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Pascual A, Vilardo ES, Taibo C, Sabio Y García J, Pomar RR. Bicaudal C is required for the function of the follicular epithelium during oogenesis in Rhodnius prolixus. Dev Genes Evol 2021; 231:33-45. [PMID: 33704576 DOI: 10.1007/s00427-021-00673-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 02/09/2021] [Indexed: 11/25/2022]
Abstract
The morphology and physiology of the oogenesis have been well studied in the vector of Chagas disease Rhodnius prolixus. However, the molecular interactions that regulate the process of egg formation, key for the reproductive cycle of the vector, is still largely unknown. In order to understand the molecular and cellular basis of the oogenesis, we examined the function of the gene Bicaudal C (BicC) during oogenesis and early development of R. prolixus. We show that R. prolixus BicC (Rp-BicC) gene is expressed in the germarium, with cytoplasmic distribution, as well as in the follicular epithelium of the developing oocytes. RNAi silencing of Rp-BicC resulted in sterile females that lay few, small, non-viable eggs. The ovaries are reduced in size and show a disarray of the follicular epithelium. This indicates that Rp-BicC has a central role in the regulation of oogenesis. Although the follicular cells are able to form the chorion, the uptake of vitelline by the oocytes is compromised. We show evidence that the polarity of the follicular epithelium and the endocytic pathway, which are crucial for the proper yolk deposition, are affected. This study provides insights into the molecular mechanisms underlying oocyte development and show that Rp-BicC is important for de developmental of the egg and, therefore, a key player in the reproduction of this insect.
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Affiliation(s)
- Agustina Pascual
- Centro de Bioinvestigaciones (UNNOBA-CICBA), CITNOBA (UNNOBA-CONICET), 2700, Pergamino, Buenos Aires, Argentina.
| | - Emiliano S Vilardo
- Centro Regional de Estudios Genómicos (Facultad de Ciencias Exactas, CREG-UNLP), 1900, La Plata, Buenos Aires, Argentina
| | - Catalina Taibo
- Laboratorio de Microscopia Integral (LIM), (CICVyA, INTA), 1686, Hurlingham, Buenos Aires, Argentina
| | - Julia Sabio Y García
- Laboratorio de Microscopia Integral (LIM), (CICVyA, INTA), 1686, Hurlingham, Buenos Aires, Argentina
| | - Rolando Rivera Pomar
- Centro de Bioinvestigaciones (UNNOBA-CICBA), CITNOBA (UNNOBA-CONICET), 2700, Pergamino, Buenos Aires, Argentina.
- Centro Regional de Estudios Genómicos (Facultad de Ciencias Exactas, CREG-UNLP), 1900, La Plata, Buenos Aires, Argentina.
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Souza-Ferreira PS, Moreira MF, Atella GC, Oliveira-Carvalho AL, Eizemberg R, Majerowicz D, Melo ACA, Zingali RB, Masuda H. Molecular characterization of Rhodnius prolixus' embryonic cuticle. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 51:89-100. [PMID: 24418313 DOI: 10.1016/j.ibmb.2013.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 11/05/2013] [Accepted: 12/09/2013] [Indexed: 06/03/2023]
Abstract
The embryonic cuticle (EC) of Rhodnius prolixus envelopes the entire body of the embryo during hatching and provides physical protection, allowing the embryo to pass through a narrow chorionic border. Most of the knowledge about the EC of insects is derived from studies on ultrastructure and secretion processes during embryonic development, and little is known about the molecular composition of this structure. We performed a comprehensive molecular characterization of the major components extracted from the EC of R. prolixus, and we discuss the role of the different molecules that were identified during the eclosion process. The results showed that, similar to the post-embryonic cuticles of insects, the EC of R. prolixus is primarily composed of carbohydrates (57%), lipids (19%), and proteins (8%). Considering only the carbohydrates, chitin is by far the major component (approximately 70%), and it is found primarily along the body of the EC. It is scarce or absent in its prolongations, which are composed of glycosaminoglycans. In addition to chitin, we also identified amino (15%), neutral (12%) and acidic (3%) carbohydrates in the EC of R. prolixus. In addition carbohydrates, we also identified neutral lipids (64.12%) and phospholipids (35.88%). Proteomic analysis detected 68 proteins (55 were identified and 13 are hypothetical proteins) using the sequences in the R. prolixus genome (http://www.vectorbase.org). Among these proteins, 8 out of 15 are associated with cuticle metabolism. These proteins are unequivocally cuticle proteins, and they have been described in other insects. Approximately 35% of the total proteins identified were classified as having a structural function. Chitin-binding protein, amino peptidase, amino acid oxidase, oxidoreductase, catalase and peroxidase are all proteins associated with cuticle metabolism. Proteins known to be cuticle constituents may be related to the function of the EC in assisting the insect during eclosion. To our knowledge, this is the first study to describe the global molecular composition of an EC in insects.
