in SCA2-Q73 mice showed significant changes in muscle differentiation and development gene expression at 56 weeks,with no significant differences at 16 weeks compared to SCA2-Q23 mice.The expression level of the Myf6 gene significantly changed in the muscles of aged mice.Conclusion:In summary,the establishment of this model not only provides a stable animal model for studying CAG transmission in SCA2 but also indicates that the lack of long-term neural stimulation leads to muscle atrophy.
基金financially supported by grants from the Chang-Gung Memorial Hospital(CMRPG3J0971~3,CMRPVVP0111,and CMRPVVQ0041 to CEWCMRPG3P0101 to HJS)the National Science and Technology Council(113-2628-B-182-001-MY3 and 113-2811-B-182-024 to CEW).
文摘Background:KIT proto-oncogene,receptor tyrosine kinase(KIT,CD117)and platelet-derived growth factor-alpha(PDGFRA)are key drivers of gastrointestinal stromal tumors(GIST),but resistance to targeted therapy often arises from tumor protein p53(p53)alterations and loss of cell cycle control.However,the role of p53 status in GIST therapeutic potential has rarely been studied,so this study aimed to employ both wild-type andmutant p53 GIST models to investigate how p53 dysfunction influences the efficacy of p53 pathway-targeted therapies.Methods:The efficacy of the mouse double minute 2 homolog(MDM2)inhibitor(HDM201)and the Wee1 G2 checkpoint kinase(Wee1)inhibitor(adavosertib)was confirmed in both p53 wild-type(p53 WT)and p53 mutant(p53 MT)GIST cells.The anti-proliferative effects were assessed using the Cell Counting Kit-8(CCK-8)assay.Flow cytometry(FACS)and immunoblotting were employed to evaluate apoptosis and the expression of proteins related to drug efficacy.These findings were further validated in a xenograft model.Results:HDM201 selectively inhibited growth and triggered apoptosis in p53WT GIST cells,while adavosertib was effective mainly in p53 MT cells.Western blot analysis revealed thatHDM201 increased p53 and p21 levels in p53WT cells,and adavosertib affectedWee1 and phospho-cdc2 expression in both p53WT and p53 MT cells.In a xenograft mouse model,HDM201 significantly reduced the tumor volume and weight in p53WTGIST cells,whereas p53MT tumors showed only a moderate size reduction with adavosertib,without significant changes.Conclusions:Our results highlight the importance of p53 status in guiding GIST treatment.p53 WT tumors respond toMDM2 inhibitors,while p53 MTtumors show greater sensitivity toWee1 inhibitors,supporting p53 pathway targeting as a promising strategy for GIST patients.
基金funded by the Government program of basic research in Koltzov Institute of Developmental Biology of the Russian Academy of Sciences,number 0088-2024-0009the Ministry of Science and Higher Education of the Russian Federation,project number 075-15-2020-773(NPS).
文摘Objectives:Proteasomes,multi-subunit proteases,are key actors of cellular protein catabolism and a number of regulatory processes.The detection of subtle proteasome functioning in tumors may contribute to our understanding of the mechanisms of cancer development.The current study aimed to identify the role of low molecular mass protein 2(LMP2),a proteasome immune subunit,in the development of mouse colon 26(C26)adenocarcinoma.Methods:The functions of the LMP2 subunit in tumor development in Balb/c mice were studied using its irreversible inhibitor KZR-504.LMP2 activity was detected by the hydrolysis of the fluorogenic substrate Ac-Pro-Ala-Leu-AMC.Western blotting and Quantitative Reverse Transcription Polymerase Chain Reaction(qRT-PCR)were used.We applied fluorescent tests for cell proliferation and apoptosis.M2 macrophages were obtained by polarization of mouse bone marrow-derived macrophages using the corresponding cytokines.Results:KZR-504 showed high specificity only for the LMP2 subunit and had no negative effect on C26 cells in culture.However,KZR-504 suppressed the formation of tumor conglomerates(by 74%,p<0.001)after C26 cell transplantation in vivo,inhibited the expression of chitinase-<3-like protein 3(Chil3)gene(by 90%,p<0.001),a key marker of immunosuppressive M2 macrophages,in the tumor<microenvironment,and reduced the tumor weight compared to the control(by 48%,p<0.01).KZR-504 also suppressed<the expression of Chil3(by 68%,p<0.05)and arginase-1(Arg1)(by 90%,p<0.001),another marker gene,in M2<<macrophages and violated M0-M2 macrophage polarization in culture.Conclusion:We discovered earlier unknown functions of the proteasome LMP2 subunit to facilitate the formation of tumor conglomerates and maintain Chil3 and Arg1 expression in immunosuppressive M2 macrophages.Our work demonstrates that the proteasome LMP2 subunit can be a target for antitumor treatment.
