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Medina BNSP, Portal TM, de Andrade Gomes CAB, Nunes-da-Fonseca R, Allodi S, Monteiro-de-Barros C. Identification of astrocyte-like cells in an adult ascidian during regeneration of the central nervous system. Glia 2024. [PMID: 39152717 DOI: 10.1002/glia.24605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 06/30/2024] [Accepted: 08/01/2024] [Indexed: 08/19/2024]
Abstract
The mechanisms underlying regeneration of the central nervous system (CNS) following lesions have been studied extensively in both vertebrate and invertebrate models. To shed light on regeneration, ascidians, a sister group of vertebrates and with remarkable ability to regenerate their brains, constitute an appropriate model system. Glial cells have been implicated in regeneration in vertebrates; however, their role in the adult ascidian CNS regeneration is unknown. A model of degeneration and regeneration using the neurotoxin 3-acetylpyridine (3AP) in the brain of the ascidian Styela plicata was used to identify astrocyte-like cells and investigate their role. We studied the CNS of control ascidians (injected with artificial sea water) and of ascidians whose CNS was regenerating (1 and 10 days after the injection with 3AP). Our results show that the mRNA of the ortholog of glutamine synthetase (GS), a glial-cell marker in vertebrates, is increased during the early stages of regeneration. Confirming the identity of GS, the protein was identified via immunostaining in a cell population during the same regeneration stage. Last, a single ortholog of GS (GSII) is present in ascidian and amphioxus genomes, while two types exist in fungi, some invertebrates, and vertebrates, suggesting that ascidians have lost the GSI type. Taken together, our findings revealed that a cell population expressing glial-cell markers may play a role in regeneration in adult ascidians. This is the first report of astrocyte-like cells in the adult ascidian CNS, and contributes to understanding of the evolution of glial cells among metazoans.
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Affiliation(s)
- Bianca Nicole Santos Paes Medina
- Laboratório Integrado de Biociências Translacionais Instituto de Biodiversidade e Sustentabilidade, NUPEM, Universidade Federal do Rio de Janeiro, Macaé, RJ, Brazil
- Programa de Pós-Graduação em Ciências Morfológicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Laboratório de Neurobiologia Comparativa e do Desenvolvimento, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, RJ, Brazil
| | - Taynan Motta Portal
- Laboratório Integrado de Biociências Translacionais Instituto de Biodiversidade e Sustentabilidade, NUPEM, Universidade Federal do Rio de Janeiro, Macaé, RJ, Brazil
- Programa de Pós-Graduação em Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - Carlos Augusto Borges de Andrade Gomes
- Laboratório de Neurobiologia Comparativa e do Desenvolvimento, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, RJ, Brazil
- Programa de Pós-Graduação em Ciências Biológicas - Biofísica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, RJ, Brazil
| | - Rodrigo Nunes-da-Fonseca
- Laboratório Integrado de Ciências Morfofuncionais, Instituto de Biodiversidade e Sustentabilidade - NUPEM - Universidade Federal do Rio de Janeiro -, Macaé, RJ, Brazil
| | - Silvana Allodi
- Laboratório de Neurobiologia Comparativa e do Desenvolvimento, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, RJ, Brazil
- Programa de Pós-Graduação em Ciências Biológicas - Biofísica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, RJ, Brazil
| | - Cintia Monteiro-de-Barros
- Laboratório Integrado de Biociências Translacionais Instituto de Biodiversidade e Sustentabilidade, NUPEM, Universidade Federal do Rio de Janeiro, Macaé, RJ, Brazil
- Programa de Pós-Graduação em Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
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Wu Y, Devotta A, José-Edwards DS, Kugler JE, Negrón-Piñeiro LJ, Braslavskaya K, Addy J, Saint-Jeannet JP, Di Gregorio A. Xbp1 and Brachyury establish an evolutionarily conserved subcircuit of the notochord gene regulatory network. eLife 2022; 11:e73992. [PMID: 35049502 PMCID: PMC8803312 DOI: 10.7554/elife.73992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
Gene regulatory networks coordinate the formation of organs and structures that compose the evolving body plans of different organisms. We are using a simple chordate model, the Ciona embryo, to investigate the essential gene regulatory network that orchestrates morphogenesis of the notochord, a structure necessary for the proper development of all chordate embryos. Although numerous transcription factors expressed in the notochord have been identified in different chordates, several of them remain to be positioned within a regulatory framework. Here, we focus on Xbp1, a transcription factor expressed during notochord formation in Ciona and other chordates. Through the identification of Xbp1-downstream notochord genes in Ciona, we found evidence of the early co-option of genes involved in the unfolded protein response to the notochord developmental program. We report the regulatory interplay between Xbp1 and Brachyury, and by extending these results to Xenopus, we show that Brachyury and Xbp1 form a cross-regulatory subcircuit of the notochord gene regulatory network that has been consolidated during chordate evolution.
