Consistent Alterations of Human Fecal Microbes After Transplantation into Germ-free Mice

Fecal microbiota transplantation(FMT)of human fecal samples into germ-free(GF)mice is useful for establishing causal relationships between the gut microbiota and human phenotypes.However,due to the intrinsic differences between human and mouse intestines and the different diets of the two organisms,it may not be possible to replicate human phenotypes in mice through FMT;similarly,treatments that are effective in mouse models may not be effective in humans.In this study,we aimed to identify human gut microbes that undergo significant and consistent changes(i.e.,in relative abundances)after transplantation into GF mice in multiple experimental settings.We collected 16S rDNA-seq data from four published studies and analyzed the gut microbiota profiles from 1713 human–mouse pairs.Strikingly,on average,we found that only 47%of the human gut microbes could be re-established in mice at the species level,among which more than 1/3 underwent significant changes(referred to as“variable taxa”).Most of the human gut microbes that underwent significant changes were consistent across multiple human–mouse pairs and experimental settings.Consequently,about 1/3 of human samples changed their enterotypes,i.e.,significant changes in their leading species after FMT.Mice fed with a controlled diet showed a lower enterotype change rate(23.5%)than those fed with a noncontrolled diet(49.0%),suggesting a possible solution for rescue.Most of the variable taxa have been reported to be implicated in human diseases,with some recognized as the causative species.Our results highlight the challenges of using a mouse model to replicate human gut microbiota-associated phenotypes,provide useful information for researchers using mice in gut microbiota studies,and call for additional validations after FMT.An online database named FMT-DB is publicly available at http://fmt2mice.humangut.info/#/.

Colonization of germ-free mice with a mixture of three lactobacillus strains enhances the integrity of gut mucosa and ameliorates allergic sensitization

Increasing numbers of clinical trials and animal experiments have shown that probiotic bacteria are promising tools for allergy prevention. Here, we analyzed the immunomodulatory properties of three selected lactobacillus strains and the impact of their mixture on allergic sensitization to Bet v I using a gnotobiotic mouse model. We showed that Lactobacillus （L.） rhamnosus LOCK0900, L. rhamnosus LOCK0908 and L. casei LOCK0919 are recognized via Toll-like receptor 2 （TLR2） and nucleotide-binding oligomerization domain-containing protein 2 （NOD2） receptors and stimulate bone marrow-derived dendritic cells to produce cytokines in species- and strain-dependent manners. Colonization of germ-free （GF） mice with a mixture of all three strains （Lmix） improved the intestinal barrier by strengthening the apical junctional complexes of enterocytes and restoring the structures of microfilaments extending into the terminal web. Mice colonized with Lmix and sensitized to the Bet v I allergen showed significantly lower levels of allergen-specific IgE, IgG 1 and IgG2a and an elevated total IgA level in the sera and intestinal lavages as well as an increased transforming growth factor （TGF）-β level compared with the sensitized GF mice. Splenocytes and mesenteric lymph node cells from the Lmix-colonized mice showed the significant upregulation of TGF-β after in vitro stimulation with Bet v 1. Our results show that Lmix colonization improved the gut epithelial barrier and reduced allergic sensitization to Bet v 1. Furthermore, these findings were accompanied by the increased production of circulating and secretory IgA and the regulatory cytokine TGF-β. Thus, this mixture of three lactobacillus strains shows potential for use in the prevention of increased gut permeability and the onset of allergies in humans,

Potential therapeutic role of spermine via Rac1 in osteoporosis:Insights from zebrafish and mice

