Eng. Acta 761, 1722. Mater. doi: 10.1248/bpb.b13-00933, Ozsvar, J., Tarakanova, A., Wang, R., Buehler, M. J., and Weiss, A. S. (2019). Specific instructions are found in the Directions for Use. Thus, the current computational model unifies the global and regional characteristics of tropoelastin, inferring mechanisms that complement observed experimental phenomena. This suggests the ERCs primary signal pathways are involved in wound recognition through fragments of elastin, where EDPs are formed as a result of elastic tissue damage. Frontiers | Tropoelastin and Elastin Assembly This model revealed that tropoelastin maintains a canonical or average structure based on the distribution of its possible conformations in spite of its flexible nature (Figure 2), as well as the possible roles that local structures play in biological processes, specifically, elastogenesis (Tarakanova et al., 2019b). Elastin biomaterials in dermal repair. 79, 277284. The cross-linking domains are enriched for either Lys-Pro (KP) or Lys-Ala (KA) motifs and form cross-links that link growing tropoelastin chains during elastogenesis; note that exon 6 encodes a KA domain. (2016). Int. The presence of tropoelastin spherules fusing to fibrils has been noted in native tissue, demonstrating marked similarities between in vitro and in vivo coacervation (Haust et al., 1965; Albert, 1972; Kozel et al., 2006). Elastagen Pty Ltd, a clinical stage company developing medical device products based on recombinant tropoelastin, today announced. Biopolymers 107:e23007. (2017). doi: 10.1016/j.matbio.2009.07.003, Mithieux, S. M., Wise, S. G., Raftery, M. J., Starcher, B., and Weiss, A. S. (2005). FEBS J. Tropoelastin aggregates at physiological temperature due to interactions between hydrophobic domains in a process called coacervation. Patient Homepage | Accredo The hydrophobic domains contain aliphatic amino acids with proline variations that provide flexibility and the ability to assemble into higher order structures. The last 17 amino acid residues of the C-terminus of domain 36 are also implicated in HS interactions; the last four residues are Arg-Lys-Arg-Lys and are positively charged at physiological pH which provides a charged cluster capable of binding negatively charged HS (Broekelmann et al., 2005). It is likely that, as a general rule, integrin binding to tropoelastin is mediated via GAGs, which is facilitated by the repetition of tropoelastins primary sequence and the surface exposure of positively charged similar domains (Lee et al., 2017; Bochicchio et al., 2021). ACS Biomater. Natl. In order to eliminate this limitation, human tropoelastin has been expressed in a recombinant bacterial system and the protein has been highly purified. The process of tropoelastin aggregation is initially reversible, as spherules dissipate if the temperature is lowered (Clarke et al., 2006), however, maintenance of a physiological temperature results in maturation, which is indicated by spherule coalescence and the irreversible formation of fibrillar structures (Cox et al., 1974; Bressan et al., 1983; Mithieux et al., 2005). Healthcare Investment Banking - The Walden Group 432, 57365751. The hydrophobic domains vary in length, with the majority of the shorter (95 residues) domains occurring near the N-terminus, while the longer (up to 55 residues) domains are found within tropoelastins central and C-terminal regions (Indik et al., 1989). Allergan to acquire University of Sydney spinoff Elastagen 126, 563574. The company is particularly pointing to usage in the treatment of acne scars, stretch marks, aesthetic skin repair and surgical wound repair. U.S.A. 116, 20422051. Proc. 1, 2 Elastogenesis, the process of elastin formation, mainly occurs during the fetal and early neonatal development of organs such as blood vessels, lungs, and skin. 33, 54685481. (2013). Tropoelastin has 2 alternating domains: (1) hydrophilic, cross-linked, domains rich in Lys and Ala; and (2) hydrophobic domains (responsible for elasticity) rich in Val, Pro, and Gly, which often occur in repeats of VPGVG or VGGVG. Cytochem. (2015). PLoS One 7:e46130. Med. Proc. For example, their inclusion in peptides derived from hydrophobic domains confers decreased