List of Publications (2011-Current)
2023
Kim, Hye In; Lee, Gi Baek; Song, Da Eun; Sanjel, Babina; Lee, Wook-Joo; Shim, Won-Sik
In: Life Sciences, vol. 325, 2023, ISSN: 0024-3205.
Abstract | Links | BibTeX | Tags: Calcium imaging, FSLLRY, Itch, MrgprC11, MRGPRX1, PAR2, Scratching behavior
@article{InKim2023,
title = {FSLLRY-NH2, a protease-activated receptor 2 (PAR2) antagonist, activates mas-related G protein-coupled receptor C11 (MrgprC11) to induce scratching behaviors in mice},
author = {Hye In Kim and Gi Baek Lee and Da Eun Song and Babina Sanjel and Wook-Joo Lee and Won-Sik Shim},
doi = {10.1016/j.lfs.2023.121786},
issn = {0024-3205},
year = {2023},
date = {2023-07-00},
urldate = {2023-07-00},
journal = {Life Sciences},
volume = {325},
publisher = {Elsevier BV},
abstract = {Aims: Protease-activated receptor 2 (PAR2), a type of G protein-coupled receptor (GPCR), plays a significant role in pathophysiological conditions such as inflammation. A synthetic peptide SLIGRL-NH2 (SLIGRL) can activate PAR2, while FSLLRY-NH2 (FSLLRY) is an antagonist. A previous study showed that SLIGRL activates both PAR2 and mas-related G protein-coupled receptor C11 (MrgprC11), a different type of GPCR expressed in sensory neurons. However, the impact of FSLLRY on MrgprC11 and its human ortholog MRGPRX1 was not verified. Hence, the present study aims to verify the effect of FSLLRY on MrgprC11 and MRGPRX1.
Methods: The calcium imaging technique was applied to determine the effect of FSLLRY in HEK293T cells expressing MrgprC11/MRGPRX1 or dorsal root ganglia (DRG) neurons. Scratching behavior was also investigated in wild-type and PAR2 knockout mice after injecting FSLLRY.
Key findings: It was surprisingly discovered that FSLLRY specifically activates MrgprC11 in a dose-dependent manner, but not other MRGPR subtypes. Furthermore, FSLLRY also moderately activated MRGPRX1. FSLLRY stimulates downstream pathways including Gαq/11, phospholipase C, IP3 receptor, and TRPC ion channels to evoke an increase in the intracellular calcium levels. The molecular docking analysis predicted that FSLLRY interacts with the orthosteric binding pocket of MrgprC11 and MRGPRX1. Finally, FSLLRY activated primary cultures of mouse sensory neurons, and induced scratching behaviors in mice.
Significance: The present study has revealed that FSLLRY is capable of triggering itch sensation through activation of MrgprC11. This finding highlights the importance of considering the unexpected activation of MRGPRs in future therapeutic approaches aimed at the inhibition of PAR2.},
keywords = {Calcium imaging, FSLLRY, Itch, MrgprC11, MRGPRX1, PAR2, Scratching behavior},
pubstate = {published},
tppubtype = {article}
}
Aims: Protease-activated receptor 2 (PAR2), a type of G protein-coupled receptor (GPCR), plays a significant role in pathophysiological conditions such as inflammation. A synthetic peptide SLIGRL-NH2 (SLIGRL) can activate PAR2, while FSLLRY-NH2 (FSLLRY) is an antagonist. A previous study showed that SLIGRL activates both PAR2 and mas-related G protein-coupled receptor C11 (MrgprC11), a different type of GPCR expressed in sensory neurons. However, the impact of FSLLRY on MrgprC11 and its human ortholog MRGPRX1 was not verified. Hence, the present study aims to verify the effect of FSLLRY on MrgprC11 and MRGPRX1.
Methods: The calcium imaging technique was applied to determine the effect of FSLLRY in HEK293T cells expressing MrgprC11/MRGPRX1 or dorsal root ganglia (DRG) neurons. Scratching behavior was also investigated in wild-type and PAR2 knockout mice after injecting FSLLRY.
Key findings: It was surprisingly discovered that FSLLRY specifically activates MrgprC11 in a dose-dependent manner, but not other MRGPR subtypes. Furthermore, FSLLRY also moderately activated MRGPRX1. FSLLRY stimulates downstream pathways including Gαq/11, phospholipase C, IP3 receptor, and TRPC ion channels to evoke an increase in the intracellular calcium levels. The molecular docking analysis predicted that FSLLRY interacts with the orthosteric binding pocket of MrgprC11 and MRGPRX1. Finally, FSLLRY activated primary cultures of mouse sensory neurons, and induced scratching behaviors in mice.
Significance: The present study has revealed that FSLLRY is capable of triggering itch sensation through activation of MrgprC11. This finding highlights the importance of considering the unexpected activation of MRGPRs in future therapeutic approaches aimed at the inhibition of PAR2.
Methods: The calcium imaging technique was applied to determine the effect of FSLLRY in HEK293T cells expressing MrgprC11/MRGPRX1 or dorsal root ganglia (DRG) neurons. Scratching behavior was also investigated in wild-type and PAR2 knockout mice after injecting FSLLRY.
Key findings: It was surprisingly discovered that FSLLRY specifically activates MrgprC11 in a dose-dependent manner, but not other MRGPR subtypes. Furthermore, FSLLRY also moderately activated MRGPRX1. FSLLRY stimulates downstream pathways including Gαq/11, phospholipase C, IP3 receptor, and TRPC ion channels to evoke an increase in the intracellular calcium levels. The molecular docking analysis predicted that FSLLRY interacts with the orthosteric binding pocket of MrgprC11 and MRGPRX1. Finally, FSLLRY activated primary cultures of mouse sensory neurons, and induced scratching behaviors in mice.
Significance: The present study has revealed that FSLLRY is capable of triggering itch sensation through activation of MrgprC11. This finding highlights the importance of considering the unexpected activation of MRGPRs in future therapeutic approaches aimed at the inhibition of PAR2.
2022
Afzal, Ramsha; Shim, Won-Sik
In: Biochimica et Biophysica Acta (BBA) - Biomembranes, vol. 1864, no. 11, 2022, ISSN: 0005-2736.