Osteoporosis(OP)is a prevalent metabolic bone disease.While drug therapy is essential to prevent bone loss in osteoporotic patients,current treatments are limited by side effects and high costs,necessitating the development of more effective and safer targeted therapies.Utilizing a zebrafish(Danio rerio)larval model of osteoporosis,we explored the influence of the metabolite spermine on bone homeostasis.Results showed that spermine exhibited dual activity in osteoporotic zebrafish larvae by increasing bone formation and decreasing bone resorption.Spermine not only demonstrated excellent biosafety but also mitigated prednisolone-induced embryonic neurotoxicity and cardiotoxicity.Notably,spermine showcased protective attributes in the nervous systems of both zebrafish embryos and larvae.At the molecular level,Rac1 was identified as playing a pivotal role in mediating the antiosteoporotic effects of spermine,with P53 potentially acting downstream of Rac1.These findings were confirmed using mouse(Mus musculus)models,in which spermine not only ameliorated osteoporosis but also promoted bone formation and mineralization under healthy conditions,suggesting strong potential as a bonestrengthening agent.This study underscores the beneficial role of spermine in osteoporotic bone homeostasis and skeletal system development,highlighting pivotal molecular mediators.Given their efficacy and safety,human endogenous metabolites like spermine are promising candidates for new anti-osteoporotic drug development and daily bone-fortifying agents.

Effects of Rosa roxburghii&edible fungus fermentation broth on immune response and gut microbiota in immunosuppressed mice

With the rise of probiotics fermentation in food industry,fermented foods have attracted worldwide attention.In this study,protective effects of Rosa roxburghii&edible fungus fermentation broth(REFB)on immune function and gut health in Cyclophosphamide induced immunosuppressed mice were investigated.Results showed that REFB could improve the immune organ index,and promote the proliferation and differentiation of splenic T lymphocytes.In addition,it attenuated intestinal mucosal damage and improved intestinal cellular immunity.REFB administration also up-regulated the expression of IL-4,INF-γ,TNF-α,T-bet and GATA-3 mRNA in small intestine.Furthermore,administration of REFB modulated gut microbiota composition and increased the relative abundance of beneficial genus,such as Bacteroides.It also increased the production of fecal short-chain fatty acids.These indicate that REFB has the potential to improve immunity,alleviate intestinal injury and regulate gut microbiota in immunosuppressed mice.

Carrageenan oligosaccharides and associated carrageenan-degrading bacteria induce intestinal inflammation in germ-free mice

Carrageenans(CGNs)are widely used in foods and pharmaceuticals although their safety remains controversial.To investigate the effects of CGNs and CGN-degrading bacteria in the human colon,we screened for CGN degradation by human fecal microbiota,and for inflammatory response to CGNs and/or CGN-degrading bacteria in germ free mice.Thin-layer chromatography indicated that high molecular weight(MW)CGNs(!100 kDa)remained undegraded in the presence of human fecal microbiota,whereas low MW CGNs,i.e.,k-carrageenan oligosaccharides(KCO,~4.5 kDa)were degraded when exposed to seven of eight human fecal samples,although sulfate groups were not removed during degradation.Bacteroides xylanisolvens and Escherichia coli isolates from fecal samples apparently degraded KCO synergistically,with B.xylanisolvens serving as the primary degrader.Combined treatment of KCO with KCO-degrading bacteria led to greater pro-inflammatory effects in the colon and rectum of germ-free mice than either KCO or bacteria alone.Similarly,p-p38-,CD3-,and CD79a-positive immune cells were more abundant in combined treatment group mice than in either single treatment group.Our study shows that KCO-degrading bacteria and the low MW products of KCO can promote proinflammatory effects in mice,and represent two key markers for evaluating CGN safety in foods or medicines.

Application of transgenic mice to the molecular pathogenesis of cataract

One of the most prevalent disorders that cause blindness worldwide is cataract,and its essence is the visual disorder caused by the opacity of the lens.The significant degree of variation in cataracts and the fact that a variety of factors can impact a patient’s lens transparency make it especially crucial to investigate the pathogenesis of cataracts at the molecular level.It has been found that more than 60 genes are linked to the formation of cataracts,and the construction of a transgenic mouse model of cataract similar to the selection of human lens clouding due to a variety of causes has become an important means of studying the pathogenesis of cataract.Therefore,the research on the application of transgenic mice to the molecular pathogenesis of cataracts will be the main topic of this review of the literature.

