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ABSTRACT: Previous microRNA (miRNA) array results have shown that the expression of miR-27b is upregulated in heart tissues from human cardiomyopathy and pressure-overloaded hypertrophic mouse model, implying that miR-27b might play an important role in heart diseases. To study the in vivo function of miR-27b, we generated a transgenic mouse line overexpressing miR-27b under the control of the 5.5 kb promoter of a-myosin heavy chain (a-MHC). Real-time PCR results demonstrated that miR-27b precursor and mature miR-27b were significantly increased in the heart tissues of miR-27b transgenic mice. miR-27b transgenic mice not only displayed cardiac hypertrophy, but also exhibited significant cardiac fibrosis. Further study showed that matrix metalloproteinase 13 (MMP13), a key regulator involved in cardiac fibrosis, was the target of miR-27b. The expression of MMP13 was decreased and the expression of Col I and III was increased in miR-27b transgenic mice.. In addition, defects in ultrastructral architecture were also found in miR-27b trans-genic mice. The above results demonstrated that miR-27b might promote cardiac fibrosis through inhibiting MMP13.
Hereditas (Beijing) 03/2012; 34(3):326-34.
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ABSTRACT: The aim of this work is to prepare a controlled-release formulation of uniconazole using porous hollow silica nanoparticles (PHSNs) as carrier, and to investigate the biological effects on rice growth.
PHSNs with a shell thickness of ~15 nm and a particle size of 80-100 nm were synthesised through a sol-gel route using nanosized calcium carbonate particles as templates. Simple immersing (SI) and supercritical fluid drug loading (SFDL) technologies were employed to load uniconazole into PHSNs with loading efficiencies of ~22 and ~26% respectively. The prepared uniconazole-loaded PHSNs (UCZ-PHSNs) by SI and SFDL both demonstrated sustained release properties, and the latter showed better controlled release ability with a slower release rate. Compared with free uniconazole, UCZ-PHSNs exhibited a weaker growth retardation effect in the early stage but more significant retardation ability in later stages for agar-cultured rice seedlings. For the rice that grew in clay, UCZ-PHSNs demonstrated a weaker plant height retardation effect than free uniconazole at the early jointing stage by foliar spraying, but exhibited a stronger retardation capacity than free uniconazole by being applied into soil before seedling transplantation.
The results indicated that the prepared UCZ-PHSNs possessed good controlled-release properties and had improved retardation effects on rice growth. It is recommended that UCZ-PHSNs be applied into soil before seedling transplantation rather than administered by foliar spraying at the early jointing stage.
Pest Management Science 03/2012; 68(3):437-43. · 2.25 Impact Factor
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ABSTRACT: Geft is a guanine nucleotide exchange factor, which can specifically activate Rho family of small GTPase by catalyzing the exchange of bound GDP for GTP. Geft is highly expressed in the excitable tissue as heart and skeletal muscle and plays important roles in many cellular processes, such as cell proliferation, migration, and cell fate decision. However, the in vivo role of Geft remains unknown. Here, we generated a Geft conditional knockout mouse by flanking exons 5-17 of Geft with loxP sites. Cre-mediated deletion of the Geft gene in heart using Mef2c-Cre transgenic mice resulted in a dramatic decrease of Geft expression. Geft knockout mice develop normally and exhibit no discernable phenotype, suggesting Geft is dispensable for the development of the second heart field in mouse. The Geft conditional knockout mouse will be a valuable genetic tool for uncovering the in vivo roles of Geft during development and in adult homeostasis. [BMB reports 2012; 45(3): 153-158].