基金supported by the National Basic Research Program of China (973 Program),No.2003CB517104the National Natural Science Foundation of China,No.30973513+3 种基金Beijing Municipal Science and Technology Program,No.D0206001043191the Natural Science Foundation of Beijing,No.7112061Beijing Key Foundation of Traditional Chinese Medicine,No.KJTS2011-04Beijing Health and Technical Personal of High-Level Plan,No.2009-3-66
文摘In the present study, we hypothesized that 5-hydroxymethyl-2-furfural could attenuate ischemic brain damage by reducing oxidative injury. Thus, mice were subjected to bilateral common carotid artery occlusion to establish a model of permanent forebrain ischemia. The mice were intraperitoneally injected with 5-hydroxymethyl-2-furfura130 minutes before ischemia or 5 minutes after ischemia. The survival time of mice injected with 5-hydroxymethyl-2-furfural was longer compared with untreated mice. The mice subjected to ischemia for 30 minutes and reperfusion for 5 minutes were intraperitoneally injected with 5-hydroxymethyl-2-furfural 5 minutes prior to reperfusion, which increased superoxide dismutase content and reduced malondialdehyde content, similar to the effects of Edaravone, a hydroxyl radical scavenger used for the treatment of stroke. These findings indicate that intraperitoneal injection of 5-hydroxymethyl-2-furfural can prolong the survival of mice with permanent forebrain ischemia. This outcome may be mediated by its antioxidative effects.
基金This project was supported by a grant from the National Natural Sciences Foundation of China (No 30471753)
文摘To study the cartilage differentiation of mouse mesenchymal stem cells （MSCs） induced by cartilage-derived morphogenetic proteins-2 in vitro, the MSCs were isolated from mouse bone marrow and cultured in vitro. The cells in passage 3 were induced into chondrogenic differentiation with different concentrations of recombinant human cartilage-derived morphogenetic proteins-2 （0, 10, 20, 50 and 100 ng/mL）. After 14 days of induction, morphology of cells was observed under phase-contrast microscope. Collagen Ⅱ mRNA and protein were examined with RT-PCR, Western blotting and immunocytochemistry respectively and the sulfate glycosaminoglycan was measured by Alcian blue staining. RT-PCR showed that CDMP-2 could promote expression of collagen Ⅱ mRNA in an dose-dependant manner, especially at the concentration of 50 ng/mL and 100 ng/mL. Immunocytochemistry and Western blotting revealed a similar change. Alcian blue staining exhibited deposition of typical cartilage extracellular matrix. Our results suggest that mouse bone marrow mesencymal stem cells can differentiate into chondrogenic phonotype with the induction of CDMP-2 in vitro, which provides a basis for further research on the role of CDMP-2 in chondrogenesis.
基金supported by the National Natural Science Foundation of China(82041017)Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(2016-I2M-1-014)。
文摘Understanding the pathogenesis of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and clarifying antiviral immunity in hosts are critical aspects for the development of vaccines and antivirals.Mice are frequently used to generate animal models of infectious diseases due to their convenience and ability to undergo genetic manipulation.However,normal adult mice are not susceptible to SARS-CoV-2.Here,we developed a viral receptor(human angiotensin-converting enzyme 2,hACE2)pulmonary transfection mouse model to establish SARS-CoV-2 infection rapidly in the mouse lung.Based on the model,the virus successfully infected the mouse lung 2 days after transfection.Viral RNA/protein,innate immune cell infiltration,inflammatory cytokine expression,and pathological changes in the infected lungs were observed after infection.Further studies indicated that neutrophils were the first and most abundant leukocytes to infiltrate the infected lungs after viral infection.In addition,using infected CXCL5-knockout mice,chemokine CXCL5 was responsible for neutrophil recruitment.CXCL5 knockout decreased lung inflammation without diminishing viral clearance,suggesting a potential target for controlling pneumonia.
