Therapeutic effects of Saikosapoin D on bleomycininduced pulmonary fibrosis in mice via regulation of IL- 33/ST2 pathway

Jin-xu Zheng,Jiao Xu,Xiao-hui Miao,Zhi-fang Zhuang,Ming Ding

doi:10.4314/tjpr.v16i3.12

Abstract

Purpose: To investigate the therapeutic effects of saikosapoin D (SSD) on bleomycin (BLM)-induced pulmonary fibrosis (PF) in mice and its probable mechanisms.Methods: PF mice were prepared by intraperitoneal (i.p.) injection of BLM (5 mg/kg). Twenty-four hours later, 72 mice in SSD group were administered SSD (1.8 mg/kg, ip). After 3, 7, 14 and 28 days of injection, the mice were sacrificed. Blood samples and lung tissues were collected from 6 mice in each group. The lung tissues were subjected to histological examination. In addition, expressions of MyD88, TRAF6, IL-33 and ST2 in lung tissue were determined by western blotting assay. Serum levels of hydroxyproline (HYP), interleukin (IL)-4, IL-13 and interferon (IFN)-γ were measured by enzyme-linked immunosorbent assay (ELISA).Results: Pathological results showed that SSD treatment alleviated alveolitis and lung fibrosis (p < 0.05) in lung tissues of PF mice at 14 and 28 days post-BLM injection. HYP and IL-13 levels of mice in SSD group were significantly lower than that in BLM group at days 14 and 28 post-BLM injection (p < 0.05). Levels of IL-4 and IFN-γ were significantly lower when compared with values in BLM group on day 28 (p < 0.05). Western blotting results revealed that expressions of MyD88, TRAF6, IL-33 and ST2 proteins were significantly decreased by SSD treatment (p < 0.05).Conclusion: SSD exerts therapeutic effects on BLM-induced experimental PF in mice via regulation ofIL-33/ST2 pathway.Keywords: Saikosapoin D, Idiopathic pulmonary fibrosis, Myeloid differentiation factor, Hydroxyproline, Interleukin, Interferon, IL-33/ST2 pathway

Highlights

Idiopathic pulmonary fibrosis (IPF) is a common and complex disease with high mortality and morbidity, and the median survival time is only 2 to 5 years [1,2]
Ltd (Jiangxi, China); chloral hydrate was obtained from the Jiangbin Hospital (Zhenjiang, China); Bleomycin (BLM) was purchased from the Nippon Kayaku Co., Ltd. (Tokyo, Japan); Hematoxylin and Eosin (H&E), Masson’s Trichrome, hydroxyproline (HYP) commercial kit, tissue RIPA buffer, primary antibodies for myeloid differentiation factor 88 (MyD88) and βactin were purchased from the Wuhan Boster Biotech Co. (Wuhan, China); PVDF membranes and skimmed milk powder were obtained from the Millipore Co
The results showed that when the lung exposed to bleomycin, there were damages to the lung tissues, accompanying some epithelial or endothelial cells over-apoptosis passively respond to the injury

Summary

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a common and complex disease with high mortality and morbidity, and the median survival time is only 2 to 5 years [1,2]. Current clinical trials have evaluated various therapeutic approaches for IPF, such as dual endothelin receptor antagonist bosentan, imatinib, sildenafil, etanercept and interferon-c-1β, etc [5,6,7]. None of these ways attained the primary aims. In the present investigation, we evaluated the potential therapeutic effects of SSD on bleomycin (BLM)induced pulmonary fibrosis (PF) in mice, and the role of IL-33/ST2 pathway in this process. (Tokyo, Japan); Hematoxylin and Eosin (H&E), Masson’s Trichrome, hydroxyproline (HYP) commercial kit, tissue RIPA buffer, primary antibodies for myeloid differentiation factor 88 (MyD88) and βactin were purchased from the Wuhan Boster Biotech Co.

RESULTS

DISCUSSION

Conflict of Interest