title: An important role of α-hemolysin in extracellular vesicles on the development of atopic dermatitis induced by Staphylococcus aureus.
abstract: Skin barrier disruption and dermal inflammation are key phenotypes of atopic dermatitis (AD). Staphylococcus aureus secretes extracellular vesicles (EVs), which are involved in AD pathogenesis. Here, we evaluated the role of EVs-associated α-hemolysin derived from S. aureus in AD pathogenesis. α-hemolysin production from S. aureus was detected using western blot analyses. The cytotoxic activity of α-hemolysin on HaCaT keratinocytes was evaluated by measuring cell viability after treating cells with soluble and EVs-associated α-hemolysin. To determine the type of cell death, HaCaT keratinocytes were stained with annexin V and 7-AAD. The in vivo effects of α-hemolysin were evaluated by application of soluble and EV-associated α-hemolysin on the mouse skin. The present study showed that increased α-hemolysin was produced by S. aureus colonized on AD patients compared to healthy subjects. α-hemolysin production was also related to AD severity. In addition, EV-associated α-hemolysin was more cytotoxic to HaCaT keratinocytes than soluble α-hemolysin, and α-hemolysin-negative EVs did not induce keratinocyte death. EV-associated α-hemolysin induced necrosis, but soluble α-hemolysin induced apoptosis of keratinocytes. In vivo, skin barrier disruption and epidermal hyperplasia were induced by soluble and EV-associated α-hemolysin. However, AD-like dermal inflammation was only caused by EV-associated α-hemolysin. Moreover, neither skin barrier disruption nor AD-like skin inflammation was induced by α-hemolysin-negative EVs. Taken together, α-Hemolysin secreted from S. aureus, particularly the EV-associated form, induces both skin barrier disruption and AD-like skin inflammation, suggesting that EV-associated α-hemolysin is a novel diagnostic and therapeutic target for the control of AD.
authors.affiliation: Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
authors.forename: Sung-Wook
authors.initials: SW
authors.lastname: Hong
authors.affiliation: Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
authors.forename: Eun-Byul
authors.initials: EB
authors.lastname: Choi
authors.affiliation: Department of Pediatrics, Sooncheonhyang University College of Medicine, Seoul, Republic of Korea.
authors.forename: Taek-Ki
authors.initials: TK
authors.lastname: Min
authors.affiliation: Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Medicine and Institute of Convergence Medicine, Ewha Womans Medical Center, Seoul, Republic of Korea.
authors.forename: Min-Hye
authors.initials: MH
authors.lastname: Kim
authors.affiliation: Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
authors.forename: Seong Gyu
authors.initials: SG
authors.lastname: Jeon
authors.affiliation: Department of Allergy and Clinical Immunology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Byung-Jae
authors.initials: BJ
authors.lastname: Lee
authors.affiliation: Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
authors.forename: Yong Song
authors.initials: YS
authors.lastname: Gho
authors.affiliation: Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Republic of Korea.
authors.forename: Young-Koo
authors.initials: YK
authors.lastname: Jee
authors.affiliation: Department of Pediatrics, Sooncheonhyang University College of Medicine, Seoul, Republic of Korea.
authors.forename: Bok-Yang
authors.initials: BY
authors.lastname: Pyun
authors.affiliation: Department of Medicine and Institute of Convergence Medicine, Ewha Womans Medical Center, Seoul, Republic of Korea.
authors.forename: Yoon-Keun
authors.initials: YK
authors.lastname: Kim
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000276:immunology*; D002460:Cell Line; D003876:Dermatitis, Atopic / Q000276:immunology* / Q000473:pathology; D006460:Hemolysin Proteins / Q000276:immunology*; D006801:Humans; D015603:Keratinocytes / Q000276:immunology / Q000473:pathology; D051379:Mice; D008812:Mice, Hairless; D012867:Skin / Q000276:immunology / Q000473:pathology; D013207:Staphylococcal Skin Infections / Q000276:immunology* / Q000473:pathology; D013211:Staphylococcus aureus / Q000276:immunology*
chemical_list: D001426:Bacterial Proteins; D006460:Hemolysin Proteins