The mechanism of androgen action is complex. Recently, significant advances have been made into our understanding of how androgens act via the androgen receptor （AR） through the use of genetically modified mouse mod...The mechanism of androgen action is complex. Recently, significant advances have been made into our understanding of how androgens act via the androgen receptor （AR） through the use of genetically modified mouse models. A number of global and tissue-specific AR knockout （ARKO） models have been generated using the Cre-loxP system which allows tissue- and/or cell-specific deletion. These ARKO models have examined a number of sites of androgen action including the cardiovascular system, the immune and hemopoetic system, bone, muscle, adipose tissue, the prostate and the brain. This review focuses on the insights that have been gained into human androgen deficiency through the use of ARKO mouse models at each of these sites of action, and highlights the strengths and limitations of these Cre-loxP mouse models that should be considered to ensure accurate interpretation of the phenotype.展开更多
An allelic variant of the protein tyrosin phosphatase non-receptor 22(PTPN22) gene, PTPN22 R620 W, constitutes the strongest non-HLA genetic risk factor for the development of type 1 diabetes(T1D). A numberstudies usi...An allelic variant of the protein tyrosin phosphatase non-receptor 22(PTPN22) gene, PTPN22 R620 W, constitutes the strongest non-HLA genetic risk factor for the development of type 1 diabetes(T1D). A numberstudies using mouse models have addressed how PTPN22 predisposes to T1D. PTPN22 downmodulation, overexpression or expression of the variant gene in genetically manipulated mice has generated controversial results. These discrepancies probably derive from the fact that PTPN22 has differential effects on innate and adaptive immune responses. Moreover, the effects of PTPN22 are dependent on other genetic variables. Here we discuss these findings and try to explain the discrepancies. Exploring the mechanism by which PTPN22 contributes to islet-specific autoimmunity could help us understand its role in T1D pathogenesis and exploit it as a potential therapeutic target to prevent the disease.展开更多
Tissue-specific knockout technology enables the analysis of the gene function in specific tissues in adult mammals.However,conventional strategy for producing tissue-specific knockout mice is a time- and labor-consumi...Tissue-specific knockout technology enables the analysis of the gene function in specific tissues in adult mammals.However,conventional strategy for producing tissue-specific knockout mice is a time- and labor-consuming process,restricting rapid study of the gene function in vivo.CRISPR-Cas9 system from bacteria is a simple and efficient gene-editing technique,which has enabled rapid generation of gene knockout lines in mouse by direct injection of CRISPR-Cas9 into zygotes.Here,we demonstrate CRISPR-Cas9-mediated spermatogenic cell-specific disruption of Scp3 gene in testes in one step.We first generated transgenic mice by pronuclear injection of a plasmid containing Hspa2 promoter driving Cas9 expression and showed Cas9 specific expression in spermatogenic cells.We then produced transgenic mice carrying Hspa2 promoter driven Cas9 and constitutive expressed sgRNA targeting Scp3 gene.Male founders were infertile due to developmental arrest of spermatogenic cells while female founders could produce progeny normally.Consistently,male progeny from female founders were infertile and females could transmit the transgenes to the next generation.Our study establishes a CRISPR-Cas9-based one-step strategy to analyze the gene function in adult tissues by a temporal-spatial pattern.展开更多
