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
Alzheimer'sdisease(AD)isaprogressive neurodegenerative disorder characterized by cognitive impairment and distinct neuropathological features,including amyloid-βplaques,neurofibrillary tangles,and reactive astrog...Alzheimer'sdisease(AD)isaprogressive neurodegenerative disorder characterized by cognitive impairment and distinct neuropathological features,including amyloid-βplaques,neurofibrillary tangles,and reactive astrogliosis.Developing effective diagnostic,preventative,and therapeutic strategies for AD necessitates the establishment of animal models that accurately recapitulate the pathophysiological processes of the disease.Existing transgenic mouse models have significantly contributed to understanding AD pathology but often fail to replicate the complexity of human AD.Additionally,these models are limited in their ability to elucidate the interplay among amyloid-βplaques,neurofibrillary tangles,and reactive astrogliosis due to the absence of spatially and temporally specific genetic manipulation.In this study,we introduce a novel AD mouse model(APP/PS1-TauP301L-Adeno mice)designed to rapidly induce pathological symptoms and enhance understanding of AD mechanisms.Neurofibrillary tangles and severe reactive astrogliosis were induced by injecting AAVDJ-EF1a-hTauP301L-EGFP and Adeno-GFAP-GFP viruses into the hippocampi of 5-month-old APP/PS1 mice.Three months post-injection,these mice exhibited pronounced astrogliosis,substantial amyloid-βplaque accumulation,extensiveneurofibrillarytangles,accelerated neuronal loss,elevated astrocytic GABA levels,and significant spatial memory deficits.Notably,these pathological features were less severe in AAVTauP301L-expressing APP/PS1 mice without augmented reactive astrogliosis.These findings indicate an exacerbating role of severe reactive astrogliosis in amyloid-βplaque and neurofibrillary tangle-associated pathology.The APP/PS1-TauP301L-Adeno mouse model provides a valuable tool for advancing therapeutic research aimed at mitigating the progression of AD.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
Background:Glucocorticoids are used as anti-inflammatory drugs for the treatment of various diseases,however,their side effects on normal brain tissue remain underinvestigated.Objectives:The study aimed to investigate...Background:Glucocorticoids are used as anti-inflammatory drugs for the treatment of various diseases,however,their side effects on normal brain tissue remain underinvestigated.Objectives:The study aimed to investigate dexamethasone(DXM)effects on cell composition and myelin content in the mouse brain tissue.Methods:C57Bl/6 male mice(n 60)received single and ten multiple intraperitoneal DXM injections(2.5 mg/kg),and the studied=parameters were analysed at 1,3,7,10 days after a single DXM injection and 15,30,60,and 90 days after the multiple injections.Oligodendrocytes,microglia,and astrocytes were assayed by immunohistochemistry with specific antibodies(Olig2,CD68,and GFAP,respectively)in the corpus callosum of the normal brain tissue.The myelin content was estimated by staining with LuxolFastBlue.The presence of GFAP isoforms was determined by western blotting.Results:DXM administration did not affect oligodendrocytes in the mouse brain but temporarily significantly decreased myelin content(1.2-fold,p 0.0058;1.4-fold,p 0.0001)at 3–15 days time points.At the same time,DXM significantly=<decreased the number of microglial cells(1.5–3.5-fold,p 0.0001)and significantly increased astrocytes(1.8-fold,p<<0.0001).Prolonged administration of DXM resulted in the decrease of the main GFAPα-isoform(50 kDa)and the appearance of shorter GFAP isoforms(30 kDa,42 kDa,44 kDa)similar to that in some neurodegenerative animal models.Conclusion:DXM can modify the cell composition of the normal mouse brain tissue by decreasing microglial cells and increasing astrocytes.Long-term use of DXM results in the inhibition of myelin formation and the appearance of truncated GFAP isoforms,suggesting its ability to induce neurodegeneration-like changes in the normal mouse brain.展开更多
The Leprdb/db mouse is a common and well-studied model of type II diabetes mel-litus that is often employed in biomedical research.Despite being one of the most commonly used models for the investigation of diabetic w...The Leprdb/db mouse is a common and well-studied model of type II diabetes mel-litus that is often employed in biomedical research.Despite being one of the most commonly used models for the investigation of diabetic wound healing,there are a few specific guidelines for its husbandry,and wound complications such as infection and expansion are common.This study presents a modified animal husbandry ap-proach for the Leprdb/db mouse to reduce the incidence of complications during wound healing experiments.Compared to standard rodent housing protocols,the use of this modified protocol leads to decreased rates of complications among experimental animals across several experiments.The protocol includes increased cage size,de-creased housing density,and more frequent cage replacements.The use of improved husbandry for the Leprdb/db mouse decreases the total number of animals required,minimizes harm during experimentation,and improves the consistency and reproduc-ibility of wound healing studies.展开更多
