Experimental mice play a critical role in biomedical research.The phenotype and application of different substrains vary due to genetic differentiation and variation.To ensure validity and reliability of results,it is...Experimental mice play a critical role in biomedical research.The phenotype and application of different substrains vary due to genetic differentiation and variation.To ensure validity and reliability of results,it is imperative to adhere to standardized experiments and controls.This paper objectively reviews the origin,differentiation,and phenotypic and genetic differences between the C57BL/6 and BALB/c mouse substrains.Furthermore,an optimal selection strategy is proposed based on the genetic quality control technology to facilitate the precise application of these two mouse substrains.展开更多
Objective This study aimed to comprehensively investigate the potential protective effects and underlying mechanisms of taurine against dihydrotestosterone(DHT)-induced androgenetic alopecia(AGA)in male C57BL/6 mice,w...Objective This study aimed to comprehensively investigate the potential protective effects and underlying mechanisms of taurine against dihydrotestosterone(DHT)-induced androgenetic alopecia(AGA)in male C57BL/6 mice,with a focus on hair follicle cycle modulation,cellular proliferation/apoptosis,and key related signaling pathways.Methods Six-week-old female C57BL/6 mice were initially used to assess the hair growth-promoting potential of taurine.After acclimatization,they were randomly assigned to three groups(n=8):control(regular drinking water),taurine(drinking water containing 1%taurine),and minoxidil(topical 2%minoxidil,positive control).For the AGA study,male C57BL/6 mice were randomly divided into five groups(n=8):control(physiological saline),DHT(model group,1 mg/d DHT),DHT+low-dose taurine(1 mg/d DHT+2 mg/d taurine),DHT+high-dose taurine(1 mg/d DHT+10 mg/d taurine),and DHT+minoxidil(positive control,1 mg/d DHT+topical 2%minoxidil).One day before treatment initiation,dorsal hair was shaved with scissors,and residual hair was removed using a depilatory cream.DHT and taurine were administered via daily intraperitoneal injection.Hair regrowth was assessed by photographing the depilated area at regular intervals and quantified using a four-point grading system(0-3).Dorsal skin samples were collected on day 14 for histological analysis(H&E staining),immunofluorescence staining(Ki67 for proliferation,TUNEL for apoptosis),ELISA(DHT quantification),RT-qPCR,and Western blot analysis to evaluate the expression of key genes and proteins(androgen receptor(AR),transforming growth factor(TGF)‑β1,TGF‑β2,Dickkopf-1(DKK1)).Results In female mice,taurine supplementation significantly accelerated hair growth,with effects comparable to minoxidil.This was evidenced by an earlier transition from pink(telogen)to black(anagen)skin and increased hair growth scores.Histological analysis showed that taurine increased hair follicle count and dermal thickness.Immunofluorescence confirmed enhanced keratinocyte proliferation in the hair matrix.In the DHTinduced AGA model,DHT significantly extended the telogen phase,inhibited hair growth,increased skin DHT content,and induced hair follicle miniaturization.Taurine treatment,particularly at the high dose,effectively counteracted these effects:it promoted the telogen-to-anagen transition and improved hair growth scores.Histomorphometric analysis showed that taurine significantly restored DHT-induced reductions in dermal thickness,hair follicle count,hair bulb depth,and follicle size.Taurine treatment also reduced apoptosis and promoted the proliferation of hair follicle cells,as demonstrated by Ki67 and TUNEL assays.Crucially,RT-qPCR and Western blot analyses revealed that DHT significantly up-regulated the expression of AR,TGF‑β1,TGF‑β2,and DKK1 at both mRNA and protein levels in dorsal skin.Taurine administration markedly down-regulated the expression of these pathogenic factors,bringing them closer to the levels observed in the control group.Conclusion Taurine demonstrates significant efficacy in alleviating DHT-induced AGA in male C57BL/6 mice.Its protective effects are mediated through multi-faceted mechanisms.(1)Promoting hair follicle cycle progression:it accelerates the transition from telogen to anagen,counteracting DHT-induced prolongation of the telogen phase.(2)Modulating cellular dynamics:it stimulates the proliferation of hair matrix keratinocytes and reduces DHT-induced apoptosis within hair follicle cells.(3)Suppressing androgen-driven pathogenic pathways:it downregulates the expression of critical molecules in the AGA pathway,including AR,the cytokines TGF-β1 and TGF-β2,and the Wnt pathway inhibitor DKK1.Given its favorable safety profile and multi-targeted action,taurine emerges as a promising novel therapeutic candidate or adjunct for treating AGA.Further investigation into its clinical potential and precise molecular mechanisms is warranted.This study provides a robust preclinical foundation for considering taurine supplementation or topical application in hair loss management strategies.展开更多
Dengue is a significant public health concern across tropical and subtropical regions worldwide,principally causing disease in children.Very young children are at increased risk of severe manifestations of dengue infe...Dengue is a significant public health concern across tropical and subtropical regions worldwide,principally causing disease in children.Very young children are at increased risk of severe manifestations of dengue infection.The mechanism of dengue disease in this population is not fully understood.In this study,we present a murine model of dengue virus primary infection in suckling C57BL/6 and BALB/c mice in order to investigate disease pathogenesis.Three-day-old C57BL/6 mice intraperitoneally infected with DENV-2 NGC were more susceptible to infection than BALB/c mice,showing increased liver enzymes,extended viremia,dissemination to organs and histological alterations in liver and small intestine.Furthermore,the immune response in DENV-infected C57BL/6 mice exhibited a marked Th1 bias compared to BALB/c mice.These findings highlight the possibility of establishing an immunocompetent mouse model of DENV-2 infection in suckling mice that reproduces certain signs of disease observed in humans and that could be used to further study agerelated mechanisms of dengue pathogenesis.展开更多