基金Supported by So Paulo Research Foundation (FAPESP), Proc 05/04752-0
文摘AIM:To examine whether the ob/ob mouse model of obesity is accompanied by enteric nervous system ab-normalities such as altered motility METHODS:The study examined the distribution of the P2X 2 receptor (P2X 2 R) in myenteric neurons of female ob/ob mice. Specifically, we used immunohistochemistry to analyze the co-expression of the P2X 2 R with neuronal nitric oxide synthase (nNOS), choline acetyltrans-ferase (ChAT), and calretinin (CalR) in neurons of the small intestine myenteric plexus in ob/ob and control female mice In these sections, we used scanning confocal microscopy to analyze the co-localization of these markers as well as the neuronal density (cm 2 ) and area profile (μm2) of P2X 2 R-positive neurons In addition, enteric neurons were labeled using the nicotinamide adenine dinucleotide (NA H) diaphorase method and analyzed with light microscopy as an alternate means by which to analyze neuronal density and areaRESULTS:In the present study, we observed a 29 6% increase in the body weight of the ob/ob animals (OG) compared to the control group (CG) In addition, the average small intestine area was increased by approxi-mately 29 6% in the OG compared to the CG Immu-noreactivity (IR) for the P2X 2 R, nNOS, ChAT and CalR was detectable in the myenteric plexus, as well as in the smooth muscle, in both groups This IR appeared to be mainly cytoplasmic and was also associated with the cell membrane of the myenteric plexus neurons, where it outlined the neuronal cell bodies and their processes P2X 2 R-IR was observed to co-localize 100% with that for nNOS, ChAT and CalR in neurons of both groups In the ob/ob group, however, we observed that the neuronal density (neuron/cm 2 ) of P2X 2 R-IR cells was in-creased by 62% compared to CG, while that of NOS-IR and ChAT-IR neurons was reduced by 49% and 57%, respectively, compared to control mice The neuronal density of CalR-IR neurons was not different between the groups Morphometric studies further demonstrated that the cell body profile area (μm2) of nNOS-IR, ChAT-IR and CalR-IR neurons was increased by 34%, 20% and 55%, respectively, in the OG compared to controls Staining for NA H diaphorase activity is widely used to detect alterations in the enteric nervous system; however, our qualitative examination of NA H-diaphorase positive neurons in the myenteric ganglia revealed an overall similarity between the two groups CONCLUSION:We demonstrate increases in P2X2R expression and alterations in nNOS, ChAT and CalR IR in ileal myenteric neurons of female ob/ob mice compared to wild-type controls.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (CAS) (XDB29010102)National Natural Science Foundation of China (NSFC) (91957124,82161148010,32041010)+4 种基金Self-supporting Program of Guangzhou Laboratory (SRPG22-001)National Science and Technology Infrastructure of China (National Pathogen Resource Center-NPRC-32)Management Strategy of the Tertiary Prevention and Treatment of Diabetes Based on DIP system (supported by China Health Promotion Foundation)supported by the Youth Innovation Promotion Association of CAS (Y2021034)Innovation Team and Talents Cultivation Program of the National Administration of Traditional Chinese Medicine (ZYYCXTD-D-202208)。
文摘Severe acute respiratory syndrome coronavirus 2(SARSCo V-2)infection can result in more severe syndromes and poorer outcomes in patients with diabetes and obesity.However,the precise mechanisms responsible for the combined impact of coronavirus disease 2019(COVID-19)and diabetes have not yet been elucidated,and effective treatment options for SARS-Co V-2-infected diabetic patients remain limited.To investigate the disease pathogenesis,K18-h ACE2 transgenic(h ACE2^(Tg))mice with a leptin receptor deficiency(h ACE2-Lepr^(-/-))and high-fat diet(h ACE2-HFD)background were generated.The two mouse models were intranasally infected with a 5×10^(5) median tissue culture infectious dose(TCID_(50))of SARSCo V-2,with serum and lung tissue samples collected at 3days post-infection.The h ACE2-Lepr^(-/-)mice were then administered a combination of low-molecular-weight heparin(LMWH)(1 mg/kg or 5 mg/kg)and insulin via subcutaneous injection prior to intranasal infection with1×10^(4) TCID_(50)of SARS-Co V-2.Daily drug administration continued until the euthanasia of the mice.Analyses of viral RNA loads,histopathological changes in lung tissue,and inflammation factors were conducted.Results demonstrated similar SARS-Co V-2 susceptibility in h ACE2^(Tg)mice under both lean(chow diet)and obese(HFD)conditions.However,compared to the h ACE2-Lepr^(+/+)mice,h ACE2-Lepr^(-/-)mice exhibited more severe lung injury,enhanced expression of inflammatory cytokines and hypoxia-inducible factor-1α(HIF-1α),and increased apoptosis.Moreover,combined LMWH and insulin treatment effectively reduced disease progression and severity,attenuated lung pathological changes,and mitigated inflammatory responses.In conclusion,preexisting diabetes can lead to more severe lung damage upon SARS-Co V-2 infection,and LMWH may be a valuable therapeutic approach for managing COVID-19patients with diabetes.
