The PFKFB3 Inhibitor AZ67 Inhibits Angiogenesis Independently of Glycolysis Inhibition

Funding: This study was funded by the University of Antwerp (BOF project ID 29068, 40183 and iBOF project ID 21-053). Besa Emini Veseli is a PhD fellow of the Horizon 2020 program of the Eu-ropean Union - Marie Skłodowska-Curie Actions, Innovative Training Networks (ITN), Call: H2020-MSCA-ITN-2015, NUMBER—675527—MOGLYNET. Data Availability Statement: The data presented in this study are available on request from the corresponding author. Acknowledgments: The authors thank Mandy Vermont for excellent technical support and Anne-Marie Lambeir for scientific advice. The authors are grateful to Bronwen Martin for critical reading of the manuscript.Peer reviewedPublisher PD

Identification and validation of housekeeping genes in brains of the desert locust Schistocerca gregaria under different developmental conditions

<p>Abstract</p> <p>Background</p> <p>To obtain reliable quantitative RT-PCR data, normalization relative to stable housekeeping genes is required. However, in practice, expression levels of 'typical' housekeeping genes have been found to vary between tissues and under different experimental conditions. To date, validation studies of reference genes in insects are extremely rare and have never been performed in locusts. In this study, putative housekeeping genes were identified in the desert locust, <it>Schistocerca gregaria </it>and two different software programs (geNorm and Normfinder) were applied to assess the stability of thesegenes.</p> <p>Results</p> <p>We have identified seven orthologs of commonly used housekeeping genes in the desert locust. The selected genes were the orthologs of actin, <it>EF1a, GAPDH, RP49, TubA1, Ubi</it>, and <it>CG13220</it>. By employing real time RT-PCR we have analysed the expression of these housekeeping genes in brain tissue of fifth instar nymphs and adults. In the brain of fifth instar nymphs geNorm indicated <it>Sg-EF1a</it>, <it>Sg-GAPDH </it>and <it>Sg-RP49 </it>as most stable genes, while Normfinder ranked <it>Sg-RP49</it>, <it>Sg-EF1a </it>and <it>Sg-ACT </it>as most suitable candidates for normalization. The best normalization candidates for gene expression studies in the brains of adult locusts were <it>Sg-EF1a, Sg-GAPDH </it>and <it>Sg-Ubi </it>according to geNorm, while Normfinder determined <it>Sg-GAPDH</it>, <it>Sg-Ubi </it>and <it>Sg-ACT </it>as the most stable housekeeping genes.</p> <p>Conclusion</p> <p>To perform transcript profiling studies on brains of the desert locust, the use of <it>Sg-RP49</it>, <it>Sg-EF1a </it>and <it>Sg-ACT </it>as reference genes is proposed for studies of fifth instar nymphs. In experiments with adult brains, however, the most preferred reference genes were <it>Sg-GAPDH</it>, <it>Sg-Ubi </it>and <it>Sg-EF1a</it>. These data will facilitate transcript profiling studies in desert locusts and provide a good starting point for the initial selection of genes for validation studies in other insects.</p

Orcokinin neuropeptides regulate ecdysis in the hemimetabolous insect Rhodnius prolixus

To grow and develop insects must undergo ecdysis. During this process, the individual sheds the old cuticle to emerge as the following developmental stage. During ecdysis, different programed behaviors are regulated by neuropeptidergic pathways. In general, components of these pathways are better characterized in crustacean and holometabolous insects than in hemimetabola. In insects, the orkoninin gene produces two different neuropeptide precursors by alternative splicing: orcokinin A and orcokinin B. Although orcokinins are well conserved in insect species, their physiological role remains elusive. Here we describe a new splicing variant of the orcokinin gene in the hemimetabolous triatomine Rhodnius prolixus. We further analyze the expression pattern and the function of the alternatively spliced RhoprOK transcripts by means of immunohistochemistry and RNAi-mediated gene silencing. Our results indicate that orkoninis play an essential role in the peptidergic signaling pathway regulating ecdysis in the hemimetabolous insect Rhodnius prolixus.Centro Regional de Estudios GenómicosCentro de Endocrinología Experimental y Aplicad

CRF-Like Diuretic Hormone Negatively Affects Both Feeding and Reproduction in the Desert Locust, Schistocerca gregaria