BMB reports 03/2012; 45(3):153-8. · 1.72 Impact Factor
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ABSTRACT: Protein phosphatase magnesium-dependent 1A (PPM1A), a protein serine/threonine phosphatase, controls several signal pathways through cleavage of phosphate from its substrates. However, the in vivo function of Ppm1a in mammals remains unknown. Here we reported that mice lacking Ppm1a developed normally but were impaired in re-epithelialization process during cutaneous wound healing. Specifically, complete or keratinocyte-specific deletion of Ppm1a led to delayed re-epithelialization with reduced keratinocyte migration upon wounding. We showed that this effect was the result of an increase in Smad2/3 phosphorylation in keratinocytes. Keratinocyte-specific Smad2 deficient mice displayed accelerated re-epithelialization with enhanced keratinocyte migration. Importantly, Smad2 and Ppm1a double mutant mice also exhibited accelerated re-epithelialization, demonstrating that the effect of Ppm1a on promoting re-epithelialization is mediated by Smad2 signaling. Furthermore, the decreased expression of specific integrins and matrix metalloproteinases (MMPs) may contribute to the retarded re-epithelialization in Ppm1a mutant mice. These data indicate that Ppm1a, through suppressing Smad2 signaling, plays a critical role in re-epithelialization during wound healing.
Journal of Biological Chemistry 12/2011; 286(49):42267-73. · 4.77 Impact Factor
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Yangmeng Wang,
Dianjun Wang,
Fangli Ren,
Yuanjiang Zhang,
Fuyu Lin, Ning Hou,
Xuan Cheng,
Peng Zhang,
Yinyin Wang,
Baoqing Jia,
Xiao Yang,
Zhijie Chang
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ABSTRACT: GdX (also named Ubl4A) is a house-keeping gene located on the X chromosome and encodes a protein harboring an ubiquitin-like domain in human and mouse. Although identified in 1988, the function of GdX remains unknown. To elucidate the role of GdX in vivo, we generated a conditional GdX knockout mouse in which Exon 2 was flanked by two loxP sites. We obtained viable and fertile mice with homozygous GdX(flox/flox) or GdX(flox/Y) allele. Germ-line transmission was confirmed by crossing the mouse bearing conditionally targeted allele with an EIIα-Cre transgenic mouse. GdX was successfully depleted in tissues of EIIα-Cre-GdX-null mice. GdX(-/-) and GdX(-/Y) mice are viable and exhibit normal development compared with wild-type littermates within 6 months during our observation. We also observed that GdX knockout male mice were functionally normal in the reproductive system where Ubl4B was specifically expressed. GdX(flox/flox) and GdX(flox/Y) conditional mice provide a tool for further tissue-specific function analysis of the GdX protein under different conditions.
genesis 12/2011; 50(7):534-42. · 2.53 Impact Factor
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Jian Wang,
Yao Song,
Yan Zhang,
Han Xiao,
Qiang Sun, Ning Hou,
Shuilong Guo,
Youliang Wang,
Kaiji Fan,
Dawei Zhan,
Lagabaiyila Zha,
Yang Cao,
Zhenhua Li,
Xuan Cheng,
Youyi Zhang,
Xiao Yang
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ABSTRACT: Recent studies have begun to reveal critical roles of microRNAs (miRNAs) in the pathogenesis of cardiac hypertrophy and dysfunction. In this study, we tested whether a transforming growth factor-β (TGF-β)-regulated miRNA played a pivotal role in the development of cardiac hypertrophy and heart failure (HF). We observed that miR-27b was upregulated in hearts of cardiomyocyte-specific Smad4 knockout mice, which developed cardiac hypertrophy. In vitro experiments showed that the miR-27b expression could be inhibited by TGF-β1 and that its overexpression promoted hypertrophic cell growth, while the miR-27b suppression led to inhibition of the hypertrophic cell growth caused by phenylephrine (PE) treatment. Furthermore, the analysis of transgenic mice with cardiomyocyte-specific overexpression of miR-27b revealed that miR-27b overexpression was sufficient to induce cardiac hypertrophy and dysfunction. We validated the peroxisome proliferator-activated receptor-γ (PPAR-γ) as a direct target of miR-27b in cardiomyocyte. Consistently, the miR-27b transgenic mice displayed significantly lower levels of PPAR-γ than the control mice. Furthermore, in vivo silencing of miR-27b using a specific antagomir in a pressure-overload-induced mouse model of HF increased cardiac PPAR-γ expression, attenuated cardiac hypertrophy and dysfunction. The results of our study demonstrate that TGF-β1-regulated miR-27b is involved in the regulation of cardiac hypertrophy, and validate miR-27b as an efficient therapeutic target for cardiac diseases.
