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Krishnan N. Endocrine Control of Lipid Metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024. [PMID: 38782869 DOI: 10.1007/5584_2024_807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Lipids are essential in insects and play pleiotropic roles in energy storage, serving as a fuel for energy-driven processes such as reproduction, growth, development, locomotion, flight, starvation response, and diapause induction, maintenance, and termination. Lipids also play fundamental roles in signal transduction, hormone synthesis, forming components of the cell membrane, and thus are essential for maintenance of normal life functions. In insects, the neuroendocrine system serves as a master regulator of most life activities, including growth and development. It is thus important to pay particular attention to the regulation of lipid metabolism through the endocrine system, especially when considering the involvement of peptide hormones in the processes of lipogenesis and lipolysis. In insects, there are several lipogenic and lipolytic hormones that are involved in lipid metabolism such as insulin-like peptides (ILPs), adipokinetic hormone (AKH), 20-hydroxyecdysone (20-HE), juvenile hormone (JH), and serotonin. Other neuropeptides such as diapause hormone-pheromone biosynthesis activating neuropeptide (DH-PBAN), CCHamide-2, short neuropeptide F, and the cytokines Unpaired 1 and 2 may play a role in inducing lipogenesis. On the other hand, neuropeptides such as neuropeptide F, allatostatin-A, corazonin, leukokinin, tachykinins, limostatins, and insulin-like growth factor (ILP6) stimulate lipolysis. This chapter briefly discusses the current knowledge of the endocrine regulation of lipid metabolism in insects that could be utilized to reveal differences between insects and mammalian lipid metabolism which may help understand human diseases associated with dysregulation of lipid metabolism. Physiological similarities of insects to mammals make them valuable model systems for studying human diseases characterized by disrupted lipid metabolism, including conditions like diabetes, obesity, arteriosclerosis, and various metabolic syndromes.
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Affiliation(s)
- Natraj Krishnan
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS, USA.
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2
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Santos-Araujo S, Gomes F, Carvalho-Kelly LF, Meyer-Fernandes JR, Gondim KC, Ramos I. In the fed state, autophagy plays a crucial role in assisting the insect vector Rhodnius prolixus mobilize TAG reserves under forced flight activity. Front Physiol 2024; 15:1352766. [PMID: 38725570 PMCID: PMC11079428 DOI: 10.3389/fphys.2024.1352766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 02/09/2024] [Indexed: 05/12/2024] Open
Abstract
Autophagy is a cellular degradation pathway mediated by highly conserved autophagy-related genes (Atgs). In our previous work, we showed that inhibiting autophagy under starvation conditions leads to significant physiological changes in the insect vector of Chagas disease Rhodnius prolixus; these changes include triacylglycerol (TAG) retention in the fat body, reduced survival and impaired locomotion and flight capabilities. Herein, because it is known that autophagy can be modulated in response to various stimuli, we further investigated the role of autophagy in the fed state, following blood feeding. Interestingly, the primary indicator for the presence of autophagosomes, the lipidated form of Atg8 (Atg8-II), displayed 20%-50% higher autophagic activation in the first 2 weeks after feeding compared to the third week when digestion was complete. Despite the elevated detection of autophagosomes, RNAi-mediated suppression of RpAtg6 and RpAtg8 did not cause substantial changes in TAG or protein levels in the fat body or the flight muscle during blood digestion. We also found that knockdown of RpAtg6 and RpAtg8 led to modest modulations in the gene expression of essential enzymes involved in lipid metabolism and did not significantly stimulate the expression of the chaperones BiP and PDI, which are the main effectors of the unfolded protein response. These findings indicate that impaired autophagy leads to slight disturbances in lipid metabolism and general cell proteostasis. However, the ability of insects to fly during forced flight until exhaustion was reduced by 60% after knockdown of RpAtg6 and RpAtg8. This change was accompanied by TAG and protein increases as well as decreased ATP levels in the fat body and flight muscle, indicating that autophagy during digestion, i.e., under fed conditions, is necessary to sustain high-performance activity.
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Affiliation(s)
- Samara Santos-Araujo
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fabio Gomes
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Katia C. Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Isabela Ramos
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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3
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Reynoso-Ducoing OA, González-Rete B, Díaz E, Candelas-Otero FN, López-Aviña JA, Cabrera-Bravo M, Bucio-Torres MI, Torres-Gutiérrez E, Salazar-Schettino PM. Expression of Proteins, Glycoproteins, and Transcripts in the Guts of Fasting, Fed, and Trypanosoma cruzi-Infected Triatomines: A Systematic Review. Pathogens 2023; 12:1124. [PMID: 37764932 PMCID: PMC10534304 DOI: 10.3390/pathogens12091124] [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: 07/18/2023] [Revised: 08/27/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Chagas disease is caused by the hemoflagellate protozoan Trypanosoma cruzi. The main transmission mechanism for the parasite in endemic areas is contact with the feces of an infected triatomine bug. Part of the life cycle of T. cruzi occurs in the digestive tract of triatomines, where vector and parasite engage in a close interaction at a proteomic-molecular level. This interaction triggers replication and differentiation processes in the parasite that can affect its infectivity for the vertebrate host. With the aim of compiling and analyzing information from indexed publications on transcripts, proteins, and glycoproteins in the guts of fasting, fed, and T. cruzi-infected triatomines in the period 2000-2022, a systematic review was conducted following the PRISMA guidelines. Fifty-five original research articles retrieved from PubMed and ScienceDirect were selected; forty-four papers reported 1-26,946 transcripts, and twenty-one studies described 1-2603 peptides/proteins.
