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Claeys L, Zhytnik L, Wisse LE, van Essen HW, Eekhoff EMW, Pals G, Bravenboer N, Micha D. Exploration of the skeletal phenotype of the Col1a1 +/Mov13 mouse model for haploinsufficient osteogenesis imperfecta type 1. Front Endocrinol (Lausanne) 2023; 14:1145125. [PMID: 36967771 PMCID: PMC10031054 DOI: 10.3389/fendo.2023.1145125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 02/17/2023] [Indexed: 03/29/2023] Open
Abstract
INTRODUCTION Osteogenesis Imperfecta is a rare genetic connective tissue disorder, characterized by skeletal dysplasia and fragile bones. Currently only two mouse models have been reported for haploinsufficient (HI) mild Osteogenesis Imperfecta (OI); the Col1a1 +/Mov13 (Mov13) and the Col1a1 +/-365 mouse model. The Mov13 mice were created by random insertion of the Mouse Moloney leukemia virus in the first intron of the Col1a1 gene, preventing the initiation of transcription. Since the development of the Mov13 mice almost four decades ago and its basic phenotypic characterization in the 90s, there have not been many further studies. We aimed to extensively characterize the Mov13 mouse model in order to critically evaluate its possible use for preclinical studies of HI OI. METHODS Bone tissue from ten heterozygous Mov13 and ten wild-type littermates (WT) C57BL/6J mice (50% males per group) was analyzed at eight weeks of age with bone histomorphometry, micro computed tomography (microCT), 3-point bending, gene expression of different collagens, as well as serum markers of bone turnover. RESULTS The Mov13 mouse presented a lower bone strength and impaired material properties based on our results of 3-point bending and microCT analysis respectively. In contrast, no significant differences were found for all histomorphometric parameters. In addition, no significant differences in Col1a1 bone expression were present, but there was a significant lower P1NP concentration, a bone formation marker, measured in serum. Furthermore, bone tissue of Mov13 mice presented significantly higher expression of collagens (Col1a2, Col5a1 and Col5a2), and bone metabolism markers (Bglap, Fgf23, Smad7, Edn1 and Eln) compared to WT. Finally, we measured a significantly lower Col1a1 expression in heart and skin tissue and also determined a higher expression of other collagens in the heart tissue. CONCLUSION Although we did not detect a significant reduction in Col1a1 expression in the bone tissue, a change in bone structure and reduction in bone strength was noted. Regrettably, the variability of the bone phenotype and the appearance of severe lymphoma in adult Mov13 mice, does not favor their use for the testing of new long-term drug studies. As such, a new HI OI type 1 mouse model is urgently needed.
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Affiliation(s)
- Lauria Claeys
- Department of Human Genetics, Amsterdam Movement Sciences, Tissue Function & Regeneration and Musculoskeletal Health, Amsterdam University Medical Centers (UMC) location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Lidiia Zhytnik
- Department of Human Genetics, Amsterdam Movement Sciences, Tissue Function & Regeneration and Musculoskeletal Health, Amsterdam University Medical Centers (UMC) location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Department of Traumatology and Orthopeadics, Institute of Clinical Medicine, The University of Tartu, Tartu, Estonia
| | - Lisanne E. Wisse
- Department of Human Genetics, Amsterdam Movement Sciences, Tissue Function & Regeneration and Musculoskeletal Health, Amsterdam University Medical Centers (UMC) location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Huib W. van Essen
- Department of Clinical Chemistry, Amsterdam Movement Sciences, Tissue Function & Regeneration and Ageing & Vitality, Amsterdam University Medical Centers (UMC) location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - E. Marelise W. Eekhoff
- Department of Endocrinology and Metabolism, Amsterdam Rare Bone Disease Center, Amsterdam University Medical Centers (UMC), Amsterdam, Netherlands
| | - Gerard Pals
- Department of Human Genetics, Amsterdam Movement Sciences, Tissue Function & Regeneration and Musculoskeletal Health, Amsterdam University Medical Centers (UMC) location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Nathalie Bravenboer
- Department of Clinical Chemistry, Amsterdam Movement Sciences, Tissue Function & Regeneration and Ageing & Vitality, Amsterdam University Medical Centers (UMC) location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Dimitra Micha
- Department of Human Genetics, Amsterdam Movement Sciences, Tissue Function & Regeneration and Musculoskeletal Health, Amsterdam University Medical Centers (UMC) location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- *Correspondence: Dimitra Micha,
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Identification of a biomass unaffected pale green mutant gene in Chinese cabbage (Brassica rapa L. ssp. pekinensis). Sci Rep 2022; 12:7731. [PMID: 35546169 PMCID: PMC9095832 DOI: 10.1038/s41598-022-11825-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 04/27/2022] [Indexed: 11/29/2022] Open
Abstract
Chlorophyll (Chl) is an essential component of the photosynthetic apparatus and pigments in plant greening. Leaf color is an important agronomic and commercial trait of Chinese cabbage. In this study, we identified a pale green mutant pgm created by ethyl methane sulfonate (EMS) mutagenesis in Chinese cabbage. Compared with wild-type (FT), pgm had a lower Chl content with a higher Chl a/b ratio, imperfect chloroplast structure, and lower non-photochemical quenching. However, its net photosynthetic rate and biomass showed no significant differences. Genetic analysis revealed that the pale green phenotype of pgm was controlled by a recessive nuclear gene, designated as Brpgm. We applied BSR-Seq, linkage analysis, and whole-genome resequencing to map Brpgm and predicted that the target gene was BraA10g007770.3C (BrCAO), which encodes chlorophyllide a oxygenase (CAO). Brcao sequencing results showed that the last nucleotide of its first intron changed from G to A, causing the deletion of the first nucleotide in its second CDS and termination of the protein translation. The expression of BrCAO in pgm was upregulated, and the enzyme activity of CAO in pgm was significantly decreased. These results provide an approach to explore the function of BrCAO and create a pale green variation in Chinese cabbage.
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Diao P, Sun H, Bao Z, Li W, Niu N, Li W, Wuriyanghan H. Expression of an Antiviral Gene GmRUN1 from Soybean Is Regulated via Intron-Mediated Enhancement (IME). Viruses 2021; 13:2032. [PMID: 34696462 PMCID: PMC8539222 DOI: 10.3390/v13102032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/28/2021] [Accepted: 09/29/2021] [Indexed: 12/18/2022] Open
Abstract
Most of R (resistance) genes encode the protein containing NBS-LRR (nucleotide binding site and leucine-rich repeat) domains. Here, N. benthamiana plants were used for transient expression assays at 3-4 weeks of age. We identified a TNL (TIR-NBS-LRR) encoding gene GmRUN1 that was resistant to both soybean mosaic virus (SMV) and tobacco mosaic virus (TMV). Truncation analysis indicated the importance of all three canonical domains for GmRUN1-mediated antiviral activity. Promoter-GUS analysis showed that GmRUN1 expression is inducible by both salicylic acid (SA) and a transcription factor GmDREB3 via the cis-elements as-1 and ERE (ethylene response element), which are present in its promoter region. Interestingly, GmRUN1 gDNA (genomic DNA) shows higher viral resistance than its cDNA (complementary DNA), indicating the existence of intron-mediated enhancement (IME) for GmRUN1 regulation. We provided evidence that intron2 of GmRUN1 increased the mRNA level of native gene GmRUN1, a soybean antiviral gene SRC7 and also a reporter gene Luciferase, indicating the general transcriptional enhancement of intron2 in different genes. In summary, we identified an antiviral TNL type soybean gene GmRUN1, expression of which was regulated at different layers. The investigation of GmRUN1 gene regulatory network would help to explore the mechanism underlying soybean-SMV interactions.
