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trouble
06-13-2006, 01:27 AM
If there be only one post that you ever read of the hundreds I author here, let it be this one. I wrote to a friend not too long ago:

I am the wind of change.

This article, with its portent for understanding the fine tuning of our cells and derived belief in the plausability that metabolic dysregulation may be addressed by dietary, supplement and behavioral tweeks, is the reason why I made that bold statement.

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The Nuclear Receptor Superfamily: A Rosetta Stone for Physiology

Ronald M. Evans. Howard Hughes Medical Institute, Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, CA. Molecular Endocrinology 19 (6): 1429-1438 2005.


ROMANCING THE STONE

In the December 1985 issue of Nature, we described the cloning of the first nuclear receptor cDNA encoding the human glucocorticoid receptor (GR) (1). In the 20 yr since that event, our field has witnessed a quantum leap by the subsequent discovery and functional elaboration of the nuclear receptor superfamily (2)—a family whose history is linked to the evolution of the entire animal kingdom and whose actions, by decoding the genome, span the vast diversity of biological functions from development to physiology, pathology, and treatment.

A messenger is an envoy or courier charged with transmitting a communication or message. In one sense, the cloning of that first messenger (the GR) represented the completion of a prediction that began with Elwood Jensen’s characterization of the first steroid receptor protein (3) and continued with the pioneering work of others in the steroid receptor field (including Gorski, O’Malley, Gustafsson, and Yamamoto).

Yet, like the discovery of the Rosetta stone in 1799, the revelation of the GR sequence heralded a completely unpredictable demarcation in the field, helping to solve mysteries unearthed nearly 100 yr ago as well as opening a portal to the future.

The beginnings of the adventure lie in disciplines such as medicine and nutrition, which gave rise to the emergent field of endocrinology in the first half of the last century. The purification of chemical messengers ultimately known as hormones from organs and vitamins from foods spurred the study of these compounds and their physiologic effects on the body.

At about the same time, the field of molecular biology was emerging from the disciplines of chemistry, physics, and their application to biological problems such as the structure of DNA and the molecular events surrounding its replication and transcription. It would not be until the late 1960s and 1970s that endocrinology and molecular biology would begin to intersect as the link between receptors and transcriptional control were being laid down.

During this time, the work of Jensen (4) and Gorski (5) identified a high-affinity estrogen receptor (ER) that suggested an action in the nucleus. Gordon Tomkins and his associates (J. Baxter, G. Ringold, E. B. Thompson, H. Samuels, H. Bourne, and others) were one of the most creative forces studying glucocorticoid action (6). Concurrent work by O’Malley, Gustafsson, and Yamamoto provided further, important evidence supporting a link between steroid receptor action and transcription (you may wish to read the accompanying perspective articles in this issue of Molecular Endocrinology).

But whereas the steroid hormone field continued to evolve in this direction, it is of interest to note that the mechanism of action of thyroid hormone and retinoids remained clouded and controversial until the eventual cloning of their receptors in the late 1980s.

Likewise, no one had foreseen the possibility that other lipophilic molecules (like oxysterols, bile acids, and fatty acids) would also function through a similar mechanism, or that other steroid receptor-like proteins existed that would play an important role in transcriptional regulation of so many diverse pathways.

Thus, the GR isolation in 1985 led to the concept of a hidden superfamily of receptors that in a very real way provided the needed molecular code to unravel the puzzle of physiologic homeostasis.



Read the story (http://mend.endojournals.org/cgi/content/full/19/6/1429) and see why I believe that these are the golden keys to health and longevity through metabolic pathway optimization.

DougoeFre5h
06-13-2006, 01:37 AM
Ahh, sheds some light on a lot of your previous posts on the subject. Very interesting read indeed.

trouble
06-29-2006, 08:46 PM
This paper, more than any other, beyond the first post in this series (more to come in this thread), is an answer to the one question I am often asked.

This is the reason I am here, on-line, in the world of athletic performance and strength training. Nuclear receptors the molecular magic behind biochemical chemical karma of human performance and health. Their primary expression is first through liver, and then brain, thyroid and pancreas, gut, kidney, heart and cardiovascular system.

This discussion here on IronAddicts is unique to the internet.

It is your bonus for patiently sifting through the many posts and threads on this forum.

Knowledge is power.

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Skeletal muscle and nuclear hormone receptors: implications for cardiovascular and metabolic disease. Int J Biochem Cell Biol. Oct 2005 37(10):2047-63.

Smith AG, Muscat GE.

Skeletal muscle is a major mass peripheral tissue that accounts for approximately 40% of the total body mass and a major player in energy balance.

It accounts for >30% of energy expenditure, is the primary tissue of insulin stimulated glucose uptake, disposal, and storage. Furthermore, it influences metabolism via modulation of circulating and stored lipid (and cholesterol) flux.

Lipid catabolism supplies up to 70% of the energy requirements for resting muscle.

However, initial aerobic exercise utilizes stored muscle glycogen but as exercise continues, glucose and stored muscle triglycerides become important energy substrates. Endurance exercise increasingly depends on fatty acid oxidation (and lipid mobilization from other tissues). This underscores the importance of lipid and glucose utilization as an energy source in muscle. Consequently skeletal muscle has a significant role in insulin sensitivity, the blood lipid profile, and obesity.

Moreover, caloric excess, obesity and physical inactivity lead to skeletal muscle insulin resistance, a risk factor for the development of type II diabetes. In this context skeletal muscle is an important therapeutic target in the battle against cardiovascular disease, the worlds most serious public health threat. Major risk factors for cardiovascular disease include dyslipidemia, hypertension, obesity, sedentary lifestyle, and diabetes. These risk factors are directly influenced by diet, metabolism and physical activity. Metabolism is largely regulated by nuclear hormone receptors which function as hormone regulated transcription factors that bind DNA and mediate the patho-physiological regulation of gene expression.

Metabolism and activity, which directly influence laiver lipid metabolism (cardiovascular disease risk factors), are primarily driven by skeletal muscle. Recently, many nuclear receptors expressed in skeletal muscle have been shown to improve glucose tolerance, insulin resistance, and dyslipidemia. Skeletal muscle and nuclear receptors are rapidly emerging as critical targets in the battle against cardiovascular disease risk factors.

Understanding the function of nuclear receptors in skeletal muscle has enormous pharmacological utility for the treatment of cardiovascular disease.

More importantly, and its totally missed by these authors, its the key to counter the serious debilitating diseases of chronic stress disorders.

Now hear this: the model for chronic stress disorders, the genes affected by it, are the same as those for obesity and cardiovascular disease.

This is a billion dollar fact.