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 heart, previous research has identified a number of common nuclear receptors. These include estrogen receptors (ERs), thyroid receptors (TRs), and peroxisome proliferation activating receptors (PPARs). The specific versions, or isoforms, of these receptors can be different in heart cells than, say, liver cells or brain cells (neurons). Many endocrine hormones, like estrogen and T3, are crucial for working heart function.
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 heart, previous research has identified a number of common nuclear receptors. These include estrogen receptors (ERs), thyroid receptors (TRs), and peroxisome proliferation activating receptors (PPARs). The specific versions, or isoforms, of these receptors can be different in heart cells than, say, liver cells or brain cells (neurons). Many endocrine hormones, like estrogen and T3, are crucial for working heart function.
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