Diuretic hormones (DH) related to the vertebrate Corticotropin Releasing Factor (CRF) have been identified in diverse insect species. In the migratory locust, Locusta migratoria, the CRF-like DH (CRF/DH) is localized in the same neurosecretory cells as the Ovary Maturating Parsin (OMP), a neurohormone that stimulates oocyte growth, vitellogenesis and hemolymph ecdysteroid levels in adult female locusts. In this study, we investigated whether CRF-like DH can influence feeding and reproduction in the desert locust, Schistocerca gregaria. We identified two highly similar S. gregaria CRF-like DH precursor cDNAs, each of which also encodes an OMP isoform. Alignment with other insect CRF-like DH precursors shows relatively high conservation of the CRF/DH sequence while the precursor region corresponding to OMP is not well conserved. Quantitative real-time RT-PCR revealed that the precursor transcripts mainly occur in the central nervous system and their highest expression level was observed in the brain. Injection of locust CRF/DH caused a significantly reduced food intake, while RNAi knockdown stimulated food intake. Therefore, our data indicate that CRF-like DH induces satiety. Furthermore, injection of CRF/DH in adult females retarded oocyte growth and caused lower ecdysteroid titers in hemolymph and ovaries, while RNAi knockdown resulted in opposite effects. The observed effects of CRF/DH may be part of a wider repertoire of neurohormonal activities, constituting an integrating control system that affects food intake and excretion, as well as anabolic processes like oocyte growth and ecdysteroidogenesis, following a meal. Our discussion about the functional relationship between CRF/DH and OMP led to the hypothesis that OMP may possibly act as a monitoring peptide that can elicit negative feedback effects

Neuropeptides controlling food uptake and reproduction in the desert locust Schistocerca gregaria