Dear Editor,Crimean–Congo hemorrhagic fever(CCHF),caused by the CCHF virus(CCHFV),is a severe tick-borne illness with a wide geographical distribution,posing a significant threat with case fatality rates ranging from...Dear Editor,Crimean–Congo hemorrhagic fever(CCHF),caused by the CCHF virus(CCHFV),is a severe tick-borne illness with a wide geographical distribution,posing a significant threat with case fatality rates ranging from 5%to 70%(Hawman and Feldmann,2023).Due to the lack of approved vaccines and therapeutics,the World Health Organization(WHO)has listed CCHF as one of the priority diseases(Semper et al.,2024).CCHF initially presents as a nonspecific febrile illness,characterized by fever,malaise,myalgia,and nausea,which can rapidly progress to hemorrhagic disease.The hemorrhagic stage is particularly pronounced in severe cases,with rapid progression to disseminated intravascular coagulation(DIC),overt bleeding,kidney or liver failure,and shock(Frank et al.,2024).Up to date,there is an absence of a suitable animal model that can accurately mimic the coagulopathy and bleeding associated with CCHFV infection.Consequently,our understanding of the pathogenic mechanisms underlying these conditions remains limited(Rodriguez et al.,2022).展开更多
Craniometaphyseal dysplasia(CMD),a rare craniotubular disorder,occurs in an autosomal dominant(AD)or autosomal recessive(AR)form.CMD is characterized by hyperostosis of craniofacial bones and metaphyseal flaring of lo...Craniometaphyseal dysplasia(CMD),a rare craniotubular disorder,occurs in an autosomal dominant(AD)or autosomal recessive(AR)form.CMD is characterized by hyperostosis of craniofacial bones and metaphyseal flaring of long bones.Many patients with CMD suffer from neurological symptoms.The pathogenesis of CMD is not fully understood.展开更多
Melanosomes are specialized membrane-bound organelles within which melanin is synthesized and stored.The levels of melanin can be effectively reduced by inhibiting melanin synthesis or promoting melanosome degradation...Melanosomes are specialized membrane-bound organelles within which melanin is synthesized and stored.The levels of melanin can be effectively reduced by inhibiting melanin synthesis or promoting melanosome degradation via autophagy.Ceramide,a central molecule in sphingolipid metabolism,has been widely implicated in the regulation of autophagy.Few researchers have addressed the potential effects of ceramide analogs on suppressing melanin synthesis.However,whether ceramide can induce melanosome autophagy and the potential autophagy-dependent mechanism underlying this phenomenon remain unknown.Here,an active compound from the marine microalgae Emiliania huxleyi extract was firstly isolated and identified as a long-chain C22-ceramide(C22-Cer).In vitro results of mouse B16 melanoma cell experiments showed that treatment with 2-5µmol/L C22-Cer significantly suppressed the increase ofα-MSH-induced melanin levels and tyrosinase activity without cytotoxicity.C22-Cer induced typical hallmarks of autophagy such as accumulation of autophagosomes,enhanced autophagic flux and microtubule-associated protein light chain 3,LC3-II expression,and p62 degradation through activating c-Jun N-terminal kinase(JNK)directly.Furthermore,C22-Cer activated JNK-Bcl-2 signaling,dissociated the Beclin1/Bcl-2 complex,and induced melanosome autophagy without affecting the expression of MITF.Besides,the Ca^(2+)influx induced by treatment with C22-Cer further increased the substantial accumulation of autophagosomes.Together,we found a novel marine-derived compound,C22-Cer,targeting JNK pathway and Ca^(2+)signaling to induce melanosome autophagy and suppress melanin accumulation in B16 cells.This study implicates that C22-Cer might be a potential therapeutic mediator against skin pigmentation in mammals.展开更多
Murine subarachnoid hemorrhage(SAH)induced using the filament perforation method is a useful in vivo experimental model to investigate the pathophysiological mechanisms in the brain underlying SAH.However,identifying ...Murine subarachnoid hemorrhage(SAH)induced using the filament perforation method is a useful in vivo experimental model to investigate the pathophysiological mechanisms in the brain underlying SAH.However,identifying mice with comorbid acute neurogenic pulmonary edema(NPE),a life-threatening systemic consequence often induced by SAH,in this model is difficult without histopathological investiga-tions.Herein,we present an imaging procedure involving dual-energy X-ray absorp-tiometry(DXA)to identify NPE in a murine model of SAH.We quantified the lung lean mass(LM)and compared the relationship between micro-computed tomography(CT)evidence of Hounsfield unit(HU)values and histopathological findings of PE.Of the 85 mice with successful induction of SAH by filament perforation,16(19%)had NPE,as verified by postmortem histology.The DXA-LM values correlate well with CT-HU levels(r=0.63,p<0.0001).Regarding the relationship between LM and HU in mice with post-SAH NPE,the LM was positively associated with HU values(r2=0.43;p=0.0056).A receiver operating characteristics curve of LM revealed a sensitivity of 87%and specificity of 57%for detecting PE,with a similar area under the curve as the HU(0.79±0.06 vs.0.84±0.07;p=0.21).These data suggest that confirming acute NPE using DXA-LM is a valuable method for selecting a clinically relevant murine NPE model that could be used in future experimental SAH studies.展开更多