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Affiliation(s)
- Paula S Souza-Ferreira
- Universidade Federal do Rio de Janeiro, Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, 21941-902 Rio de Janeiro, RJ, Brazil
| | - Mônica F Moreira
- Universidade Federal do Rio de Janeiro, Instituto de Química, 21941-909 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, 21941-902 Rio de Janeiro, Brazil
| | - Geórgia C Atella
- Universidade Federal do Rio de Janeiro, Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, 21941-902 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, 21941-902 Rio de Janeiro, Brazil
| | - Ana Lúcia Oliveira-Carvalho
- Universidade Federal do Rio de Janeiro, Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, 21941-902 Rio de Janeiro, RJ, Brazil
| | - Roberto Eizemberg
- Universidade Federal do Rio de Janeiro, Escola de Educação Física e Desportos, 21941-599 Rio de Janeiro, RJ, Brazil
| | - David Majerowicz
- Universidade Federal do Rio de Janeiro, Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, 21941-902 Rio de Janeiro, RJ, Brazil
| | - Ana C A Melo
- Universidade Federal do Rio de Janeiro, Instituto de Química, 21941-909 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, 21941-902 Rio de Janeiro, Brazil
| | - Russolina B Zingali
- Universidade Federal do Rio de Janeiro, Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, 21941-902 Rio de Janeiro, RJ, Brazil
| | - Hatisaburo Masuda
- Universidade Federal do Rio de Janeiro, Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, 21941-902 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, 21941-902 Rio de Janeiro, Brazil.
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Entringer PF, Grillo LAM, Pontes EG, Machado EA, Gondim KC. Interaction of lipophorin with Rhodnius prolixus oocytes: biochemical properties and the importance of blood feeding. Mem Inst Oswaldo Cruz 2013; 108:836-44. [PMID: 24037104 PMCID: PMC3970653 DOI: 10.1590/0074-0276130129] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Indexed: 11/11/2023] Open
Abstract
Lipophorin (Lp) is the main haemolymphatic lipoprotein in insects and transports lipids between different organs. In adult females, lipophorin delivers lipids to growing oocytes. In this study, the interaction of this lipoprotein with the ovaries of Rhodnius prolixus was characterised using an oocyte membrane preparation and purified radiolabelled Lp (125I-Lp). Lp-specific binding to the oocyte membrane reached equilibrium after 40-60 min and when 125I-Lp was incubated with increasing amounts of membrane protein, corresponding increases in Lp binding were observed. The specific binding of Lp to the membrane preparation was a saturable process, with a K(d) of 7.1 ± 0.9 x 10-8M and a maximal binding capacity of 430 ± 40 ng 125I-Lp/µg of membrane protein. The binding was calcium independent and pH sensitive, reaching its maximum at pH 5.2-5.7. Suramin inhibited the binding interaction between Lp and the oocyte membranes, which was completely abolished at 0.5 mM suramin. The oocyte membrane preparation from R. prolixus also showed binding to Lp from Manduca sexta. When Lp was fluorescently labelled and injected into vitellogenic females, the level of Lp-oocyte binding was much higher in females that were fed whole blood than in those fed blood plasma.
