Alteração na representação de subpopulações de neurônios no epitélio olfatório de camundongos Ric8b cKO / Altered representation of neuronal sub-populations in the olfactory epithelium of Ric8b conditional knock-out mice

O objetivo desse trabalho foi identificar as consequências moleculares e funcionais da falta da proteína Ric8b no epitélio olfatório de camundongos. Para esse fim, comparamos o transcriptoma de epitélio olfatório de camundongos knock-out tecido específico para a proteína RIC8B (Ric8b cKO) com o dos seus irmãos tipo selvagem (WT). Identificamos muitos genes que apresentaram expressão reduzida no epitélio olfatório do camundongo Ric8b cKO, mas também vários genes que apresentaram a sua expressão aumentada. A maioria dos genes com expressão reduzida corresponde a genes normalmente expressos em neurônios olfatórios maduros, como por exemplo os genes de receptores olfatórios, o que é compatível com o fato já conhecido de que os camundongos Ric8b cKO apresentam um menor número desses neurônios. Inesperadamente, apesar de a maioria dos genes de receptores olfatórios ter a sua expressão diminuída no camundongo Ric8b cKO, observamos que um grupo destes genes de receptores teve a sua expressão aumentada. Os camundongos Ric8b cKO apresentaram também genes marcadores de outros tipos celulares que não neurônios canônicos com expressão aumentada no seu epitélio olfatório. Dentre eles, os mais significativamente alterados foram os genes marcadores de neurônios Trpc2+ tipo B (que expressam a guanilato ciclase solúvel Gucy1b2). Sabe-se que este tipo de neurônio é responsável pela sensibilidade a diferentes gases, e concordantemente, observamos que os camundongos Ric8b cKO apresentaram um aumento da sensibilidade a gás carbônico. Como o olfato apresenta um papel importante na regulação de ingestão alimentar, analisamos como os camundongos Ric8b cKO se comportam frente a diferentes dietas. Interessantemente, observamos que esses animais não apresentam preferência por alimento rico em gorduras quando comparado aos seus irmãos tipo selvagem. Nossos resultados sugerem, portanto, que a ausência da proteína RIC8B resulta na alteração de representatividade de neurônios canônicos e não canônicos no epitélio olfatório de camundongos, o que por sua vez leva a alterações funcionais e comportamentais

The objective of this work was to identify the molecular and functional consequences of the lack of the RIC8B protein in the main olfactory epithelium of mice. To this end, we compared the olfactory epithelium transcriptome of Ric8b tissue-specific knock-out mice (Ric8b cKO) with that of their wild-type littermates (WT). We identified many genes with differential expression, many of which were downregulated and also some which were upregulated in the olfactory epithelium of the Ric8b cKO mice. Most of the downregulated genes correspond to genes normally expressed in mature olfactory sensory neurons, such as olfactory receptor genes. This is compatible with the already known fact that the Ric8b cKO mice have less of this kind of neuron. Unexpectedly, even though most of the olfactory receptor genes were downregulated, we observed a subset of these genes that had their expression upregulated in the Ric8b cKO mice. The Ric8b cKO mice also showed upregulation for genes that are markers for cell types other than canonic neurons in their olfactory epithelium. Among these, the most significantly altered were the markers for neurons Trpc2+ type B (that express the soluble guanylate cyclase Gucy1b2). It is known that this kind of neuron is responsible for sensitivity to different gases. Accordingly, we observed that the Ric8b cKO mice presented a higher sensitivity to carbon dioxide. Since olfaction has an important role in food intake, we analyzed how the Ric8b cKO mice behaved with different diets. Interestingly, we observed that the Ric8b cKO mice lack preference for high fat diet when compared to their wild-type littermates. Our results indicate, therefore, that the lack of the RIC8B protein results in altered representativity of canonic and non-canonic neurons in the olfactory epithelium of mice, which then leads to altered function and behavior

Study on herb property expression of pungent-aromatic Citri Reticulatae Pericarpium, Caryophylli Flos, and Foeniculi Fructus based on network pharmacology of olfactory receptors / 中草药

Objective: In this study, network pharmacology techniques and methods were used to screen the material basis, targets and pathways of the interaction between the pungent-aromatic herbs (Citri Reticulatae Pericarpium, Caryophylli Flos, and Foeniculi Fructus) and olfactory receptor. To explain the molecular mechanism of the expression of pungent properties of the pungent-aromatic herb. Methods: TCMSP database was used to collect the chemical components of Citri Reticulatae Pericarpium, Caryophylli Flos, and Foeniculi Fructus, in order to screen out the effective components and predict the related targets. All the proteins related to olfactory receptors were collected from UniProt database. The selected targets and ORs proteins were uploaded to the online STRING database for protein interaction analysis. The interaction network was drawn by using the software of Cytoscape software, and the key targets was further analyzed by GO functional enrichment analysis and KEGG pathway enrichment analysis. Results: Five active components of Citri Reticulatae Pericarpium, five of Caryophylli Flos and two of Foeniculi Fructus, 224 targets and 515 olfactory receptors were obtained. Protein interaction network showed 25 targets (such as GNB2, CHRM2, CHRM3, GNGT2, ADRA2A) were the key targets for ORs of three pungent-aromatic herbs. The enrichment analysis of GO and KEGG identified 31 biological processes and 78 signaling pathways. Conclusion: Olfactory receptors are mainly activated by volatile oil components of the pungent-aromatic herb. And the classical cAMP signaling pathway may not be the only one after the olfactory receptor activated, which may be involved in the expression of pungent properties of the pungent-aromatic herb together with several other signaling pathways, so as to produce "pungent flavor".

Approaches and methods of property-flavour material basis of Chinese materia medica based on molecular docking technology of taste and olfactory receptors / 中草药

The theory on the property of Chinese materia medica (CMM) is one of the core contents of CMM theory, among which five flavors theory is the core content of CMM theory. The objective characterization of the five flavors of CMM is the key to the theoretical study of CMM, which is an important way to explain the scientific connotation of CMM. Based on the basic definition of five tastes medicinal properties and the interaction of drug molecules-taste, olfactory receptors, authors put forward the research methods using molecular docking technology and the research approach. In this study, the expression of five tastes drug property was systematically discussed from the aspects of biological mechanisms of taste, olfactory perception, molecular docking, homology modeling, and receptor selection, which provides a reference method for the study of drug property theory from the perspective of taste and smell attribute of five tastes.