BCL11B Regulates Arterial Stiffness and Related Target Organ Damage

Rationale: 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. Objective: Based on these human findings, we sought to examine the relation between BCL11B and arterial function. Methods and Results: 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 decreased levels of their common phosphorylation target, vasodilator-stimulated phosphoprotein (pVASP S239 ), a regulator of cytoskeletal actin rearrangements. Decreased pVASP S239 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. Conclusions: We have identified VSM BCL11B as a crucial regulator of aortic smooth muscle function and a potential therapeutic target for vascular stiffness.

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Bcl11b is a Newly Identified Regulator of Vascular Smooth Muscle Phenotype and Arterial Stiffness

10.1101/193110 ◽

2017 ◽

Cited By ~ 2

Author(s):

Jeff Arni C. Valisno ◽

Pavania Elavalakanar ◽

Christopher Nicholson ◽

Kuldeep Singh ◽

Dorina Avram ◽

...

Keyword(s):

Smooth Muscle ◽

Arterial Stiffness ◽

Vascular Smooth Muscle ◽

Actin Polymerization ◽

Genome Wide Association Study ◽

Ex Vivo ◽

Aortic Aneurysms ◽

Cell Phenotype ◽

Gene Desert ◽

A Genome

ABSTRACTB-cell leukemia 11b (Bcl11b) is a zinc-finger transcription factor known as master regulator of T lymphocytes and neuronal development during embryogenesis. Bcl11b-interacting protein COUP-TFII is required for atrial development and vasculogenesis, however a role of Bcl11b in the adult cardiovascular system is unknown. A genome-wide association study (GWAS) recently showed that a gene desert region downstream ofBCL11Band known to function asBCL11Benhancer harbors single nucleotide polymorphisms (SNPs) associated with increased arterial stiffness. Based on these human findings, we sought to examine relations between Bcl11b and arterial function using mice with Bcl11b deletion. We report for the first time that Bcl11b is expressed in vascular smooth muscle (VSM) and transcriptionally regulates the expression of VSM contractile proteins smooth muscle myosin and smooth muscle α-actin. Lack of Bcl11b in VSM-specific Bcl11b null mice (BSMKO) resulted in increased expression of Ca++-calmodulin-dependent serine/threonine phosphatase calcineurin in BSMKO VSM cells, cultured in serum-free condition, and in BSMKO aortas, which showed an inverse correlation with levels of phosphorylated VASPS239, a regulator of cytoskeletal actin rearrangements. Moreover, decreased pVASPS239in BSMKO aortas was associated with increased actin polymerization (F/G actin ratio). Functionally, aortic force, stress and wall tension, measured ex vivo in organ baths, were increased in BSMKO aortas and BSMKO mice had increased pulse wave velocity, thein vivoindex of arterial stiffness, compared to WT littermates. Despite having no effect on baseline blood pressure or angiotensin II-induced hypertension, Bcl11b deletion in VSM increased the incidence of aortic aneurysms in BSMKO mice. Aneurysmal aortas from angII-treated BSMKO mice had increased number of apoptotic VSM cells. In conclusion, we identified VSM Bcl11b as a novel and crucial regulator of VSM cell phenotype and vascular structural and functional integrity.

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Cooperative action of APJ and α1A-adrenergic receptor in vascular smooth muscle cells induces vasoconstriction

The Journal of Biochemistry ◽

10.1093/jb/mvz071 ◽

2019 ◽

Vol 166 (5) ◽

pp. 383-392 ◽

Cited By ~ 2

Author(s):

Katsumasa Nagano ◽

Chulwon Kwon ◽

Junji Ishida ◽

Tatsuo Hashimoto ◽

Jun-Dal Kim ◽

...