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Affiliation(s)
| | | | | | | | | | | | | | - Elia Torres-Gutiérrez
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Coyoacán, México City 04510, Mexico; (O.A.R.-D.); (B.G.-R.); (E.D.); (F.N.C.-O.); (J.A.L.-A.); (M.C.-B.); (M.I.B.-T.)
| | - Paz María Salazar-Schettino
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Coyoacán, México City 04510, Mexico; (O.A.R.-D.); (B.G.-R.); (E.D.); (F.N.C.-O.); (J.A.L.-A.); (M.C.-B.); (M.I.B.-T.)
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4
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Xiang L, Niu K, Peng Y, Zhang X, Li X, Ye R, Yu G, Ye G, Xiang H, Song Q, Feng Q. DNA G-quadruplex structure participates in regulation of lipid metabolism through acyl-CoA binding protein. Nucleic Acids Res 2022; 50:6953-6967. [PMID: 35748856 PMCID: PMC9262599 DOI: 10.1093/nar/gkac527] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/31/2022] [Accepted: 06/06/2022] [Indexed: 12/24/2022] Open
Abstract
G-quadruplex structure (G4) is a type of DNA secondary structure that widely exists in the genomes of many organisms. G4s are believed to participate in multiple biological processes. Acyl-CoA binding protein (ACBP), a ubiquitously expressed and highly conserved protein in eukaryotic cells, plays important roles in lipid metabolism by transporting and protecting acyl-CoA esters. Here, we report the functional identification of a G4 in the promoter of the ACBP gene in silkworm and human cancer cells. We found that G4 exists as a conserved element in the promoters of ACBP genes in invertebrates and vertebrates. The BmACBP G4 bound with G4-binding protein LARK regulated BmACBP transcription, which was blocked by the G4 stabilizer pyridostatin (PDS) and G4 antisense oligonucleotides. PDS treatment with fifth instar silkworm larvae decreased the BmACBP expression and triacylglycerides (TAG) level, resulting in reductions in fat body mass, body size and weight and growth and metamorphic rates. PDS treatment and knocking out of the HsACBP G4 in human hepatic adenocarcinoma HepG2 cells inhibited the expression of HsACBP and decreased the TAG level and cell proliferation. Altogether, our findings suggest that G4 of the ACBP genes is involved in regulation of lipid metabolism processes in invertebrates and vertebrates.
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Affiliation(s)
- Lijun Xiang
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Kangkang Niu
- Correspondence may also be addressed to Kangkang Niu. Tel: +86 20 85215291; Fax: +86 20 85215291;
| | - Yuling Peng
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Xiaojuan Zhang
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Xiaoyu Li
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Ruoqi Ye
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Guoxing Yu
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Guojun Ye
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Hui Xiang
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Qisheng Song
- Division of Plant Sciences and Technology, University of Missouri, Columbia, MO 65211, USA
| | - Qili Feng
- To whom correspondence should be addressed. Tel: +86 20 85215291; Fax: +86 20 85215291;
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Saraiva FB, Alves-Bezerra M, Majerowicz D, Paes-Vieira L, Braz V, Almeida MGMD, Meyer-Fernandes JR, Gondim KC. Blood meal drives de novo lipogenesis in the fat body of Rhodnius prolixus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2021; 133:103511. [PMID: 33278628 DOI: 10.1016/j.ibmb.2020.103511] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/18/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
In insects, lipids are stored in the fat body mainly as triacylglycerol. Lipids can be directly provided by digestion and incorporated from the hemolymph, or synthesized de novo from other substrates such as carbohydrates and amino acids. The first step in de novo lipid synthesis is catalyzed by acetyl-CoA carboxylase (ACC), which carboxylates acetyl-CoA to form malonyl-CoA. Rhodnius prolixus is a hematophagous insect vector of Chagas disease and feeds exclusively on large and infrequent blood meals. Adult females slowly digest the blood and concomitantly accumulate lipids in the fat body. In this study, we investigated the regulation of R. prolixus ACC (RhoprACC) expression and de novo lipogenesis activity in adult females at different nutritional and metabolic conditions. A phylogenetic analysis showed that insects, similar to other arthropods and unlike vertebrate animals, have only one ACC gene. In females on the fourth day after a blood meal, RhoprACC transcript levels were similar in the anterior and posterior midgut, fat body and ovary and higher in the flight muscles. In the fat body, gene expression was higher in fasted females and decreased after a blood meal. In the posterior midgut it increased after feeding, and no variation was observed in the flight muscle. RhoprACC protein content analysis of the fat body revealed a profile similar to the gene expression, with higher protein contents before feeding and in the first two days after a blood meal. Radiolabeled acetate was used to follow de novo lipid synthesis in the fat body and it was incorporated mainly into triacylglycerol, diacylglycerol and phospholipids. This lipogenic activity was inhibited by soraphen A, an ACC inhibitor, and it varied according to the insect metabolic status. De novo lipogenesis was very low in starved females and increased during the initial days after a blood meal. The flight muscles had a very low capacity to synthesize lipids when compared to the fat body. Radiolabeled leucine was also used as a substrate for de novo lipogenesis and the same lipid classes were formed. In conclusion, our results indicate that the blood meal induces the utilization of diet-derived amino acids by de novo lipogenesis in the fat body, and that the control of this activity does not occur at the RhoprACC gene or protein expression level.
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Affiliation(s)
- Felipe B Saraiva
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Brazil
| | - Michele Alves-Bezerra
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - David Majerowicz
- Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Brazil
| | - Lisvane Paes-Vieira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Brazil
| | - Valdir Braz
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Brazil
| | - Muriel G M D Almeida
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Brazil
| | | | - Katia C Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Brazil.