Membrane-initiated estrogen receptorα(mERα)signaling has been shown to affect bone mass in murine models.However,it remains unknown which cell types mediate the mERα-dependent effects on bone.In this study,we gener...Membrane-initiated estrogen receptorα(mERα)signaling has been shown to affect bone mass in murine models.However,it remains unknown which cell types mediate the mERα-dependent effects on bone.In this study,we generated a novel mouse model with a conditional C451A mutation in Esr1,which enables selective knockout of the palmitoylation site essential for the membrane localization of ERα(C451A^(f/f)).First,we used Runx2-Cre mice to generate Runx2-C451A^(f/f)mice with conditional inactivation of mERαsignaling in Runx2-expressing osteoblast lineage cells.No significant changes were observed in body weight,weights of estrogen-responsive organs,or serum concentrations of estradiol between female Runx2-C451A^(f/f)and homozygous C451A^(f/f)littermate controls.High-resolution microcomputed tomography analysis showed a consistent decrease in cortical bone mass in the tibia,femur,and vertebra L5 of Runx2-C451A^(f/f)mice and three-point bending analysis of humerus revealed an impaired mechanical bone strength in Runx2-C451A^(f/f)female mice compared to controls.Additionally,primary osteoblast cultures from mice lacking mERαsignaling showed impaired differentiation compared to controls.展开更多
目的:探讨Kindlin-2对小鼠子宫发育及雌鼠生育能力的影响及其作用机制。方法:利用Cdh16-Cre工具鼠和Kindlin-2^(flox/flox)小鼠构建在子宫内膜中特异性敲除Kindlin-2的小鼠模型,观察敲除Kindlin-2对雌鼠子宫内膜发育和生殖力的影响。在...目的:探讨Kindlin-2对小鼠子宫发育及雌鼠生育能力的影响及其作用机制。方法:利用Cdh16-Cre工具鼠和Kindlin-2^(flox/flox)小鼠构建在子宫内膜中特异性敲除Kindlin-2的小鼠模型,观察敲除Kindlin-2对雌鼠子宫内膜发育和生殖力的影响。在子宫内膜癌细胞系HEC-1和Ish中分别进行高表达和敲低Kindlin-2的实验,检测雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)信号通路的激活变化,并且提取特异性敲除Kindlin-2的雌鼠(实验组,基因型为Cdh16-Cre;Kindlin-2^(flox/flox))和未特异性敲除Kindlin-2的雌鼠(对照组,基因型为Kindlin-2^(flox/flox))子宫蛋白,每组包含6~8只小鼠,重复3次独立实验,检测mTOR信号通路和Hippo信号通路关键分子的蛋白水平。结果:成功构建了子宫内膜特异性敲除Kindlin-2的小鼠模型,通过鼠尾聚合酶链式反应(polymerase chain reaction,PCR)、Western blot、免疫组织化学染色(immunohistochemistry,IHC)等方法鉴定和验证Kindlin-2在小鼠子宫中的敲除效率。子宫内膜特异性敲除Kindlin-2的雌鼠与对照组相比体质量减轻、生殖能力严重受损、出生仔鼠数量减少,但出生仔鼠中雌鼠和雄鼠的比例未发生改变,通过苏木精-伊红染色实验观察表明实验组子宫内膜发育不完整、子宫壁厚度变薄。机制方面,子宫内膜癌细胞系HEC-1和Ish中敲除Kindlin-2能够下调mTOR、磷酸化mTOR、腺嘌呤核糖核苷酸激活蛋白激酶(adenosine monophosphate-activated protein kinase,AMPK)、磷酸化的AMPK和磷酸化的核糖体蛋白(ribosomal protein S6,S6)的蛋白水平,在雌鼠子宫中发现特异性敲除Kindlin-2能够上调Mps结合1(Mps one binding 1,MOB1)、磷酸化的Yes相关蛋白(Yes-associated protein,YAP)的蛋白水平。结论:Kindlin-2通过抑制mTOR信号通路、激活Hippo信号通路抑制子宫内膜的发育,进而抑制雌鼠的生育能力。展开更多
Phosphatidylserine(PS)is distributed asymmetrically in the plasma membrane of eukaryotic cells.Phosphatidylserine flippase(P4-ATPase)transports PS from the outer leaflet of the lipid bilayer to the inner leaflet of th...Phosphatidylserine(PS)is distributed asymmetrically in the plasma membrane of eukaryotic cells.Phosphatidylserine flippase(P4-ATPase)transports PS from the outer leaflet of the lipid bilayer to the inner leaflet of the membrane to maintain PS asymmetry.TheβsubunitTMEM30 Ais indispensable for transport and proper function of P4-ATPase.Previous studies have shown that the ATP11 A and TMEM30 A complex is the molecular switch for myotube formation.However,the role of Tmem30 a in skeletal muscle regeneration remains elusive.In the current study,Tmem30 a was highly expressed in the tibialis anterior(TA)muscles of dystrophin-null(mdx)mice and BaCl2-induced muscle injury model mice.We generated a satellite cell(SC)-specific Tmem30 a conditional knockout(cKO)mouse model to investigate the role of Tmem30 a in skeletal muscle regeneration.The regenerative ability of cKO mice was evaluated by analyzing the number and diameter of regenerated SCs after the TA muscles were injured by BaCl2-injection.Compared to the control mice,the cKO mice showed decreased Pax7+and MYH3+SCs,indicating diminished SC proliferation,and decreased expression of muscular regulatory factors(MYOD and MYOG),suggesting impaired myoblast proliferation in skeletal muscle regeneration.Taken together,these results demonstrate the essential role of Tmem30 a in skeletal muscle regeneration.展开更多