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Affiliation(s)
- Pengfei Diao
- Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China; (P.D.); (H.S.); (Z.B.); (W.L.); (N.N.)
| | - Hongyu Sun
- Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China; (P.D.); (H.S.); (Z.B.); (W.L.); (N.N.)
| | - Zhuo Bao
- Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China; (P.D.); (H.S.); (Z.B.); (W.L.); (N.N.)
| | - Wenxia Li
- Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China; (P.D.); (H.S.); (Z.B.); (W.L.); (N.N.)
| | - Niu Niu
- Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China; (P.D.); (H.S.); (Z.B.); (W.L.); (N.N.)
| | - Weimin Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
| | - Hada Wuriyanghan
- Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China; (P.D.); (H.S.); (Z.B.); (W.L.); (N.N.)
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Lin W, Ren T, Li W, Liu M, He D, Liang S, Luo W, Zhang X. Novel 61-bp Indel of RIN2 Is Associated With Fat and Hatching Weight Traits in Chickens. Front Genet 2021; 12:672888. [PMID: 34276778 PMCID: PMC8280519 DOI: 10.3389/fgene.2021.672888] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 06/09/2021] [Indexed: 11/28/2022] Open
Abstract
The Ras and Rab interactor 2 (RIN2) gene, which encodes RAS and Rab interacting protein 2, can interact with GTP-bound Rab5 and participate in early endocytosis. This study found a 61-bp insertion/deletion (indel) in the RIN2 intron region, and 3 genotypes II, ID, and DD were observed. Genotype analysis of mutation sites was performed on 665 individuals from F2 population and 8 chicken breeds. It was found that the indel existed in each breed and that yellow feathered chickens were mainly of the DD genotype. Correlation analysis of growth and carcass traits in the F2 population of Xinghua and White Recessive Rock chickens showed that the 61-bp indel was significantly correlated with abdominal fat weight, abdominal fat rate, fat width, and hatching weight (P < 0.05). RIN2 mRNA was expressed in all the tested tissues, and its expression in abdominal fat was higher than that in other tissues. In addition, the expression of the RIN2 mRNA in the abdominal fat of the DD genotype was significantly higher than that of the II genotype (P < 0.05). The transcriptional activity results showed that the luciferase activity of the pGL3-DD vector was significantly higher than that of the pGL3-II vector (P < 0.01). Moreover, the results indicate that the polymorphisms in transcription factor binding sites (TFBSs) of 61-bp indel may affect the transcriptional activity of RIN2, and thus alter fat traits in chicken. The results of this study showed that the 61-bp indel was closely related to abdominal fat-related and hatching weight traits of chickens, which may have reference value for molecular marker-assisted selection of chickens.
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Affiliation(s)
- Wujian Lin
- Department of Animal Genetics, Breeding, and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Tuanhui Ren
- Department of Animal Genetics, Breeding, and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Wangyu Li
- Department of Animal Genetics, Breeding, and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Manqing Liu
- Department of Animal Genetics, Breeding, and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Danlin He
- Department of Animal Genetics, Breeding, and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Shaodong Liang
- Department of Animal Genetics, Breeding, and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Wen Luo
- Department of Animal Genetics, Breeding, and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Xiquan Zhang
- Department of Animal Genetics, Breeding, and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
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He Q, Wu J, Xue Y, Zhao W, Li R, Zhang L. The novel gene BrMYB2, located on chromosome A07, with a short intron 1 controls the purple-head trait of Chinese cabbage ( Brassica rapa L.). HORTICULTURE RESEARCH 2020; 7:97. [PMID: 32637125 PMCID: PMC7326913 DOI: 10.1038/s41438-020-0319-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/10/2020] [Accepted: 04/14/2020] [Indexed: 05/06/2023]
Abstract
Anthocyanins are important secondary metabolites in plants, but information on anthocyanin biosynthesis mechanisms in Chinese cabbage is limited. The new purple head Chinese cabbage cultivar 11S91 was analyzed, and an R2R3-MYB regulatory gene BrMYB2, located on chromosome A07, controlling the dominant purple-head trait was isolated. High expression of BrMYB2 generated a large accumulation of anthocyanins in 11S91, accompanied by highly upregulated BrTT8, BrF3'H, BrDFR1, BrANS1, BrUGTs, BrATs, and BrGSTs. 11S91 inherited the purple locus from purple trait donor 95T2-5, and they shared consensus CDSs and gDNAs with those of BrMYB2 (cBrMYB2 and gBrMYB2). Two SNPs in cBrMYB2 in 11S91 did not cause loss of function; in addition to several SNPs at both ends of intron 1, a large deletion had occurred in intron 1 of gBrMYB2 in 11S91. Genetic transformation of Arabidopsis showed that gBrMYB2 overexpression lines presented deeper purple color and higher expression than did the cBrMYB2 and cBrmyb2 lines, whereas gBrmyb2 with a long intron 1 did not cause the purple phenotype. We first show that BrMYB2 promotes anthocyanin biosynthesis under the control of the short intron 1 of gBrMYB2 in purple head Chinese cabbage, and gBrmyb2 with a long intron 1 represses anthocyanin production in white head Chinese cabbage. This evidence provides a new understanding of anthocyanin biosynthesis and purple germplasm generation in Brassica vegetables.
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Affiliation(s)
- Qiong He
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi People’s Republic of China
- College of Life Sciences, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi People’s Republic of China
| | - Junqing Wu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi People’s Republic of China
| | - Yihua Xue
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi People’s Republic of China
| | - Wenbin Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi People’s Republic of China
| | - Ru Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi People’s Republic of China
| | - Lugang Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi People’s Republic of China
- State Key Laboratory of Vegetable Germplasm Innovation, Tianjin, People’s Republic of China
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Jo SS, Choi SS. Analysis of the Functional Relevance of Epigenetic Chromatin Marks in the First Intron Associated with Specific Gene Expression Patterns. Genome Biol Evol 2019; 11:786-797. [PMID: 30753418 PMCID: PMC6424223 DOI: 10.1093/gbe/evz033] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/2019] [Indexed: 01/03/2023] Open
Abstract
We previously showed that the first intron of genes exhibits several interesting characteristics not seen in other introns: 1) it is the longest intron on average in almost all eukaryotes, 2) it presents the highest number of conserved sites, and 3) it exhibits the highest density of regulatory chromatin marks. Here, we expand on our previous study by integrating various multiomics data, leading to further evidence supporting the functionality of sites in the first intron. We first show that trait-associated single-nucleotide polymorphisms (TASs) are significantly enriched in the first intron. We also show that within the first intron, the density of epigenetic chromatin signals is higher near TASs than in distant regions. Furthermore, the distribution of several chromatin regulatory marks is investigated in relation to gene expression specificity (i.e., housekeeping vs. tissue-specific expression), essentiality (essential genes vs. nonessential genes), and levels of gene expression; housekeeping genes or essential genes contain greater proportions of active chromatin marks than tissue-specific genes or nonessential genes, and highly expressed genes exhibit a greater density of chromatin regulatory marks than genes with low expression. Moreover, we observe that genes carrying multiple first-intron TASs interact with each other within a large protein-protein interaction network, ultimately connecting to the UBC protein, a well-established protein involved in ubiquitination. We believe that our results shed light on the functionality of first introns as a genomic entity involved in gene expression regulation.
