Arsenic methyltransferase（As3mt） catalyzes the conversion of inorganic arsenic（i As） to its methylated metabolites, including toxic methylarsonite（MAs~Ⅲ） and dimethylarsinite（DMAs~Ⅲ）. Knockout（KO） of As3 m...Arsenic methyltransferase（As3mt） catalyzes the conversion of inorganic arsenic（i As） to its methylated metabolites, including toxic methylarsonite（MAs~Ⅲ） and dimethylarsinite（DMAs~Ⅲ）. Knockout（KO） of As3 mt was shown to reduce the capacity to methylate i As in mice. However, no data are available on the oxidation states of As species in tissues of these mice. Here, we compare the oxidation states of As species in tissues of male C57BL/6 As3mt-KO and wild-type（WT） mice exposed to arsenite（iA s~Ⅲ） in drinking water. WT mice were exposed to50 mg/L As and As3mt-KO mice that cannot tolerate 50 mg/L As were exposed to 0, 15, 20, 25 or30 mg/L As. iA s~Ⅲaccounted for 53% to 74% of total As in liver, pancreas, adipose, lung, heart, and kidney of As3mt-KO mice; tri- and pentavalent methylated arsenicals did not exceed 10% of total As. Tissues of WT mice retained iA s and methylated arsenicals： iA s~Ⅲ, MAs~Ⅲand DMAs~Ⅲ represented 55%‐68% of the total As in the liver, pancreas, and brain. High levels of methylated species, particularly MAs~Ⅲ, were found in the intestine of WT, but not As3mt-KO mice,suggesting that intestinal bacteria are not a major source of methylated As. Blood of WT mice contained significantly higher levels of As than blood of As3mt-KO mice. This study is the first to determine oxidation states of As species in tissues of As3mt-KO mice. Results will help to design studies using WT and As3mt-KO mice to examine the role of iA s methylation in adverse effects of iA s exposure.展开更多
Objective The protein interacting with C kinase 1(PICK1)plays a critical role in vesicle trafficking,and its deficiency in sperm cells results in abnormal vesicle trafficking from Golgi to acrosome,which eventually di...Objective The protein interacting with C kinase 1(PICK1)plays a critical role in vesicle trafficking,and its deficiency in sperm cells results in abnormal vesicle trafficking from Golgi to acrosome,which eventually disrupts acrosome formation and leads to male infertility.Methods An azoospermia sample was filtered,and the laboratory detection and clinical phenotype indicated typical azoospermia in the patient.We sequenced all of the exons in the PICK1 gene and found that there was a novel homozygous variant in the PICK1 gene,c.364delA(p.Lys122SerfsX8),and this protein structure truncating variant seriously affected the biological function.Then we constructed a PICK1 knockout mouse model using clustered regularly interspaced short palindromic repeat cutting technology(CRISPRc).Results The sperm from PICK1 knockout mice showed acrosome and nucleus abnormalities,as well as dysfunctional mitochondrial sheath formation.Both the total sperm and motility sperm counts were decreased in the PICK1 knockout mice compared to wild-type mice.Moreover,the mitochondrial dysfunction was verified in the mice.These defects in the male PICK1 knockout mice may have eventually led to complete infertility.Conclusion The c.364delA novel variant in the PICK1 gene associated with clinical infertility,and pathogenic variants in the PICK1 may cause azoospermia or asthenospermia by impairing mitochondrial function in both mice and humans.展开更多
OBJECTIVE To observe the effects of serum metabolites by using ~1H-NMR-based metabonomic approach to explore the possible mechanisms of total flavonoids in Ocimum BasilicumLinn(OBL) on atherosclerosis in apolipomtein ...OBJECTIVE To observe the effects of serum metabolites by using ~1H-NMR-based metabonomic approach to explore the possible mechanisms of total flavonoids in Ocimum BasilicumLinn(OBL) on atherosclerosis in apolipomtein E knockout(ApoE-/-) mice.METHODS Six-week-old male apoE knockout mice were divided into four groups(n=10) and fed with high fet diet:model,Simv.astatin,OBL-H,OBL-M and OBL-L groups.The homogeneous male mice of C57 BL/6 J were used as the normol group and fed with normal chow diet.After 14 weeks,~1H-NMR technology was used to ex.plore the variability of serum metabolites by the method of PLS-DA and OPLS-DA.RESULTS Com.pared with normal group,Model group showed a significant increase in the serum levels of VLDL,LDL,β-hydroxyisobutyrate,lactate,myo-inositol and showed a significant decrease in the serum levels of al.anine,glutamine,proline,carnitine,methylamine,citrate,creatine,choline,taurine,pyruvate,β-glu.cose,α-glucose,glycine,lysine.Combined with model group OBL-H,OBL-M,OBL-L groups showed the effects of regulating the levels of different metabolites of the glucose,lipid and amino acid metabo.lism.CONCLUSION The anti-atheros-clerotic activity of total flavonoids in Ocimum BasilicumLinn may be related not only to regulation of lipid metabolism,but also glycometabolism and amino acid metabolism.展开更多
Abstract Objectives To investigate the tissue specificity of reactive oxygen species (ROS) damage to mitochondrial DNA (mtDNA) and to determine whether cochlear mtDNA is a sensitive target for ROS damage. Methods 10...Abstract Objectives To investigate the tissue specificity of reactive oxygen species (ROS) damage to mitochondrial DNA (mtDNA) and to determine whether cochlear mtDNA is a sensitive target for ROS damage. Methods 10 Cu/ZnSOD gene (Cu/Zn superoxide dismutase gene, Sod1) knockout mice and 16 wild-type mice were analyzed by nested polymerase chain reaction (PCR).Results Three deletions were detected in various tissues of Sod1 knockout mice. MtDNA3867bp and mtDNA3726bp deletions were the most visible, and mtDNA4236bp deletion was barely detected in these tissues. There were obvious differences in the ratio of deleted mtDNA/total mtDNA in different tissue. Deleted mtDNA was most abundant in the liver and kidney and less in cochlea, heart and brain. The lowest was in spleen and skin. The ratio in various tissues was 3-20 times in Sod1 knockout mice over wild-type mice. In cochlea, the ratio was about 15. Conclusions Without the protection of Sod1, ROS can lead to mtDNA deletions in various tissues with significant tissue specificity. Cochlear mtDNA is a sensitive target for ROS damage.展开更多
