scholarly journals Monoterpenes alter TAR1-driven physiology in Drosophila species

2020 ◽  
Vol 224 (1) ◽  
pp. jeb232116
Author(s):  
Luca Finetti ◽  
Lasse Tiedemann ◽  
Xiaoying Zhang ◽  
Stefano Civolani ◽  
Giovanni Bernacchia ◽  
...  

ABSTRACTMonoterpenes are molecules with insecticide properties whose mechanism of action is, however, not completely elucidated. Furthermore, they seem to be able to modulate the monoaminergic system and several behavioural aspects in insects. In particular, tyramine (TA) and octopamine (OA) and their associated receptors orchestrate physiological processes such as feeding, locomotion and metabolism. Here, we show that monoterpenes not only act as biopesticides in Drosophila species but also can cause complex behavioural alterations that require functional type 1 tyramine receptors (TAR1s). Variations in metabolic traits as well as locomotory activity were evaluated in both Drosophila suzukii and Drosophila melanogaster after treatment with three monoterpenes. A TAR1-defective D. melanogaster strain (TAR1PL00408) was used to better understand the relationships between the receptor and monoterpene-related behavioural changes. Immunohistochemistry analysis revealed that, in the D. melanogaster brain, TAR1 appeared to be mainly expressed in the pars intercerebralis, lateral horn, olfactory and optic lobes and suboesophageal ganglion lobes. In comparison to wild-type D. melanogaster, the TAR1PL00408 flies showed a phenotype characterized by higher triglyceride levels and food intake as well as lower locomotory activity. The monoterpenes, tested at sublethal concentrations, were able to induce a downregulation of the TAR1 coding gene in both Drosophila species. Furthermore, monoterpenes also altered the behaviour in wild-type D. suzukii and D. melanogaster 24 h after continuous monoterpene exposure. Interestingly, they were ineffective in modifying the physiological performance of TAR1-defective flies. In conclusion, it appears that monoterpenes not only act as biopesticides for Drosophila but also can interfere with Drosophila behaviour and metabolism in a TAR1-dependent fashion.

2020 ◽  
Author(s):  
Luca Finetti ◽  
Lasse Tiedemann ◽  
Xiaoying Zhang ◽  
Stefano Civolani ◽  
Giovanni Bernacchia ◽  
...  

AbstractMonoterpenes are molecules with insecticide properties whose mechanism of action is however not completely elucidated. Furthermore, they seem to be able to modulate the monoaminergic system and several behavioural aspects in insects. In particular, tyramine (TA) and octopamine (OA) and their associated receptors orchestrate physiological processes such as feeding, locomotion and metabolism. Here we show that monoterpenes not only act as biopesticides in Drosophila species but can cause complex behavioural alterations that require a functional type 1 tyramine receptors (TAR1s). Variations in metabolic traits as well as locomotory activity were evaluated in both Drosophila suzukii and Drosophila melanogaster after treatment with three monoterpenes. A TAR1−/−D. melanogaster strain was used to better understand the relationships between the receptor and monoterpenes-related behavioural changes. Immunohistochemistry analysis revealed that, in the D. melanogaster brain, TAR1 appeared to be expressed in areas controlling metabolism. In comparison to the D. melanogaster wild type, the TAR−/− flies showed a phenotype characterized by higher triglyceride levels and food intake as well as lower locomotory activity. The monoterpenes, tested at sublethal concentrations, were able to induce a downregulation of the TAR1 coding gene in both Drosophila species. Furthermore, monoterpenes also altered the behaviour in D. suzukii and D. melanogaster wild types 24 h after a continuous monoterpene exposure. Interestingly, they were ineffective in modifying the physiological performances of TAR1−/− flies. In conclusion, it appears that monoterpenes not only act as biopesticides for Drosophila but they can also interfere with its behaviour and metabolism in a TAR1-dependent fashion.


1970 ◽  
Vol 14 (5) ◽  
pp. 405-412
Author(s):  
Chieko Nakao ◽  
Isamu Tagaya ◽  
Toshihiko Komatsu ◽  
Hideo Kodama
Keyword(s):  

mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Gurvani B. Singh ◽  
Hyewon Byun ◽  
Almas F. Ali ◽  
Frank Medina ◽  
Dennis Wylie ◽  
...  