The discontinuation of denosumab[antibody targeting receptor activator of nuclear factor kappa B ligand(RANKL)]therapy may increase the risk of multiple vertebral fractures;however,the underlying pathophysiology is la...The discontinuation of denosumab[antibody targeting receptor activator of nuclear factor kappa B ligand(RANKL)]therapy may increase the risk of multiple vertebral fractures;however,the underlying pathophysiology is largely unknown.In patients who underwent discontinuation after multiple injections of denosumab,the levels of tartrate-resistant acid phosphatase 5b increased compared to pretreatment levels,indicating a phenomenon known as“overshoot.”The rate of decrease in bone mineral density during the withdrawal period was higher than the rate of decrease associated with aging,suggesting that the physiological bone metabolism had broken down.Overshoot and significant bone loss were also observed in mice receiving continuous administration of anti-RANKL antibody after treatment was interrupted,resembling the original pathology.In mice long out of overshoot,bone resorption recovered,but osteoblast numbers and bone formation remained markedly reduced.The bone marrow exhibited a significant reduction in stem cell(SC)antigen 1-and platelet-derived growth factor receptor alpha-expressing osteoblast progenitors(PαS cells)and alkaline phosphatase-positive early osteoblasts.Just before the overshoot phase,the osteoclast precursor cell population expands and RANKL-bearing extracellular vesicles(EVs)became abundant in the serum,leading to robust osteoclastogenesis after cessation of anti-RANKL treatment.Thus,accelerated bone resorption due to the accumulation of RANKLbearing EVs and long-term suppression of bone formation uncoupled from bone resorption leads to the severe bone loss characteristic of denosumab discontinuation.展开更多
Background:Rabies virus(RABV)-derived neuronal tracing tools are extensively applied in retrograde tracing due to their strict retrograde transsynaptic transfer property and low neurotoxicity.However,the RABV infectio...Background:Rabies virus(RABV)-derived neuronal tracing tools are extensively applied in retrograde tracing due to their strict retrograde transsynaptic transfer property and low neurotoxicity.However,the RABV infection and expression of fluorescence products would be gradually cleared while the infected neurons still survive,a phenomenon known as non-cytolytic immune clearance(NCLIC).This phenomenon introduced the risk of fluorescence loss and led to the omission of a subset of neurons that should be labeled,thereby interfering in the analysis of tracing results.Methods:To compensate for the fluorescence loss problem,in this study,we developed a novel marker footprints(MF)mouse,involving a Cre recombinase-dependent red fluorescent reporter system and systemic expression of glycoprotein(G)and ASLV-A receptor(TVA).Using this mouse model combined with the well-developed RABV-EnvA-ΔG-GFP-Cre viral tool,we developed a novel green-to-red spectral labeling strategy.Results:Neurons in the MF mouse could be co-labeled with green fluorescence from the very quick expression of the viral tool and with red fluorescence from the relatively slow expression of the neuron itself,so neurons undergoing NCLIC with green fluorescence loss could be relabeled red.Furthermore,newly infected neurons could be labeled green and other neurons could be labeled yellow due to the temporal expression difference between the two fluorescent proteins.Conclusions:This is the first polysynaptic retrograde tracing labeling strategy that could label neurons using spectral fluorescence colors with only one injection of the viral tool,enabling its application in recognizing the labeling sequence of neurons in brain regions and enhancing the spatiotemporal resolution of neuronal tracing.展开更多
Age-related osteoporosis poses a significant challenge in musculoskeletal health;a condition characterized by reduced bone density and increased fracture susceptibility in older individuals necessitates a better under...Age-related osteoporosis poses a significant challenge in musculoskeletal health;a condition characterized by reduced bone density and increased fracture susceptibility in older individuals necessitates a better understanding of underlying molecular and cellular mechanisms.Emerging evidence suggests that osteocytes are the pivotal orchestrators of bone remodeling and represent novel therapeutic targets for age-related bone loss.Our study uses the prematurely aged PolgD257A/D257A(PolgA)mouse model to scrutinize age-and sex-related alterations in musculoskeletal health parameters(frailty,grip strength,gait data),bone and particularly the osteocyte lacuno-canalicular network(LCN).Moreover,a new quantitative in silico image analysis pipeline is used to evaluate the alterations in the osteocyte network with aging.Our findings underscore the pronounced degenerative changes in the musculoskeletal health parameters,bone,and osteocyte LCN in PolgA mice as early as 40 weeks,with more prominent alterations evident in aged males.Our findings suggest that the PolgA mouse model serves as a valuable model for studying the cellular mechanisms underlying age-related bone loss,given the comparable aging signs and age-related degeneration of the bone and the osteocyte network observed in naturally aging mice and elderly humans.展开更多
The advancement of tissue clearing technology has significantly propelled neuroscience research.Nevertheless,the fluorescent proteins used in traditional transgenic mouse strains were not specifically optimized for ti...The advancement of tissue clearing technology has significantly propelled neuroscience research.Nevertheless,the fluorescent proteins used in traditional transgenic mouse strains were not specifically optimized for tissue clearing procedures,resulting in a substantial decrease in fluorescent intensity after clearing.In this study,we developed the Ci1 reporter mouse strain(where Ci stands for the Chinese Institute for Brain Research,CIBR)based on the bright red fluorescent protein mScarlet.The Ci1 reporter exhibits no fluorescence leakage in various organs or tissue types and can be readily crossed with multiple tissue-specific Cre lines.Compared to the Ai14 mouse strain,the Ci1 reporter strain demonstrates lower non-specific leakage,stronger fluorescence intensity in different tissues,and better preservation of fluorescence following tissue clearing treatment.The creation of the Ci1 reporter provides a more effective tool for both neuroscience and other biomedical research applications.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
