LNK deficiency promotes acute aortic dissection and rupture

Area of Science:

• Vascular Biology
• Immunology
• Genetics

Background:

• Aortic dissection (AD) is a critical vascular condition with few therapeutic options.
• The SH2B3 gene, encoding lymphocyte adaptor protein LNK, has been linked to AD through genome-wide association studies.

Purpose of the Study:

• To investigate the role of LNK in the pathogenesis of acute aortic dissection (AD).
• To explore potential therapeutic strategies for AD by targeting LNK-related pathways.

Main Methods:

• Utilized a mouse model of angiotensin II-induced AD to assess the impact of LNK deficiency.
• Employed adoptive transfer of leukocytes and pharmacological intervention (doxycycline) to evaluate disease mechanisms and treatment efficacy.
• Conducted PrediXcan analysis on a large human biobank to correlate SH2B3 expression with AD phenotypes.

Main Results:

• LNK deficiency in mice led to altered aortic mechanics, increased neutrophil infiltration, and elevated MMP-9 activity preceding AD development.
• LNK-deficient leukocytes induced AD and rupture in recipient mice, highlighting the role of hematopoietic cells.
• Doxycycline treatment reduced neutrophil accumulation and significantly decreased AD incidence.
• Decreased SH2B3 expression was associated with increased AD-related phenotypes in humans.

Conclusions:

• LNK plays a critical protective role in preventing AD by regulating aortic integrity and inflammatory responses.
• LNK deficiency in hematopoietic cells is a key driver of AD pathogenesis.
• Targeting neutrophil accumulation presents a potential therapeutic avenue for AD.