Objective To study characteristics of hearing loss after exposure to moderate noise exposure in C57BL/6J mice. Methods Male C57BL/6J mice with normal hearing at age of 5-6 weeks were chosen for this study. The mice we...Objective To study characteristics of hearing loss after exposure to moderate noise exposure in C57BL/6J mice. Methods Male C57BL/6J mice with normal hearing at age of 5-6 weeks were chosen for this study. The mice were randomly sclccted to be studied immediately after exposure （Group P0）, or 1 day （Group P1）, 3 days （Group P3）, 7 day （Group P7） or 14 days （P14） after exposure. Their before exposure condition served as the normal control. All mice were exposed to a broad-band white noise at 100 dB SPL for 2 hours, ABR thresholds were used to estimate hearing status at each time point. Results ABR threshold elevation was seen at every tested frequency at P0 （P〈0.01）. Elevation at high-frequencies （16 kHz and 32 kHz） was greater than at lower frequencies （4 kHz and 8 kHz, P〈0.05）. From P1 to P14, ABR thresholds continuously improved, and there was no significant difference between P14 and before exposure （P〉0.05）. Conclusion There is a frequency specific re- sponse to 100 dB SPL broad-band white noise in C57BL/6J mice, with the high-frequency being more susceptible. Hearing loss induced by moderate noise exposure appears reversible in C57BL/6J mice.展开更多
Background: D-Limonene, a monoterpene from citrus fruit has been found to have chemopreventive and chemotherapeutic activities in various types of cancers. In this study, we evaluated the in vivo effect of D-Limonene ...Background: D-Limonene, a monoterpene from citrus fruit has been found to have chemopreventive and chemotherapeutic activities in various types of cancers. In this study, we evaluated the in vivo effect of D-Limonene on a K562-induced model of chronic myeloid leukemia(CML) in C57 BL/6 mice.Method: The tail vein injection model of K562 cells in immunocompromised C57 BL/6 mice was developed and evaluated for characteristics of the disease. The mice were treated with D-Limonene and evaluated for haematological parameters. We also evaluated the effect of D-Limonene on angiogenesis using the chick chorioallantoic membrane(CAM) assay.Results: In a complete blood count, a significant dose-dependent reduction in white blood cell, neutrophil and lymphocyte counts, but an elevation in red blood cell count and haemoglobin content was observed with D-Limonene treatment compared to the disease control or untreated group. In the CAM assay, D-Limonene produced a significant dose-dependent reduction in number of blood vessels in treatment groups compared to the vehicle-treated group.Conclusion: These studies suggest promising anti-leukemic and anti-angiogenic effects of D-Limonene in the treatment of CML.展开更多
Action potentials(APs)in neurons are generated at the axon initial segment(AIS).AP dynamics,including initiation and propagation,are intimately associated with neuronal excitability and neurotransmitter release kineti...Action potentials(APs)in neurons are generated at the axon initial segment(AIS).AP dynamics,including initiation and propagation,are intimately associated with neuronal excitability and neurotransmitter release kinetics.Most learning and memory studies at the single-neuron level have relied on the use of animal models,most notably rodents.Here,we studied AP initiation and propagation in cultured hippocampal neurons from Sprague-Dawley(SD)rats and C57BL/6(C57)mice with genetically encoded voltage indicator(GEVI)-based voltage imaging.Our data showed that APs traveled bidirectionally in neurons from both species;forward-propagating APs(fpAPs)had a different speed than backpropagating APs(bpAPs).Additionally,we observed distinct AP propagation characteristics in AISs emerging from the somatic envelope compared to those originating from dendrites.Compared with rat neurons,mouse neurons exhibited higher bpAP speed and lower fpAP speed,more distally located ankyrin G(AnkG)in AISs,and longer Nav1.2 lengths in AISs.Moreover,during AIS plasticity,AnkG and Nav1.2 showed distal shifts in location and shorter lengths of labeled AISs in rat neurons;in mouse neurons,however,they showed a longer AnkG-labeled length and more distal Nav1.2 location.Our findings suggest that hippocampal neurons in SD rats and C57 mice may have different AP propagation speeds,different AnkG and Nav1.2 patterns in the AIS,and different AIS plasticity properties,indicating that comparisons between these species must be carefully considered.展开更多
OBJECTIVE： Traditional Korean Chungtaejeon （CTJ） tea is a type of fermented tea, which has received increasing attention in recent years because of its purported health benefits. The present study was designed to i...OBJECTIVE： Traditional Korean Chungtaejeon （CTJ） tea is a type of fermented tea, which has received increasing attention in recent years because of its purported health benefits. The present study was designed to investigate the effect and mechanism of CTJ tea extract on body weight gain using C57BL/6J-Lep ob/ob mice and 3T3-L1 adipocytes, respectively. METHODS： The effects of CTJ on cell viability, lipid accumulation, and expression of protein and mRNA were measured in 3T3-L1 adipocytes by using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, oil red O staining, Western blotting, and reverse transcriptase-polymerase chain reaction analyses. C57BL6J-Lep ob/ob mice were administered with CTJ （200 or 400 mg/kg body weight） for ten weeks. Then, body weight, food intake, total cholesterol, and triglyceride were measured in ob/ob mice. RESULTS： CTJ tea extract treated at 250 wg/mL （CTJ250） significantly suppressed lipid accumulation in the differentiated 3T3-L1 adipocytes. Likewise, CTJ250 significantly decreased the protein expression of peroxisome proliferator-activated receptor Y （PPARy）, CCJ^u~,T/enhancer-binding protein a, and adipocyte lipid- binding protein, and regulated the mRNA expression of PPART, sterol regulatory element-binding protein- lc gene, fatty acid synthase, adipocyte lipid-binding protein, hormone-sensitive lipase, carnitine palmitoyl transferase 1, cluster of differentiation 36, and acetyl-CoA carboxylase in the differentiated 3T3-L1 adipocytes. Mice administered with CTJ showed dose-dependent decrease in body weight gain, starting from week 4 of the experiment. CTJ tea extract administered at 400 mg/kg body weight significantly decreased fat mass, food efficacy ratio, and levels of plasma triglyceride and total cholesterol. CONCLUSION： CTJ attenuated weight gain in ob/ob mice and regulated the activity of the molecules involved in adipogenesis and lipolysis in 3T3-L1 adipocytes. CTJ is a potentially valuable herbal therapy for the prevention of obesity and/or obesity-related disorders.展开更多
Objective： To better understand the reason that Schistosoma japonicurn （S. japonicum） ultraviolet （UV）- radiated cercariae could not induce high level of protection in C57BL/6 mice. Methods： Microarray technolog...Objective： To better understand the reason that Schistosoma japonicurn （S. japonicum） ultraviolet （UV）- radiated cercariae could not induce high level of protection in C57BL/6 mice. Methods： Microarray technology was performed to investigate the gene transcription profile in skin draining lymph nodes （sdLNs） at 1 w after exposure to attenuated cercariae （AC） or normal cercariae （NC） of S. japonicum in C57BL/6 mice. The expressions of some representative genes were further confirmed by real-time PCR. Subsequently, the expressions of Th1/Th2 cytokine genes, cytotoxicity-related genes, as well as co-stimulator genes in spleens from AC-vaccinated and NC- infected mice were analyzed by real-time PCR at w 3 and 6 post-exposure. Results： The gene expressions of Th1 cytokines, including interferon-y （IFN-γ）, interleukin （IL）-12 and tumor necrosis factor-α （TNF-α） in the sdLNs were significantly lower in AC-vaccinated mice than in NC-infected mice. Furthermore, the gene expressions of Th1- and Th2- cytokines, including IFN-γ, IL-12, TNF-α, IL-4 and IL-10, in the spleens from AC-vaccinated mice showed little changes at w 3 and 6 post-vaccination. In addition, cytotoxicity-related molecules including granzyme A, granzyme B, granzyme K, perforin 1 and Fas L were up-regulated from the early stage of vaccination, and peaked at the 3rd w after vaccination with UV-AC. Conclusion： UV-AC of S. japonicum could not ef- fectively induce a Thl response in C57BL/6 mice, which may be an explanation for the low protection against parasite challenge, and the role played by up-regulated expression of cytotoxicity-related genes in mice needs to be further investigated.展开更多
Since stem cell therapy is the most effective treatment in the field of tissue reparation and reconstitution,the present study aimed to explore the different sources of mesenchymal stem cells(MSCs)on the different eff...Since stem cell therapy is the most effective treatment in the field of tissue reparation and reconstitution,the present study aimed to explore the different sources of mesenchymal stem cells(MSCs)on the different effects of pulmonary fibrosis-related cytokines in C57BL/6 mice.For reaching this goal,we isolated MSCs from umbilical cord blood and placenta and used for stem cell therapy in a mouse model of pulmonary fibrosis model.The pulmonary fibrosis model was done by injecting bleomycin into the trachea of C57BL/6 mice.Then we assessed the degree of pulmonary fibrosis in each mouse lung tissue at weeks 1,2,3,and 4.In addition,flow cytometry was used to evaluate the frequency of CD73,CD90,CD106,CD34,CD45,CD14 cells at the mononuclear cell level;and western blotting assays revealed the expression of IκB-α.Our results showed that stem cell therapy by placenta-derived MSC had a lower level of CD34,CD45,CD14 cells at the mononuclear cell level,and that improved pulmonary fibrosis at both molecular and pathological levels.In addition,western blotting assays revealed that the expression of IκB-αwas down-regulated in MSC-treated animals.In addition,placenta-derived MSC was the most effective in improving pulmonary fibrosis in comparison to other sources.This study suggests that MSC might be a novel therapeutic approach in pulmonary fibrosis due to an enhanced anti-inflammatory effect.Also,MSC modification by gene editing could enhance their therapeutic effect in mouse pulmonary fibrosis.展开更多
The purpose of this study was to evaluate the influence of squalene (SQ) on plasma and hepatic lipid levels of obese/diabetic KK-Ay mice and wild-type C57BL/6J mice. SQ supplementation significantly increased the HDL ...The purpose of this study was to evaluate the influence of squalene (SQ) on plasma and hepatic lipid levels of obese/diabetic KK-Ay mice and wild-type C57BL/6J mice. SQ supplementation significantly increased the HDL cholesterol of KK-Ay mice, which was paralleled with no significant difference in the total and non-HDL cholesterol levels. The increase in HDL cholesterol was also found in the plasma of normal C57BL/6J mice, but the difference was not significant. SQ administration significantly increased neutral lipids (NL) in the liver of KK-Ay mice, while no significant difference was observed in the polar lipids and the total cholesterol levels. The increase in NL was primarily due to the increase in TAG. However, the cholesterol level significantly increased due to SQ intake in the liver of C57BL/6J mice, while no significant difference was found in other lipid levels. The present study suggests that SQ may effectively increase HDL cholesterol level, an important anti-atherosclerotic factor, especially in subjects with metabolic disorders.展开更多
