Blood flow patterns regulate PCSK9 secretion via MyD88-mediated pro-inflammatory cytokines

Area of Science:

• Cardiovascular Biology
• Molecular Medicine
• Atherosclerosis Research

Background:

• Blood flow patterns influence atherosclerosis development; low flow is pro-atherogenic, helical flow is protective.
• Proprotein convertase subtilisin/kexin type 9 (PCSK9) is crucial for cholesterol metabolism and highly expressed in atherosclerotic tissues.

Purpose of the Study:

• To investigate the impact of different blood flow patterns on PCSK9 expression.
• To elucidate the signaling pathways involved in flow-mediated PCSK9 regulation.

Main Methods:

• An experimental model was used to generate stable helical blood flow in rabbit thoracic aortas.
• PCSK9 expression was analyzed under conditions of normal, low, and helical flow in an inflammatory state.
• Signaling pathways including TLR4-MyD88-NF-κB and TRIF were investigated.

Main Results:

• Low blood flow significantly increased PCSK9 expression, while helical flow inhibited it in an inflammatory setting.
• The TLR4-MyD88-NF-κB pathway was identified as critical for PCSK9 regulation, whereas the TRIF pathway had minimal effect.
• Pro-inflammatory cytokines downstream of NF-κB directly influenced PCSK9 expression, with high-fat diet exacerbating this effect.

Conclusions:

• Abnormal blood flow patterns, particularly low flow, are linked to increased PCSK9 expression in inflammatory conditions.
• Helical flow and modulation of pro-inflammatory cytokines represent potential therapeutic targets for PCSK9-related cardiovascular diseases.