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Santos-Araujo S, Bomfim L, Araripe LO, Bruno R, Ramos I, Gondim KC. Silencing of ATG6 and ATG8 promotes increased levels of triacylglycerol (TAG) in the fat body during prolonged starvation periods in the Chagas disease vector Rhodnius prolixus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 127:103484. [PMID: 33022370 DOI: 10.1016/j.ibmb.2020.103484] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 09/18/2020] [Accepted: 09/29/2020] [Indexed: 06/11/2023]
Abstract
Rhodnius prolixus is an obligatorily hematophagous insect known as an important vector of Chagas disease. Autophagy is a conserved cellular mechanism that acts in response to nutrient starvation, where components of the cytoplasm are sequestered by a double membrane organelle, named autophagosome, which is targeted to fuse with the lysosome for degradation. Lipophagy is the process of lipid degradation by selective autophagy, where autophagosomes sequester lipid droplets and degrade triacylglycerol (TAG) generating free fatty acids for β-oxidation. Here, two essential genes of the autophagic pathway, Atg6/Beclin1 (RpAtg6) and Atg8/LC3 (RpAtg8), were silenced and the storage of lipids during starvation in Rhodnius prolixus was monitored. We found that RNAi knockdown of both RpAtg6 and RpAtg8 resulted in higher levels of TAG in the fat body and the flight muscle, 24 days after the blood meal, as well as a larger average diameter of the lipid droplets in the fat body, as seen by Nile Red staining under the confocal fluorescence microscope. Silenced starved insects had lower survival rates when compared to control insects. Accordingly, when examined during the starvation period for monitored activity, silenced insects had lower spontaneous locomotor activity and lower forced flight rates. Furthermore, we found that some genes involved in lipid metabolism had their expression levels altered in silenced insects, such as the Brummer lipase (down regulated) and the adipokinetic hormone receptor (up regulated), suggesting that, as previously observed in mammalian models, the autophagy and neutral lipolysis machineries are interconnected at the transcriptional level. Altogether, our data indicate that autophagy in the fat body is important to allow insects to mobilize energy from lipid stores.
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Affiliation(s)
- Samara Santos-Araujo
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Brazil
| | - Larissa Bomfim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Brazil
| | - Luciana O Araripe
- Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz. Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular - INCT-EM/CNPq, Brazil
| | - Rafaela Bruno
- Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz. Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular - INCT-EM/CNPq, Brazil
| | - Isabela Ramos
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular - INCT-EM/CNPq, Brazil
| | - Katia C Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular - INCT-EM/CNPq, Brazil.
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7
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Leyria J, Orchard I, Lange AB. What happens after a blood meal? A transcriptome analysis of the main tissues involved in egg production in Rhodnius prolixus, an insect vector of Chagas disease. PLoS Negl Trop Dis 2020; 14:e0008516. [PMID: 33057354 PMCID: PMC7591069 DOI: 10.1371/journal.pntd.0008516] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/27/2020] [Accepted: 09/23/2020] [Indexed: 12/17/2022] Open
Abstract
The blood-sucking hemipteran Rhodnius prolixus is a vector of Chagas disease, one of the most neglected tropical diseases affecting several million people, mostly in Latin America. The blood meal is an event with a high epidemiological impact since adult mated females feed several times, with each meal resulting in a bout of egg laying, and thereby the production of hundreds of offspring. By means of RNA-Sequencing (RNA-Seq) we have examined how a blood meal influences mRNA expression in the central nervous system (CNS), fat body and ovaries in order to promote egg production, focusing on tissue-specific responses under controlled nutritional conditions. We illustrate the cross talk between reproduction and a) lipids, proteins and trehalose metabolism, b) neuropeptide and neurohormonal signaling, and c) the immune system. Overall, our molecular evaluation confirms and supports previous studies and provides an invaluable molecular resource for future investigations on different tissues involved in successful reproductive events. These analyses serve as a starting point for new investigations, increasing the chances of developing novel strategies for vector population control by translational research, with less impact on the environment and more specificity for a particular organism.
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Affiliation(s)
- Jimena Leyria
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Ian Orchard
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Angela B. Lange
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
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8
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Toprak U, Hegedus D, Doğan C, Güney G. A journey into the world of insect lipid metabolism. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2020; 104:e21682. [PMID: 32335968 DOI: 10.1002/arch.21682] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/08/2020] [Accepted: 04/08/2020] [Indexed: 06/11/2023]
Abstract
Lipid metabolism is fundamental to life. In insects, it is critical, during reproduction, flight, starvation, and diapause. The coordination center for insect lipid metabolism is the fat body, which is analogous to the vertebrate adipose tissue and liver. Fat body contains various different cell types; however, adipocytes and oenocytes are the primary cells related to lipid metabolism. Lipid metabolism starts with the hydrolysis of dietary lipids, absorption of lipid monomers, followed by lipid transport from midgut to the fat body, lipogenesis or lipolysis in the fat body, and lipid transport from fat body to other sites demanding energy. Lipid metabolism is under the control of hormones, transcription factors, secondary messengers and posttranscriptional modifications. Primarily, lipogenesis is under the control of insulin-like peptides that activate lipogenic transcription factors, such as sterol regulatory element-binding proteins, whereas lipolysis is coordinated by the adipokinetic hormone that activates lipolytic transcription factors, such as forkhead box class O and cAMP-response element-binding protein. Calcium is the primary-secondary messenger affecting lipid metabolism and has different outcomes depending on the site of lipogenesis or lipolysis. Phosphorylation is central to lipid metabolism and multiple phosphorylases are involved in lipid accumulation or hydrolysis. Although most of the knowledge of insect lipid metabolism comes from the studies on the model Drosophila; other insects, in particular those with obligatory or facultative diapause, also have great potential to study lipid metabolism. The use of these models would significantly improve our knowledge of insect lipid metabolism.
