Increased augmentation index in patients with Ehlers-Danlos syndrome

Patient-derived extracellular matrix demonstrates role of COL3A1 in blood vessel mechanics

Vascular Ehlers-Danlos Syndrome (vEDS) is a rare autosomal dominant disease caused by mutations in the COL3A1 gene, which renders patients susceptible to aneurysm and arterial dissection and rupture. To determine the role of COL3A1 variants in the biochemical and biophysical properties of human arterial ECM, we developed a method for synthesizing ECM directly from vEDS donor fibroblasts. We found that the protein content of the ECM generated from vEDS donor fibroblasts differed significantly from ECM from healthy donors, including upregulation of collagen subtypes and other proteins related to ECM structural integrity. We further found that ECM generated from a donor with a glycine substitution mutation was characterized by increased glycosaminoglycan content and unique viscoelastic mechanical properties, including increased time constant for stress relaxation, resulting in a decrease in migratory speed of human aortic endothelial cells when seeded on the ECM. Collectively, these results demonstrate that vEDS patient-derived fibroblasts harboring COL3A1 mutations synthesize ECM that differs in composition, structure, and mechanical properties from healthy donors. These results further suggest that ECM mechanical properties could serve as a prognostic indicator for patients with vEDS, and the insights provided by the approach demonstrate the broader utility of cell-derived ECM in disease modeling. STATEMENT OF SIGNIFICANCE: The role of collagen III ECM mechanics remains unclear, despite reported roles in diseases including fibrosis and cancer. Here, we generate fibrous, collagen-rich ECM from primary donor cells from patients with vascular Ehlers-Danlos syndrome (vEDS), a disease caused by mutations in the gene that encodes collagen III. We observe that ECM grown from vEDS patients is characterized by unique mechanical signatures, including altered viscoelastic properties. By quantifying the structural, biochemical, and mechanical properties of patient-derived ECM, we identify potential drug targets for vEDS, while defining a role for collagen III in ECM mechanics more broadly. Furthermore, the structure/function relationships of collagen III in ECM assembly and mechanics will inform the design of substrates for tissue engineering and regenerative medicine.

Modelling of the dilated sagittal sinuses found in multiple sclerosis suggests increased wall stiffness may be a contributing factor

The cross-sectional area of the superior sagittal sinus (SSS) is larger in multiple sclerosis than normal and correlates with disease severity and progression. The sinus could be enlarged due to a decrease in the pressure difference between the lumen and the subarachnoid space, an increase in wall thickness or increased wall stiffness. The cross-sectional area of the SSS and straight sinus (ST) were measured in 103 patients with multiple sclerosis and compared to 50 controls. The cross-sectional area of the SSS and ST were increased by 20% and 13% compared to the controls (p = 0.005 and 0.02 respectively). The deflection of the wall of the sinus was estimated. The change in pressure gradient, wall thickness or elastic modulus between groups was calculated by modelling the walls as simply supported beams. To account for these findings, the modelling suggests either a 70% reduction in transmural venous pressure or a 2.4 fold increase in SSS wall stiffness plus an 11% increase in wall thickness or a combination of changes. An increase in sinus pressure, although the most straight forward possibility to account for the change in sinus size may exist in only a minority of patients. An increase in sinus wall stiffness and thickness may need further investigation.

Effects of mind-body practice on arterial stiffness, central hemodynamic parameters and cardiac autonomic function of college students

A substantial number of studies have shown the beneficial effects of mind-body practice on physical fitness among both the healthy middle-aged and elderly adults and patients with chronic diseases. However, its positive effects on college students remain poorly understood. This study aimed to systematically investigate the potential efficiency of the Baduanjin exercise on the maintenance of the homeostasis of body composition and the improvement of the cardiovascular function of the college students. The study revealed a promising efficacy of the Baduanjin exercise in the prevention of the loss of water, inorganic salts, protein, and muscle contents and the accumulation of body fat. Furthermore, the present study also demonstrated the positive efficacy of Baduanjin exercise in decreasing of peripheral and central arterial blood pressure and carotid and femoral artery pulse wave velocity (cfPWV) of the college students. Moreover, the heart rate variability (HRV) analysis was also performed using the assessment of time and frequency domain indices. The data showed that all of the time-domain indices and the high-frequency (HF) band of the HRV relatively increased, whereas the low-frequency (LF) band of the HRV relatively decreased after the long-term Baduanjin exercise. Collectively, the present study suggested that a 12-week Baduanjin exercise could maintain the body composition in a relatively healthy and stable range and improve blood pressure, central hemodynamics, and the arterial stiffness of the college students. The underlying mechanism might be due to the improvement of parasympathetic activity and the suppression of sympathetic activity of college students via Baduanjin exercise.