Abstract | Links | BibTeX | Tags: 5-HT2R, Calcium imaging, Glucosylsphingosine, TRPA1, TRPV1
@article{Afzal2022,
title = {Activation of serotonin receptor 2 by glucosylsphingosine can be enhanced by TRPA1 but not TRPV1: Implication of a novel glucosylsphingosine-mediated itch pathway},
author = {Ramsha Afzal and Won-Sik Shim},
doi = {10.1016/j.bbamem.2022.184014},
issn = {0005-2736},
year = {2022},
date = {2022-11-00},
urldate = {2022-11-00},
journal = {Biochimica et Biophysica Acta (BBA) - Biomembranes},
volume = {1864},
number = {11},
publisher = {Elsevier BV},
abstract = {Glucosylsphingosine (GS) is an endogenous sphingolipid that specifically accumulates in the skin of patients with atopic dermatitis (AD). Notably, it was recently found that GS can induce itch sensation by activating serotonin receptor 2A and TRPV4 ion channels. However, it is still uncertain whether other molecules are involved in GS-induced itch sensation. Therefore, by using the calcium imaging technique, we investigated whether serotonin receptor 2 - specifically 2A and 2B - can interact with TRPV1 and TRPA1, because these are representative ion channels in the transmission of itch. As a result, it was found that GS did not activate TRPV1 or TRPA1 per se. Moreover, cells expressing both serotonin receptor 2 and TRPV1 did not show any changes in calcium responses. However, enhanced calcium responses were observed in cells expressing serotonin receptor 2 and TRPA1, suggesting a possible interaction between these two molecules. Similar synergistic effects were also observed in cells expressing serotonin receptor 2 and TRPA1, but not TRPV1. Furthermore, a phospholipase C inhibitor (U73122) and a store-operated calcium entry blocker (SKF96365) significantly reduced GS-induced responses in cells expressing both serotonin receptor 2 and TRPA1, but not with pre-treatment with a Gβγ-complex blocker (gallein). Therefore, we propose a putative novel pathway for GS-induced itch sensation, such that serotonin receptor 2 could be coupled to TRPA1 but not TRPV1 in sensory neurons.},
keywords = {5-HT2R, Calcium imaging, Glucosylsphingosine, TRPA1, TRPV1},
pubstate = {published},
tppubtype = {article}
}
Glucosylsphingosine (GS) is an endogenous sphingolipid that specifically accumulates in the skin of patients with atopic dermatitis (AD). Notably, it was recently found that GS can induce itch sensation by activating serotonin receptor 2A and TRPV4 ion channels. However, it is still uncertain whether other molecules are involved in GS-induced itch sensation. Therefore, by using the calcium imaging technique, we investigated whether serotonin receptor 2 - specifically 2A and 2B - can interact with TRPV1 and TRPA1, because these are representative ion channels in the transmission of itch. As a result, it was found that GS did not activate TRPV1 or TRPA1 per se. Moreover, cells expressing both serotonin receptor 2 and TRPV1 did not show any changes in calcium responses. However, enhanced calcium responses were observed in cells expressing serotonin receptor 2 and TRPA1, suggesting a possible interaction between these two molecules. Similar synergistic effects were also observed in cells expressing serotonin receptor 2 and TRPA1, but not TRPV1. Furthermore, a phospholipase C inhibitor (U73122) and a store-operated calcium entry blocker (SKF96365) significantly reduced GS-induced responses in cells expressing both serotonin receptor 2 and TRPA1, but not with pre-treatment with a Gβγ-complex blocker (gallein). Therefore, we propose a putative novel pathway for GS-induced itch sensation, such that serotonin receptor 2 could be coupled to TRPA1 but not TRPV1 in sensory neurons.
Adhikari, Nisha; Shim, Won-Sik
Caffeic acid phenethyl ester inhibits pseudo-allergic reactions via inhibition of MRGPRX2/MrgprB2-dependent mast cell degranulation Journal Article
In: Arch. Pharm. Res., vol. 45, no. 9, pp. 644–657, 2022, ISSN: 1976-3786.
Abstract | Links | BibTeX | Tags: Allergy, Calcium imaging, Mast cell, MrgprB2, MRGPRX2
@article{Adhikari2022,
title = {Caffeic acid phenethyl ester inhibits pseudo-allergic reactions via inhibition of MRGPRX2/MrgprB2-dependent mast cell degranulation},
author = {Nisha Adhikari and Won-Sik Shim},
doi = {10.1007/s12272-022-01405-2},
issn = {1976-3786},
year = {2022},
date = {2022-09-00},
urldate = {2022-09-00},
journal = {Arch. Pharm. Res.},
volume = {45},
number = {9},
pages = {644--657},
publisher = {Springer Science and Business Media LLC},
abstract = {Mast cells play essential role in allergic reactions through the process called mast cell degranulation. Recent studies have found that a basic secretagogue compound 48/80 (C48/80) induces non-IgE-mediated mast cell degranulation via activation of human Mas-related G protein-coupled receptor X2 (MRGPRX2) and mouse MrgprB2. Although previous studies have revealed that caffeic acid (CA) and its derivatives possess anti-allergic effects via IgE-dependent manner, it is largely elusive whether these compounds have impact on MRGPRX2/MrgprB2 to exert inhibitory effects. Therefore, the present study investigated whether CA as well as its derivatives - rosmarinic acid (RA) and caffeic acid phenethyl ester (CAPE) - has the ability to inhibit the activity of MRGPRX2/MrgprB2 to evoke pseudo-allergic effects. As a result, it was found that CAPE inhibits C48/80-induced activation of MRGPRX2/MrgprB2, but neither CA nor RA showed discernible inhibition. Furthermore, the β-hexosaminidase release assay showed that CAPE inhibits mouse peritoneal mast cell degranulation in both IgE-dependent and MrgprB2-dependent manners. Additionally, mouse paw edema induced by C48/80 was dramatically suppressed by co-treatment of CAPE, suggesting that CAPE possesses a protective effect on C48/80-evoked pseudo-allergic reactions. The pretreatment of CAPE also significantly decreased scratching bouts of mice evoked by C48/80, demonstrating that CAPE also has an anti-pruritic effect. Therefore, these data implicate that CAPE can suppress pseudo-allergic reactions evoked by C48/80 via MrgprB2-dependent manner. Finally, molecular docking analysis showed that CAPE is predicted to bind to human MRGPRX2 in the region where C48/80 also binds, implying that CAPE can be a competitive inhibitor of MRGPRX2. In conclusion, it is found that CAPE has the ability to inhibit MRGPRX2/MrgprB2, leading to the prevention of mast cell degranulation and further to the alleviation of mast cell reactions. These results indicate that CAPE as a CA derivative could be developed as a new protective agent that exerts dual inhibition of mast cell degranulation mediated by IgE and MRGPRX2/MrgprB2.},