Keyword(s):

Smooth Muscle ◽

Smooth Muscle Cells ◽

Adrenergic Receptor ◽

Calcium Influx ◽

Ex Vivo ◽

Smooth Muscle Actin ◽

Muscle Cells ◽

Cooperative Action ◽

A Genome

Abstract The apelin receptor (APJ), a receptor for apelin and elabela/apela, induces vasodilation and vasoconstriction in blood vessels. However, the prolonged effects of increased APJ-mediated signalling, involving vasoconstriction, in smooth muscle cells have not been fully characterized. Here, we investigated the vasoactive effects of APJ gain of function under the control of the smooth muscle actin (SMA) gene promoter in mice. Transgenic overexpression of APJ (SMA-APJ) conferred sensitivity to blood pressure and vascular contraction induced by apelin administration in vivo. Interestingly, ex vivo experiments showed that apelin markedly increased the vasoconstriction of isolated aorta induced by noradrenaline (NA), an agonist for α- and β-adrenergic receptors, or phenylephrine, a specific agonist for α1-adrenergic receptor (α1-AR). In addition, intracellular calcium influx was augmented by apelin with NA in HEK293T cells expressing APJ and α1A-AR. To examine the cooperative action of APJ and α1A-AR in the regulation of vasoconstriction, we developed α1A-AR deficient mice using a genome-editing technique, and then established SMA-APJ/α1A-AR-KO mice. In the latter mouse line, aortic vasoconstriction induced by a specific agonist for α1A-AR, A-61603, were significantly less than in SMA-APJ mice. These results suggest that the APJ-enhanced response requires α1A-AR to contract vessels coordinately.

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Measuring Arterial Stiffness in Animal Experimental Studies

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvbaha.119.313861 ◽

2020 ◽

Vol 40 (5) ◽

pp. 1068-1077

Author(s):

Mark Butlin ◽

Isabella Tan ◽

Bart Spronck ◽

Alberto P. Avolio

Keyword(s):

Smooth Muscle ◽

Arterial Stiffness ◽

Animal Studies ◽

Ex Vivo ◽

Experimental Studies ◽

Full Characterization ◽

Invasive Techniques

The arterial wall is a composite material of elastin, collagen, and extracellular matrix with acutely modifiable material properties through the action of smooth muscle cells. Therefore, arterial stiffness is a complex parameter that changes not only with long-term remodeling of the wall constituents but also with acute contraction or relaxation of smooth muscle or with changes in the acute distending pressure to which the artery is exposed. It is not possible to test all these aspects using noninvasive or even invasive techniques in humans. Full characterization of the mechanical properties of the artery and the specific arterial factors causing changes to stiffness with disease or modified lifestyle currently require animal studies. This article summarizes the major in vivo and ex vivo techniques to measure the different aspects of arterial stiffness in animal studies.

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P0888FIBROBLAST GROWTH FACTOR 23 PRODUCES ARTERIAL STIFFNESS THROUGH CHANGES IN VASCULAR SMOOTH MUSCLE CELL PHENOTYPE

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfaa142.p0888 ◽

2020 ◽

Vol 35 (Supplement_3) ◽

Author(s):

Juan R Muñoz-Castañeda ◽

Cristian Rodelo-Haad ◽

M Victoria Pendon-Ruiz de Mier ◽

Noemi Vergara ◽

Gonzalo Revilla-Gonzalez ◽

...

Keyword(s):

Smooth Muscle ◽

Growth Factor ◽

Arterial Stiffness ◽

Vascular Smooth Muscle ◽

Plasma Levels ◽

Vascular Dysfunction ◽

Vascular Stiffness ◽

Cell Phenotype ◽

Contractile Phenotype ◽

Synthetic Phenotype

Abstract Background and Aims In patients with chronic kidney disease (CKD), high levels of c-terminal fibroblast growth factor 23 (FGF23) are associated with cardiovascular disease and mortality. Vascular smooth muscle cells (VSMC) may present two clearly differentiated functional phenotypes, contractile and synthetic. The abundance of synthetic phenotype is associated with vascular dysfunction and it is unknown whether in FGF23 may promote transition from a contractile to a synthetic phenotype in VSMC causing vascular stiffness. The present study was conducted to evaluate whether FGF23 affects VSMC phenotype and arterial stiffness. Method and Results High levels of FGF23 promoted VSMC transition from a contractile to a synthetic phenotype. These effects were mediated through FGFR1 and Ras/MAPK signaling activation. Inhibition of both pathways enhanced contractile phenotype of VSMC. The pro-contractile microRNAs, miR-221 and miR-222 were reduced by FGF23 and miR-221 transfection recovered the contractile phenotype of VSMC decreased by FGF23. In experimental rats, exogenous infusion of FGF23 produced an increase in vascular wall thickness with VSMC exhibiting synthetic phenotype and reduction of plasma levels of miR-221. Functional studies performed on aortic arterial rings revealed that passive and active forces were altered in rats treated with FGF23. In a group of CKD stage 2-3 patients with rather high levels of FGF23 it was observed an increased in pulse pressure reflecting vascular stiffness together with low plasma levels of miR-221 and miR-222. Conclusion FGF23 favors the transition of VSMC from contractile to synthetic phenotype causing vascular dysfunction and arterial stiffness; this may be a mechanism by which FGF23 contribute directly to the development of vascular disease in CKD patients.