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Affiliation(s)
- Yushi Wu
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Arun Devotta
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Diana S José-Edwards
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Jamie E Kugler
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Lenny J Negrón-Piñeiro
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Karina Braslavskaya
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Jermyn Addy
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | | | - Anna Di Gregorio
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
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Ocampo Daza D, Haitina T. Reconstruction of the Carbohydrate 6-O Sulfotransferase Gene Family Evolution in Vertebrates Reveals Novel Member, CHST16, Lost in Amniotes. Genome Biol Evol 2020; 12:993-1012. [PMID: 32652010 PMCID: PMC7353957 DOI: 10.1093/gbe/evz274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2019] [Indexed: 12/24/2022] Open
Abstract
Glycosaminoglycans are sulfated polysaccharide molecules, essential for many biological processes. The 6-O sulfation of glycosaminoglycans is carried out by carbohydrate 6-O sulfotransferases (C6OSTs), previously named Gal/GalNAc/GlcNAc 6-O sulfotransferases. Here, for the first time, we present a detailed phylogenetic reconstruction, analysis of gene synteny conservation and propose an evolutionary scenario for the C6OST family in major vertebrate groups, including mammals, birds, nonavian reptiles, amphibians, lobe-finned fishes, ray-finned fishes, cartilaginous fishes, and jawless vertebrates. The C6OST gene expansion likely started early in the chordate lineage, giving rise to four ancestral genes after the divergence of tunicates and before the emergence of extant vertebrates. The two rounds of whole-genome duplication in early vertebrate evolution (1R/2R) only contributed two additional C6OST subtype genes, increasing the vertebrate repertoire from four genes to six, divided into two branches. The first branch includes CHST1 and CHST3 as well as a previously unrecognized subtype, CHST16 that was lost in amniotes. The second branch includes CHST2, CHST7, and CHST5. Subsequently, local duplications of CHST5 gave rise to CHST4 in the ancestor of tetrapods, and to CHST6 in the ancestor of primates. The teleost-specific gene duplicates were identified for CHST1, CHST2, and CHST3 and are result of whole-genome duplication (3R) in the teleost lineage. We could also detect multiple, more recent lineage-specific duplicates. Thus, the vertebrate repertoire of C6OST genes has been shaped by gene duplications and gene losses at several stages of vertebrate evolution, with implications for the evolution of skeleton, nervous system, and cell-cell interactions.
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Affiliation(s)
- Daniel Ocampo Daza
- Department of Organismal Biology, Uppsala University, Sweden
- School of Natural Sciences, University of California Merced
| | - Tatjana Haitina
- Department of Organismal Biology, Uppsala University, Sweden
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Yasuoka Y. Morphogenetic mechanisms forming the notochord rod: The turgor pressure-sheath strength model. Dev Growth Differ 2020; 62:379-390. [PMID: 32275068 DOI: 10.1111/dgd.12665] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/14/2022]
Abstract
The notochord is a defining feature of chordates. During notochord formation in vertebrates and tunicates, notochord cells display dynamic morphogenetic movement, called convergent extension, in which cells intercalate and align at the dorsal midline. However, in cephalochordates, the most basal group of chordates, the notochord is formed without convergent extension. It is simply developed from mesodermal cells at the dorsal midline. This suggests that convergent extension movement of notochord cells is a secondarily acquired developmental attribute in the common ancestor of olfactores (vertebrates + tunicates), and that the chordate ancestor innovated the notochord upon a foundation of morphogenetic mechanisms independent of cell movement. Therefore, this review focuses on biological features specific to notochord cells, which have been well studied using clawed frogs, zebrafish, and tunicates. Attributes of notochord cells, such as vacuolation, membrane trafficking, extracellular matrix formation, and apoptosis, can be understood in terms of two properties: turgor pressure of vacuoles and strength of the notochord sheath. To maintain the straight rod-like structure of the notochord, these parameters must be counterbalanced. In the future, the turgor pressure-sheath strength model, proposed in this review, will be examined in light of quantitative molecular data and mathematical simulations, illuminating the evolutionary origin of the notochord.