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Affiliation(s)
- Shin-Sang Jo
- Division of Biomedical Convergence, College of Biomedical Science, Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon, Korea
| | - Sun Shim Choi
- Division of Biomedical Convergence, College of Biomedical Science, Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon, Korea
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Jo SS, Choi SS. Enrichment of rare alleles within epigenetic chromatin marks in the first intron. Genomics Inform 2019; 17:e9. [PMID: 30929410 PMCID: PMC6459166 DOI: 10.5808/gi.2019.17.1.e9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 03/10/2019] [Indexed: 11/20/2022] Open
Abstract
In previous studies, we demonstrated that some sites in the first intron likely regulate gene expression. In the present work, we sought to further confirm the functional relevance of first intron sites by estimating the quantity of rare alleles in the first intron. A basic hypothesis posited herein is that genomic regions carrying more functionally important sites will have a higher proportion of rare alleles. We estimated the proportions of rare single nucleotide polymorphisms with a minor allele frequency < 0.01 located in several histone marks in the first introns of various genes, and compared them with those in other introns and those in 2-kb upstream regions. As expected, rare alleles were found to be significantly enriched in most of the regulatory sites located in the first introns. Meanwhile, transcription factor binding sites were significantly more enriched in the 2-kb upstream regions (i.e., the regions of putative promoters of genes) than in the first introns. These results strongly support our proposal that the first intron sites of genes may have important regulatory functions in gene expression independent of promoters.
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Affiliation(s)
- Shin-Sang Jo
- Division of Biomedical Convergence, College of Biomedical Science, Institute of Bioscience & Biotechnology, Kangwon National University, Chuncheon 24341, Korea
| | - Sun Shim Choi
- Division of Biomedical Convergence, College of Biomedical Science, Institute of Bioscience & Biotechnology, Kangwon National University, Chuncheon 24341, Korea
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Xu DH, Wang XY, Jia YL, Wang TY, Tian ZW, Feng X, Zhang YN. SV40 intron, a potent strong intron element that effectively increases transgene expression in transfected Chinese hamster ovary cells. J Cell Mol Med 2018; 22:2231-2239. [PMID: 29441681 PMCID: PMC5867124 DOI: 10.1111/jcmm.13504] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 11/15/2017] [Indexed: 12/20/2022] Open
Abstract
Chinese hamster ovary (CHO) cells have become the most widely utilized mammalian cell line for the production of recombinant proteins. However, the product yield and transgene instability need to be further increased and solved. In this study, we investigated the effect of five different introns on transgene expression in CHO cells. hCMV intron A, adenovirus tripartite leader sequence intron, SV40 intron, Chinese hamster EF-1alpha gene intron 1 and intervening sequence intron were cloned downstream of the eGFP expression cassette in a eukaryotic vector, which was then transfected into CHO cells. qRT-PCR and flow cytometry were used to explore eGFP expression levels. And gene copy number was also detected by qPCR, respectively. Furthermore, the erythropoietin (EPO) protein was used to test the selected more strong intron. The results showed that SV40 intron exhibited the highest transgene expression level among the five compared intron elements under transient and stable transfections. In addition, the SV40 intron element can increase the ratio of positive colonies and decrease the coefficient of variation in transgene expression level. Moreover, the transgene expression level was not related to the gene copy number in stable transfected CHO cells. Also, the SV40 intron induced higher level of EPO expression than IVS intron in transfected CHO cell. In conclusion, SV40 intron is a potent strong intron element that increases transgene expression, which can readily be used to more efficient transgenic protein production in CHO cells.
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Affiliation(s)
- Dan-Hua Xu
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Xiao-Yin Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Yan-Long Jia
- Pharmacy collage, Xinxiang Medical University, Xinxiang, Henan, China
| | - Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Zheng-Wei Tian
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Xin Feng
- Grade 2014, The Third Clinical Medical College of Xinxiang Medical University, Xinxiang, Henan, China
| | - Yin-Na Zhang
- Grade 2014, The Third Clinical Medical College of Xinxiang Medical University, Xinxiang, Henan, China
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Papke CL, Tsunezumi J, Ringuette LJ, Nagaoka H, Terajima M, Yamashiro Y, Urquhart G, Yamauchi M, Davis EC, Yanagisawa H. Loss of fibulin-4 disrupts collagen synthesis and maturation: implications for pathology resulting from EFEMP2 mutations. Hum Mol Genet 2015. [PMID: 26220971 DOI: 10.1093/hmg/ddv308] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Homozygous recessive mutations in either EFEMP2 (encoding fibulin-4) or FBLN5 (encoding fibulin-5), critical genes for elastogenesis, lead to autosomal recessive cutis laxa types 1B and 1A, respectively. Previously, fibulin-4 was shown to bind lysyl oxidase (LOX), an elastin/collagen cross-linking enzyme, in vitro. Consistently, reported defects in humans with EFEMP2 mutations are more severe and broad in range than those due to FBLN5 mutations and encompass both elastin-rich and collagen-rich tissues. However, the underlying disease mechanism in EFEMP2 mutations has not been fully addressed. Here, we show that fibulin-4 is important for the integrity of aortic collagen in addition to elastin. Smooth muscle-specific Efemp2 loss in mouse (termed SMKO) resulted in altered fibrillar collagen localization with larger, poorly organized fibrils. LOX activity was decreased in Efemp2-null cells, and collagen cross-linking was diminished in SMKO aortas; however, elastin cross-linking was unaffected and the level of mature LOX was maintained to that of wild-type aortas. Proteomic screening identified multiple proteins involved in procollagen processing and maturation as potential fibulin-4-binding partners. We showed that fibulin-4 binds procollagen C-endopeptidase enhancer 1 (Pcolce), which enhances proteolytic cleavage of the procollagen C-terminal propeptide during procollagen processing. Interestingly, however, procollagen cleavage was not affected by the presence or absence of fibulin-4 in vitro. Thus, our data indicate that fibulin-4 serves as a potential scaffolding protein during collagen maturation in the extracellular space. Analysis of collagen in other tissues affected by fibulin-4 loss should further increase our understanding of underlying pathologic mechanisms in patients with EFEMP2 mutations.
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Affiliation(s)
- Christina L Papke
- Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jun Tsunezumi
- Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Léa-Jeanne Ringuette
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
| | - Hideaki Nagaoka
- NC Oral Health Institute, University of North Carolina, Chapel Hill, NC 27599, USA and
| | - Masahiko Terajima
- NC Oral Health Institute, University of North Carolina, Chapel Hill, NC 27599, USA and
| | - Yoshito Yamashiro
- Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA, Life Science Center, Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Greg Urquhart
- Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Mitsuo Yamauchi
- NC Oral Health Institute, University of North Carolina, Chapel Hill, NC 27599, USA and
| | - Elaine C Davis
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
| | - Hiromi Yanagisawa
- Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA, Life Science Center, Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
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Wu D, Shen YH, Russell L, Coselli JS, LeMaire SA. Molecular mechanisms of thoracic aortic dissection. J Surg Res 2013; 184:907-24. [PMID: 23856125 PMCID: PMC3788606 DOI: 10.1016/j.jss.2013.06.007] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/31/2013] [Accepted: 06/05/2013] [Indexed: 12/22/2022]
Abstract
Thoracic aortic dissection (TAD) is a highly lethal vascular disease. In many patients with TAD, the aorta progressively dilates and ultimately ruptures. Dissection formation, progression, and rupture cannot be reliably prevented pharmacologically because the molecular mechanisms of aortic wall degeneration are poorly understood. The key histopathologic feature of TAD is medial degeneration, a process characterized by smooth muscle cell depletion and extracellular matrix degradation. These structural changes have a profound impact on the functional properties of the aortic wall and can result from excessive protease-mediated destruction of the extracellular matrix, altered signaling pathways, and altered gene expression. Review of the literature reveals differences in the processes that lead to ascending versus descending and sporadic versus hereditary TAD. These differences add to the complexity of this disease. Although tremendous progress has been made in diagnosing and treating TAD, a better understanding of the molecular, cellular, and genetic mechanisms that cause this disease is necessary to developing more effective preventative and therapeutic treatment strategies.