文摘This study examined the expression and distribution of angiopoietin-1/-2 （Ang-1/-2） in the endometrium of early pregnant mice. The expression of Ang-1/-2 was detected by immunohistochemical staining and in situ hybridization respectively. Computerized image analysis system was used to measure the average optical intensity of Ang-1/-2 in endometria at different time points after gestation. Mice were randomly divided into 5 groups： control group, D2 group （2 days after pregnancy）, D4 group （4 days after pregnancy）, D6 group （6 days after pregnancy） and D8 group （8 days after pregnancy）, each containing 15 mice. The results showed that the expression of Ang-1 and Ang-2 was very different among 4 groups （P〈0.01）. Immunohistochemical staining revealed that Ang-1 was localized in the cytoplasma of stromal cells 2 days after pregnancy （day 2）, and in luminal epithelial cells on day 4. The protein of Ang-2 was mainly expressed in the cytoplasma of glandular epithelia and stromal cells. With gestation time, the positive reactions of Ang-1/-2 were stronger in the endometria of the pregnant mice （P〈0.01）. In situ hybridization showed Ang-I mRNA in stromal cells on day 2. Hybridization signal was localized in both stromal cells and vessel epithelial cells on day 4; Ang-2 mRNA was expressed in stromal cells and glandular epithelia on day 2; high mRNA levels appeared in stromal cells, glandular epithelia and vascular endothelia on day 4; an increasing in mRNA expression of Ang-1/-2 was observed on day 6 and day 8 （P〈0.01）. It is suggested that Ang-1/-2 may play an important role in the cross-talk between blastocyst and maternal endometrium during the process of embryo implantation.
基金supported by the Basic Research Program of the Guizhou Science Cooperation Foundation Project(Grant Number:ZK[2021]466)Guizhou Provincial Health Commission(Grant Number:gzwkj2022-062).
文摘Background:Terpinen-4-ol(T4O),a key constituent of tea tree essential oil and various aromatic plants,has shown promising antiproliferative and pro-apoptotic effects in melanoma and other cancer types.However,its efficacy against cutaneous squamous cell carcinoma(cSCC)remains unclear.Thus,in this study,we investigated the in vivo and in vitro effects of T4O on cSCC cell lines and preliminarily explored its impacting pathways.Methods:Using CCK8 and assay colony formation,we assessed the viability of cSCC A431,SCL-1,and COLO-16 cells treated with T40 at varying concentrations(0,1,2,and 4μM).Flow cytometry was employed to evaluate T4O’s effect on cSCC cell’s cycle progression and apoptosis induction.Additionally,western blotting was utilized to examine the expression intensities of N-cadherin and E-cadherin,two indicative markers of the epithelial-mesenchymal transition(EMT)pathway.T4O’s in vivo effect on inhibiting tumor progression was evaluated on an established xenograft tumor model.Then,the molecular mechanisms of T4O’s antitumor effect were explored by an integrated genome-wide transcriptomics and proteomics study on cSCC A431c cells.Finally,calpain-2’s potential mediator role in T4O’s anti-tumor mechanism was investigated in calpain-2 knockdown cell lines prepared via siRNA transfection.Result:It’s demonstrated that T4O treatment inhibited cSCC proliferation,clonogenicity,migration,and invasion while inducing apoptosis and suppressing the EMT pathway.T4O administration also inhibited cSCC tumorigenesis in the xenograft tumor model.RNA-sequencing and iTRAQ analysis detected significant upregulation of calpain-2 expression in T4O-treated cSCC cells.Western blotting confirmed that T4O significantly increased calpain-2 expression and promoted proteolytic cleavage ofβ-catenin and caspase-12,two calpain-2 target proteins.Importantly,siRNA-mediated calpain-2 knockdown relieved T4O’s suppressive effect on cSCC cell proliferation and motility.Mechanistically,T4O upregulates calpain-2 expression and promotes the cleavage ofβ-catenin and caspase-12,with siRNA-mediated calpain-2 knockdown mitigating T4O’s suppressive effects.Conclusion:These findings suggest that T4O’s antitumor activity in cSCC is mediated through the upregulation of calpain-2 expression and subsequent modulation ofβ-catenin and caspase-12.
