The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Jennifer L. Pluznick - One of the best experts on this subject based on the ideXlab platform.
-
olfactory taste and photo Sensory Receptors in non Sensory organs it just makes sense
Frontiers in Physiology, 2018Co-Authors: Nicholas M Dalesio, Jennifer L. Pluznick, Sebastian Barreto F Ortiz, Dan E BerkowitzAbstract:: Sensory Receptors that detect and respond to light, taste, and smell primarily belong to the G-protein-coupled receptor (GPCR) superfamily. In addition to their established roles in the nose, tongue, and eyes, these Sensory GPCRs have been found in many 'non-Sensory' organs where they respond to different physicochemical stimuli, initiating signaling cascades in these extraSensory systems. For example, taste Receptors in the airway, and photoReceptors in vascular smooth muscle cells, both cause smooth muscle relaxation when activated. In addition, olfactory Receptors are present within the vascular system, where they play roles in angiogenesis as well as in modulating vascular tone. By better understanding the physiological and pathophysiological roles of Sensory Receptors in non-Sensory organs, novel therapeutic agents can be developed targeting these Receptors, ultimately leading to treatments for pathological conditions and potential cures for various disease states.
-
Identification and Characterization of Novel Renal Sensory Receptors
PLOS ONE, 2014Co-Authors: Premraj Rajkumar, William H. Aisenberg, Omar W. Acres, Ryan J. Protzko, Jennifer L. PluznickAbstract:: Recent studies have highlighted the important roles that "Sensory" Receptors (olfactory Receptors, taste Receptors, and orphan "GPR" Receptors) play in a variety of tissues, including the kidney. Although several studies have identified important roles that individual Sensory Receptors play in the kidney, there has not been a systematic analysis of the renal repertoire of Sensory Receptors. In this study, we identify novel renal Sensory Receptors belonging to the GPR (n = 76), olfactory receptor (n = 6), and taste receptor (n = 11) gene families. A variety of reverse transcriptase (RT)-PCR screening strategies were used to identify novel renal Sensory Receptors, which were subsequently confirmed using gene-specific primers. The tissue-specific distribution of these Receptors was determined, and the novel renal ORs were cloned from whole mouse kidney. Renal ORs that trafficked properly in vitro were screened for potential ligands using a dual-luciferase ligand screen, and novel ligands were identified for Olfr691. These studies demonstrate that multiple Sensory Receptors are expressed in the kidney beyond those previously identified. These results greatly expand the known repertoire of renal Sensory Receptors. Importantly, the mRNA of many of the Receptors identified in this study are expressed highly in the kidney (comparable to well-known and extensively studied renal GPCRs), and in future studies it will be important to elucidate the roles that these novel renal Receptors play in renal physiology.
-
Renal and cardiovascular Sensory Receptors and blood pressure regulation
American journal of physiology. Renal physiology, 2013Co-Authors: Jennifer L. PluznickAbstract:Studies over the past decade have highlighted important roles played by Sensory Receptors outside of traditionally Sensory tissues; for example, taste Receptors participate in pH sensing in the cerebrospinal fluid, bitter taste Receptors mediate bronchodilation and ciliary beating in the lung (Deshpande DA, Wang WC, McIlmoyle EL, Robinett KS, Schillinger RM, An SS, Sham JS, Liggett SB. Nat Med 16: 1299-1304, 2010; Shah AS, Ben-Shahar Y, Moninger TO, Kline JN, Welsh MJ. Science 325: 1131-1134, 2009), and olfactory Receptors play roles in both sperm chemotaxis and muscle cell migration (Griffin CA, Kafadar KA, Pavlath GK. Cell 17: 649-661, 2009). More recently, several studies have shown that Sensory Receptors also play important roles in the regulation of blood pressure. This review will focus on several recent studies examining the roles that Sensory Receptors play in blood pressure regulation, with an emphasis on three pathways: the adenylate cyclase 3 (AC3) pathway, the Gpr91-succinate signaling pathway, and the Olfr78/Gpr41 short-chain fatty acid signaling pathway. Together, these pathways demonstrate that Sensory Receptors play important roles in mediating blood pressure control and that blood pressure regulation is coupled to the metabolism of the host as well as the metabolism of the gut microbiota.