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Affiliation(s)
- Darrell Wu
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, BCM 390, One Baylor Plaza, Houston, Texas 77030
- Department of Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, 6770 Bertner Ave., Houston, Texas 77030
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, BCM 335, One Baylor Plaza, Houston, Texas 77030
| | - Ying H. Shen
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, BCM 390, One Baylor Plaza, Houston, Texas 77030
- Department of Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, 6770 Bertner Ave., Houston, Texas 77030
| | - Ludivine Russell
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, BCM 390, One Baylor Plaza, Houston, Texas 77030
- Department of Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, 6770 Bertner Ave., Houston, Texas 77030
| | - Joseph S. Coselli
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, BCM 390, One Baylor Plaza, Houston, Texas 77030
- Department of Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, 6770 Bertner Ave., Houston, Texas 77030
| | - Scott A. LeMaire
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, BCM 390, One Baylor Plaza, Houston, Texas 77030
- Department of Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, 6770 Bertner Ave., Houston, Texas 77030
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, BCM 335, One Baylor Plaza, Houston, Texas 77030
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11
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Marjamaa J, Tulamo R, Abo-Ramadan U, Hakovirta H, Frösen J, Rahkonen O, Niemelä M, Bornstein P, Penttinen R, Kangasniemi M. Mice with a deletion in the first intron of the Col1a1 gene develop dissection and rupture of aorta in the absence of aneurysms: high-resolution magnetic resonance imaging, at 4.7 T, of the aorta and cerebral arteries. Magn Reson Med 2006; 55:592-7. [PMID: 16453315 DOI: 10.1002/mrm.20798] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Deletion of the majority of the first intron of the Col1a1 gene in mice leads to decreased type I collagen synthesis and content in the aortic wall. In 54% of cases, mice homozygous for the Col1a1 mutation die of thoracic hemorrhage by the age of 18 months. It is unknown whether the fatal bleeding results from an acute dissection of the aortic wall or a gradually developing dilatation of the medial layer prior to rupture. We optimized high-resolution MRI methods using a 4.7 T MR scanner to obtain in vivo images of the entire mouse aorta. The MR images were acquired in three imaging planes using gradient echo, spin echo, and spin echo with inversion recovery pulse sequences with a maximum in-plane resolution of 68 x 68 microm and acquisition times less than 10 min. In five Col1a1 mutated mice aged 16 months, the MR images showed no signs of aneurysmal dilatation, wall defects, or former dissection, suggesting that the mechanism for aortic rupture is an acute dissection of the aortic medial layer. Cerebral arteries were imaged using a three-dimensional time of fight pulse sequence. The resolution of 73 x 73 x 94 microm showed normal cerebral arteries. Histology showed a 22% thinner cerebral artery wall in Col1a1 mutated mice.
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Affiliation(s)
- J Marjamaa
- Neurosurgery Research Group, Biomedicum, Helsinki, Finland.
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12
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Pochampally RR, Horwitz EM, DiGirolamo CM, Stokes DS, Prockop DJ. Correction of a mineralization defect by overexpression of a wild-type cDNA for COL1A1 in marrow stromal cells (MSCs) from a patient with osteogenesis imperfecta: a strategy for rescuing mutations that produce dominant-negative protein defects. Gene Ther 2005; 12:1119-25. [PMID: 15815702 DOI: 10.1038/sj.gt.3302514] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Gene therapy for dominant-negative disorders presents a more difficult challenge than gene therapy for recessive disorders, since even partial replacement of a protein for a recessive disorder can reverse symptoms. Osteogenesis imperfecta (OI) has frequently served as a model disorder for dominant-negative defects of structural proteins. The disease is caused by mutations in type I collagen (COL1A1), the major structural component of bone, skin and other connective tissues. The severity of the phenotype is largely dependent on the ratio of normal to mutant type I procollagen synthesized by cells. Recently, attempts have been made to develop strategies for cell and gene therapies using the adult stem cells from bone marrow referred to as mesenchymal stem cells or marrow stromal cells (MSCs). In this study, we used MSCs from a patient with type III OI who was heterozygous for an IVS 41A+4C mutation in COL1A1. A hybrid genomic / cDNA construct of COL1A1 was transfected into the MSCs and the transfectants were expanded over a 200-fold. Transfected MSCs showed increased expression of the wild-type mRNA and protein. In vitro assays demonstrated that the transfected cells more efficiently differentiated into mineralizing cells. The results indicated that it is possible to overexpress COL1A1 cDNA in OI MSCs and thereby to correct partially the dominant-negative protein defect.
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Affiliation(s)
- R R Pochampally
- Center for Gene Therapy, Tulane University Health Sciences Center, New Orleans, LA 70112, USA
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13
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Choi YS, Lee JE, Cheong C, Sung YH, Yang EY, Park CB, Song J, Park SC, Lee HW. Generation of reversible Rb-knockdown mice. Mech Ageing Dev 2005; 126:1164-9. [PMID: 16087217 DOI: 10.1016/j.mad.2005.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2005] [Indexed: 11/30/2022]
Abstract
This study describes the generation of reversible Rb-knockdown mice using Tet-off system coupled with Rb-deficient mice currently available. Mice expressing pRB conditionally in Rb-/- background were generated by crossings P(hCMV)-tTA/TRE-Rb transgenic mice with conventional Rb+/- mice. Transgenic Rb was tightly controlled with reversibility and biologically effective as exemplified by cyclin E expression in a doxycycline-dependent manner in mouse embryonic fibroblasts. However, its ectopic expression was not sufficient to rescue the phenotypes of Rb-/- embryos at organismal level, suggesting the requirement of more sophisticated regulation of pRB. With all, these results demonstrate that our experimental strategy can be an alternative way to convert classical gene-disrupted mice into reversible conditional ones.
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Affiliation(s)
- Yoon Sik Choi
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Samsung Biomedical Research Institute, 300 Chonchon-Dong, Changan-Gu, Suwon 440-746, Republic of Korea
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14
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Rahkonen O, Su M, Hakovirta H, Koskivirta I, Hormuzdi SG, Vuorio E, Bornstein P, Penttinen R. Mice with a deletion in the first intron of the Col1a1 gene develop age-dependent aortic dissection and rupture. Circ Res 2003; 94:83-90. [PMID: 14630726 DOI: 10.1161/01.res.0000108263.74520.15] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The functional significance of the first intron of the Col1a1 gene in regulation of type I collagen synthesis remains uncertain. A previous study in mice established that a mutated Col1a1 allele that lacked a large fraction of the first intron, but retained the sequences required for normal splicing, was subject to an age- and tissue-dependent decrease in expression. In this study, we report that mice homozygous for this deletion are predisposed to dissection and rupture of the aorta during their adult life. Aortic dissection was not detected in autopsies of heterozygous animals or their littermate controls. Electron micrographs revealed fewer collagen fibrils and less compacted, irregular elastic lamellae in the aortic walls of homozygous mutant animals. Northern analysis of aortic RNA from 2.5- and 12-month-old homozygous mutant mice revealed that Col1a1 mRNA levels were decreased by 29% and 42%, respectively, relative to those of control littermates. In 12-month-old heterozygotes, the decrease was 32%. Allele-specific amplification of heterozygous cDNAs demonstrated that this reduction was limited to transcripts from the mutant allele. The collagen content of the aortas of homozygous mutant mice was also significantly lower in comparison to that of age-matched, control animals. These data establish that the integrity of the aortic wall depends on an adequate content of type I collagen, and that continued synthesis of collagen in the aorta as a function of age is critically dependent on sequences in the first intron of the Col1a1 gene.
