Background:The precise insertion of large DNA fragments(>3–5 kb)remains one of the key obstacles in establishment of genetically modified murine models.Methods:A 21 kb large DNA fragment containing three tandemly ...Background:The precise insertion of large DNA fragments(>3–5 kb)remains one of the key obstacles in establishment of genetically modified murine models.Methods:A 21 kb large DNA fragment containing three tandemly linked copies of the human HRAS gene was inserted into the genome of C57BL/6J mouse,generating a mouse model designated as KI.C57-ras(or named NF-h HRAS).Whole-genome sequencing and Sanger sequencing were utilized to it confirm precise insertion and copy number.The stability of transgene expression among different generations was verified from multiple aspects using by digital PCR,western blot and DNA sequencing.To assess tumor susceptibility in the mouse model,N-Nitroso-N-methylurea(MNU)was administered at a dosage of 75 mg/kg.Histopathological examinations were conducted using hematoxylin and eosin(H&E)staining.Results:The HRAS DNA fragment was inserted into mouse chromosome 15E1 site,locating between 80623202 bp and 80625020 bp.NF-h HRAS mice exhibited stable inheritance and displayed consistent phenotypes across individuals.Moreover,this mouse model exhibited a high susceptibility to carcinogens.Upon administration of MNU the earliest mortality onset was earlier than that of wild-type littermates(day 65 vs.day 78 for male and day 56 vs.day 84 for female).Notably,100%of the NF-h HRAS transgenic mice developed tumors,with approximately 84%of male NF-h HRAS mice exhibiting specific tumor types,such as squamous cell carcinoma or squamous cell papilloma,which was consistent with the previously reported carcinogenic rasH2 mouse model.The types of tumors and the target organs exhibited diversity in NFh HRAS mice,while the spontaneous tumor incidence remained low(1/50).Conclusions:The NF-h HRAS mice demonstrated excellent genetic stability,a reproducible phenotype,and high susceptibility to carcinogens,indicating their potential utility in non-clinical safety evaluations of drugs as per the S1B guidelines issued by the ICH(The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use).展开更多
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
Aim： To investigate the stage-specific localization of metastasis-associated protein 1 （MTA1） during spermatogenesis in adult human and mouse testis. Methods： The immunolocalization of MTA1 was studied by immunohi...Aim： To investigate the stage-specific localization of metastasis-associated protein 1 （MTA1） during spermatogenesis in adult human and mouse testis. Methods： The immunolocalization of MTA1 was studied by immunohistochemistry and Western blot analysis. The distribution pattern of MTA1 in mouse testis was confirmed by using quantitative analysis of purified spermatogenic cells. Results： The specificity of polyclonal antibody was confirmed by Western blot analysis. MTA1 was found expressed in the nucleus of germ cells, except elongate spermatids, and in the cytoplasm of Sertoli cells; Leydig cells did not show any specific reactivity. MTA1 possessed different distribution patterns in the two species： in humans, the most intensive staining was found in the nucleus of round spermatids and of primary spermatocytes while in mice, the most intense MTA 1 staining was in the nucleus of leptotene, zygotene and pachytene spermatocytes. In both species the staining exhibited a cyclic pattern. Conclusion： The present communication initially provides new evidence for the potential role of MTA1 in mature testis. In addition, its distinctive expression in germ cells suggests a regulatory role of the peptide during spermatogenesis.展开更多
The mechanism of androgen action is complex. Recently, significant advances have been made into our understanding of how androgens act via the androgen receptor （AR） through the use of genetically modified mouse mod...The mechanism of androgen action is complex. Recently, significant advances have been made into our understanding of how androgens act via the androgen receptor （AR） through the use of genetically modified mouse models. A number of global and tissue-specific AR knockout （ARKO） models have been generated using the Cre-loxP system which allows tissue- and/or cell-specific deletion. These ARKO models have examined a number of sites of androgen action including the cardiovascular system, the immune and hemopoetic system, bone, muscle, adipose tissue, the prostate and the brain. This review focuses on the insights that have been gained into human androgen deficiency through the use of ARKO mouse models at each of these sites of action, and highlights the strengths and limitations of these Cre-loxP mouse models that should be considered to ensure accurate interpretation of the phenotype.展开更多
BACKGROUND： Total saponins of Panax ginseng （TSPG） exhibits neuroprotection against Parkinson＇s disease in the substantia nigra. OBJECTIVE： To investigate the effects of TSPG on human embryonic neural stem cells ...BACKGROUND： Total saponins of Panax ginseng （TSPG） exhibits neuroprotection against Parkinson＇s disease in the substantia nigra. OBJECTIVE： To investigate the effects of TSPG on human embryonic neural stem cells （NSCs） proliferation and differentiation into dopaminergic neurons using in vitro studies, and to observe NSC differentiation in a mouse model of Parkinson＇s disease, as well as behavioral changes before and after transplantation. DESIGN, TIME AND SETTING： In vitro neural cell biology trial and in vivo randomized, controlled animal trial were performed at the Institute of Basic Medical Sciences, Chongqing Medical University between September 2004 and December 2007. MATERIALS： TSPG （purity 〉 95%） was isolated, extracted, and identified by Chongqing Academy of Chinese Materia Medica. Recombinant human basic fibroblast growth factor （bFGF） and recombinant human epidermal growth factor （EGF） were purchased from PeproTech, USA. A total of 25 C57/BL6J mice, aged 18-20 weeks were included. Twenty were used to establish a Parkinson＇s disease model with i.p. injection of MPTP （1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine） and TSPG alone or combined with interleukin-1 （IL-1）-treated NSCs prior to transplantation into the corpus striatum. The remaining five mice were pretreated for 3 days with TSPG prior to MPTP injection, serving as the TSPG prevention group. METHODS： Primary NSCs were isolated, cultured and purified from embryonic cerebral cortex. Immunocytochemistry was employed to detect specific antigen expression in the NSCs. In vitro experiment： （1） to induce proliferation, NSCs were treated with TSPG, EGF＋bFGF, or TSPG＋EGF＋bFGF, respectively; （2） to induce dopaminergic neuronal differentiation, NSCs were treated with TSPG, IL-1, or TSPG＋IL-1, respectively. MAIN OUTCOME MEASURES： In vitro experiment： the effects of TSPG on NSCs proliferation were evaluated with flow cytometry and MTT assay. Tyrosine hydroxylase expression was determined by immunocytochemistry assay to observe effects of TSPG on dopaminergic neuronal differentiation. In vivo experiment： differentiation of grafted NSCs in the mouse brain was determined by immunohistochemical staining. Behavioral changes were evaluated by spontaneous activity frequency, memory function, and score of paralysis agitans. RESULTS： （1） NSCs were cultured and passaged for more than three passages. Immunocytochemistry revealed positive nestin staining, as well as neurofilament protein and glial fibrillary acidic protein. （2） TSPG significantly increased NSC proliferation, in particular when combined with EGF and bFGF, which was twice as effective as FGF or bFGF alone. TSPG also induced dopaminergic differentiation in NSCs, in particular when TSPG was added together with IL-1, resulting in an effect five times greater than that of IL-1 alone. （3） At day 30 following transplantation, most NSCs in the TSPG prevention group differentiated into dopaminergic neurons, and the scores of paralysis agitans, spontaneous activity, and memory function were significantly increased compared with TSPG alone or TSPG＋IL-1 groups （P 〈 0.05）. CONCLUSION： TSPG stimulated NSC proliferation, in particular when combined with FGF and bFGF. TSPG significantly induced dopaminergic neuronal differentiation of NSCs, and the effect was greater when combined with IL-1. In addition, TSPG greatly improved behavior in the Parkinson＇s disease mouse model following NSC transplantation. Following NSC transplantation, TSPG pretreatment exhibited superior efficacy over either TSPG alone or TSPG in combination with IL-1, in terms of behavioral improvements in the Parkinson＇s disease mouse model.展开更多