Epithelial ovarian cancer(EOC) is the leading cause of gynecological cancer-related mortality in the developed world. EOC is a heterogeneous disease represented by several histological and molecular subtypes. Therefor...Epithelial ovarian cancer(EOC) is the leading cause of gynecological cancer-related mortality in the developed world. EOC is a heterogeneous disease represented by several histological and molecular subtypes. Therefore, exploration of relevant preclinical animal models that consider the heterogenic nature of EOC is of great importance for the development of novel therapeutic strategies that can be translated clinically to combat this devastating disease. In this review, we discuss recent progress in the development of preclinical mouse models for EOC study as well as their advantages and limitations.展开更多
Cutaneous exposure to food allergens through a disrupted skin barrier is recognized as an important cause of food allergy,and the cutaneous sensitized mouse model has been established to investigate relevant allergic ...Cutaneous exposure to food allergens through a disrupted skin barrier is recognized as an important cause of food allergy,and the cutaneous sensitized mouse model has been established to investigate relevant allergic disorders.However,the role of different genetic backgrounds of mice on immune responses to food allergens upon epicutaneous sensitization is largely unknown.In this study,two strains of mice,i.e.,the BALB/c and C57BL/6 mice,were epicutaneously sensitized with ovalbumin on atopic dermatitis(AD)-like skin lesions,followed by intragastric challenge to induce IgE-mediated food allergy.Allergic outcomes were measured as clinical signs,specific antibodies and cytokines,and immune cell subpopulations,as well as changes in intestinal barrier function and gut microbiota.Results showed that both strains of mice exhibited typical food-allergic symptoms with a Th2-skewed response.The C57BL/6 mice,rather than the BALB/c mice,were fitter for establishing an epicutaneously sensitized model of food allergy since a stronger Th2-biased response and severer disruptions in the intestinal barrier and gut homeostasis were observed.This study provides knowledge for selecting an appropriate mouse model to study food-allergic responses associated with AD-like skin lesions and highlights the role of genetic variations in the immune mechanism underlying pathogenesis of food allergy.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
Genetically engineered mouse(GEM)models are commonly used in biomedical research.Generating GEMs involve complex set of experimental procedures requiring sophisticated equipment and highly skilled technical staff.Beca...Genetically engineered mouse(GEM)models are commonly used in biomedical research.Generating GEMs involve complex set of experimental procedures requiring sophisticated equipment and highly skilled technical staff.Because of these reasons,most research institutes set up centralized core facilities where custom GEMs are created for research groups.Researchers,on the other hand,when they begin thinking about generating GEMs for their research,several questions arise in their minds.For example,what type of model(s)would be best useful for my research,how do I design them,what are the latest technologies and tools available for developing my model(s),and finally how to breed GEMs in my research.As there are several considerations and options in mouse designs,and as it is an expensive and time-consuming endeavor,careful planning upfront can ensure the highest chance of success.In this article,we provide brief answers to several frequently asked questions that arise when researchers begin thinking about generating mouse model(s)for their work.展开更多
Regulation of cell fate requires the establishment and erasure of 5-methylcytosine(5mC) in genomic DNA.The formation of 5mC is achieved by DNA cytosine methyltransferases(DNMTs),whereas the removal of5mC can be accomp...Regulation of cell fate requires the establishment and erasure of 5-methylcytosine(5mC) in genomic DNA.The formation of 5mC is achieved by DNA cytosine methyltransferases(DNMTs),whereas the removal of5mC can be accomplished by various pathways.Aside from ten-eleven translocation(TET)-mediated oxidation of 5mC followed by thymine DNA glycosylase(TDG)-initiated base excision repair(BER),the direct deformylation of 5-formylcytosine(5fC) and decarboxylation of 5-carboxylcytosine(5caC) have also been discovered as the novel DNA demethylation pathways.Although these novel demethylation pathways have been identified in stem cells and somatic cells,their precise roles in regulating cell fate remain unclear.Here,we differentiate mouse embryonic stem cells(mESCs) into mouse embryoid bodies(mEBs),followed by further differentiation into mouse neural stem cells(mNSCs) and finally into mouse neurons(mNeurons).During this sequential differentiation process,we employ probe molecules,namely2'-fluorinated 5-formylcytidine(F-5fC) and 2'-fluorinated 5-carboxyldeoxycytidine(F-5caC),for metabolic labeling.The results of mass spectrometry(MS) analysis demonstrate the deformylation and decarboxylation activities are progressively decreased and increased respectively during differentiation process,and this opposite demethylation tendency is not associated with DNMTs and TETs.展开更多
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.