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Affiliation(s)
- Yuuri Yasuoka
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.,Laboratory for Comprehensive Genomic Analysis, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
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Biological function of unique sulfated glycosaminoglycans in primitive chordates. Glycoconj J 2016; 34:277-283. [PMID: 27614617 DOI: 10.1007/s10719-016-9728-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 08/23/2016] [Accepted: 08/29/2016] [Indexed: 12/17/2022]
Abstract
Glycosaminoglycans with unique sulfation patterns have been identified in different species of ascidians (sea squirts), a group of marine invertebrates of the Phylum Chordata, sub-phylum Tunicata (or Urochordata). Oversulfated dermatan sulfate composed of [4-α-L-IdoA-(2-O-SO3)-1 → 3-β-D-GalNAc(4-OSO3)-1]n repeating disaccharide units is found in the extracellular matrix of several organs, where it seems to interact with collagen fibers. This dermatan sulfate co-localizes with a decorin-like protein, as indicated by immunohistochemical analysis. Low sulfated heparin/heparan sulfate-like glycans composed mainly of [4-α-L-IdoA-(2-OSO3)-1 → 4-α-D-GlcN(SO3)-1 (6-O-SO3)-1]n and [4-α-L-IdoA-(2-O-SO3)-1 → 4-α-D-GlcN(SO3)-1]n have also been described in ascidians. These heparin-like glycans occur in intracellular granules of oocyte assessory cells, named test cells, in circulating basophil-like cells in the hemolymph, and at the basement membrane of different ascidian organs. In this review, we present an overview of the structure, distribution, extracellular and intracellular localization of the sulfated glycosaminoglycans in different species and tissues of ascidians. Considering the phylogenetic position of the subphylum Tunicata in the phylum Chordata, a careful analysis of these data can reveal important information about how these glycans evolved from invertebrate to vertebrate animals.
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Nakamura J, Tetsukawa A, Fujiwara S. Chondroitin 4-O-sulfotransferases are required for cell adhesion and morphogenesis in the Ciona intestinalis embryo. Dev Growth Differ 2014; 57:58-67. [PMID: 25495122 DOI: 10.1111/dgd.12188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 10/20/2014] [Accepted: 10/30/2014] [Indexed: 11/30/2022]
Abstract
Chondroitin sulfate (CS) is a carbohydrate component of proteoglycans. Several types of sulfotransferases determine the pattern of CS sulfation, and thus regulate the biological functions of proteoglycans. The protochordate ascidians are the closest relatives of vertebrates, but the functions of their sulfotransferases have not been investigated. Here, we show that two chondroitin 4-O-sulfotransferases (C4STs) play important roles in the embryonic morphogenesis of the ascidian Ciona intestinalis. Ci-C4ST-like1 is predominantly expressed in the epidermis and muscle. Epidermal and muscle cells became spherical upon the injection of a Ci-C4ST-like1-specific morpholino oligo (MO), thus suggesting weakened cell adhesion. Co-injection of a Ci-C4ST-like1-expressing transgene rescued the phenotype, suggesting that the effects of the MO were specific. Ci-C4ST-like3 was expressed in the central nervous system, muscle, and mesenchyme. A specific MO appeared to affect cell adhesion in the epidermis and muscle. Convergent extension movement of notochordal cells was also impaired. Forced expression of Ci-C4ST-like3 restored normal morphogenesis, suggesting that the effects of the MO were specific. The present study suggests that Ci-C4ST-like1 and Ci-C4ST-like3 are required for cell adhesion mainly in the epidermis and muscle.
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Affiliation(s)
- Jun Nakamura
- Department of Applied Science, Kochi University, 2-5-1 Akebono-cho, Kochi-shi, Kochi, 780-8520, Japan
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Nakamura J, Yoshida K, Sasakura Y, Fujiwara S. Chondroitin 6-O-sulfotransferases are required for morphogenesis of the notochord in the ascidian embryo. Dev Dyn 2014; 243:1637-45. [PMID: 25298188 DOI: 10.1002/dvdy.24213] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 08/29/2014] [Accepted: 09/29/2014] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Chondroitin sulfate (CS) is a sulfated polysaccharide chain that binds to various core proteins to form proteoglycans. The amount and position of sulfate groups in CS are variable among different tissues, and are determined by specific sulfotransferases. Although the ascidians are the closest relatives of vertebrates, the functions of their sulfotransferases have not been studied. RESULTS The genome of the ascidian Ciona intestinalis contains eight genes encoding proteins similar to chondroitin 6-O-sulfotransferases (C6STs), which appear to have independently diverged in the ascidian lineage during evolution. Among them, Ci-C6ST-like1 and Ci-C6ST-like7 were predominantly expressed in the developing notochord. In addition, they were weakly expressed in the neural tube. The disruption of either one of them affected the convergent extension movement of notochordal cells. Presumptive notochord cells coming from both sides of the embryo did not intercalate. The results suggest that both of them are necessary. In some cases, the anterior neural tube failed to close. Forced expression of Ci-C6ST-like1 or Ci-C6ST-like7 in the notochord restored the normal intercalation of notochordal cells, indicating that the effects of morpholino oligos are specific. CONCLUSIONS Ci-C6ST-like1 and Ci-C6ST-like7 are required for the morphogenesis of the notochord in the ascidian embryo.
