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Liu S, Chen T, Chen B, Liu Y, Lu X, Li J. Lrpap1 deficiency leads to myopia through TGF-β-induced apoptosis in zebrafish. Cell Commun Signal 2022; 20:162. [PMID: 36261846 PMCID: PMC9580148 DOI: 10.1186/s12964-022-00970-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 09/03/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Frameshift mutations in LRPAP1 are responsible for autosomal recessive high myopia in human beings but its underlying mechanism remains elusive. This study aims to investigate the effect of LRPAP1 defect on ocular refractive development and its involved mechanism. METHODS A lrpap1 mutant zebrafish line with homozygous frameshift mutation was generated by CRISPR/Cas9 technology and confirmed by Sanger sequencing. The ocular refractive phenotype was analyzed by calculating the relative refractive error (RRE) with vivo photography and histological analysis at different development stages, together with examining ocular structure change via transmission electron microscopy. Further, RNA sequencing and bioinformatics analysis were performed. The potentially involved signaling pathway as well as the interacted protein were investigated in vivo. RESULTS The lrpap1 homozygous mutant zebrafish line showed myopic phenotype. Specifically, the mutant lines showed larger eye axial length-to-body length in one-month old individuals and a myopic shift with an RRE that changed after two months. Collagen fibers became thinning and disordered in the sclera. Further, RNA sequencing and bioinformatics analysis indicated that apoptosis signaling was activated in mutant line; this was further confirmed by acridine orange and TUNEL staining. Moreover, the expression of TGF-β protein was elevated in the mutant lines. Finally, the treatment of wild-type embryos with a TGF-β agonist aggravated the degree of eyeball apoptosis; conversely, the use of a TGF-β inhibitor mitigated apoptosis in mutant embryos. CONCLUSION The study provides functional evidence of a link between lrpap1 and myopia, suggesting that lrpap1 deficiency could lead to myopia through TGF-β-induced apoptosis signaling. Video abstract.
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Affiliation(s)
- Shanshan Liu
- grid.284723.80000 0000 8877 7471Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Ting Chen
- grid.284723.80000 0000 8877 7471Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Binghao Chen
- grid.459579.30000 0004 0625 057XDepartment of Orthopedics, Guangdong Women and Children Hospital, Guangzhou, China
| | - Yijun Liu
- grid.413107.0Department of Foot and Ankle Surgery, Center for Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China
| | - Xiaohe Lu
- grid.284723.80000 0000 8877 7471Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jiali Li
- grid.284723.80000 0000 8877 7471Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
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Lisi S, Botta R, Pinchera A, Di Cosmo C, Perri A, De Marco G, Menconi F, Marinò M. Sequencing of the entire coding region of the receptor associated protein (RAP) in patients with primary hypothyroidism of unknown origin. J Endocrinol Invest 2007; 30:839-43. [PMID: 18075286 DOI: 10.1007/bf03349225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The LDL receptor-associated protein (RAP) is involved in secretion of thyroglobulin (Tg) from the thyrocyte to the colloid. Disruption of the RAP gene in mice results in a reduced Tg content within the colloid, leading to subclinical hypothyroidism and histological alterations resembling early goiter. Here we studied the entire coding sequence of RAP in genomic DNA samples from 18 patients with primary hypothyroidism not due to thyroid autoimmunity or dysgenesis. The control group included 21 subjects with no evidence of thyroid alterations. Eleven different polymorphisms with amino-acid substitution and 4 different missense polymorphisms without amino-acid substitution were found in various regions of the RAP gene. Only one polymorphism in exone 7 (V311M) was observed exclusively in patients, but it had been previously reported in normal subjects as well. The remaining polymorphisms were found either both in patients and controls or only in controls and had not been previously reported. The frequency of the various polymorphisms did not differ significantly between patients and controls. Based on these findings, we conclude that alterations of the RAP gene are not a common cause of hypothyroidism, although it cannot be excluded that other, rarer alterations with a pathogenic effect exist, and that they should be investigated in a larger number of patients.
