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Gabe CM, Bui AT, Lukashova L, Verdelis K, Vasquez B, Beniash E, Margolis HC. Role of amelogenin phosphorylation in regulating dental enamel formation. Matrix Biol 2024; 131:17-29. [PMID: 38759902 DOI: 10.1016/j.matbio.2024.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/08/2024] [Accepted: 05/14/2024] [Indexed: 05/19/2024]
Abstract
Amelogenin (AMELX), the predominant matrix protein in enamel formation, contains a singular phosphorylation site at Serine 16 (S16) that greatly enhances AMELX's capacity to stabilize amorphous calcium phosphate (ACP) and inhibit its transformation to apatitic enamel crystals. To explore the potential role of AMELX phosphorylation in vivo, we developed a knock-in (KI) mouse model in which AMELX phosphorylation is prevented by substituting S16 with Ala (A). As anticipated, AMELXS16A KI mice displayed a severe phenotype characterized by weak hypoplastic enamel, absence of enamel rods, extensive ectopic calcifications, a greater rate of ACP transformation to apatitic crystals, and progressive cell pathology in enamel-forming cells (ameloblasts). In the present investigation, our focus was on understanding the mechanisms of action of phosphorylated AMELX in amelogenesis. We have hypothesized that the absence of AMELX phosphorylation would result in a loss of controlled mineralization during the secretory stage of amelogenesis, leading to an enhanced rate of enamel mineralization that causes enamel acidification due to excessive proton release. To test these hypotheses, we employed microcomputed tomography (µCT), colorimetric pH assessment, and Fourier Transform Infrared (FTIR) microspectroscopy of apical portions of mandibular incisors from 8-week old wildtype (WT) and KI mice. As hypothesized, µCT analyses demonstrated significantly higher rates of enamel mineral densification in KI mice during the secretory stage compared to the WT. Despite a greater rate of enamel densification, maximal KI enamel thickness increased at a significantly lower rate than that of the WT during the secretory stage of amelogenesis, reaching a thickness in mid-maturation that is approximately half that of the WT. pH assessments revealed a lower pH in secretory enamel in KI compared to WT mice, as hypothesized. FTIR findings further demonstrated that KI enamel is comprised of significantly greater amounts of acid phosphate compared to the WT, consistent with our pH assessments. Furthermore, FTIR microspectroscopy indicated a significantly higher mineral-to-organic ratio in KI enamel, as supported by µCT findings. Collectively, our current findings demonstrate that phosphorylated AMELX plays crucial mechanistic roles in regulating the rate of enamel mineral formation, and in maintaining physico-chemical homeostasis and the enamel growth pattern during early stages of amelogenesis.
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Affiliation(s)
- Claire M Gabe
- Department of Oral and Craniofacial Sciences, University of Pittsburgh School of Dental Medicine, 335 Sutherland Drive (UPSDM), Pittsburgh, PA 15260, USA; Center for Craniofacial Regeneration, UPSDM, Pittsburgh, PA, USA
| | - Ai Thu Bui
- Department of Oral and Craniofacial Sciences, University of Pittsburgh School of Dental Medicine, 335 Sutherland Drive (UPSDM), Pittsburgh, PA 15260, USA; Center for Craniofacial Regeneration, UPSDM, Pittsburgh, PA, USA
| | | | - Kostas Verdelis
- Center for Craniofacial Regeneration, UPSDM, Pittsburgh, PA, USA; Department of Endodontics, UPSDM, Pittsburgh, PA, USA
| | - Brent Vasquez
- Department of Oral and Craniofacial Sciences, University of Pittsburgh School of Dental Medicine, 335 Sutherland Drive (UPSDM), Pittsburgh, PA 15260, USA; Center for Craniofacial Regeneration, UPSDM, Pittsburgh, PA, USA
| | - Elia Beniash
- Department of Oral and Craniofacial Sciences, University of Pittsburgh School of Dental Medicine, 335 Sutherland Drive (UPSDM), Pittsburgh, PA 15260, USA; Center for Craniofacial Regeneration, UPSDM, Pittsburgh, PA, USA
| | - Henry C Margolis
- Department of Oral and Craniofacial Sciences, University of Pittsburgh School of Dental Medicine, 335 Sutherland Drive (UPSDM), Pittsburgh, PA 15260, USA; Center for Craniofacial Regeneration, UPSDM, Pittsburgh, PA, USA; Department of Periodontics and Preventive Dentistry, UPSDM, Pittsburgh, PA, USA.
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Kegulian NC, Visakan G, Bapat RA, Moradian-Oldak J. Ameloblastin and its multifunctionality in amelogenesis: A review. Matrix Biol 2024; 131:62-76. [PMID: 38815936 PMCID: PMC11218920 DOI: 10.1016/j.matbio.2024.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/16/2024] [Accepted: 05/24/2024] [Indexed: 06/01/2024]
Abstract
Extracellular matrix proteins play crucial roles in the formation of mineralized tissues like bone and teeth via multifunctional mechanisms. In tooth enamel, ameloblastin (Ambn) is one such multifunctional extracellular matrix protein implicated in cell signaling and polarity, cell adhesion to the developing enamel matrix, and stabilization of prismatic enamel morphology. To provide a perspective for Ambn structure and function, we begin this review by describing dental enamel and enamel formation (amelogenesis) followed by a description of enamel extracellular matrix. We then summarize the established domains and motifs in Ambn protein, human amelogenesis imperfecta cases, and genetically engineered mouse models involving mutated or null Ambn. We subsequently delineate in silico, in vitro, and in vivo evidence for the amphipathic helix in Ambn as a proposed cell-matrix adhesive and then more recent in vitro evidence for the multitargeting domain as the basis for dynamic interactions of Ambn with itself, amelogenin, and membranes. The multitargeting domain facilitates tuning between Ambn-membrane interactions and self/co-assembly and supports a likely overall role for Ambn as a matricellular protein. We anticipate that this review will enhance the understanding of multifunctional matrix proteins by consolidating diverse mechanisms through which Ambn contributes to enamel extracellular matrix mineralization.
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Affiliation(s)
- Natalie C Kegulian
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar St., CSA 148, Los Angeles, CA 90033, USA
| | - Gayathri Visakan
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar St., CSA 148, Los Angeles, CA 90033, USA
| | - Rucha Arun Bapat
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar St., CSA 148, Los Angeles, CA 90033, USA
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar St., CSA 148, Los Angeles, CA 90033, USA.
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3
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Øvrebø Ø, De Lauretis A, Ma Q, Lyngstadaas SP, Perale G, Nilsen O, Rossi F, Haugen HJ. Towards bone regeneration: Understanding the nucleating ability of proline-rich peptides in biomineralisation. BIOMATERIALS ADVANCES 2024; 159:213801. [PMID: 38401402 DOI: 10.1016/j.bioadv.2024.213801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/26/2024] [Accepted: 02/18/2024] [Indexed: 02/26/2024]
Abstract
Obtaining rapid mineralisation is a challenge in current bone graft materials, which has been attributed to the difficulty of guiding the biological processes towards osteogenesis. Amelogenin, a key protein in enamel formation, inspired the design of two intrinsically disordered peptides (P2 and P6) that enhance in vivo bone formation, but the process is not fully understood. In this study, we have elucidated the mechanism by which these peptides induce improved mineralisation. Our molecular dynamics analysis demonstrated that in an aqueous environment, P2 and P6 fold to interact with the surrounding Ca2+, PO43- and OH- ions, which can lead to apatite nucleation. Although P2 has a less stable backbone, it folds to a stable structure that allows for the nucleation of larger calcium phosphate aggregates than P6. These results were validated experimentally in a concentrated simulated body fluid solution, where the peptide solutions accelerated the mineralisation process compared to the control and yielded mineral structures mimicking the amorphous calcium phosphate crystals that can be found in lamella bone. A pH drop for the peptide groups suggests depletion of calcium and phosphate, a prerequisite for intrinsic osteoinduction, while S/TEM and SEM suggested that the peptide regulated the mineral nucleation into lamella flakes. Evidently, the peptides accelerate and guide mineral formation, elucidating the mechanism for how these peptides can improve the efficacy of P2 or P6 containing devices for bone regeneration. The work also demonstrates how experimental mineralisation study coupled with molecular dynamics is a valid method for understanding and predicting in vivo performance prior to animal trials.
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Affiliation(s)
- Øystein Øvrebø
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, 0318 Oslo, Norway; Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, 20133 Milano, Italy; Material Biomimetic AS, Oslo Science Park, 0349 Oslo, Norway
| | - Angela De Lauretis
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, 0318 Oslo, Norway; Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, 20133 Milano, Italy
| | - Qianli Ma
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, 0318 Oslo, Norway
| | - Ståle Petter Lyngstadaas
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, 0318 Oslo, Norway
| | - Giuseppe Perale
- Industrie Biomediche Insubri SA, Mezzovico-Vira 6805, Switzerland; Faculty of Biomedical Sciences, University of Southern Switzerland, Lugano 6900, Switzerland; Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Donaueschingenstrasse 13, 1200 Vienna, Austria
| | - Ola Nilsen
- Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, Gaustadalléen 21, NO-0349 Oslo, Norway
| | - Filippo Rossi
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, 20133 Milano, Italy
| | - Håvard J Haugen
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, 0318 Oslo, Norway.
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Vetyskova V, Hubalek M, Sulc J, Prochazka J, Vondrasek J, Vydra Bousova K. Proteolytic profiles of two isoforms of human AMBN expressed in E. coli by MMP-20 and KLK-4 proteases. Heliyon 2024; 10:e24564. [PMID: 38298721 PMCID: PMC10828707 DOI: 10.1016/j.heliyon.2024.e24564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 12/16/2023] [Accepted: 01/10/2024] [Indexed: 02/02/2024] Open
Abstract
Ameloblastin is a protein in biomineralization of tooth enamel. However recent results indicate that this is probably not its only role in an organism. Enamel matrix formation represents a complex process enabled via specific crosslinking of two proteins - the most abundant amelogenin and the ameloblastin (AMBN). The human AMBN (hAMBN) gene possesses 13 protein coding exons with alternatively spliced transcripts and the longest isoform about 447 amino acid residues. It has been described that AMBN molecules in vitro assemble into oligomers via a sequence encoded by exon 5. Enamel is formed by the processing of enamel proteins by two specific proteases - enamelysin (MMP-20) and kallikrein 4 (KLK-4). The scaffold made of AMEL and non-amelogenin proteins is cleaved and removed from the developed tooth enamel. The hAMBN is expressed in two isoforms (ISO I and II), which could lead to their different utilization determined by distinct proteolytic profiles. In this study, we compared proteolytic profiles of both isoforms of hAMBN expressed in E. coli after proteolysis by MMP-20, KLK-4, and their 1:2 mixture. Proteolysis products were analysed and cleavage sites were identified by mass spectrometry. The proteolytic profiles of two AMBN isoforms showed different results, although we have to determine that the analysed AMBN was not post-translationally modified as expressed in prokaryotic cells. These results may lead to the suggestion of potentially divergent roles of AMBN isoforms cleavage products in various cell signalling pathways such as calcium buffering or signalling cascades.