keywords = {Allergy, Calcium imaging, Mast cell, MrgprB2, MRGPRX2},
pubstate = {published},
tppubtype = {article}
}
Mast cells play essential role in allergic reactions through the process called mast cell degranulation. Recent studies have found that a basic secretagogue compound 48/80 (C48/80) induces non-IgE-mediated mast cell degranulation via activation of human Mas-related G protein-coupled receptor X2 (MRGPRX2) and mouse MrgprB2. Although previous studies have revealed that caffeic acid (CA) and its derivatives possess anti-allergic effects via IgE-dependent manner, it is largely elusive whether these compounds have impact on MRGPRX2/MrgprB2 to exert inhibitory effects. Therefore, the present study investigated whether CA as well as its derivatives - rosmarinic acid (RA) and caffeic acid phenethyl ester (CAPE) - has the ability to inhibit the activity of MRGPRX2/MrgprB2 to evoke pseudo-allergic effects. As a result, it was found that CAPE inhibits C48/80-induced activation of MRGPRX2/MrgprB2, but neither CA nor RA showed discernible inhibition. Furthermore, the β-hexosaminidase release assay showed that CAPE inhibits mouse peritoneal mast cell degranulation in both IgE-dependent and MrgprB2-dependent manners. Additionally, mouse paw edema induced by C48/80 was dramatically suppressed by co-treatment of CAPE, suggesting that CAPE possesses a protective effect on C48/80-evoked pseudo-allergic reactions. The pretreatment of CAPE also significantly decreased scratching bouts of mice evoked by C48/80, demonstrating that CAPE also has an anti-pruritic effect. Therefore, these data implicate that CAPE can suppress pseudo-allergic reactions evoked by C48/80 via MrgprB2-dependent manner. Finally, molecular docking analysis showed that CAPE is predicted to bind to human MRGPRX2 in the region where C48/80 also binds, implying that CAPE can be a competitive inhibitor of MRGPRX2. In conclusion, it is found that CAPE has the ability to inhibit MRGPRX2/MrgprB2, leading to the prevention of mast cell degranulation and further to the alleviation of mast cell reactions. These results indicate that CAPE as a CA derivative could be developed as a new protective agent that exerts dual inhibition of mast cell degranulation mediated by IgE and MRGPRX2/MrgprB2.
Sanjel, Babina; Kim, Bo‐Hyun; Song, Myung‐Hyun; Carstens, Earl; Shim, Won‐Sik
Glucosylsphingosine evokes pruritus via activation of 5‐HT2A receptor and TRPV4 in sensory neurons Journal Article
In: British J Pharmacology, vol. 179, no. 10, pp. 2193–2207, 2022, ISSN: 1476-5381.
Abstract | Links | BibTeX | Tags: 5-HT2R, Atopic dermatitis, Calcium imaging, Dorsal root ganglia, Glucosylsphingosine, TRPV4
@article{Sanjel2022b,
title = {Glucosylsphingosine evokes pruritus via activation of 5‐HT_{2A} receptor and TRPV4 in sensory neurons},
author = {Babina Sanjel and Bo‐Hyun Kim and Myung‐Hyun Song and Earl Carstens and Won‐Sik Shim},
doi = {10.1111/bph.15733},
issn = {1476-5381},
year = {2022},
date = {2022-05-00},
urldate = {2022-05-00},
journal = {British J Pharmacology},
volume = {179},
number = {10},
pages = {2193--2207},
publisher = {Wiley},
abstract = {Background and purpose
Glucosylsphingosine (GS), an endogenous sphingolipid, is highly accumulated in the epidermis of patients with atopic dermatitis (AD) due to abnormal ceramide metabolism. More importantly, GS can evoke scratching behaviours. However, the precise molecular mechanism by which GS induces pruritus has been elusive. Thus, the present study aimed to elucidate the molecular signalling pathway of GS, especially at the peripheral sensory neuronal levels.
Experimental approach
Calcium imaging was used to investigate the responses of HEK293T cells or mouse dorsal root ganglion (DRG) neurons to application of GS. Scratching behaviour tests were also performed with wild-type and Trpv4 knockout mice.
Key results
GS activated DRG neurons in a manner involving both the 5-HT2A receptor and TRPV4. Furthermore, GS-induced responses were significantly suppressed by various inhibitors, including ketanserin (5-HT2A receptor antagonist), YM254890 (Gαq/11 inhibitor), gallein (Gβγ complex inhibitor), U73122 (phospholipase C inhibitor), bisindolylmaleimide I (PKC inhibitor) and HC067047 (TRPV4 antagonist). Moreover, DRG neurons from Trpv4 knockout mice exhibited significantly reduced responses to GS. Additionally, GS-evoked scratching behaviours were greatly decreased by pretreatment with inhibitors of either 5-HT2A receptor or TRPV4. As expected, GS-evoked scratching behaviour was also significantly decreased in Trpv4 knockout mice.
Conclusion and implications
Overall, the present study provides evidence for a novel molecular signalling pathway for GS-evoked pruritus, which utilizes both 5-HT2A receptor and TRPV4 in mouse sensory neurons. Considering the high accumulation of GS in the epidermis of patients with AD, GS could be another pruritogen in patients with AD.},
keywords = {5-HT2R, Atopic dermatitis, Calcium imaging, Dorsal root ganglia, Glucosylsphingosine, TRPV4},
pubstate = {published},
tppubtype = {article}
}
Background and purpose
Glucosylsphingosine (GS), an endogenous sphingolipid, is highly accumulated in the epidermis of patients with atopic dermatitis (AD) due to abnormal ceramide metabolism. More importantly, GS can evoke scratching behaviours. However, the precise molecular mechanism by which GS induces pruritus has been elusive. Thus, the present study aimed to elucidate the molecular signalling pathway of GS, especially at the peripheral sensory neuronal levels.
Experimental approach
Calcium imaging was used to investigate the responses of HEK293T cells or mouse dorsal root ganglion (DRG) neurons to application of GS. Scratching behaviour tests were also performed with wild-type and Trpv4 knockout mice.