ABSTRACT Complex human-pathogenic retroviruses cause high morbidity and mortality worldwide, but resist antiviral drugs and vaccine development due to evasion of the immune response. A complex retrovirus, mouse mammary tumor virus (MMTV), requires replication in B and T lymphocytes for mammary gland transmission and is antagonized by the innate immune restriction factor murine Apobec3 (mA3). To determine whether the regulatory/accessory protein Rem affects innate responses to MMTV, a splice-donor mutant (MMTV-SD) lacking Rem expression was injected into BALB/c mice. Mammary tumors induced by MMTV-SD had a lower proviral load, lower incidence, and longer latency than mammary tumors induced by wild-type MMTV (MMTV-WT). MMTV-SD proviruses had many G-to-A mutations on the proviral plus strand, but also C-to-T transitions within WRC motifs. Similarly, a lymphomagenic MMTV variant lacking Rem expression showed decreased proviral loads and increased WRC motif mutations relative to those in wild-type-virus-induced tumors, consistent with activation-induced cytidine deaminase (AID) mutagenesis in lymphoid cells. These mutations are typical of the Apobec family member AID, a B-cell-specific mutagenic protein involved in antibody variable region hypermutation. In contrast, mutations in WRC motifs and proviral loads were similar in MMTV-WT and MMTV-SD proviruses from tumors in AID-insufficient mice. AID was not packaged in MMTV virions. Rem coexpression in transfection experiments led to AID proteasomal degradation. Our data suggest that rem specifies a human-pathogenic immunodeficiency virus type 1 (HIV-1) Vif-like protein that inhibits AID and antagonizes innate immunity during MMTV replication in lymphocytes. IMPORTANCE Complex retroviruses, such as human-pathogenic immunodeficiency virus type 1 (HIV-1), cause many human deaths. These retroviruses produce lifelong infections through viral proteins that interfere with host immunity. The complex retrovirus mouse mammary tumor virus (MMTV) allows for studies of host-pathogen interactions not possible in humans. A mutation preventing expression of the MMTV Rem protein in two different MMTV strains decreased proviral loads in tumors and increased viral genome mutations typical of an evolutionarily ancient enzyme, AID. Although the presence of AID generally improves antibody-based immunity, it may contribute to human cancer progression. We observed that coexpression of MMTV Rem and AID led to AID destruction. Our results suggest that Rem is the first known protein inhibitor of AID and that further experiments could lead to new disease treatments.


2019 ◽  
Vol 476 (6) ◽  
pp. 991-1003 ◽  
Author(s):  
Vijaykumar Pillalamarri ◽  
Tarun Arya ◽  
Neshatul Haque ◽  
Sandeep Chowdary Bala ◽  
Anil Kumar Marapaka ◽  
...  

Abstract Natural product ovalicin and its synthetic derivative TNP-470 have been extensively studied for their antiangiogenic property, and the later reached phase 3 clinical trials. They covalently modify the conserved histidine in Type 2 methionine aminopeptidases (MetAPs) at nanomolar concentrations. Even though a similar mechanism is possible in Type 1 human MetAP, it is inhibited only at millimolar concentration. In this study, we have discovered two Type 1 wild-type MetAPs (Streptococcus pneumoniae and Enterococcus faecalis) that are inhibited at low micromolar to nanomolar concentrations and established the molecular mechanism. F309 in the active site of Type 1 human MetAP (HsMetAP1b) seems to be the key to the resistance, while newly identified ovalicin sensitive Type 1 MetAPs have a methionine or isoleucine at this position. Type 2 human MetAP (HsMetAP2) also has isoleucine (I338) in the analogous position. Ovalicin inhibited F309M and F309I mutants of human MetAP1b at low micromolar concentration. Molecular dynamics simulations suggest that ovalicin is not stably placed in the active site of wild-type MetAP1b before the covalent modification. In the case of F309M mutant and human Type 2 MetAP, molecule spends more time in the active site providing time for covalent modification.