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Affiliation(s)
- Veronika Vetyskova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 2, 16000, Prague, Czech Republic
| | - Martin Hubalek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 2, 16000, Prague, Czech Republic
| | - Josef Sulc
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 2, 16000, Prague, Czech Republic
- Department of Physical and Macromolecular Chemistry, Faculty of Natural Sciences, Charles University, Hlavova 8, 128 00 Prague 2, Czech Republic
| | - Jan Prochazka
- Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 5, 14000, Prague, Czech Republic
| | - Jiri Vondrasek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 2, 16000, Prague, Czech Republic
| | - Kristyna Vydra Bousova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 2, 16000, Prague, Czech Republic
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Zhang Z, Zou X, Feng L, Huang Y, Chen F, Sun K, Song Y, Lv P, Gao X, Dong Y, Tian H. Splicing mutations in AMELX and ENAM cause amelogenesis imperfecta. BMC Oral Health 2023; 23:893. [PMID: 37985977 PMCID: PMC10662561 DOI: 10.1186/s12903-023-03508-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 10/08/2023] [Indexed: 11/22/2023] Open
Abstract
BACKGROUND Amelogenesis imperfecta (AI) is a developmental enamel defect affecting the structure of enamel, esthetic appearance, and the tooth masticatory function. Gene mutations are reported to be relevant to AI. However, the mechanism underlying AI caused by different mutations is still unclear. This study aimed to reveal the molecular pathogenesis in AI families with 2 novel pre-mRNA splicing mutations. METHODS Two Chinese families with AI were recruited. Whole-exome sequencing and Sanger sequencing were performed to identify mutations in candidate genes. Minigene splicing assays were performed to analyze the mutation effects on mRNA splicing alteration. Furthermore, three-dimensional structures of mutant proteins were predicted by AlphaFold2 to evaluate the detrimental effect. RESULTS The affected enamel in family 1 was thin, rough, and stained, which was diagnosed as hypoplastic-hypomature AI. Genomic analysis revealed a novel splicing mutation (NM_001142.2: c.570 + 1G > A) in the intron 6 of amelogenin (AMELX) gene in family 1, resulting in a partial intron 6 retention effect. The proband in family 2 exhibited a typical hypoplastic AI, and the splicing mutation (NM_031889.2: c.123 + 4 A > G) in the intron 4 of enamelin (ENAM) gene was observed in the proband and her father. This mutation led to exon 4 skipping. The predicted structures showed that there were obvious differences in the mutation proteins compared with wild type, leading to impaired function of mutant proteins. CONCLUSIONS In this study, we identified two new splicing mutations in AMELX and ENAM genes, which cause hypoplastic-hypomature and hypoplastic AI, respectively. These results expand the spectrum of genes causing AI and broaden our understanding of molecular genetic pathology of enamel formation.
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Affiliation(s)
- Zhenwei Zhang
- Department of Cariology and Endodontology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, No. 22 Zhongguancun Nandajie, Haidian District, Beijing, 100081, PR China
| | - Xiaoying Zou
- Department of Cariology and Endodontology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, No. 22 Zhongguancun Nandajie, Haidian District, Beijing, 100081, PR China
| | - Lin Feng
- Department of Cariology and Endodontology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, No. 22 Zhongguancun Nandajie, Haidian District, Beijing, 100081, PR China
| | - Yu Huang
- Department of Medical Genetics, School of Basic Medical Sciences, Peking University Health and Science Center, Beijing, PR China
| | - Feng Chen
- Central Laboratory, National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Kai Sun
- Department of Prosthodontics, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Yilin Song
- Department of Cariology and Endodontology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, No. 22 Zhongguancun Nandajie, Haidian District, Beijing, 100081, PR China
| | - Ping Lv
- Department of Cariology and Endodontology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, No. 22 Zhongguancun Nandajie, Haidian District, Beijing, 100081, PR China
| | - Xuejun Gao
- Department of Cariology and Endodontology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, No. 22 Zhongguancun Nandajie, Haidian District, Beijing, 100081, PR China
| | - Yanmei Dong
- Department of Cariology and Endodontology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, No. 22 Zhongguancun Nandajie, Haidian District, Beijing, 100081, PR China.
| | - Hua Tian
- Department of Cariology and Endodontology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, No. 22 Zhongguancun Nandajie, Haidian District, Beijing, 100081, PR China.
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Shao C, Bapat RA, Su J, Moradian-Oldak J. Regulation of Hydroxyapatite Nucleation In Vitro through Ameloblastin-Amelogenin Interactions. ACS Biomater Sci Eng 2023; 9:1834-1842. [PMID: 35068157 PMCID: PMC9308824 DOI: 10.1021/acsbiomaterials.1c01113] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Amelogenin (Amel) and ameloblastin (Ambn) are two primary extracellular enamel matrix proteins that play crucial roles for proper thickness, prismatic structure, and robust mechanical properties. Previous studies have shown that Amel and Ambn bind to each other, but the effect of their coassembly on the nucleation of hydroxyapatite (HAP) is unclear. Here, we systematically investigated the coassembly of recombinant mouse Amel and Ambn in various ratios using in situ atomic force microscopy, dynamic light scattering, and transmission electron microscopy. The size of protein particles decreased as the Ambn:Amel ratio increased. To define the coassembly domain on Ambn, we used Ambn-derived peptides and Ambn variants to examine their effects on the amelogenin particle size distribution. We found that the peptide sequence encoded by exon 5 of Ambn affected Amel self-assembly but the variant lacking this sequence did not have any effect on Amel self-assembly. Furthermore, through monitoring the pH change in bulk mineralization solution, we tracked the nucleation behavior of HAP in the presence of Ambn and Amel and found that their coassemblies at different ratios showed varying abilities to stabilize amorphous calcium phosphate. These results demonstrated that Ambn and Amel coassemble with each other via a motif within the sequence encoded by exon 5 of Ambn and cooperate in regulating the nucleation of HAP crystals, enhancing our understanding of the important role of enamel matrix proteins in amelogenesis.
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Affiliation(s)
- Changyu Shao
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, California 90033, United States
| | - Rucha Arun Bapat
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, California 90033, United States
| | - Jingtan Su
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, California 90033, United States
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, California 90033, United States
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Wald T, Verma A, Cooley V, Marangoni P, Cazares O, Sharir A, Sandoval EJ, Sung D, Najibi H, Drennon TY, Bush JO, Joester D, Klein OD. A Suite of Mouse Reagents for Studying Amelogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.30.534992. [PMID: 37034814 PMCID: PMC10081212 DOI: 10.1101/2023.03.30.534992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Amelogenesis, the formation of dental enamel, is driven by specialized epithelial cells called ameloblasts, which undergo successive stages of differentiation. Ameloblasts secrete enamel matrix proteins (EMPs), proteases, calcium, and phosphate ions in a stage-specific manner to form mature tooth enamel. Developmental defects in tooth enamel are common in humans, and they can greatly impact the well-being of affected individuals. Our understanding of amelogenesis and developmental pathologies is rooted in past studies using epithelial Cre driver and knockout alleles. However, the available mouse models are limited, as most do not allow targeting different ameloblast sub-populations, and constitutive loss of EMPs often results in severe phenotype in the mineral, making it difficult to interpret defect mechanisms. Herein, we report on the design and verification of a toolkit of twelve mouse alleles that include ameloblast-stage specific Cre recombinases, fluorescent reporter alleles, and conditional flox alleles for the major EMPs. We show how these models may be used for applications such as sorting of live stage specific ameloblasts, whole mount imaging, and experiments with incisor explants. The full list of new alleles is available at https://dev.facebase.org/enamelatlas/mouse-models/ .
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Kegulian NC, Langen R, Moradian-Oldak J. The Dynamic Interactions of a Multitargeting Domain in Ameloblastin Protein with Amelogenin and Membrane. Int J Mol Sci 2023; 24:3484. [PMID: 36834897 PMCID: PMC9966149 DOI: 10.3390/ijms24043484] [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] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/28/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
The enamel matrix protein Ameloblastin (Ambn) has critical physiological functions, including regulation of mineral formation, cell differentiation, and cell-matrix adhesion. We investigated localized structural changes in Ambn during its interactions with its targets. We performed biophysical assays and used liposomes as a cell membrane model. The xAB2N and AB2 peptides were rationally designed to encompass regions of Ambn that contained self-assembly and helix-containing membrane-binding motifs. Electron paramagnetic resonance (EPR) on spin-labeled peptides showed localized structural gains in the presence of liposomes, amelogenin (Amel), and Ambn. Vesicle clearance and leakage assays indicated that peptide-membrane interactions were independent from peptide self-association. Tryptophan fluorescence and EPR showed competition between Ambn-Amel and Ambn-membrane interactions. We demonstrate localized structural changes in Ambn upon interaction with different targets via a multitargeting domain, spanning residues 57 to 90 of mouse Ambn. Structural changes of Ambn following its interaction with different targets have relevant implications for the multifunctionality of Ambn in enamel formation.
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Affiliation(s)
- Natalie C. Kegulian
- Center for Craniofacial Molecular Biology, Department of Biomedical Sciences, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
| | - Ralf Langen
- Department of Neuroscience and Physiology, Department of Biochemistry and Molecular Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Department of Biomedical Sciences, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
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Early evolution of enamel matrix proteins is reflected by pleiotropy of physiological functions. Sci Rep 2023; 13:1471. [PMID: 36702824 PMCID: PMC9879986 DOI: 10.1038/s41598-023-28388-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/18/2023] [Indexed: 01/27/2023] Open
Abstract
Highly specialized enamel matrix proteins (EMPs) are predominantly expressed in odontogenic tissues and diverged from common ancestral gene. They are crucial for the maturation of enamel and its extreme complexity in multiple independent lineages. However, divergence of EMPs occured already before the true enamel evolved and their conservancy in toothless species suggests that non-canonical functions are still under natural selection. To elucidate this hypothesis, we carried out an unbiased, comprehensive phenotyping and employed data from the International Mouse Phenotyping Consortium to show functional pleiotropy of amelogenin, ameloblastin, amelotin, and enamelin, genes, i.e. in sensory function, skeletal morphology, cardiovascular function, metabolism, immune system screen, behavior, reproduction, and respiratory function. Mice in all KO mutant lines, i.e. amelogenin KO, ameloblastin KO, amelotin KO, and enamelin KO, as well as mice from the lineage with monomeric form of ameloblastin were affected in multiple physiological systems. Evolutionary conserved motifs and functional pleiotropy support the hypothesis of role of EMPs as general physiological regulators. These findings illustrate how their non-canonical function can still effect the fitness of modern species by an example of influence of amelogenin and ameloblastin on the bone physiology.