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Affiliation(s)
- Otto Rahkonen
- Department of Medical Biochemistry and Molecular Biology, University of Turku, Finland.
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15
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Wang H, Zhu YZ, Farook JM, Moochhala S, Teo AL, Lee LKH, Wong PTH. Genetic variations in CCK2 receptor in PVG hooded and Sprague-Dawley rats and its mRNA expression on cat exposure. Behav Neurosci 2003; 117:385-90. [PMID: 12708535 DOI: 10.1037/0735-7044.117.2.385] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study examined differential freezing behavior, mediated by cholecystokinin-2 (CCK2) receptors (J. M. Farook et al., 2001), in PVG hooded and Sprague-Dawley (SD) rats exposed to a predator. The authors confirmed by reverse transcription polymerase chain reaction that CCK2 receptor expression in the PVG rats was increased in the hippocampus and cerebral cortex compared with that of SD rats. In addition, 4 variations in the coding region of the CCK2 receptor gene were detected between the PVG hooded and SD rats: 1 in Exon 4, 1 in Intron 2, and 2 in Intron 3. Acute treatment with a CCK2 agonist (CCK-4) or antagonist (LY225910) did not alter the level of CCK2 receptor expression, indicating no difference between the 2 strains in sensitivity of the CCK2 receptor to drugs.
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Affiliation(s)
- H Wang
- Department of Pharmacology, Faculty of Medicine, National University of Singapore, Singapore
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16
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Choi YS, Hong SB, Jeon HK, Kim EJ, Oh WJ, Joe SY, Han JS, Lee MJ, Lee HW. Insertional Mutation in the Intron 1 of Unc5h3 Gene Induces Ataxic, Lean and Hyperactive Phenotype in mice. Exp Anim 2003; 52:273-83. [PMID: 14562603 DOI: 10.1538/expanim.52.273] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Mice carrying a mutation in the first intron of Unc5h3 were accidentally produced by transgenic insertion and characterized for their homozygous mutant phenotypes. Morphological and histological analysis revealed cerebellar and midbrain abnormalities, which are similar to the previously reported phenotypes of the Unc5h3 mutant. Behavioral analysis showed higher ambulatory activity and circling, and defects in habituation in a novel environment. Their body weights were 10-30% less than wildtype mice from 2-3 weeks of age to 22 months possibly due to reduced accumulation of adipose tissues. The transgenic insertion site was identified and mapped to the intron 1 of Unc5h3 gene with approximately 50 kb deletion of the intron sequence. This intronic mutation interfered with the mRNA expression of the Unc5h3 gene not in testes, but in many tissues including the brain, implying that this intronic region may play a role in regulating tissue-specific transcription of Unc5h3.
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Affiliation(s)
- Yoon Sik Choi
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine and Samsung Biomedical Research Institute, Suwon 440-746, Republic of Korea
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17
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Treuting PM, Hopkins HC, Ware CA, Rabinovitch PR, Ladiges WC. Generation of genetically altered mouse models for aging studies. Exp Mol Pathol 2002; 72:49-55. [PMID: 11784122 DOI: 10.1006/exmp.2001.2405] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A number of mouse models have been identified and are being used for aging and age-associated disease research. However, the use of the genetically manipulated mouse model is still a relatively untapped resource for the study of the biology of aging. Genetically altered mice can be powerful tools for biology of aging research because gene expression can be controlled and correlated with established biomarkers. Standard transgene overexpression and gene targeting techniques were modified and used to generate 30 mouse lines during a 4-year period. These lines include models of Werner's syndrome (premature aging or progeria), Alzheimer's disease, other neurodegenerative condition, atherosclerosis, diabetes, immune dysfunction, musculoskeletal disorders, and oxidative stress. These new mouse models are providing additional insights into aging processes and will be useful for developing intervention strategies and collaborative interactions.
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Affiliation(s)
- P M Treuting
- Nathan Shock Center for Excellence in the Biology of Aging, School of Medicine, Seattle, Washington 98195, USA
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18
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Bornstein P, Walsh V, Tullis J, Stainbrook E, Bateman JF, Hormuzdi SG. The globular domain of the proalpha 1(I) N-propeptide is not required for secretion, processing by procollagen N-proteinase, or fibrillogenesis of type I collagen in mice. J Biol Chem 2002; 277:2605-13. [PMID: 11705995 DOI: 10.1074/jbc.m106181200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The globular domain in the NH(2)-terminal propeptide (N-propeptide) of the proalpha1(I) chain is largely encoded by exon 2 of the Col1a1 gene and has been implicated in a number of processes that are involved in the biogenesis, maturation, and function of type I collagen. These include intracellular chain association, transcellular transport and secretion, proteolytic processing of the precursor, feedback regulation of synthesis, and control of fibrillogenesis. However, none of these proposed functions has been firmly established. To evaluate the function of this procollagen domain we have used a targeted mutagenesis approach to generate mice that lack exon 2 in the Col1a1 gene. Mouse lines were established on both a mixed 129 OlaHsd/Sv and C57BL/6 background and a pure 129 OlaHsd/Sv background. Adult mice on the mixed background are normal in appearance and are fertile. To the extent that they have been studied, procollagen synthesis, secretion, and proteolytic processing are normal in these mice, and collagen fibrillogenesis is only slightly altered. However, breeding of heterozygous mutant mice on the 129 background generated homozygous mutants at only 64% of the expected frequency. These findings suggest that although the N-propeptide is not essential for collagen biogenesis in mice it may play some essential role during embryonic development.
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Affiliation(s)
- Paul Bornstein
- Department of Biochemistry, the University of Washington, Seattle, Washington 98195, USA.
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19
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Mielke C, Christensen MO, Westergaard O, Bode J, Benham CJ, Breindl M. Multiple collagen I gene regulatory elements have sites of stress-induced DNA duplex destabilization and nuclear scaffold/matrix association potential. J Cell Biochem 2002. [DOI: 10.1002/jcb.10034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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20
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Terraz C, Toman D, Delauche M, Ronco P, Rossert J. delta Ef1 binds to a far upstream sequence of the mouse pro-alpha 1(I) collagen gene and represses its expression in osteoblasts. J Biol Chem 2001; 276:37011-9. [PMID: 11473112 DOI: 10.1074/jbc.m104185200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The transcription of type I collagen genes is tightly regulated, but few cis-acting elements have been identified that can modulate the levels of expression of these genes. Generation of transgenic mice harboring various segments of the mouse pro-alpha1(I) collagen promoter led us to suspect that a repressor element was located between -10.5 and -17 kilobase pairs. Stable and transient transfection experiments in ROS17/2.8 osteoblastic cells confirmed the existence of such a repressor element at about -14 kilobase pairs and showed that it consisted in an almost perfect three-time repeat of a 41-base pair sequence. This element, which we named COIN-1, contains three E2-boxes, and a point mutation in at least two of them completely abolished its repressor effect. In gel shift assays, COIN-1 bound a DNA-binding protein named delta EF1/ZEB-1, and mutations that abolished the repressor effect of COIN-1 also suppressed the binding of delta EF1. We also showed that the repressor effect of COIN-1 was not mediated by chromatin compaction. Furthermore, overexpression of delta EF1 in ROS17/2.8 osteoblastic cells enhanced the inhibitory effect of COIN-1 in a dose-dependent manner and repressed the expression of the pro-alpha 1(I) collagen gene. Thus, delta EF1 appears to repress the expression of the mouse pro-alpha 1(I) collagen gene, through its binding to COIN-1.
