Silencing of Carbohydrate Sulfotransferase 15 Hinders Murine Pulmonary Fibrosis Development
Yoshiro Kai1, Koichi Tomoda1, Hiroyuki Yoneyama2
1Second Department of Internal Medicine, Nara Medical University, Nara 634-8522, Japan.
Abstract:
Pulmonary fibrosis is a progressive lung disorder characterized by interstitial fibrosis, for which no effective treatments are available. Chondroitin sulfate proteoglycan (CSPG) has been shown to be a mediator, but the specific component of glycosaminoglycan chains of CSPG has not been explored. We show that chondroitin sulfate E-type (CS-E) is involved in fibrogenesis. Small interfering RNA (siRNA) targeting carbohydrate sulfotransferase 15 (CHST15) was designed to inhibit CHST15 mRNA and its product, CS-E. CS-E augments cell contraction and CHST15 siRNA inhibits collagen production. We found that bleomycin treatment increased CHST15 expression in interstitial fibroblasts at day 14. CHST15 siRNA was injected intranasally on days 1, 4, 8, and 11, and CHST15 mRNA was significantly suppressed by day 14. CHST15 siRNA reduced lung CSPG and the grade of fibrosis. CHST15 siRNA repressed the activation of fibroblasts, as evidenced by suppressed expression of α smooth muscle actin (αSMA), connective tissue growth factor (CTGF), lysyl oxidase like 2 (LOXL2), and CC-chemokine ligand 2 (CCL2)/monocyte chemoattractant protein-1 (MCP-1). Inflammatory infiltrates in the bronchoalveolar lavage fluid (BALF) and interstitium were diminished by CHST15 siRNA. These results indicate a pivotal role for CHST15 in fibroblast-mediated lung fibrosis and suggest a possible new therapeutic role for CHST15 siRNA in pulmonary fibrosis.
Insights
Chondroitin sulfate E-type (CS-E), a component of proteoglycans, drives lung fibrosis. Inhibiting its production via CHST15 siRNA significantly reduced fibrosis and fibroblast activation in a mouse model, suggesting a new therapeutic target.
Area of Science:
- Pulmonary Medicine
- Biochemistry
- Molecular Biology
Background:
- Pulmonary fibrosis is a progressive lung disease with no effective treatments.
- Chondroitin sulfate proteoglycan (CSPG) is implicated in fibrosis, but specific components are unexplored.
Purpose of the Study:
- To investigate the role of chondroitin sulfate E-type (CS-E) in lung fibrogenesis.
- To evaluate the therapeutic potential of targeting carbohydrate sulfotransferase 15 (CHST15) using small interfering RNA (siRNA) to inhibit CS-E production.
Main Methods:
- Developed CHST15 siRNA to inhibit CS-E synthesis.
- Administered CHST15 siRNA intranasally in a bleomycin-induced pulmonary fibrosis mouse model.
- Assessed CHST15 mRNA suppression, lung CSPG levels, fibrosis grade, fibroblast activation markers (αSMA, CTGF, LOXL2, CCL2), and inflammatory infiltrates.
Main Results:
- CHST15 siRNA significantly suppressed CHST15 mRNA and reduced lung CS-E levels.
- CHST15 siRNA treatment decreased collagen production and the overall grade of pulmonary fibrosis.
- Fibroblast activation, evidenced by reduced αSMA, CTGF, LOXL2, and CCL2 expression, was repressed.
- Inflammatory cell infiltration in the lungs and bronchoalveolar lavage fluid was diminished.
Conclusions:
- Chondroitin sulfate E-type plays a critical role in mediating lung fibrosis.
- CHST15 is a key enzyme in CS-E synthesis and fibroblast activation in pulmonary fibrosis.
- CHST15 siRNA represents a promising therapeutic strategy for treating pulmonary fibrosis.
