Endothelial Glycocalyx in Aging and Age-related Diseases

Role of endothelial glycocalyx in central nervous system diseases and evaluation of the targeted therapeutic strategies for its protection: a review of clinical and experimental data

Central nervous system (CNS) diseases, such as stroke, traumatic brain injury, dementia, and demyelinating diseases, are generally characterized by high morbidity and mortality, which impose a heavy economic burden on patients and their caregivers throughout their lives as well as on public health. The occurrence and development of CNS diseases are closely associated with a series of pathophysiological changes including inflammation, blood-brain barrier disruption, and abnormal coagulation. Endothelial glycocalyx (EG) plays a key role in these changes, making it a novel intervention target for CNS diseases. Herein, we review the current understanding of the role of EG in common CNS diseases, from the perspective of individual pathways/cytokines in pathophysiological and systematic processes. Furthermore, we emphasize the recent developments in therapeutic agents targeted toward protection or restoration of EG. Some of these treatments have yielded unexpected pharmacological results, as previously unknown mechanisms underlying the degradation and destruction of EG has been brought to light. Furthermore, the anti-inflammatory, anticoagulative, and antioxidation effects of EG and its protective role exerted via the blood-brain barrier have been recognized.

A morphological post mortem profile in minor salivary glands changes in females

Women experience several systemic changes over all stages of life, many due to hormonal fluctuations. The sensation of dry mouth is the most common oral clinical symptom in women from climacteric period onwards, suggesting that sex hormones are important in maintaining salivary glands and oral homeostasis. Although the oral cavity is not conventional considered a target tissue for oestrogen, the extent to which salivary glands morphology and function are impacted by ageing and hormonal variations remain unknown. Due to the clinical demand for understanding oral changes related to the ageing process, this study aimed to portray the glandular morphological aspects in female during the different stages of life. To achieve this, 85 post-mortem specimens of labial minor salivary glands were obtained from females; they were distributed into three groups: group I (reproductive phase: up to 44 years, n = 18); group II (climateric phase: 45-55 years, n = 21) and group III (post-menopausal phase: over 56 years, n = 46). The most significant changes observed included degenerative parenchymal aspects including the replacement of parenchymal structures by fibrous tissue, inflammatory infiltrate as well as vascular and endothelial changes. Ageing was associated with acinar serous metaplasia (p = 0.011), acinar fibrosis (p = 0.042) and ductal ectasia (p = 0.003). The process of acinar atrophy was observed in all groups, with an increase in severity in group III. These degenerative aspects appear to be age-dependent.

Vascular Extracellular Matrix in Atherosclerosis

The extracellular matrix (ECM) plays a central role in the structural integrity and functionality of the cardiovascular system. Moreover, the ECM is involved in atherosclerotic plaque formation and stability. In fact, ECM remodeling affects plaque stability, cellular migration, and inflammatory responses. Collagens, fibronectin, laminin, elastin, and proteoglycans are crucial proteins during atherosclerosis development. This dynamic remodeling is driven by proteolytic enzymes such as matrix metalloproteinases (MMPs), cathepsins, and serine proteases. Exploring and investigating ECM dynamics is an important step to designing innovative therapeutic strategies targeting ECM remodeling mechanisms, thus offering significant advantages in the management of cardiovascular diseases. This review illustrates the structure and role of vascular ECM, presenting a new perspective on ECM remodeling and its potential as a therapeutic target in atherosclerosis treatments.

Unraveling neurovascular mysteries: the role of endothelial glycocalyx dysfunction in Alzheimer's disease pathogenesis

While cardiovascular disease, cancer, and human immunodeficiency virus (HIV) mortality rates have decreased over the past 20 years, Alzheimer's Disease (AD) deaths have risen by 145% since 2010. Despite significant research efforts, effective AD treatments remain elusive due to a poorly defined etiology and difficulty in targeting events that occur too downstream of disease onset. In hopes of elucidating alternative treatment pathways, now, AD is commonly being more broadly defined not only as a neurological disorder but also as a progression of a variety of cerebrovascular pathologies highlighted by the breakdown of the blood-brain barrier. The endothelial glycocalyx (GCX), which is an essential regulator of vascular physiology, plays a crucial role in the function of the neurovascular system, acting as an essential vascular mechanotransducer to facilitate ultimate blood-brain homeostasis. Shedding of the cerebrovascular GCX could be an early indication of neurovascular dysfunction and may subsequently progress neurodegenerative diseases like AD. Recent advances in in vitro modeling, gene/protein silencing, and imaging techniques offer new avenues of scrutinizing the GCX's effects on AD-related neurovascular pathology. Initial studies indicate GCX degradation in AD and other neurodegenerative diseases and have begun to demonstrate a possible link to GCX loss and cerebrovascular dysfunction. This review will scrutinize the GCX's contribution to known vascular etiologies of AD and propose future work aimed at continuing to uncover the relationship between GCX dysfunction and eventual AD-associated neurological deterioration.

Disruption of the endothelial glycocalyx layer is associated with idiopathic complete atrioventricular block in the elderly population: An observational pilot study

Idiopathic atrioventricular block (iCAVB) is the most common reason for the need for a permanent pacemaker in the elderly population. The fibrotic process that occurs in the conduction system of the heart with aging is the main pathogenesis in the development of iCAVB. However, the processes that trigger the development of iCAVB in the elderly population have not been fully elucidated. In this study, we aimed to reveal the possible relationship between the endothelial glycocalyx (EG) layer and idiopathic complete atrioventricular block. A group of 68 consecutive patients who developed iCAVB and a group of 68 healthy subjects matched for age, sex, and cardiovascular risk factors were included in the study. The groups were compared for clinical, laboratory, and levels of Syndecan-1 (SDC1), an EG layer marker. In the study, SDC1 levels were found to be significantly higher in the iCAVB group compared to the control group (23.7 ± 7.5 vs 16.7 ± 5.2; p = 0.009). In multivariable regression analysis, SDC1 was determined as an independent potential predictor for iCAVB (OR: 1.200; 95% CI: 1.119-1.287; p < 0.001). In the receiver operating characteristic curve analysis, SDC1 predicted iCAVB with 74% sensitivity and 72% specificity at the best cut-off value of 18.5 ng/mL (area under the curve: 0.777; confidence interval: 0.698-0.856; p < 0.001). Disruption of the endothelial glycolic layer may be one of the main triggering factors for the process leading to iCAVB.