Skeletal phenotypes and molecular mechanisms in aging mice

Aging is an inevitable physiological process,often accompanied by age-related bone loss and subsequent bone-related diseases that pose serious health risks.Research on skeletal diseases caused by aging in humans is challenging due to lengthy study durations,difficulties in sampling,regional variability,and substantial investment.Consequently,mice are preferred for such studies due to their similar motor system structure and function to humans,ease of handling and care,low cost,and short generation time.In this review,we present a comprehensive overview of the characteristics,limitations,applicability,bone phenotypes,and treatment methods in naturally aging mice and prematurely aging mouse models(including SAMP6,POLG mutant,LMNA,SIRT6,ZMPSTE24,TFAM,ERCC1,WERNER,and KL/KL-deficient mice).We also summarize the molecular mechanisms of these aging mouse models,including cellular DNA damage response,senescence-related secretory phenotype,telomere shortening,oxidative stress,bone marrow mesenchymal stem cell(BMSC)abnormalities,and mitochondrial dysfunction.Overall,this review aims to enhance our understanding of the pathogenesis of aging-related bone diseases.

Textile dyeing wastewater negatively influences the hematological profile and reproductive health of male Swiss albino mice

Objective:To determine the effects of textile dyeing industrial wastewater on the hematological parameters and reproductive health including histoarchitecture of male gonad(testes)of mice.Methods:Twenty-four Swiss albino mice at 4-weeks old were divided into four groups(n=6 per group).Mice of group 1 supplied with normal drinking water were served as the control group.Mice of group 2,3 and 4 were supplied normal drinking water mixed with textile dyeing wastewater at 5%,10% and 20% concentration,respectively.After completing 24 weeks of treatment,different hematological profile,weight of testes,gonadosomatic index(GSI),sperm concentration and morphology were measured.Moreover,histopathological changes in testes were examined.Results:Hematocrit value and hemoglobin concentrations were decreased in all groups of wastewater-treated mice compared to the control group.Likewise,weight of testes,GSI and sperm concentration were decreased significantly in wastewater-treated mice in comparison to the control group.The percentage of morphologically healthy epididymal sperm was significantly reduced in wastewater-treated mice.Histopathological examination revealed degenerative changes in seminiferous tubules,a smaller number of spermatogenic cells,elongation of seminiferous tubules and degenerative changes of seminiferous tubules in wastewater-treated mice.Conclusions:Textile dyeing wastewater has harmful effects on hematological profile and reproductive health of male mice.

Investigation of the apoptotic mechanism in hippocampal and retinal neurons of db/db mice induced by Dihuangyinzi decoction

In the present study,we utilized db/db mice to investigate the mechanisms of apoptosis in brain and retinal neurons.A total of 30 male db/db mice aged 8–9 weeks were randomly assigned to the model group,Dihuangyinzi decoction(DHYZ)group(30.03 g/kg),and metformin(MET)group(0.58 g/kg),with 10 mice in each group.The control group comprised 10 db/m mice of the same background and age.Paired-associate learning(PAL)tests were conducted to evaluate the learning and memory functions of the mice.Histological assessments,including Hematoxylin-Eosin(H&E)and Nissl staining,were employed to observe changes in nerve cells in the hippocampus and retina.Immunohistochemistry and real-time fluorescence quantitative PCR were employed to detect the positive expression of anti-apoptotic factor Bcl-2 and pro-apoptotic factor Bax at the protein and mRNA levels in the hippocampus and retina.Western blotting analysis was adopted to assess protein expression levels of JNK,p-JNK,p38 MAPK,and p-p38 MAPK.Results revealed a significant decline in the correct rate of PAL test results in the model group(P<0.001),accompanied by increased reaction and delay times(P<0.001)and higher blood glucose levels(P<0.001).H&E and Nissl staining indicated a reduction in the number of nerve cells in the CA1 area of the hippocampus in the model group,with scattered arrangement and decreased Nissl corpuscles.Positive expression and mRNA expression of Bax in the hippocampus and retina increased significantly(P<0.001),while positive expression and mRNA expression of Bcl-2 decreased(P<0.001).Protein expression levels of p-JNK/JNK and p-p38 MAPK/p38 MAPK showed a significant increase(P<0.001).The DHYZ and MET groups exhibited enhanced accuracy in PAL experiments(P<0.05),decreased reaction time and delay time(P<0.05),and reduced blood glucose levels(P<0.05).The number of neurons in the CA1 region of the hippocampus increased,morphological structure improved,and the arrangement of the hippocampal structure became more orderly.Additionally,no obvious vacuolization was observed in the neuronal cell layer.The number of Nissl bodies increased,and the layers of the retina were closely arranged,with an increase in the number of Nissl bodies.Positive expressions of Bax in the hippocampus and retina,both at the protein and mRNA levels,decreased significantly(P<0.001),while positive expressions of Bcl-2 and its mRNA increased(P<0.01,P<0.001).Furthermore,the protein expressions of p-JNK/JNK and p-p38 MAPK/p38 MAPK decreased significantly(P<0.01).This study suggested that DHYZ decoction could inhibit the JNK/p38 MAPK signaling pathway,thereby increasing the anti-apoptotic factor Bcl-2 and reducing the expression of the pro-apoptotic factor Bax,consequently inhibiting apoptosis in the hippocampal CA1 region and retinal neurons of db/db mice.

