1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Wang Y, Zhang S, Liu P, Li F, Chen X, Wang H, Li Z, Zhang X, Zhang X, Zhang X. L-serine combined with carboxymethyl chitosan guides amorphous calcium phosphate to remineralize enamel. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2023; 34:45. [PMID: 37658964 PMCID: PMC10474979 DOI: 10.1007/s10856-023-06745-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 08/01/2023] [Indexed: 09/05/2023]
Abstract
The aim of this study is to investigate a robust and stable calcium-phosphorus system to remineralize human early enamel caries lesions with nanocomplexes of carboxymethyl chitosan/L-serine/amorphous calcium phosphate (CMC-Ser-ACP) to develop an effective method for mimicking the amelogenin (AMEL) mineralization pattern through ACP assembly. A CMC-Ser-ACP nanocomplex solution was first synthesized by a chemical precipitation method, and then 1% sodium hypochlorite (NaClO) was added to induce ACP phase formation. The morphologies of the nanocomplexes were characterized by transmission electron microscopy (TEM), and zeta potential analysis and Fourier transform infrared spectroscopy (FTIR) were performed to detect surface charge and functional group changes. The subtle changes of the demineralized enamel models induced by the remineralization effect were observed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The CMC-Ser-ACP nanocomplex solution could be preserved without any precipitation for 45 days. After the application of NaClO and through the guidance of Ser, ACP nanoparticles transformed into relatively orderly arranged hydroxyapatite (HAP) crystals, generating an aprismatic enamel-like layer closely integrated with the demineralized enamel, which resulted in enhanced mechanical properties for the treatment of early enamel caries lesions. The CMC-Ser-ACP nanocomplex solution is a remineralization system with great solution stability, and when NaClO is added, it can rapidly regenerate an aprismatic enamel-like layer in situ on the demineralized enamel surface. This novel remineralization system has stable chemical properties and can greatly increase the therapeutic effects against early enamel caries.
Collapse
Affiliation(s)
- Yinghui Wang
- School and Hospital of Stomatology, Tianjin Medical University, Tianjin, 300070, China
| | - Shuting Zhang
- School and Hospital of Stomatology, Tianjin Medical University, Tianjin, 300070, China
| | - Peiwen Liu
- School and Hospital of Stomatology, Tianjin Medical University, Tianjin, 300070, China
- Department of stomatology, Economic and Technological Development Zone, No.7 people's hospital of Zhengzhou, No. 17, Jingnan 5th Road, Zhengzhou City, Henan Province, 450003, China
| | - Fan Li
- School and Hospital of Stomatology, Tianjin Medical University, Tianjin, 300070, China
| | - Xu Chen
- School and Hospital of Stomatology, Tianjin Medical University, Tianjin, 300070, China
| | - Haorong Wang
- School and Hospital of Stomatology, Tianjin Medical University, Tianjin, 300070, China
| | - Zhangyi Li
- Department of Stomatology, the Fifth Central Hospital of Tianjin, No. 41, Zhejiang Road, Tanggu, Binhai New District, Tianjin, 300450, China
| | - Xi Zhang
- School and Hospital of Stomatology, Tianjin Medical University, Tianjin, 300070, China
| | - Xiangyu Zhang
- School and Hospital of Stomatology, Tianjin Medical University, Tianjin, 300070, China.
| | - Xu Zhang
- School and Hospital of Stomatology, Tianjin Medical University, Tianjin, 300070, China.
- Institute of Stomatology, Tianjin Medical University, Tianjin, 300070, China.
| |
Collapse
|
3
|
Cell-Free Biomimetic Mineralization Strategies to Regenerate the Enamel Microstructure. CRYSTALS 2021. [DOI: 10.3390/cryst11111385] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The distinct architecture of native enamel gives it its exquisite appearance and excellent intrinsic-extrinsic fracture toughening properties. However, damage to the enamel is irreversible. At present, the clinical treatment for enamel lesion is an invasive method; besides, its limitations, caused by the chemical and physical difference between restorative materials and dental hard tissue, makes the restorative effects far from ideal. With more investigations on the mechanism of amelogenesis, biomimetic mineralization techniques for enamel regeneration have been well developed, which hold great promise as a non-invasive strategy for enamel restoration. This review disclosed the chemical and physical mechanism of amelogenesis; meanwhile, it overviewed and summarized studies involving the regeneration of enamel microstructure in cell-free biomineralization approaches, which could bring new prospects for resolving the challenges in enamel regeneration.