To determine the mechanistic role of fibrinogen, a key regulator of inflammation and fibrosis, in early and delayed radiation enteropathy. METHODSFibrinogen wild-type (Fib<sup>+/+</sup>), fibrinogen hetero...To determine the mechanistic role of fibrinogen, a key regulator of inflammation and fibrosis, in early and delayed radiation enteropathy. METHODSFibrinogen wild-type (Fib<sup>+/+</sup>), fibrinogen heterozygous (Fib<sup>+/-</sup>), and fibrinogen knockout (Fib<sup>-/-</sup>) mice were exposed to localized intestinal irradiation and assessed for early and delayed structural changes in the intestinal tissue. A 5-cm segment of ileum of mice was exteriorized and exposed to 18.5 Gy of x-irradiation. Intestinal tissue injury was assessed by quantitative histology, morphometry, and immunohistochemistry at 2 wk and 26 wk after radiation. Plasma fibrinogen level was measured by enzyme-linked immunosorbent assay. RESULTSThere was no difference between sham-irradiated Fib<sup>+/+</sup> and Fib<sup>+/-</sup> mice in terms of fibrinogen concentration in plasma and intestinal tissue, intestinal histology, morphometry, intestinal smooth muscle cell proliferation, and neutrophil infiltration. Therefore, Fib<sup>+/-</sup> mice were used as littermate controls. Unlike sham-irradiated Fib<sup>+/+</sup> and Fib<sup>+/-</sup> mice, no fibrinogen was detected in the plasma and intestinal tissue of sham-irradiated Fib<sup>-/-</sup> mice. Moreover, fibrinogen level was not elevated after irradiation in the intestinal tissue of Fib<sup>-/-</sup> mice, while significant increase in intestinal fibrinogen level was noticed in irradiated Fib<sup>+/+</sup> and Fib<sup>+/-</sup> mice. Importantly, irradiated Fib<sup>-/-</sup> mice exhibited substantially less overall intestinal structural injury (RIS, P = 0.000002), intestinal wall thickness (P = 0.003), intestinal serosal thickness (P = 0.009), collagen deposition (P = 0.01), TGF-β immunoreactivity (P = 0.03), intestinal smooth muscle proliferation (P = 0.046), neutrophil infiltration (P = 0.01), and intestinal mucosal injury (P = 0.0003), compared to irradiated Fib<sup>+/+</sup> and Fib<sup>+/-</sup> mice at both 2 wk and 26 wk. CONCLUSIONThese data demonstrate that fibrinogen deficiency directly attenuates development of early and delayed radiation enteropathy. Fibrinogen could be a novel target in treating intestinal damage.展开更多
文摘The mechanism of androgen action is complex. Recently, significant advances have been made into our understanding of how androgens act via the androgen receptor （AR） through the use of genetically modified mouse models. A number of global and tissue-specific AR knockout （ARKO） models have been generated using the Cre-loxP system which allows tissue- and/or cell-specific deletion. These ARKO models have examined a number of sites of androgen action including the cardiovascular system, the immune and hemopoetic system, bone, muscle, adipose tissue, the prostate and the brain. This review focuses on the insights that have been gained into human androgen deficiency through the use of ARKO mouse models at each of these sites of action, and highlights the strengths and limitations of these Cre-loxP mouse models that should be considered to ensure accurate interpretation of the phenotype.
文摘An allelic variant of the protein tyrosin phosphatase non-receptor 22(PTPN22) gene, PTPN22 R620 W, constitutes the strongest non-HLA genetic risk factor for the development of type 1 diabetes(T1D). A numberstudies using mouse models have addressed how PTPN22 predisposes to T1D. PTPN22 downmodulation, overexpression or expression of the variant gene in genetically manipulated mice has generated controversial results. These discrepancies probably derive from the fact that PTPN22 has differential effects on innate and adaptive immune responses. Moreover, the effects of PTPN22 are dependent on other genetic variables. Here we discuss these findings and try to explain the discrepancies. Exploring the mechanism by which PTPN22 contributes to islet-specific autoimmunity could help us understand its role in T1D pathogenesis and exploit it as a potential therapeutic target to prevent the disease.