Apolipoprotein E4 interferes with lipid metabolism to exacerbate depression-like behaviors in 5xFAD mice

Background:Apolipoprotein E4(ApoE4)allele is the strongest genetic risk factor for late-onset Alzheimer's disease,and it can aggravate depressive symptoms in non-AD patients.However,the impact of ApoE4 on AD-associated depression-l ike behaviors and its underlying pathogenic mechanisms remain unclear.Methods:This study developed a 5xFAD mouse model overexpressing human ApoE4(E4FAD).Behavioral assessments and synaptic function tests were conducted to explore the effects of ApoE4 on cognition and depression in 5xFAD mice.Changes in peripheral and central lipid metabolism,as well as the levels of serotonin(5-HT)andγ-aminobutyric acid(GABA)neurotransmitters in the prefrontal cortex,were examined.In addition,the protein levels of 24-dehydrocholesterol reductase/glycogen synthase kinase-3 beta/mammalian target of rapamycin(DHCR24/GSK3β/m TOR)and postsynaptic density protein 95/calmodulin-dependent protein kinase II/brain-derived neurotrophic factor(PSD95/CaMK-II/BDNF)were measured to investigate the molecular mechanism underlying the effects of ApoE4 on AD mice.Results:Compared with 5xFAD mice,E4FAD mice exhibited more severe depressionlike behaviors and cognitive impairments.These mice also exhibited increased amyloid-beta deposition in the hippocampus,increased astrocyte numbers,and decreased expression of depression-related neurotransmitters 5-HT and GABA in the prefrontal cortex.Furthermore,lipid metabolism disorders were observed in E4FAD,manifesting as elevated low-density lipoprotein cholesterol and reduced high-density lipoprotein cholesterol in peripheral blood,decreased cholesterol level in the prefrontal cortex,and reduced expression of key enzymes and proteins related to cholesterol synthesis and homeostasis.Abnormal expression of proteins related to the DHCR24/GSK3β/m TOR and PSD95/CaMK-II/BDNF pathways was also observed.Conclusion:This study found that ApoE4 overexpression exacerbates depressionlike behaviors in 5xFAD mice and confirmed that ApoE4 reduces cognitive function in these mice.The mechanism may involve the induction of central and peripheral lipid metabolism disorders.Therefore,modulating ApoE expression or function to restore cellular lipid homeostasis may be a promising therapeutic target for AD comorbid with depression.This study also provided a better animal model for studying AD comorbid with depression.