Collapse
|
4
|
Zhang J, Wang J, Ma C, Lu J. Hydroxyapatite Formation Coexists with Amyloid-like Self-Assembly of Human Amelogenin. Int J Mol Sci 2020; 21:E2946. [PMID: 32331340 PMCID: PMC7216246 DOI: 10.3390/ijms21082946] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/28/2020] [Accepted: 04/07/2020] [Indexed: 12/19/2022] Open
Abstract
Tooth enamel is formed in an extracellular environment. Amelogenin, the major component in the protein matrix of tooth enamel during the developing stage, could assemble into high molecular weight structures, regulating enamel formation. However, the molecular structure of amelogenin protein assembly at the functional state is still elusive. In this work, we found that amelogenin is able to induce calcium phosphate minerals into hydroxyapatite (HAP) structure in vitro at pH 6.0. Assessed using X-ray diffraction (XRD) and 31P solid-state NMR (SSNMR) evidence, the formed HAP mimics natural enamel closely. The structure of amelogenin protein assembly coexisting with the HAP was also studied using atomic force microscopy (AFM), transmission electron microscopy (TEM) and XRD, indicating the β-amyloid structure of the protein. SSNMR was proven to be an important tool in detecting both the rigid and dynamic components of the protein assembly in the sample, and the core sequence 18EVLTPLKWYQSI29 was identified as the major segment contributing to the β-sheet secondary structure. Our research suggests an amyloid structure may be an important factor in controlling HAP formation at the right pH conditions with the help of other structural components in the protein assembly.
Collapse
Affiliation(s)
- Jing Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.Z.); (J.W.); (C.M.)
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.Z.); (J.W.); (C.M.)
| | - Chengwei Ma
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.Z.); (J.W.); (C.M.)
| | - Junxia Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.Z.); (J.W.); (C.M.)
| |
Collapse
|
5
|
Pandya M, Diekwisch TGH. Enamel biomimetics-fiction or future of dentistry. Int J Oral Sci 2019. [PMID: 30610185 DOI: 10.1038/s41368-018-0038-6,1-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023] Open
Abstract
Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering, (i) enamel synthesis using physico-chemical means, (ii) protein matrix-guided enamel crystal growth, (iii) enamel surface remineralization, (iv) cell-based enamel engineering, and (v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as pH, heat and pressure have resulted in the formation of enamel-like crystal assemblies. Biochemical methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogenin-derived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. Going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues.
Collapse
Affiliation(s)
- Mirali Pandya
- Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, USA
| | - Thomas G H Diekwisch
- Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, USA.
| |
Collapse
|
6
|
Abstract
Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering, (i) enamel synthesis using physico-chemical means, (ii) protein matrix-guided enamel crystal growth, (iii) enamel surface remineralization, (iv) cell-based enamel engineering, and (v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as pH, heat and pressure have resulted in the formation of enamel-like crystal assemblies. Biochemical methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogenin-derived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. Going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues. Five pathways for tooth enamel engineering hold great promise for developing new technologies, leading to novel biomaterials and biotechnologies to regenerate enamel tissue. Tooth enamel is a unique tissue-specific biomaterial with exceptional structural and mechanical properties. In recent years, many approaches have been adopted to generate or regenerate this complex tissue; Mirali Pandya and Thomas Diekwisch of Texas A&M College of Dentistry, USA conducted a review of the current state and future directions of enamel tissue engineering. In their review, the authors focused on five pathways for enamel tissue engineering: (1) physical synthesis of enamel; (2) biochemical enamel engineering; (3) in situ enamel engineering; (4) cell-based enamel engineering; and (5) whole tooth regeneration. The authors conclude that those five approaches will help identify the biological mechanisms that lead to the generation of tooth enamel.