Background:There are remarkable genetic differences between animal major histocompatibility complex(MHC)systems and the human leukocyte antigen(HLA)system.HLA transgenic humanized mouse model systems offer a much bett...Background:There are remarkable genetic differences between animal major histocompatibility complex(MHC)systems and the human leukocyte antigen(HLA)system.HLA transgenic humanized mouse model systems offer a much better method to study the HLA-A-related principal mechanisms for vaccine development and HLA-Arestricted responses against infection in human.Methods:A recombinant gene encoding the chimeric HLA-A30 monochain was constructed.This HHD molecule contains the following:α1-α2 domains of HLA-A30,α3 and cytoplasmic domains of H-2D~b,linked at its N-terminus to the C-terminus of humanβ2m by a 15-amino-acid peptide linker.The recombinant gene encoding the chimeric HLA-A30 monochain cassette was introduced into bacterial artificial chromosome(BAC)CH502-67J3 containing the HLA-A01 gene locus by Red-mediated homologous recombination.Modified BAC CH502-67J3 was microinjected into the pronuclei of wild-type mouse oocytes.This humanized mouse model was further used to assess the immune responses against influenza A virus(H1N1)pdm09 clinically isolated from human patients.Immune cell population,cytokine production,and histopathology in the lung were analyzed.Results:We describe a novel humanβ2m-HLA-A30(α1α2)-H-2D~b(α3 transmembrane cytoplasmic)(HHD)monochain transgenic mouse strain,which contains the intact HLA-A01 gene locus including 49 kb 5’-UTR and 74 kb 3’-UTR of HLA-A01*01.Five transgenic lines integrated into the large genomic region of HLA-A gene locus were obtained,and the robust expression of exogenous transgene was detected in various tissues from A30-18#and A30-19#lines encompassing the intact flanking sequences.Flow cytometry revealed that the introduction of a large genomic region in HLA-A gene locus can influence the immune cell constitution in humanized mice.Pdm09 infection caused a similar immune response among HLA-A30 Tg humanized mice and wild-type mice,and induced the rapid increase of cytokines,including IFN-γ,TNF-α,and IL-6,in both HLA-A30 humanized Tg mice and wild-type mice.The expression of HLA-A30 transgene was dramatically promoted in tissues from A30-9#line at 3 days post-infection(dpi).Conclusions:We established a promising preclinical research animal model of HLA-A30 Tg humanized mouse,which could accelerate the identification of novel HLA-A30-restricted epitopes and vaccine development,and support the study of HLA-A-restricted responses against infection in humans.展开更多
BACKGROUND The high prevalence of human papillomavirus(HPV)infection in oropharyngeal squamous cell carcinoma(SCC)is well established,and p16 expression is a strong predictor.HPV-related tumors exhibit unique mechanis...BACKGROUND The high prevalence of human papillomavirus(HPV)infection in oropharyngeal squamous cell carcinoma(SCC)is well established,and p16 expression is a strong predictor.HPV-related tumors exhibit unique mechanisms that target p16 and p53 proteins.However,research on HPV prevalence and the combined predictive value of p16 and p53 expression in head and neck cutaneous SCC(HNCSCC),particularly in Asian populations,remains limited.This retrospective study surveyed 62 patients with HNSCC(2011-2020),excluding those with facial warts or other skin cancer.AIM To explore the prevalence of HPV and the predictive value of p16 and p53 expression in HNCSCC in Asian populations.METHODS All patients underwent wide excision and biopsy.Immunohistochemical staining for HPV,p16,and p53 yielded positive and negative results.The relevance of each marker was investigated by categorizing the tumor locations into high-risk and middle-risk zones based on recurrence frequency.RESULTS Of the 62 patients,20(32.26%)were male,with an average age of 82.27 years(range 26-103 years).High-risk included 19 cases(30.65%),with the eyelid and lip being the most common sites(five cases,8.06%).Middle-risk included 43 cases(69.35%),with the cheek being the most common(29 cases,46.77%).The p16 expression was detected in 24 patients(38.71%),p53 expression in 42 patients(72.58%),and HPV in five patients(8.06%).No significant association was found between p16 expression and the presence of HPV(P>0.99),with a positive predictive value of 8.33%.CONCLUSION This study revealed that p16,a surrogate HPV marker in oropharyngeal SCC,is not reliable in HNCSCC,providing valuable insights for further research in Asian populations.展开更多
AIM To establish an inducible liver injury mouse model and transplant human hepatocytes to obtain liverhumanized mice.METHODS We crossed three mouse strains,including albumin(Alb)-cre transgenic mice,inducible diphthe...AIM To establish an inducible liver injury mouse model and transplant human hepatocytes to obtain liverhumanized mice.METHODS We crossed three mouse strains,including albumin(Alb)-cre transgenic mice,inducible diphtheria toxin receptor(DTR) transgenic mice and severe combined immune deficient(SCID)-beige mice,to create Alb-cre/DTR/SCID-beige(ADSB) mice,which coincidentally harbor Alb-cre and DTR transgenes and are immunodeficient. As the Cre expression is driven by the liver-specific promoter Alb(encoding ALB),the DTR stop signal flanked by two lox P sites can be deleted in the ADSB mice,resulting in DTR expression in the liver. ADSB mice aged 8-10 wk were injected intraperitoneally(i.p.) with diphtheria toxin(DT) and liver damage was assessed by serum alanine aminotransferase(ALT) level. Two days later,mouse livers were sampled for histological analysis,and human hepatocytes were transplanted into the livers on the same day. A human ALB enzyme-linked immunosorbent assay was performed 7,14,21 and 28 d after transplantation. Human CD68 immunohistochemistry was performed 30 and 90 d after transplantation.RESULTS We crossed Alb-cre with DTR and SCID-beige mice to obtain ADSB mice. These mice were found to have liver damage 4 d after i.p. injection of 2.5 ng/g bodyweight DT. Bodyweight began to decrease on day 2,increased on day 7,and was lowest on day 4(range,10.5%-13.4%). Serum ALT activity began to increase on day 2 and reached a peak value of 289.7 ± 16.2 IU/m L on day 4,then returned to background values on day 7. After transplantation of human liver cells,peripheral blood human ALB level was 1580 ± 454.8 ng/m L(range,750.2-3064.9 ng/m L) after 28 d and Kupffer cells were present in the liver at 30 d in ADSB mice.CONCLUSION Human hepatocytes were successfully repopulated in the livers of ADSB mice. The inducible mouse model of humanized liver in ADSB mice may have functional applications,such as hepatocyte transplantation,hepatic regeneration and drug metabolism.展开更多
The intestinal microbiome has emerged as an important component involved in various diseases.Therefore,the interest in understanding the factors shaping its composition is growing.The gut microbiome,often defined as a...The intestinal microbiome has emerged as an important component involved in various diseases.Therefore,the interest in understanding the factors shaping its composition is growing.The gut microbiome,often defined as a complex trait,contains diverse components and its properties are determined by a combination of external and internal effects.Although much effort has been invested so far,it is still difficult to evaluate the extent to which human genetics shape the composition of the gut microbiota.However,in mouse studies,where the environmental factors are better controlled,the effect of the genetic background was significant.The purpose of this paper is to provide a current assessment of the role of human host genetics in shaping the gut microbiome composition.Despite the inconsistency of the reported results,it can be estimated that the genetic factor affects a portion of the microbiome.However,this effect is currently lower than the initial estimates,and it is difficult to separate the genetic influence from the environmental effect.Additionally,despite the differences between the microbial composition of humans and mice,results from mouse models can strengthen our knowledge of host genetics underlying the human gut microbial variation.展开更多
An overview of a long-gap peripheral nerve therapy： A long- gap peripheral nerve transection injury is an irreparable injury to the living body, and mostly leads to permanent loss of re- lated motor and sensory funct...An overview of a long-gap peripheral nerve therapy： A long- gap peripheral nerve transection injury is an irreparable injury to the living body, and mostly leads to permanent loss of re- lated motor and sensory functions. In such long gap injuries, nerve end-to-end suture is physically impossible. Therefore, bridging a long nerve-gap is critical to re-establish adequate mechanical support for separated nerve ends, and prevent the diffusion of neurotrophic and neurotropic factors secreted by transected stumps （Deumens et al., 2010）.展开更多