-
Renal and cardiovascular Sensory Receptors and blood pressure regulation
American Journal of Physiology-renal Physiology, 2013Co-Authors: Jennifer L. PluznickAbstract:Studies over the past decade have highlighted important roles played by Sensory Receptors outside of traditionally Sensory tissues; for example, taste Receptors participate in pH sensing in the cer...
Dieter Wicher - One of the best experts on this subject based on the ideXlab platform.
-
Sensory Receptors—design principles revisited
Frontiers in Cellular Neuroscience, 2013Co-Authors: Dieter WicherAbstract:This research topic was aimed toward collecting the present knowledge of structure and function of Sensory Receptors in animal kingdom as well as the mechanisms of signal transduction and amplification. To translate external signals such as light, sound, smell, etc., into an appropriate intracellular signal, Sensory Receptors use either a fast, direct or a slow, indirect way. These qualitatively different signal transduction pathways are now usually called ionotopic or metabotropic. Historically, the term metabotropic receptor has been introduced to distinguish a subtype of glutamate Receptors that triggers chemical reactions (cell metabolism) in the postsynaptic cell from other glutamate Receptors that pass an ion current (ionotropic) (Eccles and McGeer, 1979). Metabotropic glutamate Receptors were found to be linked to inositol phospholipid metabolism (Sugiyama et al., 1987), and were subsequently identified as G-protein-coupled Receptors (GPCRs) (Masu et al., 1991). The terminology ionotropic/metabotropic has been extended to other neurotransmitter Receptors, such as for nicotinic/muscarinergic acetyl choline or GABAA/GABAB Receptors. All metabotropic neurotransmitter Receptors are GPCRs. There are, however, a large number of non-GPCRs that also fulfill the original definition for a metabotropic receptor, namely “that the transmitter acts indirectly, by triggering a chemical reaction or a series of reactions” (Eccles and McGeer, 1979). Accordingly, it has been used to extent the term metabotropic receptor to receptor kinases, receptor cyclases, etc., as well. Sensory Receptors are often part of complex signal transduction cascades. An ion current through an ionotropic receptor may initiate metabotropic signaling, as well as a metabotropic receptor may downstream affect the function of ion channels. An example for protein–protein interaction in chemosensation is given in the original article by Liu et al. (2012). The authors identified so far unknown binding partners of Gγ13, a G-protein subunit expressed in mammalian taste and olfactory receptor cells. These binding partners are PDZ-domain containing proteins assumed to target Gγ13 to specific subcellular locations or represent parts of the chemoSensory signal transduction cascade. The evolution of chemoReceptors shows that—from bacteria to mammals—both, ionotropic as well as metabotropic mechanisms were conserved. Functional aspects of chemoReceptors, including the interaction of electrical and chemical signaling, and the amplification of Sensory information are discussed in the perspective article (Wicher, 2012). Intriguingly, insect chemoReceptors operate as ionotropic Receptors, namely odorant Receptors (ORs), ionotropic glutamate-like Receptors (IRs), and gustatory Receptors (GRs). Getahun et al. (2012) investigate the temporal response dynamics of insect chemoReceptors and demonstrate that olfactory Sensory neurons (OSNs) expressing ORs, GRs, or IRs differ in their response kinetics to brief stimuli. OR-expressing neurons respond faster and with higher sensitivity, while IR-expressing neurons do not adapt to long stimulations. Although ORs primarily operate as ionotropic Receptors, metabotropic signaling was seen to modulate the ionotropic odor response (Olsson et al., 2011; Sargsyan et al., 2011). Stimulation of cAMP production enhanced the response to a given odor concentration, corresponding to an increased sensitivity. This type of modulation may constitute the mechanistic basis for the higher sensitivity of ORs compared with IRs. Chemical information released from different sources may interfere during processing in the nervous system and affect the response of an organism. Odor mixtures can act in synergistic or in an inhibitory way. On the level of the chemoReceptors the existence of a huge number of different chemical signal molecules leads to the intriguing question of receptor specificity and whether a given chemical signal is perceived independent of the background. The interaction of odorant and pheromone detection in