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10
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Proline-rich protein from S. mutans can perform a competitive mineralization function to enhance bacterial adhesion to teeth. Sci Rep 2022; 12:22250. [PMID: 36564474 PMCID: PMC9789152 DOI: 10.1038/s41598-022-26303-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 12/13/2022] [Indexed: 12/25/2022] Open
Abstract
A proline-rich region was found in Streptococcus mutans (S. mutans) surface antigen I/II (Ag I/II). The functions of this region were explored to determine its role in the cariogenic abilities of S. mutans; specifically, the proline-rich region was compared with human amelogenin. The full-length amelogenin genes were cloned from human (AmH) and surface antigen I/II genes from S. mutans. Then, the genes expressed and purified. We analyzed the structure and self-assembly ability of AmH and Ag I/II, compared their capacities to induce mineralization, and assessed the adhesion ability of S. mutans to AmH- and Ag I/II-coated tooth slices. AmH formed ordered chains and net frames in the early stage of protein self-assembly, while Ag I/II formed irregular and overlapping structures. AmH induced mineralization possessed a parallel rosary structure, while Ag I/II-induced mineralization is rougher and more irregular. The S. mutans adhesion assay indicated that the adhesion ability S. mutans on the Ag I/II-induced crystal layer was significantly higher than that on the AmH-induced crystal layer. S. mutans' Ag I/II may have evolved to resemble human amelogenin and form a rougher crystal layer on teeth, which play a competitive mineralization role and promotes better bacterial adhesion and colonization. Thus, the cariogenic ability of S. mutans Ag I/II is increased.
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11
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Visakan G, Bapat RA, Su J, Moradian-Oldak J. Modeling ameloblast-matrix interactions using 3D cell culture. Front Physiol 2022; 13:1069519. [PMID: 36531170 PMCID: PMC9751369 DOI: 10.3389/fphys.2022.1069519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 11/21/2022] [Indexed: 12/02/2022] Open
Abstract
The distinct morphology adopted by ameloblasts during amelogenesis is highly stage specific and involved intimately with the development of a hierarchical enamel microstructure. The molecular mechanisms that govern the development of an elongated and polarized secretory ameloblast morphology and the potential roles played by the enamel matrix proteins in this process are not fully understood. Thus far, the in vitro models that have been developed to mimic these early cell-matrix interactions have either been unable to demonstrate direct morphological change or have failed to adapt across ameloblast cell lines. Here, we use a recently established 3D cell culture model to examine the interactions between HAT-7 cells and the major enamel matrix proteins, amelogenin and ameloblastin. We demonstrate that HAT-7 cells selectively respond to functional EMPs in culture by forming clusters of tall cells. Aspect ratio measurements from three-dimensional reconstructions reveal that cell elongation is 5-times greater in the presence of EMPs when compared with controls. Using confocal laser scanning microscopy, we observe that these clusters are polarized with asymmetrical distributions of Par-3 and claudin-1 proteins. The behavior of HAT-7 cells in 3D culture with EMPs is comparable with that of ALC and LS-8 cells. The fact that the 3D model presented here is tunable with respect to gel substrate composition and ameloblast cell type highlights the overall usefulness of this model in studying ameloblast cell morphology in vitro.
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12
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Bahraminejad E, Paliwal D, Sunde M, Holt C, Carver JA, Thorn DC. Amyloid fibril formation by α S1- and β-casein implies that fibril formation is a general property of casein proteins. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140854. [PMID: 36087849 DOI: 10.1016/j.bbapap.2022.140854] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
Caseins are a diverse family of intrinsically disordered proteins present in the milks of all mammals. A property common to two cow paralogues, αS2- and κ-casein, is their propensity in vitro to form amyloid fibrils, the highly ordered protein aggregates associated with many age-related, including neurological, diseases. In this study, we explored whether amyloid fibril-forming propensity is a general feature of casein proteins by examining the other cow caseins (αS1 and β) as well as β-caseins from camel and goat. Small-angle X-ray scattering measurements indicated that cow αS1- and β-casein formed large spherical aggregates at neutral pH and 20°C. Upon incubation at 65°C, αS1- and β-casein underwent conversion to amyloid fibrils over the course of ten days, as shown by thioflavin T binding, transmission electron microscopy, and X-ray fibre diffraction. At the lower temperature of 37°C where fibril formation was more limited, camel β-casein exhibited a greater fibril-forming propensity than its cow or goat orthologues. Limited proteolysis of cow and camel β-casein fibrils and analysis by mass spectrometry indicated a common amyloidogenic sequence in the proline, glutamine-rich, C-terminal region of β-casein. These findings highlight the persistence of amyloidogenic sequences within caseins, which likely contribute to their functional, heterotypic self-assembly; in all mammalian milks, at least two caseins coalesce to form casein micelles, implying that caseins diversified partly to avoid dysfunctional amyloid fibril formation.
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Affiliation(s)
- Elmira Bahraminejad
- Research School of Chemistry, The Australian National University, Acton, ACT 2601, Australia
| | - Devashi Paliwal
- Research School of Chemistry, The Australian National University, Acton, ACT 2601, Australia
| | - Margaret Sunde
- School of Medical Sciences, Faculty of Medicine and Health, and Sydney Nano, The University of Sydney, Sydney, NSW 2006, Australia
| | - Carl Holt
- Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - John A Carver
- Research School of Chemistry, The Australian National University, Acton, ACT 2601, Australia
| | - David C Thorn
- Research School of Chemistry, The Australian National University, Acton, ACT 2601, Australia.
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13
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Vetyskova V, Zouharova M, Bousova K. Production of recombinant human ameloblastin by a fully native purification pathway. Protein Expr Purif 2022; 198:106133. [PMID: 35750297 DOI: 10.1016/j.pep.2022.106133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/16/2022] [Accepted: 06/19/2022] [Indexed: 12/29/2022]
Abstract
Ameloblastin (Ambn) is an intrinsically disordered protein (IDP) with a specific function of forming heterogenous homooligomers. The oligomeric function is led through a specific sequence encoded by exon 5 of Ambn. Due to the IDP character of Ambn to form oligomers, protein purification is subject to many challenges. Human ameloblastin (AMBN) and its two isoforms, I and II have already been purified as a recombinant protein in a bacterial expression system and functionally characterized in vitro. However, here we present a new purification protocol for the production of native AMBN in its original formation as a homooligomeric heterogeneous IDP. The purification process consists of three chromatographic steps utilizing His-tag and Twin Strep-tag affinity chromatography, along with size exclusion and reverse affinity chromatography. The presented workflow offers the production of AMBN in sufficient yield for in vitro protein characterizations and can be used to produce both AMBN isoforms I and II.
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Affiliation(s)
- V Vetyskova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Namesti 2, 16000, Prague, Czech Republic; Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technicka 5, 166 28, Prague, Czech Republic
| | - M Zouharova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Namesti 2, 16000, Prague, Czech Republic; Second Faculty of Medicine, Charles University, 150 06, Prague 5, V Uvalu 84, Czech Republic
| | - K Bousova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Namesti 2, 16000, Prague, Czech Republic.
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14
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Akkineni S, Zhu C, Chen J, Song M, Hoff SE, Bonde J, Tao J, Heinz H, Habelitz S, De Yoreo JJ. Amyloid-like amelogenin nanoribbons template mineralization via a low-energy interface of ion binding sites. Proc Natl Acad Sci U S A 2022; 119:e2106965119. [PMID: 35522709 PMCID: PMC9172371 DOI: 10.1073/pnas.2106965119] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 03/16/2022] [Indexed: 12/02/2022] Open
Abstract
Protein scaffolds direct the organization of amorphous precursors that transform into mineralized tissues, but the templating mechanism remains elusive. Motivated by models for the biomineralization of tooth enamel, wherein amyloid-like amelogenin nanoribbons guide the mineralization of apatite filaments, we investigated the impact of nanoribbon structure, sequence, and chemistry on amorphous calcium phosphate (ACP) nucleation. Using full-length human amelogenin and peptide analogs with an amyloid-like domain, films of β-sheet nanoribbons were self-assembled on graphite and characterized by in situ atomic force microscopy and molecular dynamics simulations. All sequences substantially reduce nucleation barriers for ACP by creating low-energy interfaces, while phosphoserines along the length of the nanoribbons dramatically enhance kinetic factors associated with ion binding. Furthermore, the distribution of negatively charged residues along the nanoribbons presents a potential match to the Ca–Ca distances of the multi-ion complexes that constitute ACP. These findings show that amyloid-like amelogenin nanoribbons provide potent scaffolds for ACP mineralization by presenting energetically and stereochemically favorable templates of calcium phosphate ion binding and suggest enhanced surface wetting toward calcium phosphates in general.
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Affiliation(s)
- Susrut Akkineni
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Cheng Zhu
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309
| | - Jiajun Chen
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Miao Song
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Samuel E. Hoff
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309
| | - Johan Bonde
- Division of Pure and Applied Biochemistry, Center for Applied Life Sciences, Lund University, Lund, SE-221 00, Sweden
| | - Jinhui Tao
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Hendrik Heinz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309
| | - Stefan Habelitz
- Department of Preventative and Restorative Dental Sciences, School of Dentistry, University of California, San Francisco, CA 94143
| | - James J. De Yoreo
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
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15
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Loss of biological control of enamel mineralization in amelogenin-phosphorylation-deficient mice. J Struct Biol 2022; 214:107844. [DOI: 10.1016/j.jsb.2022.107844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 11/23/2022]
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16
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Aranaz-Novaliches G, Spoutil F, Bukova I, Krejzova I, Olsinova M, Dalecka M, Benda A, Rozman J, Sedlacek R, Prochazka J. Multi-Level Approach for Comprehensive Enamel Phenotyping. Curr Protoc 2022; 2:e340. [PMID: 35007410 DOI: 10.1002/cpz1.340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Enamel is the hardest tissue in mammalian organisms and is the layer covering the tooth. It consists of hydroxyapatite (HAP) crystallites, which mineralize on a protein scaffold known as the enamel matrix. Enamel matrix assembly is a very complex process mediated by enamel matrix proteins (EMPs). Altered HAP deposition or disintegration of the protein scaffold can cause enamel defects. Various methods have been established for enamel phenotyping, including MicroCT scanning with various resolutions from 9 µm for in vivo imaging to 1.5 µm for ex vivo imaging. With increasing resolution, we can see not only the enamel layer itself but also a detailed map of mineralization. To study enamel microstructure, we combine the MicroCT analysis with scanning electron microscopy (SEM), which enables us to perform element analyses such as calcium-carbon ratio. However, the methods mentioned above only show the result-already formed enamel. Stimulated emission depletion (STED) microscopy provides extra information about protein structure in the form of EMP localization and position before enamel mineralization. A combination of all these methods allows analyzing the same sample on multiple levels-starting with the live animal being scanned harmlessly and quickly, followed by sacrifice and high-resolution MicroCT scans requiring no special sample preparation. The biggest advantage is that samples remain in perfect condition for SEM or STED microscopic analysis. © 2022 Wiley Periodicals LLC. Basic Protocol 1: In vivo MicroCT scanning of mouse Basic Protocol 2: Ex vivo HR-MicroCT of the teeth Basic Protocol 3: SEM for teeth microstructure Basic Protocol 4: Stimulated emission depletion (STED) microscopy.