2010 ◽  
Vol 298 (2) ◽  
pp. G255-G266 ◽  
Author(s):  
Takashi Mizushima ◽  
Makoto Sasaki ◽  
Tomoaki Ando ◽  
Tsuneya Wada ◽  
Mamoru Tanaka ◽  
...  

Mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1) is an important target in the treatment of inflammatory bowel disease (IBD). Recently, treatment of IBD with an antibody to α4β7-integrin, a ligand for MAdCAM-1, has been an intense focus of research. Our aim was to clarify the mechanism by which MAdCAM-1 is regulated via angiotensin II type 1 receptor (AT1R), and to verify if AT1R might be a novel target for IBD treatment. The role of AT1R in the expression of MAdCAM-1 in SVEC (a murine high endothelial venule cell) and MJC-1 (a mouse colonic endothelial cell) was examined following cytokine stimulation. We further evaluated the effect of AT1R on the pathogenesis of immune-mediated colitis using AT1R-deficient (AT1R−/−) mice and a selective AT1R blocker. AT1R blocker significantly suppressed MAdCAM-1 expression induced by TNF-α, but did not inhibit phosphorylation of p38 MAPK or of IκB that modulate MAdCAM-1 expression. However, NF-κB translocation into the nucleus was inhibited by these treatments. In a murine colitis model induced by dextran sulfate sodium, the degree of colitis, judged by body weight loss, histological damage, and the disease activity index, was much milder in AT1R−/− than in wild-type mice. The expression of MAdCAM-1 was also significantly lower in AT1R−/− than in wild-type mice. These results suggest that AT1R regulates the expression of MAdCAM-1 under colonic inflammatory conditions through regulation of the translocation of NF-κB into the nucleus. Furthermore, inhibition of AT1R ameliorates colitis in a mouse colitis model. Therefore, AT1R might be one of new therapeutic target of IBD via regulation of MAdCAM-1.


2007 ◽  
Vol 82 (1) ◽  
pp. 138-147 ◽  
Author(s):  
Mamoru Fujiwara ◽  
Junko Tanuma ◽  
Hirokazu Koizumi ◽  
Yuka Kawashima ◽  
Kazutaka Honda ◽  
...  

ABSTRACT There is much evidence that in human immunodeficiency virus type 1 (HIV-1)-infected individuals, strong cytotoxic T lymphocyte (CTL)-mediated immune pressure results in the selection of HIV-1 mutants that have escaped from wild-type-specific CTLs. If escape mutant-specific CTLs are not elicited in new hosts sharing donor HLA molecules, the transmission of these mutants results in the accumulation of escape mutants in the population. However, whether escape mutant-specific CTLs are definitively not elicited in new hosts sharing donor HLA molecules still remains unclear. A previous study showed that a Y-to-F substitution at the second position (2F) of the Nef138-10 epitope is significantly detected in HLA-A*2402+ hemophilic donors. Presently, we confirmed that this 2F mutant was an escape mutant by demonstrating strong and weak abilities of Nef138-10-specific CTL clones to suppress replication of the wild-type and 2F mutant viruses, respectively. We demonstrated the existence of the 2F-specific CTLs in three new hosts who had been primarily infected with the 2F mutant. The 2F-specific CTL clones suppressed the replication of both wild-type and mutant viruses. However, the abilities of these clones to suppress replication of the 2F virus were much weaker than those of wild-type-specific and the 2F-specific ones to suppress replication of the wild-type virus. These findings indicate that the 2F mutant is conserved in HIV-1-infected donors having HLA-A*2402, because the 2F-specific CTLs failed to completely suppress the 2F mutant replication and effectively prevented viral reversion in new hosts carrying HLA-A*2402.


Blood ◽  
2004 ◽  
Vol 103 (3) ◽  
pp. 1105-1113 ◽  
Author(s):  
Patricia Hixson ◽  
C. Wayne Smith ◽  
Susan B. Shurin ◽  
Michael F. Tosi

