BACKGROUND: Leishmaniasis is a group of neglected vector-borne diseases transmitted by phlebotomine sand flies. Leishmania parasites must overcome various defenses in the sand fly midgut, including the insects's immune response. Insect immunity is regulated by the ecdysone hormone, which binds to its nuclear receptor (EcR) and activates the transcription of genes involved in insect immunity. However, the role of ecdysone in sand fly immunity has never been studied. Phlebotomus perniciosus is a natural vector of Leishmania infantum; here, we manipulated its neuroendocrine system using azadirachtin (Aza), a natural compound known to affect ecdysone synthesis. METHODS: Phlebotomus perniciosus larvae and adult females were fed on food containing either Aza alone or Aza plus ecdysone, and the effects on mortality and ecdysis were evaluated. Genes related to ecdysone signaling and immunity were identified in P. perniciosus, and the expression of antimicrobial peptides (AMPs), EcR, the ecdysone-induced genes Eip74EF and Eip75B, and the transcription factor serpent were analyzed using quantitative polymerase chain reaction (PCR). RESULTS: Aza treatment inhibited molting of first-instar (L1) larvae to L2, with only 10% of larvae molting compared to 95% in the control group. Serpent and Eip74EF, attacin, defensin 1, and defensin 2 genes were downregulated by Aza treatment in larvae. Similarly, Aza-treated adult females also presented suppression of ecdysone signaling-related genes and the AMPs attacin and defensin 2. Notably, all gene repression caused by Aza was reversed by adding ecdysone concomitantly with Aza to the larval or female food, indicating that these genes are effective markers for ecdysone repression. CONCLUSIONS: These results highlight the critical role of ecdysone in regulating the development and immunity of P. perniciosus, which potentially could interfere with Leishmania infection.

• Klíčová slova
• Phlebotomus perniciosus, Antimicrobial peptides, Azadirachtin, Ecdysone,
• MeSH
• antimikrobiální peptidy genetika   farmakologie   MeSH
• ekdyson * MeSH
• hmyz - vektory účinky léků   genetika   parazitologie   imunologie   MeSH
• hmyzí proteiny genetika   metabolismus   MeSH
• larva * účinky léků   imunologie   genetika   MeSH
• limoniny * farmakologie   MeSH
• Phlebotomus * účinky léků   genetika   parazitologie   imunologie   MeSH
• shazování tělního pokryvu účinky léků   MeSH
• signální transdukce * účinky léků   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antimikrobiální peptidy MeSH
• azadirachtin MeSH Prohlížeč
• ekdyson * MeSH
• hmyzí proteiny MeSH
• limoniny * MeSH

Structural modification of 20-hydroxyecdysone (20E) based on photochemical transformation yielded dimeric ecdysteroid 7alphaH,7'alphaH-bis-[(20R,22R)-2beta,3beta,20,22,25-pentahydroxy-5beta-cholest-8(14)-en-6-one-7-yl] as a main product. Its structure was determined by detailed NMR analysis. Furthermore, two new monomeric analogues: 14-epi-20-hydroxyecdysone and 14-deoxy-14,18-cyclo-20-hydroxyecdysone were identified in addition to the earlier described 14-deoxy and 14-hydroperoxy derivatives of 20E. Formation of the specific and so far unique ecdysteroid dimer has not been observed in earlier photo-transformation studies. The transformed dimeric analogue of 20-hydroxyecdysone retained the high agonistic activity on the ecdysone receptor in the B(II)-bioassay compared with the original 20E.

• MeSH
• dimerizace MeSH
• Drosophila melanogaster MeSH
• ekdysteroidy analogy a deriváty   MeSH
• ekdysteron chemická syntéza   chemie   MeSH
• fotochemie metody   MeSH
• magnetická rezonanční spektroskopie MeSH
• molekulární konformace MeSH
• molekulární modely MeSH
• spektrofotometrie infračervená MeSH
• steroidní receptory agonisté   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ecdysone receptor MeSH Prohlížeč
• ekdysteroidy MeSH
• ekdysteron MeSH
• steroidní receptory MeSH