times taken for self-assembly, most likely due to their favorable interaction with aqueous solvent (Miao et al., 2003). doi: 10.1016/j.biocel.2008.03.017, Wise, S. G., Yeo, G. C., Hiob, M. A., Rnjak-Kovacina, J., Kaplan, D. L., Ng, M. K., et al. Tropoelastin is a low complexity protein on both primary and secondary sequence levels. Delineation of unusual features in the 5-flanking region. J. Biol. Tropoelastin has a defined shape in solution but paradoxically also displays a large percentage of flexible, disordered regions needed for molecular elasticity (4, 5).The tertiary structure of human tropoelastin represents an ensemble of elastic conformers (3, 6), yet occasional conserved sequence elements hint at requirements for functional demands in one or more key parts of this molecule (7 . 21:063001. doi: 10.1088/0965-0393/21/6/063001, Tarakanova, A., Huang, W., Weiss, A. S., Kaplan, D. L., and Buehler, M. J. Rep. 8, 116. Elastin is extensively cross-linked and difficult to break apart into monomers even under harsh conditions, thus, initial strategies included feeding animals a copper deficient diet to prevent lysyl oxidase (LOX) cross-linking of tropoelastin; however, this proved inefficient and time consuming (Wise and Weiss, 2009; Tarakanova et al., 2018). Elastic fibers are an important component of the extracellular matrix, providing stretch, resilience, and cell interactivity to a broad range of elastic tissues. Received: 17 December 2020; Accepted: 08 February 2021;Published: 25 February 2021. Mutations in LTBP4 cause a syndrome of impaired pulmonary, gastrointestinal, genitourinary, musculoskeletal, and dermal development. J. Med. II. Multimers may undergo further transitions, such as branching, to form spherules made of multimer aggregates (Tu et al., 2010). Sci. doi: 10.1016/j.biomaterials.2017.04.050, Keywords: elastin, elastic fibers, tropoelastin, computational modeling, assembly, Citation: Ozsvar J, Yang C, Cain SA, Baldock C, Tarakanova A and Weiss AS (2021) Tropoelastin and Elastin Assembly. The most crucial of these properties is the ability to undergo many stretch-recoil cycles whilst maintaining the structural and functional integrity of elastic tissues over an organisms lifetime. 58, 270277. doi: 10.1074/jbc.M004265200, Kadler, K. E. (2017). Am. FEBS Lett. Initially, in vitro coacervation is characterized by the rapid aggregation of tropoelastin. Four days after a heart attack, purified tropoelastin was injected into the heart. Elastases can be in the form of serine- (e.g., Ela-2), cysteine- (e.g., cathepsin I), or matrix metalloproteinases (MMP-2, -7, -9, and -12), and bioactive peptides include the VGVAPG peptide. Visconti, R. P., Barth, J. L., Keeley, F. W., and Little, C. D. (2003). Water structure and elastin-like peptide aggregation. Chem. Acad. doi: 10.1371/journal.pone.0046130, Hedtke, T., Schrader, C. U., Heinz, A., Hoehenwarter, W., Brinckmann, J., Groth, T., et al. Foster, J. The first successful experiments to define the 3D envelope of tropoelastin utilized small angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) (Baldock et al., 2011). Elastogenesis occurs during replacement fibrosis in human heart disease and can be accelerated in vitro via tropoelastin treatment. doi: 10.1016/j.matbio.2006.08.258, Clarke, A. W., Arnspang, E. C., Mithieux, S. M., Korkmaz, E., Braet, F., and Weiss, A. S. (2006). 270, 1777817783. J. Biomol. Biol. (1973). Modulation by elastin peptide VGVAPG of cell proliferation and elastin expression in human skin fibroblasts. (2014). Fluor: Q4 Earnings Snapshot. (1995). A., Starcher, B. C., and Urry, D. W. (1974). Sequence variants of human tropoelastin affecting assembly, structural characteristics and functional properties of polymeric elastin in health and disease. Domains 12 to 16 of tropoelastin promote cell attachment and spreading through interactions with glycosaminoglycan and integrins alphaV and alpha5beta1. A. Biol. 27, 441450. Sci. Dominant driving factors of assembly were examined, including water, temperature and domain pair orientations. [Epub ahead of print]. Calorim. ELN gene: MedlinePlus Genetics Figure 2. Fed. *Correspondence: Anthony S. Weiss, tony.weiss@sydney.edu.au, These authors have contributed