This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 3:Mouse.This standard was released by the China Associ...This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 3:Mouse.This standard was released by the China Association of Acupuncture and Moxibustion on May 15,2020,implemented on October 31,2020,and published by Standards Press of China.The standard was drafted by the Institute of Acupuncture and Moxibustion,China Academy of Chinese Medical Sciences,and the Nanjing University of Chinese Medicine.Principal draftsmen:Xiang-hong JING and Xing-bang HUA.Participating draftsmen:Wan-zhu BAI,Bin XU,Dong-sheng XU,Yi GUO,Tie-ming MA,Xin-jun WANG,and Sheng-feng LU.展开更多
B lymphocytes differentiate from hematopoietic stem cells through a series of distinct stages. Early B cell development proceeds in bone marrow until immature B cells migrate out to secondary lymphoid tissues, such as...B lymphocytes differentiate from hematopoietic stem cells through a series of distinct stages. Early B cell development proceeds in bone marrow until immature B cells migrate out to secondary lymphoid tissues, such as a spleen and lymph nodes, after completion of immunoglobulin heavy and light chain rearrangement. Although the information about the regulation by numerous factors, including signaling molecules, transcription factors, epigenetic changes and the microenvironment, could provide the clinical application, our knowledge on human B lymphopoiesis is limited. However, with great methodological advances, significant progress for understanding B lymphopoiesis both in human and mouse has been made. In this review, we summarize the experimental models for studies about human adult B lymphopoiesis, and the role of microenvironment and signaling molecules, such as cytokines, transforming growth factor-β superfamily, Wnt family and Notch family, with point-by-point comparison between human and mouse.展开更多
Various methods are currently under investigation to preserve fertility in males treated with high-dose chemotherapy and radiation for malignant and nonmalignant disorders. Human umbilical cord mesenchymal stem cells ...Various methods are currently under investigation to preserve fertility in males treated with high-dose chemotherapy and radiation for malignant and nonmalignant disorders. Human umbilical cord mesenchymal stem cells （HUC-MSCs）, which possess potent immunosuppressive function and secrete various cytokines and growth factors, have the potential clinical applications. As a potential alternative, we investigate whether injection of HUC-MSCs into the interstitial compartment of the testes to promote spermatogenic regeneration efficiently. HUC-MSCs were isolated from different sources of umbilical cords and injected into the interstitial space of one testis from 10 busulfan-treated mice （saline and HEK293 cells injections were performed in a separate set of mice） and the other testis remained uninjected. Three weeks after MSCs injection, Relative quantitative reverse transcription polymerase chain reaction was used to identify the expression of 10 of germ cell associated, which are all related to meiosis, demonstrated higher levels of spermatogenic gene expression （2-8 fold） in HUC-MSCs injected testes compared to the contralateral uninjected testes （five mice）. Protein levels for germ cell-specific genes, miwi, vasa and synaptonemal complex protein （Scp3） were also higher in MSC-treated testes compared to injected controls 3 weeks after treatment. However, no different expression was detected in saline water and HEK293 cells injection control group. We have demonstrated HUC-MSCs could affect mouse germ cell-specific genes expression. The results also provide a possibility that the transplanted HUC-MSCs may promote the recovery of spermatogenesis. This study provides further evidence for preclinical therapeutic effects of HUC-MSCs, and explores a new approach to the treatment of azoospermia.展开更多
Background:Over the past few decades,a threefold increase in obesity and type 2 diabetes(T2D)has placed a heavy burden on the health-care system and society.Previous studies have shown correlations between obesity,T2D...Background:Over the past few decades,a threefold increase in obesity and type 2 diabetes(T2D)has placed a heavy burden on the health-care system and society.Previous studies have shown correlations between obesity,T2D,and neurodegenera-tive diseases,including dementia.It is imperative to further understand the relation-ship between obesity,T2D,and cognitive deficits.Methods:This investigation tested and evaluated the cognitive impact of obesity and T2D induced by high-fat diet(HFD)and the effect of the host genetic background on the severity of cognitive decline caused by obesity and T2D in collaborative cross(CC)mice.The CC mice are a genetically diverse panel derived from eight inbred strains.Results:Our findings demonstrated significant variations in the recorded phenotypes across different CC lines compared to the reference mouse line,C57BL/6J.CC037 line exhibited a substantial increase in body weight on HFD,whereas line CC005 ex-hibited differing responses based on sex.Glucose tolerance tests revealed significant variations,with some lines like CC005 showing a marked increase in area under the curve(AUC)values on HFD.Organ weights,including brain,spleen,liver,and kidney,varied significantly among the lines and sexes in response to HFD.Behavioral tests using the Morris water maze indicated that cognitive performance was differentially affected by diet and genetic background.Conclusions:Our study establishes a foundation for future quantitative trait loci map-ping using CC lines and identifying genes underlying the comorbidity of Alzheimer's disease(AD),caused by obesity and T2D.The genetic components may offer new tools for early prediction and prevention.展开更多
Substantial evidence points to the early onset of peripheral inflammation in the development of Parkinson's disease(PD),supporting the“body-first”hypothesis.However,there remains a notable absence of PD-specific...Substantial evidence points to the early onset of peripheral inflammation in the development of Parkinson's disease(PD),supporting the“body-first”hypothesis.However,there remains a notable absence of PD-specific animal models induced by inflammatory cytokines.This study introduces a novel mouse model of PD driven by the proinflammatory cytokine CXCL1,identified in our previous research.The involvement of CXCL1 in PD pathogenesis was validated using subacute and chronic MPTP-induced mouse models.Based on these findings,2-month-old C57BL/6J mice were intravenously administered CXCL1(20 ng/kg/day)for 2 weeks(5 days per week),successfully replicating motor deficits and pathological alterations in the substantia nigra observed in the chronic MPTP model.These results demonstrate the potential of CXCL1-induced inflammation as a mechanism for PD modeling.The model revealed activation of the PPAR signaling pathway in CXCL1-mediated neuronal damage by CXCL1.Linoleic acid,a PPAR-γactivator,significantly mitigated MPTPand CXCL1-induced toxicity and reduced serum CXCL1levels.In addition,the CXCL1-injected mouse model shortened the timeline for developing chronic PD mouse model to 2 weeks,offering an efficient platform for studying inflammation-driven processes in PD.The findings provide critical insights into the inflammatory mechanisms underlying PD and identify promising therapeutic targets for intervention.展开更多
The comet assay was performed on mouse and human spermatozoa to examine the effect of alkaline DNA unwinding time. The spermatozoa were treated in vitrowith the DNA-damaging agents, methyl methanesulfonate （MMS） or ...The comet assay was performed on mouse and human spermatozoa to examine the effect of alkaline DNA unwinding time. The spermatozoa were treated in vitrowith the DNA-damaging agents, methyl methanesulfonate （MMS） or hydrogen peroxide （Hz02）, and then embedded in agarose gel on glass sl ides. The slides were immersed in alkaline solution （〉pH 13） for 1, 5, 10 and 20 min, and then subjected to the electrophoresis under neutral conditions. In mouse spermatozoa, comet tails seen in solvent controls became brighter and longer as the alkaline DNA unwinding time increased. However, in the MMS-treated mouse spermatozoa, a smaller difference in the damage from that in the solvent control was seen with time within a dose. DNA damage induced by H2O2 could also be detected accurately after alkali treatment for 1-20 min. In human spermatozoa, DNA damage induced by MMS and H2O2 could be detected in a dose-dependent manner after alkali treatment for 1 min. The ability of the comet assay to detect DNA damage was not adversely affected by the short period （1 min） of the alkaline DNA unwinding time.展开更多
