Towards the modelling of ageing and atherosclerosis effects in ApoE-/- mice aortic tissue

Computational modeling predicts immuno-mechanical mechanisms of maladaptive aortic remodeling in hypertension

“…It is important to note that although some material parameters had to evolve in our current G&R model, our current quantitative modeling of evolution is very different from that which was reported previously (Eberth et al, 2011), wherein different sets of best-fit parameters were determined via nonlinear regression for the same hyperelastic constitutive relation at different times of aortic coarctation-induced hypertension. Indeed, fitting different data sets with separate sets of material parameters has been common in modeling the effects of hypertension (Hayashi and Naiki, 2009) and aortic aging (Ferruzzi et al, 2011;Waffenschmidt et al, 2016). In contrast, we used a constrained mixture model of G&R to describe and predict the evolving vascular geometry and properties based primarily on validated relations for rates of mass production and removal (Valentín and Humphrey, 2009),…”

“…The latter was measured using ring tests, however, which do not capture the complexities of biaxial G&R. Indeed, our experimental findings show that the circumferential material stiffness is maintained near original values in both WT and Apoe −/− mice subject to AngII-induced hypertension (Bersi et al, 2016(Bersi et al, , 2017, which suggests that the intramural cells retain an ability to mechano-sense and -regulate the extracellular matrix (Bellini et al, 2017;Humphrey et al, 2015). Biaxial tests have also been employed by others to study the thoracic and abdominal aorta of Apoe −/− mice as a function of age and diet (Agianniotis and Stergiopulos, 2012;Cilla et al, 2016), but not as a function of AngII-induced hypertension and inflammation; it was for this reason that we focused on describing our prior biaxial data (Bersi et al, 2017).…”