Nuclear receptors, like those for steroid hormones, are found in diverse cell types. The type and quantity of each receptor can vary between cell types, as well as between species!
For the mammalian heart, previous research has identified a number of common nuclear receptors. These include receptors for steroid hormones (androgen, estrogen, glucocorticoid, mineralocorticoid, and progesterone), thyroid hormone, lipids (PPARs), retinoids (retinoic acid, retinoid X), and other small, fat-soluble molecules. Given the diversity of receptors in cardiac muscle, there's a central lack of information on their physiological roles.
Part of my thesis work will use a line of rat-derived cells, termed H9c2 cells, as an animal-alternative model. H9c2 cells are cardiomyoblasts. The "blast" in "myoblast" indicates that H9c2 cells are poised to become muscle cells (hence the "myo"), but need some help getting there. Indeed, H9c2 cells can be chemically coerced into a heart muscle-like state through the addition of retinoic acid (RA), decreases in available nutrients, and increases in total cell density. On the other hand, exclusion of RA from the differentiation protocol produces skeletal muscle cells. Both types of differentiated cells even form myotubes that resemble smooth muscle!
For the mammalian heart, previous research has identified a number of common nuclear receptors. These include receptors for steroid hormones (androgen, estrogen, glucocorticoid, mineralocorticoid, and progesterone), thyroid hormone, lipids (PPARs), retinoids (retinoic acid, retinoid X), and other small, fat-soluble molecules. Given the diversity of receptors in cardiac muscle, there's a central lack of information on their physiological roles.
Part of my thesis work will use a line of rat-derived cells, termed H9c2 cells, as an animal-alternative model. H9c2 cells are cardiomyoblasts. The "blast" in "myoblast" indicates that H9c2 cells are poised to become muscle cells (hence the "myo"), but need some help getting there. Indeed, H9c2 cells can be chemically coerced into a heart muscle-like state through the addition of retinoic acid (RA), decreases in available nutrients, and increases in total cell density. On the other hand, exclusion of RA from the differentiation protocol produces skeletal muscle cells. Both types of differentiated cells even form myotubes that resemble smooth muscle!
I'm currently using H9c2 cells as a model to understand how different nuclear receptors, as well as other heart-relevant receptors, guide the structure and function of cardiac muscle