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Affiliation(s)
- Jun Nakamura
- Department of Applied Science, Kochi University, Kochi-shi, Kochi, Japan
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8
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Ciona intestinalis notochord as a new model to investigate the cellular and molecular mechanisms of tubulogenesis. Semin Cell Dev Biol 2012; 23:308-19. [PMID: 22465520 DOI: 10.1016/j.semcdb.2012.03.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 02/20/2012] [Accepted: 03/01/2012] [Indexed: 01/13/2023]
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Choi BD, Choi YJ. Nutraceutical functionalities of polysaccharides from marine invertebrates. ADVANCES IN FOOD AND NUTRITION RESEARCH 2012; 65:11-30. [PMID: 22361178 DOI: 10.1016/b978-0-12-416003-3.00002-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Many researchers are seeking functional materials from marine resources. These marine resources can be used as traditional food additives, and specifically, these are based on polysaccharides. To date, there is a big opportunity to develop new high-value added products with indispensable functional characteristics, which can be used in nutraceuticals either as additives or supplements. Also, a crossover in the pharmaceutical market may be established. Some glycosaminoglycans (GAGs) mimetic-type molecules are already being utilized in the field of nutrition as well as in the cosmetics industry. This chemical is used as a dietary supplement to maintain the structure and function of cartilages, for the relief of pain caused by osteoarthritic joints, and can also be used as an anti-inflammatory agent. Recently, in relation to the prevalence of mad cow disease and avian influenza, the production of GAGs from marine invertebrates offers new market opportunities as compared with that obtained from bovine or avian livestock.
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Affiliation(s)
- Byeong-Dae Choi
- Department of Seafood Science and Technology, Gyeongsang National University, Tongyeong, Korea.
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Gesteira TF, Coulson-Thomas VJ, Ogata FT, Farias EHC, Cavalheiro RP, de Lima MA, Cunha GLA, Nakayasu ES, Almeida IC, Toma L, Nader HB. A novel approach for the characterisation of proteoglycans and biosynthetic enzymes in a snail model. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:1862-9. [PMID: 21854878 DOI: 10.1016/j.bbapap.2011.07.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 07/13/2011] [Accepted: 07/29/2011] [Indexed: 10/17/2022]
Abstract
Proteoglycans encompass a heterogeneous group of glycoconjugates where proteins are substituted with linear, highly negatively charged glycosaminoglycan chains. Sulphated glycosaminoglycans are ubiquitous to the animal kingdom of the Eukarya domain. Information on the distribution and characterisation of proteoglycans in invertebrate tissues is limited and restricted to a few species. By the use of multidimensional protein identification technology and immunohistochemistry, this study shows for the first time the presence and tissue localisation of different proteoglycans, such as perlecan, aggrecan, and heparan sulphate proteoglycan, amongst others, in organs of the gastropoda Achatina fulica. Through a proteomic analysis of Golgi proteins and immunohistochemistry of tissue sections, we detected the machinery involved in glycosaminoglycan biosynthesis, related to polymer formation (polymerases), as well as secondary modifications (sulphation and uronic acid epimerization). Therefore, this work not only identifies both the proteoglycan core proteins and glycosaminoglycan biosynthetic enzymes in invertebrates but also provides a novel method for the study of glycosaminoglycan and proteoglycan evolution.