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Affiliation(s)
- S Lisi
- Department of Endocrinology and Metabolism, University of Pisa, 56124 Pisa, Italy
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Hurle B, Lane K, Kenney J, Tarantino LM, Bucan M, Brownstein BH, Ornitz DM. Physical mapping of the mouse tilted locus identifies an association between human deafness loci DFNA6/14 and vestibular system development. Genomics 2001; 77:189-99. [PMID: 11597144 DOI: 10.1006/geno.2001.6632] [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: 11/22/2022]
Abstract
The tilted (tlt) mouse carries a recessive mutation causing vestibular dysfunction. The defect in tlt homozygous mice is limited to the utricle and saccule of the inner ear, which completely lack otoconia. Genetic mapping of tlt placed it in a region orthologous with human 4p16.3-p15 that contains two loci, DFNA6 and DFNA14, responsible for autosomal dominant, nonsyndromic hereditary hearing impairment. To identify a possible relationship between tlt in mice and DFNA6 and DFNA14 in humans, we have refined the mouse genetic map, assembled a BAC contig spanning the tlt locus, and developed a comprehensive comparative map between mouse and human. We have determined the position of tlt relative to 17 mouse chromosome 5 genes with orthologous loci in the human 4p16.3-p15 region. This analysis identified an inversion between the mouse and human genomes that places tlt and DFNA6/14 in close proximity.
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Affiliation(s)
- B Hurle
- Department of Molecular Biology and Pharmacology, Washington University School of Medicine, 660 South Euclid Ave., St. Louis, Missouri 63110, USA
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Umans L, Serneels L, Lorent K, Dewachter I, Tesseur I, Moechars D, Van Leuven F. Lipoprotein receptor-related protein in brain and in cultured neurons of mice deficient in receptor-associated protein and transgenic for apolipoprotein E4 or amyloid precursor protein. Neuroscience 1999; 94:315-21. [PMID: 10613521 DOI: 10.1016/s0306-4522(99)00242-0] [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: 10/18/2022]
Abstract
The role of the receptor-associated protein in controlling the expression of the low-density lipoprotein receptor-related protein was analysed in brain and in cultured neurons of receptor-associated protein - / - mice. In addition, the effect of two important ligands of lipoprotein receptor-related protein in brain, i.e. apolipoprotein E and amyloid precursor protein, was examined by crossing the receptor-associated protein - / - mice with transgenic mice overexpressing these proteins specifically in neurons. The immunohistochemical localization of lipoprotein receptor-related protein and receptor-associated protein in wild-type mouse brain was demonstrated to be congruent over all structures, including the cortex and hippocampus. In primary hippocampal neurons, lipoprotein receptor-related protein was distributed somatodendritically and receptor-associated protein was concentrated perinuclearly. In hippocampal neurons from receptor-associated protein - / - mice, lipoprotein receptor-related protein was redistributed over the cell body at the expense of the dendrites. In the absence of receptor-associated protein, maturation of lipoprotein receptor-related protein is slow, resulting in accumulation of the uncleaved 600,000 mol. wt precursor. Neither the added expression of apolipoprotein E4 nor that of amyloid precursor protein in cultured neurons influenced the maturation of lipoprotein receptor-related protein, in either the presence or absence of receptor-associated protein. This result shows that receptor-associated protein is not needed to allow co-expression of lipoprotein receptor-related protein with these ligands in neurons. Furthermore, the typical ramified neuronal morphology of cultured primary neurons and the histology and architecture of the brain were normal in receptor-associated protein - / - mice and in all of the double transgenic mice. Finally, we demonstrated that the survival of receptor-associated protein - /- hippocampal neurons was normal and unaffected by the genotype of the glial feeder cells, whether they were derived from wild-type mice or from mice deficient in receptor-associated protein or apolipoprotein E. These results show that, despite the dramatic effect on maturation and cellular localization of lipoprotein receptor-related protein, the absence of receptor-associated protein did not result in any notable physiological, functional or morphological effects.