CD146 is a newly identified endothelial biomarker that has been implicated in angiogenesis. Though in vitro angio- genic function of CD146 has been extensively reported, in vivo evidence is still lacking. To address t...CD146 is a newly identified endothelial biomarker that has been implicated in angiogenesis. Though in vitro angio- genic function of CD146 has been extensively reported, in vivo evidence is still lacking. To address this issue, we generated endothelial-specific CD146 knockout （CD146 EC-Ko） mice using the Tg（Tek-cre） system. Surprisingly, these mice did not exhibit any apparent morphological defects in the development of normal retinal vasculature. To evaluate the role of CD146 in pathological angiogenesis, a xenograft tumor model was used. We found that both tumor volume and vascular density were significantly lower in CD146Ec-KO mice when compared to WT littermates. Additionally, the ability for sprouting, migration and tube formation in response to VEGF treatment was impaired in endothelial cells （ECs）of CD146Ec-Ko mice. Mechanistic studies further confirmed that VEGF- induced VEGFR-2 phosphorylation and AKT/p38 MAPKs/ NF-KB activation were inhibited in these CD146-null ECs, which might present the underlying cause for the observed inhibition of tumor angiogenesis in CD146Ec-Ko mice. These results suggest that CD146 plays a redundant role in physiological angiogenic processes, but becomes essential during pathological angiogenesis as observed in tumorigenesis.展开更多
Objective： To explore the correlation between Fc γ R IIIA （CD16A） and aortic atherosclerotic plaque destabilization in apoE knockout （apoE KO） mice and the intervention effects of effective components of Chuanxi...Objective： To explore the correlation between Fc γ R IIIA （CD16A） and aortic atherosclerotic plaque destabilization in apoE knockout （apoE KO） mice and the intervention effects of effective components of Chuanxiong Rhizome and Red Peony Root. Methods： Eight 8-week-old male C57BL/6J mice were selected as the control group. Forty 8-week-old male apoE KO mice were randomly divided into the model group, apoE KO ＋ intraperitoneal injection immunoglobulin group （IVIG）, apoE KO ＋ simvastatin group （Sm）, apoE KO ＋ high dosage of Xiongshao Capsule （XSC,芎芍胶囊） group （XSCH）, and apoE KO ＋ low dosage of XSC group （XSCL）, 8 mice in each group. Mice in the control group were put on a normal diet, and others were fed with a high-fat diet. After 10-week different interventions, monocyte CD16 expression was detected by flow cytometry, aortic matrix metalloproteinase-9 （MMP-9） mRNA expression was detected using reverse transcription- polymerase chain reaction, and serum tumor necrosis factor （TNF）-a level was detected using enzyme-linked immunosorbent assay. Results： Compared with the control group, monocyte CD16 expression, aortic MMP-9 mRNA expression, and serum TNF-a level in the model group increased obviously （P〈0.01）. Injections of apoE KO mice with intraperitoneal immunoglobulin during a 5-day period significantly reduced the monocyte CD16 expression, aortic MMP-9 mRNA expression, and serum TNF-a level （P〈0.01 or 0.05） over a 10-week period of high-fat diet. Indices above in the Sm group, XSCH group, and XSCL group decreased in a different degree. Of them, the aortic MMP-9 mRNA expression in XSCH group was lower than that in Sm group （P〈0.05） and the monocyte CD16 expression and serum TNF-a level showed no significant difference between XSCH group and Sm group （P〉0.05）. Correlation analyses suggested positive correlation between monocyte CD16 expression and aortic MMP-9 mRNA expression or serum TNF-a level in IVIG group, XSCH group, and XSCL group. Conclusions： Fc γ/R IliA mediates systemic inflammation in the progression of coronary heart disease with blood stasis syndrome. XSC could stabilize atherosclerotic plaque by suppressing inflammation and its target was relative with Fc γ RIIIA.展开更多
Objective： TO observe the effect of Huxin Formula （护心方, HXF） on expressions of the chief reverse cholesterol transport （RCT） associated genes, caveolin-1 and scavenger receptor-B I （SR-B I ） in ApoE-gene kno...Objective： TO observe the effect of Huxin Formula （护心方, HXF） on expressions of the chief reverse cholesterol transport （RCT） associated genes, caveolin-1 and scavenger receptor-B I （SR-B I ） in ApoE-gene knockout [ApoE （-/-）] mice. Methods： Thirty ApoE （-/-） mice of 4-6 weeks old were randomly divided into three groups （A-C）. After being fed with high-fat diet for 16 weeks, they were treated with HXF （1 mL/100 g）, pravachol （0.3 mg/100 g）, and saline in equal volume respectively for 16 weeks successively; in addition, a blank group was set up with 10 C57BL/6J mice of 6-week old received 16-week high-fat feeding and saline treatment. Animals were sacrificed at the termination of the experiment, their paraffin sections of aortic tissue were used to measure the size of plaque, expressions of cavolin-1 and SR-B I were detected by immunological histochemical method. Results： As compared with the blank group, levels of caveolin-1 and SR-B I were increased in Groups A and B （P〈0.01）; but the increase in Group A was more significant than that in Group B （P〈0.05）. The plaque/aorta area ratio decreased significantly in Groups A and B, but showed insignificant difference between the two groups. Conclusion： HXF could obviously increase the expressions of RCT associated genes, caveolin-1 and SR-B I, promote the RCT process, so as to reduce the formation of aorta atherosclerotic plaque in ApoE （-/-） mice.展开更多
Estrogen deficiency mediates aging, but the underlying mechanism remains to be fully determined. We report here that estrogen deficiency caused by targeted disruption of aromatase in mice results in significant inhibi...Estrogen deficiency mediates aging, but the underlying mechanism remains to be fully determined. We report here that estrogen deficiency caused by targeted disruption of aromatase in mice results in significant inhibition of telomerase activity in the adrenal gland in vivo. Gene expression analysis showed that, in the absence of estrogen, telomerase reverse transcriptase （TERT） gene expression is reduced in association with compromised cell proliferation in the adrenal gland cortex and adrenal atrophy. Stem cells positive in c-kit are identified to populate in the parenchyma of adrenal cortex. Analysis of telomeres revealed that estrogen deficiency results in significantly shorter teiomeres in the adrenal cortex than that in wild-type （WT） control mice. To further establish the causal effects of estrogen, we conducted an estrogen replacement therapy in these estrogen-deficient animals. Administration of estrogen for 3 weeks restores TERT gene expression, telomerase activity and cell proliferation in estrogen-deficient mice. Thus, our data show for the first time that estrogen deficiency causes inhibitions of TERT gene expression, telomerase activity, telomere maintenance, and cell proliferation in the adrenal gland of mice in vivo, suggesting that telomerase inhibition and telomere shortening may mediate cell proliferation arrest in the adrenal gland, thus contributing to estrogen deficiency-induced aging under physiological conditions.展开更多