equally to this work, Fibrous Assemblies: From Synthesis and Nanostructure Characterization to Materials Development and Application, Front. Matrix Biol. doi: 10.1083/jcb.68.3.411, Noda, K., Dabovic, B., Takagi, K., Inoue, T., Horiguchi, M., Hirai, M., et al. Biol. The stiffness that arose due to amino acid substitutions partially determined resultant secondary structure which, in turn, impacted assembly (Prhashanna et al., 2019). J. Mol. doi: 10.1021/acs.biomac.8b01503, Rauscher, S., Baud, S., Miao, M., Keeley, F. W., and Poms, R. (2006). Fibulin-4 and -5, but not fibulin-2, are associated with tropoelastin deposition in elastin-producing cell culture. By probing mutations in computational studies that resolve the atomistic structure of the molecule, the deduction of mechanisms associated with changes to functional roles of specific domains has become feasible, and a connection between local structures and biological performance can be established (Figure 2; Tarakanova et al., 2018). Matrix Biol. doi: 10.1016/j.matbio.2006.09.011, Miao, M., Reichheld, S. E., Muiznieks, L. D., Huang, Y., and Keeley, F. W. (2013). J. Biol. Molecular model of human tropoelastin and implications of associated mutations. Variations in the relative abundance of alternatively spliced ELN mRNA transcripts have been observed between tissues, and this diversity is thought to be necessary for the fine tuning of the mechanical characteristics of tissues to suit their unique functional requirements (Reichheld et al., 2019). Another region of note is domain 36, which contains lysines but does not participate in cross-linking (Hedtke et al., 2019). Cell Biol. 7:32. doi: 10.3389/fphar.2016.00032, Schmelzer, C. E. H., Heinz, A., Troilo, H., Lockhart-Cairns, M. P., Jowitt, T. A., Marchand, M. F., et al. Macromol. Sci. doi: 10.1038/246461a0, Haust, M. D., More, R. H., Bencosme, S. A., and Balis, J. U. Parameter, Testing, and Method. 84, 6880. Genet. Coacervation characteristics of recombinant human tropoelastin Domain 26 of tropoelastin plays a dominant role in association by coacervation. Earnings, adjusted for non-recurring costs, came . The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. KA domains were initially thought to form -helices and poly-proline II helices (PPII) due to the presence of cross-links which require a lysine arrangement that was postulated to be achieved via -helical configuration (Brown-Augsburger et al., 1995). Our Juvederm collection of fillers has sales of over $1 billion globally and is one of the fastest growing parts of our Aesthetics business, said Bill Meury, Chief Commercial Officer at Allergan. doi: 10.1016/s0945-053x(03)00014-3, Vrhovski, B., Jensen, S., and Weiss, A. S. (1997). (2013). February 14, 2018 Michael Patrini. Colloid Interface Sci. Sci. J. Biol. doi: 10.1016/s0968-4328(99)00082-7, Tajima, S., Wachi, H., Uemura, Y., and Okamoto, K. (1997). Subtle balance of tropoelastin molecular shape and flexibility Positively charged lysine residues in domains 17 were identified to interact with negatively charged HS, most likely via ionic interactions (Lee et al., 2017). doi: 10.1016/j.matbio.2006.10.002, Dyksterhuis, L. B., and Weiss, A. S. (2010). J. 289, 14671477. Elastin is a critical skin protein consisting of crosslinked tropoelastin. Primary structure of porcine tropoelastin. Mater. FASEB J. Cross-linking requires the modification of at least one of the lysine participants by a member of the copper-containing LOX or lysine oxidase-like (LOXL) enzyme families. Elastin binding protein and FKBP65 modulate in vitro self-assembly of human tropoelastin. Anal. Localizing alpha-helices in human tropoelastin: assembly of the elastin puzzle. J. Hum. 281, 2375723765. J. Biochem. J. Struct. Elastin is heterogeneously cross-linked. Characterization of the complete human elastin gene. Elastin is the major component of elastic fibers, which are a major component of the tissue that supports the body's joints . Insights into the structure and behavior of tropoelastin have translated into increasingly sophisticated . Advanced BioMatrix - Recombinant Tropoelastin, Lyophilized #5052 This review focuses on recent developments that have shaped our current knowledge of elastin assembly