Dataset Information

Transcriptome analaysis of Bcl11b-deficient aortas

ABSTRACT: 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.

ORGANISM(S): Mus musculus

PROVIDER: GSE163551 | GEO | 2021/12/01

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:SMCs express plasminogen activator inhibitor-1 (PAI-1), which regulates SMC function and vascular remodeling. However, whether PAI-1 controls SMC cytoskeletal dynamics and stiffness is unknown, and the causal role of PAI-1 in arterial stiffening is undefined. SMCs from human coronary arteries and aortae of wild-type vs. PAI-1-deficient mice were cultured with or without PAI-039, a specific PAI-1 inhibitor, after which cell stiffness was measured by atomic force microscopy, filamentous actin structures were assessed by confocal microscopy, and the activities cofilin, LIM domain kinase 1 (LIMK), slingshot homolog 1 (SSH), and AMP-activated protein kinase (AMPK) were measured. RNA sequencing was performed to determine the effects of PAI-039 on SMC gene expression. Effects of PAI-039 on aortic stiffness were assessed by pulse wave velocity. PAI-039 significantly reduced intrinsic stiffness of human SMCs, which was accompanied by significant decreases in cytoplasmic actin filaments. Similar effects were observed in wild-type, but not in PAI-1-deficient SMCs. Mechanistically, PAI-039 significantly increased the activity of cofilin, an actin depolymerase, in SMCs expressing PAI-1, but not in PAI-1-deficient cells. PAI-039 had no significant effects on LIMK or SSH activity. RNA-sequencing analysis suggested that PAI-039 up-regulates AMPK signaling in SMCs, which was confirmed by western blotting. Inhibition of AMPK prevented activation of cofilin by PAI-039. In mice, PAI-039 significantly decreased aortic stiffness without significantly altering peri-aortic fibrosis. PAI-039 decreases intrinsic SMC stiffness by reducing cytoplasmic stress fiber content. These effects are mediated by AMPK-dependent activation of cofilin. PAI-039 also decreases aortic stiffness in vivo. These findings suggest that PAI-1 is an important regulator of the SMC cytoskeleton and that pharmacologic inhibition of PAI-1 has potential to treat cardiovascular diseases mediated by accelerated arterial stiffening.

Project description:Rho-kinase signaling and YAP signaling are related to aortic dissection (AD) formation. However, as important biomechanical signaling pathways, their relationships with aortic smooth muscle cell (AoSMC) mechanics have not been investigated in AD formation. This study aims to explore the correlation between RhoA/ROCK1 and YAP, as well as their relationship with intrinsic AoSMC stiffness during AD formation. The expression of RhoA/ROCK1 and YAP as well as F-actin polymerization were analyzed in AoSMCs isolated from normal and AD human aortas. The intrinsic cell stiffness of normal and AD AoSMCs was measured using atomic force microscopy (AFM). The correlations among RhoA/ROCK1, YAP, and intrinsic AoSMC stiffness were explored by manipulating the activity of RhoA and ROCK1, and YAP expression. Finally, the role of RhoA/ROCK1/YAP/F-actin and AoSMC stiffness during AD formation was studied in pharmaceutically induced AD mouse models.Compared to normal human AoSMCs, the expression of RhoA and ROCK1 was downregulated, while the phosphorylation of YAP was increased in AD human AoSMCs, coupled with impaired F-actin polymerization and decreased intrinsic cell stiffness. Pharmaceutical inhibition of RhoA or ROCK1 activities and depletion of YAP all led to impaired F-actin polymerization and decreased intrinsic AoSMC stiffness. Moreover, abnormal collagen deposition and impaired cell-ECM interactions were found when RhoA/ROCK1/YAP/F-actin signaling was inhibited in normal human AoSMCs. We further analyzed the normal human AoSMC treated by Y27632 or not using RNA sequencing to investigate the impact of RhoA/ROCK1/YAP/F-actin on AoSMCs. GO analysis showed that differentially expressed genes (DEGs) related to cAMP-mediated signaling, cytoskeleton organization, cell-matrix adhesion, and extracellular matrix (ECM) organization were affected when ROCK1 activity was inhibited by Y27632 in normal AoSMCs. KEGG analysis showed differences in PI3K-Akt signaling, focal adhesion, MAPK, actin cytoskeleton, and ECM-receptor interaction. Consistently, cAMP, actin cytoskeleton organization, and ECM structural constituents were all downregulated in AoSMCs treated with Y27632 according to GSEA. We also analyzed the downregulated genes in AoSMCs treated with Y27632. Results demonstrated that the downregulated genes were mainly related to the cell-ECM unit, PI3K, MAPK, focal adhesion, and cAMP signaling pathways.

Project description:The Ca2+/calmodulin-dependent kinase II is expressed in smooth muscle and believed to mediate intracellular calcium handling and calcium-dependent gene transcription. CaMKII is activated by Angiotensin-II. The multifunctional calcium/calmodulin-dependent kinase II (CaMKII) is activated by Angiotensin-II (Ang-II) in vascular smooth muscle cells (VSMC), but its impact on hypertension remains unknown. In our transgenic mice that express the inhibitor peptide CaMKIIN in smooth muscle (TG SM-CaMKIIN), the blood pressure response to chronic Ang-II infusion was significantly reduced as compared to littermate controls. Surprisingly, examination of blood pressure and heart rate under ganglionic blockade revealed a key role for VSMC CaMKII in efferent sympathetic outflow in response to Ang II hypertension. Consistently, the efferent splanchnic nerve activity and plasma phenylephrine concentrations were significantly lower in TG SM-CaMKIIN mice as compared to littermates. Moreover, the aortic depressor nerve activity was reset in hypertensive wild type animals, but not in TG SM-CaMKIIN mice, suggesting that changes in baroreceptor wall activity may be responsible for the blood pressure difference in Ang-II hypertension. The pulse wave velocity, a measure of vascular wall stiffness in vivo, was increased in aortas of hypertensive compared to normotensive WT animals. However, Ang-II infusion did not alter the pulse wave velocity in transgenic mice, suggesting that CaMKII in VSMC controls structural smooth muscle genes. Accordingly, analysis of gene expression changes in aortas from wild type and TG SM-CaMKIIN hypertensive mice demonstrated that CaMKII inhibition mainly altered the expression of muscle contractile proteins. In contrast, TG SM-CaMKIIN aortas were protected from the Ang-II induced upregulation of genes linked to proliferation, suggesting that CaMKII inhibition prevents the Ang-II-induced reprogramming of smooth muscle cell gene expression towards a proliferative phenotype. 5 WT C57Bl/6 and 5 mice that express the Ca2+/calmodulin-dependent kinase II peptide inhibitor CaMKIIN in smooth muscle only (TG SM-CaMKIIN) were infused with 1.25 ug/kg/min Angiotensin-II by osmotic minipump for 14 days. 5 WT and 5 transgenic mice infused with normal saline served as controls. The mice were sacrificed on day 14 and the thoracic aortas isolated. RNA was isolated and pooled for the following groups: WT (wild type), C (TG SM-CaMKIIN), WT-A (WT with Angiotensin-II), C-A (TG SM-CaMKIIN + Angiotensin-II)

Dataset Information

Transcriptome analaysis of Bcl11b-deficient aortas

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets