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Ahn SS, Yeo H, Jung E, Kim TY, Han J, Lee YH, Shin SY. Saikosaponin A Recovers Impaired Filaggrin Levels in Inflamed Skin by Downregulating the Expression of FRA1 and c-Jun. Molecules 2024; 29:4064. [PMID: 39274912 PMCID: PMC11396542 DOI: 10.3390/molecules29174064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2024] [Revised: 08/25/2024] [Accepted: 08/26/2024] [Indexed: 09/16/2024] Open
Abstract
Filaggrin (FLG) is an essential structural protein expressed in differentiated keratinocytes. Insufficient FLG expression contributes to the pathogenesis of chronic inflammatory skin diseases. Saikosaponin A (SSA), a bioactive oleanane-type triterpenoid, exerts anti-inflammatory activity. However, the effects of topically applied SSA on FLG expression in inflamed skin remain unclear. This study aimed to evaluate the biological activity of SSA in restoring reduced FLG expression. The effect of SSA on FLG expression in HaCaT cells was assessed through various biological methods, including reverse transcription PCR, quantitative real-time PCR, immunoblotting, and immunofluorescence staining. TNFα and IFNγ decreased FLG mRNA, cytoplasmic FLG protein levels, and FLG gene promoter-reporter activity compared to the control groups. However, the presence of SSA restored these effects. A series of FLG promoter-reporter constructs were generated to investigate the underlying mechanism of the effect of SSA on FLG expression. Mutation of the AP1-binding site (mtAP1) in the -343/+25 FLG promoter-reporter abrogated the decrease in reporter activities caused by TNFα + IFNγ, suggesting the importance of the AP1-binding site in reducing FLG expression. The SSA treatment restored FLG expression by inhibiting the expression and nuclear localization of FRA1 and c-Jun, components of AP1, triggered by TNFα + IFNγ stimulation. The ERK1/2 mitogen-activated protein kinase signaling pathway upregulates FRA1 and c-Jun expression, thereby reducing FLG levels. The SSA treatment inhibited ERK1/2 activation caused by TNFα + IFNγ stimulation and reduced the levels of FRA1 and c-Jun proteins in the nucleus, leading to a decrease in the binding of FRA1, c-Jun, p-STAT1, and HDAC1 to the AP1-binding site in the FLG promoter. The effect of SSA was evaluated in an animal study using a BALB/c mouse model, which induces human atopic-dermatitis-like skin lesions via the topical application of dinitrochlorobenzene. Topically applied SSA significantly reduced skin thickening, immune cell infiltration, and the expression of FRA1, c-Jun, and p-ERK1/2 compared to the vehicle-treated group. These results suggest that SSA can effectively recover impaired FLG levels in inflamed skin by preventing the formation of the repressor complex consisting of FRA1, c-Jun, HDAC1, and STAT1.
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Affiliation(s)
- Sung Shin Ahn
- Department of Biological Sciences, Sanghuh College of Lifesciences, Konkuk University, Seoul 05029, Republic of Korea; (S.S.A.); (H.Y.); (E.J.); (T.Y.K.); (J.H.); (Y.H.L.)
| | - Hyunjin Yeo
- Department of Biological Sciences, Sanghuh College of Lifesciences, Konkuk University, Seoul 05029, Republic of Korea; (S.S.A.); (H.Y.); (E.J.); (T.Y.K.); (J.H.); (Y.H.L.)
| | - Euitaek Jung
- Department of Biological Sciences, Sanghuh College of Lifesciences, Konkuk University, Seoul 05029, Republic of Korea; (S.S.A.); (H.Y.); (E.J.); (T.Y.K.); (J.H.); (Y.H.L.)
| | - Tae Yoon Kim
- Department of Biological Sciences, Sanghuh College of Lifesciences, Konkuk University, Seoul 05029, Republic of Korea; (S.S.A.); (H.Y.); (E.J.); (T.Y.K.); (J.H.); (Y.H.L.)
| | - Junekyu Han
- Department of Biological Sciences, Sanghuh College of Lifesciences, Konkuk University, Seoul 05029, Republic of Korea; (S.S.A.); (H.Y.); (E.J.); (T.Y.K.); (J.H.); (Y.H.L.)
| | - Young Han Lee
- Department of Biological Sciences, Sanghuh College of Lifesciences, Konkuk University, Seoul 05029, Republic of Korea; (S.S.A.); (H.Y.); (E.J.); (T.Y.K.); (J.H.); (Y.H.L.)
| | - Soon Young Shin
- Department of Biological Sciences, Sanghuh College of Lifesciences, Konkuk University, Seoul 05029, Republic of Korea; (S.S.A.); (H.Y.); (E.J.); (T.Y.K.); (J.H.); (Y.H.L.)
- Cancer and Metabolism Institute, Konkuk University, Seoul 05029, Republic of Korea
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Chen S, Wang K, Wang H, Gao Y, Nie K, Jiang X, Su H, Tang Y, Lu F, Dong H, Wang Z. The therapeutic effects of saikosaponins on depression through the modulation of neuroplasticity: From molecular mechanisms to potential clinical applications. Pharmacol Res 2024; 201:107090. [PMID: 38309381 DOI: 10.1016/j.phrs.2024.107090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 01/07/2024] [Accepted: 01/30/2024] [Indexed: 02/05/2024]
Abstract
Depression is a major global health issue that urgently requires innovative and precise treatment options. In this context, saikosaponin has emerged as a promising candidate, offering a variety of therapeutic benefits that may be effective in combating depression. This review delves into the multifaceted potential of saikosaponins in alleviating depressive symptoms. We summarized the effects of saikosaponins on structural and functional neuroplasticity, elaborated the regulatory mechanism of saikosaponins in modulating key factors that affect neuroplasticity, such as inflammation, the hypothalamic-pituitary-adrenal (HPA) axis, oxidative stress, and the brain-gut axis. Moreover, this paper highlights existing gaps in current researches and outlines directions for future studies. A detailed plan is provided for the future clinical application of saikosaponins, advocating for more targeted researches to speed up its transition from preclinical trials to clinical practice.
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Affiliation(s)
- Shen Chen
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Ke Wang
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Hongzhan Wang
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Yang Gao
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Kexin Nie
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Xinyue Jiang
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Hao Su
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Yueheng Tang
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Fuer Lu
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Hui Dong
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
| | - Zhi Wang
- Department of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
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