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Affiliation(s)
- Goretti Aranaz-Novaliches
- Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Frantisek Spoutil
- Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ivana Bukova
- Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic.,Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Irena Krejzova
- Imaging Methods Core Facility, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Marie Olsinova
- Imaging Methods Core Facility, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Marketa Dalecka
- Imaging Methods Core Facility, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Ales Benda
- Imaging Methods Core Facility, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Jan Rozman
- Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Radislav Sedlacek
- Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic.,Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Prochazka
- Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic.,Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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17
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Visakan G, Su J, Moradian-Oldak J. Ameloblastin promotes polarization of ameloblast cell lines in a 3-D cell culture system. Matrix Biol 2022; 105:72-86. [PMID: 34813898 PMCID: PMC8955733 DOI: 10.1016/j.matbio.2021.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/12/2021] [Accepted: 11/16/2021] [Indexed: 01/03/2023]
Abstract
Studies on animal models with mutations in ameloblastin gene have suggested that the extracellular matrix protein ameloblastin (AMBN) plays important roles in controlling cell-matrix adhesion and ameloblast polarization during amelogenesis. In order to examine the function of AMBN in cell polarization and morphology, we developed an in vitro 3D cell culture model to examine the effect of AMBN and amelogenin (AMEL) addition on ameloblast cell lines. We further used high resolution confocal microscopy to detect expression of polarization markers in response to AMBN addition. Addition of AMBN to the 3D culture matrix resulted in the clustering and elongation (higher aspect ratio) of ALC in a dose dependent manner. The molar concentration of AMEL required to exact this response from ALC was 2.75- times greater than that of AMBN. This polarization effect of ameloblastin was attributable directly to an evolutionary conserved domain within its exon 5-encoded region. The lack of exon 6-encoded region also influenced AMBN-cell interactions but to a lesser extent. The clusters formed with AMBN were polarized with expression of E-cadherin, Par3 and Cldn1 assembly at the nascent cell-cell junctions. The elongation effect was specific to epithelial cells of ameloblastic lineage ALC and LS8 cells. Our data suggest that AMBN may play critical signaling roles in the initiation of cell polarity by acting as a communicator between cell-cell and cell-matrix interactions. Our investigation has important implications for understanding the function of ameloblastin in enamel-cell matrix adhesion and the outcomes may contribute to efforts to develop strategies for enamel tissue regeneration.
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18
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Tang S, Dong Z, Ke X, Luo J, Li J. Advances in biomineralization-inspired materials for hard tissue repair. Int J Oral Sci 2021; 13:42. [PMID: 34876550 PMCID: PMC8651686 DOI: 10.1038/s41368-021-00147-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/31/2021] [Accepted: 11/02/2021] [Indexed: 12/24/2022] Open
Abstract
Biomineralization is the process by which organisms form mineralized tissues with hierarchical structures and excellent properties, including the bones and teeth in vertebrates. The underlying mechanisms and pathways of biomineralization provide inspiration for designing and constructing materials to repair hard tissues. In particular, the formation processes of minerals can be partly replicated by utilizing bioinspired artificial materials to mimic the functions of biomolecules or stabilize intermediate mineral phases involved in biomineralization. Here, we review recent advances in biomineralization-inspired materials developed for hard tissue repair. Biomineralization-inspired materials are categorized into different types based on their specific applications, which include bone repair, dentin remineralization, and enamel remineralization. Finally, the advantages and limitations of these materials are summarized, and several perspectives on future directions are discussed.
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Affiliation(s)
- Shuxian Tang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, PR China
| | - Zhiyun Dong
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, PR China
| | - Xiang Ke
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, PR China
| | - Jun Luo
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, PR China.
| | - Jianshu Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, PR China.
- Med-X Center for Materials, Sichuan University, Chengdu, PR China.
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19
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Juanes-Gusano D, Santos M, Reboto V, Alonso M, Rodríguez-Cabello JC. Self-assembling systems comprising intrinsically disordered protein polymers like elastin-like recombinamers. J Pept Sci 2021; 28:e3362. [PMID: 34545666 DOI: 10.1002/psc.3362] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/02/2021] [Accepted: 07/13/2021] [Indexed: 12/19/2022]
Abstract
Despite lacking cooperatively folded structures under native conditions, numerous intrinsically disordered proteins (IDPs) nevertheless have great functional importance. These IDPs are hybrids containing both ordered and intrinsically disordered protein regions (IDPRs), the structure of which is highly flexible in this unfolded state. The conformational flexibility of these disordered systems favors transitions between disordered and ordered states triggered by intrinsic and extrinsic factors, folding into different dynamic molecular assemblies to enable proper protein functions. Indeed, prokaryotic enzymes present less disorder than eukaryotic enzymes, thus showing that this disorder is related to functional and structural complexity. Protein-based polymers that mimic these IDPs include the so-called elastin-like polypeptides (ELPs), which are inspired by the composition of natural elastin. Elastin-like recombinamers (ELRs) are ELPs produced using recombinant techniques and which can therefore be tailored for a specific application. One of the most widely used and studied characteristic structures in this field is the pentapeptide (VPGXG)n . The structural disorder in ELRs probably arises due to the high content of proline and glycine in the ELR backbone, because both these amino acids help to keep the polypeptide structure of elastomers disordered and hydrated. Moreover, the recombinant nature of these systems means that different sequences can be designed, including bioactive domains, to obtain specific structures for each application. Some of these structures, along with their applications as IDPs that self-assemble into functional vesicles or micelles from diblock copolymer ELRs, will be studied in the following sections. The incorporation of additional order- and disorder-promoting peptide/protein domains, such as α-helical coils or β-strands, in the ELR sequence, and their influence on self-assembly, will also be reviewed. In addition, chemically cross-linked systems with controllable order-disorder balance, and their role in biomineralization, will be discussed. Finally, we will review different multivalent IDPs-based coatings and films for different biomedical applications, such as spatially controlled cell adhesion, osseointegration, or biomaterial-associated infection (BAI).
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Affiliation(s)
- Diana Juanes-Gusano
- BIOFORGE (Group for Advanced Materials and Nanobiotechnology) CIBER-BBN, Edificio Lucía, University of Valladolid, Valladolid, Spain
| | - Mercedes Santos
- BIOFORGE (Group for Advanced Materials and Nanobiotechnology) CIBER-BBN, Edificio Lucía, University of Valladolid, Valladolid, Spain
| | - Virginia Reboto
- BIOFORGE (Group for Advanced Materials and Nanobiotechnology) CIBER-BBN, Edificio Lucía, University of Valladolid, Valladolid, Spain
| | - Matilde Alonso
- BIOFORGE (Group for Advanced Materials and Nanobiotechnology) CIBER-BBN, Edificio Lucía, University of Valladolid, Valladolid, Spain
| | - José Carlos Rodríguez-Cabello
- BIOFORGE (Group for Advanced Materials and Nanobiotechnology) CIBER-BBN, Edificio Lucía, University of Valladolid, Valladolid, Spain
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20
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Huang Y, Bai Y, Chang C, Bacino M, Cheng IC, Li L, Habelitz S, Li W, Zhang Y. A N-Terminus Domain Determines Amelogenin's Stability to Guide the Development of Mouse Enamel Matrix. J Bone Miner Res 2021; 36:1781-1795. [PMID: 33957008 PMCID: PMC9307086 DOI: 10.1002/jbmr.4329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 04/25/2021] [Accepted: 04/29/2021] [Indexed: 12/16/2022]
Abstract
Amelogenins, the principal proteins in the developing enamel microenvironment, self-assemble into supramolecular structures to govern the remodeling of a proteinaceous organic matrix into longitudinally ordered hydroxyapatite nanocrystal arrays. Extensive in vitro studies using purified native or recombinant proteins have revealed the potential of N-terminal amelogenin on protein self-assembly and its ability to guide the mineral deposition. We have previously identified a 14-aa domain (P2) of N-terminal amelogenin that can self-assemble into amyloid-like fibrils in vitro. Here, we investigated how this domain affects the ability of amelogenin self-assembling and stability of enamel matrix protein scaffolding in an in vivo animal model. Mice harboring mutant amelogenin lacking P2 domain had a hypoplastic, hypomineralized, and aprismatic enamel. In vitro, the mutant recombinant amelogenin without P2 had a reduced tendency to self-assemble and was prone to accelerated hydrolysis by MMP20, the prevailing metalloproteinase in early developing enamel matrix. A reduced amount of amelogenins and a lack of elongated fibrous assemblies in the development enamel matrix of mutant mice were evident compared with that in the wild-type mouse enamel matrix. Our study is the first to demonstrate that a subdomain (P2) at the N-terminus of amelogenin controls amelogenin's assembly into a transient protein scaffold that resists rapid proteolysis during enamel development in an animal model. Understanding the building blocks of fibrous scaffold that guides the longitudinal growth of hydroxyapatites in enamel matrix sheds light on protein-mediated enamel bioengineering. © 2021 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Yulei Huang
- Department of Orofacial Sciences, University of California, San Francisco, CA, USA.,Preventive and Restorative Dental Sciences, University of California, San Francisco, CA, USA
| | - Yushi Bai
- Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun-Yat-sen University, Guangzhou, China
| | - Chih Chang
- Department of Orofacial Sciences, University of California, San Francisco, CA, USA
| | - Margot Bacino
- Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun-Yat-sen University, Guangzhou, China
| | - Ieong Cheng Cheng
- Department of Orofacial Sciences, University of California, San Francisco, CA, USA
| | - Li Li
- Department of Orofacial Sciences, University of California, San Francisco, CA, USA
| | - Stefan Habelitz
- Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun-Yat-sen University, Guangzhou, China
| | - Wu Li
- Department of Orofacial Sciences, University of California, San Francisco, CA, USA
| | - Yan Zhang
- Department of Orofacial Sciences, University of California, San Francisco, CA, USA
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21
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Abstract
Biomineralization of enamel, dentin, and bone involves the deposition of apatite mineral crystals within an organic matrix. Bone and teeth are classic examples of biomaterials with unique biomechanical properties that are crucial to their function. The collagen-based apatite mineralization and the important function of noncollagenous proteins are similar in dentin and bone; however, enamel is formed in a unique amelogenin-containing protein matrix. While the structure and organic composition of enamel are different from those of dentin and bone, the principal molecular mechanisms of protein-protein interactions, protein self-assembly, and control of crystallization events by the organic matrix are common among these apatite-containing tissues. This review briefly summarizes enamel and dentin matrix components and their interactions with other extracellular matrix components and calcium ions in mediating the mineralization process. We highlight the crystallization events that are controlled by the protein matrix and their interactions in the extracellular matrix during enamel and dentin biomineralization. Strategies for peptide-inspired biomimetic growth of tooth enamel and bioinspired mineralization of collagen to stimulate repair of demineralized dentin and bone tissue engineering are also addressed.