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Affiliation(s)
- Petter Franco Entringer
- Instituto de Bioquímica Médica
- Laboratório de Imunoparasitologia, Centro de Pesquisas Gonçalo Moniz-Fiocruz, Salvador, BA, Brasil
| | | | - Emerson Guedes Pontes
- Instituto de Bioquímica Médica
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brasil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular
| | - Ednildo Alcântara Machado
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular
| | - Katia Calp Gondim
- Instituto de Bioquímica Médica
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular
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Involvement of sulfated glycosaminoglycans on the development and attachment of Trypanosoma cruzi to the luminal midgut surface in the vector, Rhodnius prolixus. Parasitology 2011; 138:1870-7. [DOI: 10.1017/s0031182011001521] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
SUMMARYIn the present study, we investigated the involvement of sulfated glycosaminoglycans in both the in vivo development and adhesion of T. cruzi epimastigotes to the luminal surface of the digestive tract of the insect vector, Rhodnius prolixus. Pre-incubation of T. cruzi, Dm 28c epimastigotes with heparin, chondroitin 4-sulfate, chondroitin 6-sulfate or protamine chloridrate inhibited in vitro attachment of parasites to the insect midgut. Enzymatic removal of heparan sulfate moieties by heparinase I or of chondroitin sulfate moieties by chondroitinase AC from the insect posterior midgut abolished epimastigote attachment in vitro. These treatments also reduced the labelling of anionic sites exposed at the luminal surface of the perimicrovillar membranes in the triatomine midgut epithelial cells. Inclusion of chondroitin 4-sulfate or chondroitin 6-sulfate and to a lesser extent, heparin, in the T. cruzi-infected bloodmeal inhibited the establishment of parasites in R. prolixus. These observations indicate that sulfated glycosaminoglycans are one of the determinants for both adhesion of the T. cruzi epimastigotes to the posterior midgut epithelial cells of the triatomine and the parasite infection in the insect vector, R. prolixus.
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Effects of platelet-activating factor on the interaction of Trypanosoma cruzi with Rhodnius prolixus. Parasitol Res 2010; 108:1473-8. [DOI: 10.1007/s00436-010-2194-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Accepted: 11/26/2010] [Indexed: 10/18/2022]
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Alborn HT, Hansen TV, Jones TH, Bennett DC, Tumlinson JH, Schmelz EA, Teal PEA. Disulfooxy fatty acids from the American bird grasshopper Schistocerca americana, elicitors of plant volatiles. Proc Natl Acad Sci U S A 2007; 104:12976-81. [PMID: 17664416 PMCID: PMC1941812 DOI: 10.1073/pnas.0705947104] [Citation(s) in RCA: 177] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A previously unidentified class of compounds has been isolated from the regurgitant of the grasshopper species Schistocerca americana. These compounds (named here "caeliferins") are composed of saturated and monounsaturated sulfated alpha-hydroxy fatty acids in which the omega-carbon is functionalized with either a sulfated hydroxyl or a carboxyl conjugated to glycine via an amide bond. The regurgitant contains a series of these compounds with fatty acid chains of 15-20 carbons and in varying proportions. Of these, the 16-carbon analogs are predominant and are also most active in inducing release of volatile organic compounds when applied to damaged leaves of corn seedlings. Caeliferins are nonlepidopteran elicitors identified in insect herbivores. This adds a category of insect herbivore-produced elicitors of plant responses, providing further evidence of the ability of plants to detect and respond to a broad range of insect herbivore-produced compounds.