moths is reported by Pregitzer et al. (2012) and commented by Anton and Renou (2012). Certain plant odors are known to inhibit the activation of pheromone Receptors. The reported investigations provide evidence that the odorant-pheromone interaction already takes place at the receptor level. Since the first editorial to this topic was written in 2010 recent progress shed new light on structure and function of certain Receptors. Channelrhodopsins, for example, are photoReceptors in green algae which conduct a current upon illumination. They are seven transmembrane (7-TM)-spanning proteins as typical for GPCRs but do not couple to a heterotrimeric G-protein. With the given 7-TM topology it was as yet not clear how the channelrhodopsin proteins have to arrange to form an ion channel. Recently, the non-selective cation channel, channelrhodopsin-2 from Chlamydomonas reinhardtii has been successfully crystallized (Muller et al., 2011; Kato et al., 2012). The channelrhodopsin-2 proteins were found to stably dimerize in such an arrangement that the third and the fourth TM helix of each protein align to a tetramer thereby lining the cation-permeable pore. Another example for ion channel-forming 7-TM proteins are the above mentioned insect ORs. In contrast to homodimeric channelrhodopsin channels they are heterodimers, composed of variable, odorant-binding protein OrX, and an ubiquitous co-receptor OrCo. There is growing evidence that both OR proteins contribute to channel pore formation and determine their properties such as the ion permeability and pharmacological properties (Nichols et al., 2011; Pask et al., 2011; Nakagawa et al., 2012). It remains to be established whether OrCo form homomeric channels in the receptor neurons as seen in the heterologous expression system and whether they represent the metabotropic pathway used to tune the sensitivity of the ionotropic receptor (Olsson et al., 2011; Sargsyan et al., 2011). The role of stimulatory G-proteins in olfactory signaling has been demonstrated (Deng et al., 2011), and also downstream signaling such as cAMP production were seen to affect the odor response of receptor neurons (Olsson et al., 2011). These recent findings on insect OR function modify the view to classify them. While in the first editorial they have been considered as combined metabotropic and ionotropic Receptors, they might now be more appropriately characterized as metabotropically regulated ionotropic Receptors. This change of view illustrates the highly dynamic development in the field.
-
Sensory Receptors design principles revisited
Frontiers in Cellular Neuroscience, 2013Co-Authors: Dieter WicherAbstract:This research topic was aimed toward collecting the present knowledge of structure and function of Sensory Receptors in animal kingdom as well as the mechanisms of signal transduction and amplification. To translate external signals such as light, sound, smell, etc., into an appropriate intracellular signal, Sensory Receptors use either a fast, direct or a slow, indirect way. These qualitatively different signal transduction pathways are now usually called ionotopic or metabotropic. Historically, the term metabotropic receptor has been introduced to distinguish a subtype of glutamate Receptors that triggers chemical reactions (cell metabolism) in the postsynaptic cell from other glutamate Receptors that pass an ion current (ionotropic) (Eccles and McGeer, 1979). Metabotropic glutamate Receptors were found to be linked to inositol phospholipid metabolism (Sugiyama et al., 1987), and were subsequently identified as G-protein-coupled Receptors (GPCRs) (Masu et al., 1991). The terminology ionotropic/metabotropic has been extended to other neurotransmitter Receptors, such as for nicotinic/muscarinergic acetyl choline or GABAA/GABAB Receptors. All metabotropic neurotransmitter Receptors are GPCRs. There are, however, a large number of non-GPCRs that also fulfill the original definition for a metabotropic receptor, namely “that the transmitter acts indirectly, by triggering a chemical reaction or a series of reactions” (Eccles and McGeer, 1979). Accordingly, it has been used to extent the term metabotropic receptor to receptor kinases, receptor cyclases, etc., as well. Sensory Receptors are often part of complex signal transduction cascades. An ion current through an ionotropic receptor may initiate metabotropic signaling, as well as a metabotropic receptor may downstream affect the function of ion channels. An example for protein–protein interaction in chemosensation is given in the original article by Liu et al. (2012). The authors identified