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LIMK (LIM Kinase) Inhibition Prevents Vasoconstriction- and Hypertension-Induced Arterial Stiffening and Remodeling

Hypertension ◽

10.1161/hypertensionaha.120.15203 ◽

2020 ◽

Vol 76 (2) ◽

pp. 393-403

Author(s):

Mariana Morales-Quinones ◽

Francisco I. Ramirez-Perez ◽

Christopher A. Foote ◽

Thaysa Ghiarone ◽

Larissa Ferreira-Santos ◽

...

Keyword(s):

Smooth Muscle ◽

Arterial Stiffness ◽

Vascular Smooth Muscle ◽

Actin Polymerization ◽

Fiber Formation ◽

Cell Cortex ◽

Lim Kinase ◽

Arterial Stiffening ◽

Cofilin Phosphorylation ◽

Visceral Arteries

Increased arterial stiffness and vascular remodeling precede and are consequences of hypertension. They also contribute to the development and progression of life-threatening cardiovascular diseases. Yet, there are currently no agents specifically aimed at preventing or treating arterial stiffening and remodeling. Previous research indicates that vascular smooth muscle actin polymerization participates in the initial stages of arterial stiffening and remodeling and that LIMK (LIM kinase) promotes F-actin formation and stabilization via cofilin phosphorylation and consequent inactivation. Herein, we hypothesize that LIMK inhibition is able to prevent vasoconstriction- and hypertension-associated arterial stiffening and inward remodeling. We found that small visceral arteries isolated from hypertensive subjects are stiffer and have greater cofilin phosphorylation than those from nonhypertensives. We also show that LIMK inhibition prevents arterial stiffening and inward remodeling in isolated human small visceral arteries exposed to prolonged vasoconstriction. Using cultured vascular smooth muscle cells, we determined that LIMK inhibition prevents vasoconstrictor agonists from increasing cofilin phosphorylation, F-actin volume, and cell cortex stiffness. We further show that localized LIMK inhibition prevents arteriolar inward remodeling in hypertensive mice. This indicates that hypertension is associated with increased vascular smooth muscle cofilin phosphorylation, cytoskeletal stress fiber formation, and heightened arterial stiffness. Our data further suggest that pharmacological inhibition of LIMK prevents vasoconstriction-induced arterial stiffening, in part, via reductions in vascular smooth muscle F-actin content and cellular stiffness. Accordingly, LIMK inhibition should represent a promising therapeutic means to stop the progression of arterial stiffening and remodeling in hypertension.

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Arterial Stiffness and Vascular Aging: Effects of Hypertension

The Russian Archives of Internal Medicine ◽

10.20514/2226-6704-2021-11-3-196-202 ◽

2021 ◽

Vol 11 (3) ◽

pp. 196-202

Author(s):

E. S. Fomina ◽

V. S. Nikiforov

Keyword(s):