Key results
GS activated DRG neurons in a manner involving both the 5-HT2A receptor and TRPV4. Furthermore, GS-induced responses were significantly suppressed by various inhibitors, including ketanserin (5-HT2A receptor antagonist), YM254890 (Gαq/11 inhibitor), gallein (Gβγ complex inhibitor), U73122 (phospholipase C inhibitor), bisindolylmaleimide I (PKC inhibitor) and HC067047 (TRPV4 antagonist). Moreover, DRG neurons from Trpv4 knockout mice exhibited significantly reduced responses to GS. Additionally, GS-evoked scratching behaviours were greatly decreased by pretreatment with inhibitors of either 5-HT2A receptor or TRPV4. As expected, GS-evoked scratching behaviour was also significantly decreased in Trpv4 knockout mice.
Conclusion and implications
Overall, the present study provides evidence for a novel molecular signalling pathway for GS-evoked pruritus, which utilizes both 5-HT2A receptor and TRPV4 in mouse sensory neurons. Considering the high accumulation of GS in the epidermis of patients with AD, GS could be another pruritogen in patients with AD.
Glucosylsphingosine (GS), an endogenous sphingolipid, is highly accumulated in the epidermis of patients with atopic dermatitis (AD) due to abnormal ceramide metabolism. More importantly, GS can evoke scratching behaviours. However, the precise molecular mechanism by which GS induces pruritus has been elusive. Thus, the present study aimed to elucidate the molecular signalling pathway of GS, especially at the peripheral sensory neuronal levels.
Experimental approach
Calcium imaging was used to investigate the responses of HEK293T cells or mouse dorsal root ganglion (DRG) neurons to application of GS. Scratching behaviour tests were also performed with wild-type and Trpv4 knockout mice.
Key results
GS activated DRG neurons in a manner involving both the 5-HT2A receptor and TRPV4. Furthermore, GS-induced responses were significantly suppressed by various inhibitors, including ketanserin (5-HT2A receptor antagonist), YM254890 (Gαq/11 inhibitor), gallein (Gβγ complex inhibitor), U73122 (phospholipase C inhibitor), bisindolylmaleimide I (PKC inhibitor) and HC067047 (TRPV4 antagonist). Moreover, DRG neurons from Trpv4 knockout mice exhibited significantly reduced responses to GS. Additionally, GS-evoked scratching behaviours were greatly decreased by pretreatment with inhibitors of either 5-HT2A receptor or TRPV4. As expected, GS-evoked scratching behaviour was also significantly decreased in Trpv4 knockout mice.
Conclusion and implications
Overall, the present study provides evidence for a novel molecular signalling pathway for GS-evoked pruritus, which utilizes both 5-HT2A receptor and TRPV4 in mouse sensory neurons. Considering the high accumulation of GS in the epidermis of patients with AD, GS could be another pruritogen in patients with AD.
Song, Myung-Hyun; Shim, Won-Sik
Lithocholic Acid Activates Mas-Related G Protein-Coupled Receptors, Contributing to Itch in Mice Journal Article
In: Biomol Ther (Seoul), vol. 30, no. 1, pp. 38–47, 2022, ISSN: 2005-4483.
Abstract | Links | BibTeX | Tags: Bile acid, Calcium imaging, Itch, Lithocholic acid, MrgprA1, MrgprB2, MRGPRX4
@article{Song2022,
title = {Lithocholic Acid Activates Mas-Related G Protein-Coupled Receptors, Contributing to Itch in Mice},
author = {Myung-Hyun Song and Won-Sik Shim},
doi = {10.4062/biomolther.2021.059},
issn = {2005-4483},
year = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
journal = {Biomol Ther (Seoul)},
volume = {30},
number = {1},
pages = {38--47},
publisher = {The Korean Society of Applied Pharmacology},
abstract = {The present study focused on lithocholic acid (LCA), a secondary bile acid that contributes to cholestatic pruritus. Although recent studies have found that LCA acts on MAS-related G protein-coupled receptor family member X4 (MRGPRX4) in humans, it is unclear which subtypes of MRGPRs are activated by LCA in mice since there is no precise ortholog of human MRGPRX4 in the mouse genome. Using calcium imaging, we found that LCA could activate mouse Mrgpra1 when transiently expressed in HEK293T cells. Moreover, LCA similarly activates mouse Mrgprb2. Importantly, LCA-induced responses showed dose-dependent effects through Mrgpra1 and Mrgprb2. Moreover, treatment with QWF (an antagonist of Mrgpra1 and Mrgprb2), YM254890 (Gαq inhibitor), and U73122 (an inhibitor of phospholipase C) significantly suppressed the LCA-induced responses, implying that the LCA-induced responses are indeed mediated by Mrgpra1 and Mrgprb2. Furthermore, LCA activated primary cultures of mouse sensory neurons and peritoneal mast cells, suggesting that Mrgpra1 and Mrgprb2 contribute to LCA-induced pruritus. However, acute injection of LCA did not induce noticeable differences in scratching behavior, implying that the pruritogenic role of LCA may be marginal in non-cholestatic conditions. In summary, the present study identified for the first time that LCA can activate Mrgpra1 and Mrgprb2. The current findings provide further insight into the similarities and differences between human and mouse MRGPR families, paving a way to understand the complex roles of these pruriceptors.},
keywords = {Bile acid, Calcium imaging, Itch, Lithocholic acid, MrgprA1, MrgprB2, MRGPRX4},
pubstate = {published},
tppubtype = {article}
}
The present study focused on lithocholic acid (LCA), a secondary bile acid that contributes to cholestatic pruritus. Although recent studies have found that LCA acts on MAS-related G protein-coupled receptor family member X4 (MRGPRX4) in humans, it is unclear which subtypes of MRGPRs are activated by LCA in mice since there is no precise ortholog of human MRGPRX4 in the mouse genome. Using calcium imaging, we found that LCA could activate mouse Mrgpra1 when transiently expressed in HEK293T cells. Moreover, LCA similarly activates mouse Mrgprb2. Importantly, LCA-induced responses showed dose-dependent effects through Mrgpra1 and Mrgprb2. Moreover, treatment with QWF (an antagonist of Mrgpra1 and Mrgprb2), YM254890 (Gαq inhibitor), and U73122 (an inhibitor of phospholipase C) significantly suppressed the LCA-induced responses, implying that the LCA-induced responses are indeed mediated by Mrgpra1 and Mrgprb2. Furthermore, LCA activated primary cultures of mouse sensory neurons and peritoneal mast cells, suggesting that Mrgpra1 and Mrgprb2 contribute to LCA-induced pruritus. However, acute injection of LCA did not induce noticeable differences in scratching behavior, implying that the pruritogenic role of LCA may be marginal in non-cholestatic conditions. In summary, the present study identified for the first time that LCA can activate Mrgpra1 and Mrgprb2. The current findings provide further insight into the similarities and differences between human and mouse MRGPR families, paving a way to understand the complex roles of these pruriceptors.