through understanding the relationship between tropoelastins structure and function. Biophys. It has become increasingly evident that tropoelastins sequence, structure and subsequent functionality are in a delicate balance; thus, perturbations to tropoelastins sequence can have far-reaching consequences for self-assembly and the resultant architecture of elastic fibers. The isoform-function theory is further reinforced by the presence of two different ELN genes within teleosts that are differentially expressed both spatially and temporally during development (Miao et al., 2007). Biol. EBP plays two roles in the assembly of elastin. 15, 786801. 26, 115124. Allergans success is powered by our global colleagues commitment to being Bold for Life. Powered by Madgex Job Board Software. Coacervation involves the agglomeration of protein molecules, which is an . FEBS J. doi: 10.1016/s0022-5320(83)80021-5, Broekelmann, T. J., Kozel, B. Mechanism of helix induction by trifluoroethanol: a framework for extrapolating the helix-forming properties of peptides from trifluoroethanol/water mixtures back to water. doi: 10.1006/jmbi.2000.3901, Baldock, C., Oberhauser, A. F., Ma, L., Lammie, D., Siegler, V., Mithieux, S. M., et al. U.S.A. 112, E4408E4415. Caterpillar | Caterpillar to Relocate Global Headquarters to Dallas Elastagen has received investment from an international syndicate of venture groups including AmorePacific Ventures, Brandon Capital, Cell Innovation Partners, Cicada Innovations, GBS Ventures, Korea Investment Partners and the Wellcome Trust. Moreover, fibulins are essential for elastic fiber directionality, as fibroblasts with fibulin-4 and -5 knockdowns generate poorly formed elastic fibers (Yamauchi et al., 2010), and fibulin-4 / mice display aberrant, poorly cross-linked, and non-fibrous elastin (McLaughlin et al., 2006). Coacervation optimally occurs at physiological temperature, however, in vitro coacervation can also occur at lower temperatures depending on experimental conditions and the choice of tropoelastin isoform or derivative (Yeo et al., 2011). Rev. Fabricating organized elastin in vascular grafts. Even after being able to produce recombinant tropoelastin at scales suited to characterization studies, traditional techniques have not yet produced an experimentally verified atomistic structure (Martin et al., 1995; Tarakanova and Buehler, 2013). J. Biol. Elastagens revolutionary technology is based on recombinant human tropoelastin, the precursor of elastin which is a key component of youthful skin. Tropoelastin is characterised by alternating hydrophobic and hydrophilic domains and is highly flexible. Tropoelastin is typically used as a thin coating on tissue culture surfaces. Assembly proceeds from a nucleation event and undergoes elongation in a step-wise manner to form a multimer which can occur in a head-to-tail fashion (Wise et al., 2014). Elastogenesis in human aorta: an electron microscopic study. Similarly, a mutation model associated with cutis laxa, or loose skin disease (Hu et al., 2006), was found to exhibit higher stability compared with the wild-type molecule due to the increased longevity of its salt bridges (Hu et al., 2006; Tarakanova et al., 2018). The conversion of a single lysine to an allysine results in structural stabilization, which may serve as a checkpoint during self-assembly to ensure that molecules incapable of forming multiple cross-links are not incorporated into the growing chain. 10:034102. doi: 10.1088/1748-6041/10/3/034102, Hinek, A., Keeley, F. W., and Callahan, J. With this approach, Allergan has built one of the broadest development pipelines in the pharmaceutical industry. Computational models have also been leveraged to pinpoint the molecular consequences of synthetic and disease mutations of tropoelastin. Biol. doi: 10.1016/0304-4165(83)90357-4, Narayanan, A. S., Sandberg, L. B., Ross, R., and Layman, D. L. (1976). Human ELN gives rise to a broad variety of splice isoforms, with alternative splicing being observed with exons 22, 23, 24, 26A, 32, and 33 (Fazio et al., 1988; Parks et al., 1992) that result in 13 known human isoforms of the mature tropoelastin protein (Reichheld et al., 2019). AT acknowledges support from