TAIMAN (TAI), the only insect ortholog of mammalian Steroid Receptor Coactivators (SRCs), is a critical modulator of ecdysone and juvenile hormone (JH) signaling pathways, which govern insect development and reproduction. The modulatory effect is mediated by JH-dependent TAI's heterodimerization with JH receptor Methoprene-tolerant and association with the Ecdysone Receptor complex. Insect hormones regulate insect physiology and development in concert with abiotic cues, such as photo- and thermoperiod. Here we tested the effects of JH and ecdysone signaling on the circadian clock by a combination of microsurgical operations, application of hormones and hormone mimics, and gene knockdowns in the linden bug Pyrrhocoris apterus males. Silencing taiman by each of three non-overlapping double-strand RNA fragments dramatically slowed the free-running period (FRP) to 27-29 hours, contrasting to 24 hours in controls. To further corroborate TAIMAN's clock modulatory function in the insect circadian clock, we performed taiman knockdown in the cockroach Blattella germanica. Although Blattella and Pyrrhocoris lineages separated ~380 mya, B. germanica taiman silencing slowed the FRP by more than 2 hours, suggesting a conserved TAI clock function in (at least) some insect groups. Interestingly, the pace of the linden bug circadian clock was neither changed by blocking JH and ecdysone synthesis, by application of the hormones or their mimics nor by the knockdown of corresponding hormone receptors. Our results promote TAI as a new circadian clock modulator, a role described for the first time in insects. We speculate that TAI participation in the clock is congruent with the mammalian SRC-2 role in orchestrating metabolism and circadian rhythms, and that TAI/SRCs might be conserved components of the circadian clock in animals.

• MeSH
• buněčná membrána MeSH
• cirkadiánní hodiny * genetika   MeSH
• cirkadiánní rytmus genetika   MeSH
• ekdyson genetika   MeSH
• hmyz MeSH
• juvenilní hormony genetika   MeSH
• savci MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ekdyson MeSH
• juvenilní hormony MeSH

The biological activities of selected specific ecdysteroids obtained by photochemical or chemical transformation are compared in the B(II) bioassay, in which the potency reflects the affinity of binding to the ligand-binding site of the Drosophila melanogaster ecdysteroid receptor. The compounds tested represent 14-deoxy, 14-dehydroxy, 14-hydroperoxy and 14-epi derivatives of 20-hydroxyecdysone and were selected on the basis of their close structural relationship to elucidate the contribution of the 14-hydroxy group and the stereochemical configuration at C-14 to ecdysteroid agonist activity. The structure-activity relationship shows that a 14-hydroxy group is not required for activity. However, the alpha-configuration of -H, -OH or -OOH at C-14, which determines the C/D rings trans-annelation, is very significant for activity; it is as important for activity as the well studied A/B rings cis-annelation. Compounds containing a double bond involving C-14 showed low activity with the exception of the specific, and so far unique, ecdysteroid dimer 7,7'-bis-[14-deoxy-8(14)-ene-20-hydroxyecdysone], which was obtained as the main product of the photochemical transformation of 20-hydroxyecdysone. The relatively high biological activity of this dimeric compound is discussed.

• MeSH
• biotest MeSH
• buněčné linie MeSH
• dimerizace MeSH
• Drosophila melanogaster MeSH
• ekdysteron analogy a deriváty   chemie   MeSH
• molekulární struktura MeSH
• steroidní receptory metabolismus   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ecdysteroid receptor MeSH Prohlížeč
• ekdysteron MeSH
• steroidní receptory MeSH

Using the cDNA for the Drosophila ecdysteroid-induced member of the steroid-hormone-receptor superfamily, E75A, we isolated a genomic clone from Galleria mellonella that revealed 77% similarity with the region of E75A cDNA encoding the C-terminal zinc-finger motif. A Galleria cDNA clone was isolated that encoded a complete DNA-binding domain composed of two zinc fingers and designated GmE75A. Its deduced amino acid sequence showed 100% and 85% identities within the DNA-binding and ligand-binding domains of Drosophila E75A, respectively. The Galleria genomic clone did not encode the N-terminal zinc finger, but included a sequence similar to the B1 exon, which is unique to the B isoform of E75. Thus, the cDNA and genomic DNA sequences indicated that the Galleria gene E75 encoded at least two isoforms, GmE75A and GmE75B, which differed in their N-termini. Probes specific for GmE75A and B hybridized to two distinct transcripts of 2.6 kb. Both GmE75A and B mRNA levels correlated closely with the ecdysteroid titer during development. At the onset of larval/pupal transformation, both transcripts appeared in high amounts within 4 h of the ecdysteroid rise, then declined concurrently with the hormone titer decline. At the time of pupal ecdysis, there was another peak of GmE75A expression but not GmE75B expression, coincident with a minor ecdysteroid pulse. In isolated abdomens of final instar larvae, GmE75A mRNA was induced by 20-hydroxyecdysone within 20 min of the injection; the mRNA levels were maximal at 1 h and declined by 3 h following the treatment.