文摘GPX-GI is a cytosolic tetrameric Se-dependent glutathione peroxidase, similar in properties to GPX-1. Unlike the almost ubiquitous GPX-1, GPX-GI is mainly expressed in the epithelium of gastrointestinal tract. GPX-GI contributes to at least fifty percent of GPX activity in rodent small intestmal epithelium. The total GPX activity consists of at least 70% of selenium-dependent GPX activity in this compartment.By analyzing a panel of mouse mterspecies DNA from the Jackson Laboratory's backcross resource,we mapped Gpx2 gene to mouse chromosome 12 between D12Mit4 and D12Mit5, near the Ccs1 locus which contains a colon cancer susceptibility gene. A pseudogene, Gpx2-ps is mapped to mouse chromosome 7.Comparison of Gpx2 gene expression in three pairs of C57BL/6Ha and ICR/Ha mice which are respectively resistant and sensitive to dimethylhydrazine-induced colon cancer, we found a higher Gpx2 mRNA level in C57BL/6Ha colon than ICR/Ha colon. Interestingly, a lower level of GPX activity is found in the resistant strain of mice. Because GPX-1 has three times higher specific activity than GPX GI, our data suggest that the decreased GPX activity may result from a higher level of Gpx2 gene expression in those cells co-express GPx1 gene
基金supported by the National Key Research and Development Program of China(NKPs)(2022YFC2604101)the National Science and Technology Major Project of China(2020ZX10001016-002)。
文摘Avian H9N2 viruses have wide host range among the influenza A viruses.However,knowledge of H9N2 mammalian adaptation is limited.To explore the molecular basis of the adaptation to mammals,we performed serial lung passaging of the H9N2 strain A/chicken/Hunan/8.27 YYGK3W3-OC/2018(3W3)in mice and identified six mutations in the hemagglutinin(HA)and polymerase acidic(PA)proteins.Mutations L226Q,T511I,and A528V of HA were responsible for enhanced pathogenicity and viral replication in mice;notably,HA-L226Q was the key determinant.Mutations T97I,I545V,and S594G of PA contributed to enhanced polymerase activity in mammalian cells and increased viral replication levels in vitro and in vivo.PA-T97I increased viral polymerase activity by accelerating the viral polymerase complex assembly.Our findings revealed that the viral replication was affected by the presence of PA-97I and/or PA-545V in combination with a triple-point HA mutation.Furthermore,the double-and triple-point PA mutations demonstrated antagonistic effect on viral replication when combined with HA-226Q.Notably,any combination of PA mutations,along with double-point HA mutations,resulted in antagonistic effect on viral replication.We also observed antagonism in viral replication between PA-545V and PA-97I,as well as between HA-528V and PA-545V.Our findings demonstrated that several antagonistic mutations in HA and PA proteins affect viral replication,which may contribute to the H9N2 virus adaptation to mice and mammalian cells.These findings can potentially contribute to the monitoring of H9N2 field strains for assessing their potential risk in mammals.