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Affiliation(s)
- J Moradian-Oldak
- Center for Craniofacial Molecular Biology, Division of Biomedical Sciences, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - A George
- Brodie Tooth Development Genetics & Regenerative Medicine Research Laboratory, Department of Oral Biology, University of Illinois at Chicago, Chicago, IL, USA
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22
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Martinez-Carrasco R, Argüeso P, Fini ME. Membrane-associated mucins of the human ocular surface in health and disease. Ocul Surf 2021; 21:313-330. [PMID: 33775913 PMCID: PMC8328898 DOI: 10.1016/j.jtos.2021.03.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/02/2021] [Accepted: 03/08/2021] [Indexed: 02/06/2023]
Abstract
Mucins are a family of high molecular weight, heavily-glycosylated proteins produced by wet epithelial tissues, including the ocular surface epithelia. Densely-packed O-linked glycan chains added post-translationally confer the biophysical properties of hydration, lubrication, anti-adhesion and repulsion. Membrane-associated mucins (MAMs) are the distinguishing components of the mucosal glycocalyx. At the ocular surface, MAMs maintain wetness, lubricate the blink, stabilize the tear film, and create a physical barrier to the outside world. In addition, it is increasingly appreciated that MAMs function as cell surface receptors that transduce information from the outside to the inside of the cell. Recently, our team published a comprehensive review/perspectives article for molecular scientists on ocular surface MAMs, including previously unpublished data and analyses on two new genes MUC21 and MUC22, as well as new MAM functions and biological roles, comparing human and mouse (PMID: 31493487). The current article is a refocus for the audience of The Ocular Surface. First, we update the gene and protein information in a more concise form, and include a new section on glycosylation. Next, we discuss biological roles, with some new sections and further updating from our previous review. Finally, we provide a new chapter on MAM involvement in ocular surface disease. We end this with discussion of an emerging mechanism responsible for damage to the epithelia and their mucosal glycocalyces: the unfolded protein response (UPR). The UPR offers a novel target for therapeutic intervention.
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Affiliation(s)
- Rafael Martinez-Carrasco
- Department of Ophthalmology, Tufts University School of Medicine at New England Eye Center, Tufts Medical Center, Boston, MA, 02111, USA.
| | - Pablo Argüeso
- Department of Ophthalmology, Harvard Medical School at Schepens Eye Research Institute of Mass, Eye and Ear, Boston, MA, 02114, USA.
| | - M Elizabeth Fini
- Department of Ophthalmology, Tufts University School of Medicine at New England Eye Center, Tufts Medical Center: Program in Pharmacology & Drug Development, Graduate School of Biomedical Sciences, Tufts University, Boston, MA, O2111, USA.
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23
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Bapat RA, Su J, Moradian-Oldak J. Co-Immunoprecipitation Reveals Interactions Between Amelogenin and Ameloblastin via Their Self-Assembly Domains. Front Physiol 2020; 11:622086. [PMID: 33424645 PMCID: PMC7786100 DOI: 10.3389/fphys.2020.622086] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/04/2020] [Indexed: 01/28/2023] Open
Abstract
Macromolecular assembly of extracellular enamel matrix proteins (EMPs) is intimately associated with the nucleation, growth, and maturation of highly organized hydroxyapatite crystals giving rise to healthy dental enamel. Although the colocalization of two of the most abundant EMPs amelogenin (Amel) and ameloblastin (Ambn) in molar enamel has been established, the evidence toward their interaction is scarce. We used co-immunoprecipitation (co-IP) to show evidence of direct molecular interactions between recombinant and native Amel and Ambn. Ambn fragments containing Y/F-x-x-Y/L/F-x-Y/F self-assembly motif were isolated from the co-IP column and characterized by mass spectroscopy. We used recombinant Ambn (rAmbn) mutants with deletion of exons 5 and 6 as well as Ambn derived synthetic peptides to demonstrate that Ambn binds to Amel via its previously identified Y/F-x-x-Y/L/F-x-Y/F self-assembly motif at the N-terminus of its exon 5 encoded region. Using an N-terminal specific anti-Ambn antibody, we showed that Ambn N-terminal fragments colocalized with Amel from secretory to maturation stages of enamel formation in a single section of developing mouse incisor, and closely followed mineral patterns in enamel rod interrod architecture. We conclude that Ambn self-assembly motif is involved in its interaction with Amel in solution and that colocalization between the two proteins persists from secretory to maturation stages of amelogenesis. Our in vitro and in situ data support the notion that Amel and Ambn may form heteromolecular assemblies that may perform important physiological roles during enamel formation.
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Affiliation(s)
| | | | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, United States
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24
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Zhu H, Blahnová VH, Perale G, Xiao J, Betge F, Boniolo F, Filová E, Lyngstadaas SP, Haugen HJ. Xeno-Hybrid Bone Graft Releasing Biomimetic Proteins Promotes Osteogenic Differentiation of hMSCs. Front Cell Dev Biol 2020; 8:619111. [PMID: 33415112 PMCID: PMC7784409 DOI: 10.3389/fcell.2020.619111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 11/30/2020] [Indexed: 01/04/2023] Open
Abstract
Bone defect is a noteworthy health problem and is the second most transplanted tissue after blood. Numerous bone grafts are designed and applied in clinics. Limitations, however, from different aspects still exist, including limited supply, mechanical strength, and bioactivity. In this study, two biomimetic peptides (P2 and P6) are incorporated into a composite bioactive xeno hybrid bone graft named SmartBonePep®, with the aim to increase the bioactivity of the bone graft. The results, which include cytotoxicity, proliferation rate, confocal microscopy, gene expression, and protein qualification, successfully prove that the SmartBonePep® has multi-modal biological effects on human mesenchymal stem cells from bone marrow. The effective physical entrapment of P6 into a composite xeno-hybrid bone graft, withstanding manufacturing processes including exposure to strong organic solvents and ethylene oxide sterilization, increases the osteogenic potential of the stem cells as well as cell attachment and proliferation. P2 and P6 both show a strong biological potential and may be future candidates for enhancing the clinical performance of bone grafts.
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Affiliation(s)
- Hao Zhu
- Department of Orthopedic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Veronika Hefka Blahnová
- Department of Tissue Engineering, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
- Department of Biophysics, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Giuseppe Perale
- Industrie Biomediche Insubri S.A., Mezzovico-Vira, Switzerland
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Vienna, Austria
- Faculty of Biomedical Sciences, University of Southern Switzerland, Lugano, Switzerland
| | - Jun Xiao
- Department of Orthopedic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Felice Betge
- Industrie Biomediche Insubri S.A., Mezzovico-Vira, Switzerland
| | - Fabio Boniolo
- Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany
| | - Eva Filová
- Department of Tissue Engineering, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
- Department of Biophysics, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Ståle Petter Lyngstadaas
- Corticalis AS, Oslo, Norway
- Department of Biomaterials, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Håvard Jostein Haugen
- Corticalis AS, Oslo, Norway
- Department of Biomaterials, Faculty of Dentistry, University of Oslo, Oslo, Norway
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25
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Characterization of AMBN I and II Isoforms and Study of Their Ca 2+-Binding Properties. Int J Mol Sci 2020; 21:ijms21239293. [PMID: 33291486 PMCID: PMC7730623 DOI: 10.3390/ijms21239293] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 01/29/2023] Open
Abstract
Ameloblastin (Ambn) as an intrinsically disordered protein (IDP) stands for an important role in the formation of enamel—the hardest biomineralized tissue commonly formed in vertebrates. The human ameloblastin (AMBN) is expressed in two isoforms: full-length isoform I (AMBN ISO I) and isoform II (AMBN ISO II), which is about 15 amino acid residues shorter than AMBN ISO I. The significant feature of AMBN—its oligomerization ability—is enabled due to a specific sequence encoded by exon 5 present at the N-terminal part in both known isoforms. In this study, we characterized AMBN ISO I and AMBN ISO II by biochemical and biophysical methods to determine their common features and differences. We confirmed that both AMBN ISO I and AMBN ISO II form oligomers in in vitro conditions. Due to an important role of AMBN in biomineralization, we further addressed the calcium (Ca2+)-binding properties of AMBN ISO I and ISO II. The binding properties of AMBN to Ca2+ may explain the role of AMBN in biomineralization and more generally in Ca2+ homeostasis processes.
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26
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González-Obeso C, González-Pérez M, Mano JF, Alonso M, Rodríguez-Cabello JC. Complex Morphogenesis by a Model Intrinsically Disordered Protein. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2005191. [PMID: 33216415 DOI: 10.1002/smll.202005191] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/14/2020] [Indexed: 05/13/2023]
Abstract
The development of intricate and complex self-assembling structures in the micrometer range, such as biomorphs, is a major challenge in materials science. Although complex structures can be obtained from self-assembling materials as they segregate from solution, their size is usually in the nanometer range or requires accessory techniques. Previous studies with intrinsically disordered proteins (IDPs) have shown that the active interplay of different molecular interactions provides access to new and more complex nanostructures. As such, it is hypothesized that enriching the variety of intra- and intermolecular interactions in a model IDP will widen the landscape of sophisticated intermediate structures that can be accessed. In this study, a model silk-elastin-like recombinamer capable of interacting via three non-covalent interactions, namely hydrophobic, ion-pairing, and H-bonding is built. This model material is shown to self-assemble into complex stable micrometer-sized biomorphs. Variation of the block composition, pH, and temperature demonstrates the necessary interplay of all three interactions for the formation of such complex structures.
