Scanning and transmission electron microscopic observation of femoral head feeding vessels in stroke-prone spontaneously hypertensive rats

Proinflammation, profibrosis, and arterial aging

Aging is a major risk factor for quintessential cardiovascular diseases, which are closely related to arterial proinflammation. The age-related alterations of the amount, distribution, and properties of the collagen fibers, such as cross-links and degradation in the arterial wall, are the major sequelae of proinflammation. In the aging arterial wall, collagen types I, II, and III are predominant,  and are mainly produced by stiffened vascular smooth muscle cells (VSMCs) governed by proinflammatory signaling, leading to profibrosis. Profibrosis is regulated by an increase in the proinflammatory molecules angiotensin II, milk fat globule-EGF-VIII, and transforming growth factor-beta 1 (TGF-β1) signaling and a decrease in the vasorin signaling cascade. The release of these proinflammatory factors triggers the activation of matrix metalloproteinase type II (MMP-2) and activates profibrogenic TGF-β1 signaling, contributing to profibrosis. The age-associated increase in activated MMP-2 cleaves latent TGF-β and subsequently increases TGF-β1 activity leading to collagen deposition in the arterial wall. Furthermore, a blockade of the proinflammatory signaling pathway alleviates the fibrogenic signaling, reduces profibrosis, and prevents arterial stiffening with aging. Thus, age-associated proinflammatory-profibrosis coupling is the underlying molecular mechanism of arterial stiffening with advancing age.

Abnormalities of vascular structure and function in children with Perthes disease

BACKGROUND AND OBJECTIVES

Perthes disease is a childhood precipitant to osteoarthritis of the hip, for which the etiology and mechanism are unknown. There is mounting evidence to suggest a vascular insult is responsible for disease, and it is suggested that this may have long-term implications for the vascular health of affected individuals. This study sought to use ultrasound measures to investigate vascular structure and function in children affected by Perthes disease.

METHODS

This case control study encompassed 149 cases and 146 controls, frequency matched for age and gender. Endothelial function was measured by using the technique of flow-mediated dilation of the brachial artery, and alterations in arterial flow were recorded in response to an ischemic stimulus.

RESULTS

There was a significant structural alteration in the vasculature among individuals with Perthes disease (resting brachial artery diameter (cases 2.97 mm versus controls 3.11 mm; P = .01), which remained even after adjusting for height. In addition, there was a notable reduction in blood velocity (cases 33.84 cm/s versus controls 37.83 cm/s; P = .01) and blood flow (cases 149.82 mL/min versus controls 184.67 mL/min; P = .001), which was independent of baseline arterial size. There was no evidence to suggest that flow-mediated dilation of the brachial artery was impaired among affected individuals (P = .71).

CONCLUSIONS

Children with Perthes disease exhibit small artery caliber and reduced function, which is independent of body composition. These data imply that that Perthes disease may reflect a wider vascular phenomenon that could have long-term implications for the vascular health of affected individuals.