基金This work was supported by Guangdong Scientific researchfund (NO. 2006J1-C0051)
文摘Purpose:To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure(IOP) and retinal ganglion cells(RGCs) numbers in mice of various ages. Methods:A quantitative assessment of the pathophysiology of the DBA/2J mice was performed and the C57/BL6 mice was used as control. The IOP was measured by the servo-null micropipette system; the regional patterns of the loss of RGCs were determined by cell count of retrogradely-labeled RGCs. Results:The baseline IOP for DBA/2J mice at 7 weeks was (16.6 ± 1.2)mm Hg.Then IOP increased extend to 12 months, with the peak of (25.2 ± 1.2)mm Hg at 6 months of age. Retinal ganglion cell numbers did not decrease relative to control until 12 months of age(P=0.006), when the loss was proportionally higher in peripheral regions(P<0.05). Conclusion:The elevation in IOP precedes the loss of RGCs by several months. RGCs cell loss occurs particularly in peripheral regions of the retina. These findings expand our understanding of the changes in DBA/2J mice and provide information for experiments design when they are used as a glaucoma model for future studies of RGCs degeneration in glaucoma.
基金Israeli Science Foundation (ISF),Grant/Award Number 1085/18German Israeli Science Foundation (GIF),Grant/Award Number I-63-410.20-2017+1 种基金Binational Science Foundation (BSF),Grant/Award Number 2015077Tel-Aviv University
文摘Background: Host genetic background and sex, play central roles in defining the pathogenesis of type 2 diabetes(T2 D), obesity and infectious diseases. Our previous studies demonstrated the utilization of genetically highly diverse inbred mouse lines, namely collaborative cross(CC), for dissecting host susceptibility for the development of T2 D and obesity, showing significant variations following high-fat(42% fat) diet(HFD). Here, we aimed to assessing the host genetic background and sex effects on T2 D and obesity development in response to oral-mixed bacterial infection and HFD using the CC lines.Materials and Methods: Study cohort consists of 97 mice from 2 CC lines(both sexes), maintained on either HFD or Standard diet(CHD) for 12 weeks. At week 5 a group of mice from each diet were infected with Porphyromonas gingivalis(Pg) and Fusobacterium nucleatum(Fn) bacteria(control groups without infection). Body weight(BW) and glucose tolerance ability were assessed at the end time point of the experiment.Results: The CC lines varied(P <.05) at their BW gain and glucose tolerance ability(with sex effect) in response to diets and/or infection, showing opposite responses despite sharing the same environmental conditions. The combination of diet and infection enhances BW accumulation for IL1912, while restraints it for IL72. As for glucose tolerance ability, only females(both lines) were deteriorated in response to infection.Conclusions: This study emphasizes the power of the CC mouse population for the characterization of host genetic makeup for defining the susceptibility of the individual to development of obesity and/or impaired glucose tolerance.
基金National Key Research and Development Program of China,Grant/Award Number:2017YFD0500103National Natural Science Foundation of China,Grant/Award Number:31772747,31272385+3 种基金Jilin Province Science and Technology Development Projects,Grant/Award Number:20150204077NYGraduate Innovation Fund of Jilin Universitythe Program for Changjiang Scholarsthe University Innovative Research Team,Grant/Award Number:IRT1248
文摘PCV2 is considered the main pathogen of porcine circovirus diseases and porcine circovirus-associated diseases(PCVD/PCVAD). However, the exact mechanism underlying PCVD/PCVAD is currently unknown. Mouse models of PCV2 are valuable experimental tools that can shed light on the pathogenesis of infection and will enable the evaluation of antiviral agents and vaccine candidates. In this review, we discuss the current state of knowledge of mouse models used in PCV2 research that has been performed to date, highlighting their strengths and limitations, as well as prospects for future PCV2 studies.