Insights into sensitizing and eliciting capacity of gastric and gastrointestinal digestion products of shrimp(Penaeus vannamei)proteins in BALB/c mice

Shrimp(Penaeus vannamei)proteins have been shown an allergenic potential;however,little information is available on the sensitizing and eliciting capacity of shrimp protein digestion products.In this study,a BALB/c mice model was used to explore the allergenicity of shrimp protein sample(SPS)and their gastric and gastrointestinal digestion products(GDS/GIDS).As compared with the SPS groups,the GDS/GIDS groups caused lower specific immunoglobulins(Ig E/Ig G1)levels(P<0.05),but higher than the control groups,indicating that the digestion products sensitized the mice.Meanwhile,spleen index,mouse mast cell protease-1(m MCP-1)concentration and proportion of degranulated mast cells were significantly reduced in the GDS/GIDS groups(P<0.05);simultaneously,allergic symptoms,vascular permeability and histopathological changes of tissues were alleviated.Nevertheless,the allergenicity of digestion products cannot be eliminated and still cause systemic allergic reactions in mice.The study showed that the digestion products of shrimp still had high sensitizing and eliciting capacity.

Progress,implications,and challenges in using humanized immune system mice in CAR-T therapy-Application evaluation and improvement

In recent years,humanized immune system(HIS)mice have been gradually used as models for preclinical research in pharmacotherapies and cell therapies with major breakthroughs in tumor and other fields,better mimicking the human immune system and the tumor immune microenvironment,compared to traditional immunodeficient mice.To better promote the application of HIS mice in preclinical research,we se-lectively summarize the current prevalent and breakthrough research and evaluation of chimeric antigen receptor(CAR)-T cells in various antiviral and antitumor treat-ments.By exploring its application in preclinical research,we find that it can better reflect the actual clinical patient condition,with the advantages of providing high-efficiency detection indicators,even for progressive research and development.We believe that it has better clinical patient simulation and promotion for the updated design of CAR-T cell therapy than directly transplanted immunodeficient mice.The characteristics of the main models are proposed to improve the use defects of the existing models by reducing the limitation of antihost reaction,combining multiple models,and unifying sources and organoid substitution.Strategy study of relapse and toxicity after CAR-T treatment also provides more possibilities for application and development.

Prevelance of Bovine Cysticercosis in Egypt and the Cysticidal Effect of Two Extracts Obtained from Balanites aegyptiaca and Moringa oleifera on Mice Model Affected with T. saginata Cysticerci

The aim of the present study was to determine the prevalence of bovine cysticercosis in both cattle and buffloas, in Egypt and to assess the cysticidal efficacy of Balanites aegyptiaca fruits (B. aegyptiaca) and Moringa oleifera seeds (M. oleifera) extracts in experimentally infected mice. The study detected the level of tumor necrosis factor (TNF-α) to monitor the immune and inflammatory responses of experimentally infected mice. Through meat inspection, a total number of 2125 male bovine, 2 to 5 years old, (1125 cattle and 1000 buffloes) were examined under the authority of Albsatine and Alwaraq official abattoirs in Cairo Governorate, Egypt covering the period extended from March 2022 to April 2023. The overall prevalence of the disease among bovine was 7.8% (6.31% of cattle and 9.5% of buffloes). Besides, B. aegyptiaca and M. oleifera extracts showed cysticidal activity in experimentally infected mice. A decrease in the numbers of cysticerci was found in all treated mice groups, and up to 88% reduction was achieved in the B. aegyptiaca-treated group;higher than that was recorded in both M. oleifera (72.23%) and albendazole-treated ones (80.56%). Postmortem findings proved that M. oleifera and B. aegyptiaca reduced cysticerci numbers comparable to a commercial anthelmintic. The study showed a significant decrease (P 0.001) in TNF-α levels after treatment with Balanites and Moringa extracts, compared with the untreated control and the albendazole-treated groups.

