Computational exploration of molecular receptive fields in the olfactory bulb reveals a glomerulus-centric chemical map

© The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Progress in olfactory research is currently hampered by incomplete knowledge about chemical receptive ranges of primary receptors. Moreover, the chemical logic underlying the arrangement of computational units in the olfactory bulb has still not been resolved. We undertook a large-scale approach at characterising molecular receptive ranges (MRRs) of glomeruli in the dorsal olfactory bulb (dOB) innervated by the MOR18-2 olfactory receptor, also known as Olfr78, with human ortholog OR51E2. Guided by an iterative approach that combined biological screening and machine learning, we selected 214 odorants to characterise the response of MOR18-2 and its neighbouring glomeruli. We found that a combination of conventional physico-chemical and vibrational molecular descriptors performed best in predicting glomerular responses using nonlinear Support-Vector Regression. We also discovered several previously unknown odorants activating MOR18-2 glomeruli, and obtained detailed MRRs of MOR18-2 glomeruli and their neighbours. Our results confirm earlier findings that demonstrated tunotopy, that is, glomeruli with similar tuning curves tend to be located in spatial proximity in the dOB. In addition, our results indicate chemotopy, that is, a preference for glomeruli with similar physico-chemical MRR descriptions being located in spatial proximity. Together, these findings suggest the existence of a partial chemical map underlying glomerular arrangement in the dOB. Our methodology that combines machine learning and physiological measurements lights the way towards future high-throughput studies to deorphanise and characterise structure-activity relationships in olfaction.Peer reviewe

Elevated Levels of the Vesicular Monoamine Transporter and a Novel Repetitive Behavior in the Drosophila Model of Fragile X Syndrome

Fragile X Syndrome (FXS) is characterized by mental impairment and autism in humans, and it often features hyperactivity and repetitive behaviors. The mechanisms for the disease, however, remain poorly understood. Here we report that the dfmr1 mutant in the Drosophila model of FXS grooms excessively, which may be regulated differentially by two signaling pathways. Blocking metabotropic glutamate receptor signaling enhances grooming in dfmr1 mutant flies, whereas blocking the vesicular monoamine transporter (VMAT) suppresses excessive grooming. dfmr1 mutant flies also exhibit elevated levels of VMAT mRNA and protein. These results suggest that enhanced monoamine signaling correlates with repetitive behaviors and hyperactivity associated with FXS

Ингибирование роста и апоптоз, индуцированные 2-феноксиметил-3H-хиназолин-4-оном, в лейкозных клетках линии HL-60