so far unknown binding partners of Gγ13, a G-protein subunit expressed in mammalian taste and olfactory receptor cells. These binding partners are PDZ-domain containing proteins assumed to target Gγ13 to specific subcellular locations or represent parts of the chemoSensory signal transduction cascade. The evolution of chemoReceptors shows that—from bacteria to mammals—both, ionotropic as well as metabotropic mechanisms were conserved. Functional aspects of chemoReceptors, including the interaction of electrical and chemical signaling, and the amplification of Sensory information are discussed in the perspective article (Wicher, 2012). Intriguingly, insect chemoReceptors operate as ionotropic Receptors, namely odorant Receptors (ORs), ionotropic glutamate-like Receptors (IRs), and gustatory Receptors (GRs). Getahun et al. (2012) investigate the temporal response dynamics of insect chemoReceptors and demonstrate that olfactory Sensory neurons (OSNs) expressing ORs, GRs, or IRs differ in their response kinetics to brief stimuli. OR-expressing neurons respond faster and with higher sensitivity, while IR-expressing neurons do not adapt to long stimulations. Although ORs primarily operate as ionotropic Receptors, metabotropic signaling was seen to modulate the ionotropic odor response (Olsson et al., 2011; Sargsyan et al., 2011). Stimulation of cAMP production enhanced the response to a given odor concentration, corresponding to an increased sensitivity. This type of modulation may constitute the mechanistic basis for the higher sensitivity of ORs compared with IRs. Chemical information released from different sources may interfere during processing in the nervous system and affect the response of an organism. Odor mixtures can act in synergistic or in an inhibitory way. On the level of the chemoReceptors the existence of a huge number of different chemical signal molecules leads to the intriguing question of receptor specificity and whether a given chemical signal is perceived independent of the background. The interaction of odorant and pheromone detection in moths is reported by Pregitzer et al. (2012) and commented by Anton and Renou (2012). Certain plant odors are known to inhibit the activation of pheromone Receptors. The reported investigations provide evidence that the odorant-pheromone interaction already takes place at the receptor level. Since the first editorial to this topic was written in 2010 recent progress shed new light on structure and function of certain Receptors. Channelrhodopsins, for example, are photoReceptors in green algae which conduct a current upon illumination. They are seven transmembrane (7-TM)-spanning proteins as typical for GPCRs but do not couple to a heterotrimeric G-protein. With the given 7-TM topology it was as yet not clear how the channelrhodopsin proteins have to arrange to form an ion channel. Recently, the non-selective cation channel, channelrhodopsin-2 from Chlamydomonas reinhardtii has been successfully crystallized (Muller et al., 2011; Kato et al., 2012). The channelrhodopsin-2 proteins were found to stably dimerize in such an arrangement that the third and the fourth TM helix of each protein align to a tetramer thereby lining the cation-permeable pore. Another example for ion channel-forming 7-TM proteins are the above mentioned insect ORs. In contrast to homodimeric channelrhodopsin channels they are heterodimers, composed of variable, odorant-binding protein OrX, and an ubiquitous co-receptor OrCo. There is growing evidence that both OR proteins contribute to channel pore formation and determine their properties such as the ion permeability and pharmacological properties (Nichols et al., 2011; Pask et al., 2011; Nakagawa et al., 2012). It remains to be established whether OrCo form homomeric channels in the receptor neurons as seen in the heterologous expression system and whether they represent the metabotropic pathway used to tune the sensitivity of the ionotropic receptor (Olsson et al., 2011; Sargsyan et al., 2011). The role of stimulatory G-proteins in olfactory signaling has been demonstrated (Deng et al., 2011), and also downstream signaling such as cAMP production were seen to affect the odor response of receptor neurons (Olsson et al., 2011). These recent findings on insect OR function modify the view to classify them. While in the first editorial they have been considered as combined metabotropic and ionotropic Receptors, they might now be more appropriately characterized as metabotropically regulated ionotropic Receptors. This change of view illustrates the highly dynamic development in the field.