Morphological and functional observations of a novel model of retinal ischemia injury induced by bilateral carotid artery stenosis in mice

AIM:To investigate the features of retinal ischemic injuries in a novel mouse model with bilateral carotid artery stenosis(BCAS).METHODS:BCAS was induced with microcoil implantation in 6-8-week-old C57BL6 mice.Cerebral blood flow was monitored at 2,7,and 28d postoperatively.Retinal morphological changes were evaluated by fundus photography and hematoxylin-eosin staining.Fluorescein fundus angiography(FFA)was performed to detect retinal vascular changes and circulation.The levels of apoptosis,activation of neurogliosis,and expression of hypoxiainducible factor(HIF)-1αin the retina were assessed by Western blotting and immunofluorescence staining,followed by retinal ganglion cell(RGC)density detection.Additionally,electrophysiological examinations including photopic negative response(PhNR)was also performed.RESULTS:The mice demonstrated an initial rapid decrease in cerebral blood flow,followed by a 4-week recovery period after BCAS.The ratio of retinal artery and vein was decreased under fundus photography and FFA.Compared with the sham mice,BCAS mice showed thinner retinal thickness on day 28.Additionally,apoptosis was increased and RGC density was decreased mainly in peripheral retinal region.Neurogliosis was mainly located in the inner retinal layers,with a stable increase in HIF-1αexpression.The dark-adapted electroretinogram showed a notable reduction in the a-,b-,and oscillatory potential(OP)wave amplitudes between days 2 and 7;this gradually recovered over the following 4wk.However,the b-and OPwave amplitudes were still significantly decreased on PhNR examination on day 28.CONCLUSION:BCAS can result in relatively mild retinal ischemia injuries in mice,mainly in the inner layer and peripheral region.Our study provides a novel animal model for investigating retinal ischemic diseases.

Impacts of angiotensin II on retinal artery changes in apolipoprotein E deficient mice

AIM:To investigate the impacts of angiotensin II(Ang II)on retinal artery changes in apolipoprotein E deficient(apoE^(-/-))mice.METHODS:ApoE^(-/-)male mice were infused by minipumps with Ang II at 1000 ng/kg·min(Ang II group)or saline(control group)for 28d.They were underwent ophthalmic fundus examination on day 0,14,and 28 of infusion.Histopathologic examination,ribonucleic acid(RNA)sequencing and local Ang II measurement of retinas were conducted.RESULTS:Ophthalmic fundus examination showed Ang II infusion promoted the formation of retinal arterial aneurysm-like lesions on day 28.Optical coherence tomography revealed the ganglion cell and inner plexiform layer(GCIPL)thickness in the control group was significantly thinner than that in Ang II group(P<0.001).Hematoxylin-eosin staining demonstrated diffused swelling of GCIPL layer and its disordered structure in Ang II group.Transmission electron microscopy showed Ang II infusion caused aggravation of atherosclerotic lesions,including increased swelling,roughness,disorganization of the retinal vasculature,and vacuoles formation.RNA-sequencing and gene ontology enrichment analysis demonstrated that the structure and function of cellular membrane might be disturbed and visual function might be compromised by Ang II.The local level of Ang II was higher in Ang II infusion group but did not show significant differences compared to the control group(P=0.086).CONCLUSION:Ang II infusion promotes the formation of retinal arterial aneurysm-like lesions in apoE^(-/-)mice,causing aggravation of atherosclerotic lesions,more severe disorganization of the retinal vasculature and disturbance of the cellular membrane.

Against all odds:The road to success in the development of human immune reconstitution mice

The mouse genome has a high degree of homology with the human genome,and its physiological,biochemical,and developmental regulation mechanisms are similar to those of humans;therefore,mice are widely used as experimental animals.However,it is undeniable that interspecies differences between humans and mice can lead to experimental errors.The differences in the immune system have become an impor-tant factor limiting current immunological research.The application of immunodefi-cient mice provides a possible solution to these problems.By transplanting human immune cells or tissues,such as peripheral blood mononuclear cells or hematopoietic stem cells,into immunodeficient mice,a human immune system can be reconstituted in the mouse body,and the engrafted immune cells can elicit human-specific immune responses.Researchers have been actively exploring the development and differen-tiation conditions of host recipient animals and grafts in order to achieve better im-mune reconstitution.Through genetic engineering methods,immunodeficient mice can be further modified to provide a favorable developmental and differentiation microenvironment for the grafts.From initially only being able to reconstruct single T lymphocyte lineages,it is now possible to reconstruct lymphoid and myeloid cells,providing important research tools for immunology-related studies.In this review,we compare the differences in immune systems of humans and mice,describe the devel-opment history of human immune reconstitution from the perspectives of immuno-deficient mice and grafts,and discuss the latest advances in enhancing the efficiency of human immune cell reconstitution,aiming to provide important references for im-munological related researches.