Cell Research 08/2011; 22(3):516-27. · 8.19 Impact Factor
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Jian Wang,
Yao Song,
Yan Zhang,
Han Xiao,
Qiang Sun, Ning Hou,
Shuilong Guo,
Youliang Wang,
Kaiji Fan,
Dawei Zhan,
Lagabaiyila Zha,
Yang Cao,
Zhenhua Li,
Xuan Cheng,
Youyi Zhang,
Xiao Yang
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ABSTRACT: Recent studies have begun to reveal critical roles of microRNAs (miRNAs) in the pathogenesis of cardiac hypertrophy and dysfunction. In this study, we tested whether a transforming growth factor-β (TGF-β)-regulated miRNA played a pivotal role in the development of cardiac hypertrophy and heart failure (HF). We observed that miR-27b was upregulated in hearts of cardiomyocyte-specific Smad4 knockout mice, which developed cardiac hypertrophy. In vitro experiments showed that the miR-27b expression could be inhibited by TGF-β1 and that its overexpression promoted hypertrophic cell growth, while the miR-27b suppression led to inhibition of the hypertrophic cell growth caused by phenylephrine (PE) treatment. Furthermore, the analysis of transgenic mice with cardiomyocyte-specific overexpression of miR-27b revealed that miR-27b overexpression was sufficient to induce cardiac hypertrophy and dysfunction. We validated the peroxisome proliferator-activated receptor-γ (PPAR-γ) as a direct target of miR-27b in cardiomyocyte. Consistently, the miR-27b transgenic mice displayed significantly lower levels of PPAR-γ than the control mice. Furthermore, in vivo silencing of miR-27b using a specific antagomir in a pressure-overload-induced mouse model of HF increased cardiac PPAR-γ expression, attenuated cardiac hypertrophy and dysfunction. The results of our study demonstrate that TGF-β1-regulated miR-27b is involved in the regulation of cardiac hypertrophy, and validate miR-27b as an efficient therapeutic target for cardiac diseases.Keywords: microRNA; cardiac hypertrophy; PPAR-γ; transgenic mouse; therapeutic target
Cell Research 08/2011; 22(3):516-527. · 8.19 Impact Factor
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Yan Zhang,
Peng Xu,
Cuiyun Lu,
Youyi Kuang,
Xiaofeng Zhang,
Dingchen Cao,
Chao Li,
Yumei Chang, Ning Hou,
Hengde Li,
Shu Wang,
Xiaowen Sun
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ABSTRACT: A genetic linkage map of common carp (Cyprinus carpio L.) was constructed using Type I and Type II microsatellite markers and a pseudo-testcross mapping strategy. The microsatellite markers were isolated from microsatellite-enriched genomic libraries and tested for their segregation in a full-sib mapping panel containing 92 individuals. A total of 161 microsatellite loci were mapped into 54 linkage groups. The total lengths of the female, male and consensus maps were 2,000, 946, and 1,852 cM, with an average marker spacing of approximately 13, 7, and 11 cM, respectively. Muscle fiber-related traits, including muscle fiber cross-section area and muscle fiber density, were mapped to the genetic map. Three QTLs for muscle fiber cross-section area and two QTLs for muscle fiber density were identified when considering both significant and suggestive QTL effects. The QTLs with largest effects for muscle fiber cross-section area and muscle fiber density were 21.9% and 18.9%, and they were located in LG3, respectively.
