Human Olfactory Receptor Sensor for Odor Reconstitution

Abstract

Among the five human senses, light, sound, and force perceived by the eye, ear, and skin, respectively are physical phenomena, and therefore can be easily measured and expressed as objective, univocal, and simple digital data with physical quantity. However, as taste and odor molecules perceived by the tongue and nose are chemical phenomena, it has been difficult to express them as objective and univocal digital data, since no reference chemicals can be defined. Therefore, while the recording, saving, transmitting to remote locations, and replaying of human visual, auditory, and tactile information as digital data in digital devices have been realized (this series of data flow is defined as DX (digital transformation) in this review), the DX of human taste and odor information is not yet in the realization stage. Particularly, since there are at least 400,000 types of odor molecules and an infinite number of complex odors that are mixtures of these molecules, it has been considered extremely difficult to realize “human olfactory DX” by converting all odors perceived by human olfaction into digital data. In this review, we discuss the current status and future prospects of the development of “human olfactory DX”, which we believe can be realized by utilizing odor sensors that employ the olfactory receptors (ORs) that support human olfaction as sensing molecules (i.e., human OR sensor).

Overexpression of olfactory receptor 78 ameliorates brain injury in cerebral ischaemia–reperfusion rats by activating Prkaca‐mediated cAMP/PKA‐MAPK pathway

“…The G protein coupled receptors (GPCRs) are essential for many organs of the body to function, including visual and olfactory signal transduction, emotional and behavioural regulation, nervous and immune systems, inflammation, and many other biological processes. 40 , 42 Olfr78, a member of the GPCR family, mediates olfactory chemosensation in the nose, and has been identified the mainly receptor for Short‐chain fatty acids (SCFAs). 9 Interestingly, Olfr78 uses several different names according to the species and organ types analysed.…”

“… 9 Interestingly, Olfr78 uses several different names according to the species and organ types analysed. 12 , 42 Olfr78 was first found to be highly expressed in human prostate, so it was originally named prostate‐specific G protein coupled receptor (PSGR), 16 and Olfr78 is known as Olr59 in rats 43 and OR51E2 in humans. 44 Previous reports have shown that Olfr78 is involved in the regulation of blood pressure in the kidney, 16 , 22 while the high expression of Olfr78 in the prostate is involved in the development of cancer.…”

“…Olfr78, a member of the GPCR family, mediates olfactory chemosensation in the nose, and has been identified the mainly receptor for Short‐chain fatty acids (SCFAs) 9 . Interestingly, Olfr78 uses several different names according to the species and organ types analysed 12,42 . Olfr78 was first found to be highly expressed in human prostate, so it was originally named prostate‐specific G protein coupled receptor (PSGR), 16 and Olfr78 is known as Olr59 in rats 43 and OR51E2 in humans 44 .…”

Biosensors for Odor Detection: A Review

“…They also include some synthetic substances similar to biological substances, such as aptamers, peptides, and molecularly imprinted polymers. The biological materials used in odor biosensors are mainly extracted from the creatures' olfactory systems, for example, olfactory epithelium [32], olfactory sensory neuron (OSN) [33], olfactory receptor (OR) protein [34][35][36], and odorant binding protein (OBP) [37,38]. These odor biosensors have higher sensitivity and selectivity towards their ligands than conventional odor sensors, and also they are not sensitive to temperature and humidity changes.…”

“…Biosensors 2023, 13, x FOR PEER REVIEW 2 of 23 creatures' olfactory systems, for example, olfactory epithelium [32], olfactory sensory neuron (OSN) [33], olfactory receptor (OR) protein [34][35][36], and odorant binding protein (OBP) [37,38]. These odor biosensors have higher sensitivity and selectivity towards their ligands than conventional odor sensors, and also they are not sensitive to temperature and humidity changes.…”