Effects of P301L-TAU on post-translational modifications of microtubules in human iPSC-derived cortical neurons and TAU transgenic mice

TAU is a microtubule-associated protein that promotes microtubule assembly and stability in the axon.TAU is missorted and aggregated in an array of diseases known as tauopathies.Microtubules are essential for neuronal function and regulated via a complex set of post-translational modifications,changes of which affect microtubule stability and dynamics,microtubule interaction with other proteins and cellular structures,and mediate recruitment of microtubule-severing enzymes.As impairment of microtubule dynamics causes neuronal dysfunction,we hypothesize cognitive impairment in human disease to be impacted by impairment of microtubule dynamics.We therefore aimed to study the effects of a disease-causing mutation of TAU(P301L)on the levels and localization of microtubule post-translational modifications indicative of microtubule stability and dynamics,to assess whether P301L-TAU causes stability-changing modifications to microtubules.To investigate TAU localization,phosphorylation,and effects on tubulin post-translational modifications,we expressed wild-type or P301L-TAU in human MAPT-KO induced pluripotent stem cell-derived neurons(i Neurons)and studied TAU in neurons in the hippocampus of mice transgenic for human P301L-TAU(p R5 mice).Human neurons expressing the longest TAU isoform(2N4R)with the P301L mutation showed increased TAU phosphorylation at the AT8,but not the p-Ser-262 epitope,and increased polyglutamylation and acetylation of microtubules compared with endogenous TAU-expressing neurons.P301L-TAU showed pronounced somatodendritic presence,but also successful axonal enrichment and a similar axodendritic distribution comparable to exogenously expressed 2N4R-wildtype-TAU.P301L-TAU-expressing hippocampal neurons in transgenic mice showed prominent missorting and tauopathy-typical AT8-phosphorylation of TAU and increased polyglutamylation,but reduced acetylation,of microtubules compared with non-transgenic littermates.In sum,P301L-TAU results in changes in microtubule PTMs,suggestive of impairment of microtubule stability.This is accompanied by missorting and aggregation of TAU in mice but not in i Neurons.Microtubule PTMs/impairment may be of key importance in tauopathies.

Hepatocyte growth factor enhances the ability of dental pulp stem cells to ameliorate atherosclerosis in apolipoprotein E-knockout mice

BACKGROUND Atherosclerosis(AS),a chronic inflammatory disease of blood vessels,is a major contributor to cardiovascular disease.Dental pulp stem cells(DPSCs)are capable of exerting immunomodulatory and anti-inflammatory effects by secreting cytokines and exosomes and are widely used to treat autoimmune and inflam-mation-related diseases.Hepatocyte growth factor(HGF)is a pleiotropic cytokine that plays a key role in many inflammatory and autoimmune diseases.AIM To modify DPSCs with HGF(DPSC-HGF)and evaluate the therapeutic effect of DPSC-HGF on AS using an apolipoprotein E-knockout(ApoE-/-)mouse model and an in vitro cellular model.METHODS ApoE-/-mice were fed with a high-fat diet(HFD)for 12 wk and injected with DPSC-HGF or Ad-Null modified DPSCs(DPSC-Null)through tail vein at weeks 4,7,and 11,respectively,and the therapeutic efficacy and mechanisms were analyzed by histopathology,flow cytometry,lipid and glucose measurements,real-time reverse transcription polymerase chain reaction(RT-PCR),and enzyme-linked immunosorbent assay at the different time points of the experiment.An in vitro inflammatory cell model was established by using RAW264.7 cells and human aortic endothelial cells(HAOECs),and indirect co-cultured with supernatant of DPSC-Null(DPSC-Null-CM)or DPSC-HGF-CM,and the effect and mechanisms were analyzed by flow cytometry,RT-PCR and western blot.Nuclear factor-κB(NF-κB)activators and inhibitors were also used to validate the related signaling pathways.RESULTS DPSC-Null and DPSC-HGF treatments decreased the area of atherosclerotic plaques and reduced the expression of inflammatory factors,and the percentage of macrophages in the aorta,and DPSC-HGF treatment had more pronounced effects.DPSCs treatment had no effect on serum lipoprotein levels.The FACS results showed that DPSCs treatment reduced the percentages of monocytes,neutrophils,and M1 macrophages in the peripheral blood and spleen.DPSC-Null-CM and DPSC-HGF-CM reduced adhesion molecule expression in tumor necrosis factor-αstimulated HAOECs and regulated M1 polarization and inflammatory factor expression in lipopolysaccharide-induced RAW264.7 cells by inhibiting the NF-κB signaling pathway.CONCLUSION This study suggested that DPSC-HGF could more effectively ameliorate AS in ApoE-/-mice on a HFD,and could be of greater value in stem cell-based treatments for AS.

