01Mar/18

How PTEN May Play A Role In Vascular Disease Pathogenesis

How PTEN May Play A Role In Vascular Disease Pathogenesis Blood Vessels & Smooth Muscle Cells Vessels are the pipeline for transporting blood throughout the body. Blood, in turn, carries oxygen, nutrients, water, and other chemicals to tissues and organs throughout the body. The blood vessel is comprised of three main layers, the tunica intima, the tunica media, and the tunica adventitia. All three layers play a unique role in both physiological homeostasis and in pathological conditions. In this post, we will briefly focus on the role that the key constituents of the tunica media layer, the smooth muscle cells (SMCs), play in vascular disease pathogenesis.… Read More...
05Sep/17

Reactive Oxygen and Nitrogen Species in Pulmonary Hypertension

  In pulmonary hypertension, there is pathological remodeling of the blood vessels due to a pathological hypertensive environment within the vasculature. This hypertensive environment influences how all cells of the vasculature (endothelial cells and smooth muscle cells), as well as fibroblasts and immune cells behave. The environment typically activates fibroblasts and immune cells, causes de-differentiation in smooth muscle cells, induces the contractile phenotype in smooth muscle cells, and may even pushes endothelial cells to failure. How this pathological hypertensive environment occurs is unknown. For example, it could arise from underlying inflammation, from hypoxia, or an apoptosis process gone haywire… There are many theories.… Read More...
10Aug/17

Antioxidants and Reactive Oxygen Species in PH – Do Antioxidants Help or Hurt PH?

While it may not be the cause, evidence from several studies that supports the fact that increased oxidative stress and reactive oxygen species (ROS) together with decreased antioxidant activity can contribute to enhanced pulmonary vasoconstriction, vascular remodeling, and right heart dysfunction in pulmonary hypertension. Despite this evidence however, it is still unknown whether or not an oxidant/antioxidant imbalance contributes directly to the development of severe PAH. Answering this question is the aim of the recent paper reviewed in today’s post by Jernigan et al., “Contribution of reactive oxygen species to the pathogenesis of pulmonary arterial hypertension”. ROS in PH Many studies have shown that there is an imbalance of oxidant production and antioxidant capacity in the pulmonary vasculature of PH patients.… Read More...
08Aug/17

Inflammation in Pulmonary Hypertension – A Scientific Perspective, with a focus on Hypoxic PH

What is inflammation? Inflammation is a complex biological response of the body to remove foreign objects like pathogens (bacteria, virus, fungus), damaged cells, or irritants. It involves cells of the immune system, blood cells, tissue cells, and chemical mediators such as cytokines, chemokines, and reactive oxygen species. We typically have negative connotations associated with inflammation, which is justified, but not all cases of inflammation are negative. We need inflammatory processes to remove harmful pathogens, damaged cells or irritants. The problem arises when this inflammation goes unresolved, and becomes a chronic condition. There is another common harmful side of the immune system, however.… Read More...