文摘Mature eggs (at metaphase Ⅱ stage) produce a series of Ca2+ oscillation at fertilization. To define whether the fertilization-induced Ca2+ oscillation is restrict to the metaphase Ⅱ eggs and cell cycle dependent, mouse oocytes at prophase Ⅰ (arrested at germinal vesicle stage),metaphase Ⅰ, metaphase Ⅱ, as well as the pronuclear embryos at interphase of the first mitotic division derived from fertilization or parthenogenetic activation were inseminated after removal of zona pellucida. The results show that the fertilization-induced Ca2+ oscillation is not specific to metaphase Ⅱ eggs. This is supported by the fact that immature oocytes generated the Ca2+ oscillations at fertilization regardless of their nuclear progression from prophase Ⅰ to metaphase Ⅰ (in vitro matured) stage. More interestingly, it was first found that pronuclear embryos at interphase derived from parthenogenetic activation showed Ca2+ oscillations in response to fertilization while the zygotes at interphase did not after reinsemination or intracytoplasmic injection of sperm extracts which induce Ca2+ oscillations in MII eggs. This suggests that the ability of oocytes to generate Ca2+ oscillation in response to sperm penetration is not regulated in a cell cycle dependent manner but dependent on the cytoplasmic maturation.
基金supported by NIAMS,of the National Institutes of Health,under award numbers R01AR062074 (to DJD) and R01AR060636 (to S-JL)the Harry Headley Charitable and Research Foundation,Punta Gorda,FL(to ELG-L)
文摘Osteogenesis imperfecta（OI） comprises a group of heritable connective tissue disorders generally defined by recurrent fractures, low bone mass, short stature and skeletal fragility. Beyond the skeletal complications of OI,many patients also report intolerance to physical activity, fatigue and muscle weakness. Indeed, recent studies have demonstrated that skeletal muscle is also negatively affected by OI, both directly and indirectly. Given the well-established interdependence of bone and skeletal muscle in both physiology and pathophysiology and the observations of skeletal muscle pathology in patients with OI, we investigated the therapeutic potential of simultaneous anabolic targeting of both bone and skeletal muscle using a soluble activin receptor 2B（ACVR2B） in a mouse model of type Ⅲ OI（oim）. Treatment of 12-week-old oim mice with ACVR2 B for 4 weeks resulted in significant increases in both bone and muscle that were similar to those observed in healthy,wild-type littermates. This proof of concept study provides encouraging evidence for a holistic approach to treating the deleterious consequences of OI in the musculoskeletal system.
基金ThisstudywassupportedbytheNationalNaturalScienceFoundationofChina (No .3 0 0 70 73 1 )
文摘Objective To analyze the excitotoxicity of monosodium glutamate (MSG) in the offspring cerebral cortex and hippocampal subregions after maternal oral administration of MSG. Methods Kunming mice were given per os MSG ( 4.0 g/kg ) at 17～21 days of pregnancy and their offspring behaviors were studied at 10, 20 , 30 days postnatally. By using immunohistochemical means, the involvement of Bcl-2 and Bax in the glutamate-induced cell death in cortical and hippocampal neurons were examined. Cell damage was assessed by direct cell counting. Results Administration of monosodium glutamate during the fetal period in mice resulted in a moderate increase in the expression of Bax in principal neurons in CA1, CA2, CA3, CA4 and in the cerebral cortex at postpartum 10, 20, 30 days in the offspring mice, whereas Bcl-2 protein expressions were reduced significantly in the same regions as compared with those of controls. Conclusion These findings suggest that glutamate toxicity results in cellular death via an apoptotic mechanism in which the Bcl-2/Bax-alpha molecular complex may be involved. The glutamate-induced apoptosis appears to be related to the modulation of Bcl-2 family gene products such as Bcl-2 and Bax.
文摘Sequential exposure of mouse embryo cells to HSV-2 and TPA gave rise to a synergistic enhancement of the transformation frequency. The transformants were selected for their ability to form dense foci of cells in medium containing 10% or 1%(low) fetal bovine serum. The average number of foci induced with HSV -2 followed by TPA was about 3 or 5(in low serum) fold greater than that induced with HSV- 2 alone. HSV- 2 antigen could be detected in about 10% of transformed cells before 27th passage with immunofluorescence technique. Of two cell lines established from single focus , one designated BL which was preferable to form foci in subcultures was tumorigenic after 21th passage. All of the tumors were sarcomas with interlacing bundles of pleomorphic fibroblasts. The other,designated NP was nontumorigenic until 50th passage. The BL cell line was composed of two distict cell types, i. e.,pigmented and unpigmented. No viral DNA sequences weredetected in the cells of tumors derived from BL cell line.