Marine Biotechnology 10/2010; 13(3):376-92. · 3.43 Impact Factor
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ABSTRACT: Parietal cells are one of the largest epithelium cells of the mucous membrane of the stomach that secrete hydrochloric acid. To study the function of gastric parietal cells during gastric epithelium homeostasis, we generated a transgenic mouse line, namely, Atp4b-Cre, in which the expression of Cre recombinase was controlled by a 1.0 kb promoter of mouse (-subunit of H(+)-, K(+)-ATPase gene (Atp4b). In order to test the tissue distribution and excision activity of Cre recombinase in vivo, the Atp4b-Cre transgenic mice were bred with the reporter strain ROSA26 and a mouse strain that carries Smad4 conditional alleles (Smad4(Co/Co)). Multiple-tissue PCR of Atp4b-Cre;Smad4(Co/+) mice revealed that the recombination only happened in the stomach. As indicated by LacZ staining, ROSA26;Atp4b-Cre double transgenic mice showed efficient expression of Cre recombinase within the gastric parietal cells. These results showed that this Atp4b-Cre mouse line could be used as a powerful tool to achieve conditional gene knockout in gastric parietal cells.
Journal of Genetics and Genomics 09/2010; 37(9):647-52. · 1.88 Impact Factor
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ABSTRACT: Gastric pit cells are high-turnover epithelial cells of the gastric mucosa. They secrete mucus to protect the gastric epithelium from acid and pepsin. To investigate the genetic mechanisms underlying the physiological functions of gastric pit cells, we generated a transgenic mouse line, namely, Capn8-Cre, in which the expression of Cre recombinase was controlled by the promoter of the intracellular Ca(2+)-regulated cysteine protease calpain-8. To test the tissue distribution and excision activity of Cre recombinase, the Capn8-Cre transgenic mice were bred with the ROSA26 reporter strain and a mouse strain that carries Smad4 conditional alleles (Smad4(Co/Co)). Multiple-tissue PCR and LacZ staining demonstrated that Capn8-Cre transgenic mouse expressed Cre recombinase in the gastric pit cells. Cre recombinase activity was also detected in the liver and skin tissues. These data suggest that the Capn8-Cre mouse line described here could be used to dissect gene function in gastric pit cells.
genesis 08/2009; 47(10):674-9. · 2.53 Impact Factor
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ABSTRACT: Hypertrophic chondrocytes, which are the terminally differentiated form of chondrocytes, play a key role in endochondral ossification. In order to investigate the functions of hypertrophic chondrocytes during bone development, we generated a new transgenic line expressing Cre recombinase under the control of a 8.2 kb mouse type X collagen gene promoter (Col10a1(8.2)-Cre). Microinjection was employed to introduce the 11.5 kb transgenic fragment into 328 oocytes, from which 51 progenies were obtained. Three mice carrying the transgene in genome were identified by PCR genotyping. PCR detected expression of Col10a1(8.2)-Cre transgene within tissues containing hypertrophic chondrocytes. To examine the activity and specificity of Cre recombinase in vivo, transgenic line was crossed with ROSA26 report line. As indicated by LacZ staining, ROSA26; Col10a1(8.2)-Cre double transgenic mice showed efficient expression of Cre recombinase within hypertrophic chondrocytes. In situ hybridization analyses further confirmed the transcription of Col10a1(8.2)-Cre transgene within the upper zone of hypertrophy, indicating a better activity and specificity in contrast to the previously constructed Col10a1(1.0)-Cre transgenic line. These results showed that this Col10a1(8.2)-Cre transgenic line could be used as a powerful tool to achieve conditional gene knockout in hypertrophic chondrocytes.
Hereditas (Beijing) 02/2009; 31(1):69-74.
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ABSTRACT: Ten tri- and tetranucleotide microsatellite DNA markers were isolated and characterized from common carp (Cyprinus carpio L.) to estimate genetic potential. These markers were tested in the samples from two closely related carp populations (Cyprinus carpio var. xingguonensis and Cyprinus carpio var. wananensis). The number of the alleles ranged from three to nine, and observed and expected hererozygosities varied from 0.207 to 1.000 and from 0.499 to 0.900 in each population, respectively. No evidence for linkage disequilibrium was found, indicating that these markers will be useful for population studies.