Active vitamin D (1,25D) is a fat-soluble vitamin that is mainly produced in the skin by the conversion of 7-dehydrocholesterol under ultraviolet light stimulation.Its role in calcium homeostasis,bone growth, and prev...Active vitamin D (1,25D) is a fat-soluble vitamin that is mainly produced in the skin by the conversion of 7-dehydrocholesterol under ultraviolet light stimulation.Its role in calcium homeostasis,bone growth, and prevention of rickets and osteomalacia has been known for over two hundred years.Its展开更多
Eclipta prostrata has been extensively studied for its promoting effect on human health. Previous study proved that E. prostrata possessed anti-osteoporosis function in SAMP6 mice via gut microbiota (GM). Endophytes a...Eclipta prostrata has been extensively studied for its promoting effect on human health. Previous study proved that E. prostrata possessed anti-osteoporosis function in SAMP6 mice via gut microbiota (GM). Endophytes are widespread in plants, especially in Chinese herbal medicines. However, little is known regarding the endophytes of E. prostrata. In this study, we focus on screening and identifying the endophytes from plant E. prostrata and exploring their roles in modulating GM. According to biochemical, physiological tests and 16S rDNA sequence analysis, ten endophytes were characterized in different locations of plant E. prostrata belonging to Lactococcus, Bacillus, Enterococcus, Exiguobacterium and Pantoea. The antimicrobial activity of endophytes EP01-10 was investigated via the oxford cup method. Furthermore, the acid and bile salt resistant ability of EP01-10 was detected to explore their survival ability in gastrointestinal tract. Results indicated that strains of Lactococcus, Bacillus and Exiguobacterium (EP01, 03 and 05) showed strong antimicrobial activity against Escherichia coli and Staphylococcus aureus and strains of Lactococcus, Bacillus and Enterococcus (EP01, 02, 04, 08 and 10) have the ability to survive in the gastrointestinal tract. 16S rRNA sequencing of GM in C57BL/6J mice was performed for diversity and structure analysis responded to the administration of E. prostrata extract. E. prostrata extract acted on improving the microflora diversity, particularly in increasing the abundance of Lactococcus significantly. Thus, as an endophyte, Lactococcus plays an important role in E. prostrata modulating intestinal tract. Our study suggested that endophytes of Chinese herbal medicines might be a novel target for the treatment of diseases by regulating the GM.展开更多
K^(+)cycling in the cochlea is critical to maintain hearing.Many sodium-potassium pumps are proved to participate in K^(+)cycling,such as Na/K-ATPase.Theα2-Na/K-ATPase is an important isoform of Na/K-ATPase.The expre...K^(+)cycling in the cochlea is critical to maintain hearing.Many sodium-potassium pumps are proved to participate in K^(+)cycling,such as Na/K-ATPase.Theα2-Na/K-ATPase is an important isoform of Na/K-ATPase.The expression ofα2-Na/K-ATPase in the cochlea is not clear.In this study,we used C57BL/6 mice as a model of presbycusis and implemented immunohistochemistry staining and quantitative real time-PCR,and theα2-Na/K-ATPase expression pattern was confirmed in the inner ear.It was foundα2-Na/K-ATPase was expressed widely in cochlea and its mRNA and protein expression was gradually reduced with aging(4-,14-,26-and 48-weeks old mice).We suspected that,the down-regulation ofα2-Na/K-ATPase expression might be associated with the remodeling of K^(+)cycling,degeneration of morphological structure and decrease of hearing function in aging C57 mice.In conclusion,we speculated that the reduction ofα2-Na/K-ATPase might play an important role in the pathogenesis of age-related hearing loss.展开更多
Four embryonic stem (ES) cell lines, designated CE1, CE2, CE3 and CE4, were isolated from C57BL/6J blastocysts. The ratio of normal diploid composition of these cell lines is above 70%. To examine the differentiation...Four embryonic stem (ES) cell lines, designated CE1, CE2, CE3 and CE4, were isolated from C57BL/6J blastocysts. The ratio of normal diploid composition of these cell lines is above 70%. To examine the differentiation potential of the ES cells, the CE2 cells were injected subcutaneously into syngenic mice, and many kinds of differentiated cells were observed on the sections of the teratoma derived from this ES cell line. On the other hand, to test the chimeric ability of the ES cells, the CE2 cells were microinjected into the blastocysts of ICR mice, and a chimera was obtained among living pups. These results show that CE2 ES cells are pluripotent stem cells, which can differentiate into many kinds of cell types, and can be used as a cell system for further research.展开更多
Rodents chronically injected with D-galactose (D-gal have been used as an animal model for brain aging or antiaging pharmacology research. However, the dose of D-gal used to induce behavioral impairment has been repor...Rodents chronically injected with D-galactose (D-gal have been used as an animal model for brain aging or antiaging pharmacology research. However, the dose of D-gal used to induce behavioral impairment has been reported in a wide range. Besides, very few studies used the C57BL inbred mouse strain to construct this model, which is one of the展开更多
基金National Key R&D Program of China,Grant/Award Number:2021YFF0703200Key Technology Fund of the National Institutes for Food and Drug Control,Grant/Award Number:GJJS-2022-1-5。
文摘Experimental mice play a critical role in biomedical research.The phenotype and application of different substrains vary due to genetic differentiation and variation.To ensure validity and reliability of results,it is imperative to adhere to standardized experiments and controls.This paper objectively reviews the origin,differentiation,and phenotypic and genetic differences between the C57BL/6 and BALB/c mouse substrains.Furthermore,an optimal selection strategy is proposed based on the genetic quality control technology to facilitate the precise application of these two mouse substrains.