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Affiliation(s)
- Umut Toprak
- Molecular Entomology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ankara University, Ankara, Turkey
| | - Dwayne Hegedus
- Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, Saskatchewan, Canada
- Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Cansu Doğan
- Molecular Entomology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ankara University, Ankara, Turkey
| | - Gözde Güney
- Molecular Entomology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ankara University, Ankara, Turkey
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9
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Toprak U. The Role of Peptide Hormones in Insect Lipid Metabolism. Front Physiol 2020; 11:434. [PMID: 32457651 PMCID: PMC7221030 DOI: 10.3389/fphys.2020.00434] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/08/2020] [Indexed: 12/21/2022] Open
Abstract
Lipids are the primary storage molecules and an essential source of energy in insects during reproduction, prolonged periods of flight, starvation, and diapause. The coordination center for insect lipid metabolism is the fat body, which is analogous to the vertebrate adipose tissue and liver. The fat body is primarily composed of adipocytes, which accumulate triacylglycerols in intracellular lipid droplets. Genomics and proteomics, together with functional analyses, such as RNA interference and CRISPR/Cas9-targeted genome editing, identified various genes involved in lipid metabolism and elucidated their functions. However, the endocrine control of insect lipid metabolism, in particular the roles of peptide hormones in lipogenesis and lipolysis are relatively less-known topics. In the current review, the neuropeptides that directly or indirectly affect insect lipid metabolism are introduced. The primary lipolytic and lipogenic peptide hormones are adipokinetic hormone and the brain insulin-like peptides (ILP2, ILP3, ILP5). Other neuropeptides, such as insulin-growth factor ILP6, neuropeptide F, allatostatin-A, corazonin, leucokinin, tachykinins and limostatin, might stimulate lipolysis, while diapause hormone-pheromone biosynthesis activating neuropeptide, short neuropeptide F, CCHamide-2, and the cytokines Unpaired 1 and Unpaired 2 might induce lipogenesis. Most of these peptides interact with one another, but mostly with insulin signaling, and therefore affect lipid metabolism indirectly. Peptide hormones are also involved in lipid metabolism during reproduction, flight, diapause, starvation, infections and immunity; these are also highlighted. The review concludes with a discussion of the potential of lipid metabolism-related peptide hormones in pest management.
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Affiliation(s)
- Umut Toprak
- Molecular Entomology Lab., Department of Plant Protection Ankara, Faculty of Agriculture, Ankara University, Ankara, Turkey
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10
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Almeida MGMD, Arêdes DS, Majerowicz D, Færgeman NJ, Knudsen J, Gondim KC. Expression of acyl-CoA-binding protein 5 from Rhodnius prolixus and its inhibition by RNA interference. PLoS One 2020; 15:e0227685. [PMID: 31935250 PMCID: PMC6959561 DOI: 10.1371/journal.pone.0227685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/24/2019] [Indexed: 12/03/2022] Open
Abstract
The acyl-CoA-binding proteins (ACBP) act by regulating the availability of acyl-CoA in the cytoplasm and must have essential functions in lipid metabolism. The genome of the kissing-bug Rhodnius prolixus encodes five proteins of this family, but little is known about them. In this study we investigated the expression and function of RpACBP-5. Feeding induced RpACBP-5 gene expression in the posterior midgut, and an increase of about four times was observed two days after the blood meal. However, the amount of protein, which was only detected in this organ, did not change during digestion. The RpACBP-5 gene was also highly expressed in pre-vitellogenic and vitellogenic oocytes. Recombinant RpACBP-5 was shown to bind to acyl-CoA of different lengths, and it exhibited nanomolar affinity to lauroyl-CoA in an isothermal titration assay, indicating that RpACBP-5 is a functional ACBP. RpACBP-5 knockdown by RNA interference did not affect digestion, egg laying and hatching, survival, or accumulation of triacylglycerol in the fat body and oocytes. Similarly, double knockdown of RpACBP-1 and RpACBP-5 did not alter egg laying and hatching, survival, accumulation of triacylglycerol in the fat body and oocytes, or the neutral lipid composition of the posterior midgut or hemolymph. These results show that RpACBP-5 is a functional ACBP but indicate that the lack of a detectable phenotype in the knockdown insects may be a consequence of functional overlap of the proteins of the ACBP family found in the insect.
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Affiliation(s)
- Muriel G. M. D. Almeida
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Daniela S. Arêdes
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - David Majerowicz
- Institut for Biokemi og Molekylær Biologi, Syddansk Universitet, Odense, Denmark
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nils J. Færgeman
- Institut for Biokemi og Molekylær Biologi, Syddansk Universitet, Odense, Denmark
| | - Jens Knudsen
- Institut for Biokemi og Molekylær Biologi, Syddansk Universitet, Odense, Denmark
| | - Katia C. Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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11
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Gondim KC, Atella GC, Pontes EG, Majerowicz D. Lipid metabolism in insect disease vectors. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 101:108-123. [PMID: 30171905 DOI: 10.1016/j.ibmb.2018.08.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 08/17/2018] [Accepted: 08/26/2018] [Indexed: 06/08/2023]
Abstract
More than a third of the world population is at constant risk of contracting some insect-transmitted disease, such as Dengue fever, Zika virus disease, malaria, Chagas' disease, African trypanosomiasis, and others. Independent of the life cycle of the pathogen causing the disease, the insect vector hematophagous habit is a common and crucial trait for the transmission of all these diseases. This lifestyle is unique, as hematophagous insects feed on blood, a diet that is rich in protein but relatively poor in lipids and carbohydrates, in huge amounts and low frequency. Another unique feature of these insects is that blood meal triggers essential metabolic processes, as molting and oogenesis and, in this way, regulates the expression of various genes that are involved in these events. In this paper, we review current knowledge of the physiology and biochemistry of lipid metabolism in insect disease vectors, comparing with classical models whenever possible. We address lipid digestion and absorption, hemolymphatic transport, and lipid storage by the fat body and ovary. In this context, both de novo fatty acid and triacylglycerol synthesis are discussed, including the related fatty acid activation process and the intracellular lipid binding proteins. As lipids are stored in order to be mobilized later on, e.g. for flight activity or survivorship, lipolysis and β-oxidation are also considered. All these events need to be finely regulated, and the role of hormones in this control is summarized. Finally, we also review information about infection, when vector insect physiology is affected, and there is a crosstalk between its immune system and lipid metabolism. There is not abundant information about lipid metabolism in vector insects, and significant current gaps in the field are indicated, as well as questions to be answered in the future.