-
Design principles of Sensory Receptors - Design principles of Sensory Receptors
Frontiers in Cellular Neuroscience, 2010Co-Authors: Dieter WicherAbstract:Organisms continuously detect and process physical and chemical signals from their external and internal world, and they monitor their interaction with the environment. Aristotle was the first who defined the five external senses in humans: sight, hearing, smell, taste, and touch. In addition, we consider balance as the sixth external sense. Similarly important for the control of movement is the sense of body position, the proprioception. The physiological state of the organism is reported by a variety of internal Receptors including those for gases, temperature, or pH. According to the activating stimulus Sensory Receptors can be classified into electromagnetic Receptors (photoreceptor, thermoreceptor), mechanoReceptors (hearing, touch, balance, osmoreceptor), and chemoReceptors (odorant receptor, gustatory receptor). Sensory signals are perceived by specialized neurons equipped with one type of receptor molecules as photoreceptor cells or with various types of Receptors as nociceptive neurons to detect different noxious stimuli including heat, pressure, pH, or chemical signals. Most receptor molecules are tuned to a single Sensory modality but some are polymodal as the vanilloid receptor VR1 which is activated by heat, pungent chemicals, acids, or lipids. Activation of receptor molecules by an adequate stimulus initiates a signal transduction process in the Sensory neuron in which the physical or chemical signal is amplified and converted into an electrical signal that depolarizes or hyperpolarizes the cell. The properties of the stimulus such as strength and duration are then translated into a specific temporal pattern of action potentials which is further processed in the brain.
-
design principles of Sensory Receptors
Frontiers in Cellular Neuroscience, 2010Co-Authors: Dieter WicherAbstract:Organisms continuously detect and process physical and chemical signals from their external and internal world, and they monitor their interaction with the environment. Aristotle was the first who defined the five external senses in humans: sight, hearing, smell, taste, and touch. In addition, we consider balance as the sixth external sense. Similarly important for the control of movement is the sense of body position, the proprioception. The physiological state of the organism is reported by a variety of internal Receptors including those for gases, temperature, or pH. According to the activating stimulus Sensory Receptors can be classified into electromagnetic Receptors (photoreceptor, thermoreceptor), mechanoReceptors (hearing, touch, balance, osmoreceptor), and chemoReceptors (odorant receptor, gustatory receptor). Sensory signals are perceived by specialized neurons equipped with one type of receptor molecules as photoreceptor cells or with various types of Receptors as nociceptive neurons to detect different noxious stimuli including heat, pressure, pH, or chemical signals. Most receptor molecules are tuned to a single Sensory modality but some are polymodal as the vanilloid receptor VR1 which is activated by heat, pungent chemicals, acids, or lipids. Activation of receptor molecules by an adequate stimulus initiates a signal transduction process in the Sensory neuron in which the physical or chemical signal is amplified and converted into an electrical signal that depolarizes or hyperpolarizes the cell. The properties of the stimulus such as strength and duration are then translated into a specific temporal pattern of action potentials which is further processed in the brain.
Margaretha K. S. Gustafsson - One of the best experts on this subject based on the ideXlab platform.
-
Ultrastructure studies of preadult Proteocephalus longicollis (Cestoda, Proteocephalidea): transmission electron microscopy of scolex Sensory Receptors.
Parasitology Research, 2000Co-Authors: Magdaléna Bruňanská, Hans-peter Fagerholm, Margaretha K. S. GustafssonAbstract:The ultrastructure of five types of presumed Sensory Receptors in the scolex of preadults of Proteocephalus longicollis is described. Two types of nonciliate Sensory Receptors are situated on the inner surface of the lateral sucker. They differ from each other in the shape, presence, or absence of a large rootlet, electron-dense collars, desmosomes, microtubules, and/or vesicles. In addition, three types of ciliate Sensory Receptors are found along the edges of the lateral suckers. They can be differentiated by the length of the cilium, by the number of electron-dense collars (one or two), and by types of vesicles. Four types of vesicles were found inside the ciliate Sensory Receptors. One type of ciliate Sensory receptor occurring in preadults differs markedly from any of the Sensory Receptors previously described in adult P. longicollis.