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Affiliation(s)
- Constancio González-Obeso
- BIOFORGE (Group for Advanced Materials and Nanobiotechnology), University of Valladolid-CIBER-BBN, Paseo de Belén 19, Valladolid, 47011, Spain
- Department of Biomedical Engineering, Tufts University, 4 Colby St., Medford, MA, 02155, USA
| | - Miguel González-Pérez
- BIOFORGE (Group for Advanced Materials and Nanobiotechnology), University of Valladolid-CIBER-BBN, Paseo de Belén 19, Valladolid, 47011, Spain
| | - João F Mano
- Department of Chemistry, CICECO - Aveiro Institute of Materials, University of Aveiro, Aveiro, 3810-193, Portugal
| | - Matilde Alonso
- BIOFORGE (Group for Advanced Materials and Nanobiotechnology), University of Valladolid-CIBER-BBN, Paseo de Belén 19, Valladolid, 47011, Spain
| | - José Carlos Rodríguez-Cabello
- BIOFORGE (Group for Advanced Materials and Nanobiotechnology), University of Valladolid-CIBER-BBN, Paseo de Belén 19, Valladolid, 47011, Spain
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27
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Structural Biology of Calcium Phosphate Nanoclusters Sequestered by Phosphoproteins. CRYSTALS 2020. [DOI: 10.3390/cryst10090755] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Biofluids that contain stable calcium phosphate nanoclusters sequestered by phosphopeptides make it possible for soft and hard tissues to co-exist in the same organism with relative ease. The stability diagram of a solution of nanocluster complexes shows how the minimum concentration of phosphopeptide needed for stability increases with pH. In the stable region, amorphous calcium phosphate cannot precipitate. Nevertheless, if the solution is brought into contact with hydroxyapatite, the crystalline phase will grow at the expense of the nanocluster complexes. The physico-chemical principles governing the formation, composition, size, structure, and stability of the complexes are described. Examples are given of complexes formed by casein, osteopontin, and recombinant phosphopeptides. Application of these principles and properties to blood serum, milk, urine, and resting saliva is described to show that under physiological conditions they are in the stable region of their stability diagram and so cannot cause soft tissue calcification. Stimulated saliva, however, is in the metastable region, consistent with its role in tooth remineralization. Destabilization of biofluids, with consequential ill-effects, can occur when there is a failure of homeostasis, such as an increase in pH without a balancing increase in the concentration of sequestering phosphopeptides.
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28
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Montoya G, Lopez K, Arenas J, Zamora C, Hoz L, Romo E, Jiménez K, Arzate H. Nucleation and growth inhibition of biological minerals by cementum attachment protein-derived peptide (CAP-pi). J Pept Sci 2020; 26:e3282. [PMID: 32840040 DOI: 10.1002/psc.3282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/28/2020] [Accepted: 07/31/2020] [Indexed: 02/03/2023]
Abstract
Biomineralization is a highly regulated process where proteins/peptides-crystal interactions contribute to the shaping, phasing and aggregation of minerals. We have identified and synthesized a cementum attachment protein-derived peptide (CAP-pi), which corresponds to amino acids 40-53 of the N-terminal CAP domain (MASSDEDGTNGGAS) and its phosphorylated variant (MASpSpDEDGTNGGASp) (CAP-pip). The peptide is composed of polar and negatively charged amino acids, which are disordered, according to in silico analysis. Our results show that CAP-pi inhibits hydroxyapatite (HA) formation and growth. However, it possesses low capacity to inhibit calcium oxalate crystal growth. CAP-pip showed a stronger inhibitory effect on the formation and growth of HA. As well as a high capacity to inhibit calcium oxalate monohydrate growth, mainly due to adsorption on specific growth faces. Small peptides have many advantages over the full-size protein, including low-cost production and modulation characteristics that allow for structural changes. Our findings suggest that CAP-pip-derived peptide could possess therapeutic potential to prevent or treat pathological calcifications such as renal stones and vascular calcification.
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Affiliation(s)
- Gonzalo Montoya
- Laboratory of Periodontal Biology, Faculty of Dentistry, National Autonomous University of Mexico, Mexico City, Mexico
| | - Kevin Lopez
- Laboratory of Periodontal Biology, Faculty of Dentistry, National Autonomous University of Mexico, Mexico City, Mexico
| | - Jesús Arenas
- Institute of Physics, National Autonomous University of Mexico, Mexico City, Mexico
| | - Claudia Zamora
- Laboratory of Periodontal Biology, Faculty of Dentistry, National Autonomous University of Mexico, Mexico City, Mexico
| | - Lía Hoz
- Laboratory of Periodontal Biology, Faculty of Dentistry, National Autonomous University of Mexico, Mexico City, Mexico
| | - Enrique Romo
- Laboratory of Periodontal Biology, Faculty of Dentistry, National Autonomous University of Mexico, Mexico City, Mexico
| | - Karina Jiménez
- Faculty of Chemistry, USAII, National Autonomous University of Mexico, Mexico City, Mexico
| | - Higinio Arzate
- Laboratory of Periodontal Biology, Faculty of Dentistry, National Autonomous University of Mexico, Mexico City, Mexico
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29
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Wang D, Deng J, Deng X, Fang C, Zhang X, Yang P. Controlling Enamel Remineralization by Amyloid-Like Amelogenin Mimics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002080. [PMID: 32583928 DOI: 10.1002/adma.202002080] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/16/2020] [Indexed: 06/11/2023]
Abstract
In situ regeneration of the enamel-like structure of hydroxyapatite (HAp) crystals under oral conditions is significant for dental caries treatment. However, it is still a challenge for dentists to duplicate the elegant and well-aligned apatite structure bonding to the surface of demineralized enamel. A biocompatible amelogenin-inspired matrix, a phase-transited lysozyme (PTL) film mimicking an N-terminal amelogenin with central domain (N-Ame) combined with synthetic peptide (C-AMG) based on the functional domains of C-terminal telopeptide (C-Ame) is shown here, which is formed by amyloid-like lysozyme aggregation at the enamel interface through a rapid one-step aqueous coating process. In the PTL/C-AMG matrix, C-AMG facilitated the oriented arrangement of amorphous calcium phosphate (ACP) nanoparticles and their transformation to ordered enamel-like HAp crystals, while PTL served as a strong interfacial anchor to immobilize the C-AMG peptide and PTL/C-AMG matrix on versatile substrate surfaces. PTL/C-AMG film-coated enamel induced both of the in vivo and in vitro synthesis of HAp crystals, facilitated epitaxial growth of HAp crystals and recovered the highly oriented structure and mechanical properties to levels nearly identical to those of natural enamel. This work underlines the importance of amyloid-like protein aggregates in the biomineralization of enamel, providing a promising strategy for treating dental caries.
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Affiliation(s)
- Dong Wang
- School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an, 710048, China
| | - Jingjing Deng
- School and Hospital of Stomatology, Tianjin Medical University, 12 Observatory Road, Tianjin, 30070, China
| | - Xuliang Deng
- Department of Geriatric Dentistry, School and Hospital of Stomatology, Peking University, 22 Zhongguancun South Street, Beijing, 100081, China
| | - Changqing Fang
- School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an, 710048, China
- The Faculty of Printing, Packaging Engineering and Digital Media Technology, Xi'an University of Technology, Xi'an, 710048, China
| | - Xu Zhang
- School and Hospital of Stomatology, Tianjin Medical University, 12 Observatory Road, Tianjin, 30070, China
| | - Peng Yang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China
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30
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Su J, Bapat R, Visakan G, Moradian-Oldak J. An Evolutionarily Conserved Helix Mediates Ameloblastin-Cell Interaction. J Dent Res 2020; 99:1072-1081. [PMID: 32401578 PMCID: PMC7375739 DOI: 10.1177/0022034520918521] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Ameloblastin (Ambn) has the potential to regulate cell-matrix adhesion through familiar cell-binding domains, but the proposed sequence motifs are not highly conserved across species. Here, we report that Ambn binds to ameloblast-like cell membranes through a highly evolutionary conserved amphipathic helix-forming (AH) motif encoded by exon 5. We applied high-resolution confocal microscopy to show colocalization of Ambn with ameloblast membrane surfaces in developing mouse incisors. Using a series of Ambn-derived peptides and Ambn variants, we showed that Ambn binds to cell membranes through a motif within the sequence encoded by exon 5. Using peptides derived from the N- or C-termini of this sequence, as well as Ambn variants that lacked or had a disrupted AH motif, we demonstrated that the AH motif located at the N-terminus of the sequence is involved in cell-Ambn adhesion. Sequence analysis revealed that this highly conserved AH motif is absent from other enamel matrix proteins, including amelogenin, enamelin, and amelotin. Collectively, these data suggest that Ambn binds to the cell surface membrane via a helix-forming motif and provide insight into the molecular mechanism and function of Ambn in enamel cell-matrix interaction.
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Affiliation(s)
- J. Su
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - R.A. Bapat
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - G. Visakan
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - J. Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
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31
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Zhu H, Gomez M, Xiao J, Perale G, Betge F, Lyngstadaas SP, Haugen HJ. Xenohybrid Bone Graft Containing Intrinsically Disordered Proteins Shows Enhanced In Vitro Bone Formation. ACS APPLIED BIO MATERIALS 2020; 3:2263-2274. [DOI: 10.1021/acsabm.0c00064] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hao Zhu
- Department of Orthopedic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, 430030 Wuhan, China
- Corticalis AS, Oslo Sciencepark, Gaustadallén 21, NO-0349 Oslo, Norway
| | - Manuel Gomez
- Corticalis AS, Oslo Sciencepark, Gaustadallén 21, NO-0349 Oslo, Norway
| | - Jun Xiao
- Department of Orthopedic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, 430030 Wuhan, China
| | - Giuseppe Perale
- Industrie Biomediche Insubri SA, Via Cantonale 67, 6805 Mezzovico-Vira, Switzerland
- Faculty of Biomedical Sciences, University of Southern Switzerland, Via G. Buffi 13, 6900 Lugano, Switzerland
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Donaueschingenstrasse 13, 1200 Vienna, Austria
| | - Felice Betge
- Industrie Biomediche Insubri SA, Via Cantonale 67, 6805 Mezzovico-Vira, Switzerland
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32
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Shin NY, Yamazaki H, Beniash E, Yang X, Margolis SS, Pugach MK, Simmer JP, Margolis HC. Amelogenin phosphorylation regulates tooth enamel formation by stabilizing a transient amorphous mineral precursor. J Biol Chem 2020; 295:1943-1959. [PMID: 31919099 DOI: 10.1074/jbc.ra119.010506] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 12/30/2019] [Indexed: 11/06/2022] Open
Abstract
Dental enamel comprises interwoven arrays of extremely long and narrow crystals of carbonated hydroxyapatite called enamel rods. Amelogenin (AMELX) is the predominant extracellular enamel matrix protein and plays an essential role in enamel formation (amelogenesis). Previously, we have demonstrated that full-length AMELX forms higher-order supramolecular assemblies that regulate ordered mineralization in vitro, as observed in enamel rods. Phosphorylation of the sole AMELX phosphorylation site (Ser-16) in vitro greatly enhances its capacity to stabilize amorphous calcium phosphate (ACP), the first mineral phase formed in developing enamel, and prevents apatitic crystal formation. To test our hypothesis that AMELX phosphorylation is critical for amelogenesis, we generated and characterized a hemizygous knockin (KI) mouse model with a phosphorylation-defective Ser-16 to Ala-16 substitution in AMELX. Using EM analysis, we demonstrate that in the absence of phosphorylated AMELX, KI enamel lacks enamel rods, the hallmark component of mammalian enamel, and, unlike WT enamel, appears to be composed of less organized arrays of shorter crystals oriented normal to the dentinoenamel junction. KI enamel also exhibited hypoplasia and numerous surface defects, whereas heterozygous enamel displayed highly variable mosaic structures with both KI and WT features. Importantly, ACP-to-apatitic crystal transformation occurred significantly faster in KI enamel. Secretory KI ameloblasts also lacked Tomes' processes, consistent with the absence of enamel rods, and underwent progressive cell pathology throughout enamel development. In conclusion, AMELX phosphorylation plays critical mechanistic roles in regulating ACP-phase transformation and enamel crystal growth, and in maintaining ameloblast integrity and function during amelogenesis.