2021
Lee, Wook-Joo; Shim, Won-Sik
Cutaneous Neuroimmune Interactions of TSLP and TRPV4 Play Pivotal Roles in Dry Skin-Induced Pruritus Journal Article
In: Front. Immunol., vol. 12, 2021, ISSN: 1664-3224.
Abstract | Links | BibTeX | Tags: Calcium imaging, Dorsal root ganglia, Dry skin, Itch, TSLP
@article{Lee2021,
title = {Cutaneous Neuroimmune Interactions of TSLP and TRPV4 Play Pivotal Roles in Dry Skin-Induced Pruritus},
author = {Wook-Joo Lee and Won-Sik Shim},
doi = {10.3389/fimmu.2021.772941},
issn = {1664-3224},
year = {2021},
date = {2021-12-02},
urldate = {2021-12-02},
journal = {Front. Immunol.},
volume = {12},
publisher = {Frontiers Media SA},
abstract = {Dry skin is a symptom of skin barrier dysfunction that evokes pruritus; however, the cutaneous neuroimmune interactions underlying dry skin-induced pruritus remain unclear. Therefore, we aimed to elucidate the mechanisms underlying dry skin-induced pruritus. To this end, an acetone/ethanol/water (AEW)-induced mouse model of dry skin was used in this study. We observed that the production of thymic stromal lymphopoietin (TSLP) significantly increased in the keratinocytes of AEW mice. Importantly, treatment with an antagonist of transient receptor potential cation channel subfamily V member 4 (TRPV4), HC067047, ameliorated dry skin conditions in AEW mice. The symptoms of dry skin were significantly reduced in Trpv4 knockout (KO) mice following treatment with AEW. The increase in the intracellular calcium levels by TSLP in the dorsal root ganglia (DRG) of Trpv4 KO mice was also significantly attenuated. The spontaneous scratching bouts were significantly decreased in both the HC067047-treated and Trpv4 KO AEW mice. Importantly, the TSLP-dependent release of tryptase from the mast cells was significantly reduced in both the HC067047-treated mice and Trpv4 KO AEW mice. Notably, inhibition of the TSLP-induced signaling pathway in DRG selectively reduced the spontaneous scratching bouts in AEW mice. Overall, the results demonstrated that the cutaneous neuroimmune interactions of TSLP and TRPV4 play pivotal roles in dry skin-induced pruritus. },
keywords = {Calcium imaging, Dorsal root ganglia, Dry skin, Itch, TSLP},
pubstate = {published},
tppubtype = {article}
}
<jats:p>Dry skin is a symptom of skin barrier dysfunction that evokes pruritus; however, the cutaneous neuroimmune interactions underlying dry skin-induced pruritus remain unclear. Therefore, we aimed to elucidate the mechanisms underlying dry skin-induced pruritus. To this end, an acetone/ethanol/water (AEW)-induced mouse model of dry skin was used in this study. We observed that the production of thymic stromal lymphopoietin (TSLP) significantly increased in the keratinocytes of AEW mice. Importantly, treatment with an antagonist of transient receptor potential cation channel subfamily V member 4 (TRPV4), HC067047, ameliorated dry skin conditions in AEW mice. The symptoms of dry skin were significantly reduced in <jats:italic>Trpv4</jats:italic> knockout (KO) mice following treatment with AEW. The increase in the intracellular calcium levels by TSLP in the dorsal root ganglia (DRG) of <jats:italic>Trpv4</jats:italic> KO mice was also significantly attenuated. The spontaneous scratching bouts were significantly decreased in both the HC067047-treated and <jats:italic>Trpv4</jats:italic> KO AEW mice. Importantly, the TSLP-dependent release of tryptase from the mast cells was significantly reduced in both the HC067047-treated mice and <jats:italic>Trpv4</jats:italic> KO AEW mice. Notably, inhibition of the TSLP-induced signaling pathway in DRG selectively reduced the spontaneous scratching bouts in AEW mice. Overall, the results demonstrated that the cutaneous neuroimmune interactions of TSLP and TRPV4 play pivotal roles in dry skin-induced pruritus.</jats:p>
2020
Yum, Chorok; Ahn, Taekyoung; Shim, Won-Sik
Development of a Novel Blue Fluorescent Gene-encoded Calcium Indicator Modified from GCaMP3 Journal Article
In: J Fluoresc, vol. 30, no. 6, pp. 1287–1293, 2020, ISSN: 1573-4994.