Collapse
|
7
|
Buchko GW, Jayasinha Arachchige R, Tao J, Tarasevich BJ, Shaw WJ. Identification of major matrix metalloproteinase-20 proteolytic processing products of murine amelogenin and tyrosine-rich amelogenin peptide using a nuclear magnetic resonance spectroscopy based method. Arch Oral Biol 2018; 93:187-194. [PMID: 29960917 DOI: 10.1016/j.archoralbio.2018.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/31/2018] [Accepted: 06/01/2018] [Indexed: 01/14/2023]
Abstract
OBJECTIVE The aim of this study was to identify major matrix metalloproteinase-20 (MMP20) proteolytic processing products of amelogenin over time and determine if the tyrosine-rich amelogenin peptide (TRAP) was a substrate of MMP20. DESIGN Recombinant15N-labeled murine amelogenin and 13C,15N-labeled TRAP were incubated with MMP20 under conditions where amelogenin self-assembles into nanospheres. Digestion products were fractionated by reverse-phase high-performance liquid chromatography at various time points. Product identification took advantage of the intrinsic disorder property of amelogenin that results in little change to its fingerprint 1H-15N heteronuclear single-quantum coherence nuclear magnetic resonance spectrum in 2% acetic acid upon removing parts of the protein, allowing cleavage site identification by observing which amide cross peaks disappear. RESULTS The primary product in five out of the six major reverse-phase high-performance liquid chromatography bands generated after a 24 h incubation of murine amelogenin with MMP20 were: S55-L163, P2-L147, P2-E162, P2-A167, and P2-R176. After 72 h these products were replaced with five major reverse-phase high-performance liquid chromatography bands containing: L46-A170, P2-S152, P2-F151, P2-W45, and short N-terminal peptides. TRAP was completely digested by MMP20 into multiple small peptides with the initial primary site of cleavage between S16 and Y17. CONCLUSIONS Identification of the major MMP20 proteolytic products of amelogenin confirm a dynamic process, with sites towards the C-terminus more rapidly attacked than sites near the N-terminus. This observation is consistent with nanosphere models where the C-terminus is exposed and the N-terminus more protected. One previously reported end-product of the MMP20 proteolytic processing of amelogenin, TRAP, is shown to be an in vitro substrate for MMP20.
Collapse
Affiliation(s)
- Garry W Buchko
- Pacific Northwest National Laboratory, Richland, WA 99352, USA; School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA.
| | | | - Jinhui Tao
- Pacific Northwest National Laboratory, Richland, WA 99352, USA.
| | | | - Wendy J Shaw
- Pacific Northwest National Laboratory, Richland, WA 99352, USA.
| |
Collapse
|
8
|
Ma CW, Zhang J, Dong XQ, Lu JX. Amyloid structure of high-order assembly of Leucine-rich amelogenin revealed by solid-state NMR. J Struct Biol 2018; 206:29-35. [PMID: 29604451 DOI: 10.1016/j.jsb.2018.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/18/2018] [Accepted: 03/27/2018] [Indexed: 10/17/2022]
Abstract
High-order assemblies of amelogenin, the major protein in enamel protein matrix, are believed to act as the template for enamel mineral formation. The Leucine-rich amelogenin (LRAP) is a natural splice-variant of amelogenin, a functional protein in vivo, containing conserved domains of amelogenin. In this work, we showed LRAP aggregates hierarchically into assemblies with various sizes including scattered beads, beads-on-a-string and gel-like precipitations in the presence of both calcium and phosphate ions. Solid-state NMR combined with X-ray diffraction and microscopic techniques, was applied to give a picture of LRAP self-assemblies at the atomic level. Our results, for the first time, confirmed LRAP assemblies with different sizes all contained a consistent rigid segment with β-sheet secondary structure (residues 12-27) and the β-sheet segment would further assemble into amyloid-like structures.