Normal 0 21 false false false NL-BE X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Standaardtabel; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"TimesNew Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}For thousands ofyears, desert locusts (Schistocercagregaria Forskål) have been threatening the agriculturalproduction in large parts of Northern Africa, the Middle-East and the Indiansubcontinent. Usually, these animals occur at low population densities andbehave as loners that are relatively harmless. Under favorable environmentalconditions (higher food availability), the desert locusts will reproducemassively. Because of the resulting increase in population density, theseanimals will undergo physiological and morphological changes, as well asbehavioral changes causing the locusts to actively aggregate. This process caneventually lead to the formation of enormous swarms of billions of locusts thatcan inflict major damage, both to the natural vegetation and agriculturalcrops. Influencing locust reproduction and food intake might be a suitablestrategy for preventing locust outbreaks. Unfortunately, our knowledge onlocust physiology is still very limited and additional research is needed tofully understand the relevant physiological processes. In the context of this PhD thesis, the involvement of the neuropeptidesCRF-related diuretic hormone (CRF/DH), neuropeptide F (NPF) and ovarymaturating parsin (OMP) was analyzed in the regulation of reproduction and foodintake in the desert locust. By cloning twoprepropeptide cDNAs, we were able to demonstrate that in S. gregaria OMP and CRF/DH originate from the same precursorproteins. Interestingly, the currently known CRF/DH precursors from otherinsect species do not code for OMP-like molecules. As previously suggested, OMPseems to occur only in a limited number of taxa, although its exact taxonomicoccurrence has not been determined yet. By performing feeding experiments, wewere able to confirm that CRF/DH negatively regulates food intake in locusts,as was previously suggested. Moreover, we demonstrated that CRF/DH alsonegatively affects oocyte growth and ecdysteroid levels in the hemolymph andovaries of adult female S. gregaria.No effects of CRF/DH on insect reproductive physiology were previouslyreported.In the second part ofour research, we identified a NPF-prepropeptide sequence based on sequenceinformation from the S. gregariaEST-database. Analysis of this precursor sequence demonstrated that apreviously purified NPF-like peptide of S.gregaria is actually a C-terminal fragment of the (based on the precursorsequence) predicted long NPF peptide. This naturally occurring shorter formpreviously proved to be biologically active and was designated truncated NPF or trNPF to make the distinction with the predicted long NPF-peptide (that could not yet be demonstrated in locusts) andthe sNPF-peptide (that seems to be less related to NPF than its name suggests). We wereable to demonstrate that trNPF stimulates food intake in S. gregaria. Previously, this effect of NPF on food intake had onlybeen demonstrated in the fruit fly Drosophilamelanogaster, although indications were found for a similar role of NPF inother insect species. In accordance to the role of trNPF in the regulation offood intake, we observed that the levels of the S. gregaria NPF-precursor transcript are regulated in function ofthe animals feeding state. We were also able to demonstrate that trNPF has astimulatory effect on weight increase in S.gregaria. In addition to itspreviously described effect on female reproductive physiology, we were able to demonstratethat trNPF also influences male reproductive physiology in S. gregaria. By applying different physiological assays, weobserved effects of trNPF on sexual maturation, as well as on the reproductivesuccess of adult male S. gregaria.Only one previous report on D.melanogaster described the link between NPF and male reproduction.The results describedin this thesis shed a new light on the regulation of food intake andreproduction in the desert locust and provide new perspectives for thephysiological research in other insect species.<w:latentstyles deflockedstate="false" defunhidewhenused="true"  <w:lsdexception="" locked="false" priority="0" semihidden="false"  <w:latentstyles="" for="" thousands="" of="" years,="" desert="" locusts="" (schistocerca="" gregaria forskål)="" have="" been="" threatening="" the="" agricultural="" production="" in="" large="" parts="" northern="" africa,="" middle-east="" and="" indian="" subcontinent.="" usually,="" these="" animals="" occur="" at="" low="" population="" densities="" behave="" as="" loners="" that="" are="" relatively="" harmless.="" under="" favorable="" environmental="" conditions="" (higher="" food="" availability),="" will="" reproduce="" massively.="" because="" resulting="" increase="" density,="" undergo="" physiological="" morphological="" changes,="" well="" behavioral="" changes="" causing="" to="" actively="" aggregate.="" this="" process="" can="" eventually="" lead="" formation="" enormous="" swarms="" billions="" inflict="" major="" damage,="" both="" natural="" vegetation="" crops.="" influencing="" locust="" reproduction="" intake="" might="" be="" a="" suitable="" strategy="" preventing="" outbreaks.="" unfortunately,="" our="" knowledge="" on="" physiology="" is="" still="" very="" limited="" additional="" research="" needed="" fully="" understand="" relevant="" processes.="" context="" phd="" thesis,="" involvement="" neuropeptides="" crf-related="" diuretic="" hormone="" (crf="" dh),="" neuropeptide="" f="" (npf)="" ovary="" maturating="" parsin="" (omp)="" was="" analyzed="" regulation="" locust.by="" cloning="" two="" prepropeptide="" cdnas,="" we="" were="" able="" demonstrate="" in s.="" gregaria="" omp="" crf="" dh="" originate="" from="" same="" precursor="" proteins.="" interestingly,="" currently="" known="" precursors="" other="" insect="" species="" do="" not="" code="" omp-like="" molecules.="" previously="" suggested,="" seems="" only="" number="" taxa,="" although="" its="" exact="" taxonomic="" occurrence="" has="" determined="" yet.="" by="" performing="" feeding="" experiments,="" confirm="" negatively="" regulates="" locusts,as="" suggested.="" moreover,="" demonstrated="" also="" affects="" oocyte="" growth="" ecdysteroid="" levels="" hemolymph="" ovaries="" adult="" female="" s.="" gregaria.no="" effects="" reproductive="" reported.in="" second="" part="" research,="" identified="" npf-prepropeptide="" sequence="" based="" information="" est-database.="" analysis="" purified="" npf-like="" peptide="" gregaria is="" actually="" c-terminal="" fragment="" (based="" sequence)="" predicted="" long ="" npf="" peptide.="" naturally="" occurring="" shorter="" form="" proved="" biologically="" active="" designated="" truncated="" npf or="" trnpf ="" make="" distinction="" with="" npf-peptide="" (that="" could="" yet="" locusts)="" snpf-peptide="" less="" related="" than="" name="" suggests).="" trnpf="" stimulates="" gregaria.="" previously,="" effect="" had="" fruit="" fly="" drosophila="" melanogaster,="" indications="" found="" similar="" role="" species.="" accordance="" intake,="" observed="" the s.="" npf-precursor="" transcript="" regulated="" function="" animals ="" state.="" stimulatory="" weight="" gregaria. in="" addition="" described="" physiology,="" influences="" male="" applying="" different="" assays,="" sexual="" maturation,="" success="" gregaria.only="" one="" previous="" report="" d.="" melanogaster="" link="" between="" reproduction.the="" results="" thesis="" shed="" new="" light="" provide="" perspectives="" species.nrpages: 179status: publishe

Eat to reproduce: a key role for the insulin signaling pathway in adult insects

status: publishe

Eat to reproduce: a key role for the insulin signaling pathway in adult insects

Insects, like all heterotrophic organisms, acquire from their food the nutrients that are essential for anabolic processes that lead to growth (larval stages) or reproduction (adult stage). In adult females, this nutritional input is processed and results in a very specific output, i.e., the production of fully developed eggs ready for fertilization and deposition. An important role in this input-output transition is attributed to the insulin signaling pathway (ISP). The ISP is considered to act as a sensor of the organism's nutritional status and to stimulate the progression of anabolic events when the status is positive. In several insect species belonging to different orders, the ISP has been demonstrated to positively control vitellogenesis and oocyte growth. Whether or not ISP acts herein via a mediator action of lipophilic insect hormones (ecdysteroids and juvenile hormone) remains debatable and might be differently controlled in different insect orders. Most likely, insulin-related peptides, ecdysteroids and juvenile hormone are involved in a complex regulatory network, in which they mutually influence each other and in which the insect's nutritional status is a crucial determinant of the network's output. The current review will present an overview of the regulatory role of the ISP in female insect reproduction and its interaction with other pathways involving nutrients, lipophilic hormones and neuropeptides.status: publishe