RIG-I （retinoid acid-inducible gene-I）, a putative RNA helicase with a cytoplasmic caspase-recrultment domain （CARD）, was identified as a pattem-recognition receptor （PRR） that mediates antiviral immunity by ind...RIG-I （retinoid acid-inducible gene-I）, a putative RNA helicase with a cytoplasmic caspase-recrultment domain （CARD）, was identified as a pattem-recognition receptor （PRR） that mediates antiviral immunity by inducing type I interferon production. To further study the biological function of RIG-I, we generated Rig-I^-/- mice through homologous recombination, taking a different strategy to the previously reported strategy. Our Rig-I^-/- mice are viable and fertile. Histological analysis shows that Rig-I^-/ mice develop a colitis-like phenotype and increased susceptibility to dextran sulfate sodium-induced colitis. Accordingly, the size and number of Peyer＇s patches dramatically decreased in mutant mice. The peripheral T-cell subsets in mutant mice are characterized by an increase in effector T cells and a decrease in naive T cells, indicating an important role for Rig-I in the regulation ofT-cell activation. It was further found that Rig-I deficiency leads to the downregulation of G protein αi2 subunit （Gαi2） in various tissues, including T and B lymphocytes. By contrast, upregulation of Rig-I in NB4 cells that are treated with ATRA is accompanied by elevated Gαi2 expression. Moreover, Gαi2 promoter activity is increased in co-transfected NIH3T3 cells in a Rig-I dose-dependent manner. All these findings suggest that Rig-I has crucial roles in the regulation of Gαi2 expression and T-cell activation. The development of colitis may be, at least in part, associated with downregulation of Gαi2 and disturbed T-cell homeostasis.展开更多
Growth hormone （GH） exerts profound anabolic actions during postnatal skeletal development, in part, through stimulating the production of insulin-like growth factor-1 （IGF-1） in liver and skeletal tissues. To exa...Growth hormone （GH） exerts profound anabolic actions during postnatal skeletal development, in part, through stimulating the production of insulin-like growth factor-1 （IGF-1） in liver and skeletal tissues. To examine the requirement for the GH receptor （GHR） in osteoblast function in bone, we used Cre-LoxP methods to disrupt the GHR from osteoblasts, both in vitro and in vivo. Disruption of GHR from primary calvarial osteoblasts in vitro abolished GH-induced signaling, as assessed by JAK2/STAT5 phosphorylation, and abrogated GH-induced proliferative and anti-apoptotic actions. Osteoblasts lacking GHR exhibited reduced IGF-l-induced Erk and Akt phosphorylation and attenuated IGF-1-induced proliferation and anti-apoptotic action. In addition, differentiation was modestly impaired in osteoblasts lacking GHR, as demonstrated by reduced alkaline phosphatase staining and calcium deposition. In order to determine the requirement for the GHR in bone in vivo, we generated mice lacking the GHR specifically in osteoblasts （△GHR）, which were born at the expected Mendelian frequency, had a normal life span and were of normal size. Three week-old, female AGHR mice had significantly reduced osteoblast numbers, consistent with the in vitro data. By six weeks of age however, female AGHR mice demonstrated a marked increase in osteoblasts, although mineralization was impaired; a phenotype similar to that observed previously in mice lacking IGF-1R specifically in osteoblasts. The most striking phenotype occurred in male mice however, where disruption of the GHR from osteoblasts resulted in a ＂feminization＂ of bone geometry in 16 week-old mice, as observed by faCT. These results demonstrate that the GHR is required for normal postnatal bone development in both sexes. GH appears to serve a primary function in modulating local IGF-1 action. However, the changes in bone geometry observed in male AGHR mice suggest that, in addition to facilitating IGF-1 action, GH may function to a greater extent than previously appreciated in establishing the sexual dimorphism of the skeleton.展开更多
Androgen deprivation in men leads to increased adiposity, but the mechanisms underlying androgen regulation of fat mass have not been fully defined. Androgen receptor （AR） is expressed in monocytes/macrophages, whic...Androgen deprivation in men leads to increased adiposity, but the mechanisms underlying androgen regulation of fat mass have not been fully defined. Androgen receptor （AR） is expressed in monocytes/macrophages, which are resident in key metabolic tissues and influence energy metabolism in surrounding cells. Male mice bearing a cell-specific knockout of the AR in monocytes/macrophages （M-ARKO） were generated to determine whether selective loss of androgen signaling in these cells would lead to altered body composition. Wild-type （WT） and M-ARKO mice （12-22 weeks of age, n = 12 per group） were maintained on a regular chow diet for 8 weeks and then switched to a high-fat diet for 8 additional weeks. At baseline and on both the regular chow and high-fat diets, no differences in lean mass or fat mass were observed between groups. Consistent with the absence of differential body weight or adiposity, no differences in food intake （3.0 ± 0.5 g per day for WT mice vs 2.8 ± 0.4 g per day for M-ARKO mice） or total energy expenditure （0.6 ± 0.1 Kcal h-1 for WT mice vs 0.5 ± 0.1 Kcal h-1 for M-ARKO mice） were evident between groups during high-fat feeding. Liver weight was greater in M-ARKO than that in WT mice （1.5 ± 0.1 g vs 1.3 ± 0.0 g, respectively, P = 0.02）. Finally, M-ARKO mice did not exhibit impairments in glucose tolerance or insulin sensitivity relative to WT mice at any study time point. In aggregate, these findings suggest that AR signaling specifically in monocytes/macrophages does not contribute to the regulation of systemic energy balance, adiposity, or insulin sensitivity in male mice.展开更多