基金supported by grants from The National Natural Science Foundation of China(31772690)the Natural Science Foundation of Shanxi Province(201701D121106)PhD Research Startup Foundation of Changzhi Medical College(BS202308)。
文摘Objective This study aimed to comprehensively investigate the potential protective effects and underlying mechanisms of taurine against dihydrotestosterone(DHT)-induced androgenetic alopecia(AGA)in male C57BL/6 mice,with a focus on hair follicle cycle modulation,cellular proliferation/apoptosis,and key related signaling pathways.Methods Six-week-old female C57BL/6 mice were initially used to assess the hair growth-promoting potential of taurine.After acclimatization,they were randomly assigned to three groups(n=8):control(regular drinking water),taurine(drinking water containing 1%taurine),and minoxidil(topical 2%minoxidil,positive control).For the AGA study,male C57BL/6 mice were randomly divided into five groups(n=8):control(physiological saline),DHT(model group,1 mg/d DHT),DHT+low-dose taurine(1 mg/d DHT+2 mg/d taurine),DHT+high-dose taurine(1 mg/d DHT+10 mg/d taurine),and DHT+minoxidil(positive control,1 mg/d DHT+topical 2%minoxidil).One day before treatment initiation,dorsal hair was shaved with scissors,and residual hair was removed using a depilatory cream.DHT and taurine were administered via daily intraperitoneal injection.Hair regrowth was assessed by photographing the depilated area at regular intervals and quantified using a four-point grading system(0-3).Dorsal skin samples were collected on day 14 for histological analysis(H&E staining),immunofluorescence staining(Ki67 for proliferation,TUNEL for apoptosis),ELISA(DHT quantification),RT-qPCR,and Western blot analysis to evaluate the expression of key genes and proteins(androgen receptor(AR),transforming growth factor(TGF)‑β1,TGF‑β2,Dickkopf-1(DKK1)).Results In female mice,taurine supplementation significantly accelerated hair growth,with effects comparable to minoxidil.This was evidenced by an earlier transition from pink(telogen)to black(anagen)skin and increased hair growth scores.Histological analysis showed that taurine increased hair follicle count and dermal thickness.Immunofluorescence confirmed enhanced keratinocyte proliferation in the hair matrix.In the DHTinduced AGA model,DHT significantly extended the telogen phase,inhibited hair growth,increased skin DHT content,and induced hair follicle miniaturization.Taurine treatment,particularly at the high dose,effectively counteracted these effects:it promoted the telogen-to-anagen transition and improved hair growth scores.Histomorphometric analysis showed that taurine significantly restored DHT-induced reductions in dermal thickness,hair follicle count,hair bulb depth,and follicle size.Taurine treatment also reduced apoptosis and promoted the proliferation of hair follicle cells,as demonstrated by Ki67 and TUNEL assays.Crucially,RT-qPCR and Western blot analyses revealed that DHT significantly up-regulated the expression of AR,TGF‑β1,TGF‑β2,and DKK1 at both mRNA and protein levels in dorsal skin.Taurine administration markedly down-regulated the expression of these pathogenic factors,bringing them closer to the levels observed in the control group.Conclusion Taurine demonstrates significant efficacy in alleviating DHT-induced AGA in male C57BL/6 mice.Its protective effects are mediated through multi-faceted mechanisms.(1)Promoting hair follicle cycle progression:it accelerates the transition from telogen to anagen,counteracting DHT-induced prolongation of the telogen phase.(2)Modulating cellular dynamics:it stimulates the proliferation of hair matrix keratinocytes and reduces DHT-induced apoptosis within hair follicle cells.(3)Suppressing androgen-driven pathogenic pathways:it downregulates the expression of critical molecules in the AGA pathway,including AR,the cytokines TGF-β1 and TGF-β2,and the Wnt pathway inhibitor DKK1.Given its favorable safety profile and multi-targeted action,taurine emerges as a promising novel therapeutic candidate or adjunct for treating AGA.Further investigation into its clinical potential and precise molecular mechanisms is warranted.This study provides a robust preclinical foundation for considering taurine supplementation or topical application in hair loss management strategies.