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Affiliation(s)
- Hans T. Alborn
- *Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, 1600/1700 Southwest 23rd Drive, Gainesville, FL 32608
- To whom correspondence may be addressed. E-mail: or
| | - Trond V. Hansen
- *Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, 1600/1700 Southwest 23rd Drive, Gainesville, FL 32608
| | - Tappey H. Jones
- Department of Chemistry, Virginia Military Institute, Lexington, VA 24450; and
| | - Derrick C. Bennett
- *Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, 1600/1700 Southwest 23rd Drive, Gainesville, FL 32608
| | - James H. Tumlinson
- Department of Entomology, Center for Chemical Ecology, 111 Chemical Ecology Laboratory, University Park, PA 16802
- To whom correspondence may be addressed. E-mail: or
| | - Eric A. Schmelz
- *Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, 1600/1700 Southwest 23rd Drive, Gainesville, FL 32608
| | - Peter E. A. Teal
- *Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, 1600/1700 Southwest 23rd Drive, Gainesville, FL 32608
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dos Santos AVF, Onofre GR, Oliveira DMP, Machado EA, Allodi S, Silva LCF. Heparan sulfate is the main sulfated glycosaminoglycan species in internal organs of the male cockroach, Periplaneta americana. Micron 2006; 37:41-6. [PMID: 16169237 DOI: 10.1016/j.micron.2005.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Revised: 07/20/2005] [Accepted: 07/21/2005] [Indexed: 10/25/2022]
Abstract
Sulfated glycosaminoglycans (GAGs) were isolated and characterized in thoracic muscle, fat body, whole digestive tract (stomach+intestine) and reproductive tract of adult male cockroaches, Periplaneta americana. Heparan sulfate (HS) was the predominant sulfated GAG species in the tissues analyzed, corresponding to more than 90% of the total sulfated GAG content. In both the thoracic muscle and fat body it was the only sulfated GAG species detected. We also determined the location of sulfated GAGs in most of these organs by histochemical analysis using 1,9-dimethylmethylene blue. In the thoracic muscle, sulfated GAG metachromatic staining was detected only in the connective tissue that surrounds the muscle bundles or fascicles. In the intestinal tract, metachromatic staining was observed in both epithelial and lining columnar cells. Only spermatozoa presented metachromatic material in the male reproductive tract. Since, HS corresponds to 90-100% of total sulfated GAGs in these tissues, the metachromatic staining specifically reflects the location of this particular sulfated GAG in these organs. In conclusion, the present study extends previous observations on the GAG composition in cockroaches providing new information on the tissue distribution and location of HS in several internal organs of adult males of the cockroach P. americana.
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Affiliation(s)
- Andre V F dos Santos
- Laboratório de Tecido Conjuntivo, Hospital Universitário Clementino Fraga Filho, Caixa Postal 68041, Rio de Janeiro, Brazil
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8
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Souza MLS, Sarquis O, Gomes TF, Moreira MF, Lima MM, Silva LCF. Sulfated glycosaminoglycans in two hematophagous arthropod vectors of Chagas disease, Triatoma brasiliensis and Rhodnius prolixus (Hemiptera: Reduviidae). Comp Biochem Physiol B Biochem Mol Biol 2004; 139:631-5. [PMID: 15581795 DOI: 10.1016/j.cbpc.2004.08.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2004] [Revised: 08/03/2004] [Accepted: 08/04/2004] [Indexed: 11/22/2022]
Abstract
The characterization of sulfated glycosaminoglycans (GAGs) in hematophagous arthropod vectors in general has been limited, with the exception of the studies in the triatomine Rhodnius prolixus. Heparan sulfate (HS) and chondroitin sulfate (CS) were previously identified and structurally characterized in extracts of whole bodies of fourth instar larvae of R. prolixus. Recently, we showed the expression of these two sulfated GAGs in specific body tissues of adult males and females and in embryos of R. prolixus. In the present work, we identified and compared the sulfated GAG composition in specific tissues of adult insects and in embryos of another triatomine species, Triatoma brasiliensis. Sulfated GAGs were isolated from the fat body, intestinal tract, and the reproductive tracts of adult insects and from embryos. Only HS and CS were found in the tissues analyzed. The present results extend the initial observations on the sulfated GAG composition in R. prolixus by showing that these molecules are widely distributed among internal organs of triatomines. These observations may be useful for future investigations aiming to evaluate the possible implication of these compounds in physiological events that take place in a specific organ(s) in these insects.