Gene expression analyses suggest that more than 1000–2000 genes are expressed predominantly in mouse and human testes.Although functional analyses of hundreds of these genes have been performed,there are still many t...Gene expression analyses suggest that more than 1000–2000 genes are expressed predominantly in mouse and human testes.Although functional analyses of hundreds of these genes have been performed,there are still many testis-enriched genes whose functions remain unexplored.Analyzing gene function using knockout(KO)mice is a powerful tool to discern if the gene of interest is essential for sperm formation,function,and male fertility in vivo.In this study,we generated KO mice for 12 testis-enriched genes,1700057G04Rik,4921539E11Rik,4930558C23Rik,Cby2,Ldhal6b,Rasef,Slc25a2,Slc25a41,Smim8,Smim9,Tmem210,and Tomm20l,using the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9(CRISPR/Cas9)system.We designed two gRNAs for each gene to excise almost all the protein-coding regions to ensure that the deletions in these genes result in a null mutation.Mating tests of KO mice reveal that these 12 genes are not essential for male fertility,at least when individually ablated,and not together with other potentially compensatory paralogous genes.Our results could prevent other laboratories from expending duplicative effort generating KO mice,for which no apparent phenotype exists.展开更多
Neuropeptide Y (NPY) is a potent neurotransmitter for feeding. Besides NPY, orexigenic neuropeptides such as agouti-related protein (AgRP), and anorexi- genic neuropeptides such as α-melatonin stimulating hormone (MS...Neuropeptide Y (NPY) is a potent neurotransmitter for feeding. Besides NPY, orexigenic neuropeptides such as agouti-related protein (AgRP), and anorexi- genic neuropeptides such as α-melatonin stimulating hormone (MSH) and cocaine-amphetamine-regulated transcript (CART) are also involved in central feeding regulation. During fasting, NPY and AgRP gene expressions are up-regulated and POMC and CART gene ex- pressions are down-regulated in hypothalamus. Based on the network of peptidergic neurons, the former are involved in positive feeding regulation, and the latter are involved in negative feeding, which exert these feeding-regulated peptides especially in paraventricular nucleus (PVN). To clarify the compensatory mecha- nism of knock-out of NPY system on feeding, change in gene expressions of appetite-related neuropeptides and the feeding behavior was studied in NPY Y5-KO mice. Food intake was increased in Y5-KO mice. Fasting increased the amounts of food and water intake in the KO mice more profoundly. These data indicated the compensatory phenomenon of feeding behavior in Y5-KO mice. RT-PCR and ISH suggested that the compensation of feeding is due to change in gene expressions of AgRP, CART and POMC in hypothalamus. Thus, these fi ndings indicated that the compensatory mechanism involves change in POMC/CART gene expression in arcuate nucleus (ARC). The POMC/CART gene expression is important for central compensatory regulation in feeding behavior.展开更多
In the ApoE^-/- mouse model of atherosclerosis （AS） stable plaque, the expression and location of intracellular tissue factor （TF） in the cellular components of AS stable plaque were investigated in order to explo...In the ApoE^-/- mouse model of atherosclerosis （AS） stable plaque, the expression and location of intracellular tissue factor （TF） in the cellular components of AS stable plaque were investigated in order to explore the cellular mechanism of AS thrombosis. Pathological changes of the stable plaque were observed under a microscope. The expression of TF protein was examined in aortic stable plaque of mice by using immunohistochemistry. Color image planimetric system was used to analyze the histological components of the stable plaque and the TF distribution. Under the confocal microscope, the intracellular TF location in the stable plaque of mice was observed. The results showed the cellular area was the major part of stable plaque （67.36%±6.52%, P〈0.01）. The percentage of total area occupied by cellular area was significantly larger than atheromatous gruel and acellular area （P〈0.01）. Macrophages and smooth muscle cells （SMC） were major cells in the cellular area. The percentage of total area occupied by SMC was significantly larger than by macrophages （P〈0.01）. Multiple linear regression analysis showed there was a positive correlation between TF area and SMC area （r=0.616, P=-0.008）, and no correlation was found between TF area and macrophage area （r=0.437, P=0.08）. Pictures of color image planimetric analysis of TF and SMC were merged to highlight areas with co-localization （yellow）, it was concluded that the process could be a cell-mediated TF expression in the stable plaque. SMC may be the major source of TF in AS without plaque rupture.展开更多
AIM: To explore the pathogenesis, influencing factors, ways of medical intervention and evaluation indicators of cataract by observing changes in serum biochemical indices in mice with targeted disruption of βB2-crys...AIM: To explore the pathogenesis, influencing factors, ways of medical intervention and evaluation indicators of cataract by observing changes in serum biochemical indices in mice with targeted disruption of βB2-crystallin. · METHODS: Nine 6-week-old male mice with targeted knockout of βB2-crystallin were used as the study group, and nine age- and sex-matched normal wild-type mice as the control group. The genetype of the modeled mice was identified by PCR technique. Tropicamide and phenylephrine eye drops were used as the cycloplegic agents to observe changes in lens opacity with a slit-lamp. The lens was then removed and blood was collected for biochemical evaluation in the serum. · RESULTS: Two genotypes were successfully identified by PCR technique. Slit-lamp observation showed that the lens cortex was opaque and GSH level in the lens cortex was remarkably decreased in mice with βB2-crystallin deficiency compared with the control group (P <0.01). Serum Na+, Cl-, Ca2+, Mg2+ and Fe2+ levels, ALT and AST activities, and TP, ALP, Cr, TC, GLU content were decreased significantly compared with the control group (P <0.05). There was no difference in LDH, P, Cu2+, K+ levels between the two groups (P >0.05). · CONCLUSION: Compared with the wild-type mice, serum biochemical indices underwent significant changes in mice with targeted disruption of βB2-crystallin gene, especially with abnormal distribution of Na+&Ca2+, which induced the formation of cataract.展开更多