基金Consejo Nacional de Investigaciones Científicas y Técnicas,Grant/Award Number:PIP0118UBS Optimus Foundation,Grant/Award Number:ID 2007-00206+1 种基金Fundación Bunge y BornFondo para la Investigación Científica y Tecnológica,Grant/Award Number:PICT2008-1073。
文摘Dengue is a significant public health concern across tropical and subtropical regions worldwide,principally causing disease in children.Very young children are at increased risk of severe manifestations of dengue infection.The mechanism of dengue disease in this population is not fully understood.In this study,we present a murine model of dengue virus primary infection in suckling C57BL/6 and BALB/c mice in order to investigate disease pathogenesis.Three-day-old C57BL/6 mice intraperitoneally infected with DENV-2 NGC were more susceptible to infection than BALB/c mice,showing increased liver enzymes,extended viremia,dissemination to organs and histological alterations in liver and small intestine.Furthermore,the immune response in DENV-infected C57BL/6 mice exhibited a marked Th1 bias compared to BALB/c mice.These findings highlight the possibility of establishing an immunocompetent mouse model of DENV-2 infection in suckling mice that reproduces certain signs of disease observed in humans and that could be used to further study agerelated mechanisms of dengue pathogenesis.
基金supported by grants from the Liaoning Science and Technology Project(No.2011225017,2012225021)the National Basic Research Program of China(973 Program)(2012CB967900,2012CB967901)+2 种基金supported by the grants from the Beijing Natural Science Foundation(5122040)the China Postdoctoral Science Foundation(201003779,20100470103)the National Natural Science Foundation of China(NSFC,31040038)
文摘Objective To study characteristics of hearing loss after exposure to moderate noise exposure in C57BL/6J mice. Methods Male C57BL/6J mice with normal hearing at age of 5-6 weeks were chosen for this study. The mice were randomly sclccted to be studied immediately after exposure （Group P0）, or 1 day （Group P1）, 3 days （Group P3）, 7 day （Group P7） or 14 days （P14） after exposure. Their before exposure condition served as the normal control. All mice were exposed to a broad-band white noise at 100 dB SPL for 2 hours, ABR thresholds were used to estimate hearing status at each time point. Results ABR threshold elevation was seen at every tested frequency at P0 （P〈0.01）. Elevation at high-frequencies （16 kHz and 32 kHz） was greater than at lower frequencies （4 kHz and 8 kHz, P〈0.05）. From P1 to P14, ABR thresholds continuously improved, and there was no significant difference between P14 and before exposure （P〉0.05）. Conclusion There is a frequency specific re- sponse to 100 dB SPL broad-band white noise in C57BL/6J mice, with the high-frequency being more susceptible. Hearing loss induced by moderate noise exposure appears reversible in C57BL/6J mice.
文摘Background: D-Limonene, a monoterpene from citrus fruit has been found to have chemopreventive and chemotherapeutic activities in various types of cancers. In this study, we evaluated the in vivo effect of D-Limonene on a K562-induced model of chronic myeloid leukemia(CML) in C57 BL/6 mice.Method: The tail vein injection model of K562 cells in immunocompromised C57 BL/6 mice was developed and evaluated for characteristics of the disease. The mice were treated with D-Limonene and evaluated for haematological parameters. We also evaluated the effect of D-Limonene on angiogenesis using the chick chorioallantoic membrane(CAM) assay.Results: In a complete blood count, a significant dose-dependent reduction in white blood cell, neutrophil and lymphocyte counts, but an elevation in red blood cell count and haemoglobin content was observed with D-Limonene treatment compared to the disease control or untreated group. In the CAM assay, D-Limonene produced a significant dose-dependent reduction in number of blood vessels in treatment groups compared to the vehicle-treated group.Conclusion: These studies suggest promising anti-leukemic and anti-angiogenic effects of D-Limonene in the treatment of CML.
基金supported by the National Science and Technology Innovation 2030-Major Program of “Brain Science and Brain-Like Research”(2022ZD0211800)National Natural Science Foundation of China General Research Grant (81971679, 21727806,31771147)+4 种基金Major Research Grant (91632305, 32088101)Ministry of Science and Technology (2018YFA0507600, 2017YFA0503600)Qidong-PKU SLS Innovation Fund (2016000663)Fundamental Research Funds for the Central Universities and National Key R&D Program of China (2020AAA0105200)sponsored by the Bayer Investigator Award。
文摘Action potentials(APs)in neurons are generated at the axon initial segment(AIS).AP dynamics,including initiation and propagation,are intimately associated with neuronal excitability and neurotransmitter release kinetics.Most learning and memory studies at the single-neuron level have relied on the use of animal models,most notably rodents.Here,we studied AP initiation and propagation in cultured hippocampal neurons from Sprague-Dawley(SD)rats and C57BL/6(C57)mice with genetically encoded voltage indicator(GEVI)-based voltage imaging.Our data showed that APs traveled bidirectionally in neurons from both species;forward-propagating APs(fpAPs)had a different speed than backpropagating APs(bpAPs).Additionally,we observed distinct AP propagation characteristics in AISs emerging from the somatic envelope compared to those originating from dendrites.Compared with rat neurons,mouse neurons exhibited higher bpAP speed and lower fpAP speed,more distally located ankyrin G(AnkG)in AISs,and longer Nav1.2 lengths in AISs.Moreover,during AIS plasticity,AnkG and Nav1.2 showed distal shifts in location and shorter lengths of labeled AISs in rat neurons;in mouse neurons,however,they showed a longer AnkG-labeled length and more distal Nav1.2 location.Our findings suggest that hippocampal neurons in SD rats and C57 mice may have different AP propagation speeds,different AnkG and Nav1.2 patterns in the AIS,and different AIS plasticity properties,indicating that comparisons between these species must be carefully considered.