Molecular Ecology Resources 11/2008; 8(6):1357-1359. · 3.06 Impact Factor
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ABSTRACT: Members of the Dapper (Dpr)/Dact protein family are involved in the regulation of distinct signaling pathways, including TGFbeta/Nodal, canonical and noncanonical Wnt pathways. Three Dpr genes, Dpr1, Dpr2 and Dpr3, are expressed in mouse embryos and in many adult tissues; however, their in vivo functions have not been reported. In this study, we generated Dpr2-deficient mice using a gene-knockout approach. Homozygous Dpr2 knockout (Dpr2(-/-)) embryos developed normally and postnatal Dpr2(-/-) mice grew to adulthood without obvious morphological or behavioral defects. We found that Dpr2 was expressed highly in epidermal keratinocytes and in hair follicles of adult mice, and that Dpr2 deficiency resulted in accelerated re-epithelialization during cutaneous wound healing. Furthermore, we demonstrated that loss of Dpr2 function enhanced the responses of keratinocytes to TGFbeta stimulation, and that TGFbeta signals promoted adhesion to fibronectin and migration of keratinocytes, by regulating the expression of specific integrin genes. Thus, Dpr2 plays an inhibitory role in the re-epithelialization of adult skin wounds by attenuating TGFbeta signaling.
Journal of Cell Science 10/2008; 121(Pt 17):2904-12. · 6.11 Impact Factor
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ABSTRACT: Osteoblasts participate in bone formation, bone mineralization, osteoclast differentiation and many pathological processes. To study the function of genes in osteoblasts using Cre-LoxP system, we generated a mouse line expressing the Cre recombinase under the control of the rat Collagen1alpha1 (Col1alpha1) promoter (Col1alpha1-Cre). Two founders were identified by genomic PCR from 16 offsprings, and the integration efficiency is 12.5%. In order to determine the tissue distribution and the activity of Cre recombinase in the transgenic mice, the Col1alpha1-Cre transgenic mice were bred with the ROSA26 reporter strain and a mouse strain that carries Smad4 conditional alleles (Smad4(Co/Co)). Multiple tissue PCR of Col1alpha1-Cre;Smad4(Co/+)mice revealed the restricted Cre activity in bone tissues containing osteoblasts and tendon. LacZ staining in the Col1alpha1-Cre;ROSA26 double transgenic mice revealed that the Cre recombinase began to express in the osteoblasts of calvaria at E14.5. Cre activity was observed in the osteoblasts and osteocytes of P10 double transgenic mice. All these data indicated that the Col1alpha1-Cre transgenic mice could serve as a valuable tool for osteoblast lineage analysis and conditional gene knockout in osteoblasts.
Journal of Genetics and Genomics 10/2008; 35(9):525-30. · 1.88 Impact Factor
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ABSTRACT: Using 30 microsatellite markers and combining quantifiable characteristics such as body weight, body length and body width,
we evaluated the genetic potential of 3 German mirror carp (Cyprinus carpio L.) populations. Number of effective alleles (Ae), observed (Ho) and expected (He) heterozygosity values and polymorphic information contents (PIC) were all calculated. Two hundred and eighty-seven alleles and 559 genotypes were detected. The DNA fragment length was 109–400
bp. The Hardy-Weinberg Equilibrium was checked and the phenomenon of some disequilibrium was studied according to the χ2 test. The results showed that the level of genetic variability was moderate, but genetic potential of Shuanglai population
was much lower than that of Huanxin and Songpu breeding populations. PIC of the three populations of German mirror carp were between 0.08787 and 0.5377, both highly and moderately polymorphic markers
were 13. The number of the Ae was between 1.1014 and 6.4665. The Ho and He heterozygosity values were 0.0968–0.9892 and 0.0926–0.8554, respectively. The linkage correlation was analyzed using the
data of body weight, body length and body width, and 30 loci. The result showed that there existed 2 loci, HLJ319 and HLJ693, associated with body length. The HLJ693 locus was significantly correlated with body weight trait. The HLJ677 locus was linked with body width. And then the result was verified in Recombinant Inbred Lines (RIL) of common carp. It
showed that the HLJ319 locus was significantly linked with body length, the same as the result of quantitative trait loci (QTL) location for
common carp.