基金supported by the National Research Foundation of Korea (NRF)funded by the Ministry of Science,ICT&Future Planning (2022R1A2C2006229,2022R1A6A3A01086868)Korea Dementia Research Project through the Korea Dementia Research Center (KDRC)funded by the Ministry of Health&Welfare and Ministry of Science and ICT,Republic of Korea (RS-2024-00345328)KIST Institutional Grant (2E32851)。
文摘Alzheimer'sdisease(AD)isaprogressive neurodegenerative disorder characterized by cognitive impairment and distinct neuropathological features,including amyloid-βplaques,neurofibrillary tangles,and reactive astrogliosis.Developing effective diagnostic,preventative,and therapeutic strategies for AD necessitates the establishment of animal models that accurately recapitulate the pathophysiological processes of the disease.Existing transgenic mouse models have significantly contributed to understanding AD pathology but often fail to replicate the complexity of human AD.Additionally,these models are limited in their ability to elucidate the interplay among amyloid-βplaques,neurofibrillary tangles,and reactive astrogliosis due to the absence of spatially and temporally specific genetic manipulation.In this study,we introduce a novel AD mouse model(APP/PS1-TauP301L-Adeno mice)designed to rapidly induce pathological symptoms and enhance understanding of AD mechanisms.Neurofibrillary tangles and severe reactive astrogliosis were induced by injecting AAVDJ-EF1a-hTauP301L-EGFP and Adeno-GFAP-GFP viruses into the hippocampi of 5-month-old APP/PS1 mice.Three months post-injection,these mice exhibited pronounced astrogliosis,substantial amyloid-βplaque accumulation,extensiveneurofibrillarytangles,accelerated neuronal loss,elevated astrocytic GABA levels,and significant spatial memory deficits.Notably,these pathological features were less severe in AAVTauP301L-expressing APP/PS1 mice without augmented reactive astrogliosis.These findings indicate an exacerbating role of severe reactive astrogliosis in amyloid-βplaque and neurofibrillary tangle-associated pathology.The APP/PS1-TauP301L-Adeno mouse model provides a valuable tool for advancing therapeutic research aimed at mitigating the progression of AD.
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.
基金funded by the budgetary funding to FRC FTM for the project“Post-Genomic High-Tech Research on the Mechanisms of Development of Socially Significant Diseases and Stress-Induced Conditions”(Grant No.125031203556-7).
文摘Background:Glucocorticoids are used as anti-inflammatory drugs for the treatment of various diseases,however,their side effects on normal brain tissue remain underinvestigated.Objectives:The study aimed to investigate dexamethasone(DXM)effects on cell composition and myelin content in the mouse brain tissue.Methods:C57Bl/6 male mice(n 60)received single and ten multiple intraperitoneal DXM injections(2.5 mg/kg),and the studied=parameters were analysed at 1,3,7,10 days after a single DXM injection and 15,30,60,and 90 days after the multiple injections.Oligodendrocytes,microglia,and astrocytes were assayed by immunohistochemistry with specific antibodies(Olig2,CD68,and GFAP,respectively)in the corpus callosum of the normal brain tissue.The myelin content was estimated by staining with LuxolFastBlue.The presence of GFAP isoforms was determined by western blotting.Results:DXM administration did not affect oligodendrocytes in the mouse brain but temporarily significantly decreased myelin content(1.2-fold,p 0.0058;1.4-fold,p 0.0001)at 3–15 days time points.At the same time,DXM significantly=<decreased the number of microglial cells(1.5–3.5-fold,p 0.0001)and significantly increased astrocytes(1.8-fold,p<<0.0001).Prolonged administration of DXM resulted in the decrease of the main GFAPα-isoform(50 kDa)and the appearance of shorter GFAP isoforms(30 kDa,42 kDa,44 kDa)similar to that in some neurodegenerative animal models.Conclusion:DXM can modify the cell composition of the normal mouse brain tissue by decreasing microglial cells and increasing astrocytes.Long-term use of DXM results in the inhibition of myelin formation and the appearance of truncated GFAP isoforms,suggesting its ability to induce neurodegeneration-like changes in the normal mouse brain.
基金Funding was provided by the following National Institutes of Health grants:F30-DK123989(May Barakat)R01-GM50875(Luisa A.DiPietro)+1 种基金R35-GM139603(Luisa A.DiPietro)R01-AR065941(Terry W.Moore).Additional funding was provided by the University of Illinois Chicago Chancellor's Translational Science Initiative Award.
文摘The Leprdb/db mouse is a common and well-studied model of type II diabetes mel-litus that is often employed in biomedical research.Despite being one of the most commonly used models for the investigation of diabetic wound healing,there are a few specific guidelines for its husbandry,and wound complications such as infection and expansion are common.This study presents a modified animal husbandry ap-proach for the Leprdb/db mouse to reduce the incidence of complications during wound healing experiments.Compared to standard rodent housing protocols,the use of this modified protocol leads to decreased rates of complications among experimental animals across several experiments.The protocol includes increased cage size,de-creased housing density,and more frequent cage replacements.The use of improved husbandry for the Leprdb/db mouse decreases the total number of animals required,minimizes harm during experimentation,and improves the consistency and reproduc-ibility of wound healing studies.
基金supported in part by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0490000 to Z.H.)National Key Research and Development Program(2021YFF0702002 to J.L.,2022YFC2303300 to Z.H.,and 2023YFC2305900 to M.W.)+3 种基金“Youth Commando”project(2023QNTJ-02 TO J.L.)Key Project(2024JZZD-02 to Z.H.)of State Key Laboratory of Virology and BiosafetyWuhan Institute of Virology,the National Natural Science Foundation of China(U22A20336 to Z.H.and Y.Z.)Wuhan Natural Science Foundation(202404071010067 to M.W.and 202404071010068 to J.L.).