Abstract | Links | BibTeX | Tags: Calcium imaging, GCaMP3, GFP
@article{Yum2020,
title = {Development of a Novel Blue Fluorescent Gene-encoded Calcium Indicator Modified from GCaMP3},
author = {Chorok Yum and Taekyoung Ahn and Won-Sik Shim},
doi = {10.1007/s10895-020-02606-y},
issn = {1573-4994},
year = {2020},
date = {2020-12-00},
urldate = {2020-12-00},
journal = {J Fluoresc},
volume = {30},
number = {6},
pages = {1287--1293},
publisher = {Springer Science and Business Media LLC},
abstract = {Intracellular calcium can be monitored by various calcium-specific fluorescent dyes including gene-encoded calcium indicators (GECI). GCaMP is a widely-used GECI that emits green fluorescence proportional to the level of intracellular calcium. However, since many tagging proteins also emit green fluorescence, GCaMP cannot be used with another green fluorescent protein. Therefore, it would be ideal to develop a GECI that has a distinct color profile other than green. In this regard, we developed a novel blue fluorescentcalcium indicator modified from GCaMP called Ser222-Ala229-Cys330-BCaMP3. Specifically, a simple threonine to histidine substitution to a green fluorescent Cys330-GCaMP3 successfully changed its fluorescence to blue (Cys330-BCaMP3, B for blue). Furthermore, a couple of additional amino acid substitutions resulted in more enhanced blue fluorescence intensity. Among other Cys330-BCaMP3 variants, it was found that Ser222-Ala229-Cys330-BCaMP3 exhibited the strongest blue fluorescence intensity. When Ser222-Ala229-Cys330-BCaMP3 was co-expressed with TRPA1 – a non-selective cation channel – in HEK293T cells, it showed moderate bluefluorescence. One of the drawbacks of Ser222-Ala229-Cys330-BCaMP3 was that the fluorescence intensity was not enough when cellswere cultured under 37°C. However, this limitation was circumvented by lowering cell culture temperature to 28°C, allowing muchmore enhanced blue fluorescence. Although Ser222-Ala229-Cys330-BCaMP3 mandates further optimization, the present study hasfound a promising blue fluorescent GECI that is derived from GCaMP3.},
keywords = {Calcium imaging, GCaMP3, GFP},
pubstate = {published},
tppubtype = {article}
}
Intracellular calcium can be monitored by various calcium-specific fluorescent dyes including gene-encoded calcium indicators (GECI). GCaMP is a widely-used GECI that emits green fluorescence proportional to the level of intracellular calcium. However, since many tagging proteins also emit green fluorescence, GCaMP cannot be used with another green fluorescent protein. Therefore, it would be ideal to develop a GECI that has a distinct color profile other than green. In this regard, we developed a novel blue fluorescentcalcium indicator modified from GCaMP called Ser222-Ala229-Cys330-BCaMP3. Specifically, a simple threonine to histidine substitution to a green fluorescent Cys330-GCaMP3 successfully changed its fluorescence to blue (Cys330-BCaMP3, B for blue). Furthermore, a couple of additional amino acid substitutions resulted in more enhanced blue fluorescence intensity. Among other Cys330-BCaMP3 variants, it was found that Ser222-Ala229-Cys330-BCaMP3 exhibited the strongest blue fluorescence intensity. When Ser222-Ala229-Cys330-BCaMP3 was co-expressed with TRPA1 – a non-selective cation channel – in HEK293T cells, it showed moderate bluefluorescence. One of the drawbacks of Ser222-Ala229-Cys330-BCaMP3 was that the fluorescence intensity was not enough when cellswere cultured under 37°C. However, this limitation was circumvented by lowering cell culture temperature to 28°C, allowing muchmore enhanced blue fluorescence. Although Ser222-Ala229-Cys330-BCaMP3 mandates further optimization, the present study hasfound a promising blue fluorescent GECI that is derived from GCaMP3.
Choi, Da-Som; Ji, Yeounjung; Jang, Yongwoo; Lee, Wook-Joo; Shim, Won-Sik
In: Biomolecules & Therapeutics, vol. 28, no. 6, pp. 569–575, 2020, ISSN: 2005-4483.
Abstract | Links | BibTeX | Tags: Calcium imaging, Chloroquine, H1R, Histamine, Itch, MrgprA3, TRPA1, TRPV1
@article{Choi2020,
title = {Crotamiton, an Anti-Scabies Agent, Suppresses Histamine- and Chloroquine-Induced Itch Pathways in Sensory Neurons and Alleviates Scratching in Mice},
author = {Da-Som Choi and Yeounjung Ji and Yongwoo Jang and Wook-Joo Lee and Won-Sik Shim},
doi = {10.4062/biomolther.2020.063},
issn = {2005-4483},
year = {2020},
date = {2020-11-01},
urldate = {2020-11-01},
journal = {Biomolecules & Therapeutics},
volume = {28},
number = {6},
pages = {569--575},
publisher = {The Korean Society of Applied Pharmacology},
abstract = {Crotamiton is an anti-scabies drug, but it was recently found that crotamiton also suppresses non-scabietic itching in mice. However, the underlying mechanism is largely unclear. Therefore, aim of the study is to investigate mechanisms of the anti-pruritic effect of crotamiton for non-scabietic itching. Histamine and chloroquine are used as non-scabietic pruritogens. The effect of crotamiton was identified using fluorometric intracellular calcium assays in HEK293T cells and primary cultured dorsal root ganglion (DRG) neurons. Further in vivo effect was evaluated by scratching behavior tests. Crotamiton strongly inhibited histamine-induced calcium influx in HEK293T cells, expressing both histamine receptor 1 (H1R) and transient receptor potential vanilloid 1 (TRPV1), as a model of histamine-induced itching. Similarly, it also blocked chloroquine-induced calcium influx in HEK293T cells, expressing both Mas-related G-protein-coupled receptor A3 (MRGPRA3) and transient receptor potential A1 (TRPA1), as a model of histamine-independent itching. Furthermore, crotamiton also suppressed both histamine- and chloroquine-induced calcium influx in primary cultures of mouse DRG. Additionally, crotamiton strongly suppressed histamine- and chloroquine-induced scratching in mice. Overall, it was found that crotamiton has an anti-pruritic effect against non-scabietic itching by histamine and chloroquine. Therefore, crotamiton may be used as a general anti-pruritic agent, irrespective of the presence of scabies.},
keywords = {Calcium imaging, Chloroquine, H1R, Histamine, Itch, MrgprA3, TRPA1, TRPV1},
pubstate = {published},
tppubtype = {article}
}
Crotamiton is an anti-scabies drug, but it was recently found that crotamiton also suppresses non-scabietic itching in mice. However, the underlying mechanism is largely unclear. Therefore, aim of the study is to investigate mechanisms of the anti-pruritic effect of crotamiton for non-scabietic itching. Histamine and chloroquine are used as non-scabietic pruritogens. The effect of crotamiton was identified using fluorometric intracellular calcium assays in HEK293T cells and primary cultured dorsal root ganglion (DRG) neurons. Further in vivo effect was evaluated by scratching behavior tests. Crotamiton strongly inhibited histamine-induced calcium influx in HEK293T cells, expressing both histamine receptor 1 (H1R) and transient receptor potential vanilloid 1 (TRPV1), as a model of histamine-induced itching. Similarly, it also blocked chloroquine-induced calcium influx in HEK293T cells, expressing both Mas-related G-protein-coupled receptor A3 (MRGPRA3) and transient receptor potential A1 (TRPA1), as a model of histamine-independent itching. Furthermore, crotamiton also suppressed both histamine- and chloroquine-induced calcium influx in primary cultures of mouse DRG. Additionally, crotamiton strongly suppressed histamine- and chloroquine-induced scratching in mice. Overall, it was found that crotamiton has an anti-pruritic effect against non-scabietic itching by histamine and chloroquine. Therefore, crotamiton may be used as a general anti-pruritic agent, irrespective of the presence of scabies.
