Lucky, times ten: A career in Texas science

Lipid metabolism has been good to me

My career in research has flourished through hard work, supportive mentors, and outstanding mentees and collaborators. The Carman laboratory has contributed to the understanding of lipid metabolism through the isolation and characterization of key lipid biosynthetic enzymes as well as through the identification of the enzyme-encoding genes. Our findings from yeast have proven to be invaluable to understand regulatory mechanisms of human lipid metabolism. Several rewarding aspects of my career have been my service to the Journal of Biological Chemistry as an editorial board member and Associate Editor, the National Institutes of Health as a member of study sections, and national and international scientific meetings as an organizer. I advise early career scientists to not assume anything, acknowledge others’ accomplishments, and pay it forward.

Cholesterol metabolism pathways - are the intermediates more important than the products?

Every cell in vertebrates possesses the machinery to synthesise cholesterol and to metabolise it. The major route of cholesterol metabolism is conversion to bile acids. Bile acids themselves are interesting molecules being ligands to nuclear and G protein‐coupled receptors, but perhaps the intermediates in the bile acid biosynthesis pathways are even more interesting and equally important. Here, we discuss the biological activity of the different intermediates generated in the various bile acid biosynthesis pathways. We put forward the hypothesis that the acidic pathway of bile acid biosynthesis has primary evolved to generate signalling molecules and its utilisation by hepatocytes provides an added bonus of producing bile acids to aid absorption of lipids in the intestine.

Jean Wilson and His Legacy, 50 Years and Counting

OBJECTIVE

To evaluate the legacy of endocrinologist Jean Wilson, whose discovery in 1969 of 5 alpha-reductase (5AR) and description of dihydrotestosterone (DHT) as the primary hormone associated with prostatic growth ushered in a golden age of collaboration between endocrinologists, oncologists, and urologists that led to some of the critical discoveries in the understanding and treatment of prostatic pathology.

MATERIALS AND METHODS

A review of the medical literature between 1969 and 2020 was conducted and multiple authors interviewed.

RESULTS

In 1969, Gloyna and Wilson demonstrated the reduction of testosterone to DHT in the prostate. With Bruchovsky, Wilson established that DHT was the primary hormone associated with prostatic growth. Wilson went on to show that androgens are involved in every aspect of prostate development, growth, and function. Wenderoth and Wilson then showed that a 5AR inhibitor blocked the prostatic growth. Subsequently, clinical trials with therapies targeting 5AR were led by Roehrborn and McConnell. Tilley and Wilson with Marcelli and McPhaul cloned the human androgen receptor at UT Southwestern in 1989 and provided the first evidence that androgen receptor was a transcriptional factor that could regulate its own expression in prostate cancer. Androgen receptor mutations explaining the molecular basis of androgen resistance syndromes were first described by Wilson, McPhaul, et al in the early 1990s.

CONCLUSION

Basic, translational, and clinical research has played a pivotal role in our current understanding of prostatic disease. Much of this legacy is credited to Jean Wilson and the cross-pollination of world-class scientists across fields, whom he inspired.

Formation and metabolism of oxysterols and cholestenoic acids found in the mouse circulation: Lessons learnt from deuterium-enrichment experiments and the CYP46A1 transgenic mouse

While the presence and abundance of the major oxysterols and cholestenoic acids in the circulation is well established, minor cholesterol metabolites may also have biological importance and be of value to investigate. In this study by observing the metabolism of deuterium-labelled cholesterol in the pdgfb^ret/ret mouse, a mouse model with increased vascular permeability in brain, and by studying the sterol content of plasma from the CYP46A1 transgenic mouse overexpressing the human cholesterol 24S-hydroxylase enzyme we have been able to identify a number of minor cholesterol metabolites found in the circulation, make approximate-quantitative measurements and postulate pathways for their formation. These "proof of principle" data may have relevance when using mouse models to mimic human disease and in respect of the increasing possibility of treating human neurodegenerative diseases with pharmaceuticals designed to enhance the activity of CYP46A1 or by adeno-associated virus delivery of CYP46A1.