Neuropeptidergic regulation of reproduction in insects

Successful animal reproduction depends on multiple physiological and behavioral processes that take place in a timely and orderly manner in both mating partners. It is not only necessary that all relevant processes are well coordinated, they also need to be adjusted to external factors of abiotic and biotic nature (e.g. population density, mating partner availability). Therefore, it is not surprising that several hormonal factors play a crucial role in the regulation of animal reproductive physiology. In insects (the largest class of animals on planet Earth), lipophilic hormones, such as ecdysteroids and juvenile hormones, as well as several neuropeptides take part in this complex regulation. While some peptides can affect reproduction via an indirect action (e.g. by influencing secretion of juvenile hormone), others exert their regulatory activity by directly targeting the reproductive system. In addition to insect peptides with proven activities, several others were suggested to also play a role in the regulation of reproductive physiology. Because of the long evolutionary history of many insect orders, it is not always clear to what extent functional data obtained in a given species can be extrapolated to other insect taxa. In this paper, we will review the current knowledge concerning the neuropeptidergic regulation of insect reproduction and situate it in a more general physiological context.status: publishe

Regulation of feeding by Neuropeptide F in the desert locust, Schistocerca gregaria

Our knowledge on the physiological function of the insect Neuropeptide F (NPF) mostly comes from studies in the fruit fly, Drosophila melanogaster, where NPF was shown to regulate diverse processes, such as feeding, learning and responding to stress. In the desert locust, Schistocerca gregaria, only a truncated form of the "full-length" NPF (the biologically active "trNPF") has been isolated. In this study, we investigated whether this peptide is involved in the regulation of feeding in this orthopteran species. In the S. gregaria EST-database, an NPF-precursor encoding transcript was found. Alignment with other insect NPF-precursors showed relatively highest sequence conservation within the trNPF region (and the flanking dibasic cleavage site), as compared to other regions of the NPF-precursor. Quantitative real-time RT-PCR revealed that the Schgr-NPF-precursor encoding transcript occurs throughout the central nervous system with relatively high transcript levels in the brain, optic lobes and suboesophageal ganglion. It was also detected at relatively high levels in the midgut, which suggests that the encoded peptide also functions in the digestive system. Moreover, Schgr-NPF-transcript levels were notably higher in starved animals than in animals fed ad libitum, while transcript levels were also shown to be regulated after the consumption of a meal. Injection of locust trNPF in adults stimulated food intake, while RNAi knockdown reduced food intake. Furthermore, injection of trNPF in adults stimulated weight increase, while RNAi knockdown reduced weight gain. This effect of trNPF on body weight gain may result from its stimulatory effect on food intake. Taken together, we provide clear evidence for an important role of trNPF in the regulation of feeding in the desert locust, S. gregaria.status: publishe

Neurohormonal regulation of reproduction and feeding in the desert locust Schistocerca gregaria

In the desert locust Schistocerca gregaria (Orthoptera), several neurohormones are known to play a role in the regulation of the female reproductive physiology. In this study we concentrate on Neuropeptide F (NPF) and on the Ovary Maturating Parsins (OMP) in order to further analyze their physiological role. By means of the S. gregaria EST database and 3’-RACE (Rapid Amplification of cDNA Ends), the precursor cDNA sequences for these neurohormones were obtained. Interestingly, two very similar S. gregaria precursors were found, each encoding a CRF-like diuretic hormone (DH) as well as one of both large Scg-OMP isoforms. By means of quantitative “real-time” RT-PCR, the tissue-specific expression of these precursors was examined. The main expression was always seen in the central nervous system, while the NPF precursor was also expressed in the digestive system (mainly in the midgut). By means of feeding experiments (combined with RNAi knockdown and peptide injections), we were able to show that NPF increased food intake while the CRF-like DH decreased food intake. By means of RNAi, as well as peptide injections, the physiological effects of the studied neurohormones were further analyzed. For this, the effects on several transcript levels (neuropeptide precursors, biosynthetic enzymes, etc.) as well as certain hormone titers and other reproductive parameters were evaluated (e.g. the effect of NPF on male reproductive physiology). Taken together, our data show that the NPF and CRF-like DH/OMP signaling systems are involved in the regulation of food intake, as well as in several physiological processes related to reproduction (and probably also related to the first effect). Based on these functions, these signaling systems may represent interesting targets for locust pest management.status: publishe