Alzheimer’s disease（AD）,the main cause of dementia,is defined by the combined presence of amyloid-b（Ab）deposition and abnormal tau aggregation[1].Experimental models are critical to obtain a better understanding ...Alzheimer’s disease（AD）,the main cause of dementia,is defined by the combined presence of amyloid-b（Ab）deposition and abnormal tau aggregation[1].Experimental models are critical to obtain a better understanding of AD pathogenesis,and to evaluate the potential of novel therapeutic approaches.The most commonly used AD展开更多
AIM:To investigate the close parallels between our novel diet-related mouse model of colon cancer and human colon cancer.METHODS:Twenty-two wild-type female mice(ages 6-8 wk)were fed the standard control diet(AIN-93G)...AIM:To investigate the close parallels between our novel diet-related mouse model of colon cancer and human colon cancer.METHODS:Twenty-two wild-type female mice(ages 6-8 wk)were fed the standard control diet(AIN-93G)and an additional 22 female mice(ages 6-8 wk)were fed the control diet supplemented with 0.2%deoxycho-lic acid[diet+deoxycholic acid(DOC)]for 10 mo.Tu-mors occurred in the colons of mice fed diet+DOC and showed progression to colon cancer[adenocarcinoma(AC)].This progression is through the stages of tubular adenoma(TA),TA with high grade dysplasia or ad-enoma with sessile serrated morphology,intramucosal AC,AC stage T1,and AC stage T2.The mouse tumors were compared to human tumors at the same stages by histopathological analysis.Sections of the small and large intestines of mice and humans were evaluated for glandular architecture,cellular and nuclear morphology including cellular orientation,cellular and nuclear atyp-ia,pleomorphism,mitotic activity,frequency of goblet cells,crypt architecture,ulceration,penetration of crypts through the muscularis mucosa and presence of malignant crypts in the muscularis propria.In addition,preserved colonic tissues from genetically similar male mice,obtained from a prior experiment,were analyzed by immunohistochemistry.The male mice had been fed the control diet or diet+DOC.Four molecular markers were evaluated:8-OH-dG,DNA repair protein ERCC1,autophagy protein beclin-1 and the nuclear location of beta-catenin in the stem cell region of crypts.Also,male mice fed diet+DOC plus 0.007%chlorogenic acid(diet+DOC+CGA)were evaluated for ERCC1,beclin-1 and nuclear location of beta-catenin.RESULTS:Humans with high levels of diet-relatedDOC in their colons are at a substantially increased riskof developing colon cancer.The mice fed diet+DOChad levels of DOC in their colons comparable to that ofhumans on a high fat diet.The 22 mice without addedDOC in their diet had no colonic tumors while 20 ofthe 22 mice(91%)fed diet+DOC developed colonictumors.Furthermore,the tumors in 10 of these mice(45%of mice)included an adenocarcinoma.All micewere free of cancers of the small intestine.Histopatho-logically,the colonic tumor types in the mice werevirtually identical to those in humans.In humans,char-acteristic aberrant changes in molecular markers can be detected both in field defects surrounding cancers(from which cancers arise)and within cancers.In thecolonic tissues of mice fed diet+DOC similar changesin biomarkers appeared to occur.Thus,8-OH-dG wasincreased,DNA repair protein ERCC1 was decreased,autophagy protein beclin-1 was increased and,in thestem cell region at the base of crypts there was sub-stantial nuclear localization of beta-catenin as well asincreased cytoplasmic beta-catenin.However,in micefed diet+DOC+CGA(with reduced frequency ofcancer)and evaluated for ERCC1,beclin-1,and beta-catenin in the stem cell region of crypts,mouse tissueshowed amelioration of the aberrancies,suggestingthat chlorogenic acid is protective at the molecular levelagainst colon cancer.This is the first diet-related modelof colon cancer that closely parallels human progressionto colon cancer,both at the histomorphological level aswell as in its molecular profile.CONCLUSION:The diet-related mouse model of coloncancer parallels progression to colon cancer in humans,and should be uniquely useful in model studies of pre-vention and therapeutics.展开更多
Aim： To investigate the possible functions of human sperm membrane protein （hSMP-1） in the process of fertilization. Methods： A 576-bp cDNA fragment of HSD-1 gene coding for the extracellular domain of hSMP-1 was ...Aim： To investigate the possible functions of human sperm membrane protein （hSMP-1） in the process of fertilization. Methods： A 576-bp cDNA fragment of HSD-1 gene coding for the extracellular domain of hSMP-1 was cloned and expressed. The localization of this protein on human and mouse sperm was determined by indirect immunofluorescent staining by using anti-recombinant hSMP-1 （anti-rhSMP-1） antibodies. Sperm acrosome reaction and spermzona pellucida （ZP） binding assay were carried out in 10-week-old BALB/c mice. Results： Recombinant hSMP-1 was successfully cloned and expressed. The expression of the native protein was limited on the acrosome of human and mouse sperm. Treatment of anti-rhSMP-1 antibodies significantly decreased the average number of sperms bound to each egg. Meanwhile, the percentage of acrosome reaction was decreased in comparison to pre-immune control after treatment with anti-rhSMP-1 （P 〈 0.05）. Conclusion： The results suggest that anti-rhSMP-1 antibody inhibited mouse acrosome reaction and sperm-ZP binding.展开更多
AIM： To investigate the suppressive effects of adenoviral vector-mediated expression of NK4, an antagonist of hepatocyte growth factor （HGF）, on human colon cancer in an athymic mouse model to explore the possibili...AIM： To investigate the suppressive effects of adenoviral vector-mediated expression of NK4, an antagonist of hepatocyte growth factor （HGF）, on human colon cancer in an athymic mouse model to explore the possibility of applying NK4 to cancer gene therapy. METHODS： A human colon tumor model was developed by subcutaneous implantation of tumor tissue formed by LS174T cells grown in athymic mice. Fifteen tumorbearing mice were randomized into three groups （n= 5 in each group） at d 3 after tumor implantation and mice were injected intratumorally with phosphate-buffered saline （PBS） or with recombinant adenovirus expressing 13-galactosidase （Ad-LacZ） or NK4 （rvAdCMV/NK4） at a 6-d interval for total 5 injections in each mouse. Tumor sizes were measured during treatment to draw a tumor growth curve. At d 26 after the first treatment, all animals were sacrificed and the tumors were removed to immunohistochemically examine proliferating cell nuclear antigen （PCNA）, microvessel density （represented by CD31）, and apoptotic cells. In a separate experiment, 15 additional athymic mice were employed to develop a tumor metastasis model by intraperitoneal injection （ip） of LS174T cells. These mice were randomized into 3 groups （n = 5 in each group） at d 1 after injection and were treated by ip injection of PBS, or Ad-LacZ, or rvAdCMV/NK4 at a 6-d interval for total two injections in each mouse. All animals were sacrificed at d 14 and the numbers and weights of disseminated tumors within the abdominal cavity were measured. RESULTS： Growth of significantly suppressed human colon tumors were in the athymic mice treatedwith rvAdCMV/NK4 （2537.4± 892.3 mm^3） compared to those treated by either PBS （5175.2 ± 1228.6 mm^3） or Ad-LacZ （5578.8± 1955.7 mm^3） （P 〈 0.05）. The tumor growth inhibition rate was as high as 51%. Immunohistochemical staining revealed a similar PCNA labeling index （75.1% ± 11.2% in PBS group vs 72.8% ± 7.6% in Ad-LacZ group vs 69.3% ± 9.4% in rvAdCMV/ NK4 group） in all groups, but significantly lower microvessel density （10.7 ± 2.4 in rvAdCMV/NK4 group vs 25.6 ± 3.8 in PBS group or 21.3 ± 3.5 in Ad-LacZ group, P 〈 0.05）, and a markedly higher apoptotic index （7.3% ± 2.4% in rvAdCMV/NK4 group vs 2.6 4, 1.1% in PBS group or 2.1% ± 1.5% in Ad-LacZ group, P 〈 0.05） in the rvAdCMV/NK4 group compared to the two control groups. In the tumor metastasis model, the number and weight of disseminated tumors of mice treated with rvAdCMV/NK4 were much lower than those of the control groups （tumor number： 6.2 ± 3.3 in rvAdCMV/ NK4 group vs 22.9 ± 7.6 in PBS group or 19.8 ± 8.5 in Ad-LacZ group, P 〈 0.05; tumor weight： 324 ± 176 mg in rvAdCMV/NK4 group vs 962 ± 382 mg in PBS group or 1116 ± 484 mg in Ad-LacZ group, P 〈 0.05）. CONCLUSION： The recombinant adenovirus, rvAdCMV/ NK4, can attenuate the growth of colon cancer in vivo, probably by suppressing angiogenesis and inducing tumor cell apoptosis, but not by direct suppression of tumor cell proliferation. Moreover, rvAdCMV/NK4 may inhibit peritoneal dissemination of colon cancer cells in a murine tumor metastasis model. These findings indicate that NK4 gene transfer may be an effective tool for the treatment of colon cancer.展开更多