University of Connecticuts Institute for Collaboration on Health, Intervention, and Policy Faculty Research Seed Grant. Elastogenesis is the term that collectively describes the hierarchical process of elastic fiber formation, and is comprised of distinct phases: tropoelastin synthesis, coacervation, cross-linking, and deposition. Elastic fiber formation: a dynamic view of extracellular matrix assembly using timer reporters. Recycling of the 67-kDa elastin binding protein in arterial myocytes is imperative for secretion of tropoelastin. (2008). Unsubstituted models are also critical to understanding self-assembly. J. The spherules grow in size and are deposited onto the microfibril scaffold where they fuse into fibrillar structures (Sherratt et al., 2001). Tropoelastin, the soluble precursor to elastin, and the degradation products of fragmented elastic fibers also have important chemical signaling properties. Elastin synthesis and fiber assembly. (2020). The compositions include a coalescence-controlling agent in the form of a polysaccharide or polysaccharide derivative, in an amount effective for providing the substance with the properties of flow, enabling injection. Tropoelastin interacts with cell-surface glycosaminoglycans via its COOH-terminal domain. Mol. doi: 10.1016/j.bbagen.2017.07.020, Myers, B., Dubick, M., Last, J. The alignment of these three domains indicates that at least two tropoelastin molecules are required to form this tetrafunctional cross-link, thus, giving rise to the head-to-tail model of assembly involving the growth of a linear chain that can assemble laterally to form sheets and eventually form spherules (Baldock et al., 2011). doi: 10.1128/mcb.26.5.1700-1709.2006, Mecham, R. P. (1991). 16,17 We have previously shown that monomeric TE is utilized as a substrate by dermal fibroblasts in the formation of elastin fibroblasts in vitro, where J. Struct. doi: 10.1021/acs.biomac.6b01759, Mackay, J. P., Muiznieks, L. D., Toonkool, P., and Weiss, A. S. (2005). Upon secretion tropoelastin has the propensity to self-aggregate through a process known as coacervation. 258, 118. Injectable biomaterial compositions formed from tropoelastin for tissue repair and restoration. Stem cell growth accelerated by tropoelastin protein doi: 10.1074/jbc.M212715200, Kumashiro, K. K., Ho, J. P., Niemczura, W. P., and Keeley, F. W. (2006). Although alanine tracts within other proteins are predisposed to -helix formation (Yang and Honig, 1995; Avbelj, 2000), high helical content within tropoelastins KA domains was primarily demonstrated to persist in solvents that stabilize secondary structure, such as trifluoroethanol, rather than aqueous solution (Luo and Baldwin, 1997; Tamburro et al., 2006). For more information, visit Allergans website atwww.Allergan.com. Res. doi: 10.1016/j.actbio.2013.08.003, Wu, W. J., and Weiss, A. S. (1999). Chem. (2003). Remarkably, optimal coacervation is found at 37 degrees C, 150 mM NaCl and pH 7-8. FEBS J. Closer to the base of the molecule, the flexible hinge region between domains 21 and 23 presented with a scissors-like bending, which is now believed to contribute to elasticity and multimeric assembly through enhanced conformational space sampling (Tarakanova et al., 2019b). 249, 997998. Biophys. Studies on the reduction of elastin. A novel cell adhesion region in tropoelastin mediates attachment to integrin alphaVbeta5. Exp. Allergan's Acquisition of Elastagen - Global Legal Chronicle Attempts to characterize tropoelastins structure have seen a gradual shift from the belief that tropoelastins domains have fixed structures, to understanding that the majority of its domains are capable of transitioning between random coils and transient ordered structures. 