文摘Dear Editor,Crimean–Congo hemorrhagic fever(CCHF),caused by the CCHF virus(CCHFV),is a severe tick-borne illness with a wide geographical distribution,posing a significant threat with case fatality rates ranging from 5%to 70%(Hawman and Feldmann,2023).Due to the lack of approved vaccines and therapeutics,the World Health Organization(WHO)has listed CCHF as one of the priority diseases(Semper et al.,2024).CCHF initially presents as a nonspecific febrile illness,characterized by fever,malaise,myalgia,and nausea,which can rapidly progress to hemorrhagic disease.The hemorrhagic stage is particularly pronounced in severe cases,with rapid progression to disseminated intravascular coagulation(DIC),overt bleeding,kidney or liver failure,and shock(Frank et al.,2024).Up to date,there is an absence of a suitable animal model that can accurately mimic the coagulopathy and bleeding associated with CCHFV infection.Consequently,our understanding of the pathogenic mechanisms underlying these conditions remains limited(Rodriguez et al.,2022).
基金supported by NIH/NIDCR grant R01DE025664 to IPC.
文摘Craniometaphyseal dysplasia(CMD),a rare craniotubular disorder,occurs in an autosomal dominant(AD)or autosomal recessive(AR)form.CMD is characterized by hyperostosis of craniofacial bones and metaphyseal flaring of long bones.Many patients with CMD suffer from neurological symptoms.The pathogenesis of CMD is not fully understood.
基金supported by the National Natural Science Foundation of China(Nos.42076086 and 32202068)Fujian Province Natural Science Foundation of China(Nos.2019J01696 and 2022J01332)the Fujian Province Young and Middle-Aged Teacher Education Research Project(No.JAT200247).
文摘Melanosomes are specialized membrane-bound organelles within which melanin is synthesized and stored.The levels of melanin can be effectively reduced by inhibiting melanin synthesis or promoting melanosome degradation via autophagy.Ceramide,a central molecule in sphingolipid metabolism,has been widely implicated in the regulation of autophagy.Few researchers have addressed the potential effects of ceramide analogs on suppressing melanin synthesis.However,whether ceramide can induce melanosome autophagy and the potential autophagy-dependent mechanism underlying this phenomenon remain unknown.Here,an active compound from the marine microalgae Emiliania huxleyi extract was firstly isolated and identified as a long-chain C22-ceramide(C22-Cer).In vitro results of mouse B16 melanoma cell experiments showed that treatment with 2-5µmol/L C22-Cer significantly suppressed the increase ofα-MSH-induced melanin levels and tyrosinase activity without cytotoxicity.C22-Cer induced typical hallmarks of autophagy such as accumulation of autophagosomes,enhanced autophagic flux and microtubule-associated protein light chain 3,LC3-II expression,and p62 degradation through activating c-Jun N-terminal kinase(JNK)directly.Furthermore,C22-Cer activated JNK-Bcl-2 signaling,dissociated the Beclin1/Bcl-2 complex,and induced melanosome autophagy without affecting the expression of MITF.Besides,the Ca^(2+)influx induced by treatment with C22-Cer further increased the substantial accumulation of autophagosomes.Together,we found a novel marine-derived compound,C22-Cer,targeting JNK pathway and Ca^(2+)signaling to induce melanosome autophagy and suppress melanin accumulation in B16 cells.This study implicates that C22-Cer might be a potential therapeutic mediator against skin pigmentation in mammals.
基金supported by the Grants-in-Aid for Scientific Research from Japan Society for the Promotion of Science KAKENHI 22K09110.
文摘Murine subarachnoid hemorrhage(SAH)induced using the filament perforation method is a useful in vivo experimental model to investigate the pathophysiological mechanisms in the brain underlying SAH.However,identifying mice with comorbid acute neurogenic pulmonary edema(NPE),a life-threatening systemic consequence often induced by SAH,in this model is difficult without histopathological investiga-tions.Herein,we present an imaging procedure involving dual-energy X-ray absorp-tiometry(DXA)to identify NPE in a murine model of SAH.We quantified the lung lean mass(LM)and compared the relationship between micro-computed tomography(CT)evidence of Hounsfield unit(HU)values and histopathological findings of PE.Of the 85 mice with successful induction of SAH by filament perforation,16(19%)had NPE,as verified by postmortem histology.The DXA-LM values correlate well with CT-HU levels(r=0.63,p<0.0001).Regarding the relationship between LM and HU in mice with post-SAH NPE,the LM was positively associated with HU values(r2=0.43;p=0.0056).A receiver operating characteristics curve of LM revealed a sensitivity of 87%and specificity of 57%for detecting PE,with a similar area under the curve as the HU(0.79±0.06 vs.0.84±0.07;p=0.21).These data suggest that confirming acute NPE using DXA-LM is a valuable method for selecting a clinically relevant murine NPE model that could be used in future experimental SAH studies.