基金National Key R&D Program of China,Grant/Award Number:2023YFC3402000National Institutes for Food and Drug Control,State Key Laboratory of Drug Regulatory Science,Grant/Award Number:2023SKLDRS0124。
文摘Background:The precise insertion of large DNA fragments(>3–5 kb)remains one of the key obstacles in establishment of genetically modified murine models.Methods:A 21 kb large DNA fragment containing three tandemly linked copies of the human HRAS gene was inserted into the genome of C57BL/6J mouse,generating a mouse model designated as KI.C57-ras(or named NF-h HRAS).Whole-genome sequencing and Sanger sequencing were utilized to it confirm precise insertion and copy number.The stability of transgene expression among different generations was verified from multiple aspects using by digital PCR,western blot and DNA sequencing.To assess tumor susceptibility in the mouse model,N-Nitroso-N-methylurea(MNU)was administered at a dosage of 75 mg/kg.Histopathological examinations were conducted using hematoxylin and eosin(H&E)staining.Results:The HRAS DNA fragment was inserted into mouse chromosome 15E1 site,locating between 80623202 bp and 80625020 bp.NF-h HRAS mice exhibited stable inheritance and displayed consistent phenotypes across individuals.Moreover,this mouse model exhibited a high susceptibility to carcinogens.Upon administration of MNU the earliest mortality onset was earlier than that of wild-type littermates(day 65 vs.day 78 for male and day 56 vs.day 84 for female).Notably,100%of the NF-h HRAS transgenic mice developed tumors,with approximately 84%of male NF-h HRAS mice exhibiting specific tumor types,such as squamous cell carcinoma or squamous cell papilloma,which was consistent with the previously reported carcinogenic rasH2 mouse model.The types of tumors and the target organs exhibited diversity in NFh HRAS mice,while the spontaneous tumor incidence remained low(1/50).Conclusions:The NF-h HRAS mice demonstrated excellent genetic stability,a reproducible phenotype,and high susceptibility to carcinogens,indicating their potential utility in non-clinical safety evaluations of drugs as per the S1B guidelines issued by the ICH(The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use).
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We are grateful to Prof. Rui-An Wang （Department of Molecular and Cellular 0ncology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA） for his helpful advice and discussion regarding the pos- sible functions of MTA1. We also thank Miss Hui Wang for her careful assistance in English. This study was supported by the Natural Science Foundation of China （2006： No. 30570982 2003： No. 30370750 2003： No. 30371584）.
文摘Aim： To investigate the stage-specific localization of metastasis-associated protein 1 （MTA1） during spermatogenesis in adult human and mouse testis. Methods： The immunolocalization of MTA1 was studied by immunohistochemistry and Western blot analysis. The distribution pattern of MTA1 in mouse testis was confirmed by using quantitative analysis of purified spermatogenic cells. Results： The specificity of polyclonal antibody was confirmed by Western blot analysis. MTA1 was found expressed in the nucleus of germ cells, except elongate spermatids, and in the cytoplasm of Sertoli cells; Leydig cells did not show any specific reactivity. MTA1 possessed different distribution patterns in the two species： in humans, the most intensive staining was found in the nucleus of round spermatids and of primary spermatocytes while in mice, the most intense MTA 1 staining was in the nucleus of leptotene, zygotene and pachytene spermatocytes. In both species the staining exhibited a cyclic pattern. Conclusion： The present communication initially provides new evidence for the potential role of MTA1 in mature testis. In addition, its distinctive expression in germ cells suggests a regulatory role of the peptide during spermatogenesis.
文摘The mechanism of androgen action is complex. Recently, significant advances have been made into our understanding of how androgens act via the androgen receptor （AR） through the use of genetically modified mouse models. A number of global and tissue-specific AR knockout （ARKO） models have been generated using the Cre-loxP system which allows tissue- and/or cell-specific deletion. These ARKO models have examined a number of sites of androgen action including the cardiovascular system, the immune and hemopoetic system, bone, muscle, adipose tissue, the prostate and the brain. This review focuses on the insights that have been gained into human androgen deficiency through the use of ARKO mouse models at each of these sites of action, and highlights the strengths and limitations of these Cre-loxP mouse models that should be considered to ensure accurate interpretation of the phenotype.
文摘BACKGROUND： Total saponins of Panax ginseng （TSPG） exhibits neuroprotection against Parkinson＇s disease in the substantia nigra. OBJECTIVE： To investigate the effects of TSPG on human embryonic neural stem cells （NSCs） proliferation and differentiation into dopaminergic neurons using in vitro studies, and to observe NSC differentiation in a mouse model of Parkinson＇s disease, as well as behavioral changes before and after transplantation. DESIGN, TIME AND SETTING： In vitro neural cell biology trial and in vivo randomized, controlled animal trial were performed at the Institute of Basic Medical Sciences, Chongqing Medical University between September 2004 and December 2007. MATERIALS： TSPG （purity 〉 95%） was isolated, extracted, and identified by Chongqing Academy of Chinese Materia Medica. Recombinant human basic fibroblast growth factor （bFGF） and recombinant human epidermal growth factor （EGF） were purchased from PeproTech, USA. A total of 25 C57/BL6J mice, aged 18-20 weeks were included. Twenty were used to establish a Parkinson＇s disease model with i.p. injection of MPTP （1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine） and TSPG alone or combined with interleukin-1 （IL-1）-treated NSCs prior to transplantation into the corpus striatum. The remaining five mice were pretreated for 3 days with TSPG prior to MPTP injection, serving as the TSPG prevention group. METHODS： Primary NSCs were isolated, cultured and purified from embryonic cerebral cortex. Immunocytochemistry was employed to detect specific antigen expression in the NSCs. In vitro experiment： （1） to induce proliferation, NSCs were treated with TSPG, EGF＋bFGF, or TSPG＋EGF＋bFGF, respectively; （2） to induce dopaminergic neuronal differentiation, NSCs were treated with TSPG, IL-1, or TSPG＋IL-1, respectively. MAIN OUTCOME MEASURES： In vitro experiment： the effects of TSPG on NSCs proliferation were evaluated with flow cytometry and MTT assay. Tyrosine hydroxylase expression was determined by immunocytochemistry assay to observe effects of TSPG on dopaminergic neuronal differentiation. In vivo experiment： differentiation of grafted NSCs in the mouse brain was determined by immunohistochemical staining. Behavioral changes were evaluated by spontaneous activity frequency, memory function, and score of paralysis agitans. RESULTS： （1） NSCs were cultured and passaged for more than three passages. Immunocytochemistry revealed positive nestin staining, as well as neurofilament protein and glial fibrillary acidic protein. （2） TSPG significantly increased NSC proliferation, in particular when combined with EGF and bFGF, which was twice as effective as FGF or bFGF alone. TSPG also induced dopaminergic differentiation in NSCs, in particular when TSPG was added together with IL-1, resulting in an effect five times greater than that of IL-1 alone. （3） At day 30 following transplantation, most NSCs in the TSPG prevention group differentiated into dopaminergic neurons, and the scores of paralysis agitans, spontaneous activity, and memory function were significantly increased compared with TSPG alone or TSPG＋IL-1 groups （P 〈 0.05）. CONCLUSION： TSPG stimulated NSC proliferation, in particular when combined with FGF and bFGF. TSPG significantly induced dopaminergic neuronal differentiation of NSCs, and the effect was greater when combined with IL-1. In addition, TSPG greatly improved behavior in the Parkinson＇s disease mouse model following NSC transplantation. Following NSC transplantation, TSPG pretreatment exhibited superior efficacy over either TSPG alone or TSPG in combination with IL-1, in terms of behavioral improvements in the Parkinson＇s disease mouse model.