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Affiliation(s)
- Katia C Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Georgia C Atella
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Emerson G Pontes
- Departamento de Bioquímica, Instituto de Química, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brazil
| | - David Majerowicz
- Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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Uncoupling proteins of invertebrates: A review. IUBMB Life 2016; 68:691-9. [DOI: 10.1002/iub.1535] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 06/18/2016] [Indexed: 01/05/2023]
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13
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Majerowicz D, Hannibal-Bach HK, Castro RSC, Bozaquel-Morais BL, Alves-Bezerra M, Grillo LAM, Masuda CA, Færgeman NJ, Knudsen J, Gondim KC. The ACBP gene family in Rhodnius prolixus: Expression, characterization and function of RpACBP-1. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2016; 72:41-52. [PMID: 27001070 DOI: 10.1016/j.ibmb.2016.03.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 03/04/2016] [Accepted: 03/16/2016] [Indexed: 06/05/2023]
Abstract
The acyl-CoA-binding proteins (ACBP) constitute a family of conserved proteins that bind acyl-CoA with high affinity and protect it from hydrolysis. Thus, ACBPs may have essential roles in basal cellular lipid metabolism. The genome of the insect Rhodnius prolixus encodes five ACBP genes similar to those described for other insect species. The qPCR analysis revealed that these genes have characteristic expression profiles in insect organs, suggesting that they have specific roles in insect physiology. Recombinant RpACBP-1 was able to bind acyl-CoA in an in vitro gel-shift assay. Moreover, heterologous RpACBP-1 expression in acb1Δ mutant yeast rescued the multi-lobed vacuole phenotype, indicating that RpACBP-1 acts as a bona fide acyl-CoA-binding protein. RpACBP-1 knockdown using RNAi caused triacylglycerol accumulation in the insect posterior midgut and a reduction in the number of deposited eggs. The amount of stored triacylglycerol was reduced in flight muscle, and the incorporation of fatty acids in cholesteryl esters was increased in the fat body. These results showed that RpACBP-1 participates in several lipid metabolism steps in R. prolixus.
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Affiliation(s)
- David Majerowicz
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Institut for Biokemi og Molekylær Biologi, Syddansk Universitet, Odense, Denmark
| | - Hans K Hannibal-Bach
- Institut for Biokemi og Molekylær Biologi, Syddansk Universitet, Odense, Denmark
| | - Rodolfo S C Castro
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bruno L Bozaquel-Morais
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Michele Alves-Bezerra
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luciano A M Grillo
- Escola de Enfermagem e Farmácia, Universidade Federal de Alagoas, Maceió, Brazil
| | - Claudio A Masuda
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nils J Færgeman
- Institut for Biokemi og Molekylær Biologi, Syddansk Universitet, Odense, Denmark
| | - Jens Knudsen
- Institut for Biokemi og Molekylær Biologi, Syddansk Universitet, Odense, Denmark
| | - Katia C Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brazil.
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Alves-Bezerra M, Klett EL, De Paula IF, Ramos IB, Coleman RA, Gondim KC. Long-chain acyl-CoA synthetase 2 knockdown leads to decreased fatty acid oxidation in fat body and reduced reproductive capacity in the insect Rhodnius prolixus. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:650-62. [PMID: 27091636 DOI: 10.1016/j.bbalip.2016.04.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 03/16/2016] [Accepted: 04/13/2016] [Indexed: 10/21/2022]
Abstract
Long-chain acyl-CoA esters are important intermediates in lipid metabolism and are synthesized from fatty acids by long-chain acyl-CoA synthetases (ACSL). The hematophagous insect Rhodnius prolixus, a vector of Chagas' disease, produces glycerolipids in the midgut after a blood meal, which are stored as triacylglycerol in the fat body and eggs. We identified twenty acyl-CoA synthetase genes in R. prolixus, two encoding ACSL isoforms (RhoprAcsl1 and RhoprAcsl2). RhoprAcsl1 transcripts increased in posterior midgut on the second day after feeding, and RhoprAcsl2 was highly transcribed on the tenth day. Both enzymes were expressed in Escherichia coli. Recombinant RhoprACSL1 and RhoprACSL2 had broad pH optima (7.5-9.5 and 6.5-9.5, respectively), were inhibited by triacsin C, and were rosiglitazone-insensitive. Both showed similar apparent Km for palmitic and oleic acid (2-6 μM), but different Km for arachidonic acid (0.5 and 6 μM for RhoprACSL1-Flag and RhoprACSL2-Flag, respectively). The knockdown of RhoprAcsl1 did not result in noticeable phenotypes. However, RhoprACSL2 deficient insects exhibited a 2.5-fold increase in triacylglycerol content in the fat body, and 90% decrease in fatty acid β-oxidation. RhoprAcsl2 knockdown also resulted in 20% increase in lifespan, delayed digestion, 30% reduced oviposition, and 50% reduction in egg hatching. Laid eggs and hatched nymphs showed remarkable alterations in morphology. In summary, R. prolixus ACSL isoforms have distinct roles on lipid metabolism. Although RhoprACSL1 functions remain unclear, we propose that RhoprACSL2 is the main contributor for the formation of the intracellular acyl-CoA pool channeled for β-oxidation in the fat body, and is also required for normal reproduction.