AbstractTwo novel CD18 mutations were identified in a patient who was a compound heterozygote with type 1 leukocyte adhesion deficiency and whose phenotype was typical except that he exhibited hypertrophic scarring. A deletion of 36 nucleotides in exon 12 (1622del36) predicted the net loss of 12 amino acid (aa) residues in the third cysteine-rich repeat of the extracellular stalk region (mut-1). A nonsense mutation in exon 15 (2200G>T), predicted a 36-aa truncation of the cytoplasmic domain (mut-2). Lymphocyte function-associated antigen 1 (LFA-1) and macrophage antigen-1 (Mac-1) containing the mut-1 β2 subunit were expressed at very low levels compared with wild-type (wt) β2. Mac-1 and LFA-1 expression with the mut-2 β2 subunit were equivalent to results with wt β2. Binding function of Mac-1 with mut-2 β2 was equivalent to that with wt β2. However, binding function of LFA-1 with the mut-2 β2 subunit was reduced by 50% versus wt β2. It was concluded that (1) the portion of the CD18 stalk region deleted in mut-1 is critical for β2 integrin heterodimer expression but the portion of the cytoplasmic domain truncated in mut-2 is not; and (2) the mut-2 cytoplasmic domain truncation impairs binding function of LFA-1 but not of Mac-1. Studies with the patient's neutrophils (PMNs) were consistent with functional impairment of LFA-1 but not of Mac-1. (Blood. 2004;103:1105-1113)


2004 ◽  
Vol 78 (4) ◽  
pp. 1718-1729 ◽  
Author(s):  
Haili Zhang ◽  
Yan Zhou ◽  
Cecily Alcock ◽  
Tara Kiefer ◽  
Daphne Monie ◽  
...  

ABSTRACT Human immunodeficiency virus type 1 (HIV-1)-infected individuals who develop drug-resistant virus during antiretroviral therapy may derive benefit from continued treatment for two reasons. First, drug-resistant viruses can retain partial susceptibility to the drug combination. Second, therapy selects for drug-resistant viruses that may have reduced replication capacities relative to archived, drug-sensitive viruses. We developed a novel single-cell-level phenotypic assay that allows these two effects to be distinguished and compared quantitatively. Patient-derived gag-pol sequences were cloned into an HIV-1 reporter virus that expresses an endoplasmic reticulum-retained Env-green fluorescent protein fusion. Flow cytometric analysis of single-round infections allowed a quantitative analysis of viral replication over a 4-log dynamic range. The assay faithfully reproduced known in vivo drug interactions occurring at the level of target cells. Simultaneous analysis of single-round infections by wild-type and resistant viruses in the presence and absence of the relevant drug combination divided the benefit of continued nonsuppressive treatment into two additive components, residual virus susceptibility to the drug combination and selection for drug-resistant variants with diminished replication capacities. In some patients with drug resistance, the dominant circulating viruses retained significant susceptibility to the combination. However, in other cases, the dominant drug-resistant viruses showed no residual susceptibility to the combination but had a reduced replication capacity relative to the wild-type virus. In this case, simplification of the regimen might still allow adequate suppression of the wild-type virus. In a third pattern, the resistant viruses had no residual susceptibility to the relevant drug regimen but nevertheless had a replication capacity equivalent to that of wild-type virus. In such cases, there is no benefit to continued treatment. Thus, the ability to simultaneously analyze residual susceptibility and reduced replication capacity of drug-resistant viruses may provide a basis for rational therapeutic decisions in the setting of treatment failure.


2003 ◽  
Vol 77 (11) ◽  
pp. 6541-6545 ◽  
Author(s):  
Hein J. Boot ◽  
Daniella T. J. Kasteel ◽  
Anne-Marie Buisman ◽  
Tjeerd G. Kimman

ABSTRACT The emergence of circulating vaccine-derived poliovirus (cVDPV) strains in suboptimally vaccinated populations is a serious threat to the global poliovirus eradication. The genetic determinants for the transmissibility phenotype of polioviruses, and in particularly of cVDPV strains, are currently unknown. Here we describe the fecal excretion of wild-type poliovirus, oral polio vaccine, and cVDPV (Hispaniola) strains after intraperitoneal injection in poliovirus receptor-transgenic mice. Both the pattern and the level of fecal excretion of the cVDPV strains resemble those of wild-type poliovirus type 1. In contrast, very little poliovirus was present in the feces after oral polio vaccine administration. This mouse model will be helpful in elucidating the genetic determinants for the high fecal-oral transmission phenotype of cVDPV strains.


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