Robert Rosenfield, M.D.
The Role of Hormones in Pilosebaceous Cell
Differentiation
Research Summary
Dr. Rosenfield conducts basic research projects on androgen secretion
and action, as well as clinical research programs on reproductive
physiology and growth, with special emphasis on the role of androgens
and estrogens in females. Dr Rosenfield has held an NICHD grant Free
Plasma Sex Hormone and Androgen Action for 28 years. It began with the
demonstration that plasma free testosterone is more closely related to
the development of hirsutism in women than is the plasma total
testosterone concentration, showed that hirsutism and acne were
variably expressed manifestations of androgen excess, and culminated
with the demonstration that peroxisome proliferator-activated receptors
(PPARs), which are key regulators of the lipid metabolism necessary for
fat cell (adipocyte) differentiation, are potent mediators of sebocyte
differentiation. Some PPAR effects are amplified by androgen. Dr Dianne
Deplewski started her research training in this project and continues
to be active in it as a junior faculty member. Dr Rosenfield was funded
in by the NIH to study The Molecular Basis of Ovarian Testosterone
Production and an expansion of these studies into hyperandrogenic women
was funded by the NIH (Gonadotropin/insulin interactions in PCOS) as
part of Dr Radovick’s Reproductive Center grant. The molecular basis
for testosterone formation from androstenedione within the human ovary
was unknown until his laboratory recently demonstrated that this was
accounted for by type 5 17ß-HSD (17ß-HSD5) expression. They
have
furthermore demonstrated that 17ß-HSD5 is localized to theca
cells.
Currently under study are the factors regulating the expression of this
enzyme and the relationship of polymorphisms in this enzyme to
polycystic ovary syndrome (PCOS). This is a chronic hyperandrogenic
disorder that typically appears during adolescence and is the most
common cause of endocrine infertility in women. Dr Kenan Qin was
involved in initiating this project as a pediatric endocrinology
trainee and continues on in this project as a Research Associate.
Another clinical aspect of this project is the characterization of
insulin resistance in children at risk for having PCOS, such as those
with premature pubarche or morbid obesity. Dr. Elizabeth Baumann has
returned on as a junior faculty member on a supplemental project.
Selected Papers
Nelson VL, Qin Kn K, Rosenfield RL, Wood JR, Penning TM,
Legro RS, Strauss III JF, McAllister JM. (2001). The biochemical basis
for increased testosterone production in theca cells propagated from
patients with polycystic ovary syndrome. J Clin Endocrinol Metab
86:5925-33.
Barnes RB, Namnoum AB, Rosenfield RL, Layman LC. (2002).
The role of LH and FSH in ovarian androgen secretion and ovarian
follicular development: Clinical studies in a patient with isolated FSH
deficiency and multicystic ovaries: Case report. Hum Reprod 17:88-91.
Rosenfield RL, Wu PP, Ciletti N. (2002). Sebaceous
epithelial cell differentiation requires cyclic adenosine monophosphate
generation. In Vitro Cell Develop Biol-Animal, 38: 54-57.
Sardani Y, Qin K, Haas M, Aronson AJ, Rosenfield RL.
(2003). Bartter syndrome complicated by immune complex nephropathy.
Case report and literature review. Pediatr Nephrol. 18(9):913-8. Epub
2003 Jun 26. Rev.
Rosenfield RL. Hirsutism and the variable response of
the pilosebaceous unit to androgen. (2005). J
Investig Dermatol Symp Proc. 10(3):205-8. Review. PMID: 16382665
[PubMed - indexed for MEDLINE]
Drobac S, Rubin K, Rogol AD, Rosenfield RL. (2006). A
workshop on pubertal hormone replacement options in the United States. J
Pediatr Endocrinol Metab. 19(1):55-64. Review. PMID: 16509529
[PubMed - indexed for MEDLINE]
Mortensen M, Rosenfield RL, Littlejohn E. (2006).
Functional significance of polycystic-size ovaries in healthy
adolescents. J Clin
Endocrinol Metab. 91(10):3786-90. Epub 2006 Aug 8. PMID:
16895960 [PubMed - indexed for MEDLINE]
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