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Affiliation(s)
- C Terraz
- INSERM U489 and Université Paris VI, Paris, France
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21
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Agarwal AK. Transcriptional influence of two poly purine-pyrimidine tracts located in the HSD11B2 (11beta-hydroxysteroid dehydrogenase type 2) gene. Endocr Res 2001; 27:1-9. [PMID: 11428702 DOI: 10.1081/erc-100107163] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Alternating purine-pyrimidine (APP) sequences which might assume left handed DNA helical structures (Z-DNA) could influence the expression of genes in which they were located. There are two such repeat elements in the HSD11B2 (11beta-hydroxysteroid dehydrogenase) gene. First, a CA repeat is located in the first intron. Deletion of this element in a minigene construct leads to a significant decrease (40%) in the expression of the HSD11B2 message in human cortical collecting duct cells. The second APP tract is located approximately 0.9 kb from the last exon or 4.8 kb from the intronic CA repeat element. Deleting this APP tract in a minigene decreases gene expression by 30%. The CA repeat along with its flanking sequences increases luciferase reporter gene expression if placed 5' of the HSD11B2 promoter but not when placed downstream of the reporter gene. Similarly the second APP tract increases luciferase reporter gene expression when placed 5' of the HSD11B2 promoter in an antisense orientation but not in a sense orientation. These results suggests that these dinucleotide repeats influence expression of the HSD11B2 gene in a manner dependent on position and orientation.
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Affiliation(s)
- A K Agarwal
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas 75390-9063, USA.
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22
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Ye D, Lee CH, Queener SF. Differential splicing of Pneumocystis carinii f. sp. carinii inosine 5'-monophosphate dehydrogenase pre-mRNA. Gene 2001; 263:151-8. [PMID: 11223253 DOI: 10.1016/s0378-1119(00)00577-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Inosine 5'-monophosphate dehydrogenase (IMPDH) is a rate-limiting enzyme in guanine nucleotide metabolism that has drawn attention as a drug target in several organisms. Pneumocystis carinii f. sp. carinii IMPDH mRNA (GeneBank Accession No: U42442) previously identified from cultured organisms yielded a predicted amino acid sequence about 70 amino acids shorter at the amino terminus than IMPDH from other species. Recent research has shown that the amino terminal region is important for enzyme activity, suggesting that the previous putative P. carinii IMPDH might not represent full length, functional enzyme. To test this hypothesis, RT-PCR was performed with total RNA isolated from P. carinii f. sp. carinii. Three IMPDH splicing variants were found and splicing preference was observed: P. carinii isolated from infected rat lung contained primarily splicing variant one (introns two and four deleted), but organisms from spinner flask culture contained primarily splicing variant three (all four introns deleted). Importantly, splicing variant one (GeneBank Accession No: AF196975) contained an open reading frame for 529 amino acids, a size comparable to that of other eukaryotic IMPDH forms. The other variants contained the same open reading frame (454 amino acids) previously reported. Sequence analysis and complementation studies suggest variant one represents the full length, catalytically active form of P. carinii IMPDH. The differential splicing of the enzyme may reflect a mechanism by which the organism regulates the expression of IMPDH in response to environmental stresses.
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Affiliation(s)
- D Ye
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202-5120, USA
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23
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Zaveri NT, Green CJ, Toll L. Transcriptional regulation of the human prepronociceptin gene. Biochem Biophys Res Commun 2000; 276:710-7. [PMID: 11027536 DOI: 10.1006/bbrc.2000.3529] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have cloned regions of the 5'-untranslated region of the human prepronociceptin (ppN/OFQ) gene into a luciferase reporter plasmid, pGL3 Basic Vector. By primer extension analysis, we determined that one start site of transcription lies within the known human cDNA sequence. There are two cyclic AMP response elements (CRE) with the consensus sequence CGTCA within 250 bp of the start of transcription. We designed various constructs around these sites, performed transient transfections, and measured luciferase activity in NS20Y cells. Transcriptional activity could be regulated by a variety of factors including cAMP levels, Ca(2+), and particularly by a 125-bp region adjacent to an intron located 23 bp upstream of the translation initiating ATG. These data should help in understanding the regulatory mechanisms of ppN/OFQ gene transcription.
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Affiliation(s)
- N T Zaveri
- Pharmaceutical Discovery Division, SRI International, 333 Ravenswood Avenue, Menlo Park, California 94025, USA.
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24
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Seshasayee D, Geiger JN, Gaines P, Wojchowski DM. Intron 1 elements promote erythroid-specific GATA-1 gene expression. J Biol Chem 2000; 275:22969-77. [PMID: 10811657 DOI: 10.1074/jbc.m002931200] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The zinc finger protein GATA-1 functions in a concentration-dependent fashion to activate the transcription of erythroid and megakaryocytic genes. Less is understood, however, regarding factors that regulate the GATA-1 gene. Presently elements within intron 1 are shown to markedly affect its erythroid-restricted transcription. Within a full-length 6. 8-kilobase GATA-1 gene construct (G6.8-Luc) the deletion of a central subdomain of intron 1 inhibited transcription >/=10-fold in transiently transfected erythroid SKT6 cells, and likewise inhibited high-level transcription in erythroid FDCW2ER-GATA1 cells. In parental myeloid FDCER cells, however, low-level transcription was largely unaffected by intron 1 deletions. Within intron 1, repeated GATA and Ap1 consensus elements in a central region are described which when linked directly to reporter cassettes promote transcription in erythroid SKT6 and FDCER-GATA1 cells at high rates. Moreover, GATA-1 activated transcription from this subdomain in 293 cells, and in SKT6 cells this subdomain footprinted in vivo. For stably integrated GFP reporter constructs in erythroid SKT6 cells, corroborating results were obtained. Deletion of intronic GATA and Ap1 motifs abrogated the activity of G6.8-pEGFP; activity was decreased by 43 and 56%, respectively, by the deletion of either motif; and the above 1800-base pair region of intron 1 per se was transcribed at rates uniformly greater than G6.8-pEGFP. Also described is the differential utilization of exons 1a and 1b among primary erythromegakaryocytic and myeloid cells.
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Affiliation(s)
- D Seshasayee
- Programs in Genetics and Department of Veterinary Science, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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25
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Collie-Duguid ES, Etienne MC, Milano G, McLeod HL. Known variant DPYD alleles do not explain DPD deficiency in cancer patients. PHARMACOGENETICS 2000; 10:217-23. [PMID: 10803677 DOI: 10.1097/00008571-200004000-00002] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Dihydropyrimidine dehydrogenase (DPD) degrades over 80% of administered 5-fluorouracil (5FU), thereby regulating the efficacy of this commonly used anticancer agent. DPD activity is highly variable (8-21-fold) and individuals with reduced activity have a high risk of 5FU toxicity. DPYD encodes DPD protein and 13 different mutations have been reported in DPD-deficient subjects. However, the contribution of these variant genotypes to polymorphic DPD activity in vivo is not clear. The previously described DPYD mutations are contained in 10 exons. These 10 exons were sequenced in a cohort of cancer patients with reduced (n = 23) or normal (n = 14) DPD activity to determine the contribution of each variant allele to low DPD activity in vivo. Eight of the 13 previously defined DPYD mutations (G62A, delta TCAT295-298, C703T, G1003T, G1156T, delta C1897, G2657A, and G2983T) were not detected. A previously defined exon 13 mutation (G1601A) was detected in three individuals with reduced DPD activity. An exon 14 splice donor site mutation (intron14 G1A) was detected in a normal DPD activity individual. It was demonstrated that T85C, A1627G and G2194A are common polymorphisms. A novel exonic mutation (T1679G) was detected in a patient with reduced DPD activity and 5FU toxicity. In addition, three novel common polymorphisms were detected in introns 10 and 13. Only three patients did not have any mutations and 30 had multiple DPYD mutations in the regions examined. However, only 17% (4/23) of the patients with a low DPD phenotype have a molecular basis for reduced activity. Although novel DPYD variants have been identified in this study, the 17 DPYD mutations now described do not entirely explain polymorphic DPD activity and toxic response to 5FU. These data emphasize the complex nature of the molecular mechanisms controlling polymorphic DPD activity in vivo.