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Affiliation(s)
- Maisa L S Souza
- Laboratório de Tecido Conjuntivo, Hospital Universitário Clementino Fraga Filho, Brazil
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Vieira TCRG, Costa-Filho A, Salgado NC, Allodi S, Valente AP, Nasciutti LE, Silva LCF. Acharan sulfate, the new glycosaminoglycan from Achatina fulica Bowdich 1822. Structural heterogeneity, metabolic labeling and localization in the body, mucus and the organic shell matrix. ACTA ACUST UNITED AC 2004; 271:845-54. [PMID: 14764101 DOI: 10.1111/j.1432-1033.2004.03989.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Acharan sulfate, a recently discovered glycosaminoglycan isolated from Achatina fulica, has a major disaccharide repeating unit of -->4)-2-acetyl,2-deoxy-alpha-d-glucopyranose(1-->4)-2-sulfo-alpha-l-idopyranosyluronic acid (1-->, making it structurally related to both heparin and heparan sulfate. It has been suggested that this glycosaminoglycan is polydisperse, with an average molecular mass of 29 kDa and known minor disaccharide sequence variants containing unsulfated iduronic acid. Acharan sulfate was found to be located in the body of this species using alcian blue staining and it was suggested to be the main constituent of the mucus. In the present work, we provide further information on the structure and compartmental distribution of acharan sulfate in the snail body. Different populations of acharan sulfate presenting charge and/or molecular mass heterogeneities were isolated from the whole body, as well as from mucus and from the organic shell matrix. A minor glycosaminoglycan fraction susceptible to degradation by nitrous acid was also purified from the snail body, suggesting the presence of N-sulfated glycosaminoglycan molecules. In addition, we demonstrate the in vivo metabolic labeling of acharan sulfate in the snail body after a meal supplemented with [35S]free sulfate. This simple approach might be applied to the study of acharan sulfate biosynthesis. Finally, we developed histochemical assays to localize acharan sulfate in the snail body by metachromatic staining and by histoautoradiography following metabolic radiolabeling with [35S]sulfate. Our results show that acharan sulfate is widely distributed among several organs.
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Affiliation(s)
- Tuane C R G Vieira
- Laboratório de Tecido Conjuntivo, Hospital Universitário Clementino Fraga Filho, Brazil
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10
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Costa-Filho A, Souza MLS, Martins RCL, dos Santos AVF, Silva GV, Comaru MW, Moreira MF, Atella GC, Allodi S, Nasciutti LE, Masuda H, Silva LCF. Identification and tissue-specific distribution of sulfated glycosaminoglycans in the blood-sucking bug Rhodnius prolixus (Linnaeus). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2004; 34:251-260. [PMID: 14871621 DOI: 10.1016/j.ibmb.2003.10.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2003] [Revised: 10/21/2003] [Accepted: 10/21/2003] [Indexed: 05/24/2023]
Abstract
We have previously characterized heparan sulfate (HS) as the major ovarian sulfated glycosaminoglycan (GAG) in females of Rhodnius prolixus, while chondroitin sulfate (CS) was the minor component. Using histochemical procedures we found that GAGs were concentrated in the ovarian tissue but not found inside the oocytes. Here, we extend our initial observations of GAG expression in R. prolixus by characterizing these molecules in other organs: the fat body, intestinal tract, and the reproductive tracts. Only HS and CS were found in the three organs analyzed, however CS was the major GAG species in these tissues. We also determined the compartmental distribution of GAGs in these organs by histochemical analysis using 1,9-dimethylmethylene blue, and evaluated the specific distribution of CS within both male and female reproductive tracts by immunohistochemistry using an anti-CS antibody. We also determined the GAG composition in eggs at days 0 and 6 of embryonic development. Only HS and CS were found in eggs at day 6, while no sulfated GAGs were detected at day 0. Our results demonstrate that HS and CS are the only sulfated GAG species expressed in the fat body and in the intestinal and reproductive tracts of Rhodnius male and female adults. Both sulfated GAGs were also identified in Rhodnius embryos. Altogether, these results show no qualitative differences in the sulfated GAG composition regarding tissue-specific or development-specific distribution.