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Affiliation(s)
- L Umans
- Experimental Genetics Group, Center for Human Genetics, Flemish Institute for Biotechnology, K.U. Leuven, Belgium
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5
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Umans L, Overbergh L, Serneels L, Tesseur I, Van Leuven F. Analysis of expression of genes involved in apolipoprotein E-based lipoprotein metabolism in pregnant mice deficient in the receptor-associated protein, the low density lipoprotein receptor, or apolipoprotein E. Biol Reprod 1999; 61:1216-25. [PMID: 10529267 DOI: 10.1095/biolreprod61.5.1216] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Mice deficient in receptor-associated protein (RAP) were phenotypically normal, but in contrast to results previously reported in RAP(-/-) mice, nearly 50% of the offspring died at or shortly after birth. To attempt to determine the reason for this, we analyzed the regulation of expression of genes involved in apolipoprotein E (apoE)-based mechanisms in RAP-deficient mice and compared this to results in mice deficient in low density lipoprotein receptor (LDLR) or apoE. The major finding concerned a large increase in hepatic lipoprotein receptor-related protein (LRP) mRNA and LDLR mRNA levels in pregnant RAP knockout mice. This is in contrast to the down-regulation of LRP mRNA and LDLR mRNA, which is normally seen in wild-type mice. Also in LDLR knockout mice, a significant up-regulation in expression of LRP mRNA was demonstrated. In apoE knockout mice, hepatic LRP mRNA did not change significantly, while hepatic LDLR mRNA expression was increased. In placenta and uterus, the deficiency of RAP did not markedly affect the expression of LRP and LDLR. Lipoprotein lipase mRNA and apoE mRNA increased during pregnancy in all mice, independent of their genetic status. The current study does not directly explain the increased mortality of RAP(-/-) pups. The data demonstrate, however, important relative changes in expression of the genes analyzed, an indication that LRP and LDLR play an important role in lipid metabolism during pregnancy.
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Affiliation(s)
- L Umans
- Experimental Genetics Group, Center for Human Genetics (CME), Flemish Institute for Biotechnology (VIB), Katholieke Universiteit Leuven, Campus Gasthuisberg, B-3000 Leuven, Belgium
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Spector EB, Seltzer WK, Goodman SI. Assignment of electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) to human chromosome 4q33 by fluorescence in situ hybridization and somatic cell hybridization. Mol Genet Metab 1999; 67:364-7. [PMID: 10444348 DOI: 10.1006/mgme.1999.2873] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a nuclear-encoded protein located in the inner mitochondrial membrane. Inherited defects of ETF-QO cause glutaric acidemia type II. We here describe the localization of the ETF-QO gene to human chromosome 4q33 by somatic cell hybridization and fluorescence in situ hybridization.
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Affiliation(s)
- E B Spector
- Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado 80262, USA.
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Van Leuven F, Torrekens S, Moechars D, Hilliker C, Buellens M, Bollen M, Delabie J. Molecular cloning of a gene on chromosome 19q12 coding for a novel intracellular protein: analysis of expression in human and mouse tissues and in human tumor cells, particularly Reed-Sternberg cells in Hodgkin disease. Genomics 1998; 54:511-20. [PMID: 9878255 DOI: 10.1006/geno.1998.5609] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A novel protein, named NNX3, was molecularly characterized by cloning its cDNA, and its gene was mapped to chromosome 19q12. The equivalent mouse cDNA and gene were also cloned to allow us to analyze expression in murine in addition to human cells and tissues. Human and mouse NNX3 genes are composed of nine exons coding for proteins that are unrelated to any known protein. Signal peptides and hydrophobic domains are absent, corroborating their localization in the cytoplasm in transfected Cos cells. In Western blotting and immunoprecipitation, human NNX3 appeared as a doublet of Mr 64K-66K, while mouse NNX3 was a 70-kDa protein, both apparently much larger than the predicted 50 kDa, due in part to a stretch of 16-18 acidic residues hinging two nearly equally sized domains. In addition, phosphorylation of serine residues was demonstrated. Putative nuclear targeting signals were predicted, but NNX3 protein and two truncated versions remained localized in the cytoplasm of transfected Cos cells. NNX3 was expressed in embryonic and adult mouse tissues, particularly in brain, muscle, and lung. The expression of human NNX3 was most notable in human skeletal muscle and in ganglion cells and was also evident in human tumors and derived cell lines. This was confirmed by entries appearing in the GenBank EST database during the later phase of this study, representing partial NNX3 cDNA isolated from diverse neoplastic and developing tissues. Surprisingly, NNX3 was immunochemically detected in Reed-Sternberg cells of Hodgkin disease, in parallel with restin, a cytoplasmic protein we previously characterized (J. Delabie et al., 1993, Leuk. Lymphoma 12, 21-26). The cloning and comprehensive molecular analysis of NNX3 as presented will form the basis for elucidating its function and, conversely, will constitute a marker for Reed-Sternberg cells in Hodgkin disease.