• MeSH
• biologická proměna MeSH
• DNA vazebné proteiny chemie   genetika   izolace a purifikace   MeSH
• Drosophila genetika   MeSH
• ekdysteroidy MeSH
• ekdysteron farmakologie   MeSH
• exprese genu * účinky léků   MeSH
• hemolymfa chemie   MeSH
• hmyzí geny MeSH
• hmyzí hormony krev   MeSH
• hmyzí proteiny * MeSH
• hormony bezobratlých krev   MeSH
• klonování DNA MeSH
• komplementární DNA chemie   MeSH
• molekulární sekvence - údaje MeSH
• můry genetika   růst a vývoj   metabolismus   MeSH
• northern blotting MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• sekvenční homologie aminokyselin MeSH
• sekvenční homologie nukleových kyselin MeSH
• steroidní receptory chemie   genetika   izolace a purifikace   MeSH
• steroidy krev   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH
• srovnávací studie MeSH
• Názvy látek
• DNA vazebné proteiny MeSH
• E75 protein, insect MeSH Prohlížeč
• ekdysteroidy MeSH
• ekdysteron MeSH
• hmyzí hormony MeSH
• hmyzí proteiny * MeSH
• hormony bezobratlých MeSH
• komplementární DNA MeSH
• steroidní receptory MeSH
• steroidy MeSH

Three degenerate primers were designed to match the most conserved regions within the DNA-binding domains of several selected members of the steroid hormone receptor family. Use of these primers in the polymerase chain reaction with cDNA from Galleria mellonella prepupae detected a 177 bp fragment that had 87% identity to the Manduca sexta gene MHR3 and 75% to the Drosophila melanogaster DHR3 gene, and therefore was named "GHR3". Screening of a Galleria penultimate instar cDNA library with this fragment yielded a cDNA clone that contained a 557 codon open reading frame, predicting a 62.3 kDa protein. The deduced amino acid sequence of GHR3 showed 92% overall identity with the MHR3 protein and 97 and 70% identity with DHR3 in the putative DNA- and ligand-binding domains, respectively. Hybridization of whole body RNA revealed high GHR3 mRNA levels during both the larval and pupal molts, coincident with the molt-inducing ecdysteroid pulses, and low or undetectable levels during the first half of the last instar. During the larval-pupal transformation, no GHR3 mRNA was found at the beginning of the stemmatal pigment retraction at the onset of the ecdysteroid rise; maximal levels were observed 4 h later, coincident with the peak ecdysteroid titer (over 2.3 micrograms 20E equivalents/ml hemolymph). Two mRNAs (4.6 and 3.6 kb) were detected when the ecdysteroid titer was high. Injection of 2 micrograms/gm 20E into isolated final instar larval abdomens induced the appearance of the 4.6 kb mRNA within 1.5 h; the mRNA level then reached maximum by 3 h and declined by 6 h. No 3.6 kb mRNA was detectable during that time. A 10-fold lower 20E dose caused only trace induction by 3 h.

• MeSH
• DNA vazebné proteiny genetika   MeSH
• ekdysteroidy MeSH
• ekdysteron farmakologie   MeSH
• hmyzí geny * MeSH
• hmyzí hormony fyziologie   MeSH
• hmyzí proteiny * MeSH
• hormony bezobratlých fyziologie   MeSH
• klonování DNA MeSH
• komplementární DNA MeSH
• kukla MeSH
• messenger RNA metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• můry genetika   MeSH
• polymerázová řetězová reakce MeSH
• receptory buněčného povrchu genetika   MeSH
• receptory cytoplazmatické a nukleární * MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• steroidy fyziologie   MeSH
• vývojová regulace genové exprese účinky léků   MeSH
• zinkové prsty genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH
• Názvy látek
• DNA vazebné proteiny MeSH
• ekdysteroidy MeSH
• ekdysteron MeSH
• hmyzí hormony MeSH
• hmyzí proteiny * MeSH
• hormony bezobratlých MeSH
• komplementární DNA MeSH
• messenger RNA MeSH
• receptory buněčného povrchu MeSH
• receptory cytoplazmatické a nukleární * MeSH
• steroidy MeSH

20-Hydroxyecdysterone - (2β,3β,5β,22R)-2,3,14,20,22,25-hexahydroxycholest-7-en-6-one was isolated in satisfactory yield using ethanol extraction from the aerial part of Silene wolgensis (Hornem.) Otth; sometimes Silene wolgensis (Willd.) Bess. ex Spreng. The complexation of the phytoecdysteroid with β-cyclodextrin was studied by NMR spectroscopy. By studying the changes in chemical shifts of protons of substrates and receptors it was found that ecdysterone interacts with cyclodextrins to form supramolecular inclusion complexes of stoichiometric composition of 1:1 or 1:2. Ecdysterone-β-cyclodextrin complexes exhibit 100 times higher solubility in water than the parent compound.

• Klíčová slova
• Cyclodextrins, Ecdysterones, Inclusion complexes, NMR spectroscopy,
• MeSH
• biologická dostupnost MeSH
• cyklodextriny chemie   MeSH
• ekdysteron chemie   izolace a purifikace   farmakokinetika   MeSH
• magnetická rezonanční spektroskopie MeSH
• molekulární konformace MeSH
• rozpustnost MeSH
• Silene chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cyklodextriny MeSH
• ekdysteron MeSH