Cardiovascular Risk ◽

Arterial Stiffness ◽

Arterial Hypertension ◽

Augmentation Index ◽

Target Organ Damage ◽

Ankle Brachial Index ◽

Vascular Stiffness ◽

Vascular Aging ◽

Aging Effects ◽

Functional Changes

This review highlights the relationship of age and arterial hypertension observed in the aging process. The main structural and functional changes underlying the increase in vascular stiffness are analyzed. The similarity of vascular changes in aging and arterial hypertension was noted. The negative effect of increased central blood pressure on target organs is considered. Attention is paid to the analysis of arterial stiffness as a marker of vascular aging. The parameters of the carotid-femoral pulse wave propagation velocity, the cardio-ankle vascular index (CAVI), the ankle-brachial index, the finger-brachial index, and the augmentation index were examined separately. The prognostic and clinical value of the parameters of vascular stiffness is considered. In particular, the clinical guidelines for arterial hypertension report the need to use arterial stiffness indicators to improve the accuracy of cardiovascular risk stratification, especially in medium-risk patients. Measurement of vascular stiffness and central aortic pressure should be recommended as one of the methods for stratifying cardiovascular risk in patients with intermediate SCORE risk, as well as in those whose target organ damage was not detected by routine methods. The article also notes the independent diagnostic and prognostic value of the CAVI.

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Doxorubicin Impairs Smooth Muscle Cell Contraction: Novel Insights in Vascular Toxicity

International Journal of Molecular Sciences ◽

10.3390/ijms222312812 ◽

2021 ◽

Vol 22 (23) ◽

pp. 12812

Author(s):

Matthias Bosman ◽

Dustin N. Krüger ◽

Kasper Favere ◽

Callan D. Wesley ◽

Cédric H. G. Neutel ◽

...

Keyword(s):

Smooth Muscle ◽

Arterial Stiffness ◽

Smooth Muscle Cell ◽

Muscle Cell ◽

Vascular Reactivity ◽

Transient Receptor Potential ◽

Ex Vivo ◽

Receptor Potential ◽

Transient Receptor Potential Channels

Clinical and animal studies have demonstrated that chemotherapeutic doxorubicin (DOX) increases arterial stiffness, a predictor of cardiovascular risk. Despite consensus about DOX-impaired endothelium-dependent vasodilation as a contributing mechanism, some studies have reported conflicting results on vascular smooth muscle cell (VSMC) function after DOX treatment. The present study aimed to investigate the effects of DOX on VSMC function. To this end, mice received a single injection of 4 mg DOX/kg, or mouse aortic segments were treated ex vivo with 1 μM DOX, followed by vascular reactivity evaluation 16 h later. Phenylephrine (PE)-induced VSMC contraction was decreased after DOX treatment. DOX did not affect the transient PE contraction dependent on Ca2+ release from the sarcoplasmic reticulum (0 mM Ca2+), but it reduced the subsequent tonic phase characterised by Ca2+ influx. These findings were supported by similar angiotensin II and attenuated endothelin-1 contractions. The involvement of voltage-gated Ca2+ channels in DOX-decreased contraction was excluded by using levcromakalim and diltiazem in PE-induced contraction and corroborated by similar K+ and serotonin contractions. Despite the evaluation of multiple blockers of transient receptor potential channels, the exact mechanism for DOX-decreased VSMC contraction remains elusive. Surprisingly, DOX reduced ex vivo but not in vivo arterial stiffness, highlighting the importance of appropriate timing for evaluating arterial stiffness in DOX-treated patients.

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The Inter-Relationship of Platelets with Interleukin-1β-Mediated Inflammation in Humans

Thrombosis and Haemostasis ◽

10.1055/s-0038-1675603 ◽

2018 ◽

Vol 118 (12) ◽

pp. 2112-2125 ◽

Cited By ~ 10

Author(s):

Rahajeng Tunjungputri ◽

Yang Li ◽

Philip de Groot ◽

Charles Dinarello ◽

Sanne Smeekens ◽

...

