Borneol exerts its antipruritic effects by inhibiting TRPA1 and activating TRPM8

Miao Luoa,1, Jinfeng Hea,1, Liang Yina, Ping Zhanb, Zhongqiu Zhaoc, Hui Xionga,d,**, Zhinan Meia,e,*

a School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China
b Dermatology Hospital of Jiangxi Province, Nanchang, 330000, China
c Barnes-Jewish Hospital, St. Louis, MO, 63110, USA
d Ethnopharmacology Level 3 Laboratory of National Administration of Traditional Chinese Medicine, South-Central Minzu University, Wuhan, 430074, China e College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China

Ethnopharmacological relevance: Borneol is a long-established traditional Chinese medicine that has been found to be effective in treating pain and itchy skin. However, whether borneol has a therapeutic effect on chronic itch and its related mechanisms remain unclear.
Aim of the study: To investigate the antipruritic effect of borneol and its molecular mechanism.

Materials and methods: DrugBAN framework and molecular docking were applied to predict the targets of borneol, and the calcium imaging or patch-clamp recording analysis were used to detect the effects of borneol on TRPA1, TRPM8 or TRPV3 channels in HEK293T cells. In addition, various mouse models of acute itch and chronic itch were established to evaluate the antipruritic effects of borneol on C57BL/6J mice. Then, the borneol- induced pruritic relief was further investigated in Trpa1− /− , Trpm8− /− , or Trpa1− /− /Trpm8− /− mice. The effects of borneol on the activation of TRPM8 and the inhibition of TRPA1 were also measured in dorsal root ganglia neurons of wild-type (WT), Trpm8− /− and Trpv1− /− mice. Lastly, a randomized, double-blind study of adult patients was conducted to evaluate the clinical antipruritic effect of borneol.

Results: TRPA1, TRPV3 and TRPM8 are the potential targets of borneol according to the results of DrugBAN algorithm and molecular docking. Calcium imaging and patch-clamp recording analysis demonstrated that borneol activates TRPM8 channel-induced cell excitability and inhibits TRPA1 channel-mediated cell excitability in transfected HEK293T cells. Animal behavior analysis showed that borneol can significantly reduce acute and chronic itch behavior in C57BL/6J mice, but this effect was eliminated in Trpa1− /− , Trpm8− /− mice, or at least in Trpa1− /− /Trpm8− /− mice. Borneol elicits TRPM8 channel induced [Ca2+]i responses but inhibits AITC or SADBE- induced activation of TRPA1 channels in dorsal root ganglia neurons of WT and Trpv1− /− mice, respectively. Furthermore, the clinical results indicated that borneol could reduce itching symptoms in patients and its efficacy is similar to that of menthol.

Conclusion: Borneol has therapeutic effects on multiple pruritus models in mice and patients with chronic itch, and the mechanism may be through inhibiting TRPA1 and activating TRPM8.

TRPV3-ANO1 interaction positively regulates wound healing in keratinocytes

Yu Yamanoi1,2,3, Jing Lei1,2, Yasunori Takayama4, Shigekuni Hosogi5, Yoshinori Marunaka6,7 &Makoto Tominaga1,2

Communications Biology volume 6, Article number: 88 (2023) Cite this article

Abstract

Transient receptor potential vanilloid 3 (TRPV3) belongs to the TRP ion channel super family and functions as a nonselective cation channel that is highly permeable to calcium. This channel is strongly expressed in skin keratinocytes and is involved in warmth sensation, itch, wound healing and secretion of several cytokines. Previous studies showed that anoctamin1 (ANO1), a calcium-activated chloride channel, was activated by calcium influx through TRPV1, TRPV4 or TRPA1 and that these channel interactions were important for TRP channel-mediated physiological functions. We found that ANO1 was expressed by normal human epidermal keratinocytes (NHEKs). We observed that ANO1 mediated currents upon TRPV3 activation of NHEKs and mouse skin keratinocytes. Using an in vitro wound-healing assay, we observed that either a TRPV3 blocker, an ANO1 blocker or low chloride medium inhibited cell migration and proliferation through p38 phosphorylation, leading to cell cycle arrest. These results indicated that chloride influx through ANO1 activity enhanced wound healing by keratinocytes.

Sophorolipid inhibits histamine‐induced itch by decreasing PLC/IP3R signaling pathway activation and modulating TRPV1 activity

Rui-Qi Xu ¹, Ling Ma ², Timson Chen ³, Wei-Xiong Zhang ³, Kuan Chang ⁴, Jing Wang ⁵

• ¹Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China.
• ²Adolph Innovation Laboratory, Guangzhou Degu Personal Care Products Co., Ltd., Guangzhou, 510000, China. maling@adolph.cn.
• ³Adolph Innovation Laboratory, Guangzhou Degu Personal Care Products Co., Ltd., Guangzhou, 510000, China.
• ⁴Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China. changkuan@jiangnan.edu.cn.
• ⁵Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China. jingwang@jiangnan.edu.cn.

