Gross age-related changes and diseases in human heart valves

Overview of sialylation status in human nervous and skeletal muscle tissues during aging

Sialic acids (Sias) are a large and heterogeneous family of electronegatively charged nine-carbon monosaccharides containing a carboxylic acid and are mostly found as terminal residues in glycans of glycoproteins and glycolipids such as gangliosides. They are linked to galactose or N-acetylgalactosamine via α2,3 or α2,6 linkage, or to other Sias via α2,8 or more rarely α2,9 linkage, resulting in mono, oligo and polymeric forms. Given their characteristics, Sias play a crucial role in a multitude of human tissue biological processes in physiological and pathological conditions, ranging from development and growth to adult life until aging. Here, we review the sialylation status in human adult life focusing on the nervous and skeletal muscle tissues, which both display significant structural and functional changes during aging, strongly impacting on the whole human body and, therefore, on the quality of life. In particular, this review highlights the fundamental roles played by different types of glycoconjugates Sias in several cellular biological processes in the nervous and skeletal muscle tissues during adult life, also discussing how changes in Sia content during aging may contribute to the physiological decline of physical and nervous functions and to the development of age-related degenerative pathologies. Based on our current knowledge, further in-depth investigations could help to develop novel prophylactic strategies and therapeutic approaches that, by maintaining and/or restoring the correct sialylation status in the nervous and skeletal muscle tissues, could contribute to aging slowing and the prevention of age-related pathologies.

Valvular Disease and Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a clinical syndrome of shortness of breath and/or exercise intolerance secondary to elevated left ventricular filling pressures at rest or with exertion either as a result of primary diastolic dysfunction (primary HFpEF) or secondary to specific underlying causes (secondary HFpEF). In secondary HFpEF, early intervention of underlying valvular heart disease generally improves symptoms and prolongs survival. In primary HFpEF, there is increasing awareness of the existence and prognostic implications of secondary atrioventricular valve regurgitation. Further studies will clarify their mechanisms and the effectiveness of valvular intervention in this intriguing HFpEF subgroup.

Age related extracellular matrix and interstitial cell phenotype in pulmonary valves

Heart valve disease is a common manifestation of cardiovascular disease and is a significant cause of cardiovascular morbidity and mortality worldwide. The pulmonary valve (PV) is of primary concern because of its involvement in common congenital heart defects, and the PV is usually the site for prosthetic replacement following a Ross operation. Although effects of age on valve matrix components and mechanical properties for aortic and mitral valves have been studied, very little is known about the age-related alterations that occur in the PV. In this study, we isolated PV leaflets from porcine hearts in different age groups (~ 4-6 months, denoted as young versus ~ 2 years, denoted as adult) and studied the effects of age on PV leaflet thickness, extracellular matrix components, and mechanical properties. We also conducted proteomics and RNA sequencing to investigate the global changes of PV leaflets and passage zero PV interstitial cells in their protein and gene levels. We found that the size, thickness, elastic modulus, and ultimate stress in both the radial and circumferential directions and the collagen of PV leaflets increased from young to adult age, while the ultimate strain and amount of glycosaminoglycans decreased when age increased. Young and adult PV had both similar and distinct protein and gene expression patterns that are related to their inherent physiological properties. These findings are important for us to better understand the physiological microenvironments of PV leaflet and valve cells for correctively engineering age-specific heart valve tissues.

The Looming Geriatrician Shortage: Ramifications and Solutions

Objective: Geriatricians are skilled in the recognition of asymptomatic and atypical presentations that occur in the elderly and provide comprehensive medication management including recognizing adverse drug events, reducing polypharmacy, and de-prescribing. However, despite the increasing average age of the U.S. population, with the number of individuals above 65 years old predicted to increase 55% by 2030, the geriatric workforce capacity in the United States has actually decreased from 10,270 in 2000 to 8,502 in 2010. Method: We describe physiologic changes in older adults, historical trends in geriatric training, and propose solutions for this looming crisis. Results: Many factors are responsible for the shortage of skilled geriatric providers. Discussion: We discuss the historical context of the lack of geriatricians including changes to the training system, describe the impact of expert geriatric care on patient care and health system outcomes, and propose methods to improve recruitment and retention for geriatric medicine.