GSE163551
Transcriptome analaysis of Bcl11b-deficient aortas
B-cell leukemia 11b (BCL11B) is a transcription factor known as an essential regulator of T lymphocytes and neuronal development during embryogenesis. A genome-wide association study (GWAS) showed that a gene desert region downstream of BCL11B, known to function as a BCL11B enhancer, harbors single nucleotide polymorphisms (SNPs) associated with increased arterial stiffness. However, a role for BCL11B in the adult cardiovascular system is unknown. Based on these human findings, we sought to examine the relation between BCL11B and arterial function. Here we report that BCL11B is expressed in the vascular smooth muscle (VSM) where it regulates vascular stiffness. RNA sequencing of aortas from WT and Bcl11b null mice (BSMKO) identified the cyclic guanosine monophosphate (cGMP)-protein kinase G (PKG) as the most significant differentially regulated signaling pathway in BSMKO compared to WT mice. BSMKO aortas showed decreased levels of PKG1, increased levels of Ca++-calmodulin-dependent serine/threonine phosphatase calcineurin (PP2B) and their common phosphorylation target, vasodilator-stimulated phosphoprotein (pVASPS239), a regulator of cytoskeletal actin rearrangements. Decreased pVASPS239 in BSMKO aortas was associated with increased actin polymerization (F/G actin ratio). Functionally, aortic force, stress, wall tension and stiffness, measured ex vivo in organ baths, were increased in BSMKO aortas, and BSMKO mice had increased pulse wave velocity, the in vivo index of arterial stiffness. Despite having no effect on blood pressure or microalbuminuria, increased arterial stiffness in BSMKO mice was associated with increased incidence of cerebral microbleeds compared to age-matched WT littermates. In conclusion, we have identified VSM BCL11B as a crucial regulator of aortic smooth muscle function and a potential therapeutic target for vascular stiffness. Overall design: Examination of changes in transcriptome of whole aortas from WT and vascular smooth muscle-specific Bcl11b KO mice