Keyword(s):

Genome Wide Association Study ◽

Cytokine Production ◽

Ex Vivo ◽

Platelet Reactivity ◽

Nucleotide Polymorphisms ◽

Immune Mediated ◽

A Genome ◽

Platelet Number ◽

Relationship Of ◽

The Impact

Background Inflammation and coagulation are key processes in cardiovascular diseases (CVDs). The Canakinumab Anti-inflammatory Thrombosis Outcome Study trial affirmed the importance of inflammation in CVD by showing that inhibition of the interleukin (IL)-1β pathway prevents recurrent CVD. A bi-directional relationship exists between inflammation and coagulation, but the precise interaction of platelets and IL-1β-mediated inflammation is incompletely understood. We aimed to determine the inter-relationship between platelets and inflammation—and especially IL-1β—in a cohort of healthy volunteers. Methods We used data from the 500-Human Functional Genomics cohort, which consists of approximately 500 Caucasian, healthy individuals. We determined associations of plasma levels of IL-1β and other inflammatory proteins with platelet number and reactivity, the association of platelet reactivity with ex vivo cytokine production as well as the impact of genetic variations through a genome-wide association study (GWAS). Results Platelets were associated with IL-1β on different levels. First, platelet number was positively associated with plasma IL-1β concentrations (p = 8.9 × 10−9) and inversely with concentrations of α-1-anti-trypsin (p = 1.04 × 10−18), which is a known antagonist of IL-1β. Second, platelet degranulation capacity, as determined by agonist-induced P-selectin expression, was associated with ex vivo IL-1β and IL-6 production. Third, several platelet single-nucleotide polymorphisms (SNPs) were associated with cytokine production and there was a significant platelet SNP enrichment in specific biological important pathways. Finally, platelet SNPs were enriched among SNPs earlier identified in GWAS studies in blood-related diseases and immune-mediated diseases. Conclusion This comprehensive assessment of factors associated with platelet number and reactivity reinforces the important inter-relationship of platelets and IL-1β-mediated inflammation.

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Abstract P170: Similarities And Differences In The Vascular Impact Of Estrogen Loss Versus G Protein-coupled Estrogen Receptor Deletion

Hypertension ◽

10.1161/hyp.78.suppl_1.p170 ◽

2021 ◽

Vol 78 (Suppl_1) ◽

Author(s):

Isabella M Kilanowski-Doroh ◽

Tristen J Wong ◽

Benard O Ogola ◽

Nicholas Harris ◽

Alec Horton ◽

...

Keyword(s):

Blood Pressure ◽

Estrogen Receptor ◽

Smooth Muscle ◽

Arterial Stiffness ◽

G Protein ◽

Vascular Stiffness ◽

Area Fraction ◽

Increased Risk ◽

The Impact ◽

G Protein Coupled

Women in their postmenopausal years have an increased risk of cardiovascular disease, and recent research suggests that increased vascular stiffness can be detected within a year of the onset of menopause. We have previously demonstrated that the G Protein-Coupled Estrogen Receptor (GPER) protects the vasculature without noticeable changes in blood pressure, but little is known about the underlying structural changes that provide protection. In this study we assessed the impact of estrogen and the G protein-coupled estrogen receptor (GPER) on vascular health, with the hypothesis that loss of estrogen or deletion of smooth muscle cell (smc)-GPER would similarly increase vascular stiffness. Female mice were separated into three cohorts: intact wildtype, ovariectomized (OVX), and GPER smc-KO. OVX occurred at 8 weeks of age and 8 weeks later blood pressure was measured via tail-cuff plethysmography, arterial stiffness was measured as pulse wave velocity (PWV) via high resolution ultrasound, and carotids were excised for biaxial pressure myography and imaging. Uterine weight in OVX mice (0.03 g) was significantly lower than intact mice (0.1 g; p=0.0002) confirming the loss of estrogen. No difference was observed in systolic blood pressure, however, both the OVX (1.5 m/s) and smc-KO (1.9 m/s) groups had significantly higher PWV than intact controls (1.2 m/s; p=0.02 and p=0.03, respectively). Carotids of OVX (366 μm) and smc-KO (389 μm) mice had a smaller outer diameter versus controls (441 μm; p >0.05) without a difference in thickness. Despite the similar responses of OVX and smc-KO groups, Masson’s trichrome staining of carotid sections showed significantly more smooth muscle area fraction in OVX (p=0.005), but not KO mice, and no difference in collagen area fraction. These data indicate that while estrogen loss and smc-KO of GPER both increase arterial stiffness, increased smooth muscle due to estrogen loss is likely not modulated through GPER. Future experiments will aim to understand how other components, such as extracellular matrix genes, may be affected by loss of GPER.

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