Insulin resistance is a hallmark of type 2 diabetes. In an effort to understand and treat this condition, re searchers have used genetic manipulation of mice to uncover insulin signaling pathways and determine the eff...Insulin resistance is a hallmark of type 2 diabetes. In an effort to understand and treat this condition, re searchers have used genetic manipulation of mice to uncover insulin signaling pathways and determine the effects of their perturbation. After decades of research much has been learned, but the pathophysiology o insulin resistance in human diabetes remains contro versial, and treating insulin resistance remains a chal lenge. This review will discuss limitations of mouse models lacking select insulin signaling molecule genes In the most influential mouse models, glucose metabo lism differs from that of humans at the cellular, organ and whole-organism levels, and these differences limi the relevance and benefit of the mouse models both in terms of mechanistic investigations and therapeutic development. These differences are due partly to im mutable differences in mouse and human biology, and partly to the failure of genetic modifications to produce an accurate model of human diabetes. Several fac tors often limit the mechanistic insights gained from experimental mice to the particular species and strain including: developmental effects, unexpected meta bolic adjustments, genetic background effects, and technical issues. We conclude that the limitations and weaknesses of genetically modified mouse models of insulin resistance underscore the need for redirection of research efforts toward methods that are more directly relevant to human physiology.展开更多
基金supported by NIH grant No. 2 R01 ES010845 to M.S.the UNC Nutrition Obesity Research Center grant no. DK056350,+1 种基金NIH grant No. P30ES010126 to the UNC Center for Environmental Health and Susceptibilitysupported by a pre-doctoral traineeship (National Research Service Award T32 ES007126) from the National Institute of Environmental Health Sciences, NIH
文摘Arsenic methyltransferase（As3mt） catalyzes the conversion of inorganic arsenic（i As） to its methylated metabolites, including toxic methylarsonite（MAs~Ⅲ） and dimethylarsinite（DMAs~Ⅲ）. Knockout（KO） of As3 mt was shown to reduce the capacity to methylate i As in mice. However, no data are available on the oxidation states of As species in tissues of these mice. Here, we compare the oxidation states of As species in tissues of male C57BL/6 As3mt-KO and wild-type（WT） mice exposed to arsenite（iA s~Ⅲ） in drinking water. WT mice were exposed to50 mg/L As and As3mt-KO mice that cannot tolerate 50 mg/L As were exposed to 0, 15, 20, 25 or30 mg/L As. iA s~Ⅲaccounted for 53% to 74% of total As in liver, pancreas, adipose, lung, heart, and kidney of As3mt-KO mice; tri- and pentavalent methylated arsenicals did not exceed 10% of total As. Tissues of WT mice retained iA s and methylated arsenicals： iA s~Ⅲ, MAs~Ⅲand DMAs~Ⅲ represented 55%‐68% of the total As in the liver, pancreas, and brain. High levels of methylated species, particularly MAs~Ⅲ, were found in the intestine of WT, but not As3mt-KO mice,suggesting that intestinal bacteria are not a major source of methylated As. Blood of WT mice contained significantly higher levels of As than blood of As3mt-KO mice. This study is the first to determine oxidation states of As species in tissues of As3mt-KO mice. Results will help to design studies using WT and As3mt-KO mice to examine the role of iA s methylation in adverse effects of iA s exposure.
基金supported by grants from Zhejiang Provincial Natural Science Foundation of China(No.LQ21H200007)National Natural Science Foundation of China(No.82202605,No.81772664 and No.82172363)+1 种基金Zhejiang Provincial People’s Hospital Excellent Scientific Research Start-up Fundation of China(No.ZRY2019C008)Hangzhou Medical College Fundamental Scientific Research Project of China(No.KYQN202116).
文摘Objective The protein interacting with C kinase 1(PICK1)plays a critical role in vesicle trafficking,and its deficiency in sperm cells results in abnormal vesicle trafficking from Golgi to acrosome,which eventually disrupts acrosome formation and leads to male infertility.Methods An azoospermia sample was filtered,and the laboratory detection and clinical phenotype indicated typical azoospermia in the patient.We sequenced all of the exons in the PICK1 gene and found that there was a novel homozygous variant in the PICK1 gene,c.364delA(p.Lys122SerfsX8),and this protein structure truncating variant seriously affected the biological function.Then we constructed a PICK1 knockout mouse model using clustered regularly interspaced short palindromic repeat cutting technology(CRISPRc).Results The sperm from PICK1 knockout mice showed acrosome and nucleus abnormalities,as well as dysfunctional mitochondrial sheath formation.Both the total sperm and motility sperm counts were decreased in the PICK1 knockout mice compared to wild-type mice.Moreover,the mitochondrial dysfunction was verified in the mice.These defects in the male PICK1 knockout mice may have eventually led to complete infertility.Conclusion The c.364delA novel variant in the PICK1 gene associated with clinical infertility,and pathogenic variants in the PICK1 may cause azoospermia or asthenospermia by impairing mitochondrial function in both mice and humans.
基金supported by National Natural Science Foundation of China (81560586) and Xinjiang Natural Science Foundation (2016D01C161)
文摘OBJECTIVE To observe the effects of serum metabolites by using ~1H-NMR-based metabonomic approach to explore the possible mechanisms of total flavonoids in Ocimum BasilicumLinn(OBL) on atherosclerosis in apolipomtein E knockout(ApoE-/-) mice.METHODS Six-week-old male apoE knockout mice were divided into four groups(n=10) and fed with high fet diet:model,Simv.astatin,OBL-H,OBL-M and OBL-L groups.The homogeneous male mice of C57 BL/6 J were used as the normol group and fed with normal chow diet.After 14 weeks,~1H-NMR technology was used to ex.plore the variability of serum metabolites by the method of PLS-DA and OPLS-DA.RESULTS Com.pared with normal group,Model group showed a significant increase in the serum levels of VLDL,LDL,β-hydroxyisobutyrate,lactate,myo-inositol and showed a significant decrease in the serum levels of al.anine,glutamine,proline,carnitine,methylamine,citrate,creatine,choline,taurine,pyruvate,β-glu.cose,α-glucose,glycine,lysine.Combined with model group OBL-H,OBL-M,OBL-L groups showed the effects of regulating the levels of different metabolites of the glucose,lipid and amino acid metabo.lism.CONCLUSION The anti-atheros-clerotic activity of total flavonoids in Ocimum BasilicumLinn may be related not only to regulation of lipid metabolism,but also glycometabolism and amino acid metabolism.