基金supported by the followed funds:National Science and Technology Major Project(2017ZX10304402-001-006,2017ZX10304402-001-012,2016YFD0500208)Shanghai Science and Technology Commission“R&D public service platform and institutional capacity improvement project”(21DZ2291300)+1 种基金Shanghai scientific research projects(19140905300)Shanghai Public Health Clinical Center projects(KY-GW-2019-11,KY-GW-2019-19,and KY-GW-2021-39)。
文摘Background:There are remarkable genetic differences between animal major histocompatibility complex(MHC)systems and the human leukocyte antigen(HLA)system.HLA transgenic humanized mouse model systems offer a much better method to study the HLA-A-related principal mechanisms for vaccine development and HLA-Arestricted responses against infection in human.Methods:A recombinant gene encoding the chimeric HLA-A30 monochain was constructed.This HHD molecule contains the following:α1-α2 domains of HLA-A30,α3 and cytoplasmic domains of H-2D~b,linked at its N-terminus to the C-terminus of humanβ2m by a 15-amino-acid peptide linker.The recombinant gene encoding the chimeric HLA-A30 monochain cassette was introduced into bacterial artificial chromosome(BAC)CH502-67J3 containing the HLA-A01 gene locus by Red-mediated homologous recombination.Modified BAC CH502-67J3 was microinjected into the pronuclei of wild-type mouse oocytes.This humanized mouse model was further used to assess the immune responses against influenza A virus(H1N1)pdm09 clinically isolated from human patients.Immune cell population,cytokine production,and histopathology in the lung were analyzed.Results:We describe a novel humanβ2m-HLA-A30(α1α2)-H-2D~b(α3 transmembrane cytoplasmic)(HHD)monochain transgenic mouse strain,which contains the intact HLA-A01 gene locus including 49 kb 5’-UTR and 74 kb 3’-UTR of HLA-A01*01.Five transgenic lines integrated into the large genomic region of HLA-A gene locus were obtained,and the robust expression of exogenous transgene was detected in various tissues from A30-18#and A30-19#lines encompassing the intact flanking sequences.Flow cytometry revealed that the introduction of a large genomic region in HLA-A gene locus can influence the immune cell constitution in humanized mice.Pdm09 infection caused a similar immune response among HLA-A30 Tg humanized mice and wild-type mice,and induced the rapid increase of cytokines,including IFN-γ,TNF-α,and IL-6,in both HLA-A30 humanized Tg mice and wild-type mice.The expression of HLA-A30 transgene was dramatically promoted in tissues from A30-9#line at 3 days post-infection(dpi).Conclusions:We established a promising preclinical research animal model of HLA-A30 Tg humanized mouse,which could accelerate the identification of novel HLA-A30-restricted epitopes and vaccine development,and support the study of HLA-A-restricted responses against infection in humans.
基金Supported by the National Research Foundation of Korea,No.2020R1A2C1100891Soonchunhyang University Research Fund,No.2024-05-014.
文摘BACKGROUND The high prevalence of human papillomavirus(HPV)infection in oropharyngeal squamous cell carcinoma(SCC)is well established,and p16 expression is a strong predictor.HPV-related tumors exhibit unique mechanisms that target p16 and p53 proteins.However,research on HPV prevalence and the combined predictive value of p16 and p53 expression in head and neck cutaneous SCC(HNCSCC),particularly in Asian populations,remains limited.This retrospective study surveyed 62 patients with HNSCC(2011-2020),excluding those with facial warts or other skin cancer.AIM To explore the prevalence of HPV and the predictive value of p16 and p53 expression in HNCSCC in Asian populations.METHODS All patients underwent wide excision and biopsy.Immunohistochemical staining for HPV,p16,and p53 yielded positive and negative results.The relevance of each marker was investigated by categorizing the tumor locations into high-risk and middle-risk zones based on recurrence frequency.RESULTS Of the 62 patients,20(32.26%)were male,with an average age of 82.27 years(range 26-103 years).High-risk included 19 cases(30.65%),with the eyelid and lip being the most common sites(five cases,8.06%).Middle-risk included 43 cases(69.35%),with the cheek being the most common(29 cases,46.77%).The p16 expression was detected in 24 patients(38.71%),p53 expression in 42 patients(72.58%),and HPV in five patients(8.06%).No significant association was found between p16 expression and the presence of HPV(P>0.99),with a positive predictive value of 8.33%.CONCLUSION This study revealed that p16,a surrogate HPV marker in oropharyngeal SCC,is not reliable in HNCSCC,providing valuable insights for further research in Asian populations.
基金Supported by Shanghai Science and Technology Development Foundation Project,No.12140900300Shanghai Municipal Commission of Health and Family Planning Project,No.20144Y0073+1 种基金Shanghai Public Health Clinical Center Project,No.2014M08National Science and Technology Major Project,No.2017ZX10304402-001-012
文摘AIM To establish an inducible liver injury mouse model and transplant human hepatocytes to obtain liverhumanized mice.METHODS We crossed three mouse strains,including albumin(Alb)-cre transgenic mice,inducible diphtheria toxin receptor(DTR) transgenic mice and severe combined immune deficient(SCID)-beige mice,to create Alb-cre/DTR/SCID-beige(ADSB) mice,which coincidentally harbor Alb-cre and DTR transgenes and are immunodeficient. As the Cre expression is driven by the liver-specific promoter Alb(encoding ALB),the DTR stop signal flanked by two lox P sites can be deleted in the ADSB mice,resulting in DTR expression in the liver. ADSB mice aged 8-10 wk were injected intraperitoneally(i.p.) with diphtheria toxin(DT) and liver damage was assessed by serum alanine aminotransferase(ALT) level. Two days later,mouse livers were sampled for histological analysis,and human hepatocytes were transplanted into the livers on the same day. A human ALB enzyme-linked immunosorbent assay was performed 7,14,21 and 28 d after transplantation. Human CD68 immunohistochemistry was performed 30 and 90 d after transplantation.RESULTS We crossed Alb-cre with DTR and SCID-beige mice to obtain ADSB mice. These mice were found to have liver damage 4 d after i.p. injection of 2.5 ng/g bodyweight DT. Bodyweight began to decrease on day 2,increased on day 7,and was lowest on day 4(range,10.5%-13.4%). Serum ALT activity began to increase on day 2 and reached a peak value of 289.7 ± 16.2 IU/m L on day 4,then returned to background values on day 7. After transplantation of human liver cells,peripheral blood human ALB level was 1580 ± 454.8 ng/m L(range,750.2-3064.9 ng/m L) after 28 d and Kupffer cells were present in the liver at 30 d in ADSB mice.CONCLUSION Human hepatocytes were successfully repopulated in the livers of ADSB mice. The inducible mouse model of humanized liver in ADSB mice may have functional applications,such as hepatocyte transplantation,hepatic regeneration and drug metabolism.
基金Binational Science Foundation(BSF)grant number 2015077German Israeli Science Foundation(GIF)grant I-63-410.20-2017,Israeli Science Foundation(ISF)grant 1085/18,and Core Fund Form Tel-Aviv University.
文摘The intestinal microbiome has emerged as an important component involved in various diseases.Therefore,the interest in understanding the factors shaping its composition is growing.The gut microbiome,often defined as a complex trait,contains diverse components and its properties are determined by a combination of external and internal effects.Although much effort has been invested so far,it is still difficult to evaluate the extent to which human genetics shape the composition of the gut microbiota.However,in mouse studies,where the environmental factors are better controlled,the effect of the genetic background was significant.The purpose of this paper is to provide a current assessment of the role of human host genetics in shaping the gut microbiome composition.Despite the inconsistency of the reported results,it can be estimated that the genetic factor affects a portion of the microbiome.However,this effect is currently lower than the initial estimates,and it is difficult to separate the genetic influence from the environmental effect.Additionally,despite the differences between the microbial composition of humans and mice,results from mouse models can strengthen our knowledge of host genetics underlying the human gut microbial variation.