Collapse
Affiliation(s)
- Cheng-Wei Ma
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China; Univeristy of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China; Univeristy of Chinese Academy of Sciences, Beijing 100049, China
| | - Xing-Qi Dong
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China; Univeristy of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun-Xia Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
| |
Collapse
|
9
|
Prajapati S, Ruan Q, Mukherjee K, Nutt S, Moradian-Oldak J. The Presence of MMP-20 Reinforces Biomimetic Enamel Regrowth. J Dent Res 2017; 97:84-90. [PMID: 28846464 DOI: 10.1177/0022034517728504] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Biomimetic synthesis of artificial enamel is a promising strategy for the prevention and restoration of defective enamel. We have recently reported that a hydrogel system composed of chitosan-amelogenin (CS-AMEL) and calcium phosphate is effective in forming an enamel-like layer that has a seamless interface with natural tooth surfaces. Here, to improve the mechanical system function and to facilitate the biomimetic enamel regrowth, matrix metalloproteinase-20 (MMP-20) was introduced into the CS-AMEL hydrogel. Inspired by our recent finding that MMP-20 prevents protein occlusion inside enamel crystals, we hypothesized that addition of MMP-20 to CS-AMEL hydrogel could reinforce the newly grown layer. Recombinant human MMP-20 was added to the CS-AMEL hydrogel to cleave full-length amelogenin during the growth of enamel-like crystals on an etched enamel surface. The MMP-20 proteolysis of amelogenin was studied, and the morphology, composition, and mechanical properties of the newly grown layer were characterized. We found that amelogenin was gradually degraded by MMP-20 in the presence of chitosan. The newly grown crystals in the sample treated with MMP-20-CS-AMEL hydrogel showed more uniform orientation and greater crystallinity than the samples treated with CS-AMEL hydrogel without MMP-20. Stepwise processing of amelogenin by MMP-20 in the CS-AMEL hydrogel prevented undesirable protein occlusion within the newly formed crystals. As a result, both the modulus and hardness of the repaired enamel were significantly increased (1.8- and 2.4-fold, respectively) by the MMP-20-CS-AMEL hydrogel. Although future work is needed to further incorporate other enamel matrix proteins into the system, this study brings us one step closer to biomimetic enamel regrowth.
Collapse
Affiliation(s)
- S Prajapati
- 1 Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - Q Ruan
- 1 Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - K Mukherjee
- 1 Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - S Nutt
- 2 Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, USA
| | - J Moradian-Oldak
- 1 Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| |
Collapse
|
10
|
Ren D, Ruan Q, Tao J, Lo J, Nutt S, Moradian-Oldak J. Amelogenin Affects Brushite Crystal Morphology and Promotes Its Phase Transformation to Monetite. CRYSTAL GROWTH & DESIGN 2016; 16:4981-4990. [PMID: 28808430 PMCID: PMC5553050 DOI: 10.1021/acs.cgd.6b00569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Amelogenin protein is involved in organized apatite crystallization during enamel formation. Brushite (CaHPO4·2H2O), one of the precursors of hydroxyapatite mineralization in vitro, has been used for fabrication of biomaterials for hard tissue repair. In order to explore its potential application in biomimetic material synthesis, we studied the influence of the enamel protein amelogenin on brushite morphology and phase transformation to monetite. Our results show that amelogenin can adsorb onto the surface of brushite, leading to the formation of layered morphology on the (010) face. Amelogenin promoted the phase transformation of brushite into monetite (CaHPO4) in the dry state, presumably by interacting with crystalline water layers in brushite unit cells. Changes to the crystal morphology mediated by amelogenin continued even after the phase transformation from brushite to monetite, leading to the formation of organized platelets with an interlocked structure. This effect of amelogenin on brushite morphology and the phase transformation to monetite could provide a new approach to developing biomimetic materials.
Collapse
Affiliation(s)
- Dongni Ren
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California 90033, United States
| | - Qichao Ruan
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California 90033, United States
| | - Jinhui Tao
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Jonathan Lo
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States
| | - Steven Nutt
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California 90033, United States
| |
Collapse
|
11
|
Kwak SY, Yamakoshi Y, Simmer JP, Margolis HC. MMP20 Proteolysis of Native Amelogenin Regulates Mineralization In Vitro. J Dent Res 2016; 95:1511-1517. [PMID: 27558264 DOI: 10.1177/0022034516662814] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Recent studies have shown that native phosphorylated full-length porcine amelogenin (P173) and its predominant cleavage product (P148) can inhibit spontaneous calcium phosphate formation in vitro by stabilizing an amorphous calcium phosphate (ACP) precursor phase. Since full-length amelogenin undergoes proteolysis by matrix metalloproteinase 20 (MMP20, enamelysin) soon after secretion, the present study was conducted to assess the effect of amelogenin proteolysis on calcium phosphate formation. Calcium and phosphate were sequentially added to protein solutions without and with added MMP20 (ratio = 200:1) under physiological-like conditions of ionic strength (163 mM) in 50 mM Tris-HCl (pH 7.4) at 37 °C. Protein degradation with time was assessed by gel-electrophoresis, and mineral products formed were characterized by transmission electron microscopy (TEM). MMP20 was found to cleave P173 to primarily generate P148, along with P162, P46-148, and P63/64-148. In sharp contrast, MMP20 did not cleave P148. In addition, the formation of well-aligned bundles of enamel-like hydroxyapatite (HA) crystals was promoted in the presence of P173 with added MMP20, while only ACP particles were seen in the absence of MMP20. Although P148 was found to have a somewhat lower capacity to stabilize ACP and prevent HA formation compared with P173 in the absence of MMP20, essentially no HA formation was observed in the presence of somewhat higher concentrations of P148 regardless of MMP20 addition, due to the lack of observed protein proteolysis. Present findings suggest that ACP transformation to ordered arrays of enamel crystals may be regulated in part by the proteolysis of full-length native amelogenin, while the predominant amelogenin degradation product in developing enamel (e.g., P148) primarily serves to prevent uncontrolled mineral formation during the secretory stage of amelogenesis.