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Affiliation(s)
- F Van Leuven
- Experimental Genetics Group, Center for Human Genetics, Flemish Institute for Biotechnology, Department of Biochemistry, K.U. Leuven, Campus Gasthuisberg, Louvain, B-3000, Belgium.
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8
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Van Leuven F, Thiry E, Stas L, Nelissen B. Analysis of the human LRPAP1 gene coding for the lipoprotein receptor-associated protein: identification of 22 polymorphisms and one mutation. Genomics 1998; 52:145-51. [PMID: 9782079 DOI: 10.1006/geno.1998.5413] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The lipoprotein receptor-associated protein (RAP) is considered a chaperone protein for the lipoprotein receptor-related protein (LRP) and for the other members of the LDL receptor family. Genetic analysis is anticipated to help in delineating groups or individuals with potential defects or problems in this regard. A combined amplification/sequencing strategy was developed to analyze the human LRPAP1 gene for polymorphisms and mutations. The LRPAP1 gene was amplified from genomic DNA in four long-range PCR amplicons, 2.4 to 7.6 kb in size. Three amplicons were finally used as templates with 14 sequencing primers to obtain the sequence of the eight exons and large portions of adjacent introns from individual DNA. This strategy, applied to sequence the LRPAP1 gene of 14 unrelated, normal individuals revealed, in total, 23 distinct mutations and polymorphisms, mostly intronic substitutions and deletions. In this small group 1 expressed mutation was encountered on one allele in 2 unrelated individuals: a G to A transition results in the replacement of valine by methionine in exon 7 at position 311 of the human RAP precursor protein.
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Affiliation(s)
- F Van Leuven
- Center for Human Genetics, Flemish Institute for Biotechnology, K. U. Leuven, Campus Gasthuisberg, Leuven, B-3000, Belgium.
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Hawley P, Gibson I. Interaction of oligodeoxynucleotides with mammalian cells. ANTISENSE & NUCLEIC ACID DRUG DEVELOPMENT 1996; 6:185-95. [PMID: 8915503 DOI: 10.1089/oli.1.1996.6.185] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Many previous studies have demonstrated that antisense oligodeoxynucleotides (ODNs) bind to surface proteins in a manner compatible with receptor-mediated endocytosis and, unless specifically modified, are internalized into endosomes with little access to the cytoplasmic structures or to the nucleus. Reports vary as to the specific proteins involved in the mechanism, and this study examines the conditions of binding, some proteins that might contribute to the process, and whether changes in binding patterns occur during differentiation. Native gel electrophoresis was used to optimize the surface binding of a phosphorothioate end-capped 16-mer to T15 mouse fibroblast cells, and comparisons are made with some human epithelial tumor cell lines. Binding to individual proteins was visualized using SDS-PAGE and autoradiography. Binding at 4 degrees C was almost exclusively to a 46 kDa protein and decreased in the presence of an excess of unlabeled ODN and heparin but not ATP. Increasing the temperature of ODN binding from 4 degrees C to 37 degrees C for 10 minutes changed the binding pattern observed. ODN binding to the total cytoplasmic and membrane proteins immobilized on a membrane showed a greater number of binding proteins, the most prominent being one of 30 kDa. Examination of the effects of serum on binding were made using the human lung carcinoma cell line COR-L23, which can be grown in serum-free conditions. Serum starvation led to an increased total binding seen on native gels coinciding with increased binding to a 46 kDa protein. Demonstration that changes in binding proteins occur when cells differentiate was made using the premacrophage cell line THP-1. Differentiation of these cells increased the total ODN binding and appeared to initiate the synthesis of some new binding proteins, although binding to a 46 kDa protein was reduced.
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Affiliation(s)
- P Hawley
- School of Biological Sciences, Norwich, UK
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Overbergh L, Lorent K, Torrekens S, Van Leuven F, Van den Berghe H. Expression of mouse alpha-macroglobulins, lipoprotein receptor-related protein, LDL receptor, apolipoprotein E, and lipoprotein lipase in pregnancy. J Lipid Res 1995. [DOI: 10.1016/s0022-2275(20)41496-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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