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Affiliation(s)
- Adilson Costa-Filho
- Laboratório de Tecido Conjuntivo, Hospital Universitário Clementino Fraga Filho, Rio de Janeiro, Brazil
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11
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Onofre GR, Lara FA, Oliveira PL, Silva LCF. Heparan sulfate glycosaminoglycan expression in the intestinal tract and ovary of fully engorged adult females of the cattle tick Boophilus microplus and in their laid eggs. Mol Biochem Parasitol 2003; 130:163-6. [PMID: 12946856 DOI: 10.1016/s0166-6851(03)00169-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Glaucia R Onofre
- Laboratório de Tecido Conjuntivo, Hospital Universitário Clementino Fraga Filho, Rio de Janeiro, Brazil
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12
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Grillo LAM, Pontes EG, Gondim KC. Lipophorin interaction with the midgut of Rhodnius prolixus: characterization and changes in binding capacity. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2003; 33:429-438. [PMID: 12650691 DOI: 10.1016/s0965-1748(03)00007-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Several classes of lipids are transported in insect hemolymph by lipophorin, a major hemolymphatic lipoprotein. The binding of lipophorin to the midgut of the hematophagous insect Rhodnius prolixus was characterized in a midgut membrane preparation, using purified lipophorin radiolabelled in protein moiety ((125)I-HDLp). Lipophorin specific binding to membranes achieved equilibrium after 30-40 min, was sensitive to pH, and was maximal at pH 7.0. In the presence of increasing concentrations of membrane protein, corresponding increases in lipophorin binding were observed. The specific binding of lipophorin to the membrane preparation was a saturable process, with K(d)=0.9+/-0.06 x 10(-7) M and a maximal binding capacity of 70+/-11 ng lipophorin/microg of membrane protein. Lipophorin binding did not depend on calcium, but it was affected by ionic strength and was inhibited in the presence of increasing salt concentrations. Suramin interfered with lipophorin binding to the midgut receptor, and it was abolished in the presence of 2 mM suramin, but at concentrations between 0.05 and 0.2 mM it was slightly increased. Condroitin 4-sulfate also affected lipophorin binding, which was reduced to 56% of control. Pre-incubation of the midgut membrane preparation with trypsin or at high temperature inhibited binding. Midgut capacity to bind lipophorin varied at different days after blood meal. It was highest at second day after feeding, and then gradually decreased.
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Affiliation(s)
- L A M Grillo
- Departamento de Bioquímica Médica, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil 21941-590
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Passos CO, Onofre GR, Martins RCL, Graff DL, Pagani EA, Sodré CT, Silva LCF. Composition of urinary glycosaminoglycans in a patient with relapsing polychondritis. Clin Biochem 2002; 35:377-81. [PMID: 12270767 DOI: 10.1016/s0009-9120(02)00335-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Several investigators have reported an increase in urinary glycosaminoglycans (GAGs) in patients with relapsing polychondritis (RP). The aim of this investigation is to analyze the composition and structure of urinary GAGs from a Brazilian patient with RP. DESIGN AND METHODS The identification and structural analyses of the GAGs were made by electrophoresis and degradation with specific enzymes and identification of their disaccharides products by HPLC chromatography. RESULTS The disaccharide products formed from RP urinary chondroitin sulfate (CS) by action of chondroitin ABC lyase showed a substantial relative increase of nonsulfated disaccharides with a relative decrease of 6-sulfated disaccharides compared to control subjects. In addition, a significant change of the ratio of CS and heparan sulfate was also observed in the RP patient. CONCLUSION The RP patient analyzed has shown a structural anomaly of the urinary CS and this may contribute to the diagnosis of this disease.
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Affiliation(s)
- Claudia O Passos
- Laboratório de Tecido Conjuntivo, Hospital Universitário Clementino Fraga Filho, Rio de Janeiro, Brazil
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