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Affiliation(s)
- Nah-Young Shin
- The Forsyth Institute, Cambridge, Massachusetts 02142; Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts 02115
| | - Hajime Yamazaki
- The Forsyth Institute, Cambridge, Massachusetts 02142; Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts 02115; Department of Oral Biology, Center for Craniofacial Regeneration, University of Pittsburgh, School of Dental Medicine, Pittsburgh, Pennsylvania 15213
| | - Elia Beniash
- Department of Oral Biology, Center for Craniofacial Regeneration, University of Pittsburgh, School of Dental Medicine, Pittsburgh, Pennsylvania 15213
| | - Xu Yang
- Department of Oral Biology, Center for Craniofacial Regeneration, University of Pittsburgh, School of Dental Medicine, Pittsburgh, Pennsylvania 15213
| | - Seth S Margolis
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Megan K Pugach
- The Forsyth Institute, Cambridge, Massachusetts 02142; Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts 02115
| | - James P Simmer
- Department of Biologic and Material Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan 48108
| | - Henry C Margolis
- The Forsyth Institute, Cambridge, Massachusetts 02142; Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts 02115; Department of Periodontics and Preventive Dentistry, Center for Craniofacial Regeneration, University of Pittsburgh, School of Dental Medicine, Pittsburgh, Pennsylvania 15213.
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33
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Shao C, Jin B, Mu Z, Lu H, Zhao Y, Wu Z, Yan L, Zhang Z, Zhou Y, Pan H, Liu Z, Tang R. Repair of tooth enamel by a biomimetic mineralization frontier ensuring epitaxial growth. SCIENCE ADVANCES 2019; 5:eaaw9569. [PMID: 31497647 PMCID: PMC6716959 DOI: 10.1126/sciadv.aaw9569] [Citation(s) in RCA: 115] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 07/16/2019] [Indexed: 05/18/2023]
Abstract
The regeneration of tooth enamel, the hardest biological tissue, remains a considerable challenge because its complicated and well-aligned apatite structure has not been duplicated artificially. We herein reveal that a rationally designed material composed of calcium phosphate ion clusters can be used to produce a precursor layer to induce the epitaxial crystal growth of enamel apatite, which mimics the biomineralization crystalline-amorphous frontier of hard tissue development in nature. After repair, the damaged enamel can be recovered completely because its hierarchical structure and mechanical properties are identical to those of natural enamel. The suggested phase transformation-based epitaxial growth follows a promising strategy for enamel regeneration and, more generally, for biomimetic reproduction of materials with complicated structure.
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Affiliation(s)
- Changyu Shao
- Department of Chemistry and Center for Biomaterials and Biopathways, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Biao Jin
- Department of Chemistry and Center for Biomaterials and Biopathways, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Zhao Mu
- Department of Chemistry and Center for Biomaterials and Biopathways, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Hao Lu
- Department of Physics, Research Institute for Biomimetics and Soft Matter, Jiujiang Research Institute, Xiamen University, Xiamen, Fujian 361005, China
| | - Yueqi Zhao
- Department of Chemistry and Center for Biomaterials and Biopathways, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Zhifang Wu
- Department of Prosthodontics, Hospital of Stomatology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China
| | - Lumiao Yan
- Department of Chemistry and Center for Biomaterials and Biopathways, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Zhisen Zhang
- Department of Physics, Research Institute for Biomimetics and Soft Matter, Jiujiang Research Institute, Xiamen University, Xiamen, Fujian 361005, China
| | - Yanchun Zhou
- Zhejiang University Hospital, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Haihua Pan
- Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Zhaoming Liu
- Department of Chemistry and Center for Biomaterials and Biopathways, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Ruikang Tang
- Department of Chemistry and Center for Biomaterials and Biopathways, Zhejiang University, Hangzhou, Zhejiang 310027, China
- State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou, Zhejiang 310027, China
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34
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Ibáñez-Fonseca A, Flora T, Acosta S, Rodríguez-Cabello JC. Trends in the design and use of elastin-like recombinamers as biomaterials. Matrix Biol 2019; 84:111-126. [PMID: 31288085 DOI: 10.1016/j.matbio.2019.07.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/23/2019] [Accepted: 07/05/2019] [Indexed: 12/16/2022]
Abstract
Elastin-like recombinamers (ELRs), which derive from one of the repetitive domains found in natural elastin, have been intensively studied in the last few years from several points of view. In this mini review, we discuss all the recent works related to the investigation of ELRs, starting with those that define these polypeptides as model intrinsically disordered proteins or regions (IDPs or IDRs) and its relevance for some biomedical applications. Furthermore, we summarize the current knowledge on the development of drug, vaccine and gene delivery systems based on ELRs, while also emphasizing the use of ELR-based hydrogels in tissue engineering and regenerative medicine (TERM). Finally, we show different studies that explore applications in other fields, and several examples that describe biomaterial blends in which ELRs have a key role. This review aims to give an overview of the recent advances regarding ELRs and to encourage further investigation of their properties and applications.
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Affiliation(s)
- Arturo Ibáñez-Fonseca
- BIOFORGE Lab, CIBER-BBN, University of Valladolid, Paseo de Belén 19, 47011 Valladolid, Spain
| | - Tatjana Flora
- BIOFORGE Lab, CIBER-BBN, University of Valladolid, Paseo de Belén 19, 47011 Valladolid, Spain
| | - Sergio Acosta
- BIOFORGE Lab, CIBER-BBN, University of Valladolid, Paseo de Belén 19, 47011 Valladolid, Spain
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35
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Su J, Kegulian NC, Arun Bapat R, Moradian-Oldak J. Ameloblastin Binds to Phospholipid Bilayers via a Helix-Forming Motif within the Sequence Encoded by Exon 5. ACS OMEGA 2019; 4:4405-4416. [PMID: 30873509 PMCID: PMC6410667 DOI: 10.1021/acsomega.8b03582] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 02/12/2019] [Indexed: 06/09/2023]
Abstract
Ameloblastin (Ambn), the most abundant non-amelogenin enamel protein, is intrinsically disordered and has the potential to interact with other enamel proteins and with cell membranes. Here, through multiple biophysical methods, we investigated the interactions between Ambn and large unilamellar vesicles (LUVs), whose lipid compositions mimicked cell membranes involved in epithelial cell-extracellular matrix adhesion. Using a series of Ambn Trp/Phe variants and Ambn mutants, we further showed that Ambn binds to LUVs through a highly conserved motif within the sequence encoded by exon 5. Synthetic peptides derived from different regions of Ambn confirmed that the sequence encoded by exon 5 is involved in LUV binding. Sequence analysis of Ambn across different species showed that the N-terminus of this sequence contains a highly conserved motif with a propensity to form an amphipathic helix. Mutations in the helix-forming sequence resulted in a loss of peptide binding to LUVs. Our in vitro data suggest that Ambn binds the lipid membrane directly through a conserved helical motif and have implications for biological events such as Ambn-cell interactions, Ambn signaling, and Ambn secretion via secretory vesicles.
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Abstract
Ameloblastin is the second most abundant enamel matrix protein, and is thought to be essential for ameloblast cell polarization, cell adhesion, and enamel mineralization. However, studies of ameloblastin's function and its molecular mechanism have been limited due to difficulty in obtaining recombinant ameloblastin in vitro. Here, we present a protocol for successful ameloblastin expression and purification in E. coli.
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Lu T, Li M, Xu X, Xiong J, Huang C, Zhang X, Hu A, Peng L, Cai D, Zhang L, Wu B, Xiong F. Whole exome sequencing identifies an AMBN missense mutation causing severe autosomal-dominant amelogenesis imperfecta and dentin disorders. Int J Oral Sci 2018; 10:26. [PMID: 30174330 PMCID: PMC6119682 DOI: 10.1038/s41368-018-0027-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/15/2018] [Accepted: 05/18/2018] [Indexed: 11/25/2022] Open
Abstract
Tooth development is a complex process that involves precise and time-dependent orchestration of multiple genetic, molecular, and cellular interactions. Ameloblastin (AMBN, also named “amelin” or “sheathlin”) is the second most abundant enamel matrix protein known to have a key role in amelogenesis. Amelogenesis imperfecta (AI [MIM: 104500]) refers to a genetically and phenotypically heterogeneous group of conditions characterized by inherited developmental enamel defects. The hereditary dentin disorders comprise a variety of autosomal-dominant genetic symptoms characterized by abnormal dentin structure affecting either the primary or both the primary and secondary teeth. The vital role of Ambn in amelogenesis has been confirmed experimentally using mouse models. Only two cases have been reported of mutations of AMBN associated with non-syndromic human AI. However, no AMBN missense mutations have been reported to be associated with both human AI and dentin disorders. We recruited one kindred with autosomal-dominant amelogenesis imperfecta (ADAI) and dentinogenesis imperfecta/dysplasia characterized by generalized severe enamel and dentin defects. Whole exome sequencing of the proband identified a novel heterozygous C-T point mutation at nucleotide position 1069 of the AMBN gene, causing a Pro to Ser mutation at the conserved amino acid position 357 of the protein. Exfoliated third molar teeth from the affected family members were found to have enamel and dentin of lower mineral density than control teeth, with thinner and easily fractured enamel, short and thick roots, and pulp obliteration. This study demonstrates, for the first time, that an AMBN missense mutation causes non-syndromic human AI and dentin disorders. A mutation on a gene involved in healthy tooth development may cause both enamel and dentin disorders. The ameloblastin enamel protein, and its associated gene, AMBN, play vital roles in enamel formation and tooth remodelling. Mutations on AMBN can cause amelogenesis imperfecta (AI), a genetic and hereditory condition resulting in enamel defects and severe tooth decay. Now, Fu Xiong and Bu-Ling Wu at Southern Medical University in Guangzhou, China, and co-workers have identified an AMBN mutation found in both enamel and dentin defect disorders. The researchers analyzed extracted teeth from a Chinese patient with both AI and a severe dentin disorder, along with teeth from affected and non-affected members of the same family, and compared the results with a control group. They identified a rare mutation on AMBN common to all affected individuals.