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Affiliation(s)
- Michele Alves-Bezerra
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Eric L Klett
- Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Iron F De Paula
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Isabela B Ramos
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Rosalind A Coleman
- Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Katia C Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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15
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Alves-Bezerra M, De Paula IF, Medina JM, Silva-Oliveira G, Medeiros JS, Gäde G, Gondim KC. Adipokinetic hormone receptor gene identification and its role in triacylglycerol metabolism in the blood-sucking insect Rhodnius prolixus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2016; 69:51-60. [PMID: 26163435 DOI: 10.1016/j.ibmb.2015.06.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 06/22/2015] [Accepted: 06/23/2015] [Indexed: 06/04/2023]
Abstract
Adipokinetic hormone (AKH) has been associated with the control of energy metabolism in a large number of arthropod species due to its role on the stimulation of lipid, carbohydrate and amino acid mobilization/release. In the insect Rhodnius prolixus, a vector of Chagas' disease, triacylglycerol (TAG) stores must be mobilized to sustain the metabolic requirements during moments of exercise or starvation. Besides the recent identification of the R. prolixus AKH peptide, other components required for the AKH signaling cascade and its mode of action remain uncharacterized in this insect. In the present study, we identified and investigated the expression profile of the gene encoding the AKH receptor of R. prolixus (RhoprAkhr). This gene is highly conserved in comparison to other sequences already described and its transcript is abundant in the fat body and the flight muscle of the kissing bug. Moreover, RhoprAkhr expression is induced in the fat body at moments of increased TAG mobilization; the knockdown of this gene resulted in TAG accumulation both in fat body and flight muscle after starvation. The inhibition of Rhopr-AKHR transcription as well as the treatment of insects with the peptide Rhopr-AKH in its synthetic form altered the transcript levels of two genes involved in lipid metabolism, the acyl-CoA-binding protein-1 (RhoprAcbp1) and the mitochondrial glycerol-3-phosphate acyltransferase-1 (RhoprGpat1). These results indicate that the AKH receptor is regulated at transcriptional level and is required for TAG mobilization under starvation. In addition to the classical view of AKH as a direct regulator of enzymatic activity, we propose here that AKH signaling may account for the regulation of nutrient metabolism by affecting the expression profile of target genes.
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Affiliation(s)
- Michele Alves-Bezerra
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Iron F De Paula
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jorge M Medina
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gleidson Silva-Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jonas S Medeiros
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gerd Gäde
- Department of Biological Sciences, University of Cape Town, John Day Building, Rondebosch ZA-7701, South Africa
| | - Katia C Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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16
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Alves-Bezerra M, Cosentino-Gomes D, Vieira LP, Rocco-Machado N, Gondim KC, Meyer-Fernandes JR. Identification of uncoupling protein 4 from the blood-sucking insect Rhodnius prolixus and its possible role on protection against oxidative stress. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 50:24-33. [PMID: 24746771 DOI: 10.1016/j.ibmb.2014.03.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 03/14/2014] [Accepted: 03/24/2014] [Indexed: 06/03/2023]
Abstract
Uncoupling proteins (UCPs) play a critical role in the control of the mitochondrial membrane potential (ΔΨm) due to their ability to dissipate the proton gradient, which results in the uncoupling of mitochondrial respiration from ATP production. Most reactive oxygen species generation in mitochondria occurs in complex III, due to an increase of semiquinone (Q(-)) half-life. When active, UCPs can account as a potential antioxidant system by decreasing ΔΨm and increasing mitochondrial respiration, thus reducing Q(-) life time. The hematophagous insect Rhodnius prolixus, a vector of Chagas disease, is exposed to a huge increase in oxidative stress after a blood meal because of the hydrolysis of hemoglobin and the release of the cytotoxic heme molecule. Although some protective mechanisms were already described for this insect and other hematophagous arthropods, the putative role of UCP proteins as antioxidants in this context has not been explored. In this report, two genes encoding UCP proteins (RpUcp4 and RpUcp5) were identified in the R. prolixus genome. RpUcp4 is the predominant transcript in most analyzed organs, and both mRNA and protein expression are upregulated (13- and 3-fold increase, respectively) in enterocytes the first day after the blood feeding. The increase in UCP4 expression is coincident with the decrease in hydrogen peroxide (H2O2) generation by midgut cells. Furthermore, in mitochondria isolated from enterocytes, the modulation of UCP activity by palmitic acid and GDP resulted in altered ΔΨm, as well as modulation of H2O2 generation rates. These results indicate that R. prolixus UCP4 may function in an antioxidation mechanism to protect the midgut cells against oxidative damage caused by blood digestion.
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Affiliation(s)
- Michele Alves-Bezerra
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Daniela Cosentino-Gomes
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lisvane P Vieira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nathália Rocco-Machado
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Katia C Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brazil
| | - José R Meyer-Fernandes
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Brazil.