Collapse
Affiliation(s)
- S Y Kwak
- Center for Biomineralization, Department of Applied Oral Sciences, The Forsyth Institute, Cambridge, MA, USA.,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA
| | - Y Yamakoshi
- Department of Biochemistry and Molecular Biology, School of Dental Medicine, Tsurumi University, Yokohama, Japan
| | - J P Simmer
- Department of Biologic and Materials Science, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - H C Margolis
- Center for Biomineralization, Department of Applied Oral Sciences, The Forsyth Institute, Cambridge, MA, USA .,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA
| |
Collapse
|
12
|
Abstract
Mature tooth enamel is acellular and does not regenerate itself. Developing technologies that rebuild tooth enamel and preserve tooth structure is therefore of great interest. Considering the importance of amelogenin protein in dental enamel formation, its ability to control apatite mineralization in vitro, and its potential to be applied in fabrication of future bio-inspired dental material this review focuses on two major subjects: amelogenin and enamel biomimetics. We review the most recent findings on amelogenin secondary and tertiary structural properties with a focus on its interactions with different targets including other enamel proteins, apatite mineral, and phospholipids. Following a brief overview of enamel hierarchical structure and its mechanical properties we will present the state-of-the-art strategies in the biomimetic reconstruction of human enamel.
Collapse
Affiliation(s)
- Qichao Ruan
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
| |
Collapse
|
13
|
Ruan Q, Moradian-Oldak J. Amelogenin and enamel biomimetics. J Mater Chem B 2015. [DOI: 10.1039/c5tb00163c and 21=21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mature tooth enamel is acellular and does not regenerate itself.
Collapse
Affiliation(s)
- Qichao Ruan
- Center for Craniofacial Molecular Biology
- Herman Ostrow School of Dentistry
- University of Southern California
- Los Angeles
- USA
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology
- Herman Ostrow School of Dentistry
- University of Southern California
- Los Angeles
- USA
| |
Collapse
|
14
|
Ruan Q, Zhang Y, Yang X, Nutt S, Moradian-Oldak J. An amelogenin-chitosan matrix promotes assembly of an enamel-like layer with a dense interface. Acta Biomater 2013; 9:7289-97. [PMID: 23571002 PMCID: PMC3669649 DOI: 10.1016/j.actbio.2013.04.004] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 03/04/2013] [Accepted: 04/01/2013] [Indexed: 10/27/2022]
Abstract
Biomimetic reconstruction of tooth enamel is a significant topic of study in materials science and dentistry as a novel approach to the prevention, restoration, and treatment of defective enamel. We have developed a new amelogenin-containing chitosan hydrogel for enamel reconstruction that works through amelogenin supramolecular assembly, stabilizing Ca-P clusters and guiding their arrangement into linear chains. These amelogenin Ca-P composite chains further fuse with enamel crystals and eventually evolve into enamel-like co-aligned crystals, anchored to the natural enamel substrate through a cluster growth process. A dense interface between the newly grown layer and natural enamel was formed and the enamel-like layer improved the hardness and elastic modulus compared with etched enamel. We anticipate that this chitosan hydrogel will provide effective protection against secondary caries because of its pH-responsive and antimicrobial properties. Our studies introduce an amelogenin-containing chitosan hydrogel as a promising biomaterial for enamel repair and demonstrate the potential of applying protein-directed assembly to biomimetic reconstruction of complex biomaterials.
