Skeleton-secreted PDGF-BB mediates arterial stiffening

Arterial stiffening, a characteristic feature of obesity and type 2 diabetes, contributes to the development and progression of cardiovascular diseases (CVD). Currently, no effective prophylaxis or therapeutics is available to prevent or treat arterial stiffening. A better understanding of the molecular mechanisms underlying arterial stiffening is vital to identify newer targets and strategies to reduce CVD burden. A major contributor to arterial stiffening is increased collagen deposition. In the 5' untranslated regions of mRNAs encoding for type I collagen, an evolutionally conserved stem-loop (SL) structure plays an essential role in its stability and post-transcriptional regulation. Here, we show that feeding a high fat/high sucrose (HFHS) diet for 28 weeks increases adiposity, insulin resistance, and blood pressure in male wild-type littermates. Moreover, arterial stiffness, assessed in vivo via aortic pulse wave velocity, and ex vivo using atomic force microscopy in aortic explants or pressure myography in isolated femoral and mesenteric arteries, was also increased in those mice. Notably, all these indices of arterial stiffness, along with collagen type I levels in the vasculature, were reduced in HFHS-fed mice harboring a mutation in the 5'SL structure, relative to wild-type littermates. This protective vascular phenotype in 5'SL-mutant mice did not associate with a reduction in insulin resistance or blood pressure. These findings implicate the 5'SL structure as a putative therapeutic target to prevent or reverse arterial stiffening and CVD associated with obesity and type 2 diabetes.

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Abstract MP100: Arterial Stiffness and Pressure Amplification Associated with Markers of Cerebral Microvascular Disease: The Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS)

Circulation ◽

10.1161/circ.133.suppl_1.mp100 ◽

2016 ◽

Vol 133 (suppl_1) ◽

Author(s):

Priya Palta ◽

Jingkai Wei ◽

Michelle Meyer ◽

Melinda C Power ◽

Jennifer A Deal ◽

...

Keyword(s):

Older Adults ◽

Arterial Stiffness ◽

Pulse Pressure ◽

Aortic Stiffness ◽

Brain Mri ◽

Intracranial Volume ◽

Sampling Weights ◽

Arterial Stiffening ◽

Lacunar Infarcts ◽

Pressure Amplification

Introduction: Small vessel disease is associated with decreased cognitive function, possibly differential by race. Age-related central arterial stiffening increases pulsatility resulting in hypoperfusion, microvascular damage and remodeling in the brain, potentially impairing cognition. We examined if arterial stiffness and pressure amplification are associated with lacunar infarcts and greater volumes of white matter hyperintensities (WMH) in a sample of Caucasian and African American (AA) older adults. Methods: We analyzed a cross-sectional sample of ARIC participants aged 67-90 years (n=1486) from visit 5 (2011-2013), with brain magnetic resonance imaging (MRI). The Omron VP-1000 Plus was used to measure aortic stiffness (carotid-femoral pulse wave velocity [cfPWV]) and pressure amplification measures (pulse pressure amplification [PPA], central pulse pressure [cPP], and estimated central systolic blood pressure [cSBP]). Aortic stiffness and pressure amplification were dichotomized at race-specific 25th percentile cut points. Brain MRI using 3D-1.5T equipment quantified the presence of lacunar infarcts and volumes of WMH following a standardized protocol. Logistic regression, adjusted for age, sex, education, ApoE4, heart rate, smoking and body mass index, was used to quantify the odds of lacunar infarcts in participants with high vs. low cfPWV, cPP, cSBP, and low vs. high PPA. Linear regression models, additionally adjusted for intracranial volume, estimated the difference in log-transformed volumes of WMH among participants with high vs. low cfPWV, cPP, cSBP, and low vs. high PPA. Probability sampling weights for an MRI were included to allow for generalizability to the full visit 5 cohort. Results: Among the 1486 participants with a brain MRI (mean age: 76, 41% male, 26% AA), measures of aortic stiffness and pressure amplification were associated with lacunar infarcts in Caucasians, but not in AAs. Caucasian participants with a high cfPWV had greater odds of lacunar infarcts (Odds Ratio [OR] =2.02, 95% confidence interval [CI]: 1.23, 2.20). Caucasians with high cSBP had higher odds of lacunar infarcts (OR=1.72, 95% CI: 1.10, 2.69). In Caucasians, high cfPWV was associated with a 21% (95% CI: 6, 38) greater volume of WMH as compared to a low cfPWV; high cSBP was associated with a 28% (95% CI: 14, 45) greater volume of WMH compared to a low cSBP. In AAs, high cfPWV was associated with a 32% (95% CI: 7, 62) greater volume of WMH as compared to low cfPWV. Cerebral microvascular imaging markers did not differ quantitatively with measures of PPA and cPP. Conclusions: Central arterial stiffening and pressure amplification are plausible microvascular contributors to cognitive aging, providing new information on modifiable pathways for previously observed associations between cardiovascular disease risk factors and the rates of cognitive decline and dementia among older adults.

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Abstract 17853: Activation of AMP-activated Protein Kinase (AMPKα) by AICAR Attenuates Klotho Deficiency-induced Endothelial Dysfunction, Arterial Stiffening and Hypertension

Circulation ◽

10.1161/circ.130.suppl_2.17853 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Yi Lin ◽

Zhongjie Sun

Keyword(s):

Blood Pressure ◽

Blood Glucose ◽

Endothelial Dysfunction ◽

Protein Expression ◽

Normal Diet ◽

Collagen I ◽

Daily Injection ◽

Arterial Stiffening ◽

Glucose Levels ◽

Amp Activated Protein Kinase

Background: Arterial stiffening and hypertension are progressive aging-related disorders. Klotho (KL) is a recently-discovered anti-aging gene but its role in the pathogenesis of endothelial dysfunction, arterial stiffening and hypertension is not fully understood. Methods and Results: Heterozygous Klotho deficiency ( KL +/- ) mice and WT littermate mice were fed on high fat diet (HFD) or normal diet (ND). Plasma KL in KL heterozygeous mice (+/-) is about a half of that of the WT mice. Pulse wave velocity (PWV), an index of arterial stiffening, was increased in KL +/- mice but not in WT mice fed on HFD for 4 weeks. Systolic blood pressure and blood glucose levels were increased earlier with greater magnitudes in KL +/- mice than in WT mice fed on HFD. Notably, protein expression of collagen I, Runx2, and TGFβ1 were increased but protein expression of phosphorylated AMPKα (pAMPKα), phosphorylated eNOS (peNOS), and Mn-SOD were decreased in aortas of KL +/- mice fed on HFD for 5 weeks. Interestingly, daily injection of AICAR, an activator of AMPK, abolished the increases in PWV, blood pressure, and blood glucose in KL +/- mice fed on HFD. AICAR not only abolished the downregulation of pAMPKα, peNOS, and Mn-SOD levels but also attenuated the increased levels of collagen I, Runx2, TGFβ1 and superoxide, elastic lamellae breaks, and calcification in aortas in KL +/- mice fed on HFD. Conclusions: Klohto deficiency promotes HFD-induced endothelial dysfunction, arterial stiffening and hypertension. The promoting effects of klotho deficiency on arterial stiffening may be due to downregulation of endothelial AMPKα activity.

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