Investigating Müller glia reprogramming in mice: a retrospective of the last decade, and a look to the future

Müller glia,as prominent glial cells within the retina,plays a significant role in maintaining retinal homeostasis in both healthy and diseased states.In lower vertebrates like zebrafish,these cells assume responsibility for spontaneous retinal regeneration,wherein endogenous Müller glia undergo proliferation,transform into Müller glia-derived progenitor cells,and subsequently regenerate the entire retina with restored functionality.Conversely,Müller glia in the mouse and human retina exhibit limited neural reprogramming.Müller glia reprogramming is thus a promising strategy for treating neurodegenerative ocular disorders.Müller glia reprogramming in mice has been accomplished with remarkable success,through various technologies.Advancements in molecular,genetic,epigenetic,morphological,and physiological evaluations have made it easier to document and investigate the Müller glia programming process in mice.Nevertheless,there remain issues that hinder improving reprogramming efficiency and maturity.Thus,understanding the reprogramming mechanism is crucial toward exploring factors that will improve Müller glia reprogramming efficiency,and for developing novel Müller glia reprogramming strategies.This review describes recent progress in relatively successful Müller glia reprogramming strategies.It also provides a basis for developing new Müller glia reprogramming strategies in mice,including epigenetic remodeling,metabolic modulation,immune regulation,chemical small-molecules regulation,extracellular matrix remodeling,and cell-cell fusion,to achieve Müller glia reprogramming in mice.

AAV mediated carboxyl terminus of Hsp70 interacting protein overexpression mitigates the cognitive and pathological phenotypes of APP/PS1 mice

The E3 ubiquitin ligase,carboxyl terminus of heat shock protein 70(Hsp70)interacting protein(CHIP),also functions as a co-chaperone and plays a crucial role in the protein quality control system.In this study,we aimed to investigate the neuroprotective effect of overexpressed CHIP on Alzheimer’s disease.We used an adeno-associated virus vector that can cross the blood-brain barrier to mediate CHIP overexpression in APP/PS1 mouse brain.CHIP overexpression significantly ameliorated the performance of APP/PS1 mice in the Morris water maze and nest building tests,reduced amyloid-βplaques,and decreased the expression of both amyloid-βand phosphorylated tau.CHIP also alleviated the concentration of microglia and astrocytes around plaques.In APP/PS1 mice of a younger age,CHIP overexpression promoted an increase in ADAM10 expression and inhibitedβ-site APP cleaving enzyme 1,insulin degrading enzyme,and neprilysin expression.Levels of HSP70 and HSP40,which have functional relevance to CHIP,were also increased.Single nuclei transcriptome sequencing in the hippocampus of CHIP overexpressed mice showed that the lysosomal pathway and oligodendrocyte-related biological processes were up-regulated,which may also reflect a potential mechanism for the neuroprotective effect of CHIP.Our research shows that CHIP effectively reduces the behavior and pathological manifestations of APP/PS1 mice.Indeed,overexpression of CHIP could be a beneficial approach for the treatment of Alzheimer’s disease.