文摘An overview of a long-gap peripheral nerve therapy： A long- gap peripheral nerve transection injury is an irreparable injury to the living body, and mostly leads to permanent loss of re- lated motor and sensory functions. In such long gap injuries, nerve end-to-end suture is physically impossible. Therefore, bridging a long nerve-gap is critical to re-establish adequate mechanical support for separated nerve ends, and prevent the diffusion of neurotrophic and neurotropic factors secreted by transected stumps （Deumens et al., 2010）.
文摘This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 3:Mouse.This standard was released by the China Association of Acupuncture and Moxibustion on May 15,2020,implemented on October 31,2020,and published by Standards Press of China.The standard was drafted by the Institute of Acupuncture and Moxibustion,China Academy of Chinese Medical Sciences,and the Nanjing University of Chinese Medicine.Principal draftsmen:Xiang-hong JING and Xing-bang HUA.Participating draftsmen:Wan-zhu BAI,Bin XU,Dong-sheng XU,Yi GUO,Tie-ming MA,Xin-jun WANG,and Sheng-feng LU.
文摘B lymphocytes differentiate from hematopoietic stem cells through a series of distinct stages. Early B cell development proceeds in bone marrow until immature B cells migrate out to secondary lymphoid tissues, such as a spleen and lymph nodes, after completion of immunoglobulin heavy and light chain rearrangement. Although the information about the regulation by numerous factors, including signaling molecules, transcription factors, epigenetic changes and the microenvironment, could provide the clinical application, our knowledge on human B lymphopoiesis is limited. However, with great methodological advances, significant progress for understanding B lymphopoiesis both in human and mouse has been made. In this review, we summarize the experimental models for studies about human adult B lymphopoiesis, and the role of microenvironment and signaling molecules, such as cytokines, transforming growth factor-β superfamily, Wnt family and Notch family, with point-by-point comparison between human and mouse.
文摘Various methods are currently under investigation to preserve fertility in males treated with high-dose chemotherapy and radiation for malignant and nonmalignant disorders. Human umbilical cord mesenchymal stem cells （HUC-MSCs）, which possess potent immunosuppressive function and secrete various cytokines and growth factors, have the potential clinical applications. As a potential alternative, we investigate whether injection of HUC-MSCs into the interstitial compartment of the testes to promote spermatogenic regeneration efficiently. HUC-MSCs were isolated from different sources of umbilical cords and injected into the interstitial space of one testis from 10 busulfan-treated mice （saline and HEK293 cells injections were performed in a separate set of mice） and the other testis remained uninjected. Three weeks after MSCs injection, Relative quantitative reverse transcription polymerase chain reaction was used to identify the expression of 10 of germ cell associated, which are all related to meiosis, demonstrated higher levels of spermatogenic gene expression （2-8 fold） in HUC-MSCs injected testes compared to the contralateral uninjected testes （five mice）. Protein levels for germ cell-specific genes, miwi, vasa and synaptonemal complex protein （Scp3） were also higher in MSC-treated testes compared to injected controls 3 weeks after treatment. However, no different expression was detected in saline water and HEK293 cells injection control group. We have demonstrated HUC-MSCs could affect mouse germ cell-specific genes expression. The results also provide a possibility that the transplanted HUC-MSCs may promote the recovery of spermatogenesis. This study provides further evidence for preclinical therapeutic effects of HUC-MSCs, and explores a new approach to the treatment of azoospermia.
文摘Background:Over the past few decades,a threefold increase in obesity and type 2 diabetes(T2D)has placed a heavy burden on the health-care system and society.Previous studies have shown correlations between obesity,T2D,and neurodegenera-tive diseases,including dementia.It is imperative to further understand the relation-ship between obesity,T2D,and cognitive deficits.Methods:This investigation tested and evaluated the cognitive impact of obesity and T2D induced by high-fat diet(HFD)and the effect of the host genetic background on the severity of cognitive decline caused by obesity and T2D in collaborative cross(CC)mice.The CC mice are a genetically diverse panel derived from eight inbred strains.Results:Our findings demonstrated significant variations in the recorded phenotypes across different CC lines compared to the reference mouse line,C57BL/6J.CC037 line exhibited a substantial increase in body weight on HFD,whereas line CC005 ex-hibited differing responses based on sex.Glucose tolerance tests revealed significant variations,with some lines like CC005 showing a marked increase in area under the curve(AUC)values on HFD.Organ weights,including brain,spleen,liver,and kidney,varied significantly among the lines and sexes in response to HFD.Behavioral tests using the Morris water maze indicated that cognitive performance was differentially affected by diet and genetic background.Conclusions:Our study establishes a foundation for future quantitative trait loci map-ping using CC lines and identifying genes underlying the comorbidity of Alzheimer's disease(AD),caused by obesity and T2D.The genetic components may offer new tools for early prediction and prevention.
基金supported by the National Natural Science Foundation of China (32471049,32170984,32471188,32200802)Natural Science Foundation of Shandong Province (ZR2023QH110)。
文摘Substantial evidence points to the early onset of peripheral inflammation in the development of Parkinson's disease(PD),supporting the“body-first”hypothesis.However,there remains a notable absence of PD-specific animal models induced by inflammatory cytokines.This study introduces a novel mouse model of PD driven by the proinflammatory cytokine CXCL1,identified in our previous research.The involvement of CXCL1 in PD pathogenesis was validated using subacute and chronic MPTP-induced mouse models.Based on these findings,2-month-old C57BL/6J mice were intravenously administered CXCL1(20 ng/kg/day)for 2 weeks(5 days per week),successfully replicating motor deficits and pathological alterations in the substantia nigra observed in the chronic MPTP model.These results demonstrate the potential of CXCL1-induced inflammation as a mechanism for PD modeling.The model revealed activation of the PPAR signaling pathway in CXCL1-mediated neuronal damage by CXCL1.Linoleic acid,a PPAR-γactivator,significantly mitigated MPTPand CXCL1-induced toxicity and reduced serum CXCL1levels.In addition,the CXCL1-injected mouse model shortened the timeline for developing chronic PD mouse model to 2 weeks,offering an efficient platform for studying inflammation-driven processes in PD.The findings provide critical insights into the inflammatory mechanisms underlying PD and identify promising therapeutic targets for intervention.
文摘The comet assay was performed on mouse and human spermatozoa to examine the effect of alkaline DNA unwinding time. The spermatozoa were treated in vitrowith the DNA-damaging agents, methyl methanesulfonate （MMS） or hydrogen peroxide （Hz02）, and then embedded in agarose gel on glass sl ides. The slides were immersed in alkaline solution （〉pH 13） for 1, 5, 10 and 20 min, and then subjected to the electrophoresis under neutral conditions. In mouse spermatozoa, comet tails seen in solvent controls became brighter and longer as the alkaline DNA unwinding time increased. However, in the MMS-treated mouse spermatozoa, a smaller difference in the damage from that in the solvent control was seen with time within a dose. DNA damage induced by H2O2 could also be detected accurately after alkali treatment for 1-20 min. In human spermatozoa, DNA damage induced by MMS and H2O2 could be detected in a dose-dependent manner after alkali treatment for 1 min. The ability of the comet assay to detect DNA damage was not adversely affected by the short period （1 min） of the alkaline DNA unwinding time.