Ryo Hatsushika - One of the best experts on this subject based on the ideXlab platform.
-
Ultrastructure studies on the papillae and the nonciliated Sensory Receptors of adult Spirometra erinacei (Cestoda, Pseudophyllidea)
Parasitology Research, 1994Co-Authors: Tetsuya Okino, Ryo HatsushikaAbstract:The small numerous papillae on the ventral surface of the gravid proglottid of adultSpirometra erinacei were studied by scanning electron microscopy. The arrangement of clumps of papillae was recognized on the surface of the central portion around the genital atrium, with lateral clumps being located above a pair of longitudinal nerve cords and marginal ones, on both sides of the proglottid. By transmission electron microscopy, two types of nonciliated Sensory Receptors were observed within the papillae. The type I, single receptor was embedded within a papilla. This dome-like Sensory receptor contained two electron-dense collars and four rootlets surrounded by numerous thin filaments. The type II receptor was found arranged in groups in the area between the papillae, and the apical end was exposed to the external environment. This simple, club-like Sensory receptor contained electron-lucent vesicles and microtubules. We believe that the papillae play an important role in crossinsemination.
-
Ultrastructure studies on the papillae and the nonciliated Sensory Receptors of adultSpirometra erinacei (Cestoda, Pseudophyllidea)
Parasitology Research, 1994Co-Authors: Tetsuya Okino, Ryo HatsushikaAbstract:The small numerous papillae on the ventral surface of the gravid proglottid of adult Spirometra erinacei were studied by scanning electron microscopy. The arrangement of clumps of papillae was recognized on the surface of the central portion around the genital atrium, with lateral clumps being located above a pair of longitudinal nerve cords and marginal ones, on both sides of the proglottid. By transmission electron microscopy, two types of nonciliated Sensory Receptors were observed within the papillae. The type I, single receptor was embedded within a papilla. This dome-like Sensory receptor contained two electron-dense collars and four rootlets surrounded by numerous thin filaments. The type II receptor was found arranged in groups in the area between the papillae, and the apical end was exposed to the external environment. This simple, club-like Sensory receptor contained electron-lucent vesicles and microtubules. We believe that the papillae play an important role in crossinsemination.
Ching-yin Ho - One of the best experts on this subject based on the ideXlab platform.
-
Activation of lung vagal Sensory Receptors by circulatory endotoxin in rats
Life Sciences, 2002Co-Authors: Ching-yin HoAbstract:Abstract Although endotoxin is known to induce various pulmonary responses that are linked to the function of lung vagal Sensory Receptors, its effects on these pulmonary Receptors are still not clear. This study investigated the effects of circulatory endotoxin on the afferent activity of lung vagal Sensory Receptors in rats. We recorded afferent activity arising from vagal pulmonary C fibers (CFs), rapidly adapting Receptors (RARs), tonic pulmonary stretch Receptors (T-PSRs), and phasic pulmonary stretch Receptors (P-PSRs) in 64 anesthetized, paralyzed, and artificially ventilated rats. Intravenous injection of endotoxin (50 mg/kg; lipopolysaccharide) stimulated 7 of the 8 CFs, 8 of the 8 RARs, and 4 of the 8 T-PSRs studied, while having no effect on the 8 P-PSRs tested. The stimulation started 3–16 min after endotoxin injection and lasted until the end of the 90-min observation period. The evoked discharge of either CFs or RARs was not in phase with the ventilatory cycle, whereas that of T-PSRs showed a respiratory modulation. Injection of a saline vehicle caused no significant change in the discharge of these Receptors. Additionally, endotoxin significantly produced an increase in total lung resistance, and decreases in dynamic lung compliance and arterial blood pressure. Our results demonstrate that a majority of lung vagal Sensory Receptors are activated following intravenous injection of endotoxin, and support the notion that these pulmonary Receptors may function as an important afferent system during endotoxemia.