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Affiliation(s)
- Ting Lu
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China.,Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Meiyi Li
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Xiangmin Xu
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Biological Chip, Guangzhou, Guangdong, China
| | - Jun Xiong
- Department of Laboratory Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Cheng Huang
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Xuelian Zhang
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Aiqin Hu
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Ling Peng
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China
| | - Decheng Cai
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Leitao Zhang
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China
| | - Buling Wu
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China.
| | - Fu Xiong
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China. .,Guangdong Key Laboratory of Biological Chip, Guangzhou, Guangdong, China.
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38
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Pawluk A. Breaking the Rules. Cell 2018; 173:805-807. [PMID: 29727666 DOI: 10.1016/j.cell.2018.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Guo YR, Yang X, Feng XW, Sa Y, Wang M, Li P, Jiang T. New Insights into Effects of Aromatic Amino Acids on Hydroxyapatite. J Dent Res 2017; 97:402-408. [PMID: 29130776 DOI: 10.1177/0022034517741274] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Biomimetics inspired by superstructures and extraordinary properties of teeth have resulted in tooth repair and the generation of novel materials. However, little attention has been paid to tooth color, whose origin remains unknown. Based on recent studies, fluorophores-mainly aromatic amino acids (AAAs) in proteins-might be responsible for tooth color. We synthesized carbonated hydroxyapatite (HA; the mineral phase of teeth) in the presence of different amino acids (AAs; the basic units of protein matrix of teeth) as a simplified model of teeth to explore the color source at the AA level. After measuring the fluorescence and color characteristics of HA-AAs before and after bleaching treatment, we found that only HA, synthesized in the presence of AAAs, exhibited remarkable fluorescence and color property. Furthermore, linearly increased fluorescence intensity and deeper color were observed with an increase in AAA content in HA-AAAs. Similarly, significantly decreased absorbance of HA-AAAs between 250 and 300 nm in ultraviolet spectra, declined fluorescence intensity, and decolored performance of HA-AAAs were observed after bleaching treatment. The results showed that AAAs contributed to the fluorescence and color properties of HA and that hydrogen peroxide might whiten HA-AAAs by oxidizing the benzene ring in AAAs. These findings are of great significance in promoting the synthesis of advanced tooth-colored materials and furthering our understanding of the possible mechanisms of hydrogen peroxide. Moreover, our study shed light on the importance of AAAs and might provide new ideas for investigations of biomineralization and biomimetics.
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Affiliation(s)
- Y R Guo
- 1 The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - X Yang
- 2 Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - X W Feng
- 1 The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Y Sa
- 1 The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China.,3 Department of Prosthodontics, Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - M Wang
- 1 The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - P Li
- 1 The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - T Jiang
- 1 The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China.,3 Department of Prosthodontics, Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
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Pham CD, Smith CE, Hu Y, Hu JCC, Simmer JP, Chun YHP. Endocytosis and Enamel Formation. Front Physiol 2017; 8:529. [PMID: 28824442 PMCID: PMC5534449 DOI: 10.3389/fphys.2017.00529] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 07/10/2017] [Indexed: 12/12/2022] Open
Abstract
Enamel formation requires consecutive stages of development to achieve its characteristic extreme mineral hardness. Mineralization depends on the initial presence then removal of degraded enamel proteins from the matrix via endocytosis. The ameloblast membrane resides at the interface between matrix and cell. Enamel formation is controlled by ameloblasts that produce enamel in stages to build the enamel layer (secretory stage) and to reach final mineralization (maturation stage). Each stage has specific functional requirements for the ameloblasts. Ameloblasts adopt different cell morphologies during each stage. Protein trafficking including the secretion and endocytosis of enamel proteins is a fundamental task in ameloblasts. The sites of internalization of enamel proteins on the ameloblast membrane are specific for every stage. In this review, an overview of endocytosis and trafficking of vesicles in ameloblasts is presented. The pathways for internalization and routing of vesicles are described. Endocytosis is proposed as a mechanism to remove debris of degraded enamel protein and to obtain feedback from the matrix on the status of the maturing enamel.
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Affiliation(s)
- Cong-Dat Pham
- Department of Periodontics, School of Dentistry, University of Texas Health Science Center at San AntonioSan Antonio, TX, United States
| | - Charles E. Smith
- Department of Anatomy and Cell Biology, McGill UniversityMontreal, QC, Canada
- Department of Biologic and Materials Sciences, University of MichiganAnn Arbor, MI, United States
| | - Yuanyuan Hu
- Department of Biologic and Materials Sciences, University of MichiganAnn Arbor, MI, United States
| | - Jan C-C. Hu
- Department of Biologic and Materials Sciences, University of MichiganAnn Arbor, MI, United States
| | - James P. Simmer
- Department of Biologic and Materials Sciences, University of MichiganAnn Arbor, MI, United States
| | - Yong-Hee P. Chun
- Department of Periodontics, School of Dentistry, University of Texas Health Science Center at San AntonioSan Antonio, TX, United States
- Department of Cell Systems & Anatomy, School of Medicine, University of Texas Health Science Center at San AntonioSan Antonio, TX, United States
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Stakkestad Ø, Lyngstadaas SP, Thiede B, Vondrasek J, Skålhegg BS, Reseland JE. Phosphorylation Modulates Ameloblastin Self-assembly and Ca 2+ Binding. Front Physiol 2017; 8:531. [PMID: 28798693 PMCID: PMC5529409 DOI: 10.3389/fphys.2017.00531] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/10/2017] [Indexed: 01/10/2023] Open
Abstract
Ameloblastin (AMBN), an important component of the self-assembled enamel extra cellular matrix, contains several in silico predicted phosphorylation sites. However, to what extent these sites actually are phosphorylated and the possible effects of such post-translational modifications are still largely unknown. Here we report on in vitro experiments aimed at investigating what sites in AMBN are phosphorylated by casein kinase 2 (CK2) and protein kinase A (PKA) and the impact such phosphorylation has on self-assembly and calcium binding. All predicted sites in AMBN can be phosphorylated by CK2 and/or PKA. The experiments show that phosphorylation, especially in the exon 5 derived part of the molecule, is inversely correlated with AMBN self-assembly. These results support earlier findings suggesting that AMBN self-assembly is mostly dependent on the exon 5 encoded region of the AMBN gene. Phosphorylation was significantly more efficient when the AMBN molecules were in solution and not present as supramolecular assemblies, suggesting that post-translational modification of AMBN must take place before the enamel matrix molecules self-assemble inside the ameloblast cell. Moreover, phosphorylation of exon 5, and the consequent reduction in self-assembly, seem to reduce the calcium binding capacity of AMBN suggesting that post-translational modification of AMBN also can be involved in control of free Ca2+ during enamel extra cellular matrix biomineralization. Finally, it is speculated that phosphorylation can provide a functional crossroad for AMBN either to be phosphorylated and act as monomeric signal molecule during early odontogenesis and bone formation, or escape phosphorylation to be subsequently secreted as supramolecular assemblies that partake in enamel matrix structure and mineralization.
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Affiliation(s)
- Øystein Stakkestad
- Department of Biomaterials, Institute of Clinical Dentistry, University of OsloOslo, Norway
| | - Ståle P Lyngstadaas
- Department of Biomaterials, Institute of Clinical Dentistry, University of OsloOslo, Norway
| | - Bernd Thiede
- Section for Biochemistry and Molecular Biology, Department of Biosciences, University of OsloOslo, Norway
| | - Jiri Vondrasek
- Department of Bioinformatics, Institute of Organic Chemistry and Biochemistry, Czech Academy of SciencesPrague, Czechia
| | - Bjørn S Skålhegg
- Division of Molecular Nutrition, Department of Nutrition, University of OsloOslo, Norway
| | - Janne E Reseland
- Department of Biomaterials, Institute of Clinical Dentistry, University of OsloOslo, Norway
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Gabe CM, Brookes SJ, Kirkham J. Preparative SDS PAGE as an Alternative to His-Tag Purification of Recombinant Amelogenin. Front Physiol 2017; 8:424. [PMID: 28670287 PMCID: PMC5472695 DOI: 10.3389/fphys.2017.00424] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/01/2017] [Indexed: 11/21/2022] Open
Abstract
Recombinant protein technology provides an invaluable source of proteins for use in structure-function studies, as immunogens, and in the development of therapeutics. Recombinant proteins are typically engineered with "tags" that allow the protein to be purified from crude host cell extracts using affinity based chromatography techniques. Amelogenin is the principal component of the developing enamel matrix and a frequent focus for biomineralization researchers. Several groups have reported the successful production of recombinant amelogenins but the production of recombinant amelogenin free of any tags, and at single band purity on silver stained SDS PAGE is technically challenging. This is important, as rigorous structure-function research frequently demands a high degree of protein purity and fidelity of protein sequence. Our aim was to generate His-tagged recombinant amelogenin at single band purity on silver stained SDS PAGE for use in functionality studies after His-tag cleavage. An acetic acid extraction technique (previously reported to produce recombinant amelogenin at 95% purity directly from E. coli) followed by repeated rounds of nickel column affinity chromatography, failed to generate recombinant amelogenin at single band purity. This was because following an initial round of nickel column affinity chromatography, subsequent cleavage of the His-tag was not 100% efficient. A second round of nickel column affinity chromatography, used in attempts to separate the cleaved His-tag free recombinant from uncleaved His-tagged contaminants, was still unsatisfactory as cleaved recombinant amelogenin exhibited significant affinity for the nickel column. To solve this problem, we used preparative SDS PAGE to successfully purify cleaved recombinant amelogenins to single band purity on silver stained SDS PAGE. The resolving power of preparative SDS PAGE was such that His-tag based purification of recombinant amelogenin becomes redundant. We suggest that acetic acid extraction of recombinant amelogenin and subsequent purification using preparative SDS PAGE provides a simple route to highly purified His-tag free amelogenin for use in structure-function experiments and beyond.
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Affiliation(s)
| | - Steven J. Brookes
- Division of Oral Biology, School of Dentistry, University of LeedsLeeds, United Kingdom
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