Woo-In Ryu1, Hana Lee1, Hyun Cheol Bae1, Jiehyun Jeon1, Hwa Jung Ryu1, Jaehyung Kim1, Ji Hyun Kim1, Ji Won Son1, JaeYoung Kim2, Yasutomo Imai3, Kiyofumi Yamanishi3, Sang Hoon Jeong4, Sang Wook Son5. 1. Laboratory of Cell Signaling and Nanomedicine, Department of Dermatology, Division of Brain Korea 21 Project for Biomedical Science, Korea University College of Medicine, Seoul, Republic of Korea. 2. Research Institute for Skin Image, Korea University College of Medicine, Seoul, Republic of Korea. 3. Departments of Dermatology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan. 4. Laboratory of Cell Signaling and Nanomedicine, Department of Dermatology, Division of Brain Korea 21 Project for Biomedical Science, Korea University College of Medicine, Seoul, Republic of Korea; Research Institute for Skin Image, Korea University College of Medicine, Seoul, Republic of Korea. Electronic address: saibog21@korea.ac.kr. 5. Laboratory of Cell Signaling and Nanomedicine, Department of Dermatology, Division of Brain Korea 21 Project for Biomedical Science, Korea University College of Medicine, Seoul, Republic of Korea; Research Institute for Skin Image, Korea University College of Medicine, Seoul, Republic of Korea. Electronic address: skin4u@korea.ac.kr.
Abstract
BACKGROUND: Tight junctions (TJs) have important roles in skin barrier function. The TJ protein claudin-1 (CLDN1) is decreased in atopic dermatitis (AD). However, little is known about the mechanism of CLDN1 down-expression. OBJECTIVE: To elucidate the effect of IL-33 on CLDN1 expression in keratinocytes. METHODS: Normal human epidermal keratinocytes (NHEKs) and human skin equivalent models (HSEMs) were cultured in vitro in the presence of IL-33. Production of CLDN1, signal transducer and activator of transcription 3 (STAT3) and Mitogen-activated protein kinases (MAPK) expression were measured by real-time PCR, western blot and immunofluorescence assay. MAPK inhibitors and small interfering RNA were used to confirm the signal pathway of STAT3 and CLDN1. Barrier function was measured by transepithelial electric resistance (TEER) and FITC-dextran flux assays. Electrophoretic Mobility Shift Assay was used to detect STAT3 transcriptional activity. RESULTS: Levels of CLDN1 expression were reduced in the epidermis of AD-model mice overexpressing IL-33. IL-33 down-regulated the expression of CLDN1 mRNA and protein in NHEKs and HSEMs. IL-33 attenuated transepithelial electric resistance and induced FITC-dextran flux in NHEKs. The IL-33 suppressed CLDN1 expression was regulated by an extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription 3 (STAT3). STAT3 suppressed CLDN1 expression by direct binding to the promoters. CONCLUSION: IL-33 may down-regulate CLDN1 expression through the ERK/STAT3 pathway in keratinocytes.
BACKGROUND: Tight junctions (TJs) have important roles in skin barrier function. The TJ protein claudin-1 (CLDN1) is decreased in atopic dermatitis (AD). However, little is known about the mechanism of CLDN1 down-expression. OBJECTIVE: To elucidate the effect of IL-33 on CLDN1 expression in keratinocytes. METHODS: Normal human epidermal keratinocytes (NHEKs) and human skin equivalent models (HSEMs) were cultured in vitro in the presence of IL-33. Production of CLDN1, signal transducer and activator of transcription 3 (STAT3) and Mitogen-activated protein kinases (MAPK) expression were measured by real-time PCR, western blot and immunofluorescence assay. MAPK inhibitors and small interfering RNA were used to confirm the signal pathway of STAT3 and CLDN1. Barrier function was measured by transepithelial electric resistance (TEER) and FITC-dextran flux assays. Electrophoretic Mobility Shift Assay was used to detect STAT3 transcriptional activity. RESULTS: Levels of CLDN1 expression were reduced in the epidermis of AD-model mice overexpressing IL-33. IL-33 down-regulated the expression of CLDN1 mRNA and protein in NHEKs and HSEMs. IL-33 attenuated transepithelial electric resistance and induced FITC-dextran flux in NHEKs. The IL-33 suppressed CLDN1 expression was regulated by an extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription 3 (STAT3). STAT3 suppressed CLDN1 expression by direct binding to the promoters. CONCLUSION:IL-33 may down-regulate CLDN1 expression through the ERK/STAT3 pathway in keratinocytes.
Authors: Feng Li; Laura E Pascal; Ke Wang; Yibin Zhou; Goundappa K Balasubramani; Katherine J O'Malley; Rajiv Dhir; Kai He; Donna Stolz; Donald B DeFranco; Naoki Yoshimura; Joel B Nelson; Tie Chong; Peng Guo; Dalin He; Zhou Wang Journal: Am J Clin Exp Urol Date: 2020-02-25
Authors: P Chieosilapatham; C Kiatsurayanon; Y Umehara; J V Trujillo-Paez; G Peng; H Yue; L T H Nguyen; F Niyonsaba Journal: Clin Exp Immunol Date: 2021-02-15 Impact factor: 5.732