基金partly supported by grants from the National Key Research and Development Program of China(2016YFA0100900)the International S&T Cooperation Program of China(2015DFG32740)the National Natural Science Foundation of China(81571711 and 81425015)
文摘Alzheimer’s disease（AD）,the main cause of dementia,is defined by the combined presence of amyloid-b（Ab）deposition and abnormal tau aggregation[1].Experimental models are critical to obtain a better understanding of AD pathogenesis,and to evaluate the potential of novel therapeutic approaches.The most commonly used AD
基金Supported by National Institutes of Health,No.5 R01 CA119087Arizona Biomedical Research Commission,No.0803+1 种基金Veterans Affairs Merit Review,No.0142administered by the Southern Arizona Veterans Affairs Health Care System
文摘AIM:To investigate the close parallels between our novel diet-related mouse model of colon cancer and human colon cancer.METHODS:Twenty-two wild-type female mice(ages 6-8 wk)were fed the standard control diet(AIN-93G)and an additional 22 female mice(ages 6-8 wk)were fed the control diet supplemented with 0.2%deoxycho-lic acid[diet+deoxycholic acid(DOC)]for 10 mo.Tu-mors occurred in the colons of mice fed diet+DOC and showed progression to colon cancer[adenocarcinoma(AC)].This progression is through the stages of tubular adenoma(TA),TA with high grade dysplasia or ad-enoma with sessile serrated morphology,intramucosal AC,AC stage T1,and AC stage T2.The mouse tumors were compared to human tumors at the same stages by histopathological analysis.Sections of the small and large intestines of mice and humans were evaluated for glandular architecture,cellular and nuclear morphology including cellular orientation,cellular and nuclear atyp-ia,pleomorphism,mitotic activity,frequency of goblet cells,crypt architecture,ulceration,penetration of crypts through the muscularis mucosa and presence of malignant crypts in the muscularis propria.In addition,preserved colonic tissues from genetically similar male mice,obtained from a prior experiment,were analyzed by immunohistochemistry.The male mice had been fed the control diet or diet+DOC.Four molecular markers were evaluated:8-OH-dG,DNA repair protein ERCC1,autophagy protein beclin-1 and the nuclear location of beta-catenin in the stem cell region of crypts.Also,male mice fed diet+DOC plus 0.007%chlorogenic acid(diet+DOC+CGA)were evaluated for ERCC1,beclin-1 and nuclear location of beta-catenin.RESULTS:Humans with high levels of diet-relatedDOC in their colons are at a substantially increased riskof developing colon cancer.The mice fed diet+DOChad levels of DOC in their colons comparable to that ofhumans on a high fat diet.The 22 mice without addedDOC in their diet had no colonic tumors while 20 ofthe 22 mice(91%)fed diet+DOC developed colonictumors.Furthermore,the tumors in 10 of these mice(45%of mice)included an adenocarcinoma.All micewere free of cancers of the small intestine.Histopatho-logically,the colonic tumor types in the mice werevirtually identical to those in humans.In humans,char-acteristic aberrant changes in molecular markers can be detected both in field defects surrounding cancers(from which cancers arise)and within cancers.In thecolonic tissues of mice fed diet+DOC similar changesin biomarkers appeared to occur.Thus,8-OH-dG wasincreased,DNA repair protein ERCC1 was decreased,autophagy protein beclin-1 was increased and,in thestem cell region at the base of crypts there was sub-stantial nuclear localization of beta-catenin as well asincreased cytoplasmic beta-catenin.However,in micefed diet+DOC+CGA(with reduced frequency ofcancer)and evaluated for ERCC1,beclin-1,and beta-catenin in the stem cell region of crypts,mouse tissueshowed amelioration of the aberrancies,suggestingthat chlorogenic acid is protective at the molecular levelagainst colon cancer.This is the first diet-related modelof colon cancer that closely parallels human progressionto colon cancer,both at the histomorphological level aswell as in its molecular profile.CONCLUSION:The diet-related mouse model of coloncancer parallels progression to colon cancer in humans,and should be uniquely useful in model studies of pre-vention and therapeutics.
文摘Aim： To investigate the possible functions of human sperm membrane protein （hSMP-1） in the process of fertilization. Methods： A 576-bp cDNA fragment of HSD-1 gene coding for the extracellular domain of hSMP-1 was cloned and expressed. The localization of this protein on human and mouse sperm was determined by indirect immunofluorescent staining by using anti-recombinant hSMP-1 （anti-rhSMP-1） antibodies. Sperm acrosome reaction and spermzona pellucida （ZP） binding assay were carried out in 10-week-old BALB/c mice. Results： Recombinant hSMP-1 was successfully cloned and expressed. The expression of the native protein was limited on the acrosome of human and mouse sperm. Treatment of anti-rhSMP-1 antibodies significantly decreased the average number of sperms bound to each egg. Meanwhile, the percentage of acrosome reaction was decreased in comparison to pre-immune control after treatment with anti-rhSMP-1 （P 〈 0.05）. Conclusion： The results suggest that anti-rhSMP-1 antibody inhibited mouse acrosome reaction and sperm-ZP binding.
文摘AIM： To investigate the suppressive effects of adenoviral vector-mediated expression of NK4, an antagonist of hepatocyte growth factor （HGF）, on human colon cancer in an athymic mouse model to explore the possibility of applying NK4 to cancer gene therapy. METHODS： A human colon tumor model was developed by subcutaneous implantation of tumor tissue formed by LS174T cells grown in athymic mice. Fifteen tumorbearing mice were randomized into three groups （n= 5 in each group） at d 3 after tumor implantation and mice were injected intratumorally with phosphate-buffered saline （PBS） or with recombinant adenovirus expressing 13-galactosidase （Ad-LacZ） or NK4 （rvAdCMV/NK4） at a 6-d interval for total 5 injections in each mouse. Tumor sizes were measured during treatment to draw a tumor growth curve. At d 26 after the first treatment, all animals were sacrificed and the tumors were removed to immunohistochemically examine proliferating cell nuclear antigen （PCNA）, microvessel density （represented by CD31）, and apoptotic cells. In a separate experiment, 15 additional athymic mice were employed to develop a tumor metastasis model by intraperitoneal injection （ip） of LS174T cells. These mice were randomized into 3 groups （n = 5 in each group） at d 1 after injection and were treated by ip injection of PBS, or Ad-LacZ, or rvAdCMV/NK4 at a 6-d interval for total two injections in each mouse. All animals were sacrificed at d 14 and the numbers and weights of disseminated tumors within the abdominal cavity were measured. RESULTS： Growth of significantly suppressed human colon tumors were in the athymic mice treatedwith rvAdCMV/NK4 （2537.4± 892.3 mm^3） compared to those treated by either PBS （5175.2 ± 1228.6 mm^3） or Ad-LacZ （5578.8± 1955.7 mm^3） （P 〈 0.05）. The tumor growth inhibition rate was as high as 51%. Immunohistochemical staining revealed a similar PCNA labeling index （75.1% ± 11.2% in PBS group vs 72.8% ± 7.6% in Ad-LacZ group vs 69.3% ± 9.4% in rvAdCMV/ NK4 group） in all groups, but significantly lower microvessel density （10.7 ± 2.4 in rvAdCMV/NK4 group vs 25.6 ± 3.8 in PBS group or 21.3 ± 3.5 in Ad-LacZ group, P 〈 0.05）, and a markedly higher apoptotic index （7.3% ± 2.4% in rvAdCMV/NK4 group vs 2.6 4, 1.1% in PBS group or 2.1% ± 1.5% in Ad-LacZ group, P 〈 0.05） in the rvAdCMV/NK4 group compared to the two control groups. In the tumor metastasis model, the number and weight of disseminated tumors of mice treated with rvAdCMV/NK4 were much lower than those of the control groups （tumor number： 6.2 ± 3.3 in rvAdCMV/ NK4 group vs 22.9 ± 7.6 in PBS group or 19.8 ± 8.5 in Ad-LacZ group, P 〈 0.05; tumor weight： 324 ± 176 mg in rvAdCMV/NK4 group vs 962 ± 382 mg in PBS group or 1116 ± 484 mg in Ad-LacZ group, P 〈 0.05）. CONCLUSION： The recombinant adenovirus, rvAdCMV/ NK4, can attenuate the growth of colon cancer in vivo, probably by suppressing angiogenesis and inducing tumor cell apoptosis, but not by direct suppression of tumor cell proliferation. Moreover, rvAdCMV/NK4 may inhibit peritoneal dissemination of colon cancer cells in a murine tumor metastasis model. These findings indicate that NK4 gene transfer may be an effective tool for the treatment of colon cancer.