Frontiers of Agriculture in China 01/2008; 2(4):484-492.
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ABSTRACT: Using 30 microsatellite markers and combining quantity characters such as body weight, body size and body width, we evaluated the genetic potential of 3 Germany mirror carp populations. Number of effective alleles (Ae), observed (Ho) and expected (He) heterozygosity values and polymorphic information contents (PIC) were all calculated. 287 alleles and 559 genotypes were detected. The DNA fragment length was 109-400 bp. The Hardy-Weinberg Equilibrium was checked and phenomenon of some disequilibrium were studied according to the test of c2. The result showed that the level of genetic variability was moderate, but genetic potential of Shuanglai population was much lower than that Huanxin and Songpu breeding populations. Polymorphic Information Contents (PIC) of the 3 populations of Germany mirror carp were between 0.08787 and 0.5377, both of highly and moderately polymorphic markers were 13. The number of effective alleles (Ae) were between 1.1014 and 6.4665. The observed (Ho) and expected (He) heterozygosity values were 0.0968-0.9892 and 0.0926-0.8554 respectively. The linkage correlation was analyzed using data of body weight, body size and body width and 30 loci. The result shown that there existed 2 loci, HLJ319 and HLJ693 associated with body size. The HLJ693 locus significantly correlated with body weight character. The HLJ677 locus linked with body width. And then the result were verified in Recombinant Inbred Lines (RIL) of common carp. It shown that the HLJ319 locus was significantly linked with body size, the same as the result of common carp QTL location.
Hereditas (Beijing) 01/2008; 29(12):1509-18.
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ABSTRACT: The common carp recombinant inbred lines (RIL) derived from the cross Barbless carp x Hebao-cold tolerance red carp were used as experimental materials in this study. Based on the linkage map constructed with simple sequence repeat (SSR) markers using this RIL population, marker regression and complexity interval mapping were analyzed by Windows Map Manager2.0 software. A P-value of 0.01 was the threshold value of single-marker. A linkage group-wide permutation test (1 000 replicates) determined the significance of the maximum LOD value over the various intervals analyzed for each linkage group. The results are as follows: 1) For maker regression, a total of 7 makers related body size, were at 1% significant level, of which 3 were at 0.1% significant level. The variance explained by these loci, ranged 14.00% to 27.00%. Loci HLJ534, HLJ319, and HLJ370 at 0.1% significant level closely linked to the gene related to body size of common carp; 2) six significant QTLs related to body size were at the 5% linkage group-wide level on these linkage groups, and two of them were at 1% level. The variances explained by these QTLs ranged from 11.33% to 23.12% and their additive effects were not identical. HLJ190-HLJ497 and HLJ479-HLJ483 were major QTLs associated to body size of common carp.
Hereditas (Beijing) 11/2007; 29(10):1243-8.
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ABSTRACT: An osteoblast-specific Cre transgenic construct (pOC-Cre) containing the osteocalcin promoter, Cre recombinase gene and polyA of human growth hormone gene was generated. The 4.6 kb DNA fragment of OC-Cre was introduced into fertilized zygotes by microinjection. 2 out of 16 offspring were identified as founders carrying the transgene by PCR and Southern blot analysis, and the integration efficiency is 12.5 %. To check the tissue distribution of the OC-Cre, the OC-Cre transgenic founder mice were bred with the mice carrying Smad4 conditional alleles. PCR results showed that the genomic DNA fragments after Cre mediated recombination could be only amplified from bone tissues of the transgenic mice. LacZ staining of OC-Cre; ROSA26 double transgenic mice revealed that Cre recombinase expressed in osteoblasts and mediated DNA recombination between LoxP sites at the ROSA26 locus. All these data indicated that the Cre recombinase was ex-pressed in the osteoblasts of the OC-Cre transgenic mice and could mediate DNA recombination between LoxP sites. The OC-Cre transgenic mice we generated in this study could serve as a useful tool for generating osteoblast specific gene-knockout mice.