基金NationalOutstandingYouthSciencesFoundation (No 3972 5 0 2 6)andPostdoctoralSciencesFoundationofChina (No 2 0 0 0 2 3)
文摘Abstract Objectives To investigate the tissue specificity of reactive oxygen species (ROS) damage to mitochondrial DNA (mtDNA) and to determine whether cochlear mtDNA is a sensitive target for ROS damage. Methods 10 Cu/ZnSOD gene (Cu/Zn superoxide dismutase gene, Sod1) knockout mice and 16 wild-type mice were analyzed by nested polymerase chain reaction (PCR).Results Three deletions were detected in various tissues of Sod1 knockout mice. MtDNA3867bp and mtDNA3726bp deletions were the most visible, and mtDNA4236bp deletion was barely detected in these tissues. There were obvious differences in the ratio of deleted mtDNA/total mtDNA in different tissue. Deleted mtDNA was most abundant in the liver and kidney and less in cochlea, heart and brain. The lowest was in spleen and skin. The ratio in various tissues was 3-20 times in Sod1 knockout mice over wild-type mice. In cochlea, the ratio was about 15. Conclusions Without the protection of Sod1, ROS can lead to mtDNA deletions in various tissues with significant tissue specificity. Cochlear mtDNA is a sensitive target for ROS damage.
文摘CD146 is a newly identified endothelial biomarker that has been implicated in angiogenesis. Though in vitro angio- genic function of CD146 has been extensively reported, in vivo evidence is still lacking. To address this issue, we generated endothelial-specific CD146 knockout （CD146 EC-Ko） mice using the Tg（Tek-cre） system. Surprisingly, these mice did not exhibit any apparent morphological defects in the development of normal retinal vasculature. To evaluate the role of CD146 in pathological angiogenesis, a xenograft tumor model was used. We found that both tumor volume and vascular density were significantly lower in CD146Ec-KO mice when compared to WT littermates. Additionally, the ability for sprouting, migration and tube formation in response to VEGF treatment was impaired in endothelial cells （ECs）of CD146Ec-Ko mice. Mechanistic studies further confirmed that VEGF- induced VEGFR-2 phosphorylation and AKT/p38 MAPKs/ NF-KB activation were inhibited in these CD146-null ECs, which might present the underlying cause for the observed inhibition of tumor angiogenesis in CD146Ec-Ko mice. These results suggest that CD146 plays a redundant role in physiological angiogenic processes, but becomes essential during pathological angiogenesis as observed in tumorigenesis.
基金Supported by the National Key Basic Research and Development Program of China(No.81073086)
文摘Objective： To explore the correlation between Fc γ R IIIA （CD16A） and aortic atherosclerotic plaque destabilization in apoE knockout （apoE KO） mice and the intervention effects of effective components of Chuanxiong Rhizome and Red Peony Root. Methods： Eight 8-week-old male C57BL/6J mice were selected as the control group. Forty 8-week-old male apoE KO mice were randomly divided into the model group, apoE KO ＋ intraperitoneal injection immunoglobulin group （IVIG）, apoE KO ＋ simvastatin group （Sm）, apoE KO ＋ high dosage of Xiongshao Capsule （XSC,芎芍胶囊） group （XSCH）, and apoE KO ＋ low dosage of XSC group （XSCL）, 8 mice in each group. Mice in the control group were put on a normal diet, and others were fed with a high-fat diet. After 10-week different interventions, monocyte CD16 expression was detected by flow cytometry, aortic matrix metalloproteinase-9 （MMP-9） mRNA expression was detected using reverse transcription- polymerase chain reaction, and serum tumor necrosis factor （TNF）-a level was detected using enzyme-linked immunosorbent assay. Results： Compared with the control group, monocyte CD16 expression, aortic MMP-9 mRNA expression, and serum TNF-a level in the model group increased obviously （P〈0.01）. Injections of apoE KO mice with intraperitoneal immunoglobulin during a 5-day period significantly reduced the monocyte CD16 expression, aortic MMP-9 mRNA expression, and serum TNF-a level （P〈0.01 or 0.05） over a 10-week period of high-fat diet. Indices above in the Sm group, XSCH group, and XSCL group decreased in a different degree. Of them, the aortic MMP-9 mRNA expression in XSCH group was lower than that in Sm group （P〈0.05） and the monocyte CD16 expression and serum TNF-a level showed no significant difference between XSCH group and Sm group （P〉0.05）. Correlation analyses suggested positive correlation between monocyte CD16 expression and aortic MMP-9 mRNA expression or serum TNF-a level in IVIG group, XSCH group, and XSCL group. Conclusions： Fc γ/R IliA mediates systemic inflammation in the progression of coronary heart disease with blood stasis syndrome. XSC could stabilize atherosclerotic plaque by suppressing inflammation and its target was relative with Fc γ RIIIA.
基金Supported by the National Natural Science Foundation of China （No. 81102584）Guangdong Provincial Administration of Traditional Chinese Medicine （No. 2009386）
文摘Objective： TO observe the effect of Huxin Formula （护心方, HXF） on expressions of the chief reverse cholesterol transport （RCT） associated genes, caveolin-1 and scavenger receptor-B I （SR-B I ） in ApoE-gene knockout [ApoE （-/-）] mice. Methods： Thirty ApoE （-/-） mice of 4-6 weeks old were randomly divided into three groups （A-C）. After being fed with high-fat diet for 16 weeks, they were treated with HXF （1 mL/100 g）, pravachol （0.3 mg/100 g）, and saline in equal volume respectively for 16 weeks successively; in addition, a blank group was set up with 10 C57BL/6J mice of 6-week old received 16-week high-fat feeding and saline treatment. Animals were sacrificed at the termination of the experiment, their paraffin sections of aortic tissue were used to measure the size of plaque, expressions of cavolin-1 and SR-B I were detected by immunological histochemical method. Results： As compared with the blank group, levels of caveolin-1 and SR-B I were increased in Groups A and B （P〈0.01）; but the increase in Group A was more significant than that in Group B （P〈0.05）. The plaque/aorta area ratio decreased significantly in Groups A and B, but showed insignificant difference between the two groups. Conclusion： HXF could obviously increase the expressions of RCT associated genes, caveolin-1 and SR-B I, promote the RCT process, so as to reduce the formation of aorta atherosclerotic plaque in ApoE （-/-） mice.
