Steroid and nuclear receptors

Published on April 28, 2022   49 min

Other Talks in the Series: The Female Reproductive System: from Basic Science to Fertility Treatments

My name is Stephen Hammes. I'm a physician-scientist, and I'm the Chief of the Division of Endocrinology at the University of Rochester Medical Center in Rochester, New York. Today, I'm going to talk about nuclear receptors with a focus on steroid hormone receptors.
This is an outline of the talk. I'm going to start by discussing the classification of nuclear receptors, and I'll talk about the structure of nuclear receptors, followed by the functions of nuclear receptors. I'll then talk about receptor mutations that result in abnormal physiology or disease. I'll talk about acquired resistance to steroids, and finally, I'll spend a few minutes talking about extranuclear or non-genomic steroid signaling. The first section is going to be a classification of nuclear receptors.
There are a lot of different ways that you can classify nuclear receptors, and this is just one of many that I'm showing on this slide. The way I'm dividing it is on the left, I'm talking about endocrine receptors, and on the right, there's a little bit about lipid receptors, and we're really going to focus on the green, which are the endocrine receptors. This in particular covers most of the hormone receptors. that's the steroid hormone receptors. These are considered high-affinity receptors. They bind to hormonal lipids, often metabolites of cholesterol, and there are two different types, Type I and Type II. Type I is our steroid hormone receptors that we usually think about, estrogen receptors α and β, progesterone receptor A and B, androgen receptor, glucocorticoid receptor and mineralocorticoid receptor. These are Type I receptors, and I'll describe exactly what that means in a minute. Then we also have Type II receptors, that includes thyroid hormone receptors α and β and also vitamin D receptors. Then there's a third receptor we put into this group called the retinoic acid receptor. Again, we'll discuss the differences between Type I and Type II in a couple of minutes. We also have lipid receptors which are shown on the right in red. These are considered low-affinity receptors. They bind to dietary lipids and I listed a bunch of them in Type II. They're almost all Type II receptors. The most famous ones from this group are the PPARs, which are involved in adipocyte biology. For the points of this talk, we're really not going to discuss the lipid receptors. As mentioned, we're going to focus on the green endocrine receptors.