基金supported by the Technology Development Program for Agriculture and Forestry, Ministry for Agriculture, Forestiy and Fisheries, Republic of Korea
文摘OBJECTIVE： Traditional Korean Chungtaejeon （CTJ） tea is a type of fermented tea, which has received increasing attention in recent years because of its purported health benefits. The present study was designed to investigate the effect and mechanism of CTJ tea extract on body weight gain using C57BL/6J-Lep ob/ob mice and 3T3-L1 adipocytes, respectively. METHODS： The effects of CTJ on cell viability, lipid accumulation, and expression of protein and mRNA were measured in 3T3-L1 adipocytes by using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, oil red O staining, Western blotting, and reverse transcriptase-polymerase chain reaction analyses. C57BL6J-Lep ob/ob mice were administered with CTJ （200 or 400 mg/kg body weight） for ten weeks. Then, body weight, food intake, total cholesterol, and triglyceride were measured in ob/ob mice. RESULTS： CTJ tea extract treated at 250 wg/mL （CTJ250） significantly suppressed lipid accumulation in the differentiated 3T3-L1 adipocytes. Likewise, CTJ250 significantly decreased the protein expression of peroxisome proliferator-activated receptor Y （PPARy）, CCJ^u~,T/enhancer-binding protein a, and adipocyte lipid- binding protein, and regulated the mRNA expression of PPART, sterol regulatory element-binding protein- lc gene, fatty acid synthase, adipocyte lipid-binding protein, hormone-sensitive lipase, carnitine palmitoyl transferase 1, cluster of differentiation 36, and acetyl-CoA carboxylase in the differentiated 3T3-L1 adipocytes. Mice administered with CTJ showed dose-dependent decrease in body weight gain, starting from week 4 of the experiment. CTJ tea extract administered at 400 mg/kg body weight significantly decreased fat mass, food efficacy ratio, and levels of plasma triglyceride and total cholesterol. CONCLUSION： CTJ attenuated weight gain in ob/ob mice and regulated the activity of the molecules involved in adipogenesis and lipolysis in 3T3-L1 adipocytes. CTJ is a potentially valuable herbal therapy for the prevention of obesity and/or obesity-related disorders.
基金supported by the National Basic Research Program of China(973 Program,No.2007CB513106)the National Science Foundation of China(NSFC,No.30430600)
文摘Objective： To better understand the reason that Schistosoma japonicurn （S. japonicum） ultraviolet （UV）- radiated cercariae could not induce high level of protection in C57BL/6 mice. Methods： Microarray technology was performed to investigate the gene transcription profile in skin draining lymph nodes （sdLNs） at 1 w after exposure to attenuated cercariae （AC） or normal cercariae （NC） of S. japonicum in C57BL/6 mice. The expressions of some representative genes were further confirmed by real-time PCR. Subsequently, the expressions of Th1/Th2 cytokine genes, cytotoxicity-related genes, as well as co-stimulator genes in spleens from AC-vaccinated and NC- infected mice were analyzed by real-time PCR at w 3 and 6 post-exposure. Results： The gene expressions of Th1 cytokines, including interferon-y （IFN-γ）, interleukin （IL）-12 and tumor necrosis factor-α （TNF-α） in the sdLNs were significantly lower in AC-vaccinated mice than in NC-infected mice. Furthermore, the gene expressions of Th1- and Th2- cytokines, including IFN-γ, IL-12, TNF-α, IL-4 and IL-10, in the spleens from AC-vaccinated mice showed little changes at w 3 and 6 post-vaccination. In addition, cytotoxicity-related molecules including granzyme A, granzyme B, granzyme K, perforin 1 and Fas L were up-regulated from the early stage of vaccination, and peaked at the 3rd w after vaccination with UV-AC. Conclusion： UV-AC of S. japonicum could not ef- fectively induce a Thl response in C57BL/6 mice, which may be an explanation for the low protection against parasite challenge, and the role played by up-regulated expression of cytotoxicity-related genes in mice needs to be further investigated.
基金This work was financially supported by the National Natural Science Foundation of China(31001638&30870602)This project was supported by the key medical research plan of the Hebei province of China(No.ZD2013063)+1 种基金Tsing-hua University(2009THZ02122)National Heart,Lung,and Blood Institute Research Grant HL 104402 from the National Institutes of Health of the US Public Health Service.
文摘Since stem cell therapy is the most effective treatment in the field of tissue reparation and reconstitution,the present study aimed to explore the different sources of mesenchymal stem cells(MSCs)on the different effects of pulmonary fibrosis-related cytokines in C57BL/6 mice.For reaching this goal,we isolated MSCs from umbilical cord blood and placenta and used for stem cell therapy in a mouse model of pulmonary fibrosis model.The pulmonary fibrosis model was done by injecting bleomycin into the trachea of C57BL/6 mice.Then we assessed the degree of pulmonary fibrosis in each mouse lung tissue at weeks 1,2,3,and 4.In addition,flow cytometry was used to evaluate the frequency of CD73,CD90,CD106,CD34,CD45,CD14 cells at the mononuclear cell level;and western blotting assays revealed the expression of IκB-α.Our results showed that stem cell therapy by placenta-derived MSC had a lower level of CD34,CD45,CD14 cells at the mononuclear cell level,and that improved pulmonary fibrosis at both molecular and pathological levels.In addition,western blotting assays revealed that the expression of IκB-αwas down-regulated in MSC-treated animals.In addition,placenta-derived MSC was the most effective in improving pulmonary fibrosis in comparison to other sources.This study suggests that MSC might be a novel therapeutic approach in pulmonary fibrosis due to an enhanced anti-inflammatory effect.Also,MSC modification by gene editing could enhance their therapeutic effect in mouse pulmonary fibrosis.