Aim: The aim of the study was to investigate anticancer activity of newly synthesized 2-phenoxymethyl-3H-quinazolin-4-one (PMQ). Materials and Methods: Anticancer activity of PMQ was studied towards human HL-60 leukemia cells. Antiproliferative activity of PMQ was determined by direct counting of cells using trypan blue staining technique. Apoptosis and cell cycle profile changes were analysed using internucleosomal DNA fragmentation assay and flow cytometry. Activation of caspases and changes in glutathione level were monitored using colorimetric or luminiscent methods. Results: PMQ induced concentration-dependent cytotoxicity in leukemia cells, with IC50 of 10.8 ± 0.9 µM. DNA flow cytometry analysis and DNA ladder formation assay indicated that PMQ actively induced apoptosis of cells accompanied by a block of cells in G2/M phase and a marked loss of cells in G0/G1 and S phases. Additionally, the activities of caspase-3 and caspase-9 were increased significantly and a markedly increased level of oxidized glutahione was observed. Inhibition of glutahione synthesis using buthionine sulfoximine sensitized leukemia cells to PMQ, confirming the involvement of ROS in PMQ-induced apoptosis. Conclusion: The results of this study clearly demonstrate that PMQ is a promising anticancer drug showing cytostatic and apoptotic effects toward HL-60 leukemia cells mainly through mitochondrial/caspase-9 dependent pathway.Цель: изучить антипролиферативную активность нового синтезированного 2-феноксиметил-3Н-хиназолин-4-она (PMQ). Материалы и методы: антипролиферативную активность PMQ определяли по отношению к клеткам лейкоза линии HL-60 в тесте с трипановым синим при стандартном подсчете клеток. Апоптоз и клеточный цикл оценивали с помощью проточной цитометрии и анализа фрагментации внутриядерной ДНК. Активацию каспаз и изменения уровня глутатиона определяли колориметрическими или люминисцентными методами. Результаты: PMQ индуцирует дозозависимую цитотоксичность в клетках линии HL-60 (IC50 при 10,8 ± 0,9 μM). При проведении анализа ДНК с применением проточной цитометрии и определением формирования апоптической лестницы было показано, что PMQ активно индуцирует апоптоз и блокаду клеточного цикла в G2 /M фазе митоза и выраженной потерей клеток в G0 /G1 и S фазах. Кроме того, была достоверно повышена активность каспазы-3 и -9 и выраженно увеличен уровень окисленного глутатиона. Применение бутионин сульфоксимина привело к угнетению синтеза глутатиона и повышению чувствительности клеток HL-60 к PMQ, что подтверждает факт участия РФК в PMQ-индуцированном апоптозе. Выводы: PMQ проявил себя как потенциальное противоопухолевое средство против клеток лейкоза человека HL-60 с выраженным цитостатическим и проапоптическим действием.This study was supported by the Science and Technology Assistance Agency under the contract No. APVT-20-007304 and by the VEGA grants 2/7088/27 and 1/4305/

Антипролиферативнoe и проапоптотическoe действие 6-бромо-2-(морфолин-1-ИЛ)- 4-анилиноиназолина на лейкозные клетки

Quinazolines are known to be multitarget agents with broad spectrum of biological activity. Aim: To investigate anticancer activity of newly prepared 6-bromo-2-(morpholin-1-yl)-4-anilinoquinazoline (BMAQ) towards L1210, HL-60 and U-937 leukemia cells. Materials and Methods: Growth inhibition of BMAQ-treated cells was determined by cell counting using trypan blue staining technique. Apoptosis and cell cycle profile changes were analysed using internucleosomal DNA fragmentation assay, fluorescence microscopy and flow cytometry. Activity of caspase-3 was determined using colorimetric method. Results: Cell proliferation assay showed that BMAQ caused significant decrease of cell number in a dose-dependent manner. BMAQ induced cell death by apoptosis, based on results from DNA fragmentation, fluorescence microscopy and caspase-3 assays. Conclusion: Presented results clearly demonstrate that BMAQ is a promising anticancer agent with significant antiproliferative and apoptotic activities towards leukemia cells in vitro.Квиназолины известны как химиопрепараты широкого спектра действия. Цель: на моделях лейкозных клеток линий L1210, HL-60 и U-937 изучить противоопухолевую активность нового препарата 6-бромо-2-(морфолин-1-ил)-4-аналиноиназолина (BMAQ). Методы: ингибирование роста клеток под действием BMAQ изучали путем подсчета количества клеток, окрашенных трипановым синим. Апоптоз и изменения профиля клеточного цикла исследовали с помощью флуоресцентной микроскопии, электрофореза ДНК и проточной цитометрии. Активность каспазы-3 определяли колориметрическим методом. Результаты: показано, что BMAQ вызывает значительное дозозависимое уменьшение количества лейкозных клеток. При этом клетки, обработанные BMAQ, погибают путем апоптоза, что дается образованием апоптотических телец, межнуклеосомной фрагментацией ДНК и активацией каспазы-3. Выводы: представленные результаты свидетельствуют о том, что BMAQ обладает антипролиферативной и проапоптотической активностью в отношении лейкозных клеток in vitro.This work was supported by the Grant Agency for Science Research of the Ministry of Education of the Slovak Republic, VEGA number 1/1173/04 and Technology Assistance Agency under the contract No. APVT 20-007304