Hereditas (Beijing) 11/2007; 29(10):1237-42.
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Xiaohong Tan,
Tujun Weng,
Jishuai Zhang,
Jian Wang,
Wenlong Li,
Haifeng Wan,
Yu Lan,
Xuan Cheng, Ning Hou,
Haihong Liu,
Jun Ding,
Fuyu Lin,
Ruifu Yang,
Xiang Gao,
Di Chen,
Xiao Yang
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ABSTRACT: Transforming growth factor beta (TGFbeta) is a multifunctional cytokine involved in skeletal development. Smad4 is the central intracellular mediator of TGFbeta signaling. Our previous studies reveal that Smad4 is required for maintaining the normal development of chondrocytes in the growth plate. However, its biological function during postnatal bone remodeling is largely unknown. To investigate the role of Smad4 in maintaining bone homeostasis, we disrupted the Smad4 gene in differentiated osteoblasts using the Cre-loxP system. The Smad4 mutant mice exhibited lower bone mass up to 6 months of age. The proliferation and function of the mutant osteoblasts were significantly decreased. Bone mineral density, bone volume, bone formation rate and osteoblast numbers were remarkably reduced in Smad4 mutants. Intriguingly, the trabecular bone volume in Smad4 mutant mice older than 7 months was higher than that of controls whereas the calvarial and cortical bone remained thinner than in controls. This correlated with reduced bone resorption possibly caused by downregulation of TGFbeta1 and alteration of the ligand receptor activator of NF-kappaB (RANKL)-osteoprotegerin (OPG) axis. These studies demonstrate essential roles of Smad4-mediated TGFbeta signaling in coupling bone formation and bone resorption and maintaining normal postnatal bone homeostasis.
Journal of Cell Science 08/2007; 120(Pt 13):2162-70. · 6.11 Impact Factor
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ABSTRACT: Hemangioblast, a precursor possessing hematopoietic and endothelial potential, is identified as the blast colony-forming cell in the murine gastrulating embryos (E7.0-E7.5). Whether hemangioblast exists in the somite-stage embryos is unknown, even though hemogenic endothelium is regarded as the precursor of definitive hematopoiesis in the aorta-gonad-mesonephros (AGM) region. To address the issue, we developed a unique three-step assay of high proliferative potential (HPP) precursors. The AGM region contained a kind of HPP precursor that displayed hematopoietic self-renewal capacity and was able to differentiate into functional endothelial cells in vitro (i.e., incorporating DiI-acetylated low-density lipoprotein, expressing von Willebrand factors, and forming network structures in Matrigel). The clonal nature was verified by cell mixing assay. However, the bilineage precursor with high proliferative potential-the HPP-hemangioblast (HA)-was not readily detected in the yolk sac (E8.25-E12.5), embryonic circulation (E10.5), placenta (E10.5-E11.5), fetal liver (E11.5-E12.5), and even umbilical artery (E11.5), reflective of its strictly spatial-regulated ontogeny. Expression of CD45, a panhematopoietic marker, distinguished hematopoietic-restricted HPP-colony-forming cell from the bipotential HPP-HA. Finally, we revealed that basic fibroblast growth factor, other than vascular endothelial growth factor or transforming growth factor-beta1, was a positive modulator of the HPP-HA proliferation. Taken together, the HPP-HA represents a novel model for definitive hemangioblast in the mouse AGM region and will shed light on molecular mechanisms underlying the hemangioblast development. Disclosure of potential conflicts of interest is found at the end of this article.
Stem Cells 07/2007; 25(6):1423-30. · 7.78 Impact Factor