文摘Estrogen deficiency mediates aging, but the underlying mechanism remains to be fully determined. We report here that estrogen deficiency caused by targeted disruption of aromatase in mice results in significant inhibition of telomerase activity in the adrenal gland in vivo. Gene expression analysis showed that, in the absence of estrogen, telomerase reverse transcriptase （TERT） gene expression is reduced in association with compromised cell proliferation in the adrenal gland cortex and adrenal atrophy. Stem cells positive in c-kit are identified to populate in the parenchyma of adrenal cortex. Analysis of telomeres revealed that estrogen deficiency results in significantly shorter teiomeres in the adrenal cortex than that in wild-type （WT） control mice. To further establish the causal effects of estrogen, we conducted an estrogen replacement therapy in these estrogen-deficient animals. Administration of estrogen for 3 weeks restores TERT gene expression, telomerase activity and cell proliferation in estrogen-deficient mice. Thus, our data show for the first time that estrogen deficiency causes inhibitions of TERT gene expression, telomerase activity, telomere maintenance, and cell proliferation in the adrenal gland of mice in vivo, suggesting that telomerase inhibition and telomere shortening may mediate cell proliferation arrest in the adrenal gland, thus contributing to estrogen deficiency-induced aging under physiological conditions.
文摘RIG-I （retinoid acid-inducible gene-I）, a putative RNA helicase with a cytoplasmic caspase-recrultment domain （CARD）, was identified as a pattem-recognition receptor （PRR） that mediates antiviral immunity by inducing type I interferon production. To further study the biological function of RIG-I, we generated Rig-I^-/- mice through homologous recombination, taking a different strategy to the previously reported strategy. Our Rig-I^-/- mice are viable and fertile. Histological analysis shows that Rig-I^-/ mice develop a colitis-like phenotype and increased susceptibility to dextran sulfate sodium-induced colitis. Accordingly, the size and number of Peyer＇s patches dramatically decreased in mutant mice. The peripheral T-cell subsets in mutant mice are characterized by an increase in effector T cells and a decrease in naive T cells, indicating an important role for Rig-I in the regulation ofT-cell activation. It was further found that Rig-I deficiency leads to the downregulation of G protein αi2 subunit （Gαi2） in various tissues, including T and B lymphocytes. By contrast, upregulation of Rig-I in NB4 cells that are treated with ATRA is accompanied by elevated Gαi2 expression. Moreover, Gαi2 promoter activity is increased in co-transfected NIH3T3 cells in a Rig-I dose-dependent manner. All these findings suggest that Rig-I has crucial roles in the regulation of Gαi2 expression and T-cell activation. The development of colitis may be, at least in part, associated with downregulation of Gαi2 and disturbed T-cell homeostasis.
基金supported by grants from the NIH: R01 AR052746 to TLC and R01 AR062074 to DJD
文摘Growth hormone （GH） exerts profound anabolic actions during postnatal skeletal development, in part, through stimulating the production of insulin-like growth factor-1 （IGF-1） in liver and skeletal tissues. To examine the requirement for the GH receptor （GHR） in osteoblast function in bone, we used Cre-LoxP methods to disrupt the GHR from osteoblasts, both in vitro and in vivo. Disruption of GHR from primary calvarial osteoblasts in vitro abolished GH-induced signaling, as assessed by JAK2/STAT5 phosphorylation, and abrogated GH-induced proliferative and anti-apoptotic actions. Osteoblasts lacking GHR exhibited reduced IGF-l-induced Erk and Akt phosphorylation and attenuated IGF-1-induced proliferation and anti-apoptotic action. In addition, differentiation was modestly impaired in osteoblasts lacking GHR, as demonstrated by reduced alkaline phosphatase staining and calcium deposition. In order to determine the requirement for the GHR in bone in vivo, we generated mice lacking the GHR specifically in osteoblasts （△GHR）, which were born at the expected Mendelian frequency, had a normal life span and were of normal size. Three week-old, female AGHR mice had significantly reduced osteoblast numbers, consistent with the in vitro data. By six weeks of age however, female AGHR mice demonstrated a marked increase in osteoblasts, although mineralization was impaired; a phenotype similar to that observed previously in mice lacking IGF-1R specifically in osteoblasts. The most striking phenotype occurred in male mice however, where disruption of the GHR from osteoblasts resulted in a ＂feminization＂ of bone geometry in 16 week-old mice, as observed by faCT. These results demonstrate that the GHR is required for normal postnatal bone development in both sexes. GH appears to serve a primary function in modulating local IGF-1 action. However, the changes in bone geometry observed in male AGHR mice suggest that, in addition to facilitating IGF-1 action, GH may function to a greater extent than previously appreciated in establishing the sexual dimorphism of the skeleton.
文摘Androgen deprivation in men leads to increased adiposity, but the mechanisms underlying androgen regulation of fat mass have not been fully defined. Androgen receptor （AR） is expressed in monocytes/macrophages, which are resident in key metabolic tissues and influence energy metabolism in surrounding cells. Male mice bearing a cell-specific knockout of the AR in monocytes/macrophages （M-ARKO） were generated to determine whether selective loss of androgen signaling in these cells would lead to altered body composition. Wild-type （WT） and M-ARKO mice （12-22 weeks of age, n = 12 per group） were maintained on a regular chow diet for 8 weeks and then switched to a high-fat diet for 8 additional weeks. At baseline and on both the regular chow and high-fat diets, no differences in lean mass or fat mass were observed between groups. Consistent with the absence of differential body weight or adiposity, no differences in food intake （3.0 ± 0.5 g per day for WT mice vs 2.8 ± 0.4 g per day for M-ARKO mice） or total energy expenditure （0.6 ± 0.1 Kcal h-1 for WT mice vs 0.5 ± 0.1 Kcal h-1 for M-ARKO mice） were evident between groups during high-fat feeding. Liver weight was greater in M-ARKO than that in WT mice （1.5 ± 0.1 g vs 1.3 ± 0.0 g, respectively, P = 0.02）. Finally, M-ARKO mice did not exhibit impairments in glucose tolerance or insulin sensitivity relative to WT mice at any study time point. In aggregate, these findings suggest that AR signaling specifically in monocytes/macrophages does not contribute to the regulation of systemic energy balance, adiposity, or insulin sensitivity in male mice.