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Affiliation(s)
- Tarsis F Gesteira
- Departamento de Bioquímica, Universidade Federal de São Paulo, São Paulo, Brazil
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Yamada S, Sugahara K, Ozbek S. Evolution of glycosaminoglycans: Comparative biochemical study. Commun Integr Biol 2011; 4:150-8. [PMID: 21655428 DOI: 10.4161/cib.4.2.14547] [Citation(s) in RCA: 132] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 12/20/2010] [Indexed: 01/25/2023] Open
Abstract
Glycosaminoglycans, a major component of the extracellular matrix molecules in animal tissues, play important roles in various physiological events. Glycosaminoglycans are found in not only vertebrates but also many invertebrates, implying a conserved function in the animal kingdom. Here, we discuss the analysis of glycosaminoglycans in 11 invertebrate phyla focusing on structure as well as physiological functions elucidated in model organisms. Various sulfated structures of heparan sulfate are widely distributed from very primitive organisms to humans, indicating an involvement in fundamental biological processes. By contrast, chondroitin/dermatan sulfate from lower organisms is limited in its structural complexity and often associated with a particular function. The presence of hyaluronic acid outside of vertebrates has been reported only in a mollusk.
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Affiliation(s)
- Shuhei Yamada
- Laboratory of Proteoglycan Signaling and Therapeutics; Faculty of Advanced Life Science; Graduate School of Life Science; Hokkaido University; Sapporo, Japan
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12
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Kozlowski EO, Lima PC, Vicente CP, Lotufo T, Bao X, Sugahara K, Pavão MSG. Dermatan sulfate in tunicate phylogeny: order-specific sulfation pattern and the effect of [→4IdoA(2-sulfate)β-1→3GalNAc(4-sulfate)β-1→] motifs in dermatan sulfate on heparin cofactor II activity. BMC BIOCHEMISTRY 2011; 12:29. [PMID: 21619699 PMCID: PMC3127831 DOI: 10.1186/1471-2091-12-29] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 05/29/2011] [Indexed: 01/30/2023]
Abstract
Background Previously, we have reported the presence of highly sulfated dermatans in solitary ascidians from the orders Phlebobranchia (Phallusia nigra) and Stolidobranchia (Halocynthia pyriformis and Styela plicata). Despite the identical disaccharide backbone, consisting of [→4IdoA(2S)β-1→3GalNAcβ-1→], those polymers differ in the position of sulfation on the N-Acetyl galactosamine, which can occur at carbon 4 or 6. We have shown that position rather than degree of sulfation is important for heparin cofactor II activity. As a consequence, 2,4- and 2,6-sulfated dermatans have high and low heparin cofactor II activities, respectively. In the present study we extended the disaccharide analysis of ascidian dermatan sulfates to additional species of the orders Stolidobranchia (Herdmania pallida, Halocynthia roretzi) and Phlebobranchia (Ciona intestinalis), aiming to investigate how sulfation evolved within Tunicata. In addition, we analysed how heparin cofactor II activity responds to dermatan sulfates containing different proportions of 2,6- or 2,4-disulfated units. Results Disaccharide analyses indicated a high content of disulfated disaccharide units in the dermatan sulfates from both orders. However, the degree of sulfation decreased from Stolidobranchia to Phlebobranchia. While 76% of the disaccharide units in dermatan sulfates from stolidobranch ascidians are disulfated, 53% of disulfated disaccharides are found in dermatan sulfates from phlebobranch ascidians. Besides this notable difference in the sulfation degree, dermatan sulfates from phlebobranch ascidians contain mainly 2,6-sulfated disaccharides whereas dermatan sulfate from the stolidobranch ascidians contain mostly 2,4-sulfated disaccharides, suggesting that the biosynthesis of dermatan sulfates might be differently regulated during tunicates evolution. Changes in the position of sulfation on N-acetylgalactosamine in the disaccharide [→4IdoA(2-Sulfate)β-1→3GalNAcβ-1→] modulate heparin cofactor II activity of dermatan sulfate polymers. Thus, high and low heparin cofactor II stimulating activity is observed in 2,4-sulfated dermatan sulfates and 2,6-sulfated dermatan sulfates, respectively, confirming the clear correlation between the anticoagulant activities of dermatan sulfates and the presence of 2,4-sulfated units. Conclusions Our results indicate that in ascidian dermatan sulfates the position of sulfation on the GalNAc in the disaccharide [→4IdoA(2S)β-1→3GalNAcβ-1→] is directly related to the taxon and that the 6-O sulfation is a novelty apparently restricted to the Phlebobranchia. We also show that the increased content of [→4IdoA(2S)β-1→3GalNAc(4S)β-1→] disaccharide units in dermatan sulfates from Stolidobranchia accounts for the increased heparin cofactor II stimulating activity.
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Affiliation(s)
- Eliene O Kozlowski
- Laboratório de Bioquímica e Biologia Celular de Glicoconjugados, Hospital Universitário Clementino Fraga Filho and Programa de Glicobiologia, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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