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17
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Santos R, Alves-Bezerra M, Rosas-Oliveira R, Majerowicz D, Meyer-Fernandes JR, Gondim KC. Gene identification and enzymatic properties of a membrane-bound trehalase from the ovary of Rhodnius prolixus. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2012; 81:199-213. [PMID: 22851503 DOI: 10.1002/arch.21043] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Trehalose represents the main hemolymph sugar in most insects and its metabolic availability is regulated by trehalase. In this study, trehalase activity associated with the reproductive system was investigated in the insect Rhodnius prolixus, a hematophagous hemipteran vector of Chagas' disease. A single-copy gene that encodes a membrane-bound trehalase (RpTre-2) was identified in the genome of R. prolixus. RpTre-2 deduced amino acid sequence is closely related to other insect membrane-bound trehalases. The expression of this gene was detected in all analyzed organs, including ovary, where total trehalase enzymatic activity was determined, and was highest at day 7 after blood meal. Ovary membranes showed a major trehalase specific activity, which confirmed the presence of a membrane-bound trehalase in this insect. This trehalase activity seemed not to be regulated at transcriptional level, as the expression of RpTre-2 gene in the ovary did not change over the days after feeding. Similarly, ovarian follicles at different developmental stages did not show any variation in the transcription level of this gene. The RpTre-2 kinetic parameters were also investigated. Activity was highest at pH 5.5 and followed Michaelis-Menten kinetics, with an apparent K(m) = 1.42 ± 0.36 mM and Vmax = 167.90 ± 12.91 nmol/mg protein/h. These data reveal the presence of a membrane-bound trehalase in R. prolixus that is active in ovary and probably takes part in the insect carbohydrate metabolism associated with the reproductive process.
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Affiliation(s)
- Rachel Santos
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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18
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Triacylglycerol biosynthesis occurs via the glycerol-3-phosphate pathway in the insect Rhodnius prolixus. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:1462-71. [DOI: 10.1016/j.bbalip.2012.08.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 07/21/2012] [Accepted: 08/02/2012] [Indexed: 11/17/2022]
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Paim RM, Pereira MH, Di Ponzio R, Rodrigues JO, Guarneri AA, Gontijo NF, Araújo RN. Validation of reference genes for expression analysis in the salivary gland and the intestine of Rhodnius prolixus (Hemiptera, Reduviidae) under different experimental conditions by quantitative real-time PCR. BMC Res Notes 2012; 5:128. [PMID: 22395020 PMCID: PMC3337225 DOI: 10.1186/1756-0500-5-128] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 03/06/2012] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Rhodnius prolixus is a blood-feeding insect that can transmit Trypanosoma cruzi and Trypanosoma rangeli to vertebrate hosts. Recently, genomic resources for invertebrate vectors of human pathogens have increased significantly, and R. prolixus has been one of the main species studied among the triatomines. However, the paucity of information on many of the fundamental molecular aspects of this species limits the use of the available genomic information. The present study aimed to facilitate gene expression studies by identifying the most suitable reference genes for the normalization of mRNA expression data from qPCR. RESULTS The expression stability of five candidate reference genes (18S rRNA, GAPDH, β-actin, α-tubulin and ribosomal protein L26) was evaluated by qPCR in two tissues (salivary gland and intestine) and under different physiological conditions: before and after blood feeding and after infection with T. cruzi or T. rangeli. The results were analyzed with three software programs: geNorm, NormFinder and BestKeeper. All of the evaluated candidate genes proved to be acceptable as reference genes, but some were found to be more appropriate depending on the experimental conditions. 18S, GAPDH and α-tubulin showed acceptable stability for studies in all of the tissues and experimental conditions evaluated. β-actin, one of the most widely used reference genes, was confirmed to be one of the most suitable reference genes in studies with salivary glands, but it had the lowest expression stability in the intestine after insect blood feeding. L26 was identified as the poorest reference gene in the studies performed. CONCLUSIONS The expression stability of the genes varies in different tissue samples and under different experimental conditions. The results provided by three statistical packages emphasize the suitability of all five of the tested reference genes in both the crop and the salivary glands with a few exceptions. The results emphasise the importance of validating reference genes for qRT-PCR analysis in R. prolixus studies.
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Affiliation(s)
- Rafaela M Paim
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, Pampulha, Belo Horizonte, MG, Brazil
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Lapointe JF, Dunphy GB, Mandato CA. Hemocyte-hemocyte adhesion and nodulation reactions of the greater wax moth, Galleria mellonella are influenced by cholera toxin and its B-subunit. RESULTS IN IMMUNOLOGY 2012; 2:54-65. [PMID: 24371567 DOI: 10.1016/j.rinim.2012.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 02/15/2012] [Accepted: 02/17/2012] [Indexed: 10/28/2022]
Abstract
Nodulation, the lepidopteran insect immune response to large numbers of microbes in the blood (hemolymph) consists of the coordination of the blood cell (hemocyte) types the granular cells and plasmatocytes in terms of granular cell-bacteria adhesion and hemocyte-hemocyte adhesion (microaggregation). Hemocyte-microbe adhesion is influenced by the secondary messenger, cAMP, and cAMP-dependent protein kinase A. In the present study, cholera toxin, an AB5 protein known to indirectly stimulate adenylate cyclase, is used to examine the hemocyte responses to glass, bacteria and hemocyte-hemocyte microaggregates. In vitro, this toxin induces a bimodal hemocyte adhesion response that varies with the holotoxin concentration in terms of the individual and aggregated hemocyte adhesion responses: the lower CTX concentration (1.2 nM) increases microaggregate adhesion and decreases individual hemocyte binding to glass, as does higher concentrations (6-120 nM), however microaggregates induced by lower concentrations do not adhere to glass. Cholera toxin-induced microaggregation is inhibited by RGDS, suggestive of integrin involvement. In vivo, cholera toxin (1.2-120 nM) injected into larvae induces also a bimodal hemocytic response: low levels (1.2-6 nM) cause reduced hemocyte adhesion, while high levels (12-120 nM) increase hemocyte release or mobilization of adhesive hemocyte counts in the hemolymph. Increasing levels of cholera toxin concomitantly injected with the non-pathogenic bacterium, Bacillus subtilis produces a bimodal pattern in bacterial removal from the hemolymph which correlates with nodule frequency in larvae injected with cholera toxin only. The effects of higher concentrations of cholera toxin in vitro (6-120 nM) and in vivo (12-120 nM) are mediated by the B-subunit, whereas the isolated A-subunit has no effect on hemocyte activity. Cholera toxin and its individual subunits did not detectably alter levels of intracellular cAMP in the hemocytes, suggesting a cAMP-independent mechanism stimulating the nodulation response.