Collapse
Affiliation(s)
- Qichao Ruan
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
| | - Yuzheng Zhang
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA
| | - Xiudong Yang
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
| | - Steven Nutt
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
| |
Collapse
|
15
|
Bromley KM, Lakshminarayanan R, Thompson M, Lokappa SB, Gallon VA, Cho KR, Qiu SR, Moradian-Oldak J. Amelogenin processing by MMP-20 prevents protein occlusion inside calcite crystals. CRYSTAL GROWTH & DESIGN 2012; 12:4897-4905. [PMID: 23226976 PMCID: PMC3513936 DOI: 10.1021/cg300754a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Calcite crystals were grown in the presence of full-length amelogenin and during its proteolysis by recombinant human matrix metalloproteinase 20 (rhMMP-20). Recombinant porcine amelogenin (rP172) altered the shape of calcite crystals by inhibiting the growth of steps on the {104} faces and became occluded inside the crystals. Upon co-addition of rhMMP-20, the majority of the protein was digested resulting in a truncated amelogenin lacking the C-terminal segment. In rP172-rhMMP-20 samples, the occlusion of amelogenin into the calcite crystals was drastically decreased. Truncated amelogenin (rP147) and the 25-residue C-terminal domain produced crystals with regular shape and less occluded organic material. Removal of the C-terminal diminished the affinity of amelogenin to the crystals and therefore prevented occlusion. We hypothesize that HAP and calcite interact with amelogenin in a similar manner. In the case of each material, full-length amelogenin binds most strongly, truncated amelogenin binds weakly and the C-terminus alone has the weakest interaction. Regarding enamel crystal growth, the prevention of occlusion into maturing enamel crystals might be a major benefit resulting from the selective cleavage of amelogenin at the C-terminus by MMP-20. Our data have important implications for understanding the hypomineralized enamel phenotype in cases of amelogenesis imperfecta resulting from MMP-20 mutations and will contribute to the design of enamel inspired biomaterials.
Collapse
Affiliation(s)
- Keith M. Bromley
- Center for Craniofacial Molecular Biology, University of Southern California, 2250 Alcazar Street, Los Angeles, CA 90033, USA
| | - Rajamani Lakshminarayanan
- Centre for Translational Medicine, NUS, Yong Loo Lin School of Medicine, 14 Medical Drive, Singapore Eye Research Institute (SERI), Level 8-South Core, Singapore 117599
| | - Mitchell Thompson
- Center for Craniofacial Molecular Biology, University of Southern California, 2250 Alcazar Street, Los Angeles, CA 90033, USA
| | - Sowmya B. Lokappa
- Center for Craniofacial Molecular Biology, University of Southern California, 2250 Alcazar Street, Los Angeles, CA 90033, USA
| | - Victoria A. Gallon
- Center for Craniofacial Molecular Biology, University of Southern California, 2250 Alcazar Street, Los Angeles, CA 90033, USA
| | - Kang R. Cho
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
- Lawrence Berkeley National Laboratory, One Cyclotron Rd., MS 67R1235A, Berkeley, CA 94720, USA
| | - S. Roger Qiu
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, University of Southern California, 2250 Alcazar Street, Los Angeles, CA 90033, USA
| |
Collapse
|
16
|
Abstract
Enamel is a hard nanocomposite bioceramic with significant resilience that protects the mammalian tooth from external physical and chemical damages. The remarkable mechanical properties of enamel are associated with its hierarchical structural organization and its thorough connection with underlying dentin. This dynamic mineralizing system offers scientists a wealth of information that allows the study of basic principels of organic matrix-mediated biomineralization and can potentially be utilized in the fields of material science and engineering for development and design of biomimetic materials. This chapter will provide a brief overview of enamel hierarchical structure and properties and the process and stages of amelogenesis. Particular emphasis is given to current knowledge of extracellular matrix protein and proteinases, and the structural chemistry of the matrix components and their putative functions. The chapter will conclude by discussing the potential of enamel for regrowth.
Collapse
Affiliation(s)
- Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA.
| |
Collapse
|