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Affiliation(s)
- E S Collie-Duguid
- University of Aberdeen, Department of Medicine and Therapeutics, Institute of Medical Sciences, Foresterhill, UK.
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26
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Stoddart JH, Ladd D, Bronson RT, Harmon M, Jaworski J, Pritzker C, Lausen N, Smith BD. Transgenic mice with a mutated collagen promoter display normal response during bleomycin-induced fibrosis and possess neurological abnormalities. J Cell Biochem 2000; 77:135-48. [PMID: 10679824 DOI: 10.1002/(sici)1097-4644(20000401)77:1<135::aid-jcb14>3.0.co;2-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have previously identified a potential TGF-beta activation element (TAE) in the rat collagen alpha1(I) promoter at -1624 upstream of the transcriptional start site [Ritzenthaler et al., 1991, 1993]. To determine the importance of the TAE in vivo, we produced transgenic mice carrying 3.6 kb of the rat collagen alpha1(I) promoter linked to the reporter gene chloramphenicol acetyl transferase with and without site-directed mutations that eliminate DNA-protein binding at the TAE site. Tissue-specific expression of the reporter gene in transgenic mice with the mutated collagen promoter was similar to that of transgenic mice with the normal promoter in two genetic backgrounds as judged by in situ hybridization, reporter assays, and immunochemistry. Endotracheal instillation of bleomycin induces lung fibrosis, mediated in part by TGF-beta. Earlier studies indicated that expression of wild-type collagen-reporter gene was upregulated in transgenic mice lungs in response to endotracheal instillation of bleomycin. A similar level of reporter gene upregulation was observed in transgenic mice carrying the mutation in the TAE. Two lines of transgenic mice carrying the mutated promoter construct displayed unexpected neurological abnormalities. In the FVB genetic background, there was a higher than normal incidence of mortality, spontaneous seizures, and an inability to nurture offspring. Histological evidence demonstrated clear abnormalities, including disorderly arrangement of neurons in the hippocampus and significant laminar cortical necrosis in the cerebrum in animals after seizures. In the C57Bl/6 background, there was a high incidence of severe communicating hydrocephalus, early runting, and increased mortality similar to that in transgenic animals with astroglial overexpression of TGF-beta. These animals provide an interesting model system to investigate molecular mechanisms responsible for seizures and hydrocephalus.
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Affiliation(s)
- J H Stoddart
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Theis M, Magin TM, Plum A, Willecke K. General or cell type-specific deletion and replacement of connexin-coding DNA in the mouse. Methods 2000; 20:205-18. [PMID: 10671314 DOI: 10.1006/meth.1999.0938] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Here we describe several gene targeting approaches currently used in our laboratory for the generation of deletion or replacement mutants of connexin genes in the mouse and discuss the advantage of the double-replacement strategy for the generation of conditional mutants. For the analysis of complementary functions of connexins, it will be necessary to generate mice with mutations in several connexin genes. We also report how this can be effectively accomplished. The replacement of targeted connexin-coding DNA with a reporter gene, to mimic expression of the deleted gene product, is currently being used in several laboratories. The use of different reporter genes or their differently localized gene products could allow distinction of promoter activity in double or triple connexin mutant mice.
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Affiliation(s)
- M Theis
- Institut fuer Genetik, Abteilung Molekulargenetik, Universitaet Bonn, Roemerstrasse 164, Bonn, D-53117, Germany
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Forlino A, Porter FD, Lee EJ, Westphal H, Marini JC. Use of the Cre/lox recombination system to develop a non-lethal knock-in murine model for osteogenesis imperfecta with an alpha1(I) G349C substitution. Variability in phenotype in BrtlIV mice. J Biol Chem 1999; 274:37923-31. [PMID: 10608859 DOI: 10.1074/jbc.274.53.37923] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We utilized the Cre/lox recombination system to develop the first knock-in murine model for osteogenesis imperfecta (OI). The moderately severe OI phenotype was obtained from an alpha1(I) Gly(349) --> Cys substitution in type I collagen, reproducing the mutation in a type IV OI child. We introduced four single nucleotide (nt) changes into murine col1a1 exon 23: the disease causing G-->T transversion (nt 1546), an adjacent G-->T change (nt 1551) to generate a GUC ribozyme cleavage site, and two transversions (nt 1567 C-->A and nt 1569 C-->G) to cause a Leu --> Met substitution. We also introduced a 3.2-kilobase pair transcription/translation stop cassette in intron 22, flanked by directly repeating lox recombination sites. After homologous recombination in ES cells, two male chimeras were obtained. Chimeras were mated with transgenic females expressing Cre recombinase to remove the stop cassette from a portion of the progeny's cells. To generate mice with full expression of the Gly(349) --> Cys mutation, these offspring were then mated with wild-type females. Skeletal staining and bone histology of the F2 revealed a classical OI phenotype with deformity, fragility, osteoporosis and disorganized trabecular structure. We designate these mice BrtlIV (Brittle IV). BrtlIV mice have phenotypic variability ranging from perinatal lethality to long term survival with reproductive success. The phenotypic variability is not associated with differences in expression levels of the mutant allele in total RNA derived from tissue extracts. Expression of the mutant protein is also equivalent in different phenotypes. Thus, these mice are an excellent model for delineation of the modifying factors postulated to affect human OI phenotypes. In addition, we generated knock-in mice carrying an "intronic" inclusion by mating chimeras with wild-type females. Alternative splicing involving the stop cassette results in retention of non-collagenous sequences. These mice reproduce the lethal phenotype of similar human mutations and are designated BrtlII.
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Affiliation(s)
- A Forlino
- Heritable Disorders Branch, NICHD, National Institutes of Health, Bethesda, Maryland 20892, USA
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29
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Polakowska RR, Graf B, Falciano V, LaCelle P. Transcription regulatory elements of the first intron control human transglutaminase type I gene expression in epidermal keratinocytes. J Cell Biochem 1999. [DOI: 10.1002/(sici)1097-4644(19990601)73:3<355::aid-jcb7>3.0.co;2-d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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30
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Hormuzdi SG, Strandjord TP, Madtes DK, Bornstein P. Mice with a targeted intronic deletion in the Col1a1 gene respond to bleomycin-induced pulmonary fibrosis with increased expression of the mutant allele. Matrix Biol 1999; 18:287-94. [PMID: 10429947 DOI: 10.1016/s0945-053x(99)00017-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Experiments designed to examine the role of the first intron in regulation of the Col1a1 gene by transfection and in transgenic mice have led to conflicting conclusions. Recently, Hormuzdi et al. [Hormuzdi, S.G., Penttinen, R., Jaenisch, R., Bornstein, P., 1998. A gene-targeting approach identifies a function for the first intron in expression of the alpha1(I) collagen. Mol. Cell. Biol. 18, 3368-3375.] created a targeted deletion in this intron in mice and demonstrated an age-dependent reduction in expression of the mutated allele in lung and skeletal muscle. In this study, intratracheal instillation of bleomycin in mice was used to induce pulmonary fibrosis in control and intron-deleted animals. This stimulus for collagen synthesis was associated with a marked upregulation of the intron-deleted allele in mutant mice. Our results establish that the inhibition of expression of the mutant Col1a1 gene is not fixed, since the gene can still respond to physiological signals. We propose that cis-acting elements, elsewhere in the gene, can compensate for the lack of intronic sequences in the mutated Col1a1 allele and account for the conditional nature of the inhibition. This model has the potential to resolve the conflicting results of previous transfection and transgenic experiments in which different fragments of the Col1a1 gene were used.
