Distinct cAMP Regulation in Scleroderma Lung and Skin Myofibroblasts Governs Their Dedifferentiation via p38α...

Area of Science:

• Cell Biology
• Fibrosis Research
• Rheumatology

Background:

• Systemic sclerosis (SSc) involves progressive fibrosis due to activated fibroblasts (myofibroblasts, MFs) in multiple organs.
• MFs contribute to tissue stiffness and scarring through collagen secretion and contraction.
• Therapeutic strategies targeting MFs are crucial for SSc treatment.

Purpose of the Study:

• To compare the cAMP-mediated dedifferentiation of MFs from SSc skin and lung.
• To investigate the role of prostaglandin E2 (PGE2) signaling in SSc MF dedifferentiation.
• To evaluate the potential of targeting cAMP and p38α pathways for SSc fibrosis.

Main Methods:

• Comparison of cAMP generation and dedifferentiation in lung and skin SSc MFs.
• Stimulation with cAMP, PGE2, and phosphodiesterase 4 inhibitors.
• Pharmacologic inhibition of MAPK p38α.

Main Results:

• Direct cAMP increase induced comparable MFs dedifferentiation in lung and skin.
• PGE2-induced dedifferentiation was reduced in skin MFs compared to lung MFs, linked to G protein-coupled receptor expression.
• Phosphodiesterase 4 inhibition restored PGE2 responsiveness in skin MFs.
• Both cAMP activation and p38α inhibition promoted MFs dedifferentiation in both tissues.

Conclusions:

• The cAMP pathway, via p38α inhibition, effectively dedifferentiates SSc MFs from both lung and skin.
• Targeting cAMP and p38α pathways offers a potential therapeutic strategy for systemic sclerosis-associated multi-organ fibrosis.