文摘The purpose of this study was to evaluate the influence of squalene (SQ) on plasma and hepatic lipid levels of obese/diabetic KK-Ay mice and wild-type C57BL/6J mice. SQ supplementation significantly increased the HDL cholesterol of KK-Ay mice, which was paralleled with no significant difference in the total and non-HDL cholesterol levels. The increase in HDL cholesterol was also found in the plasma of normal C57BL/6J mice, but the difference was not significant. SQ administration significantly increased neutral lipids (NL) in the liver of KK-Ay mice, while no significant difference was observed in the polar lipids and the total cholesterol levels. The increase in NL was primarily due to the increase in TAG. However, the cholesterol level significantly increased due to SQ intake in the liver of C57BL/6J mice, while no significant difference was found in other lipid levels. The present study suggests that SQ may effectively increase HDL cholesterol level, an important anti-atherosclerotic factor, especially in subjects with metabolic disorders.
基金Sao Paulo Research Foundation(FAPESP),[Grant No.2013/26257-8]
文摘Active vitamin D (1,25D) is a fat-soluble vitamin that is mainly produced in the skin by the conversion of 7-dehydrocholesterol under ultraviolet light stimulation.Its role in calcium homeostasis,bone growth, and prevention of rickets and osteomalacia has been known for over two hundred years.Its
文摘Eclipta prostrata has been extensively studied for its promoting effect on human health. Previous study proved that E. prostrata possessed anti-osteoporosis function in SAMP6 mice via gut microbiota (GM). Endophytes are widespread in plants, especially in Chinese herbal medicines. However, little is known regarding the endophytes of E. prostrata. In this study, we focus on screening and identifying the endophytes from plant E. prostrata and exploring their roles in modulating GM. According to biochemical, physiological tests and 16S rDNA sequence analysis, ten endophytes were characterized in different locations of plant E. prostrata belonging to Lactococcus, Bacillus, Enterococcus, Exiguobacterium and Pantoea. The antimicrobial activity of endophytes EP01-10 was investigated via the oxford cup method. Furthermore, the acid and bile salt resistant ability of EP01-10 was detected to explore their survival ability in gastrointestinal tract. Results indicated that strains of Lactococcus, Bacillus and Exiguobacterium (EP01, 03 and 05) showed strong antimicrobial activity against Escherichia coli and Staphylococcus aureus and strains of Lactococcus, Bacillus and Enterococcus (EP01, 02, 04, 08 and 10) have the ability to survive in the gastrointestinal tract. 16S rRNA sequencing of GM in C57BL/6J mice was performed for diversity and structure analysis responded to the administration of E. prostrata extract. E. prostrata extract acted on improving the microflora diversity, particularly in increasing the abundance of Lactococcus significantly. Thus, as an endophyte, Lactococcus plays an important role in E. prostrata modulating intestinal tract. Our study suggested that endophytes of Chinese herbal medicines might be a novel target for the treatment of diseases by regulating the GM.
基金National Natural Science Foundation of China(Nos.81771004,81271078,81500791,81500794 and 81300827).
文摘K^(+)cycling in the cochlea is critical to maintain hearing.Many sodium-potassium pumps are proved to participate in K^(+)cycling,such as Na/K-ATPase.Theα2-Na/K-ATPase is an important isoform of Na/K-ATPase.The expression ofα2-Na/K-ATPase in the cochlea is not clear.In this study,we used C57BL/6 mice as a model of presbycusis and implemented immunohistochemistry staining and quantitative real time-PCR,and theα2-Na/K-ATPase expression pattern was confirmed in the inner ear.It was foundα2-Na/K-ATPase was expressed widely in cochlea and its mRNA and protein expression was gradually reduced with aging(4-,14-,26-and 48-weeks old mice).We suspected that,the down-regulation ofα2-Na/K-ATPase expression might be associated with the remodeling of K^(+)cycling,degeneration of morphological structure and decrease of hearing function in aging C57 mice.In conclusion,we speculated that the reduction ofα2-Na/K-ATPase might play an important role in the pathogenesis of age-related hearing loss.
文摘Four embryonic stem (ES) cell lines, designated CE1, CE2, CE3 and CE4, were isolated from C57BL/6J blastocysts. The ratio of normal diploid composition of these cell lines is above 70%. To examine the differentiation potential of the ES cells, the CE2 cells were injected subcutaneously into syngenic mice, and many kinds of differentiated cells were observed on the sections of the teratoma derived from this ES cell line. On the other hand, to test the chimeric ability of the ES cells, the CE2 cells were microinjected into the blastocysts of ICR mice, and a chimera was obtained among living pups. These results show that CE2 ES cells are pluripotent stem cells, which can differentiate into many kinds of cell types, and can be used as a cell system for further research.
文摘Rodents chronically injected with D-galactose (D-gal have been used as an animal model for brain aging or antiaging pharmacology research. However, the dose of D-gal used to induce behavioral impairment has been reported in a wide range. Besides, very few studies used the C57BL inbred mouse strain to construct this model, which is one of the