2019
Sanjel, Babina; Maeng, Han-Joo; Shim, Won-Sik
BAM8-22 and its receptor MRGPRX1 may attribute to cholestatic pruritus Journal Article
In: Sci Rep, vol. 9, no. 1, 2019, ISSN: 2045-2322.
Abstract | Links | BibTeX | Tags: Animal model, Calcium imaging, Cholestasis, Dorsal root ganglia, MrgprC11, MRGPRX1, Scratching behavior
@article{Sanjel2019,
title = {BAM8-22 and its receptor MRGPRX1 may attribute to cholestatic pruritus},
author = {Babina Sanjel and Han-Joo Maeng and Won-Sik Shim},
doi = {10.1038/s41598-019-47267-5},
issn = {2045-2322},
year = {2019},
date = {2019-12-00},
urldate = {2019-12-00},
journal = {Sci Rep},
volume = {9},
number = {1},
publisher = {Springer Science and Business Media LLC},
abstract = {Pruritus is an unexpected symptom observed in cholestasis and its mechanism is still unclear. Here, we show that bovine adrenal medulla (BAM) 8–22, an endogenous itch-inducing peptide, could be involved in cholestatic pruritus. It was found that bile duct ligation (BDL) mice, an obstructive cholestasis model, showed increased spontaneous scratching behaviour. Importantly, the mRNA level of proenkephalin, a precursor polypeptide of BAM8-22, was significantly increased in the skin of BDL mice. Furthermore, the mRNA level of Mrgprx1, which encodes a receptor for BAM8-22, was significantly increased in the dorsal root ganglia (DRG) of BDL mice. This was further confirmed by elevation of intracellular calcium levels upon BAM8-22 treatment in primarily-cultured DRG neurons. In addition, BDL mice showed augmented scratching behaviour by BAM8-22, indicating enhanced activity of MRGPRX1. Moreover, the skin homogenate of BDL mice induced elevation of intracellular calcium levels through MRGPRX1. Finally, among the various bile acids, chenodeoxycholic acid significantly increased proenkephalin transcription in a human keratinocyte cell line (HaCaT). In conclusion, cholestatic pruritus could be attributed in part to enhanced action of both BAM8-22 in the skin and its receptor MRGPRX1 in sensory neurons.},
keywords = {Animal model, Calcium imaging, Cholestasis, Dorsal root ganglia, MrgprC11, MRGPRX1, Scratching behavior},
pubstate = {published},
tppubtype = {article}
}
Pruritus is an unexpected symptom observed in cholestasis and its mechanism is still unclear. Here, we show that bovine adrenal medulla (BAM) 8–22, an endogenous itch-inducing peptide, could be involved in cholestatic pruritus. It was found that bile duct ligation (BDL) mice, an obstructive cholestasis model, showed increased spontaneous scratching behaviour. Importantly, the mRNA level of proenkephalin, a precursor polypeptide of BAM8-22, was significantly increased in the skin of BDL mice. Furthermore, the mRNA level of Mrgprx1, which encodes a receptor for BAM8-22, was significantly increased in the dorsal root ganglia (DRG) of BDL mice. This was further confirmed by elevation of intracellular calcium levels upon BAM8-22 treatment in primarily-cultured DRG neurons. In addition, BDL mice showed augmented scratching behaviour by BAM8-22, indicating enhanced activity of MRGPRX1. Moreover, the skin homogenate of BDL mice induced elevation of intracellular calcium levels through MRGPRX1. Finally, among the various bile acids, chenodeoxycholic acid significantly increased proenkephalin transcription in a human keratinocyte cell line (HaCaT). In conclusion, cholestatic pruritus could be attributed in part to enhanced action of both BAM8-22 in the skin and its receptor MRGPRX1 in sensory neurons.
Kim, Bo Hyun; Lee, Wook-Joo; Sanjel, Babina; Cho, Kyohee; Son, Youn Kyoung; Park, Hye Yoon; Kim, Sun Yeou; Shim, Won-Sik
Extracts of the leaves of Pyrus ussuriensis Maxim. Alleviate itch sensation via TSLP-dependent manner in mouse models of atopic dermatitis Journal Article
In: Physiology & Behavior, vol. 210, 2019, ISSN: 0031-9384.
Abstract | Links | BibTeX | Tags: Animal model, Atopic dermatitis, Calcium imaging, Itch, Scratching behavior, TSLP
@article{Kim2019,
title = {Extracts of the leaves of Pyrus ussuriensis Maxim. Alleviate itch sensation via TSLP-dependent manner in mouse models of atopic dermatitis},
author = {Bo Hyun Kim and Wook-Joo Lee and Babina Sanjel and Kyohee Cho and Youn Kyoung Son and Hye Yoon Park and Sun Yeou Kim and Won-Sik Shim},
doi = {10.1016/j.physbeh.2019.112624},
issn = {0031-9384},
year = {2019},
date = {2019-10-00},
urldate = {2019-10-00},
journal = {Physiology & Behavior},
volume = {210},
publisher = {Elsevier BV},
abstract = {Pyrus ussuriensis Maxim. commonly known as “Sandolbae” in Korean is a pear tree widely distributed across East Asia. Recent studies indicate that P. ussuriensis Maxim. leaves (PUL) have antipruritic effects. This study aimed to determine the effects of PUL extract and its fractions in decreasing the itch sensation and skin lesions in two distinct animal models of atopic dermatitis (AD) induced by dinitrofluorobenzene (DNFB) or house dust mite(HDM). Our results showed that the total ethanol extract of PUL decreased the scratching behavior in mice withDNFB- and HDM-induced AD. Moreover, the ethyl acetate fraction of PUL significantly improved the overallcondition of the mice with AD induced by HDM. Further, we used HEK293T cells that express receptors and ion channels for thymic stromal lymphopoietin (TSLP), a potent pruritogen for AD, to determine the mechanismsunderlying the antipruritic effects of PUL extract/fractions. Specific subfractions of the PUL strongly inhibited the increase in calcium levels induced by TSLP. In addition, the specific subfraction of PUL inhibited the TSLP-induced increase in calcium levels in cultured mouse dorsal root ganglia neurons. Thus, our results showed thatthe PUL extract could be effective for alleviating pruritus, and the antipruritic effects were exerted probably viathe inhibition of the TSLP pathway in peripheral sensory neurons governing the itch sensation in AD.},
keywords = {Animal model, Atopic dermatitis, Calcium imaging, Itch, Scratching behavior, TSLP},
pubstate = {published},
tppubtype = {article}
}
Pyrus ussuriensis Maxim. commonly known as “Sandolbae” in Korean is a pear tree widely distributed across East Asia. Recent studies indicate that P. ussuriensis Maxim. leaves (PUL) have antipruritic effects. This study aimed to determine the effects of PUL extract and its fractions in decreasing the itch sensation and skin lesions in two distinct animal models of atopic dermatitis (AD) induced by dinitrofluorobenzene (DNFB) or house dust mite(HDM). Our results showed that the total ethanol extract of PUL decreased the scratching behavior in mice withDNFB- and HDM-induced AD. Moreover, the ethyl acetate fraction of PUL significantly improved the overallcondition of the mice with AD induced by HDM. Further, we used HEK293T cells that express receptors and ion channels for thymic stromal lymphopoietin (TSLP), a potent pruritogen for AD, to determine the mechanismsunderlying the antipruritic effects of PUL extract/fractions. Specific subfractions of the PUL strongly inhibited the increase in calcium levels induced by TSLP. In addition, the specific subfraction of PUL inhibited the TSLP-induced increase in calcium levels in cultured mouse dorsal root ganglia neurons. Thus, our results showed thatthe PUL extract could be effective for alleviating pruritus, and the antipruritic effects were exerted probably viathe inhibition of the TSLP pathway in peripheral sensory neurons governing the itch sensation in AD.