基金supported by the grants from the Ministry of Science and Technology of China(Nos.2014CB964803 and 2015AA020307)the National Natural Science Foundation of China(Nos.91319310,31225017 and 31530048)the Chinese Academy of Sciences(No.XDA01010403)
文摘Tissue-specific knockout technology enables the analysis of the gene function in specific tissues in adult mammals.However,conventional strategy for producing tissue-specific knockout mice is a time- and labor-consuming process,restricting rapid study of the gene function in vivo.CRISPR-Cas9 system from bacteria is a simple and efficient gene-editing technique,which has enabled rapid generation of gene knockout lines in mouse by direct injection of CRISPR-Cas9 into zygotes.Here,we demonstrate CRISPR-Cas9-mediated spermatogenic cell-specific disruption of Scp3 gene in testes in one step.We first generated transgenic mice by pronuclear injection of a plasmid containing Hspa2 promoter driving Cas9 expression and showed Cas9 specific expression in spermatogenic cells.We then produced transgenic mice carrying Hspa2 promoter driven Cas9 and constitutive expressed sgRNA targeting Scp3 gene.Male founders were infertile due to developmental arrest of spermatogenic cells while female founders could produce progeny normally.Consistently,male progeny from female founders were infertile and females could transmit the transgenes to the next generation.Our study establishes a CRISPR-Cas9-based one-step strategy to analyze the gene function in adult tissues by a temporal-spatial pattern.
基金supported by the Swedish Research Council(2017-01286,2020-01840)the Swedish state under the agreement between the Swedish government and the county councils(ALF-agreement)(ALFGBG721581)+2 种基金the Gustaf V 80-years fund(FAI-2018-0466)the IngaBritt and Arne Lundberg Foundation(LU2017-0076)the Novo Nordisk Foundation(26844).
文摘Membrane-initiated estrogen receptorα(mERα)signaling has been shown to affect bone mass in murine models.However,it remains unknown which cell types mediate the mERα-dependent effects on bone.In this study,we generated a novel mouse model with a conditional C451A mutation in Esr1,which enables selective knockout of the palmitoylation site essential for the membrane localization of ERα(C451A^(f/f)).First,we used Runx2-Cre mice to generate Runx2-C451A^(f/f)mice with conditional inactivation of mERαsignaling in Runx2-expressing osteoblast lineage cells.No significant changes were observed in body weight,weights of estrogen-responsive organs,or serum concentrations of estradiol between female Runx2-C451A^(f/f)and homozygous C451A^(f/f)littermate controls.High-resolution microcomputed tomography analysis showed a consistent decrease in cortical bone mass in the tibia,femur,and vertebra L5 of Runx2-C451A^(f/f)mice and three-point bending analysis of humerus revealed an impaired mechanical bone strength in Runx2-C451A^(f/f)female mice compared to controls.Additionally,primary osteoblast cultures from mice lacking mERαsignaling showed impaired differentiation compared to controls.
文摘目的:探讨Kindlin-2对小鼠子宫发育及雌鼠生育能力的影响及其作用机制。方法:利用Cdh16-Cre工具鼠和Kindlin-2^(flox/flox)小鼠构建在子宫内膜中特异性敲除Kindlin-2的小鼠模型,观察敲除Kindlin-2对雌鼠子宫内膜发育和生殖力的影响。在子宫内膜癌细胞系HEC-1和Ish中分别进行高表达和敲低Kindlin-2的实验,检测雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)信号通路的激活变化,并且提取特异性敲除Kindlin-2的雌鼠(实验组,基因型为Cdh16-Cre;Kindlin-2^(flox/flox))和未特异性敲除Kindlin-2的雌鼠(对照组,基因型为Kindlin-2^(flox/flox))子宫蛋白,每组包含6~8只小鼠,重复3次独立实验,检测mTOR信号通路和Hippo信号通路关键分子的蛋白水平。结果:成功构建了子宫内膜特异性敲除Kindlin-2的小鼠模型,通过鼠尾聚合酶链式反应(polymerase chain reaction,PCR)、Western blot、免疫组织化学染色(immunohistochemistry,IHC)等方法鉴定和验证Kindlin-2在小鼠子宫中的敲除效率。子宫内膜特异性敲除Kindlin-2的雌鼠与对照组相比体质量减轻、生殖能力严重受损、出生仔鼠数量减少,但出生仔鼠中雌鼠和雄鼠的比例未发生改变,通过苏木精-伊红染色实验观察表明实验组子宫内膜发育不完整、子宫壁厚度变薄。机制方面,子宫内膜癌细胞系HEC-1和Ish中敲除Kindlin-2能够下调mTOR、磷酸化mTOR、腺嘌呤核糖核苷酸激活蛋白激酶(adenosine monophosphate-activated protein kinase,AMPK)、磷酸化的AMPK和磷酸化的核糖体蛋白(ribosomal protein S6,S6)的蛋白水平,在雌鼠子宫中发现特异性敲除Kindlin-2能够上调Mps结合1(Mps one binding 1,MOB1)、磷酸化的Yes相关蛋白(Yes-associated protein,YAP)的蛋白水平。结论:Kindlin-2通过抑制mTOR信号通路、激活Hippo信号通路抑制子宫内膜的发育,进而抑制雌鼠的生育能力。
