Pericyte-myofibroblast transition in the human lung

Area of Science:

• Pulmonary Medicine
• Cell Biology
• Fibrosis Research

Background:

• Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease characterized by excessive collagen deposition.
• Fibroblastic foci (FF) are key pathological features in IPF lungs.
• The cellular origin of myofibroblasts within FF remains incompletely understood.

Purpose of the Study:

• To characterize human lung pericytes (HuL-P) and their role in IPF.
• To investigate the origin and characteristics of fibroblastic foci (FF) in IPF lungs.
• To explore potential therapeutic strategies targeting pericyte activation in IPF.

Main Methods:

• Isolation and characterization of human lung pericytes (HuL-P).
• Assessment of pericyte markers (PDGFRB, CSPG4) and in vitro functional assays.
• Immunohistochemical analysis of fibroblastic foci (FF) in IPF lung tissue.
• Investigation of pericyte-myofibroblast transition under TGF-β signaling.

Main Results:

• HuL-P express pericyte markers (PDGFRB, CSPG4) and exhibit pericyte functions.
• HuL-P undergo pericyte-myofibroblast transition influenced by TGF-β signaling.
• FF in IPF lungs are specifically located between lung epithelia and capillary endothelia, containing PDGFRB+ and CSPG4+ cells.
• HuL-P showed resistance to apoptosis induced by Bcl-xL and MCL1 silencing.

Conclusions:

• Lung pericytes are the likely origin of myofibroblasts in IPF fibroblastic foci.
• Targeting the pericyte-myofibroblast transition, rather than myofibroblast apoptosis, may be a more effective therapeutic approach for IPF.