2018
Lee, Wook-Joo; Kim, Young-Sik; Shim, Won-Sik
In: Journal of Ginseng Research, vol. 42, no. 4, pp. 470–475, 2018, ISSN: 1226-8453.
Abstract | Links | BibTeX | Tags: Calcium imaging, Chloroquine, Korean Red Ginseng, MrgprA3, Scratching behavior, TRPA1
@article{Lee2018,
title = {Korean Red Ginseng extract and ginsenoside Rg3 have anti-pruritic effects on chloroquine-induced itch by inhibition of MrgprA3/TRPA1-mediated pathway},
author = {Wook-Joo Lee and Young-Sik Kim and Won-Sik Shim},
doi = {10.1016/j.jgr.2017.05.004},
issn = {1226-8453},
year = {2018},
date = {2018-10-00},
urldate = {2018-10-00},
journal = {Journal of Ginseng Research},
volume = {42},
number = {4},
pages = {470--475},
publisher = {Elsevier BV},
abstract = {Background: It was previously found that Korean Red Ginseng water extract (KRGE) inhibits the histamine-induced itch signaling pathway in peripheral sensory neurons. Thus, in the present study, we investigated whether KRGE inhibited another distinctive itch pathway induced by chloroquine (CQ); a representative histamine-independent pathway mediated by MrgprA3 and TRPA1. Methods: Intracellular calcium changes were measured by the calcium imaging technique in theHEK293T cells transfected with both MrgprA3 and TRPA1 (“MrgprA3/TRPA1”), and in primary culture ofmouse dorsal root ganglia (DRGs). Mouse scratching behavior tests were performed to verify proposed antipruritic effects of KRGE and ginsenoside Rg3.Results: CQ-induced Ca2þ influx was strongly inhibited by KRGE (10 mg/mL) in MrgprA3/TRPA1, and notablyginsenoside Rg3 dose-dependently suppressed CQ-induced Ca2þ influx in MrgprA3/TRPA1. Moreover, bothKRGE (10 mg/mL) and Rg3 (100 mM) suppressed CQ-induced Ca2þ influx in primary culture of mouse DRGs,indicating that the inhibitory effect of KRGE was functional in peripheral sensory neurons. In vivo tests revealed that not only KRGE (100 mg) suppressed CQ-induced scratching in mice [bouts of scratching:274.0 51.47 (control) vs. 104.7 17.39 (KRGE)], but also Rg3 (1.5 mg) oral administration significantly reduced CQ-induced scratching as well [bouts of scratching: 216.8 33.73 (control) vs.115.7 20.94 (Rg3)]. Conclusion: The present study verified that KRGE and Rg3 have a strong antipruritic effect against CQ-induced itch. Thus, KRGE is as a promising antipruritic agent that blocks both histamine-dependent and -independent itch at peripheral sensory neuronal levels.},
keywords = {Calcium imaging, Chloroquine, Korean Red Ginseng, MrgprA3, Scratching behavior, TRPA1},
pubstate = {published},
tppubtype = {article}
}
Background: It was previously found that Korean Red Ginseng water extract (KRGE) inhibits the histamine-induced itch signaling pathway in peripheral sensory neurons. Thus, in the present study, we investigated whether KRGE inhibited another distinctive itch pathway induced by chloroquine (CQ); a representative histamine-independent pathway mediated by MrgprA3 and TRPA1. Methods: Intracellular calcium changes were measured by the calcium imaging technique in theHEK293T cells transfected with both MrgprA3 and TRPA1 (“MrgprA3/TRPA1”), and in primary culture ofmouse dorsal root ganglia (DRGs). Mouse scratching behavior tests were performed to verify proposed antipruritic effects of KRGE and ginsenoside Rg3.Results: CQ-induced Ca2þ influx was strongly inhibited by KRGE (10 mg/mL) in MrgprA3/TRPA1, and notablyginsenoside Rg3 dose-dependently suppressed CQ-induced Ca2þ influx in MrgprA3/TRPA1. Moreover, bothKRGE (10 mg/mL) and Rg3 (100 mM) suppressed CQ-induced Ca2þ influx in primary culture of mouse DRGs,indicating that the inhibitory effect of KRGE was functional in peripheral sensory neurons. In vivo tests revealed that not only KRGE (100 mg) suppressed CQ-induced scratching in mice [bouts of scratching:274.0 51.47 (control) vs. 104.7 17.39 (KRGE)], but also Rg3 (1.5 mg) oral administration significantly reduced CQ-induced scratching as well [bouts of scratching: 216.8 33.73 (control) vs.115.7 20.94 (Rg3)]. Conclusion: The present study verified that KRGE and Rg3 have a strong antipruritic effect against CQ-induced itch. Thus, KRGE is as a promising antipruritic agent that blocks both histamine-dependent and -independent itch at peripheral sensory neuronal levels.