Biosurfactants are attracting much interest due to their potential application as therapeutic agents in the medical and cosmetic field. Previous studies have demonstrated that biosurfactant such as sophorolipid (SL) exhibits immunomodulatory effects. In this article, we found the potential of sophorolipid for inhibiting histamine‐induced itch and preliminarily explored its molecular basis. First, behavioral tests indicated that SL can remit the histamine‐induced scratching behaviors of mice. Second, SL can suppress the the calcium influx induced by histamine, HTMT and VUF8430 in HaCaT cells. RT‐PCR analysis showed that the histamine‐induced upregulation of mRNA levels of phospholipase Cγ1, 1,4,5‐trisphosphate receptor (IP3R), and protein kinase Cα can be inhibted by SL, suggesting that SL may impede the PLC/IP3R signaling pathway activated by histamine. In further tests, the capsaicin‐induced calcium influx can also be inhibited by SL. The and molecular docking analysis indicated that SL acts as an inhibitor of transient receptor potential vanilloid‐1 (TRPV1) activation to decrease calcium influx against stimuli. In summary, these results revealed that SL may inhibit histamine‐induced itch by decreasing PLC/IP3R signaling pathway activation and modulating TRPV1 activity. This paper indicates that SL can be a useful treatment for histamine‐dependent itch.immunofluorescence

Hair growth promotion by Necrostatin‐1s

Mei Zheng1, Nahyun Choi1, YaeJi Jang1, Da Eun Kwak2, YoungSoo Kim2, Won‐Serk Kim3,Sang Ho Oh4 & Jong‐Hyuk Sung2*

1STEMORE Co. Ltd, Incheon, South Korea. 2College of Pharmacy, Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahakro, Yeonsu-gu, Incheon 21983, South Korea. 3Department of Dermatology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul 03181, South Korea. 4Department of Dermatology, Severance Hospital and Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul 03722, South Korea.*email: brian99@yonsei.ac.kr

Necrostatins (Necs) have been developed as a receptor‐interacting protein kinase 1 (RIPK1) inhibitor, thus inhibiting necroptosis. In this current study, we have investigated the possible involvement of necroptosis in the hair cycle regulation and further examined its underlying molecular mechanisms. Diverse RIPK1/3 inhibitors and siRNA were tested in the human outer‐root sheath (ORS) cells and animal models. The expression and hair cycle‐dependent expression of RIPK 1, respectively, were investigated in the hair follicles (HF) of human, pig, and the mouse. Resulting from the experiment, Nec‐1s was most effective in the hair growth promotion among several inhibitors. Nec‐1s induced the ORS cell proliferation and migration, and increased the HF length in mouse and pig organ cultures.

In addition, it accelerated the telogen‐to‐anagen transition and elongated the anagen period in
the mouse model. Both apoptosis and necroptosis were detected in hair cycle. RIPK1 and RIPK3 were highly expressed in ORS cells during the hair regression period. Nec‐1s upregulated the mRNA expression of Wnt3a and Wnt5b, and the activity of β‐catenin. Collectively, Nec‐1s promotes hair growth through inhibiting necroptosis and activating the Wnt/β‐catenin pathway. Necroptosis is involved in hair cycle regression, and Nec‐1s is a promising target for hair‐loss treatment.

Thymic stromal lymphopoietin controls hair growth

Jessica L. Shannon,1,2 David L. Corcoran,3 John C. Murray,1 Steven F. Ziegler,4,5 Amanda S. MacLeod,1,2,6

and Jennifer Y. Zhang1,7,*
1Department of Dermatology, Duke University, P.O. Box 103052, Durham, NC 27710, USA 2Department of Immunology, Duke University, Durham, NC 27710, USA
3Genomic and Computational Biology, Duke University, Durham, NC 27705, USA 4Benaroya Research Institute, Seattle, WA 98101, USA
5Department of Immunology, University of Washington, Seattle, WA 98195, USA 6Molecular Genetics and Microbiology, Duke University, Durham, NC 27710, USA 7Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA

SUMMARY

Skin tissue regeneration after injury involves the production and integration of signals by stem cells residing in hair follicles (HFSCs). Much remains unknown about how specific wound-derived factors modulate stem cell contribution to hair growth. We demonstrate that thymic stromal lymphopoietin (TSLP) is produced in response to skin injury and during the anagen phase of the hair cycle. Intra- dermal injection of TSLP promoted wound-induced hair growth (WIHG), whereas neutralizing TSLP receptor (TSLPR) inhibited WIHG. Using flow cytometry and fluorescent immunostaining, we found that TSLP promoted proliferation of transit-amplifying cells. Lgr5CreER- mediated deletion of Tslpr in HFSCs inhibited both wound-induced and exogenous TSLP-induced hair growth. Our data highlight a novel function for TSLP in regulation of hair follicle activity during homeostasis and wound healing.