文摘The discontinuation of denosumab[antibody targeting receptor activator of nuclear factor kappa B ligand(RANKL)]therapy may increase the risk of multiple vertebral fractures;however,the underlying pathophysiology is largely unknown.In patients who underwent discontinuation after multiple injections of denosumab,the levels of tartrate-resistant acid phosphatase 5b increased compared to pretreatment levels,indicating a phenomenon known as“overshoot.”The rate of decrease in bone mineral density during the withdrawal period was higher than the rate of decrease associated with aging,suggesting that the physiological bone metabolism had broken down.Overshoot and significant bone loss were also observed in mice receiving continuous administration of anti-RANKL antibody after treatment was interrupted,resembling the original pathology.In mice long out of overshoot,bone resorption recovered,but osteoblast numbers and bone formation remained markedly reduced.The bone marrow exhibited a significant reduction in stem cell(SC)antigen 1-and platelet-derived growth factor receptor alpha-expressing osteoblast progenitors(PαS cells)and alkaline phosphatase-positive early osteoblasts.Just before the overshoot phase,the osteoclast precursor cell population expands and RANKL-bearing extracellular vesicles(EVs)became abundant in the serum,leading to robust osteoclastogenesis after cessation of anti-RANKL treatment.Thus,accelerated bone resorption due to the accumulation of RANKLbearing EVs and long-term suppression of bone formation uncoupled from bone resorption leads to the severe bone loss characteristic of denosumab discontinuation.
基金Hubei Natural Science Foundation of China,Grant/Award Number:2024AFB593。
文摘Background:Rabies virus(RABV)-derived neuronal tracing tools are extensively applied in retrograde tracing due to their strict retrograde transsynaptic transfer property and low neurotoxicity.However,the RABV infection and expression of fluorescence products would be gradually cleared while the infected neurons still survive,a phenomenon known as non-cytolytic immune clearance(NCLIC).This phenomenon introduced the risk of fluorescence loss and led to the omission of a subset of neurons that should be labeled,thereby interfering in the analysis of tracing results.Methods:To compensate for the fluorescence loss problem,in this study,we developed a novel marker footprints(MF)mouse,involving a Cre recombinase-dependent red fluorescent reporter system and systemic expression of glycoprotein(G)and ASLV-A receptor(TVA).Using this mouse model combined with the well-developed RABV-EnvA-ΔG-GFP-Cre viral tool,we developed a novel green-to-red spectral labeling strategy.Results:Neurons in the MF mouse could be co-labeled with green fluorescence from the very quick expression of the viral tool and with red fluorescence from the relatively slow expression of the neuron itself,so neurons undergoing NCLIC with green fluorescence loss could be relabeled red.Furthermore,newly infected neurons could be labeled green and other neurons could be labeled yellow due to the temporal expression difference between the two fluorescent proteins.Conclusions:This is the first polysynaptic retrograde tracing labeling strategy that could label neurons using spectral fluorescence colors with only one injection of the viral tool,enabling its application in recognizing the labeling sequence of neurons in brain regions and enhancing the spatiotemporal resolution of neuronal tracing.
基金the European Research Council(ERC Advanced MechAGE-ERC-2016-ADG-741883)the Swiss National Science Foundation(no.188522).
文摘Age-related osteoporosis poses a significant challenge in musculoskeletal health;a condition characterized by reduced bone density and increased fracture susceptibility in older individuals necessitates a better understanding of underlying molecular and cellular mechanisms.Emerging evidence suggests that osteocytes are the pivotal orchestrators of bone remodeling and represent novel therapeutic targets for age-related bone loss.Our study uses the prematurely aged PolgD257A/D257A(PolgA)mouse model to scrutinize age-and sex-related alterations in musculoskeletal health parameters(frailty,grip strength,gait data),bone and particularly the osteocyte lacuno-canalicular network(LCN).Moreover,a new quantitative in silico image analysis pipeline is used to evaluate the alterations in the osteocyte network with aging.Our findings underscore the pronounced degenerative changes in the musculoskeletal health parameters,bone,and osteocyte LCN in PolgA mice as early as 40 weeks,with more prominent alterations evident in aged males.Our findings suggest that the PolgA mouse model serves as a valuable model for studying the cellular mechanisms underlying age-related bone loss,given the comparable aging signs and age-related degeneration of the bone and the osteocyte network observed in naturally aging mice and elderly humans.
基金supported by the startup funding from the Chinese Institute for Brain Research to Hu Zhao.
文摘The advancement of tissue clearing technology has significantly propelled neuroscience research.Nevertheless,the fluorescent proteins used in traditional transgenic mouse strains were not specifically optimized for tissue clearing procedures,resulting in a substantial decrease in fluorescent intensity after clearing.In this study,we developed the Ci1 reporter mouse strain(where Ci stands for the Chinese Institute for Brain Research,CIBR)based on the bright red fluorescent protein mScarlet.The Ci1 reporter exhibits no fluorescence leakage in various organs or tissue types and can be readily crossed with multiple tissue-specific Cre lines.Compared to the Ai14 mouse strain,the Ci1 reporter strain demonstrates lower non-specific leakage,stronger fluorescence intensity in different tissues,and better preservation of fluorescence following tissue clearing treatment.The creation of the Ci1 reporter provides a more effective tool for both neuroscience and other biomedical research applications.