文摘Gene expression analyses suggest that more than 1000–2000 genes are expressed predominantly in mouse and human testes.Although functional analyses of hundreds of these genes have been performed,there are still many testis-enriched genes whose functions remain unexplored.Analyzing gene function using knockout(KO)mice is a powerful tool to discern if the gene of interest is essential for sperm formation,function,and male fertility in vivo.In this study,we generated KO mice for 12 testis-enriched genes,1700057G04Rik,4921539E11Rik,4930558C23Rik,Cby2,Ldhal6b,Rasef,Slc25a2,Slc25a41,Smim8,Smim9,Tmem210,and Tomm20l,using the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9(CRISPR/Cas9)system.We designed two gRNAs for each gene to excise almost all the protein-coding regions to ensure that the deletions in these genes result in a null mutation.Mating tests of KO mice reveal that these 12 genes are not essential for male fertility,at least when individually ablated,and not together with other potentially compensatory paralogous genes.Our results could prevent other laboratories from expending duplicative effort generating KO mice,for which no apparent phenotype exists.
文摘Neuropeptide Y (NPY) is a potent neurotransmitter for feeding. Besides NPY, orexigenic neuropeptides such as agouti-related protein (AgRP), and anorexi- genic neuropeptides such as α-melatonin stimulating hormone (MSH) and cocaine-amphetamine-regulated transcript (CART) are also involved in central feeding regulation. During fasting, NPY and AgRP gene expressions are up-regulated and POMC and CART gene ex- pressions are down-regulated in hypothalamus. Based on the network of peptidergic neurons, the former are involved in positive feeding regulation, and the latter are involved in negative feeding, which exert these feeding-regulated peptides especially in paraventricular nucleus (PVN). To clarify the compensatory mecha- nism of knock-out of NPY system on feeding, change in gene expressions of appetite-related neuropeptides and the feeding behavior was studied in NPY Y5-KO mice. Food intake was increased in Y5-KO mice. Fasting increased the amounts of food and water intake in the KO mice more profoundly. These data indicated the compensatory phenomenon of feeding behavior in Y5-KO mice. RT-PCR and ISH suggested that the compensation of feeding is due to change in gene expressions of AgRP, CART and POMC in hypothalamus. Thus, these fi ndings indicated that the compensatory mechanism involves change in POMC/CART gene expression in arcuate nucleus (ARC). The POMC/CART gene expression is important for central compensatory regulation in feeding behavior.
基金supported by a grant from the National Natural Sciences Foundation of China(No.30200109)
文摘In the ApoE^-/- mouse model of atherosclerosis （AS） stable plaque, the expression and location of intracellular tissue factor （TF） in the cellular components of AS stable plaque were investigated in order to explore the cellular mechanism of AS thrombosis. Pathological changes of the stable plaque were observed under a microscope. The expression of TF protein was examined in aortic stable plaque of mice by using immunohistochemistry. Color image planimetric system was used to analyze the histological components of the stable plaque and the TF distribution. Under the confocal microscope, the intracellular TF location in the stable plaque of mice was observed. The results showed the cellular area was the major part of stable plaque （67.36%±6.52%, P〈0.01）. The percentage of total area occupied by cellular area was significantly larger than atheromatous gruel and acellular area （P〈0.01）. Macrophages and smooth muscle cells （SMC） were major cells in the cellular area. The percentage of total area occupied by SMC was significantly larger than by macrophages （P〈0.01）. Multiple linear regression analysis showed there was a positive correlation between TF area and SMC area （r=0.616, P=-0.008）, and no correlation was found between TF area and macrophage area （r=0.437, P=0.08）. Pictures of color image planimetric analysis of TF and SMC were merged to highlight areas with co-localization （yellow）, it was concluded that the process could be a cell-mediated TF expression in the stable plaque. SMC may be the major source of TF in AS without plaque rupture.
文摘AIM: To explore the pathogenesis, influencing factors, ways of medical intervention and evaluation indicators of cataract by observing changes in serum biochemical indices in mice with targeted disruption of βB2-crystallin. · METHODS: Nine 6-week-old male mice with targeted knockout of βB2-crystallin were used as the study group, and nine age- and sex-matched normal wild-type mice as the control group. The genetype of the modeled mice was identified by PCR technique. Tropicamide and phenylephrine eye drops were used as the cycloplegic agents to observe changes in lens opacity with a slit-lamp. The lens was then removed and blood was collected for biochemical evaluation in the serum. · RESULTS: Two genotypes were successfully identified by PCR technique. Slit-lamp observation showed that the lens cortex was opaque and GSH level in the lens cortex was remarkably decreased in mice with βB2-crystallin deficiency compared with the control group (P <0.01). Serum Na+, Cl-, Ca2+, Mg2+ and Fe2+ levels, ALT and AST activities, and TP, ALP, Cr, TC, GLU content were decreased significantly compared with the control group (P <0.05). There was no difference in LDH, P, Cu2+, K+ levels between the two groups (P >0.05). · CONCLUSION: Compared with the wild-type mice, serum biochemical indices underwent significant changes in mice with targeted disruption of βB2-crystallin gene, especially with abnormal distribution of Na+&Ca2+, which induced the formation of cataract.
文摘Insulin resistance is a hallmark of type 2 diabetes. In an effort to understand and treat this condition, re searchers have used genetic manipulation of mice to uncover insulin signaling pathways and determine the effects of their perturbation. After decades of research much has been learned, but the pathophysiology o insulin resistance in human diabetes remains contro versial, and treating insulin resistance remains a chal lenge. This review will discuss limitations of mouse models lacking select insulin signaling molecule genes In the most influential mouse models, glucose metabo lism differs from that of humans at the cellular, organ and whole-organism levels, and these differences limi the relevance and benefit of the mouse models both in terms of mechanistic investigations and therapeutic development. These differences are due partly to im mutable differences in mouse and human biology, and partly to the failure of genetic modifications to produce an accurate model of human diabetes. Several fac tors often limit the mechanistic insights gained from experimental mice to the particular species and strain including: developmental effects, unexpected meta bolic adjustments, genetic background effects, and technical issues. We conclude that the limitations and weaknesses of genetically modified mouse models of insulin resistance underscore the need for redirection of research efforts toward methods that are more directly relevant to human physiology.