基金supported by the National Natural Science Foundation of China(81770950,81970841)Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(2019-12M-5-032)Department of Science and Technology of Sichuan Province(21ZDYF4279,2020JDZH0026,2021JDZH0022)。
文摘Phosphatidylserine(PS)is distributed asymmetrically in the plasma membrane of eukaryotic cells.Phosphatidylserine flippase(P4-ATPase)transports PS from the outer leaflet of the lipid bilayer to the inner leaflet of the membrane to maintain PS asymmetry.TheβsubunitTMEM30 Ais indispensable for transport and proper function of P4-ATPase.Previous studies have shown that the ATP11 A and TMEM30 A complex is the molecular switch for myotube formation.However,the role of Tmem30 a in skeletal muscle regeneration remains elusive.In the current study,Tmem30 a was highly expressed in the tibialis anterior(TA)muscles of dystrophin-null(mdx)mice and BaCl2-induced muscle injury model mice.We generated a satellite cell(SC)-specific Tmem30 a conditional knockout(cKO)mouse model to investigate the role of Tmem30 a in skeletal muscle regeneration.The regenerative ability of cKO mice was evaluated by analyzing the number and diameter of regenerated SCs after the TA muscles were injured by BaCl2-injection.Compared to the control mice,the cKO mice showed decreased Pax7+and MYH3+SCs,indicating diminished SC proliferation,and decreased expression of muscular regulatory factors(MYOD and MYOG),suggesting impaired myoblast proliferation in skeletal muscle regeneration.Taken together,these results demonstrate the essential role of Tmem30 a in skeletal muscle regeneration.
基金Supported by Arkansas Space Grant Consortium and National Space Biomedical Research Institute through National Aeronautics and Space Administration,No.NNX15AK32A(RP)and No.RE03701(MH-J)National Institutes of Health,No.P20 GM109005(MH-J)
文摘To determine the mechanistic role of fibrinogen, a key regulator of inflammation and fibrosis, in early and delayed radiation enteropathy. METHODSFibrinogen wild-type (Fib<sup>+/+</sup>), fibrinogen heterozygous (Fib<sup>+/-</sup>), and fibrinogen knockout (Fib<sup>-/-</sup>) mice were exposed to localized intestinal irradiation and assessed for early and delayed structural changes in the intestinal tissue. A 5-cm segment of ileum of mice was exteriorized and exposed to 18.5 Gy of x-irradiation. Intestinal tissue injury was assessed by quantitative histology, morphometry, and immunohistochemistry at 2 wk and 26 wk after radiation. Plasma fibrinogen level was measured by enzyme-linked immunosorbent assay. RESULTSThere was no difference between sham-irradiated Fib<sup>+/+</sup> and Fib<sup>+/-</sup> mice in terms of fibrinogen concentration in plasma and intestinal tissue, intestinal histology, morphometry, intestinal smooth muscle cell proliferation, and neutrophil infiltration. Therefore, Fib<sup>+/-</sup> mice were used as littermate controls. Unlike sham-irradiated Fib<sup>+/+</sup> and Fib<sup>+/-</sup> mice, no fibrinogen was detected in the plasma and intestinal tissue of sham-irradiated Fib<sup>-/-</sup> mice. Moreover, fibrinogen level was not elevated after irradiation in the intestinal tissue of Fib<sup>-/-</sup> mice, while significant increase in intestinal fibrinogen level was noticed in irradiated Fib<sup>+/+</sup> and Fib<sup>+/-</sup> mice. Importantly, irradiated Fib<sup>-/-</sup> mice exhibited substantially less overall intestinal structural injury (RIS, P = 0.000002), intestinal wall thickness (P = 0.003), intestinal serosal thickness (P = 0.009), collagen deposition (P = 0.01), TGF-β immunoreactivity (P = 0.03), intestinal smooth muscle proliferation (P = 0.046), neutrophil infiltration (P = 0.01), and intestinal mucosal injury (P = 0.0003), compared to irradiated Fib<sup>+/+</sup> and Fib<sup>+/-</sup> mice at both 2 wk and 26 wk. CONCLUSIONThese data demonstrate that fibrinogen deficiency directly attenuates development of early and delayed radiation enteropathy. Fibrinogen could be a novel target in treating intestinal damage.