Ursolic acid downregulates thymic stromal lymphopoietin through the blockade of intracellular calcium/caspase‐1/NF‐κB signaling cascade in HMC‐1 cells

PHIL-DONG MOON1,2*, NA-RA HAN1*, JIN SOO LEE1, HYUNG-MIN KIM1 and HYUN-JA JEONG3

1department of Pharmacology, college of Korean Medicine, 2center for converging Humanities, Kyung Hee University, Seoul 02447; 3department of Food Science and Technology and Research Institute for Basic Science, Hoseo University, Asan, chungnam 31499, Republic of Korea

Received december 14, 2018; Accepted March 20, 2019 dOI: 10.3892/ijmm.2019.4144

Thymic stromal lymphopoietin (TSLP) plays an important role in allergic disorders, including atopic dermatitis and asthma. Ursolic acid (UA) has various pharmacological properties, such as antioxidant, anti‐inflammatory and anti- cancer. However, the effect of UA on TSLP regulation has not been fully elucidated. The aim of the present study was to analyze how UA regulates the production of TSLP in the human mast cell line HMc-1. Enzyme-linked immunosorbent assay, quantitative polymerase chain reaction analysis, western blotting, caspase-1 assay and fluorescent measurements of intracellular calcium levels were conducted to analyze the regulatory effects of UA. The results revealed that UA inhib- ited TSLP production and mRNA expression. In addition, UA reduced the activation of nuclear factor-κB and degradation of IκBα. caspase-1 activity was increased by exposure to phorbol myristate acetate plus calcium ionophore, whereas it was reduced by UA. Finally, UA treatment prevented an increase in intracellular calcium levels. These results indicated that UA may be a useful agent for the treatment and/or prevention of atopic and inflammatory diseases, and its effects are likely mediated by TSLP downregulation.

Transient stimulation of TRPV4-expressing keratinocytes promotes hair follicle regeneration in mice

Pu Yang ¹, Ping Lu ^1 2, Jialie Luo ¹, Lixia Du ¹, Jing Feng ¹, Tao Cai ^1 3, Yi Yuan ¹, Hunter Cheng ¹, Hongzhen Hu ¹

1Department of Anesthesiology, The Center for the Study of Itch and Sensory Disorders, Washington University School of Medicine, St. Louis, Missouri, USA

2Experimental Research Center, Dermatology Hospital, Southern Medical University, Guangzhou, China

3Department of Dermatology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China

Background and Purpose: Hair follicle telogen to anagen transition results in a break in cellular quiescence of the hair follicle stem cells, which subsequently promotes hair follicle regeneration. Many critical molecules and signalling pathways are involved in hair follicle cycle progression. Transient receptor potential vanilloid 4 (TRPV4) is a polymodal sensory transducer that regulates various cutaneous functions under both normal and disease conditions. However, the role of TRPV4 in hair follicle regenera- tion in vivo remains incompletely understood.

Experimental Approach: Using adult C57BL/6J mice, keratinocyte (K14Cre; Trpv4f/f) and macrophage (Cx3cr1Cre; Trpv4f/f) Trpv4 conditional knockout (cKO) mice, Trpv4−/− mice, we investigated the effect of a single intradermal injection of GSK1016790A, a potent and selective small molecule TRPV4 activator, on hair follicle regenera- tion. Chemical cues and signal molecules involved in hair follicle cycle progression were measured by immunofluorescence staining, quantitative RT-PCR and western blotting.

Key Results: Here, we show that a single intradermal injection of GSK1016790A is sufficient to induce telogen to anagen transition and hair follicle regeneration in mice by increasing the expression of the anagen-promoting growth factors and down- regulating the expression of growth factors that inhibit anagen. The action of GSK1016790A relies largely on the function of TRPV4 in skin and involves activation of downstream ERK signalling.

Conclusion and Implications: Our results suggest that transient chemical activation of TRPV4 in the skin induces hair follicle regeneration in mice, which might provide an effective therapeutic strategy for the treatment of hair loss and alopecia.