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Biology subjects

Valentin Cabrera, A. M.

Publications and source records attributed to Valentin Cabrera, A. M..

2 recordsLinked to original sources

Intrinsic Phenotypic Differences, Not Hemodynamic Shear, Associate with Cusp-Specific Remodeling in Aortic Valve Disease

Aortic valve disease (AVD) is asymmetric. Various clinical reports indicate that the non- coronary cusp (NCC) is disproportionally burdened by pathological remodeling like inflammation, fibrosis, and calcification. This has long been attributed to the resulting differences in hemodynamic load that arise from the presence, or lack thereof, of coronary ostia in respective sinuses. However, there is little to no empirical evidence to suggest that these differences in hemodynamic shear alone are enough to drive the difference in pathological remodeling that is observed. C57BL/6J mice exhibit a high variance in right coronary ostium (RCO) positioning with respect to the right coronary cusp (RCC). Through computational fluid dynamics (CFD) simulations of a mouse aortic valve (AoV) during end diastolic loading, we show negligible differences in wall shear stress (WSS) between a high RCO on the RCC and no ostium on the NCC. Also, though CFD analyses depict at least an order of magnitude difference in WSS through physiologically relevant ostia positions within the sinuses, ostium position does not correlate with calcification burden in a CKD mouse model of calcific AVD. Cusp dependent extracellular matrix (ECM) abundance analysis reveals asymmetric collagen and elastin content in healthy adult mice, but this does not follow the same trend as pathological remodeling. Instead, asymmetric abundance of elastin (P=0.034) and collagen (P=0.018) was mainly driven by an increase of these ECM proteins in the left coronary cusp (LCC) with no differences in leaflet thickness. Cusp dependent transcriptomic (spatial and bulk RNA sequencing) analyses reveal asymmetric phenotypic profiles between the three cusps in healthy adult mice. Of note, genes associated with vascular smooth muscle cell contraction and known modulators of AoV remodeling were upregulated in the NCC and downregulated in both the RCC and LCC. Together, these data suggest that the differences in shear resulting from the coronary ostia are not sufficient to explain the asymmetric onset of calcific AVD.

physiology↗

Sex-Specific Changes in Cardiac Function and Electrophysiology During Progression of Adenine-Induced Chronic Kidney Disease in Mice

BACKGROUNDChronic kidney disease (CKD) and cardiovascular disease (CVD) often co-exist and interact; however, notable sex-dependent differences are observed in how these conditions manifest and progress in parallel, despite men and women sharing similar risk factors. Identifying sex-specific diagnostic markers of cardiac structure and function throughout CKD progression could elucidate why the development and progression of these diseases differ by sex. METHODS AND RESULTSAdult, C57BL/6J male and female mice were subjected to a high-adenine (0.2%) diet throughout 12-weeks to induce CKD. Control mice were fed a normal chow diet. Every three weeks, electrocardiogram (ECG) and echocardiogram-based markers of cardiac physiology were evaluated. Adenine-induced CKD showed markers of left ventricular (LV) hypertrophy in male mice only. CKD males had markers indicative of LV systolic and diastolic dysfunction throughout regimen duration, worsening as disease progressed. Adenine males had a prolonged QTc and STc intervals when compared to Adenine females and Control males. Sex-dependent differences in the duration of the Speak-J marker, measured via ECG, was identified, with Adenine males showing increases in duration earlier than Adenine females compared to their Control counterparts. CONCLUSIONSIn this study, we identified sex-dependent differences in cardiac structure, function, and electrophysiology in a mouse model of CKD-induced CVD throughout disease progression. We found that male mice are more prone to developing LV hypertrophy, systolic dysfunction, and diastolic dysfunction, with significant increases in ECG markers indicative of ventricular dysfunction observed in adenine-treated males at late stages of the disease. Additionally, we identified a new ECG parameter, Speak-J duration, that highlights sex-specific cardiac electrophysiological changes, demonstrating the models utility in studying sex-dependent cardiac differences.

pathology↗