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Affiliation(s)
- S G Hormuzdi
- Department of Biochemistry, University of Washington, Seattle 98195, USA
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31
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Kim CH, Kim HS, Cubells JF, Kim KS. A previously undescribed intron and extensive 5' upstream sequence, but not Phox2a-mediated transactivation, are necessary for high level cell type-specific expression of the human norepinephrine transporter gene. J Biol Chem 1999; 274:6507-18. [PMID: 10037744 DOI: 10.1074/jbc.274.10.6507] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The synaptic action of norepinephrine is terminated by NaCl-dependent uptake into presynaptic noradrenergic nerve endings, mediated by the norepinephrine transporter (NET). NET is expressed only in neuronal tissues that synthesize and secrete norepinephrine and in most cases is co-expressed with the norepinephrine-synthetic enzyme dopamine beta-hydroxylase (DBH). To understand the molecular mechanisms regulating human NET (hNET) gene expression, we isolated and characterized an hNET genomic clone encompassing approximately 9. 5 kilobase pairs of the 5' upstream promoter region. Here we demonstrate that the hNET gene contains an as-yet-unidentified intron of 476 base pairs within the 5'-untranslated region. Furthermore, both primer extension and 5'-rapid amplification of cDNA ends analyses identified multiple transcription start sites from mRNAs expressed only in NET-expressing cell lines. The start sites clustered in two subdomains, each preceded by a TATA-like sequence motif. As expected for mature mRNAs, transcripts from most of these sites each contained an additional G residue at the 5' position. Together, the data strongly support the authenticity of these sites as the transcriptional start sites of hNET. We assembled hNET-chloramphenicol acetyltransferase reporter constructs containing different lengths of hNET 5' sequence in the presence or the absence of the first intron. Transient transfection assays indicated that the combination of the 5' upstream sequence and the first intron supported the highest level of noradrenergic cell-specific transcription. Forced expression of the paired-like homeodomain transcription factor Phox2a did not affect hNET promoter activity in NET-negative cell lines, in marked contrast to its effect on a DBH-chloramphenicol acetyltransferase reporter construct. Together with our previous studies suggesting a critical role of Phox2a for noradrenergic-specific expression of the DBH gene, these data support a model in which distinct, or partially distinct, molecular mechanisms regulate cell-specific expression of the NET and DBH genes.
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Affiliation(s)
- C H Kim
- Department of Neurology and Department of Anatomy and Neurobiology, University of Tennessee College of Medicine, Memphis, Tennessee 38163, USA
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32
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Wang Q, Raghow R. Molecular mechanisms of regulation of type I collagen biosynthesis. J CHEM SCI 1999. [DOI: 10.1007/bf02869908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Chen A, Davis BH. UV irradiation activates JNK and increases alphaI(I) collagen gene expression in rat hepatic stellate cells. J Biol Chem 1999; 274:158-64. [PMID: 9867824 DOI: 10.1074/jbc.274.1.158] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hepatic stellate cells (HSCs) become activated into myofibroblast-like cells during the early stages of hepatic injury associated with fibrogenesis. The subsequent dysregulation of alphaI(I) collagen gene expression is a central pathogenetic step during the development of cirrhosis. Our recent study in rat HSCs (Davis, B. H., Chen, A., and Beno, D. (1996) J. Biol. Chem. 271, 11039-11042) found that ERK1,2 activation might be required for maximal alphaI(I) collagen gene expression. However, the role of the parallel JNK cascade in regulating alphaI(I) collagen gene expression was unknown. In this study, we initially found that UV irradiation of HSCs activated JNK but not ERK1,2. Furthermore, UV irradiation increased endogenous alpha I(I) collagen mRNA abundance and stimulated alpha I(I) collagen gene transcription in HSCs. The effect of the activation of JNK and Jun on alpha I(I) collagen gene expression was further evaluated via transfection of chloramphenicol acetyltransferase reporter plasmids with various sizes of truncated 5' upstream promoter sequence (UPS) of the alphaI(I) collagen gene. This revealed that dominant negative transcription factor JUN suppressed alpha I(I) collagen gene transcription in HSCs maintained in media with 20% serum and constitutively activated JUN increased alphaI(I) collagen gene transcription in HSCs cultured in media with 0.4% serum. UV activated JNK utilized a distal GC box in the 5'-UPS of the collagen gene to regulate gene transcription. This observation was confirmed by site-directed mutagenesis. In co-transfection experiments, the col-chloramphenicol acetyltransferase reporter with a mutagenized GC box was not suppressed by dn-JUN and was not stimulated by activated JUN or by UV irradiation. Southwestern blotting analyses and gel shift assays with basic transcription element-binding protein antiserum suggested that the GC box was bound by basic transcription element-binding protein, a recently described DNA-binding protein. In conclusion, the current study combined with our previous report suggests that ERK1,2 and JNK cascades regulate alphaI(I) collagen expression in HSCs through different regions of the 5'-UPS of the gene. The distal GC box in the 5'-UPS of the alphaI(I) collagen gene may play a central role in receiving extracellular signals through the JNK pathway.
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Affiliation(s)
- A Chen
- Gastroenterology Section, Department of Medicine, University of Chicago Medical Center, Chicago, Illinois 60637, USA
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Jimenez SA, Saitta B. Alterations in the regulation of expression of the alpha 1(I) collagen gene (COL1A1) in systemic sclerosis (scleroderma). SPRINGER SEMINARS IN IMMUNOPATHOLOGY 1999; 21:397-414. [PMID: 10945033 DOI: 10.1007/bf00870302] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
At present, the mechanisms that regulate the expression of collagen genes in normal and pathologic fibroblasts are not known. Thus, the detailed study of transcriptional regulation of COL1A1 in SSc cells will increase our current understanding of the pathophysiology of fibrotic diseases. These studies will yield valuable information regarding the important biological process of regulation of collagen gene expression under normal and pathologic conditions, a process that has remained elusive despite intense recent investigations. It is now evident that persistent overproduction of collagen is responsible for the progressive nature of tissue fibrosis in SSc. Up-regulation of collagen gene expression in SSc fibroblasts appears to be a critical event in this process. The coordinate transcriptional activation of numerous collagen genes suggests a fundamental alteration in the regulatory control of gene expression in SSc fibroblasts. Trans-acting nuclear factors which bind to cis-acting elements in enhancer (intronic) and promoter regions of the genes modulate the basal and inducible transcriptional activity of the collagen genes. The identification of the nuclear transcription factors that regulate normal collagen gene expression may provide promising approaches to the therapy of this incurable disease.
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Affiliation(s)
- S A Jimenez
- Department of Medicine, Thomas Jefferson University, Philadelphia, PA 19107-5541, USA.
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