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Affiliation(s)
- Jason F Lapointe
- Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montreal, Quebec, Canada H3A 2B2
| | - Gary B Dunphy
- Department of Natural Resource Sciences, Macdonald Campus of McGill University, 21, 111 Lakeshore Road, Ste. Anne de Bellevue, Québec, Canada H9X 3V9
| | - Craig A Mandato
- Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montreal, Quebec, Canada H3A 2B2
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Majerowicz D, Alves-Bezerra M, Logullo R, Fonseca-de-Souza AL, Meyer-Fernandes JR, Braz GRC, Gondim KC. Looking for reference genes for real-time quantitative PCR experiments in Rhodnius prolixus (Hemiptera: Reduviidae). INSECT MOLECULAR BIOLOGY 2011; 20:713-722. [PMID: 21929722 DOI: 10.1111/j.1365-2583.2011.01101.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Quantitative real-time PCR (qPCR) has become one of the most used techniques to measure gene expression. However, normalization of gene expression data against reference genes is essential, although these are usually used without any kind of validation. The expression of seven genes was compared in organs of Rhodnius prolixus under diverse conditions, using published software to test gene expression stability. Rp18S and elongation factor 1 (RpEF -1) were the most reliable genes for normalization in qPCR when gene expression in different organs was compared. Moreover, both genes were found to be the best references when transcript levels were compared in the posterior midgut of insects infected with Trypanosoma cruzi. Rp18S was also the best reference gene in the fat bodies of unfed and fed insects. By contrast, RpEF-1 was found to be the best reference gene for comparison between posterior midguts, and RpMIP or RpActin should be used to compare gene expression in the ovaries. Although Rp18S is indicated here as the best reference in most cases, reports from the literature show that it is difficult to find an optimum reference gene. Nevertheless, validation of candidate genes to be taken as references is important when new experimental conditions are tested to avoid incorrect data interpretation.
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Affiliation(s)
- D Majerowicz
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, RJ, Brazil.
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22
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Medeiros MN, Logullo R, Ramos IB, Sorgine MHF, Paiva-Silva GO, Mesquita RD, Machado EA, Coutinho MA, Masuda H, Capurro ML, Ribeiro JM, Cardoso Braz GR, Oliveira PL. Transcriptome and gene expression profile of ovarian follicle tissue of the triatomine bug Rhodnius prolixus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2011; 41:823-31. [PMID: 21736942 PMCID: PMC3740404 DOI: 10.1016/j.ibmb.2011.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 06/13/2011] [Accepted: 06/16/2011] [Indexed: 05/24/2023]
Abstract
Insect oocytes grow in close association with the ovarian follicular epithelium (OFE), which escorts the oocyte during oogenesis and is responsible for synthesis and secretion of the eggshell. We describe a transcriptome of OFE of the triatomine bug Rhodnius prolixus, a vector of Chagas disease, to increase our knowledge of the role of FE in egg development. Random clones were sequenced from a cDNA library of different stages of follicle development. The transcriptome showed high commitment to transcription, protein synthesis, and secretion. The most abundant cDNA was a secreted (S) small, proline-rich protein with maximal expression in the vitellogenic follicle, suggesting a role in oocyte maturation. We also found Rp45, a chorion protein already described, and a putative chitin-associated cuticle protein that was an eggshell component candidate. Six transcripts coding for proteins related to the unfolded-protein response (UPR) by were chosen and their expression analyzed. Surprisingly, transcripts related to UPR showed higher expression during early stages of development and downregulation during late stages, when transcripts coding for S proteins participating in chorion formation were highly expressed. Several transcripts with potential roles in oogenesis and embryo development are also discussed. We propose that intense protein synthesis at the FE results in reticulum stress (RS) and that lowering expression of a set of genes related to cell survival should lead to degeneration of follicular cells at oocyte maturation. This paradoxical suppression of UPR suggests that ovarian follicles may represent an interesting model for studying control of RS and cell survival in professional S cell types.
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Affiliation(s)
- Marcelo N. Medeiros
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
| | - Raquel Logullo
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
| | - Isabela B. Ramos
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
| | - Marcos H. F. Sorgine
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
| | - Gabriela O. Paiva-Silva
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
| | - Rafael D. Mesquita
- Instituto Federal de Educação do Rio de Janeiro, Rio de Janeiro, RJ
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
| | - Ednildo Alcantara Machado
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
| | - Maria Alice Coutinho
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
| | - Hatisaburo Masuda
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
| | - Margareth L. Capurro
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo; São Paulo; SP
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
| | - José M.C. Ribeiro
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, 12735 Twinbrook Parkway, Room 2E32, Rockville MD 20852 USA
| | - Glória Regina Cardoso Braz
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
| | - Pedro L Oliveira
- Instituto Federal de Educação do Rio de Janeiro, Rio de Janeiro, RJ
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil
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