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 US National Institutes of Health (R01CA160331, R01CA163377, R01CA202919,R01CA239128, P01AG031862, P50CA228991 to R.G.Z. and K99CA241395 to S.K.)US Department of Defense (OC180109 and OC190181 to R.G.Z.)+2 种基金The Honorable Tina Brozman Foundation for Ovarian Cancer Research (to R.G.Z.)Ovarian Cancer Research Alliance Collaborative Research Development Grant (to R.G.Z.)Core facilities support was provided by a Cancer Centre Support Grant(CA010815) to the Wistar Institute。
文摘Epithelial ovarian cancer(EOC) is the leading cause of gynecological cancer-related mortality in the developed world. EOC is a heterogeneous disease represented by several histological and molecular subtypes. Therefore, exploration of relevant preclinical animal models that consider the heterogenic nature of EOC is of great importance for the development of novel therapeutic strategies that can be translated clinically to combat this devastating disease. In this review, we discuss recent progress in the development of preclinical mouse models for EOC study as well as their advantages and limitations.
基金the financial support received from the Natural Science Foundation of China(32202202 and 31871735)the Zhejiang Provincial Natural Science Foundation of China(LGN22C200027)the Open Fund of the Key Laboratory of Biosafety Detection for Zhejiang Market Regulation(2022BS004)。
文摘Cutaneous exposure to food allergens through a disrupted skin barrier is recognized as an important cause of food allergy,and the cutaneous sensitized mouse model has been established to investigate relevant allergic disorders.However,the role of different genetic backgrounds of mice on immune responses to food allergens upon epicutaneous sensitization is largely unknown.In this study,two strains of mice,i.e.,the BALB/c and C57BL/6 mice,were epicutaneously sensitized with ovalbumin on atopic dermatitis(AD)-like skin lesions,followed by intragastric challenge to induce IgE-mediated food allergy.Allergic outcomes were measured as clinical signs,specific antibodies and cytokines,and immune cell subpopulations,as well as changes in intestinal barrier function and gut microbiota.Results showed that both strains of mice exhibited typical food-allergic symptoms with a Th2-skewed response.The C57BL/6 mice,rather than the BALB/c mice,were fitter for establishing an epicutaneously sensitized model of food allergy since a stronger Th2-biased response and severer disruptions in the intestinal barrier and gut homeostasis were observed.This study provides knowledge for selecting an appropriate mouse model to study food-allergic responses associated with AD-like skin lesions and highlights the role of genetic variations in the immune mechanism underlying pathogenesis of food allergy.
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We thank D.D.Meigs(University of Nebraska Medical Center)and Tonya Cejka(freelance English editor)for editing assistance.C.B.G.is funded by NIH grants R35HG010719,R21GM129559,R21AI143394 and R21DA046831.M.O.is funded by 2016–2017 Tokai University School of Medicine Project Research,the Research Aid from the Institute of Medical Sciences in Tokai University,Grant-in-Aid for Scientific Research(25290035)from MEXTa Grant-in-Aid for Challenging Exploratory Research(15K14371)from JSPS.
文摘Genetically engineered mouse(GEM)models are commonly used in biomedical research.Generating GEMs involve complex set of experimental procedures requiring sophisticated equipment and highly skilled technical staff.Because of these reasons,most research institutes set up centralized core facilities where custom GEMs are created for research groups.Researchers,on the other hand,when they begin thinking about generating GEMs for their research,several questions arise in their minds.For example,what type of model(s)would be best useful for my research,how do I design them,what are the latest technologies and tools available for developing my model(s),and finally how to breed GEMs in my research.As there are several considerations and options in mouse designs,and as it is an expensive and time-consuming endeavor,careful planning upfront can ensure the highest chance of success.In this article,we provide brief answers to several frequently asked questions that arise when researchers begin thinking about generating mouse model(s)for their work.
基金supported by the National Key R&D Program of China (Nos.2022YFC3400700,2022YFA0806600)the National Natural Science Foundation of China (No.22074110)+3 种基金Guangdong Basic and Applied Basic Research Foundation (No.2022A1515110550)Central Public-interest Scientific Institution Basal Research Fund,South China Sea Fisheries Research Institute,CAFS (No.2021TS02)Guangzhou Basic and Applied Basic Research Foundation (No.2023A04J1337)Central Public-interest Scientific Institution Basal Research Fund,CAFS (No.2023TD78)。
文摘Regulation of cell fate requires the establishment and erasure of 5-methylcytosine(5mC) in genomic DNA.The formation of 5mC is achieved by DNA cytosine methyltransferases(DNMTs),whereas the removal of5mC can be accomplished by various pathways.Aside from ten-eleven translocation(TET)-mediated oxidation of 5mC followed by thymine DNA glycosylase(TDG)-initiated base excision repair(BER),the direct deformylation of 5-formylcytosine(5fC) and decarboxylation of 5-carboxylcytosine(5caC) have also been discovered as the novel DNA demethylation pathways.Although these novel demethylation pathways have been identified in stem cells and somatic cells,their precise roles in regulating cell fate remain unclear.Here,we differentiate mouse embryonic stem cells(mESCs) into mouse embryoid bodies(mEBs),followed by further differentiation into mouse neural stem cells(mNSCs) and finally into mouse neurons(mNeurons).During this sequential differentiation process,we employ probe molecules,namely2'-fluorinated 5-formylcytidine(F-5fC) and 2'-fluorinated 5-carboxyldeoxycytidine(F-5caC),for metabolic labeling.The results of mass spectrometry(MS) analysis demonstrate the deformylation and decarboxylation activities are progressively decreased and increased respectively during differentiation process,and this opposite demethylation tendency is not associated with DNMTs and TETs.
