Shang-Hung Lin1, Hung-Yi Chuang2, Ji-Chen Ho3, Chih-Hung Lee4, Chang-Chun Hsiao5. 1. Department of Dermatology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan; Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taiwan. Electronic address: hong51@cgmh.org.tw. 2. Department of Environmental and Occupational Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Public Health, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: ericch@kmu.edu.tw. 3. Department of Dermatology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan. Electronic address: jichenho@cgmh.org.tw. 4. Department of Dermatology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan. Electronic address: zieben@cgmh.org.tw. 5. Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taiwan; Center for Shockwave Medicine and Tissue Engineering, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan. Electronic address: cchsiao@mail.cgu.edu.tw.
Abstract
BACKGROUND: Psoriasis is a systemic inflammatory disease with dramatic responses to TNF-α inhibitors. TNF-α is mainly produced by macrophages. However, how macrophage polarization contributes to psoriasis remains unknown. OBJECTIVE: We aimed to investigate the molecular mechanisms of macrophage polarization in psoriasis. METHODS: 8 patients with moderate to severe psoriasis (Male/Female: 4/4, average age: 47.9 years old) and 8 healthy controls (Male/Female: 4/4, average age: 49.3 years old) were recruited. Their peripheral CD14+ monocytes were isolated with magnetic beads and then were differentiated into macrophages. The differential macrophage polarization was compared among normal controls, psoriatic patients before and after TNF-α inhibitors. The U937 cells were used to investigate the mechanisms by which TNF-α altered the macrophage polarization. RESULTS: The ratio of M1 to M2a macrophage polarization was higher in psoriatic patients comparing with that in controls. The decreasing M1/M2a ratio was parallel to decreasing PASI severity score after adalimumab treatment. Consistently, TNF-α blockage decreased M1/M2a ratio in U937 cells. The induction of STAT1 and IRF-1 in polarized U937 M1 cells was inhibited by TNF-α inhibitor. However, STAT1 and/or IRF-1 interference could not resume M1 polarization. In skin, the increased M1 and M2 infiltration in lesions returned to baseline after successful treatment with TNF-α inhibitor. CONCLUSIONS: Increased M1 polarization is associated with higher disease severity in psoriasis, resuming to baseline after successful treatment by TNF-α inhibitors. TNF-α blockage inhibits M1 polarization through STAT1- and IRF-1-independent pathways. Macrophage polarization may contribute to disease progression in psoriasis.
BACKGROUND:Psoriasis is a systemic inflammatory disease with dramatic responses to TNF-α inhibitors. TNF-α is mainly produced by macrophages. However, how macrophage polarization contributes to psoriasis remains unknown. OBJECTIVE: We aimed to investigate the molecular mechanisms of macrophage polarization in psoriasis. METHODS: 8 patients with moderate to severe psoriasis (Male/Female: 4/4, average age: 47.9 years old) and 8 healthy controls (Male/Female: 4/4, average age: 49.3 years old) were recruited. Their peripheral CD14+ monocytes were isolated with magnetic beads and then were differentiated into macrophages. The differential macrophage polarization was compared among normal controls, psoriaticpatients before and after TNF-α inhibitors. The U937 cells were used to investigate the mechanisms by which TNF-α altered the macrophage polarization. RESULTS: The ratio of M1 to M2a macrophage polarization was higher in psoriaticpatients comparing with that in controls. The decreasing M1/M2a ratio was parallel to decreasing PASI severity score after adalimumab treatment. Consistently, TNF-α blockage decreased M1/M2a ratio in U937 cells. The induction of STAT1 and IRF-1 in polarized U937 M1 cells was inhibited by TNF-α inhibitor. However, STAT1 and/or IRF-1 interference could not resume M1 polarization. In skin, the increased M1 and M2 infiltration in lesions returned to baseline after successful treatment with TNF-α inhibitor. CONCLUSIONS: Increased M1 polarization is associated with higher disease severity in psoriasis, resuming to baseline after successful treatment by TNF-α inhibitors. TNF-α blockage inhibits M1 polarization through STAT1- and IRF-1-independent pathways. Macrophage polarization may contribute to disease progression in psoriasis.