Faculty Bibliography

In isolation, we are physically apart; in solidarity, we are together. The COVID-19 pandemic emphasizes our social responsibility to maintain physical distance from one another. In doing so, we solidify our collective strength.

During spaceflight, the human cardiovascular system undergoes major changes primarily related to the effects of decreased gravitational force, or microgravity, on the human body. These changes present challenges to human adaptation and operation in space. This article reviews the knowledge gained in human experiments in the past half century of spaceflight, and summarizes our knowledge on the effects of short- and long-duration microgravity exposure on cardiovascular physiology and functioning, including fluid redistribution, autonomic reflexes, cardiac parameters, orthostatic intolerance, arrhythmias, aerobic capacity, and cardiac atrophy. This review also discusses current countermeasures for risk reduction during spaceflight, as well as future directions in cardiovascular research in space.

BackgroundLow birth weight (LBW) neonates have impaired kidney development that leaves them susceptible to kidney disease and hypertension during adulthood. The study here identifies events that blunt nephrogenesis and kidney development in the murine LBW neonate.MethodsWe examined survival, kidney development, GFR, gene expression, and cyto-/chemokines in the LBW offspring of malnourished (caloric and protein-restricted) pregnant mice.ResultsMalnourished pregnant mothers gave birth to LBW neonates that had 40% reduced body weight and 54% decreased survival. Renal blood perfusion was reduced by 37%, whereas kidney volume and GFR were diminished in the LBW neonate. During gestation, the LBW neonatal kidney had 2.2-fold increased apoptosis, 76% decreased SIX2+ progenitor cells, downregulation of mesenchymal-to-epithelial signaling factors Wnt9b and Fgf8, 64% less renal vesicle formation, and 32% fewer nephrons than controls. At birth, increased plasma levels of IL-1β, IL-6, IL-12(p70), and granulocyte-macrophage colony-stimulating factor in the LBW neonate reduced SIX2+ progenitor cells.ConclusionIncreased pro-inflammatory cytokines in the LBW neonate decrease SIX2+ stem cells in the developing kidney. Reduced renal stem cells (along with the decreased mesenchymal-to-epithelial signaling) blunt renal vesicle generation, nephron formation, and kidney development. Subsequently, the mouse LBW neonate has reduced glomeruli volume, renal perfusion, and GFR.

Pulmonary artery hypertension (PAH) refers to several subgroups of disease in which the mean pulmonary artery pressure (mPAP) is elevated to more than 25 mm Hg, pulmonary artery wedge pressure (PAWP) ≤ 15 mmHg, and an elevated pulmonary vascular resistance (PVR) > 3 Wood units as confirmed by right heart catheterization. The prevalence and geographic distribution of PAH vary depending on the type and etiology of the disease. Despite enormous efforts in the research and development of therapeutic agents in the last twenty years, the disease remains relatively incurable and the overall prognosis remains guarded. Median survival for an untreated patient is 2.8 years. In the last three decades, there have been dramatic advances in understanding the molecular mechanisms and signaling pathways involved in the disease, resulting in emerging new treatment strategies. In the following pages, we will review currently approved treatments for PAH, as well as a new generation of investigational drugs.