PIK-III exerts anti-fibrotic effects in activated fibroblasts by regulating p38 activation.
Santiago SanchezAaron K McDowell-SanchezSharaz B Al-MeeraniJuan D Cala-GarciaAlan R Waich CohenScott A OchsnerNeil J McKennaLindsay J CeladaMinghua WuShervin AssassiIvan O RosasKonstantin TsoyiPublished in: PloS one (2024)
Systemic sclerosis (SSc), also known as scleroderma, is an autoimmune-driven connective tissue disorder that results in fibrosis of the skin and internal organs such as the lung. Fibroblasts are known as the main effector cells involved in the progression of SSc through the induction of extracellular matrix (ECM) proteins and myofibroblast differentiation. Here, we demonstrate that 4'-(cyclopropylmethyl)-N2-4-pyridinyl-[4,5'-bipyrimidine]-2,2'-diamine (PIK-III), known as class III phosphatidylinositol 3-kinase (PIK3C3/VPS34) inhibitor, exerts potent antifibrotic effects in human dermal fibroblasts (HDFs) by attenuating transforming growth factor-beta 1 (TGF-β1)-induced ECM expression, cell contraction and myofibroblast differentiation. Unexpectedly, neither genetic silencing of PIK3C3 nor other PIK3C3 inhibitors (e.g., SAR405 and Autophinib) were able to mimic PIK-III-mediated antifibrotic effect in dermal fibroblasts, suggesting that PIK-III inhibits fibroblast activation through another signaling pathway. We identified that PIK-III effectively inhibits p38 activation in TGF-β1-stimulated dermal fibroblasts. Finally, PIK-III administration significantly attenuated dermal and lung fibrosis in bleomycin-injured mice.
Keyphrases
- extracellular matrix
- transforming growth factor
- systemic sclerosis
- epithelial mesenchymal transition
- signaling pathway
- interstitial lung disease
- pulmonary fibrosis
- induced apoptosis
- wound healing
- stem cells
- rheumatoid arthritis
- gene expression
- genome wide
- poor prognosis
- endothelial cells
- mesenchymal stem cells
- dna methylation
- cell therapy
- cell death
- adipose tissue
- single cell
- diabetic rats
- regulatory t cells
- insulin resistance
- cell proliferation
- stress induced
- endoplasmic reticulum stress