87, 18281834. J. doi: 10.1002/chem.200305661. Unlike other companies that use paid endorsements and questionable data, NULASTIN science is proven by 3rd party clinical evaluation. On the cell surface, EBP forms a complex with protective protein/cathepsin A (PPCA) and neuraminidase-1 (Neu-1), giving rise to the ERC (Duca et al., 2007). doi: 10.1021/bi00835a022, Lockhart-Cairns, M. P., Newandee, H., Thomson, J., Weiss, A. S., Baldock, C., and Tarakanova, A. How to Get LONGER Eyelashes - Guaranteed | NULASTIN More surprisingly, tropoelastins cross-linking domains are also capable of similar transitions between ordered and disordered structures. Overview of the computational and experimental methodologies that have recently contributed to our understanding of elastic fiber assembly. Biosci. Eur. Novel Recombinant Tropoelastin Implants Restore Skin - PubMed The conserved C-terminus is an area of the molecule of particular biological importance in that it is required for both incorporation into elastin and for cellular interactions. This deduction has been corroborated by the observation that tropoelastin with multiple allysine modifications displays conformational sampling comparable to that of the wild-type molecule, suggesting it is more likely to readily participate in self-assembly. doi: 10.1021/bi981641y, Kozel, B. Of most importance, the inability to acquire large quantities of pure tropoelastin historically presented a significant obstacle to experimentally characterizing its structure. Meanwhile, modifications to the full-atomistic model have revealed the mechanisms that contribute to aberrant fiber structure (Tarakanova et al., 2018) that have been hypothesized to predispose patients to diseases such as acquired cutis laxa (Hu et al., 2006). Possible role in nucleated assembly. For example, models involving single point mutations at negatively charged residues demonstrated both regional and global destabilization of tropoelastins structure, which were validated by SAXS structures (Yeo et al., 2012; Tarakanova et al., 2018). doi: 10.1038/sj.jid.5700047, Indik, Z., Yeh, H., Ornstein-Goldstein, N., Kucich, U., Abrams, W., Rosenbloom, J. C., et al. For many years it was difficult to study tropoelastin at an atomic scale, but the application of computational methods, such as full-atomistic molecular dynamics and elastic network models, in combination with powerful low-resolution structural studies, have expanded the field and delivered an enhanced understanding of the mechanisms that contribute to self-assembly. Indeed, studies examining the consequences of domain insertions and deletions note changes in the intrinsic functionality of tropoelastin, corroborating the hypothesis that domain insertions and deletions result in altered tissue mechanics (Jensen et al., 2000; Kozel et al., 2003; Yeo et al., 2016; Miao et al., 2017). The self-assembly properties and nanostructure of these extra teleost isoforms are yet to be investigated. Elastin: Structure, Function, Skin Care & Supplements - Cleveland Clinic U.S.A. 110, 28522857. (1977). This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). However, higher resolution data were required to map out its elusive properties and performance within a hierarchical assembly (Tarakanova et al., 2018; Ozsvar et al., 2019). Cardiovasc. Allergan is an industry leader in Open Science,a model of research and development, which defines our approach to identifying and developing game-changing ideas and innovation for better patient care. doi: 10.1203/00006450-199010000-00015, Nonaka, R., Sato, F., and Wachi, H. (2014). Model. Self-healing and thermoreversible rubber from supramolecular assembly. Crucially, these simulations revealed that self-assembly starts with a nucleation event and elongation proceeds via both globular and fibrillar structures (Tarakanova et al., 2019a). Copyright 2021 Ozsvar, Yang, Cain, Baldock, Tarakanova and Weiss. Acta Biomater. Chem. Biotechnol., 25 February 2021, View all Elastagen Pty Ltd, a clinical stage company developing medical device products based on recombinant tropoelastin, today announced that it has entered into a definitive agreement under which Allergan plc, a leading global biopharmaceutical company, has agreed to acquire Elastagen. doi: 10.1073/pnas.1111615108, Yeo, G. C., Baldock, C., Wise, S. G., and Weiss, A. S. (2017). However, there are aspects of this model that warrant further investigation. Elastagen's technology is based on human tropoelastin . (2006). Direct observation of structure and dynamics during phase separation of an elastomeric protein. Cellular activities are mediated through interactions between tropoelastin or EDPs and specific receptors on the cell surface.